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Small Scale Mechatronics Devices as Educational and Research Engineering Tools
11th IFAC Symposium on Advances Control Education June 1-3, 2016. Bratislava, Slovakia in 11th IFAC Symposium on Advances Control Education June 1-3, 2016. Bratislava, Slovakia in 11th Symposium on Control 11th IFAC IFAC Symposium on Advances Advances in Control Education Education June 1-3, 2016. Bratislava, Slovakia in Available online at www.sciencedirect.com June 1-3, 1-3, 2016. 2016. Bratislava, Bratislava, Slovakia Slovakia June
ScienceDirect IFAC-PapersOnLine 49-6 (2016) 248–255 Devices as Small Scale Mechatronics Small Scale Mechatronics Devices as Small Scale Devices as Educational andMechatronics Research Engineering Small Scale Mechatronics Devices asTools Educational and Research Engineering Tools Educational Research Engineering Tools Educational and andMauro Research Engineering Tools Speranza Neto*
Mauro SperanzaMarília Neto* Allan Nogueira de Albuquerque**, Mauro Speranza Neto* Maurell Assad*** Mauro Speranza Neto* Allan Nogueira de Albuquerque**, Marília Mauro Speranza Neto* Maurell Allan Nogueira de Albuquerque**, Marília Maurell Assad*** Assad*** Allan Nogueira de Albuquerque**, Marília Maurell Allan Nogueira de Albuquerque**, MaríliaUniversity, Maurell Assad*** Assad*** Mechanical Engineering Department, Pontifical Catholic Rio de Janeiro, Brazil Mechanical Engineering Department, Pontifical Catholic University, Rio de Janeiro, Brazil puc-rio.br * msn@ Mechanical Engineering Department, Pontifical Catholic University, Rio de Janeiro, Brazil Mechanical Engineering Engineering Department, Department, Pontifical Catholic University, University, Rio Rio de de Janeiro, Janeiro, Brazil Brazil * msn@ puc-rio.br Mechanical Pontifical Catholic ** [email protected] * msn@ puc-rio.br * msn@ puc-rio.br ** [email protected] * msn@ puc-rio.br *** [email protected] ** [email protected] ** [email protected] [email protected] *** [email protected] ** *** [email protected] *** *** [email protected] [email protected] Abstract: This paper presents several mechatronics equipments of low cost and small scale, employing Abstract: This presentsapplied several mechatronics equipments of low and small employing components andpaper technology model building. All systems werecost developed and scale, built by students Abstract: This paper presents severaltomechatronics equipments of low cost and small scale, employing Abstract: This paper presents several mechatronics equipments of low cost and small scale, employing components and technology applied toPontifical model building. All systems were developed and built by students Abstract: This paper presents several mechatronics equipments of low cost and small scale, employing with different levels of knowledge in Catholic University of Rio de Janeiro to aid the teaching, components and technology applied to model building. All systems were developed and built by students components and technology applied to model building. All systems were developed and built by students with different levels of knowledge in Pontifical Catholic University of Rio de Janeiro to aid the teaching, components technology appliedintoPontifical model building. systems byteaching, students learning andand research in Engineering, particularly onAll the Controlwere Automation, Mechanical and with different levels of knowledge Catholic University ofand Riodeveloped de Janeiroand to built aid the with different levels of knowledge in Pontifical Catholic University of Rio de Janeiro to aid the teaching, learning and research in Engineering, particularly on the Control and Automation, Mechanical and with different levels of knowledge in Pontifical Catholic University Rio Automation, de Janeiro to Mechanical aid the teaching, Mechatronics learning and fields. research in Engineering, particularly on the Controlofand and learning and research in Engineering, particularly on the Control and Automation, Mechanical Mechatronics fields. learning and fields. research in Engineering, particularly on the Control and Automation, Mechanical and and Mechatronics Keywords: Teaching, Control Engineering, Embedded systems, Education Laboratory, Aids © 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. AllEducational rights reserved. Mechatronics fields. Mechatronics fields. Keywords: Teaching, Control Engineering, Embedded systems, Education Laboratory, Educational Aids Keywords: Teaching, Control Engineering, Embedded systems, Education Laboratory, Educational Aids Keywords: Teaching, Teaching, Control Control Engineering, Engineering, Embedded Embedded systems, Education Education Laboratory, Laboratory, Educational Educational Aids Aids Keywords: systems, automatic traction elevator and railroad, all on a small scale 1. INTRODUCTION automatic elevator and railroad, on a small and using traction the same basic concepts and all devices of itsscale real automatic traction elevator and railroad, all on a small scale 1. INTRODUCTION automatic traction elevator and railroad, all on a small and using the same basic concepts and devices of kind itsscale real 1. INTRODUCTION automatic traction elevator and railroad, all on a small scale equivalent systems. The main advantage of this of The Control and Automation, Mechanical and Mechatronics and using the same basic concepts and devices of its real 1. INTRODUCTION INTRODUCTION 1. and using the same basic concepts and devices of its real equivalent systems. The main advantage of this kind of The Control and Automation, Mechanical and Mechatronics and using the same basic concepts and devices of its real operation is, in addition to requiring small footprint, Engineering arouse interest of a large number of students; equivalent systems. The main advantage of this kind ofa The Control and Automation, Mechanical and Mechatronics equivalent systems. The main advantage of this kind of operation is, in addition to requiring small footprint, The Control and Automation, Mechanical and Mechatronics Engineering arouse interest of a large number of students; equivalent systems. The main advantage of this kind ofaa The Control and Automation, and Mechatronics since most of its components can be one of its most interesting application vehicles in general Engineering arouse interest ofMechanical a largeis number of students;– relatively operation low is, incost, addition to requiring small footprint, operation is,accessible incost, addition tobuilding requiring small footprint, footprint, relatively low since most of itsmarket. components can beaa Engineering arouse interest of an large number students; one of its most interesting is number vehicles of in general operation is, in addition to requiring small Engineering arouse of aa large students; found in the model aerial, ground and interest marineapplication –, interdisciplinary field in– low cost, since most of its components can be one of its most interesting application is vehicles of in general – relatively relatively low cost, since most of its components can be be found in the accessible model building market. one of its most interesting application is vehicles in general – aerial, ground and marine –, an interdisciplinary field in relatively low cost, since most of its components can one of its most interesting application is vehicles in general – which ground theoretical practical of modelling, in the accessible model building market. aerial, and and marine –, an knowledge interdisciplinary field in found Every project in the model LDSMbuilding was designed and built at found in the accessible model building market. aerial, ground and marine –, an interdisciplinary field in which theoretical and practical knowledge of modelling, found in the accessible market. aerial, ground and marine –, an interdisciplinary field in simulation and control dynamic systems are needed. in LDSM at which theoretical andofpractical knowledge of modelling, Every University Rio designed de Janeiro,and withbuilt the aid Every project project in the theCatholic LDSMofwas was designed and built at which theoretical theoretical andofpractical practical knowledge of modelling, modelling, Pontifical simulation and control dynamic systems are needed. which and knowledge of Every project in the LDSM was designed and built at Pontifical University Catholic of Rio de Janeiro, with the aid simulation and control of dynamic systems are needed. Every project indevelopment theCatholic LDSMof was designed and built at of a prototype workshop, also implemented In order to further motivate the students and attract potential Pontifical University Rio de Janeiro, with the aid simulation and control of dynamic systems are needed. simulation control of dynamic systemsand areattract needed. Pontifical University Catholic of Rio de Janeiro, Janeiro, with theaxis aid of prototype development workshop, also implemented In order to and further motivate the students potential Pontifical University Catholic of Rio de with the aid withaa funds provided by FAPERJ, which contains a three candidates this area, the Mechatronic Development prototype development workshop, also implemented In order to to further motivate the studentsSystem and attract potential of of a prototype development workshop, also implemented with funds provided by FAPERJ, which contains a three axis In order to further motivate the students and attract potential candidates to this area, the Mechatronic System Development of a prototype development workshop, also implemented In order to further motivate the students and attract potential CNC funds milling machine, a 3D printer a laser cutting Laboratory to (LDSM, in Mechatronic portuguese)System was Development created, a with provided by FAPERJ, which and contains a three axis candidates this area, the with funds provided by FAPERJ, FAPERJ, which and contains three axis CNC milling machine, a to3Dundergraduates printer aand laser cutting candidates to (LDSM, this area, area, the Mechatronic System Development Laboratory in Mechatronic portuguese) was of created, funds provided by which contains aa three axis candidates to this the machine, all exclusively graduates multidisciplinary environment where a System series equipmentaa with CNC milling machine, a 3D printer and a laser cutting Laboratory (LDSM, in portuguese) was Development created, CNC milling machine, a 3D printer and a laser cutting machine, all exclusively to undergraduates and graduates Laboratory (LDSM, in portuguese) was created, a multidisciplinary environment where a series of equipment CNC milling machine, a 3D printer and a laser cutting Laboratory (LDSM, in portuguese) was created, a involved with projects linked to the research group. and components ofenvironment ground vehicles testing, machine, all exclusively to undergraduates and graduates multidisciplinary wherearea available series of for equipment machine, all exclusively to undergraduates and with linked the research group. multidisciplinary where a available series of equipment and components ofenvironment ground vehicles testing, machine, all projects exclusively to to and graduates graduates multidisciplinary whereare seriessystem of for equipment evaluation and experiments. Every and its involved involved with projects linked toundergraduates the research group. and components ofenvironment ground vehicles areascale available for testing, The main intention behind LDSM’s creation was to disclose involved with projects linked to the research group. and components of ground vehicles are available for testing, evaluation and experiments. Every scale system and its involved with projects linked to the research group. and components of ground vehicles are available for testing, components is properly instrumented; control techniques and main intention behind LDSM’s creation engineers was to disclose evaluation and experiments. Every scale system and its The for high school students and freshmen what main intention behind LDSM’s creation was to disclose evaluation and experiments. Every scale and its components is properly instrumented; control techniques evaluation experiments. Everysuch scale assystem system and and its The electronic monitoring devices, transducers, The main intention behind LDSM’s creation wasAutomation to disclose disclose for high school students and freshmen engineers what componentsand is properly instrumented; control techniques and The main intention behind LDSM’s creation was to projects can be done in Mechanics, Control and for high school students and freshmen engineers what components is properly instrumented; control techniques and electronic monitoring devices, such as transducers, components is properly instrumented; control and for microprocessors and computers, are widely used, all of which electronic monitoring devices, such astechniques transducers, high school students and freshmen engineers what projects can be done in Mechanics, Control and Automation for high school students and freshmen engineers what and Mechatronics Engineering, as this type of equipment and projects can be done in Mechanics, Control and Automation electronic monitoring devices, such as transducers, microprocessors and computers, are widely used, all of which electronic monitoring devices, such used, as all transducers, with technology marketed to model projects can be done in Mechanics, Control and Automation Mechatronics Engineering, as this type of equipment and microprocessors and computers, are building. widely of which and projects can be done in Mechanics, Control and Automation technology has appeal to young people. The laboratory has microprocessors and computers, computers, are building. widely used, used, all all of of which which and Mechatronics Engineering, as this type of equipment and with technology marketed to model microprocessors and are widely and Mechatronics Engineering, as this type of equipment and technology has appeal to young people. The laboratory has with technology marketed to model building. and Mechatronics Engineering, as this type of equipment and been a great advertisement for the mentioned courses. The LDSM activities are geared exclusively to the academic technology has appeal to young people. The laboratory has with technology technology marketed marketed to to model model building. building. with technology has appeal to young people. The laboratory been a great advertisement for the mentioned courses. The LDSM activities are geared exclusively to the academic appeal to young people. Thecourses. laboratory has has field, beingactivities developed by undergraduate graduate technology beenapparatuses, a greathas advertisement forinthe mentioned The LDSM are geared exclusively toand the academic All described the following chapter, have been a great advertisement for the mentioned courses. The LDSM activities are geared exclusively to the academic field, being developed by undergraduate and graduate beenapparatuses, a great advertisement for the mentioned courses. The aremonograph geared exclusively toand the academic students as activities research or topics. The devices are All field,LDSM being developed by undergraduate graduate described the following chapter,levels, have developed by studentsin different knowledge All apparatuses, described inat the following chapter, have field, developed by undergraduate and graduate students as research or and monograph topics. classes The are been field, being developed bydemonstrative undergraduate anddevices graduate used inbeing presentations for high All apparatuses, described in following chapter, have developed by students at the different knowledge levels, students as research or monograph topics. The devices are been All apparatuses, described in the following chapter, have from second year undergraduates to bachelor’s thesis, students as research or and monograph topics. classes The engineering devices are been developed by students at different knowledge levels, used presentations for high students as research or monograph topics. The devices are schoolin freshmen of demonstrative the aforementioned been developed by students at different knowledge levels, from second year undergraduates to bachelor’s thesis, used instudents, presentations and demonstrative classes for high been developed by students at different knowledge levels, master’s theses and even doctoral dissertations. The main used inand presentations andof demonstrative demonstrative classes for high high from second year undergraduates to bachelor’s thesis, school students, freshmen the more aforementioned engineering used presentations and classes for fields in undergraduates advanced disciplines from year undergraduates to thesis, master’s theses and doctoral The main school students, freshmen of in the aforementioned engineering from second year undergraduates to bachelor’s bachelor’s goal ofsecond this project to help studentsdissertations. practice the theoretical master’s theses andis even even doctoral dissertations. Thethesis, main school students, freshmen of the aforementioned engineering fields and undergraduates in more advanced disciplines school students, freshmen of the aforementioned engineering related and to the area. In the in future, projects will be master’s theses and even doctoral dissertations. The main goal of this project is to help students practice the theoretical fields undergraduates morethose advanced disciplines master’s theses and even doctoral dissertations. The main knowledge acquired in classroom by developing systems that goal of this project is to help students practice the theoretical fields and undergraduates in more advanced disciplines related and to the area. by In the future, those projects will be fields undergraduates in more advanced disciplines remotely students from other educational goal of this this acquired project isinto toclassroom help students practice the thesystems theoretical knowledge by developing that related to operated the area. In the future, those projects will be goal of project is help students practice theoretical will improve the training of future engineers. knowledge acquired in classroom by developing systems that related to the area. In the future, those projects will be remotely operated by students from other educational related to operated the area. by In the future,from thoseother projects will be will institutions. knowledge acquired in classroom classroom by developing systems systems that that improveacquired the training of future by engineers. remotely students educational knowledge in developing will improve the training of future engineers. remotely operated by students from other educational institutions. remotely operated by students from other educational will improve the training3.of PROJECTS future engineers. institutions. will improve the training of future engineers. 2. MECHATRONIC SYSTEM DEVELOPMENT institutions. 3. PROJECTS institutions. 3. PROJECTS 2. MECHATRONIC SYSTEM DEVELOPMENT LABORATORY The LDSM is directly 3. linked to scientific research and the PROJECTS 2. MECHATRONIC SYSTEM DEVELOPMENT 3. PROJECTS 2. MECHATRONIC SYSTEM DEVELOPMENT LABORATORY The LDSM is of directly linked to research the 2. MECHATRONIC SYSTEM DEVELOPMENT development knowledge andscientific technology in and System LABORATORY The LDSM is directly linked to scientific research and the The Mechatronic System Development Laboratory was development LABORATORY The LDSM is directly linked to research the of knowledge andscientific technology in and System LABORATORY The LDSM is directly linked to scientific research and the Dynamics. So far, three doctoral dissertations, several development of knowledge and technology in System The Mechatronic System Development Laboratory was created in 2007 with financial support Laboratory from FAPERJ development of knowledge and technology in System So far, three doctoral dissertations, several The Mechatronic System Development was Dynamics. development of knowledge and technology in System masters and bachelor’s theses numerous undergraduate The Mechatronic System Development Laboratory was Dynamics. So far, three doctoral dissertations, several created in 2007 with financial from FAPERJ The Mechatronic System was (Foundation for Research of Development Rio de support Janeiro).Laboratory The laboratory Dynamics. So far, dissertations, several masters bachelor’s theses and undergraduate created in 2007 with financial support from FAPERJ Dynamics. So far, three doctoral dissertations, several research projects havethree beendoctoral conducted on the laboratory. masters and and bachelor’s theses and numerous numerous undergraduate created in 2007 with financial support from FAPERJ (Foundation for Research of Rio de Janeiro). The laboratory created in 2007 with financial support from FAPERJ consists of a for number of commonly equipments in actual masters and bachelor’s theses and numerous undergraduate research projects have been conducted on the laboratory. (Foundation Research of Rio deused Janeiro). The laboratory masters and bachelor’s theses and numerous undergraduate They are all aimed at the design, simulation, construction, research projects have been conducted on the laboratory. (Foundation Research of Rio Rio deused Janeiro). The laboratory laboratory consists oflike a for number of commonly equipments in actual (Foundation Research of de Janeiro). The vehicles dynamometers, motion simulators, scales for research research projects been conducted on the theconstruction, laboratory. They allvalidation aimedhave atofthe simulation, consists of a for number of commonly used equipments in actual projects been conducted on laboratory. testingare and the design, following apparatuses, presented are all aimedhave at the design, simulation, construction, consists of aa number of commonly used equipments in actual vehicles like dynamometers, motion simulators, scales for They consists of number of commonly used equipments in actual measuring the distribution of weight and moments of inertia, They are all aimed at the design, simulation, construction, testing and validation of the following apparatuses, presented vehicles like dynamometers, motion simulators, scales for They are all aimed at the design, simulation, construction, in chronological order. testing and validation of the following apparatuses, presented vehicles like dynamometers, motion simulators, scales for measuring the distribution of weight and moments of inertia, vehicles like motionand simulators, scales besides daily mechatronics systems such as for an testing testing and validation validation of the the following following apparatuses, apparatuses, presented presented in chronological order.of measuringother the dynamometers, distribution of weight moments of inertia, and in chronological order. measuring the distribution of weight and moments of inertia, besides other daily mechatronics systems such as an measuring the distribution of weight and moments of inertia, besides other daily mechatronics systems such as an in in chronological chronological order. order. besides other daily besides © other daily mechatronics mechatronics systems systems such such as as an an 248 Copyright 2016 IFAC 2405-8963 © IFAC (International Federation of Automatic Control) Copyright © 2016, 2016 IFAC 248Hosting by Elsevier Ltd. All rights reserved. Copyright 2016 responsibility IFAC 248Control. Peer review© of International Federation of Automatic Copyright ©under 2016 IFAC IFAC 248 Copyright © 2016 248 10.1016/j.ifacol.2016.07.185
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3.1 Vertical motion simulator with three degrees of freedom
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As shown in Figure 3, this mechanism consists of six limbs (with variable lengths d1, d2, d3, d4, d5 and d6) that are connected to a fixed base by six spherical joints (A1, A2, A3, A4, A5 and A6) and to a moving platform by six universal joints (B1, B2, B3, B4, B5 and B6). The position and the orientation of the moving platform are given by x, y, z, φ, θ and ψ.
The equipment designed during a master’s thesis by Llerena (2000) and shown on Figure 1, reproduces the vertical dynamics of a ground vehicle’s under suspension, that is, the bounce, pitch and roll movements. At the time, this apparatus did not exist in the market and was considered a technological innovation. The work consisted of a computational simulation of the project, in order to define its components and characteristic parameters; a study on the similarity of the dynamic scale models and their real equivalents, as to establish the relationship between the small scale and actual vehicle subjected to similar inputs; and fuzzy logic to control the highly nonlinear pneumatic actuation system. When LDSM was implemented, undergraduate students built the simulator using an open loop actuation system, which reproduced, with restrictions, the typical base inputs suffered by tires in contact with the ground. Currently, this pioneering apparatus is disabled due to new equipment, which replaced it with great advantages, as the next sub item describes.
Figure 3. Geometric scheme of a Stewart platform The inverse geometry could be obtained by the vector sum shown in (1) with i = 1, …, 6, where RAB is the transformation matrix between the fixed frame A(x, y, z) and the moving frame B(u, v, w) (Tsai, 1999). B A ̅̅̅̅̅̅ ̅̅̅̅ ̅̅̅̅̅ ̅̅̅̅̅ A i Bi = OP + PBi - OAi ∴ di = p + RB 𝒃𝒃𝑖𝑖 - ai
(1)
ḋi = si ∙vP + (bi ×si )∙ωP
(2)
Equation (2) is obtained applying the time derivative in (1). si ̅̅̅̅̅̅ is the unit vector on the direction of the segment 𝐴𝐴 𝑖𝑖 𝐵𝐵𝑖𝑖 . vP and ωP are the linear and angular speed of the moving platform, respectively, and they form the vector 𝐱𝐱̇ , which describes the kinematic state of this platform (3). 𝑑𝑑̇𝑖𝑖 , with i = 1, …, 6, are the actuator’s linear velocities from the mechanism and they form the vector 𝐪𝐪̇ .
Figure 1. Vertical motion simulator with three degrees of freedom 3.2 Stewart Platform motion simulator with six degrees of freedom The Stewart platform is a known closed kinetic chain mechanism. Vianna (2002) virtually simulated the device, shown in Figure 2; in 2008, Albuquerque designed and built a first version as a research topic and, in the following year the machine was redesigned to its current form. As a master’s thesis object of study (Albuquerque, 2012), the system was modelled, analysed and improved. This work obtained the semi-analytical equations of the platform, using power flow concepts and bond graphs. The study also evaluated its movement’s control through acceleration and angular velocity feedback.
vp (ẋ ẏ ẋ = [ω ] = [ P (ϕ̇ θ̇
ż )T ] ψ̇ )T
(3)
The inverse jacobian matrix relates the linear and angular speed of the moving platform (𝐱𝐱̇ ) to the linear velocity of the actuators (𝐪𝐪̇ ), Separating the variables related to the limbs from the variables related to the moving platform in (2), the inverse jacobian of the mechanism can be written. More details about this procedure can be found in Albuquerque (2012) and in Albuquerque et al (2013). To solve the problem of the control based on the acceleration of the moving platform, the differential of the jacobian has to be obtained in order to achieve the relation between the velocities and accelerations of the limbs and the linear and angular accelerations of the moving platform as shown in (4).
Figure 2. Stewart platform motion simulator with six degrees of freedom
̇ ̇ + 𝐽𝐽𝐪𝐪̈ 𝐱𝐱̈ = 𝐽𝐽𝐪𝐪 249
(4)
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The control strategy based on linear accelerations and angular velocities of the moving platform of parallel mechanisms is in Figure 5. The position, velocity and linear accelerations as well as the orientations, angular velocities and accelerations form the set of data that describes the desired path. This information passes through the inverse kinematics models of the mechanisms to obtain the desired velocities and accelerations of the actuators. The error signal 𝑒𝑒𝐪𝐪̈ and their integrals 𝑒𝑒𝐪𝐪̇ and 𝑒𝑒𝐪𝐪 are handled in the controller and passes to the actuating system model to generate the actual actuators state (𝐪𝐪̈ , 𝐪𝐪̇ and 𝐪𝐪). With the direct jacobian model the actual moving platform state is obtained (𝐱𝐱̈ , 𝐱𝐱̇ and 𝐱𝐱). The effective linear accelerations and angular velocities of the moving platform are measured by an inertial unit to then be compared with the desired values (Costa, 2014 and 2015).
Figure 6. Vertical displacement of the moving platform with a sinusoidal input
Figure 4. Control strategy diagram The kinematic model based on the differential of the jacobian was compared with the jacobian model by the integration of its outputs. For input, a vertical smooth step was given on the coordinate z of the moving platform. Figure 6 shows the response of the moving platform when entering with 𝐱𝐱̈ , 𝐱𝐱̇ and 𝐱𝐱 on the inverse kinematic model and then entering its outputs (𝐪𝐪̈ , 𝐪𝐪̇ and 𝐪𝐪) on the direct kinematic model to obtain the moving platform variables to compare that output with the inputs of the inverse kinematic model.
Figure 7. Numeric simulation of the Stewart platform motion A pneumatic actuation system was adopted due to its small cost and suitable size; however, its nonlinearities and valve’s limitations prevented, at the time, to implement the proposed control strategy. Currently (Albuquerque, 2016) is developing a new version of the platform with electric actuation, aiming to validate experimentally the aforementioned control using an inertial measurement unit. The pneumatic platform has been the focus of the presentations made in LDSM for high school and engineering students. 3.3 Pneumatic test rig Due to the difficulties cited before in the characterization and calibration of pneumatic components, Assad (2013) designed a test rig, shown in Figure 8. The device determined parameters of the various pneumatic components and tested alternatives to the actuator’s speed and position control, using combinations of low cost proportional valves (Figure 9).
Figure 5. Vertical displacement of the moving platform For the closed loop control strategy shown (with the dynamic model of the actuator and the kinematic models of the mechanisms) and using the same parameters, the time response for the moving platform with a sinusoidal movement on the z direction as a desired trajectory was obtained (Figure 7). Simulations with other input conditions were done and they showed encouraging results (Figure 8). 250
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K vp =
251
𝑞𝑞max [𝑎𝑎𝑥𝑥𝑣𝑣4 + 𝑏𝑏𝑥𝑥𝑣𝑣3 + 𝑐𝑐𝑥𝑥𝑣𝑣2 + 𝑑𝑑𝑥𝑥𝑣𝑣 ] 𝑞𝑞max
𝑖𝑖𝑖𝑖 𝑥𝑥𝑣𝑣 < 0.75 𝑖𝑖𝑖𝑖 𝑥𝑥𝑣𝑣 ≥ 0.75
(6)
Table 1. Proportional valve model coefficients Increasing current Decreasing current
a 10.93
b -18.95
c 8.52
d 1.00
9.86
-19.30
10.95
0.21
𝑞𝑞max 9.25 10-5 9.15 10-5
Figure 8. Pneumatic test rig
Figure 10. Experimental flow rate through control valve Figure 11 illustrates a comparison between the path developed by the actuator and the results calculated by the model simulation. This ongoing project has been employed in LDSM demonstrations for Control Systems students, illustrating the actuator’s behaviour to different settings of PID controller gain, frequency response, feedback linearization and state variables control.
Figure 9. Diagram of pneumatic test rig The highly complex component’s mathematical model were calibrated by the test rig’s experimental evaluations and the numeric simulation results confirmed the adopted procedure’s validity (Assad et al, 2013). The main component to be identified was the proportional control valves, whose flow rate equation depends on specific geometric details (Fox et al, 2006), as show in (5).
q=
𝐶𝐶𝑑𝑑 𝐴𝐴𝑜𝑜 (𝑥𝑥𝑣𝑣 )𝐶𝐶1
𝐶𝐶𝑑𝑑 𝐴𝐴𝑜𝑜 (𝑥𝑥𝑣𝑣 )𝐶𝐶2
𝑝𝑝𝑢𝑢
√𝑇𝑇
𝑝𝑝
1/𝑘𝑘
𝑝𝑝𝑢𝑢
√𝑇𝑇
( 𝑑𝑑) √1 − 𝑃𝑃𝑢𝑢
𝑝𝑝𝑑𝑑 (𝑘𝑘−1)/𝑘𝑘
𝑝𝑝𝑢𝑢
𝑖𝑖𝑖𝑖 𝑖𝑖𝑖𝑖
𝑝𝑝𝑑𝑑 𝑝𝑝𝑢𝑢
𝑝𝑝𝑑𝑑 𝑝𝑝𝑢𝑢
≤ 𝑝𝑝𝑐𝑐𝑐𝑐 > 𝑝𝑝𝑐𝑐𝑐𝑐
(5)
Being q the mass flow rate through the orifice; Cd the discharge coefficient; Ao the orifice cross-sectional area; xv the signal sent to the servovalve; T the temperature, pd and pu the downstream and upstream pressures; C1, C2 and pcr constants relative to the air’s specific heat ratio. Figure 11. Comparison between experimental and simulated results
A function, Kvp, was determined experimentally, to include the dependence of both the discharge coefficient and area change with control signal, that is, CdAo(xv). The result is presented in (6) and Figure 10.
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3.4 Electric motor dynamometer Machado (2001) designed an apparatus to test and evaluate brushed DC electric motors commonly adopted in model building, shown in Figure 12; unlike the motion simulator, this equipment already existed on the market but at high costs. The aim of this study was to completely understand its working principle in order to optimize its components, and propose new solutions. Firstly, the relation between a variable power supply (rechargeable batteries) and the motor’s performance was determined (Figure 13 and 14); then the load influence under various operating conditions was verified, and how the electronic and mechanical control systems are used for setting and reversing the motor speed. There was thus a more accurate idea of how the engine behaved and what results should be expected on the dynamometer. Mathematical models for the various components and effects were established, its parameters were experimentally determined, and the behaviour of the system simulated computationally. The required electronics to control, monitoring and data acquisition was also implemented.
Figure 14. Motor’s curves for control application 3.5 Small scale instrumented car Aiming to apply in practice vehicle dynamics concepts, a small scale car was used to provide mathematical models and simulations in order to predict its behaviour under varied conditions. Therefore, it was studied all major systems of a commercial competition vehicle, 1:10 scale, such as its transmission system, rear-wheel drive, brushed electric motor, mechanical and electrical control speed, suspension and its geometry, steering system, servomotor and remote control.
The design and construction of the dynamometer was carried out with the financial support of FAPERJ. The apparatus allows to directly measure voltage, current, and angular speed, but the torque is indirectly obtained through the inertial load imposed by a drive attached to the motor shaft. Currently the dynamometer has been employed to determine the characteristics of the various motors used in other devices from the lab. A new version is being tested, specific to brushless motors, and including three-phase current and voltage sensors.
A mathematical model of the car, with its suspension but without its geometry (caster and camber angles) is complete and illustrates how spring stiffness influences the speed in a curve. It is also possible to determine maximum acceleration and velocity to a certain transmission relation and the possibility of drifting due to type of tire. The radio and speed control model has not been developed yet, but an assessment of how the battery pack drainage influences the engine performance has already been done. The result of this study reached its peak in a master’s thesis (Sereno, 2012), when an autonomous 1:8 scale car (Figure 15) was implemented and tested, showing results close to simulations and previous analyses. The greatest difficulty of this project, the inertial measurement unit, led to another thesis (Costa, 2014 and 2015) to filter its six degree of freedom data, whose results will be used in other autonomous vehicles. The 1:8 car and all its embedded instrumentation are still being employed in other undergraduate students projects and is recognized as one of the most interesting devices in LDSM.
Figure 12. Electric motor dynamometer
Figure 13. Motor’s performance Figure 15. Small scale instrumented car 252
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3.6 Small scale instrumented motorcycle
3.7 Serial motion simulator with six degrees of freedom
All the knowledge acquired from the project before is currently being employed on a motorcycle (Martins, 2016 and Assad, 2017). The first prototype was built with Lego Mindstorms (Figure 16) with inertial sensors and PID controller. The second and current prototype is a motorcycle at scale 1:5, also shown in Figure 16, with electric propulsion –brushless motor – that has characteristics similar to an actual vehicle. New mathematical models are being developed (Martins, 2016) and other adapted so that a numerical simulation will accurately represent the two-wheeled vehicle.
This apparatus was built in order to simplify the construction, modelling and control of vehicle simulators, using a sequential mechanism with an open kinematic chain to produce movements, actuated by electric servo motors. With an architecture simpler than the Stewart platform described before, this system can be modelled using the commonly adopted methodology of Denavit-Hartenberg parameters, which facilitates the equating procedure. The use of servo motors in this type of system also greatly simplifies the modelling process and implementation of the position, velocity and acceleration control.
The experience acquired with the electric car was fundamentally important to achieve the goal to reproduce the behaviour of a motorcycle on computer. The numerical model will check the validity of methodologies employed in order to stabilize and control the trajectory of this inherently unstable vehicle. Future experimental verification of this conducted study will be performed in two stages (Assad, 2017): initially on a passive basis and later on a test track, both specially built for this purpose. Currently, the transducers and embedded system are being assessed and validated so they may monitor the vehicle performance and provide the necessary data to compare with simulation.
The design of this apparatus began as an undergraduate research theme and the first working prototype built (Figure 18) showed satisfactory and promising performance. There is a tendency to use this type of architecture in the actual vehicle simulators, such as the recently released McLaren Formula 1 simulator. The serial simulator can be employed in classes of ‘Dynamic of Rigid Bodies’ and even in the discipline of ‘Introduction to Robotics’ to both undergraduates and graduates students as an excellent teaching tool.
This project is being developed jointly with undergraduate students, working in the determination of the parameters and characterization of the system. Figure 17 shows a detailed virtual prototype developed in order to provide inertial parameters like mass distribution and moments of inertia of the motorcycle. The results of this research project will be gradually used in undergraduate classes.
Figure 18. Serial motion simulator Figure 16. Small scale instrumented motorcycles Lego and in 1:5 scale
3.8 Traction elevator This equipment (Figure 19) was developed with the specific purpose of presenting the basic control actions in a system used daily, mainly targeting presentations to high school students and teachers. Although the elevator is not a vehicle like the rest of LDSM’s projects, it is nonetheless an autonomous equipment composed of masses - cabin and balance - under the action of gravity, moving in narrow path with regulated torque; the tension of the brushed electric motor is controlled through the desired position, i.e., the desired floor. The cabin employs a single axis accelerometer and position sensors installed on the floors as feedback elements; a specific electronic was developed for the PID controller implemented in Arduino. The lift system has a relatively simple model, which was completely simulated and analysed.
Figure 17. Virtual prototype of 1:5 scale motorcycle
Also built thanks to funding provided by FAPERJ, the equipment has often been used in demonstrations at LDSM, 253
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and recently was one of the themes, along with the dynamometer previously treated, of a course offered especially for teachers from Colégio Estadual André Maurois by the heads of LDSM in partnership with PIUES / PUC-Rio, (University School and Society Integration Program), in which physics and mathematics in high school were presented within the context of real systems. This apparatus is expected to be adopted in compulsory practical classes of subjects ‘Systems Control’ and ‘Control and Servomechanisms’, mandatory part of the curricula of Control and Automation, Mechanical, and Electrical engineering.
As these are vehicles with electric propulsion, the dynamometer described before was of fundamental importance to characterize these components. It is being developed another dynamometer specific to slot vehicles, in order to determine the power that actually reaches the wheels and losses in the transmission system. A next step is the integration of mathematical models and their simulations, with instrumentation embedded in vehicles and installed on the tracks, forming the structure called HIL (Hardware In the Loop), one of the most interesting mechatronic applications.
Figure 20. Autonomous slot car with instrumentation 3.10 Autonomous railway Following the previous design idea line, an autonomous railway in scale was created to illustrate the dynamics and vehicle control for those interested in engineering involved in the conception, design, specification, construction, operation, commissioning, and maintenance of rail systems. Figure 19. Traction elevator
The project was developed in a new partnership between LDSM / PIUES and Escola Parque (one of the most renowned high schools in Rio de Janeiro city) which led to the creation of an Introduction to Engineering class exclusive to their students. Because of the interdisciplinary nature inherent in the system, this course had the participation of Environmental, Production, Civil, Computer, Electrical, Mechanical and Control and Automation Engineering teachers. The end result is shown in Figure 21, when the railway was exposed in the school science fair, in Gávea’s unit, November 2015.
3.9 Autonomous slot car Considering the difficulties inherent to autonomous vehicles, and aiming to present some concepts and basic tools of dynamics and vehicle control to engineering freshmen, was created the AutoPUC project (Autonomous slot car). The work employs slot model car technology, topics of Physics, Calculus and Linear Algebra, and softwares like MAPLE and Scilab, all related to the problems associated with this type of vehicle and competition.
Noteworthy is the participation of Control and Automation Engineer Bruno Dantas, graduated from PUC-Rio, who worked one year in LDSM implementing and improving a command interface through WiFi and Bluetooth in its design, used to monitor and control the locomotives position. This unprecedented solution in model railroading should be used in the future in the autonomous cars systems.
At the Introduction to Engineering classes, formed by freshmen interested in Control and Automation, Mechanical or Electrical Engineering, the students – with the support of LDSM’s equipment and personnel – build projects related to a central theme, different every semester and ranging from instrumentation of a conventional slot car to a specially designed car and its tracks, as illustrated in Figure 20.
It is also planned to develop a similar system by PUC-Rio freshmen students in the Introduction to Engineering course, which should be employed in LDSM’s presentation of Control and Automation Engineering to high school students, offered regularly to selected students from various schools of Rio de Janeiro.
At the moment, the slot car speed is controlled through the computer, in each section of a predefined track. Computer simulations have been carried out to verify the vehicle’s performance at certain tracks, using relatively complex models due to its restricted trajectory and yaw attitude. To determine the dynamic characteristics of the system, it was necessary to instrument both vehicle and tracks, so that all relevant parameters and variables numerical values could be determined from experimental tests.
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autônomas, Doctoral dissertation, PUC-Rio. Unpublished Costa, M.S.M. (2014) Controle de veículos aéreos quadrirrotores – uso de filtros de Kalman para minimização de erros na unidade de medida inercial, In portuguese, Master’s thesis, PUC-Rio. Costa, M.S.M; Meggiolaro, M.A.; Speranza, M.N; Albuquerque, A.N; Assad, M.M. (2015) Performance evaluation of a sensor fusion algorithm for attitude estimation using commercial IMU and a scale Stewart platform. In 23nd COBEM, Rio de Janeiro, Brasil. Fox, R.W; McDonald, A.T; Pritchard, P.J., 2006. Introduction to fluid mechanics, 6th edition, John Wiley & Sons Llerena, R.W.A. (2000) Modelagem de um simulador de movimentos para veículos terrestres em escala, Master’s thesis, PUC-Rio. Machado J.A. (2001) Modelagem e simulação de um dinamômetro para motores elétricos utilizados nos veículos terrestres em escala, In portuguese, Master’s thesis, PUC-Rio. Martins, G.N. (2016) Concepção, modelagem e simulação de aparatos (objetos educacionais) para compreensão e análise da dinâmica e controle de motocicletas/bicicletas, Doctoral dissertation, PUC-Rio. Unpublished Ogata, K. (2009) Modern control engineering, 5th Edition, Prentice Hall. Sereno, H.R.S. (2012) Análise e validação experimental do sistema de monitoramento e controle empregado em um veículo autônomo em escala, In portuguese, Master’s thesis, PUC-Rio. Tsai, L.W. (1999) Robot analysis – The mechanical of serial and parallel manipulators, Department of Mechanical Engineering and Institute for Systems Research, University of Maryland, John Wiley and Sons, Inc., USA. Vianna, F.L.V. (2002) Análise cinemática de um simulador de movimentos de seis graus de liberdade com estrutura paralela, In portuguese, Master’s thesis, PUC-Rio.
Figure 21. Autonomous railway 4. CONCLUSION This paper presented ten mechatronics devices of low cost and small scale to aid the teaching, learning and research in Engineering, particularly on the Control and Automation, Mechanical and Mechatronics fields. New devices are being continually designed so that, in the future, other academic institutions may use it as educational kits. This work reiterated that model building components can be used as teaching and learning tools to many courses, such as Physics and Mathematics. This type of practical project can provide a quality gain in training of technicians and engineers futures. The positive results are immediate: the student is motivated to learn and the teacher has an excellent opportunity to complement theory with practice. REFERENCES Albuquerque, A.N.; Speranza, M.N.; Meggiolaro, M.A. (2013) Parallel mechanism controlled by nonconventional control strategies, DINAME 2013 – Proceedings of the XV International Symposium on Dynamic Problems of Mechanics, ABCM, Buzios, RJ, Brazil. Albuquerque, A.N. (2012). Modelagem e simulação de uma plataforma de Stewart controlada usando sensores inerciais, In portuguese, Master’s thesis, PUC-Rio. Albuquerque, A.N. (2016) Dinâmica e controle de mecanismos paralelos inseridos em uma estrutura HIL – hardware in the loop: integração modelo analítico fechado, transdutores inerciais e atuadores elétricos lineares, Doctoral dissertation, PUC-Rio. Unpublished Assad, M.M. (2013). Caracterização experimental do comportamento dinâmico de um sistema pneumático de atuação de controle de sistemas mecânicos em escala, In portuguese, Master’s thesis, PUC-Rio. Assad, M.M; Speranza, M.N; Meggiolaro, M.A. (2013) Characterization of components dynamic behavior in an industrial pneumatic actuation system for unconventional applications. In 22nd COBEM, São Paulo, Brasil. Assad, M.M. (2017) Implementação e validação experimental de estratégias de controle para estabilização e acompanhamento de trajetórias de motocicletas 255
ScienceDirect IFAC-PapersOnLine 49-6 (2016) 248–255 Devices as Small Scale Mechatronics Small Scale Mechatronics Devices as Small Scale Devices as Educational andMechatronics Research Engineering Small Scale Mechatronics Devices asTools Educational and Research Engineering Tools Educational Research Engineering Tools Educational and andMauro Research Engineering Tools Speranza Neto*
Mauro SperanzaMarília Neto* Allan Nogueira de Albuquerque**, Mauro Speranza Neto* Maurell Assad*** Mauro Speranza Neto* Allan Nogueira de Albuquerque**, Marília Mauro Speranza Neto* Maurell Allan Nogueira de Albuquerque**, Marília Maurell Assad*** Assad*** Allan Nogueira de Albuquerque**, Marília Maurell Allan Nogueira de Albuquerque**, MaríliaUniversity, Maurell Assad*** Assad*** Mechanical Engineering Department, Pontifical Catholic Rio de Janeiro, Brazil Mechanical Engineering Department, Pontifical Catholic University, Rio de Janeiro, Brazil puc-rio.br * msn@ Mechanical Engineering Department, Pontifical Catholic University, Rio de Janeiro, Brazil Mechanical Engineering Engineering Department, Department, Pontifical Catholic University, University, Rio Rio de de Janeiro, Janeiro, Brazil Brazil * msn@ puc-rio.br Mechanical Pontifical Catholic ** [email protected] * msn@ puc-rio.br * msn@ puc-rio.br ** [email protected] * msn@ puc-rio.br *** [email protected] ** [email protected] ** [email protected] [email protected] *** [email protected] ** *** [email protected] *** *** [email protected] [email protected] Abstract: This paper presents several mechatronics equipments of low cost and small scale, employing Abstract: This presentsapplied several mechatronics equipments of low and small employing components andpaper technology model building. All systems werecost developed and scale, built by students Abstract: This paper presents severaltomechatronics equipments of low cost and small scale, employing Abstract: This paper presents several mechatronics equipments of low cost and small scale, employing components and technology applied toPontifical model building. All systems were developed and built by students Abstract: This paper presents several mechatronics equipments of low cost and small scale, employing with different levels of knowledge in Catholic University of Rio de Janeiro to aid the teaching, components and technology applied to model building. All systems were developed and built by students components and technology applied to model building. All systems were developed and built by students with different levels of knowledge in Pontifical Catholic University of Rio de Janeiro to aid the teaching, components technology appliedintoPontifical model building. systems byteaching, students learning andand research in Engineering, particularly onAll the Controlwere Automation, Mechanical and with different levels of knowledge Catholic University ofand Riodeveloped de Janeiroand to built aid the with different levels of knowledge in Pontifical Catholic University of Rio de Janeiro to aid the teaching, learning and research in Engineering, particularly on the Control and Automation, Mechanical and with different levels of knowledge in Pontifical Catholic University Rio Automation, de Janeiro to Mechanical aid the teaching, Mechatronics learning and fields. research in Engineering, particularly on the Controlofand and learning and research in Engineering, particularly on the Control and Automation, Mechanical Mechatronics fields. learning and fields. research in Engineering, particularly on the Control and Automation, Mechanical and and Mechatronics Keywords: Teaching, Control Engineering, Embedded systems, Education Laboratory, Aids © 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. AllEducational rights reserved. Mechatronics fields. Mechatronics fields. Keywords: Teaching, Control Engineering, Embedded systems, Education Laboratory, Educational Aids Keywords: Teaching, Control Engineering, Embedded systems, Education Laboratory, Educational Aids Keywords: Teaching, Teaching, Control Control Engineering, Engineering, Embedded Embedded systems, Education Education Laboratory, Laboratory, Educational Educational Aids Aids Keywords: systems, automatic traction elevator and railroad, all on a small scale 1. INTRODUCTION automatic elevator and railroad, on a small and using traction the same basic concepts and all devices of itsscale real automatic traction elevator and railroad, all on a small scale 1. INTRODUCTION automatic traction elevator and railroad, all on a small and using the same basic concepts and devices of kind itsscale real 1. INTRODUCTION automatic traction elevator and railroad, all on a small scale equivalent systems. 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Every and its involved involved with projects linked toundergraduates the research group. and components ofenvironment ground vehicles areascale available for testing, The main intention behind LDSM’s creation was to disclose involved with projects linked to the research group. and components of ground vehicles are available for testing, evaluation and experiments. Every scale system and its involved with projects linked to the research group. and components of ground vehicles are available for testing, components is properly instrumented; control techniques and main intention behind LDSM’s creation engineers was to disclose evaluation and experiments. Every scale system and its The for high school students and freshmen what main intention behind LDSM’s creation was to disclose evaluation and experiments. Every scale and its components is properly instrumented; control techniques evaluation experiments. Everysuch scale assystem system and and its The electronic monitoring devices, transducers, The main intention behind LDSM’s creation wasAutomation to disclose disclose for high school students and freshmen engineers what componentsand is properly instrumented; control techniques and The main intention behind LDSM’s creation was to projects can be done in Mechanics, Control and for high school students and freshmen engineers what components is properly instrumented; control techniques and electronic monitoring devices, such as transducers, components is properly instrumented; control and for microprocessors and computers, are widely used, all of which electronic monitoring devices, such astechniques transducers, high school students and freshmen engineers what projects can be done in Mechanics, Control and Automation for high school students and freshmen engineers what and Mechatronics Engineering, as this type of equipment and projects can be done in Mechanics, Control and Automation electronic monitoring devices, such as transducers, microprocessors and computers, are widely used, all of which electronic monitoring devices, such used, as all transducers, with technology marketed to model projects can be done in Mechanics, Control and Automation Mechatronics Engineering, as this type of equipment and microprocessors and computers, are building. widely of which and projects can be done in Mechanics, Control and Automation technology has appeal to young people. The laboratory has microprocessors and computers, computers, are building. widely used, used, all all of of which which and Mechatronics Engineering, as this type of equipment and with technology marketed to model microprocessors and are widely and Mechatronics Engineering, as this type of equipment and technology has appeal to young people. The laboratory has with technology marketed to model building. and Mechatronics Engineering, as this type of equipment and been a great advertisement for the mentioned courses. The LDSM activities are geared exclusively to the academic technology has appeal to young people. The laboratory has with technology technology marketed marketed to to model model building. building. with technology has appeal to young people. The laboratory been a great advertisement for the mentioned courses. The LDSM activities are geared exclusively to the academic appeal to young people. Thecourses. laboratory has has field, beingactivities developed by undergraduate graduate technology beenapparatuses, a greathas advertisement forinthe mentioned The LDSM are geared exclusively toand the academic All described the following chapter, have been a great advertisement for the mentioned courses. The LDSM activities are geared exclusively to the academic field, being developed by undergraduate and graduate beenapparatuses, a great advertisement for the mentioned courses. The aremonograph geared exclusively toand the academic students as activities research or topics. The devices are All field,LDSM being developed by undergraduate graduate described the following chapter,levels, have developed by studentsin different knowledge All apparatuses, described inat the following chapter, have field, developed by undergraduate and graduate students as research or and monograph topics. classes The are been field, being developed bydemonstrative undergraduate anddevices graduate used inbeing presentations for high All apparatuses, described in following chapter, have developed by students at the different knowledge levels, students as research or monograph topics. The devices are been All apparatuses, described in the following chapter, have from second year undergraduates to bachelor’s thesis, students as research or and monograph topics. classes The engineering devices are been developed by students at different knowledge levels, used presentations for high students as research or monograph topics. The devices are schoolin freshmen of demonstrative the aforementioned been developed by students at different knowledge levels, from second year undergraduates to bachelor’s thesis, used instudents, presentations and demonstrative classes for high been developed by students at different knowledge levels, master’s theses and even doctoral dissertations. The main used inand presentations andof demonstrative demonstrative classes for high high from second year undergraduates to bachelor’s thesis, school students, freshmen the more aforementioned engineering used presentations and classes for fields in undergraduates advanced disciplines from year undergraduates to thesis, master’s theses and doctoral The main school students, freshmen of in the aforementioned engineering from second year undergraduates to bachelor’s bachelor’s goal ofsecond this project to help studentsdissertations. practice the theoretical master’s theses andis even even doctoral dissertations. Thethesis, main school students, freshmen of the aforementioned engineering fields and undergraduates in more advanced disciplines school students, freshmen of the aforementioned engineering related and to the area. In the in future, projects will be master’s theses and even doctoral dissertations. The main goal of this project is to help students practice the theoretical fields undergraduates morethose advanced disciplines master’s theses and even doctoral dissertations. The main knowledge acquired in classroom by developing systems that goal of this project is to help students practice the theoretical fields and undergraduates in more advanced disciplines related and to the area. by In the future, those projects will be fields undergraduates in more advanced disciplines remotely students from other educational goal of this this acquired project isinto toclassroom help students practice the thesystems theoretical knowledge by developing that related to operated the area. In the future, those projects will be goal of project is help students practice theoretical will improve the training of future engineers. knowledge acquired in classroom by developing systems that related to the area. In the future, those projects will be remotely operated by students from other educational related to operated the area. by In the future,from thoseother projects will be will institutions. knowledge acquired in classroom classroom by developing systems systems that that improveacquired the training of future by engineers. remotely students educational knowledge in developing will improve the training of future engineers. remotely operated by students from other educational institutions. remotely operated by students from other educational will improve the training3.of PROJECTS future engineers. institutions. will improve the training of future engineers. 2. MECHATRONIC SYSTEM DEVELOPMENT institutions. 3. PROJECTS institutions. 3. PROJECTS 2. MECHATRONIC SYSTEM DEVELOPMENT LABORATORY The LDSM is directly 3. linked to scientific research and the PROJECTS 2. MECHATRONIC SYSTEM DEVELOPMENT 3. PROJECTS 2. MECHATRONIC SYSTEM DEVELOPMENT LABORATORY The LDSM is of directly linked to research the 2. MECHATRONIC SYSTEM DEVELOPMENT development knowledge andscientific technology in and System LABORATORY The LDSM is directly linked to scientific research and the The Mechatronic System Development Laboratory was development LABORATORY The LDSM is directly linked to research the of knowledge andscientific technology in and System LABORATORY The LDSM is directly linked to scientific research and the Dynamics. So far, three doctoral dissertations, several development of knowledge and technology in System The Mechatronic System Development Laboratory was created in 2007 with financial support Laboratory from FAPERJ development of knowledge and technology in System So far, three doctoral dissertations, several The Mechatronic System Development was Dynamics. development of knowledge and technology in System masters and bachelor’s theses numerous undergraduate The Mechatronic System Development Laboratory was Dynamics. So far, three doctoral dissertations, several created in 2007 with financial from FAPERJ The Mechatronic System was (Foundation for Research of Development Rio de support Janeiro).Laboratory The laboratory Dynamics. So far, dissertations, several masters bachelor’s theses and undergraduate created in 2007 with financial support from FAPERJ Dynamics. So far, three doctoral dissertations, several research projects havethree beendoctoral conducted on the laboratory. masters and and bachelor’s theses and numerous numerous undergraduate created in 2007 with financial support from FAPERJ (Foundation for Research of Rio de Janeiro). The laboratory created in 2007 with financial support from FAPERJ consists of a for number of commonly equipments in actual masters and bachelor’s theses and numerous undergraduate research projects have been conducted on the laboratory. (Foundation Research of Rio deused Janeiro). The laboratory masters and bachelor’s theses and numerous undergraduate They are all aimed at the design, simulation, construction, research projects have been conducted on the laboratory. (Foundation Research of Rio Rio deused Janeiro). The laboratory laboratory consists oflike a for number of commonly equipments in actual (Foundation Research of de Janeiro). The vehicles dynamometers, motion simulators, scales for research research projects been conducted on the theconstruction, laboratory. They allvalidation aimedhave atofthe simulation, consists of a for number of commonly used equipments in actual projects been conducted on laboratory. testingare and the design, following apparatuses, presented are all aimedhave at the design, simulation, construction, consists of aa number of commonly used equipments in actual vehicles like dynamometers, motion simulators, scales for They consists of number of commonly used equipments in actual measuring the distribution of weight and moments of inertia, They are all aimed at the design, simulation, construction, testing and validation of the following apparatuses, presented vehicles like dynamometers, motion simulators, scales for They are all aimed at the design, simulation, construction, in chronological order. testing and validation of the following apparatuses, presented vehicles like dynamometers, motion simulators, scales for measuring the distribution of weight and moments of inertia, vehicles like motionand simulators, scales besides daily mechatronics systems such as for an testing testing and validation validation of the the following following apparatuses, apparatuses, presented presented in chronological order.of measuringother the dynamometers, distribution of weight moments of inertia, and in chronological order. measuring the distribution of weight and moments of inertia, besides other daily mechatronics systems such as an measuring the distribution of weight and moments of inertia, besides other daily mechatronics systems such as an in in chronological chronological order. order. besides other daily besides © other daily mechatronics mechatronics systems systems such such as as an an 248 Copyright 2016 IFAC 2405-8963 © IFAC (International Federation of Automatic Control) Copyright © 2016, 2016 IFAC 248Hosting by Elsevier Ltd. All rights reserved. Copyright 2016 responsibility IFAC 248Control. Peer review© of International Federation of Automatic Copyright ©under 2016 IFAC IFAC 248 Copyright © 2016 248 10.1016/j.ifacol.2016.07.185
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3.1 Vertical motion simulator with three degrees of freedom
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As shown in Figure 3, this mechanism consists of six limbs (with variable lengths d1, d2, d3, d4, d5 and d6) that are connected to a fixed base by six spherical joints (A1, A2, A3, A4, A5 and A6) and to a moving platform by six universal joints (B1, B2, B3, B4, B5 and B6). The position and the orientation of the moving platform are given by x, y, z, φ, θ and ψ.
The equipment designed during a master’s thesis by Llerena (2000) and shown on Figure 1, reproduces the vertical dynamics of a ground vehicle’s under suspension, that is, the bounce, pitch and roll movements. At the time, this apparatus did not exist in the market and was considered a technological innovation. The work consisted of a computational simulation of the project, in order to define its components and characteristic parameters; a study on the similarity of the dynamic scale models and their real equivalents, as to establish the relationship between the small scale and actual vehicle subjected to similar inputs; and fuzzy logic to control the highly nonlinear pneumatic actuation system. When LDSM was implemented, undergraduate students built the simulator using an open loop actuation system, which reproduced, with restrictions, the typical base inputs suffered by tires in contact with the ground. Currently, this pioneering apparatus is disabled due to new equipment, which replaced it with great advantages, as the next sub item describes.
Figure 3. Geometric scheme of a Stewart platform The inverse geometry could be obtained by the vector sum shown in (1) with i = 1, …, 6, where RAB is the transformation matrix between the fixed frame A(x, y, z) and the moving frame B(u, v, w) (Tsai, 1999). B A ̅̅̅̅̅̅ ̅̅̅̅ ̅̅̅̅̅ ̅̅̅̅̅ A i Bi = OP + PBi - OAi ∴ di = p + RB 𝒃𝒃𝑖𝑖 - ai
(1)
ḋi = si ∙vP + (bi ×si )∙ωP
(2)
Equation (2) is obtained applying the time derivative in (1). si ̅̅̅̅̅̅ is the unit vector on the direction of the segment 𝐴𝐴 𝑖𝑖 𝐵𝐵𝑖𝑖 . vP and ωP are the linear and angular speed of the moving platform, respectively, and they form the vector 𝐱𝐱̇ , which describes the kinematic state of this platform (3). 𝑑𝑑̇𝑖𝑖 , with i = 1, …, 6, are the actuator’s linear velocities from the mechanism and they form the vector 𝐪𝐪̇ .
Figure 1. Vertical motion simulator with three degrees of freedom 3.2 Stewart Platform motion simulator with six degrees of freedom The Stewart platform is a known closed kinetic chain mechanism. Vianna (2002) virtually simulated the device, shown in Figure 2; in 2008, Albuquerque designed and built a first version as a research topic and, in the following year the machine was redesigned to its current form. As a master’s thesis object of study (Albuquerque, 2012), the system was modelled, analysed and improved. This work obtained the semi-analytical equations of the platform, using power flow concepts and bond graphs. The study also evaluated its movement’s control through acceleration and angular velocity feedback.
vp (ẋ ẏ ẋ = [ω ] = [ P (ϕ̇ θ̇
ż )T ] ψ̇ )T
(3)
The inverse jacobian matrix relates the linear and angular speed of the moving platform (𝐱𝐱̇ ) to the linear velocity of the actuators (𝐪𝐪̇ ), Separating the variables related to the limbs from the variables related to the moving platform in (2), the inverse jacobian of the mechanism can be written. More details about this procedure can be found in Albuquerque (2012) and in Albuquerque et al (2013). To solve the problem of the control based on the acceleration of the moving platform, the differential of the jacobian has to be obtained in order to achieve the relation between the velocities and accelerations of the limbs and the linear and angular accelerations of the moving platform as shown in (4).
Figure 2. Stewart platform motion simulator with six degrees of freedom
̇ ̇ + 𝐽𝐽𝐪𝐪̈ 𝐱𝐱̈ = 𝐽𝐽𝐪𝐪 249
(4)
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The control strategy based on linear accelerations and angular velocities of the moving platform of parallel mechanisms is in Figure 5. The position, velocity and linear accelerations as well as the orientations, angular velocities and accelerations form the set of data that describes the desired path. This information passes through the inverse kinematics models of the mechanisms to obtain the desired velocities and accelerations of the actuators. The error signal 𝑒𝑒𝐪𝐪̈ and their integrals 𝑒𝑒𝐪𝐪̇ and 𝑒𝑒𝐪𝐪 are handled in the controller and passes to the actuating system model to generate the actual actuators state (𝐪𝐪̈ , 𝐪𝐪̇ and 𝐪𝐪). With the direct jacobian model the actual moving platform state is obtained (𝐱𝐱̈ , 𝐱𝐱̇ and 𝐱𝐱). The effective linear accelerations and angular velocities of the moving platform are measured by an inertial unit to then be compared with the desired values (Costa, 2014 and 2015).
Figure 6. Vertical displacement of the moving platform with a sinusoidal input
Figure 4. Control strategy diagram The kinematic model based on the differential of the jacobian was compared with the jacobian model by the integration of its outputs. For input, a vertical smooth step was given on the coordinate z of the moving platform. Figure 6 shows the response of the moving platform when entering with 𝐱𝐱̈ , 𝐱𝐱̇ and 𝐱𝐱 on the inverse kinematic model and then entering its outputs (𝐪𝐪̈ , 𝐪𝐪̇ and 𝐪𝐪) on the direct kinematic model to obtain the moving platform variables to compare that output with the inputs of the inverse kinematic model.
Figure 7. Numeric simulation of the Stewart platform motion A pneumatic actuation system was adopted due to its small cost and suitable size; however, its nonlinearities and valve’s limitations prevented, at the time, to implement the proposed control strategy. Currently (Albuquerque, 2016) is developing a new version of the platform with electric actuation, aiming to validate experimentally the aforementioned control using an inertial measurement unit. The pneumatic platform has been the focus of the presentations made in LDSM for high school and engineering students. 3.3 Pneumatic test rig Due to the difficulties cited before in the characterization and calibration of pneumatic components, Assad (2013) designed a test rig, shown in Figure 8. The device determined parameters of the various pneumatic components and tested alternatives to the actuator’s speed and position control, using combinations of low cost proportional valves (Figure 9).
Figure 5. Vertical displacement of the moving platform For the closed loop control strategy shown (with the dynamic model of the actuator and the kinematic models of the mechanisms) and using the same parameters, the time response for the moving platform with a sinusoidal movement on the z direction as a desired trajectory was obtained (Figure 7). Simulations with other input conditions were done and they showed encouraging results (Figure 8). 250
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K vp =
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𝑞𝑞max [𝑎𝑎𝑥𝑥𝑣𝑣4 + 𝑏𝑏𝑥𝑥𝑣𝑣3 + 𝑐𝑐𝑥𝑥𝑣𝑣2 + 𝑑𝑑𝑥𝑥𝑣𝑣 ] 𝑞𝑞max
𝑖𝑖𝑖𝑖 𝑥𝑥𝑣𝑣 < 0.75 𝑖𝑖𝑖𝑖 𝑥𝑥𝑣𝑣 ≥ 0.75
(6)
Table 1. Proportional valve model coefficients Increasing current Decreasing current
a 10.93
b -18.95
c 8.52
d 1.00
9.86
-19.30
10.95
0.21
𝑞𝑞max 9.25 10-5 9.15 10-5
Figure 8. Pneumatic test rig
Figure 10. Experimental flow rate through control valve Figure 11 illustrates a comparison between the path developed by the actuator and the results calculated by the model simulation. This ongoing project has been employed in LDSM demonstrations for Control Systems students, illustrating the actuator’s behaviour to different settings of PID controller gain, frequency response, feedback linearization and state variables control.
Figure 9. Diagram of pneumatic test rig The highly complex component’s mathematical model were calibrated by the test rig’s experimental evaluations and the numeric simulation results confirmed the adopted procedure’s validity (Assad et al, 2013). The main component to be identified was the proportional control valves, whose flow rate equation depends on specific geometric details (Fox et al, 2006), as show in (5).
q=
𝐶𝐶𝑑𝑑 𝐴𝐴𝑜𝑜 (𝑥𝑥𝑣𝑣 )𝐶𝐶1
𝐶𝐶𝑑𝑑 𝐴𝐴𝑜𝑜 (𝑥𝑥𝑣𝑣 )𝐶𝐶2
𝑝𝑝𝑢𝑢
√𝑇𝑇
𝑝𝑝
1/𝑘𝑘
𝑝𝑝𝑢𝑢
√𝑇𝑇
( 𝑑𝑑) √1 − 𝑃𝑃𝑢𝑢
𝑝𝑝𝑑𝑑 (𝑘𝑘−1)/𝑘𝑘
𝑝𝑝𝑢𝑢
𝑖𝑖𝑖𝑖 𝑖𝑖𝑖𝑖
𝑝𝑝𝑑𝑑 𝑝𝑝𝑢𝑢
𝑝𝑝𝑑𝑑 𝑝𝑝𝑢𝑢
≤ 𝑝𝑝𝑐𝑐𝑐𝑐 > 𝑝𝑝𝑐𝑐𝑐𝑐
(5)
Being q the mass flow rate through the orifice; Cd the discharge coefficient; Ao the orifice cross-sectional area; xv the signal sent to the servovalve; T the temperature, pd and pu the downstream and upstream pressures; C1, C2 and pcr constants relative to the air’s specific heat ratio. Figure 11. Comparison between experimental and simulated results
A function, Kvp, was determined experimentally, to include the dependence of both the discharge coefficient and area change with control signal, that is, CdAo(xv). The result is presented in (6) and Figure 10.
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3.4 Electric motor dynamometer Machado (2001) designed an apparatus to test and evaluate brushed DC electric motors commonly adopted in model building, shown in Figure 12; unlike the motion simulator, this equipment already existed on the market but at high costs. The aim of this study was to completely understand its working principle in order to optimize its components, and propose new solutions. Firstly, the relation between a variable power supply (rechargeable batteries) and the motor’s performance was determined (Figure 13 and 14); then the load influence under various operating conditions was verified, and how the electronic and mechanical control systems are used for setting and reversing the motor speed. There was thus a more accurate idea of how the engine behaved and what results should be expected on the dynamometer. Mathematical models for the various components and effects were established, its parameters were experimentally determined, and the behaviour of the system simulated computationally. The required electronics to control, monitoring and data acquisition was also implemented.
Figure 14. Motor’s curves for control application 3.5 Small scale instrumented car Aiming to apply in practice vehicle dynamics concepts, a small scale car was used to provide mathematical models and simulations in order to predict its behaviour under varied conditions. Therefore, it was studied all major systems of a commercial competition vehicle, 1:10 scale, such as its transmission system, rear-wheel drive, brushed electric motor, mechanical and electrical control speed, suspension and its geometry, steering system, servomotor and remote control.
The design and construction of the dynamometer was carried out with the financial support of FAPERJ. The apparatus allows to directly measure voltage, current, and angular speed, but the torque is indirectly obtained through the inertial load imposed by a drive attached to the motor shaft. Currently the dynamometer has been employed to determine the characteristics of the various motors used in other devices from the lab. A new version is being tested, specific to brushless motors, and including three-phase current and voltage sensors.
A mathematical model of the car, with its suspension but without its geometry (caster and camber angles) is complete and illustrates how spring stiffness influences the speed in a curve. It is also possible to determine maximum acceleration and velocity to a certain transmission relation and the possibility of drifting due to type of tire. The radio and speed control model has not been developed yet, but an assessment of how the battery pack drainage influences the engine performance has already been done. The result of this study reached its peak in a master’s thesis (Sereno, 2012), when an autonomous 1:8 scale car (Figure 15) was implemented and tested, showing results close to simulations and previous analyses. The greatest difficulty of this project, the inertial measurement unit, led to another thesis (Costa, 2014 and 2015) to filter its six degree of freedom data, whose results will be used in other autonomous vehicles. The 1:8 car and all its embedded instrumentation are still being employed in other undergraduate students projects and is recognized as one of the most interesting devices in LDSM.
Figure 12. Electric motor dynamometer
Figure 13. Motor’s performance Figure 15. Small scale instrumented car 252
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3.6 Small scale instrumented motorcycle
3.7 Serial motion simulator with six degrees of freedom
All the knowledge acquired from the project before is currently being employed on a motorcycle (Martins, 2016 and Assad, 2017). The first prototype was built with Lego Mindstorms (Figure 16) with inertial sensors and PID controller. The second and current prototype is a motorcycle at scale 1:5, also shown in Figure 16, with electric propulsion –brushless motor – that has characteristics similar to an actual vehicle. New mathematical models are being developed (Martins, 2016) and other adapted so that a numerical simulation will accurately represent the two-wheeled vehicle.
This apparatus was built in order to simplify the construction, modelling and control of vehicle simulators, using a sequential mechanism with an open kinematic chain to produce movements, actuated by electric servo motors. With an architecture simpler than the Stewart platform described before, this system can be modelled using the commonly adopted methodology of Denavit-Hartenberg parameters, which facilitates the equating procedure. The use of servo motors in this type of system also greatly simplifies the modelling process and implementation of the position, velocity and acceleration control.
The experience acquired with the electric car was fundamentally important to achieve the goal to reproduce the behaviour of a motorcycle on computer. The numerical model will check the validity of methodologies employed in order to stabilize and control the trajectory of this inherently unstable vehicle. Future experimental verification of this conducted study will be performed in two stages (Assad, 2017): initially on a passive basis and later on a test track, both specially built for this purpose. Currently, the transducers and embedded system are being assessed and validated so they may monitor the vehicle performance and provide the necessary data to compare with simulation.
The design of this apparatus began as an undergraduate research theme and the first working prototype built (Figure 18) showed satisfactory and promising performance. There is a tendency to use this type of architecture in the actual vehicle simulators, such as the recently released McLaren Formula 1 simulator. The serial simulator can be employed in classes of ‘Dynamic of Rigid Bodies’ and even in the discipline of ‘Introduction to Robotics’ to both undergraduates and graduates students as an excellent teaching tool.
This project is being developed jointly with undergraduate students, working in the determination of the parameters and characterization of the system. Figure 17 shows a detailed virtual prototype developed in order to provide inertial parameters like mass distribution and moments of inertia of the motorcycle. The results of this research project will be gradually used in undergraduate classes.
Figure 18. Serial motion simulator Figure 16. Small scale instrumented motorcycles Lego and in 1:5 scale
3.8 Traction elevator This equipment (Figure 19) was developed with the specific purpose of presenting the basic control actions in a system used daily, mainly targeting presentations to high school students and teachers. Although the elevator is not a vehicle like the rest of LDSM’s projects, it is nonetheless an autonomous equipment composed of masses - cabin and balance - under the action of gravity, moving in narrow path with regulated torque; the tension of the brushed electric motor is controlled through the desired position, i.e., the desired floor. The cabin employs a single axis accelerometer and position sensors installed on the floors as feedback elements; a specific electronic was developed for the PID controller implemented in Arduino. The lift system has a relatively simple model, which was completely simulated and analysed.
Figure 17. Virtual prototype of 1:5 scale motorcycle
Also built thanks to funding provided by FAPERJ, the equipment has often been used in demonstrations at LDSM, 253
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and recently was one of the themes, along with the dynamometer previously treated, of a course offered especially for teachers from Colégio Estadual André Maurois by the heads of LDSM in partnership with PIUES / PUC-Rio, (University School and Society Integration Program), in which physics and mathematics in high school were presented within the context of real systems. This apparatus is expected to be adopted in compulsory practical classes of subjects ‘Systems Control’ and ‘Control and Servomechanisms’, mandatory part of the curricula of Control and Automation, Mechanical, and Electrical engineering.
As these are vehicles with electric propulsion, the dynamometer described before was of fundamental importance to characterize these components. It is being developed another dynamometer specific to slot vehicles, in order to determine the power that actually reaches the wheels and losses in the transmission system. A next step is the integration of mathematical models and their simulations, with instrumentation embedded in vehicles and installed on the tracks, forming the structure called HIL (Hardware In the Loop), one of the most interesting mechatronic applications.
Figure 20. Autonomous slot car with instrumentation 3.10 Autonomous railway Following the previous design idea line, an autonomous railway in scale was created to illustrate the dynamics and vehicle control for those interested in engineering involved in the conception, design, specification, construction, operation, commissioning, and maintenance of rail systems. Figure 19. Traction elevator
The project was developed in a new partnership between LDSM / PIUES and Escola Parque (one of the most renowned high schools in Rio de Janeiro city) which led to the creation of an Introduction to Engineering class exclusive to their students. Because of the interdisciplinary nature inherent in the system, this course had the participation of Environmental, Production, Civil, Computer, Electrical, Mechanical and Control and Automation Engineering teachers. The end result is shown in Figure 21, when the railway was exposed in the school science fair, in Gávea’s unit, November 2015.
3.9 Autonomous slot car Considering the difficulties inherent to autonomous vehicles, and aiming to present some concepts and basic tools of dynamics and vehicle control to engineering freshmen, was created the AutoPUC project (Autonomous slot car). The work employs slot model car technology, topics of Physics, Calculus and Linear Algebra, and softwares like MAPLE and Scilab, all related to the problems associated with this type of vehicle and competition.
Noteworthy is the participation of Control and Automation Engineer Bruno Dantas, graduated from PUC-Rio, who worked one year in LDSM implementing and improving a command interface through WiFi and Bluetooth in its design, used to monitor and control the locomotives position. This unprecedented solution in model railroading should be used in the future in the autonomous cars systems.
At the Introduction to Engineering classes, formed by freshmen interested in Control and Automation, Mechanical or Electrical Engineering, the students – with the support of LDSM’s equipment and personnel – build projects related to a central theme, different every semester and ranging from instrumentation of a conventional slot car to a specially designed car and its tracks, as illustrated in Figure 20.
It is also planned to develop a similar system by PUC-Rio freshmen students in the Introduction to Engineering course, which should be employed in LDSM’s presentation of Control and Automation Engineering to high school students, offered regularly to selected students from various schools of Rio de Janeiro.
At the moment, the slot car speed is controlled through the computer, in each section of a predefined track. Computer simulations have been carried out to verify the vehicle’s performance at certain tracks, using relatively complex models due to its restricted trajectory and yaw attitude. To determine the dynamic characteristics of the system, it was necessary to instrument both vehicle and tracks, so that all relevant parameters and variables numerical values could be determined from experimental tests.
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autônomas, Doctoral dissertation, PUC-Rio. Unpublished Costa, M.S.M. (2014) Controle de veículos aéreos quadrirrotores – uso de filtros de Kalman para minimização de erros na unidade de medida inercial, In portuguese, Master’s thesis, PUC-Rio. Costa, M.S.M; Meggiolaro, M.A.; Speranza, M.N; Albuquerque, A.N; Assad, M.M. (2015) Performance evaluation of a sensor fusion algorithm for attitude estimation using commercial IMU and a scale Stewart platform. In 23nd COBEM, Rio de Janeiro, Brasil. Fox, R.W; McDonald, A.T; Pritchard, P.J., 2006. Introduction to fluid mechanics, 6th edition, John Wiley & Sons Llerena, R.W.A. (2000) Modelagem de um simulador de movimentos para veículos terrestres em escala, Master’s thesis, PUC-Rio. Machado J.A. (2001) Modelagem e simulação de um dinamômetro para motores elétricos utilizados nos veículos terrestres em escala, In portuguese, Master’s thesis, PUC-Rio. Martins, G.N. (2016) Concepção, modelagem e simulação de aparatos (objetos educacionais) para compreensão e análise da dinâmica e controle de motocicletas/bicicletas, Doctoral dissertation, PUC-Rio. Unpublished Ogata, K. (2009) Modern control engineering, 5th Edition, Prentice Hall. Sereno, H.R.S. (2012) Análise e validação experimental do sistema de monitoramento e controle empregado em um veículo autônomo em escala, In portuguese, Master’s thesis, PUC-Rio. Tsai, L.W. (1999) Robot analysis – The mechanical of serial and parallel manipulators, Department of Mechanical Engineering and Institute for Systems Research, University of Maryland, John Wiley and Sons, Inc., USA. Vianna, F.L.V. (2002) Análise cinemática de um simulador de movimentos de seis graus de liberdade com estrutura paralela, In portuguese, Master’s thesis, PUC-Rio.
Figure 21. Autonomous railway 4. CONCLUSION This paper presented ten mechatronics devices of low cost and small scale to aid the teaching, learning and research in Engineering, particularly on the Control and Automation, Mechanical and Mechatronics fields. New devices are being continually designed so that, in the future, other academic institutions may use it as educational kits. This work reiterated that model building components can be used as teaching and learning tools to many courses, such as Physics and Mathematics. This type of practical project can provide a quality gain in training of technicians and engineers futures. The positive results are immediate: the student is motivated to learn and the teacher has an excellent opportunity to complement theory with practice. REFERENCES Albuquerque, A.N.; Speranza, M.N.; Meggiolaro, M.A. (2013) Parallel mechanism controlled by nonconventional control strategies, DINAME 2013 – Proceedings of the XV International Symposium on Dynamic Problems of Mechanics, ABCM, Buzios, RJ, Brazil. Albuquerque, A.N. (2012). Modelagem e simulação de uma plataforma de Stewart controlada usando sensores inerciais, In portuguese, Master’s thesis, PUC-Rio. Albuquerque, A.N. (2016) Dinâmica e controle de mecanismos paralelos inseridos em uma estrutura HIL – hardware in the loop: integração modelo analítico fechado, transdutores inerciais e atuadores elétricos lineares, Doctoral dissertation, PUC-Rio. Unpublished Assad, M.M. (2013). Caracterização experimental do comportamento dinâmico de um sistema pneumático de atuação de controle de sistemas mecânicos em escala, In portuguese, Master’s thesis, PUC-Rio. Assad, M.M; Speranza, M.N; Meggiolaro, M.A. (2013) Characterization of components dynamic behavior in an industrial pneumatic actuation system for unconventional applications. In 22nd COBEM, São Paulo, Brasil. Assad, M.M. (2017) Implementação e validação experimental de estratégias de controle para estabilização e acompanhamento de trajetórias de motocicletas 255