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A Role of mechanical engineering in mechatronics
A ROLE OF MECHANICAL ENGINEERING IN MECHATRONICS Ceccarelli Marco, Ottaviano Erika, Carbone Giuseppe LARM: Laboratory of Robotics and Mechatronics, University of Cassino, Italy Abstract: In this short paper we have discussed the role of Mechanical Engineering both in education and practice of Mechatronics. In particular we have outlined main features of the mechatronic systems as strongly related with mechanical engineering when one considers that generally a task of a system is devoted to operation with interaction with environment or human beings. Since the final operation goal of a mechatronic system has a mechanical nature, mechanical characteristics both for design and operation of mechatronic systems should be considered with a careful attention both during design developments and operation management of mechatronic systems. Experiences developed at University of Cassino are reported to show examples of the practical implementation of the above-mentioned issues. Copyright © IFAC 2006 Keywords: Mechatronics, Education, Mechanical Engineering
1. MECHATRONIC SYSTEMS AND MECHATRONICS
Engineering multidisciplinary vision for modern integrated systems that are more and more conceived as a combination of parts with different natures both in design and operation.
Mechatronics has been established since 1990’s as a multidisciplinary Engineering dealing with the complexity nature of modern systems. As shown in Fig.1 Mechatronics is understood as a fusion of the disciplines Mechanics, Electronics, Electric Engineering, Control, Measurement, and Computer Science.
In Table 1 illustrative examples are reported on how systems have evolved to mechatronic designs.
A mechatronics system is, indeed, composed of mechanical parts, electric devices, electronics components, sensors, hardware and it is operated and controlled under the supervisions and commands that are programmed through suitable software. Thus, main characteristics of mechatronics systems are the integration and complementarities of the several aspects from the many disciplines that describe the design and operation of the components and overall system. In addition, for a suitable operation of a mechatronic system engineering issues and human-system aspects must be considered as looking at features and constraints from the environment within a system operates, the design by which it has been developed, the operation performance through which it fulfil the task, and the production by which it has been built.
Fig.1- A scheme for definition of Mechatronics Table 1- Illustrative examples of evolution of systems to mechatronic designs
Thus, summarizing the Mechatronics is a modern
29
Mechanics % 1960-2000
Electronics & Informatics % 1960-2000
CAR
90 - 50
10 - 50
CALCULATOR
100 - 10
0 - 90
CAMERA
100 - 30
0 - 70
Cars, whose aim is transportation, were built essentially with mechanical components in the past, but increasing performance and speed has required regulation and control of motors with sophisticated systems. Even inside comfort and safety have improved by using sensored equipment with more and more mechatronic designs so that today a car can be understood as a full mechatronic design, being pure mechanical designs limited to less than 50% of the system.
In Fig.2 an actuation system is shown with its basic components: actuator, sensor, control unit, and a regulator device. The operation of the system is controlled through a suitable programming that allows the control unit to receive and elaborate signals from sensors and then to send command signals to regulator for operating the actuator. The task is modelled by a load indicating both a payload and its movement according to the final goal of the system. The components in Fig,.2 correspond to the fields of disciplines that are indicated in Fig.1 even without any sophistication. This is because today systems are always conceived, designed and regulated to achieve optimal performance by using a mechatronic design.
Cameras were conceived and built as pure mechanical design since the photo task did not require any motion of parts. Today regulated operations, like zooming, and even photo creation, are obtained with electronics components and the only mechanical parts are left for interaction with human operators, like command buttons.
In Fig.3 a block diagram is shown to model the operation of the system in Fig.2 both for simulation/design and control purposes. G function models the system behaviour, mainly from mechanical viewpoint by taking into account also sensor signals. H is a control function that is formulated by using the mechatronic design to regulate the system operation at suitable required levels of performance. Although the scheme is directed to certain autonomy of the system, human operators always interact with the system through definition and check of the operation and even through overlooking the system by means of suitable interfaces both for starting and updating system operation.
Calculators have evolved even more deeply and the complicated pure mechanical systems, that were conceived since 18-th century, are completely disappeared and today only informatics and electronic hardware are used for calculators up to 100% of parts. The only mechanical parts with pure mechanical operations are the key buttons in the keyboards for being pushed by fingers of a human user. The above-mentioned aspects are summarized in the schemes in Figs.2 and 3 as concerning with a general layout and model for a mechatronic design as related to a servo-controlled actuator.
As already mentioned, mechanical nature of system goal is of fundamental importance for the system success and must be considered both in terms of load characteristics and operation performance, and by considering the action and supervision of human operators, as synthetically shown in Figs.2 and 3. Thus, an optimal operation of mechatronic systems requires both at level of design stages and operation managements that all components are fully understood and their integration is exploited by running the components at similar levels of their capabilities. This requires a suitable knowledge of the different engineering disciplines pertaining to the several fields of technology for the several areas in Fig.1. Thus, formation and practice for Mechatronics must be thought since the first stages of Engineering curricula in order to have engineers ready in a suitable short time for professional activity and capable to handle successfully mechatronics systems even for innovation.
Fig.2 A mechatronic design for a manipulator actuator
The multidisciplinary character of Mechatronics requires a differentiation of roles in practicing and experts engineers. Practicing engineers should be able to operate and/or adapt mechatronic systems in given application fields. Expert engineers should have capability to make innovation both in
Fig.3 A block diagram for mechatronic actuation in Fig.2
30
mechatronic systems and their applications.
Mechanics of interaction is interesting in evaluating situations with mechanical contacts and force transmissions between the system parts or its extremity and environment or task object. It is fundamental to size the system actions according to the task requirements and specific analysis of the corresponding mechanics is necessary to achieve desired goals and proper working of the overall system.
These two levels of competence refer to different level of formation: a short term with practice capabilities and a long term with design and innovation capabilities. 2. MECHANICAL ISSUES
Dynamics of Multibody systems is a mechanical discipline that is oriented to consider complex systems during complex motions like spatial movement at high acceleration and velocity, with the aim to take into account any inertia effect. Indeed, this discipline has been developed by looking at integrated systems and very often the dynamics of Multibody systems include suitable modelling of components of other nature than pure mechanical one, like for example servo-controlled actuators whose motion and dynamics can strongly affect the system behaviour and operation characteristics, as it is mechatronic systems.
A mechatronic system can be characterized synthetically by versatility and flexibility as two main aspects whose integration gives mechatronic behaviour of modern systems. Versatility is mainly related to operation capability and performance that are needed for mechanical activity of a mechatronic system. Flexibility is mainly related to regulation capability and performance that are needed for controlled actions of a mechatronic system. Thus, mechanical issues in mechatronic systems are related to versatility mainly in terms of Kinematics and Dynamics of a load movement, Mechanics of interactions (like contact and grasp), Dynamics of Multibody Systems. However, the mechanical attention is always linked to aspects of the mechatronic design and indeed, simulation of mechanical actions is usually performed by taking into account also models for the controlled actuation.
Besides the above-mentioned topics, mechanical issues in mechatronic systems can be considered for specific goals and operation tasks, like for example locomotion mobility, object grasping and manipulation, force transmission, and so on. Versatility of a mechatronic system can be seen and understood under different aspects, and the abovementioned considerations can be related to main aspects which make the role of Mechanical Engineering fundamental for the success of the mechatronic systems, but within a frame of multidisciplinary integration yet.
Thus, the role of Mechanical Engineering in Mechatronics can be understood according to two main aspects, namely the mechanical design and operation, and the mechanical interaction with environment in performing system tasks. Those mechanical aspects both for design and operation aims are studied by looking at traditional disciplines for machinery but even at specific novel disciplines.
3. EXPERIENCES AT UNIVERSITY OF CASSINO At University of Cassino experiences on Mechatronics have been carried out since early 1990’s both in educational programs and research activity.
Thus, Kinematics and Dynamics of load movement are studied to analyse and investigate on the motion of mechatronic systems and load body during the operation performing or not a task.
Conventional Engineering education in Universities does not yet use widely the denomination of Mechatronics for those Engineering curricula dealing with specific formation in Mechatronics. Indeed only recently, specific curricula on Mechatronics have been started in European Universities with a teaching plan of multidisciplinary integration since the beginning of formation programs.
Particular attention is usually directed to mechanical aspects of the motion in the system and load as due to the flexibility and control of the operation of the system. In addition the task is studied by looking both at kinematic and dynamic features of the motion and related actions against the environment and within the mechatronic system yet. The particular attention to motion issues is also motivated by the attention to safety and security issues both for the system and human operators that can be in the operation area of the system.
The name of Mechatronics is not often used but since the early 1990’s many Universities have adopted specializations of Engineering curricula in last part of
31
the formation program and they have included Mechatronics as an important specialization.
Dynamics of industrial manipulators; Analysis and programming of industrial robotized manipulations; Practice with industrial robots within laboratory activity.
As an illustrative case indicating such a specialization and how it can be planned, we shall report the experiences at University of Cassino. However, this case has common aspects with many other similar teaching programs in Italy and Europe yet.
Mechanics of automatic machines - The objective of this course is to teach modelling, analysis, simulation and design of mechanical systems for automatic machines. Topics: Automatic machines; classification and basic components; Classification and design of law of motions and quality indices for the transmission; Irregularity and transitory of the motion; Planar and spatial cams; Articulated mechanisms for planar and spatial applications; Geneva wheels; Indexing mechanical systems; Analysis and use of a mechanical systems for industrial application; Practice with test-beds within laboratory activity.
In Cassino, within the curriculum for Mechanical Engineering there is a specialization program of 20 credits among the 180 credits. However, even in the core program aspects of Mechatronics are given in courses like Informatics, Control of mechanical systems, and electric Measures. The specialist program that is oriented to Mechatronics is denominated as “Automation and Robotics”. It is planned with the possibility for the student to spend a period of 8 credits for a stage in a company for developing professional experiences. The specialization is characterized by the courses that are offered, among which a student can select the credits of the specialization. The courses are of 4 credits each: Fluid Automation, Mechanics of industrial robots, Mechanics of automatic machines, Electrical actuation for automation, Laboratory for electrical actuation in automation, Instrumentation and measures for automation.
Electrical actuation for automation - The objective of this course is to give knowledge for understanding basic aspects and choice of electrical actuation for automation. Topics: Classification of systems for electrical actuation; DC motors; Brushless motors; Stepper motors; Fundamentals of electronics for industrial power supply: components, ca/dc, dc/ca; control schemes for electrical actuation. Laboratory for electrical actuation in automation The objective of this course is to give knowledge and teach the use, programming, and operation for electrical actuation for automatic systems. Topics: Automatic integrated structures (CIM); PLC: hardware and basic components; Basics of Ladder programming; Operation and use of digital and analogic I/O; Synchronization for electrical actuation; Technical specification for civil and industrial applications.
In the following a short summary for each course is reported in order to show the formation plan that is directed to give to students ability of using mechatronic systems, since in each course a practical activity is scheduled in laboratory or at industrial plants. Mechanical aspects are yet emphasized but with an integration with other disciplines according to the scheme in Fig.1.
Instrumentation and measures for automation - The objective of this course is to give knowledge of theoretical and experimental issues for the use of electrical instrumentation and measuring systems for automation. Topics: Use of electrical basic instrumentation: multimeters, oscilloscopes, frequency measuring systems; interaction between sensor and measuring system; Signal conditioners; Acquisition systems; Classification of systems for automatic measuring systems for industrial applications; Labview software for operating measures for industrial applications.
Fluid Automation - The objective of this course is to teach fundamental issues for the analysis and use of automatic systems with on/off pneumatic actuation. Topics: Classification of components for pneumatic actuation; FRL systems for providing pneumatic actuation; Pneumatic cylinders and valves, components and on/off sensors; Analysis of grafcet; Basics on PLC: components and programming for industrial applications. Mechanics of industrial robots - The objective of this course is to give fundamental knowledge and basic methodology for the analysis and use of industrial robots. Topics: Classification and comparison of industrial robots as based on their mechanical structure, technical characteristics and components; Denavit-Hartenberg notation for the analysis of industrial robots; Classification and operation of industrial grippers; Fundamentals of Kinematics: transformation matrices and workspace analysis; Trajectory planning; Fundamentals of Statics and
Similar plan is scheduled for the Master program with a specialization in Automation and Robotics with 20 credits among the available 120. The courses are: Modelling and Simulation of robots, ServoSystems, Integrated systems for production, Programmable Systems for electric locomotion, Laboratory of electromechanical systems, Digital Control, and Automatic measuring systems.
32
Teaching activity on the Mechatronics is supported by experimental and research activity that is carried out in several Engineering laboratories with different approaches within main discipline issues. In particular, within the Mechanical Engineering frame main activity is carried out at LARM: Laboratory of Robotics and Mechatronics. Detailed information on LARM can be found in the webpage http://webuser.unicas.it. As an illustrative example of activity on mechatronic systems, the experiences for LARM Hand in Fig.4 are shortly discussed. LARM hand is composed of three fingers whose design is aimed for an anthropomorphic behaviour. In particular, a humanlike grasping is obtained by each finger with 1 d.o.f. (degree of freedom) motion by using a suitable mechanism whose design has been obtained through cross four-bar linkages to be fitted in the finger body. The design compactness is useful to achieve a suitable stiffness at grasp too. The current low-cost solution can be completed with force sensors on phalanx surfaces and palm area that have been designed with a suitable surface configurations. Consequently the grasp can be regulated through a simple control using those force sensor signals and an industrial small PLC for an easy programming. The LARM Hand can be used as a grasping endeffector in robots and automatic systems, and even it has a potential feasibility as biomechanical prosthesis, once suitable adjustments are made.
Fig.4
LARM Hand for student mechatronic aspects 4.
practice
in
CONCLUSION
Two main considerations may summarize the discussion in this paper: - whatever Electronics, Informatics, Telecommunications and so on, will be enhanced and expanded in Mechatronics Technology, Mechanical Design will be always needed since a woman/man will always live and interact with the environment on the basis of mechanical phenomena of the human nature; - enhancements in knowledge and Technology needs for human life and industrial production have changed and evolved over time, also because of the evolution of systems, requiring innovation that have brought to Mechatronic design and operation of modern systems.
As shown in Fig.4 LARM Hand is a mechatronic system which is obtained as integration of mechanical parts (the fingers), measurement equipments (force sensor and monitoring software), control unit (PLC and its programming). Research activity has been carried out to design suitable mechanisms for anthropomorphic operation of the fingers with 1 dof only, to use and program a lowcost PLC, to operate firm grasp through low-cost sensors and suitable control scheme.
REFERENCES (Citation of references are not included in the paper for space limits. References are listed for giving sources of further reading even with different or complementary views with respect to the authors’ opinions) Ceccarelli M. (2004), Fundamentals of Mechanics of Robotic Manipulation, Dordrecht, 2004. Ceccarelli M and Acevedo M. (Editors) (2002), Int. Symposium on Multybody Systems and Mechatronics MUSME2002, Mexico City, 2002, CD Proceedings. Ceccarelli M and Carvalho J.C. (Editors) (2004), Int. Symposium on Multybody Systems and Mechatronics MUSME2004, Uberlandia, 2004, CD Proceedings, Bishop, R. H.(editor-in-chief) (2002), The mechatronics handbook 2002. ASME Education (2006), “ASME Mechatronics online course”, http://www.asme.org/Education/, 2006.
LARM Hand has been developed also with the help of students through master theses and course practices. It is still used in teaching activity for student practices on grasping experiences and PLC management. Thus, students learn the specific mechatronic design and operation of LARM Hand but they also get practical experience in operating a mechatronic system after classes on different disciplines. At LARM several other systems are available and used for student practices on mechatronic systems with the aim to teach them how to manage Mechatronics in practice.
33
Kelly L., De Silva C.W. (2004), “Mechatronics: An Integrated Approach”, CRC Press, 2004. Alciatore D.G., Histand M.B. (2002), “Introduction to Mechatronics & Measurement Systems”, McGraw-Hill Professional, 2002. Miu D. K. (1992) “Mechatronics: Electromechanics and Contromechanics” Springer Verlag, 1992. Bradley D.A., Dawson D., Burge S., Seward D (2000), “Mechatronics and the Design of Intelligent Machines and Systems”, 2000. Giurgiutiu V., Lyshevski S.E. (2003), “Micromechatronics: Modeling, Analysis, and Design with MATLAB”, CRC Press, 2003. Braga N.C. (2001), “Robotics, Mechatronics, and Artificial Intelligence: Experimental Circuit Blocks for Designers”, 2001. Necsulescu D (2002)., “Mechatronics”, Prentice Hall, 2002. Auslander D.M., Kempf C.J. (1995), “Mechatronics Mechanical System Interfacing” , Prentice Hall, 1995. Conferences and Proceedings: International Conference on Advanced Intelligent Mechatronics (AIM) International Conference on Mechatronics (MECH) International Conferences on Mechatronic Design and Modeling International Workshop on Education in Mechatronics (MDM) Mechatronics Forum International Conference Journals: International Journal on Intelligent Mechatronics Journal of Robotics and Mechatronics Journal of Mechatronics Journal on Micromechatronics Transactions on Mechatronics
34
1. MECHATRONIC SYSTEMS AND MECHATRONICS
Engineering multidisciplinary vision for modern integrated systems that are more and more conceived as a combination of parts with different natures both in design and operation.
Mechatronics has been established since 1990’s as a multidisciplinary Engineering dealing with the complexity nature of modern systems. As shown in Fig.1 Mechatronics is understood as a fusion of the disciplines Mechanics, Electronics, Electric Engineering, Control, Measurement, and Computer Science.
In Table 1 illustrative examples are reported on how systems have evolved to mechatronic designs.
A mechatronics system is, indeed, composed of mechanical parts, electric devices, electronics components, sensors, hardware and it is operated and controlled under the supervisions and commands that are programmed through suitable software. Thus, main characteristics of mechatronics systems are the integration and complementarities of the several aspects from the many disciplines that describe the design and operation of the components and overall system. In addition, for a suitable operation of a mechatronic system engineering issues and human-system aspects must be considered as looking at features and constraints from the environment within a system operates, the design by which it has been developed, the operation performance through which it fulfil the task, and the production by which it has been built.
Fig.1- A scheme for definition of Mechatronics Table 1- Illustrative examples of evolution of systems to mechatronic designs
Thus, summarizing the Mechatronics is a modern
29
Mechanics % 1960-2000
Electronics & Informatics % 1960-2000
CAR
90 - 50
10 - 50
CALCULATOR
100 - 10
0 - 90
CAMERA
100 - 30
0 - 70
Cars, whose aim is transportation, were built essentially with mechanical components in the past, but increasing performance and speed has required regulation and control of motors with sophisticated systems. Even inside comfort and safety have improved by using sensored equipment with more and more mechatronic designs so that today a car can be understood as a full mechatronic design, being pure mechanical designs limited to less than 50% of the system.
In Fig.2 an actuation system is shown with its basic components: actuator, sensor, control unit, and a regulator device. The operation of the system is controlled through a suitable programming that allows the control unit to receive and elaborate signals from sensors and then to send command signals to regulator for operating the actuator. The task is modelled by a load indicating both a payload and its movement according to the final goal of the system. The components in Fig,.2 correspond to the fields of disciplines that are indicated in Fig.1 even without any sophistication. This is because today systems are always conceived, designed and regulated to achieve optimal performance by using a mechatronic design.
Cameras were conceived and built as pure mechanical design since the photo task did not require any motion of parts. Today regulated operations, like zooming, and even photo creation, are obtained with electronics components and the only mechanical parts are left for interaction with human operators, like command buttons.
In Fig.3 a block diagram is shown to model the operation of the system in Fig.2 both for simulation/design and control purposes. G function models the system behaviour, mainly from mechanical viewpoint by taking into account also sensor signals. H is a control function that is formulated by using the mechatronic design to regulate the system operation at suitable required levels of performance. Although the scheme is directed to certain autonomy of the system, human operators always interact with the system through definition and check of the operation and even through overlooking the system by means of suitable interfaces both for starting and updating system operation.
Calculators have evolved even more deeply and the complicated pure mechanical systems, that were conceived since 18-th century, are completely disappeared and today only informatics and electronic hardware are used for calculators up to 100% of parts. The only mechanical parts with pure mechanical operations are the key buttons in the keyboards for being pushed by fingers of a human user. The above-mentioned aspects are summarized in the schemes in Figs.2 and 3 as concerning with a general layout and model for a mechatronic design as related to a servo-controlled actuator.
As already mentioned, mechanical nature of system goal is of fundamental importance for the system success and must be considered both in terms of load characteristics and operation performance, and by considering the action and supervision of human operators, as synthetically shown in Figs.2 and 3. Thus, an optimal operation of mechatronic systems requires both at level of design stages and operation managements that all components are fully understood and their integration is exploited by running the components at similar levels of their capabilities. This requires a suitable knowledge of the different engineering disciplines pertaining to the several fields of technology for the several areas in Fig.1. Thus, formation and practice for Mechatronics must be thought since the first stages of Engineering curricula in order to have engineers ready in a suitable short time for professional activity and capable to handle successfully mechatronics systems even for innovation.
Fig.2 A mechatronic design for a manipulator actuator
The multidisciplinary character of Mechatronics requires a differentiation of roles in practicing and experts engineers. Practicing engineers should be able to operate and/or adapt mechatronic systems in given application fields. Expert engineers should have capability to make innovation both in
Fig.3 A block diagram for mechatronic actuation in Fig.2
30
mechatronic systems and their applications.
Mechanics of interaction is interesting in evaluating situations with mechanical contacts and force transmissions between the system parts or its extremity and environment or task object. It is fundamental to size the system actions according to the task requirements and specific analysis of the corresponding mechanics is necessary to achieve desired goals and proper working of the overall system.
These two levels of competence refer to different level of formation: a short term with practice capabilities and a long term with design and innovation capabilities. 2. MECHANICAL ISSUES
Dynamics of Multibody systems is a mechanical discipline that is oriented to consider complex systems during complex motions like spatial movement at high acceleration and velocity, with the aim to take into account any inertia effect. Indeed, this discipline has been developed by looking at integrated systems and very often the dynamics of Multibody systems include suitable modelling of components of other nature than pure mechanical one, like for example servo-controlled actuators whose motion and dynamics can strongly affect the system behaviour and operation characteristics, as it is mechatronic systems.
A mechatronic system can be characterized synthetically by versatility and flexibility as two main aspects whose integration gives mechatronic behaviour of modern systems. Versatility is mainly related to operation capability and performance that are needed for mechanical activity of a mechatronic system. Flexibility is mainly related to regulation capability and performance that are needed for controlled actions of a mechatronic system. Thus, mechanical issues in mechatronic systems are related to versatility mainly in terms of Kinematics and Dynamics of a load movement, Mechanics of interactions (like contact and grasp), Dynamics of Multibody Systems. However, the mechanical attention is always linked to aspects of the mechatronic design and indeed, simulation of mechanical actions is usually performed by taking into account also models for the controlled actuation.
Besides the above-mentioned topics, mechanical issues in mechatronic systems can be considered for specific goals and operation tasks, like for example locomotion mobility, object grasping and manipulation, force transmission, and so on. Versatility of a mechatronic system can be seen and understood under different aspects, and the abovementioned considerations can be related to main aspects which make the role of Mechanical Engineering fundamental for the success of the mechatronic systems, but within a frame of multidisciplinary integration yet.
Thus, the role of Mechanical Engineering in Mechatronics can be understood according to two main aspects, namely the mechanical design and operation, and the mechanical interaction with environment in performing system tasks. Those mechanical aspects both for design and operation aims are studied by looking at traditional disciplines for machinery but even at specific novel disciplines.
3. EXPERIENCES AT UNIVERSITY OF CASSINO At University of Cassino experiences on Mechatronics have been carried out since early 1990’s both in educational programs and research activity.
Thus, Kinematics and Dynamics of load movement are studied to analyse and investigate on the motion of mechatronic systems and load body during the operation performing or not a task.
Conventional Engineering education in Universities does not yet use widely the denomination of Mechatronics for those Engineering curricula dealing with specific formation in Mechatronics. Indeed only recently, specific curricula on Mechatronics have been started in European Universities with a teaching plan of multidisciplinary integration since the beginning of formation programs.
Particular attention is usually directed to mechanical aspects of the motion in the system and load as due to the flexibility and control of the operation of the system. In addition the task is studied by looking both at kinematic and dynamic features of the motion and related actions against the environment and within the mechatronic system yet. The particular attention to motion issues is also motivated by the attention to safety and security issues both for the system and human operators that can be in the operation area of the system.
The name of Mechatronics is not often used but since the early 1990’s many Universities have adopted specializations of Engineering curricula in last part of
31
the formation program and they have included Mechatronics as an important specialization.
Dynamics of industrial manipulators; Analysis and programming of industrial robotized manipulations; Practice with industrial robots within laboratory activity.
As an illustrative case indicating such a specialization and how it can be planned, we shall report the experiences at University of Cassino. However, this case has common aspects with many other similar teaching programs in Italy and Europe yet.
Mechanics of automatic machines - The objective of this course is to teach modelling, analysis, simulation and design of mechanical systems for automatic machines. Topics: Automatic machines; classification and basic components; Classification and design of law of motions and quality indices for the transmission; Irregularity and transitory of the motion; Planar and spatial cams; Articulated mechanisms for planar and spatial applications; Geneva wheels; Indexing mechanical systems; Analysis and use of a mechanical systems for industrial application; Practice with test-beds within laboratory activity.
In Cassino, within the curriculum for Mechanical Engineering there is a specialization program of 20 credits among the 180 credits. However, even in the core program aspects of Mechatronics are given in courses like Informatics, Control of mechanical systems, and electric Measures. The specialist program that is oriented to Mechatronics is denominated as “Automation and Robotics”. It is planned with the possibility for the student to spend a period of 8 credits for a stage in a company for developing professional experiences. The specialization is characterized by the courses that are offered, among which a student can select the credits of the specialization. The courses are of 4 credits each: Fluid Automation, Mechanics of industrial robots, Mechanics of automatic machines, Electrical actuation for automation, Laboratory for electrical actuation in automation, Instrumentation and measures for automation.
Electrical actuation for automation - The objective of this course is to give knowledge for understanding basic aspects and choice of electrical actuation for automation. Topics: Classification of systems for electrical actuation; DC motors; Brushless motors; Stepper motors; Fundamentals of electronics for industrial power supply: components, ca/dc, dc/ca; control schemes for electrical actuation. Laboratory for electrical actuation in automation The objective of this course is to give knowledge and teach the use, programming, and operation for electrical actuation for automatic systems. Topics: Automatic integrated structures (CIM); PLC: hardware and basic components; Basics of Ladder programming; Operation and use of digital and analogic I/O; Synchronization for electrical actuation; Technical specification for civil and industrial applications.
In the following a short summary for each course is reported in order to show the formation plan that is directed to give to students ability of using mechatronic systems, since in each course a practical activity is scheduled in laboratory or at industrial plants. Mechanical aspects are yet emphasized but with an integration with other disciplines according to the scheme in Fig.1.
Instrumentation and measures for automation - The objective of this course is to give knowledge of theoretical and experimental issues for the use of electrical instrumentation and measuring systems for automation. Topics: Use of electrical basic instrumentation: multimeters, oscilloscopes, frequency measuring systems; interaction between sensor and measuring system; Signal conditioners; Acquisition systems; Classification of systems for automatic measuring systems for industrial applications; Labview software for operating measures for industrial applications.
Fluid Automation - The objective of this course is to teach fundamental issues for the analysis and use of automatic systems with on/off pneumatic actuation. Topics: Classification of components for pneumatic actuation; FRL systems for providing pneumatic actuation; Pneumatic cylinders and valves, components and on/off sensors; Analysis of grafcet; Basics on PLC: components and programming for industrial applications. Mechanics of industrial robots - The objective of this course is to give fundamental knowledge and basic methodology for the analysis and use of industrial robots. Topics: Classification and comparison of industrial robots as based on their mechanical structure, technical characteristics and components; Denavit-Hartenberg notation for the analysis of industrial robots; Classification and operation of industrial grippers; Fundamentals of Kinematics: transformation matrices and workspace analysis; Trajectory planning; Fundamentals of Statics and
Similar plan is scheduled for the Master program with a specialization in Automation and Robotics with 20 credits among the available 120. The courses are: Modelling and Simulation of robots, ServoSystems, Integrated systems for production, Programmable Systems for electric locomotion, Laboratory of electromechanical systems, Digital Control, and Automatic measuring systems.
32
Teaching activity on the Mechatronics is supported by experimental and research activity that is carried out in several Engineering laboratories with different approaches within main discipline issues. In particular, within the Mechanical Engineering frame main activity is carried out at LARM: Laboratory of Robotics and Mechatronics. Detailed information on LARM can be found in the webpage http://webuser.unicas.it. As an illustrative example of activity on mechatronic systems, the experiences for LARM Hand in Fig.4 are shortly discussed. LARM hand is composed of three fingers whose design is aimed for an anthropomorphic behaviour. In particular, a humanlike grasping is obtained by each finger with 1 d.o.f. (degree of freedom) motion by using a suitable mechanism whose design has been obtained through cross four-bar linkages to be fitted in the finger body. The design compactness is useful to achieve a suitable stiffness at grasp too. The current low-cost solution can be completed with force sensors on phalanx surfaces and palm area that have been designed with a suitable surface configurations. Consequently the grasp can be regulated through a simple control using those force sensor signals and an industrial small PLC for an easy programming. The LARM Hand can be used as a grasping endeffector in robots and automatic systems, and even it has a potential feasibility as biomechanical prosthesis, once suitable adjustments are made.
Fig.4
LARM Hand for student mechatronic aspects 4.
practice
in
CONCLUSION
Two main considerations may summarize the discussion in this paper: - whatever Electronics, Informatics, Telecommunications and so on, will be enhanced and expanded in Mechatronics Technology, Mechanical Design will be always needed since a woman/man will always live and interact with the environment on the basis of mechanical phenomena of the human nature; - enhancements in knowledge and Technology needs for human life and industrial production have changed and evolved over time, also because of the evolution of systems, requiring innovation that have brought to Mechatronic design and operation of modern systems.
As shown in Fig.4 LARM Hand is a mechatronic system which is obtained as integration of mechanical parts (the fingers), measurement equipments (force sensor and monitoring software), control unit (PLC and its programming). Research activity has been carried out to design suitable mechanisms for anthropomorphic operation of the fingers with 1 dof only, to use and program a lowcost PLC, to operate firm grasp through low-cost sensors and suitable control scheme.
REFERENCES (Citation of references are not included in the paper for space limits. References are listed for giving sources of further reading even with different or complementary views with respect to the authors’ opinions) Ceccarelli M. (2004), Fundamentals of Mechanics of Robotic Manipulation, Dordrecht, 2004. Ceccarelli M and Acevedo M. (Editors) (2002), Int. Symposium on Multybody Systems and Mechatronics MUSME2002, Mexico City, 2002, CD Proceedings. Ceccarelli M and Carvalho J.C. (Editors) (2004), Int. Symposium on Multybody Systems and Mechatronics MUSME2004, Uberlandia, 2004, CD Proceedings, Bishop, R. H.(editor-in-chief) (2002), The mechatronics handbook 2002. ASME Education (2006), “ASME Mechatronics online course”, http://www.asme.org/Education/, 2006.
LARM Hand has been developed also with the help of students through master theses and course practices. It is still used in teaching activity for student practices on grasping experiences and PLC management. Thus, students learn the specific mechatronic design and operation of LARM Hand but they also get practical experience in operating a mechatronic system after classes on different disciplines. At LARM several other systems are available and used for student practices on mechatronic systems with the aim to teach them how to manage Mechatronics in practice.
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Kelly L., De Silva C.W. (2004), “Mechatronics: An Integrated Approach”, CRC Press, 2004. Alciatore D.G., Histand M.B. (2002), “Introduction to Mechatronics & Measurement Systems”, McGraw-Hill Professional, 2002. Miu D. K. (1992) “Mechatronics: Electromechanics and Contromechanics” Springer Verlag, 1992. Bradley D.A., Dawson D., Burge S., Seward D (2000), “Mechatronics and the Design of Intelligent Machines and Systems”, 2000. Giurgiutiu V., Lyshevski S.E. (2003), “Micromechatronics: Modeling, Analysis, and Design with MATLAB”, CRC Press, 2003. Braga N.C. (2001), “Robotics, Mechatronics, and Artificial Intelligence: Experimental Circuit Blocks for Designers”, 2001. Necsulescu D (2002)., “Mechatronics”, Prentice Hall, 2002. Auslander D.M., Kempf C.J. (1995), “Mechatronics Mechanical System Interfacing” , Prentice Hall, 1995. Conferences and Proceedings: International Conference on Advanced Intelligent Mechatronics (AIM) International Conference on Mechatronics (MECH) International Conferences on Mechatronic Design and Modeling International Workshop on Education in Mechatronics (MDM) Mechatronics Forum International Conference Journals: International Journal on Intelligent Mechatronics Journal of Robotics and Mechatronics Journal of Mechatronics Journal on Micromechatronics Transactions on Mechatronics
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