Design method for temporarily energy self-sufficient vacuum gripping systems

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Procedia CIRP 00 (2017) 000–000 Procedia CIRP 84 (2019) 593–598 www.elsevier.com/locate/procedia

29th CIRP Design 2019 (CIRP Design 2019) 29th CIRP Design 2019 (CIRP Design 2019)

Design for temporarily energy self-sufficient vacuum Design method method28th forCIRP temporarily energy self-sufficient vacuum gripping gripping Design Conference, May 2018, Nantes, France systems systems A new methodology to analyze the functional and physical architecture of David Straubab ab* Davidoriented Straub * product family identification existing products for an assembly Graduate School of Excellence advanced Manufacturing Engineering in Stuttgart (GsaME), Universität Stuttgart, Nobelstraße 12, 70569 Stuttgart, Germany a a

Graduate School of Excellence advanced bManufacturing Engineering in Stuttgart (GsaME), Universität J. Schmalz GmbH, Johannes-Schmalz-Straße 1, 72293 Glatten,Stuttgart, GermanyNobelstraße 12, 70569 Stuttgart, Germany b J. Schmalz Johannes-Schmalz-Straße 1, 72293 Glatten, Germany * Corresponding author. Tel.: +49-7442-2403-470; fax: GmbH, +49-7443-2403-9470. E-mail address: [email protected] * Corresponding author. Tel.: +49-7442-2403-470; fax: +49-7443-2403-9470. E-mail address: [email protected] École Nationale Supérieure d’Arts et Métiers, Arts et Métiers ParisTech, LCFC EA 4495, 4 Rue Augustin Fresnel, Metz 57078, France

Paul Stief *, Jean-Yves Dantan, Alain Etienne, Ali Siadat

*Abstract Corresponding author. Tel.: +33 3 87 37 54 30; E-mail address: [email protected]

Abstract

Rising sales in the past and ongoing predicted growing sales in the future of industrial robots and especially collaborative robots endorse the Rising in the past and ongoing predicted growing sales future of industrial there robotsare andpossible especially collaborative robots endorsethere the trend ofsales increasing human-robot-collaboration. Depending on in thethe form of collaboration application scenarios in which trend of increasing human-robot-collaboration. Depending on the form of collaboration there are possible application scenarios in which there is no barrier between robot and worker whereby they share a common working space with the possibility of a mutual interference resulting in a Abstract is no barrier between robot and worker whereby they used shareto a common thevacuum possibility of a mutual interference resulting in a potential safety hazard. Industrial robots are often perform working handlingspace tasks with using gripping systems. But vacuum gripping potential safety hazard. Industrial robots are often used to perform handling tasks using vacuum gripping systems. But vacuum gripping systems manufacturers face new challenges when it comes to HRC. In case of an outage of all supply energy carrier like electrical power In today’s business environment, the trend towards more product variety and customization is unbroken. Due to this development, the needand of systems manufacturers neweventually challengesdrops whenafter it comes to HRC.period In case oftime an outage of all supply carrier like electrical power and compressed air the workface piece an cope undefined leakage. Thisenergy canTo lead to severe damage considering agile and reconfigurable production systems emerged to with various of productsdue andtoproduct families. design and optimize production compressed airhandling the workheavy pieceobjects eventually drops after an period of time duecan to leakage. This canthan lead to severe damage considering that in case of likeproduct car batteries theundefined weight said work pieces up Indeed, to more kg.known systems as well as to choose the optimal matches, productofanalysis methods are reach needed. most 100  of the methods aim to that in case of handling heavy objects like car batteries the weight of said work pieces can reach up to more than 100  k g. Currenta methods designing vacuumongripping systems focusproduct on either positioning of the point in orterms the transmission ofand the analyze product orforone product family the physical level.solely Different families, however, maygripping differ largely of the number Current methods for designing vacuum gripping solely focus on presents either positioning of designing the gripping point orgripping the transmission of the gripping force between gripping system and work systems piece. This contribution a method product of a vacuum focusing nature of components. This fact impedes an efficient comparison and choice of appropriate family combinations forsystem the production gripping between gripping system andthe work piece.system This contribution presents a to method a vacuum gripping system focusing on howAtoforce determine which characteristics gripping should remainofand indesigning a physical safe state for a predefined amount time system. new methodology is proposed to analyze existing products in have view in of order their functional architecture. The aim is to of cluster on how to determine which characteristics the gripping system should have in order to remain in a safe state for a predefined amount time afterproducts the supply energy fails. This method allows expanding theoptimization current design processassembly by implementing to HRC tasksofbased these in new assembly oriented product families for the of existing lines andthe the applicability creation of future reconfigurable after the supply energy fails. This method allows expanding the current design process by implementing the applicability to HRC tasks based on an extended It canChain, be applied to a broad rangeofofthe useproducts case scenarios as it Functional is based onsubassemblies the use of scalable off the shelf assembly systems.functional Based onanalysis. Datum Flow the physical structure is analyzed. are identified, and on an extended functional analysis. It can based be applied to a broad range ofespecially use case scenarios as itthis is purpose. based on the use of scalable off the shelf which are individually combined on previous calculations designedgraph for aproducts functional analysis is performed. Moreover, a hybrid functional and physical architecture (HyFPAG) is the output which depicts the products which are individually combined based on previous calculations especially designed for this purpose. similarity between product families by providing design support to both, production system planners and product designers. An illustrative © 2019 of The Authors. Published Elsevierthe B.V. example a nail-clipper is used by to explain proposed methodology. An industrial case study on two product families of steering columns of © 2019 Published Elsevier B.V. © 2019 The The Authors. Authors. Published by by Elsevier B.V. committee of the CIRP Design Conference 2019 Peer-review under responsibility of the scientific thyssenkrupp Presta France is then carried out to give a first industrial evaluation Conference of the proposed approach. Peer-review Peer-review under under responsibility responsibility of of the the scientific scientific committee committee of of the the CIRP CIRP Design Design Conference 2019. 2019 © 2017 The Authors. Published by Elsevier B.V. Keywords: handling; vacuum gripping system, system confuguration, human-robot collaboration Peer-review under responsibility of the scientific committee of the 28th CIRP Design Conference 2018. Keywords: handling; vacuum gripping system, system confuguration, human-robot collaboration

Keywords: Assembly; Design method; Family identification

1. Introduction 1. Introduction

[8]. So especially in HRC applications but also in fully [8]. So especially HRC applications but alsohas in to fully automated handling in processes vacuum technology be automated handling processes vacuum technology has to be 1. Introduction of the product range and characteristics manufactured The steady increase in sales of industrial robots in the past considered a possible safety hazard in case of a failure and/or of the The steady increase in sales of industrial robots in the past considered a possible safety hazard in case of a failure of the assembled in thisThe system. mainmaterials, challengethe in years is caused, among other things, by the contrasting supply energy. costsInforthis thecontext, supply the of raw years among other contrasting supply energy. The costsisproducts for thenot supply raw the Due istocaused, the fast development in byProgress thethe domain of modelling and analysis now only to copematerials, with single development of labor and robotsthings, [1–3]. in robot relocation of unfinished and theof removal of finished developmentallow ofand labor and [1–3]. in robot relocationaas of unfinished products and thecaused removal finished communication ongoing of Progress digitization and products, limited product rangedamage or existing product families, technology thean use of robots robotstrend in additional applications products well as material byofimproper technology allow the use of robots in additional applications products as well as material damage caused by improper digitalization, manufacturing enterprises facingisimportant but also tomust be able analyze and compare to define like human-robot collaboration (HRC)arewhich said to handling be to minimized [9].toEven if theproducts challenges in the like human-robot collaboration (HRC) which said are to handling must be minimized Even ifare themastered, challenges in the heavily grow 5]. The majority of those HRC tasks challenges in [4, today’s market environments: a is continuing design and deployment systems operator new product families. It of cansuch be[9]. observed that classical existing heavily grow [4, 5]. The majority of those HRC tasks are design and deployment of such systems are mastered, operator difficult towards to fullyreduction automate, but could be performed in safety will always the mostinimportant for or acceptance tendency of product development times and product families arebe regrouped function factor of clients features. difficult to fully automate, but could beis performed in safetyCurrent willassembly always be the most important factor for acceptance collaboration withlifecycles. one or more persons [6]. However, there [10]. design guidelines for families vacuum gripping systems shortened product In addition, there an increasing However, oriented product are hardly to find. collaboration with one or being more persons [6].time However, there [10]. guidelines for gripping systems are several disadvantages that at prevent collaborative robots solely focus ondesign either positioning of vacuum the gripping points ortwo the demand of customization, the same in a global On Current the product family level, products differ mainly in are several disadvantages that solely focus onofeither ofofthe gripping or the from being widely used in production as the requirement transmission force between systempoints and(ii) work competition with competitors all prevent over such thecollaborative world. This robots trend, main characteristics: (i)positioning the numbergripping components and the from being widely used in production such as the requirement transmission of force between gripping system and work of particular safety regulations [7]. pieceof but do not take accountelectrical, the case electronical). of a possible which is inducing the development from macro to micro type components (e.g. into mechanical, of particular safety [7]. piece but do not take into account an the casesingle of on a products possible A large part of regulations the industrial to perform energy failure. This paper presents approach how to markets, results in diminished lotrobots sizes are dueused to augmenting Classical methodologies considering mainly A large part of the industrial robots are used to perform energy failure. This paper presents an approach on howsafe to handling tasks where vacuum totechnology is production) commonly used design vacuum gripping systems that are able to analyze remain product varieties (high-volume low-volume [1]. or solitary, already existing product families the handling tasks where vacuum technology is commonly used design vacuum gripping systems that are able to remain safe To cope with this augmenting variety as well as to be able to product structure on a physical level (components level) which identify potentials in the existing causes difficulties regarding an efficient definition and 2212-8271possible © 2019 The optimization Authors. Published by Elsevier B.V. 2212-8271 ©under 2019responsibility TheitAuthors. Published Elsevier B.V.of the Peer-review of the scientific committee CIRP Design Conference 2019 of different product families. Addressing this production system, is important tobyhave a precise knowledge comparison Peer-review under responsibility of the scientific committee of the CIRP Design Conference 2019

2212-8271©©2017 2019The The Authors. Published by Elsevier 2212-8271 Authors. Published by Elsevier B.V. B.V. Peer-review under responsibility of scientific the scientific committee theCIRP CIRP Design Conference 2019. Peer-review under responsibility of the committee of the of 28th Design Conference 2018. 10.1016/j.procir.2019.04.320

David Straub / Procedia CIRP 84 (2019) 593–598 Author name / Procedia CIRP 00 (2019) 000–000

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over a predefined amount of time in case an energy failure occurs. Nomenclature p pend IL FTH n S t A P M

pressure (always absolute) target pressure leakage (current) theoretical gripping force number of suction cups factor of safety time area (Index) permissible (Index) measured

which contains one or more vacuum systems, each consisting of a vacuum generator with optionally integrated sensor technology (2), one or more suction cups (3) and the fluidic connections (4) which are fastened to a load-bearing structure (5). Contact with the work piece (6) is established by the suction cups [17, 18]. Additional integrated components like a connecter right above the suction cup can visualize the current operating state and display when leakage reaches a threshold [19].

2. State of the art 2.1. Human-robot interaction The goal is to use the strength of both the human and the robot. Robots can operate continuously while at the same time delivering high force, precision and repeatability. Thus they are highly productive when performing simple assembly tasks while complex tasks usually come with high programming effort. Whereas humans are doing a better job when handling limp parts and adapting to a new process sequence due to their intelligence. The synergy takes the greatest effect when it comes to small scale production requiring adaptability and reconfigurability. In general, most of the tasks performed by the robot focus on holding an object for the person, laying it aside or retrieving it on demand [11–13]. Figure 1 shows the different forms of the interaction between a human and a robot. Especially those where a mutual workspace is shared dropping a work piece could result in severe damage. Those work pieces can range from small parts like cell phones where damage mainly affects the worker to heavy ones like batteries for hybrid cars which weight more than 100 𝑘𝑘𝑘𝑘.

Figure 2: layout of a vacuum gripping system [20]

2.3. Safety and normative directives Safety has a very high priority. It must be impossible for robots and handling devices to injure people [21]. To ensure this there are several norms dictating requirements as follows. Energy failure may not cause any hazards. In case the energy returns, the handling device may not move but the vacuum generation can return to normal operation [22]. In general, reactivation of the vacuum system must not result in any safety hazard, such as objects being drawn into the vacuum system [23]. The installation must be designed to allow safe separation from the energy sources during operation. Leakage (internal or external) must not cause any hazards [24]. 2.4. Design of systems, gripping systems and components

Figure 1: forms of human-robot interaction according to [14]

2.2. Vacuum gripping systems The handling process can generally be described by five domains which all interact with each other. These are the environment, the handling device, the work piece, the task and the gripper [15, 16]. The handling device (Figure 2) consists of a robot (1) in combination with a vacuum gripper

Methodic design procedures of overall systems are based on several steps that are carried out either entirely, partly or several times iteratively [25–27]. The foundation for every design process should be the basic approach “clear, simple, secure” [28]. The basic design for every vacuum gripping system contains the process of making sure the gripping force is sufficient for the load cases that occur during the handling process. In addition to that there are various methods to choose a suiting gripping concept and gripping points based on the gripping task, the work piece and the environment [15, 16, 29–33]. For vacuum gripping systems in particular the design methods mostly focus on the load transfer between the gripping system and work piece as well as the location of gripping points [34–37]. The suction cup as a standalone



David Straub / Procedia CIRP 84 (2019) 593–598 Author name / Procedia CIRP 00 (2019) 000–000

component is investigated either by experiment or simulation. The focus is on its static and dynamic load, the behavior under this load and how the suction cup can be improved [38– 42]. But none of those methods take into account the normative directives considering safety in case of an energy failure. 3. Systems and functions An overview of the relevant systems necessary for a vacuum gripper that is able to cope with energy failure is depicted in Figure 3 along with their respective functions. The difference compared to a conventional vacuum gripper is the additional secondary vacuum system. As it has to compensate occurring leakage storage is required. And as it should be connected to the primary vacuum system only in cases of energy failure the control has to be extended by an actuator.

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primary vacuum system fails. Possible configurations of all subsystems that are connected to vacuum generation of some sort are listed in Table 1. In addition to the configuration A and B there is the possibility of combining them e.g. in the subsystem energy carrier and the possibility that the subsystem is not present at all. This concerns the subsystems secondary vacuum generation, storage as well as actuator technology. Table 1: Subsystems and possible suitable configurations Subsystem

Configuration A

Configuration B

Energy carrier

electrical power

pressure air

Primary vacuum generation

electric

pneumatic

Secondary vacuum generation

electric

pneumatic

Storage

electrical storage

fluidic reservoir

Actuator technology

electric

pneumatic

4. Behavior and impact of leakage No system is completely air tight. This means for vacuum gripping system operating in rough vacuum that they have to deal with leakage especially between the suction cup and work piece [45]. In order to ensure that the work piece stays attached to the vacuum gripper it is necessary to have enough gripping force. This can be calculated for approximately air tight and rigid work pieces for the difference from ambient pressure p0 and the target pressure pend as follows

Figure 3: systems and their respective functions

The primary vacuum system is responsible for the supply of vacuum during the handling process under regular operation. It is part of the vacuum gripper which connects the handling device and the work piece. It can be either pneumatic or electric. Compared to pneumatic vacuum generators the electric ones have a significantly higher efficiency whereas the pneumatic vacuum generators are better when it comes to low process times and have a higher robustness due to the lack of moving parts [43, 44]. The work piece is located in its initial position until the handling process is started. The evacuation phase is initiated by the control and the vacuum generation is active until the target pressure 𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒 is reached. If a failure of the support energy carriers occurs during the following handling cycle the control has to switch on the secondary vacuum system. This secondary vacuum system has to provide a sufficient low pressure over a predefined time in order to bring the work piece in a temporary final position. This amount of time and the temporary final and most of all safe position of the work piece for the surrounding persons is defined by application. In order to fulfill the function of compensating occurring leakage the secondary vacuum system needs storage and an actuator system to connect the storage. Thus the secondary vacuum system can support the gripping system when the

𝐹𝐹𝑇𝑇𝑇𝑇 = (𝑝𝑝0 − 𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒 ) ⋅ 𝐴𝐴 ⋅ 𝑛𝑛 ⋅

1 𝑆𝑆

(1)

The theoretical gripping force 𝐹𝐹𝑇𝑇𝑇𝑇 depends on the load case and differs depending on the different accelerations and friction coefficients [46, 47]. So when applying a factor of safety greater than one there is a difference ∆𝑝𝑝 between the pressure 𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒 the system is evacuated to and the pressure the work piece is dropped. This range has to be known as well as the amount of time ∆𝑡𝑡 the work piece has to remain attached to the gripper until it can be transferred into a safe state. So the permissible leakage rate is defined as 𝐼𝐼𝐿𝐿 =

∆𝑝𝑝 ∆𝑡𝑡

(2)

In general this rate shows a linear behavior below 𝑝𝑝𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 which is at around 530 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 [48]. This is confirmed by measurements. In addition, the linear approximation can be extended until 800  𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 (compare the qualitative representation of the curves in Figure 4). The deviation of the linear approximation from the actual course is less than 3%. As the linear approximation is above the actual curve the approximation is a conservative one and therefore not a safety issue. So the behavior of the leakage current can be considered approximately linear below an absolute pressure of 800 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚. This means that this approximation can be used for a gripping system that requires a pressure difference of

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200 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 or more according to equation (1) with a factor of security of 1. As this factor is usually 2 or higher [49, 50] and the operating pressure ranges down to 100 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 [47] this

approximation should be suitable for the vast majority of applications as within these in the pressure area above 800 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 the work piece is already dropped.

of a failure of the support energy carriers. The process to determine which approach should be applied is depicted in Figure 5. The three approaches that can be used to design temporary self-sufficient vacuum gripping systems based on the outcome of the selection process are described in the following.

Figure 4: qualitative pressure courses as a result of leakage

The correlation (3) [48] describes the dependency between the time 𝑡𝑡(𝑝𝑝) it takes until the pressure 𝑝𝑝 increases to a certain level due to leakage and the inner volume of the gripping system as well as the area 𝐴𝐴. 𝐴𝐴 can be interpreted as the area of the opening between the suction cup and the work piece due to its surface roughness. 𝑡𝑡(𝑝𝑝) ∼

5. Method

𝑉𝑉

𝐴𝐴

(3)

As there always is leakage in the gripper the method aims to design a system that is able to compensate the leakage over a predefined amount of time. This leads to temporarily energy self-sufficient vacuum griping system. The approach to get to such a system is divided into two steps. First, the vacuum gripping system is designed according to equation (1) in order to ensure it is capable of applying sufficient gripping force. When considering rigid and air tight work pieces leakage is negligible at this point as it is compensated by the primary vacuum system. On this basis the gripping system can fulfill the demanded handling task under normal conditions. Second, it has to be checked whether the system meets the requirements of the permissible leakage current 𝐼𝐼𝐿𝐿,𝑃𝑃 including a possible factor of safety. Therefore, the system has to complete a test cycle where it is placed onto the work piece and is evacuated until 𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒 is reached. Then the vacuum generator is turned off. After that the leakage rate 𝐼𝐼𝐿𝐿 is measured. Due to the linear behavior of 𝐼𝐼𝐿𝐿 the time until the work piece would be dropped can be calculated using equation (2). There are three possible approaches in order to make sure the permissible leakage rate is not exceeded in case

Figure 5: selection process for a suitable approach to dimension the temporary self-sufficient vacuum gripping system

5.1. Sufficiency (by default) If 𝐼𝐼𝐿𝐿,𝑀𝑀 < 𝐼𝐼𝐿𝐿,𝑃𝑃 (and a possible factor of safety is considered) the gripping system can be enabled for use. In order to consider the abrasion of the parts of the gripping systems especially of the suction cups the test cycle has to be repeated after a certain amount of cycles. This amount of cycles cannot be determined in general. The abrasion of the suction cups varies depending on their material and its possible degradation due to UV rays as well as the duration of the handling process. The duration defines how fast and hard the suction cups contact the work piece. Therefore the roughness of the work piece’s surface that comes into contact with the suction cups has a great influence on their abrasion behavior. So if the suction cups show abrasion that could result in an insufficient holding time they have to be replaced. Regarding to the system design no further steps have to be taken. 5.2. Minor adaptions If 𝐼𝐼𝐿𝐿,𝑀𝑀 > 𝐼𝐼𝐿𝐿,𝑃𝑃 measures have to be taken to increase the holding time. If the evacuation time and the energy consumption play a minor role according to correlation (3) the



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volume can be increased. If the cycle time and energy consumption are relevant the sole increase in inner volume of the gripping system would result in either too high evacuation times, too high energy consumption or both. The way to increase the holding time would be by smoothing the work piece’s surface. After both minor adaptions the leakage rate has to be measured again in order to make sure it fulfills the requirements. If not the process has to be started over. When the system fulfills the requirements the test cycle must be repeated after a certain amount of time in order to take the abrasion of the suction cups into consideration so they can be replaced in time.

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components can be exchanged or altered to suit the demands. This can affect components of the primary vacuum system like the suction cup where the diameter can be reduced or the secondary vacuum system where e.g. the storage can be reduced or increased. These new parameters are the output as well as the factor of security of the holding time that can be calculated as the leakage rate of the new system is known.

5.3. Secondary vacuum system If 𝐼𝐼𝐿𝐿,𝑀𝑀 > 𝐼𝐼𝐿𝐿,𝑃𝑃 and the cycle time and energy consumption are relevant it has to be taken into account that an increased volume raises the evacuation time. This may interfere with the desired duration of the overall handling cycle. If the surface of the work piece cannot be altered either the remaining solution is the secondary vacuum system. Here the additional volume is not integrated into the gripping system the whole time but implemented by storage that is connected in case of an energy failure. The actuator has to be triggered if the vacuum generation fails. Therefore the actuator has to be in a normally closed (NC) position when there is no energy supply. 5.3.1. Basic approach Based on the measured value of the leakage current 𝐼𝐼𝐿𝐿,𝑀𝑀 the required Volume 𝑉𝑉 to compensate the leakage current over the requested time ∆𝑡𝑡 can be calculated with equation (2). Depending on the application scenario a suitable configuration of the components listed in Table 1 is chosen. According to correlation (3) the volume has a linear impact so a fluidic reservoir is used. This can be brought to the desired pressure level either by a vacuum pump. The size of the reservoir can be determined by the same correlation. Due to the separation from the primary vacuum system the increased volume does not affect the process time. Depending on the energy carrier the respecting actuator is chosen. 5.3.2. Quantitative approach The quantitative approach requires knowledge of the leakage behavior of the individual components. The proceeding is depicted in Figure 6. The input parameters are the available form of energy and the basic concept of the gripper that has been designed to apply the necessary gripping force. In addition to that the properties of the work piece like weight and surface roughness and the required holding time are input parameters as well. For all those input parameters and their characteristics the leakage behavior has to be known and stored in a database. In the database there is also the leakage data of the setup of a reference gripping system containing both the primary and secondary vacuum system of which the leakage current is known. Due to the data the difference in the leakage rate of the actual setup and the reference setup can be determined. Based on the difference

Figure 6: Flow diagram of the design process using the quantitative approach

6. Conclusion This paper describes a method for designing temporarily energy self-sufficient vacuum gripping system based on the permissible leakage rate. After the system is designed to apply sufficient gripping force the presented method describes a process in which the system is adapted to not exceed the permissible leakage rate. Depending on the requirements the approaches range from no changes over minor adaptions to adding additional components to ensure the work piece is not dropped over a predefined amount of time in case the energy supply fails. References [1] [2] [3] [4] [5] [6] [7] [8]

International Federation of Robotics, 2016. World Robotics: Industrial Robots. Korus, S. Industrial Robot Cost Decline. https://arkinvest.com/research/industrial-robot-costs. Accessed 8 April 2019. OECD. Labour compensation per hour worked (indicator). https://data.oecd.org/lprdty/labour-compensation-per-hourworked.htm. Accessed 8 April 2019. Murphy, A. Industrial: Robotics Outlook 2025. http://loupventures.com/industrial-robotics-outlook-2025/. Accessed 8 April 2019. Brorson, l., Maldi, R., Stettler, J., Vos, D., 2015. European Capital Goods: The rise of co-bots: Sizing the market. Kosuge, K., Hirata, Y., 2004. Human-Robot Interaction, in 2004 IEEE International Conference on Robotics and Biomimetics, IEEE, p. 8. International Organization for Standardization. Robots and robotic devices - Collaborative robots, 2016(15066). Wolf, A., Schunk, H.A., 2018. Grippers in Motion: The Fascination of Automated Handling Tasks.

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David Straub / Procedia CIRP 84 (2019) 593–598 Author name / Procedia CIRP 00 (2019) 000–000

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