Abstract
Collaborative robots have finally found their way into the factories as companions to human workers for releasing them from repetitive and exhausting tasks. Internal torque sensors or tactile skins make these robots sensitive to external forces, which is a critical requirement for acting safely, as their direct force feedback allows them to react instantaneously on dangerous collisions with humans. Biomechanical limit values give robot users a reference to determine the injury potential of their robots. In some cases, those limits are available as energy limits. A valuable advantage of such limits is that any user can easily convert them into velocity constraints if the apparent mass of the robot is known. The apparent mass is a virtual quantity that projects the inertia properties of the robot to a directional point mass. In our paper, we show why the currently-available method to determine the apparent mass needs to be extended. Our findings reveal that the impact conditions determine whether the drive inertia must be taken into account or the apparent mass may only be calculated based on the dynamic mass parameters of the link. The verification relies on data from collision tests with two real collaborative robots. Our results fit well to the results we obtained from the simulation models, why our proposed modification seems to be necessary in order to achieve reliable velocity constraints for operating collaborative robots safely.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
Change history
17 June 2021
The original version of the book was inadvertently published without abstracts in chapters 19, 20. The erratum chapter and the book have been updated with the changes.
References
2012 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Vilamoura, Portugal, October 2012
2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Vancouver, Canada, September 2017
ISO/TS 15066. Robots and robotic devices - collaborative robots. Standard, International Organization for Standardization (2016)
Albu-Schaffer, A., Fischer, M., Schreiber, G., Schoeppe, F., Hirzinger, G.: Soft robotics: what cartesian stiffness can obtain with passively compliant, uncoupled joints? In: Proceedings of the 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 3295–3301, vol. 4, Sendai, Japan, February 2004. https://doi.org/10.1109/IROS.2004.1389925
Behrens, R., Elkmann, N.: Study on meaningful and verified thresholds for minimizing the consequences of human-robot collisions. In: Proceedings of the 2014 IEEE International Conference on Robotics & Automation (ICRA), pp. 3378–3383, Hong Kong, China, May 2014. https://doi.org/10.1109/icra.2014.6907345
Behrens, R., Saenz, J., Vogel, C., Elkmann, N.: Upcoming technologies and fundamentals for safeguarding all forms of human-robot collaboration. In: Proceedings of the 8th International Conference Safety of Industrial Automated Systems, pp. 18–23, Königswinter, Germany, November 2015
Bicchi, A., Tonietti, G.: Fast and “soft-arm” tactics.IEEE Robot. Autom. Mag. 11(2), 22–33 (2004). ISSN 1070-9932. https://doi.org/10.1109/MRA.2004.1310939
Chawda, V., Niemeyer, G.: Toward torque control of a kuka lbr iiwa for physical human-robot interaction. In: Proceedings of [2], pp. 6387–6392. https://doi.org/10.1109/iros.2017.8206543
Haddadin, S., Albu-Schäffer, A., Hirzinger, G.: Requirements for safe robots: measurements, analysis and new insights. Int. J. Robot. Res. 28(11–12), 1507–1527 (2009)
Haddadin, S., Albu-Schäffer, A., Eiberger, O., Hirzinger, G.: New insights concerning intrinsic joint elasticity for safety. In: Proceedings of the 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 2181–2187, Taipei, Taiwan, October 2010. https://doi.org/10.1109/IROS.2010.5652037
Haddadin, S., Haddadin, S., Khourym, A., Rokahr, T., Parusel, S., Burgkart, R., Bicchi, A., Albu-Schäffer, A.: On making robots understand safety: Embedding injury knowledge into control. Int. J. Robot. Res. 31(13), 1578–1602 (2012). ISSN 0278-3649. https://doi.org/10.1177/0278364912462256
Haddadin, S., Haddadin, S., Khoury, A., Rokahr, T., Parusel, S., Burgkart, R., Bicchi, A., Albu-Schäffer, A.: A truly safely moving robot has to know what injury it may cause. In: Proceedings of [1], pp. 5406–5413. https://doi.org/10.1109/iros.2012.6386163
Haddadin, S., Krieger, K., Mansfeld, N., Albu-Schäffer, A.: On impact decoupling properties of elastic robots and time optimal velocity maximization on joint level. In: Proceedings of [1], pp. 5089–5096. https://doi.org/10.1109/IROS.2012.6385913
Haninger, K., Surdilovic, D.: Bounded collision force by the sobolev norm. In: Proceedings of the 2019 IEEE International Conference on Robotics & Automation (ICRA), pp. 8529–8535, Montreal, Canada, May 2019. https://doi.org/10.1109/ICRA.2019.8793711
Hu, M., Wang, H., Pan, X., Tian, Y.: Research on elastic deformation modeling of collaborative robots. In: Proceedings of the 2017 IEEE International Conference on Robotics and Biomimetics (ROBIO), pp. 2462–2467, Macau, China, December 2017. https://doi.org/10.1109/ROBIO.2017.8324789
Khatib, O.: A unified approach for motion and force control of robot manipulators: the operational space formulation. IEEE J. Robot. and Autom. 3(1), 43–53 (1987). https://doi.org/10.1109/JRA.1987.1087068
Khatib, O.: Inertial properties in robotic manipulation: An object-level framework. Int. J. Robot. Res. 14(1), 19–36 (1995). ISSN 0278-3649. https://doi.org/10.1177/027836499501400103
Lee, S.-D., Kim, B.-S., Song, J.-B.: Human-robot collision model with effective mass and manipulability for design of a spatial manipulator. Adv. Robot. 27(3), 189–198 (2013). https://doi.org/10.1080/01691864.2012.754076
Liang, J., Meng, D., Wang, X., Liang, B., She, Y.: Modeling and optimization of head-collision of a flexible joint robot. In: Proceedings of the 36th Chinese Control Conference (CCC), pp. 6298 – 6933, Dalian, China, June 2017. https://doi.org/10.23919/ChiCC.2017.8028450
Lucci, N., Lacevic, B., Zanchettin, A.M., Rocco, P.: Combining speed and separation monitoring with power and force limiting for safe collaborative robotics applications. IEEE Robot. Autom. Lett. 5(4), 6121–6128 (2020). https://doi.org/10.1109/LRA.2020.3010211
Mansfeld, N., Djellab, B., Veuthey, J.R., Beck, F., Ott, C., Haddadin, S.: Improving the performance of biomechanically safe velocity control for redundant robots through reflected mass minimization. In: Proceedings of [2], pp. 5390–5397. https://doi.org/10.1109/IROS.2017.8206435
Moorhouse, K.: An improved normalization methodology for developing mean human response curves. In: Proceedings of the 23rd International Technical Conference on the Enhanced Safety of Vehicles (ESV), pp. Moorhouse 1–11, Seoul, South Korea, May 2013
Pailler-Mattei, C., Bec, S., Zahouani, H.: In vivo measurements of the elastic mechanical properties of human skin by indentation tests. Med. Eng. Phys. pp. 599–606 (2008). https://doi.org/10.1016/j.medengphy.2007.06.011
Rossi, R., Polverini, M.P., Zanchettin, A.M., Rocco, P.: A pre-collision control strategy for human-robot interaction based on dissipated energy in potential inelastic impacts. In: 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 26–31 (2015). https://doi.org/10.1109/IROS.2015.7353110
Salisbury, J.-K.: Active stiffness control of a manipulator in cartesian coordinates. In: Proceedings of the Conference on Decision and Control including the Symposium on Adaptive Processes, pp. 95–100 (1980). https://doi.org/10.1109/CDC.1980.272026
Sloth, S., Petersen, H.G.: Computation of safe path velocity for collaborative robots. In: Proceedings of the 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 6142–6148, Madrid, Spain, October 2018. https://doi.org/10.1109/IROS.2018.8594217
Vemula, B.R., Ramteen, M., Spampinato, G., Fagerström, B.: Human-robot impact model: For safety assessment of collaborative robot design. In: Proceedings of the 2017 IEEE 5th International Symposium on Robotics and Intelligent Sensors (IRIS), pp. 236–242, Ottawa, Canada, October 2017. https://doi.org/10.1109/IRIS.2017.8250128
Wang, Z., Behrens, R., Elkmann, N.: Fe-simulation of impact loads on the human body: Methodology for the development of tissue models. In: Proceedings of the Dynamore Forum 15, Bamberg, Germany, October 2018
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2021 The Author(s), under exclusive license to Springer Nature Switzerland AG
About this paper
Cite this paper
Herbster, S., Behrens, R., Elkmann, N. (2021). A New Approach to Estimate the Apparent Mass of Collaborative Robot Manipulators. In: Siciliano, B., Laschi, C., Khatib, O. (eds) Experimental Robotics. ISER 2020. Springer Proceedings in Advanced Robotics, vol 19. Springer, Cham. https://doi.org/10.1007/978-3-030-71151-1_19
Download citation
DOI: https://doi.org/10.1007/978-3-030-71151-1_19
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-71150-4
Online ISBN: 978-3-030-71151-1
eBook Packages: Intelligent Technologies and RoboticsIntelligent Technologies and Robotics (R0)