Abstract
We present a design for a manipulator that is intrinsically mechanically safe, i.e. it can not cause pain (let alone damage) to a human being even if the control system has a failure. Based on the pressure pain thresholds for human skin, we derive a pinching safety constraint that limits the actuator torque, and an impact safety constraint that results in a trade-off between mass and velocity. To fulfill all constraints, the manipulator requires a spring balancing system that counteracts gravity in all configurations of the manipulator. This allows the use of extremely low-power DC motors (only 4.5 W). Thanks to the torque and speed limitations of these motors the manipulator is indeed intrinsically safe, yet still capable of moving a useful payload of 1.2 kg over a distance of 0.8 m in 1.5 s.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Agrawal SK, Fattah A (2004) Gravity-balancing of spatial robotic manipulators. Mech Mach Theory 39(12):1331–1344
Albu-Schäffer A, Haddadin S, Ott C, Stemmer A, Wimböck T, Hirzinger G (2007) The dlr lightweight robot: design and control concepts for robots in human environments. Ind Rob Int J 34(5):376–385
Bicchi A, Tonietti G (2004) Fast and soft-arm tactics. IEEE Robot Autom Mag 11(2):22–33
Bonney MC, Yong YF (eds) (1985) Robot safety. IFS Publications/Springer, Berlin
Buchanan HM, Midgley JA (1987) Evaluation of pain threshold using a simple pressure algometer. Clin Rheumat 6(4):510–517
Corke PI (1999) Safety of advanced robots in human environments: a discussion paper. Proc IARP
De Luca A, Albu-Schäffer A, Haddadin S, Hirzinger G (2006) Collision detection and safe reaction with the dlr-iii lightweight manipulator arm. In: IEEE-RSJ international conference on intelligent robots and systems, pp 1623–1630
Dechev N, Cleghorn WL, Naumann S (2001) Multiple finger, passive adaptive grasp prosthetic hand. Mech Mach Theory 36(10):1157–1173
Fattah A, Agrawal SK (2006) Gravity-balancing of classes of industrial robots. In: Proc of IEEE international conference on robotics and automation, pp 2872–2877
Gekhman D (2006) The mass of a human head. http://hypertextbook.com/facts/2006/DmitriyGekhman.shtml (accessed March 9, 2010)
Gosselin CM (2008) Gravity compensation, static balancing and dynamic balancing of parallel mechanisms. Springer, London, pp 27–48. ISBN 978-1-84800-146-6 (Print), 978-1-84800-147-3 (Online)
Graham JH, Meagher JF, Derby SJ (1986) A safety and collision avoidance system for industrial robots. IEEE Trans Ind App IA-22(1):195–203
Haddadin S, Albu-Schäffer A, Hirzinger G (2008) The role of the robot mass and velocity in physical human-robot interaction—part I: Non-constrained blunt impacts. In: Proc of IEEE international conference on robotics and automation, pp 1339–1345
Haddadin S, Albu-Schäffer A, Hirzinger G (2008) The role of the robot mass and velocity in physical human-robot interaction—part II: Constrained blunt impacts. In: Proc of IEEE international conference on robotics and automation
Haddadin S, Albu-Schäffer A, Hirzinger G (2009) Requirements for safe robots: measurements, analysis and new insights. Int J Robot Res. doi:10.1177/0278364909343970
Heinzmann J, Zelinsky A (2003) Quantitative safety guarantees for physical human-robot interaction. Int J Robot Res 22(7–8):479–504
Herder JL (2001) Energy-free systems: theory, conception and design of statically balanced spring mechanisms. PhD thesis, Delf University of Technology
Ikuta K, Ishii H, Nokata M (2003) Safety evaluation method of design and control for human-care robots. Int J Robot Res 22(5):281–298
Jain A, Kemp CC (2009) El-e: an assistive mobile manipulator that autonomously fetches objects from flat surfaces. Auton Robots. doi:10.1007/s10514-009-9148-5
Jensen K, Andersen HO, Olesen J, Lindblom U (1986) Pressure-pain threshold in human temporal region: evaluation of a new pressure algometer. Pain 25(3):313–323
Kulic D, Croft E (2007) Pre-collision strategies for human robot interaction. Auton Robots 22(2):149–164
Lim H-O, Tanie K (2000) Human safety mechanisms of human-friendly robots: passive viscoelastic trunk and passively movable base. Int J Robot Res 19(4):307–335
Matsuoka Y (1997) The mechanisms in a humanoid robot hand. Auton Robots 4(2):199–209
Nagamachi M (1986) Human factors of industrial robots and robot safety management in Japan. Appl Ergonom 17(1):9–18
Oberer S, Schraft RD (2007) Robot-dummy crash tests for robot safety assessment. In: Proc of IEEE international conference on robotics and automation, pp 2934–2939
Rahman T, Ramanathan R, Seliktar R, Harwin W (1995) A simple technique to passively gravity-balance articulated mechanisms. J Mech Des 117:655–658
Segla S, Kalker-Kalkman CM, Schwab AL (1998) Statical balancing of a robot mechanism with the aid of a genetic algorithm. Mech Mach Theory 33:163–174
Shin D, Sardellitti I, Khatib O (2008) Hybrid actuation approach for human-friendly robot design. In: Proc of IEEE international conference on robotics and automation
Streit DA, Bj Gilmore (1989) Perfect spring equilibrators for rotatable bodies. J Mech Transm Autom Des 111(12):451–458
Tuijthof GJM, Herder JL (2000) Design, actuation and control of an anthropomorphic robot arm. Mech Mach Theory 35(7):945–962
Ulrich N, Kumar V (1991) Passive mechanical gravity compensation for robot manipulators. In: Proc of IEEE international conference on robotics and automation, pp 1536–1541
van der Helm FCT (1997) A standardized protocol for motion recordings of the shoulder. In: First conference of the international shoulder group, pp 7–12
Vanderborght B, Verrelst B, Ham RV, Damme MV, Lefeber D, Duran B, Beyl P (2006) Exploiting natural dynamics to reduce energy consumption by controlling the compliance of soft actuators. Int J Robot Res 25(4):343–358
Vermeulen MMA, Wisse M (2008) Maximum allowable manipulator mass based on cycle time, impact safety and pinching safety. Ind Rob Int J 35(5):410–420
Walsh GJ, Streit DA, Gilmore BJ (1991) Spatial spring equilibrator theory. Mech Mach Theory 26(2):155–170
Wang J, Gosselin CM (2000) Static balancing of spatial four-degree-of-freedom parallel mechanisms. Mech Mach Theory 35:563–592
Wassink M, Stramigioli S (2007) Towards a novel safety norm for domestic robots. In: Proc of IEEE-RSJ international conference on intelligent robots and systems, pp 3354–3359
Wolf S, Hirzinger G (2008) A new variable stiffness design: matching requirements of the next robot generation. In: Proc of IEEE international conference on robotics and automation, pp 1741–1746
Wyrobek KA, Berger EH, Van der Loos HFM, Salisbury JK (2008) Towards a personal robotics development platform: Rationale and design of an intrinsically safe personal robot. In: Proc of IEEE international conference on robotics and automation, pp 2165–2170
Yamada Y, Hirasawa Y, Huand S, Umetani Y (1996) Fail-safe human/robot contact in the safety space. In: IEEE international workshop on robot and human communication, pp 59–64
Yamada Y, Suita K, Imai K, Ikeda H, Sugimoto N (1996) A failure-to-safety robot system for human-robot coexistence. Robot Auton Syst 18:283–291
Zinn M, Khatib O, Roth B (2004) A new actuation approach for human friendly robot design. Int J Robot Res 23:379–398
Zinn M, Khatib O, Roth B, Salisbury JK (2002) Towards a human-centered intrinsically safe robotic manipulator. In: IARPIEEE/RAS joint workshop on technical challenges for dependable robots in human environments, Toulouse, France
Zurada J, Wright AL, Graham JH (2001) A neuro-fuzzy approach for robot system safety. IEEE Trans Syst Man Cybern, Part C, Appl Rev 31(1):49–64
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (https://creativecommons.org/licenses/by-nc/2.0), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
About this article
Cite this article
Vermeulen, M., Wisse, M. Intrinsically Safe Robot Arm: Adjustable Static Balancing and Low Power Actuation. Int J of Soc Robotics 2, 275–288 (2010). https://doi.org/10.1007/s12369-010-0048-9
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12369-010-0048-9