Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous finger

Abstract

This study traces the development of dexterous hand research and proposes a novel antagonistic variable stiffness dexterous finger mechanism to improve the safety of dexterous hand in unpredictable environments, such as unstructured or man-made operational errors through comprehensive consideration of cost, accuracy, manufacturing, and application. Based on the concept of mechanical passive compliance, which is widely implemented in robots for interactions, a finger is dedicated to improving mechanical robustness. The finger mechanism not only achieves passive compliance against physical impacts, but also implements the variable stiffness actuator principle in a compact finger without adding supererogatory actuators. It achieves finger stiffness adjustability according to the biologically inspired stiffness variation principle of discarding some mobilities to adjust stiffness. The mechanical design of the finger and its stiffness adjusting methods are elaborated. The stiffness characteristics of the finger joint and the actuation unit are analyzed. Experimental results of the finger joint stiffness identification and finger impact tests under different finger stiffness presets are provided to verify the validity of the model. Fingers have been experimentally proven to be robust against physical impacts. Moreover, the experimental part verifies that fingers have good power, grasping, and manipulation performance.

Graphical abstract

Keywords

multifingered hand / mechanism design / robot safety / variable stiffness actuator

References

[1] Mattar E. A survey of bio-inspired robotics hands implementation: new directions in dexterous manipulation. Robotics and Autonomous Systems, 2013, 61(5): 517–544

[2] Salisbury J K, Craig J J. Articulated hands: force control and kinematic issues. The International Journal of Robotics Research, 1982, 1(1): 4–17

[3] Jacobsen S C, Wood J E, Knutti D F, Biggers K B. The UTAH/M.I.T. dextrous hand: work in progress. The International Journal of Robotics Research, 1984, 3(4): 21–50

[4] Bridgwater L B, Ihrke C A, Diftler M A, Abdallah M E, Radford N A, Rogers J M, Yayathi S, Askew R S, Linn D M. The Robonaut 2 hand−designed to do work with tools. In: Proceedings of 2012 IEEE International Conference on Robotics and Automation. Saint Paul: IEEE, 2012, 3425–3430

[5] Butterfass J, Grebenstein M, Liu H, Hirzinger G. DLR-hand II: next generation of a dextrous robot hand. In: Proceedings of 2001 ICRA. IEEE International Conference on Robotics and Automation. Seoul: IEEE, 2001, 109–114

[6] Liu H, Wu K, Meusel P, Seitz N, Hirzinger G, Jin M H, Liu Y W, Fan S W, Lan T, Chen Z P. Multisensory five-finger dexterous hand: the DLR/HIT hand II. In: Proceedings of 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems. Nice: IEEE, 2008, 3692–3697

[7] Hurst J W, Chestnutt J E, Rizzi A A. An actuator with physically variable stiffness for highly dynamic legged locomotion. In: Proceedings of IEEE International Conference on Robotics and Automation. New Orleans: IEEE, 2004, 5: 4662–4667

[8] Wolf S, Hirzinger G. A new variable stiffness design: matching requirements of the next robot generation. In: Proceedings of 2008 IEEE International Conference on Robotics and Automation. Pasadena: IEEE, 2008, 1741–1746

[9] Lotti F, Tiezzi P, Vassura G, Biagiotti L, Palli G, Melchiorri C. Development of UB hand 3: early results. In: Proceedings of the 2005 IEEE International Conference on Robotics and Automation. Barcelona: IEEE, 2005, 4488–4493

[10] Teeple C B, Koutros T N, Graule M A, Wood R J. Multi-segment soft robotic fingers enable robust precision grasping. The International Journal of Robotics Research, 2020, 39(14): 1647–1667

[11] Wolf S, Eiberger O, Hirzinger G. The DLR FSJ: energy based design of a variable stiffness joint. In: Proceedings of 2011 IEEE International Conference on Robotics and Automation. Shanghai: IEEE, 2011, 5082–5089

[12] Tsagarakis N G, Sardellitti I, Caldwell D G. A new variable stiffness actuator (CompAct-VSA): design and modelling. In: Proceedings of 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems. San Francisco: IEEE, 2011, 378–383

[13] Choi J, Hong S, Lee W, Kang S. A variable stiffness joint using leaf springs for robot manipulators. In: Proceedings of 2009 IEEE International Conference on Robotics and Automation. Kobe: IEEE, 2009, 4363–4368

[14] Catalano M G, Grioli G, Bonomo F, Schiavi R, Bicchi A. VSA-HD: from the enumeration analysis to the prototypical implementation. In: Proceedings of 2010 IEEE/RSJ 2010 International Conference on Intelligent Robots and Systems. Taipei: IEEE, 2010, 3676–3681

[15] Grebenstein M, Chalon M, Hirzinger G, Siegwart R. Antagonistically driven finger design for the anthropomorphic DLR hand arm system. In: Proceedings of 2010 the 10th IEEE-RAS International Conference on Humanoid Robots. Nashville: IEEE, 2010, 609–616

[16] Koyama K, Shimojo M, Senoo T, Ishikawa M. Development and application of low-friction, compact size actuator “MagLinkage”. The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec), 2019, 2P1–H02

[17] Walkler R. Developments in dextrous hands for advanced robotic applications. In: Proceedings of World Automation Congress. Seville: IEEE, 2004, 123–128

[18] Mouri T, Kawasaki H, Yoshikawa K, Takai J, Ito S. Anthropomorphic robot hand: Gifu Hand III. In: Proceedings of International Conference on Control, Automation, and Systems. Jeonbuk, 2002, 1288–1293

[19] Ficuciello F, Palli G, Melchiorri C, Siciliano B. Experimental evaluation of postural synergies during reach to grasp with the UB hand IV. In: Proceedings of 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems. San Francisco: IEEE, 2011, 1775–1780

[20] Chalon M, Wedler A, Baumann A, Bertleff W, Beyer A, Butterfaß J, Grebenstein M, Gruber R, Hacker F, Kraemer E, Landzettel K, Maier M, Sedlmayr H J, Seitz N, Wappler F, Willberg B, Wimboeck T, Hirzinger G, Didot F. Dexhand: a space qualified multi-fingered robotic hand. In: Proceedings of 2011 IEEE International Conference on Robotics and Automation. Shanghai: IEEE, 2011, 2204–2210

[21] GrebensteinM. The Awiwi Hand: an Artificial Hand for the DLR Hand Arm System. Cham: Springer, 2014

[22] Quigley M, Salisbury C, Ng A Y, Salisbury J K. Mechatronic design of an integrated robotic hand. The International Journal of Robotics Research, 2014, 33(5): 706–720

[23] Ruehl S W, Parlitz C, Heppner G, Hermann A, Roennau A, Dillmann R. Experimental evaluation of the schunk 5-finger gripping hand for grasping tasks. In: Proceedings of 2014 IEEE International Conference on Robotics and Biomimetics (ROBIO 2014). Bali: IEEE, 2014, 2465–2470

[24] Grossard M, Martin J, da Cruz Pacheco G F. Control-oriented design and robust decentralized control of the CEA dexterous robot hand. IEEE/ASME Transactions on Mechatronics, 2015, 20(4): 1809–1821

[25] Fang B, Sun F C, Chen Y, Zhu C, Xia Z W, Yang Y Y. A tendon-driven dexterous hand design with tactile sensor array for grasping and manipulation. In: Proceedings of 2019 IEEE International Conference on Robotics and Biomimetics (ROBIO). Dali: IEEE, 2019, 203–210

[26] Kim Y J, Yoon J, Sim Y W. Fluid lubricated dexterous finger mechanism for human-like impact absorbing capability. IEEE Robotics and Automation Letters, 2019, 4(4): 3971–3978

[27] Vanderborght B, Albu-Schaeffer A, Bicchi A, Burdet E, Caldwell D G, Carloni R, Catalano M, Eiberger O, Friedl W, Ganesh G, Garabini M, Grebenstein M, Grioli G, Haddadin S, Hoppner H, Jafari A, Laffranchi M, Lefeber D, Petit F, Stramigioli S, Tsagarakis N, Van Damme M, Van Ham R, Visser L C, Wolf S. Variable impedance actuators: a review. Robotics and Autonomous Systems, 2013, 61(12): 1601–1614

[28] Wolf S, Grioli G, Eiberger O, Friedl W, Grebenstein M, Höppner H, Burdet E, Caldwell D G, Carloni R, Catalano M G, Lefeber D, Stramigioli S, Tsagarakis N, Van Damme M, Van Ham R, Vanderborght B, Visser L C, Bicchi A, Albu-Schäffer A. Variable stiffness actuators: review on design and components. IEEE/ASME Transactions on Mechatronics, 2016, 21(5): 2418–2430

[29] Catalano M G, Grioli G, Garabini M, Bonomo F, Mancini M, Tsagarakis N, Bicchi A. VSA-cubebot: a modular variable stiffness platform for multiple degrees of freedom robots. In: Proceedings of 2011 IEEE International Conference on Robotics and Automation. Shanghai: IEEE, 2011, 5090–5095

[30] Jafari A, Tsagarakis N G, Sardellitti I, Caldwell D G. A new actuator with adjustable stiffness based on a variable ratio lever mechanism. IEEE/ASME Transactions on Mechatronics, 2014, 19(1): 55–63

[31] Shao Y X, Zhang W X, Ding X L. Configuration synthesis of variable stiffness mechanisms based on guide-bar mechanisms with length-adjustable links. Mechanism and Machine Theory, 2021, 156: 104153

[32] Oh J, Lee S, Lim M, Choi J. A mechanically adjustable stiffness actuator (MASA) of a robot for knee rehabilitation. In: Proceedings of 2014 IEEE International Conference on Robotics and Automation (ICRA). Hong Kong: IEEE, 2014, 3384–3389

[33] Shao Y X, Zhang W X, Su Y J, Ding X L. Design and optimisation of load-adaptive actuator with variable stiffness for compact ankle exoskeleton. Mechanism and Machine Theory, 2021, 161: 104323

[34] Grebenstein M, van der Smagt P. Antagonism for a highly anthropomorphic hand–arm system. Advanced Robotics, 2008, 22(1): 39–55

[35] Petit F, Friedl W, Höppner H, Grebenstein M. Analysis and synthesis of the bidirectional antagonistic variable stiffness mechanism. IEEE/ASME Transactions on Mechatronics, 2015, 20(2): 684–695

[36] Grebenstein M, Chalon M, Friedl W, Haddadin S, Wimböck T, Hirzinger G, Siegwart R. The hand of the DLR hand arm system: designed for interaction. The International Journal of Robotics Research, 2012, 31(13): 1531–1555

Nomenclature

Abbreviations
AVS	Antagonistic variable stiffness
CAU	Compliant actuation unit
CS	Circular spline
DOF	Degree of freedom
DSA	Distal-joint-locked stiffness adjusting
FS	Flexspline
PD	Proportional plus derivative
PSA	Proximal-joint-locked stiffness adjusting
SEA	Series elastic actuator
SEJ	Series elastic joint
VSA	Variable stiffness actuator
VSJ	Variable stiffness joint
DIP	Distal interphalangeal
PIP	Proximal interphalangeal
WG	Wave generator
Variables
ECAUi	Potential energy
Efinger	Finger potential energy
F(φ)	Generalized force exerted to the actuation frame
Fext	Generalized force at the load frame
Fsi, F0i, ∆xsi, Ks, θCSi, τCSi	Resultant spring force on the slider, the initial spring force, the deflection of the slider, the stiffness of linear spring, the angular displacement of CS, and CS torque of the ith CAU, respectively
JM	Motor inertia of deceleration
KCAUi	Stiffness of the ith CAU
Kp, Kd	Proportional gain and differential gain of the PD controller, respectively
KJi (i = 1,2)	ith finger joint stiffness
ksys	Stiffness of a flexible mechanical system
kT	Transmission stiffness of the coupling block
KJ	Stiffness vector of the finger joints
N	Deceleration ratio of the harmonic drive gear
pa, pb	Synchronous belt transmission ratio and differential gear transmission ratio, respectively
q	Generalized load frame deflection
qi (i = 1,2)	Output shaft angular position the ith CAU
R	Distance between the CS axis and the slider routine
TD	Transformation matrix of forward joint dynamics
TK	Transformation matrix of forward joint kinematics
x	Generalized actuation frame deflection
θCS, θFS, θWG	Angular deflections of CS, FS, and WG, respectively
θi (i = 1,2)	Angular positions of joint i abduction/adduction
θmi	Angular displacement of motor of the ith CAU
θMi	Motor side displacement
Θ	Position vector
μ1, μ2	Coefficients of coulomb friction of CAU1 and CAU2, respectively
ν1, ν2	Coefficients of sliding friction of CAU1 and CAU2, respectively
τ1, τ2	J1 torque and J2 torque, respectively
τCAUi	Torque
τCS, τFS	CS torque and FS torque, respectively
τJi (i = 1,2)	ith finger joint torque
τJ	Torque vector
φ	Compliant deflection

Acknowledgements

This work was supported by the National Key R&D Program of China (Grant No. 2017YFB1300400), and the Major Research Plan of the National Natural Science Foundation of China (Grant No. 91848202).

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