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

doi:10.1007/s11465-022-0691-5

Front. Mech. Eng.

2022, Vol. 17

Issue (3) : 35 https://doi.org/10.1007/s11465-022-0691-5

RESEARCH ARTICLE

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

Handong HU, Yiwei LIU(

), Zongwu XIE, Jianfeng YAO, Hong LIU

State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China

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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.

Keywords multifingered hand mechanism design robot safety variable stiffness actuator

Corresponding Author(s): Yiwei LIU

About author: Tongcan Cui and Yizhe Hou contributed equally to this work.

Just Accepted Date: 15 April 2022 Issue Date: 14 October 2022

Cite this article:

Handong HU,Yiwei LIU,Zongwu XIE, et al. Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous finger[J]. Front. Mech. Eng., 2022, 17(3): 35.

URL:

https://academic.hep.com.cn/fme/EN/10.1007/s11465-022-0691-5
https://academic.hep.com.cn/fme/EN/Y2022/V17/I3/35

Tab.1 Overview of prevalent dexterous hands

Fig.1 Schematic of a flexible mechanical system.

Fig.2 Two configurations of VSA. (a) Series VSA, (b) antagonism VSA.

Fig.3 Active human body stiffness variations in different manipulations. (a) Finger stirring with DIP joint and PIP joint fully abducted to achieve higher finger stiffness, (b) punching with elbow joint locked at 90° to increase arm stiffness, (c) finger stiffness is increased by adducting finger joints to resist static friction in the tight phase of cap screwing, (d) more finger joints are abducted, and their stiffness decrease in the loose phase of cap screwing, (e) filliping without energy storage, and (f) filliping with energy storage.

Tab.2 Primary physical design goals of the mechanical finger

Fig.4 Mechanical system of the AVS finger. (a) Sectional view of the finger CAD model, and (b) sketch of the finger mechanism.

Fig.5 Sectional view of CAU.

Fig.6 Finger operating mode switches between SEJ and VSJ modes. (a) SEJ mode and (b) VSJ mode.

Fig.7 Kinematics models of finger links and CAUs.

Fig.8 Circular spline in deflected position.

Fig.9 Characteristics of CAU. (a) External load of CAU versus compliance deflection at different pre-compressions and (b) CAU stiffness versus compliance deflection at different pre-compressions.

Fig.10 Eigen triangle of the CAU statics model.

Fig.11 Simulation results of the finger model. (a) J1 stiffness versus τ_CAU1 and τ_CAU2, (b) J2 stiffness versus τ_CAU1 and τ_CAU2, and (c) finger potential energy versus τ_CAU1 and τ_CAU2.

Fig.12 Positions of the ith finger joint and the harmonic gear components of the ith CAU in different stiffness adjusting modes.

Tab.3 Parameters of finger motion control system

Fig.13 Prototype of AVS-finger and its controller hardware.

Fig.14 Finger motion control system and its control effects. (a) Finger motion control block diagram, (b) desired joint trajectories, and (c) position errors of J1 and J2.

Fig.15 Physical impact, lifting, grasping, and manipulating tests. (a) Hammering the finger with a steel hammer at a speed of 1.2 m/s, (b) lifting tests, (c) precise grasping and power grasping, (d) screwing the cap, and (e) clicking the roller of the mouse.

Fig.16 Model validation of finger joint stiffness characteristics. (a) Experimental setup; experimental and model results of (b) J1 and (c) J2.

Fig.17 Finger joint stiffness adjusting operation tests. (a) Experimental setup; (b) J1 positions and (c) J2 positions during finger impact with different finger stiffness presets.

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
E_CAUi	Potential energy
E_finger	Finger potential energy
F(φ)	Generalized force exerted to the actuation frame
F_ext	Generalized force at the load frame
F_si, F_0i, ?x_si, K_s, θ_CSi, τ_CSi	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
J_M	Motor inertia of deceleration
K_CAUi	Stiffness of the ith CAU
K_p, K_d	Proportional gain and differential gain of the PD controller, respectively
K_Ji (i = 1,2)	ith finger joint stiffness
k_sys	Stiffness of a flexible mechanical system
k_T	Transmission stiffness of the coupling block
K_J	Stiffness vector of the finger joints
N	Deceleration ratio of the harmonic drive gear
p_a, p_b	Synchronous belt transmission ratio and differential gear transmission ratio, respectively
q	Generalized load frame deflection
q_i (i = 1,2)	Output shaft angular position the ith CAU
R	Distance between the CS axis and the slider routine
T_D	Transformation matrix of forward joint dynamics
T_K	Transformation matrix of forward joint kinematics
x	Generalized actuation frame deflection
θ_CS, θ_FS, θ_WG	Angular deflections of CS, FS, and WG, respectively
θ_i (i = 1,2)	Angular positions of joint i abduction/adduction
θ_mi	Angular displacement of motor of the ith CAU
θ_Mi	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
τ_CAUi	Torque
τ_CS, τ_FS	CS torque and FS torque, respectively
τ_Ji (i = 1,2)	ith finger joint torque
τ_J	Torque vector
φ	Compliant deflection

1	E Mattar. A survey of bio-inspired robotics hands implementation: new directions in dexterous manipulation. Robotics and Autonomous Systems, 2013, 61(5): 517–544 https://doi.org/10.1016/j.robot.2012.12.005
2	J K Salisbury, J J Craig. Articulated hands: force control and kinematic issues. The International Journal of Robotics Research, 1982, 1(1): 4–17 https://doi.org/10.1177/027836498200100102
3	S C Jacobsen, J E Wood, D F Knutti, K B Biggers. The UTAH/M.I.T. dextrous hand: work in progress. The International Journal of Robotics Research, 1984, 3(4): 21–50 https://doi.org/10.1177/027836498400300402
4	L B Bridgwater, C A Ihrke, M A Diftler, M E Abdallah, N A Radford, J M Rogers, S Yayathi, R S Askew, D M Linn. 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 https://doi.org/10.1109/ICRA.2012.6224772
5	J Butterfass, M Grebenstein, H Liu, G Hirzinger. 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 https://doi.org/10.1109/ROBOT.2001.932538
6	H Liu, K Wu, P Meusel, N Seitz, G Hirzinger, M H Jin, Y W Liu, S W Fan, T Lan, Z P Chen. 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 https://doi.org/10.1109/IROS.2008.4650624
7	J W Hurst, J E Chestnutt, A A Rizzi. 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 https://doi.org/10.1109/ROBOT.2004.1302453
8	S Wolf, G Hirzinger. 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 https://doi.org/10.1109/ROBOT.2008.4543452
9	F Lotti, P Tiezzi, G Vassura, L Biagiotti, G Palli, C Melchiorri. Development of UB hand 3: early results. In: Proceedings of the 2005 IEEE International Conference on Robotics and Automation. Barcelona: IEEE, 2005, 4488–4493 https://doi.org/10.1109/ROBOT.2005.1570811
10	C B Teeple, T N Koutros, M A Graule, R J Wood. Multi-segment soft robotic fingers enable robust precision grasping. The International Journal of Robotics Research, 2020, 39(14): 1647–1667 https://doi.org/10.1177/0278364920910465
11	S Wolf, O Eiberger, G Hirzinger. 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 https://doi.org/10.1109/ICRA.2011.5980303
12	N G Tsagarakis, I Sardellitti, D G Caldwell. 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 https://doi.org/10.1109/IROS.2011.6095006
13	J Choi, S Hong, W Lee, S Kang. 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 https://doi.org/10.1109/ROBOT.2009.5152716
14	M G Catalano, G Grioli, F Bonomo, R Schiavi, A Bicchi. 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 https://doi.org/10.1109/IROS.2010.5649774
15	M Grebenstein, M Chalon, G Hirzinger, R Siegwart. 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 https://doi.org/10.1109/ICHR.2010.5686342
16	K Koyama, M Shimojo, T Senoo, M Ishikawa. Development and application of low-friction, compact size actuator “MagLinkage”. The Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec), 2019, 2P1–H02 https://doi.org/10.1299/jsmermd.2019.2P1-H02
17	R Walkler. Developments in dextrous hands for advanced robotic applications. In: Proceedings of World Automation Congress. Seville: IEEE, 2004, 123–128
18	T Mouri, H Kawasaki, K Yoshikawa, J Takai, S Ito. Anthropomorphic robot hand: Gifu Hand III. In: Proceedings of International Conference on Control, Automation, and Systems. Jeonbuk, 2002, 1288–1293
19	F Ficuciello, G Palli, C Melchiorri, B Siciliano. 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 https://doi.org/10.1109/IROS.2011.6094671
20	M Chalon, A Wedler, A Baumann, W Bertleff, A Beyer, J Butterfaß, M Grebenstein, R Gruber, F Hacker, E Kraemer, K Landzettel, M Maier, H J Sedlmayr, N Seitz, F Wappler, B Willberg, T Wimboeck, G Hirzinger, F Didot. Dexhand: a space qualified multi-fingered robotic hand. In: Proceedings of 2011 IEEE International Conference on Robotics and Automation. Shanghai: IEEE, 2011, 2204–2210 https://doi.org/10.1109/ICRA.2011.5979923
21	M Grebenstein. The Awiwi Hand: an Artificial Hand for the DLR Hand Arm System. Cham: Springer, 2014
22	M Quigley, C Salisbury, A Y Ng, J K Salisbury. Mechatronic design of an integrated robotic hand. The International Journal of Robotics Research, 2014, 33(5): 706–720 https://doi.org/10.1177/0278364913515032
23	S W Ruehl, C Parlitz, G Heppner, A Hermann, A Roennau, R Dillmann. 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 https://doi.org/10.1109/ROBIO.2014.7090710
24	M Grossard, J Martin, G F da Cruz Pacheco. Control-oriented design and robust decentralized control of the CEA dexterous robot hand. IEEE/ASME Transactions on Mechatronics, 2015, 20(4): 1809–1821 https://doi.org/10.1109/TMECH.2014.2355040
25	B Fang, F C Sun, Y Chen, C Zhu, Z W Xia, Y Y Yang. 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 https://doi.org/10.1109/ROBIO49542.2019.8961671
26	Y J Kim, J Yoon, Y W Sim. Fluid lubricated dexterous finger mechanism for human-like impact absorbing capability. IEEE Robotics and Automation Letters, 2019, 4(4): 3971–3978 https://doi.org/10.1109/LRA.2019.2929988
27	B Vanderborght, A Albu-Schaeffer, A Bicchi, E Burdet, D G Caldwell, R Carloni, M Catalano, O Eiberger, W Friedl, G Ganesh, M Garabini, M Grebenstein, G Grioli, S Haddadin, H Hoppner, A Jafari, M Laffranchi, D Lefeber, F Petit, S Stramigioli, N Tsagarakis, M Van Damme, R Van Ham, L C Visser, S Wolf. Variable impedance actuators: a review. Robotics and Autonomous Systems, 2013, 61(12): 1601–1614 https://doi.org/10.1016/j.robot.2013.06.009
28	S Wolf, G Grioli, O Eiberger, W Friedl, M Grebenstein, H Höppner, E Burdet, D G Caldwell, R Carloni, M G Catalano, D Lefeber, S Stramigioli, N Tsagarakis, Damme M Van, Ham R Van, B Vanderborght, L C Visser, A Bicchi, A Albu-Schäffer. Variable stiffness actuators: review on design and components. IEEE/ASME Transactions on Mechatronics, 2016, 21(5): 2418–2430 https://doi.org/10.1109/TMECH.2015.2501019
29	M G Catalano, G Grioli, M Garabini, F Bonomo, M Mancini, N Tsagarakis, A Bicchi. 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 https://doi.org/10.1109/ICRA.2011.5980457
30	A Jafari, N G Tsagarakis, I Sardellitti, D G Caldwell. A new actuator with adjustable stiffness based on a variable ratio lever mechanism. IEEE/ASME Transactions on Mechatronics, 2014, 19(1): 55–63 https://doi.org/10.1109/TMECH.2012.2218615
31	Y X Shao, W X Zhang, X L Ding. Configuration synthesis of variable stiffness mechanisms based on guide-bar mechanisms with length-adjustable links. Mechanism and Machine Theory, 2021, 156: 104153 https://doi.org/10.1016/j.mechmachtheory.2020.104153
32	J Oh, S Lee, M Lim, J Choi. 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 https://doi.org/10.1109/ICRA.2014.6907346
33	Y X Shao, W X Zhang, Y J Su, X L Ding. Design and optimisation of load-adaptive actuator with variable stiffness for compact ankle exoskeleton. Mechanism and Machine Theory, 2021, 161: 104323 https://doi.org/10.1016/j.mechmachtheory.2021.104323
34	M Grebenstein, P van der Smagt. Antagonism for a highly anthropomorphic hand–arm system. Advanced Robotics, 2008, 22(1): 39–55 https://doi.org/10.1163/156855308X291836
35	F Petit, W Friedl, H Höppner, M Grebenstein. Analysis and synthesis of the bidirectional antagonistic variable stiffness mechanism. IEEE/ASME Transactions on Mechatronics, 2015, 20(2): 684–695 https://doi.org/10.1109/TMECH.2014.2321428
36	M Grebenstein, M Chalon, W Friedl, S Haddadin, T Wimböck, G Hirzinger, R Siegwart. The hand of the DLR hand arm system: designed for interaction. The International Journal of Robotics Research, 2012, 31(13): 1531–1555 https://doi.org/10.1177/0278364912459209

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