Abstract

This paper proposes a novel reconfigurable exoskeleton for ankle rehabilitation, which is capable of realizing both static and dynamic rehabilitation exercises. The conceptual design is based on a reduced representation that regards the ankle–foot complex as a movable spherical joint, so as to better replicate the physical scenario. The screw theory-based analysis results indicate that in both rehabilitation modes, the proposed exoskeleton is capable of auto-matching its rotation center with that of the ankle complex no matter how the latter moves, once it is worn by the patients. In the 2-degrees-of-freedom (DOF) rehabilitation configuration, an analysis based on a 15-point reduced model provides the basis for assessing the kinematics performance in a case where the motion of complex's center is considered. Also, the results verify that the achieved workspace can always cover the prescribed rotation range without generating singularities, as long as the center moves within the defined cylindrical area. The demonstrated 3-DOF rehabilitation configuration possesses a partially decoupled-control capability. The singularity surface can be effectively expelled from the prescribed workspace by rotating the brace. Besides, the exoskeleton's dexterity varies smoothly in the whole workspace, and its performance can be further improved by evenly distributing the drive links.

References

1.
Díaz
,
I.
,
Gil
,
J. J.
, and
Sánchez
,
E.
,
2011
, “
Lower-Limb Robotic Rehabilitation: Literature Review and Challenges
,”
J. Robot.
,
2011
(
2
), pp.
1
11
.
2.
Meng
,
W.
,
Liu
,
Q.
,
Zhou
,
Z.
,
Ai
,
Q.
,
Sheng
,
B.
, and
Xie
,
S. S.
,
2015
, “
Recent Development of Mechanisms and Control Strategies for Robot-Assisted Lower Limb Rehabilitation
,”
Mechatronics
,
31
, pp.
132
145
.
3.
Saglia
,
J. A.
,
Tsagarakis
,
N. G.
,
Dai
,
J. S.
, and
Caldwell
,
D. G.
,
2009
, “
A High-Performance Redundantly Actuated Parallel Mechanism for Ankle Rehabilitation
,”
Int. J. Rob. Res.
,
28
(
9
), pp.
1216
1227
.
4.
Yoon
,
J.
,
Ryu
,
J.
, and
Lim
,
K. B.
,
2006
, “
Reconfigurable Ankle Rehabilitation Robot for Various Exercises
,”
J. Robot. Syst.
,
22
(
S1
), pp.
15
33
.
5.
Jiang
,
J.
,
Lee
,
K.-M.
, and
Ji
,
J.
,
2018
, “
Review of Anatomy-Based Ankle–Foot Robotics for Mind, Motor and Motion Recovery Following Stroke: Design Considerations and Needs
,”
Int. J. Intell. Robot. Appl.
,
2
(
3
), pp.
267
282
.
6.
Huo
,
W.
,
Mohammed
,
S.
,
Moreno
,
J. C.
, and
Amirat
,
Y.
,
2016
, “
Lower Limb Wearable Robots for Assistance and Rehabilitation: A State of the Art
,”
IEEE Syst. J.
,
10
(
3
), pp.
1068
1081
.
7.
Dong
,
M. J.
,
Zhou
,
Y.
,
Li
,
J. F.
,
Rong
,
X.
,
Fan
,
W. P.
,
Zhou
,
X. D.
, and
Kong
,
Y.
,
2021
, “
State of the Art in Parallel Ankle Rehabilitation Robot: A Systematic Review
,”
J. NeuroEng. Rehabil.
,
18
(
1
), pp.
1
15
.
8.
Ferris
,
D. P.
,
Sawicki
,
G. S.
, and
Domingo
,
A. R.
,
2005
, “
Powered Lower Limb Orthoses for Gait Rehabilitation
,”
Top. Spinal Cord Inj. Rehabil.
,
11
(
2
), pp.
34
49
.
9.
Girone
,
M. J.
,
Burdea
,
G. C.
, and
Bouzit
,
M.
,
1999
, “
‘Rutgers Ankle’ Orthopedic Rehabilitation Interface
,”
Am. Soc. Mech. Eng. Dyn. Syst. Control Div. DSC
,
67
, pp.
305
312
.
10.
Dai
,
J. S.
, and
Massicks
,
C. P.
,
1999
, “
An Equilateral Ankle Rehabilitation Device Based on Parallel Mechanisms
,”
BMC Psychiatry
,
12
(
1
), p.
229
.
11.
Dai
,
J. S.
,
Zhao
,
T.
, and
Nester
,
C.
,
2004
, “
Sprained Ankle Physiotherapy Based Mechanism Synthesis and Stiffness Analysis of a Robotic Rehabilitation Device
,”
Auton. Robot
,
16
(
2
), pp.
207
218
.
12.
Dai
,
J. S.
, and
Kerr
,
D. R.
,
2000
, “
A Six-Component Contact Force Measurement Device Based on the Stewart Platform
,”
Proc. Inst. Mech. Eng., Part C
,
214
(
5
), pp.
687
697
.
13.
Liu
,
G.
,
Gao
,
J.
,
Yue
,
H.
,
Zhang
,
X.
, and
Lu
,
G.
,
2006
, “
Design and Kinematics Simulation of Parallel Robots for Ankle Rehabilitation
,”
Proceedings of the 2006 IEEE International Conference on Mechatronics Automation. ICMA 2006
,
Luoyang
,
China, June 25–28
, pp.
1109
1113
.
14.
Saglia
,
J. A.
,
Dai
,
J. S.
, and
Caldwell
,
D. G.
,
2008
, “
Geometry and Kinematic Analysis of a Redundantly Actuated Parallel Mechanism That Eliminates Singularities and Improves Dexterity
,”
ASME J. Mech. Des.
,
130
(
12
), p.
124501
.
15.
Saglia
,
J. A.
,
Tsagarakis
,
N. G.
,
Dai
,
J. S.
, and
Caldwell
,
D. G.
,
2013
, “
Control Strategies for Patient-Assisted Training Using the Ankle Rehabilitation Robot (ARBOT)
,”
IEEE/ASME T. Mech.
,
18
(
6
), pp.
1799
1808
.
16.
Saglia
,
J. A.
,
Tsagarakis
,
N. G.
,
Dai
,
J. S.
, and
Caldwell
,
D. G.
,
2009
, “
Inverse-Kinematics-Based Control of a Redundantly Actuated Platform for Rehabilitation
,”
IMechE J. Syst. Control Eng.
,
223
(
1
), pp.
53
70
.
17.
Tsoi
,
Y. H.
,
Xie
,
S. Q.
, and
Graham
,
A. E.
,
2009
, “
Design, Modeling and Control of an Ankle Rehabilitation Robot,” Stud
,”
Comput. Intell.
,
177
, pp.
377
399
.
18.
Zhang
,
M.
,
Cao
,
J.
,
Zhu
,
G.
,
Miao
,
Q.
,
Zeng
,
X.
, and
Xie
,
S. Q.
,
2017
, “
Reconfigurable Workspace and Torque Capacity of a Compliant Ankle Rehabilitation Robot (CARR)
,”
Rob. Auton. Syst.
,
98
, pp.
213
221
.
19.
Kuo
,
C. H.
, and
Dai
,
J. S.
,
2012
, “
Kinematics of a Fully-Decoupled Remote Center-of-Motion Parallel Manipulator for Minimally Invasive Surgery
,”
ASME J. Med. Devices
,
6
(
2
), p.
021008
.
20.
Wang
,
C.
,
Fang
,
Y.
,
Guo
,
S.
, and
Chen
,
Y.
,
2013
, “
Design and Kinematical Performance Analysis of a 3-RUS/RRR Redundantly Actuated Parallel Mechanism for Ankle Rehabilitation
,”
ASME J. Mech. Rob.
,
5
(
4
), p.
041003
.
21.
Wang
,
C.
,
Fang
,
Y.
,
Guo
,
S.
, and
Zhou
,
C.
,
2015
, “
Design and Kinematic Analysis of Redundantly Actuated Parallel Mechanisms for Ankle Rehabilitation
,”
Robotica
,
33
(
2
), pp.
366
384
.
22.
Chang
,
T. C.
, and
Zhang
,
X. D.
,
2019
, “
Kinematics and Reliable Analysis of Decoupled Parallel Mechanism for Ankle Rehabilitation
,”
Microelectron. Reliab.
,
99
, pp.
203
212
.
23.
Malosio
,
M.
,
Negri
,
S. P.
,
Pedrocchi
,
N.
,
Vicentini
,
F.
,
Caimmi
,
M.
, and
Molinari Tosatti
,
L.
,
2012
, “
A Spherical Parallel Three Degrees-of-Freedom Robot for Ankle-Foot Neuro-Rehabilitation
,”
Proceedings of the Annual International Conference on IEEE Engineering in Medicine and Biology Society. EMBS
,
San Diego, CA
,
Aug. 28–Sept. 1
, pp.
3356
3359
.
24.
Du
,
Y.
,
Li
,
R.
,
Li
,
D.
, and
Bai
,
S.
,
2017
, “
An Ankle Rehabilitation Robot Based on 3-RRS Spherical Parallel Mechanism
,”
Adv. Mech. Eng.
,
9
(
8
), pp.
1
8
.
25.
Agrawal
,
A.
,
Sangwan
,
V.
,
Banala
,
S. K.
,
Agrawal
,
S. K.
, and
Binder-Macleod
,
S. A.
,
2007
, “
Design of a Novel Two Degree-of-Freedom Ankle-Foot Orthosis
,”
ASME J. Mech. Des.
,
129
(
11
), pp.
1137
1143
.
26.
Erdogan
,
A.
,
Celebi
,
B.
,
Satici
,
A. C.
, and
Patoglu
,
V.
,
2017
, “
Assist On-Ankle: A Reconfigurable Ankle Exoskeleton With Series-Elastic Actuation
,”
Auton. Robots
,
41
(
3
), pp.
743
758
.
27.
Krebs
,
H. I.
, and
Hogan
,
N.
,
2006
, “
Therapeutic Robotics: A Technology Push
,”
Proc. IEEE
,
94
(
9
), pp.
1727
1738
.
28.
Wang
,
H.
,
Li
,
W.
,
Liu
,
H.
,
Zhang
,
J.
, and
Liu
,
S.
,
2019
, “
Conceptual Design and Dimensional Synthesis of a Novel Parallel Mechanism for Lower-Limb Rehabilitation
,”
Robotica
,
37
(
3
), pp.
469
480
.
29.
Nurahmi
,
L.
,
Caro
,
S.
, and
Solichin
,
M.
,
2019
, “
A Novel Ankle Rehabilitation Device Based on a Reconfigurable 3-RPS Parallel Manipulator
,”
Mech. Mach. Theory
,
134
, pp.
135
150
.
30.
Blaya
,
J. A.
, and
Herr
,
H.
,
2004
, “
Adaptive Control of a Variable-Impedance Ankle-Foot Orthosis to Assist Drop-Foot Gait
,”
IEEE Trans. Neural Syst. Rehabil. Eng.
,
12
(
1
), pp.
24
31
.
31.
Gordon
,
K. E.
,
Sawicki
,
G. S.
, and
Ferris
,
D. P.
,
2006
, “
Mechanical Performance of Artificial Pneumatic Muscles to Power an Ankle-Foot Orthosis
,”
J. Biomech.
,
39
(
10
), pp.
1832
1841
.
32.
Costa
,
N.
, and
Caldwell
,
D. G.
,
2006
, “
Control of a Biomimetic ‘Soft-Actuated’ 10DoF Lower Body Exoskeleton
,”
IFAC Proc. Vol.
,
39
(
15
), pp.
785
790
.
33.
Zanotto
,
D.
,
Stegall
,
P.
, and
Agrawal
,
S.
,
2013
, “
ALEX III: A Novel Robotic Platform for Gait Training—Design of the 4-DOF Leg
,”
Proceedings of IEEE International Conference on Robotics and Automaton
,
Karlsruhe
,
Germany, May 6–10
, pp.
3914
3919
.
34.
Bacek
,
T.
,
Moltedo
,
M.
,
Langlois
,
K.
,
Prieto
,
G. A.
,
Sanchez-Villamañan
,
M. C.
,
Gonzalez-Vargas
,
J.
,
Vanderborght
,
B.
,
Lefeber
,
D.
, and
Moreno
,
J. C.
,
2017
, “
BioMot Exoskeleton—Towards a Smart Wearable Robot for Symbiotic Human-Robot Interaction
,”
IEEE International Conference in Rehabilitation Robotics
,
London
,
July 17–20
, pp.
1666
1671
.
35.
Bharadwaj
,
K.
,
Sugar
,
T. G.
,
Koeneman
,
J. B.
, and
Koeneman
,
E. J.
,
2005
, “
Design of a Robotic Gait Trainer Using Spring Over Muscle Actuators for Ankle Stroke Rehabilitation
,”
ASME J. Biomech. Eng.
,
127
(
6
), pp.
1009
1013
.
36.
Wang
,
T.
,
Olivoni
,
E.
,
Spyrakos-Papastavridis
,
E.
,
O'Connor
,
R. J.
, and
Dai
,
J. S.
,
2021
, “
Novel Design of a Rotation Centre Auto-matched Ankle Rehabilitation Exoskeleton With Decoupled Control Capacity
,”
ASME. J. Mech. Des.
,
144
(
5
), p.
053301
.
37.
Finistauri
,
D.
, and
Xi
,
F.
,
2013
, “
Reconfiguration Analysis of a Fully Reconfigurable Parallel Robot
,”
ASME J. Mech. Rob.
,
5
(
4
), p.
041002
.
38.
Dai
,
J. S.
,
Huang
,
Z.
, and
Lipkin
,
H.
,
2005
, “
Mobility of Overconstrained Parallel Mechanisms
,”
ASME. J. Mech. Des.
,
128
(
1
), pp.
220
229
.
39.
Dai
,
J. S.
, and
Rees Jones
,
J.
,
2002
, “
Null-Space Construction Using Cofactors From a Screw-Algebra Context
,”
Proc. R. Soc. A Math. Phys. Eng. Sci.
,
458
(
2024
), pp.
1845
1866
.
40.
Roth
,
B.
,
1993
, “
Computational in Kinematics
,”
Computational Kinematics
, J. Angeles, G. Hommel, and P. Kovacs, eds.,
Kluwer Academic Publishers
,
Dordrecht, The Netherlands
, pp.
3
14
.
41.
Merlet
,
J. P.
,
2006
, “
Jacobian, Manipulability, Condition Number, and Accuracy of Parallel Robot
,”
ASME J. Mech. Des.
,
128
(
1
), pp.
199
206
.
You do not currently have access to this content.