The joint velocity jump for redundant robots in the presence of locked-joint failures is discussed in this paper. First, the analytical formula of the optimal joint velocity with minimum jump is derived, and its specific expressions for both all joint failure and certain single joint failure are presented. Then, the jump difference between the minimum jump solution and the least-norm velocity solution is mathematically analyzed, and the influence factors on this difference are also discussed. Based on this formula, a new fault tolerant algorithm with the minimum jump is proposed. Finally, simulation examples are implemented with a planar 3R robot and a 4R spatial robot, and an experimental study is also done. Study results indicate that the new algorithm proposed in this paper is well suited for real time implementation, and can further reduce the joint velocity jump thereby improving the motion stability of redundant robots in fault tolerant operations. Also, the fewer the possible failed joints are, the more obvious the effect of this new algorithm becomes.

Issue Section:
Mechanisms and Robotics
Keywords:
failure (mechanical), fault tolerance, mathematical analysis, robots
Topics:
Robots, Failure, Algorithms, Fault tolerance
1.
Visentin
,
G.
, and
Didot
,
F.
, 1999, “
Testing Space Robotics on the Japanese ETS-VII Satellite
,” ESA Bulletin-European Space Agency, pp.
61
–
65
.
2.
Babcock
,
P. S.
, and
Zinchuk
,
J. J.
, 1990, “
Fault-Tolerant Design Optimization: Application to an Autonomous Underwater Vehicle Navigation Systems
,” in
Proceedings of the Symposium Autonomon Underwater Vehicle Technology
,
Washington, DC
, pp.
34
–
43
.
3.
Leuschen
,
M. L.
,
Walker
,
I. D.
, and
Cavallaro
,
J. R.
, 1999, “
Investigation of Reliability of Hydraulic Robots for Hazardous Environment Using Analytic Redundancy
,”
Proceedings of the Annual Reliability and Maintainability Symposium
,
Washington, DC
, pp.
122
–
128
.
4.
English
,
J. D.
, and
Maciejewski
,
A. A.
, 2001, “
Failure Tolerance Through Active Braking: A Kinematic Approach
,”
Int. J. Robot. Res.
0278-3649,
20
(
4
), pp.
287
–
299
.
Crossref
Search ADS
 
5.
Maciejewski
,
A. A.
, 1990, “
Fault Tolerant Properties of Kinematically Redundant Manipulator
,” in
Proceedings of the IEEE International Conference on Robotics and Automation
, pp.
638
–
642
.
6.
Roberts
,
R. G.
, and
Maciejewski
,
A. A.
, 1996, “
A Local Measure of Fault Tolerance for Kinematically Redundant Manipulators
,”
IEEE Trans. Rob. Autom.
1042-296X,
12
(
4
), pp.
543
–
552
.
Crossref
Search ADS
 
7.
Caldwell
,
C.
, and
Roberts
,
R. G.
, 2002, “
Fault-Tolerant Kinematically Redundant Robots
,” in
Proceedings of the 34th Southeastern Symposium on System Theory
, pp.
281
–
285
.
8.
Lewis
,
C. L.
, and
Maciejewski
,
A. A.
, 1997, “
Fault Tolerant Operation of Kinematically Redundant Manipulators for Locked Joint Failures
,”
IEEE Trans. Rob. Autom.
1042-296X,
13
(
4
), pp.
622
–
629
.
Crossref
Search ADS
 
9.
Jing
,
Z.
, and
Hongmei
,
J.
, 2004, “
Fault Tolerant Motion Planning for Two Coordinating Manipulators
,”
Chin. J. Mech. Eng.
0577-6686,
40
(
12
), pp.
172
–
176
.
10.
Goel
,
M.
,
Maciejewsk
,
A. A.
, and
Balakrishnan
,
V.
, 2005, “
Analyzing Unidentified Locked-Joint Failures in Kinematically Redundant Manipulators
,”
J. Rob. Syst.
0741-2223,
22
(
1
), pp.
15
–
29
.
Crossref
Search ADS
 
11.
Renato
,
T.
,
Marco
,
H. T.
, and
Marcel
,
B.
, 2002, “
Fault Tolerance in Cooperative Manipulators
,” in
Proceedings of the IEEE International Conference on Robotics and Automation
,
Washington, DC
, pp.
470
–
475
.
12.
Groom
,
K. N.
,
Maciejewski
,
A. A.
, and
Balakrishnan
,
V.
, 1999, “
Real-Time Failure Tolerant Control of Kinematically Redundant Manipulators
,”
IEEE Trans. Rob. Autom.
1042-296X,
15
(
6
), pp.
1109
–
1116
.
Crossref
Search ADS
 
13.
Jing
,
Z.
,
Xuebin
,
Y.
, and
Lei
,
Z.
, 2005, “
The Optimization of Initial Posture With Avoidance of the Sudden Change in Joint Velocity for Fault Tolerant Operations of Two Coordinating Redundant Manipulators
,”
Mech. Mach. Theory
0094-114X,
40
(
6
), pp.
659
–
668
.
Crossref
Search ADS
 
14.
Jing
,
Z.
,
Kailiang
,
Z.
, and
Xuebin
,
Y.
, 2006, “
Study on Fault Tolerant Workspace and Fault Tolerant Planning Algorithm Based on Optimal Initial Position for Two Spatial Coordinating Manipulators
,”
Mech. Mach. Theory
0094-114X,
41
(
5
), pp.
584
–
595
.
15.
Liegeois
,
A.
, 1977, “
Automation Supervisory Control of the Configuration and Behavior of Multi-Body Mechanisms
,”
IEEE Trans. Syst. Man Cybern.
0018-9472,
SMC-7
(
12
), pp.
868
–
871
.
16.
Salibury
,
J. K.
, and
Craig
,
J.
, 1982, “
Articulated Hands: Kinematic and Force Control
,”
Int. J. Robot. Res.
0278-3649,
1
(
11
), pp.
4
–
17
.
17.
Merlet
,
J. P.
, 2006, “
Jacobian, Manipulability, Condition Number, and Accuracy of Parallel Robots
,”
ASME J. Mech. Des.
1050-0472,
128
(
1
), pp
199
–
206
.
Crossref
Search ADS
 
18.
Chang
,
P. H.
, 1985, “
A Closed-Form Solution for Control of Manipulators With Kinematic Redundancy
,” in
Proceedings of the IEEE International Conference on Robotics and Automation
, pp.
722
–
728
.
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