Kinematic and Structural Design Assessment of Fault-Tolerant Manipulators

Tosunoglu, Sabri; Monteverde, V.

doi:10.1080/10798587.1998.10750736

Cited by 23 publications

(15 citation statements)

References 10 publications

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“…5,6 Research on fault tolerance of the manipulators is on either the design of the manipulators (design of faulttolerant manipulators or fault-tolerant structures) or the control of the manipulators (fault analysis and fault-tolerant motion planning or control). Within the literature of design of fault-tolerant manipulators, either different structure of serial or parallel manipulators have been studied, [7][8][9][10][11][12] or a manipulator with a specific fault-tolerant property has been designed that includes design of degrees of freedom (DOF), link lengths, and redundancy in actuation. 13,14 The design procedure usually optimizes fault-tolerance measures of the manipulators.…”

Section: Introductionmentioning

confidence: 99%

Optimal mapping of joint faults into healthy joint velocity space for fault-tolerant redundant manipulators

Asayesh¹,

Nahavandi²,

Frayman³

et al. 2011

Robotica

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SUMMARYSelf-reconfiguration of robotic manipulators under joint failure can be achieved via fault-tolerance strategies. Faulttolerant manipulators are required to continue their endeffector motion with a minimum velocity jump, when failures occur to their joints. Optimal fault tolerance of the manipulators requires a framework that can map the velocity jump of the end-effector to the compensating joint velocity commands. The main objective of the present paper is to propose a general framework for the fault tolerance of the manipulators, which can minimize the end-effector velocity jump. In the present paper, locked joint failures of the manipulators are modeled using matrix perturbation methodology. Then, the optimal mapping for the faults with a minimum end-effector velocity jump is presented. On the basis of this mapping, the minimum end-effector velocity jump is calculated. A generalized framework is derived from the extension of optimal mapping toward multiple locked joint failures. Two novel expressions are derived representing the generalized optimal mapping framework and the generalized minimum velocity jump. These expressions are suitable for the optimal fault tolerance of the serial link redundant manipulators. The required conditions for a zero end-effector velocity jump of the manipulators are analyzed. The generalized framework in this paper is then evaluated for different failure scenarios for a 5-DOF planar manipulator and a 5-DOF spatial manipulator. The validation includes three case studies. While the first two are instantaneous studies, the third one is for the whole trajectory of the manipulators. From the results of these case studies, it is shown that, when locked joint faults occur, the faulty manipulator is able to optimally maintain its velocity with a zero end-effector velocity jump if the conditions of a zero velocity jump are hold.

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Section: Introductionmentioning

confidence: 99%

Optimal mapping of joint faults into healthy joint velocity space for fault-tolerant redundant manipulators

Asayesh¹,

Nahavandi²,

Frayman³

et al. 2011

Robotica

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“…Example applications include space exploration [2], [3], underwater exploration [4], and nuclear waste remediation [5], [6] where there has been a great deal of research to improve manipulator reliability [7], [8], design fault-tolerant robots [9], [10], and determine mechanisms for analyzing [11], detecting [12], [13], identifying [14]- [16], and recovering [17]- [20] from failures. Typical failure modes that have been considered include locked joint failures [21], where a joint is immobilized either due to the failure itself or due to the application of fail-safe brakes, and free-swinging joint failures [22] where the joint's associated actuator is no longer able to generate a force or torque.…”

Section: Introductionmentioning

confidence: 99%

Examples of spatial positioning redundant robotic manipulators that are optimally fault tolerant

Ben-Gharbia

Maciejewski

Roberts

2011

2011 IEEE International Conference on Systems, Man, and Cybernetics

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Abstract-It is common practice to design a robot's kinematics from the desired properties that are locally specified by a manipulator Jacobian. For the case of optimality with respect to fault tolerance, one common definition is that the post-failure Jacobian possesses the largest possible minimum singular value over all possible locked-joint failures. This work considers a Jacobian that has been designed to be optimally fault tolerant for a simple spatial positioning manipulator. It is shown that despite the fact that the Jacobian is "unique", up to column permutations and multiplications by ±1, there are a large family of physical manipulators that correspond to the optimal Jacobian. Two example manipulators are presented and analyzed. It is shown that there is a large degree of variability in the global kinematic properties of these designs, despite being generated from the same Jacobian.

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“…Example applications include space exploration [1,2], underwater exploration [3], and nuclear waste remediation [4,5] where there has been a great deal of research to improve manipulator reliability [6,7], design fault-tolerant robots [8,9], and determine mechanisms for analyzing [10], detecting [11,12], identifying [13][14][15], and recovering [16][17][18][19] from failures. Typical failure modes that have been considered include locked joint failures [20], where a joint is immobilized either due to the failure itself or due to the application of fail-safe brakes, and freeThis work was supported in part by the National Science Foundation under Contract IIS-0812437.…”

Section: Introductionmentioning

confidence: 99%

An Illustration of Generating Robots from Optimal Fault-Tolerant Jacobians

Ben-Gharbia¹,

Maciejewski²,

Roberts³

2010

IASTED Technology Conferences / 705: ARP / 706: RA / 707: NANA / 728: CompBIO

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The local kinematic properties of a robotic manipulator's configuration can be described by its corresponding Jacobian matrix. Conversely, one can determine a manipulator that possesses certain desirable kinematic properties by specifying the required Jacobian. In this work, design criteria that require a manipulator to function in a configuration that is optimal under normal operation and after an arbitrary single joint fails and is locked in position is first described. Specifically, the desired Jacobian matrix must be isotropic, i.e., possess all equal singular values prior to a failure, and have equal minimum singular values for every possible single column being removed. Then a simple planar three degree-of-freedom example is used to illustrate how one can identify all of the possible manipulator designs that possess the desired local properties described by the required structure of the Jacobian matrix. This paper concludes by showing that despite having identical local properties, the resulting manipulator designs have significantly different global kinematic properties that can be used to match a design to additional application-specific performance criteria.

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Kinematic and Structural Design Assessment of Fault-Tolerant Manipulators

Cited by 23 publications

References 10 publications

Optimal mapping of joint faults into healthy joint velocity space for fault-tolerant redundant manipulators

Optimal mapping of joint faults into healthy joint velocity space for fault-tolerant redundant manipulators

Examples of spatial positioning redundant robotic manipulators that are optimally fault tolerant

An Illustration of Generating Robots from Optimal Fault-Tolerant Jacobians

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