A dexterity measure for the design evaluation and optimization of robot (redundant) manipulators is presented. It is shown that an upper bound for the condition number of the Jacobian matrix depends significantly on t...
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A dexterity measure for the design evaluation and optimization of robot (redundant) manipulators is presented. It is shown that an upper bound for the condition number of the Jacobian matrix depends significantly on this measure. The proposed criterion has been applied (in an absolute fashion) to evaluate the kinematic dexterity and optimize each one of five different designs of a HERA arm as a redundant manipulator to be used in space operations.< >
The authors investigate dexterity measures of a manipulator based on its Jacobian matrix. The goal is to derive dexterity measures which can be used for both design and control of a manipulator. Generally, a dexterity...
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The authors investigate dexterity measures of a manipulator based on its Jacobian matrix. The goal is to derive dexterity measures which can be used for both design and control of a manipulator. Generally, a dexterity measure must be independent of the scale of a manipulator for design, and must be expressed analytically so that it can be used for real-time control. Every dexterity measure must bear a physical meaning. The measure of manipulability has an analytical expression, but it depends on the scale of a manipulator. On the other hand, the condition number is independent of the scale, but cannot be expressed analytically. These two main problems (scale dependency and analytical expression) of previous dexterity measures derived from the Jacobian matrix are solved and applied in design and control of manipulators. In addition, a dexterity measure called the measure of isotropy is introduced.< >
作者：
CHIANG, PTYANG, JCSResearch Engineer
Advanced Technology and Research Corporation Laurel MD 20707 14900 Sweitzer Lane United States Robotics Laboratory
Department of Mechanical Engineering University of Maryland College Park MD 20742 United States
With the given geometrical data of a model, this paper presents a technique: (1) to prepare a workpiece with minimal material required to fabricate the model;(2) to automatically determine the necessary manufacturing ...
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With the given geometrical data of a model, this paper presents a technique: (1) to prepare a workpiece with minimal material required to fabricate the model;(2) to automatically determine the necessary manufacturing processes utilizing the concept of feature-based recognition;and (3) to optimally sequence these processes based on a tabulated optimization scheme. Four types of feature, face, hole, slot, and pocket, are considered. Computational results are provided to demonstrate the capability and advantage of the technique. Conclusions are given and recommendations for future research are discussed.
The intelligent coordination of multiple robots requires modularization of robots at some level higher than the joint, corresponding task representations, and a concept of time that allows the dynamic specification of...
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The intelligent coordination of multiple robots requires modularization of robots at some level higher than the joint, corresponding task representations, and a concept of time that allows the dynamic specification of task synchronization. The necessary representations of robots and tasks are developed, and the structural and operational semantics of the primitive task and reflex models are specified. A concept of time, called functional time-dependency, that allows the dynamic specification of the distributed semantics during task execution by multiple robots is developed. The utility of functional time-dependency is shown using two examples.< >
The stability of linear systems subject to possibly fast time-varying uncertainties is analyzed. A necessary and sufficient condition of quadratic stability is derived. An uncertainty stability margin coefficient rho ...
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The stability of linear systems subject to possibly fast time-varying uncertainties is analyzed. A necessary and sufficient condition of quadratic stability is derived. An uncertainty stability margin coefficient rho is introduced to give a quantitative measure of the stability. It is proposed that the uncertain region be approximated by a convex hyperpolyhedron. In this case, the computation of rho becomes a two-level optimization problem, in which the extremum of the inner level can be reached by one of the corners of the hyperpolyhedron.
This paper proposes an alternate approach for adaptive robust control of linear systems with structured, wide-ranging parametric uncertainties. The overall scheme consists of two steps; namely, off-line design of a ro...
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This paper proposes an alternate approach for adaptive robust control of linear systems with structured, wide-ranging parametric uncertainties. The overall scheme consists of two steps; namely, off-line design of a robust observer for the partial states of the system, and design of an on-line adaptive pole placement scheme. It is shown that by using this approach, both direct as well as indirect adaptive pole placement can be achieved. Proofs of stability of the schemes are also given.
Utilization of the fuzzy self organizing control(SOC) algorithm for the control of robotic manipulators is becoming increasingly of interest. However, the control performance of the present self-organizing control(SOC...
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A dexterity measure is presented which can be used for the design evaluation of robot (redundant) manipulators. The proposed criterion is applied (in an absolute fashion) to the evaluation of the kinematic dexterity o...
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A dexterity measure is presented which can be used for the design evaluation of robot (redundant) manipulators. The proposed criterion is applied (in an absolute fashion) to the evaluation of the kinematic dexterity of five different designs of a HERA redundant manipulator to be used in space operations. The selection of these designs is based on augmenting the original HERA six-degree-of-freedom design with an extra joint and considering only the resultant manipulators to be capable of avoiding all possible kinds of internal singularity. The results are in agreement with the conclusions from previous subjective studies conducted for the design analysis of an industrial arm as a redundant manipulator.< >
A spatially variant seasonal multiplicative autoregressive model which treats an image as an inhomogeneous random process with a nonstationary mean and possibly nonstationary covariance is introduced. The principal fe...
A spatially variant seasonal multiplicative autoregressive model which treats an image as an inhomogeneous random process with a nonstationary mean and possibly nonstationary covariance is introduced. The principal features of this model are the ability to guarantee stability online, efficient one-dimensional recursive parameter estimation and explicit coefficient representation necessary for classification and synthesis applications
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