摘要:

AbstractIn this article, a systematic method to derive dynamic equations of motion for flexible robot manipulators is developed by using the Lagrangian assumed modes method. The proposed method can be applied to dynamic simulation and control system design for flexible robot manipulators. In the proposed method, the link deflection is described by a truncated modal expansion. The operations of only 3x3 matrices and/or 3 × 1 vectors exist in the method. All the dynamics computations are performed in the link coordinate systems, where the kinematics informations are computed with the forward recursion from the base to the hand tip and the dynamics informations are computed with the return recursion. As generally compared with other existing methods, the method proposed in this article is, computationally, more simple, systematic, and efficient. A computational simulation for a single‐link flexible robot manipulator is presented to verify the proposed method. © 1992 John Wiley&Sons,

ISSN:0741-2223    

DOI:10.1002/rob.4620090702

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis article deals with the stabilization problem of a class of nonlinear second‐order multivariable dynamical systems with bounded uncertainties. A robust discontinuous controller is proposed to guarantee asymptotic stability of this class of systems. Then, to guarantee the continuity of the control, aquasi‐saturation function is introduced into the control law. Guaranteed eventual stability‐in‐the‐large (ESL) of the dynamical systems is proved with the continuous, robust controller, which is much different from the standard “computed‐torque control.” The controller requires known bounding functions that are easier to determine as well as more general than the bounds needed in other approaches. An application is given to trajectory‐following control for a two‐link mobile robot. © 1992

ISSN:0741-2223    

DOI:10.1002/rob.4620090703

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractMany computer vision, sensor fusion, and robotic applications require the estimation of a 3 × 3 rotation matrix from a set of measured or computed 3 × 3 noisy rotation matrices. This article classifies solution methods into three categories: nonlinear least squares, linear optimal, and linear suboptimal algorithms. Their performance is compared through simulation studies. It is shown that the linear suboptimal algorithms proposed in this article have an accuracy comparable to that of the optimal algorithms and are about five times faster. Furthermore, a particular nonlinear optimization algorithm is presented that has computational complexity similar to that of the linear optimal procedures. © 1992 John Wiley&Sons, I

ISSN:0741-2223    

DOI:10.1002/rob.4620090704

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe effect of robotic manipulator structural compliance on system stability and trajectory tracking performance and the compensation of this structural compliance has been the subject of a number of publications for the case of robotic manipulator noncontact task execution. The subject of this article is the examination of dynamics and stability issues of a robotic manipulator modeled with link structural flexibility during execution of a task that requires the robot tip to contact fixed rigid objects in the work environment. The dynamic behavior of a generalndegree of freedom flexible link manipulator is investigated with a previously proposed nonlinear computed torque constrained motion control applied, computed based on the rigid link equations of motion. Through the use of techniques from the theory of singular perturbations, the analysis of the system stability is investigated by examining the stability of the “slow” and “fast” subsystem dynamics. The conditions under which the fast subsystem dynamics exhibit a stable response are examined. It is shown that if certain conditions are satisfied a control based on only the rigid link equations of motion will lead to asymptotic trajectory tracking of the desired generalized position and force trajectories during constrained motion. Experiments reported here have been carried out to investigate the performance of the nonlinear computed torque control law during constrained motion of the manipulator. While based only on the rigid link equations of motion, experimental results confirm that high‐frequency structural link modes, exhibited in the response of the robot, are asymptotically stable and do not destabilize the slow subsystem dynamics, leading to asymptotic trajectory tracking of the overall system. © 1992 John Wiley

ISSN:0741-2223    

DOI:10.1002/rob.4620090705

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis article studies the forward kinematics of walking machines with pantograph legs. The walking machine is supported by three legs and each leg has 3 degrees of freedom (dof). Because the body has 6 dof motion, only 6 joint variables among the 9 are independent. Thus, there are 84 possible ways to select the 6 independent joint variables. It is shown that the complexity of the forward position solutions is very much dependent on the selection of independent joints. In the category of3:2:1(the 3 numbers denote the number of independent joints at each of the supporting legs), all 54 combinations give closed‐form solutions. Among the 27 combinations ofcategory 2:2:2, 10 possess closed‐form solutions, 16 yield to higher‐order polynomials, and 1 gives no solutions. The 3 combinations ofcategory 3:3:0give no solutions. The results are useful to control and simulation of walking machines and other parallel systems consisting of pantograph subchains such as parallel manipulators, multifingered hands, and multiply coordinated manipulators. © 1992 John Wiley&Son

ISSN:0741-2223    

DOI:10.1002/rob.4620090706

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis article presents a meaningful, practical, and theoretically sound solution that solves the problem of grasping a rigid object with a hand that has redundant (>6) grasping contacts. This is accomplished by introducing compliance at each contact point in such a way as to provide the engineer with the capabilities of object manipulation via controlled forces at the contact points. This method of solution is adapted straight‐away to compute the static forces generated in the legs of a redundant in‐parallel manipulator that equilibrates a wrench applied to the moving/platform or end‐effector. In a way similar to the redundant grasping problem, this is accomplished by introducing the knowledge of the compliances that exist in the legs. The solution thus obtained stems from physical parameters that model the in‐parallel manipulator. The in‐depth study of the duality between the statics of in‐parallel manipulators and the kinematics of serial manipulators reveals a meaningful, practical, and theoretically sound solution for the inverse kinematics of a redundant serial manipulator. This is accomplished by incorporating the knowledge of the compliances that exist or are desired to exist in the joints of the manipulator. (For instance, the torsional compliance in revolute joints or the linear compliance in prismatic joints.) Such information provides a physically meaningful model of the serial manipulator that in turn yields a physically meaningful set of joint increments for a given end‐effector twist. © 1992 John W

ISSN:0741-2223    

DOI:10.1002/rob.4620090707

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0741-2223    

DOI:10.1002/rob.4620090701

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY