摘要:

AbstractA recent development in robotics is the increase of intelligence in robots. One of the research fields is to enable robots to autonomously avoid collisions with surrounding objects. This article presents an efficient method for planning collision‐free paths for an articulated robot that is surrounded by polyhedral objects. The algorithm plans a hypothetical Archimedes's spiral path from the initial position to the goal position. When a collision among the arms and obstacles is detected, the hypothetical path will be modified to avoid the collision. The algorithm applies geometric methods to determine the upper and lower bounds of the reachable area of the wrist and then determines a collision‐free path point on that reachable area. Because the equations, which represent the upper and lower bounds, are simple, the algorithm can rapidly determine a collision‐free path. Moreover, with minor modifications, this path planning algorithm can also be applied to other robots such as spherical, cylindrical, and Cartesian types of robots. ©1995 John Wiley&Son

ISSN:0741-2223    

DOI:10.1002/rob.4620121002

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

年代:1995

数据来源: WILEY

摘要:

AbstractA new robot control scheme for the specific application to conveyor tracking is presented. To improve the performance of conveyor tracking, the robot arm dynamics is incorporated into the control scheme. The tracking problem for the workpiece on a variable‐speed conveyor is formulated as a stochastic optimal tracking problem with specified criteria. Dividing the conveyor speed into the nominal term and the perturbed term, a two‐stage control strategy is employed to cope with the nonlinearity and uncertainty of the robot‐conveyor system. Simulation results are given to verify the good tracking performance with fast cycle time and high accuracy obtained in a robotic workcell. ©1995 John Wiley&Son

ISSN:0741-2223    

DOI:10.1002/rob.4620121003

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

年代:1995

数据来源: WILEY

摘要:

AbstractThis article presents the direct kinematics of a 6 degrees of freedom fully parallel manipulator that features five connection points on both base and platform. The considered leg arrangement is one of the two possible, the other having been referred to in a previous paper. The base and platform have a general geometry, i.e., the connection points are not bound to lie on planes. The direct kinematics is solved in analytical form, which allows determination of every possible solution. After a suitable set of five equations in five unknowns has been laid down, and an original elimination procedure applied, a final polynomial equation of the 24th order is found whose 24 solutions correspond to as many assembly configurations for the considered fully parallel manipulator. A case study is reported. ©1995 John Wiley&Sons, Inc

ISSN:0741-2223    

DOI:10.1002/rob.4620121004

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

年代:1995

数据来源: WILEY

摘要:

AbstractA novel active‐vision system for 3‐D object recognition was developed. The vision system combines object pre‐marking and active sensing. Therein, an object is modeled by a few of its 2‐D perspective (standard) views, each with a corresponding viewing axis defined by a marker placed on the object. The operation of the active‐vision system is characterized by its off‐line planning and on‐line recognition phases. The primary objective of this article is to address two issues in regard to the former: optimal object pre‐marking and optimal camera placement. The optimal object pre‐marking problem is defined as the determination of the minimum number of markers, and their best locations on a given set of objects to yield maximum “distinctiveness” for the 2‐D standard‐views defined by these markers. The optimal camera‐placement problem targets minimization of camera movements in detecting the markers. Following a brief description of the proposed on‐line recognition process, the techniques developed for the off‐line planning stage are described in this article. For experimental verification purposes, a prototype of the proposed active‐vision system was also implemented and is described h

ISSN:0741-2223    

DOI:10.1002/rob.4620121005

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

年代:1995

数据来源: WILEY

摘要:

AbstractIn recent years, researchers have been dedicated to the study of underactuated manipulators, which have more joints than control actuators. In previous work, researchers always assumed that there was enough dynamic coupling between the active and the passive joints of the manipulator for it to be possible to control the position of the passive joints via the dynamic coupling. In this work, the authors aim to develop an index to measure the dynamic coupling, so as to address when control of the under‐actuated system is possible, and how the motion and robot configuration can be designed. We discuss extensively the nature of the dynamic coupling and of the proposed coupling index, and their applications in the analysis and design of underactuated systems, through a detailed mathematical analysis and several illustrative examples. ©1995 John Wiley&Sons, I

ISSN:0741-2223    

DOI:10.1002/rob.4620121006

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

年代:1995

数据来源: WILEY

ISSN:0741-2223    

DOI:10.1002/rob.4620121001

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

年代:1995

数据来源: WILEY