1、 毕业设计外文资料翻译 题 目 人工和工业机器人重复操作定位 学 院 机械工程学院 专 业 机械工程及自动化 班 级 学 生 学 号 指导教师 二一四 年 三 月 三十 日 Computers in Biology and Medicine 28 (1998) 415-421 Comparison of position repeatability of a human operator and an industrial manipulating robot Jure Zupancic*, Tadej Bajd Faculty of Electrical Engineering, Unive
2、rsity of Ljubljana, Trzaska 25, SI-1000 Ljubljana, Slovenia Received 8 December 1997 Abstract Robot performance criteria of position repeatability are studied. Weight-to-payload ratio is in manipulating robots significantly higher than in human operators. Bracing strategy improving the robot perform
3、ances is introduced in the paper. The strategy copies human behavior during fine motion operations. A comparison is made between the robot and the human operator performing approximately the same manipulating task. Contactless measurements of position repeatability were accomplished with the OPTOTRA
4、K motion analysis system. The results of tests demonstrate considerable improvement of robot and human operators position repeatability when using bracing. 1998 Elsevier Science Ltd. All rights reserved. Keywords: Industrial robot； Human operator； Repeatability； Standards； Measurements； Bracing stra
5、tegy 1 Introduction Modern robot manipulators replacing human operator in assembly tasks 1 are usually designed in accordance with the principles encountered in humans and their arms and hands.The main goal of developing a mechanical counterpart to human operator is achieving of improved performance
6、s such as speed, payload capacity, position accuracy and repeatability.However, when the loads are not exceeding 3 kilograms, weight-to-payload ratio found in robots is reported to be ten times higher than the same ratio assessed in human operator 2.The reduction of this ratio is highly related to o
7、verall robot efficiency from technical and economical point of view. Traditional principles for improving this ratio are introducing lighter materials 3, new construction solutions and design of new actuators. In a special case, it is possible to increase the robot absolute accuracy and repeatabilit
8、y by using appropriate bracing 4. The method of bracing 5 is a direct copy of human behavior where the adaptation to higher accuracy and repeatability requirements during the fine motion operation is required. A human operator, when performing precise manipulation tasks, often finds supports for his
9、 forearm, wrist or elbow like in many working situations watch-makers are practicing. The same simple idea can be transferred - 1 - into robotics. Apart from some estimations, there was no explicit comparison made between human operator and adequate robot performances. The aim of this investigation
10、was to make concise technical comparison of robot and human operator performance with and without bracing. 2 Method Position repeatability tests were performed in accordance with ISO 9283 standard for manipulating industrial robots 6. The cube with maximum volume was located in the workspace of the
11、most frequent anticipated use. Five points (P1-P5) were located on the diagonals of the selected plane as shown in Fig.1 . Contactless OPTOTRAK/3010 motion analysis system was used for measuring of the actual positions (see Fig. 2). Measurements were taken at the poses P1, P2, P3, P4 and P5. The pos
12、ition repeatability expresses the closeness of the attained positions after 30 repeated visits to the same commanded position, as required by the ISO 9283 standard. The repeatability is calculated by the following equations: ,3 DSDr (1) ,11 nj jDnD (2) ,)()()( 222 zzyyxxD jjjj (3) Fig. 1. Definition of the measuring points (P1-P5) inside the robot workspace.
