Distributed digital control of a robot arm

Abstract

Most robot arms use a central control box that contains the power electronics,.. the motor controllers and the coordinating computer. This paper presents a distributed control network that allows the power electronics and motor controllers to be placed adjacent to the motors. Each controller uses a DSP for all motor control w~th the individual controllers communicating wIth each other and a host computer using a Controller Area Network (CAN). The design eliminates the bulky multi-core cable that is a major source of downtime for robots such as the PUMA 560, while improving controller bandwidth and facilitating greater software control ofmotor response. 1