Research On CAN Bus Based Distributed Control System Of Four Axis Robot

In consideration of the mixed-driven characteristic of the four axis robot system, we developed a full-distributed control system in using the advanced FieldBus and computer control technology. In the process of development, we also take into account the up to date robot control technology and the special need of teaching.The robot system consists of two main parts: the mechanism and the control system. The mechanism is based on the 4-axis rectangular coordinate system. The driven mode of X-Axis is proportional pneumatic-servo control system; Y-Axis is driven by a digital AC servomotor; Z-Axis is driven by a linear cylinder; The driven mode of the axis of R is same to that of Y-Axis. We also applied a cupule at the end of R-Axis, the function of which is to carry work pieces.This paper is focused on the matching of the pneumatic servo system and the electrical servo system and the interconnection of Multi-Bus.At the beginning of this paper, I introduce the structure and function of the robot system. Then I put a comprehensive presentation of the control system of the four-axis robot. I discuss the design principle of the control system and the design method of both the hardware and software system of the robot completely. I also put the hardware and software implementation of the full-distributed computer network based control system.The hardware is developed on the basis of the single-wire and multi-master network structure of CAN bus. Taking into account the special need of teaching and experiment, we make the system work in two different modes: master-slave mode and multi-master mode. In the mode of master-slave, the PC with CAN adapter performs as the master node and the other five Field controllers perform as the slave nodes. With the help of Visual Basic 6, which runs on the platform of MS-Windows NT 4.0, we developed a PC-based and open-featured control program for the robot system. At the same time, we also developed the general-purpose communication module, which runs on the P80C592 micro-controller. The developing environment that we use is Keil C51.We use the full-distributed control technology as the basic control mode, and distributed the control system of the pneumatic servo sub-system and the electrical servo sub-system. Also, we coordinate them through CAN-Bus. The experiment results have proved that it is a good solution for the mixed-driven system. We also use the technology of the Integration of Multi-Bus to solve the problem of interconnection between the CAN-device and the non-CAN-device.At last, we give the experiment results of the 4-axis robot system. The results prove that the CAN-Bus based full-distributed control system can work steadily, operate concisely and can be adapted to various kinds of system. Based on the experiment results, I think I to say that the system we developed have fulfilled the objective of design.