The Design Of Multi-Motor Motion Controller Based On ARM And CPLD

In recent years, China has been playing a role as a global manufacturing powerhouse. However, Chinese manufacturing industry has to upgrade machinery automation, because the advantage of low labor costs are gradually disappearing. Therefore, our motion control technology makes rapid improvement in such an environment. After 2005, our country has basically mastered the key of five-axis motion control technology and greatly narrowed the gap with foreign technology. So the control precision of existing motion controller is improved and the market applications of motion controller is opened up. Since the servo motors are widely used in the field of automation, the requirements for the reliability and openness of servo motor motion controller are getting higher and higher. Therefore, it’s important for our country manufacturing industry to research the reliable and practical motion controller with open system.In order to choose an appropriate design, several designs of motion controller are compared and analyzed in this paper. Taking advantage of commonality of CAN bus communication, a multi-motor motion controller for servo motors, which is based on ARM and CPLD and used CAN bus communication as the interface between PC and motion controller, is designed. The controller uses the ARM processor to do motion control unit and the CPLD is used to generate a pulse motor drive control and I / O expansion. This design solves the problem of shortage of single processor performance. At the same time, the CAN bus communication enhances the openness of motion controller.The hardware system is composed of the core control unit ARM, part of the CAN communication module circuit, driver core CPLD, optocoupler isolation circuit, I/O expansion and clock power supply module. In order to meet the demands of real time of motion controller, the software of ARM system uses μCOS-III embedded operating system to complete all kinds of task scheduling. In the ARM system, there are three tasks establishing to realize the following function. Firstly, the CAN bus communication between PC and motion controller is done. Secondly, the control of the multi-motor, which is used the trapezoidal acceleration and deceleration curve to achieve the speed control of multi-motor, is finished. Finally, the communication interaction between ARM and CPLD is also completed. The CPLD generates pulse to drive motors by modular designing with VHDL language. And it achieves I/O expansion and the control of output pulse frequency and number. The CPLD system including the address decoder module, input and output buffer module, DDS frequency module, counter modules and I / O expansion modules, etc. Besides, simulation about the integrated circuits has done in Quartus II to verify the correctness of the design.