FPGA-Realization of a Motion Control IC for Robot Manipulator

摘要

This study presents a motion control IC for robot manipulator based on novel FPGA technology. The main contributions herein are summarized as follows. 1. The functionalities required to build a fully digital motion controller of a five-axis robot manipulator, such as the function of a motion trajectory planning, an inverse kinematics, five axes position and speed controller, five sets of PWM and five sets of QEP circuits have been integrated and realized in one FPGA chip. 2. The function of inverse kinematics is successfully implemented by hardware in FPGA; as the result, it diminishes the computation time from 5.6ms using Nios II processor to 840ns using FPGA hardware, and increases the system performance. 3. The software/hardware co-design technology under SoPC environment has been successfully applied to the motion controller of robot manipulator. Finally, the experimental results by the step response, the point-to-point motion trajectory response and the linear and circular motion trajectory response, have been revealed that based on the novel FPGA technology, the software/hardware co-design method with parallel operation ensures a good performance in the motion control system of robot manipulator. Compared with DSP, using FPGA in the proposed control architecture has the following benefits. 1. Inverse kinematics and servo position controllers are implemented by hardware and the trajectory planning is implemented by software, which can all be programmable design. Therefore, the flexibility of designing a specified function of robot motion controller is greatly increased. 2. Parallel processing in each block function of the motion controller makes the dynamic performance of the robot’s servo drive increasable. 3. In the commercial DSP product, it is difficult to integrate all the functions of implementing a five-axis motion controller for robot manipulator into only one chip.