A high performance FPGA-based joint controller with hardware/software co-design method

Abstract

This work presents studies on application and implementation on the field programmable gate array (FPGA) technology into a robot joint controller in order to improve the tracking performance. The controller can be divided into two parts and designed with software and hardware separately. The first part is developed in Nios II embedded processor which is used to realize the velocity and torque control in C language. The second part is to implement the current vector control which includes coordinate transformation, PI controller, SVPWM (Space Vector Pulse Width Modulation) and some other function modules in Hardware Description Language (HDL). The two parts are integrated in the System-on-a-Programmable-Chip (SoPC) developing environment. Experiments on a PMSM are done and the results demonstrate the effectiveness and correctness of the proposed FPGA-based controller. Joint friction parameters can be estimated by the proposed controller with velocity and current control. Consequently, the controller is applied on a robotic manipulator together with DSP to verify the high performance.