基于FPGA的实时Pythagorean Hodograph曲线运动控制器的设计

Design of the Real-time Motion Controller for Pythagorean Hodograph Curve Based on FPGA

提出了一种采用SOPC技术在单个FPGA芯片上构建的新型实时PH曲线运动控制器的架构;该运动控制器在QuartusⅡ9.0中设计,由一个NiosⅡ软核处理器和多个功能模块构成;它通过采用二次插补方式以减少PH曲线插补的计算量;NiosⅡ处理器执行主控程序和PH曲线粗插补算法,FPGA硬件逻辑执行精插补算法并输出两组用于控制执行机构(XY工作台)的控制脉冲;实验数据表明,该运动控制器完成恒进给速度的单次PH曲线插补的平均耗时均小于2ms,终点坐标的定位误差均低于0.0079mm。

A novel architecture of the real-time motion controller for Pythagorean Hodograph curve built on a single FPGA chip using SOPC technology is proposed. The motion controller is designed in Quartus II 9.0. It consists of a Nios II processor core and several functional modules. It uses a two--stage interpolation scheme to reduce the computational burden of PH curve interpolation. Firstly, the Nios II proces- sor performs master control program and the 1st-stage interpolation algorithm. The FPGA hardware logic performs the 2nd-stage interpolation and outputs two groups of pulses for the motion control of actuators （XY table）. The experimental data show that the motion controller completed single PH curve interpolation within 2 ms averagely and position errors of end coordinates were all lower than 0. 0079 mm.