A new motion control hardware architecture with FPGA-based IC design for robotic manipulators

In this paper, a new motion control hardware architecture is proposed for improved motion performance of robotic manipulators during high speed motion. The main idea is to remove the servo control loop from the DSP (Digital Signal Processor) to a FPGA (Field Programmable Gate Array), and utilize the high speed hardwired logic of the FPGA to enhance the computation capability and relieve the computing load on the DSP. The control algorithm is partitioned into a linear portion and a nonlinear portion. The linear portion with position/velocity feedback represents the major control loop and is implemented in the FPGA. The nonlinear portion acts as dynamic compensation to the linear portion to perform complex modeling related calculations, and is implemented in the DSP. A new FPGA-based motion control IC is designed to realize this new control hardware structure. Experiments were conducted on a Yamaha robot manipulator to compare new control architecture and the existing one, when the same control algorithm was used. Experimental results demonstrate that the proposed new control architecture exhibits much improved motion performance especially during high-speed motions.