Design of acceleration control system considering current dynamics

Sampling periods in digital control systems have been shortened thanks to the development of both hardware and software technologies. In recent years, FPGA (Field Programmable Gate Array) has been applied to robot systems to achieve hard real-time system with short sampling periods. Due to the short sampling periods, the effect of the time quantization has been reduced. Some other hardware restrictions, however, become critical issue. In this paper, current dynamics in motor driver is considered as the hardware restriction. The current response dynamics acts as a low-pass filter, and it can be the restrictions of performance improvement. In the proposed method, the dynamics is modeled as low-pass filter, and the modeled dynamics is compensated by a phase-lead compensator. The tracking performance in an acceleration control system is improved by the proposed method. The effectiveness of the proposed method is validated through simulations and experimental results.