Control system design for a Double-Prism Scanner

摘要

A control system designed for a Double-Prism scanner is discussed in this paper. This control system is required to regulate the speed of prisms accurately and change the scan pattern as quickly as possible. Therefore, we designed a digital double closed-loop control system which consists of an inner loop and an outer loop to achieve that function. In this double closed-loop control system, the inner loop uses linear Proportional-Integral (PI) controller for the current control and the outer loop uses saturated Proportional-Integral controller for the speed control. To verify the feasibility and rationality of this control method, simulation based on MATLAB was performed. And the simulation results indicate that the step response of prism speed is stable and there is no steady state error. After building the digital control system, many experiments were performed to obtain key characteristics. The experiment results show that the speed regulation time is about 0.4s when the reference speed is 1rps. The accuracy of speed regulation reaches 10~(-4) level, and the fluctuation ratio of speed regulation reaches 10~(-2) level over its operation range(0rps-3rps).