Error based self-regulating PID angle control of variable structure redundant brushed DC motors

In this paper, a new algorithm is proposed for online regulation of a Proportional, Integral and Derivative (PID) controller parameters, which is used for angular position control of a permanent magnet (PM) DC motor. A conventional PID controller with constant gains fails to provide satisfactory results under time-varying operation conditions. In the proposed method, values of the proportional, integral and derivative coefficients of the controller are tuned based on error trend and are confined to a predetermined range. Therefore, performance of the system is kept as close as possible to a desired response. By using an innovative setup with variable parameters consisting of redundant brushed DC motors, the performance of the proposed control algorithm has been assessed extensively. To test the performance of both conventional PID and the proposed method, various experimental scenarios have been carried out. The obtained experimental results show improvements over regular PID both in transient and steady-state responses. As per diverse situations were held during experiments, in the strictest scenario improvements of 29.7%, 17.6% and 44.8% were achieved for the IAE, ISE and ITAE, respectively. Moreover, overshoot percentage enhancements are apparent in system responses.