A better non-linear PID controller of digital electromechanical actuator system

To our knowledge, existing non-linear PID controllers require that the parameters of the actuator model be either completely accurate or at least partially accurate. We propose a non-linear PID controller that does not make such a requirement on the actuator model; the design of such a controller is explained in sections 1 and 2 of the full paper. Their core is that: we use the tracking differentiator to obtain the position tracking error and the differential error, and then we use their non-linear combination to design the non-linear PID controller, whose block diagram is shown in Fig. 2. Section 3 simulates our non-linear PID controller and does experiments on the control of a real digital electromechanical actuator. The simulation and experimental results, given in Figs. 4, 5 and 6 and Table 1, show preliminarily that our PID controller has good dynamic performance, small steady-state error, the robust control of the uncertainties of the parameters of the digital electromechanical actuator and the robust control of the changes in its external load.