Systematic design of two-degree-of-freedom PID controller for positioning and tracking drives of linear servo motors

This paper presents a new pole-zero-assignment-based design method of a two-degree-of-freedom (TDOF) PID controller, which is applicable to both positioning and tracking drives of linear servo motors. This design method involves easy determination of five PID control parameters from six items: mover mass, maximum load mass, thrust constant, cutoff frequency of the position control system, crossover frequency of sensitivity and complementary sensitivity functions, and pole-angle in the s-plane. Consequently, it is possible to design a suitable TDOF PID controller for both positioning and tracking drives by changing the pole-angle in the s-plane. Simulation and experimental results validate the proposed design method. © 2017 The Institute of Electrical Engineers of Japan.