Robust Control for a Biaxial Servo with Time Delay System Based on Neural Network

Abstract

A robust control method for synchronizing a biaxial servo system motion is proposed in this paper. A new neural network based cross-coupled control and neural network techniques are used together to cancel out the skew error. In the proposed control scheme, the conventional fixed gain PID cross-coupled controller (PIDCCC) is replaced with the neural network cross-coupled controller (NNCCC) to maintain synchronization motion of biaxial servo system. In addition, neural network PID (NNPID) position and velocity controllers provide the necessary control actions to maintain synchronization while following a variable command trajectory. A delay-time compensator (DTC) with a neural network controller was augmented to set the time delay element be effectively moved outside the closed loop such that the stability of the robust controlled system is enhanced. This scheme provides strong robustness with respect to uncertain dynamics and nonlinearities. The simulation results reveal that the proposed control structure adapts to a wide range of operating conditions and provides promising results under parameter variations and load changes.