Abstract
In this paper, we investigated the cascade controller of a motor-driven deep-sea robot cable system (MDRCS), which consists of the outer loop system and the inner loop system connected by a motor thrust with unknown factors, typically forming a crucial problem along with actuator failures, and is accommodated by a fault control created for the deep-sea model. Furthermore, the non-linear disturbance observer compensates for the external disturbance by using the high-gain state observer to estimate parameters and reduce the effects of measurement inaccuracy from the sensors. We suggested an output feedback boundary controller for the outer loop system to get the thrust and eliminate the transverse cable vibration as well as a multiplicative inverse controller for the motor system to form a cascade controller. The Lyapunov approach is then used to demonstrate the stability of the deep-sea robot cable system and motor system. The results demonstrated the effectiveness of the suggested controller and fault control in the presence of the actuator fault, presented with the appropriate parameters on MDRCS.