Adaptive neural network control of an arm-string system with actuator fault based on a PDE model

Abstract

In this paper, an adaptive boundary controller for an undersea detection robot system with actuator failure, unknown disturbance and boundary deflection constraint is proposed. Using Hamilton’s principle, a partial differential equation (PDE) model is established for the detection system, which consists of a rigid arm, a flexible string and a sensor. Considering the actuator failure, a fault-tolerant scheme is proposed to tackle it. To handle the unknown disturbance, we employ radial basis function (RBF) neural networks (NNs) to neutralize the boundary uncertain nonlinear disturbance. The proposed adaptive controller includes a proportional–derivative (PD) feedback structure, a fault-tolerant strategy and a NN control scheme. By choosing an appropriate Lyapunov-Krasovskii function and applying LaSalle’s Invariance Principle, the asymptotic stability of the closed-loop system is rigorously proven. Simulation results validate the proposed controller.

Tangent barrier Lyapunov function‐based constrained control of flexible manipulator system with actuator failure

“…Theorem 1. Consider the flexible manipulator system described by PDEs ( 5)-( 8), under Assumptions 1 and 2, the designed adaptive NNs boundary controllers (36) and (37), adaptive joint motor fault compensation controller (39), and adaptive laws (40), (41), and ( 42) can insure the boundness of all signals in the system even if joint motor fault occurs. The states joint angle and vibration deflection satisfy the constraints.…”

Combined feedback linearization and sliding mode control for vibration suppression of a robotic excavator on an elastic foundation

“…Numerous methods (Cao and Liu, 2018;Li et al, 2019;Nikkhoo et al, 2019) have been successfully applied for general vibration suppression. Vibration suppression in the multibody system has been studied by Lin et al (2018) and Wegerhoff et al (2018).…”

Coordination and vibration control for two sets of flexible satellites with input constraints and actuator failures

“…Some researchers have also explored displacement suppression control measures for flexible structures (He and Zhang, 2016; He et al, 2018a, 2018b; Jiang et al, 2016; Liu et al, 2017; Wang et al, 2012; Zhao et al, 2016). In Cao and Liu (2019a, 2019b), an adaptive boundary controller is designed for an undersea detection robot system to suppress displacement with considering actuator failure, unknown disturbance, and boundary deflection constraint. Input quantization and displacement suppression of the two-link rigid–flexible manipulator is investigated in Cao and Liu (2019a, 2019b).…”

“…In Cao and Liu (2019a, 2019b), an adaptive boundary controller is designed for an undersea detection robot system to suppress displacement with considering actuator failure, unknown disturbance, and boundary deflection constraint. Input quantization and displacement suppression of the two-link rigid–flexible manipulator is investigated in Cao and Liu (2019a, 2019b). We consider the flexible satellite system in this study, and some researches are done on the flexible spacecraft modelled as PDEs.…”