Adaptive Boundary Control for Multiconstrained RigidFlexible Robot With Actuator and Sensor Concurrent Failures

In this article, an adaptive boundary control strategy of a rigid-flexible robot with concurrence failures and multiple constraints is studied based on a distributed parameter model. The complex dynamic of the rigid-flexible robot system is expressed by ordinary differential equation (ODE) and partial differential equation (PDE), which can avoid control overflow problem. The multifault concurrent cases of joint torque and force actuator failures as well as angular velocity and vibration displacement sensor failures are considered. An adaptive fault-tolerant control for flexible-rigid robot is presented to compensate the effects of actuator and sensor failures. Then, the tangent barrier Lyapunov function (BLF) and the integral BLF are designed to ensure multiple output states within their constraints. The finite-dimensional boundary controller consisting of measurable sensor signals can achieve position tracking and vibration suppression. The closed-loop system of the asymptotic stability is proved by using the extended LaSalle's invariance principle. According to the comparative simulations, the effectiveness of the presented controller is verified.