Reconfigurable control of networked nonlinear Euler-Lagrange systems subject to fault diagnostic imperfections

The main objective of this paper is to design a distributed reconfigurable controller for networked nonlinear Euler-Lagrange (EL) systems in presence of actuator faults and imperfections in the fault detection and identification (FDI) algorithm. Specifically, we propose an adaptive distributed control algorithm which has the capability of estimating the faults (both intermittent and permanent). We incorporate the information provided from the FDI algorithm (which is assumed to be running in parallel with the controller) in the design of the adaptive controller. We consider three main types of imperfections in the FDI algorithm, namely, (1) fault detection imperfection, that is when fault is not detected by the FDI algorithm, (2) fault isolation imperfection, that is when the fault is detected in the wrong channel or in the wrong agent, and (3) fault identification imperfection, that is when the fault estimation is not exact. We show that our proposed distributed reconfigurable controller can maintain the closed-loop networked EL systems stability under these scenarios and can improve the performance of the closed-loop system in the third scenario. Simulation results for the attitude control of a network of spacecraft demonstrate the effectiveness and capabilities of our proposed distributed reconfigurable control algorithm.