Fault-tolerant control under controller-driven sampling using virtual actuator strategy

TL;DR

This paper introduces a fault-tolerant control method for continuous-time linear systems that uses a virtual actuator strategy combined with controller-driven sampling to maintain stability and performance during actuator faults.

Contribution

It extends VA-based controller reconfiguration to systems with controller-driven sampling, ensuring stability and setpoint tracking under faults and varying sampling rates.

Findings

Maintains stability under varying sampling rates and faults.

Ensures setpoint tracking in fault conditions.

Extends VA-based reconfiguration to controller-driven sampling.

Abstract

We present a new output feedback fault tolerant control strategy for continuous-time linear systems. The strategy combines a digital nominal controller under controller-driven (varying) sampling with virtual-actuator (VA)-based controller reconfiguration to compensate for actuator faults. In the proposed scheme, the controller controls both the plant and the sampling period, and performs controller reconfiguration by engaging in the loop the VA adapted to the diagnosed fault. The VA also operates under controller-driven sampling. Two independent objectives are considered: (a) closed-loop stability with setpoint tracking and (b) controller reconfiguration under faults. Our main contribution is to extend an existing VA-based controller reconfiguration strategy to systems under controller-driven sampling in such a way that if objective (a) is possible under controller-driven sampling (without VA) and objective (b) is possible under uniform sampling (without controller-driven sampling), then closed-loop stability and setpoint tracking will be preserved under both healthy and faulty operation for all possible sampling rate evolutions that may be selected by the controller.