Predictive Control for Systems with Loss of Actuator Effectiveness Resulting from Degradation Effects

Abstract

Predictive control is a promising strategy for the mitigation of faults that result in more stringent operational constraints on the inputs and outputs of a system. In this context, the present work proposes a predictive control approach for accommodation of faults associated with the loss of actuator effectiveness. More specifically, it is assumed that the actuator is subject to degradation effects with progress rate proportional to the control effort. The loss of effectiveness occurs when the degradation reaches an intermediate threshold between the nominal operating condition and the total failure of the actuator. The resulting predictive control law involves the solution of a mixed-integer programming problem to be solved at each sampling instant. By imposing a suitable terminal constraint, convergence to equilibrium and recursive feasibility of the input and state constraints are ensured, provided that the optimization problem is initially feasible. Simulation results are presented for illustration.

Review of Post-Prognostics Decision-Making in Prognostics and Health Management

“…The output RUL is then used to configure an adaptive controller. Vieira et al (Vieira, Galvão, & Yoneyama, 2015) proved the existing relationship between the degradation of the actuator and the loss of its effectiveness. They also used the results in the configuration of the LQR controller parameters.…”

“…They also used the results in the configuration of the LQR controller parameters. The results obtained in (Vieira et al, 2015), were used by Langeron et al in (Langeron, Grall, & Barros, 2015) to model a closed loop system that can fully implement the control law regardless of its degradation. The system is controlled by a LQR in which its parameters are adapted using the degradation level of the actuators through its RUL.…”

Enhancing Decisions in Prognostics and Health Management Framework

“…The partial decision duration or the duration between two stages of decision is an important parameter of the proposed framework. If this duration is reduced to be equal to the duration of a local decision, then the proposed framework is similar to the activities of real-time decision-making like in the case proposed by Zhang in (Zhang et al, 2014), or the automatic control decisions detailed by Pereira et al in (Pereira et al, 2010), Nguyen et al (Nguyen, Dieulle, & Grall, 2014) or by Vieira et al in (Vieira, Kawakami, Galvao, & Yoneyama, 2015) in which the dynamic of the RUL estimation is high. On the Opposite, if the duration of the partial decision is extended to be equal to the decision horizon duration, here the proposed framework is similar to the works that integrates a rolling horizon like the work of Van Horenbeek and Pintelon (Van Horenbeek & Pintelon, 2013), plus if we suppose that the PHM process will be executed only once, the framework will be treating the post-prognostic decision-making like the one presented by Herr et al in (Herr et al, 2014) or (Herr et al, 2017).…”

Joint maintenance and controller reconfiguration policy for a gradually deteriorating control system

“…Some papers share the same view on that subject. In Vieira et al, 18 the degradation increment is proportional to the control effort u ( t ) with a constant proportionality coefficient. The authors use the degradation information for designing a life extending control of a linear motion system.…”