Fault-Tolerant Networked Control Systems Using Control Allocation for Failures in Multiple Control Surfaces

Abstract

In this paper, the methodology of a CA (Control Allocation) based FTNCS (Fault-Tolerant Networked Control System) is proposed. Control allocation is a control surface management technique by redistributing the redundant control surfaces in overactuated systems. In modern high performance aircrafts, they adopt many redundant control surfaces to provide high performance and to satisfy various tactical requirements. Moreover, redundant control surfaces provide an opportunity to compensate performance degradation due to failures in more than one actuator by re-allocating redundant control surfaces. Simulation results with an F-18 HARV demonstrate that the proposed CA based FTNCS can achieve a fast and accurate tracking performance even in the presence of actuator faults.

Networked Fault-Tolerant Control Allocation for Multiple Actuator Failures

“…where B V ∈ R × with ≤ is a full column rank matrix. Then the control allocation problem (CAP) can be stated as follows [9,10].…”

“…From the FTCAP, the reconfiguration law finds the suitable control inputs corresponding to the virtual inputs generated by the controller. Hence, the reconfiguration law can be designed by adding two inputs: (a) the normal control inputs that satisfy the CAP in (10) and (b) the additional inputs that can tolerate the degraded performance due to failures. The following theorem proposes the method of designing the reconfiguration inputs.…”

“…However, adopting redundant actuators takes disadvantages of fuel-, space-, cost-, and weightinefficiency during normal operation. In contrast to adopting redundant actuators, techniques based on control theory have been proposed for last 30 years: for example, pseudoinverse [1], model reference adaptive control [2], sliding mode control [3], multiple model switching and tuning [4], control allocation [5][6][7][8][9][10], and so forth. The goal of these methods is to provide the feasible control input for a faulty system by reconfiguring a controller.…”

“…Recent advances in network communication provide opportunities to transmit failure-information data among controllers, actuators, and sensors by interconnecting the control nodes through fieldbus network such as CAN and FlexRay [9,10,12,13]. The control system interconnected by network is defined as networked control system (NCS).…”

Reconfiguration Criterion for Fault-Tolerant Control

“…For this reason, these methods are defined as fault-tolerant control (FTC) or reconfiguration. There have been proposed various fault-tolerant control techniques: pseudoinverse [1], model reference adaptive control [2], sliding mode control [3][4][5], multiple model switching and tuning [6], control allocation [3,[7][8][9][10], and so forth.…”