Fault tolerant control of active trailer steering systems for multi-trailer articulated heavy vehicles

Abstract

Faults in a controlled plant often deteriorate the system performance. In severe cases, faults pose a risk of component damage, plant shutdown or even personnel safety. Fault Tolerant Control (FTC) aims at preventing the escalation of rectifiable faults to serious failure. A FTC system combines fault diagnosis with reconfiguration methods to manage faults intelligently. This thesis focuses on FTC systems for Multi-Trailer Articulated Heavy Vehicles (MTAHVs), particularly for Active Trailer Steering (ATS) systems. MTAHVs are vital to the trucking industry, and it is crucial to enhance their safety, reliability and usability. In this research, a 4-DOF linear yaw-plane model of a B-Train double is generated. The vehicle model is validated using the commercial software package, TruckSim. Additionally, this thesis presents an ATS system for the B-Train double. The ATS mechanism is modeled as a hydraulic control system, consisting of a hydraulic actuator and an electrohydraulic control valve. The hydraulics for the ATS system are validated using MathWorks Simscape. To enhance the hydraulic control system’s robustness and reliability, FTC is applied. Numerous model-based fault diagnosis techniques such as Kalman Filter, Luenberger Observer, parity equations and residual generation are employed. Furthermore, for the control system synthesis, Linear Quadratic Regulator (LQR) and H∞ control techniques are utilized. Control techniques’ influence on FTC is analyzed, and the most appropriate technique is proposed for the FTC-ATS control system. Several fault scenarios, such as actuator malfunction(s) and sensor failure are explored, and their impact on system dynamics is investigated.