Design and Experimental Assessment of an Active Fault-Tolerant LPV Vertical Dynamics Controller

This article addresses the design of an active fault-tolerant full-vehicle semi-active suspension controller by linear parameter-varying (LPV) control methods. The restrictive force constraints of the semi-active damper are modeled by saturation indicator parameters and treated as scheduling parameters in the LPV design. The synthesized LPV controller is subsequently augmented by a damper force reconfiguration exploring the weak input redundancy provided by four dampers in a full-vehicle application. In this way, the controller compensates for damper forces lost in the case of saturation or failure by the remaining dampers. The performance of the proposed LPV controller is validated by experiments on a four-post test-rig. The results show the improved tradeoff between ride comfort and road-holding of the full-vehicle LPV controller compared with a quarter-vehicle LPV controller and a Skyhook-Groundhook controller

Damper Fault-Tolerant Linear Parameter-Varying Semi-Active Suspension Control

This paper addresses the design of a fault-tolerant semi-active suspension controller. The fault-tolerant properties of the controller are realized by an LPV anti-windup approach using saturation indicator scheduling parameters. The saturation indicators model the force limitations of the semi-active dampers in the LPV framework and thus allow for the synthesis of semi-active suspension controllers with guaranteed closed-loop stability and performance. Additionally, the saturation indicators readily describe damper failures like e.g. oil leakage which extends the controller validity from normal operation to faulty operation modes. This property of the saturation indicator concept is exploited by augmenting the LPV controller by a damper force reconfiguration which explores the weak input redundancy provided by four semi-active dampers. The damper force reconfiguration aims at a maximization of ride comfort performance in the presence of damper failures. The achievable ride comfort improvement is illustrated by a simulation study with a full-vehicle model excited by sine sweeps