A Virtual Fuzzy Actuator for the Fault-tolerant Control of a Rescue Vehicle

Abstract

This paper intends to present a novel and promising application field for fuzzy logic: the realization of fuzzy virtual actuators. In the field of control and diagnosis, virtual sensors are successfully applied since several years. This kind of sensor applies a mathematical model and different sources of information, for instance the state of actuators or information from already existing sensors, in order to generate virtual measurements. Current research activities aim at complementing the concept of virtual sensors with the concept of virtual actuators. Virtual actuators are parts of a fault-tolerant control strategy and aim to accommodate faults and to achieve a safe operation of a faulty plant. So far, only few authors report the application of fuzzy logic to the concept of virtual actuators and this application is limited on a representation of the non-linear system with the Takagi-Sugeno fuzzy model. In the focus of this paper is a novel fuzzy virtual actuator which applies fuzzy rules in order to include experts knowledge. The application example is a rescue vehicle. The application of fuzzy logic rules allows to integrate experts knowledge into the decision making of the virtual actuator in the control system of the vehicle. It enables the accommodation of several possible faults, such as a slippery surface under one of the chains of the rescue vehicle.