Implementation of an Embedded Control System for Electronically Adjustable Suspension in a Formula Student Racing Car

Abstract

Good road handling is one of the most important characteristics of a racing car. To expand the capabilities of conventional suspension setups, the usage of adaptive suspension has become increasingly popular in high performance cars. Advancements in electronics and embedded technology has allowed such systems to be implemented with little weight gain over conventional suspension. The Formula Student team Revolve NTNU therefore wishes to implement a system for adaptive suspension on their car - the KA Aquilo R. A previous prestudy by the same author has evaluated the feasibility of such a solution, and proposed a top level design for an embedded control system. This thesis will present the design, implementation and testing of a distributed embedded system to control a continuously controlled electronic suspension(CES). Based on the top level design proposed in the prestudy, a complete hardware design has been prepared for the system. The system was distributed into a Central Controller Unit, and Wheel Controller Units for each damper. A complete set of prototype system units has also been implemented, by the help of electronics manufacturer SimPro. The implemented hardware design has been tested and verified to be working.Furthermore, a software implementation for the system's units has been implemented. For the Central Controller Unit a execution framework has been implemented, to allow the development of controller algorithm to be continued easily. The wheel controller units has implemented necessary software to control damping parameters of each shock absorber, according to supervisory control signals sent by the Central Controller. A common communication protocol to interconnect the CES system with the other electronic systems of Revolve's car has also been implemented.Some elementary tests has also been performed to verify the performance of the system. The result is a a prototype system that may be used for evaluation of concept and on-car performance.