Multiobjective performance optimisation of a new differential steering concept

Abstract

Differential steering is an emerging steering concept based on traction force differences between left and right sides of vehicles equipped with independently actuated wheels. Actually, this concept is only used to support classical vehicle designs utilising rack and pinion steering components. However, it may fully substitute such devices to reduce complexity and cut down costs. Since we do not have well-established design rules for such kind of vehicles, this paper will overcome the missing experience and explore the general applicability of such a new steering concept by using multiobjective optimisation. Three design objectives and three constraints are defined with respect to the dynamic, steady-state and low-speed steering performance of the vehicle. Since mechanical and control parts are strongly coupled, their parameters are optimised simultaneously by a multiobjective genetic algorithm aided by iteratively updated neural network-based response surface metamodels. Optimisation results in a variety of technically feasible Pareto-optimal designs. Investigation of a particular optimal design shows that a vehicle with differential steering is able to provide convincing steering performance.