Mechatronic Suspension Design for Vehicle Dynamic Performance Enhancement

This paper investigates the performance advantages of an mechatronic suspension strut for a road vehicle. Mechatronic struts have attracted growing research interest since the interior electrical circuit has the potential to realise the high-order impedances with sensible size and weight to achieve desirable performance. In addition, to deal with different driving conditions (speed and road roughness, for example) it is much more straightforward to adjust electrical element values in real-time compared with changing pure mechanical elements. To obtain the optimal mechatronic suspension design, a methodology is proposed by considering all possible design parameters and constraints such as nominal voltage and current for the motor maximum force acting on the ball-screw mechanism, and size and weight of the electrical elements. Based on a qualitative analysis of a proposed mechatronic strut, it is concluded that in order to achieve improved performance, the ball-screw needs to have small rotational inertia and large bearable force, and the motor should have small inertia, internal resistance, internal inductance and large nominal current and voltage. This qualitative analysis provides brief guideline for ball-screw and motor selection. Case studies are carried out with a quarter car model using two electrical candidate layouts. They show the potential performance advantages of the mechatronic strut using a motor with sufficiently large nominal current.