On the model-based design of front-to-total anti-roll moment distribution controllers for yaw rate tracking

Abstract

In passenger cars active suspensions have been traditionally used to enhance comfort through body control, and handling through the reduction of the tyre load variations induced by road irregularities. However, active suspensions can also be designed to track a desired yaw rate profile through the control of the anti-roll moment distribution between the front and rear axles. The effect of the anti-roll moment distribution relates to the nonlinearity of tyre behaviour, which is difficult to capture in the linearised vehicle models normally used for control design. Hence, the tuning of anti-roll moment distribution controllers is usually based on heuristics. This paper includes an analysis of the effect of the lateral load transfer on the lateral axle force and cornering stiffness. A linearised axle force formulation is presented, and compared with a formulation from the literature, based on a quadratic relationship between cornering stiffness and load transfer. Multiple linearised vehicle models for control design are assessed in the frequency domain, and the respective controllers are tuned through optimisation routines. Simulation results from a nonlinear vehicle model are discussed to analyse the performance of the controllers, and show the importance of employing accurate models of the lateral load transfer effect during control design.

On the Energy Efficiency Potential of Multi-Actuated Electric Vehicles

“…The variation of 𝑓, achievable through AS systems, has a nonlinear effect on the cornering response, i.e., the level of understeer in steady-state and transient conditions, and thus on the tire slip power losses. Only the recent literature [31] has proposed accurate models for the design of front-to-total antiroll moment distribution controllers. The involved relationships cannot be described by explicit formulations.…”

Nonlinear Model Predictive Control for Integrated Energy-Efficient Torque-Vectoring and Anti-Roll Moment Distribution

“…In parallel with the proposed NMPC, a benchmarking controller was implemented, based on independent proportional integral (PI) contributions for the actuation of the direct yaw moment and front-to-total anti-roll moment distribution. The tuning of the direct yaw moment contribution ensures desirable tracking performance and stability, according to the design method in [21], while the PI controller computing the front-to-total anti-roll moment distribution was designed according to the model based method recently proposed in [10] and [11].  The brake blending controller, defining the torque distribution between IWMs and friction brakes, by prioritizing brake regeneration within each corner.…”

“…Given the nonlinearity of the influence of the anti-roll moment distribution on vehicle dynamics, this kind of suspension controllers is usually empirically tuned. Very recent studies [11] have proposed linearized models for considering the effect of the anti-roll moment distribution on the cornering response.…”