Comparison of optimal driving policies for limit handling manoeuvres

2011-04-27T15:06:47Z (GMT) by T.J. Gordon Matt C. Best
This paper concerns the synthesis of optimal control inputs for automotive handling dynamics, a typical application being in the evaluation of active safety systems operating near the limits of friction. The paper considers an example of an emergency limit handling manoeuvre – combined acceleration and steering to achieve obstacle avoidance whilst also maximising speed and maintaining stability. Two independent methods are applied to the problem. The first is a general numerical optimiser for nonlinear control systems (Generalised Optimal Control, or GOC). The second is an indirect Dual Model (DM) method, which has the advantage that no differential analysis of the vehicle model is required, and it can therefore be applied directly to a wide range of complex multibody dynamic models. A relatively low-order handling model is actually used within this study, since this allows comparison between the two methods and an evaluation of the general usefulness of the DM approach in the future.