On the Stability and Agility of Aggressive Vehicle Maneuvers: A Pendulum-Turn Maneuver Example

We present a dynamic stability and agility study of a pendulum-turn vehicle maneuver. Instead of optimizing the controlled inputs to mimic expert human driver performance, we focus on understanding the stability and agility performance of the vehicle motion using professional racing car driver testing data. We propose to use the rear side slip angle, rather than the vehicle mass center side slip angle, as one state variable to obtain the precise stable region. A hybrid physical/dynamic tire/road friction model is used to capture the dynamic friction force characteristics. We also introduce the use of vehicle lateral jerk and acceleration information as the agility metrics to compare maneuvering performance under the racing car driver and a typical human driver. The analysis and testing results show that during the pendulum-turn maneuvers, the professional driver operates the vehicle outside the stable regions of the vehicle dynamics to achieve superior agility performance than that under typical human driver control. Comparison results also show that the racing car driver outperforms in both the traveling time and the agility metrics. It is ongoing work to design a control strategy for autonomous aggressive maneuvers by using the new stability and agility results presented in this paper.