Driver Warning Strategies for a Critical Cornering Maneuver

Other conference contribution, 2009

The hypothesis in this paper is that the involvement of the driver in mitigating vehicle instability would (i) require less control action from the active system and (ii) improve the overall performance by faster stabilization. Several indicators of instability during a lane-change type maneuver are developed to support a driver warning. First the focus is on indicators which are related to variables which are measured in vehicles equipped with stability control (ESC) systems. These indicators could trigger a warning for which the driver would have around one second to take corrective action. These indicators are compared to classical evaluation tools such as the moment method, phase portrait analysis and Lyapunov analysis. It is concluded that stability indicators based on side-slip rate and yaw acceleration give an early indication of possible instability. It is further shown that a combination of countersteer and ESC intervention triggered a quicker ESC intervention with a shorter duration. This is understood to show that a cooperation between the driver and the ESC system gives a better overall system performance.