Abstract: An analytical methodology for the specification of progressive optimal compression damping of a suspension system to negotiate severe events, yet provides very acceptable ride quality and handling during routine events. In a broad aspect, the method provides a progressive optimal unconstrained damping response of the wheel assembly with respect to the body. In a preferred aspect, the method provides a progressive optimal constrained damping response of the wheel assembly with respect to the body, wherein below a predetermined velocity a conventional damper force is retained.

Abstract: A system and method for estimating vehicle side-slip velocity that includes measuring the lateral acceleration of the vehicle, measuring the yaw rate of the vehicle, measuring the longitudinal speed of the vehicle and measuring the steering angle of the vehicle. The measured longitudinal speed is corrected to provide a true longitudinal speed using a filter factor based on the vehicle-dependent parameters and a steering angle. A constant is defined based on the measured longitudinal speed and a function is defined based on the combination of the vehicle-dependent parameters and the lateral acceleration. Side-slip acceleration is calculated using the measured lateral acceleration, the true longitudinal speed, the yaw rate, the constant and the function.

Abstract: A command interpreter for a vehicle stability enhancement system that uses a three degree-of-freedom vehicle model employing non-linear suspension and tire characteristics to calculate stability commands. The command interpreter includes a calculator that calculates a front tire lateral force, a calculator that calculates a rear tire lateral force and a command calculator that calculates a yaw-rate command signal, a lateral velocity command signal and a roll angle command signal. The front tire lateral force calculator and the rear tire lateral force calculator calculate the front and rear side-slip angles. The side-slip angles are then converted to a lateral force, where the conversion is selected based on the tire vertical load. The rear tire lateral force is modified for high side-slip angles so that the rear tire lateral force does not become saturated.

Abstract: A rollover avoidance system for changing the damping characteristics of suspension dampers at each wheel of a vehicle so as to mitigate the potential for vehicle rollover. The system includes a plurality of vehicle parameter sensors for measuring vehicle parameters and providing vehicle parameter signals. The system also includes a controller for generating a damper suspension command signal for each damper using the vehicle parameter signals. The controller considers a roll control factor representing a rollover condition of the vehicle and a yaw stability control factor representing a yaw condition of the vehicle to set the damping of the dampers to mitigate the potential for vehicle rollover.