Abstract: A system and method for determining vehicle CG height and mass in real-time. The method includes selecting a set of vehicle parameters to be considered that includes the vehicle mass and the center of gravity height of the vehicle. Frequency responses are generated using the dynamic model and a plurality of different values for the selected vehicle parameters. During vehicle operation, frequency responses are calculated from a measured vehicle lateral acceleration to a roll angle and/or a roll rate of the vehicle. The generated frequency responses and the calculated frequency responses are compared to determine which of the generated frequency responses more closely matches the calculated frequency responses. The generated frequency responses that most closely match the calculated frequency responses are used to determine the center of gravity height and the vehicle mass from the values for the vehicle parameters.

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 system and method for identifying a vehicle driver using a portable electronic device that the driver may be carrying that transmits a unique identification signal, and then using the identification of the driver to automatically put vehicle devices and systems in a desirable pre-set location for that driver. In one embodiment, the portable device is a wireless device employing Bluetooth communications protocol that wirelessly transmits an identification signal received by the vehicle to identify the driver. In another embodiment, the device is a USB device that is plugged into an appropriate USB port in the vehicle that allows the vehicle to identify the driver by the identified signal from the portable device.

Abstract: A method is provided for initiating a parking maneuver for parallel parking a vehicle between a first object and a second object. A target parking space is measured. A determination is made whether the measured target parking space is sufficient to allow an autonomous parallel parking maneuver. A region of feasible starting locations is determined to successfully perform the parallel parking maneuver between the first object and the second object if the available parking space is sufficient. A position of a midpoint of a rear axle is determined in relation to the designated region. A determination is made whether the midpoint of the rear axle is within the designated region. A driver of the vehicle is signaled in response to an instantaneous location of the midpoint of the rear axle vehicle being a feasible starting location to initiate the parallel parking maneuver.

Abstract: An active front-wheel vehicle steering control system that employs closed-loop control includes an adaptive compensation sub-system that compensates for changes in vehicle dynamic parameters. The control system includes a dynamic parameter estimation sub-system that provides an estimated front cornering compliance and rear cornering compliance based on a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal. The closed-loop control includes active gain for each of vehicle yaw rate, yaw acceleration, side-slip and side-slip rate, all based on the vehicle speed and vehicle dynamic parameter changes for use in generating a steering angle control signal to the front wheels of the vehicle.

Abstract: A system and method for providing a vehicle roll stability indicator that estimates the propensity for vehicle rollover. The system determines vehicle kinematics from vehicle sensors, such as roll rate, yaw rate, lateral acceleration, vehicle speed, etc. From these kinematic values, the system estimates a roll angle of the vehicle and a bank angle of the vehicle. From the estimated bank angle, the system provides a corrected roll angle. From the corrected roll angle, the system determines a roll energy of the vehicle and a roll energy rate of the vehicle. From the roll energy and the roll energy rate, the system calculates a roll stability indicator that defines the potential that the vehicle will tip-up or roll over. From the roll stability indicator, vehicle stability control systems can take suitable action.

Abstract: A method is provided for determining a vehicle path for autonomously parallel parking a vehicle in a space between a first object and a second object. A distance is remotely sensed between the first object and the second object. A determination is made whether the distance is sufficient to parallel park the vehicle between. A first position to initiate a parallel parking maneuver is determined. A second position within the available parking space corresponding to an end position of the vehicle path is determined. A first arc shaped trajectory of travel is determined between the first position and an intermediate position, and a second arc shaped trajectory of travel is determined between the second position and the intermediate position. The first arc shaped trajectory is complementary to the second arc shaped trajectory for forming a clothoid which provides a smoothed rearward steering maneuver between the first position to the second position.

Abstract: A system and method for providing a vehicle roll stability indicator that dynamically estimates the probability for vehicle rollover. The system determines vehicle kinematics from various vehicle sensors. From these kinematic values, the system estimates a roll angle of the vehicle and a bank angle of the vehicle. The estimated bank angle is used to correct the roll angle. The system determines a roll energy of the vehicle and a roll energy rate of the vehicle from the corrected roll angle. The system also calculates a tire lateral load transfer of the relative forces on the vehicle tires, and the duration that any of the tires have been off of the ground. From the roll energy, the roll energy rate, the tire lateral load transfer and the wheel airborne duration, the system calculates the roll stability indicator.

Abstract: An active front-wheel vehicle steering control system that employs closed-loop control includes an adaptive compensation sub-system that compensates for changes in vehicle dynamic parameters. The control system includes a dynamic parameter estimation sub-system that provides an estimated front cornering compliance and rear cornering compliance based on a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal. The closed-loop control includes active gain for each of vehicle yaw rate, yaw acceleration, side-slip and side-slip rate, all based on the vehicle speed and vehicle dynamic parameter changes for use in generating a steering angle control signal to the front wheels of the vehicle.

Abstract: A method is provided for controlling a parallel parking of a vehicle. A distance between the first object and the second object is remotely sensed. The distance is compared to a first predetermined distance and a second predetermined distance. An autonomous first steering strategy maneuver is performed for parking the vehicle between the first object and second object if the distance is greater than the first predetermined distance. The first steering strategy maneuver consists of a first predetermined number of steering cycles for parking the vehicle. An autonomous second steering strategy maneuver is performed for parking the vehicle between the first and second object if the distance is between the first predetermined distance and the second predetermined distance. The second steering strategy maneuver consists of a second predetermined number of steering cycles for parking the vehicle where the second is greater than the first predetermined number of steering cycles.

Abstract: An active front-wheel vehicle steering control system that employs closed-loop control includes an adaptive compensation sub-system that compensates for changes in vehicle dynamic parameters. The control system includes a dynamic parameter estimation sub-system that provides an estimated front cornering compliance and rear cornering compliance based on a steering wheel angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal. The closed-loop control includes active gain for each of vehicle yaw rate, yaw acceleration, side-slip and side-slip rate, all based on the vehicle speed and vehicle dynamic parameter changes for use in generating a steering angle control signal to the front wheels of the vehicle.

Abstract: A system and method for determining vehicle CG height and mass in real-time. The method includes selecting a set of vehicle parameters to be considered that includes the vehicle mass and the center of gravity height of the vehicle. Frequency responses are generated using the dynamic model and a plurality of different values for the selected vehicle parameters. During vehicle operation, frequency responses are calculated from a measured vehicle lateral acceleration to a roll angle and/or a roll rate of the vehicle. The generated frequency responses and the calculated frequency responses are compared to determine which of the generated frequency responses more closely matches the calculated frequency responses. The generated frequency responses that most closely match the calculated frequency responses are used to determine the center of gravity height and the vehicle mass from the values for the vehicle parameters.

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.

Abstract: A system and method for estimating vehicle roll rate and roll angle. The system includes a suspension deflection sensor provided at each wheel of the vehicle that provides suspension measurement signals indicative of the roll of the vehicle. The system also includes a roll rate estimator that uses the suspension measurement signals and an estimated tire deflection of the wheels to provide a roll rate estimation signal. The system also includes a vehicle roll angle and a roll rate estimator that uses the roll rate estimation signal and a dynamic model to estimate the roll angle and refine the roll rate. The roll rate estimator calculates the roll rate one way if none of the vehicle wheels are off of the ground and calculates it another way if any of the wheels are off of the ground.

Abstract: An active front steering (AFS) system that provides hand-wheel damping. The AFS system includes a damping control sub-system that determines a hand-wheel angular velocity based on the rate of change of a hand-wheel angle signal. The damping control sub-system determines the damping control signal by multiplying the angular velocity of the hand-wheel angle signal with a control gain. The damping control signal is added to a steering signal from a variable gear ratio control sub-system to generate a steering command signal. The damping control sub-system sets to the damping control signal to zero if a signal from a vehicle stability enhancement sub-system is activated.

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: An active front-wheel vehicle steering control system that employs open-loop control that includes an adaptive compensation sub-system that compensate for changes in vehicle dynamic parameters. The control system includes a dynamic parameter estimation sub-system that provides an estimated understeer coefficient based on a front-wheel steering angle signal, a vehicle lateral acceleration signal, a vehicle yaw rate signal and a vehicle speed signal. An open-loop control sub-system generates a steering angle control signal for controlling steering of the front wheels using a combination of a nominal open-loop steering angle control signal and a corrected open-loop steering angle control signal that is based on a real-time estimated understeer coefficient.

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.

Abstract: A system and method for estimating vehicle roll rate and roll angle. The system includes a suspension deflection sensor provided at each wheel of the vehicle that provides suspension measurement signals indicative of the roll of the vehicle. The system also includes a roll rate estimator that uses the suspension measurement signals and an estimated tire deflection of the wheels to provide a roll rate estimation signal. The system also includes a vehicle roll angle and a roll rate estimator that uses the roll rate estimation signal and a dynamic model to estimate the roll angle and refine the roll rate. The roll rate estimator calculates the roll rate one way if none of the vehicle wheels are off of the ground and calculates it another way if any of the wheels are off of the ground.