Abstract: A vehicle stability system for a vehicle. In an embodiment the vehicle stability system includes a yaw rate sensor, an acceleration sensor, a steering sensor, a torque request sensor, and a controller. The controller is configured to receive an output of the yaw rate sensor, the lateral acceleration sensor, the steering sensor, and the torque request sensor, generate a torque signal and a braking signal, and transmit the torque signal to a differential in addition to transmitting the braking signal to a braking system.

Abstract: A system and method for estimating vehicle lateral velocity that defines a relationship between front and rear axle lateral forces and front and rear axle side-slip angles. The method includes providing measurements of vehicle yaw-rate, lateral acceleration, longitudinal speed, and steering angle. The method also includes using these measurements to provide a measurement of the front and rear axle forces. The method calculates a front axle lateral velocity and a rear axle lateral velocity, and calculates a front axle side-slip angle based on the rear axle lateral velocity and a rear axle side-slip angle based on the front axle lateral velocity. The method then estimates front and rear axle forces, and selects a virtual lateral velocity that minimizes an error between the estimated and measured lateral axle forces. The method then provides an estimated vehicle lateral velocity using the selected virtual lateral velocity.

Abstract: A method is provided for estimating vehicle velocity for a vehicle using a single-antenna global positioning system (GPS). An absolute speed and a course angle of the vehicle is measured using the single-antenna GPS. The yaw rates of the vehicle are measured independently of the GPS. An integrated yaw rate of the vehicle is calculated as a function of the measured yaw rates over a period of time. A yaw angle is determined as a function of a reference yaw angle and the integrated yaw rate. Aside slip angle is calculated as a function of the estimated yaw angle and the course angle provided by the GPS. The vehicle velocity is determined as a function of the absolute speed and the side slip angle. The vehicle velocity is provided to a vehicle dynamic control application.

Abstract: A system and method for estimating vehicle lateral velocity that defines a relationship between front and rear axle lateral forces and front and rear axle side-slip angles. The method includes providing measurements of vehicle yaw-rate, lateral acceleration, longitudinal speed, and steering angle. The method also includes using these measurements to provide a measurement of the front and rear axle forces. The method calculates a front axle lateral velocity and a rear axle lateral velocity, and calculates a front axle side-slip angle based on the rear axle lateral velocity and a rear axle side-slip angle based on the front axle lateral velocity. The method then estimates front and rear axle forces, and selects a virtual lateral velocity that minimizes an error between the estimated and measured lateral axle forces. The method then provides an estimated vehicle lateral velocity using the selected virtual lateral velocity.

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 vehicle includes wheels, force sensors adapted for a vertical force and lateral force of each wheel, an onboard device, and a controller. The controller calculates vehicle values using the vertical force and lateral force, compares the values to a corresponding threshold, and automatically deploys the device when each element value does not exceed a corresponding threshold. A method for determining when to deploy an airbag includes measuring a vertical and lateral force at each wheel, and measuring a yaw rate and roll angle. A lateral velocity is calculated using the lateral force, and a lift of each wheel is calculated using the vertical force. The roll angle, roll rate, and stopping time are processed to generate a point on a 3D rollover plane. A rollover energy rate is calculated, and the airbag deploys when the point, rollover energy rate, and lift do not exceed a threshold.

Abstract: In a rollover stability method for a vehicle in a situation which is critical with respect to the driving dynamics, a critical rollover situation is detected by analyzing a control variable and the stabilization intervention is activated or de-activated as a function of the control variable. The regulation intervention is maintained even in driving situations featuring relatively low transverse acceleration if the control variable or a characteristic property of the stability algorithm is calculated as a function of the steering angle and/or the longitudinal vehicle velocity.

Abstract: A system and method is provided for determining a lateral velocity and a longitudinal velocity of a vehicle equipped. The vehicle includes only one antenna for a GPS receiver and a magnetic compass. A magnitude of a velocity vector of the vehicle is determined. A course angle with respect to a fixed reference using the single antenna GPS receiver is determined. A yaw angle of the vehicle is measured with respect to the fixed reference using a magnetic compass. A side slip angle is calculated as a function of the course angle and the yaw angle. The lateral velocity and longitudinal velocity is determined as a function of the magnitude of the velocity vector and the side slip angle.

Abstract: A method of stabilizing a vehicle is provided. The vehicle is travelling at a forward speed and a lateral speed, and comprises a lateral acceleration sensor, a yaw sensor adapted to detect an actual yaw rate of the vehicle around a central axis, a steering mechanism adapted to steer the vehicle by a steered yaw rate, and an electronic stability control system.

Abstract: A system and method for estimating vehicle lateral velocity that defines a relationship between front and rear axle lateral forces and front and rear axle side-slip angles. The method includes providing measurements of vehicle yaw-rate, lateral acceleration, longitudinal speed, and steering angle. The method also includes using these measurements to provide a measurement of the front and rear axle forces. The method calculates a front axle lateral velocity and a rear axle lateral velocity, and calculates a front axle side-slip angle based on the rear axle lateral velocity and a rear axle side-slip angle based on the front axle lateral velocity. The method then estimates front and rear axle forces, and selects a virtual lateral velocity that minimizes an error between the estimated and measured lateral axle forces. The method then provides an estimated vehicle lateral velocity using the selected virtual lateral velocity.

Abstract: A system and method for estimating surface coefficient of friction in a vehicle system. The method includes providing a kinematics relationship between vehicle yaw-rate, vehicle speed, vehicle steering angle and vehicle front and rear axle side-slip angles that is accurate for all surface coefficient of frictions on which the vehicle may be traveling. The method defines a nonlinear function for the front and rear axle side-slip angles relating to front and rear lateral forces and coefficient of friction, and uses the nonlinear function in the kinematics relationship. The method also provides a linear relationship of the front and rear axle side-slip angles and the front and rear lateral forces using the kinematics relationship. The method determines that the vehicle dynamics have become nonlinear using the linear relationship and then estimates the surface coefficient of friction when the vehicle dynamics are nonlinear.

Abstract: A system and method for estimating vehicle lateral velocity. The method uses a kinematic estimator constructed as a closed-loop Leunberger observer. The kinematic estimator is based on a kinematic relationship between lateral acceleration measurement and rate of change of lateral velocity. The method provides measurement updates based on virtual lateral velocity measurements from front and rear axle lateral force versus axle side-slip angle tables using the lateral acceleration, yaw-rate, longitudinal speed, and steering angle measurements. The method calculates front and rear axle lateral forces from the lateral acceleration and yaw-rate measurements. The method estimates front and rear axle side-slip angles from the calculated front and rear axle lateral forces using the tables.

Abstract: A method for estimating the normal force at a wheel of a vehicle and the vertical acceleration of the vehicle that has particular application for ride and stability control of the vehicle. The method includes obtaining a suspension displacement value from at least one of a plurality of suspension displacement sensors mounted on the vehicle and estimating a spring force acting on a spring of a suspension element of the vehicle, a damper force acting on a damper of the suspension element of the vehicle, and a force acting at a center of a wheel. The method further includes determining a normal force at the wheel of the vehicle and a vertical acceleration of the vehicle based on the spring force, the damper force and the force at the center of the wheel of the vehicle.

Abstract: A system and method for estimating vehicle lateral velocity and surface coefficient of friction using front and rear axle lateral force versus side-slip angle tables and sensor measurements. The sensor measurements include lateral acceleration, yaw-rate, longitudinal speed and steering angle of the vehicle. The method includes calculating front and rear axle lateral forces and front and rear side-slip angles on the axles of the vehicle. The method also includes identifying two equations from the calculated lateral forces and the vehicle measurements. The method provides tables that identify a relationship between the calculated front and rear axle lateral forces and the front and rear side-slip angles, and determines the vehicle lateral velocity and surface coefficient of friction from the tables.

Abstract: A method for road bank detection that has particular application in vehicle stability control systems and vehicle roll-over avoidance systems. The method for detection of a road bank includes obtaining a yaw rate value and a front and/or rear axle force value for a vehicle travelling on the road. It further includes comparing the obtained vehicle yaw rate value with a corresponding predetermined vehicle yaw rate value to obtain a vehicle yaw rate error value and comparing the obtained vehicle front and/or rear axle force value with a corresponding predetermined vehicle front and/or rear axle force value to obtain a vehicle front and/or rear axle force error value, and detecting the road bank based on the obtained vehicle yaw rate error value and the vehicle front and/or rear axle force error value.

Abstract: A system and method for facilitating ride and stability control of a vehicle. The system includes a plurality of suspension displacement sensors, with each of the plurality of suspension displacement sensors positioned proximate to a suspension element of the vehicle. The system further includes a nonlinear filter for filtering out a wheel hop frequency from the suspension velocity corresponding to at least one of the plurality of suspension displacement sensors to obtain a resultant suspension velocity. The resultant suspension velocity is used by a control unit to determine the pitch velocity, roll velocity and the heave velocity of the vehicle.

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 analytical methodology for the specification of progressive optimal compression damping of a damper of a suspension system to negotiate a multiplicity of severe events, yet provides very acceptable ride quality and handling during routine events. The damping response of the damper is optimized based upon a progressive optimal constrained events damping function derived from a low envelope curve incorporated with a predetermined damper force acting on the wheel center below a predetermined wheel center velocity, u1, based on ride and handling considerations for a given vehicle or vehicle model according to the prior art methodology, whereby the low envelope curve is constructed utilizing a one degree of freedom nonlinear mechanical system model or a quarter car nonlinear mechanical system model.

Abstract: A method that detects whether the vibration level of the wheel is within the resonating frequency range by utilizing discrete velocity measurements. The method includes continuously measuring velocity levels of a wheel relative to a sprung mass vehicle component. These measurements are continuously recorded over a period of time. A periodic algorithm is provided, and the periodic algorithm and the velocity measurements are utilized to determine an output value. The output value is utilized to determine whether the vibration level of the wheel is within the resonating frequency range.

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.