Abstract: A system and a method for determining when to update a surface estimation value indicative of a condition of a roadway surface are provided. The method includes determining a front axle cornering force error value based on a predicted front axle cornering force value and a first front axle cornering force value. The method further includes determining a threshold yaw rate error value based on the front axle cornering force error value. The method further includes indicating that the surface estimation value is to be updated when a yaw rate error value is greater than the threshold yaw rate error value.

Abstract: A technique for determining a slip angle of a motor vehicle, while compensating for bank angle of the motor vehicle, includes a number of steps. Initially, a first lateral velocity of a motor vehicle is determined, without consideration of a bank angle and is derived from an integral of a first lateral velocity derivative (vy dot). A second lateral velocity of the motor vehicle is also determined, with consideration of the bank angle and is derived from an integral of a second lateral velocity derivative. A third lateral velocity of the motor vehicle is also determined, with consideration of the bank angle and the first and second lateral velocities and is derived from an integral of a third lateral velocity derivative. A longitudinal velocity of the motor vehicle is also determined. A slip angle of the motor vehicle is then determined, based upon the third lateral velocity and the longitudinal velocity or the first lateral velocity and the longitudinal velocity.

Abstract: A control system for controlling a brake system of a braked vehicle during a turn, the vehicle having four wheels. The control system is configured to selectively modify a brake pressure applied to each of the wheels by the brake system. The control system is configured to receive a driver input relating to a brake pressure sought to be applied. The control system includes a controller for monitoring a slip status of each of the four wheels during a turn. The controller is configured to direct the brake system to independently increase, decrease, or hold the brake pressure applied to each of the four wheels based at least in part upon slip status of each respective wheel. The controller is configured to direct the brake system to modify the brake pressure applied to each of the wheels such that the brake pressure applied to a given wheel of the four wheels is always equal to or less than the brake pressure sought to be applied.

Abstract: The invention provides a method for controlling a vehicle with a braking system including a modulator pump. A first fluid line can communicate brake fluid from the master cylinder to a brake caliper. An isolation valve including a pressure bypass can be disposed along the fluid line between the master cylinder and the brake caliper. A second fluid line can extend from a first position along the first fluid line between the master cylinder and the isolation valve to a second position along the first fluid line between the isolation valve and the brake caliper. A modulating pump is disposed along the second fluid line to pump fluid to the brake caliper during a controlled brake event. The modulator pump is engaged to pump fluid to the brake caliper until the pressure in the first fluid line reached slightly below the predetermined pressure to prevent the isolation valve from opening in response to excessive pressure.

Abstract: A control system for controlling a brake system of a vehicle during a turn, the vehicle having four wheels. The brake system is configured to selectively control brake pressure to each of the wheels and includes a controller for monitoring a slip status of each of the four wheels during a turn. The controller is configured to direct the brake system to independently increase, decrease, or hold the brake pressure applied to each of the four wheels based at least in part upon slip status of each respective wheel.

Abstract: A method is directed to controlling a differential within an active antilock brake system. The method provides for receiving a secondary axle wheel speed, receiving a vehicle speed, determining a difference value between the vehicle speed and the secondary axle wheel speed, and activating the differential responsive to the difference value. The step of activating the differential responsive to the difference value may include steps for comparing the difference value to a threshold value and activating the differential based on the comparison.

Abstract: A system and method of controlling a brake system of a vehicle comprising determining a coefficient condition; determining vehicle yaw; determining a driver's corrective action; and determining a brake pressure control response based on the coefficient condition, vehicle yaw and the driver's corrective action.

Abstract: A method is directed to controlling a differential within an active antilock brake system. The method provides for receiving a secondary axle wheel speed, receiving a vehicle speed, determining a difference value between the vehicle speed and the secondary axle wheel speed, and activating the differential responsive to the difference value. The step of activating the differential responsive to the difference value may include steps for comparing the difference value to a threshold value and activating the differential based on the comparison.

Abstract: A brake circuit comprises a master cylinder in communication with a front wheel brake, and in communication with a rear wheel brake through a hydraulic line. A sensor senses pressure in the master cylinder, and an electronic control unit in communication with the sensor controls an apply valve to proportion pressure between the front wheel brake and the rear wheel brake.

Abstract: A system and method for ABS stability control is provided, the method comprising the steps of determining whether a first wheel is in an ABS mode; determining whether the first wheel is in an apply mode; determining whether a second parallel wheel is in the release mode; calculating an adjusted wheel slip if the first wheel is in the ABS mode, the first wheel is in the apply mode, and the second parallel wheel is in the release mode; and determining a control mode for the first wheel using the adjusted wheel slip.

Abstract: A system and method for ABS stability control is provided, the method comprising the steps of determining whether a first wheel is in an ABS mode; determining whether the first wheel is in an apply mode; determining whether a second parallel wheel is in the release mode; calculating an adjusted wheel slip if the first wheel is in the ABS mode, the first wheel is in the apply mode, and the second parallel wheel is in the release mode; and determining a control mode for the first wheel using the adjusted wheel slip.

Abstract: A system and method of vehicle stability enhancement control during ABS operation, the method comprising the steps of determining whether ABS mode is active; determining whether VSE is required; calculating a target wheel speed for each wheel if ABS mode is active and VSE is required; calculating an adjusted wheel slip for each wheel by subtracting the wheel speed for each wheel from the target wheel speed for each wheel and dividing the difference by the target wheel speed for each wheel; and determining an ABS control mode for each wheel using the adjusted wheel slip. The method further provides the step of calculating the target wheel speed for each wheel, in which the step of calculating the target wheel speed for each wheel further comprises adding a VSE modification term for each wheel to the vehicle speed to calculate the target wheel speed.

Abstract: A system and method for ABS stability control is provided, the method comprising the steps of determining whether a first wheel is in an ABS mode; determining whether the first wheel is in an apply mode; determining whether a second parallel wheel is in the release mode; calculating an adjusted wheel slip if the first wheel is in the ABS mode, the first wheel is in the apply mode, and the second parallel wheel is in the release mode; and determining a control mode for the first wheel using the adjusted wheel slip.

Abstract: A system and method of vehicle stability enhancement control during ABS operation, the method comprising the steps of determining whether ABS mode is active; determining whether VSE is required; calculating a target wheel speed for each wheel if ABS mode is active and VSE is required; calculating an adjusted wheel slip for each wheel by subtracting the wheel speed for each wheel from the target wheel speed for each wheel and dividing the difference by the target wheel speed for each wheel; and determining an ABS control mode for each wheel using the adjusted wheel slip. The method further provides the step of calculating the target wheel speed for each wheel, in which the step of calculating the target wheel speed for each wheel further comprises adding a VSE modification term for each wheel to the vehicle speed to calculate the target wheel speed.

Abstract: A system and method for ABS stability control is provided, the method comprising the steps of determining whether a first wheel is in an ABS mode; determining whether the first wheel is in an apply mode; determining whether a second parallel wheel is in the release mode; calculating an adjusted wheel slip if the first wheel is in the ABS mode, the first wheel is in the apply mode, and the second parallel wheel is in the release mode; and determining a control mode for the first wheel using the adjusted wheel slip.