Abstract: The present invention provides a method and system to use feedback control algorithms to monitor and dynamically modify front and rear braking torque to initiate braking based on driver demand, initially favoring regenerative braking more than conventional braking balance would indicate while monitoring and maintaining vehicle controllability factors such as oversteer and understeer. A simple proportional-integral-derivative feedback controller can be used. Vehicle sensors for wheel speed, lateral acceleration, yaw rate, and brake position can provide input to the controller to monitor vehicle conditions and to activate non-regenerative and regenerative braking in varying proportions based on at least one actual vehicle controllability value and predetermined target value for controllability and optimization of energy recovery. Controllability factors can include predetermined longitudinal wheel slip ratios or a comparison of tire slip angle or yaw rate to a target value.

Abstract: A method and apparatus for overcoming negative torque transfer in a passive coupling (43) in a vehicle (10) having all wheel drive. The vehicle (10) includes a front driveshaft (22), a rear driveshaft (26), with the passive coupling (43) connecting the front driveshaft (22) and the rear driveshaft (26). The vehicle (10) also includes a transmission (30) operatively connected to the passive coupling (43). The method includes determining negative torque transfer in the passive coupling (43) and requesting the vehicle (10) to increase transmission output equal to the negative torque transfer.

Abstract: A method of operating a hydraulic safety system 38 includes determining a relative roll angle, determining a relative a slip angle, determining a yaw rate and determining a pressure build rate for the hydraulic safety system 38 in response to a relative roll angle, the yaw rate, slip angle, and yaw rate. The method further includes determining a precharge pressure level in response to the relative roll rate, the slip angle and the yaw rate and controlling the safety system 38 in response to the precharge pressure level.

Abstract: A system 18 for controlling a safety system of an automotive vehicle has a first controller 76 generating a first control signal, a second controller 78 generating a second control signal and an arbitration module 80 coupled to the first controller 76 and the second controller 78. The arbitration module 80 chooses the higher of the first control signal and the second control signal to generate a final control signal. The safety system 38 is coupled to the arbitration module. The safety system 38 is operated in response to the final control signal.

Abstract: A method of controlling a safety system 38 of a vehicle 10 include determining a roll rate, determining a first control pressure in response to roll rate, determining a roll angle, and determining a second control pressure in response to the roll angle. The method further includes determining a final control pressure in response to the first control pressure and the second control pressure and controlling the safety system in response to the final control pressure.

Abstract: A control system (18) for an automotive vehicle (10) has a first roll condition detector (64A), a second roll condition detector (64B), a third roll condition detector (64C), and a controller (26) that uses the roll condition generated by the roll condition detectors (64A-C) to determine a wheel lift condition. Other roll condition detectors may also be used in the wheel lift determination. The wheel lift conditions may be active or passive or both.

Abstract: A control system (18) and method for an automotive vehicle (10) used for detecting lift of a wheel includes a speed sensor (20) coupled to the wheel producing a wheel speed signal and a torque control system (57) coupled to the wheel for generating an operating input torque to the wheel. A controller (26) is coupled to the torque control system (57) and the wheel speed sensor (20). The controller (26) determines a wheel response to the operating input torque and generates a wheel lift signal as a function of the operating input torque, the wheel speed signal and the wheel response.

Abstract: A method and system (18) for determining a side slip angle for an automotive vehicle (10) includes various sensors such as a yaw rate sensor (28), a speed sensor (20), a lateral acceleration sensor (32), a roll rate sensor (34), a steering angle sensor (35), and a longitudinal acceleration sensor (36). Each of the sensors are coupled to a controller (26) that determines a side slip angle velocity in response to the sensor signals. The side slip angle velocity is compensated for due to gravity and vehicle attitude changes. Also, the side slip angle velocity is compensated for due to the non-linearity of the side slip angle. The side slip angle velocity is integrated, preferably with an anti-drift integration filter (to determine an integrated side slip angle). A steady state side slip angle is also determined based on the sensors such as the yaw rate sensor and the lateral acceleration sensor. The steady state side slip angle is filtered using a steady state recovery filter (74).

Abstract: A control system (18) for an automotive vehicle (10) having a vehicle body includes a sensor system (16) having housing (52) oriented within the vehicle body. Positioned within the housing (52) are a roll angular rate sensor (31), a yaw angular rate sensor (30), a pitch angular rate sensor (32), a lateral acceleration sensor (27), a longitudinal acceleration sensor (28), and a vertical acceleration sensor (29). The vehicle (10) also has a safety system (38). The controller (26) determines a roll misalignment angle, a pitch misalignment angle and a yaw misalignment angle as a function of the sensor outputs of the roll rate, the pitch rate, the yaw rate, the lateral acceleration, the longitudinal acceleration and the vertical acceleration.

Abstract: A control system (18) has a roll angular rate sensor (34), a yaw angular rate sensor (28), a lateral acceleration sensor (32), a longitudinal acceleration sensor (36), and four wheel speed sensors (20). The controller (26) determines a relative pitch angle and relative roll angle using the lateral acceleration signal, the longitudinal acceleration signal and the roll rate signal; a first flatness index using the roll angular rate signal, the yaw angular rate signal, the relative roll angle and a relative pitch angle; a steady state pitch angle using the vehicle speed and the longitudinal acceleration, and a steady state roll angle using the lateral acceleration, speed, and yaw rate. The controller (26) determines a second flatness index using the steady state pitch angle, the relative pitch angle, the yaw rate, the steady state roll angle and a relative roll angle.

Abstract: The present invention is a method and system to control regenerative braking during the operation of a yaw stability control system. The method and system can use feedback control algorithms to monitor and dynamically modify regenerative and non-regenerative braking. The controller can use a simple proportional-integral-derivative feedback controller. A vehicle yaw stability control system can determine if a vehicle is experiencing an oversteer or understeer condition. The controller compares actual brake balance to a desired brake balance. The controller determines if the front axle wheels are overbraked relative to the rear axle wheels or if the rear axle wheels are overbraked relative to the front axle wheels as compared to the desired brake balance. The controller can adjust regenerative braking and non-regenerative braking levels according to the determinations.

Abstract: A stability control system (24) for an automotive vehicle includes a plurality of sensors sensing the dynamic conditions of the vehicle. The controller (26) is coupled to the sensors. The controller (26) determines a road surface coefficient of friction, calculates a maximum slip angle based on the road surface coefficient of friction, determines a calculated side slip angle in response to measured dynamic vehicle conditions, and reduces a steering wheel actuator angle when the calculated side slip angle is greater than the maximum slip angle.

Abstract: A yaw stability control system (18) is enhanced to include roll stability control function for an automotive vehicle and includes a plurality of sensors (28-39) sensing the dynamic conditions of the vehicle. The sensors may include a speed sensor (20), a lateral acceleration sensor (32), a yaw rate sensor (28) and a longitudinal acceleration sensor (36). The controller (26) is coupled to the speed sensor (20), the lateral acceleration sensor (32), the yaw rate sensor (28) and a longitudinal acceleration sensor (36). The controller (26) generates both a yaw stability feedback control signal and a roll stability feedback control signal. The priority of achieving yaw stability control or roll stability control is determined through priority determination logic. If a potential rollover event is detected, the roll stability control will take the priority.

Abstract: An apparatus for determining lateral velocity of an automotive vehicle (10) includes a vehicle speed sensor (20), a roll rate sensor (34), a yaw rate sensor (28), a lateral acceleration sensor (32), and a longitudinal acceleration sensor (36). A controller (26) is coupled to the sensors and determines a steady state pitch angle and a steady state roll angle as a function of the lateral acceleration signal, the longitudinal acceleration signal, the yaw rate signal, and the vehicle speed signal. The controller determines a sliding index as a function of the steady state pitch signal, the steady state roll angle, and the roll rate signal. The controller (26) determines lateral velocity as a function of the sliding index and controls the vehicle lateral motion based on the estimated lateral velocity.

Abstract: A stability control system (18) for an automotive vehicle includes a plurality of sensors (28-39) sensing the dynamic conditions of the vehicle. The sensors may include a speed sensor (20), a lateral acceleration sensor (32), a roll rate sensor (34), a yaw rate sensor (20) and a longitudinal acceleration sensor (36). The controller (26) is coupled to the speed sensor (20), the lateral acceleration sensor (32), the roll rate sensor (34), the yaw rate sensor (28) and a longitudinal acceleration sensor (36). The controller (26) has an anti-integration drift filter and a steady state recovery filter. The controller determines a roll attitude angle, a pitch attitude angle and a yaw attitude angle in response to the roll angular rate signal, the yaw angular rate signal, the lateral acceleration signal, the longitudinal acceleration signal, the wheel speed signal, the anti-integration drift filter and the steady state recovery filter.

Abstract: A method and apparatus for overcoming negative torque transfer in a passive coupling (43) in a vehicle (10) having all wheel drive. The vehicle (10) includes a front driveshaft (22), a rear driveshaft (26), with the passive coupling (43) connecting the front driveshaft (22) and the rear driveshaft (26). The vehicle (10) also includes a transmission (30) operatively connected to the passive coupling (43). The method includes determining negative torque transfer in the passive coupling (43) and requesting the vehicle (10) to increase transmission output equal to the negative torque transfer.

Abstract: A stability control system (24) for an automotive vehicle as includes a plurality of sensors (28-37) sensing the dynamic conditions of the vehicle and a controller (26) that controls a distributed brake pressure to reduce a tire moment so the net moment of the vehicle is counter to the roll direction. The sensors include a speed sensor (30), a lateral acceleration sensor (32), a roll rate sensor (34), and a yaw rate sensor (20). The controller (26) is coupled to the speed sensor (30), the lateral acceleration sensor (32), the roll rate sensor (34), the yaw rate sensor (28). The controller (26) determines a roll angle estimate in response to lateral acceleration, roll rate, vehicle speed, and yaw rate. The controller (26) changes a tire force vector using brake pressure distribution in response to the relative roll angle estimate.

Abstract: A system and method for detecting wheel lift of an automotive vehicle includes a yaw rate sensor (28) that generates a yaw rate signal, a lateral acceleration sensor (32) that generates a lateral acceleration signal, a roll rate sensor (34) generating a roll rate signal, and a longitudinal acceleration sensor (36) for generating a longitudinal acceleration signal. A controller (18) is coupled to the yaw rate sensor (28), the lateral acceleration sensor (32), the roll rate sensor (34), and the longitudinal acceleration sensor (36). The controller determines a dynamic load transfer acting on the plurality of wheels as a function of yaw rate, lateral acceleration roll rate, and longitudinal acceleration. Normal forces for each of the plurality of wheels is determined as a function of the dynamic load transfer. Wheel lift is indicated when at least one of the normal forces for each of the plurality of wheels is less than a normal force threshold.

Abstract: A control system (13) for an automotive vehicle (10) includes a longitudinal accelerometer (24) that generates a longitudinal acceleration signal corresponding to a longitudinal acceleration of a center of gravity (COG) of the vehicle body. A lateral velocity sensor (22) generates a lateral velocity signal corresponding to the lateral velocity of the vehicle body. A controller (14) is coupled to the yaw rate sensor (18), the longitudinal accelerometer (24) and the lateral velocity sensor (22). The controller (14) determines a longitudinal speed from the longitudinal acceleration signal. The controller determines a vehicle pitch angle in response to the longitudinal speed, the yaw rate signal and the lateral velocity signal.

Abstract: A method and system (18) for determining a side slip angle for an automotive vehicle (10) includes various sensors such as a yaw rate sensor (28), a speed sensor (20), a lateral acceleration sensor (32), a roll rate sensor (34), a steering angle sensor (35), and a longitudinal acceleration sensor (36). Each of the sensors are coupled to a controller (26) that determines a side slip angle velocity in response to the sensor signals. The side slip angle velocity is compensated for due to gravity and vehicle attitude changes. Also, the side slip angle velocity is compensated for due to the non-linearity of the side slip angle. The side slip angle velocity is integrated, preferably with an anti-drift integration filter (to determine an integrated side slip angle). A steady state side slip angle is also determined based on the sensors such as the yaw rate sensor and the lateral acceleration sensor. The steady state side slip angle is filtered using a steady state recovery filter (74).