Abstract: Relative center of gravity height in a motor vehicle changes from a nominal value to an actual value depending upon vehicle loading. Method and apparatus for determining actual relative center of gravity height are disclosed.

Abstract: A sun visor that includes a clear base portion and a small shade portion that can be selectively moved to block only the sun depending on its orientation. In one embodiment, the shade portion is manually movable relative to the base portion. In another embodiment, the shade portion is automatically moved relative to the base portion by an actuator. A controller calculates the vehicle heading and the sun-incident angle to determine the proper position of the shade portion. A switch can be used to switch the actuator on when the visor is in the down position. In an alternate embodiment, the shade portion is replaced with electro-chromic elements mounted to the base portion that are controlled to selectively block the sunlight.

Abstract: Brake pedal input is modulated to produce a consistent relationship between the brake pedal input and a deceleration of the vehicle.

Abstract: A system and method that warn a vehicle driver by shaking or dithering the steering wheel that one or more active control systems on the vehicle is providing active control. The system includes an AFS actuator for providing a steering assist signal for stability control purposes, and a VES actuator for providing resistance against turning of the steering wheel. The system also includes a controller for causing the AFS actuator to shake the steering wheel if the active control is active and for causing the VES controller to apply and release tension to the steering wheel if the steering wheel is turned and the active control is active. The controller may increase the shaking of the steering wheel as the amount of the active control increases.

Abstract: A system and method that warn a vehicle driver by shaking or dithering the steering wheel that one or more active control systems on the vehicle is providing active control. The system includes an AFS actuator for providing a steering assist signal for stability control purposes, and a VES actuator for providing resistance against turning of the steering wheel. The system also includes a controller for causing the AFS actuator to shake the steering wheel if the active control is active and for causing the VES controller to apply and release tension to the steering wheel if the steering wheel is turned and the active control is active. The controller may increase the shaking of the steering wheel as the amount of the active control increases.

Abstract: A side-slip velocity estimation module for a vehicle stability enhancement control system includes a side-slip acceleration estimation module that estimates a side-slip acceleration of a vehicle. A multiple-order integrator integrates the side-slip acceleration to generate an estimated side-slip velocity of the vehicle. A reset logic module clears an output of the multiple-order integrator when the vehicle experiences a straight-driving condition, when a speed of the vehicle is less than a predetermined speed, and/or when a sensor bias condition occurs. The multiple-order integrator includes at least two accumulators and at least two feedback loops. The estimated side-slip velocity is a weighted sum of outputs of at least one of the at least two accumulators. A sum of the at least two feedback loops offsets the estimated side-slip acceleration.

Abstract: An AFS control system that combines and weights yaw rate feedback and side-slip rate feedback to provide increased vehicle stability enhancement control. The AFS system includes a yaw rate sub-system that generates a desired yaw rate signal. The AFS system also includes a side-slip rate sub-system that generates a desired side-slip rate feedback signal. The AFS system further includes a side-slip rate feedback sub-system that generates a side-slip rate feedback signal. The AFS system also includes a yaw rate feedback sub-system that generates a yaw rate feedback signal. The yaw rate feedback signal and the side-slip rate feedback signal are integrated in a control integration sub-system that generates a stability enhancement control signal. The control integration sub-system determines whether the vehicle is in an oversteer or understeer condition, and weights the desired yaw rate feedback signal accordingly based on the vehicle condition.

Abstract: A vehicle-trailer back-up control system that employs an active front steer sub-system. The system includes a smart hitch controller that receives a vehicle speed signal and a hand-wheel angle signal, and calculates a hitch angle command signal. The system further includes a hitch angle sensor that measures the hitch angle between the vehicle and the trailer that is compared to the hitch angle command signal to generate a hitch angle error signal. A PID control unit receives the hitch angle error signal, and generates a corrected road wheel angle signal based on proportional and derivative gains. The corrected road wheel angle signal is used to generate a motor angle signal that is applied to a steering actuator to be combined with the steering angle signal to generate the front wheel steering signal during a back-up maneuver.

Abstract: A control system that employs closed-loop control for providing active vehicle rear-wheel steering, where the control system receives longitudinal wheel slip inputs to improve the vehicle directional stability. The longitudinal wheel slip inputs can be from one or more of wheel speed, traction control on and automatic braking system on. The control system includes an open-loop controller for generating an open-loop steering control signal, a yaw rate feedback controller for generating a yaw rate feedback signal, and a side-slip rate controller for generating a side-slip rate feedback signal. The open-loop steering control signal, the yaw rate feedback signal and the side-slip rate feedback signal are combined to generate the steering control signal to steer the vehicle rear wheels.

Abstract: A vehicle stability enhancement system for a vehicle having at least one vehicle subsystem includes at least one sensor for sensing at least one vehicle parameter, at least one vehicle control system for adjusting the at least one vehicle subsystem wherein the at least one vehicle control system includes a rear wheel steering control system, at least one memory including at least one set of gain factors, and a controller responsive to the at least one sensor and the at least one set of gain factors for controlling the at least one vehicle control system.

Abstract: A side-slip velocity estimation module for a vehicle stability enhancement control system includes a side-slip acceleration estimation module that determines an estimated side-slip acceleration of a vehicle. A limited-frequency integrator integrates the estimated side-slip acceleration to determine an estimated side-slip velocity of the vehicle. The limited-frequency integrator includes a feedback loop which incorporates a cutoff frequency for the integrator.

Abstract: A side-slip velocity estimation module for a vehicle stability enhancement control system includes a side-slip acceleration estimation module that determines an estimated side-slip acceleration of a vehicle. A limited-frequency integrator integrates the estimated side-slip acceleration to determine an estimated side-slip velocity of the vehicle. A reset logic module clears an output of the limited-frequency integrator when a first condition occurs. The first condition is one of a straight-driving condition, a speed condition, and a sensor bias condition. The estimated side-slip velocity is compared to a desired side-slip velocity to produce a side-slip control signal. The side-slip control signal is combined with a yaw rate control signal to produce an actuator control signal. The actuator control signal is received by one of at least one brake actuator and a rear-wheel steering actuator to create a yaw moment to correct a dynamic behavior of the vehicle.

Abstract: A vehicle stability enhancement system for a vehicle having a vehicle subsystem includes a sensor for sensing a vehicle parameter, a vehicle control system for adjusting the vehicle subsystem, a memory having a register that includes a bank angle compensation control command, and a controller responsive to the sensor and the memory for controlling the vehicle control system.

Abstract: A side-slip velocity estimation module for a vehicle stability enhancement control system includes a side-slip acceleration estimation module that determines an estimated side-slip acceleration of a vehicle. A limited-frequency integrator integrates the estimated side-slip acceleration to determine an estimated side-slip velocity of the vehicle. A reset logic module clears an output of the limited-frequency integrator when a first condition occurs. The first condition is one of a straight-driving condition, a speed condition, and a sensor bias condition. The estimated side-slip velocity is compared to a desired side-slip velocity to produce a side-slip control signal. The side-slip control signal is combined with a yaw rate control signal to produce an actuator control signal. The actuator control signal is received by one of at least one brake actuator and a rear-wheel steering actuator to create a yaw moment to correct a dynamic behavior of the vehicle.

Abstract: A vehicle stability enhancement system for a vehicle having at least one vehicle subsystem includes at least one sensor for sensing at least one vehicle parameter, at least one vehicle control system for adjusting the at least one vehicle subsystem wherein the at least one vehicle control system includes a rear wheel steering control system, at least one memory including at least one set of gain factors, and a controller responsive to the at least one sensor and the at least one set of gain factors for controlling the at least one vehicle control system.

Abstract: A vehicle stability enhancement system for a vehicle having a vehicle subsystem includes a sensor for sensing a vehicle parameter, a vehicle control system for adjusting the vehicle subsystem, a memory having a register that includes a bank angle compensation control command, and a controller responsive to the sensor and the memory for controlling the vehicle control system.

Abstract: A brake system control for use in a vehicle with four wheels comprising the steps of: determining a desired yaw rate (454); determining a yaw torque command responsive to the desired yaw rate (806); if the vehicle is in an anti-lock braking mode during driver commanded braking, applying the yaw torque command to only one of the four wheels to release brake pressure in said one of the four wheels (258-266, 274, 278, 280, 410-418); if the vehicle is in a positive acceleration traction control mode during driver commanded acceleration, applying the yaw torque command to only one of the four wheels to apply brake pressure in said one of the four wheels (258-266, 288-292, 410-418); and if the vehicle is not in the anti-lock braking mode or in the positive acceleration traction control mode, then: (i) determining whether a vehicle brake pedal is depressed (370); (ii) if the vehicle brake pedal is depressed, applying brake force to the vehicle wheels responsive to the depression of the brake pedal (374, 412, 418), w

Abstract: Before braking occurs the speed of non-driven wheels is monitored and averaged to determine vehicle speed and an integrator is initialized with that speed. Acceleration is periodically calculated from the vehicle speed, stored in a ring buffer and averaged. The output of a chassis accelerometer is also sampled during the same periods and stored in a similar ring buffer and averaged. Accelerometer bias due to slope or drift is determined as the difference of the two averaged accelerations. The noise level of the accelerometer bias is determined by filtering and rectification. After braking occurs, the accelerometer output is corrected by subtracting the bias and the noise and is then used to continuously update the integrator output to provide an estimate of vehicle speed during braking.

Abstract: A rotary encoder capable of detecting angular rotation of a rotating shaft, and identifying its neutral position without the need for multiple encoder wheels. A magnetoresistive sensor is positioned adjacent the periphery of a single multipole magnet ring attached to a steering wheel shaft. The magnet ring comprises alternating N-pole and S-pole magnetic regions along its periphery, the surface of one of the regions containing a demagnetized portion. The sensor produces a sinusoidal signal as the shaft is rotated, responsive to the passage of the magnetic regions, with a period equal to the passage of two successive magnetic regions adjacent the sensor. The angular position of the shaft which aligns the demagnetized portion adjacent the sensor corresponds to the shaft's neutral position. Aligning of the demagnetized portion adjacent the sensor causes a voltage irregularity within the sensor's otherwise sinusoidal output signal, which is detected by a signal processing circuit.

Abstract: A vehicle accelerometer measures vehicle acceleration and provides acceleration data subject to contamination by noise signals. The acceleration data is filtered by a filter. A predetermined function of the noise level in the acceleration data is compared with the filter error which is the difference between raw acceleration data and the filtered value of acceleration. When the filter error is less than the noise level, the filter time constant is set to establish a low cutoff frequency so that the filter rejects the noise like a conventional low pass filter. When the filter error becomes greater than the predetermined function of the noise level, the filter time constant is set to establish a higher cutoff frequency so that the filtered value of acceleration converges to the ideal value faster than would occur with the filter having the lower cutoff frequency.