Abstract: A method for implementing program execution integrity (PEI) for a communication-based sensor includes receiving an output communication message from the sensor, the output communication message including sensor output data internally processed within the sensor. The output communication message further includes raw data used by the sensor in internally processing the sensor output data. The raw data is independently processed, and the results thereof are compared with the internally processed sensor output data so as to verify the processing integrity of the sensor to a desired tolerance.

Abstract: A method directed to improving the stability of a motor vehicle having front and rear steering capabilities includes determining a coefficient of friction of the road surface with which the motor vehicle is engaged and adjusting a phase gain function of a rear steering mechanism to compensate for the steerability of the motor vehicle over the road surface. A system for improving the stability of a motor vehicle having front and rear steering capabilities includes a control unit, a front steering mechanism in informational communication with the control unit, and a rear steering mechanism in informational communication with the control unit. The rear steering mechanism is responsive through the control unit to road conditions of the road surface.

Abstract: Disclosed is a method for aligning a position sensor in a vehicle with steerable wheels comprising obtaining an absolute position value responsive to a position signal from a handwheel position sensor, obtaining a relative position value responsive to an encoder signal count from a position encoder, and obtaining an index position value responsive to an index position signal. The method further includes receiving an alignment enable signal and determining a correction factor responsive to the relative position value and the index position value. The method for aligning a position sensor is responsive to at least one of the absolute position value, the relative position value, and the index position value under conditions determined from the status of the alignment enable signal.

Abstract: A method for validating a signal indicative of a speed of a vehicle includes receiving a plurality of signals indicative of vehicle speed; correlating at least a first of the received signals with at least a second of the received signals to determine if either signal is invalid; and signaling a rejection of any signal found to be invalid.

Abstract: A method of swing out compensation in a vehicle with rear wheel steering, comprising: obtaining a zero speed status signal representative of when a vehicle is at zero speed; establishing a rear wheel angle threshold; obtaining a calculated rear wheel angle; and generating a commanded rear wheel angle responsive to the rear wheel angle threshold and the calculated rear wheel angle, whichever is of smaller magnitude. A swing out compensation system for a vehicle with rear wheel steering, the system comprising: a controller; and a rear steering mechanism in communication with and responsive to the controller; wherein the controller generates a commanded rear wheel angle responsive to one of a rear wheel angle threshold and a calculated rear wheel angle, whichever is of smaller magnitude.

Abstract: A vehicle steering system coupled to a steerable wheel, comprising a steering rack linked to said steerable wheel, an electric motor having an output shaft engaged with the steering rack for controlling the steerable wheel. The system also includes a position sensor configured to measure an actual steerable wheel angle of the steering rack and thereby the steerable wheel, a return spring, where the return spring is biased so as to provide a returning force to the steering rack. Finally, the system includes a controller that provides a command to the electric motor resulting in a torque, the command is responsive to the actual steerable wheel angle, a desired steerable wheel angle, and a command direction.

Abstract: A method for controlling a four-wheel steering system of a vehicle includes recognizing a driver-selectable mode, receiving a signal preferably indicative of a front wheel steering-angle, and determining a rear-to-front steering-angle ratio in correspondence with the recognized mode and the received signal; and optionally includes receiving a signal indicative of vehicle speed, recognizing a current system state, determining a desired steering-angle, generating a command based on the desired and received steering-angles and the recognized system state, and diagnosing conditions in accordance with the received signals in order to enter a output disable mode.

Abstract: A method directed to improving the stability of a motor vehicle having front and rear steering capabilities includes determining a coefficient of friction of the road surface with which the motor vehicle is engaged and adjusting a phase gain function of a rear steering mechanism to compensate for the steerability of the motor vehicle over the road surface. A system for improving the stability of a motor vehicle having front and rear steering capabilities includes a control unit, a front steering mechanism in informational communication with the control unit, and a rear steering mechanism in informational communication with the control unit. The rear steering mechanism is responsive through the control unit to road conditions of the road surface.

Abstract: A method for detecting a loss of motor control in an electric power steering system is disclosed. In an exemplary embodiment, the method includes determining a duty cycle of a steering command signal generated by a controller. The steering command signal commands a steering mechanism to be turned in either a first or a second direction, the second direction being opposite to the first direction. A steering velocity of the steering mechanism is determined, the steering velocity being characterized by a steering velocity magnitude and a steering velocity direction whenever the steering velocity is greater than zero. The steering velocity direction corresponds to either the first or the second direction. The duty cycle is then compared to a first selected value, and the steering velocity magnitude is compared to a second selected value.

Abstract: A vehicle steering system coupled to a steerable wheel, comprising a steering rack linked to said steerable wheel, an electric motor having an output shaft engaged with the steering rack for controlling the steerable wheel. The system also includes a position sensor configured to measure an actual steerable wheel angle of the steering rack and thereby the steerable wheel, a return spring, where the return spring is biased so as to provide a returning force to the steering rack. Finally, the system includes a controller that provides a command to the electric motor resulting in a torque, the command is responsive to the actual steerable wheel angle, a desired steerable wheel angle, and a command direction.

Abstract: A method for validating a signal indicative of a speed of a vehicle includes receiving a plurality of signals indicative of vehicle speed; correlating at least a first of the received signals with at least a second of the received signals to determine if either signal is invalid; and signaling a rejection of any signal found to be invalid.

Abstract: A method for detecting a loss of motor control in an electric power steering system is disclosed. In an exemplary embodiment, the method includes determining a duty cycle of a steering command signal generated by a controller. The steering command signal commands a steering mechanism to be turned in either a first or a second direction, the second direction being opposite to the first direction. A steering velocity of the steering mechanism is determined, the steering velocity being characterized by a steering velocity magnitude and a steering velocity direction whenever the steering velocity is greater than zero. The steering velocity direction corresponds to either the first or the second direction. The duty cycle is then compared to a first selected value, and the steering velocity magnitude is compared to a second selected value.

Abstract: Disclosed is a method for aligning a position sensor in a vehicle with steerable wheels comprising obtaining an absolute position value responsive to a position signal from a handwheel position sensor, obtaining a relative position value responsive to an encoder signal count from a position encoder, and obtaining an index position value responsive to an index position signal. The method further includes receiving an alignment enable signal and determining a correction factor responsive to the relative position value and the index position value. The method for aligning a position sensor is responsive to at least one of the absolute position value, the relative position value, and the index position value under conditions determined from the status of the alignment enable signal.

Abstract: A method for controlling a four-wheel steering system of a vehicle includes recognizing a driver-selectable mode, receiving a signal preferably indicative of a front wheel steering-angle, and determining a rear-to-front steering-angle ratio in correspondence with the recognized mode and the received signal; and optionally includes receiving a signal indicative of vehicle speed, recognizing a current system state, determining a desired steering-angle, generating a command based on the desired and received steering-angles and the recognized system state, and diagnosing conditions in accordance with the received signals in order to enter a output disable mode.

Abstract: Disclosed is a method of swing out compensation in a vehicle with rear wheel steering, comprising: obtaining a zero speed status signal representative of when a vehicle is at zero speed; establishing a rear wheel angle threshold; obtaining a calculated rear wheel angle; and generating a commanded rear wheel angle responsive to the rear wheel angle threshold and the calculated rear wheel angle, whichever is of smaller magnitude.

Abstract: Disclosed is a method of determining an estimate of zero speed of a vehicle, the method comprises obtaining or acquiring a drive train status signal, a brake signal, a parking brake signal, a vehicle speed signal, and a throttle position signal. The method further comprises formulating a zero speed status signal under selected conditions to in response to at least one of the abovementioned signals.