Abstract: An electric power steering system for a vehicle includes a motor for providing assistance in turning the wheels of the vehicle. The motor is electrically connected to a controller. The controller includes a power device, such as a power transistor, electrically connected to the motor to variably provide electric power to the motor as needed. The controller also includes a gate drive device electrically connected to the power device for regulating operation the power device. A shutdown mechanism is electrically connected between the gate drive device and a power input. In the event of a fault, the shutdown mechanism isolates electrical power from the gate drive device. This prevents the power device from providing electric power to the power steering motor.

Abstract: The present invention relates to a method for controlling the response of an electric steering system by implementing damping for over-speed conditions, the method comprising the steps of determining the velocity of an electric motor comprised within the electric steering system, and determining a voltage limit value, wherein the voltage limit value is calculated as a function of the velocity of the electric motor. The method further comprises the steps of associating the voltage limit value with a motor voltage command in order to produce a limited voltage command, and applying the limited voltage command to the motor in order to provide a braking torque to the motor.

Abstract: A belt tensioner apparatus is provided for a pulley assembly having an input pulley rotatably connected to an output pulley via a flexible belt. The tensioner apparatus includes a belt contact device engaged with a first portion of the belt and also engaged with a second portion of the belt different from the first portion of the belt. The belt contact device is coupled to a base so as to enable movement of the belt contact device with respect to the base, such that the belt contact device moves against the second portion of the belt responsive to a tension force created in the first portion of the belt by rotation of the input pulley, to create a tension force in the second portion of the belt.

Abstract: A vehicle steering device may include a rotatable input shaft, a motor in communication with an input augmentation shaft, the input augmentation shaft and the input shaft sharing a longitudinal axis, and the motor further having a stator stationary with respect to rotation of the input shaft. The vehicle steering device may further include a differential mechanism for providing variable ratio steering to the steering device. The differential mechanism may be a harmonic drive differential or a planetary gearing system. In one embodiment, an external wave generator may be used within the harmonic drive differential gearing mechanism. The vehicle steering device may include a sensorless synchronous machine.

Abstract: A method and system for estimating a parameter of an electric machine, including a controller and a switching device, the controller executes a parameter estimation process, which is responsive to at least one of: a current value and a torque command and the resultant of the parameter estimation process representing an estimated parameter of the electric machine. The parameter estimation includes a method for estimating a temperature of the electric machine comprising: a temperature sensor operatively connected to and transmitting a temperature signal corresponding to a measured temperature to a controller, which executes a temperature estimation process responsive to a temperature signal from a temperature sensor.

Abstract: A system and a method for controlling a steering position of at least one rear wheel of a vehicle are provided. The vehicle has both a brushless electric motor with a plurality of electrical phase windings and a steering actuator. The brushless electric motor has a rotor configured to drive the steering actuator. The steering actuator is operably coupled to at least one rear vehicle wheel. The method includes determining a desired voltage value indicative of about one-half of a peak-to-peak voltage to be applied to each of the plurality of electrical phase windings of the brushless electric motor based on a desired rear vehicle wheel steering angle and a measured rear vehicle wheel steering angle. The method further includes determining when the desired voltage value is greater than a threshold voltage level. The method further includes calculating a phase advance angle based on at least the desired voltage value and the threshold voltage level.

Abstract: A method and system for estimating a parameter of an electric machine, including a controller and a switching device, the controller responsive to at least one of: a current sensor, and a temperature sensor. Where the controller executes a parameter estimation process, which is responsive to at least one of: a current value, a torque command and the resultant of the parameter estimation process representing an estimated parameter of the electric machine. The parameter estimation includes a method for estimating a temperature of the electric machine comprising: a temperature sensor operatively connected to and transmitting a temperature signal corresponding to a measured temperature to a controller, which executes a temperature estimation process responsive to a temperature signal from a temperature sensor.

Abstract: Disclosed herein is a method and system for initializing a rotating device such as an electronically commutated electric machine. The system comprises: an electric machine; a position sensor subsystem operatively connected to the electric machine configured to measure a position and transmit a position signal to a controller. The controller executes a method initializing position for the electric machine, the method comprising: establishing a sensor subsystem datum indicative of a measurement reference point for a sensor subsystem; obtaining a calibration value corresponding to a distance to a selected magnetic reference position for the electric machine, relative to the sensor subsystem datum; and measuring a position and calculating a position delta relative to an initial reference. The method also includes: estimating an offset from the sensor subsystem datum to an initial reference; determining an absolute position estimate of the electric machine relative to the magnetic reference position.

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 herein is a method and system for initializing a rotating device such as an electronically commutated electric machine. The system comprises: an electric machine; a position sensor subsystem operatively connected to the electric machine configured to measure a position and transmit a position signal to a controller. The controller executes a method initializing position for the electric machine, the method comprising: establishing a sensor subsystem datum indicative of a measurement reference point for a sensor subsystem; obtaining a calibration value corresponding to a distance to a selected magnetic reference position for the electric machine, relative to the sensor subsystem datum; and measuring a position and calculating a position delta relative to an initial reference. The method also includes: estimating an offset from the sensor subsystem datum to an initial reference; determining an absolute position estimate of the electric machine relative to the magnetic reference position.

Abstract: A method and system for estimating a parameter of an electric machine, including a controller and a switching device, the controller responsive to at least one of: a current sensor, and a temperature sensor. Where the controller executes a parameter estimation process, which is responsive to at least one of: a current value, a torque command and the resultant of the parameter estimation process representing an estimated parameter of the electric machine. The parameter estimation includes a method for estimating a temperature of the electric machine comprising: a temperature sensor operatively connected to and transmitting a temperature signal corresponding to a measured temperature to a controller, which executes a temperature estimation process responsive to a temperature signal from a temperature sensor.

Abstract: A method and system for estimating a parameter of an electric machine, including a controller and a switching device, the controller executes a parameter estimation process, which is responsive to at least one of: a current value and a torque command and the resultant of the parameter estimation process representing an estimated parameter of the electric machine. The parameter estimation includes a method for estimating a temperature of the electric machine comprising: a temperature sensor operatively connected to and transmitting a temperature signal corresponding to a measured temperature to a controller, which executes a temperature estimation process responsive to a temperature signal from a temperature sensor.

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 control system for electric power steering develops a desired operator exerted steering torque command independent of operator exerted torque, compares that command to a measure of actual operator exerted steering torque and controls an electric motor providing electric power steering assist to minimize the difference between the desired operator exerted steering torque command and the actual operator exerted steering torque.

Abstract: An electric circuit board has a current trace thereon and a notch in the edge and an opening therethrough on opposite sides of the trace. A magnetic sensor is retained in the opening; and a flux member retained by the notch and opening forms a magnetic circuit around the current trace to concentrate current induced flux through the magnetic sensor. The flux member is made of a ductile magnetic material and is therefore easy to manufacture and handle without breakage compared to prior art ferrite flux members. It is also resilient so as to permit a "snap-on" design for ease of assembly with positive retention of the flux member on the board and of the magnetic sensor within the opening with minimal series air gap. The flux member further has high internal eddy current and hysteresis losses for inherent high frequency filtering to reduce aliasing distortion in sensor output to digital apparatus when applied to a measurement of PWM motor current.