Trw Limited

Trw Automotive U.S. LLC

Engelbert Lu

Kevin M McLaughlin

Jeremy Gonyou

Kevin Mclaughlin

An improved structure for a torque sensor assembly adapted for use in a vehicle steering system and method for producing the same. According to one embodiment, the torque sensor assembly includes a housing formed from a suitable material having a cavity; at least one flux concentrator and at least one hall effect IC disposed in the cavity of the housing; and a cover secured to the housing to close the cavity in the housing in a permanent and fluid-tight manner.

Torque sensor assembly and method for producing same

The steering angle of a vehicle is monitored using position sensors of an electric motor of an electric power assisted steering (EPAS) system. A position of the electric motor corresponding to the straight-ahead, center position of the steering system is stored in non-volatile memory during a steering calibration procedure, such as an end-of-line calibration in a vehicle assembly plant. Following power loss due to a dead battery, a steering angle zeroing procedure performed in a vehicle stability control (VSC) system generates a center position with enough accuracy to be within one electrical cycle of the motor. The pre-stored electric motor position is then used to determine the electrical cycle where the center position was located, and accurate monitoring of steering angle is resumed.

Recovery of calibrated center steering position after loss of battery power

An apparatus ( ) for controlling an electric motor ( ) having a plurality of motor phases includes a motor controller ( ) that controls energization of each phase of the plurality of motor phases. A compensation circuit ( ) is associated with each phase of the plurality of motor phases. The compensation circuit ( ) of one phase of the plurality of motor phases adjusts a control parameter of another phase of the plurality of motor phases an amount functionally related to an electrical characteristic of the one phase in response to determining a diminished operating characteristic of the one phase.

Apparatus and method for controlling an electric motor

A motor controller includes a summing circuit (186) for summing a motor current command signal (i.sub.rcmd) with a motor current feedback signal (i.sub.s) and for providing an error current command signal (.DELTA.i.sub.cmd) having a value functionally related to the difference between the motor current command signal and the motor current feedback signal. A notch filter (200) filters the error current command signal and provides a filtered current command signal. The notch filter (200) is adapted to notch out frequencies from the error current command signal about the resonant frequency of a motor (28). A drive circuit (120, 204) energizes the motor (28) in response to the filtered current command signal. A motor current sensor (97) is used for sensing motor current and providing the motor current feedback signal (i.sub.s).

Electric assist steering system having an improved motor current

A motor controller controls the operation of an electric motor (28). The motor controller includes sensors (30, 97, 102) for sensing at least one dynamic operating characteristic of the motor and for providing a signal indicative of the at least one sensed dynamic motor operating characteristic. A variable gain regulator (190) receives a current command request signal having a value and provides a motor current control signal having a value functionally related to the value of the received current command request signal and a gain control value. A gain scheduler (196) is operatively coupled to the variable gain regulator (190) and to the sensor (30, 97, 102) for providing the gain control value to the variable gain regulator (196) in response to the sensed at least one dynamic motor operating characteristic to thereby control the amount of gain of the variable gain regulator (190). The motor controller further includes a drive circuit (204, 120) operatively connected to the variable gain regulator (190) and the motor (28) for energizing the motor in response to the motor current control signal.

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Ann Arbor, MI, United States of America

Engelbert Lu