Delphi Technologies, Inc.

Gm Global Technolgoy Operations, Inc.

Steering Solutions IP Holding Corporation

Mark Philip Colosky

Ashok Chandy

Sayeed Ahmad Mir

Dennis B Skellenger

Kathryn L Pattok

Roy Alan McCann

Yuen-Kwok Chin

Julie Ann Kleinau

Steven James Collier-Hallman

Weiwen Deng

Farhad Bolourchi

Jeffery Alan Zuraski

Troy P Strieter

Sanket S Amberkar

William Chin-Woei Lin

Mark Dennis Kushion

James Charles Tallant, Ii

Christophe Etienne

Aparna S Amberkar

Roy Alan Mc Cann

Terrence D Smith

Phillip Weilhammer

Jeff Zuraski

Nabeel Bitar

Kathryn Lynn Pattok

An electric power steering system of a vehicle includes a controller for controlling an electric motor connected to a steering column or other steering mechanism. The velocity of the motor must be determined to maintain the proper current to the motor. A method of estimating the velocity includes obtaining a first and second velocity signals from one or more sensors monitoring the motor. The first and second signals have different characteristics, e.g., the first signal may have a higher resolution than the second signal. An acceleration (or deceleration) of the velocity of the electric motor is computed based on the different representations of the velocity supplied by the different signals. An estimate of the velocity of the motor is then determined based on the acceleration/deceleration and the different representations of the velocity. The electric current provided to the electric motor is then adjusted based on the estimated velocity to meet the desired motor output (i.e., motor torque and velocity).

Electric power steering system control methods

A method, system, and apparatus for providing enhanced steering pull compensation are provided. The method compensates for steering pull in a vehicle steering system that includes a handwheel. The method includes monitoring the vehicle to determine whether the vehicle is heading forward along a substantially linear straight-ahead path and, if so, measuring handwheel torque, as a sensed torque signal, to determine an amount of steering pull existing at the handwheel. The method also includes generating a torque assist signal in response to the sensed torque signal and calculating an offset signal for reducing the amount of steering pull to substantially zero. The method further includes producing a modified torque assist signal by adding the offset signal to the torque assist signal, and applying the modified torque assist signal to the vehicle steering system.

Method, system, and apparatus for providing enhanced steering pull compensation

An electric power steering system includes a steering wheel, an electric assist motor operatively coupled to the steering wheel, and an electronic controller operatively coupled to the assist motor. A steering wheel position sensor provides an output indicative of an angular position of the steering wheel. A motor position sensor provides an output indicative of a relative angular position for the motor. Steering wheel position sensor output is acquired at each of a plurality of angular positions of the motor, thereby establishing a set of points defining a curvilinear relationship between steering wheel sensor output and motor position sensor output. The set of points is sampled to calculate a straight line which approximates the curvilinear relationship, thereby reducing periodic errors in the steering wheel sensor output. The straight line is employed to determine a position offset for the motor position sensor output corresponding to a system zero position. The system zero position is a position for which the vehicle will travel along a linear, substantially straight-ahead path.

Compensation of periodic sensor errors in electric power steering systems

A method for generatig a fault tolerant sensor signal for a motor control system in a vehicle steering system. The method includes receiving at least three sensor signals indicative of a sensed parameter and generating a plurality of parameter pair signals responsive to the at least one sensor signal of the at least three sensor signals. Additionally, the method includes selecting one parameter pair signal of the plurality of parameter pair signals and generating a measured parameter signal responsive to the selecting.

Fault tolerant torque sensor signal processing

A method and system for determining a torque current in an electric machine coupled to a polyphase bus. The method comprises: detecting a rotational position of the electric machine with a position encoder; controlling an inverter comprising a plurality of switching devices, the inverter having an input coupled to a direct current bus, and an output coupled to the polyphase bus. Where the inverter is responsive to commands from a controller coupled to the inverter and to the position encoder. The method also includes measuring a current from the direct current bus; and capturing the current at a predefined interval of time.

Current determination in a permanent magnet electric machine

A controller () for a vehicular system () that includes a hand-wheel () and an electric motor () includes a torque-assist function () responsive to a signal representing the torque applied to the hand-wheel () for providing a torque-assist command to the motor (), and a steering-pull compensator () responsive to a signal representing a valid ignition cycle for modifying the torque-assist command to the motor () by an offset corresponding to a detected steering-pull condition; where the method of control includes receiving the signal indicative of the torque applied to the hand-wheel (), providing a torque-assist command to the motor () in response to the received torque signal, detecting an enabling signal related to the signal representing a valid ignition cycle, quantifying a steering-pull condition in response to the received and detected signals, and modifying the torque-assist command to the motor () by an offset corresponding to the quantified steering-pull condition.

Robust steering-pull torque compensation

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. The absolute position estimate is responsive to the calibration value, the position delta, and the offset from the sensor subsystem datum to the initial reference.

Method and apparatus for calibrating and initializing an electronically commutated motor

A method and system for phase angle diagnostics in a sinusoidally excited PM electric machine, including: a controller that executes a process to facilitate the method including receiving a position value indicative of the rotational position from a position sensor configured to measure a rotor position of said electric machine and transmit a position signal; receiving a phase advance value indicative of a commanded phase advance angle; determining an expected phase voltage and expected status thereof; observing a selected phase voltage signal and determining an actual status corresponding thereto; and comparing the expected status and the actual status.

Phase angle diagnostics for sinusoidal controlled electric machine

A method for updating a sensor offset and a medium encoded with a machine-readable computer program code for updating a sensor using a robust sensor learning algorithm wherein the method includes obtaining vehicle data signals, obtaining a position sensor data signal, the position sensor data signal being responsive to a stored positional offset data signal, determining whether algorithm initial conditions are satisfied, formulating a new positional offset data signal conditioned on satisfaction of the initial conditions, and storing said new positional offset data signal so as to combine said new positional offset data signal with said stored positional offset data signal and replace said stored positional offset data signal.

Method for updating a sensor using a robust sensor offset learning algorithm

An absolute hand-wheel position tracking system for an electric power steering system having a hand-wheel, an assist motor for providing an assist torque disposed relative to the hand-wheel, and a motor position sensor responsive to the assist motor, includes a hand-wheel position initialization function responsive to the hand-wheel; a motor position correction and scaling function responsive to the motor position sensor and responsive to the assist torque; an enable function responsive to the assist torque and responsive to the hand-wheel position initialization function; and an absolute hand-wheel position generation function in signal communication with the hand-wheel position initialization function, the motor position correction and scaling function, and the enable function.

Robust determination of hand-wheel position

A method of estimating the angular velocity of an electric power steering motor for an automobile is disclosed. The method comprises estimating an average angular velocity of the motor; estimating an instantaneous angular velocity of the motor; weighting the estimated average angular velocity of the motor; weighting the estimated instantaneous angular velocity of the motor; and combining the weighted estimated average angular velocity of the motor and the weighted estimated instantaneous angular velocity of the motor.

Enhanced motor velocity measurement using a blend of fixed period and fixed distance techniques

A method of compensating for errors in the measurement of the kinematic properties of an electric power steering motor for an automobile is disclosed. The method comprises generating a set of M-ary signals; measuring the pulse width of the set of M-ary signals; and measuring the time between the edges of the set of M-ary signals. The motor velocity may be directly measured by a tachometer or other such device. The motor position signal can be used to estimate the angular velocity of the motor, by determining the change in angular position of the motor divided by the change in time.

Symmetry compensation for encoder pulse width variation

A method of minimizing the torque ripple produced by unbalanced phase currents in a sinusoidally excited motor is disclosed. The method comprises measuring the position of the motor; sampling the phase currents of the motor generating thereby at least one phase current; synchronizing the at least one phase current of the motor with the position of the motor; determining the imbalance in the magnitudes of the at least one phase current of the motor; generating a set of modulation index terms for reducing the imbalance in the magnitudes of the at least one phase current to ensure acceptable torque ripple characteristics over the operating velocity of the motor; and generating a set of minimized line-to-ground voltage commands.

Minimization of motor torque ripple due to unbalanced conditions

A method and system for diagnostics and ascertaining status of an electric machine coupled to a polyphase bus. The method and system include: detecting a rotational position with a position encoder coupled to the electric machine; controlling an inverter having an input coupled to a direct current bus and an output coupled to the polyphase bus, where the inverter is responsive to commands from a controller coupled to the inverter and to the position encoder. The method and system further include measuring a current from the direct current bus; capturing a torque current; calculating a current error; establishing a bound limit for the torque current; comparing the current error to the bound limit. The method and system also include: determining whether a fault exists by evaluating if the bound limit has been exceeded; incrementing a fault counter if a fault exists; decrementing a fault counter if no fault exists; and indicating a failure if the fault counter exceeds a predetermined limit.

Torque current comparison for current reasonableness diagnostics in a permanent magnet electric machine

A system and method of discriminating faults in an error signal, such as that from a control input sensor, comprises a system for and method of determining allowable limits of an error signal versus time, passing the error signal through a low-pass filter, comparing output of the low-pass filter with a threshold and outputting a fault condition when the output of the low-pass filter exceeds the threshold. The time constant or constants of the low-pass filter and the threshold are selected so that a fault condition is detected when the error signal approaches the allowable limits before exceeding them.

Growing community of inventors

Vassar, MI, United States of America

Mark Philip Colosky