Patents by Inventor Stephen T. West

Stephen T. West has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8065050
    Abstract: A method is provided for detecting an insufficient or missing phase current in a permanent magnet synchronous motor, and includes determining a composite vector position of a combined three-phase phase current with respect to a stationary portion of the motor, and assigning a sector to the position. The method includes comparing the phase current to a calibrated threshold current corresponding to the sector, and executing a response when the absolute value is less than the threshold. A vehicle includes an energy storage device (ESD), a motor/generator configured as a permanent magnet synchronous motor, a voltage inverter, and a bus for conducting DC current from the ESD to the inverter. A controller detects an insufficient phase current, determines a current vector position of the three-phase AC, assigns a sector to the position, and executes a response when an absolute value of the phase current is less than a calibrated threshold.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: November 22, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Stephen T. West, Wei D. Wang, Sean E. Gleason
  • Patent number: 8013554
    Abstract: A diagnostic system for a hybrid vehicle comprises a motor control module and a fault diagnostic module. The motor control module controls torque output of an electric motor having a predetermined number of phases. The fault diagnostic module determines a position of a rotor of the electric motor, aligns the rotor with a phase angle of one of the phases, selectively diagnoses a fault based on a current of at least one of the phases, and selectively disables the electric motor based on the diagnosis.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: September 6, 2011
    Inventors: Stephen T. West, Wei D. Wang
  • Publication number: 20110043145
    Abstract: A method of processing a resolver fault in a motor generator unit (MGU) includes receiving a position signal from a resolver describing a measured angular position of a rotor of the MGU, determining the presence of the resolver fault using the position signal, and calculating or extrapolating an estimated rotor position when the resolver fault is determined. A predetermined resolver fault state may be determined using a measured duration of the resolver fault, and the MGU may be controlled using the estimated rotor position for at least a portion of the duration of the resolver fault. A motor control circuit is operable for processing the resolver fault using the above method, and may automatically vary a torque output or a pulse-width modulation (PWM) of the MGU depending on the duration of the resolver fault.
    Type: Application
    Filed: August 19, 2009
    Publication date: February 24, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Wei D. Wang, Bon Ho Bae, Stephen T. West, Rick H. Schroeder
  • Patent number: 7848902
    Abstract: Temperature of an electric power device of a hybrid transmission is managed based upon device temperatures and power flow, ambient temperature, and a cooling circuit flow rate.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: December 7, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Andrew M. Zettel, Charles J Van Horn, Peter E. Wu, Ryan D Martini, Wei D. Wang, Stephen T. West
  • Patent number: 7834574
    Abstract: In various embodiments, a phase current sampling apparatus (300, 600, FIGS. 3, 6), an electric motor drive system (100, FIG. 1), and a motor vehicle (1200, FIG. 12) include switching circuitry adapted to receive first and second phase current waveforms. The switching circuitry provides the first phase current waveform during at least two offset sampling instants, and provides the second phase current waveform during a reference sampling instant. An analog-to-digital converter is adapted to sample the first phase current waveform at the offset sampling instants, and to sample the second phase current waveform at the reference sampling instant. An embodiment of a method for regulating phase current waveforms includes an analog-to-digital converter generating samples of a first phase current waveform at sampling instants that occur before and after a reference sampling instant, and generating a sample of a second phase current waveform at the reference sampling instant.
    Type: Grant
    Filed: November 26, 2007
    Date of Patent: November 16, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Stephen T. West, Brian A. Welchko, Steven E. Schulz, Silva Hiti
  • Patent number: 7755310
    Abstract: Methods and apparatus are provided for monitoring an achieved motor torque produced by an electric motor. The method includes determining the achieved motor torque based on a rotor position of the electric motor and a phase current of the electric motor when the motor speed is not greater than a first pre-determined threshold, determining the achieved motor torque based on a loss-compensated power supplied to the electric motor when the motor speed is greater than the first pre-determined threshold, comparing the achieved motor torque with the torque command, and indicating a fault when the achieved motor torque is not within a pre-determined margin of the torque command.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: July 13, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Stephen T. West, Wei D. Wang, Sean E Gleason
  • Patent number: 7679309
    Abstract: Methods and systems are provided for controlling an electric machine via an inverter while compensating for one or more hardware delays. The method includes receiving a control signal, producing a first sampling signal based on the control signal, and adjusting the sampling signal to compensate for a first delay of the one or more hardware delays. The inverter is operable to produce a voltage signal based on the control signal, and the electric machine is operable to produce a current based on the voltage signal. A sampling of the current is performed based on the first sampling signal.
    Type: Grant
    Filed: May 3, 2007
    Date of Patent: March 16, 2010
    Assignee: GM Global Technologies Operations, Inc.
    Inventors: Steven E. Schulz, Nitinkumar R. Patel, Bonho Bae, Stephen T. West
  • Patent number: 7652443
    Abstract: Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. The various embodiments control the power inverter by, responsive to a commanded torque of the electric motor being below a first torque level, controlling the power inverter to set a switching frequency of the power inverter at a first set frequency; and, responsive to the commanded torque of the electric motor being between the first torque level and a second torque level, controlling the power inverter to determine the switching frequency of the power inverter as a function of the commanded torque of the electric motor while maintaining the switching frequency above a dynamic frequency limit. The method reduces switching frequencies in the inverter at high commanded torques, while maintaining the switching frequencies above dynamic frequency limit that provides effective control over the motor.
    Type: Grant
    Filed: October 24, 2007
    Date of Patent: January 26, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Steven E. Schulz, Stephen T. West, Brian A. Welchko, Silva Hiti
  • Publication number: 20090271060
    Abstract: A method is provided for detecting an insufficient or missing phase current in a permanent magnet synchronous motor, and includes determining a composite vector position of a combined three-phase phase current with respect to a stationary portion of the motor, and assigning a sector to the position. The method includes comparing the phase current to a calibrated threshold current corresponding to the sector, and executing a response when the absolute value is less than the threshold. A vehicle includes an energy storage device (ESD), a motor/generator configured as a permanent magnet synchronous motor, a voltage inverter, and a bus for conducting DC current from the ESD to the inverter. A controller detects an insufficient phase current, determines a current vector position of the three-phase AC, assigns a sector to the position, and executes a response when an absolute value of the phase current is less than a calibrated threshold.
    Type: Application
    Filed: April 25, 2008
    Publication date: October 29, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Stephen T. West, Wei D. Wang, Sean E. Gleason
  • Patent number: 7555411
    Abstract: A method and an article of manufacture are provided to monitor a temperature sensing circuit and detect a fault therein. The method comprises monitoring sensor readings output from a plurality of temperature sensing circuits. An average sensor reading is determined, calculated from the sensor readings output from a subset of the temperature sensing circuits. Each of the sensor readings is compared to the average sensor reading. A fault is identified when one of the sensor readings deviates from the average sensor reading by an amount greater than a threshold, more particularly when one of the sensor readings deviates from the average sensor reading by an amount greater than the threshold at least a quantity of X times out of Y sensor readings.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: June 30, 2009
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Wei D. Wang, Peter E. Wu, Slobodan Gataric, Stephen T. West, Harry J. Bauer
  • Publication number: 20090134833
    Abstract: In various embodiments, a phase current sampling apparatus (300, 600, FIGS. 3, 6), an electric motor drive system (100, FIG. 1), and a motor vehicle (1200, FIG. 12) include switching circuitry adapted to receive first and second phase current waveforms. The switching circuitry provides the first phase current waveform during at least two offset sampling instants, and provides the second phase current waveform during a reference sampling instant. An analog-to-digital converter is adapted to sample the first phase current waveform at the offset sampling instants, and to sample the second phase current waveform at the reference sampling instant. An embodiment of a method for regulating phase current waveforms includes an analog-to-digital converter generating samples of a first phase current waveform at sampling instants that occur before and after a reference sampling instant, and generating a sample of a second phase current waveform at the reference sampling instant.
    Type: Application
    Filed: November 26, 2007
    Publication date: May 28, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: STEPHEN T. WEST, BRIAN A. WELCHKO, STEVEN E. SCHULZ, SILVA HITI
  • Publication number: 20090121668
    Abstract: A diagnostic system for a hybrid vehicle comprises a motor control module and a fault diagnostic module. The motor control module controls torque output of an electric motor having a predetermined number of phases. The fault diagnostic module determines a position of a rotor of the electric motor, aligns the rotor with a phase angle of one of the phases, selectively diagnoses a fault based on a current of at least one of the phases, and selectively disables the electric motor based on the diagnosis.
    Type: Application
    Filed: September 29, 2008
    Publication date: May 14, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Stephen T. West, Wei D. Wang
  • Publication number: 20090125171
    Abstract: A diagnostic system for a hybrid vehicle comprises a processor module and a motor control module. The processor module outputs a first seed value. The motor control module controls torque output by an electric motor of the hybrid vehicle and outputs a key value based on the first seed value. The processor module outputs a second seed value after receiving the key value, and the motor control module selectively diagnoses a fault in the processor module based on a comparison of the second seed value with the first seed value.
    Type: Application
    Filed: September 29, 2008
    Publication date: May 14, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Stephen T. West, Wei D. Wang, Hanne Buur
  • Publication number: 20090115408
    Abstract: A rotatable shaft is equipped with a measurement device that generates output signals corresponding to discrete angular positions of the shaft. Rotational angles of the shaft are measured for a complete rotational period. A true angular velocity of the shaft is determined. Angular velocity is calculated between contiguous pairs of the discrete angular positions. A velocity correction is determined, and a rotational angle error term is determined based upon the velocity correction.
    Type: Application
    Filed: October 6, 2008
    Publication date: May 7, 2009
    Applicants: GM GLOBAL TECHNOLOGY OPERATIONS, INC., Daimler AG, Chrysler LLC, Bayerishe Motoren Werke Aktiengesellschaft
    Inventors: Stephen T. West, Sean E. Gleason
  • Publication number: 20090118916
    Abstract: A powertrain includes an electromechanical transmission operative to transmit torque between an input member and an electric machine and an output member to transmit tractive torque. The electric machine is electrically connected to an inverter device which is electrically connected to an energy storage device. A method for operating the powertrain includes detecting a shutdown event, commanding the transmission to neutral, commanding the electric machine to cease operating in a torque generating mode, and electrically disconnecting the energy storage device from the inverter device.
    Type: Application
    Filed: October 28, 2008
    Publication date: May 7, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Aniket Kothari, Nicholas Kokotovich, Stephen T. West, James E. Tarchinski, Sean Em Gleason, William R. Cawthorne
  • Publication number: 20090118881
    Abstract: A diagnostic system for a hybrid vehicle comprises a processor module and a motor control module. The processor module outputs a seed value. The motor control module controls torque output by an electric motor of the hybrid vehicle, receives the seed value, generates a final key value based on the seed value, and outputs the final key value to the processor module.
    Type: Application
    Filed: September 29, 2008
    Publication date: May 7, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Stephen T. West, Wei D. Wang, Hanne Buur
  • Publication number: 20090108780
    Abstract: Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. The various embodiments control the power inverter by, responsive to a commanded torque of the electric motor being below a first torque level, controlling the power inverter to set a switching frequency of the power inverter at a first set frequency; and, responsive to the commanded torque of the electric motor being between the first torque level and a second torque level, controlling the power inverter to determine the switching frequency of the power inverter as a function of the commanded torque of the electric motor while maintaining the switching frequency above a dynamic frequency limit. The method reduces switching frequencies in the inverter at high commanded torques, while maintaining the switching frequencies above dynamic frequency limit that provides effective control over the motor.
    Type: Application
    Filed: October 24, 2007
    Publication date: April 30, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: STEVEN E. SCHULZ, STEPHEN T. WEST, BRIAN A. WELCHKO, SILVA HITI
  • Publication number: 20090107742
    Abstract: Methods and systems for controlling a power inverter in automobiles utilizing two-mode transmissions are provided. The various embodiments control the power inverter by, responsive to a commanded torque of the electric motor being below a first torque level, controlling the power inverter to set a switching frequency of the power inverter at a first set frequency; and, responsive to the commanded torque of the electric motor being between the first torque level and a second torque level, controlling the power inverter to determine the switching frequency of the power inverter as a function of the commanded torque of the electric motor while maintaining the switching frequency above a dynamic frequency limit. The method reduces switching frequencies in the inverter at high commanded torques, while maintaining the switching frequencies above dynamic frequency limit that provides effective control over the motor.
    Type: Application
    Filed: October 24, 2007
    Publication date: April 30, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: STEVEN E. SCHULZ, STEPHEN T. WEST, BRIAN A. WELCHKO, SILVA HITI
  • Publication number: 20090112392
    Abstract: A method for monitoring a main control module operative to command first and second motor control processors of a hybrid powertrain system includes signally connecting a programmable logic device to the main control module and the first and second motor control processors, communicating a first seed signal from the programmable logic device to the main control module, and determining an invalid key signal in the main control module in response to the first seed signal. The invalid key signal is communicated to the programmable logic device.
    Type: Application
    Filed: October 3, 2008
    Publication date: April 30, 2009
    Applicants: GM GLOBAL TECHNOLOGY OPERATIONS, INC., Daimler AG, Chrysler LLC, Bayerishe Motoren Werke Aktiengesellschaft
    Inventors: HANNE BUUR, JAMES T. KURNIK, STEPHEN T. WEST, DAVID TARBY
  • Publication number: 20090099791
    Abstract: Temperature of an electric power device of a hybrid transmission is managed based upon device temperatures and power flow, ambient temperature, and a cooling circuit flow rate.
    Type: Application
    Filed: October 10, 2007
    Publication date: April 16, 2009
    Applicant: GM Global Technology Operations, Inc.
    Inventors: Andrew M. Zettel, Charles J. Van Horn, Peter E. Wu, Ryan D. Martini, Wei D. Wang, Stephen T. West