Patents by Inventor James E. Walters
James E. Walters 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).
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Patent number: 9897466Abstract: A motor control system includes a shaft configured to be rotationally driven by a motor. A rotor position sensor is configured to detect rotation of the shaft and output a rotor position signal. A controller is in communication with the motor and the rotor position sensor. The controller converts the rotor position signal to an angle with error, tracks the angle with error to provide an angle that retains mechanical dynamics as stationary reference frame signals, transforms the stationary reference frame signals and the angle with mechanical dynamics to rotating reference frame signals, filters the rotating reference frame signals, transforms the filtered rotating reference frame signals to provide filtered stationary frame signals, and takes an arctangent of the filtered stationary reference frame signals to create a corrected motor control angle. The controller commands the motor based upon the corrected motor control angle.Type: GrantFiled: July 18, 2016Date of Patent: February 20, 2018Assignee: DELPHI TECHNOLOGIES, INC.Inventor: James E. Walters
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Publication number: 20180017413Abstract: A motor control system includes a shaft configured to be rotationally driven by a motor. A rotor position sensor is configured to detect rotation of the shaft and output a rotor position signal. A controller is in communication with the motor and the rotor position sensor. The controller converts the rotor position signal to an angle with error, tracks the angle with error to provide an angle that retains mechanical dynamics as stationary reference frame signals, transforms the stationary reference frame signals and the angle with mechanical dynamics to rotating reference frame signals, filters the rotating reference frame signals, transforms the filtered rotating reference frame signals to provide filtered stationary frame signals, and takes an arctangent of the filtered stationary reference frame signals to create a corrected motor control angle. The controller commands the motor based upon the corrected motor control angle.Type: ApplicationFiled: July 18, 2016Publication date: January 18, 2018Inventor: JAMES E. WALTERS
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Patent number: 9618582Abstract: A system for detecting faults in a motor includes a drive circuit, a detection circuit, and a controller. The drive circuit is configured to apply a drive signal to a motor. The detection circuit is configured to detect a response signal generated when the drive signal is applied to the motor. The controller is configured to determine a motor fault based on a comparison of the response signal to an expected signal for the drive signal applied to the motor. The drive signal is selected to generate a rotating magnetic field in the motor with a rotation-frequency greater than a maximum mechanical-response-frequency of the motor.Type: GrantFiled: October 30, 2014Date of Patent: April 11, 2017Assignee: Delphi Technologies, Inc.Inventor: James E. Walters
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Patent number: 9463713Abstract: A system and method for controlling a rotating E-machine and for correcting a rotational position signal output by an angular position sensor operatively connected to the E-machine in conjunction with a sensor digital converter is disclosed. For each angular operating speed of interest, a set of signals as a function of position is taken such that the harmonics (or sub-harmonics) related to the position sensor may be determined and isolated from errors due to an associated digital converter. From this information, the magnitude and phase of the position sensor harmonics is determined. The effects of the sensor digital converter (or other signal processing equipment) are then determined and accounted for, allowing the control system to apply the total position error signal to the position sensor output signal to determine a corrected position sensor signal for use in controlling the E-machine.Type: GrantFiled: February 12, 2016Date of Patent: October 11, 2016Assignee: Allison Transmission, Inc.Inventors: James E. Walters, Ronald J. Krefta
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Publication number: 20160193941Abstract: A system and method for controlling a rotating E-machine and for correcting a rotational position signal output by an angular position sensor operatively connected to the E-machine in conjunction with a sensor digital converter is disclosed. For each angular operating speed of interest, a set of signals as a function of position is taken such that the harmonics (or sub-harmonics) related to the position sensor may be determined and isolated from errors due to an associated digital converter. From this information, the magnitude and phase of the position sensor harmonics is determined. The effects of the sensor digital converter (or other signal processing equipment) are then determined and accounted for, allowing the control system to apply the total position error signal to the position sensor output signal to determine a corrected position sensor signal for use in controlling the E-machine.Type: ApplicationFiled: February 12, 2016Publication date: July 7, 2016Inventors: James E. Walters, Ronald J. Krefta
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Publication number: 20160124049Abstract: A system for detecting faults in a motor includes a drive circuit, a detection circuit, and a controller. The drive circuit is configured to apply a drive signal to a motor. The detection circuit is configured to detect a response signal generated when the drive signal is applied to the motor. The controller is configured to determine a motor fault based on a comparison of the response signal to an expected signal for the drive signal applied to the motor. The drive signal is selected to generate a rotating magnetic field in the motor with a rotation-frequency greater than a maximum mechanical-response-frequency of the motor.Type: ApplicationFiled: October 30, 2014Publication date: May 5, 2016Inventor: JAMES E. WALTERS
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Patent number: 9260036Abstract: A system and method for controlling a rotating E-machine and for correcting a rotational position signal output by an angular position sensor operatively connected to the E-machine in conjunction with a sensor digital converter is disclosed. For each angular operating speed of interest, a set of signals as a function of position is taken such that the harmonics (or sub-harmonics) related to the position sensor may be determined and isolated from errors due to an associated digital converter. From this information, the magnitude and phase of the position sensor harmonics is determined. The effects of the sensor digital converter (or other signal processing equipment) are then determined and accounted for, allowing the control system to apply the total position error signal to the position sensor output signal to determine a corrected position sensor signal for use in controlling the E-machine.Type: GrantFiled: February 13, 2015Date of Patent: February 16, 2016Assignee: Allison Transmission, Inc.Inventors: James E. Walters, Ronald J. Krefta
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Publication number: 20150158396Abstract: A system and method for controlling a rotating E-machine and for correcting a rotational position signal output by an angular position sensor operatively connected to the E-machine in conjunction with a sensor digital converter is disclosed. For each angular operating speed of interest, a set of signals as a function of position is taken such that the harmonics (or sub-harmonics) related to the position sensor may be determined and isolated from errors due to an associated digital converter. From this information, the magnitude and phase of the position sensor harmonics is determined. The effects of the sensor digital converter (or other signal processing equipment) are then determined and accounted for, allowing the control system to apply the total position error signal to the position sensor output signal to determine a corrected position sensor signal for use in controlling the E-machine.Type: ApplicationFiled: February 13, 2015Publication date: June 11, 2015Inventors: James E. Walters, Ronald J. Krefta
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Patent number: 8120200Abstract: A control methodology for an engine-driven electric machine of a hybrid vehicle electrical system for enabling continued operation of the vehicle electrical system under failure mode conditions that require or result in disconnection of the battery pack from the electrical system. At the onset of a fault condition requiring battery disconnection, the electric machine is controlled to drive the battery pack current toward zero before disconnecting the battery pack. Once the battery pack is disconnected, whether by relay or fuse, the electric machine is controlled to maintain the bus voltage of the electrical system at a specified value. In both operating modes, the electric machine is controlled based on a synchronous vector current command that is determined directly as a function of the control objective (zero battery pack current or maintaining bus voltage) for improved response time compared to a traditional torque-based control.Type: GrantFiled: March 3, 2009Date of Patent: February 21, 2012Assignee: Delphi Technologies, Inc.Inventors: James E. Walters, Gerald T. Fattic
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Publication number: 20100110594Abstract: A control methodology for an engine-driven electric machine of a hybrid vehicle electrical system for enabling continued operation of the vehicle electrical system under failure mode conditions that require or result in disconnection of the battery pack from the electrical system. At the onset of a fault condition requiring battery disconnection, the electric machine is controlled to drive the battery pack current toward zero before disconnecting the battery pack. Once the battery pack is disconnected, whether by relay or fuse, the electric machine is controlled to maintain the bus voltage of the electrical system at a specified value. In both operating modes, the electric machine is controlled based on a synchronous vector current command that is determined directly as a function of the control objective (zero battery pack current or maintaining bus voltage) for improved response time compared to a traditional torque-based control.Type: ApplicationFiled: March 3, 2009Publication date: May 6, 2010Applicant: DELPHI TECHNOLOGIES, INC.Inventors: James E. Walters, Gerald T. Fattic
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Publication number: 20090132120Abstract: A system and method of detecting a rough road condition is provided. The system includes a shaft, a wheel connected to the shaft, wherein as the shaft rotates, the wheel rotates. The system further includes a sensor in communication with the wheel, wherein the sensor monitors the rotation of the wheel, and a processor in communication with the sensor. The processor performs the steps of receiving sensor monitoring data from the sensor, wherein the sensor monitoring data includes at least one predetermined point of the wheel sensed by the sensor, and the sensor monitoring data is timestamped by one of the sensor and the processor. The processor further performs the steps of forming a representative signal, and processing the representative signal to analyze the harmonics of the wheel rotation, such that a rough road condition can be detected based upon the harmonic analysis.Type: ApplicationFiled: November 20, 2007Publication date: May 21, 2009Inventor: James E. Walters
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Patent number: 7530261Abstract: A computer implemented system for engine misfire detection employs a crankshaft-originated speed signal that includes normal variability due to target wheel tooth error and the like. A Discrete Fourier Transform (DFT) is performed on the speed signal to convert it into a frequency-domain raw misfire detection metric. The system is configured to normalize the raw misfire detection metric using a non-misfire metric that is obtained by and corresponds to non-misfire operation of an internal combustion engine. A resulting normalized misfire detection metric has such normal variations removed leaving variations attributable to misfire. The system detects a misfire when the normalized misfire detection metric exceeds a predetermined threshold and is bounded by a predetermined phase angle region. The system detects both continuous misfire as well as intermittent misfire. The system also detects single cylinder misfire and multiple cylinder misfire.Type: GrantFiled: February 12, 2007Date of Patent: May 12, 2009Assignee: Delphi Technologies, Inc.Inventor: James E. Walters
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Publication number: 20080190184Abstract: A computer implemented system for engine misfire detection employs a crankshaft-originated speed signal that includes normal variability due to target wheel tooth error and the like. A Discrete Fourier Transform (DFT) is performed on the speed signal to convert it into a frequency-domain raw misfire detection metric. The system is configured to normalize the raw misfire detection metric using a non-misfire metric that is obtained by and corresponds to non-misfire operation of an internal combustion engine. A resulting normalized misfire detection metric has such normal variations removed leaving variations attributable to misfire. The system detects a misfire when the normalized misfire detection metric exceeds a predetermined threshold and is bounded by a predetermined phase angle region. The system detects both continuous misfire as well as intermittent misfire. The system also detects single cylinder misfire and multiple cylinder misfire.Type: ApplicationFiled: February 12, 2007Publication date: August 14, 2008Inventor: James E. Walters
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Patent number: 7320308Abstract: A method/system for measuring cylinder pressures of an internal combustion engine includes a crank angle sensor utilized to generate pressure readings at known angular intervals. Additional time-based pressure measurements are taken in selected angular windows between a pair of the angle-based pressure readings. Because the angle-based pressure measurements and the time-based pressure measurements occur at known times, the pressure as a function of the crank angle for the time-based pressure measurements can be determined. The cylinder pressure measurements can be utilized to calculate combustion parameters used for closed-loop engine control of fuel supply or other engine inputs.Type: GrantFiled: December 5, 2006Date of Patent: January 22, 2008Assignee: Delphi Technologies, Inc.Inventors: Clinton W. Erickson, James E. Walters, Karl A. Schten
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Patent number: 7242163Abstract: A device to regulate current produced by a permanent magnet machine responsive to a plurality of phase current signals. The motor produces torque for application on a shaft. A processing and drive circuit responsive to a direct current command signal and a quadrature current command signal produces phase current signals for input to the motor. A command circuit responsive to the phase current signals, an angular position of said shaft, and a voltage input command signal to produce a direct current error signal and a quadrature current error signal. A control circuit responsive to the direct and quadrature current error signals produces the direct voltage signal command and the quadrature voltage signal command. The control circuit has a direct and quadrature proportional gain, integrator and clamp circuits. An algorithm produces limited or clamped voltage modulation index signals to obtain maximum efficiency and maximum torque per ampere in the speed range.Type: GrantFiled: August 26, 2003Date of Patent: July 10, 2007Assignee: Delphi Technologies, Inc.Inventors: Gabriel Gallegos-Lopez, Fani S. Gunawan, James E. Walters
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Patent number: 7026776Abstract: The invention provides a method for controlling current in a direct current motor having a back emf constant (ke), which may be a function of field current if the direct current motor is a field wound machine, and motor resistance (Rs) in all 4 quadrants of operation. The method includes the step of rotating a motor shaft of the direct current motor with a controller by applying a first voltage across the direct current motor's terminals. The first voltage corresponds to a first value of current passing through the armature windings of the direct current motor. The method also includes the step of determining a maximum value of current to pass through the armature windings of the direct current motor. The maximum value of current is selected to prevent undesirable over current conditions, such as thermal overload as one example. The method also includes the step of receiving a signal corresponding to a desired motor speed (?*) with the controller during the rotating step.Type: GrantFiled: June 30, 2005Date of Patent: April 11, 2006Assignee: Delphi Technologies, Inc.Inventor: James E. Walters
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Patent number: 6876169Abstract: Method for providing current regulation and a current controller (10) for an electric machine (30) are provided. The method includes receiving a state vector time signal (36) indicative of a time interval when a switching state vector is activated and comparing the received state vector time signal to a commanded state vector time signal (38). The method further includes using the result of the comparison to regulate a direct axis current signal (42, 44) input to an electric machine controller. The current controller (10) includes a state vector error comparator for comparing a received state vector time signal to a commanded state vector time signal and generating a state vector time error. This error is processed by a PI controller, coupled to the state vector error comparator, for providing a direct axis current signal output responsive to the state vector time error to an electric machine.Type: GrantFiled: January 14, 2003Date of Patent: April 5, 2005Assignee: Delphi Technologies, Inc.Inventors: Gabriel Gallegos-Lopez, James E. Walters, Fani S. Gunawan
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Patent number: 6850033Abstract: A device to regulate current produced by an induction machine responsive to a plurality of phase current signals. The motor produces torque for application on a shaft. A processing and drive circuit responsive to a direct current command signal and a quadrature current command signal produces phase current signals for input to the motor. A command circuit responsive to the phase current signals, an angular position of said shaft, and a voltage input command signal to produce a direct current error signal and a quadrature current error signal. A control circuit responsive to the direct and quadrature current error signals produces the direct voltage signal command and the quadrature signal command. The control circuit has a direct and quadrature proportional gain, integrator and clamp circuits. An algorithm produces limited or clamped voltage modulation index signals to obtain maximum efficiency and maximum torque per ampere in the speed range.Type: GrantFiled: August 26, 2003Date of Patent: February 1, 2005Assignee: Delphi Technologies, Inc.Inventors: Gabriel Gallegos-Lopez, Fani S. Gunawan, James E. Walters
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Patent number: 6774592Abstract: Method and system for controlling a permanent magnet machine are provided. The method provides a sensor assembly for sensing rotor sector position relative to a plurality of angular sectors. The method allows starting the machine in a brushless direct current mode of operation using a calculated initial rotor position based on angular sector position information from the sensor assembly. Upon reaching a predefined mode-crossover criterion, the method allows switching to a sinusoidal mode of operation using rotor angle position based on extrapolating angular sector position information from the sensor assembly.Type: GrantFiled: December 3, 2001Date of Patent: August 10, 2004Assignee: Delphi Technologies, Inc.Inventors: James E. Walters, John Derek Williams
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Publication number: 20040135538Abstract: Method for providing current regulation and a current controller (10) for an electric machine (30) are provided. The method includes receiving a state vector time signal (36) indicative of a time interval when a switching state vector is activated and comparing the received state vector time signal to a commanded state vector time signal (38). The method further includes using the result of the comparison to regulate a direct axis current signal (42, 44) input to an electric machine controller. The current controller (10) includes a state vector error comparator for comparing a received state vector time signal to a commanded state vector time signal and generating a state vector time error. This error is processed by a PI controller, coupled to the state vector error comparator, for providing a direct axis current signal output responsive to the state vector time error to an electric machine.Type: ApplicationFiled: January 14, 2003Publication date: July 15, 2004Inventors: Gabriel Gallegos-Lopez, James E. Walters, Fani S. Gunawan