Patents by Inventor Larry G. Gepfrey
Larry G. Gepfrey 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: 11865891Abstract: A system for active roll control for a vehicle body is provided and includes a sensor operable to monitor a tilt of the body and a suspension system. The suspension system includes an active sway bar including a first bar portion, a second bar portion, and an active roll control motor disposed between the first bar portion and the second bar portion. The active roll control motor is operable to turn the first bar portion in relation to the second bar portion. The system further includes a computerized active roll control controller which is operative to monitor a driving mode including one of straight-line driving and rounding a curve on a road, monitor an output of the sensor, determine a desired roll moment based upon the driving mode and the output of the sensor, and control the active roll control motor based upon the desired roll moment.Type: GrantFiled: October 30, 2020Date of Patent: January 9, 2024Assignee: GM Global Technology Operations LLCInventors: Robert G. Izak, Nojan Medinei, Larry G. Gepfrey, Bo Yu
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Patent number: 11498383Abstract: A vehicle fluid spring system is adapted to absorb road shock imparted onto at least one road wheel of a vehicle. The vehicle fluid spring system includes a fluid spring and a variable volume unit. The fluid spring includes a fluid chamber adapted to change in volume. The variable volume unit including a rigid piston cylinder, a piston, a fluid cavity, and an actuator. The piston is adapted to reciprocate within, and is in sliding contact with, the rigid piston cylinder. The fluid cavity is defined by the piston cylinder and the piston. The actuator is adapted to drive the piston changing a volume of the fluid cavity. The fluid cavity is in fluid communication with the fluid chamber.Type: GrantFiled: February 13, 2020Date of Patent: November 15, 2022Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Larry G. Gepfrey, Andrei Balaceanu, Walter B. Cwycyshyn, Robert G. Izak
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Patent number: 11383575Abstract: A method of controlling relative roll torque in vehicles having a front active sway bar and a rear active sway bar is provided. The front active sway bar varies roll torque of a front axle and the rear active sway bar varies roll torque of a rear axle. The method includes monitoring dynamic driving conditions during operation of the vehicle and biasing tire lateral load transfer distribution (TLLTD) relative to the front axle based on the monitored dynamic driving conditions. Positive bias of the TLLTD increases the portion of a total roll torque carried by the front active sway bar. Biasing TLLTD occurs during one or more dynamic bias events triggered as monitored dynamic driving conditions exceed one or more calibrated thresholds.Type: GrantFiled: February 25, 2020Date of Patent: July 12, 2022Assignee: GM Global Technology Operations LLCInventors: Brian K. Saylor, Michael W. Neal, Larry G. Gepfrey, Robert G. Izak, Robert P. Marble, Hojjat Izadi
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Patent number: 11326664Abstract: A method for reshaping an electric drive signal of a real-time damper in a sprung mass system includes detecting a periodic frequency and magnitude of a target periodic vibration of a sprung mass. The periodic vibration has velocity and elasticity components that are 90 degrees out-of-phase. An electric drive signal to the real-time damper is reshaped by a controller depending on polarity of the velocity component to thereby generate a composite drive signal. The damper is energized using the composite drive signal to modify a damper force. Reshaping the electric drive signal includes injecting a force and/or an intermittent drive suppression component onto the electric drive signal based on the frequency and magnitude. The sprung mass system may have a frame and body, motion and wheel speed sensors, the real-time dampers, road wheels, and a controller programmed to perform the method.Type: GrantFiled: June 7, 2019Date of Patent: May 10, 2022Assignee: GM Global Technology Operations LLCInventors: Kenneth L. Oblizajek, Larry G. Gepfrey, John D. Sopoci
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Publication number: 20220134835Abstract: A system for active roll control for a vehicle body is provided and includes a sensor operable to monitor a tilt of the body and a suspension system. The suspension system includes an active sway bar including a first bar portion, a second bar portion, and an active roll control motor disposed between the first bar portion and the second bar portion. The active roll control motor is operable to turn the first bar portion in relation to the second bar portion. The system further includes a computerized active roll control controller which is operative to monitor a driving mode including one of straight-line driving and rounding a curve on a road, monitor an output of the sensor, determine a desired roll moment based upon the driving mode and the output of the sensor, and control the active roll control motor based upon the desired roll moment.Type: ApplicationFiled: October 30, 2020Publication date: May 5, 2022Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Robert G. Izak, Nojan Medinei, Larry G. Gepfrey, Bo Yu
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Publication number: 20220041030Abstract: A vehicle, system and method of controlling a roll of the vehicle is disclosed. The system includes a roll control actuator, a first switch, a second switch and a processor. The first switch is configured to couple the roll control actuator to a first power source. The second switch configured to control an electrical connection between the roll control actuator and ground. The processor is configured to operate the first switch to electrically decouple the roll control actuator from the first power source and operate a second switch to ground to short the ARC motor to ground to control the roll of the vehicle.Type: ApplicationFiled: August 10, 2020Publication date: February 10, 2022Inventors: Brian K. Saylor, Robert G. Izak, Larry G. Gepfrey
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Publication number: 20210339593Abstract: A process for correcting longitudinal roll from an offset load using active roll control within a vehicle is provided. The process includes, within a computerized controller using axle-based control to control a suspension system, operating programming to control pneumatic pressure supplied to each of a plurality of air spring devices within the suspension system to execute a vehicle leveling event including one of adjusting a height of the vehicle or maintaining the height of the vehicle. The process further includes operating programming to, simultaneously with the controlling the pneumatic pressure, utilize a plurality of active sway bars to provide an offset torque to the vehicle body. Each of the plurality of active sway bars is associated with one of a plurality of axles. Providing the offset torque is based upon a number of moles of air in each of the plurality of air spring devices and reducing the longitudinal roll.Type: ApplicationFiled: April 30, 2020Publication date: November 4, 2021Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Brian K. Saylor, Larry G. Gepfrey, Adam D. Stanton, Robert G. Izak, Bo Yu
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Patent number: 11161383Abstract: A process for correcting longitudinal roll from an offset load using active roll control within a vehicle is provided. The process includes, within a computerized controller using axle-based control to control a suspension system, operating programming to control pneumatic pressure supplied to each of a plurality of air spring devices within the suspension system to execute a vehicle leveling event including one of adjusting a height of the vehicle or maintaining the height of the vehicle. The process further includes operating programming to, simultaneously with the controlling the pneumatic pressure, utilize a plurality of active sway bars to provide an offset torque to the vehicle body. Each of the plurality of active sway bars is associated with one of a plurality of axles. Providing the offset torque is based upon a number of moles of air in each of the plurality of air spring devices and reducing the longitudinal roll.Type: GrantFiled: April 30, 2020Date of Patent: November 2, 2021Assignee: GM Global Technology Operations LLCInventors: Brian K. Saylor, Larry G. Gepfrey, Adam D. Stanton, Robert G. Izak, Bo Yu
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Publication number: 20210260952Abstract: A method of controlling relative roll torque in vehicles having a front active sway bar and a rear active sway bar is provided. The front active sway bar varies roll torque of a front axle and the rear active sway bar varies roll torque of a rear axle. The method includes monitoring dynamic driving conditions during operation of the vehicle and biasing tire lateral load transfer distribution (TLLTD) relative to the front axle based on the monitored dynamic driving conditions. Positive bias of the TLLTD increases the portion of a total roll torque carried by the front active sway bar. Biasing TLLTD occurs during one or more dynamic bias events triggered as monitored dynamic driving conditions exceed one or more calibrated thresholds.Type: ApplicationFiled: February 25, 2020Publication date: August 26, 2021Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Brian K. Saylor, Michael W. Neal, Larry G. Gepfrey, Robert G. Izak, Robert P. Marble, Hojjat Izadi
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Publication number: 20210252934Abstract: A vehicle fluid spring system is adapted to absorb road shock imparted onto at least one road wheel of a vehicle. The vehicle fluid spring system includes a fluid spring and a variable volume unit. The fluid spring includes a fluid chamber adapted to change in volume. The variable volume unit including a rigid piston cylinder, a piston, a fluid cavity, and an actuator. The piston is adapted to reciprocate within, and is in sliding contact with, the rigid piston cylinder. The fluid cavity is defined by the piston cylinder and the piston. The actuator is adapted to drive the piston changing a volume of the fluid cavity. The fluid cavity is in fluid communication with the fluid chamber.Type: ApplicationFiled: February 13, 2020Publication date: August 19, 2021Inventors: Larry G. Gepfrey, Andrei Balaceanu, Walter B. Cwycyshyn, Robert G. Izak
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Publication number: 20200386292Abstract: A method for reshaping an electric drive signal of a real-time damper in a sprung mass system includes detecting a periodic frequency and magnitude of a target periodic vibration of a sprung mass. The periodic vibration has velocity and elasticity components that are 90 degrees out-of-phase. An electric drive signal to the real-time damper is reshaped by a controller depending on polarity of the velocity component to thereby generate a composite drive signal. The damper is energized using the composite drive signal to modify a damper force. Reshaping the electric drive signal includes injecting a force and/or an intermittent drive suppression component onto the electric drive signal based on the frequency and magnitude. The sprung mass system may have a frame and body, motion and wheel speed sensors, the real-time dampers, road wheels, and a controller programmed to perform the method.Type: ApplicationFiled: June 7, 2019Publication date: December 10, 2020Applicant: GM Global Technology Operations LLCInventors: Kenneth L. Oblizajek, Larry G. Gepfrey, John D. Sopoci
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Patent number: 8051687Abstract: A system, method, and computer program product for detecting and compensating for a traction steer event is provided. A first wheel speed of a first driven wheel is compared with a second wheel speed of a second driven wheel to determine whether a wheel slip condition has occurred. If a wheel slip condition is determined to have occurred, a current operating state of a vehicle is compared to an expected operating state of the vehicle to determine if a traction steer event has occurred. If a traction steer event is determined to have occurred, brake pressure is selectively applied to the first or second driven wheel to compensate for the traction steer event.Type: GrantFiled: October 31, 2007Date of Patent: November 8, 2011Assignee: GM Global Technology Operations LLCInventors: David T. De Carteret, Larry G. Gepfrey, Gregory K. Peterson, Mark S. Hogle
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Publication number: 20090112436Abstract: A system, method, and computer program product for detecting and compensating for a traction steer event is provided. A first wheel speed of a first driven wheel is compared with a second wheel speed of a second driven wheel to determine whether a wheel slip condition has occurred. If a wheel slip condition is determined to have occurred, a current operating state of a vehicle is compared to an expected operating state of the vehicle to determine if a traction steer event has occurred. If a traction steer event is determined to have occurred, brake pressure is selectively applied to the first or second driven wheel to compensate for the traction steer event.Type: ApplicationFiled: October 31, 2007Publication date: April 30, 2009Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: DAVID T. DE CARTERET, LARRY G. GEPFREY, GREGORY K. PETERSON, MARK S. HOGLE