Patents by Inventor Deron C. Littlejohn
Deron C. Littlejohn 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: 7976109Abstract: A hybrid brake apparatus for a vehicle includes a front hydraulically actuated brake circuit, a rear electrically actuated brake circuit, and a controller. The front hydraulically actuated brake circuit includes a master cylinder for providing pressurized fluid to the front brake circuit in response to an input applied to the master cylinder for applying a frictional front braking force. The rear electrically actuated brake circuit is controllable in response to the input for providing a frictional rear braking force. The rear brake circuit is controlled in accordance with a first predetermined relationship between the input and rear braking force during normal operation of the front brake circuit. If the controller detects a degradation of front braking force, the rear brake circuit is controlled in accordance with a second predetermined relationship between the input and the rear braking force, to thereby compensate for the degradation of front braking force.Type: GrantFiled: October 8, 2003Date of Patent: July 12, 2011Assignee: BWI Company Limited S.A.Inventors: David F. Reuter, E. Wayne Lloyd, Deron C. Littlejohn
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Patent number: 7926888Abstract: The present invention discloses a braking apparatus for a vehicle having a brake pedal. The braking apparatus includes a master cylinder having a reservoir for retaining a brake fluid. At least one hydraulically actuated brake is in fluid communication with the master cylinder and a control unit is in electrical communication with the hydraulically actuated brake. A replenishment system is in fluid communication with the master cylinder and in electrical communication with the control unit for feeding the brake fluid into the replenishment system during a first condition and feeding the brake fluid from the replenishment system into the hydraulically actuated brake during a second condition after initial depression of the brake pedal to provide consistent pedal feel and braking pressure.Type: GrantFiled: July 14, 2006Date of Patent: April 19, 2011Assignee: BWI Company Limited S.A.Inventors: David F. Reuter, Earl Wayne Lloyd, Schuyler Scott Shaw, Deron C. Littlejohn
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Patent number: 7681962Abstract: A method for estimating master cylinder pressure during brake apply of a brake system of a vehicle, wherein the brake system includes a brake pedal. A first master cylinder pressure is estimated from brake pedal position during brake apply. A second master cylinder pressure is estimated from vehicle deceleration during brake apply. The master cylinder pressure is estimated during brake apply to be equal to the first master cylinder pressure when the vehicle deceleration is below a predetermined deceleration value. The master cylinder pressure is estimated during brake apply to be equal to a value which is less than the first master cylinder pressure and greater than or equal to the second master cylinder pressure when the vehicle deceleration is at or above the predetermined deceleration value. At least the estimated master cylinder pressure during brake apply is used to control the vehicle.Type: GrantFiled: April 26, 2007Date of Patent: March 23, 2010Inventors: Bryan Todd Fulmer, Deron C. Littlejohn, Rebecca L Wang
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Publication number: 20080265664Abstract: A method for estimating master cylinder pressure during brake apply of a brake system of a vehicle, wherein the brake system includes a brake pedal. A first master cylinder pressure is estimated from brake pedal position during brake apply. A second master cylinder pressure is estimated from vehicle deceleration during brake apply. The master cylinder pressure is estimated during brake apply to be equal to the first master cylinder pressure when the vehicle deceleration is below a predetermined deceleration value. The master cylinder pressure is estimated during brake apply to be equal to a value which is less than the first master cylinder pressure and greater than or equal to the second master cylinder pressure when the vehicle deceleration is at or above the predetermined deceleration value. At least the estimated master cylinder pressure during brake apply is used to control the vehicle.Type: ApplicationFiled: April 26, 2007Publication date: October 30, 2008Inventors: Bryan Todd Fulmer, Deron C. Littlejohn, Rebecca L. Wang
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Publication number: 20080257669Abstract: The present invention discloses a braking apparatus for a vehicle having a brake pedal. The braking apparatus includes a master cylinder having a reservoir for retaining a brake fluid. At least one hydraulically actuated brake is in fluid communication with the master cylinder and a control unit is in electrical communication with the hydraulically actuated brake. A replenishment system is in fluid communication with the master cylinder and in electrical communication with the control unit for feeding the brake fluid into the replenishment system during a first condition and feeding the brake fluid from the replenishment system into the hydraulically actuated brake during a second condition after initial depression of the brake pedal to provide consistent pedal feel and braking pressure.Type: ApplicationFiled: July 14, 2006Publication date: October 23, 2008Inventors: David F. Reuter, Earl Wayne Lloyd, Schuyler Scott Shaw, Deron C. Littlejohn
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Publication number: 20080238189Abstract: A system for vacuum booster assist including a vacuum booster having an input and an output, a brake pedal connected to the input of the vacuum booster, a brake pedal travel sensor positioned to monitor travel of the brake pedal, a master cylinder having an input and an output, the input of the master cylinder being connected to the output of the vacuum booster, a master cylinder pressure sensor connection to the master cylinder to monitor a fluid pressure in the master cylinder, a brake fluid pressurizing device in fluid communication with the output of the master cylinder, and a controller in communication with the brake pedal travel sensor, the master cylinder pressure sensor and the brake fluid pressurizing device, wherein the controller is adapted to communicate a command signal to the brake fluid pressurizing device based upon signals received from the brake pedal travel sensor and the master cylinder pressure sensor.Type: ApplicationFiled: March 27, 2007Publication date: October 2, 2008Inventors: Ching-Chuang G. Kuo, Deron C. Littlejohn
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Publication number: 20080191854Abstract: A method for actuating a controlled device in response to a pre-crash condition of a vehicle, wherein the vehicle includes at least two sensors each of which is capable of generating a signal, wherein the method includes the steps of monitoring the signals, determining a panic index based upon the signals and, when the determined panic index exceeds a predetermined threshold value, actuating the controlled device.Type: ApplicationFiled: February 14, 2007Publication date: August 14, 2008Inventors: Deron C. LittleJohn, Ching C. (George) Kuo, Sanket S. Amberkar
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Patent number: 6956471Abstract: The present invention provides a method, a computer usable medium including a program, and a system for monitoring inflation in a plurality of vehicle tires. The method and computer usable medium include the steps of determining a direct pressure in at least one primary tire and determining a rolling radius for the primary tire and at least one secondary tire. A pressure difference is determined based on the determined rolling radius for the primary and secondary tires. The determined pressure difference is adjusted based on the determined direct pressure of the primary tire. The determined pressure difference is compared to at least one threshold value. The system includes means for achieving the method steps of the invention.Type: GrantFiled: April 16, 2003Date of Patent: October 18, 2005Assignee: Delphi Technologies, Inc.Inventors: Mohammad A. Tamimi, Deron C. Littlejohn, Bryan T. Fulmer
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Publication number: 20040207518Abstract: The present invention provides a method, a computer usable medium including a program, and a system for monitoring inflation in a plurality of vehicle tires. The method and computer usable medium include the steps of determining a direct pressure in at least one primary tire and determining a rolling radius for the primary tire and at least one secondary tire. A pressure difference is determined based on the determined rolling radius for the primary and secondary tires. The determined pressure difference is adjusted based on the determined direct pressure of the primary tire. The determined pressure difference is compared to at least one threshold value. The system includes means for achieving the method steps of the invention.Type: ApplicationFiled: April 16, 2003Publication date: October 21, 2004Applicant: DELPHI TECHNOLOGIES INC.Inventors: Mohammad A. Tamimi, Deron C. Littlejohn, Bryan T. Fulmer
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Publication number: 20040135432Abstract: A hybrid brake apparatus for a vehicle includes a front hydraulically actuated brake circuit, a rear electrically actuated brake circuit, and a controller. The front hydraulically actuated brake circuit includes a master cylinder for providing pressurized fluid to the front brake circuit in response to an input applied to the master cylinder for applying a frictional front braking force. The rear electrically actuated brake circuit is controllable in response to the input for providing a frictional rear braking force. The rear brake circuit is controlled in accordance with a first predetermined relationship between the input and rear braking force during normal operation of the front brake circuit. If the controller detects a degradation of front braking force, the rear brake circuit is controlled in accordance with a second predetermined relationship between the input and the rear braking force, to thereby compensate for the degradation of front braking force.Type: ApplicationFiled: October 8, 2003Publication date: July 15, 2004Applicant: DELPHI TECHNOLOGIES INC.Inventors: David F. Reuter, E. Wayne Lloyd, Deron C. Littlejohn
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Patent number: 5539641Abstract: A method of brake system control, and apparatus for performing same, comprising the steps of (i) determining a brake command for right and left wheel brakes; (ii) monitoring right and left wheel speeds; (iii) comparing the right and left wheel speeds to determine a speed difference; (iv) if the right wheel speed is greater than the left wheel speed, adjusting a left gain of the of a left brake command to reduce torque provided by the left wheel brake; (v) if the left wheel speed is greater than the right wheel speed, adjusting a right gain of a right brake command to reduce torque provided by the right wheel brake.Type: GrantFiled: February 14, 1994Date of Patent: July 23, 1996Assignee: General Motors CorporationInventor: Deron C. Littlejohn
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Patent number: 5423600Abstract: In a motor vehicle braking system wherein a first brake device has a first mode of operation in which power-assisted braking is provided and a second mode of operation in which manual braking is provided, wherein the second braking system has a second brake device controlled by a control command, a method of controlling the braking system comprising the steps of receiving a signal indicative of an operator brake request, determining the control command in response to the signal and a first gain factor if the first brake device is in the first mode of operation, determining the control command in response to the signal and a second gain factor if the first brake device is in the second mode of operation, wherein the second gain factor is less than the first gain factor, applying the control command to the second brake device.Type: GrantFiled: February 14, 1994Date of Patent: June 13, 1995Assignee: General Motors CorporationInventors: Bryan P. Riddiford, Deron C. Littlejohn
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Patent number: 5366281Abstract: A method of controlling a brake system comprising the steps of: (i) receiving a brake command from a brake pedal; (ii) responsive to the received command, applying full power to the brake actuator for a first time period after the brake command is received; (iii) after the first time period, applying power to the brake actuator responsive to the brake command and a first gain factor for a second time period; (iv) after the second time period, applying power to the brake actuator responsive to the brake command and a second gain factor, wherein the second gain factor is less than the first gain factor, wherein the brake actuator is initialized responsive to the brake command.Type: GrantFiled: February 14, 1994Date of Patent: November 22, 1994Assignee: General Motors CorporationInventor: Deron C. Littlejohn
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Patent number: 5366280Abstract: A method of controlling an electric brake having an actuator controllable for moving brake pads against and away from a friction brake surface comprising the steps of (i) retracting a brake actuator after a braking operation; (ii) measuring a parameter indicative of work during the retraction; and (iii) moving the brake actuator to a position at which the brake actuator is ready for a next brake operation, wherein step (iii) is responsive to the measured parameter, wherein the brakes are rehomed adaptively to compensate for brake wear.Type: GrantFiled: February 14, 1994Date of Patent: November 22, 1994Assignee: General Motors CorporationInventor: Deron C. Littlejohn
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Patent number: 5362135Abstract: In a vehicle brake system having braking control responsive to a pressure signal from a pressure transducer in a hydraulic brake line, a method of operation comprising the steps of: (a) determining whether a brake pedal is depressed; (b) when the brake pedal is determined to be depressed: (i) controlling the brake system responsive to the pressure signal and a stored offset value for the pressure transducer, and (ii) resetting a timer; (c) when the brake pedal is determined to be not depressed: (i) cycling the timer, (ii) determining whether the timer has timed out, and (iii) if the timer has timed out, (iii.i) receiving the pressure signal from the pressure transducer, (iii.ii) comparing the pressure signal to a predetermined limit value indicative of an acceptable maximum sensor output when the pedal is not depressed, and (iii.iii) updating the stored offset value responsive to the pressure signal.Type: GrantFiled: February 14, 1994Date of Patent: November 8, 1994Assignee: General Motors CorporationInventors: Bryan P. Riddiford, Deron C. Littlejohn