Patents by Inventor Davorin Hrovat
Davorin Hrovat 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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Publication number: 20060135316Abstract: A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.Type: ApplicationFiled: December 16, 2004Publication date: June 22, 2006Applicant: FORD GLOBAL TECHNOLOGIES, LLCInventors: Yuji Fujii, Marvin Kraska, Gregory Pietron, William Tobler, Walter Ortmann, Bradley Riedle, Ronald Cowan, Davorin Hrovat
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Patent number: 6929582Abstract: A system is described for minimizing engine torque disturbances that would otherwise cause degraded drive feel by a vehicle driver. The system utilizes multiple torque transmission paths of a transaxle unit mounted to the engine. The system manipulates the torque transmitted by adjusting the clutches of multiple torque transmission paths so that the torque disturbance in the engine results in relatively constant vehicle drive torque. In one example, a potential torque increase due to variation in engine compression ratio is reduced using multiple paths of the transmission. In this way, relatively constant output torque can be maintained.Type: GrantFiled: October 1, 2003Date of Patent: August 16, 2005Assignee: Ford Global Technologies, LLCInventors: Woong-chul Yang, Ilya Kolmanovsky, Davorin Hrovat
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Publication number: 20050075212Abstract: A system is described for minimizing engine torque disturbances that would otherwise cause degraded drive feel by a vehicle driver. The system utilizes multiple torque transmission paths of a transaxle unit mounted to the engine. The system manipulates the torque transmitted by adjusting the clutches of multiple torque transmission paths so that the torque disturbance in the engine results in relatively constant vehicle drive torque. In one example, a potential torque increase due to variation in engine compression ratio is reduced using multiple paths of the transmission. In this way, relatively constant output torque can be maintained.Type: ApplicationFiled: October 1, 2003Publication date: April 7, 2005Inventors: Woong-Chul Yang, Ilya Kolmanovsky, Davorin Hrovat
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Patent number: 5696681Abstract: An electronic controller applies a braking force to selected wheels when sudden tire rupture is detected. A tire rupture signal indicative of whether a tire on the vehicle has ruptured is generated. Signals corresponding to a desired trajectory of the and the actual trajectory of the vehicle are calculated. Corresponding brake actuator signals are generated and applied to appropriate brakes of the vehicle, controlling the actual trajectory of the vehicle.Type: GrantFiled: June 5, 1995Date of Patent: December 9, 1997Assignee: Ford Global Technologies, Inc.Inventors: Davorin Hrovat, Anthony T. Ander
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Patent number: 5682316Abstract: A vehicle traction controller includes engine control and brake control routines to improve vehicle traction. The engine control routine reduces average slip of driven wheels of the vehicle by retarding spark timing and by reducing air flow into the engine via an electronically controlled throttle. The engine control routine is entered if the average wheel speed of the driven wheels is above a predetermined threshold speed. Control of spark timing is performed by a Proportional-Differential (PD) control technique. The electronically controlled throttle is controlled by a Proportional-Integral-Differential (PID) control technique. The brake control routine operates to reduce the rotational speed of the driven wheel which has the highest rotational speed. The brake control routine is entered if one of the driven wheels has a rotational speed which is greater than a maximum desired speed and if the difference in speed between the driven wheels is greater than a maximum difference value.Type: GrantFiled: June 5, 1995Date of Patent: October 28, 1997Assignee: Ford Motor CompanyInventors: Davorin Hrovat, Minh Ngoc Tran, Craig John Simonds, John Loring Yester
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Patent number: 5563792Abstract: A technique for estimating a traction characteristic of a surface under a moving vehicle, such as the coefficient of friction of the surface. The traction characteristic can be estimated by generating a torque signal representative of at least an estimate of the amount of torque applied to the driven wheels of the vehicle. A load signal representative of at least an estimate of the load or weight applied to the driven wheels also is generated. The value of the torque signal is divided by the value of the load signal in order to generate a characteristic signal. Depending on the amount of slippage between the driven and non-driven wheels of the vehicle, the characteristic signal can be stored in order to provide an estimate of the traction characteristic of the surface in real time.Type: GrantFiled: December 19, 1994Date of Patent: October 8, 1996Assignee: Ford Motor CompanyInventors: Anthony T. Ander, Davorin Hrovat, Craig J. Simonds, Lee-Fei Chen
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Patent number: 5520146Abstract: An electronic controller for automatically adjusting the position of a throttle valve in either a single valve or a series valve throttle mechanism. A primary controller (20) produces an output signal (18) suitable for directly operating the single throttle valve in a "drive by wire" throttle system. When used to position a valve (32) in a two-valve series throttle system, the other valve (34) being directly controlled by the accelerator pedal, a signal translation unit (30) is employed to modify the output signal (18) from the primary controller in response to the current setting of the accelerator-controlled valve (34) and values indicating the current air flow rate (Q.sub.1) and the intake manifold pressure (P.sub.m). The primary controller (20) and the signal translation unit are implemented using a conventional electronic engine control processor, with the signal translation being performed by table lookup operations (51-54).Type: GrantFiled: March 3, 1995Date of Patent: May 28, 1996Assignee: Ford Motor CompanyInventors: Davorin Hrovat, Michael Fodor, Minh N. Tran
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Patent number: 5515279Abstract: An electronic traction controller for a vehicle reduces oscillations between a pair of driving wheels which may occur when the the traction controller attempts to control wheel spin of the driving wheels on surfaces which have differing frictional resistances, such as roads partially covered by snow and ice. The traction controller estimates the coefficient of friction beneath each of the driving wheels, and if the frictional resistance of the surfaces beneath each of the driving wheels varies by more than a predetermined amount, or if only one wheel is spinning, a value indicative of the inertia torque of the driving wheel and powertrain combination is determined, and compared against a predetermined value. A slip error value for each of the driving wheels is generated, which is indicative of the difference between the actual rotational speed of the driving wheel and the desired rotational speed of the driving wheel.Type: GrantFiled: March 6, 1995Date of Patent: May 7, 1996Assignee: Ford Motor CompanyInventors: Davorin Hrovat, Minh N. Trans, Craig J. Simonds
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Patent number: 5471386Abstract: A vehicle traction controller controls vehicle traction and directional stability by determining the rotational velocity of the vehicle. The rotational velocity of the vehicle is measured and compared to a predefined range. If the rotational velocity is outside of the predefined range, then a wheel torque value, which is indicative of a braking force to be applied independently of driver initated braking, is generated for each wheel which is on a side of the vehicle as determined by the rotational velocity. The wheel torque value is compared to a range of values, which is based on road surface friction, and altered if the wheel torque value is outside of the range of values. Wheel spin and skid control is employed to reduce wheel spin and skid.Type: GrantFiled: October 3, 1994Date of Patent: November 28, 1995Assignee: Ford Motor CompanyInventors: Davorin Hrovat, Jahanbakhsh Asgari, Michael G. Fodor
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Patent number: 5365441Abstract: Techniques for controlling the spin of driven wheels of a vehicle also including non-driven wheels and an engine controlled by a spark angle and/or throttle position. The spark angle is controlled by a signal responsive to a slip error signal and a slip error derivative signal in order to alter the spark angle in a manner that controls the spin of the driven wheels. The throttle position is controlled by a throttle position control signal that is responsive to a slip error signal, a slip error derivative signal, and a slip error integration signal, in order to adjust the throttle position in a manner that controls the spin of the driven wheels. Wheel spin also can be controlled by the combination of a spark angle control signal and a throttle position control signal.Type: GrantFiled: August 31, 1992Date of Patent: November 15, 1994Assignee: Ford Motor CompanyInventors: Anthony T. Ander, Andrew A. Adamczyk, Davorin Hrovat, Lee-Fei Chen
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Patent number: 5278761Abstract: Techniques for controlling the spin of driven wheels of a vehicle being driven over a surface, the vehicle also including nondriven wheels and an engine having a fuel system for varying engine torque. A characteristic signal representative of at least an estimate of the value of a traction characteristic of a surface under the vehicle is generated. A drive signal having a value dependent on the value of the characteristic signal is then generated. The engine torque is varied in response to the drive signal in order to control the spin of the driven wheels of the vehicle.Type: GrantFiled: November 12, 1992Date of Patent: January 11, 1994Assignee: Ford Motor CompanyInventors: Anthony T. Ander, Davorin Hrovat, Craig J. Simonds, Lee-Fei Chen
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Patent number: 4792902Abstract: A system and method for controlling the ignition timing of a spark ignition internal combustion engine in a driveline that includes a multiple speed ratio transmission, at least one of whose operating speed ratios depends on the engaged or disengaged state of a clutch, the rotating inertia of the engine, equivalent vehicle inertia, a spring associated with the stiffness of the axle, inherent structural damping, and a spark advance controller-filter, whose output advances and retards the spark timing of the engine in accordance with the magnitude of engine speed and transmission output speed according to a control algorithm, which improves speed ratio control during shifts and minimizes the underdamped oscillations that result after the clutch is fully engaged.Type: GrantFiled: December 12, 1985Date of Patent: December 20, 1988Assignee: Ford Motor CompanyInventors: Davorin Hrovat, Charles Heermann, William E. Tobler
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Patent number: 4768608Abstract: A method and control system for controlling the wheel slip of a vehicle having at least one driven wheel coupled to an internal combustion engine. Feedback variables are generated and summed to generate a feedback control signal for controlling the engine throttle to reduce the wheel slip. One feedback variable is related to engine torque output at the time the torque output is delivered from the engine. More specifically, a measurement of intake manifold pressure is delayed for a time approximately equal to an integer multiple of the time delay between an intake stroke and power stroke of an engine cylinder.Type: GrantFiled: October 1, 1987Date of Patent: September 6, 1988Assignee: Ford Motor CompanyInventor: Davorin Hrovat