On Split Coefficient Surface (u) Patents (Class 701/73)
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Patent number: 7775608Abstract: A method for controlling a brake pressure in at least two wheel brakes preferably mounted on one axle of the vehicle, is performed during a braking operation on a road surface having a heterogeneous coefficient of friction. This method works as follows: A low coefficient of friction side and/or a high coefficient of friction side is detected, a stability index representing the driving state of the vehicle is formed, the stability index is evaluated on the basis of the low coefficient of friction side and/or of the high coefficient of friction side and the brake pressure is altered in at least one wheel brake as a function of the value of the stability index and as a function of the result of the evaluation of the stability index on the basis of the low coefficient of friction side and/or the high coefficient of friction side.Type: GrantFiled: December 21, 2004Date of Patent: August 17, 2010Assignee: Continental Teves, Inc.Inventors: Holger Schmidt, Anthony Dollet, Urs Bauer, Stephan Capellaro
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Patent number: 7765048Abstract: In deceleration control apparatus and method for an automotive vehicle, a deceleration control is performed on the basis of a turning of the vehicle; and a controlled variable of the deceleration control is decreased when the vehicle is traveling on an outlet of a curved road.Type: GrantFiled: October 8, 2004Date of Patent: July 27, 2010Assignee: Nissan Motor Co., Ltd.Inventors: Tatsuya Suzuki, Shinji Matsumoto
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Acceleration/deceleration induced real-time identification of maximum tire-road friction coefficient
Patent number: 7751961Abstract: A method for classifying a road surface condition by estimating the maximum tire/road surface coefficient of friction and actively inducing acceleration or deceleration. In one embodiment, the induced acceleration/deceleration is provided by applying torque to the driven wheels of the vehicle. The speeds of the driven and non-driven wheels are measured. The tire/road surface coefficient of friction and the driven wheel slip ratio are calculated from the wheel speeds. The tire/road surface coefficient of friction and the wheel slip ratio are used to determine the slope of the wheel slip/coefficient of friction curve, which is used to classify the road surface condition.Type: GrantFiled: September 15, 2005Date of Patent: July 6, 2010Assignee: GM Global Technology Operations, Inc.Inventors: Mutasim A. Salman, Sarmad Y. Hermiz -
Patent number: 7715964Abstract: A method of operating a vehicle at a substantially low speed based on change in the vehicle position. The method comprises the following steps: (A) transforming a steering control algorithm into a substantially low speed (SLS) steering control algorithm, wherein the (SLS) steering control algorithm is configured to operate the vehicle in an asynchronous low speed mode; and (B) implementing the SLS steering control algorithm as a controller configured to operate the vehicle in the asynchronous low speed mode.Type: GrantFiled: May 10, 2005Date of Patent: May 11, 2010Assignee: Trimble Navigation, Ltd.Inventor: John Arnold Connally
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Patent number: 7699137Abstract: A motor-driven steering controller for controlling a steering wheel of a vehicle. The controller includes a steering torque controlling unit, a braking force estimating unit, a right and left braking force difference estimating unit and an assist steering torque providing unit. The steering torque controlling unit controls a steering torque on the steering wheel depending on a steering operation. The braking force estimating unit estimates braking forces to be imposed on wheels of the vehicle. The right and left braking force difference estimating unit estimates difference between the braking forces to be imposed on the right and left wheels each estimated by the braking forces estimating unit. The assist steering torque providing unit provides an assist steering torque for the steering torque controlling unit on the basis of the difference in braking force between right and left wheels estimated by the right and left braking force difference estimating unit.Type: GrantFiled: August 16, 2007Date of Patent: April 20, 2010Assignees: Aisin Seiki Kabushiki Kaisha, Jtekt Corporation, Advics Co., Ltd.Inventors: Yoshiyuki Yasui, Wataru Tanaka, Yuji Muragishi, Eiichi Ono, Katsuhiro Asano, Minekazu Momiyama, Hiroaki Kato, Kenji Asano
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Patent number: 7702446Abstract: A road surface ? is updated with time on the basis of a present value (an estimation value E) of the road surface ? estimated to estimate the road surface ?. In this case, if there is acquired road-surface information in a vehicle travel direction that is detected by a road-side infrastructure, a specifying unit 11 specifies a road-surface friction coefficient based on the road-surface information. An estimating unit 12 sets the road surface ? (?inf) thus specified as an initial value, resets the present value of the road surface ? to the initial value, and then starts estimation of the road-surface friction coefficient based on this initial value. Accordingly, estimation precision of a road-surface friction coefficient is enhanced by using an initial value having high reliability in autonomous estimation of the road-surface friction coefficient.Type: GrantFiled: July 6, 2004Date of Patent: April 20, 2010Assignee: Fuji Jukogyo Kabushiki KaishaInventor: Yutaka Hiwatashi
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Publication number: 20100017088Abstract: A method for estimating a brake pressure, a longitudinal tire force and a tire-road ? during periods of antilock control that measures deceleration of a wheel during a period of constant brake pressure, reduces a brake pressure to cause slip on the wheel to begin reducing, measures reacceleration of the wheel after a point in time in which the change in brake pressure is completed, calculates a change in acceleration based on the measured reacceleration and the measured deceleration, estimates a change in brake pressure from a proportional relationship between the change in acceleration and a brake pressure value, estimates a brake pressure from the relationship between a time for valve activation during a change in acceleration and the change in brake pressure. The method also estimates a longitudinal tire force from a mathematical relationship between the change in acceleration, a tire radius, and the estimated brake pressure.Type: ApplicationFiled: March 17, 2009Publication date: January 21, 2010Inventor: John Patrick Joyce
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Publication number: 20100010710Abstract: A system and a device are provided for influencing the driving behavior of a vehicle by way of first and second closed-loop controls.Type: ApplicationFiled: March 29, 2007Publication date: January 14, 2010Inventors: Johannes Kopp, Martin Moser, Reinhold Schneckenburger, Christian Urban
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Patent number: 7584042Abstract: There is provided a new and novel vehicle running control device for correcting a yaw angle of a vehicle toward the yaw direction intended by a driver, together with vehicle stability control, through generating yaw moments. In order to accomplish the yaw angle correction, the inventive device operates a yaw moment generating apparatus e.g. a steering apparatus, so as to generate a direction correcting yaw moment based upon an integration value of the deviations between an actual yaw rate and its target value. The direction correcting yaw moment may be generated for correcting the yaw angle deviation remaining after the stability control is ended.Type: GrantFiled: April 21, 2005Date of Patent: September 1, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masato Suzumura, Yoshikazu Hattori
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Patent number: 7571033Abstract: System for detecting stability/instability of behavior of a motor vehicle upon occurrence of tire slip or lock. State of the motor vehicle is determined on the basis of an alignment torque (Ta) applied from a road and a side slip angle (?). By taking advantage of such torque/slip-angle characteristic that although the alignment torque is proportional to a side slip angle when the latter is small, the alignment torque becomes smaller as the side slip angle increases, a normal value is determined from a straight line slope and the side slip angle in a region where the latter is small. Unstable behavior of the motor vehicle is determined when deviation of actual measured value from the normal value increases. Further, unstable state is determined when the slope of the alignment torque for the slip angle departs significantly from that of approximate straight line slope.Type: GrantFiled: January 7, 2005Date of Patent: August 4, 2009Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Fujioka, Takanori Matsunaga, Takashi Maeda, Toshinori Matsui, Masahiko Kurishige, Hideyuki Tanaka
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Patent number: 7512473Abstract: A judgment method of road surface condition includes steps of: periodically detecting the wheel rotational speeds of the four wheel tires of a vehicle, memorizing the wheel rotational speed of each of tires, determining a slip ratio from said wheel rotational speeds, determining the acceleration or deceleration of the vehicle, determining a relation equation between said slip ratio and the acceleration or deceleration of the vehicle, determining a judgment value for judging a friction coefficient between the road surface and tires based on the slope of said relation equation determined, and setting a threshold which is used for judging the friction coefficient from the judgment value using the information of wireless tags which were buried in the tires.Type: GrantFiled: October 4, 2004Date of Patent: March 31, 2009Assignee: Sumitomo Rubber Industries, Ltd.Inventor: Yukio Nakao
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Patent number: 7499786Abstract: A system and a method for determining when to update a surface estimation value indicative of a condition of a roadway surface are provided. The method includes determining a front axle cornering force error value based on a predicted front axle cornering force value and a first front axle cornering force value. The method further includes determining a threshold yaw rate error value based on the front axle cornering force error value. The method further includes indicating that the surface estimation value is to be updated when a yaw rate error value is greater than the threshold yaw rate error value.Type: GrantFiled: July 18, 2006Date of Patent: March 3, 2009Assignee: Delphi Technologies, Inc.Inventors: Kevin A. O'Dea, Aleksander B. Hac, Todd A. Belvo
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Patent number: 7454279Abstract: System for detecting stability/instability of behavior of a motor vehicle upon occurrence of tire slip or lock. State of the motor vehicle is determined on the basis of an alignment torque (Ta) applied from a road and a side slip angle (?). By taking advantage of such torque/slip-angle characteristic that although the alignment torque is proportional to a side slip angle when the latter is small, the alignment torque becomes smaller as the side slip angle increases, a normal value is determined from a straight line slope and the side slip angle in a region where the latter is small. Unstable behavior of the motor vehicle is determined when deviation of actual measured value from the normal value increases. Further, unstable state is determined when the slope of the alignment torque for the slip angle departs significantly from that of approximate straight line slope.Type: GrantFiled: January 7, 2005Date of Patent: November 18, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Fujioka, Takanori Matsunaga, Takashi Maeda, Toshinori Matsui, Masahiko Kurishige, Hideyuki Tanaka
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Patent number: 7434896Abstract: A method for brake regulation in a vehicle when driving off on a split-? roadway is provided, in which method the presence of a drive-off procedure on a split-? roadway having a high coefficient of friction side and a low coefficient of friction side is recognized, and as a result, the brake pressure on a driven wheel on the high coefficient of friction side of the vehicle is increased.Type: GrantFiled: March 24, 2003Date of Patent: October 14, 2008Assignee: Robert Bosch GmbHInventor: Thomas Sauter
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Patent number: 7418329Abstract: A steering device is provided for controlling steering torque applied to a steering wheel of a vehicle. A braking device is provided for controlling longitudinal force applied to each wheel, and a control device is provided for performing at least one of an anti-skid control and a traction control. It is observed whether the control device is performing the control on a split road surface. The steering torque is controlled on the basis of a difference of longitudinal force applied to the right and left wheels, and a turning state amount deviation between a turning state amount and a desired amount thereof. The desired amount of turning state is calculated, on the basis of the turning state of the vehicle obtained when one of the anti-skid control and the traction control is performed on the split road surface.Type: GrantFiled: June 8, 2007Date of Patent: August 26, 2008Assignee: Advics Co., Ltd.Inventors: Yoshiyuki Yasui, Hiroyuki Kodama, Kenji Asano, Toshihisa Kato
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Patent number: 7398145Abstract: A grip factor estimating apparatus includes a steering torque detecting unit M1, and an assist torque detecting unit M2. When a self-aligning torque estimating unit M6 estimates self-aligning torque generated in front wheels on the basis of detection result of the detecting unit, the quantity of influence of longitudinal force on self-aligning torque is removed on the basis of longitudinal force acting on the front wheels and estimated by a longitudinal force estimating unit M15 and a front wheel slip angle estimated by a front wheel slip angle estimating unit M9y. A grip factor estimating unit M12 estimates the grip factor of the front wheels on the basis of change in self-aligning torque in accordance with the side force.Type: GrantFiled: September 2, 2004Date of Patent: July 8, 2008Assignees: Jtekt Corporation, Advics Co., Ltd.Inventors: Hiroaki Kato, Minekazu Momiyama, Yoshiyuki Yasui, Yuji Muragishi, Yuzo Imoto, Hiroaki Aizawa
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Patent number: 7374014Abstract: A motor-driven steering controller for controlling a steering wheel of a vehicle. The controller includes a steering torque controlling unit, a braking force estimating unit, a right and left braking force difference estimating unit and an assist steering torque providing unit. The steering torque controlling unit controls a steering torque on the steering wheel depending on a steering operation. The braking force estimating unit estimates braking forces to be imposed on wheels of the vehicle. The right and left braking force difference estimating unit estimates difference between the braking forces to be imposed on the right and left wheels each estimated by the braking forces estimating unit. The assist steering torque providing unit provides an assist steering torque for the steering torque controlling unit on the basis of the difference in braking force between right and left wheels estimated by the right and left braking force difference estimating unit.Type: GrantFiled: April 8, 2003Date of Patent: May 20, 2008Assignees: Aisin Seiki Kabushiki Kaisha, Jtekt Corporation, Advics Co., Ltd.Inventors: Yoshiyuki Yasui, Wataru Tanaka, Yuji Muragishi, Eiichi Ono, Katsuhiro Asano, Minekazu Momiyama, Hiroaki Kato, Kenji Asano
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Patent number: 7356401Abstract: A drivetrain protection and management system (DPMS) monitors and determines individual wheel speeds to detect wheel spin and slip conditions on a drive axle. Wheel spin is caused by low surface friction, excessive input torque, lack of inter-axle differential and differential locks, excessive operating temperatures, or poor driving techniques. When wheel spin or slip exceeds a threshold, the DPMS automatically controls input torque to the drive axle by controlling engine or retarder torque. In addition to monitoring wheel speeds, the DPMS monitors other vehicle characteristics such as engine torque/speed, transmission ratio, transmission output speed, vehicle speed, throttle position, for example. The DPMS monitors and stores these vehicle characteristics over time and generates a data output that summarizes a history of vehicle operating conditions. The DPMS can communicate this data output real time during vehicle operation, which can be used by a fleet to maximize vehicle performance.Type: GrantFiled: August 13, 2004Date of Patent: April 8, 2008Assignee: ArvinMeritor Technology, LLCInventors: Richard A. Romer, Robert S. Harrison
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Patent number: 7349775Abstract: System for detecting stability/instability of behavior of a motor vehicle upon occurrence of tire slip or lock. State of the motor vehicle is determined on the basis of an alignment torque (Ta) applied from a road and a side slip angle (?). By taking advantage of such torque/slip-angle characteristic that although the alignment torque is proportional to a side slip angle when the latter is small, the alignment torque becomes smaller as the side slip angle increases, a normal value is determined from a straight line slope and the side slip angle in a region where the latter is small. Unstable behavior of the motor vehicle is determined when deviation of actual measured value from the normal value increases. Further, unstable state is determined when the slope of the alignment torque for the slip angle departs significantly from that of approximate straight line slope.Type: GrantFiled: January 7, 2005Date of Patent: March 25, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Fujioka, Takanori Matsunaga, Takashi Maeda, Toshinori Matsui, Masahiko Kurishige, Hideyuki Tanaka
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Publication number: 20070208484Abstract: An object of the invention is to provide a vehicle automatic running control system, according to which the vehicle automatic control operation is carried out as long as possible, even when the vehicle is running on a punishing road. For that purpose, the system of the invention determines a degree of concavity and convexity of a road surface and prohibits the automatic running control operation when the degree of concavity and convexity of the road surface is larger than a predetermined value.Type: ApplicationFiled: February 27, 2007Publication date: September 6, 2007Applicant: DENSO CORPORATIONInventors: Tomohiro Tsujimura, Ikurou Hasimoto
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Patent number: 7248958Abstract: A tire-generated sound detection sensor detects a tire-generated sound that is generated from a tire while the vehicle is running. A wheel rotation sensor detects a wheel rotation speed. A preprocessor calculates feature quantities corresponding to a road surface state and tire-generated sound sources. A feature vector generator generates a feature vector having, as components, the feature quantities calculated by the preprocessor and the detected wheel rotation speed. A judgment processor estimates a state of a road surface on which the vehicle is running on the basis of the feature vector generated by the feature vector generator and feature vectors that are stored in a judgment map memory so as to be correlated with a plurality of road surface states, respectively, and each of which corresponds to a road surface state and tire-generated sound sources.Type: GrantFiled: November 7, 2003Date of Patent: July 24, 2007Assignee: Kabushiki Kaisha Toyota Chuo KenkyushoInventors: Yoshitoshi Watanabe, Katsuhiro Asano, Takaji Umeno, Shu Asami, Masaru Sugai
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Patent number: 7191048Abstract: A vehicle motion control apparatus is provided for performing a vehicle stability control on the basis of a parameter indicative of lateral margin for a tire on a road. The apparatus includes a steering control device for controlling a relationship between a steering angle and a tire angle to be varied, and a decelerating control device for controlling a vehicle speed to be decreased. The parameter indicative of lateral margin for the tire is monitored, and the steering control device and the decelerating control device are controlled on the basis of the monitored parameter.Type: GrantFiled: August 26, 2004Date of Patent: March 13, 2007Assignees: Advics Co., Ltd., Toyoda Koki Kabushiki KaishaInventors: Hiroaki Aizawa, Hiroaki Niino, Minekazu Momiyama, Hiroaki Kato, Eiichi Ono, Yuji Muragishi, Yoshiyuki Yasui
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Patent number: 7171297Abstract: A comparison/determination part 7 recieves the input of a front wheel speed filtered value ?fF from a front wheel speed filtered value calculation part 5 and a rear wheel speed filtered value ?rF from a rear wheel speed filtered value calculation part 6. It is determined whether the front wheel speed filtered value ?fF has exceeded a preset first threshold C1. It is determined whether the rear wheel speed filtered value ?rF has exceeded a preset second threshold C2 within a time for transmission of vibration from the front wheels to the rear wheels which is experimentally set in advance after the front wheel speed filtered value ?fF exceeded the first threshold C1. The road surface is then determined to be rough when it is determined that the rear wheel speed filtered value ?rF has exceeded the preset second threshold C2.Type: GrantFiled: August 19, 2004Date of Patent: January 30, 2007Assignee: Fuji Jukogyo Kabushiki KaishaInventor: Masaru Kogure
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Patent number: 7107138Abstract: A new automotive (speed control system) safety feature is disclosed. A vehicle with an engaged speed control could be dangerous to drive on a road surface that changes from dry, offering little rolling resistance, to a surface that offers increased resistance to tire rotation. Resistance to tire rotation by water or snow on a road surface will cause an engaged speed control system to try and maintain the set vehicle speed by accelerating the vehicle into the rolling resistance. A driver may lose control of the vehicle in this circumstance if the speed control cannot be disabled immediately. The new safety feature disclosed would automatically disable the vehicle speed control system when the vehicle decelerates due to significant water or snow accumulation on the road surface.Type: GrantFiled: November 2, 2004Date of Patent: September 12, 2006Inventor: Joseph Edward Currie
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Patent number: 7099765Abstract: A method of determining the grip coefficient ? in the contact area of a tire on a road includes the steps of selecting a plurality of fixed points in space (that is to say ones that are fixed in the reference frame associated with the vehicle) which points lie at different azimuths along the circumference in at least one sidewall of the tire, obtaining a corresponding number of measurements of circumferential distance variation (extension or contraction) at these fixed points when the tire is rolling on the road, and the measurement signals are processed so as to extract the grip coefficient ?.Type: GrantFiled: August 4, 2004Date of Patent: August 29, 2006Assignee: Michelin Recherche et Technique S.A.Inventor: David Bertrand
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Patent number: 7069135Abstract: A method for estimation of the maximum grip coefficient on the basis of knowledge of the forces and the self-alignment torque which are generated in the contact area of a tire, includes the steps of: selecting a plurality of fixed points in space, which lie at different azimuths along the circumference in at least one sidewall of the tire, carrying out a corresponding number of measurements of circumferential distance variation (extension or contraction) at these fixed points when the tire is rolling on the road, processing the measurement signals so as to extract the three components of a resultant of forces which are exerted by the road on the contact area of a tire and the self-alignment torque generated by the tire from them, processing the evaluation signals of the three components of a resultant of forces which are exerted by the road on the contact area of a tire and of the self-alignment torque generated by the tire so as to extract the said grip coefficient ? from them.Type: GrantFiled: August 4, 2004Date of Patent: June 27, 2006Assignee: Michelin Recherche Et Technique S.A.Inventor: David Bertrand
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Patent number: 7035726Abstract: A steering characteristic control apparatus and method for a vehicle is disclosed which can carry out behavior control of the vehicle regarding a steering characteristic and so forth appropriately in accordance with the type of turning and the road surface situation. To this end, if the steering characteristic of the vehicle is placed into an oversteer or understeer state exceeding a reference level, then the control end condition when the steering characteristic is controlled to the neutral steer side by control of a braking mechanism is set in accordance with an estimated road surface ? state and the type of turning (steady turning or non-steady turning) of the vehicle. Upon steady turning, during traveling on a low ? road, it is set as the control end condition that the stability of the vehicle behavior is restored sufficiently, but during traveling on a high ? road, it is set as the condition that the stability of the vehicle behavior is restored to some degree so that the control can be ended rapidly.Type: GrantFiled: March 7, 2005Date of Patent: April 25, 2006Assignee: Mitsubishi Fuso Truck and Bus CorporationInventor: Kunio Sakata
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Patent number: 6954140Abstract: A rollover prevention device and method detects an impending rollover situation for a vehicle (10) having a high center of gravity (cg). The system alerts the operator to potentially dangerous driving conditions and/or automatically slows the velocity of the vehicle (10) to prevent rollover. An electronic control unit for receives output signals from wheel velocity, engine revolution, and engine load sensors and then calculates lateral acceleration, wheel slip difference, and drive torque from the signals. A lateral acceleration limit is defined by plotting lateral acceleration, wheel slip difference and drive torque as a three dimensional surface.Type: GrantFiled: March 14, 2002Date of Patent: October 11, 2005Assignee: Bendix Commercial Vehicle Systems LLCInventor: Gusztav Holler
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Patent number: 6898505Abstract: A system is provided, which controls a starting and the subsequent vehicle acceleration procedure of a motor vehicle. The system compares a predetermined variable that grows continuously during the starting procedure to a threshold value. It determines a first desired value of torque in response to operator demand, and a second desired value torque in response to acceleration slip. The system performs a feed-forward 4WD control in response to the first desired value of torque when the predetermined variable is lower than or equal to the threshold value. The system determines whether or not driving situation justifies a change from performing the feed-forward 4WD control to performing a feed-back 2/4WD control in response to the second desired value of torque.Type: GrantFiled: April 30, 2003Date of Patent: May 24, 2005Assignee: Nissan Motor Co., Ltd.Inventors: Keiji Kadota, Kouichi Shimizu, Hidetoshi Suzuki
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Patent number: 6895317Abstract: The present invention is directed to a wheel grip factor estimation apparatus, which includes a steering factor detection unit for detecting at least one of steering factors including a steering torque and steering effort applied to a steering system extending from a steering wheel to a suspension of a vehicle, an aligning torque estimation unit for estimating an aligning torque produced on at least a wheel of the vehicle on the basis of the steering factor detected by the steering factor detection unit, and a vehicle state variable detection unit for detecting a state variable of the vehicle. The apparatus further includes a wheel factor estimation unit for estimating at least one of wheel factors including a side force and slip angle applied to the wheel on the basis of the vehicle state variable, and a grip factor estimation unit for estimating a grip factor of at least a tire of the wheel, in accordance with a relationship between the estimated alignment torque and the estimated wheel factor.Type: GrantFiled: April 23, 2003Date of Patent: May 17, 2005Assignees: Aisin Seiki Kabushiki Kaisha, Toyoda Koki Kabushiki Kaisha, Advics Co., Ltd.Inventors: Yoshiyuki Yasui, Wataru Tanaka, Eiichi Ono, Yuji Muragishi, Katsuhiro Asano, Minekazu Momiyama, Syoji Ogawa, Kenji Asano, Yuzo Imoto, Hiroaki Kato
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Patent number: 6893380Abstract: A method and a device for protecting a torque converter of an automatic transmission from overheating during standing-start of a motor vehicle, a slipping wheel being decelerated by a traction control system by a braking intervention. To improve the protective function of the traction control system, the energy loss converted in the torque converter or a value proportional to it is calculated and the engine torque is reduced if a specified threshold value is exceeded.Type: GrantFiled: March 25, 2003Date of Patent: May 17, 2005Assignee: Robert Bosch GmbHInventor: Thomas Sauter
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Patent number: 6882921Abstract: A vehicle traction control system is actuated when driven wheel slip (S1) exceeds a predetermined slip threshold (Ts) to reduce the amount of driven wheel slip (S1) by reducing the driven wheel speed. The traction control system also monitors vehicle deceleration. Upon detecting that the vehicle is decelerating and that the vehicle deceleration has exceed a deceleration threshold, the traction control system determines that the vehicle has encountered a deformable surface such as mud or deep snow. Upon detecting entry onto a deformable surface, the slip threshold (Ts) is linearly increased over a period of time to increase the driven wheel speed and thereby allow the wheels to churn through the deformable surface.Type: GrantFiled: July 6, 2001Date of Patent: April 19, 2005Assignee: Kelsey-Hayes CompanyInventors: Douglas J. Priemer, Bernard W. Dumm
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Patent number: 6816769Abstract: A traction control system having a braking intervention in particular for motor vehicles in which a slipping wheel is braked by a braking intervention on exceeding a slippage threshold. To improve the stability and steerability of the vehicle on slopes having different adhesive friction values between the right and left sides of the vehicle (&mgr;-split), the slippage threshold of the slipping low-&mgr; wheel is adjusted as a function of the slope, the slippage threshold of the slipping wheel being increased with an increase in slope in the case of a front-wheel drive vehicle and is decreased with an increase in slope in the case of a rear-wheel drive vehicle.Type: GrantFiled: March 27, 2003Date of Patent: November 9, 2004Assignee: Robert Bosch GmbHInventor: Norbert Polzin
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Patent number: 6810981Abstract: A traction control system (TCS) in which the engine torque is reduced after a slip threshold has been exceeded by at least one driven wheel and is raised again after the slip has fallen below the threshold, the traction control system further including an arrangement for detecting cornering and coefficient of friction. In order to improve vehicle stability when cornering, upon detection of cornering on a road surface having a low coefficient of friction, the gradient of the engine torque increase during the TCS control action is set lower than when traveling straight ahead.Type: GrantFiled: March 18, 2003Date of Patent: November 2, 2004Assignee: Robert Bosch GmbHInventor: Thomas Sauter
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Publication number: 20040204812Abstract: An apparatus and method for detecting the road condition for use in a motor vehicle. The system and method detect road data through a temperature sensor, an ultrasonic sensor, and a camera. The road data is filtered for easier processing. A comparison of the filtered road data to reference data is made, and a confidence level of that comparison is generated. Based on the comparison of filtered road data to reference data, the road condition is determined. The driver may be informed and/or stability control systems may be adjusted based on the detected road surface condition.Type: ApplicationFiled: April 9, 2003Publication date: October 14, 2004Applicant: Continental Teves Inc.Inventor: Vinh H. Tran
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Patent number: 6804592Abstract: A method directed to improving the stability of a motor vehicle having front and rear steering capabilities includes determining a coefficient of friction of the road surface with which the motor vehicle is engaged and adjusting a phase gain function of a rear steering mechanism to compensate for the steerability of the motor vehicle over the road surface. A system for improving the stability of a motor vehicle having front and rear steering capabilities includes a control unit, a front steering mechanism in informational communication with the control unit, and a rear steering mechanism in informational communication with the control unit. The rear steering mechanism is responsive through the control unit to road conditions of the road surface.Type: GrantFiled: October 18, 2001Date of Patent: October 12, 2004Assignees: Delphi Technologies, Inc., General Motors CorporationInventors: Steven Donald Klein, Scott M. Wendling, Paul A. Grougan, Scott P Sherman, Eugene A Rodden, Roderick L Lemmer
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Patent number: 6728621Abstract: A method and apparatus for operating a vehicle anti-lock braking system includes a brake pedal and a brake modulator that reduces braking pressure by an initial pressure reduction after detecting insipient wheel lock. Vehicle deceleration is measured as a function of brake pedal position. A first table is updated with the vehicle deceleration and the brake pedal position. A coefficient of friction of a road surface is estimated based on the first table. A slip target for at least one wheel is estimated and is based on an estimated maximum slip of the at least one wheel before losing traction minus an estimated potential for vehicle rollover. A deceleration target for at least one wheel is estimated and is based on an estimated maximum deceleration of the at least one wheel before losing traction minus the estimated potential for vehicle rollover.Type: GrantFiled: October 4, 2002Date of Patent: April 27, 2004Assignee: General Motors CorporationInventors: Allen John Walenty, Kevin Gerard Leppek, David Alan Thatcher
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Patent number: 6704622Abstract: Stability is an important factor in vehicle safety. Yaw rate error can be used to improve stability. Yaw rate is measured through a yaw rate sensor. Desired yaw rate can be determined from vehicle conditions and driver input. The yaw rate error is calculated by subtracting the measured yaw rate from the desired yaw rate. Based on this calculation, yaw torque target signals can be calculated to apply torque to the wheels through the application of one or more electric drivelines. The application of torque can provide side-to-side and front-to-rear torque biasing to improve stability. Furthermore, the application of torque at specific times can improve braking and launch capabilities.Type: GrantFiled: December 28, 2001Date of Patent: March 9, 2004Assignee: Visteon Global Technologies, Inc.Inventors: Michael R. Tinskey, Hualin Tan, Yohannes G. Haile
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Patent number: 6704635Abstract: A vehicle anti-lock braking system includes a brake pedal and a brake modulator. The brake system reduces braking pressure by an initial pressure reduction after detecting insipient wheel lock. Vehicle deceleration is measured as a function of brake pedal position. A first table is updated with the vehicle deceleration and the brake pedal position. A coefficient of friction of a road surface is estimated based on the first table. Wheel slip and deceleration target thresholds are determined based on the coefficient of friction. The wheel slip and deceleration target thresholds are used to populate a command table for the anti-lock braking system. Brake heat, brake torque, vehicle weight and grade are estimated. Release and apply pressures are calculated from an adjusted coefficient of friction, a coefficient of friction and the grade.Type: GrantFiled: June 26, 2002Date of Patent: March 9, 2004Assignee: General Motors CorporationInventors: Allen John Walenty, Kevin Gerard Leppek, David Alan Thatcher
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Patent number: 6691017Abstract: A vehicle behavior control device includes a turning limit state detecting device for detecting a turning limit state of a vehicle and an engine output control device for performing a torque-down control by decreasing an engine output when the turning limit state of the vehicle is detected.Type: GrantFiled: December 12, 2002Date of Patent: February 10, 2004Assignee: Aisin Seiki Kabushiki KaishaInventors: Masaki Banno, Shiro Monzaki
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Patent number: 6681168Abstract: A traction control device for a vehicle that has at least one axle, to which two driven wheels are assigned, the traction control device, when one of the driven wheels of the axle shows a tendency to spin, regulating the kinematic behavior of the wheel tending to spin by building up a first wheel brake pressure such that the wheel tending to spin of the axle remains within a permissible slip range. In order to reduce disturbance torques caused by the first wheel brake pressure for a wheel that is not tending to spin of the axle, a second wheel brake pressure is built up, which is adjustable independently of the first wheel brake pressure. Also described is a method for controlling the slip of at least one driven wheel of an axle of a vehicle.Type: GrantFiled: October 29, 2001Date of Patent: January 20, 2004Assignee: Robert Bosch GmbHInventor: Norbert Polzin
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Publication number: 20030216851Abstract: A method and an apparatus for regulating the speed of the low-&mgr; wheel as a vehicle starts from rest or accelerates on a road surface having adhesive friction values that differ between the left and right sides of the vehicle (split-&mgr;), the low-&mgr; wheel being braked by braking intervention when it has exceeded a defined slip threshold.Type: ApplicationFiled: March 28, 2003Publication date: November 20, 2003Inventors: Mirko Trefzer, Rainer Heinsohn
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Patent number: 6618660Abstract: An improved anti-lock rear brake yaw control method utilizes a measure of braking intensity to regulate both the initiation of yaw control and the anti-lock braking control parameters once yaw control is initiated. The brake torque and the rate of brake pedal depression provide measures of braking intensity, and are used to develop variable slip and deceleration thresholds to which the rear wheel differential slip and deceleration are compared. The variable thresholds permit initiation of yaw control at relatively low levels of differential wheel slip or deceleration during panic braking, while requiring higher levels of differential wheel slip or deceleration to initiate yaw control during moderate braking.Type: GrantFiled: October 15, 2001Date of Patent: September 9, 2003Assignee: General Motors CorporationInventors: Allen John Walenty, Kevin Gerard Leppek
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Patent number: 6556912Abstract: A control section of a road friction coefficient estimating apparatus inputs a vehicle speed, a steering wheel angle and a yaw rate from a vehicle speed sensor, a steering wheel angle sensor and a yaw rate sensor, respectively. The control section comprises a reference yaw rate calculating section, a yaw rate deviation calculating section, a yaw rate deviation dispersion calculating section and a road friction coefficient establishing section. The reference yaw rate calculating section calculates a reference yaw rate based on vehicle speed and steering angle in accordance with a vehicle motion model. The yaw rate deviation calculating section calculates a yaw rate deviation based on the reference yaw rate and the actual yaw rate. The yaw rate deviation dispersion calculating section calculates a dispersion of the yaw rate deviation for a specified sampling number.Type: GrantFiled: June 18, 2001Date of Patent: April 29, 2003Assignee: Fuji Jukogyo, Kabushiki KaishaInventor: Koji Matsuno
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Publication number: 20030074125Abstract: An improved anti-lock rear brake yaw control method utilizes a measure of braking intensity to regulate both the initiation of yaw control and the anti-lock braking control parameters once yaw control is initiated. The brake torque and the rate of brake pedal depression provide measures of braking intensity, and are used to develop variable slip and deceleration thresholds to which the rear wheel differential slip and deceleration are compared. The variable thresholds permit initiation of yaw control at relatively low levels of differential wheel slip or deceleration during panic braking, while requiring higher levels of differential wheel slip or deceleration to initiate yaw control during moderate braking.Type: ApplicationFiled: October 15, 2001Publication date: April 17, 2003Inventors: Allen John Walenty, Kevin Gerard Leppek
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Patent number: 6549842Abstract: The present invention provides a method of estimating a coefficient of adhesion between a road surface and a plurality of tires disposed on a vehicle. An estimated coefficient of adhesion for each of the plurality of tires is provided. First values of longitudinal and lateral forces on the tires are determined from a first set of vehicle dynamic parameters requiring no explicit knowledge of the coefficient of adhesion; and second values of the same forces are determined from a second set of vehicle parameters in an analytic tire model including the estimated value of the coefficient of adhesion. Differences between the first and the second values of the forces on the tires are determined in the longitudinal and lateral directions. Longitudinal and lateral adaptation speeds are determined for each of the plurality of tires; and a coefficient of adhesion adjustment for each of the plurality of tires is estimated from the differences and the adaptation speeds.Type: GrantFiled: October 31, 2001Date of Patent: April 15, 2003Assignee: Delphi Technologies, Inc.Inventors: Aleksander Boguslaw Hac, Mark Olen Bodie
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Patent number: 6533367Abstract: A method for controlling the traction slip of a vehicle on a roadway with sidewise different coefficients of friction includes the following steps: identifying a driving situation on a roadway with sidewise different coefficients of friction and, when the driving situation is identified and traction slip is encountered on both wheels, decreasing the brake pressure of the driven wheel on the low coefficient-of-friction side. A device for controlling the traction slip of a vehicle on a roadway with sidewise different coefficients of friction includes a determining device for determining a driving situation on a roadway with sidewise different coefficients of friction, and a brake actuation control which decreases the brake pressure of the driven wheel on the low coefficient-of-friction side when the driving situation is identified and traction slip is encountered on both wheels.Type: GrantFiled: April 24, 2001Date of Patent: March 18, 2003Assignee: Continental Teves AG & Co. OHGInventors: Michael Latarnik, Harald Kahl, Siegfried Halat, Ulrich Stöckmann, Bernd-Uwe Hartmann
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Patent number: 6535808Abstract: A deceleration control for automotive vehicle speed control apparatus includes first and second memories storing values of closed and open loop deceleration commands, respectively, as functions of the desired vehicle deceleration rate signal. During commanded vehicle deceleration, closed loop brake command signals, derived from values of the closed loop deceleration command in the first memory, are provided to the vehicle braking system while the determined vehicle speed exceeds a transition threshold value; and, alternatively, open loop brake command signals derived from values of the open loop deceleration command in the second memory are provided to the vehicle braking system while the determined vehicle speed does not exceed the transition threshold value. The values in the first memory means are updated on the basis of deceleration error while the determined vehicle speed exceeds the transition threshold value.Type: GrantFiled: December 19, 2001Date of Patent: March 18, 2003Assignee: Delphi Technologies, Inc.Inventor: Jon Tomas Zumberge
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Publication number: 20030028308Abstract: In a brake control apparatus for a vehicle, a left and right road friction coefficient estimating section calculates each of left and right estimated road surface friction coefficients from a relation between a pressure decrease control time in one cycle and a maximum wheel acceleration during the pressure decrease time. A split friction discriminating section discriminates a split friction road surface condition from a non-split condition in accordance with a difference between the left and right estimated road surface friction coefficients. A control modifying section modifies a brake fluid pressure control for a wheel cylinder to differentiate brake control characteristics for left and right wheels from each other in the case of the split friction road surface condition.Type: ApplicationFiled: July 2, 2002Publication date: February 6, 2003Applicant: UNISIA JECS CORPORATIONInventors: Atsushi Ishikawa, Gen Inoue, Nobuyuki Ohtsu
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Patent number: 6502029Abstract: A system and method for ABS stability control is provided, the method comprising the steps of determining whether a first wheel is in an ABS mode; determining whether the first wheel is in an apply mode; determining whether a second parallel wheel is in the release mode; calculating an adjusted wheel slip if the first wheel is in the ABS mode, the first wheel is in the apply mode, and the second parallel wheel is in the release mode; and determining a control mode for the first wheel using the adjusted wheel slip.Type: GrantFiled: January 3, 2001Date of Patent: December 31, 2002Assignee: Delphi Technologies, Inc.Inventor: Kevin A. O'Dea