Having Coefficient Of Friction Or Road Condition Determining Means Patents (Class 701/80)
  • Patent number: 6484089
    Abstract: A vehicle navigation system includes a map database and at least one inertial sensor. When the vehicle encounters a problem road condition, such as a pothole, the problem road condition induces acceleration in the inertial sensor. The navigation system identifies the occurrence of a problem road condition by monitoring the signals generated by the inertial sensor. The navigation system then stores the occurrence and location of the problem road condition. This data can be used later to identify, locate and repair problem road conditions.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: November 19, 2002
    Assignee: Magellan DIS, Inc.
    Inventor: Jeffrey Alan Millington
  • Patent number: 6473682
    Abstract: An apparatus and method that determines a maximum road friction coefficient for each wheel regardless of whether the tire is in a predetermined drive slip state, and whether the wheel is a driving wheel. The braking force of each wheel is calculated, and the longitudinal force of the tire of each wheel is calculated. Then, the driving force of the vehicle is calculated, and the lateral force of the tire of each wheel is calculated. Next, the reaction force of the road to each wheel is calculated, and the vertical load of each wheel is calculated. Finally, the ratio of variation in reaction force of the road to variation in composite slip ratio is calculated for each wheel. The sum of the ratio of the reaction force of the road to the vertical load, and the product of a predetermined coefficient and the ratio of variation in reaction force of the road to variation in composite slip ratios is calculated for each wheel as the maximum road friction coefficient.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: October 29, 2002
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Akira Nakamura
  • Patent number: 6463376
    Abstract: An apparatus for determining a condition of road surface comprising: rotational speed detecting means for periodically detecting rotational speeds of four tires of a vehicle; first computing means for computing a slip ratio from measurement values of the rotational speed detecting means; second computing means for obtaining a relational formula between the slip ratio and either the acceleration or deceleration of the vehicle; and friction coefficient judging means for judging a coefficient of friction occurring between a road and a tire on the basis of a slope of the relational formula obtained by the second computing means. The road friction coefficient can be judged with high accuracy in a short time using only the wheel rotational speed information of four wheels, whereby the performance and safety of a vehicle can be increased.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: October 8, 2002
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Hiroaki Kawasaki, Yukio Nakao
  • Patent number: 6459971
    Abstract: In an electric power steering control system, a road surface reaction torque estimator estimates a road surface reaction torque on the basis of steering wheel angle. A neutral point learning unit and a neutral point compensator learn a neutral point of the steering wheel on the basis of the road surface reaction torque with respect to the steering wheel angle. A return torque for returning the steering wheel to the neutral point is computed from a difference between a current angle of the motor and the learned neutral point. As a result, the steering wheel returns to the neutral point under the current driving condition without application of any force to the steering wheel by the driver.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: October 1, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Kurishige, Noriyuki Inoue, Ryoji Nishiyama, Kazumichi Tsutsumi, Takayuki Kifuku
  • Publication number: 20020120383
    Abstract: The road surface friction sensor of this invention comprises means for measuring the strain of the tire or around the wheel of a vehicle. By using this sensor, a vehicle antilock braking device can be constructed which is adapted to cyclically increase the pressure of brake fluid while the road surface frictional force increases in response to elevation of brake fluid pressure, decrease the brake fluid pressure when the road surface frictional force declines despite elevation of brake fluid pressure and increase the brake fluid pressure again when the road surface frictional force has declined in response to fall-off of brake fluid pressure. The output signal from the above road surface friction sensor can be subjected to mathematical operation to find a road surface friction coefficient.
    Type: Application
    Filed: July 5, 2001
    Publication date: August 29, 2002
    Applicant: Japan Electronics Industry, Ltd.
    Inventor: Nagao Miyazaki
  • Patent number: 6442470
    Abstract: The invention consists in the determination of road conditions during unbraked or partially braked ride of a vehicle through a time derivative of characteristics which are detected on at least one wheel of the vehicle and whose averages are created.
    Type: Grant
    Filed: December 16, 2000
    Date of Patent: August 27, 2002
    Assignee: Continental Teves AG & Co., OHG
    Inventors: Wolfgang Kling, Robert Schmidt
  • Patent number: 6429788
    Abstract: In alarming apparatus and method for an automotive vehicle, a vehicular running state is detected, a frictional coefficient of a road surface on which the vehicle is running is detected, a vehicle using road surface frictional coefficient that corresponds to a road surface frictional force the presently running vehicle is using is calculated on the basis of the detected vehicular running state, a road surface frictional coefficient utilization rate is calculated which is a rate of the calculated vehicle using road surface frictional coefficient of the road surface to a maximum frictional coefficient detected by the road surface frictional coefficient detector, and an alarm controlling section is calculated to output an alarm command to an alarm device to issue an alarm when the calculated road surface frictional coefficient utilization rate is equal to or larger than a set value.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: August 6, 2002
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Shinji Matsumoto, Masahiko Iwasaki
  • Patent number: 6421598
    Abstract: An anti-lock brake control system is provided which applies appropriate antilocking control while at the same time reduce the amount of brake fluid consumption normally experienced in vehicles with anti-lock brake systems. To that end, this invention is designed to provide an anti-lock brake control system where the rear wheel is individually controlled upon activating the brake force distribution control and the rear wheel is controlled on a select-low bases if the brake force distribution control is not activated. Various other methods of control are described.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: July 16, 2002
    Assignee: Nisshinbo Industries, Inc.
    Inventor: Hiroshi Oshiro
  • Patent number: 6418369
    Abstract: A road surface friction coefficient estimating apparatus is provided for estimating a road surface friction coefficient of a vehicle that is traveling at a steady state. The road surface friction coefficient estimating apparatus basically has a driving/braking force controller, a driving force controller, a braking force controller (brake fluid pressure controller), a plurality of wheel velocity sensors, a wheel load sensor and a control unit. The driving/braking force controller sets a pre-selected force to be generated and calculates the road surface friction coefficient. The driving force controller generates a driving force in accordance with the pre-selected force. The braking force controller generates a braking force in accordance with the pre-selected force. The wheel velocity sensors produce a wheel velocity signal indicative of a wheel velocity. The wheel load detecting sensor produces a wheel load signal indicative of a wheel load.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: July 9, 2002
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Shinji Matsumoto, Takeshi Kimura, Taku Takahama, Hiromitsu Toyota
  • Publication number: 20020087251
    Abstract: A road friction coefficient estimating apparatus primarily includes an adaptive control road friction coefficient estimating section and an actual value comparison road friction coefficient estimating section. The adaptive control road friction coefficient estimating section inputs signals indicative of a road surface condition with low friction coefficient from a wiper switch, low outside air temperature judging section and the like and estimates an accurate road friction coefficient even under the low friction coefficient road surface condition. When the vehicle travels at high speeds, the actual value comparison road friction coefficient estimating section renders a road friction coefficient estimating value by a yaw rate comparison method gradually close to a road friction coefficient of an asphalted road surface.
    Type: Application
    Filed: November 14, 2001
    Publication date: July 4, 2002
    Inventors: Masaru Kogure, Yutaka Hiwatashi
  • Publication number: 20020072841
    Abstract: A road friction coefficients estimating apparatus for a vehicle comprises a first road friction coefficient estimating section for calculating a first road friction coefficient based on a vehicle behavior in a lateral direction, a second road friction coefficient estimating section for calculating a second road friction coefficient based on a vehicle behavior in a longitudinal direction, a third road friction coefficient estimating section for calculating a third road friction coefficient based on road conditions and an estimating value selection section for selecting either one of the first, second and third road friction coefficients as a final road friction coefficient estimating value.
    Type: Application
    Filed: October 25, 2001
    Publication date: June 13, 2002
    Inventor: Masaru Kogure
  • Publication number: 20020072842
    Abstract: A road friction coefficient estimating apparatus for a vehicle includes a high friction coefficient road reference value estimating section for calculating a high friction coefficient road reference yaw rate based on a vehicle motion model when the vehicle travels on a road surface with high friction coefficient, an actual value estimating section for calculating an actual yaw rate, a Lissajou figure processing section for forming a Lissajou's figure based on the high friction coefficient road reference yaw rate and the actual yaw rate and for calculating a gradient and area of this Lissajou's figure, a road friction coefficient estimating section for estimating a road friction coefficient based on the area of the Lissajou's figure when the gradient is in the neighborhood of 45 degrees and for estimating a road friction coefficient based on a lateral acceleration when the gradient is out of the neighborhood of 45 degrees.
    Type: Application
    Filed: October 30, 2001
    Publication date: June 13, 2002
    Inventor: Masaru Kogure
  • Patent number: 6401020
    Abstract: Device for control of headlight range of a motor vehicle including a front axle transmitter (1) and a rear axle transmitter (2), which generate signals depending on a position of a vehicle chassis relative to a front axle and a rear axle of the vehicle, wherein the device further includes adjustment devices (14, 15), which can adjust the headlight range of the motor vehicle depending on these signals. The device further includes a speed transmitter (3) and a terrain recognition unit (24), with the terrain recognition unit (24) being connected to the front axle transmitter (1), the rear axle transmitter (2), and the speed transmitter (3).
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: June 4, 2002
    Assignee: Hella KG Hueck & Co.
    Inventor: Andreas Neumann
  • Patent number: 6385524
    Abstract: An automotive brake control system with an anti-brake skid (ABS) unit which controls a wheel-brake cylinder pressure to each individual wheel cylinder of the road wheels to prevent a wheel lock-up condition during braking, and an ABS control unit being configured to be connected electrically to at least wheel speed sensors and the ABS unit to execute skid control having at least a reduce-pressure operating mode and a pressure build-up operating mode, when the wheel speed sensor signals indicate that at least one of the road wheels is locking up. The ABS control unit includes a road-surface-condition change determination section which determines, based on both a time length of brake-fluid-pressure control continuously executed during the skid control and a recovery acceleration of the wheel speed of the road wheel subjected to the skid control, whether there is a road-surface &mgr; change from low-&mgr; road to high-&mgr; road.
    Type: Grant
    Filed: March 12, 2001
    Date of Patent: May 7, 2002
    Assignee: Unisia Jecs Corporation
    Inventors: Sunao Hano, Tamotsu Yamaura, Gen Inoue, Nobuyuki Ohtsu
  • Patent number: 6385525
    Abstract: An apparatus for detecting a condition of a road surface includes a vehicle wheel speed detecting device for outputting a vehicle wheel speed signal representing a speed of a wheel of a vehicle. A vehicle wheel speed summating device operates for summating variations in the vehicle wheel speed represented by the vehicle wheel speed signal during every time period corresponding to one revolution of the vehicle wheel, and for generating a summation value representing a result of the summating. A road-surface condition detecting device for detecting a road-surface condition on the basis of a difference between a current summation value and a previous summation value generated by the vehicle wheel speed summating device.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: May 7, 2002
    Assignee: Denso Corporation
    Inventors: Takashi Watanabe, Shoichi Masaki
  • Publication number: 20020052681
    Abstract: A target yaw rate setting unit of a control characteristics changing unit computes a first target yaw rate based on the radius of curvature of a curve. A target yaw rate setting unit of a braking force control unit computes a second target yaw rate based on driving conditions. When a cornering decision unit decides a turning intention, if the absolute value of the first target yaw rate is larger than the absolute value of the second target yaw rate, the second target yaw rate is corrected with the first target yaw rate, and the corrected second target yaw rate is outputted to a target yaw rate changing unit. A braking force control unit controls the braking force with the second target yaw rate corrected.
    Type: Application
    Filed: October 10, 2001
    Publication date: May 2, 2002
    Inventor: Koji Matsuno
  • Patent number: 6381531
    Abstract: The braking effect in a vehicle is set in the sense of preventing a tendency to lock-up with at least two wheels which are arranged on at least one axle on the right and left and whose motion characteristics are detected. The braking effect on the two wheels is set jointly, with at least two operating modes (select low, select high) being provided; they can be selected depending on the coefficients of friction prevailing on the wheels and/or depending on the vehicle speed. An operating mode is selected according to the value of the prevailing coefficients of friction when there are coefficient of friction differences of a preselectable lower value. As an alternative or in addition, an operating mode is selected according to the detected vehicle speed when there are coefficient of friction differences of a preselectable greater value.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: April 30, 2002
    Assignee: Robert Bosch GmbH
    Inventor: Günther Schmidt
  • Patent number: 6377885
    Abstract: A braking force control device is provided in which wheel speeds of respective wheels of a vehicle are detected. On the basis of detected wheel speeds, a road surface &mgr; slope, which is a slope of a coefficient of friction &mgr; between a wheel and a road surface, is estimated for each wheel. On the basis of the road surface &mgr; slope estimated for each wheel, a braking force of each wheel is controlled such that the braking force of each wheel is adjusted.
    Type: Grant
    Filed: April 3, 2001
    Date of Patent: April 23, 2002
    Assignees: Aisin Seiki Kabushiki Kaisha, Toyota Jidosha Kabushiki Kaisha, Denso Corporation
    Inventors: Yoshiyuki Yasui, Kenji Asano, Shoji Ito, Akira Tanaka, Hiroaki Yoshida, Mamoru Sawada, Yuji Muragishi, Michio Ishiguro, Tsugiharu Matsunaga, Eiichi Ono
  • Publication number: 20020045981
    Abstract: A correction factor setting unit sets correction factors for a front-rear traction distribution control unit, an anti-lock brake control unit, a traction control unit, and a braking power control unit according to the situation of a road and the shape thereof which are inputted from a road information recognizing unit. At this time, the correction factors are preset values according to the situation of the road and the shape thereof so that the actions of the control units will be balanced with each other. Consequently, the plurality of vehicle behavior control units mounted in a vehicle act efficiently according to the situation of the road, on which the vehicle is driven forwards, and the shape thereof while quickly responding to the situation of the road and the shape thereof. Besides, the actions of the vehicle behavior control units are balanced with one another.
    Type: Application
    Filed: July 19, 2001
    Publication date: April 18, 2002
    Applicant: Fuji Jukogyo Kabushiki Kaisha
    Inventors: Katsufumi Ichikawa, Takayuki Ushijima, Ryo Nitta, Katsumi Tomioka, Osamu Kobayashi
  • Patent number: 6374173
    Abstract: An electronic vehicle system monitors vehicle parameters and calculates variables such as acceleration to determine when the vehicle is cresting a hill. An action is taken to alter operation of the cruise control to avoid expending excess fuel or braking as the vehicle descends the downward grade. In one implementation, a message is displayed to a driver indicating the driver should reset the cruise set speed. In another implementation, the system automatically resets the cruise set speed without driver intervention. In yet another implementation, the system automatically resets the cruise set speed and automatically increases the set speed as the vehicle accelerates. An exemplary embodiment employs variable smoothing and a fuzzy logic system with a degree of confidence variable and an increase-in-acceleration rule.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: April 16, 2002
    Assignee: Freightliner LLC
    Inventor: James M. Ehlbeck
  • Patent number: 6360837
    Abstract: A method and an apparatus for estimating a maximally transmissible drive torque in a motor vehicle. The actual drive torque is set as the maximally transmissible drive torque when an average wheel slip of the drive wheels passes through a predefined slip threshold value in the direction of increasing drive slip.
    Type: Grant
    Filed: October 26, 1999
    Date of Patent: March 26, 2002
    Assignee: Robert Bosch GmbH
    Inventor: Rolf Maier-Landgrebe
  • Patent number: 6349256
    Abstract: The turning behavior state of a vehicle is determined by a determining device, by comparing a front wheel slip angle and a rear wheel slip angle calculated based on a lateral slip angle of a vehicle body by a wheel slip angle calculating device, with a front wheel slip angle limit value and a rear wheel slip angle limit value which are determined based on a vehicle speed detected by a vehicle speed detecting device and a friction coefficient presumed by a friction coefficient presuming device. Thus, even in a state in which the road surface friction coefficient is low, the turning behavior state of the vehicle can be detected precisely.
    Type: Grant
    Filed: September 7, 1999
    Date of Patent: February 19, 2002
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Keiyu Kin, Hiroyuki Urabe
  • Publication number: 20020017986
    Abstract: A contact free vehicle brake failure sensor receives IR emissions from a brake region of a vehicle to determine the temperature of the brake region. A determination of non-functionality of a brake is made based on whether the brake region is near the ambient temperature.
    Type: Application
    Filed: February 6, 2001
    Publication date: February 14, 2002
    Inventors: Gary C. Causley, Wayne L. Mann, Douglas Mark
  • Publication number: 20020013652
    Abstract: A braking force control device is provided in which wheel speeds of respective wheels of a vehicle are detected. On the basis of detected wheel speeds, a road surface &mgr; slope, which is a slope of a coefficient of friction &mgr; between a wheel and a road surface, is estimated for each wheel. On the basis of the road surface &mgr; slope estimated for each wheel, a braking force of each wheel is controlled such that the braking force of each wheel is adjusted.
    Type: Application
    Filed: April 3, 2001
    Publication date: January 31, 2002
    Inventors: Yoshiyuki Yasui, Kenji Asano, Shoji Ito, Akira Tanaka, Hiroaki Yoshida, Mamoru Sawada, Yuji Muragishi, Michio Ishiguro, Tsugiharu Matsunaga, Eiichi Ono
  • Publication number: 20020013650
    Abstract: The disclosed automatic transmission controller is capable of changing shift timing set for non-flat roads in correspondence to a judged driver type. The automatic transmission controller executes a driver type judging routine SUB2 to generate a judgment output related to the driver type by monitoring the driving of the vehicle and judges the driver type based on the judgment output. Shift timing is changed in running a non-flat road to correspond to the judged driver type. The shift timing in running the non-flat road may be changed by changing from an uphill slope mode 1 shift map to an uphill slope mode 2 shift map corresponding to the driver type or by increasing an upshift inhibiting section of a single map.
    Type: Application
    Filed: February 21, 2001
    Publication date: January 31, 2002
    Inventors: Muneo Kusafuka, Masamichi Unoki, Masakatsu Iwase
  • Publication number: 20020010537
    Abstract: A tire parameter estimation device that is economical and can accurately estimate tire parameters while taking into consideration both states of a vehicle and states of a road environment. A &mgr; gradient detecting circuit detects a &mgr; gradient on the basis of a wheel speed detected by a wheel speed detecting circuit. A gradient value comparing circuit determines a &mgr; gradient section value &mgr;r, which is a mean value of the &mgr; gradients from the &mgr; gradient detecting circuit, and calculates a rate (=&mgr;r/&mgr;I) of the &mgr; gradient mean value &mgr;r with respect to a &mgr; gradient initial value &mgr;. A tire temperature estimating circuit stores a table representing the relation between the rate and a tire temperature, and estimates a tire temperature corresponding to the rate calculated by the gradient value comparing circuit as the present tire temperature.
    Type: Application
    Filed: April 3, 2001
    Publication date: January 24, 2002
    Applicant: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO
    Inventors: Hiroyuki Yamaguchi, Yasushi Amano, Katsuhiro Asano, Noboru Sugiura, Masanori Miyashita, Yoshitoshi Watanabe, Akira Tanaka, Yoshiyuki Yasui, Mamoru Sawada
  • Publication number: 20020002437
    Abstract: 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: Application
    Filed: June 18, 2001
    Publication date: January 3, 2002
    Applicant: Fuji Jukogyo Kabushiki Kaisha
    Inventor: Koji Matsuno
  • Publication number: 20020002435
    Abstract: An apparatus for determining a road-wheel vibration for an automotive vehicle comprises wheel-speed sensors for detecting wheel speeds of each of road wheels, and a control unit which is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors.
    Type: Application
    Filed: June 21, 2001
    Publication date: January 3, 2002
    Applicant: UNISIA JECS CORPORATION
    Inventor: Nobuyuki Ohtsu
  • Patent number: 6324461
    Abstract: Disclosed is a road surface condition estimating apparatus including: a converting portion having a table showing a relation among a vehicle speed, a braking force and a resonance gain for each road surface condition and converting a detected value of the input vehicle speed and braking force into a resonance gain on the basis of the table, a subtracting device for computing each of differences between the resonance gain for each road surface condition converted by each of the converting portions and the detected value of the input resonance gain, and a minimum value selecting portion selecting the minimum value among the computed values in the subtracting device and outputting an information of the road surface condition corresponding to the converting portion giving the minimum value.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: November 27, 2001
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Hiroyuki Yamaguchi, Katsuhiro Asano, Eiichi Ono, Takaji Umeno, Masaru Sugai
  • Publication number: 20010032045
    Abstract: An automotive brake control system with an anti-brake skid (ABS) unit which controls a wheel-brake cylinder pressure to each individual wheel cylinder of the road wheels to prevent a wheel lock-up condition during braking, and an ABS control unit being configured to be connected electrically to at least wheel speed sensors and the ABS unit to execute skid control having at least a reduce-pressure operating mode and a pressure build-up operating mode, when the wheel speed sensor signals indicate that at least one of the road wheels is locking up. The ABS control unit includes a road-surface-condition change determination section which determines, based on both a time length of brake-fluid-pressure control continuously executed during the skid control and a recovery acceleration of the wheel speed of the road wheel subjected to the skid control, whether there is a road-surface &mgr; change from low-&mgr; road to high-&mgr; road.
    Type: Application
    Filed: March 12, 2001
    Publication date: October 18, 2001
    Applicant: UNISIA JECS CORPORATION
    Inventors: Sunao Hano, Tamotsu Yamaura, Gen Inoue, Nobuyuki Ohtsu
  • Publication number: 20010029420
    Abstract: An apparatus for presuming a condition of road surface comprising: rotational speed detecting means for periodically detecting rotational speeds of four tires of a vehicle; first computing means for computing a slip ratio from measurement values of the rotational speed detecting means; second computing means for obtaining a relational formula between the slip ratio and acceleration/deceleration of the vehicle; and friction coefficient judging means for judging a coefficient of friction occurring between a road and a tire on the basis of a slope of the relational formula obtained by the second computing means. The road friction coefficient &mgr; can be judged with high accuracy in short time by using only the wheel rotational speed information of four wheels. Thus, the performance and safety of a vehicle can be increased.
    Type: Application
    Filed: March 9, 2001
    Publication date: October 11, 2001
    Inventors: Hiroaki Kawasaki, Yukio Nakao
  • Publication number: 20010029421
    Abstract: An apparatus for detecting a condition of a road surface includes a vehicle wheel speed detecting device for outputting a vehicle wheel speed signal representing a speed of a wheel of a vehicle. A vehicle wheel speed summating device operates for summating variations in the vehicle wheel speed represented by the vehicle wheel speed signal during every time period corresponding to one revolution of the vehicle wheel, and for generating a summation value representing a result of the summating. A road-surface condition detecting device for detecting a road-surface condition on the basis of a difference between a current summation value and a previous summation value generated by the vehicle wheel speed summating device.
    Type: Application
    Filed: March 29, 2001
    Publication date: October 11, 2001
    Inventors: Takashi Watanabe, Shoichi Masaki
  • Publication number: 20010029419
    Abstract: A road surface friction coefficient estimating apparatus is provided for estimating a road surface friction coefficient of a vehicle that is traveling at a steady state. The road surface friction coefficient estimating apparatus basically has a driving/braking force controller, a driving force controller, a braking force controller (brake fluid pressure controller), a plurality of wheel velocity sensors, a wheel load sensor and a control unit. The driving/braking force controller sets a pre-selected force to be generated and calculates the road surface friction coefficient. The driving force controller generates a driving force in accordance with the pre-selected force. The braking force controller generates a braking force in accordance with the pre-selected force. The wheel velocity sensors produce a wheel velocity signal indicative of a wheel velocity. The wheel load detecting sensor produces a wheel load signal indicative of a wheel load.
    Type: Application
    Filed: December 15, 2000
    Publication date: October 11, 2001
    Inventors: Shinji Matsumoto, Takeshi Kimura, Taku Takahama, Hiromitsu Toyota
  • Patent number: 6301540
    Abstract: The present invention is directed to a system for detecting a difference in level on a road, wherein an acceleration sensor is provided for detecting an acceleration of a vehicle, and a wheel speed sensor is provided for detecting a wheel speed of at least one wheel of the vehicle. A wheel acceleration is calculated continuously on the basis of the wheel speed detected by the wheel speed sensor. It is determined if a variation of the signal output from the acceleration sensor is greater than a predetermined range. And, it is determined if the calculated wheel acceleration varied in the same direction as that of the variation of the signal output from the acceleration sensor, and then varied in the reverse direction to exceed a predetermined reference value. On the basis of the result of each determination, it is determined if the wheel ran over the difference in level on the road. If the affirmative result is obtained in each determination, the difference in level on the road can be detected.
    Type: Grant
    Filed: May 25, 1999
    Date of Patent: October 9, 2001
    Assignees: Aisin Seiki, Toyota Jidosha
    Inventors: Toshihisa Kato, Masaki Banno, Yasuhiro Abe, Shinji Tsugawa, Hiroyuki Matsubayashi
  • Patent number: 6278930
    Abstract: A moving behavior control device for a vehicle calculates first target braking forces to be applied to the respective wheels for stabilizing the vehicle against a turn instability, second target braking forces to be applied to the respective wheels for stabilizing the vehicle against a roll instability, and target overall braking forces to be applied to the respective wheels by integrating the first and second target braking forces, and applies braking forces to the respective wheels according to the target overall braking forces, wherein the applied braking forces are decreased according to a first rate schedule by which the applied braking forces are decreased at a first rate according to an excess of the applied braking forces relative to the target overall braking forces when the vehicle is running at no probability of rolling beyond a predetermined threshold roll, and according to a second rate schedule by which the braking forces are lowered at a second rate smaller than the first rate according to the
    Type: Grant
    Filed: April 25, 2000
    Date of Patent: August 21, 2001
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Noritaka Yamada, Akira Nagae
  • Patent number: 6272417
    Abstract: A vehicle braking system including a controller, in an initial anti-skid cycle, performs a first determination to select a high or a low control mode in accordance with wheel speed parameters. The controller in a second, or subsequent anti-skid cycle, performs a second determination to determine whether a near &mgr; test is to be performed in accordance with wheel speed parameters. The controller consequent upon selection of low control mode performs a near &mgr; test. The near &mgr; test includes performing a rise in the brake pressure and then selecting a high or low mode in accordance with the speed of the wheels resulting from the rise in brake pressure in the near &mgr; test.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: August 7, 2001
    Assignee: Haldex Brake Products Limited
    Inventors: Colin F. Ross, Dudley J. Harrison
  • Patent number: 6269296
    Abstract: A vehicle driving force control apparatus includes an element for calculating a normal target driving force representing a desired vehicle driving force on a level road in accordance with sensed accelerator input quantity and vehicle speed, an element for calculating a modification quantity in accordance with a vehicle grade resistance, an element for determining a grade-adapted target driving force in accordance with the normal driving force and the modification quantity. The grade-adapted target driving force is achieved in a vehicle to provide adequate feeling of acceleration even on an ascending slope.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: July 31, 2001
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Nobusuke Toukura, Hiroshi Abe, Masaaki Uchida
  • Patent number: 6266602
    Abstract: A road surface condition determination system for an automotive vehicle comprises wheel-speed sensors, and a control unit being configured to be electrically connected to the wheel-speed sensors for data-processing a wheel-speed data signal. The control unit calculates a wheel-speed fluctuation of each of the road wheels on the basis of a previous value of the wheel-speed data signal and a current value of the wheel-speed data signal, and calculates an absolute value of the wheel-speed fluctuation of each of the road wheels. A integration circuit is provided to produce a first integrated value of the absolute values of the wheel-speed fluctuations of the road wheels. A smoothing circuit is provided to make a smoothing operation to the integrated value to produce a smoothed value. A road-surface condition determining section is also provided to determine a road surface condition on the basis of the smoothed value.
    Type: Grant
    Filed: February 18, 2000
    Date of Patent: July 24, 2001
    Assignee: Unisia Jecs Corporation
    Inventor: Tamotsu Yamaura
  • Patent number: 6266600
    Abstract: A system is provided wherein road surface friction is sensed by measuring strain on a structure of a vehicle in a vicinity of a wheel of the vehicle. A road surface friction coefficient is determined by measuring strain on a structure of the vehicle in the vicinity of the wheel to produce signal outputs proportional to road surface frictional force and vertical load, and calculating the road surface friction coefficient from the outputs.
    Type: Grant
    Filed: July 8, 1999
    Date of Patent: July 24, 2001
    Assignee: Japan Electronics Industry, Ltd.
    Inventor: Nagao Miyazaki
  • Patent number: 6253142
    Abstract: The coefficient of friction &mgr;s between the wheels of the vehicle and the road surface is identified as a function of the slip, and the maximum drive torque MAmax which can be transmitted is determined as a function of this slip-dependent coefficient of friction &lgr;. &lgr; is corrected when there is an increased slip requirement &lgr;erf as a result of the speed of the vehicle and/or the tire mixture used.
    Type: Grant
    Filed: August 25, 1995
    Date of Patent: June 26, 2001
    Assignee: Robert Bosch GmbH
    Inventors: Thomas Sauter, Peter Daubner
  • Patent number: 6223107
    Abstract: A device to monitor sensors in a motor vehicle, with the sensors generating signals, each representing different physical is provided. The device includes first arrangement with which identically defined comparison variables for the sensors are determined for at least two sensors on the basis of at least the signals generated by them. Furthermore, the device includes a second arrangement with which a reference variable is determined on the basis of at least two of the identically defined comparison variables and is taken into account in monitoring performed in a third arrangement for at least one sensor. To form the reference variable, a variable describing the difference between the identically defined comparison variable and the other identically defined comparison variables of the minimum of two identically defined comparison variables is determined for each of the minimum of two identically defined comparison variables. The identically defined comparison variable is evaluated using this variable.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: April 24, 2001
    Assignee: Robert Bosch GmbH
    Inventors: Rolf-Hermann Mergenthaler, Werner Urban
  • Patent number: 6212463
    Abstract: An antiskid control apparatus has magnetic rotational speed sensors for the respective wheels and is adapted to control the brake force, based on a speed of a first wheel and a speed of a second wheel during braking of a vehicle. When an antiskid control computer detects a road surface under road heating during execution of the brake force control of the vehicle, the computer terminates the brake force control of the vehicle where it is assumed that the vehicle is in a state of a predetermined speed.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: April 3, 2001
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Hideyuki Aizawa
  • Patent number: 6208097
    Abstract: An adhesion control system for a locomotive is provided for achieving and maintaining a maximum adhesion value.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: March 27, 2001
    Assignee: General Electric Company
    Inventors: Suresh Baddam Reddy, Jeffrey Louis Diagle, Bret Dwayne Worden, Harry Kirk Mathews, Jr., Edgar Thomas Balch, Allan John Connolly, Ajith K. Kumar
  • Patent number: 6203121
    Abstract: The present invention is directed to an apparatus for estimating the peak of a coefficient of friction in a coefficient of friction—slip rate characteristic, wherein a wheel acceleration of each wheel of a vehicle is detected, and a vehicle acceleration of the vehicle is detected. A peak estimation device is provided for estimating the peak of the coefficient of friction, and adapted to determine that the coefficient of friction is the peak when the wheel acceleration is lower than the vehicle acceleration, by more than a predetermined difference. An anti-skid control system for an automotive vehicle may be formed to include the coefficient of friction peak estimation apparatus, and a reference speed setting device for setting a reference speed for initiating a pressure decrease mode on the basis of a wheel speed and a vehicle speed detected when the peak was detected.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: March 20, 2001
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Toshihisa Kato, Yasuhiro Abe
  • Patent number: 6202020
    Abstract: A method and system for determining the condition of a road travelled by a vehicle includes a sensor for sensing a speed of the vehicle and an accelerometer for sensing a vertical acceleration of the vehicle. A central processing unit have control logic programmed therein determines a first road profile interval having upper and lower threshold values based on the speed of the vehicle and determines the condition of the road based on the vertical acceleration and the first road profile interval.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: March 13, 2001
    Assignee: Meritor Heavy Vehicle Systems, LLC
    Inventor: Christos Kyrtsos
  • Patent number: 6185485
    Abstract: A system and method for vehicle dynamic control processes a compensated yaw rate signal measurement and a compensated lateral acceleration signal measurement (30, 32) to derive a signal measurement of road bank angle disturbance not compensated for in a compensated steering angle signal measurement and provides the derived signal to a controller (12). The compensated steering angle signal measurement is an input to the controller. Because a disturbance already compensated in the compensated steering angle signal measurement is transparent to the controller, the controller is able to adjust the control action of the vehicle dynamic control system based on the derived signal measurement of road bank angle disturbance not compensated for in a compensated steering angle signal measurement, thereby providing enhanced robustness of control.
    Type: Grant
    Filed: December 22, 1998
    Date of Patent: February 6, 2001
    Assignee: Ford Global Technologies, Inc
    Inventors: Behrouz Ashrafi, Dinu Petre Madau, Hongtei Eric Tseng
  • Patent number: 6182001
    Abstract: An apparatus for diagnosing a fault in a dynamic system includes a controller which controls the dynamic system through use of a control input signal and vibrates the dynamic system through use of an vibration signal irrelevant to the internal state quantity of the dynamic system; an observer for estimating, on the basis of a response output from the vibration dynamic system, total disturbance which is a sum of an internal disturbance vector stemming from a fault in the dynamic system and a vibration disturbance vector occurring in the dynamic system through vibration; a correlation calculation unit which calculates cross-correlation between the thus-estimated total disturbance and the internal state quantity of the dynamic system and separates a component related to the internal disturbance from the total disturbance; and a diagnostic unit for diagnosing a fault in the dynamic system on the basis of the thus-separated component related to the internal disturbance.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: January 30, 2001
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Masaru Sugai, Katsuhiro Asano, Takaji Umeno, Eiichi Ono, Hiroyuki Yamaguchi
  • Patent number: 6163747
    Abstract: A road friction coefficient detecting apparatus and method of a vehicle includes a vehicle data calculating section, a tire characteristic initial value judging section and a road friction coefficient estimating section. In the vehicle data calculating section, parameters needed for the calculation of road friction coefficients are established based on signals from a steering wheel rotation angle sensor, a vehicle speed sensor and a yaw rate sensor. The tire characteristic initial value judging section sends a signal to establish parameters corresponding to a low friction coefficients to the vehicle data calculating section, when road condition sensing means such as an outside air temperature, a rain fall sensor and the like detect a road surface having a relatively low friction coefficient.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: December 19, 2000
    Assignee: Fuji Jukogyo Kabushiki Kaisha
    Inventor: Koji Matsuno
  • Patent number: 6134491
    Abstract: A system for controlling steering of a vehicle, including a steering unit having an electric motor which steers driven wheels of the vehicle, a first steering control unit (EPS ECU 76) for controlling the actuator, a CCD camera for detecting a condition of a lane on a road on which the vehicle travels, a steering assist torque determining unit for determining a steering assist torque necessary for holding a positional relationship between the vehicle and the lane condition, a torque sensor for detecting a steering torque manually applied to the steering unit by the driver, second steering control unit for calculating a torque command to be output to the first steering control unit based on the steering assist torque calculated by the steering assist torque calculating unit and the detected steering torque to control the motor such that the torque command decreases.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: October 17, 2000
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Hiroyuki Kawagoe, Shinnosuke Ishida, Tomoaki Teramoto, Kaoru Matsuno
  • Patent number: 6125319
    Abstract: A brake system control method, comprising the steps of: determining a maximum acceleration of a vehicle on a high coefficient of adhesion road surface; measuring an acceleration of the vehicle; determining a ratio between the measured acceleration of the vehicle and the maximum acceleration of the vehicle on the high coefficient of adhesion road surface; responsive to the ratio, determining a signal indicative of present coefficient of adhesion; determining a brake actuator command responsive to the signal; and providing the brake actuator command to a brake actuator, wherein an accurate estimation of coefficient of friction between the vehicle wheels and the road surface is used in the brake system control.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: September 26, 2000
    Assignee: General Motors Corporation
    Inventors: Aleksander Boguslaw Hac, John Francis Hoying, Kamal Naif Majeed, Hsien Heng Chen, Joachim Busshardt