Toyota Jidosha Kabushiki Kaisha

Nippon Soken, Inc.

Nippondenso Co., Ltd.

Toyoto Jidosha Kabushiki Kaisha

Hideo Inoue

Tatsuo Sugitani

Kiyoyuki Uchida

Takaharu Idogaki

Osamu Takeda

Toshihisa Ishihara

Yoshihiko Tsuzuki

Satoshi Haseda

Akira Fukushima

Ikuo Hayashi

Hiroaki Tanaka

Shigeyuki Akita

Kouichi Yamanoue

Kazunori Sakai

Nobuhiko Makino

Hideki Kusunoki

Ichiro Akahori

Shinji Fukui

Masashi Ohta

Hiroyuki Hirano

Koyoyuki Uchida

A steering angle detecting apparatus for accurately and surely detecting a steering angle of a motor vehicle. The apparatus is equipped with a turning angle detector for detecting a turning angle of a steering wheel of the motor vehicle. In addition, the apparatus estimates a turning angle of the steering wheel on the basis of the difference in speed between left and right wheels of the motor vehicle so as to calculate the difference in phase between the detection turning angle and the estimation turning angle. For detecting the accurate vehicle steering angle, the detection turning angle is corrected on the basis of the calculated phase difference therebetween.

Steering angle detecting apparatus for motor vehicles based on the phase

In a four-wheel steering system for an automotive vehicle, a travel speed of the vehicle is detected to determine parameter related to the detected vehicle speed, and lateral deviation of the vehicle is further detected to determine a steering angle of rear road wheels on a basis of the detected lateral deviation of the vehicle and the determined parameter. When the detected vehicle speed becomes unreliable due to skid condition of either one of the road wheels, the steering angle of the rear road wheels is determined on a basis of the detected lateral deviation and the fixed parameter.

Four-wheel steering system for automotive vehicle

A signal processing circuit for removing a noise component from a detection signal of a yaw-rate sensor for detecting a yaw rate generated in a motor vehicle. The processing circuit detects the magnitude of variation of the detection signal of the yaw-rate sensor so as to compare the magnitude of the detection signal with a predetermined reference value. In accordance with the comparison result, the processing circuit outputs a limitation detection signal to limit the variation to below the predetermined reference value. Further, when the magnitude of variation of the detection signal exceeds the predetermined reference value, the processing circuit outputs as the limitation detection signal the yaw rate detection signal immediately before the exceeding, and the predetermined reference value is corrected on the basis of the steering angular velocity of the steering wheel of the motor vehicle. This arrangement allows effectively eliminating a spear-like noise from the detection signal of the yaw-rate sensor.

Signal processing circuit for yaw-rate sensor

An angular velocity sensor having a casing in which a disk shaped permanent magnet member is arranged so that it floats on a magnetic fluid filled in the casing. A Hall motor is provided for rotating the permanent magnet about its axis in the casing, and a detection unit is provided detecting an inclination of the magnet member about an axis which is transverse to the axis about which the magnet member rotates, which inclination is generated when the sensor is subjected to an angular movement. An angular velocity of such an angular movement is calculated from the detected degree of inclination of the magnet member.

Device for detecting angular velocity

An anti-skid control system for use in a motor vehicle having wheels whose rotational speeds are sensed by wheel sensors. The anti-skid control system decides the condition of the road-surface, on which the motor vehicle is running, on the basis of signals from wheel sensors. A reference speed is further calculated on the basis of the sensed speeds of the wheels symmetrically provided at the rear-right and rear-left sides with respect to the advancing direction of the motor vehicle. That is a selected one of an average value of the speeds of the rear-right and rear-left wheels sensed by the wheel sensors and the maximum one of the sensed rear-right and rear-left wheel speeds is selected in accordance with the decided road-surface condition. The reference speed is calculated on the basis of the selected one. A control unit of the anti-skid control system performs slip control of the wheels in accordance with the calculated reference speed. With this arrangement, the anti-skid control system can improve the braking efficiency and controllability irrespective of turning of the motor vehicle.

Anti-skid control system for use in motor vehicle

An acceleration sensor for detecting an acceleration in a plane, and having a housing, and a disk magnet arranged in a magnetic fludi stored in the housing. The movement of disk magnet is limited, i.e., a translational movement or rotational movement thereof can occur only in the plane, by projections formed in the housing, between which projections portions of the magnetic fluid having an increased density are formed adjacent to the poles of the disk magnet so that only a translational movement is allowed, or by small circumferential walls between the housing and the disk magnet and radial projections formed between end walls of the housing and disk magnet so that only a rotational movement is allowed. A Hall element issues a signal corresponding to a position of the disk magnet, to thereby determine the acceleration rate.

Two-dimensional acceleration sensor

According to this invention, a device for detecting the speed of transference of a moving body, having a construction such that the device comprises a magnetizing element for forming a magnetic pole on a surface of a moving body made of a magnetic material and disposed in the vicinity of the moving body, a magnetic field detecting circuit provided adjacent to the moving body, for linking therewith the magnetic field of the magnetic pole formed by the magnetizing element and for outputting an electrical voltage in accordance with a variation of the magnetic field caused by the transference of the moving body, and an output signal processing circuit for processing a signal output by the magnetic field detecting circuit and for determining the speed of transference of the moving body can be obtained, and by utilizing the device mentioned above, an effect whereby a signal corresponding to the displacement speed of a moving body is continuously obtained and therefore, a moving body need not be precisely fabricated with a specific configuration such as forming concave and convex portions on the surface of the moving body, and moreover, to continuously obtain precise information about the speed of the moving body, because even when the moving body moves at an extremely low speed, an increment of a ripple and a phase shift can not occur, can be realized.

Moving body speed detecting device which produces and detects a magnetic

An acceleration sensor including a magnetic fluid, a permanent magnet emplaced movably in the magnetic fluid, a nonmagnetic case, in which case the magnetic fluid and the permanent magnet are sealed and from which case air is substantially excluded, the shape of internal receptacle of the case dominating the shape of the magnetic fluid, whereby the path of the magnetic flux generated by the permanent magnet is restricted and the permanent magnet in the magnetic fluid is given an automatic positioning function, a unit for detecting the position of the permanent magnet, and a processing circuit for processing signals from the detection unit.

Acceleration sensor

An anti-skid braking system for a vehicle, having (a) hydraulic brakes for wheels of the vehicle, (b) actuators provided for respective brake groups each including at least one of the brakes, for controlling a braking pressure or pressures of the brake or brakes of the corresponding groups, (c) speed sensors, at least one of which is provided corresponding to each actuator, for detecting speeds of the wheels, and (d) to controller operable for: normally presuming that an actual speed of the vehicle is represented by a highest one of the detected wheel speeds; after a deceleration value of the highest speed has exceeded a preset upper limit, fixing the deceleration value of the vehicle at the preset upper limit, and presuming the actual vehicle speed based on the upper limit; and calculating a slip amount of each wheel based on a difference between the presumed vehicle speed and the detected wheel speed, to control each actuator so as to prevent the wheel from skidding. The system includes a detector generating a signal whose level is changed in at least two steps indicative of at least two values of an actual deceleration value of the vehicle. The system further includes a setting device for determining the upper limit of the deceleration value such that the upper limit is changed with the detected actual deceleration value.

Anti-skid braking system for automotive vehicle

A braking system including a hydraulically operated brake for braking a drive wheel of a motor vehicle, a slip detector for detecting an amount of slip of the drive wheel, and a pressure-regulating controller for increasing or decreasing a fluid pressure to be applied to the brake, in response to each output signal of the slip detector, whose value indicated a pressure-increase or pressure-decrease condition which requires an increase or decrease in the fluid pressure, respectively, such that the amount of slip of the drive wheel is maintained within an optimum range. The braking system incorporates a device for commanding the pressure-regulating controller to delay commencement to increase and/or decrease the fluid pressure to be applied to the brake, with respect to a part of the occurrences of the pressure-increase condition and/or the pressure-decrease condition, for a predetermined time duration as measured from a point of time at which the pressure-increase and/or said pressure-decrease condition is/are established.

Vehicle braking system for drive wheels, having means for delaying

A method of automatically controlling a braking system for an automotive vehicle, by changing a plurality of control parameters in at least two steps, depending upon a determined one of three or more ranges of a variable in which a detected value of the variable falls. At least one of the control parameters is changed in two steps corresponding to two adjacent ranges of the variable, while at least one of the other control parameter or parameters is kept unchanged for the two adjacent ranges of the variable. The variable may be a deceleration rate of the vehicle, or other variables which are changed with a coefficient of friction between a vehicle wheel and the road surface. The control parameters may include an upper limit of the deceleration rate, and a duration for which the braking pressure is reduced, to prevent locking of the wheel due to excessive braking force applied to the wheel, or prevent an excessive mount of slip of the wheel due to excessive drive torque applied to the drive wheel during start or acceleration of the vehicle.

A braking system for an automotive vehicle, having a first brake system and a second brake system. The first brake system includes a master cylinder responsive to an operation of an operator-controller brake operating member, for generating a fluid pressure which corresponds to an operation value of the brake operating member, and a first brake actuated by the fluid pressure generated by the master cylinder. The first brake is adapted to produce a braking effect which is smaller than a desired or optimum braking effect corresponding to the operation value of the brake operating member. The second brake system has a second brake and is controlled by a controller such that the second brake produces a braking effect which is equal to a difference between an actual braking effect applied to the vehicle, and the desired braking effect.

Braking system for automotive vehicle

An anti-skid braking system for an automotive vehicle, including a first brake system and a second brake system. The first brake system has a master cylinder for generating a fluid pressure corresponding to an operation value of a brake operating member, a first brake for a wheel of the vehicle equipped with a brake cylinder actuated by the pressure of the master cylinder, and a first solenoid valve device between the master and brake cylinders and operable between a first and a second position for communication of the brake cylinder with the master cylinder and a reservoir, respectively. The braking system includes a second brake system which has a second brake cooperating with the first brake to apply a brake to the wheel; a speed sensor for detecting a speed of the wheel; and an anti-skid controller for estimating a slip ratio of the wheel based on the detected speed. The anti-skid controller controls the first solenoid valve device, if the estimated slip ratio of the wheel has exceeded a predetermined upper limit, to lower the pressure in the brake cylinder to a level at which the slip ratio is in a predetermined optimum range, the anti-skid controller subsequently controlling a brake force of the second brake, to maintain the slip ratio within the optimum range.

An anti-squeal braking system for an automotive vehicle, including a first brake having a brake rotor, a friction member disposed opposite to the brake rotor, and a hydraulically operated actuator for forcing the friction member against the brake rotor, and further including a second brake cooperating with the first brake to apply a brake to the vehicle. The first and second brakes are controlled by an anti-squeal controller such that the first brake is operated without a braking squeal, while the second brake is operated so as to provide a braking effect equal to a difference between an actual braking effect applied to the vehicle by the first brake, and a desired braking effect that should be applied to the vehicle. The desired braking effect is predetermined corresponding to an operation value of an operator-controlled brake operating member sensed by a detector device.

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Ashigarakami, Japan

Hideo Inoue