Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Aisin Seiki K.k.

Other

Kenji Tozu

Takayuki Itoh

Masanobu Fukami

Norio Yamazaki

Yoshiyuki Yasui

Kazutaka Kuwana

Tsuyoshi Yoshida

Satoshi Yokoyama

Akitaka Nishio

Kenji Asano

Hiroyuki Ichikawa

Noriaki Hattori

Jun Mihara

Takeshi Goto

Ryuichi Kurosawa

Hiroaki Kawai

Michiharu Nishii

Toshihisa Kato

Hiroyuki Yamaguchi

Katsuhiro Asano

Shoji Inagaki

Shinsuke Sakane

Seiichi Kojima

Masaki Yamamoto

Yoshiharu Nishizawa

Shingo Sugiura

Satoshi Ishida

Tatsuo Sugitani

Masamoto Ando

Hiromu Kuromitsu

Daisuke Yamada

Yasushi Amano

Genji Mizuno

Toshiyuki Mikida

Akio Sakai

In a vehicle steering apparatus of a steer-by-wire system, front wheels are controlled to be turned by a computer program processing. A displacement/torque conversion sectionconverts a steering angle &#x3b8; into a steering torque Td that is in relation of exponential function. A torque/lateral-acceleration conversion sectionconverts the steering torque Td into an anticipated lateral acceleration Gd (or anticipated yaw rate &#x3b3;d and anticipated turning curvature &#x3c1;d) that is in relation of exponentiation function and that serves as a vehicle motion state quantity that can be perceived by a human. A turning angle conversion sectioncalculates a target turning angles &#x3b4;d necessary for the vehicle to move with the anticipated lateral acceleration Gd (or anticipated yaw rate &#x3b3;d and anticipated turning curvature &#x3c1;d). A turning control sectioncontrols the steered wheels to be turned into the target turning angle &#x3b4;d. A driver turns the handle, feeling the lateral acceleration, and hence, the driver can easily drive the vehicle.

Control system for a steer-by-wire vehicle

In a vehicle steering apparatus, front wheels are controlled to be turned by a computer program processing. A displacement/torque conversion sectionconverts a steering angle &#x3b8; into a steering torque Td that is in relation of exponential function. A torque/lateral-acceleration conversion section, torque/yaw-rate conversion sectionand torque/curvature conversion sectionconvert into an anticipated lateral acceleration Gd, anticipated yaw rate &#x3b3;d and anticipated turning curvature &#x3c1;d based upon the steering torque Td. Turning angle conversion sectionsandcalculate target turning angles &#x3b4;g, &#x3b4;&#x3b3; and &#x3b4;&#x3c1;. A turning angle deciding sectiondecides a target turning angle &#x3b4;d among the target turning angles &#x3b4;g, &#x3b4;&#x3b3; and &#x3b4;&#x3c1; according to the detected vehicle speed V. A turning control sectioncontrols the steered wheels to be turned into the target turning angle &#x3b4;d. Herewith, the vehicle steering apparatus of the present invention can turn the vehicle so as to be adapted to a man's perception characteristic in all speed areas with respect to an operation on a steering handle by a driver. Therefore, the driver can easily drive the vehicle in all speed areas.

Vehicle steering apparatus

In a vehicle steering apparatus, front wheels are controlled to be turned by a computer program processing. A displacement/torque conversion sectionconverts a steering angle &#x3b8; into a steering torque Td that is in relation of exponential function. A torque/lateral-acceleration conversion sectionconverts into an anticipated lateral acceleration Gd based upon the steering torque Td. A turning angle conversion sectioncalculates target turning angles &#x3b4;d. A turning angle correcting sectionobtains a slip angle &#x3b2; of a slip generated on a vehicle. Then, the turning angle correcting sectioncorrects the target turning angle &#x3b4;d based upon the obtained slip angle &#x3b2;, thereby calculating a corrected target turning angle &#x3b4;da. A drive control sectioncontrols the steered wheels to be turned into the corrected target turning angle &#x3b4;da. According to this, a driver can correctly perceive the generated anticipated lateral acceleration Gd, whereby he/she can easily drive the vehicle.

A hydraulic brake pressure controller and method for pressure increase in a wheel cylinder of a hydraulic brake pressure controller is adapted to obtain favorable ABS control performance in light of the vehicle driving road surface and the stepping force of the brake pedal involves adjusting the pressure increase output time of the pulse pressure increase from a master cylinder to the wheel cylinder based on the pressure differential between the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure of each wheel cylinder. The wheel cylinder hydraulic pressure of each wheel cylinder is calculated based on an estimated vehicle deceleration obtained from an estimated vehicle speed.

Hydraulic brake pressure controller and method for pressure increase in a wheel brake cylinder

The present invention is directed to an apparatus for estimating a vehicle side slip angle, which includes a monitor for monitoring quantity of motion state of a vehicle including such signals as a vehicle speed, a vehicle lateral acceleration, a yaw rate and a steering angle, and includes a motion model memory for storing a vehicle motion model. A first estimation device estimates a vehicle side slip angle by calculating a vehicle side slip angular velocity on the basis of the vehicle speed, vehicle lateral acceleration and yaw rate, and integrating the vehicle side slip angular velocity in a predetermined calculating cycle. Also, a second estimation device estimates the vehicle side slip angle on the basis of the quantity of motion state monitored by the monitor, and the vehicle motion model stored in the motion model memory. A tire load determination device determines a lateral load to each tire of the vehicle on the basis of the result monitored by the monitor. And, a changing device changes between the estimation of the vehicle side slip angle made by the first estimation device and the estimation of the vehicle side slip angle made by the second estimation device, in accordance with the result of determination of the tire load determination device.

Apparatus for estimating a vehicle side slip angle

The present invention is directed to a brake control system, which includes wheel brake cylinders, a master cylinder, a reservoir communicated with the wheel brake cylinders, normally open solenoid valves disposed between the master cylinder and the wheel brake cylinders, respectively, normally closed solenoid valves disposed between the wheel brake cylinders and the reservoir, respectively, a hydraulic pump for supplying the brake fluid to a passage for connecting the master cylinder with the normally open valves, and an automatically pressurizing device (e.g., a vacuum booster with a changeover valve) which is provided for advancing the master piston irrespective of operation of the pump and the brake pedal to generate hydraulic braking pressure from the master cylinder. It is so controlled that a distance of the master piston, which is advanced by the automatically pressurizing device when all of the normally open valves are closed during the hydraulic pressure control of the wheel brake cylinders, is greater than the distance of the master piston, which is advanced by the automatically pressurizing device when at least one of the normally open valves is open during the hydraulic pressure control of the wheel brake cylinders.

Brake control system for a vehicle

A vehicle motion control system which generates a minimized switching noise when a hydraulic pressure control valve is switched. The vehicle motion control system includes an automatic hydraulic pressure generator generating a hydraulic pressure irrespective of a brake pedal operation and a hydraulic pressure control valve adjusting the hydraulic brake pressure by opening or blocking a connection between the automatic hydraulic pressure generator and a wheel brake cylinder, and performs a motion control by controlling at least the hydraulic pressure control valve in accordance with the motion of a vehicle. The vehicle motion control system has a hydraulic pressure sensor detecting a generated hydraulic pressure of the automatic hydraulic pressure generator, setting a necessary hydraulic pressure for control, and adjusting the generated hydraulic pressure of the automatic hydraulic pressure generator by controlling the automatic hydraulic pressure generator in accordance with the result of a comparison between the actually generated hydraulic pressure of the automatic hydraulic pressure generator and the necessary hydraulic pressure for the motion control.

Vehicle motion control system

A vehicle driving condition detection device is adapted to detect a vehicle running along a banked or laterally sloping road, as well as a lateral acceleration, and sideslip angle with good accuracy. The sideslip angle is estimated at a vehicle-body sideslip angle estimating circuit based on a steering angle &dgr;f, a lateral acceleration &yuml;, a yaw rate {dot over (&thgr;)}, and a vehicle speed V. In addition, using a differentiating device, the estimated sideslip angle is differentiated to calculate a slip angular velocity. A subtracting device is provided at which a deviation is calculated between the slip angular velocity and a slip angular velocity detected at a slip angular velocity calculating circuit. The deviation can detect a banked or laterally sloping road due to the fact that the detected slip angular velocity at the slip angular velocity calculating circuit includes the gravity acceleration component that depends on the slope or bank of the road. Upon detecting a banked or sloping road, a deviation &Dgr;&yuml; (&equals;{dot over (&thgr;)}&middot;V&minus;&yuml;) is outputted from a switching device, and at a subtracting device the detected lateral acceleration &yuml; is corrected by being subtracted with the deviation &Dgr;&yuml;. On the basis of the resultant or corrected lateral acceleration &yuml;, the vehicle-body sideslip angle is estimated. Such an estimation is made irrespective of the slope or bank of the road.

Vehicle driving condition detection device

A braking force distribution control device for an automotive vehicle is designed to make it possible to initiate a braking force distribution control as rapidly as possible upon rapid braking operation while at the same time being capable of preventing a malfunction of the braking force distribution control even when one of hydraulic pressure lines fails. The braking force distribution control establishes a predetermined relationship between the wheel cylinder pressure of a front wheel and a wheel cylinder pressure of a rear wheel on the basis of a comparison between the wheel speeds of the front and rear wheels. The braking force distribution control is initiated when the decelerations of all the wheels exceed a set value.

Brake force distribution control device for automotive vehicles

The present invention is directed to a brake control system for a vehicle, wherein a first valve device for opening or closing a main passage, a hydraulic pressure pump, and a second valve device for opening or closing an auxiliary passage are disposed in each hydraulic pressure circuit of a dual hydraulic pressure circuit system. At least one of the first and second valve devices is controlled to equalize the slip rates of a pair of wheels, with the wheel brake cylinders operatively mounted thereon and disposed in different hydraulic circuits, and placed at the left side and right side of the vehicle, respectively, when a difference between the slip rates of the wheels placed at the left side and right side exceeds a predetermined value.

The present invention is directed to a yaw rate detecting system for a vehicle, which includes a yaw rate sensor for measuring a yaw rate of the vehicle. The apparatus is adapted to determine a stopped state of the vehicle, set a zero point at the yaw rate measured by the yaw rate sensor when the stopped state of the vehicle is determined, and calculate an actual yaw rate in response to an output of the yaw rate sensor, on the basis of the zero point. The actual yaw rate is calculated by subtracting the yaw rate at the zero point from the yaw rate measured by the yaw rate sensor. It may be so arranged that a desired yaw rate is set on the basis of a vehicle speed and a steering angle, and the zero point is corrected in response to a comparison of the desired yaw rate and the actual yaw rate. For example, a temporary zero point is set when the stopped state of the vehicle is determined, and a deviation between the desired yaw rate and the actual yaw rate is calculated. In this case, the actual yaw rate is calculated by subtracting the yaw rate at the temporary zero point from the yaw rate measured by the yaw rate sensor. Then, the zero point is corrected on the basis of the temporary zero point in response to the deviation.

Yaw rate detecting system for a vehicle

A vehicle running condition judgment device for accurately detecting a change in a road surface condition and a vehicle's limit running condition. With substitution of respective tire characteristics and a detected state quantity into a vehicle motion model, vehicle slip angles are estimated for respective assumed road surface conditions. Based on the current state quantity and the last estimated vehicle slip angle, currently estimated vehicle slip angles for the respective assumed road surface conditions are compensated. A differential operation section calculates an estimation value of a vehicle slip angular velocity for each of the assumed road surface conditions based on the compensated vehicle slip angles for the respective assumed road surface conditions. Meanwhile, an operation section calculates a detection value of a vehicle slip angular velocity based on the detected state quantity. By comparing the detection value and the respective estimation values for the assumed road surface conditions, the current road surface condition is determined. Further, a lateral acceleration is calculated based on a vehicle slip angle, and compared with the detection value for determination of the road surface condition, and also with a predetermined limit value for determination of a vehicle's limit running condition.

Vehicle running condition judgement device

The present invention is directed to a vehicle motion control system, which includes a hydraulic braking pressure control apparatus for controlling braking force applied to each wheel of a vehicle at least in response to depression of a brake pedal. A vehicle condition monitor is disposed in the vehicle for monitoring a condition of the vehicle in motion, and a vehicle condition determining device is provided for determining stability of the vehicle in motion, including a turning motion of the vehicle on the basis of the output of the monitor. A braking force controller is provided for controlling the pressure control apparatus in response to the result of determination of the vehicle condition determining device to control the braking force applied to each wheel of the vehicle. A starting reference setting device is provided for setting a starting reference to start the braking force control by the braking force controller in response to the result of determination of the vehicle condition determining device. Then, an error estimating device is provided for estimating an error caused by the monitor, and a correction device is provided for correcting the starting reference set by the starting reference setting device in response to the error estimated by the error estimating device.

The present invention is directed to a brake control system for a vehicle, wherein a first valve device for opening or closing a main passage, which communicates a master cylinder with wheel brake cylinders, a hydraulic pressure pump for supplying the hydraulic pressure to the main passage, and a second valve device for opening or closing an auxiliary passage, which communicates the inlet of the pressure pump with the master cylinder, are disposed in each hydraulic pressure circuit of a dual hydraulic pressure circuit system. In the case where the slip rate of at least one of the front wheels is smaller than the slip rate of at least one of the wheels belonging to a different hydraulic pressure circuit from the hydraulic pressure circuit to which the one of the front wheels belongs, when the brake pedal is being operated, the hydraulic braking pressure discharged from the pressure pump is applied to one of the wheel brake cylinders operatively mounted on at least one of the front wheels, by controlling the second valve device for example.

A brake control apparatus includes a first valve to open and close a main line between a master cylinder and a wheel cylinder, a pump connected between a first valve and the wheel cylinder to supply pressurized brake fluid to the wheel cylinder, an auxiliary line connecting the inlet side of the pump to a master cylinder, a second valve to open and close the auxiliary line, a pressure sensor to detect the output pressure of the master cylinder and an electronic control unit which controls the first valve, the second valve, and the pump based upon the pressure detected by the pressure sensor so that the wheel cylinder receives a higher pressure than that of the master cylinder. The electronic control unit also closes the second valve while the pressure sensor detects the pressure over a certain pressure determined by the road surface condition.

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Yokkaichi, Japan

Kenji Tozu