Toyota Jidosha Kabushiki Kaisha

Ryochi Watanabe

Hiroaki Endo

Yoshihisa Yamada

Shirou Monzaki

Hidehisa Kato

Hiroshi Ohmine

Provided is a control apparatus for a vehicle, the control apparatus being configured to determine a road surface &#x3bc; state of a road in front of the vehicle based on an image of a front region of the vehicle, and change a magnitude of an amount of reduction in a braking force per unit time in accordance with the determined road surface &#x3bc; state in braking force cancel control executed after hill-hold control

Control apparatus for vehicle

A vehicle control device controls a driving device in such a manner that driving torque coincides with normal torque. The vehicle control device starts a traction control for controlling the driving device in such a manner that the driving torque coincides with suppressed torque which is smaller than the normal torque, when a predetermined traction control start condition is satisfied. The vehicle control device determines that the driver is in a non-grasp state, when an operation amount has changed to satisfy a condition in an initial determination time period. The vehicle control device starts, at an acceleration time point, an operation priority control for controlling the driving device in such a manner that the driving torque coincides with acceleration priority torque which is larger than the suppressed torque and smaller than the normal torque, if the control device had not determined that the driver was in the non-grasp state.

Vehicle control device

An ECU determines whether or not a road surface changes from a low &#x3bc; road surface to a high &#x3bc; road surface based on image data obtained by a camera sense. When the ECU determines that the accelerator pedal operation amount deceases greatly in a predetermined determination period from a time point at which a drive wheel slip state occurs in a case where the ECU determines that the road surface changes from the low &#x3bc; road surface to the high &#x3bc; road surface, it prohibits upshift operation of an automatic transmission over a predetermined period from that time point.

Vehicle

A vehicle control ECU determines a road surface &#x3bc; state of a forward road of a vehicle based on a front image. The vehicle control ECU changes, in accordance with a determined result, a split determination threshold value which is used to determine whether to perform a vehicle behavior stabilization control for stabilizing a behavior of the vehicle.

Vehicle control apparatus

A vehicle stability control device is mounted on a vehicle in which a front tire wears faster than a rear tire. Understeer degree increases as a target yaw rate becomes higher than an actual yaw rate. When the understeer degree exceeds a first activation threshold, vehicle stability control is activated. When the understeer degree exceeds a second activation threshold, rear brake control that applies a braking force to an inner rear wheel is activated. A wear degree parameter is wear degree of the front tire or a difference in wear degree between the front tire and the rear tire. In response to a fact that the wear degree parameter exceeds a first wear threshold, the vehicle stability control device performs rear wear promotion processing that changes the second activation threshold to an adjusted value smaller than a default value and the first activation threshold.

Vehicle stability control device

A vehicle stability control device is mounted on a vehicle in which a front tire wears faster than a rear tire. An equation for calculating a target yaw rate includes a stability factor of the vehicle as a parameter, wherein the calculated target yaw rate becomes lower as the stability factor becomes larger. Understeer degree increases as the target yaw rate becomes higher than an actual yaw rate. When the understeer degree exceeds an activation threshold, vehicle stability control is activated. The vehicle stability control device further performs wear coping processing. In the wear coping processing, a wear degree parameter being wear degree of the front tire or a difference in wear degree between the front tire and the rear tire is calculated. When the wear degree parameter exceeds a wear threshold, the vehicle stability control device corrects the stability factor to be larger than a default setting value.

A control device is to be applied to a four-wheel drive vehicle including a first coupling device interposed between a rear-wheel final gear device and a rear left wheel axle and a second coupling device interposed between the rear-wheel final gear device and a rear right wheel axle. The control device includes a controller changes a coupling torque of the first coupling device and a coupling torque of the second coupling device independently of each other. The controller estimates, when the vehicle is accelerating, a vehicle body speed of the vehicle under a state in which the coupling torque of any one of the first coupling device and the second coupling device is set to a value larger than zero and the coupling torque of another one thereof is set to zero. Thereby, the control device can accurately estimate the vehicle body speed when the vehicle is traveling while accelerating.

Control device for four-wheel drive vehicle

A control apparatus for a four-wheel-drive vehicle is configured to, during braking of the vehicle in a two-wheel-drive state, determine whether or not a degree of a yaw movement for deflecting the vehicle is larger than a predetermined first degree. When the degree of the yaw movement is larger than the first degree, the control apparatus increases a first coupling torque of a first coupling device and a second coupling torque of a second coupling device to a predetermined first torque value which is larger than zero, and controls a ground contact load adjusting device in such a manner that a first ground contact load at a rear wheel at an outer side with respect to the yaw movement becomes larger than a second ground contact load at a rear wheel at an inner side with respect to the yaw movement by a predetermined first load difference or more.

Control apparatus for four-wheel-drive vehicle

The control device of a four-wheel drive vehicle is applied to a four-wheel drive vehicle having a differential restriction device which can change a differential restriction degree between a front wheel rotary shaft and a rear wheel rotary shaft, a braking device can separately change a braking force of the front wheels and a braking force of the rear wheels. The control device determines whether a specific state which has a high possibility that a state where a rear wheel slip ratio becomes larger than a front wheel slip ratio is generated occurs assuming that the differential restriction degree is set to a first degree when the differential restriction degree is set to a second degree so as not to allow the differential operation and change the differential restriction degree from the second degree to the first degree when it is determined that the specific state has occurred.

A behavior control apparatus for a four-wheel drive vehicle comprising a driving unit, front and rear wheel driving torque transmission paths that transmit driving torques of the driving unit to front and rear wheels, respectively, and control unit. The rear wheel driving torque transmission path includes a speed increasing device for increasing speed of the rear wheels relative to the front wheels and two clutches for the left rear w heel and right rear wheel disposed between the speed, increasing device and the left rear wheel and the right rear wheel, respectively. The control unit engages the clutch on the turning inside when the vehicle is in oversteer state during turning under braking in a situation where the two clutches are disengaged.

Behavior control apparatus for a four-wheel drive vehicle

A wheel speed estimation device is to be applied to a four-wheel drive vehicle including a first coupling device for a rear left-wheel axle and a second coupling device for a rear right-wheel axle. These coupling devices respectively change states of engagement of a left engagement state and a right engagement state to the any one of a completely restraint state, a release state, and an incompletely restraint state. The wheel speed estimation device includes a correction parameter calculator that calculates correction parameters affected by a difference in wheel radius between wheels based on all wheel rotation speed signals, and a wheel speed calculator that calculates wheel speeds based on the wheel rotation speed signals and the correction parameters. Further, the correction parameter calculator stops calculation of the correction parameters when at least one of the left engagement state or the right engagement state is the incompletely restraint state.

Wheel speed estimation device

A behavior control device for a four-wheel drive vehicle that is applied to a vehicle which includes a center differential device that transmits a driving force from a driving device to front and rear wheel rotation shafts, and permits differential of the front and rear wheel rotation shafts; and a braking force distribution ratio of the front and rear wheels being set to a value in which a proportion of front wheels is larger than that in an ideal distribution ratio. The behavior control device includes a differential limiting device that changes the limitation degree of a differential between the wheel rotation shafts, and a control unit that controls the differential limiting device to increase the limitation degree of the differential during the vehicle is braked as a degree of an understeer state of the vehicle is high.

Behavior control device for four-wheel drive vehicle

A control apparatus for a four-wheel-drive vehicle is configured to determine whether or not a degree of a yaw movement for deflecting the vehicle to a left or right side is larger than a predetermined first degree. When the degree of the yaw movement is larger than the first degree, the control apparatus increases a coupling torque of a coupling device corresponding to a rear wheel at the same side as a direction of the yaw movement to a predetermined first torque value, and maintains at zero a coupling torque of a coupling device corresponding to a rear wheel at an opposite side to the direction of the yaw movement.

A control device for a four-wheel drive vehicle includes a differential restriction device which varies a differential restriction degree between a front wheel rotary shaft and a rear wheel rotary shaft, a differential restriction device and control units for controlling the differential restriction device. The control device is configured to control a behavior when the vehicle is being braked. Further, the control unit is configured to lower the differential restriction degree when a yaw rate of the vehicle is lower than a predetermined yaw rate threshold and a time decreasing rate of an estimated vehicle body speed which is a vehicle body speed estimated based on a wheel speed of the vehicle falls below a predetermined decreasing rate when the vehicle is being braked, in a vicinity of a maximum value.

A behavior control apparatus for a vehicle, comprising a control unit that controls braking/driving forces of wheels so that the magnitude of a deviation between a steering angle and a steering angle conversion value of a yaw rate decreases when it is determined that the deviation exceeds a threshold value in magnitude and the vehicle is in an understeer state; the vehicle has a steering device including a variable gear ratio type rack bar; and, when the sign of the steering angle is the same as the sign of the offset amount and the zero point offset amount exceeds a reference value in magnitude, the control device corrects at least one of the threshold value and the magnitude of the deviation according to the steering angle and the zero point offset amount so that it becomes difficult to determine that the magnitude of the deviation exceeds the threshold value.

Growing community of inventors

Susono, Japan

Ryochi Watanabe