Toyota Jidosha Kabushiki Kaisha

Jtekt Corporation

Ippei Yamazaki

Eiji Kasai

Shuji Fujita

Masaharu Yamashita

Shiro Monzaki

Yutaka Aoki

Yuichiro Ido

Hideo Kometani

Koichi Itoh

Junro Yamamoto

Yuichi Onoda

Yasunori Shintani

Takatoshi Saito

Yoichi Fujinori

A suspension system for a vehicle, includes (a) a shock absorber disposed between a sprung portion and an unsprung portion and having a damping-force changing mechanism, the shock absorber being configured to generate a damping force with respect to a relative movement of the sprung portion and the unsprung portion such that the magnitude of the damping force is changeable, and (b) a controller configured to control the damping-force changing mechanism. The controller includes a target sprung-speed determining portion configured to determine, as a target sprung speed, a speed of the sprung portion in a behavior of a body of the vehicle that matches an operation input to the vehicle by a driver, for permitting the behavior to match the operation input, the controller being configured to control the damping force such that the speed of the sprung portion becomes equal to the target sprung speed.

Suspension system for vehicle

A steering control apparatus includes: a friction torque setting mechanism setting a friction torque value to be applied to a steering based on information representing a status of a vehicle; a target steering angle setting mechanism setting a target steering angle based on the set friction torque value; an adding friction torque setting mechanism setting an adding friction torque based on a deviation between the set target steering angle and a steering angle; and a steering friction torque controller controlling a friction torque applied to the steering by an actuator based on the set adding friction torque.

Steering control apparatus and a steering apparatus using the same

A shock absorber system, including: a hydraulic shock absorber configured to generate a damping force with respect to a relative movement of a sprung portion and an unsprung portion; a damping-force changer configured to change the damping force; and a controller configured to determine a damping-force index and to control the damping-force changer, wherein the controller is configured to determine, as the index, a required application force to be applied to the sprung portion for damping its movement in an up-down direction, according to a determination rule in which the required application force has the same direction as a direction of a speed of the sprung portion in the up-down direction when the sprung speed is relatively small and acceleration of the sprung portion in the up-down direction is relatively large in a situation in which the direction of the speed and a direction of the acceleration are mutually different.

Shock absorber system

An absorber system for a vehicle includes a controller. The controller determines a reference control amount as a reference of a target control amount which is a target of a control amount for controlling a damping force with respect to an operation of a cylinder in its extension and an operation of the cylinder in its compression. The controller determines the target control amount to the reference control amount for one of the operation of the cylinder in its extension and the operation of the cylinder in its compression and determines the target control amount to a value obtained by multiplying the reference control amount by an extension-compression gain for the other. The controller changes the extension-compression gain in at least one of a driving-stability-emphasized situation in which driving stability is to be emphasized and a ride-comfort-emphasized situation in which ride comfort is to be emphasized.

Absorber system for vehicle

A vehicle body tilting apparatus includes: a right/left-wheels holding member having an elongated shape, and holding a right side wheel and a left side wheel of a vehicle which are disposed to be spaced apart from each other in a width direction of the vehicle such that each of the wheels is movable in a vertical direction; and a lean actuator disposed between the right/left-wheels holding member and a body of the vehicle, and configured to tilt at least the body of the vehicle in a lateral direction with respect to a normal line that is perpendicular to a road surface, by pivoting the right/left-wheels holding member and the body of the vehicle relative to each other. An output shaft of the lean actuator is fixed to the right/left-wheels holding member, and the body of the vehicle is fixed to a main body of the lean actuator.

Vehicle body tilting apparatus

When a change in an output voltage of a main power supply is a decrease, and a degree of the decrease is larger than a reference value, a power supply control portion decreases a boosted voltage of a voltage-boosting circuit according to the degree of the decrease. When the change in the output voltage of the main power supply is an increase, and a degree of the increase is larger than the reference value, the power supply control portion increases the boosted voltage of the voltage-boosting circuit according to the degree of the increase.

Power supply apparatus for vehicle and method of controlling power supply apparatus for vehicle

A vehicle behavior control device (S) determines, by using a vehicle velocity (V), a transmission function (K(s)) which is determined based on a specification of the vehicle, receives as an input a wheel turning speed (&#x3c9;) obtained by differentiating a wheel turning angle (&#x3b4;) of left and right front wheels (FW, FW) with respect to time, and outputs a target yaw moment (M). The device (S) also calculates, by using the determined target yaw moment (M), a left-wheel-side forward/backward force (F) imparted to a left wheel side (left front wheel FWand left rear wheel RW) of a vehicle () and a right-wheel-side forward/backward force (F) imparted to a right wheel side (right front wheel FWand right rear wheel RW) of the vehicle (). Then, the device (S) performs control to drive brake units (-) and in-wheel motors (IWMfl, IWMfr, IWMrl, IWMrr) depending on a turning direction of the vehicle (), with the left-wheel-side forward/backward force (F) serving as a braking force (or driving force) and the right-wheel-side forward/backward force (F) serving as a driving force (or braking force). It is thus possible to ensure directional stability and responsiveness when the vehicle turns, taking into account a frequency response characteristic of a motion state amount generated on the vehicle ().

Vehicle behavior control device

A vehicle steering apparatus that can prevent a large returning torque from acting when a steering wheel is turned. Through processing of an assist control program, rotational torque (assist torque) of an electric motor is calculated by adding returning torque g&#xb7;Trto to turning torque Tc (in actuality, subtracting the returning torque g&#xb7;Trto from the turning torque Tc). The electric motor is driven and controlled in accordance with the calculated assist torque. When the steering torque is large, the calculated returning torque gain g decreases, and therefore, the returning torque g&#xb7;Trto decreases or becomes zero. With this control, the greater the force (torque) required to operate the steering wheel, the smaller the influence of the returning torque, and steering feel at the time of turning the steering wheel is improved.

Vehicle steering apparatus

An electric power steering device, including an electric motor supplied with power from a power supply device to generate a predetermined steering assistance force for a steered wheel, and an assistance control device the controls the amount of electrical power supplied to the electric motor, according to the steering state of a steering wheel. The assistance control device detects the power supply voltage of the power supply device. The assistance control device controls the electrical current supplied to the electric motor, so as to maintain the power supply voltage greater than or equal to a set voltage which is set in advance.

Electric power steering device

A first compensation torque T, a second compensation torque Tand a third compensation torque Tare added to a basic assist torque Tas. In this case, the second compensation torque Tand the third compensation torque Tare corrected by multiplying them by a common control gain G that is determined by the steering torque Th and the vehicle speed v. Therefore, since the two compensation control amounts are corrected through multiplication by the common control gain G, no interference occurs between the compensation controls. Besides, when the direction in which the total (T+T) of the pre-correction second compensation torque Tand the pre-correction third compensation torque Tacts is the same direction as the steering torque Th, the multiplication by the control gain G is avoided.

Electric power steering device, and control method thereof

A target turning angle calculation partcalculates a target turning angle &#x3b4; on the basis of a steering angle &#x3b8; and a vehicle speed V. A correction turning angle calculation partcalculates a transfer function K(s) which is a second transfer function, depending on the vehicle speed V, by using a difference between a transfer function G(s) which is a first transfer function determined on the basis of the specification of the vehicle and a stationary component G() of the transfer function G(s), the first transfer function having as an input a turning angle &#x3b4; and as an output a yaw rate &#x3b3; of the vehicle, the second transfer function having as an input a target turning rate &#x3b4;*' obtained by temporally differentiating the target turning angle &#x3b4;* and as an output a correction turning angle &#x3b4;. The correction turning angle calculation partcalculates a correction turning angle &#x3b4;c by multiplying the transfer function K(s) by the target turning rate &#x3b4;*&#x2032;. A final target turning angle calculation partinputs thereto the target turning angle &#x3b4;* from the target turning angle calculation partand the correction turning angle &#x3b4;c from the correction turning angle calculation partand calculates a final target turning angle &#x3b4;by adding the correction turning angle &#x3b4;c to the target turning angle &#x3b4;*.

Steering device of vehicle

In a power supply apparatus, a power supply circuit includes a primary power supply circuit including a high-voltage battery and a step-down circuit for stepping down the voltage of the high-voltage battery, and a secondary power supply circuit including a low-voltage battery and a step-up circuit for stepping up the voltage of the low-voltage battery. The primary power supply circuit and the secondary power supply circuit are connected in parallel. An output voltage of the secondary power supply circuit is set to be lower than an output voltage of the primary power supply circuit. When the output voltage of the primary power supply circuit becomes lower than a target voltage of the secondary power supply circuit, the voltage stepped-up by the step-up circuit is supplied to a motor drive circuit. Accordingly, power supply backup of an electric power steering apparatus can be performed at low cost.

Electric power steering system apparatus

When it is determined that a malfunction has occurred in a rotational angle sensor, an electronic control unit changes the control manner from the normal assist control to the sensorless assist control. In the sensorless assist control, an assist stop command unit receives the information concerning the motor rotational angular speed &#x3c9;m from an angular speed conversion unit. Then, the motor rotational angular speed &#x3c9;m is compared with the threshold value &#x3c9;m. If the motor rotational angular speed &#x3c9;m is equal to or higher than the threshold value &#x3c9;m, an assist enabling signal is transmitted to a PWM voltage production unit to continue the power assist. On the other hand, if the motor rotational angular speed &#x3c9;m is lower than the threshold value &#x3c9;m, a stop command signal is transmitted to the PWM voltage production unit to stop the power assist.

Electric power steering apparatus

An actual detected current value and a target voltage value of an electric motor are subjected to a low-pass filter process, and amounts of change per time in the filtered actual current value and the filtered target voltage value are calculated. If the amount of change in the actual current value on the increase side is greater than a criterion value and the amount of change in the target voltage value on the decrease side is greater than a criterion value, it is judged that the stroke end has been reached. Then, the upper limit value of the target current value is set at the actual current value obtained in the immediately previous cycle of the feedback control, so as to prevent generation of unnecessary torque.

The CPU calculates axial force matching external force that acts on a rack bar by combining steering torque MT that acts on a steering shaft with assist torque AT generated by an electric motor. The CPU then determines whether a vehicle is running straight based on a steering angle &#x3b8;, a vehicle speed V, and the axial force F. Thus, even in a state where a control steering angle midpoint is deviated and a driver applies torque so as to return a turning position of a steering wheel to a neutral position, whether the vehicle is running straight can be accurately determined by making a determination by using the axial force F that acts on the rack bar. The CPU can set a considerably accurate control steering angle midpoint by calculating a smoothed steering angle midpoint by using an instantaneous steering angle midpoint in an accurately determined straight-running state.

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Toyota, Japan

Ippei Yamazaki