Toyota Jidosha Kabushiki Kaisha

Yanqing Liu

Masaaki Tabata

Yuichi Mizuta

Jin Hozumi

Motohiko Honma

Taisuke Hayashi

A vehicle vibration damping system includes a suspension; an actuator; and a control device configured to calculate a damping force to be applied to the sprung structure based on a theory of skyhook control, and control the actuator. The control device calculates the damping force based on a correction control parameter obtained by multiplying a control parameter of a denominator of a transfer function of the sprung structure with respect to a road surface displacement of a vibration model having a virtual skyhook damper by a function for canceling a coefficient of a control parameter term. The control parameter is a product of an attenuation coefficient of the skyhook damper and a Laplace operator. The function is a function having a coefficient of the control parameter term of the transfer function as a denominator, and includes at least a quadratic term of the Laplace operator in a numerator.

Vehicle vibration damping system

Out of two areas divided by a virtual line passing through the center of gravity position in the front-back direction of a vehicle, a second acceleration sensor is arranged in an area different from the area where a first acceleration sensor is arranged. Out of two areas divided by a virtual line passing through the center of gravity position in the vehicle width direction, the third acceleration sensor is arranged in an area different from the area where the first acceleration sensor is arranged. At least one of the following conditions is satisfied: the first condition where the third acceleration sensor is located between the first acceleration sensor and the second acceleration sensor in the vehicle width direction; and the second condition where the second acceleration sensor is located between the first acceleration sensor and the third acceleration sensor in the front-back direction of the vehicle.

Vehicle travel control system

A control unit that controls control currents supplied to shock absorbers that generate damping forces according to the control currents determines coefficients of two functions that functionally identify an equivalent damping coefficient and an equivalent spring constant of each suspension based on relationships between the control current supplied to each shock absorber and the coefficients of the two functions that change according to the control current and a frequency of a relative vibration between a sprung and an unsprung of a vehicle, and calculates a relative displacement or a relative velocity between the sprung and the unsprung based on a vertical acceleration detected by a detection device and the two functions in which the coefficients are determined.

Suspension stroke related value estimation device and method

A vibration damping control apparatus which has a control unit that calculate a pitch damping driving torque based on a pitch angular velocity of a vehicle body, and control an engine based on at least the pitch damping driving torque. The control unit stores a vehicle speed corresponding to a phase difference of &#x2212;180&#xb0; in a relationship between a phase difference and a vehicle speed as an upper limit reference vehicle speed, the relationship being derived by obtaining phase characteristic of a wheelbase filter function for various vehicle speeds and obtaining a relationship between the phase difference of vertical displacements of the vehicle body at positions of front and rear wheels and a vehicle speed with respect to a pitch resonance frequency of the vehicle, and reduces the pitch damping driving torque when a vehicle speed is not higher than the upper limit reference vehicle speed.

Vibration damping control apparatus for vehicle

A suspension device for a vehicle includes a spring device disposed between a sprung member and an unsprung member of a vehicle and allowing a relative displacement between the sprung member and the unsprung member. The spring constant kof the spring device when the spring device is deformed in the direction in which the spring device contracts with respect to the predetermined reference length is configured to be smaller than the spring constant kof the spring device when the spring device is deformed in the direction in which the spring device expands with respect to the predetermined reference length. Consequently, it is possible to obtain a characteristic opposite to the spring characteristic of the seat, and as a result, ride quality can be improved.

Suspension device for vehicle

A device includes a road surface input calculating unit that calculates an estimated value of a road surface input to the wheel, by letting an inverse matrix of a product of a vehicle motion model matrix and a wheel speed influencing element model matrix act on a wheel speed of a vehicle. The vehicle motion model matrix represents a mechanical vehicle motion model, and the wheel speed influencing element model matrix using a quantity of influence due to pitch about a center of gravity of a vehicle body, a suspension geometry influence quantity, and a quantity of influence of a change in a rolling radius of the wheel. The device also includes a vehicle body state quantity calculating unit that calculates an estimated value of a vehicle body state quantity by letting the vehicle motion model matrix on the calculated estimated value of the road surface input.

Vehicle body state quantity estimating device

A vehicle control device includes a spring mechanism configured to connect a sprung member and an unsprung member of a vehicle, generate a spring force according to a relative displacement between the sprung member and the unsprung member, and be able to variably control the spring force, and a damping mechanism configured to connect the sprung member and the unsprung member, generate a damping force for damping a relative motion between the sprung member and the unsprung member, and be able to variably control the damping force, wherein the spring mechanism and the damping mechanism are controlled based on a first physical quantity relating to a sprung vibration of the vehicle and a second physical quantity relating to an unsprung vibration of the vehicle.

Vehicle control device

A suspension control system includes a suspension device () that connects a sprung member () and an unsprung member () of a vehicle, an actuator () operable to adjust frictional force along a stroke direction of the suspension device (), and a control device () configured to control the actuator (), based on a velocity direction of the sprung member () parallel to the stroke direction of the suspension device (), and a stroke velocity direction of the suspension device (), so as to adjust suspension frictional force as the frictional force along the stroke direction of the suspension device (). The control device () is configured to adjust a magnitude of the suspension frictional force, so that it becomes substantially equal to a required frictional force determined based on a value obtained by exponentiating the velocity of the sprung member (), and a value obtained by exponentiating the stroke velocity of the suspension device ().

Suspension control system and method of controlling suspension device

Disclosed is a damping force control device for a vehicle that controls the damping coefficient of a damping force generation device on the basis of a final target control amount that is based on the target control amount for attitude control, which suppresses changes in the vehicle body attitude in at least the rolling direction, and the target control amount for riding comfort control, which increases riding comfort with regards to vehicle body vibrations in at least the rolling direction. The target control amount for riding comfort control is a control amount calculated as the total of a fixed basic control amount and a variable control amount. The target control amount and the variable control amount for attitude control are calculated, a post-correction basic control amount, which is nearer to the target control amount for attitude control than the basic control amount, is calculated, and the total of the post-correction basic control amount and the variable control amount is set as the final target control amount, thereby excellently achieving both the suppression of attitude changes and an increase in riding comfort.

Damping force control device for vehicle

A control mode for a damping force characteristic is set to be a variable control when a product of the sum x' of sprung member speeds and a sprung-member-unsprung-member-relative-speed x&#x2032; is positive. Accordingly, when the vibration in a middle/high frequency range is not being input to a suspension apparatus, an operation of a variable throttle mechanism is controlled so that a step number representing the damping force characteristic of a damper varies with a vibration state of a sprung member HA based on a Nonlinear Hcontrol theory. When the product of x&#x2032; and x&#x2032; is negative, the control mode is set to be an operation prohibiting control. When the vibration in the middle/high frequency range is input to the suspension apparatus, operation of the variable throttle mechanism is prohibited, and suppresses an increase in the operation frequency or in the operation amount of the variable throttle mechanism.

Growing community of inventors

Susono, Japan

Yanqing Liu