Abstract: A roll control apparatus for a vehicle which comprises front wheel side and rear wheel side active stabilizer devices and a control unit that is configured to control the stabilizer devices, to calculate a target anti-roll moment, to determine optimum control gains of electric actuators of the stabilizer devices among pre-stored control gains based on a vehicle speed and a frequency of change in a roll angle of a vehicle body, and to control the electric actuators so that a sum of anti-roll moments generated by the front wheel side and rear wheel side active stabilizer devices becomes the target anti-roll moment and control gains of the electric actuators become the optimum control gains.

Abstract: A vehicle attitude control device includes a controller including a low-pass filter. The controller calculates a manipulated variable of the actuator that allows the roll of the vehicle to be suppressed. The controller processes the roll angle acceleration with the low-pass filter, integrates the roll angle acceleration in which a high-frequency component has been removed by the low-pass filter, and converts a roll angle velocity obtained by the integration, into the manipulated variable. The low-pass filter has a first vehicle speed-cutoff frequency characteristic in which a cutoff frequency becomes higher with increase in the vehicle speed, and the first vehicle speed-cutoff frequency characteristic is designed such that a peak frequency in roll vibration coincides with a local minimum roll frequency in wheelbase filtering, the roll vibration being amplified by a dead time and a phase delay in control by the controller.

Abstract: Provided is a vehicle state estimation device (10) having a calculation unit (28) that calculates state quantities of at least a sprung of a vehicle based on wheel speeds of front left and right wheels and rear left and right wheels detected by detection devices. The calculation unit (28) calculates in-phase and reverse phase components of wheel speeds of left and right wheels for the front and rear wheels and calculates a pitch angular speed and a yaw angular speed of the sprung based on the in-phase and reverse phase components of the wheel speeds, respectively. The calculation unit (28) calculates in-phase and reverse phase components of vertical strokes of left and right suspensions for the front and rear wheels and calculates a vertical speed and a roll angular speed of the sprung based on the in-phase and reverse phase components of vertical strokes of the suspensions, respectively.

Abstract: A vehicle attitude control device includes a controller including a low-pass filter. The controller calculates a manipulated variable of the actuator that allows the roll of the vehicle to be suppressed. The controller processes the roll angle acceleration with the low-pass filter, integrates the roll angle acceleration in which a high-frequency component has been removed by the low-pass filter, and converts a roll angle velocity obtained by the integration, into the manipulated variable. The low-pass filter has a first vehicle speed-cutoff frequency characteristic in which a cutoff frequency becomes higher with increase in the vehicle speed, and the first vehicle speed-cutoff frequency characteristic is designed such that a peak frequency in roll vibration coincides with a local minimum roll frequency in wheelbase filtering, the roll vibration being amplified by a dead time and a phase delay in control by the controller.

Abstract: A roll control apparatus for a vehicle which comprises front wheel side and rear wheel side active stabilizer devices and a control unit that is configured to control the stabilizer devices, to calculate a target anti-roll moment, to determine optimum control gains of electric actuators of the stabilizer devices among pre-stored control gains based on a vehicle speed and a frequency of change in a roll angle of a vehicle body, and to control the electric actuators so that a sum of anti-roll moments generated by the front wheel side and rear wheel side active stabilizer devices becomes the target anti-roll moment and control gains of the electric actuators become the optimum control gains.

Abstract: Provided is a vehicle state estimation device (10) having a calculation unit (28) that calculates state quantities of at least a sprung of a vehicle based on wheel speeds of front left and right wheels and rear left and right wheels detected by detection devices. The calculation unit (28) calculates in-phase and reverse phase components of wheel speeds of left and right wheels for the front and rear wheels and calculates a pitch angular speed and a yaw angular speed of the sprung based on the in-phase and reverse phase components of the wheel speeds, respectively. The calculation unit (28) calculates in-phase and reverse phase components of vertical strokes of left and right suspensions for the front and rear wheels and calculates a vertical speed and a roll angular speed of the sprung based on the in-phase and reverse phase components of vertical strokes of the suspensions, respectively.

Abstract: A vehicle suspension device includes a suspension device main body configured to support a wheel of a vehicle to a vehicle body of the vehicle; an upper intervening member configured to be intervened between a vertically upper portion of the suspension device main body and the vehicle body so that a front-back stiffness of the vehicle is relatively decreased at a time of smooth-braking of the vehicle at which an absolute value of a braking force of the vehicle is relatively small, compared to at a time of non-braking of the vehicle; and a lower intervening member configured to be intervened between a vertically lower portion of the suspension device main body and the vehicle body so that the front-back stiffness of the vehicle is relatively increased at the time of smooth-braking of the vehicle, compared to at the time of non-braking of the vehicle.

Abstract: A vehicle state estimating device for estimating the state amount of the vehicle at high accuracy from the wheel speed irrespective of the change in the vehicle property. A vehicle state estimating device includes a wheel speed detection unit that detects a wheel speed of each vehicle wheel; a vehicle speed detection unit that detects a vehicle speed; and a state amount estimation unit that estimates an unsprung state amount and/or a sprung state amount of the vehicle, based on a wheel speed of reverse phase of left and right wheels based on the wheel speed of each wheel detected by the wheel speed detection unit, and a value obtained by dividing a wheel base of a predetermined front-rear wheel by the vehicle speed detected by the vehicle speed detection unit.

Abstract: A vehicle state estimating device includes a wheel speed detection unit; a brake operation amount detection unit; a drive operation amount detection unit; a steering operation amount detection unit; a first state amount estimating unit configured to estimate a sprung state amount caused by an operation input; a first fluctuation estimating unit configured to estimate a wheel speed fluctuation amount caused by an operation input; a second fluctuation estimating unit configured to estimate an actual wheel speed fluctuation amount from which a wheel speed fluctuation amount by a brake/drive force is excluded; a third fluctuation estimating unit configured to estimate a wheel speed fluctuation amount caused by a road surface input; and a second state amount estimating unit configured to estimate at least one of a sprung state amount and an unsprung state amount caused by a road surface input.

Abstract: The height of a vehicle can be estimated inexpensively by: detecting a wheel speed, which is a speed of each wheel; performing frequency analysis of the detected wheel speed of a pair of left and right wheels and calculating respective wheel speed characteristics of the left and right wheels at a gain-specific frequency; calculating a left-right wheel speed gain difference on the basis of the calculated wheel speed characteristics of the left and right wheels; and estimating the vehicle height on the basis of a corresponding relationship between a wheel height of the wheel with respect to a vehicle body and a value (wheel speed/road surface input gain) that is based on wheel speed and a road surface input that is inputted from the road surface to the wheels, and on the basis of the left-right wheel speed gain difference.

Abstract: There is provided a vibration analysis technique using vibration measured while a vehicle is made to run on a real road, enabling the detection of vibration characteristics while distinguishing various vibrational input modes. In the inventive vibration analysis technique, a vehicle is made to run on a road surface whose height varies at various wavelengths along its movement, and using a vibration characteristic value in a site of a vehicle body measured during the vehicle running as a response variable and using at least two vibration input values causing the vibration characteristic value as explanatory variables, a transfer function of the vibration characteristic value for each of at least two vibration input values is computed as partial regression coefficients by multiple regression analysis.

Abstract: A vehicle suspension device includes a suspension device main body configured to support a wheel of a vehicle to a vehicle body of the vehicle; a varying device configured to cause an upper connecting portion stiffness and a lower connecting portion stiffness to be variable, the upper connecting portion stiffness being a stiffness between a vertically upper portion of the suspension device main body and the vehicle body, and the lower connecting portion stiffness being a stiffness between a vertically lower portion of the suspension device main body and the vehicle body; and a control device configured to control the varying device at a time of braking of the vehicle to perform control which causes the upper connecting portion stiffness to be relatively decreased and causes the lower connecting portion stiffness to be relatively increased, compared to at a time of non-braking of the vehicle.

Abstract: A vehicle state estimating device for estimating the state amount of the vehicle at high accuracy from the wheel speed irrespective of the change in the vehicle property. A vehicle state estimating device includes a wheel speed detection unit that detects a wheel speed of each vehicle wheel; a vehicle speed detection unit that detects a vehicle speed; and a state amount estimation unit that estimates an unsprung state amount and/or a sprung state amount of the vehicle, based on a wheel speed of reverse phase of left and right wheels based on the wheel speed of each wheel detected by the wheel speed detection unit, and a value obtained by dividing a wheel base of a predetermined front-rear wheel by the vehicle speed detected by the vehicle speed detection unit.

Abstract: A vehicle state estimating device includes a wheel speed detection unit; a brake operation amount detection unit; a drive operation amount detection unit; a steering operation amount detection unit; a first state amount estimating unit configured to estimate a sprung state amount caused by an operation input; a first fluctuation estimating unit configured to estimate a wheel speed fluctuation amount caused by an operation input; a second fluctuation estimating unit configured to estimate an actual wheel speed fluctuation amount from which a wheel speed fluctuation amount by a brake/drive force is excluded; a third fluctuation estimating unit configured to estimate a wheel speed fluctuation amount caused by a road surface input; and a second state amount estimating unit configured to estimate at least one of a sprung state amount and an unsprung state amount caused by a road surface input.

Abstract: When a vehicle travels, due to an input from a road surface to the front wheels and rear wheels of the vehicle, unsprung vertical accelerations are generated in unsprung portions of the vehicle. An electronic control unit detects such unsprung vertical accelerations. The electronic control unit calculates a front-back force generated at each of the wheels by use of the detected unsprung vertical acceleration, and estimates a front-back vibration generated in each of the wheels. The electronic control unit calculates a front-back vibration suppressing force for absorbing the front-back vibration by use of the detected unsprung vertical acceleration. The electronic control unit subtracts the calculated front-back vibration suppressing force from the calculated front-back force, and operates the in-wheel motors via an inverter, while controlling the output torques of the in-wheel motors. Thus, the front-back vibrations of the unsprung portions of the vehicle can be suppressed.

Abstract: The height of a vehicle can be estimated inexpensively by: detecting a wheel speed, which is a speed of each wheel; performing frequency analysis of the detected wheel speed of a pair of left and right wheels and calculating respective wheel speed characteristics of the left and right wheels at a gain-specific frequency; calculating a left-right wheel speed gain difference on the basis of the calculated wheel speed characteristics of the left and right wheels; and estimating the vehicle height on the basis of a corresponding relationship between a wheel height of the wheel with respect to a vehicle body and a value (wheel speed/road surface input gain) that is based on wheel speed and a road surface input that is inputted from the road surface to the wheels, and on the basis of the left-right wheel speed gain difference.

Abstract: A vehicle suspension device includes a suspension device main body configured to support a wheel of a vehicle to a vehicle body of the vehicle; an upper intervening member configured to be intervened between a vertically upper portion of the suspension device main body and the vehicle body so that a front-back stiffness of the vehicle is relatively decreased at a time of smooth-braking of the vehicle at which an absolute value of a braking force of the vehicle is relatively small, compared to at a time of non-braking of the vehicle; and a lower intervening member configured to be intervened between a vertically lower portion of the suspension device main body and the vehicle body so that the front-back stiffness of the vehicle is relatively increased at the time of smooth-braking of the vehicle, compared to at the time of non-braking of the vehicle.

Abstract: A vehicle suspension device includes a suspension device main body configured to support a wheel of a vehicle to a vehicle body of the vehicle; a varying device configured to cause an upper connecting portion stiffness and a lower connecting portion stiffness to be variable, the upper connecting portion stiffness being a stiffness between a vertically upper portion of the suspension device main body and the vehicle body, and the lower connecting portion stiffness being a stiffness between a vertically lower portion of the suspension device main body and the vehicle body; and a control device configured to control the varying device at a time of braking of the vehicle to perform control which causes the upper connecting portion stiffness to be relatively decreased and causes the lower connecting portion stiffness to be relatively increased, compared to at a time of non-braking of the vehicle.

Abstract: To provide a vehicle control device capable of improving the ride comfort on the vehicle. A vehicle control device for controlling operation of a vehicle including a vehicle body, and a tire for supporting the vehicle body and contacting with a ground surface, the vehicle control device includes an operation condition detecting unit configured to detect an operation condition that influences a side vibration of the vehicle body; a suspension geometry adjusting unit configured to adjust a suspension geometry of the vehicle; and a control unit configured to control operation of the suspension geometry adjusting unit based on a detection result of the operation condition detecting unit.

Abstract: An attachment structure of a stabilizer link is provided having one end pivotally fitted to an end of a stabilizer and the other end coupled to a wheel support member by a coupling device. A positional relationship of pivot points of the one end and the other end of the stabilizer link relative to the kingpin axis is set such that when the stabilizer link is displaced relative to the wheel support member in accordance with rolling of a vehicle at the time of turning, the wheel support member is pivotally displaced about the kingpin axis in the direction where a steered angle of the steered wheel is increased, and when a magnitude of roll angle of the vehicle is large, the coupling device increases a ratio of a pivotal displacement amount of the wheel support member relative to the roll angle of the vehicle as compared with a situation where a magnitude of roll angle of the vehicle is small.