Abstract: A correction torque command is outputted to a driving/braking torque producing means in accordance with a correction torque to suppress vehicle body spring vibration. When a state of the correction torque amplitude being greater than a predetermined amplitude continues for a given predetermined time, a control apparatus outputs a hunting time correction torque command smaller than a normal time correction toque command. When a state of the correction torque amplitude being smaller than or equal to the predetermined amplitude continues for a first predetermined time, the control apparatus returns the output of correction torque command from the hunting time correction torque command to the normal time correction torque command. The control apparatus continues the output of the hunting time correction torque command if the state in which the correction torque amplitude exceeds the predetermined amplitude continues for the given predetermined time, before the expiration of the first time period.

Abstract: A vehicle body vibration estimating device for estimating a vehicle body vibration as a sprung mass of a vehicle where wheels are suspended via a suspension device. The vehicle body vibration estimating device includes a wheel speed physical quantity detecting section and a vibration estimating section. The wheel speed physical quantity detecting section detects a wheel speed physical quantity related to wheel speed, which is a circumferential velocity of a wheel. The vibration estimating section estimates the vehicle body vibration from a correlation relationship between displacements in a back-and-forth direction and displacements in an up-and-down direction of the wheels with respect to the vehicle body, and the wheel speed physical quantity detected by the wheel speed physical quantity detecting section.

Abstract: Apparatus for estimating a ground contact surface gripping characteristic of a vehicle wheel of a vehicle comprises an input section and an output section. The input section sets an input representing a ratio of a wheel force acting on the vehicle wheel in the ground contact surface, and a wheel slipping degree of the vehicle wheel. The output section determines, from the input, an output representing a grip characteristic parameter indicative of the gripping characteristic of the vehicle wheel.

Abstract: Predetermined weights are assigned, in accordance with a traveling state, to a first correction toque to suppress a sprung vibration of the vehicle in accordance with a wheel speed, and a second correction toque to suppress the sprung vibration of the vehicle in accordance with a driving/braking torque. With this configuration, it becomes possible to calculate the vibration suppressing torque corresponding to the traveling state.

Abstract: A vehicular vibration damping control apparatus calculates a correction torque to suppress vehicle body sprung vibration. In outputting a correction torque command to a driving/braking torque producing device, the control apparatus outputs a hunting time correction torque command smaller than a normal time correction toque command when a state in which amplitude of the correction torque is greater than or equal to a predetermined amplitude continues for a predetermined time length, and thereafter to return an output of the correction torque command from the hunting time correction torque command to the normal time correction torque command if a state in which the amplitude of the correction torque is smaller than or equal to the predetermined amplitude continues for a first predetermined time length. The frequency of performing the vibration damping control is increased by suppressing occurrence of hunting at the time of return to the normal vibration damping control.

Abstract: A correction torque command is outputted to a driving/braking torque producing means in accordance with a correction torque to suppress vehicle body sprung vibration. When a state of the correction torque amplitude being greater than or equal to a predetermined amplitude continues for a predetermined time, a control apparatus outputs a hunting time correction torque command smaller than a normal time correction toque command. When a state of the correction torque amplitude being smaller than or equal to the predetermined amplitude continues for a first predetermined time, the control apparatus returns the output of correction torque command from the hunting time correction torque command to the normal time correction torque command. The control apparatus continues the output of the hunting time correction torque command if the state in which the correction torque amplitude exceeds the predetermined amplitude continues for the predetermined time, before the expiration of the first time period.

Abstract: A steered condition vehicle behavior improving apparatus is provided for a vehicle, wherein the vehicle is capable of running with a road wheel driven by a driving force from a power source. The steered condition vehicle behavior improving apparatus includes a steering operation detecting means and a driving force reducing means. The steering operation detecting means detects a steering operation of steering a steerable wheel of the vehicle. The driving force reducing means temporarily reduces the driving force to the road wheel a set time period after the steering operation is detected by the steering operation detecting means.

Abstract: A steered condition vehicle behavior improving apparatus is provided for a vehicle, wherein the vehicle is capable of running with a road wheel driven by a driving force from a power source. The steered condition vehicle behavior improving apparatus a steering operation detecting means and a driving force increasing means. The steering operation detecting means detects a steering operation of steering a steerable wheel of the vehicle. The driving force increasing means increases the driving force to the road wheel in response to detection of the steering operation by the steering operation detecting means, and reduces the driving force a predetermined time period after the increase of the driving force.

Abstract: Apparatus (or method) for estimating a gripping characteristic of a vehicle wheel of a vehicle on a ground contact surface includes first input section (or step), a second input section (or step) and an output section (or step). The first input section sets a first input which is a ratio of a first wheel force acting on the vehicle wheel in the ground contact surface in a first direction, and a first wheel slip degree. The second input section sets a second input which is a ratio of a second wheel force acting on the vehicle wheel in the ground contact surface in a second direction, and a second wheel slip degree of the vehicle wheel. The output section determines, from the first and second inputs, an output which is a grip characteristic parameter indicative of the gripping characteristic of the vehicle wheel.

Abstract: A road surface friction coefficient estimating device includes a braking/driving force detecting section for detecting the braking/driving force of a wheel during traveling, a slip ratio detecting section for detecting the slip ratio of the wheel during traveling, and a road surface ? calculating section for estimating the relationship between the detected braking/driving force and the detected slip ratio on the basis of the ratio between the detected braking/driving force and the detected slip ratio, the correlation between the braking/driving force and the slip ratio in the case of the reference road surface, and at least either the detected braking/driving force or the detected slip ratio.

Abstract: A road surface friction coefficient estimating device includes a lateral force detecting section for detecting the lateral force of a wheel during traveling, a slip angle detecting section for detecting the slip angle of the wheel during traveling, and a road surface ? calculating section for estimating the relationship between the detected lateral force and the detected slip angle on the basis of the ratio between the detected lateral force and the detected slip angle, the correlation between the lateral force and the slip angle in the case of the reference road surface, and at least either the detected lateral force or the detected slip angle.

Abstract: A vehicle steering apparatus includes a vehicle steering system and a supplemental steering force applying device. The supplemental steering force applying device is configured and arranged to apply a supplemental steering force to the vehicle steering system to reduce a steering load on the operator. The supplemental steering force applying device includes a steering torque detecting section, a rectilinear driving condition detecting section, a pulling suppression control section. The rectilinear driving condition detecting section is configured and arranged to detect a rectilinear driving condition of the vehicle. The pulling suppression control section is configured and arranged to adjust the supplemental steering force in a direction canceling a pulling force imparted on the vehicle during the rectilinear driving condition by using a pulling suppression force calculated based on historical data of the steering torque detected during the rectilinear driving condition.

Abstract: Apparatus for estimating a ground contact surface gripping characteristic of a vehicle wheel of a vehicle comprises an input section and an output section. The input section sets an input representing a ratio of a wheel force acting on the vehicle wheel in the ground contact surface, and a wheel slipping degree of the vehicle wheel. The output section determines, from the input, an output representing a grip characteristic parameter indicative of the gripping characteristic of the vehicle wheel.

Abstract: In order to enhance the accuracy of estimation of sideslip angle ?, a sideslip angle estimation apparatus calculates a first sideslip angle ?2 between the direction of centrifugal force acting on the vehicle body during cornering and the lateral direction of the vehicle body based on accelerations exerted on the vehicle body and acting in two different directions. A sideslip angle between the longitudinal direction of the vehicle body and the direction of travel of the vehicle is calculated based on the calculated first sideslip angle ?2.

Abstract: A vehicle steering apparatus includes a vehicle steering system and a supplemental steering force applying device. The supplemental steering force applying device is configured and arranged to apply a supplemental steering force to the vehicle steering system to reduce a steering load on the operator. The supplemental steering force applying device includes a steering torque detecting section, a rectilinear driving condition detecting section, a pulling suppression control section. The rectilinear driving condition detecting section is configured and arranged to detect a rectilinear driving condition of the vehicle. The pulling suppression control section is configured and arranged to adjust the supplemental steering force in a direction canceling a pulling force imparted on the vehicle during the rectilinear driving condition by using a pulling suppression force calculated based on historical data of the steering torque detected during the rectilinear driving condition.