Abstract: A Kalman filter in a roll angle estimation device estimates a roll angle of a vehicle body, a vehicle speed, a roll angular velocity sensor offset, a yaw angular velocity sensor offset, and a vertical acceleration sensor offset on the basis of detected values of a roll angular velocity sensor, a yaw angular velocity sensor, a vertical acceleration sensor, a longitudinal acceleration sensor, a lateral acceleration sensor, and a rear-wheel speed sensor, and also on the basis of estimated values of the roll angle, the vehicle speed, the roll angular velocity sensor offset, the yaw angular velocity sensor offset, and the vertical acceleration sensor offset obtained in a previous estimation operation.

Abstract: A vehicle speed while curving through steering maneuver is determined. A vehicle speed determination system is applicable to a vehicle having a front wheel and a rear wheel. The system includes: a wheel speed sensor configured to detect a wheel speed Vf of the front wheel; and an arithmetic circuit configured to determine a vehicle speed V(r) at a rear-wheel tangential point, based on a difference in vehicle speed between the front-wheel tangential point and the rear-wheel tangential point which occurs due to a difference between a locus of travel of the front wheel and a locus of travel of the rear wheel, and on the wheel speed Vf of the front wheel.

Abstract: An attitude controller eliminates a skid motion of a banked vehicle when travelling through a curve. The attitude controller includes a lateral acceleration sensor that obtains lateral acceleration, as rightward or leftward accelerations, acting on a vehicle of a motorcycle, a bank angle detector that detects a bank angle of the vehicle, and a longitudinal force controller that decreases, independently of each of the wheels, an absolute value of a longitudinal force as the sum of forward and backward forces acting on front and rear wheels based on the obtained lateral acceleration and the detected bank angle.

Abstract: Provided is a longitudinal force control apparatus. A lateral acceleration acquisition section acquires a lateral acceleration along a right-left direction acting on a vehicle. A bank angle acquisition circuit acquires a bank angle of the vehicle. A longitudinal force controller may decrease an absolute value of a longitudinal force at least with respect to a driving wheel of the vehicle based on the acquired lateral acceleration and the bank angle when it is determined that a calculated lateral-skid acceleration is equal to or greater than a predetermined threshold. The longitudinal force is a sum of forces along a front-rear direction acting on the driving wheel.

Abstract: Provided is a longitudinal force control apparatus. A lateral acceleration acquisition section acquires a lateral acceleration along a right-left direction acting on a vehicle. A bank angle acquisition circuit acquires a bank angle of the vehicle. A longitudinal force controller may decrease an absolute value of a longitudinal force at least with respect to a driving wheel of the vehicle based on the acquired lateral acceleration and the bank angle when it is determined that a calculated lateral-skid acceleration is equal to or greater than a predetermined threshold. The longitudinal force is a sum of forces along a front-rear direction acting on the driving wheel.

Abstract: A vehicle speed while curving through steering maneuver is determined. A vehicle speed determination system is applicable to a vehicle having a front wheel and a rear wheel. The system includes: a wheel speed sensor configured to detect a wheel speed Vf of the front wheel; and an arithmetic circuit configured to determine a vehicle speed V(r) at a rear-wheel tangential point, based on a difference in vehicle speed between the front-wheel tangential point and the rear-wheel tangential point which occurs due to a difference between a locus of travel of the front wheel and a locus of travel of the rear wheel, and on the wheel speed Vf of the front wheel.

Abstract: An attitude controller eliminates a skid motion of a banked vehicle when travelling through a curve. The attitude controller includes a lateral acceleration sensor that obtains lateral acceleration, as rightward or leftward accelerations, acting on a vehicle of a motorcycle, a bank angle detector that detects a bank angle of the vehicle, and a longitudinal force controller that decreases, independently of each of the wheels, an absolute value of a longitudinal force as the sum of forward and backward forces acting on front and rear wheels based on the obtained lateral acceleration and the detected bank angle.

Abstract: A Kalman filter in a roll angle estimation device estimates a roll angle of a vehicle body, a vehicle speed, a roll angular velocity sensor offset, a yaw angular velocity sensor offset, and a vertical acceleration sensor offset on the basis of detected values of a roll angular velocity sensor, a yaw angular velocity sensor, a vertical acceleration sensor, a longitudinal acceleration sensor, a lateral acceleration sensor, and a rear-wheel speed sensor, and also on the basis of estimated values of the roll angle, the vehicle speed, the roll angular velocity sensor offset, the yaw angular velocity sensor offset, and the vertical acceleration sensor offset obtained in a previous estimation operation.