Abstract: In a turning control apparatus for a vehicle, a torque calculation unit calculates a target lateral acceleration of the vehicle according to detection signals from a steering angle sensor for detecting the direction of a steering wheel and a vehicle speed sensor for detecting the speed of the vehicle. It then sets target driving torque of the engine according to the target lateral acceleration. An electronic control unit controls the operation of a torque control device for reducing driving of the engine so that the driving torque of the engine is a target driving torque independent of manipulation by the driver. This thereby rapidly estimates lateral acceleration applied to the vehicle during turning and prevents control delay to enable stable and positive traveling through a curved road.

Abstract: An apparatus for effecting a method for estimating the friction coefficient of a road surface according to the present invention comprises front- and rear-wheel rotation sensors for detecting the running speed of a vehicle, a linear G sensor for detecting an actual transverse acceleration of the vehicle, a steering angle sensor for detecting the steering angle of front wheels, and a torque calculating unit supplied with the vehicle speed, actual transverse acceleration, and steering angle detected by means of these sensors. In the torque calculating unit, which takes account of an assumed value of the stability factor of the vehicle in addition to the vehicle speed, actual transverse acceleration, and steering angle, a target transverse acceleration required by a driver is calculated, for example, and whether or not the friction coefficient of the road surface is low is then estimated according to the relationship between the calculated target transverse acceleration and the actual transverse acceleration.

Abstract: A motor vehicle output power control system quickly reduces the drive torque produced by an engine on a motor vehicle depending on the magnitude of a lateral acceleration which is produced when the motor vehicle makes a turn, or the amount by which drive wheels slips when the motor vehicle is accelerated. A target drive torque depending on the lateral acceleration and a demanded drive torque demanded by the driver of the motor vehicle are added at a predetermined ratio into a turn target drive torque, which is selected as a final target drive torque. The motor vehicle output power control system includes an electronic control unit for controlling an actuator to lower the output drive torque of the engine, independent from controlling action of the driver, such that the output drive torque of the engine is equalized to the final target drive torque.