Abstract: A lateral deviation &dgr;d which is a lateral distance between an intrinsic appropriate course R for a vehicle Ai and a contact position P at which the vehicle Ai will come into contact with an on-coming vehicle Ao, is calculated based on a relative angle &thgr;, a relative distance L and a relative speed Vs which are detected by a radar device, and based on a vehicle speed Vi of the vehicle Ai detected by vehicle speed sensors. When the lateral deviation &dgr;d is in a range of &dgr;dn<&dgr;d<&dgr;dx, it is determined that there is the possibility that the vehicle Ai will collide frontally with the on-coming vehicle Ao. The lateral deviation &dgr;d can be calculated based on the relative angle &thgr;, the relative distance L and the relative speed Vs provided in one cycle of transmission and reception of beam by the radar device.

Abstract: A relative lateral deviation calculating device calculates a relative lateral deviation between a vehicle and an on-coming vehicle, based on the state of the on-coming vehicle detected by an object detecting device and a future locus of movement for the vehicle estimated by a movement locus estimating device. When the relative lateral deviation is in a predetermined range, a contact-possibility determining device determines that there is a possibility that the vehicle will come into contact with the on-coming vehicle. Even when the relative lateral deviation is not in the predetermined range, if a steering-state detecting device has detected an involuntary steering operation by a driver, a contact avoiding device increases the steering reaction force of the steering wheel to inhibit the steering operation by the driver in a direction for the vehicle to approach the on-coming vehicle.

Abstract: A collision avoiding system is provided to enhance a collision avoiding effect by stabilizing a vehicle behavior during automatic braking. Steering controlling apparatus includes not only an ordinary electric power steering control unit but also an active steering reaction calculating unit for driving a motor of a steering system to compensate for the influence of disturbances, if the vehicle is shocked by an unusual bounce from an uneven road or the like. When obstacle detecting apparatus such as a laser-radar detects an obstacle which requires operation of automatic braking, a control parameter changing unit receives the automatic braking activating signal to make a change in the control parameters for an active steering reaction control.

Abstract: A system for controlling behavior of a vehicle having a laser radar for detecting an obstacle present on a road on which the vehicle is traveling and operating the brake automatically to avoid contact with the obstacle, and having a power-assist steering actuator including an electric motor installed in the steering system. In the system, it is determined whether the vehicle is steered by the steering wheel as manipulated by the vehicle operator or the vehicle is steered by a force generated by the interplay between the tire and road due to the automatic braking and, when vehicle is steered by the force generated by the tire/road interplay, the electric motor of the steering actuator is controlled to drive in the direction to cancel the force, thereby preventing the vehicle behavior from degrading to deviate from the desired course of travel and preventing various disadvantages such as failure to achieve the desired obstacle detection necessary for an effective obstacle avoidance control.