Abstract: An obstacle warning system for a vehicle includes a distance measuring device for emitting a transmission wave or laser light in a given angular range in a direction of a width of the vehicle in a scanning manner, and for detecting a distance between the vehicle and an obstacle in correspondence with a scan angle on the basis of a reflected wave or reflected light from the obstacle. A relative position calculating device calculates a relative position of the obstacle with respect to the vehicle on the basis of the distance detected by the distance measuring device and a corresponding scan angle. A radius calculating device calculates a radius of an estimated relative curved path of the vehicle with respect to the obstacle on the basis of relative positions of at least two points of the obstacle which are calculated by the relative position calculating device.

Abstract: As provided here, an obstacle warning system for a vehicle is capable of issuing an alarm accurately according to the curved state of a road. When the road is curved, the system sets the correction time counter on the basis of the following conditions: whether or not the curvature radius of the curved road is small; whether or not a guardrail is detected immediately ahead of the vehicle; whether or not an erroneously-recognized object, such as a set of guardrail reflectors exhibiting large relative acceleration is immediately ahead of the vehicle; and whether or not the number of obstacles recognized reaches a value indicating that the vehicle is approaching a curved section of the road. When a stationary object enters the field of view indicating that there is a possibility of a collision, the obstacle warning system corrects the warning distance in response to the value of the correction time counter, thus making it possible to avoid a false alarm during cornering.

Abstract: An intervehicle distance control system for automotive vehicles is provided which includes a laser scanning type distance sensor for scanning a laser beam in a width-wise direction of a system vehicle to determine relative positions and relative angles of objects within a forward detectable zone and determines same lane probabilities that the objects exist in the same lane of a road as the system vehicle using a variable probability distribution based on the relative positions and the relative angles of the objects. A target preceding vehicle is then selected from the objects based on the same lane probabilities for controlling the speed of the system vehicle to maintain a distance to the target preceding vehicle constant.

Abstract: A measuring apparatus for measuring an actual distance between vehicles and comparing the measured distance with a reference distance. The reference distance (SL) is obtained on the basis of: a personal space (VR.multidot.TIMEK) being an uneasy distance peculiar to a driver and obtained in accordance with the own vehicle speed; a free running distance (VRR.multidot.TIMEN) corresponding to a response time of a driver's braking operation and a relative speed between two vehicles; a braking distance (VRR.sup.2 /(2.multidot.GR)) corresponding to a depressing strength of a braking pedal in the driver's braking operation and the relative speed; and an acceleration change distance (.alpha.G.multidot.GA) corresponding to a relative acceleration between the two vehicles, using the following equation:SL=VR.multidot.TIMEK-VRR.multidot.TIMEN+VRR.sup.2 /(2.multidot.GR)-.alpha.G.multidot.

Abstract: A collision alarm system for an automotive vehicle is provided which includes an object identifying circuit, a stationary object alarm circuit, a moving object alarm circuit, and an alarm inhibiting circuit. The object identifying circuit determines whether an object falling within a given detection zone is a stationary object or a moving object. The stationary object alarm circuit issues an alarm when a distance between the object identified as a stationary object and a system vehicle equipped with this system falls within a given stationary object warning distance. The moving object alarm circuit issues an alarm when a distance between the object identified as a moving object and the system vehicle falls within a given moving object warning distance.

Abstract: A radar device emits a wave beam into a given angular range outside a vehicle, and scans the given angular range by the wave beam. The radar device detects a reflected wave beam. A recognizing device is operative for recognizing an obstacle with respect to the vehicle on the basis of the result of detection of the reflected wave beam by the radar device. In the recognizing device, a point recognizing section recognizes obstacles as points, and a uniting section is operative for uniting adjacent points among the points provided by the point recognizing section. The uniting section provides sets each having adjacent points. A line-segment recognizing section is operative for detecting a specific set or specific sets of adjacent points among the adjacent-point sets provided by the uniting section, and for recognizing every detected specific set as a line segment having a length only along a width direction of the vehicle.

Abstract: A vehicle speed control system for controlling the speed of a controlled vehicle to follow a preceding vehicle detected at a constant interval is provided. In this system, when a preceding vehicle traveling ahead of the controlled vehicle is detected, it is checked if the preceding vehicle detected meets a given tracking condition. When the tracking condition is encountered, it is reported to a driver. The system is responsive to a manual operation of the driver after the driver has perceived that the preceding vehicle can be tracked to initiate constant inter-vehicle distance control.

Abstract: An anticollision radar system for a vehicle is provided. This system includes a distance sensor for measuring distance to an object present in a given forward detectable range, and determines a curvature of a road on which the system vehicle is moving, determines the probability that the object present in a given forward detectable range of the distance sensor is identified as a preceding vehicle traveling on the same lane as the system vehicle in a preselected relation to the distance to the object measured by the distance sensor and the curvature of the road determined, determines a target speed based on the probability determined, and modifies the speed of the system vehicle to the target speed determined.

Abstract: First, a variable gain amplifier amplifies an output of a light-receiving element with the gain fixed at the maximum value and a laser diode is repeatedly actuated. Distance data obtained in each measurement is stored in a RAM. Second, the measurement is executed by varying the gain of the variable gain amplifier based on automatic gain control AGC technology. Meanwhile, a full gain distance calculation and a full gain relative speed calculation are carried out based on the distance data stored during the first step. Furthermore, in a third step, an AGC distance calculation and an AGC relative speed calculation are carried out based on the distance data stored during the second step. The full-gain based detection and the AGC based detection are alternately repeated, thereby accurately and reliably detecting a plurality of obstacles in a radar detection area.

Abstract: An apparatus includes an inter-vehicle distance sensor for measuring a distance from a self vehicle to a vehicle traveling ahead, and a relative speed is calculated on the basis of the inter-vehicle distance data detected by the inter-vehicle distance sensor. When a variation of the relative speed is small, it is recognized that a vehicle is present ahead of the self vehicle. An acceleration/deceleration is obtained from a stored acceleration/deceleration basic map on the basis of a difference between the inter-vehicle distance and a target inter-vehicle distance, and the relative speed with the vehicle ahead, and an acceleration/deceleration correction coefficient is calculated from a correction map set with adjustment constants in correspondence with the measured inter-vehicle distance. An acceleration/deceleration is calculated by multiplying the acceleration/deceleration with the correction coefficient.

Abstract: A position control device includes a fluid-operated directional control valve for controlling the position of the piston of a cylinder assembly under fluid pressure in response to a control signal from an electronic controller. The position of the piston is predicted based on the control signal. A position detector detects when the piston has actually reached a predetermined position. When it is detected that the piston has actually reached the predetermined position, the predicted position of the piston is corrected. The electronic controller applies a control signal to the directional control valve so that the predicted position as corrected will be equalized to a target position for the piston. The predetermined position is a substantially intermediate position of the stroke of the piston. The directional control valve comprises a solenoid-controlled valve for controlling the flow rate of the fluid depending on the magnitude of a current supplied to the solenoid-operated valve.