Abstract: An optical distance measuring apparatus is provided which is designed to transmit a laser beam in a cycle to scan a two-dimensional detection zone and to receive a return of the laser beam from a target through a light sensitive unit to determine data on the distance to the target. The light sensitive unit is made of a matrix of cells which are selectively activated in each scan cycle of the laser beam for minimizing optical interference with incoming light other than the return of the laser beam from the target in determining the data on the distance to the target.

Abstract: Height-wise positions of objects are detected on the basis of distances to the objects from a vehicle, angles of the objects in a width-wise direction of the vehicle, and angles of the objects in a height-wise direction of the vehicle. A plurality of objects, which satisfy conditions predetermined depending on physical characteristics of delineators, are determined to be objects composing a delineator group. When the detected height-wise position of an object in the delineator group which is nearest to the vehicle corresponds to a predetermined value or less, the delineator group is determined to be a delineator group on a road surface. A determination is made as to whether each object in the on-road-surface delineator group is a non-delineator in response to conditions of the detected height-wise positions of the objects in the on-road-surface delineator group.

Abstract: A transmission wave is applied to a predetermined angular range in a width-wise direction of a vehicle. Object-unit data pieces containing at least data pieces representing distances to objects in correspondence with vehicle-width-wise direction angles are generated on the basis of a reflected wave. A determination is made as to whether each object is moving or stationary on the basis of a speed of the vehicle and a relative speed of the object. From the object-unit data pieces, ones are extracted which are effective for road shape recognition on the basis of a result of determining whether each object is moving or stationary. Ones of the extracted object-unit data pieces which represent monotonically increasing distances as viewed along one of clockwise and counterclockwise angle directions are grouped to generate data representing a road-side-object group. A road edge is recognized on the basis of the data representing the road-side-object group.

Abstract: A transmission wave is applied to a predetermined angular range in a width-wise direction of a vehicle. A position of each object and a relative speed of the object are detected on the basis of the reflected wave. A determination is made as to whether each object is moving or stationary on the basis of the detected relative speed of the object and a speed of the vehicle. For at least one of right-hand and left-hand sides of the vehicle, calculation is given of a vehicle width-wise direction position where each stationary object effective for road shape recognition passes through the related side of the vehicle. The calculated vehicle width-wise direction position is memorized. A line connecting the memorized vehicle width-wise direction position and the detected position of the currently handled object corresponding to the effective stationary object is recognized as a road edge.

Abstract: The present invention aims to facilitate easy correction of the center axis of an obstacle detecting apparatus for a vehicle by calculating deflection of the center axis with respect to the vehicle. Each of most obstacles recognized as moving objects is a preceding vehicle 93, and when the subject vehicle 91 is moving straight, the preceding vehicle 93 is detected in a position straight ahead of the subject vehicle 91. If the optical axis 95 of the transmitting/receiving section 31 is oriented straight ahead of the subject vehicle 91, the preceding vehicle 93 will be detected on the optical axis 95. On the other hand, when the optical axis 95 deviates from the center axis of the vehicle, the preceding vehicle 93 is detected in a position deviated from the optical axis 95 by an angle &thgr; m. In this case, the value &thgr; of deflection of optical axis 95 is equal to −&thgr; m.

Abstract: A pseudo random noise code is generated synchronously with a reference clock signal. A first forward electromagnetic wave is transmitted in response to the pseudo random noise code. A first echo wave is received which is caused by reflection of the first forward electromagnetic wave at an object. The received first echo wave is converted into a binary signal. A value of a correlation between the binary signal and the pseudo random noise code is repetitively calculated at a predetermined period having a synchronous relation with the reference clock signal. A time interval taken by the first forward electromagnetic wave and the first echo wave to travel to and from the object is measured in response to a timing at which the calculated correlation value peaks. Then, a second forward electromagnetic wave is transmitted in response to a transmitted pulse signal is transmitted. A second echo wave related to the second forward electromagnetic wave is received.

Abstract: An angular shift determining apparatus is provided which may be employed in an automotive obstacle detection system designed to determine a distance to and angular direction of a target tracked by a radar. The angular shift determining apparatus determines an angular shift of the central axis of radiation of radar waves from the longitudinal center line of a vehicle equipped with the obstacle detection system based on a relative position of the target and removes from the determined angular shift an error component produced when a preceding vehicle traveling with a lateral offset from the system vehicle is tracked as the target and an error component produced when a stationary object located on a curved road is tracked by the radar as the target to mathematically project an actual angular shift of the central axis of radiation of radar waves.

Abstract: An obstacle recognition system for automotive vehicles is provided which is designed to distinguish preceding vehicles from other objects and uses data thereof in intervehicle distance control, for example. The system includes a radar unit and a preceding vehicle determining circuit. The radar unit receives a signal produced by reflection of at least one of transmitted radar signals from an obstacle present in a given obstacle detectable zone to determine a distance to the obstacle and a horizontal and a vertical angle of the obstacle from a preselected reference direction.

Abstract: An estimated travelling curve La (radius Rea) of a system vehicle is obtained based on a first group of sampling data (X1, Y1) through (X5, Y5). Alarm area WA1a is set as a region surrounded by a pair of circular arcs parallel shifted from curve La by .+-.1 m and a pair of straight lines (Y=Y1 and Y=Y5). Similarly, an estimated travelling curve Lb (radius Reb) is obtained based on a second group of sampling data (X3, Y3) through (X5, Y5). Alarm area WA1b is set as a region surrounded by a pair of circular arcs parallel shifted from curve Lb by .+-.1 m and straight lines (Y=Y1 and Y=Y5). At the entrance and exit of a curved road, values of radii Rea and Reb are differentiated. Hence, the collision judgement is performed by using different alarm areas WA1a and WA1b.

Abstract: A distance measuring apparatus includes a wave transmitting device for emitting a transmission wave. A wave receiving device is operative for receiving a reflection wave, which results from reflection of the transmission wave by a reflection object, as a reception wave. A time difference measuring device is operative for measuring a time difference between a moment at which the wave transmitting device emits the transmission wave and a moment at which the wave receiving device receives the reception wave. A distance calculating device is operative for calculating a distance to the reflection object on the basis of the time difference calculated by the time difference measuring device.

Abstract: In an obstacle recognition system for a vehicle, transmission wave is irradiated per given angle for recognizing an obstacle ahead of the subject vehicle based on angle/distance data obtained from received reflected wave. A position of the obstacle is estimated based on a previously recognized position of the obstacle. The estimated position of the obstacle and an actually recognized position of the obstacle are compared so as to determine whether the obstacle currently recognized is identical with the obstacle previously recognized. Relative acceleration is derived for the obstacle which has been determined plural times to be identical with the previously recognized obstacle. When the derived relative acceleration is outside a given range, the corresponding obstacle is excluded from objects of further obstacle recognition.

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 power-supply control circuit comprises a power-supply conversion circuit for converting a primary power-supply voltage into a secondary power-supply voltage; a first switching element for placing the power-supply conversion circuit into an active state or an inactive stage; a capacitor for smoothing the secondary power-supply voltage; a second switching element for placing a load circuit powered by the smoothed secondary power-supply voltage into an active state or an inactive state; and a control circuit for supplying a control mode signal to the first switching element and the second switching element, respectively. A radio select call receiver comprises a radio reception unit driven by a first power-supply voltage for receiving radio carrier waves and identifying a unique call signal conveyed by the radio carrier waves; a signal processing unit performing various kinds of call processing based on the unique call signal; and a power-supply control circuit.

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.