A method and an apparatus for following a vehicle are disclosed by which the distance from a vehicle to a preceding target vehicle running ahead thereof can be exactly measured and, based on the thus measured distance, an appropriate vehicle following window can be automatically set with respect to a target image of the preceding vehicle at the start of vehicle following. Images of objects including the preceding vehicle are taken from two different points. The distance to the preceding vehicle is measured based on the images thus taken from the two points. On the basis of the measured distance, the size of an image-following window to be set within an image area displayed on a screen of a display is determined for following the preceding vehicle. The image of the preceding vehicle is found among various images of objects in the image area on the screen, and the position of the window on the screen is properly set and then temporarily stored in a memory. From various images of objects presently taken from the one of the two points, a new image is found which most resembles the image of the preceding vehicle in the last window stored in the memory. Based on the new image, a new window containing it is set on the screen. The position of the new window is adjusted to a location at which the best symmetry of the image within the new window is obtained while shifting the window stepwise. Then, the above steps are repeated.
A processional travel control apparatus that allows processional travel with a leading vehicle driven by a driver and a plurality of succeeding vehicles automatically following the leading vehicle, each of the vehicles 1-1 is provided with: an input device 1-2 for entering the total number of vehicles in a procession and the sequence number of each vehicle in the procession; a vehicle setting device 1-3 for setting each vehicle 1-1 as either a leading vehicle or a succeeding vehicle according to the sequence number of each vehicle 1-1 in the procession set by the input device 1-2; and a vehicle travelling control device 1-4 for instructing each vehicle 1-1 to travel in a procession according to the set sequence number in the procession. Hence a procession or the like can be formed essentially anywhere, including outside of conventional parking ports.
An image tracking device comprising: an image taking means for taking an image in front of a vehicle and outputting an image signal; a memory for memorizing the image signal from the image taking means; and a tracking means for tracking a plurality of vehicles by discerning the plurality of vehicles in a monitoring region which is set with respect to the image signal memorized in the memory.
A vehicle tracking system for a vehicle is configured to track a remote vehicle by template matching between a reference image and an input image obtained by a camera mounted on the vehicle. The position and distance of a remote vehicle is determined by calculating a position and an enlargement/reduction ratio of a portion of the input image that provide a maximum correlation value between the portion of the input image and the reference template that is greater than a threshold value. The reference template is updated by calculating a dispersion of at least one pixel of the reference template with respect to a corresponding pixel in a vehicle image extracted from the input image that provides the maximum correlation value, and by deleting the at least one pixel when the dispersion of the at least one pixel is equal to or greater than a threshold value.
A vehicle area detector correctly detects a vehicle area. The vehicle area detector detects a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. For the correct detection of the vehicle area, the detector includes a horizontal symmetry evaluator to evaluate a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluator to evaluate a degree of variance in the degree of gradation in the image of the area, a lower-area mean gradation evaluator to evaluate a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area exceeds a predetermined threshold value, and an area determining unit to determine a vehicle candidate area as the vehicle area in accordance with results of evaluation from the symmetry evaluator, the variance evaluator, and the lower-are mean gradation evaluator.
The computer (CPU) of a distance measurement device determines the inter-vehicular distance by applying a software filter (weighing means) upon successive values obtained directly from measurement. A vehicle velocity control device for maintaining the inter-vehicular distance include a distance measurement device for measuring the inter-vehicular distance, and the deviation .DELTA.R of the inter-vehicular distance with respect to the target inter-vehicle distance R.sub.S is determined. The vehicle velocity is controlled on the basis of the deviation .DELTA.R in accordance with the PID (proportion plus integral plus differential) control method, and the gains are varied in accordance with the current value of the inter-vehicular distance.
