Method for determining the vertical distance between an object and a device with a variable position

A method for determining the perpendicular distance between an object and a device whose position varies, in particular a motor vehicle, to enable a distinguishing between imaginary and real obstructions by use of direct and indirect measurements;

• wherein, according to the method:
• a first sensor on this device emits a signal which is reflected by the object, giving a reflected signal to be received by this first sensor;
• employing the delay time of the signal from transmission to reception by the first sensor to determine the distance between the first sensor and the object;
• employing this distance to determine all possible positions of the object with respect to the first sensor, the signal reflected by the object being received also by a second sensor on the device;
• employing the delay time of the signal from the first sensor to the second sensor to determine a path from the first sensor to the object and from this object to the second sensor, this path enabling determination of all possible positions of the object with respect to the second sensor;
• comparing the positions determined by the first sensor and the second sensor which have the same distance;
• establishing a corridor extending from the device between the first sensor and the second sensor;
• determining whether a position of the object is within the corridor;
• and
• determining the perpendicular distance to the device for those positions of the object which are in the corridor and are detected by both the first sensor and the second sensor, wherein the measurements by the first sensor are direct measurements, and the measurements by the second sensor are indirect measurements for distinguishing between real and imaginary obstructions.