Communications: electrical – Land vehicle alarms or indicators – Of relative distance from an obstacle
Patent
1997-09-12
1999-02-16
Lefkowitz, Edward
Communications: electrical
Land vehicle alarms or indicators
Of relative distance from an obstacle
340436, 367 96, 367 99, 367909, 701301, B60Q 100
Patent
active
058725075
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a procedure for non-contact distance measurement, in particular for measuring the distance from obstacles in the immediate vicinity of motor vehicles.
BACKGROUND INFORMATION
Various distance measuring procedures are known for collision warning devices also known as parking aids. German Patent Application No. 40 23 538 describes a collision warning device based on ultrasound in which at least two ultrasound sensors are mounted at a specified distance from each other. In this procedure, the delay times between the time when an ultrasound signal is emitted and a reflected ultrasound signal is received from the same and from the other ultrasound sensors are measured and evaluated.
The measuring range of ultrasound sensors is limited by the beam angle, the size of the obstacle, its reflective properties and by the detection threshold of the sensor. This means, for one thing, that a "dead angle" results for each of the ultrasound sensors. In addition, within the recording angle, no distance measurement will be carried out within the immediate vicinity because of the decay period of the sensors.
In contrast, capacitive sensors have the advantage that measurement is possible up to the shortest distances. In addition, if the sensor is designed appropriately, a measurement without voids can be carried out over the entire vehicle width. However, these advantages are countered by the disadvantage that, due to the various materials, sizes and shapes of the possible obstacles, no firm connection exists between the distance and the measurable capacitance in each case, i.e. only relative distance values are determined.
British Patent No. 2,266,397 describes a motor vehicle parking aid in which a distance to a possible obstacle is monitored using an ultrasound sensor. Since the ultrasound sensor cannot monitor all areas, in particular not the area in the proximity of the vehicle, a second measuring system is provided. This measuring system is configured as a capacitive system and detects obstacle at a minimum distance from the vehicle. The publication, Kramar E., "Funksysteme fur Ortung und Navigation" (Radio systems for location and navigation), 1973, Verl. Berliner Union GmbH, Stuttgart, Germany, pp. 28 and 29, discloses a phase difference measuring process for measuring the distance between two radiation sources A and B, in which radiation sources A and B transmit in-phase HF signals, received at the receiving station with a certain phase difference.
The object of the present invention is to provide a procedure for non-contact distance measurement, in particular for measurement of the distances from obstacles in the immediate vicinity of motor vehicles, in which measurement of short distance values is also possible.
SUMMARY OF THE INVENTION
This object is achieved by using the present invention in that measurements are made using a first measuring procedure in which absolute values are determined for the current distances in a first measuring range; that using a second measuring procedure relative values are determined in the measuring range that overlaps the first one, and that absolute values of the first measuring procedure which lie within the overlapping area are used to calibrate the relative values from the second measuring procedure.
The procedure according to the present invention has the advantage that the distance measurement calibration is performed using the second measuring procedure, which does not give any absolute values per se, so that ultimately absolute values will be available.
Although the process for the procedure according to the present invention can be implemented using a number of measuring procedures, it is advantageous if the first measuring procedure is based on a delay time measurement of waves emitted, reflected and received again and the second measuring procedure is based on a measurement of an electrical, magnetic, or optical variable. According to the present invention, the first measuring procedure will be preferably carr
REFERENCES:
patent: 4095666 (1978-06-01), Baba et al.
patent: 4887066 (1989-12-01), Marek
patent: 5508974 (1996-04-01), Meyer et al.
patent: 5574426 (1996-11-01), Shisgel et al.
patent: 5724141 (1998-03-01), Nishiro
patent: 5739901 (1998-04-01), Fujiska et al.
patent: 5754099 (1998-05-01), Nishimura et al.
Lawrenz, W. et al., "CAN-Control unit Area Network for In-vehicle Applications," SAE Information Report.
Botzenhardt, W. et al., "Bus System for Vehicle Control Modules," VDI Reports No. 612, 1986, pp. 459-470.
Lawrenz, W., "Entwicklungswerkzeuge fur Controller-Netzwerke," Elekronik 16, Sep. 4, 1987, pp. 136-140.
Hoetzel Jurgen
Tschiskale Ega
Weber Jens
Lefkowitz Edward
Robert & Bosch GmbH
LandOfFree
Process for non-contact distance measurement does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for non-contact distance measurement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for non-contact distance measurement will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2065706