Device for determination of distances between close-range objects

• US 5,247,296 A
• Filed: 05/12/1992
• Issued: 09/21/1993
• Est. Priority Date: 07/05/1989
• Status: Expired due to Term

• Current Assignee: Messerschmitt-Bolkow-Blohm GmbH
• Original Assignee: Messerschmitt-Bolkow-Blohm GmbH
• Inventors: Spies, Hans
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US07/884,413
• Time in Patent Office: 497 Days
• Field of Search: 340/903, 340/436, 340/902, 340/901, 340/435, 340/555, 342/53, 342/54, 342/70, 342/455, 342/52, 342/118, 180/167, 359/109, 359/111, 359/143, 359/145, 359/154, 359/155
• US Class Current: 340/903
• CPC Class Codes: B60K 28/00 Safety devices for propulsion-unit control, specially adapted for, or arranged in, vehicles, e.g. preventing fuel supply or ignition in the event of potentially dangerous conditions for electrically-propelled vehicles B60L3/00; road vehicle drive control systems for purposes not related to the control of a particular sub-unit B60W30/00; drive control systems specially adapted for autonomous road vehicles B60W60/00
• CPC Class Codes: B60R 16/0231 Circuits relating to the driving or the functioning of the vehicle monitoring tyres B60C23/00; indicating overspeed B60K31/00; for dash boards B60K37/00, B60Q3/10; for indicating emergencies B60Q1/52; brake control systems B60T; registering or indicating the working of vehicles G07C5/00; measuring distance G01C, e.g. combinations of speed and distance G01C23/00; engine indicators G01L; measuring speed or acceleration G01P
• CPC Class Codes: B60R 19/40 in the direction of an obstacle before a collision , or extending during driving of the vehicle, i.e. to increase the energy absorption capacity of the bumper inflatable bumpers B60R19/20
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/931 of land vehicles

Abstract

Device for determining distances in the close range (under 100 m), hereby characterized in that both light pulses and high-frequency pulses are transmitted and received and the correct distance is determined in an evaluating device in a simple way and with reliability under nearly all atmospheric conditions.

Claims

1. A device for determining distances between two objects, the device comprising:

a pulse generator on the first object;

optical transmission means connected to said pulse generator, for transmitting light-pulses;

decoupling means for decoupling high-frequency energy from said optical transmission means and radiating said high-frequency energy via a connected antenna, said antenna also receiving said high-frequency energy after said high frequency energy is backscattered by the second object;

optical receiver means for receiving light-pulses reflected by the second object; and

evaluating logic means connected to said decoupling means and said optical receiver means for determining a distance between the first object and the second object, said evaluating logic measuring a light pulse propagation delay time between said transmitted and received light pulse, said evaluating logic also measuring a high-frequency propagation delay time between said radiated and received high-frequency energy, said distance between the first object and the second object being calculated from said light pulse and high-frequency delay times and propagation times of said light pulse and high frequency energy.

2. A device according to claim 1, wherein:

said coupling means includes a strip line circuit for coupling said high-frequency energy from said optical transmission means to said antenna.

3. A device according to claim 1, wherein:

a directional coupler is connected to said antenna for distinguishing between radiated and received high-frequency energy or for distinguishing between pulses occurring over time.

4. A device according to claim 1, wherein said high-frequency pulses are introduced over a single channel to said evaluating circuit means.

5. A device according to claim 1, further comprising:

trigger means for receiving a distance signal from said evaluating logic means and generating a trigger signal if said distance signal exceeds a predetermined level.

6. A device according to claim 1, wherein:

said optical transmission means includes a strip line circuit for coupling said high-frequency energy from said pulse generator connected to said optical transmission means, said high-frequency energy periodically radiated by said antenna when said light-pulse is transmitted.

7. A device according to claim 1, wherein:

a directional coupler is connected to said antenna for distinguishing between an radiated and received high-frequency energy.

8. A device according to claim 1, wherein:

said received light-pulses and received high-frequency energy are introduced over a common signal channel to a dual gate stage associated with said evaluating logic means.

9. A system for determining close-range distances (smaller than 100 m) between two objects such as a vehicle provided with the system and another object, comprising:

light-pulsed transmitter means for transmitting a light-pulse;

light-pulse receiving means for receiving a reflected light-pulse and delivering a received light-pulse signal representative of said reflected light-pulse;

high-frequency pulse transmitter means for transmitting a high-frequency pulse;

high-frequency pulse receiver means for receiving a back scattered high-frequency pulse and delivering a back scattered high-frequency pulse signal representative of said back scattered high-frequency pulse; and

, processor controlled evaluating logic means for receiving said reflected light-pulse signal and receiving said back scattered high-frequency pulse signal for determining a light-pulse distance measurement signal based on propagation time of a transmitted light-pulse and determining a high-frequency pulse distance measurement signal based on a propagation time of the high-frequency pulse.

10. A system according to claim 9, wherein:

said light-pulse measurement signal and said high-frequency pulse measurement signal are compared, said evaluating circuit means delivering a signal based on the comparison of said light-pulse measurement signal and high-frequency measurement signal for forming an output signal; and

, trigger means for receiving said output signal and generating a trigger signal if said output signal exceeds a predetermined level.

11. A device for determining close-range distances between two objects, the device being provided in a first object, the device comprising:

an optical transmitter on the first object;

a transmitting pulse generator connected to said optical transmitter for supplying pulsed energy to said optical transmitter for transmitting light-pulses;

a strip line circuit connected to said transmitting pulse generator and connected to an antenna, high-frequency energy from said optical transmitter being decoupled by said transmitting pulse generator via said strip line circuit and said high-frequency energy being radiated by said antenna, said antenna also receiving said high-frequency energy after said high frequency energy is backscattered by the second object;

a directional coupler connected to said strip line circuit for distinguishing between radiated and received high-frequency energy;

output control means connected with said transmitting pulse generator for supplying a control signal to said transmitting pulse generator;

an optical receiver for receiving a light-pulse reflected by the second object and supplying a received light-pulse signal;

delay line means for delaying said received high frequency energy;

a dual gate stage for receiving said received light-pulse signal and said delayed high-frequency energy, said dual gate stage dividing said received light-pulse signal and said received high-frequency energy into two portions at a specific time corresponding to a predetermined distance; and

evaluating logic means connected to said dual gate stage and said output control means for determining a distance between the first object and the second object based on propagation time and delay time between each of said transmitted light-pulse and said received light pulse and between said radiated high-frequency energy and said received high-frequency energy, said evaluating logic means integrating each of said two portions of said light pulse signal and said received high-frequency energy, comparing integrated values for both of said portions, and determining when the second object is at said predetermined distance by first noticing when said integrated value of a latter portion is higher and then substantially equal to said integrated value of an earlier portion.