System for traffic information acquisition in vehicles

• US 5,831,551 A
• Filed: 10/09/1996
• Issued: 11/03/1998
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Leica Geosystems AG (Hexagon AB)
• Inventors: Geduld, Georg Otto
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): LIEU, JULIE BICHNGOC
• Application Number:
  US08/718,443
• Time in Patent Office: 755 Days
• Field of Search: 340/905, 340/903, 340/904, 340/438, 340/435, 340/825.04, 340/825.54, 340/825.55, 180/169, 359/152, 359/169, 359/170
• US Class Current: 340/905
• CPC Class Codes: G01S 17/74 Systems using reradiation of electromagnetic waves other than radio waves, e.g. IFF, i.e. identification of friend or foe
• CPC Class Codes: G01S 7/483 Details of pulse systems
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096758 where no selection takes place on the transmitted or the received information
• CPC Class Codes: G08G 1/096783 where the origin of the information is a roadside individual element
• CPC Class Codes: G08G 1/096791 where the origin of the information is another vehicle

Abstract

The invention concerns traffic information acquisition systems for vehicles, which systems have a first opto-electrical transceiver on the vehicle side and a second opto-electrical transceiver provided at predetermined locations in traffic lanes. The first transceiver emits a first signal and receives and decodes a second signal from the second transceiver. The second transceiver receives the first signal from the first transceiver and sends back a coded, second signal to the first transceiver. The first transceiver is in the form of a reflection-operating time-distance measuring device. The emitted optical distance-measuring pulse signal is simultaneously the signal received by the second transceiver. The second transceiver emits the second signal after a delay time following reception of the first signal. The delay time should be longer than the maximum amount of time required for a distance measurement. It is thereby ensured that a signal from the second transceiver is not erroneously interpreted as a signal reflected by a target.

Claims

1. A traffic information system, comprising:

a first transceiver disposed on a vehicle travelling on a road, the first transceiver configured as an optical transceiver for outputting an optical signal for determining a relative distance to another vehicle based on reflection of the optical signal off said other vehicle so as to cause a reflected signal that is received by the first transceiver; and

a second transceiver disposed on an object on a side of the road, the second transceiver configured as an optical transceiver for receiving the optical signal and delaying outputting a reply signal back to the first transceiver until at least a predetermined period of time after receiving the optical signal,

wherein the predetermined period of time is greater than a second period of time during which the reflected signal is capable of being received from the another vehicle at a predetermined maximum distance away from the vehicle.

2. A traffic information system of claim 1, wherein the reply signal contains data related to traffic information.

3. A traffic information system of claim 1, wherein the second transceiver is disposed on a sign located on the side of the road.