System for targeted braking of vehicles

• US 5,436,631 A
• Filed: 03/08/1994
• Issued: 07/25/1995
• Est. Priority Date: 03/31/1993
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Bulst, Wolf-Eckhart, Magori, Valentin
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US08/207,162
• Time in Patent Office: 504 Days
• Field of Search: 246/182 R, 246/182 A, 246/182 B, 246/182 C, 246/187 B, 342/42, 342/43, 342/44, 342/70, 342/71
• US Class Current: 342/42
• CPC Class Codes: B61L 15/0062 On-board target speed calculation or supervision
• CPC Class Codes: B61L 25/021 Measuring and recording of train speed
• CPC Class Codes: B61L 25/025 Absolute localisation, e.g. providing geodetic coordinates
• CPC Class Codes: G01S 13/505 using Doppler effect for determining closest range to a target or corresponding time, e.g. miss-distance indicator
• CPC Class Codes: G01S 13/755 using delay lines, e.g. acoustic delay lines
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00

Abstract

A system for identifying momentary location and the momentary velocity of, in particular, a rail-bound vehicle, has a transmission/evaluation unit having an antenna for emitting a high-frequency pulse and for receiving a reflected pulse reply signal. Surface wave identification marks having individual coding are arranged at intervals from one another in an area of and along a prescribed travel path of the vehicle. The mutual phase shift of at least two pulse reply signals can be measured as a Doppler shift and the travel velocity can be calculated therefrom via the relative velocity with pulse interrogations of an identification mark following one another at least twice at a predetermined location before/after traversing a specific identification mark. The point in time change in operational sign of the Doppler shift is acquired for this identification mark, and is the point in time of traversal of the location of the specific identification mark.

Claims

1. A system for identifying momentary location and the momentary velocity of a rail-bound vehicle, comprising:

a transmission/evaluation means having an antenna for emitting a high-frequency pulse and for receiving a reflected pulse reply signal arranged on the vehicle;

surface wave identification marks having individual coding and arranged at intervals from one another in an area of and along a prescribed travel path of the vehicle;

the transmission/evaluation means having means for measuring a mutual phase shift of at least two received pulse reply signals as a Doppler shift and having means for calculating a travel velocity therefrom via a relative velocity with pulse interrogations of a respective identification mark following one another at least twice at a predetermined location before/after traversing said respective identification mark; and

having means for acquiring a point in time of a change in operational sign of the Doppler shift for said respective identification mark, said point in time of said change in operational sign being a point in time of traversal of a location of the respective identification mark.

2. The system according to claim 1, wherein the transmission/evaluation means has means for calculating an exact path velocity for a known height of a motion path of the antenna of the transmission/evaluation means, from the relative velocity measured at the predetermined location, and from a chronological duration of traversal of a distance between the predetermined location and the location of the respective identification mark.

3. The system according to claim 1, wherein the transmission/evaluation means has means for calculating location and velocity values for targeted braking of the vehicle.

4. A system for determining momentary location and momentary velocity of a rail-bound vehicle, comprising:

surface wave identification marks, having individual coding, spaced from one another along a travel path of the rail-bound vehicle;

an evaluation means for emitting at least one high frequency burst pulse and for receiving at least one reflected pulse reply signal, said evaluation means being arranged on the rail-bound vehicle;

said evaluation means having means for determining at least two respective Doppler frequency shifts of said respective burst pulses and said respective reply signals and for determining a momentary velocity of the vehicle from the frequency shift between said at least two Doppler frequency shifts;

said evaluation means having means for determining a zero-axis crossing of the Doppler frequency shifts, said zero-axis crossing being indicative of the vehicle directly passing said respective surface wave identification mark thereby establishing a momentary location of the vehicle.

5. A method for determining momentary location and momentary velocity of a rail-bound vehicle, comprising the steps of:

providing surface wave identification marks, having individual coding, spaced from one another along a travel path of the rail-bound vehicle;

proving an evaluator for emitting at least one high frequency burst pulse, for receiving at least one reflected pulse reply signal, and for evaluating said at least one reply signal, said evaluator being arranged on the rail-bound vehicle;

emitting at least two burst pulses toward a respective surface wave identification mark while the rail-bound vehicle is moving;

receiving at least two respective reply signals from said respective surface wave identification mark;

determining at least two respective Doppler frequency shifts of said respective burst pulses and said respective reply signals, and determining a momentary velocity of the vehicle from a frequency shift between said at least two Doppler frequency shifts; and

determining a zero-axis crossing of the Doppler frequency shifts, said zero-axis crossing being indicative of the vehicle directly passing said respective surface wave identification mark thereby establishing a momentary location of the vehicle.