EP1776267A1

EP1776267A1 - Method and device for measuring the separation between vehicles

Info

Publication number: EP1776267A1
Application number: EP05768010A
Authority: EP
Inventors: Jörg SCHWEIZER
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-06
Filing date: 2005-08-04
Publication date: 2007-04-25
Anticipated expiration: 2025-08-04
Also published as: DE502005002685D1; US20080297144A1; EP1776267B1; ITBO20040510A1; CN101001776A; WO2006012662A1; ES2301038T3; KR20090043413A; AU2005269240A1; ATE384653T1

Abstract

Device for measuring the separation, between any vehicle of a number of vehicles and the preceding vehicle along a stretch and for a direction, includes a reference conductor and a measuring conductor, along the stretch, the latter including a number of serial separate sections. Each section is electrically-connected to the previous section, via a diode. A constant current generator is provided in each vehicle, whose contacts are each connected to a section of the measuring conductor, corresponding to the position of the vehicle and to the reference conductor, via first and second moving contacts. Each second electric contact is connected to a segment, following the section, lying behind the first electrical contact, the direction of travel, via a corresponding third moving electrical contact. The contacts of the constant current generator form an output, which provides a voltage signal correlated to the distance between the relevant vehicle and the previous vehicle.

Description

METHOD AND DEVICE FOR MEASURING THE DISTANCE BETWEEN VEHICLES

The invention relates to a method and an arrangement for measuring the distance of means of transport, such as vehicles, in particular of vehicles, driving one behind the other on a route (road, rail) in one direction. The invention relates to the field which concerns the regulation of means of transport (vehicles) in motion and relates to a device as well as a method for determining the distance between vehicles, in particular between any two consecutive vehicles of a vehicle body is in motion to measure.

Devices are known, e.g. Distance meters that work on the basis of laser or ultrasound and that allow to measure the distance from an obstacle. However, these known devices often work incorrectly and are expensive and sensitive due to their complex structure.

Devices are also known which are usually used to exchange digital data between two trains, with the aim of stopping the following train, if the connection has a certain time duration which is greater than a predetermined safety limit (for example 2 seconds). , is interrupted. These known devices have the disadvantage that they have a complex structure and can be subject to errors and interference.

The object of the present invention is to provide a simple and reliable device (device) and a similar method for measuring (detecting) the distance between transport means (vehicles).

This problem is solved with a method and with a device having the features of the independent claims.

The invention proposes a safe method and a secure, robust device (arrangement) which is also capable of indicating anomalies and disturbances. In an exemplary embodiment of the invention, the means for measuring the distance (d _n ) between any vehicle (V _n ) comprises a plurality of vehicles (V) and the vehicle ahead of it (V _n _ _x ), wherein the vehicles along a route (rail, road or similar) and moving in one direction. This device contains along the entire route laid a reference conductor (LG) and a measuring conductor (LD). The measuring conductor (LD) consists of several consecutive mutually electrically separated sections (S _m ), each of which has a certain length (1). The segments (S _m ) of the measuring conductor (LD) are electrically connected to the preceding with respect to the direction of travel segment (S ^ ₁ ) by a diode (D).

In an exemplary embodiment of the invention, a constant current generator (G _n ) is provided in each vehicle that moves along the specific route and in the specific direction. The contacts of the constant current generator (G _n ), first contacts (P _n ) and second contacts (Q _n ) are respectively connected to a position of the vehicle (V _n ) corresponding portion (SJ of the measuring conductor (LD) and the reference conductor (LG) electrically connected along this movable.

The second contact to the electrical connection (Q _n ) is preferably by a corresponding third movable electrical connection (contact T _n ) with a portion (S _m ) subsequent section (S _k ) of the measuring conductor (LD) behind the first electrical Ver ¬ bond (P _n ) is connected.

The contacts of the constant current generator (G _n ) form, in particular an output (E _n ), which provides a voltage signal with the distance (d _n ) between the corresponding vehicle (V _n ) the preceding vehicle (V _n - _I1 ) is correlated.

Preferred embodiments of the method and the device according to the invention are the subject of the dependent subclaims.

The invention (method and device) can be used with particular advantage in transport systems with rail-bound transport vehicles, such as they are known from WO 02/04273 Al, are applied.

Further details and features of the invention will become apparent from the following description of exemplary embodiments with reference to the partially schematic drawings. 1 shows a schematic view of vehicles traveling along a roadway and equipped with the device according to the invention; FIG. 2 shows a partially schematized view of the device according to the invention; FIG. 3 shows a partially schematic view of a part of FIG Device according to the invention at a point at which the carriageway bifurcates, Figs. 4 to 6 are diagrams showing the course of signals which occur in the device according to the invention, and Fig. 7 schematically shows the electrical conditions when measuring the distance.

1 and 2 is a device 1 (arrangement) for measuring the distance (d _n ) between any two successive means of transport (V _n ) and (V ^ ₁ ), the vehicles such as vehicles (road ßenfahrzeuge, rail-bound transport u. Like.) From a plurality of vehicles (V) are behind the other, eg in a column at any speed on a (vorbestimm¬ th) route 2 in a (certain) direction. It should be pointed out that the device according to the invention also works successfully for measuring the distance between any two vehicles when the vehicles are stationary.

The device 1 has components that are stationary and, for example, in the roadway (road, highway, tracks, rails, etc.) are integrated, and also has components that are provided on the vehicles.

The device 1 has a reference conductor (LG) and a Meßlei¬ ter (LD), which are laid along the roadway 2.

The reference conductor (LG) is a bare conductor (conductor line) and may consist of rails or outdoor ropes.

The measuring conductor (LD) is also a bare line and consists of several successive separate sections (S _m ), wherein each section (SJ has a certain length (1).

The sections (S _m ) of the measuring conductor (LD) are arranged in a row on the carriageway parallel to the reference conductor (LG), their adjacent ends being electrically isolated from one another by interruptions or insulating spacers. Such Ab¬ spacers may consist of plastic or ceramic and have a length which is less than a third, preferably less than one-hundredth of the length (1) of the sections (SJ is.

Each section (SJ is electrically connected to the preceding section (S ₁ ^ ₁ ) by a diode (D), wherein the passage direction of the diode (D) coincides with the predetermined direction of travel of the vehicles on the road 2.

Further, each portion (SJ of the sense conductor (LD) is electrically connected to the reference conductor (LG) through resistors (R) having a resistance of 50K ohms.

The components of the device 1 according to the invention provided on vehicles (V _n ) are movable electrical connections (contacts), eg sliding contacts, skids or brushes, first connections (contacts P _n ) and second connections (contacts QJ and third connections (contacts T _n ) are provided.

Further components of the device 1 according to the invention, which are arranged on vehicles (V _n ), are electrical generators, of which a constant current (G _n ) and a variable voltage (W _n ), eg voltages with a sinusoidal course, are emitted.

The first electrical movable contact (P _n ) connects the first contact of the constant current generator (G _n ) with a portion (SJ of the measuring conductor (LD) corresponding to the position of the vehicle (VJ).

The second movable contact (Q _n ) connects the second contact of the constant current generator (GJ and the first contact of the variable voltage generator (W _n ) with the reference conductor (LG). The third movable electrical contact (T _n ) connects the second contact of the variable voltage generator (W _n ) with the portion (S _k ) of the measuring conductor (LD), this portion (S _k ) with respect to the direction of travel of the vehicle behind the section (S _m ) is located.

In an alternative, it can be provided that the variable voltage generator (W _n ) is replaced by a simple direct electrical connection between the second movable contact (Q _n ) and the third electrically movable contact (T _n ).

Usually, it is provided in the context of the invention that the section (S _m ) with the first movable electrical contact (P _n ) of the portion (S _k ), which is the third movable electrical Kon¬ clock (T ₁ J assigned by two or more intermediate portions (S ₁ J is separated, wherein the number of intermediate portions (S _1n ) depends on the distance between the movable contacts.

The contacts of the constant current generator (G _n ) represent a two-pole output, which provides voltage signals which are correlated with the distance (d _n ) between the relevant vehicle (V _n ) and the preceding vehicle (V _n-1 ) ,

In Fig. 3, an embodiment of the device according to the invention in the area of a (road) fork, or a (road) branch is shown. Here branches of the route 2 from a branch 3. In this case, the first three consecutive sections (SJ of one branch 2 of the road are connected by connecting conductors 4 to the corresponding sections (S _1n ) of the other branch 3 of the road.

Successive connecting conductors 4 are connected to each other by a diode (D) and are alternately connected via resistors (R) to the reference conductor (LG) of one branch 2 and that of the other branch 3, respectively.

The device according to the invention comprises in one embodiment for each vehicle (V _n ) a device for estimating the distance (d _n ), which can operate analog or digital and has A / D interface, which is connected to the output (E _n ) and in the standard de is to calculate the estimate of the distance (d _n ).

The operation of the method according to the invention provides, the distance (d _n ) in the vehicle (V _n ) by means of the voltage (u _n ) between the two contacts of the power source (G _n ), the qualitatively in Fig. 4 as a function of distance ( d _n ) is evaluated.

When a signal (u _sn . _{1 (t)} ), as shown in Fig. 5, which is the voltage at the contacts of the generator (W _n ^ ₁ ) is modulated in the preceding vehicle (V _n . _! ), Can such signal in the vehicle (V _n ) from the signal (u _{n (t)} ) as shown in Fig. 6, are restored to the terminals of the generator.

In this case, a short-time average (U _n ) of (u _{n (t)} ) is calculated to estimate the distance (d _n ).

The mean value (U _n ) must be recalculated every time the distance (d _n ) is changed.

In order to demodulate (u _{s # nl (t)} ), at least the mean value (U _61n - _! ) Of the same signal in the vehicle (VJ) must be known in advance.

Furthermore, it is assumed that the current in the measuring conductor (L _d ) between (T _n and P _n ) is always zero.

In general, (U _n ) is a monotonically increasing function of the spacing (d _n ), as shown in FIG. 4.

In order to evaluate the measured value (U _n ), it is advantageously provided within the scope of the invention to divide this function into three ranges. A linear area, a non-linear area, and an open circuit area.

In this way, in addition to the distance measurement, it can also be determined whether there is a preceding vehicle or if there is an interruption in the circuit.

The exact subdivision of these ranges depends on the value of the resistor (R) and the type of the diode (D). Measurements in the linear range:

For short distances (U _n ) increases linearly stepped, as shown in Fig. 4.

In this case, the distance can be estimated by the formula d _n = 1 * (U _n -U ₃ , ^ ₁ ) / U _D of with an accuracy of + / - 1, which maximally error in the length of a section (S _n ) corresponds. In this case, the voltage (U _D ) is the voltage difference between the terminals of each of the diodes (D), each of which is traversed by the same current (I).

In the linear section, the voltage (U _{s # n} _ ₁ (t) in the vehicle (V _n ) can be demodulated according to the formula u ^^ (t) = U _{s, n} -U _n + U _n (t).

Measurements in non-linear range:

When increasing the distance (d _n ) between a vehicle (V _n ) and a preceding vehicle (V _n-1 ), the distance (d _n ) does not increase linearly with (U _n ), which means that the steps become smaller and smaller as shown in Fig. 4 between the horizontal dashed line and the horizontal solid line.

If (d _n ) goes to infinity, the voltage (U _n ) approaches the limit (U _inf ).

If (ü _n = U _lnf ), it means that a vehicle (V _n-1 ) ahead of the vehicle (V _n ) is not present or that it is very far away.

Measurements in the "open circuit" area:

If the circuit between the contacts of the Konstantstromgener¬ ators (Gn), which are the reference conductor (LG), the measuring conductor (LD) and the movable contacts P _n , Q _n , T _n between two aufeinan¬ following vehicles (V _n and V _n-1 ), then (U _n ) reaches a value greater than (U _inf ).

Figure 7 illustrates once again the electrical conditions and the procedure of carriage (V _n ), which measures its distance to the preceding vehicle (V _n-1 ). The power source of car (V _n ) impresses the measuring current (I _n ) in the measuring rail (LD), which flows to the left due to the selected polarity of the diode chain. If there is no carriage in the measuring range, the voltage will be at the measuring point (E _n )

(U ₀₀ ). If, however, the carriage (V _n-1 ) is within the detection range, a portion of the measuring current (I _n ) is short-circuited in terms of the DC voltage by the voltage source of the carriage (V _n-1 ). An impressed signal voltage (u _n _ ₁ (t)) can be coupled out and evaluated via appropriate filters. The short circuit reduces the voltage to (u _n (t)). As soon as the measuring voltage is below (U _11n ), ie within the linear range, the car can

(V _n ) now the estimate of the distance to the car (V _n _!! ) By measuring the voltage at the current source (u _n (t)) according to the simplified formula (d _n = 1 * u _n (t) / U _D ) calculate. When approaching the carriage (V _n-1 ), the measured voltage (u _n (t)) at each transition to the next segment is stepped around the forward voltage of a diode

(U _D ) reduce.

It should be noted that the accuracy of the distance measurement can be increased by additionally increasing the height of the steps, i. the Durch¬ flow voltage of the diodes are measured. This is mainly dependent on the temperature.

It should also be noted that the measuring current I determines the range of the measurement. It must be dimensioned for a measurement in the linear range so that the current through the voltage source (i _Q ) is significantly greater than the current through the resistors (i _R ). If this condition is fulfilled, (u _n (t)) will be almost independent of the measuring current (I). Carriage (V _n ) can check this by resizing the measuring current (I) and checking the effect on the measured value (u _n (t)).

It should also be noted that the direction of the measurement can be reversed by reversing the measuring current (I). This makes it possible to use the distance measuring method according to the invention for both directions of travel of the carriages.

It should also be noted that the accuracy of measurement is lower as the ratio of (U _D ) to the measured voltage (u _n (t)) increases.

It is advantageous that the device of the invention is safe with respect to two types of possible disturbances:

A break in the reference conductor (LD) or in the measuring conductor (LG) between successive vehicles (V _n and V _n-1 ) can be identified by the method described in the "open circuit". If one or more diodes (D) have a short circuit, the measured distance (d _n ) is always shorter than the actual one. This fact is considered safe for anti-collision systems.

An advantage of the invention is a simple safe and reliable means of measuring the distance between vehicles, which is capable of detecting anomalies and disturbances.

In the inventive determination of the distance between vehicles with the aid of the device according to the invention, a method is used which is based on the measurement of the forward voltage of the diode chain. Semiconductor diodes have a characteristic in the flow direction, which is characterized in that the diode is not a similar switch, but that a voltage drop (UD) occurs in the forward direction, which is essentially logarithmically dependent on the current.

The measurement principle according to the invention is based on the fact that a measuring current (I) is impressed between the current grinders of two consecutively moving cars (vehicles) and then a voltage is measured which is n.UD, where (n) the number of sections (S _1n ) of the interrupted contact conductor (LD) with the length (1) (ie the Fluß¬ voltage of the diode chain). The distance between the carriages is therefore equal to the product of the length (1) of the sections (SJ of the _{sliding conductor} (LD) and the measured voltage (U _meas )) broken by the voltage drop across the diode (UD) (1 * U _meas / UD 4 (in which the staircase width corresponds to the length (1) of the sections (SJ).) The staircase is approximately at the bottom but not quite linear due to the resistors (R). The non-linear The area in the upper part is based on the fact that part of the impressed measuring current in each section is conducted across the resistor (R). At some point there will be no current and the Fluß¬ voltage over the last diodes of the measuring range, as mentioned above, smaller. The measuring current (I) defines only the range of the measurement, not the result itself.

An advantage of the device according to the invention is that decoupling takes place through the use of the diodes, so that each car can measure the distance to the car traveling in front of it. This advantage is due to the blocking characteristic of the diodes, i. those diodes which are located between the two sections (SJ (front and rear contact points) which are contacted by the same carriage are pre-poled in the reverse direction, so that the length (1) of the sections (SJ) must always be smaller than the distance between the front This results in the situation that all diodes between two carriages are poled in the forward direction and can therefore be used for distance measurement, but the diodes underneath the carriage are poled in the blocking direction and thus the measuring paths are decoupled from one another ,

In summary, an embodiment of the invention can be described as follows:

The device for measuring the distance (d _n ) between an arbitrary vehicle (V _n ) from a plurality of vehicles (V) and the preceding vehicle (V _n-1 ) along a (certain) Stre¬ bridge and for a (certain direction.

The device 1 comprises along the said path a reference conductor (LG) and a measuring conductor (LD), the latter consisting of a multiplicity of successive, mutually separate sections (SJ having a predetermined length 1. Each section (SJ) electrically connected to the preceding section (SJ through a diode (D).

In each vehicle (V _n ), a constant current generator (G _n ) of the device 1 is provided whose contacts are each connected to one of the positives. on the vehicle (V _n ) corresponding portion (SJ of the measuring conductor (LD) and with the reference conductor (LG) by first movable elektri¬ cal contacts (P _n ), and by second movable electrical contacts (Q _n ) are connected.

Every second electrical contact (Q _n ) is connected through a corresponding third, movable electrical contact (T _n ) with a segment (S _k ) following the section (SJ), with respect to the direction behind the first electrical contact (P _n ). connected.

The contacts of the constant current generator (G _n ) form an output (E _n ) which provides a voltage signal which corresponds to the distance (d _n ) between the relevant vehicle (V _n ) and the preceding vehicle (V _n-1 ) is correlated.

Claims

claims:

1. Device for measuring the distance (d _n ) between a vehicle

(V _n ) and another vehicle (V _{^ 1} ), wherein both vehicles move on a route, characterized in that along the route on which the vehicles (V _n ) and (V _n-1 ) move, a Reference conductor (LG) and a measuring conductor (LD) are arranged an¬, that the measuring conductor (LD) from several vonein¬ other separate sections (S _m ) is formed with a length (1) that the sections (SJ of the measuring conductor (LD ) are connected to adjacent sections (S _n ^ ₁ ) by a diode (D), that in each vehicle (V _n ) a constant current generator (G _n ) is provided, that the contacts of the constant current generator (G _n ) with one of the respective position of the vehicle (V _n ) corresponding portion (S _m ) of the measuring conductor (LD) on the one hand and with the reference conductor (LG) on the other hand by first movable electrical contacts (P _n ) and by second movable electrical contacts (Q _n ) is that the second electrical contact (Q _n ) by a third en movable electrical contact (T _n ) with a the section (S _m ) following Ab¬ section (S _k ), which is related to the direction behind the first electrical contact (P _n ) is connected, that the terminals of the constant current generator (G _n ) form an output (E _n ) which outputs a voltage signal which is correlated with the distance (d _n ) between the vehicle (V _n ) and the further vehicle (V _n-1 ).

2. Device according to claim 1, characterized in that each segment (SJ via a resistor (R) with the reference enzleiter (LG) is electrically connected.

3. Device according to claim 2, characterized in that the resistor (R) has a value of more than 50 kOHM.

4. Device according to one of claims 1 to 3, characterized gekenn¬ characterized in that in each vehicle (V _n ) a variable voltage generator (W _n ) is provided, which in series in the connection between the second electrical contact (Q _n ) and the third electrical movable contact (T _n ) is connected.

5. Device according to one of claims 1 to 4, characterized gekenn¬ characterized in that the ends of successive sections (S _m ) by interruptions or insulating spacers vonein¬ other are electrically isolated.

6. Device according to claim 5, characterized in that the length of the interruptions between successive Ab¬ cuts (S _m ) of the measuring conductor (LD) is smaller than half the length (1) of the sections (S _m ).

7. Device according to one of claims 1 to 6, characterized gekenn¬ characterized in that in the region of a branch or branching of the route in at least one first branch (2) and a zwe¬ ten branch (3) after the branch at least one of the branches ( 2, 3), the following section (S _m ) of one branch (2, 3) is connected to the corresponding section (S _m ) of the other branch (3, 2) by connection conductors (4).

8. A device according to claim 7, characterized in that at least three of the branch following sections (S ₁ J of a branch (2, 3) with corresponding sections (3, 2) of the other branch (3, 2) are connected.

9. Device according to one of claims 2 to 8, characterized in that the connecting conductors alternately connected to a single diode (D) and alternately with the Refer¬ enzleiter (LG) of one or the other branch (2, 3) via a Resistance (R) are connected.

10. Device according to one of claims 1 to 9, characterized gekenn¬ characterized in that all sections (S ₁ J have the same length (1).

11. Device according to one of claims 1 to 10, characterized gekenn¬ characterized in that all diodes (D) have substantially the same electrical properties.

12. Device according to one of claims 1 to 11, characterized ge indicates that that the current strength of the Konstanstromgener- ators (G _n ) of the device is adjustable during operation.

13. Device according to one of claims 1 to 12, characterized gekenn¬ characterized in that the polarity of the constant current generator (G _n ) of the device during operation is selectable.

14. A method for determining the distance between two transport means (V _n ) with the aid of the device according to one of claims 1 to 13, characterized in that the estimated value for the distance (d _n ) to the vehicle ahead of the Gleich¬ voltage component of Measurement of the voltage (u _n (t)) at the terminal (E _n ) by dividing with the forward voltage of the diodes (U _D ) and multiplication by the length (1) of the sections (SJ is determined.

15. The method according to claim 14, characterized in that the Durchflußspannung the diodes by at least one measurement of

Voltage difference of the DC component of the measured value of

Stress (u _n (t)) before and after the transition from a section

(SJ to the next section (S ^ ₁ ) is determined.