EP1738029B1 - Method for measuring tracks - Google Patents

Abstract

The invention relates to a method for measuring tracks in relation to a measuring plan of the track which contains the actual position of the track, in relation to an absolute coordinate system. A measuring platform (2) is guided along the track (1), whereon an inertia platform (6) is arranged, which is initialised, respectively, calibrated to the beginning of the measurement and is aligned in relation to the coordinate system. The inertia platform (6) detects the respective positions of the measuring platform (2) in relation to the coordinate system during the journey of the measuring platform (2). Positional data of the inertia platform (6) is periodically examined based on fixed points (9; 9') which are arranged in the vicinity of the track and deviations in relation to the coordinate system are corrected by novel calibration, respectively, alignment.

Description

The present invention relates to a method for surveying according to the preamble of claim 1.

For the maintenance and new construction of roadways, such as roads or tracks for railways, the course of the road has to be measured accurately, compared with a target road course and then made any corrections to the road course by means of suitable track-laying machines.

In principle, the course of the lane from outside the carriageway with respect to geographical reference points can be measured very accurately with corresponding measuring means. However, these are static measurements in which, for the measurement of larger road sections, the measuring location next to the carriageway has to be newly set up, calibrated and the measurement must be carried out. In particular, such measuring methods are not suitable for the control of continuously operating track-laying machines, which are intended to correct the course of the lane in relation to a predetermined desired course, if necessary. Track-laying machines of this kind are dependent on the most continuous and up-to-date measurement of the current road course directly in the processing area of the track-laying machine so that this work can be carried out in as short a time as possible and with the greatest possible accuracy.

Such a method for the maintenance of tracks for railways is for example from the EP 0 559 850 known. Therein, a measuring platform which can be moved on the track is used, which detects optical position change values of the measuring platform by optical means based on reference points arranged next to the track. These values are converted into position data and compared with setpoints of a stored survey plan. The deviations between these values provide correction values which can be evaluated by a special maintenance track-laying machine in order to be able to correct the track course accordingly. In this case, the values can be determined and converted continuously with a single measuring base, which can preferably be coupled directly in front of the maintenance track-laying machine.

In order to obtain absolute values for the maintenance track-laying machine as a result of the changes, it is necessary to determine their position absolutely before starting the measurement with this measuring platform. This is done by a separate, static position determination at the beginning of the measurement. Although the optical measurement achieves very high accuracy, it can not be performed under all conditions because of the need for a continuous optical connection between the measuring platform and the reference points. Thus, in particular environmental influences such as fog or the view interrupting resp. Preventive elements such as construction machinery or workers lead to measurement errors or even make the measurement impossible.

Out DE 196 52 627 A1 is a method for the dynamic control of a continuous machine for handling of linear production processes known as road construction. In this case, a measuring device installed on a towing device attached behind the continuously operating machine is from time to time suspended from the continuously operating machine and brought into a rest position in which a determination of the position of the measuring device is carried out. During the determination of the position, the distance between the measuring device and the continuously operating machine is determined with simple, partly mechanical testing devices. From the result of the position determination and the determined distance, the position of the continuously operating machine is determined and a target-actual comparison is performed.

The object of the present invention was to provide a measuring method which allows a reliable and accurate detection of the change in position of the measuring platform and thus the road course, without a permanent connection to reference points is necessary and thus the method, even over long distances resp. longer distances can be used continuously with high accuracy.

This object is achieved according to the invention by a method according to the features of claim 1. Preferred embodiments will become apparent from the features of further claims 2 to 10.

According to the invention, in the method for measuring lanes with respect to a lane of the lane, which contains the target position of the lane with respect to an absolute coordinate system, a measuring platform is moved along the lane on which an inertial platform is located, which at the beginning initializes the measurement resp. calibrated and aligned with respect to the coordinate system, and which detects the respective positions of the measuring platform with respect to the coordinate system during the travel of the measuring platform, the position data of the inertial platform with respect to the coordinate system are periodically automatically checked and any deviations with respect to the coordinate system recorded as correction values and for correcting the measurement data resp. the measured actual position of the measuring platform can be used.

By using an inertial platform which is calibrated periodically with respect to the coordinate system, i. whose positional data are corrected with respect to the coordinate system, the course of the position of the measuring platform can continuously be recorded and recorded very accurately. The advantage of the inertial platform is that it provides very accurate values, virtually independent of weather conditions, and can be used universally everywhere. By periodically checking the position data of the inertial platform with its effective position with respect to the coordinate system, deviations of the platform from the actual position can be detected continuously and quickly and taken into account as correction values in the calculation of the position data.

The periodic checking of the position data of the inertial platform preferably takes place by optical measurement of the position of the measuring platform in relation to fixed points arranged next to the roadway. In each case, a very accurate determination of the actual position of the measuring platform can take place and the possibly deviating values of the inertial platform can be corrected. Since the optical measurement in contrast to conventional systems does not have to be continuous, but only periodically and at defined locations, this is much less sensitive to external influences, such as the view of the fixed points obscuring obstacles. If necessary, even such a measurement can be dispensed with if it does not give accurate results deliver, and only at the following fixed point, a measurement and correction if necessary.

Preferably, a gyrostabilized platform or a laser platform is used as the inertial platform. The laser platform usually has a higher accuracy and has a smaller drift, i. a smaller deviation from the actual position after the calibration, as gyrostabilized platforms, which are cheaper to buy and have sufficient for only small changes in direction roadways sufficient accuracy.

Preferably, the measurement platform is additionally equipped with a satellite-based navigation system and the position data of the inertial platform are compared with the position data of this navigation system, wherein when deviations of these position data mutually corrected position data are calculated and stored. This is an ongoing adaptation resp. Correction of the position data originating from the inertial platform is also possible between two fixed points and the accuracy of the method is thus further improved overall.

Preferably, the position data of the satellite-based navigation system are also checked periodically with respect to their effective position to the coordinate system and corrected according to deviations. Furthermore, the position data of the satellite-based navigation system can be obtained by including values of a second, defined at a defined with respect to the coordinate system Navigation system are corrected and thus the accuracy of the results are further increased.

Preferably, deviations of the position data of the inertial platform determined at a fixed point are applied linearly to the previously measured points in the sense of a correction. The already recorded and stored position values of the measuring platform can be subsequently corrected when a deviation at a fixed point is detected. The correction is advantageously applied linearly in relation to the distance to the previous fixed point on the position values. Thus, for example, the actual course of a roadway with respect to the coordinate system and thus also with respect to the desired course of the survey plan can be determined and possibly recorded.

The measuring platform is preferably connected to reference platforms which can also be moved on the roadway and follow the course of the roadway, the relative position of which with respect to the measuring platform is detected by optical means and supplement or correct the measured resp. calculated values are used. By these additional relative reference points, for example, the curve radius of the road can be detected and determined very accurately. For this purpose, preferably two reference platforms arranged one behind the other and connected to the measuring platform at a constant, defined distance are used.

Preferably, the reference platforms are equipped with optical reflectors and on the measuring platform is at least one light scanner used. The light scanner communicates visually with the reflectors and can very accurately detect their relative angular deviations, for example with respect to the longitudinal axis of the measuring platform. Due to the known geometric relationships between the measuring platform and reference platforms, it is thus possible to determine very precisely, for example, the curve radius of a roadway.

Preferably, the inventive method for the measurement of tracks for railways is used. Precisely in this case, defined conditions prevail, in particular with regard to the orientation of the measuring platform, so that it can precisely detect the course of the center line and, by detecting the inclination with respect to the horizontal, also the course of the two parallel track strands.

Preferably, the deviations of the raw or corrected position data from the target position are fed directly as control data to a road surface processing machine following or directly connected to the measuring platform in order to align the roadway with the desired position. The measuring platform can advantageously be coupled directly in front of a roadworking machine or even arranged on such a resp. be integrated and control them such that the course of the road is adjusted to the desired course. This can be a continuous and fast processing of the road. Especially with tracks for railways, this is particularly important, since there is a processing usually only during the non-operating hours of the railway can get shorter and shorter with longer and longer operating times.

• Fig. 1 schematisch die Ansicht auf eine Messplattform zur Durchführung des erfindungsgemässen Verfahrens;
• Fig. 2 schematisch den Verlauf von Messpunkten des erfindungsgemässen Verfahrens unter Einbezug eines satellitengestützten Navigationssystems;
• Fig. 3 schematisch den Verlauf von Messpunkten allein aufgrund der Erfassung durch die Trägheitsplattform;
• Fig. 4 schematisch den korrigierten Verlauf der Messpunkte nach Figur 3 aufgrund der festgestellten Abweichung der Trägheitsplattform;
• Fig. 5 schematisch die Ansicht einer Messplattform mit zugeordneten Referenzplattformen zur Durchführung des erfindungsgemässen Verfahrens; und
• Fig. 6 schematisch die Aufsicht auf eine Messanordnung nach Figur 5 beim Durchfahren einer Kurvenbahn.

An embodiment of the inventive method will be explained in more detail with reference to FIGS. Show it

• Fig. 1 schematically the view of a measuring platform for carrying out the inventive method;
• Fig. 2 schematically the course of measuring points of the inventive method with the inclusion of a satellite-based navigation system;
• Fig. 3 schematically the course of measuring points solely due to the detection by the inertial platform;
• Fig. 4 schematically the corrected course of the measuring points FIG. 3 due to the detected deviation of the inertial platform;
• Fig. 5 schematically the view of a measuring platform with associated reference platforms for carrying out the inventive method; and
• Fig. 6 schematically the supervision of a measuring arrangement according to FIG. 5 when driving through a curved path.

In FIG. 1 schematically the view of a traveling on tracks 1 measuring platform 2 is shown. The measuring platform 2 is formed by a measuring carriage 3, which is equipped with two axles 4, 5.

On the measuring platform 2, an inertial platform 6, an optical scanner 7 and a satellite-based navigation system 8 are arranged.

The inertial platform 6 provides absolute position data with respect to a coordinate system, with initialization of the inertial platform 6 first being required. In the initialization of the inertial platform 6, this is due to the known, i. measured resp. determined, absolute position of the measuring platform 2 aligned in a known manner. Thus, the inertial platform 6 in the process of measuring platform 2 resp. of the measuring carriage 3 along the tracks 1, the current position data with respect to the coordinate system.

As an inertial platform 6 can be used conventionally known devices which either work on a mechanical basis with gyroscope-based platform, or lighting technology resp. Laser technology based on virtually wear-free elements are equipped. Depending on the operating time since initialization and the movements and forces exerted on the inertial platform 6, the position data deviate from the effective position of the measuring platform 2. As a rule, these deviations increase with increasing operating time and thus lead to falsified position results. This requires a periodic reinitialization resp. Calibration of the inertial platform 6 due to known resp. measured position data of the measuring platform to ensure sufficiently accurate position data.

The calibration can now be carried out automatically in each case in the vicinity of fixed points 9, which are each preferably arranged in the vicinity of the tracks 1. For example, these may be registered in the surveying plan of the tracks and accurately measured fixed points 9, which are attached to catenary masts 10, for example. The position of the measuring carriage 3 and thus of the measuring platform 2 can be determined exactly by measuring with respect to such fixed points 9. Such a measurement is preferably carried out by means of the optical scanner 7, which is arranged on the measuring platform 2, respectively. connected to this. Such optical scanners can automatically provide very accurate measurement results, and based on these measurement results, the current absolute position of the measuring carriage 3 and thus the measuring platform 2 with respect to the coordinate system can be determined in a known manner.

The deviation of the thus measured position values from the position values supplied by the inertial platform 6 directly indicates the effective deviation of the inertial platform 6 and can be used for the calibration of the inertial platform 6.

In order to be able to correct the position values delivered by the inertial platform 6 already between two fixed points 9, the position of the measuring platform 2 is additionally determined with the aid of the satellite-supported navigation system 8. This navigation system 8 also supplies parallel to the inertial platform 6 absolute position data of the measuring platform 2. A deviation of the position values of the inertial platform 6 and the navigation system 8 now indicates a deviation or drift of the inertial platform 6. When such deviations occur, the position values of the inertial platform 6 can now be corrected accordingly.

Since also the satellite-based navigation system 8 does not provide absolutely accurate position data, since these are dependent on the reception quality of the signals originating from satellite 11, the deviations are preferably not with the full value but only with a certain percentage as a trend value for correcting the position data of the inertial platform 6 used.

In FIG. 2 is shown schematically the result of this measurement process graphically. Between the two fixed points 9 resp. 9 'is the desired course S of the tracks 1 shown in dashed lines according to surveying. The points M represent the result of the position determination due to a travel of the measuring carriage 3 on the actual track course. The arrow D indicates the direction of the deviation resp. the drift of the inertial platform 6 again, which is usually not directed parallel to the track course. From the point M 'on, a correction of the position values based on determined differences between the position values of the inertial platform 6 and the satellite-based navigation system 8 is made, which leads to the illustrated course of the position values. Preferably, immediately adjacent to the fixed point 9 'is now the effective position of the measuring platform 2 as already described determined and a Calibration of the inertial platform 6 made. Since the position values M resp. M 'have already undergone a correction and thus the deviation from the effective position is minimized, now at the point M "at the calibration point no large deviation with respect to the preceding points M' will be noted.

Thus, a very good quality of the measuring points M, M 'resp. M ", ie these reflect the actual course of the tracks 1 in high accuracy.The method can now for example be used to create an accurate survey plan of the actual position of the track 1. The data can also be used to in order to control a track-laying machine, which can change the position of the tracks 1 and thus adapt them to the desired position according to the survey plan or to correct them.

In order to improve the accuracy of the position data of the satellite-based navigation system 8, this data can be corrected on the basis of measurements of an adjacent stationary second satellite-based navigation system 12 located at a defined position. This correction signal, which results from the difference between the position value ascertained in the second navigation system 12 and the effective position of the second navigation system 12, can be supplied via a receiver 13 to the evaluation unit 14 of the measuring platform 2, in which all other calculations are carried out and the determined values are stored resp. to be recorded.

In FIG. 3 is again schematically the course of measured resp. corrected by the above method position data between two fixed points 9 resp. 9 'shown. The distance A between two consecutive measuring points M ₁ and M ₂ with respect to the desired course S represents the error resp. the deviation of the track position. The distance D between the measuring point M _n and the calibration measuring point M _k represents the accumulated deviation resp. Drift of the inertial platform 6. If, for example, the measuring platform 2 resp. the measuring carriage 3 is moved at an approximately constant speed to record the actual track course, ie perform a test drive, then it can be assumed that the deviation resp. Drift of the inertial platform 6 between two fixed points 9 resp. 9 'has occurred linearly. Thus, the 9 between the two fixed points. 9 'determined position values are subsequently corrected linearly as a function of the distance of the first fixed point 9 in accordance with this deviation, as in FIG. 4 is shown schematically. The thus corrected position values M represent a very exact image of the actual course of the tracks 1 in the coordinate system.

In FIG. 5 Another embodiment of a measuring carriage 3 for carrying out the measuring method according to the invention is shown. The measuring carriage 3 is with two additional reference cars 15 respectively. 16 connected. These reference cars 15 resp. 16 each advantageously have a reference axis 17 respectively. 18, which with optical reflectors 19, respectively. 20 are connected. With the help of an optical scanner 21, the relative position of the reference cars 15 can now. 16 measured automatically in relation to the measuring carriage 3, respectively. be determined.

As seen from the schematic view FIG. 6 As can be seen, this information, advantageously angle information, can serve, for example, to determine the curve radius R of the tracks 1. Since the reference cars 15 resp. 16 are connected with a certain, known distance to the measuring carriage 3 with this, the radius can be easily calculated due to the known geometric conditions.

It is clear to those skilled in the art that the measuring method is not for use with rails resp. Rail 1 is limited, but can also be used for example for roads. In this case, the measuring carriage 3 must be moved manually along the center line of the road, if necessary, in order to supply the corresponding position values.

Claims (10)

1. Method for measuring tracks/roadways in relation to a survey plan of the track/roadway, the survey plan containing the desired position of the track/roadway in relation to an absolute system of coordinates, wherein a measuring platform (2) is moved along the track/roadway (1) and arranged thereon is an inertia platform (6), which is initialized resp. calibrated at the beginning of the measurement and aligned in relation to the system of coordinates, and which determines the respective position of the measuring platform (2) in relation to the system of coordinates during the movement of the measuring platform (2), characterized in that the inertia platform (6) is calibrated periodically in relation to the system of coordinates by automatically and periodically checking the position data of the inertia platform (6) in relation to the system of coordinates and by determining possible deviations in relation to the system of coordinates as correction values and by using them for a correction of the measured data and/or the measured actual position of the measuring platform (2).
2. Method according to claim 1, characterized in that the periodically checking of position data of the inertia platform (6) is accomplished by optically measuring the position of the measuring platform (2) in relation to fixed points (9; 9') being arranged adjacent to the track/roadway.
3. Method according to claim 1 or 2, characterized in that a gyrostabilized platform or a laser platform is used as the inertia platform (6).
4. Method according to one of the claims 1 to 3, characterized in that the measuring platform (2) is equipped with a satellite-supported navigational system (8) and the position data (M) of the inertia platform (6) is compared to the position data of the navigational system (8), wherein in case of deviations of this position data (M) inter-component corrected position data (M') is calculated and stored as correction values.
5. Method according to claim 4, characterized in that the position data of the satellite-supported navigational system (8) is also checked periodically in relation to its effective position relative to the system of coordinates and is corrected correspondingly in case of deviations.
6. Method according to one of the claims 1 to 5, characterized in that deviations (A) of the position data of the inertia platform (6) being determined at the location of a fixed point (9; 9') is applied linearly to the previously measured points (M) in the sense of a correction.
7. Method according to one of the claims 1 to 6, characterized in that the measuring platform (2) is connected to reference platforms (15; 16) also being movable along the track/roadway (1) and following the course of track/roadway, the relative locations of which being determined in relation to the measuring platform (2) by optical means (21) and being used for supplementing or correcting the measured resp. calculated values.
8. Method according to claim 7, characterized in that the reference platforms (15; 16) are equipped with optical reflectors (19; 20) and that at least one light scanner (21) is used on the measuring platform (20).
9. Method according to one of the claims 1 to 8 for the measuring of railroad tracks.
10. Method according to one of the claims 1 to 9, characterized in that the deviation of raw or corrected position data (M; M) from the desired position is fed directly as control data to a track/roadway working machine that follows the measuring platform (2) or that is directly connected thereto, for adjusting the track/roadway to the desired position.

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