GB2334061A - Method for detecting track measuring values - Google Patents

Abstract

The actual track position is detected by continuously measuring versines (f) of the track and/or the longitudinal track inclination in the region of a leading machine frame part 5. This frame part 5 is superimposed by calculation onto a locus with reference to three points, an articulation 6 between the part 5 and a trailing frame part 6, and the parts 5,6, thereby finding the theoretical desired position of the trailing frame part 6 with respect to the locus. A desired frame angle (#α) enclosed by the theoretical desired position of the trailing frame part 6 and the leading frame part 5 as well as the actual position of the trailing frame part with respect to the locus, based on the actual frame angle (#) is computed. After determining the control value for the machine by forming the difference between the theoretical and actual position of the trailing frame part 6, a drive for relative displacement of the machine with respect to the trailing frame part 6 in accordance with the determined control value is actuated.

Description

The invention relates to a method for detecting track measuring values, defining the track position and referring to versines for the lateral track position and/or to the longitudinal inclination of the track for the vertical track position, for restoring the track position immediately after said position has been destroyed due to the action of working units, the working units being arranged on a trailing frame part, with respect to an operating direction of a machine, which is connected to a leading frame part by means of an articulation.

From GB 2 268 021, a ballast cleaning machine composed of two frame parts articulatedly connected to one another is known. A laser reference system serves for detecting the longitudinal inclination of the track in the region of the leading frame part in order to be able to control, according to said measurement, the vertical position of working units located on the second frame part. To that end, a laser transmitter is provided which is permanently kept in a horizontal position. Arranged on the front on-track undercarriage of the leading frame part is a laser receiver which serves for detecting the longitudinal inclination of the leading frame part by referring to the horizontal laser reference plane. The longitudinal inclination value computed via an algorithm is conveyed in a time-delayed manner to a further laser receiver, located on a clearing chain on the second frame part, in order to thereby be able to control the vertical position of the clearing chain.

Additionally known from GB 2 268 529 is a ballast cleaning machine in which respective longitudinal and transverse inclination meters are fastened to a first as well as to a second frame part. The longitudinal inclination of the track measured in the region of the first frame part is stored as a desired value and passed on in a timedelayed manner for controlling the vertical position of a clearing chain. In this. the actual inclination detected by the longitudinal inclination meter of the second frame part must be taken into account. For controlling the vertical position of the clearing chain, a tensioned-cable potentiometer is provided between the second frame part and the clearing chain.

The object of the present invention lies in creating a method of the specified type, with which it is possible with the aid of simple means to relatively accurately restore the track position destroyed by the operation of working units.

This object is achieved according to the invention with the method described at the beginning and being characterized by the following steps: a) detecting the actual track position by continuously measuring versines (f) and/or the longitudinal inclination of the track in the region of the leading frame part, b) computing, based on the detected track measuring values, a locus corresponding to the actual track position and tied to a distance-based coordinate system, c) the machine frame is superimposed by calculation onto the locus with reference to three points, namely the articulation and the two undercarriages adjoining the same, thereby finding the theoretical desired position of the trailing frame part with respect to the locus, d) computing a desired frame angle (to*) enclosed by the theoretical desired position of the trailing frame part and the leading frame part, e) computing the actual position of the trailing frame part with respect to the locus, based on the actual frame angle (P), f) determining the control value for the working unit by forming the difference between the theoretical and actual position of the trailing frame part, g) actuating a drive for relative displacement of the working unit with respect to the trailing frame part in accordance with the determined control value.

This method makes it possible with relatively small structural expense to survey the actual track position immediately before it is destroyed, and to reproduce the detected actual track position, for the purpose of controlling working units, via the angular relationship of the trailing frame part with respect to the leading frame part which is permanently situated at the actual track position. In doing so. one starts from the realization that the theoretical desired position of the trailing frame part can be easily computed in the locus which is to be formed from the measured track values and corresponds to the actual track position. Since it is possible to also find the actual position of the trailing frame part via the angle-measuring device, the displacement values required for controlling the working units may be computed very easily and reliably by subtraction.

Advantageous further developments of the invention become apparent from the drawings.

The invention will be described in more detail below with reference to embodiments shown in the drawing in which Fig. 1 shows a simplified side view of a track working machine for ballast bed cleaning, having a reference system for controlling working units which measures faults in the lateral position of the track, Fig. 2 shows a coordinate system having a locus formed by versine measurement, Fig. 3 shows another track working machine, suitable for track renewal, and Fig. 4 shows a schematically simplified representation of an angle measuring device.

The machine 1 shown in Fig. 1 has a machine frame 3 supported on rail-bound undercarriages 2. The machine frame 3 is composed of a leading frame part 5. with respect to the operating direction (arrow 4), and a trailing frame part 7 connected thereto by means of an articulation 6. Located on the trailing frame part 7 are various working units 8 in the shape of a clearing chain 9 and a track lifting device 10.

The working units 8 are adjustable relative to the trailing frame part 7 by means of drives 11. The ballast taken up from the track bed by the endless clearing chain 9 is transported by a conveyor belt 12 of a screening installation, not shown for reasons of simplicity, to a screening wagon coupled to the trailing frame part 7. cleaned therein and discharged via a conveyor belt arrangement 13 upon a track 14 or an exposed earth formation for restoring the track bed.

A reference system 15 for detecting lateral position faults of the actual track position is situated on the leading frame part 5. Said reference system 1 5 is composed of a reference line 16 formed by a steel chord, extending in the longitudinal direction of the track and arranged centrally with respect to the transverse direction of the track. a measuring axle 17 designed to roll on the track 14, and a measuring device 18 connected thereto. The measuring device 18 consists of a linear potentiometer. displaceable in the transverse direction of the machine, for detecting the relative displacement between the measuring axle 17 and the reference line 16. The measuring axle 17, fastened to the frame part 5 and designed to roll on the track 14 by means of flanged rollers 19, is pressed against one of the two rails of the track 14 in the transverse direction of the machine by means of a drive, not shown, in order to thereby be able to follow the precise lateral course of the track while eliminating any gauge play. An odometer 20 is provided for detecting the distance travelled by the machine 1. For detecting an actual frame angle ss (Fig. 2) enclosed by the two frame parts 5,7 - with respect to a plane extending horizontally or parallel to points of wheel contact of the undercarriages 2 - an angle-measuring device 21 is provided in the region of the articulation 6. If, parallel to the detection of the lateral track position, one wishes to also detect the vertical track position, it is necessary to additionally provide an angle-measuring device 21 for detecting a vertical angle enclosed between both frame parts 5,7 with respect to a vertical plane.

A coordinate system evident in Fig. 2 shows on the x-axis the track distance x detected by the odometer 20 of the machine 1, while the y-axis shows the lateral positional deviations (lining faults) of a locus 22 representing the actual track position.

From the versines f, measured at the leading frame part 5 by the measuring device 18 of the reference system 15, it is possible to approximate the said locus 22 of the track 1 4 in connection with a polygonal curve 23 shown in dash-dotted lines.

The bogie pivot distance between the two front undercarriages 2, serving to support the leading frame part 5, is 12 meters. The measuring axle 17 is located centrally between the two undercarriages 2. so that the versine measurement is carried out at intervals of 6 meters (resulting in a polygonal length of 6 meters). The bogie pivot distance between the two rear undercarriages 2. supporting the trailing frame part 7, is 24 meters, thus greatly simplifying the developing of corresponding mathematical formulas for determining the control values for the working units 8. Prior to starting working operations, a length of track corresponding to one machine length (that is 36 meters) leading up to the work site should already be surveyed. so that a locus 22 (Fig. 2) is available from the five versines f resulting therefrom. Due to the geometry mentioned, the articulation 6 of the two frame parts 5.7 is positioned exactly at y3 in the locus 22, a front bogie pivot 24 of the machine frame 3 is positioned at y5.

A rear bogie pivot of the trailing frame part 7 is denoted by the numeral 25. The actual frame angle enclosed by the two frame parts 5.7 and detected by the angle-measuring device 21 is indicated by ss. The desired frame angle enclosed by the theoretical desired position of the trailing frame part 7 and the leading frame part 5, given in the form of a pitch (k2), is indicated by a2.

As shown in Fig. 2, versines f1, f2, ..... are continuously registered at 6-meterintervals with the aid of the reference system 15 during working forward travel of the machine 1. As soon as a total of five versines f are known within the space of the machine frame 3, the locus 22 can be approximated on the basis of the polygonal curve 23. The position of the machine 1 is calculated into said locus 22, the articulation 6 being located precisely at y3. Since the leading frame part 5 is always situated at the actual track position, the articulation 6 as well as the front bogie pivot 24 are positioned on the locus 22. The length of the trailing frame part 7 is also a known dimension.

From these given data, the theoretical desired position (indicated by the dashed line 26) of the trailing frame part 7 may be computed quite easily, in which position the rear bogie pivot 25 must lie on the locus 22.

From the theoretical desired position of the trailing frame part 7 it is possible to determine the desired frame angle da enclosed with the leading frame part 5. appropriately specified in the form of a pitch (k). The actual frame angle ss determined by the angle-measuring device 21 is also to be specified appropriately as a pitch hy/Ax. The deviation or positional fault of the trailing frame part 7 with respect to the theoretical desired position may be specified by subtraction between the actual frame angle 3 and the desired frame angle Aa or between the actual and desired pitch (k1 k2) of the trailing frame part 7. The lateral deviation from the desired position. for instance at the rear bogie pivot 25, is then found simply by multiplying the pitch difference with the length of the machine. Corresponding actuation of the drive 11 results in a consolidation relative to the trailing frame part 7 until the working unit 8 is positioned in the desired position (corresponding to the actual position as it was present before the operation of the working units 8) for restoring the actual track position surveyed at the leading frame part 5.

The formula for calculation will now be explained in more detail. For the yvalues of the locus 22, the following formulas apply: Y1 =2-f1 Y2 2 2- (2f1 +f2) y3 = 2 (3f1 + 2f2 22 +3) y4 = 2 . (4f1 + 3f2 + 2f3 + f4) y5 = 2 . (5f1 + 4f2 + 3f3 + 2f4 + f5) For the pitch difference Sk=Ay/Ax, the following formulas apply (precisely when a new versine is measured at 6 meters): y3 - y5-y3 3y3-2y5 #k(#α) = k2(α2) - k1(α1) = 2s s 2s s = length of leading frame part 5, 2s = length of trailing frame part 7.

During forward travel between two measured versines f, the following formulas are used for interpolation (x = distance, from 0 to 6 meters respectively): y4-y3 y'3 = y3 + 2x . s y'5 = 2(5f1 + 4f2 + 3f3 + 2f4 + f'5 (x)) 3y'3-2y'5 #k = 2s In order to obtain pitches independent of units, the versines, chords and the location must be entered in the computation formulas using the same unit. for example in [m ].

Fig. 3 shows a further embodiment of a machine 1 which is suited for track renewal. For the sake of simplicity, parts having the same function are denoted by the same reference numerals as in Fig. 1. A machine frame 3 is likewise designed in two parts, with a leading frame part 5 being connected to a trailing frame part 7 by means of an articulation 6. The leading frame part 5 is equipped with a reference system 15. a reference line 16 and a measuring axle 17 for detecting the lateral position of a track 14. An angle-measuring device 21 is provided at the articulation 6. The rear end of the trailing frame part 7 is supported on a graded ballast bed 28 via a caterpillartracked undercarriage 27. Working units 8 are provided in the shape of a vertically and transversely adjustable grading device 29 and a device 34 for laying down new sleepers 30. A further device 31 serves for taking up old sleepers 32. For restoring the track position, it is also possible to actuate drives 33. serving to steer the caterpillartracked undercarriage 27, in dependence upon the control value determined with the aid of the reference system 15 and the angle-measuring device 21, since, along with steering the caterpillar-tracked undercarriage 27, the working units 8 can be automatically centered also.

The angle-measuring device 21 shown schematically and enlarged in Fig. 4 comprises a tensioned-cable potentiometer 35, arranged in the region of the articulation 6 and connected to both frame parts 5,7, in order to thereby detect an actual frame angle (3) enclosed with reference to a horizontal plane. A tensioned-cable potentiometer 36, extending in the vertical direction and connecting both frame parts 5,7 to one another, is provided for combining the twist of the two frame parts 5,7 with regard to one another.

As a variant of embodiment, the reference line 16 could, of course, also be shaped as a laser beam. Also, instead of an articulation 6, a regular wagon coupling could be used to connect the two frame parts 5 and 7.

Claims (2)

1. CLAIMS: 1. A method for detecting track measuring values, defining the track position and referring to versines (f) for the lateral track position and/or to the longitudinal inclination of the track for the vertical track position, for restoring the track position immediately after said position has been destroyed due to the action of working units, the working units being arranged on a trailing frame part, with respect to an operating direction of a machine, which is connected to a leading frame part by means of an articulation. characterized by the following steps: a) detecting the actual track position by continuously measuring versines (f) and/or the longitudinal inclination of the track in the region of the leading frame part. b) computing, based on the detected track measuring values. a locus corresponding to the actual track position and tied to a distance-based coordinate system,

   c) the machine frame is superimposed by calculation onto the locus with reference to three points, namely the articulation and the two undercarriages adjoining the same, thereby finding the theoretical desired position of the trailing frame part with respect to the locus, d) computing a desired frame angle (Au) enclosed by the theoretical desired position of the trailing frame part and the leading frame part. e) computing the actual position of the trailing frame part with respect to the locus, based on the actual frame angle (ss), f) determining the control value for the working unit by forming the difference between the theoretical and actual position of the trailing frame part, g) actuating a drive for relative displacement of the working unit with respect to the trailing frame part in accordance with the determined control value.
2. 2. A method according to claim 1, substantially as herein described with reference to the accompanying drawings.