EP3031983B1 - An improved method for guiding a device for inserting elements into the ground for the building of a structure; insertion device and associated vehicle - Google Patents

Description

The invention relates to a method for guiding a device for inserting elements into the ground, for producing a structure. More particularly, the invention relates to a guide method of a saddle insertion device for the realization of a railway track. The invention also relates to a system for implementing such a guiding method.

We know, for example by the document EP 0 803 609 , a device for inserting saddles into concrete, making it possible to quickly make a railroad track. Such a saddle insertion device however requires, to be effective, to be positioned very precisely, so that the implantation position of each saddle is accurate to the millimeter.

To guide such an insertion device, the document FR 2 812 671 discloses a guiding method.

For this, the movable arm of the insertion device, which makes it possible to bring a saddle into a predetermined position and orientation of implantation, then the implantation of the saddle in the concrete, is provided with a first prism and a second prism. Each prism is able to reflect a beam of laser light emitted by a remote total measurement station, placed along the railroad track to achieve.

The guiding method then consists in installing a total measurement station near the railway track to be carried out and in determining the coordinates of the geographical point of installation of the total measuring station. These coordinates are absolute in the sense that they are given relative to an absolute reference XYZ.

A total measurement station includes an optical device capable of emitting a laser beam towards a reflecting target. From the reflected beam, the total measuring station is able to determine the distance between the total measuring station and the target, as well as the angle that forms the direction between the total measuring station and the target, with a plane of measurement. reference, which is a horizontal plane passing through the optical device.

Then, during each cycle of implantation of a saddle, the absolute positioning of the arm is determined periodically. By "positioning" of an object in the present patent application is meant both the position of a reference point of this object (three coordinates), and the orientation of a reference segment of this object ( three angles).

Thus, the absolute positioning of the arm, that is to say the positioning in the absolute reference XYZ, is for example given by the position of the first prism, as a reference point, and the orientation of the segment between the first prism and the second prism, as a reference segment.

Thus, to determine the absolute positioning of the arm, the method consists in manually directing the total measuring station so that its laser beam points towards the first prism and to measure the distance and the angle between the total measurement station and this first one. prism, then manually steer the total measuring station so that its laser beam points to the second prism and measure the distance and angle between the total measuring station and the second prism.

These measurements, as well as the absolute position of the total measuring station, are transmitted to a computer of the implantation device, which calculates the absolute positioning of the arm. This information makes it possible to control the movement of the arm of the insertion device to bring the saddle, to a ready uncertainty, into the absolute position and orientation of implantation, as defined by a theoretical plan of realization of the pathway. of iron.

Such a guiding method remains difficult to implement. In fact, over the 90 seconds that a cycle of implantation of a saddle takes, 30 seconds correspond to the actual implantation of the saddle in the fresh concrete of the railroad track, while the other 60 seconds are devoted to a single determination of the absolute positioning of the arm. That is, if the positioning of the saddle before implantation is not within the required tolerance interval, it is necessary to resume the step of determining the absolute positioning of the arm.

In determining arm positioning, half of the time is used to orient the laser beam first to the first prism and then to the second prism. This is not practical and increases the risk of error. In addition, in the environment of the construction site, the presence of an operator in the immediate vicinity of the structure remains inconvenient and presents risks in terms of personnel safety.

From an operational point of view, it is necessary that a target prism be in direct vision of the total measurement station. However, on a site, there are many risks that the laser beam between the station and the prism is masked, if only by the passage of personnel around the insertion device.

Finally, the optical device of a total measurement station has a range of only about 100 meters. It is therefore necessary to move the total measuring station as and when the vehicle 1 and the progress of the realization of the route of railway. With each movement of the total measuring station, the step of installing the total measuring station and determining its absolute position must be carried out again, before transmitting this information to the on-board computer so that a new set of stool delivery cycles can not begin.

It should be emphasized that the step of setting up a total measurement station is not easy. Indeed, it is necessary that the optical device is very precisely placed in a horizontal plane. If this is not the case, the optical device does not work and the total measurement station delivers erroneous measurements.

It may take up to 20 minutes to install and determine the new position of the total measurement station.

The invention therefore aims to overcome these problems.

To this end, the subject of the invention is a method of guiding an insertion device for the insertion of elements into the ground for the production of a structure, characterized in that it comprises the following steps: surveying a plurality of geographical points in proximity to the work to be performed, the position of each point being determined in an absolute reference XYZ; installing a plurality of reflectors, each reflector being placed at a geographical point of the topographic survey; measuring, with the aid of at least three optical devices, located on a movable arm of the insertion device which carries the element to be inserted, distances between reflectors and optical devices; calculating, by trilateration, the absolute positioning of the arm of the insertion device from the measured distances and the known position of each optical reflector; and moving the arm of the insertion device according to the calculated absolute positioning, so as to bring the element to be implanted, in a predetermined implantation position.

• chaque dispositif optique est propre à suivre un réflecteur placé dans l'environnement du dispositif d'insertion, le dispositif optique correspondant étant propre à mesurer la distance entre son point d'implantation sur le bras du dispositif d'insertion et le réflecteur qui lui est associé ;
• un dispositif optique ayant une portée limitée, au fur et à mesure de l'avancement de l'ouvrage, de nouveau réflecteurs sont installés et associés à chaque dispositif optique dont est muni le dispositif d'insertion ;
• l'actionnement du bras du dispositif d'insertion est réalisé par des actionneurs, pilotés par un automate embarqué, lui-même commandé par un ordinateur, l'ordinateur effectuant le calcul du positionnement absolu du bras à partir des données qui lui sont communiquées, à chaque instant, parles dispositifs optiques dont est équipé le dispositif d'insertion ;
• le bras est motorisé en translation et en rotation suivant trois axes orthogonaux entre eux, le mouvement du bras étant piloté par l'automate de manière à amener l'élément à implanter dans le positionnement absolu d'implantation à partir du positionnement absolue du bras qui lui est transmis par l'ordinateur ; et
• l'ouvrage à réaliser étant une voie de chemin de fer, l'élément à insérer est une selle destinée à supporter un rail, la selle étant insérée dans une dalle de béton non encore durci.

According to particular embodiments, the method comprises one or more of the following characteristics, taken separately or in any technically possible combination:

• each optical device is adapted to follow a reflector placed in the environment of the insertion device, the corresponding optical device being able to measure the distance between its point of implantation on the arm of the insertion device and the reflector which is partner;
• an optical device having a limited range, as and when advancement of the structure, new reflectors are installed and associated with each optical device which is provided with the insertion device;
• the actuation of the arm of the insertion device is performed by actuators, controlled by an onboard automaton, itself controlled by a computer, the computer performing the calculation of the absolute positioning of the arm from the data communicated to it, at every moment, by the optical devices of which the insertion device is equipped;
• the arm is motorized in translation and in rotation along three axes orthogonal to each other, the movement of the arm being controlled by the automaton so as to bring the element to be implanted in the absolute positioning of implantation from the absolute positioning of the arm which it is transmitted by the computer; and
• the work to be done is a railroad track, the element to be inserted is a saddle for supporting a rail, the saddle being inserted into a concrete slab not yet hardened.

The invention also relates to an insertion device for inserting an element into the ground, intended to be guided by the implementation of a guiding method according to the preceding method, comprising an arm, movable in translation and rotation along three axes orthogonal to each other and carrying the element to be inserted in the ground, actuators of said arm, an automaton for controlling said actuators and a control computer of said automaton, characterized in that it comprises at least three optical devices, implanted on the arm of the insertion device, each optical device being able to measure a distance between its point of implantation on the arm and a remote optical reflector placed in the environment of the work to be performed, in one known installation position, and in that said computer is programmed to calculate an absolute positioning of said arm, by implementing a trilateration algorithm, starting from measurements transmitted by the optical devices and the known positions of the optical reflectors.

• chaque dispositif optique est propre à suivre une cible, de manière à pouvoir associer chaque dispositif optique à un réflecteur optique de l'environnement.
• l'élément est une selle destinée à supporter un rail de chemin de fer, la selle étant insérée dans une dalle de béton non encore durci.

According to particular embodiments, the device comprises one or more of the following characteristics, taken separately or in any technically possible combination:

• each optical device is adapted to follow a target, so that each optical device can be associated with an optical reflector of the environment.
• the element is a saddle for supporting a railway rail, the saddle being inserted in a concrete slab not yet hardened.

The invention also relates to a vehicle characterized in that it comprises an insertion device according to the preceding device.

The invention will be better understood on reading the following description of a particular embodiment, given solely for illustrative and nonlimiting purposes, and with reference to the appended drawing in which is schematically represented a system for carrying out the method of guiding a device for inserting elements into the ground according to the invention.

In the figure, there is shown a vehicle 1 equipped with an insertion device 2 of elements in the ground for the realization of a structure. In the present case, the structure is a portion of a railway track, for example for a tramway, metro or mainline line. The elements to be inserted are then saddles 3, sealed in the concrete of the raft 4 of the track and intended to maintain rails.

The saddles 3 are of conventional type and respectively comprise a plate of rigid material, such as cast iron, and two anchors. The saddles 3 are held in the concrete slab once it has hardened. They each have a device for fixing a rail.

The vehicle 1 is mounted on four wheels 5, two of which are steered and the other two are driving. It comprises propulsion and steering means (not shown in the figure) for moving the vehicle 1 in a given direction, essentially the direction D of the track to achieve.

The vehicle 1 is moved above the raft 4 whose concrete, just poured, has not yet hardened.

The insertion device 2 comprises, mounted at the rear of the vehicle 1, an arm 6. Alternatively, the insertion device comprises several arms.

The arm 6 has on its lower part gripping systems at the end of which are placed two saddles 2 intended to be inserted into the concrete of the raft 4 freshly poured, each saddle corresponding to a track wire of the track.

The arm 6 of the insertion device is movable. It is moved, in translation along three axes and in rotation along three axes, with respect to a chassis of the vehicle 1, by a set of actuators (not shown in the figure).

These actuators are controlled by an embedded controller (not shown in the figure), itself controlled by an on-board computer.

The computer 10 provides in particular the calculation of the absolute positioning of the arm 6, that is to say the absolute position of a reference point P of the arm and the absolute orientation of a reference segment A associated with the arm 6 For example, a reference segment is parallel to the central bar of the "H" shaped arm and derived from the reference point P.

The automaton, as a function of the absolute positioning of the arm 6 and of an absolute position of implantation of a saddle 3 (that is to say an absolute position of implantation of a saddle and an absolute orientation of implantation of this saddle) actuates the means of propulsion and direction of the vehicle 1 to approach the absolute position of implantation, then actuates the displacement of the arm 6 to bring the saddle into the absolute positioning of implantation (to an uncertainty ready). Once the saddle in this position, the controller is able to actuate the cylinders so as to insert the two saddles in the fresh concrete, then to release the stool implanted and to control the jacks and the arm to return to the position of rest for a next cycle.

For guiding the insertion device 2, the arm 6 carries three optical devices 12, 13 and 14. The first optical device 12 is implanted at a point P1, the second optical device 13 is implanted at a point P2 and the third device Optical 14 is implanted at a point P3 of the arm. The points of implantation are determined by construction of the arm with great precision. In particular the segments separating each pair of points are known with great precision.

Each optical device is equipped with an emitting optic capable of emitting a laser beam 22, 23, 24. Each optical device is equipped with a receiving optics for collecting the beam reflected by a target. From the flight time separating the emission from the reception of a laser pulse, an optical device is able to determine a distance between the implantation point of the laser device and the target.

The operating frequency of an optical device is high: between 200 and 100 Hz.

For carrying out the guiding method, a plurality of reflective prisms, such as prisms 32, 33, 34, are disposed in the environment. A prism is able to reflect the laser beam emitted by an optical device, such as the devices 12, 13, 14.

The prisms are placed at geographical points of a topographic survey. Thus, the absolute position of each prism is known. By the qualifier of "absolute", we mean information relative to an absolute reference XYZ.

Each optical device 12, 13, 14 of the insertion device 2 is adapted to follow a particular target. For example, the first device 12 follows the prism 32, the second device 23 follows the prism 33 and the third device 14 follows the prism 34. To do this, each optical device 12, 13, 14 are equipped with a motor and a target tracking system.

The distance between the implantation point of a device and the prism that it follows is delivered at each instant by the optical device and transmitted to the on-board computer 10.

It should be noted that an optical device having a range of only about 100 meters, it is necessary to associate the optical devices equipping the arm 6 with new prisms of the environment as the vehicle moves 1 and the advancement of the railroad track.

The guiding method for the insertion of a pair of saddles 3 by the device 2 will now be described in detail.

Prior to the completion of the railroad track, a topographic survey is performed to define the absolute position of a plurality of geographical points located successively along the profile of the railway track to achieve.

Given the range of the optical devices 12, 13, 14, these geographical points are distributed at intervals of the order of 50 m to 100 m. They are marked by terminals 30 placed stably along the path to achieve.

For the realization of a portion of the railway track, the vehicle 1 is moved over the portion of the slab 4 whose concrete, just poured, is not yet hardened.

Prisms are then accurately placed on visible terminals 30 and within reach of the optical devices 12, 13, 14 embedded on the vehicle 1. The prisms 32, 33 and 34 are thus positioned.

The optical devices 12, 13 and 14 are then set to follow the prisms 32, 33 and 34 respectively. The identifier of the prism followed by an optical device is entered in the computer 10. From this identifier, by consulting a database of the geographical points of the topographic survey memorized by the computer 10, the latter knows the absolute position of each of the bonuses 32, 33, 34.

Then, an implantation cycle of two saddles 3 is performed by the insertion device 2 in the following manner.

• du premier dispositif optique 12, une première distance d1 entre le point P1 et le prisme 32.
• du second dispositif optique 13, une seconde distance d2 entre le point P2 et le prisme 33.
• du troisième dispositif optique 14, une troisième distance d3 entre le point P3 et le prisme 34.

At each instant of the cycle, each optical device delivers to the computer 10 the instantaneous distance between the point of implantation of this device on the arm 6, and the prism that this device follows. Thus, at every moment, the computer 10 receives:

• of the first optical device 12, a first distance d1 between the point P1 and the prism 32.
• second optical device 13, a second distance d2 between the point P2 and the prism 33.
• of the third optical device 14, a third distance d3 between the point P3 and the prism 34.

Thanks to these instantaneous distance measurements, and the absolute position of each prism, the computer 10 then calculates the absolute positioning of the arm 6 in the absolute reference XYZ.

The calculation made by the computer 10 is of the trilateration calculation type. Trilateration is a mathematical method for determining the position of a point, in this case each point P1, P2 and P3, using the geometry of triangles, just like triangulation. But, unlike triangulation, which uses both angles and distances to determine the position of the point, trilateration uses only distances.

For the determination of the absolute positioning of the arm (six degrees of freedom) it is necessary that the insertion device comprises at least three optical devices, also knowing the geometry of the implantation of these devices (vectors P1 P2 and P1 P3 for example). ).

This absolute positioning of the arm 6 is transmitted by the computer 10 to the automaton.

According to the absolute positioning position of each saddle, mentioned in a database stored in the memory of the automaton, it controls the movement of the vehicle 1 to bring the arm 6, in a rest position with respect to a chassis of the vehicle 1, substantially in line with the position of implantation of the saddles 3.

Once the vehicle 1 stopped in this position, the controller controls the actuators of the arm 6 to bring, at a ready uncertainty, the saddles 3 carried by the arm 6 in the absolute positioning of each saddle implantation.

Once in this position, the controller then controls the jacks of the arm 6 to insert the saddle 2 in the concrete raft 4.

Once both saddles 2 have been inserted, the automaton controls the release by the arm 6 of the saddles 3 and brings the arm back to its rest position relative to the chassis of the vehicle 1.

Two new saddles are then placed at the ends of the jacks of the arm 6 and the next cycle of implantation of these two new saddles is executed.

Gradually, the saddles of the portion of the railway track are established.

Such a guiding method has the advantage of being very rapid, since, during a stool implantation cycle, the optical devices operate automatically and constantly follow the prism on which they perform the measurement of distance. Absolute positioning of the arm can be obtained at any time, which facilitates and improves the accuracy of the movement of the movable arm.

With the present method, it eliminates the use of a total measuring station. Problems related to the installation of such a station are avoided. In particular, such a total measuring station to deliver a measurement of angle with respect to a horizontal plane, it is necessary that it is perfectly installed. This is also why such a total measurement station is never on board a vehicle.

In contrast, the optical devices of the present invention are able to determine only a distance measurement. Since they do not have to issue angle measurements, these optical devices do not have to be held in a horizontal plane. This is the reason why they can be embedded in the vehicle 1. Such optical device delivers a distance measurement with very good accuracy regardless of the movements of its support.

Compared to the state of the art, on a cycle which generally takes about 90 seconds, the present guiding method makes it possible to gain the necessary 30 seconds for the reorientation of the measuring station and the acquisition of the distance and from the angle of the other prism.

By shortening the time required for determining the absolute positioning of the arm, with equivalent implantation accuracy, the stool implantation rate can be increased.

In addition, the positioning of prisms in the environment for the realization of a portion of the railway track can be done in parallel with the use of the insertion device for the realization of the previous portion of the track a railway.

For the realization of a portion of railroad track, the prisms placed in the environment encumber only very slightly the site. Since their use does not require the intervention of an operator, the safety of the operators is improved.

Of course, the invention is not limited to the embodiment described above and many variations are possible by the skilled person.

Claims (10)

1. A method for guiding an insertion device (2) for inserting elements (3) into the ground for building a structure, characterized in that it comprises the following steps:

   - taking a topographical survey of a plurality of geographical points near the structure to be built, the position of each point being determined in an absolute frame of reference XYZ;

   - installing a plurality of reflectors (32, 33, 34), each reflector being placed at a geographical point of the topographical survey;

   - measuring, using at least three optical devices (12, 13, 14), fixed on a moving arm (6) of the insertion device that bears the element (3) to be inserted, distances between the reflectors and the optical devices;

   - computing, by trilateration, an absolute position of the arm of the insertion device from the distances measured and from the known position of each optical reflector; and

   - moving the arm of the insertion device based on the absolute position computed, so as to bring the element to be inserted into a predetermined insertion position.
2. The method according to claim 1, wherein, each optical device (12, 13, 14) is capable of tracking a reflector (32, 33, 34) placed in the environment of the insertion device (2), the corresponding optical device measuring the distance between its fixation point (P1, P2, P3) on the arm (6) of the insertion device and the reflector associated with it.
3. The method according to claim 2, wherein, an optical device having a limited range, over the course of the advancement of the structure, new reflectors are installed and associated with each optical device with which the insertion device (2) is provided.
4. The method according to claim 1, wherein the actuation of the arm (6) of the insertion device (2) is done by actuators, controlled by an onboard automaton, which in turn is controlled by a computer (10), the computer computing the absolute position of the arm (6) from data sent to it, at each moment, by the optical devices (12, 13, 14) with which the insertion device is equipped.
5. The method according to claim 4, wherein said arm (6) is motorized in translation and rotation along three axes orthogonal to one another, the movement of the arm (6) being controlled by the automaton so as to bring the element (3) to be inserted into the absolute implantation position, based on the absolute position of the arm sent to the automaton by the computer (10).
6. The method according to claim 1, wherein the structure to be built being a railroad track, the element to be inserted is a tie rod (3) designed to support a rail, the tie rod being inserted into a concrete slab (4) not yet hardened.
7. An insertion device (2) for inserting an element (3) into the ground, designed to be guided by the implementation of a method according to any one of claims 1 to 6, including an arm (6), translatable and rotatable along three axes orthogonal to one another, bearing the element (3) to be inserted into the ground, actuators of said arm, an automaton for controlling said actuators and a computer for commanding said automaton, characterized in that it includes at least three optical devices (12, 13, 14), fixed on the arm (6) of the insertion device, each optical device being able to measure a distance between its fixation point (P1, P2, P3) on the arm (6) and a remote optical reflector placed in the environment of the structure to be built, at a known installation position, and in that said computer is programmed to compute an absolute position of said arm, by implementing a trilateration algorithm, from measurements sent by the optical devices and the known positions of the optical reflectors.
8. The device according to claim 7, wherein each optical device tracks a target, so as to be able to associate each optical device with an optical reflector in the environment.
9. The device according to claim 7 or claim 8, characterized in that said element (3) is a tie rod designed to support a railroad rail, the tie rod (3) being inserted into a concrete slab (10) not yet hardened.
10. A vehicle (1), characterized in that it includes an insertion device (2) according to any one of claims 7 to 9.

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