Method and system for controlling construction machine

Abstract

In a method according to the invention for controlling slip form pavers, it is intended to determine the positions of two reflectors arranged on the longitudinal beams of a machine frame by measuring means for position determination, in particular tacheometers, which are arranged at defined points in a reference terrain. From the position information and the measurement by means of two tilt sensors arranged on the machine frame, the positions of four points on the slip form paver or on the slip form paver screed are determined in the reference terrain. On the basis of a comparison of the determined actual positions of the four points with the required positions thereof, the slip form paver, and hence the installation height and position of the screed having a defined relationship with said slip form paver, are automatically controlled.

Description

The invention relates to a method for controlling construction machines according to the preamble of claim 1, and a system according to the preamble of claim 6.

The invention relates to the control of construction machines in general, in particular of slip form pavers with variable frame and broad screeds.

Slip form pavers are construction machines with a characteristic screed which serves, for example, for the installation of concrete or asphalt. The screed can also be formed with a characteristic profile, for example for the production of rails, channels or water grooves. Screeds are therefore produced for a wide variety of applications, i.e. with different screed profiles and in particular screed widths. Thus, slip form pavers dimensioned according to the generic type and having the broadest possible screeds are required, for example, for use on airports, such as, for example, for the construction of aircraft runways. The need for variable screeds for a wide variety of potential applications of slip form pavers is taken into account by machine manufacturers with the development of pavers having a variable frame which permit variation of the screed width. The control of such road finishers is generally effected by means of reference line scanning devices. A sensor scans the required direction/required height of a reference line, such as, for example, a tensioned wire; deviations from the required direction/required height are corrected by a regulating means.

Thus, DE 101 38 563 discloses a wheel-type road finisher which automatically follows a reference line. In U.S. Pat. No. 5,599,134, scanning of a reference line is effected without contact, by means of ultrasonic sensors. However, this method of controlling a machine requires setting out of the area to be processed before the use of the construction vehicle and is very time-consuming and labor-intensive.

A method developed by the Applicant Leica-Geosystems envisages mounting two masts with prisms on the crossbeams of a rigid machine frame formed from longitudinal beams and crossbeams and determining the distance and direction to the prisms by means of two tacheometers or total stations, and hence determining the position of the prisms or of the machine. These tacheometers or total stations are advantageously motor-powered and capable of automatically following the reflector.

Moreover, a two-dimensional inclination of the frame and hence the orientation of the paver are measured by means of two tilt sensors. The slip form paver is controlled via in each case a point calculated at the front and rear crossbeam—in the working direction—or via the connection of the two points in the form of a straight line. However, this solution cannot be used in the case of pavers having variable frames and screed widths of more than 10 m. In the case of screed widths of the order of magnitude of 10 meters or more with control via two points, the method of control no longer gives the accuracy required according to the generic type and also cannot be applied in terms of construction technology to pavers having variable frames.

The object of the present invention is therefore to eliminate the disadvantages of the prior art and to provide a method by means of which control of construction machines, in particular of slip form pavers is permitted, in particular independently of the screed width and frame variability.

It is a further object of the invention to provide a system for carrying out the method according to the invention.

These objects are achieved by realizing the characterizing features of claim 1 and of claim 6, respectively. Alternative and/or preferred solutions are described by the characterizing features of the dependent claims.

The method according to the invention is described below in the application to slip form pavers or to the control of slip form pavers. However, the method is by no means limited to slip form pavers but can be applied to all kinds of mobile machines, in particular vehicles and construction machines.

In a first variant for carrying out a method according to the invention, at least two reflectors and at least one tilt sensor—in general two tilt sensors—are coordinated with a slip form paver—or a construction machine—having a characteristic screed. The slip form paver is in general a commercial construction machine having a chassis which is composed of a machine frame having longitudinal beams parallel to the working direction and crossbeams transverse to the working direction, and a plurality of undercarriages which are adjustable in height, for example having steerable crawler units. The undercarriages can be adjusted in height and position, in particular independently of one another, for example by means of cylinders and they keep the plane of the machine frame at a predetermined height and in a predetermined position. The undercarriages could also be adjustable transversely to the working direction, for example by means of movable sliding girders. Furthermore, the vehicle could be designed as a wheel-type paver having wheels as running gear, or as a rail vehicle.

The frame of the paver is preferably variable, for example capable of being extended laterally, in order to permit the use of screeds of different widths. However, the method is not limited to variable frames but can of course also be applied in the case of construction machines having a rigid frame.

Many of the commercial slip form pavers are, however, now equipped with a variable frame, and the frame can be made to be variable in all possible variants—for example with telescopically extendable units. Such slip form pavers are offered, for example, by Wirtgen in Germany or Gomaco in the USA. A variable frame is composed, for example, of two strong, rigid longitudinal beams and two variable crossbeams. The crossbeams are, for example, telescopically extendable. A platform—a type of “virtual” inner frame, for example for a control platform—can be provided on the frame which so to speak is extendable. A screed is fixed, advantageously rigidly, to the bottom of the machine frame. The screed is preferably fixed to the longitudinal beams and is connected in the middle to the so-called inner frame via a cylinder which is adjustable in height. The screed may be in the form of a smoothing screed, i.e. without a profile, but may equally have a characteristic profile, such as, for example, for track construction. It may also be in the form of two or more parts and, when it does not consist of one part, may have, for example, screed parts connected to one another in an articulated manner in the middle of the working width. The screed or machine is preferably formed in such a way that it is adjustable in its width (working width). Thus, extendable screed means could be present, or the screed could be formed in such a way that further screed parts can be joined on or attached. Potential applications for slip form paver screeds and characteristic screed profiles associated therewith are, for example, the construction of roads and curbs, aircraft runways, tracks, etc. In particular, the various applications also set different requirements with regard to the desired screed width. Thus, a broader screed is of course desired for the construction of an aircraft runway than for the construction of a sidewalk. Screeds having widths of up to about 16 m are commercially available. In order to be able to use one and the same vehicle for different applications, slip form pavers having the possibility for changing the screed width are now offered. This also requires in particular the above-mentioned variable machine frame.

The screed is generally fixed to the longitudinal beams of the frame. Advantageously, the screed is also connected in its middle and in the middle of the slip form paver frame to the frame, generally via a cylinder, by means of which an initial adjustment or adjustment of the screed with regard to the sag thereof can be chosen or set.

Since the screed may be very broad—e.g. 16 m—sagging of the screed is to be expected. This sagging of the screed can be adapted to the working circumstances and conditions before the beginning of work by means of the adjustable cylinder. If required or desired, the screed can also be adjusted to have a certain sag or rise in the middle. This step is preferably effected before the active use of the vehicle, but automatic adaptation or correction of the screed sag while the construction work is being carried out would also be conceivable. In the case of manual (or automatic) adjustment before the beginning of work, a further adjustment in the course of the work may be required. Because of the extendable cylinders, the paver frame is adjustable in its position and height, and hence also the installation height and position of the screed fixed to the paver.

The method according to the invention envisages, in the first variant, measurement in each case of the distance, the height and the directions relative to reflectors coordinated with the slip form paver frame, preferably the longitudinal beams, and in general fixed thereon. This gives the position of the machine frame or of the screed. For this purpose, the longitudinal tilt and transverse tilt of the frame, and hence also of the screed, are determined by means of tilt sensors coordinated with the frame, in particular the longitudinal beams, in particular mounted thereon or integrated in the beams (or in certain circumstances only one tilt sensor). The tilt of the frame could also be established by another means for tilt determination, for example by polarization filters coordinated with the reflectors, in particular located upstream thereof.

Measuring instruments by means of which reflective elements on the construction machine are surveyed from a suitable position on the ground are used for determining the position of the machine frame or of the screed. Preferably, the position of two reflectors mounted on the machine is measured by means of theodolites and laser telemeters or tacheometers. For a measurement to two reflective regions, for example, two tacheometers are used, each of which measures the distance, the height and the directions relative to a reflective region. The measurement is effected from a defined position on the ground. The position of the reflectors or of the paver can be determined by means of the direction, height and distance measurement with the tacheometers to the reflective regions having a defined geometrical relationship with the slip form paver and by means of the known position of the tacheometers. In conjunction with automated target recognition and target tracking, a quasi-continuous position determination can be achieved. A line of sight between tacheometers and reflectors is required for the measurement.

The reflectors indirectly or directly mounted on the paver frame or on the screed are preferably in the form of all-round reflectors and are connected to a reflector support—generally a mast. It is possible to use cylindrical or spherical 360° reflectors, as well as triple prisms, polished steel elements, reflecting glass elements, elements surrounded by reflector foil, or elements, in particular spheres, formed from reflective material. All-round reflectors are preferably used for the measurement, in order to permit a measurement in any position of the slip form paver.

The masts with the reflectors can be coordinated with the machine frame or with the screed and are generally mounted on the frame. Depending on the application, the height of the mast and type of reflectors may be varied. The mounting is preferably effected at the rear end—in the direction of travel of the machine—of the strong longitudinal beam of the frame, as close as possible to the undercarriages and the screed, in order to provide a system which is as sensitive as possible. This arrangement of the prisms or of the masts results in the greatest possible sensitivity of the measurement with respect to changes in the position of the machine.

A second variant for determining the position of a construction machine and hence for the control thereof is a position determination by means of global positioning systems, such as, for example, GPS together with the orientation determination of the first variant. However, global positioning systems do not always provide the required accuracy of the position determination and generally require a considerable effort, for example through use of a reference station, or with the acceptance of longer measuring times. There is also the problem that coordinates determined from GPS signals do not have sufficient accuracy—especially with regard to the height of the construction machine—for most construction projects. However, with corresponding effort and/or depending on the intended use, a possible, advantageous position determination of points on the construction machine using a global positioning system—GPS—in which the antennas of the GPS receiving system are coordinated according to the arrangement of the reflectors of the construction machine is also conceivable for position determination for carrying out the method according to the invention. A signal processing unit may be positioned independently of the GPS receiver antennas. Furthermore, a GPS reference station may advantageously be provided in the second variant.

For the position determination, the system according to the invention can, if required, be extended with components for increasing the vertical accuracy, for example with one or more laser plane generators and corresponding receivers.

The determination of the longitudinal and transverse tilt of the slip form paver or of the frame or of the screed is effected in the first and second variant preferably by means of tilt sensors on the longitudinal beams of the machine frame—in general, a tilt sensor is mounted on each of the two longitudinal beams. Depending on the application and required accuracy of measurement, one tilt sensor may also be sufficient for tilt determination. The respective tilt sensor is preferably positioned in the middle of the respective longitudinal beam, and the tilt is determined both in the longitudinal direction and in the transverse direction, i.e. a two-axis tilt sensor is used.

It is of course also possible to use other known positioning systems for position determination of—in particular two—points on the construction machine for carrying out the method according to the invention. In particular, it is also possible to use systems which also provide orientation information for the respective position, whereby it is additionally possible to replace the tilt sensors.

For example, the first and second variants can also be modified in such a way that only one position is determined with the aid of reflectors, GPS or other positioning systems and at least the vehicle axis parallel or transverse to the travel direction is determined by means of a compass or another direction indicator, and the points A1 to A4 are derived therefrom.

In a first step, the method according to the invention envisages feeding of a reference terrain model to a control unit communicating with the slip form paver. The control unit is composed, for example, of a data processing and control module (e.g. computer and controller).

A reference terrain model is to be understood as meaning a model in which a planned project—e.g. a road—is embedded in the existing terrain. The reference terrain model describes the planned required terrain. From the reference terrain model, it is possible to derive in a known manner required positions for terrain processing equipment, such as, for example, a screed. Of course, a reference terrain model can equally provide required values for, for example, a travel path and therefrom required values for vehicle positions.

In the reference terrain, measuring instruments, preferably total stations or tacheometers, are set up, with which measuring instruments defined points—coordinates in the reference terrain or in the reference terrain model—are coordinated—for example by positioning the instruments at defined coordinates (already measured points) of the reference terrain or by incorporating the instruments in the reference terrain by measurement.

In the first variant, two reflective elements are coordinated with the slip form paver, and preferably masts having reflector prisms are mounted on the frame. The reflector prisms have coordinates defined by a previously performed measurement in a local machine coordinate system. If a measurement is carried out from the measuring device or the measuring devices in the reference terrain to the prism or prisms, coordinates in the reference terrain or in the reference terrain model are assigned to the respective prisms by means of this measurement.

The measurement information of the measuring devices in the reference terrain and of the tilt sensors is communicated to the control unit—for example by radio. By means of the determination of the positions of the reflector prisms—and hence the position of the paver having a defined geometrical relationship with the prisms, or of the screed—in the reference terrain or in the reference terrain model, together with the information from the measurements by the tilt sensors, the actual positions of four points A1-A4 on the paver frame or on the screed can be calculated in the reference terrain or in the reference terrain model. The actual position of these four points A1-A4 in the reference terrain model are compared with the required positions specified in the reference terrain model for the points, and the deviation of the position of the machine or of the screed is correspondingly corrected—for example by means of the running gears which are adjustable in height. The calculation is generally performed by means of a data processing module, such as a computer, of the control unit, and the control is performed by means of a control module, such as a controller, of the control unit. For example, the data processing module calculates the deviation of the actual position from the required position and provides corresponding correction values for the cylinders to the control module. The control unit is preferably present on the construction machine and can be operated by a driver or can control the machine automatically.

On the basis of the method according to the invention, control of the machine and hence of the installation height and position of the screed is thus effected via four points on the machine frame or on the screed, the actual positions of which are determined in the first variant on the basis of the determination of the positions of the reflectors and the measurements by the tilt sensors on the frame.

In the second variant, the actual positions of the four points A1-A4 in the reference terrain are determined substantially analogously to the first variant, except that, instead of the determination of the position of the reflectors of the first variant, a determination of the position of two GPS receiver antennas is effected. As in the first variant, the actual positions of the points A1-A4 in the reference terrain model are then calculated by means of the control unit, in particular the data processing module, and compared with the required positions of the points A1-A4 in the reference terrain model. The machine is then controlled via the control unit, in particular the control module.

The method according to the invention and the system according to the invention are described in more detail below, purely by way of example, with reference to specific embodiments shown schematically in the drawings, further advantages of the invention also being discussed. Specifically:

FIG. 1 shows a system according to the invention,

FIG. 2 shows a slip form paver having reflectors and tilt sensors,

FIG. 3 shows, in two partial FIGS. 3a and 3b, a tacheometer and a mast with a reflector as components of the system according to the invention,

FIG. 4 shows, in two partial FIGS. 4a and 4b, diagrams for explaining the method according to the invention for controlling the slip form paver, and

FIG. 5 shows a slip form paver with GPS.

The figures are described below in relation to one another. The size ratios of the objects shown are not to be considered as being to scale. FIGS. 1 to 4 relate to a first variant of the invention, which uses tacheometers and reflectors for the position determination. It is understood that further variants are also described thereby, global or local positioning systems with their antennas being provided instead of the tacheometers and reflectors. In the following description, the conditions for the first embodiment are also applicable in context to the further embodiments.

FIG. 1 schematically shows a system according to the invention for controlling a slip form paver. A slip form paver having a screed 5 which travels over a surface 11 is shown. It is possible to imagine that, for example, fresh concrete has been poured onto the surface 11. The slip form paver draws the screed 5 over the surface 11 for producing a level surface, for example for an aircraft runway. Since irregularities as small as the order of magnitude of mm are noticeable in level smooth surfaces, high accuracy in the installation height and position of the screed 5 is required. In order to control the slip form paver or the screed 5 with high accuracy, according to the invention two reflectors 6, 6′ are mounted on the paver. The reflectors 6, 6′ are formed here as all-round prisms and mounted on masts 7, 7′. Such a reflector mast 8, 8′ is fixed in each case on a longitudinal beam 1, 1′ of the paver frame. The reflector mast 8, 8′ is arranged at the rear end—in the working direction AR of the paver—of the longitudinal beam of the frame and as far as possible at the outer edge of the beam, i.e. as close as possible to the undercarriages 4, 4′. This results in high sensitivity of the system-in that changes-in the position of the paver are transmitted to the positions of the reflectors 6, 6′, and the system therefore responds to very small changes in the position and height of the paver or of the screed 5. Also mounted on the frame are two tilt sensors 9, 9′, one tilt sensor 9, 9′ on one longitudinal beam 1, 1′ each of the frame. The sensors are fixed in the middle of the frame and measure both the longitudinal tilt and the transverse tilt of the frame or of the paver or of the screed 5.

On the ground, two tacheometers 10, 10′ are set up at defined points, by means of which tacheometers of reflectors 6, 6′ on the slip form paver are surveyed. By means of one tacheometer 10, 10′ each, the position of one reflector 6, 6′ each on the paver is determined. For the simultaneous surveying of the two reflective regions, two tacheometers 10, 10′ are used.

With the information from tacheometers 10, 10′ and tilt sensors 9, 9′, it is possible to calculate points A1, A2, A3, A4 on the slip form paver, which can be controlled automatically in position and orientation on the basis thereof via a comparison of the measured actual positions with the required positions of the points A1, A2, A3, A4. At the same time, the installation height and position of the screed associated with the paver are controlled thereby.

FIG. 2 shows a slip form paver having a variable frame and variable screed width. The paver frame is composed of two strong longitudinal beams 1, 1′ (beams parallel to the travel direction and working direction AR) and two crossbeams 2, 2′ running transversely to the working direction AR. A sort of platform or inner frame 3 is placed above the crossbeams 2, 2′. Furthermore, the slip form paver is equipped here with a superstructure 12, which may comprise, for example, a motor, a control platform and a control unit. Of course, the vehicle can also be controlled by means of an external control unit.

The crossbeams 2, 2′ are adjustable in width, for example telescopically extendable. This permits in particular the use of a screed 5 whose width is variable. Since different screed widths are generally required for different applications, it is expedient and economical to be able to use a single slip form paver for different tasks by virtue of the fact that the screed 5 thereof can be adjusted to different widths. Also shown are the two reflector masts 8, 8′ with reflectors 6, 6′ fixed to the masts 7, 7′, in that region of the two longitudinal beams 1, 1′ which is at the rear in the travel direction, as close as possible to the undercarriages 4, 4′. The tilt sensors 9, 9′ are mounted in the middle of the longitudinal beams 1, 1′. Here, the slip form paver also has a beam 13 for a smoothing device.

FIG. 3 shows two components of the system according to the invention. FIG. 3a shows a tacheometer 10, by means of which the position of the reflector 6 is determined in the coordinate system of the tacheometer 10. The tacheometer 10 is set up at a position of defined coordinates—in the coordinate system of a reference terrain model. By surveying a reflector 6 by means of a tacheometer 10, the coordinates of the reflector 6 in the reference terrain model or in the reference terrain described by the model are therefore determined.

FIG. 3b shows a reflector mast 8 which is used on the slip form paver or mounted thereon and can be connected indirectly or directly to the paver. The reflector mast 8 is composed of a mast 7, for example a metal rod, and a reflective element. Here, the reflector 6 is in the form of an all-round prism. It is just as possible to use spherical or cylindrical all-round reflectors or elements surrounded by reflector foil or simply reflective forms, for example spheres, or more than only one individual reflective region.

In FIG. 4, the method according to the invention is explained by means of a diagram.

FIG. 4a schematically shows a slip form paver frame in plan view. The frame is composed of two strong, rigid longitudinal beams 1, 1′ and two crossbeams 2, 2′. The crossbeams 2, 2′ are telescopically extendable and permit a variation in the width of the paver. The positions of the reflector masts 8, 8′ and tilt sensors 9, 9′ are shown on the longitudinal beams 1, 1′. It is evident that the reflector masts 8, 8′ are positioned in each case at the rear end—in the working direction AR—of the two longitudinal beams 1, 1′ and as close as possible to the undercarriages 4, 4′. Moreover, a tilt sensor 9, 9′ is arranged on each longitudinal beam 1, 1′—preferably in the middle. In the middle of the paver frame, a sort of “virtual” inner frame 3 is indicated by dot-dash lines. Here, this is a frame superstructure which is fixed to the frame crossbeams. The dashed lines indicate the position of the screed 5, which is mounted under the frame. The screed 5 is fixed to the longitudinal beams 1, 1′ of the machine frame and also fixed to the frame in the middle of the inner frame 3 by means of a cylinder which is not shown. The cylinder permits a height adjustment of the screed 5; in particular, it is possible thereby to counteract the sag of screed 5, which in particular plays a role in the case of wide screeds 5. The height adjustment of the screed 5—in the middle thereof—is generally carried out before the beginning of operation of the slip form paver. For some applications, it may be necessary to set up the screed 5 not as flat screed 5 but with a sag or rise in the middle of the screed. The settings are generally readjusted during the work.

FIG. 4b shows a diagram of the screed 5 with projections of the reflector positions and tilt sensor positions 8, 8′, 9, 9′, and the four points A1, A2, A3, A4 calculated from the tacheometer and tilt sensor measurements. Through the measurements by means of the tacheometers 10, 10′ arranged in a reference terrain to the reflectors 6, 6′, the positions thereof in the reference terrain are determined. From this information, the additional measured values of the tilt sensors 9, 9′ and the known geometrical relationship of the reflectors 6, 6′ with the machine frame or with the screed 5, the points A1, A2, A3 and A4 can be calculated. These calculated positions of the points A1-A4 represent actual values with respect to the screed position in the coordinate system of the reference terrain. By comparison with required values (or required coordinates) of the reference terrain, adjustment values for the cylinders of the running gears 4, 4′ can be derived and the slip form paver or the screed 5 can be automatically controlled in position and height.

FIG. 5 shows an embodiment for a second variant of a system for carrying out the method according to the invention. Analogously to FIG. 2, a slip form paver is shown, on the longitudinal beams (1, 1′) of which, however, GPS receiver antennas (8a, 8a′) are arranged instead of the reflector masts (8, 8′). The (global) position of the slip form paver is determined via satellite signals of GPS satellites (14, 14′ 14″)—which are shown here in their number and arrangement purely by way of clearer explanation. Signal processing units can be positioned in a known manner—for example on the machine or externally.

Claims

1. A method for control in relation to direction and vertical position of a construction machine in a reference terrain, comprising

a machine frame having a left and right longitudinal beam (1, 1′) substantially parallel to the working direction (AR),

running gears (4, 4′) which are adjustable in direction and height by means of final control elements, in particular cylinders, and

a terrain processing apparatus, in particular a screed (5), the terrain processing apparatus being indirectly or directly connected to the longitudinal beams (1, 1′),

comprising the steps

provision of information about the required state of a terrain to be processed,

derivation of information about the required position of the terrain processing apparatus,

provision of information about the actual position of the terrain processing apparatus relative to the required position,

derivation of a control instruction for the construction machine by comparison of required and actual positions,

control of the construction machine according to the derived control instruction,

wherein

the information about the actual position is obtained on the basis of the determination of the positions of at least four points (A1, A2, A3, A4) which can be coordinated with the terrain processing apparatus

relative to the positions of, in particular at least two, points in the reference terrain, or

by a corresponding number of satellite signals.

2. The method as claimed in claim 1, wherein the positions of the at least four points (A1, A2, A3, A4) on the terrain processing apparatus are determined by:

determination of the longitudinal and transverse tilt of the left and/or right longitudinal beam (1, 1′),

determination of the position of a point on the left longitudinal beam (1) relative to the position of a point in the reference terrain,

determination of the position of a point on the right longitudinal beam (1′) relative to the position of a point in the reference terrain,

derivation of the positions of the at least four points (A1, A2, A3, A4) in the reference terrain.

3. The method as claimed in claim 1 or 2, wherein one reflector (6, 6′) in each case is coordinated with the left and right longitudinal beam (1, 1′) and the positions of the at least four points (A1, A2, A3, A4) on the terrain processing apparatus are determined by a procedure in which

the positions of the reflectors (6, 6′) in the reference terrain are determined,

the tilt of the left and/or right longitudinal beam (1, 1′) is determined and

the positions of the at least four points (A1, A2, A3, A4) in the reference terrain are derived therefrom.

4. The method as claimed in claim 3, wherein the positions of the reflectors (6, 6′) are determined on the basis of a position determination of at least two positions in the reference terrains in particular by means of two tacheometers (10, 10′).

5. The method as claimed in any of the preceding claims, wherein the tilts of the longitudinal beams (1, 1′) are determined by means of at least one, in particular two-axis, tilt sensor (9, 9′) coordinated with at least one of the longitudinal beams (1, 1′).

6. A system for control in relation to direction and vertical position of a construction machine, comprising

a construction machine having a machine frame which comprises a left and right longitudinal beam (1, 1′) substantially parallel to the working direction (AR), running gears (4, 4′) which are adjustable in direction and height by means of final control elements, in particular cylinders, and a terrain processing apparatus, in particular a screed (5), the terrain processing apparatus being indirectly or directly connected to the longitudinal beams (1, 1′),

points assigned for determination of the position of the construction machine at least two measuring means, in particular tacheometers (10, 10′), or GPS, and

a means for providing and processing information about the required state of a terrain to be processed, information about the required position of the terrain processing apparatus, information about the actual position of the terrain processing apparatus relative to the required position, control instructions for the construction machine through comparison of required and actual positions, wherein

coordinated with the left and right longitudinal beams (1, 1′) is in each case a reflector (6, 6′), in particular a prism, or a GPS receiver antenna (8a, 8a′), and

a tilt sensor (9, 9′), in particular two-axis tilt sensor, is coordinated with at least one of the longitudinal beams (1, 1′).

7. The system as claimed in claim 6, wherein masts (7,7′) are coordinated with the reflectors (6, 6′), which masts (7, 7′) can be fixed on the longitduinal beams (1, 1′).

8. The system as claimed in claim 7, wherein the reflectors (6, 6′) are firmly connected to the masts (7, 7′), and wherein the connection is effected in the upper third of the masts.

9. The system as claimed in any of claims 6 to 8, wherein the at least two measuring means for position determination comprise tacheometers (10, 10′).

10. The system as claimed in any of claims 6 to 9, wherein the reflectors (6, 6′) or the masts (7, 7′) or the GPS receiver antennas (8a, 8a′) are coordinated with those ends of the longitudinal beams (1, 1′) which are at the rear in the working direction AR of the construction machine.

11. The system as claimed in claim 6 or 10, wherein a GPS reference station is coordinated with the system.

12. The system as claimed in any of claims 6 to 11, wherein the tilt sensor (9, 9′) coordinated with at least one longitudinal beam (1, 1′) is arranged in the middle.

13. The system as claiemd in any of claims 6 to 10 or 12, wherein local positioning systems based on electromagnetic emission are proivded for determining the positions of teh points coordinated with the construciton machine, the receiving antennas of said positioning systems being arranged instead of the reflectors (6, 6′).

14. The system as claimed in any of claims 6 or 10 to 13, wherein at least one laser plane generator having a corresponding receiver is proivded for increasing the vertical accuracy of the global or local positioning system.