U.S. patent application number 11/071942 was filed with the patent office on 2006-09-07 for method and system for controlling construction machine.
Invention is credited to Jurgen Maier, Hansjorg Petschko.
Application Number | 20060198700 11/071942 |
Document ID | / |
Family ID | 36572144 |
Filed Date | 2006-09-07 |
United States Patent
Application |
20060198700 |
Kind Code |
A1 |
Maier; Jurgen ; et
al. |
September 7, 2006 |
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.
Inventors: |
Maier; Jurgen; (Lauchringen,
DE) ; Petschko; Hansjorg; (Rebstein, CH) |
Correspondence
Address: |
Warn, Hoffmann, Miller,;LaLone & McCulloch P.C.
5291 Colony Drive North
Saginaw
MI
48603
US
|
Family ID: |
36572144 |
Appl. No.: |
11/071942 |
Filed: |
March 4, 2005 |
Current U.S.
Class: |
404/84.1 |
Current CPC
Class: |
G01C 15/002 20130101;
E01C 19/004 20130101; E01C 19/006 20130101 |
Class at
Publication: |
404/084.1 |
International
Class: |
E01C 23/07 20060101
E01C023/07 |
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.
Description
[0001] 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.
[0002] The invention relates to the control of construction
machines in general, in particular of slip form pavers with
variable frame and broad screeds.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] It is a further object of the invention to provide a system
for carrying out the method according to the invention.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.degree.
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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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).
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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:
[0033] FIG. 1 shows a system according to the invention,
[0034] FIG. 2 shows a slip form paver having reflectors and tilt
sensors,
[0035] 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,
[0036] 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
[0037] FIG. 5 shows a slip form paver with GPS.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] In FIG. 4, the method according to the invention is
explained by means of a diagram.
[0047] 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.
[0048] 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.
[0049] 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.
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