EP2990532B1 - Self-propelled construction machine and method for the visualization of the processing environment of a construction machine moving in the terrain - Google Patents

Description

The invention relates to a self-propelled construction machine, in particular a road milling machine or a slipform paver, which has a chassis, the front and rear wheels or drives in the working direction, carried by the chassis machine frame, a drive device for driving the front and / or rear wheels or drives and a steering device for directing the front and / or rear wheels or drives, so that the construction machine can perform translational and / or rotational movements in the field. In addition, the invention relates to a method for visualizing the processing environment of a terrain machine moving in the field, in particular a road milling machine or a slipform paver.

There are various types of self-propelled construction machines known. These machines include in particular the known slipform pavers or road milling machines. These construction machines are characterized by the fact that they have a working device for erecting building structures on the site or for altering the terrain.

The slipform pavers have a device for forming flowable material, in particular concrete, which is also referred to as concrete hollow. With the concrete trough structures of different education, such as baffles or gutters can be produced. In the road milling machines, the working device has a milling drum equipped with milling tools, with the material from the road surface can be milled in a given working width.

The EP 2 336 424 A2 describes a self-propelled construction machine having data describing a target curve descriptive data in an independent of the position and orientation of the construction machine reference system and a control unit which is designed such that a reference point on the construction machine starting from a predetermined starting point at which the construction machine has a predetermined position and orientation in the field, moves on the target curve.

From the EP 2 719 829 A1 a method for controlling a construction machine is known, in which the data describing a setpoint curve in an independent of the position and orientation of the construction machine reference system by means of a measuring device (rover) determined in the field and read into a working memory of the construction machine. The known method allows the control of the construction machine without major surveying effort with high accuracy.

When planning a construction project that is to be carried out using the known slipform pavers or road milling machines, the problem arises that objects already present in the terrain, for example water drains, hydrants or manhole covers, must be taken into account. For example, the building should not be located on a water drain, or the area of the terrain, such as a fire hydrant or manhole cover, should not be altered.

To take account of existing objects in the field an intervention in the machine control is necessary, which can be done manually.

The milling drum of a road milling machine, for example, when driving over a hydrant, taking into account a safety distance within a predetermined distance, which is dependent on the dimensions of the hydrant, must be raised from a predetermined position with respect to the surface to be machined. The operator can not see the exact position of the hydrant at the level of the milling drum in practice, however, because the milling drum is located below the control station. Therefore, the position of a hydrant in the field is in practice marked with lateral lines that are recognizable to the operator or to another person. The marking of existing objects in the field proves to be disadvantageous in practice. First, the marking of the objects requires an additional step. In addition, it is difficult to draw the lines exactly at right angles to the direction of travel. Furthermore, the lines are not or difficult to reach in the dark detect. Incidentally, the marking of the objects in the rain is not readily possible. Because of the inaccuracies, it is therefore necessary to choose a relatively large safety margin, which requires major reworking.

In a slipform paver, the same problem arises when a building is to be erected, which should not be on but adjacent to existing objects. For example, if the structure is to extend along a curb, water courses adjacent to the curb can not be detected by the operator if the water drains are immediately in front of or adjacent to the machine. A slipform paver adds to the difficulty that no short-term corrections to the trajectory are possible if it is determined shortly before the water intake that the planned trajectory is on this.

For an automatic control of the construction machine, also taking into account objects existing in the terrain, it is fundamentally possible to determine the shape and position of the objects in the terrain. If the shape and position of the objects are known, an intervention in the machine control can also be carried out automatically, for example, when driving over the object, the milling drum of a road milling machine can be raised automatically. However, this requires an exact determination of the shape and position of the object, for example the hydrant with respect to the coordinate system in which the construction machine is to move. Otherwise the hydrant or the construction machine may be damaged.

The invention has for its object to provide a self-propelled construction machine, in particular a road milling machine or a slipform paver, which simplifies the consideration of off-site objects in the control of the construction machine for the construction of a building or the change of the terrain in practice. Another object of the invention is to provide a method with which the consideration of existing in the field objects can be simplified.

The solution of these objects is achieved according to the invention with the features of the independent claims. The subject matters of the dependent claims relate to preferred embodiments of the invention.

The construction machine according to the invention is a self-propelled construction machine, which has a working device for the construction of structures on the site, for example a device for forming concrete, or a device for changing the terrain, for example a milling drum. For the invention is not important how the working device is formed in detail. The construction machine can be, for example, a road milling machine or a slipform paver. It can also be a paver with the same problem of considering objects already in the terrain.

The construction machine has an image recording or recording unit for recording an image of the terrain, which is in a dependent on the position and orientation of the construction machine in the field coordinate system, and a display unit for displaying the image of the area. The image section should be selected so that all areas relevant to the control of the construction machine are detected, wherein the image section may also include areas that are not visible to the operator from the control station. The image recording unit may include one or more camera systems. If the image recording unit has a plurality of camera systems, the image section can be composed of a plurality of images, each recorded with a camera system. Each camera system can also be assigned a separate image section.

The camera system may include one camera or two cameras (stereo camera system). If a three-dimensional scene is imaged onto the two-dimensional image plane of the camera when shooting with a camera, a clear correlation between the coordinates of an object, the coordinates of the image of the object on the image plane and the focal length of the camera results. However, the depth information is lost due to the two-dimensional image.

For the invention is sufficient if the camera system has only one camera, since in practice, the curvature of the terrain surface in the captured by the camera image detail can be neglected. Moreover, only two-dimensional scenes are relevant to the invention, i. H. the outlines of objects in a plane (terrain surface). However, the invention is not limited thereto.

For detecting three-dimensional scenes and / or taking into account a curvature of the terrain surface, the at least one camera system of the image recording unit can also be a stereo camera system comprising two cameras, which are arranged parallel to the axis at a predetermined horizontal distance, in accordance with the known methods the disparity to gain the depth information.

The invention requires a device for providing project data which describes the shape and position of at least one project in a coordinate system independent of the position and orientation of the construction machine. A project is understood to mean all work to be carried out with the construction machine, which forms the basis for the control of the construction machine, whereby the project is determined by which works (form) are carried out at a specific location (location). The project may involve the construction of a building or the alteration of the site. Thus, the project data may be the data describing the shape and location of a building to be erected in the field. In the known slipform pavers, the project data can be, for example, the shape and position of a baffle to be constructed descriptive data or in the known road milling machines to be processed in the area or not to be processed surface descriptive data. The project data represent parameters for the control of the construction machine, which include, for example, the feed rate and inclination of the concrete trough of a slipform paver or the milling depth of a milling machine. For the invention it is only crucial that project data of one or more arbitrary projects are available.

In addition, the construction machine has a data processing unit which is configured such that the image section of the terrain displayed on the display unit the part of the project lying in the image section is superimposed so that at least a part of the project is displayed in the image section. The display unit thus shows not only the real image detail, but also a virtual image of the project, so that the perception of the machine operator is extended. Consequently, the operator can recognize on the display unit whether the project underlying the control matches reality.

If an error has occurred during the generation of the project data, the machine operator can intervene in the machine control in advance. Alternatively, an automatic intervention in the machine control can be made. This error may, for example, be that the terrain object (s) that reflect reality have not been or have not been detected correctly for the control of the construction machine. For example, the machine operator can recognize when the surface to be machined, for example the surface to be milled with a road milling machine, lies on a hydrant or the structure to be erected with a slipform paver, for example a guide wall, should run over a water inlet.

A preferred embodiment of the invention provides that the construction machine has a device for determining position / orientation data describing the position and orientation of the construction machine in a coordinate system independent of the construction machine. The project data are determined in a coordinate system independent of the position and orientation of the construction machine, which does not change with the movement of the construction machine in the field.

The means for determining the position / orientation data describing the position and orientation of the construction machine preferably comprises a global navigation satellite system (GNSS) comprising first and second GNSS receivers for decoding GNSS signals of the Global Navigation Satellite System (GNSS) and Correction signals of a reference station for determining the position and orientation of the construction machine may have, wherein the first and second GNSS receiver on the construction machine in different positions are arranged. With the first and second GNSS receiver, the measurement accuracy can be increased. Instead of a global navigation satellite system (GNSS), the position and orientation of the construction machine can also be determined with a satellite-independent system, for example with a tachymeter.

A further preferred embodiment provides that the project data describing the shape and position of the at least one project in the coordinate system independent of the position and orientation of the construction machine in dependence on the known position and orientation of the construction machine in the non-construction machine coordinate system in be transformed depending on the position and orientation of the construction machine coordinate system. The project data available in the fixed coordinate system can then be superimposed on the image section in real time, so that the project is always visible in correct alignment with the real image, which can constantly change with the movement of the construction machine.

From the project data, different image data can be obtained with the image processing unit with which the project can be visualized on the display unit for the machine operator. For visualization, a simplified representation of the project is generally sufficient. Preferably, the project data comprise at least one outline of the project descriptive data, wherein the data processing unit is configured such that in the image section of the terrain, the at least one outline of the project is displayed. The outline and the shape of the project in the image section are sufficiently marked. If the project is, for example, a building, the building can also be highlighted by a colored underlay or a hatching or can be represented by it alone.

In a further particularly preferred embodiment, the data processing unit is configured to determine object data describing the shape and location of at least one real object in the image area of the terrain, the project data then being compared to the object data. In In this context, object data is understood to be all data describing the shape and position of the objects present in the terrain and recorded with the image recording unit, which objects are represented as real objects in the image detail. The object data can describe, for example, the position and shape of a structure, for example a hydrant or a water inlet in the area, which should not be covered or damaged during the construction of a building or the change of the terrain. The comparison of the project data with the object data allows beyond the extension of the perception of the machine operator, a computer-aided monitoring of the control of the construction machine, where it can be determined that the determined project data does not match the object data (reality). In the comparison, the known mathematical algorithms can be used, for example, to be able to determine whether the building is actually next to the water inlet.

A particularly simple evaluation of the data provides for determining the distance between at least one reference point related to the outline of the project and at least one reference point related to the outline of the object. The reference point can lie even on the outline, for example on a circle or circular arc, or next to the outline, for example, lie on the center of a circle. The determined distance is preferably compared with a predetermined limit value. If the distance between reference points lying on the contour lines is smaller than a predetermined limit, it can be concluded that a minimum distance is not maintained. This minimum distance can be visualized on the display unit. Another possibility is to base the areas enclosed by the contours on the evaluation. It is also possible to determine whether the outline of the project defined around the object, taking into account a predetermined minimum distance, intersects with the outline of the object. In the case that the project line intersects the object line, it can be concluded that the project line does not enclose the object line, ie the project and the object do not match, but at least partially overlap.

The construction machine preferably has an alarm unit which gives an optical and / or audible and / or tactile alarm when the data processing unit has determined that the project and the object do not match, for example the project line and object line intersect and / or or the determined distance between the outlines of project and object is less than a predetermined limit. It is also possible to generate a control signal for intervention in the machine control.

For the invention is irrelevant how project data are provided. In a preferred embodiment, the construction machine has an interface for reading in the project data and a memory unit for storing the read-in project data. This makes it possible to determine the project data required for controlling the construction machine in advance. The project data are preferably determined in the field with a preferably satellite-based measuring device (rover).

In the following, various embodiments of the invention will be explained in more detail with reference to the drawings.

Show it:

Fig. 1A

an embodiment of a slipform paver in the side view,

Fig. 1B

the slipform paver from Fig. 1A in the plan view,

Fig. 2A

an embodiment of a road milling machine in side view,

Fig. 2B

the road milling machine of Fig. 2A in the plan view,

Fig. 3

the road surface to be worked with a road milling machine together with the coordinate system independent of the movement of the construction machine and the coordinate system dependent on the movement of the construction machine,

Fig. 4

the image of the terrain displayed on the display unit of the road milling machine,

Fig. 5A

an example of the superposition of the outline of a project and of an object in the image section, whereby the outlines of project and object do not intersect,

Fig. 5B

an example of the superimposition of the outline of a project and of an object in the image section, where the outlines of the project and the object intersect,

Fig. 6

the image of the terrain displayed on the display unit of a slipform paver, where the project and the object are exactly matched,

Fig. 7

the image of the terrain displayed on the display unit of a slipform paver, where the project and the object do not match, and

Fig. 8

a block diagram with the essential components for the visualization of the processing environment of the construction machine according to the invention.

The Figures 1A and 1B show in side view and plan view as an example of a self-propelled construction machine a slipform paver. Such slipform paver is in the EP 1 103 659 B1 described in detail. Since slipform pavers as such belong to the prior art, only the essential components of the construction machine of the invention will be described here.

The slipform paver 1 has a machine frame 2, which is supported by a chassis 3. The chassis 3 has two front and two rear crawler tracks 4A, 4B, which are attached to front and rear lifting columns 5A, 5B. The working direction (Direction of travel) of the slipform paver is marked with an arrow A. But it can also be provided only a front or rear drive.

The track drives 4A, 4B and lifting columns 5A, 5B constitute the drive means of the slipform paver for performing translational and / or rotational movements of the construction machine on the field. By raising and lowering the lifting columns 5A, 5B, the machine frame 2 can be moved with respect to the ground in the height and inclination. With the chain drives 4A, 4B, the slipform paver can be moved back and forth. Thus, the construction machine has three translatory and three rotational degrees of freedom.

The slipform paver 1 has an only hinted illustrated device 6 for forming concrete, which is referred to below as a concrete trough. The concrete trough 6 represents the working device of the slipform paver for the construction of a building structure with a predetermined shape on the site.

The FIGS. 2A and 2B show as a further example of a self-propelled construction machine, a road milling machine in the side view, wherein the same reference numerals are used for the corresponding parts. The road milling machine 1 has a machine frame 2, which is supported by a chassis 3. The chassis 3 again has front and rear crawler tracks 4A, 4B mounted on front and rear lifting columns 5A, 5B. But it can also be provided only a front or rear drive. The road milling machine has a working device for changing the terrain. This is a milling device 6 with a equipped with milling tools milling drum, which is not recognizable in the figures. The milled material is transported away with a conveyor F.

The road surface to be worked with a road milling machine is in Fig. 3 shown. On the site runs a curb 7 laterally limited road 8. In this embodiment, the project is to milled the pavement of the road. It should be noted that there are certain objects O on the road, such as manhole cover in the middle of the road surface and water inlets at the Side of the road surface. Fig. 3 shows two manhole covers 9, 10 and a water inlet 11, which are run over by the road milling machine when milling the road surface. The representation in Fig. 3 but does not correspond to the field of vision of the machine operator. The objects O on the road can not be seen by the operator on the platform of the construction machine, since they are located directly in front of the construction machine or below the machine. The machine operator can not recognize the manhole cover, in particular, when the milling drum is only a short distance in front of the manhole cover, ie exactly at the time when the machine operator has to lift the milling drum. However, this area can not be monitored with a camera because of the flying milling material in the milling drum housing.

Since the machine operator can not recognize the manhole cover, in practice at the height of the manhole cover side markings are mounted, which in Fig. 3 with M ₁ and M _{2 are} designated. These markings are to allow the operator or another person to recognize the position of the manhole cover, so that the milling drum can be lifted in time. However, such markings are not required in the construction machine according to the invention.

The position and shape of the circular manhole covers 9, 10 are clearly described by three lying on the circumference reference points O ₁₁ , O ₁₂ , O ₁₃ and O ₂₁ , O ₂₂ , O ₂₃ . The position and shape of the rectangular water inlets are described by four reference points O ₃₁ , O ₃₂ , O ₃₃ , O _{34 located} at the corners of the water inlet.

The project is described by previously created project data, which are read in via a suitable interface 12A in a working memory 12 of the construction machine ( Fig. 8 ). The project data contains the coordinates of reference points characteristic of the project, which are detected in a coordinate system (X, Y, Z) independent of the position and orientation of the construction machine. In this embodiment, the reference points lie on the contours 13, 14, 15, which enclose the contours 16, 17, 18 of the objects O at a predetermined minimum distance Δ. In this embodiment, since the objects O are circular Manhole covers 9, 10 and rectangular water inlets 11 are, the outlines describing the project are also circles and rectangles. The circular outlines 13, 14 of the project are uniquely identified by the coordinates of three reference points P ₁₁ , P ₁₂ , P ₁₃ and P ₂₁ , P ₂₂ , P ₂₃ and the rectangular outlines 15 of the project by the coordinates of four reference points P ₃₁ , P ₃₂ , P ₃₃ , P ₃₄ in the independent of the movement of the construction machine coordinate system (X, Y, Z) described.

The project data comprises the coordinates of the reference points of the project in the fixed coordinate system independent of the movement of the construction machine (X, Y, Z). They mark the area to be cut, which lies outside the outlines 13, 14, 15 of the project. The area not to be processed is the area within the outlines 13, 14, 15 of the project, in which the objects O lie. This clearly determines the project.

The project data can be determined as follows. The fixed coordinate system (X, Y, Z) is preferably the coordinate system of a global navigation satellite system (GNSS), so that the reference points of the objects can be easily detected with a measuring device (rover). From the reference points O ₁₁ , O ₁₂ , O ₁₃ and O ₂₁ , O ₂₂ , O ₂₃ and O ₃₁ , O ₃₂ , O ₃₃ , O _{34 of} the objects are taking into account a minimum distance Δ between the outline 13, 14, 15 of the project and the outline 16, 17, 18 of the object, the reference points P ₁₁ , P ₁₂ , P ₁₃ and P ₂₁ , P ₂₂ , P ₂₃ and P ₃₁ , P ₃₂ , P ₃₃ , P _{34 of} the project determined. The project data can be stored in an external storage unit, for example a USB stick, and read into the internal storage unit 12 of the construction machine via the interface 12A. With this data, the construction machine can then be controlled. When the road milling machine reaches a surface that is not to be machined, the milling drum is automatically raised with respect to the ground. As soon as the road milling machine has traveled over the area not to be worked, the milling drum is lowered again. This avoids that the manhole cover 9, 10 or water inlet 11 or the construction machine is damaged. The raising and lowering of the milling drum can also be done with a manual intervention in the machine control, with the machine operator, the time at which the intervention is to be signaled.

In practice, it may happen that the reference points of the project are not detected correctly in the GNSS coordinate system independent of the road milling machine taking into account the object O. Then there is a risk that the manhole cover 9, 10 or water inlet 11 is not within the predetermined outline 16, 17, 18, with the result that the manhole cover or water inlet or the machine is damaged.

The road milling machine has an image recording unit 19, which has a camera system 19A arranged on the machine frame 2, with which an image section 20A of the terrain to be processed, ie the road surface with the manhole covers and water inlets, is taken. The camera system 19A detects an area not visible to the operator by the operator. The image section 20A is displayed on a display unit 20, for example an LC display. Fig. 4 shows the display of the display unit 20. While the road milling machine moves in the field, constantly changing the image shown in the image section 20A, so that the operator can recognize that he moves with the road milling machine on a manhole cover 9, 10 or water inlet 11.

In addition, the road milling machine has a data processing unit 21, with which the project data available is processed. The data processing unit 21 is configured such that the image section 20A of the terrain displayed on the display unit 20 is superimposed on the project lying in the image section. In this embodiment, the outlines 16, 17, 18 of the project, which identify the surface to be worked or the surface not to be processed, are displayed in the image section 20A as they correspond to the previously determined project data. The operator can thus immediately recognize on the display unit 20 if the project data should not correspond to reality, ie the outlines 16, 17, 18 of the project do not concentrically surround the outlines 13, 14, 15 of the objects O in the predetermined minimum distance Δ should. If the manhole cover and water inlets within the displayed outlines On the other hand, the control of the road milling machine can take place without any further intervention in the machine control.

The image section 20A is assigned a coordinate system (x, y, z) which depends on the movement of the construction machine in the terrain and which is in Fig. 3 is shown. The position (origin) and orientation of this coordinate system corresponds to the location and viewing angle of the camera 19A on the construction machine. In this coordinate system, the position and shape of the objects O are also described by corresponding coordinates.

The coordinate system (x, y, z) dependent on the movement of the construction machine in the field can be a three-dimensional or two-dimensional coordinate system. In Fig. 3 the general case of a coordinate system with an x-axis, y-axis and z-axis is shown. With a negligible curvature of the terrain surface and the consideration of only two-dimensional objects but a two-dimensional coordinate system is sufficient. However, this presupposes that the x / y plane of the coordinate system is parallel to the terrain surface assumed to be assumed, which is assumed below.

The camera system may be a stereo camera system or a camera system with only one camera. With negligible curvature of the terrain surface and / or the consideration of only two-dimensional objects but a camera system with only one camera is sufficient. If the camera system is a stereo camera system, three-dimensional images can also be displayed on the display unit 20 using the known methods.

For determining the position and orientation of the construction machine and thus also the position and orientation (viewing angle) of the camera system 19A in the coordinate system (X, Y, Z) independent of the position and orientation of the construction machine, the construction machine has a device 22 which Provides position / orientation data of the construction machine ( Fig. 8 ). This device may comprise a first GNSS receiver 22A and second GNSS receiver 22B arranged on the construction machine at different positions S1, S2. Fig. 1B shows the position S1 and S2 of the two GNSS receivers 22A and 22B on the slipform paver. The first and second GNSS receivers 22A, 22B decode the GNSS signals of the global navigation satellite system (GNSS) and correction signals of a reference station for determining the position and orientation of the construction machine. Such systems, which enable a highly accurate determination of the position / orientation data, belong to the state of the art. Instead of the second GNNS receiver but also an electronic compass K may be provided to detect the orientation of the construction machine. Fig. 2B shows the position S1 of the first GNSS receiver 22A and the position S2 of the compass K on the road milling machine. The compass can also be dispensed with if the orientation of the construction machine is calculated. The orientation can be calculated by determining the position of a reference point of the construction machine at successive times and determining the direction of the movement from the change in position. The accuracy can be additionally increased by including the steering angle in the calculation.

The data processing unit 21 receives the current position / orientation data, which is continuously provided by the device 22 for determining the position and orientation of the construction machine, and transforms the shape and position of the project in the coordinate system independent of the position and orientation of the construction machine (FIG. X, Y, Z) depending on the position and orientation of the construction machine in the non-construction machine coordinate system in the dependent on the position and orientation of the construction machine machine coordinate system (x, y, z). This data transformation takes place in real time. After the coordinates of the reference points characterizing the outlines of the project in the machine coordinate system are known, the outlines 16, 17, 18 of the project are displayed in the image section 20A ( Fig. 4 ). The operations of the data processing unit required to generate the contours belong to the state of the art.

If there is no project data for the displayed image section 20A, no visualization takes place on the display unit 20. Otherwise, the relevant information is presented to the machine operator in addition to the figure of the real objects (hydrant 9, 10 or water inlet 11) by means of the contours 16, 17, 18 displayed as virtual objects that are to match with the captured in the camera image real objects O. Consequently, the operator can constantly monitor the control of the construction machine.

The data processing unit 21 can comprise an image processing unit which can automatically recognize whether the real objects O match the virtual objects, ie the real outline 13, 14, 15 of an object O (hydrant or water inlet) shown in the image section, actually within the associated virtual one Outline 16, 17, 18 of the project lies. The data processing unit 21 is configured such that the shape and position of the real object O (hydrant or water inlet) recorded by the camera system 19A is determined in the image section 20A. For this purpose, the data processing unit 21 can make use of the known methods for image recognition. The shape and position of the real object in the image section are described by object data. For example, the circular outline of the manhole cover 9 is described by the three contoured reference points P ₁₁ , P ₁₂ , P ₁₃ ( Fig. 3 ).

The object data is compared in the data processing unit 21 with the project data to determine whether the real objects match the virtual objects. In this embodiment, the data processing unit checks whether the outline 13 of the real object, for example the manhole cover 9, lies within the outline 16 of the project. For this purpose, the data processing unit 21 checks whether the two contour lines 13, 16 intersect. If the contours 13, 16 do not intersect, it is concluded that the object data corresponds to reality. Otherwise, an erroneous determination of the object data is concluded.

Fig. 5A shows the case that the object data match the project data, ie the outlines 13, 16 have no intersection while Fig. 5B the case shows that the object data do not match the project data, ie the outlines 13, 16 intersect at two points P _s .

In addition, in a preferred embodiment, the data processing unit 21 can still determine whether a minimum distance Δ is maintained. For this purpose, the data processing unit determines two reference points P _A1 and P _A2 , which are assigned to the outline 13 of the object or the outline 16 of the project. For example, as reference points P _A1, P _A2 points are determined lying on the circular contour lines 13, 16 especially close to each other ( Fig. 5A ). The data processing unit 21 determines the distance a between the lines lying on the outline of reference points P _A1, P _A2 and compares the distance with a predetermined limit value. If the distance between the points is smaller than the predetermined limit value, it is concluded that the outline 13 of the object lies within the project, since the outlines 13, 16 do not intersect. It is concluded, however, that a minimum distance Δ is not met, so there is still the risk of damage to the manhole cover or the construction machine. The reference points can also be the midpoints or line or area centers of the circular outlines. In an exact alignment taking into account the predetermined minimum distance Δ the outlines 13, 16 have a common center or line or centroid, ie the distance between the centers should be as small as possible.

The above embodiment is only to be understood as an embodiment for comparing the project data and object data with each other. The data can also be evaluated with all other known algorithms to infer whether the real objects match the virtual objects.

The construction machine has an alarm unit 23 which gives an optical and / or audible and / or tactile alarm when the data processing unit 21 has determined that the two contour lines 13, 16 do not match and / or the distance a is smaller than a predetermined one Limit is ( Fig. 8 ). The operator can be pointed to an erroneous determination of the object data also by color shading of certain surfaces, hatching or by markings. On the display unit 20, the distance a can also be displayed.

The following is with reference to the FIGS. 6 and 7 described a further embodiment of the invention, which differs from the previous embodiment in that the project does not change the terrain with a road milling machine ( Fig. 2 ), but the erection of a structure with a slipform paver ( Fig. 1 ). The slipform paver, like the road milling machine, has an image recording unit 12 and a data processing unit 21 and a device 12 for providing the project data (FIG. Fig. 8 ). The corresponding parts are provided with the same reference numerals.

In the present embodiment, the slipform paver project is a traffic island bounded laterally by a curb 25 of concrete. The curb 25 has, for example, a straight section 25A, followed by a semicircular section 25B. The curb 25 should be adjacent to a rectangular water inlet 26, which requires precise control of the slipform paver.

The project data again contains the coordinates of characteristic reference points for the project, which are detected in a coordinate system (X, Y, Z) independent of the position and orientation of the construction machine. The project data describe the shape and position of the curb 25. The shape and position of the straight portion 25A can be described, for example, by two reference points P ₁ , P ₂ and P ₃ , P ₄ at the beginning and end of the inner and outer Outline 27, 28 of the curb 25 are. The semi-circular portion 25B may be described, for example, by three reference points P ₂ , P ₅ , P ₆ and P ₄ , P ₇ , P ₈ lying on the inner and outer contour lines 27, 28, respectively.

The previously determined project data relating to the GNSS system independent of the position and orientation are read into the working memory 12 of the slipform paver via the interface 12A. The control unit of the slipform paver is configured such that the slipform paver moves on a path corresponding to the course of the curb 25 to be erected.

The FIGS. 6 and 7 show the image section 20A taken by the camera system 19A of the image recording unit 19 and displayed on the display unit 20, in which the terrain lying in working direction A in front of the slipform paver and a part of the slipform paver with the concrete recess 6 can be seen.

The terrain position and orientation determining means 22 of the slipform paver continuously calculates the current position / orientation data, and the data processing unit 21 obtains the project data which is in the GNSS system (X, Y, P) independent of the position and orientation of the slipform paver. Z) are transformed into the machine coordinate system (x, y, z) which depends on the position and orientation of the slipform paver and which corresponds to the viewing angle of the camera system. After determining the coordinates of the reference points in the machine coordinate system, the inner and outer contours 27, 28 of the straight and semicircular portions 25A, 25B are superimposed on the camera image.

The FIGS. 6 and 7 show a possibility of displaying the curb 25 in the image section 20A by the contour lines 27, 28, which show the machine operator the course of the curb, which is made with the slipform paver, if the stored project data of the control are based. In order to visualize the curb 25 in the camera image, in addition to the inner and outer contour lines 27, 28, color backgrounds, hatchings, auxiliary lines or markings can also be generated by the data processing unit 21 and displayed on the display unit 20. The machine operator can check the correct course of the curb 25 in the image section 20A. He can see in advance whether the curb 25, for example, runs next to the water inlet 26.

Fig. 6 shows the case of a correct course of the curb 25 close to, ie at a predetermined minimum distance from the water inlet 26, while Fig. 7 the case shows that the curb 25 extends over the water inlet 26. In this case, the Alarm unit 23 an alarm signal, so that the operator can make an intervention in the machine control.

In a preferred embodiment, the data processing unit 21 with an image recognition determines the coordinates of reference points O ₁ , O ₂ , O ₃ , O _{4 of} the rectangular water inlet 26 in the machine coordinate system (x, y, z) corresponding to the camera image. Since the standardized shape and size of the water inlet 26 is known, for example, the coordinates of the corner points of the water inlet can be determined with an image recognition without much computational effort. These coordinates then provide the object data that is compared to the project data to determine if the design is consistent with reality. For this purpose, it can be checked with the data processing unit 21, for example, whether the contours of the curb and water inlet intersect, and / or with the data processing unit, for example, the distance between the contours can be calculated, as described with reference to the other embodiment.

Claims (18)

1. Self-propelled construction machine comprising
   a chassis (3) which comprises front and rear wheels or running gears (4A 4B) in the working direction,
   a machine frame (2) supported by the chassis,
   a drive device for driving the front and/or rear wheels or running gears (4A, 4B),
   a working device (6) for installing structures on the terrain or for modifying the terrain,
   an image recording unit (19) for recording an image segment (20A) of the terrain located in a coordinate system (x, y, z) dependent on the position and orientation of the construction machine on the terrain, and
   a display unit (20) for displaying the image segment (20A) of the terrain, characterised in that
   the construction machine further comprises:

   a device (12) for providing project data describing the shape and location of at least one project in a coordinate system (X, Y, Z) independent of the position and orientation of the construction machine, and

   a data processing unit (21) which is configured in such a way that a depiction of the part of the at least one project located in the image segment is superimposed on the image segment (20A) of the terrain displayed on the display unit (20), such that at least part of the at least one project is visualised in the image segment.
2. Self-propelled construction machine according to claim 1, characterised in that the construction machine comprises a device (22) for determining position/orientation data describing the position and orientation of the construction machine in the coordinate system (X, Y, Z) independent of the construction machine.
3. Self-propelled construction machine according to claim 2, characterised in that the device (22) for determining the position/orientation data describing the position and orientation of the construction machine comprises a global navigation satellite system (GNSS).
4. Self-propelled construction machine according to either claim 2 or claim 3, characterised in that the device (22) for determining the position/orientation data describing the position and orientation of the construction machine comprises a first and a second GNSS receiver (22A, 22B) for decoding GNSS signals from the global navigation satellite system (GNSS) and correction signals from a reference station in order to determine the position and orientation of the construction machine, the first and second GNSS receivers (22A, 22B) being arranged in different positions (S 1, S2) on the construction machine.
5. Self-propelled construction machine according to any of claims 2 to 4, characterised in that the data processing unit (21) is configured in such a way that the project data describing the shape and location of the at least one project in the coordinate system (X, Y, Z) independent of the position and orientation of the construction machine is transformed, on the basis of the position and orientation of the construction machine in the coordinate system (X, Y, Z) independent of the construction machine, into a coordinate system (x, y, z) dependent on the position and orientation of the construction machine.
6. Self-propelled construction machine according to any of claims 1 to 5, characterised in that the project data describing the shape and location of the at least one project comprise data describing at least one contour (16, 17, 18; 27, 28) of the project, the data processing unit (21) being configured in such a way that the at least one contour (16, 17, 18; 27, 28) of the project is displayed in the image segment of the terrain.
7. Self-propelled construction machine according to any of claims 1 to 6, characterised in that the data processing unit (21) is configured in such a way that the shape and location of at least one actual object (O) in the object data describing the image segment of the terrain is determined, the object data being compared with the project data.
8. Self-propelled construction machine according to claim 7, characterised in that the spacing (a) between at least one reference point (P_A2) relating to the contour (16, 17, 18) of the project and at least one reference point (P_A1) relating to the contour (13, 14, 15) of the object is determined.
9. Self-propelled construction machine according to claim 8, characterised in that the construction machine comprises an alarm unit (23) which emits an optical and/or acoustic and/or tactile alarm or generates a control signal for intervention in the machine control if the data processing unit (21) has identified that the spacing (a) is smaller than a predefined threshold value.
10. Self-propelled construction machine according to any of claims 1 to 9, characterised in that the device (12) for providing the project data describing the shape and location of at least one project in the coordinate system (X, Y, Z) independent of the position and orientation of the construction machine comprises an interface (12A) for inputting the project data and a storage unit for storing the project data.
11. Method for visualising the working environment of a construction machine moving on the terrain and installing a structure on the terrain or modifying the terrain, the image segment (20A) of the terrain located in a coordinate system (x, y, z) dependent on the position and orientation of the construction machine on the terrain being recorded by means of an image recording unit (19) and displayed on a display unit (20),
    characterised in that
    the shape and location of at least one project are provided in project data describing a coordinate system (X, Y, Z) independent of the position and orientation of the construction machine, and in that
    a depiction of the part of the at least one project located in the image segment is superimposed on the image segment (20A) of the terrain displayed on the display unit (20), such that at least part of the at least one project is visualised in the image segment.
12. Method according to claim 11, characterised in that the position/orientation data describing the position and orientation of the construction machine are determined in the coordinate system (X, Y, Z) independent of the construction machine.
13. Method according to claim 12, characterised in that the position/orientation data describing the position and orientation of the construction machine are determined by means of a global navigation satellite system (GNSS).
14. Method according to either claim 12 or claim 13, characterised in that the project data describing the shape and location of the at least one project in the coordinate system (X, Y, Z) independent of the position and orientation of the construction machine is transformed, on the basis of the position and orientation of the construction machine in the coordinate system (X, Y, Z) independent of the position and orientation of the construction machine, into a coordinate system (x, y, z) dependent on the position and orientation of the construction machine.
15. Method according to any of claims 11 to 14, characterised in that the project data describing the shape and location of the at least one project comprise data describing at least one contour (16, 17, 18; 27, 28) of the project, the at least one contour (16, 17, 18; 27, 28) of the project being displayed in the image segment (20A) of the terrain.
16. Method according to any of claims 11 to 15, characterised in that the shape and location of at least one actual object (O) in the object data describing the image segment (20A) of the terrain is determined, the object data being compared with the project data.
17. Method according to claim 16, characterised in that the spacing (a) between at least one reference point (P_A2) relating to the contour (16, 17, 18) of the project and at least one reference point (P_A1) relating to the contour (13, 14, 15) of the object is determined.
18. Method according to any of claims 11 to 17, characterised in that the shape and location of the at least one project in the project data describing the coordinate system (X, Y, Z) independent of the position and orientation of the construction machine is determined on the terrain by means of a measuring device.

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