Field of invention

The present invention relates to a control system for a construction vehicle. The invention also relates to a construction vehicle comprising such control system. The invention furthermore relates to a method for operating a construction vehicle. The system is applicable in autonomous construction vehicles because system can also act as a 3D navigation system for operators, in those cases where the operator takes over manual control of the construction vehicle.

Prior art

Several different types of construction vehicles exist. Common to all of them is that they are all able to move around at a construction site performing various tasks, operated by an operator. Earthmoving construction vehicles such as Dozers, Excavators and Loaders typically move earth, these construction vehicles are usually either mounted with wheels or tracks to aid the move around on site, they have moving parts which are usually (but not always) hydraulically controlled, and they usually have the option of mounting various tools such as buckets, blades, drills. Other construction vehicles than earthmoving vehicles also exist, for example, soil compactors, drill rigs, forklifts and piling vehicles.

It requires a skilled operator to operate a construction vehicle efficiently. Often the construction vehicle comprises multiple couplings between the vehicle base and tool edge and extending or retracting any single hydraulic cylinder will cause the position of the tool to move.

One problem associated with the operation of a construction vehicle is how to indicate to the operator the position of the tool. For most construction vehicles various devices for determining the relative and absolute positions of the tool and other parts of the vehicle have been developed. These devices use a combination of Inertial Measurement Unit (IMU) sensors, Global Navigation Satellite System (GNSS) antennas and other sensors mounted on the construction vehicle to gather information about the posture of each part of the construction vehicle. Sensor data will then be processed on a control unit to calculate relative and absolute positions of different machine parts. The results are hereafter shown to the operator on a display and combined with other information such as design plans etc. These devices are often referred to as "Machine control systems", "Machine guidance", "3D navigation systems", "2D or 3D systems". In this document such a system will generally be referred to as a navigation system. The information may be used for a variety of purposes, such as documentation of work, guiding the driver, sending data to surveyor, foremen or other, and other purposes.

Another problem associated with construction vehicles is that it requires an operator to operate the vehicle, and that it requires experience to control the construction vehicle accurately and efficiently.

Retrofit systems exist that are able to take over control of parts of the vehicle based on sensor data, and a digital description of the desired result. We will in this document refer to such a system as a semiautomatic control system.

Furthermore, retrofit systems exist that are able to take over full control of the vehicle based on sensor data and a digital description of the desired result, without any need for involving an operator during operation. Such a system will in this document be referred to as an autonomous control system.

A challenge for a fully autonomous system is that it is for various reasons not always possible to deploy an autonomous construction vehicle for any given task at a construction site. In such situations an operator has to manually take over control of the construction vehicle. In these situations the operator could still benefit from a 3D navigation system in order to work more efficiently.

Thus, there is a need for a control system which can control the construction vehicle in autonomous mode when possible, wherein the control system also can guide the operator/user of the construction vehicle in the same way as a navigation system, when the user is operating the construction vehicle in manual mode.

It is an object of the invention to provide a retrofit control system for construction vehicles.

EP3567396A1 discloses a work vehicle equipped with an autonomous control system. The control system is, however, not user-friendly with respect to enabling the user to configure a design. Accordingly, it would be advantageous to have a control system that is suitable for providing improved guidance capabilities in a manual mode.

Definitions

Construction vehicle: A vehicle designed to work on construction sites. This includes excavators, dozers, backhoe loaders, Wheel loaders, skid steers, soil compactors, drill rigs, piling machines, forklifts and lifting machines.

Navigation system: An assembly of sensors, brackets, cables, control unit, display unit(s) and communication devices mounted on a construction vehicle with the purpose of providing information about the position or height of specific parts of the construction vehicle, measured as either absolute values in a predetermined coordinate system or relative to a reference point.

Interface: The graphical information displayed to the user by the navigation system on a display unit. The interface also encompasses the graphical design (interface elements) and user interactions with the display unit. Control system: An assembly of sensors, brackets, cables, control unit, display unit(s) and communication devices mounted on or configured to be mounted on a construction vehicle, where the control unit is connected to the construction vehicle's steering system and is able to control movement of some or all parts of the vehicle. Typically, these parts will be hydraulically controlled, i.e. controlled by a hydraulic valve which is able to process electrical input signals, but other variants also exist.

Operating mode: Mode in which the vehicle is operated. In this document we distinguish between "Navigation mode" where the vehicle is operated manually, with guidance from a navigation system, "Semiautomatic" mode where the vehicle is partly operated manually, and partly by a control system, and an "Autonomous" mode where the vehicle is fully controlled by a control system.

Mission: A single job for which the construction vehicle is designed, and which is well-defined and which can be described in a couple of simple sentences. One task could be drilling a set of holes based on a digital description. Another second task could be moving a pile of earth from one location to another. And a third task could be spreading a pile of material onto a given surface at a specified height.

Design: A design is a set of files describing the desired end result of the job performed, and end result of intermediate steps of the job performed. Furthermore, design files can contain information about already existing features of the jobsite, such as existing sewers in the ground, terrain height at beginning of construction. A design file can consist of one or more surfaces describing different physical layers of the job (this could be different layers of a road, consisting of different materials). A design can also contain side references such as lines and points defining locations of water pipers, edges of a road, sides of a foundation. In an embodiment, the design is defined by a set of parameters instead of defined through files. These parameters can be issued by the operator through the display.

As-built: As-built information is information about how the job of the construction vehicle was performed. As-built could be logged points marked with the edge of the bucket of the excavator, indicating location of pipes and sewers. It could also be a surface log based on calculation of height of the belts of a dozer driving over an area of terrain.

Side reference: Side references are typically points or lines that are either part of the design or as-built. Side references are typically elements to which the operator is interested in seeing horizontal distance or direction from the tool. Side references can also be used as a vertical reference. This could be the case where a line represents where a pipe needs to be laid in the ground. In this case the operator is interested in the location of the pipe in a horizontal plane, but also the depth of the pipe. When working with side references it is important to note that distance between side reference and tool can also be the distance in a horizontal plane.

Focus point: For practical purposes it is useful for the operator to be able to select which part of the construction vehicle/tool that should be used for logging points, calculations for side references and others. Therefore, in many navigation systems it is possible for the operator to change which part of the construction vehicle is of particular interest. This point is called the focus point. In other contexts this point might be called log point or tool point.

In an embodiment, there can be multiple focus points, each for their different purpose. By way of example, one focus point for logging points and another for calculating side references.

Cut/flll values: A cut/fill value is used as a term of how much further down or up the tool needs to move, to reach the desired depth of the design. Typically, there are multiple cut/fill values for different parts of the construction vehicle such as left and right corner of the bucket

Active tool: A construction vehicle is often designed in such a way that it is easy to replace the tool. By way of example, on an excavator, it is possible quickly to change the bucket. This is reflected in the system, such that it is possible to pre-configure several tools, and during operation possible to select which of the preconfigured tools should be used for calculations in the system. On some occasions the active tool will also be named differently such as a current bucket or an active bucket.

Coordinate transformations: In the prior art of surveying, positions are usually given in different coordinate systems that are projections from a spherical shape to a plane. Besides projections to a plane, often a height transformation is also applied. Height transformations are usually called geoids. Other transformations are sometimes also applied such as user defined vertical transformation referred to as height offset and vertical transformation perpendicular to current surface. In this document any definition of a transformation from one notation to another will be referred to as a coordinate transformation.

User interface configuration: Depending on the specific work situation it is desirable to see different types of values on the display, to have different buttons available on the screen, and to see the construction vehicle and/or designs from different perspectives. Specific setup of the display is referred to as a user interface configuration. Often it is possible to switch between different predefined user interface configurations using touch gestures on the display or pressing buttons. Also, it is usually possible for the user to define new user interface configurations adapting the user interface to his current needs.

It is an object of the invention to provide a control system for retrofitting on construction vehicles, which can also be used as a 3D navigation system hereby enabling the user to use the system in different operating modes depending on the task that needs to be performed. Adding navigation capabilities to an autonomous control system has the advantage that the system will increase the efficiency of the construction vehicle, even when it is not possible to deploy the construction vehicle in autonomous mode.

Though different construction vehicles may appear not very alike, they all share common properties, which makes this invention applicable to all of them.

The system consists of several submodules, each submodule not necessarily understood as a separate physical module, but more as a conceptual module with a specific responsibility as a sub-part of the overall system (such a conceptual module is termed a digital module):

Control box: Central for the system is the control box which takes in sensor data, outputs data to the control module to move the construction vehicle parts and outputs data to the display. The control box is also designed to receive input from other devices physically connected to the construction vehicle, for example buttons or joystick input. Furthermore, the control box will receive input in the form of user interaction with the display. In an embodiment, the control box comprises several physical units.

Positioning module: To work with designs it is necessary for the control unit(s) to have an exact absolute position and heading of the vehicle. For this a position sensor such as one or more RTK GNSS antennas and an RTK GNSS receiver communicatively connected to the control box is used. This gives a cm accurate position of the measured part of the construction vehicle. The position received from the GNSS receiver is transformed from a position expressed in degrees and height above an ellipsoid into a Euclidean coordinate system suited for the local jobsite in use. In an embodiment, the RTK GNSS antenna is replaced by a prism and a total station. In an embodiment, the RKT GNSS is replaced by a visionbased system. In an embodiment, the RTK GNSS receiver is part of the control box

Kinematic module: Usually construction vehicles consist of several parts which can move independently of each other. On each part other parts might also be attached which again can be moved independently of the first part. Usually, a tool is attached to the last part in this chain, and usually it is the specific point on this tool that is of special interest for the task performed. To enable the system to take into account the tool point, a set of sensors is arranged on the vehicle such that each moving part from the positioning devices to the edge of the tool is measured. Typically, these sensors will be IMU sensors measuring the angle for sensor towards gravity field, rotational sensors measuring joining angles and distance sensors measuring lengths. These sensors will be communicatively connected to the control box, which by using sensor input and a proper measurement of the construction vehicle is able to construct a real time kinematic model of the construction vehicle.

Control module: Module translating output from control box into actual movements of the construction vehicle. These can be electrical signals controlling the hydraulic valve block of the construction vehicle. But other variants also exist.

Safety module: To ensure safety of personnel working on the jobsite while in autonomous and semi-automatic mode, a system is put in place ensuring that the construction vehicle enters safe mode whenever certain safety conditions are not met.

Vision module: To enable the system to keep real time track of its surroundings and the progress of the current task a vision module is in place to update the control box of current status. The vision module consists of one or more sensors communicatively connected to the control box. The vision module sensor can be either lidar, radar or cameras, mounted either on the construction vehicle, for example on top of the construction vehicle or on the arm, or not mounted on the vehicle.

Mission programming module: To instruct the system of which jobs to perform and how to perform it, the mission programming module will take input from the user prior to the task, defining which job to perform, and specific input parameters defining the job. The input parameters can be in the form of inputting instructions through the display, inputting positions, measured by the construction vehicle itself, uploading of design files and others. After programming a task, the task will be defined well enough for the autonomous task module to perform the task.

Mission supervisor: The mission supervisor module has the task of breaking down the overall mission into subtasks which the construction vehicle can perform. The mission planner module will do this in a continuous manner based on input from sensors.

Task execution: The system is able to execute a variety of specific tasks, provided by the mission planner. This could be the task of moving the construction vehicle from point A to point B, loading a bucket with material, or offloading a bucket of material. Each task can be viewed independently of the next or previous task.

Display: The display takes care of visualizing data to the user, but also takes user input and sends it to the control box. The display will display navigational data to the operator for use in navigation mode and semiautomatic mode but can act as the main user interface for setting up job tasks for autonomous mode.

To aid the operator while in navigation mode the display has several key user elements which characterize a navigation system for construction vehicles.

• Visualization of design surface and side references from design

• Visualization of logged points and surfaces

• Visualization of the construction vehicle in relation to loaded design and logged points/surfaces

• Cut/Fill values indicating to the operator if the tool needs to move up or down at specific tool points of the tool, to reach the desired surface. Cut/fill values can be represented both with numerical values, colours and arrows pointing in different directions

• Side distance values indicating to the operator the distance to specific side reference elements. Side reference elements can be either logged points/lines or points/lines from design. Direction and distance to side references can be represented both with numerical values, colours and arrows pointing in different directions.

• Sound - Cut/fill values and side references might also be represented through different sound patterns, such that it is possible for the operator to navigate without looking at the display, but by hearing different sound patterns or tones

• Section views displaying the tool from either the side or the back, showing the surface as a cut along an axis going through a specified point on the construction vehicle or on a tool of the construction vehicle.

• Cross slope, indicating the slope of the tool towards the ground plane. Cross slope can be represented both with numerical values, colours and arrows pointing in different directions.

• Through interaction with the touchscreen of the display it is also possible for the operator to log points or initiate surface logs as as- built. Typically, this will be a predefined point (tool point) on the construction vehicle, and when the log point button is pressed, the current absolute position of the tool point is stored and available for later use and analysis. Logging of points can also be triggered by physical buttons on the display itself or by buttons or other triggers communicatively connected to the display. In an embodiment, the control box and the display constitute the same single physical unit.

In an embodiment, the display can be a remote device, such as a mobile phone, with an application or a webservice being an integral part of the system.

In an embodiment, the display can be a multiple screen device, some serving as presentation screen and the other as an input user interface to the system.

Summary of the invention

The object of the present invention can be achieved by a control system as defined in claim 1, a construction vehicle as defined in claim 19 and a method as defined in claim 20. Preferred embodiments are defined in the dependent subclaims, explained in the following description, and illustrated in the accompanying drawings.

The control system according to the invention is a control system configured to be arranged and used on a construction vehicle, wherein the control system comprises: a control unit, a navigation system configured to provide 3D navigation guidance to a user of the control system, a display communicatively connected to the control unit, sensors mounted on the construction vehicle, wherein the control unit is communicatively connected to the construction vehicle in such a manner that the control unit is configured to control the movements of the construction vehicle, wherein the control unit is arranged and configured to process data from the sensors and instructions from a user provided by means of the display, wherein the control system is configured to be operated in:

- a manual mode, in which the construction vehicle is operated manually while the navigation system provides 3D navigation guidance to the user by means of the display and

- an autonomous mode, in which the construction vehicle is fully controlled by the control system, wherein the display comprises a mode selection key, by which the user can select the mode in which the construction vehicle has to be operated, wherein the control system is configured to enable the user to configure a design by using the display, wherein the control system is configured to determine and show a cut/fill value to a configured design through the display.

Hereby, the user can be assisted by operating the construction vehicle in an autonomous mode and at the same time the user can apply the control system as a 3D navigation system when the user operates the construction vehicle in the manual mode (takes over manual control of the construction vehicle).

The control system is configured to be arranged and used on an autonomous construction vehicle.

The sensors may include IMU sensors and one or more GNSS antenna.

The sensors may include any type of sensors that capable of detecting distance, angle, or position. In principle any suitable sensor technology can be applied.

The mode selection key may be a physical button (e.g. a knob) or a part of a touch screen. The mode selection key may alternatively be provided as a voice-based device configured to detect a spoken sentence from the user.

In an embodiment, the control system is configured to be operated in a semi-automatic mode (also referred to as semi-autonomous), in which the construction vehicle is partly operated manually, and partly operated autonomously by means of the control system. Operation in this mode may be advantageous if part of a task can be carried out autonomously and part of the task needs the user to operate the construction manually.

In an embodiment, the control unit comprises several either physical or digital modules each being arranged and configured to carry out a specific action.

In an embodiment, the control unit comprises a positioning module.

In an embodiment, the control unit comprises a kinematic module.

In an embodiment, the control unit comprises a safety module.

In an embodiment, the control unit comprises a vision module.

In an embodiment, the control unit comprises a mission program module.

In an embodiment, the control unit comprises a mission supervisor module.

In an embodiment, the control unit comprises a task execution module.

In an embodiment, the control unit comprises a mission supervisor module that is configured to be controlled by interacting with the display.

In an embodiment, the control system is configured to enable the user to configure a design by using the display.

It is an advantage that the control system is configured to enable the user to configure a design by using the display, wherein the control system is configured to determine and show a cut/fill value to a configured design through the display. A configured design is a design as defined. The design will typically be configured/defined by a user.

In an embodiment, the control system comprises a sound generator configured to generate a sound signal and hereby signal a value to the operator.

In an embodiment, the value is the cut/fill value.

In an embodiment, the control unit is configured to calculate the cut/fill value as a predefined and/or user entered height from a predefined point on the construction vehicle to a current side reference.

In an embodiment, the control unit is configured, preferably by means of the display, to enable the user to offset the cut/fill value with a vertical height offset which is added to the cut/fill value.

In an embodiment, the display is configured to indicate a horizontal distance from a configured point on the construction vehicle to a vector by means of the display.

In an embodiment, the display is configured to indicate a horizontal distance from a configured point on the construction vehicle to a configured side reference by means of the display.

In an embodiment, the configured point on the construction vehicle is selectable in the display as a focus point.

In an embodiment, the control system is configured to automatically select the configured side reference as the closest side reference of all selectable side references, wherein the display preferably is configured to enable the user to select the configured side reference by means of the display. It may be an advantage that the sound generator is configured to generate a sound signal and hereby signal the displayed side reference vector to the user.

In an embodiment, the display is configured to calculate and show a cross slope at a desired point on the construction vehicle.

In an embodiment, the control system is configured to trigger logging of as-built data through interaction with the display, or buttons communicatively connected to the display, wherein the logged as-built data is preferably calculated on the basis of the currently selected focus point.

In an embodiment, the display is arranged and configured to enable the user to load one or more design files by interacting with the display.

Accordingly, the one or more design files can be used for side references and cut/fill values.

In an embodiment, the control system is configured to carry out a coordinate transformation of the loaded design, and the control system is configured to enable the user to select or change a coordinate transformation by means of the display.

In an embodiment, the control system is configured to calculate an overview of the design and visualise on the display the design, a graphical representation of the construction vehicle and preferably as- built data.

In an embodiment, the control system is configured to allow the user to zoom in and out to change the extent of the area shown on the display.

In an embodiment, the display has different interface configurations that are selectable through interaction with the display, or buttons communicatively connected to the display, wherein the display preferably is configured to receive instructions via the display and hereby define a new user interface configuration, wherein the display preferably is configured to allow the user to change the user interface configuration by a touch gesture on the display.

The construction vehicle according to the invention is a construction vehicle that comprises a control system according to the invention.

The method according to the invention is a method for operating a construction vehicle by means of a control system that comprises: a control unit, navigation system configured to provide 3D navigation guidance to a user of the control system, a display communicatively connected to the control unit, sensors mounted on the construction vehicle, wherein the control unit is communicatively connected to the construction vehicle in such a manner that the control unit is configured to control the movements of the construction vehicle, wherein the control unit is arranged and configured to process data from the sensors and instructions from a user provided by means of the display, wherein the method comprises the step of by using the display setting the mode of operation to: a manual mode, in which the construction vehicle is operated manually while the navigation system provides 3D navigation guidance to the user by means of the display or an autonomous mode, in which the construction vehicle is fully controlled by the control system, wherein the display comprises a mode selection key, by which the use can select the mode in which the construction vehicle has to be operated.

Hereby, the method makes operation of the construction vehicle more user-friendly. In an embodiment, the method comprises the step of setting the mode of operation to a semi-automatic mode, in which the construction vehicle is partly operated manually, and partly operated autonomously by means of the control system.

Description of the Drawings

The invention will become more fully understood from the detailed description given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:

Fig. 1 shows a schematic side view of a construction vehicle (a backhoe) according to the invention;

Fig. 2 shows a schematic side view of a construction vehicle (a skid steer) according to the invention;

Fig. 3 shows an overview of the components of a construction vehicle (a skid steer) according to the invention

Fig. 4 shows a user interface display of a control system according to the invention in a first configuration;

Fig. 5 shows a user interface display of a control system according to the invention in a second configuration;

Fig. 6 shows a user interface display of a control system according to the invention in a third configuration;

Fig. 7 shows a user interface display of a control system according to the invention in a fourth configuration;

Fig. 8 shows a flow chart indicating how the control system according to the invention can be used;

Fig. 9 shows a user interface display of a control system according to the invention in an autonomous mode and

Fig. 10 shows a user interface display of a control system according to the invention in a manual mode.

Detailed description of the Invention

Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, a construction vehicle 4 of the present invention is illustrated in Fig. 1.

Fig. 1 is a schematic side view of a construction vehicle 4 according to the invention. The construction vehicle 2 is a backhoe that is provided with a control system 2 according to the invention. The control system 2 enables the user to operate the construction vehicle 2 in a manual mode and in an autonomous mode. In the autonomous mode, the construction vehicle 2 can perform one or more working tasks such as drilling a hole, spreading gravel, loading a container by way of example.

Fig. 2 illustrates a schematic side view of another construction vehicle 2 according to the invention. The construction vehicle 2 is a skid steer provided with continuous tracks 18. The construction vehicle 2 comprises a control system 2 according to the invention. Accordingly, by using the control system 2, the operator (user) can operate the construction vehicle 2 in either a manual mode or an autonomous mode. In a preferred embodiment, the control system 2 comprises a user interface comprising one or more structures (e.g. a touch screen, a button or a key), by which the operator can select between the manual mode and the anonymous mode. In an embodiment, the user interface is a user interface display.

Fig. 3 illustrates an overview of the components of a construction vehicle 4 (a skid steer) and a control system according to the invention. The construction vehicle 4 corresponds to the one shown in and explained with reference to Fig. 2.

The control system 2 comprises at least one IMU sensor 8 that is attached to the bucket 20 of the construction vehicle 4. Accordingly, the IMU sensor 8 can collect kinematic data for the bucket 20. In an embodiment, the control system 2 comprises several IMU sensors 8 that are attached to the bucket 20 of the construction vehicle 4. The control system 2 comprises at least one IMU sensor 8' that is attached to the arm 22 of the construction vehicle 4. Accordingly, the IMU sensor 8' can collect kinematic data for the arm 22. In an embodiment, the control system 2 comprises several IMU sensors 8' that are attached to the arm 22 of the construction vehicle 4.

The control system 2 comprises at least one IMU sensor 8" that is attached to the body 24 of the construction vehicle 4. Accordingly, the IMU sensor 8" can collect kinematic data for the body 24. In an embodiment, the control system 2 comprises several IMU sensors 8" that are attached to the body 24 of the construction vehicle 4.

The IMU sensors 8, 8', 8" are communicatively connected to a control unit of the control system 2. In an embodiment, the control unit is integrated in or electrically connected to a display 6. In a preferred embodiment, the control system 2 comprises a user interface display 6 that comprises a control unit that is communicatively connected to the IMU sensors 8, 8', 8". Hereby, the IMU sensors 8, 8', 8" can send the collected data to the control unit.

In a preferred embodiment, the control system 2 comprises a user interface display 6 that comprises or is electrically or communicatively connected to a control unit that is configured to process data received from the IMU sensors 8, 8', 8".

The control system 2 comprises a 3-D laser scanning sensor 10 (also known as a 3D LIDAR sensor). Hereby, the control system 2 can provide a high accuracy long-range (e.g. up to 100 m) laser 3D scanning. Thus, the control system 2 can capture objects in the surroundings of the construction vehicle 4.

The 3-D laser scanning sensor 10 is communicatively connected to a control unit of the control system 2. Hereby, the control system 2 can receive and directly or indirectly process data from the 3-D laser scanning sensor 10.

The control system 2 comprises at least one global navigation satellite system (GNSS) antenna 12. Hereby, the control system 2 can provide information about location, speed, direction, and nearby points of interest. Thus the control system 2 can use the data to calculate and ensure that the construction vehicle 4 can automatically move along a predefined path.

The GNSS antenna 12 is communicatively connected to a control unit of the control system 2. Hereby, the control system 2 can receive and directly or indirectly process data from the at least one GNSS antenna 12.

In an embodiment, the control system 2 comprises a control box (GNSS receiver) 14 configured to be electrically connected to the at least one GNSS antenna 12. In an embodiment, the control system 2 comprises several GNSS antennas 12.

In an embodiment, the control box 14 constitutes the control unit of the control system 2. In an embodiment, the control box 14 is communicatively connected to a control unit of the control system 2.

The control system 2 comprises an electric-to-hydraulic valve block 16 that is configured to control the hydraulic system of the construction vehicle 4. The control unit of the control system 2 is electrically connected to and configured to control the electric-to-hydraulic valve block 16.

Fig. 4 illustrates a user interface display 6 of a control system according to the invention in a first configuration. The user interface display 6 comprises an area 26 showing a 3D visualization of a construction vehicle 4 seen from above. The user interface display 6 moreover comprises a number of information panels 28, 30, 32 arranged in the upper portion of the display 6. The leftmost information panel 28 indicates the vertical position of the left side of the bucket of the construction vehicle 4. The rightmost information panel 32, however, indicates the vertical position of the right side of the bucket of the construction vehicle 4. The information panel 30, on the other hand, indicates the horizontal distance to a predefined indication line.

The user interface display 6 comprises a side panel 24 provided in the right side of the display 6. The side panel 24 includes buttons or keys that can be activated or selected by the user. The buttons or keys may be part of a touch screen. The lowermost key is a mode selection key 34, by which the user can select the mode of operation. In Fig. 4, the construction vehicle 4 is operated in an autonomous mode. This is indicated by the letter A.

Fig. 5 illustrates a user interface display 6 of a control system according to the invention in a second configuration. The user interface display 6 comprises an area 26 showing two 3D visualizations of the bucket 20 of a construction vehicle seen from behind and from the right side, respectively. Just like the user interface display 6 shown in Fig. 4, the display 6 comprises a plurality of information panels 28, 30, 32 arranged in the upper portion of the display 6. The leftmost information panel 28 indicates the vertical position of the left side of the bucket of the construction vehicle 4. The rightmost information panel 32, however, indicates the vertical position of the right side of the bucket of the construction vehicle 4, while the information panel 30 indicates the horizontal distance to a predefined indication line.

The user interface display 6 is equipped with a side panel 24 provided in the right side of the display 6. The side panel 24 comprises buttons or keys that are configured to be used by the user. The buttons or keys may be part of a touch screen. The lowermost key is a mode selection key 34, by which the user can select the mode of operation. In Fig. 5, the construction vehicle 4 is operated in a manual mode. This is indicated by the letter M.

Fig. 6 illustrates a user interface display 6 of a control system according to the invention in a third configuration. The user interface display 6 comprises an area 26 showing two 3D visualizations of a construction vehicle 4 seen from above. A selected job type is indicated. It can be seen that the construction vehicle 4 has to make a rectangular frame with a zigzag pattern.

The user interface display 6 comprises a main top panel 36 indicating that the job type can be selected. Although it is not shown, it is possible to show a number of predefined tasks (job types), from which the user may select. In the right side of the display 6 a plurality of panels are provided. Each of these panels represent one parameter that the user may specify. The uppermost panel indicates if the job should be conducted with or without navigation positions assistance (with or without GPS).

The second panel from the top says "Surface design file" and gives the user the option of selecting or specifying a predefined surface design file from a list.

The third panel from the top says "Flat surface" and represents the option of specifying the characteristics of the surface (flat, inclined or curved by way of example).

The fourth panel from the top says "Slope" and allows the user to set the slope of a surface to be created.

The fifth panel from the top says "Height to point/line" and allows the user to set a height to a predefined line or point.

The user interface display 6 is equipped with a mode selection key 34.

The mode selection key 34 is positioned in the upper right corner of the display 6. The mode selection key 34 is configured to be used by the user to select the mode of operation. In Fig. 6, the construction vehicle 4 is operated in an autonomous mode. This is indicated by the letter A.

Fig. 7 illustrates a user interface display 6 of a control system according to the invention in a fourth configuration. The user interface display 6 corresponds to the one shown in and explained with reference to Fig. 6. A mode selection key 34 is positioned in the upper right corner of the display 6. The mode selection key 34 is configured to be used by the user to select the mode of operation. In Fig. 7, the construction vehicle 4 is operated in a manual mode. This is indicated by the letter M.

Fig. 8 illustrates a flow chart indicating how the control system according to the invention can be used. In the first step I, the control system is turned on in order to start the control system.

In the second step II, the operator/user selects the type of job to be performed. The job type may by way of example be: a) drilling a hole, b) collecting or spreading gravel or c) loading or emptying a container.

The job type may preferably be selected by using a user interface display 6 as shown in Fig. 4, Fig. 5, Fig. 6 or Fig. 7.

When the job type is selected, the user can in a third step III select which mode the vehicle should be operated in. In an embodiment, the user can select between two modes of operation: a) Manual mode M, in which the vehicle is operated manually, with guidance from the navigation system of the control system according to the invention or b) Autonomous mode, in which the vehicle is fully controlled by a control system. In an embodiment, the user can select between three modes of operation: a) Manual mode M, in which the vehicle is operated manually, with guidance from the navigation system of the control system according to the invention; b) Autonomous mode A, in which the vehicle is fully controlled by the control system or c) Semi-automatic mode S, in which the vehicle is partly operated manually, and partly by the control system.

The mode of operation is preferably selected by using a user interface display 6 as shown in Fig. 4, Fig. 5, Fig. 6 or Fig. 7.

In the fourth step IV, the operator/user initiates the work. This is done by using a user interface display 6 as shown in Fig. 4, Fig. 5, Fig. 6 or Fig. 7. In practice, the user input on the user interface display 6 generates electric control signals that are fed to an electric-to-hydraulic valve block (like the one illustrated in Fig. 3). The electric-to-hydraulic valve block controls the hydraulic system of the construction vehicle 4. The control unit of the control system is electrically connected to and configured to control the electric-to-hydraulic valve block.

During the work process, one or more IMU sensors, a 3-D laser scanning sensor and a GNSS antenna like the ones shown in and explained with reference to Fig. 3 are used to provide data. This data is used by the control unit of the control system in order to carry out the work as intended. The data may for instance be used to secure that the construction vehicle moves along a predefined path and that the bucket of the construction vehicle engages the ground when being positioned in the optimum position.

Eventually the process stops in the fifth step V. In an embodiment, the control unit of the control system is configured to automatically determine when the job has been successfully carried out and hereby automatically stop the construction vehicle.

Fig. 9 illustrates a user interface display 6 of a control system according to the invention in an autonomous mode and Fig. 10 illustrates a user interface display of a control system according to the invention in a manual mode. The user interface display 6 basically corresponds to the one shown in and explained with reference to Fig. 5.

List of reference numerals

2 Control system

4 Construction vehicle

6 Display (e.g. user interface display)

8, 8', 8" Inertial Measurement Units (IMU) sensor

10 3-D laser scanning sensor (3D LIDAR sensor)

12 Global navigation satellite system (GNSS) antenna

14 Control box (GNSS receiver)

16 Electric to hydraulic valve block

18 Continuous track

20 Bucket

22 Arm

24 Body

26 Area

28 Panel

30 Panel

32 Panel

34 Mode selection key

36 Main top panel

M Manual mode

A Autonomous mode

S Semi-automatic mode