Scraper, system and method for moving earth

Abstract

The invention relates to a scraper (10) which includes - a frame (12) including a first end (14) and a second end (16), - a load space (18) attached to the frame (12), - a scraper blade (17) for collecting earth from the ground into the load space (18), - a pusher plate (15) for the load space (18) for expelling earth from the load space (18), - a hatch (19) of the load space (18) for closing the load space (18), - wheels (22) for supporting the frame (12) on a substrate (200), - a power unit (26) for transmitting power to the wheels (22) for moving the scraper (10). The power unit (26) in the scraper (10) includes - a battery pack (30) that can be attached in a detachable manner to the power unit (26) for the changing of the battery pack (30), and - an electric motor (32) for driving the wheels (22) of the scraper (10) using the current supplied by the battery pack (30), and the scraper (10) further includes - an autonomous guidance system (38) for automatically guiding the scraper (10) according to a pre-selected plan, wherein the guidance system (38) includes geopositioning means (40) for geopositioning the scraper (10) and at least two sensor units (42) pointing in opposite directions relative to each other. The invention also relates to a system and to a method for moving earth.

Description

[0001] SCRAPER, SYSTEM AND METHOD FOR MOVING EARTH

[0002] The invention relates to a scraper which includes

[0003] - a frame including a first end and a second end,

[0004] - a load space attached to the frame for earth that is loaded on board the scraper,

[0005] - a scraper blade for collecting earth from the ground into the load space,

[0006] - a pusher plate for the load space for expelling earth from the load space,

[0007] - a hatch of the load space for closing the load space,

[0008] - wheels for supporting the frame on a substrate, and

[0009] - a power unit for transmitting power to the wheels for moving the scraper, wherein the scraper is self-propelled in such a manner that the scraper is configured to move by itself using the power unit of the scraper.

[0010] The invention also relates to a system and to a method for moving earth.

[0011] A scraper or scraper tractor is a heavy-duty, wheeled work machine used for moving earth. Scrapers can be utilized in work stages in excavation, farming and mining operations. The scraper blade of the scraper scrapes earth from the surface of the ground into the load space on board the scraper as the scraper moves forward on the wheels. After scraping, the load space can be closed and the earth can be transported to another location, where the scraped earth can be discharged from the load space and spread onto the ground surface as a thin layer. Scrapers are used in particular in North America east of the Rocky Mountains, where the terrain is flat and the earth does not contain large stones, so that the soft earth is very suitable for scraping. The scraper can also be used in other locations and for scraping different types of earth. The economic advantage of scrapers over excavators, for example, is highlighted in situations in which the moving of earth can be carried out more quickly using scrapers. With a scraper, earth can be collected quickly into the load space by means of the scraper blade, moved to another location in the load space and spread out from the load space, which yields the advantage that all work stages can be carried out with one and the same work machine .

[0012] Self-propelled and towed scrapers are known in the prior art. The scrapers according to the prior art include an internal combustion engine, so that there is the problem of a high fuel consumption and harmful emissions into the atmosphere. The scrapers according to the prior art also require an operator on board the scraper to operate the scraper.

[0013] A scraper according to the prior art is known from patent publication US 9951497 B2.

[0014] An object of the invention is to provide an improved scraper, system and method with which carbon dioxide emissions are lower and the use of which in a work situation requires fewer manhours than to date. The characteristic features of a scraper according to the invention are indicated in the attached claim 1, the characteristic features of a system according to the invention are indicated in the attached claim 16, and the characteristic features of a method according to the invention are indicated in the attached claim 18.

[0015] The scraper according to the invention includes a frame including a first end and a second end, a load space attached to the frame for earth that is loaded on board the scraper, a scraper blade for collecting earth from the ground into the load space, a pusher plate for the load space for expelling earth from the load space, a hatch of the load space for closing the load space, wheels for supporting the frame on a substrate, and a power unit for transmitting power to the wheels for moving the scraper, wherein the scraper is self-propelled in such a manner that the scraper is configured to move by itself using the power unit of the scraper. The power unit in the scraper includes a battery pack for supplying the power unit with electric current and an electric motor for driving the wheels of the scraper using the current supplied by the battery pack, and the scraper further includes an autonomous guidance system for automatically guiding the scraper according to a pre-selected plan, wherein the guidance system includes geopositioning means for geopositioning the scraper for an autonomous guidance and at least two sensor units pointing in opposite directions relative to each other for a positioning of the scraper that occurs with a precision of 0.1 - 10 cm, preferably 1 - 5 cm, also in connection with a collecting and spreading of earth.

[0016] In other words, emissions of the electrically powered scraper are zero or low compared to scrapers that use an internal combustion engine, and the scraper is autonomous, i.e. selfdriving, by virtue of its guidance system. As it is electrically powered, the scraper does not produce carbon dioxide emissions in the manner of an internal combustion engine and is very well suited for use, for example, in situations where noise and exhaust fumes are a problem. The autonomous guidance reduces the need for the presence of a human, and the scraper can be configured to operate in a work area without a single human being present. The self-propelled scraper can move around in the work area without a separate towing vehicle and is also considerably shorter in length than the combination of a towed scraper and a towing vehicle, so that the self-propelled scraper is considerably more agile. The load space is also located in the same vehicle as the power unit of the vehicle in a self-propelled scraper, so that the traction of the scraper in a loaded state is improved by the mass of the load, whereas in the case of a towed scraper the mass of the load has the opposite effect.

[0017] The use of two sensor units allows the scraper to be positioned with precision in the situations required by the different work stages, which is exceptional. The autonomous guidance of a scraper according to the invention is based on the use of both geographic data obtained through the geopositioning means and environmental data obtained with the sensor units, so that it is not necessary for the scraper, for example, to follow other implements or devices. A collision avoidance system of the scraper by means of which collisions with objects in the environment are avoided is advantageously implemented using the sensor units .

[0018] Preferably, the battery pack can be attached in a detachable manner to the power unit for the changing of the battery pack. The scraper can thus have multiple batteries, if necessary, which can be changed as required.

[0019] Preferably, the frame includes a front frame and a rear frame attached to the front frame by means of a vertical articulated joint, and the scraper includes steering means arranged between the front frame and the rear frame for an articulated steering of the scraper. As a result of the articulated steering, the scraper has a small turning radius, which facilitates a turning of the scraper in confined spaces. The use of an articulated steering further facilitates a suspension of the wheels, as the wheels do not need to be pivotable, a turning of the scraper instead occurring by means of the articulated steering. The implementation of pivotable wheels in a preferable size class of a scraper is very challenging and expensive.

[0020] Preferably, the power unit is arranged on the front frame and the load space is arranged on the rear frame, or vice versa. This distributes the weight of the scraper more evenly when there is earth to be transported in the load space, so that the power unit and the earth form a balanced whole.

[0021] Preferably, the electric motor is a hub motor. In particular a hub motor is particularly advantageous for use in connection with an electric transfer vehicle, as it transmits power directly to a drive wheel without a separate transmission. This renders the structure more energy efficient and simpler, thus reducing the number of parts that require servicing.

[0022] Preferably, the electric motor is a hub motor and one hub motor is arranged on each wheel of the rear frame. Force is thus transmitted via the rear frame, so that traction is better than in an apparatus designed to be towed from the front.

[0023] Preferably, the sensor unit is a laser scanner or lidar. A laser scanner, also known as a light radar, can be used to scan the environment in order to detect potential obstacles, as well as for a precise positioning of a scraper, for example in order to change the battery pack. A laser scanner allows a very large amount of data regarding the environment to be formed as a three-dimensional point cloud, which can be used, for example, for shape recognition in order to detect obstacles.

[0024] According to one embodiment, 4-6 laser scanners, preferably 5 laser scanners, are provided to map the environment of the scraper. The environment of the scraper can thereby be mapped in its entirety, which is important for an autonomous guidance, so that collisions with particular objects in the environment, such as, for example, other work machines, can be avoided.

[0025] Preferably, the guidance system includes an artificial intelligence (Al) unit that is configured to make a decision regarding a stopping of the autonomously guided scraper based on user-generated guidance rules and a guidance plan entered into the guidance system and using the data generated by the sensor units. By means of the Al unit, it is possible to effectively avoid collisions in a changing environment in which there are other moving objects.

[0026] Preferably, the Al unit is configured to carry out a preselected plan for guiding the transfer vehicle based on usergenerated guidance rules and a guidance plan entered into the guidance system and using the data generated by the sensor units .

[0027] In addition to or instead of data generated by the geopositioning means of the scraper, it is also possible to use, for example, data generated by a top-level guidance system of the work area as input for the Al unit. A top-level guidance system can be configured to guide all scrapers and other work machines in the work area and contains data relating to their movements and positions. This data can be used in the Al unit of the scraper to avoid collisions.

[0028] According to one embodiment, a height of the load space from the substrate is configured to be adjustable by means of lifting means. The load space can thereby be lowered closer to the substrate in an earth-collection stage, so that the scraper can be arranged so as to collect earth into the load space more efficiently . According to one embodiment, the lifting means includes a supporting arm with a first end and a second end, wherein the first end is attached in an articulated manner to a wheel, and wherein the second end is attached in an articulated manner to the frame, a height-adjustment cylinder with a first end and a second end, wherein the first end is attached in an articulated manner to the frame, a damping element with a first end and a second end, wherein the first end is attached in an articulated manner to the first end of the supporting arm, a linking element with a first support point, a second support point and a third support point, wherein the second end of the height-ad ustment cylinder is attached in an articulated manner to the first support point of the linking element, the second end of the damping element is attached in an articulated manner to the second support point of the linking element, and the linking element is attached in an articulated manner by the third support point to the supporting arm. In other words, a height of the load space can be adjusted by means of an adjustable suspension of the wheels. This type of suspension makes it possible to lower the load space closer to the substrate, so that the scraper can be arranged so as to collect earth into the load space more efficiently.

[0029] Preferably, the scraper includes a spreader plate, actuators for adjusting a height and an inclination of the spreader plate, and a control system for operating the actuators. The scraper can thus level the earth to be spread so that it forms an even layer, so that a separate bulldozer or other work machine used for levelling is not needed.

[0030] Preferably, the control system for controlling the spreader plate includes geopositioning means for geopositioning the spreader plate. The spreader plate can thus be arranged so as to level the earth to a selected height and inclination at a selected location.

[0031] The spreader plate can be arranged on the frame of the scraper, preferably behind the rear wheels. A pressure can thereby be generated on the spreader plate by the mass of the scraper for levelling earth and it is advantageously not necessary to drive over earth that has been levelled with the spreader plate with the wheels .

[0032] Preferably, the spreader plate includes at least two satellite geopositioning antennas arranged on the ends of the spreader plate. Positional data is thus obtained for both ends of the spreader plate, so that the position and the angle of inclination of the entire spreader plate are known.

[0033] The spreader plate can include a gyroscope. This is an alternative option that allows data to be obtained regarding an angle of inclination of the spreader plate.

[0034] Preferably, the actuators include at least two hydraulic lifting cylinders for lifting the spreader plate. A height and an inclination of the spreader plate can thereby be adjusted.

[0035] The spreader plate described in the foregoing with all its features is independent of the rest of the structure of the scraper. The spreader plate described herein can consequently be arranged on a scraper which is self-propelled or towed, equipped with an electric motor or an internal combustion engine, or which is autonomous or manned.

[0036] Preferably, the scraper includes a pushing bumper arranged on the frame on the rear part of the scraper. The pushing bumper is configured to be structurally strong enough to allow the scraper to be pushed using the pushing bumper in a selected work stage by another work machine such as, for example, another scraper. It is thereby possible to increase a thrust for a selected work stage.

[0037] Preferably, the load space is configured to be tiltable with respect to a pivot point. The scraper can thereby be arranged to collect earth into the load space.

[0038] A system for moving earth according to the invention includes at least one scraper as described in the foregoing, at least two identical battery packs of the scraper, a charging station for charging a battery pack of the scraper, wherein the scraper is configured to use the battery packs alternately. The scraper can thereby be kept in operation almost continuously with only a short interruption in the operation of the scraper caused by the changing of a battery pack.

[0039] Preferably, the system includes a satellite geopositioning station for generating a geopositioning corrective signal in order to improve a precision of the geopositioning means of the scraper. The scraper can thereby be guided in a work area with a greater precision than to date.

[0040] In a method for moving earth according to the invention, work is performed using at least one scraper described in the foregoing, at least two detachable battery packs are employed alternately in connection with the scraper, each battery pack is charged in turns at a charging station, the charge of the battery pack being used by the scraper is monitored remotely, and the guidance system of the scraper is configured to schedule a changing of the battery pack at the charging station in such a manner that the charge of the battery pack being used by the scraper is 10 % - 35 %, preferably 20 % - 30 %, when the scraper arrives at the charging station. The scraper can thus be kept in operation nearly continuously and the service life of the battery packs can be extended by always keeping the battery packs within an optimum range of operation while the battery packs are not allowed to run down.

[0041] According to one embodiment, energy can be discharged from the battery packs by means of a separate transformer unit for a rapid charging of other equipment, e.g. mining vehicles or other work machines, which can require an MW-class charging power .

[0042] The invention, which is not limited to the embodiments described in the following, is explained in more detail with reference to the attached figures, wherein

[0043] Figure 1 shows the design of a scraper according to the invention from a first perspective,

[0044] Figure 2 shows the design of a scraper according to the invention from a second perspective,

[0045] Figure 3 shows the design of a scraper according to the invention from a third perspective,

[0046] Figure 4 shows the design of another scraper according to the invention,

[0047] Figures 5a-5c show side views of work stages of a scraper according to the invention,

[0048] Figures 6a-6b show the design of the front frame of a scraper according to the invention,

[0049] Figure 7 shows the design of the suspension of a wheel of the rear frame of a scraper according to the invention,

[0050] Figure 8 schematically shows a scraper according to the invention arranged to change a battery pack, Figure 9 schematically shows a scraper according to the invention configured to work along a route defined by pre-set route points in a work area.

[0051] Figures 1 - 3 show the design of a scraper 10 according to the invention from different perspectives. The scraper 10 includes a frame 12, which is preferably formed of two parts, namely a front frame 44 and a rear frame 48 attached in an articulated manner to the front frame 44 by means of a vertical articulated joint 46. The frame 12 is supported on the substrate by means of wheels 22. Preferably, a power unit 26 is arranged on the front frame 44, which power unit 26 is powered by a battery pack 30 attached to the power unit 26 in a detachable manner. Connected to the power unit 26 is an electric motor 32, which drives the drive wheels 22 of the scraper 10, which are preferably at least the wheels 22 of the rear frame 48 of the scraper 10. It is also possible for all wheels 22 of the scraper 10 to be drive wheels. Preferably, the power unit 26 includes components connected to the electric power transmission of the scraper 10, such as an inverter, a battery-pack control unit (Battery Management System, BMS) and power electronics by means of which the electrical energy stored in the battery pack 30 can be utilized by the electric motor 32. The power electronics can include, inter alia, current-regulating elements, voltage transformers and controllers by means of which the transfer of power from the battery pack 30 to the electric motor 32 can be regulated and controlled. The scraper 10 is self-propelled, i.e. the scraper 10 is configured to move by itself by means of the power unit 26 of the scraper 10 in such a manner that the amount of energy contained in the battery pack 30 and the power of the electric motor 32 are configured to move the scraper 10 without a separate towing vehicle. The power transmission of the scraper 10 can be an electric hybrid power transmission, which enables a transfer of electric power without the use of drive shafts, which saves space by its compact design. The power transmission preferably includes the option of reducing the speed of the scraper 10 while charging the battery pack 30 of the scraper 10. Two hub motors arranged in connection with the wheels of the rear frame are preferably employed as the electric motors. A planetary gearing is also preferably employed in connection with the hub motors in order to adapt the speed of the power transmission so as to be appropriate for an intended use. A power of the hub motors can be, for example, respectively 220 kW, with which a torque of approximately 1600 Nm is obtained. The power transmission can also encompass hub motors by means of which power is transmitted to the wheels 22 of the front frame 44. The rear frame 48 can include one or two or even more pairs of wheels 22, of which one or two or more pairs can be drive wheels.

[0052] The battery packs 30 can be formed by, for example, LiFePCE or NMC battery technology in which the capacity of a single battery pack 30 can be 200-600 kWh. In this case, for example, 280 kW DC generators can be used for charging. A detachment and attachment of a battery pack 30 of the scraper 10 can be automated by means of quick couplings 66 with a design analogous to the quick-coupling mechanisms of excavators, as shown in Figures 6a and 6b. As illustrated in Figure 6a, the quick couplings 66 preferably include lifting hooks 67, which are attached to the power unit 26 and which can be moved on guides by means of an actuator in a vertical direction, and complementary lifting elements 68 shown in Figure 6b, which are attached in a fixed manner to the battery pack 30. Preferably, the battery pack 30 and the power unit 26 both include contact connections 65 that form a contact between them when the battery pack 30 is lifted on board the scraper 10 by means of the quick couplings 66. The known solution disclosed in EP 3026004

[0053] Al can also be employed as quick couplings.

[0054] A load space 18 that can be used for moving earth is in turn formed in the rear frame 48 between the wheels 22. For the purpose of moving earth, the scraper 10 includes collecting means for collecting earth from the ground into the load space 18. The collecting means includes a scraper blade 17, which is formed at the edge of the floor of the load space 18. The load space 18 and the scraper blade 17 are located between the wheels 22, more specifically between the front wheels and the rear wheels. The floor of the load space 18 is tiltable at one end relative to a pivot shaft 143 so that the scraper blade 17 can be lowered by means of a hydraulic tilting cylinder 142 of the load space 18 essentially to the level of the substrate, so that earth can be collected from the surface of the ground into the load space 18 by scraping with the scraper blade 17. The load space 18 further includes a hatch 19 for closing the load space 18 and a pusher plate 15 for expelling earth from the load space 18, by means of which pusher plate 15 it is possible to change the volume of the load space 18. In order to move the hatch 19 of the load space 18, the scraper 10 includes a hydraulic cylinder 141 for the hatch 19 of the load space 18. In order to move the pusher plate 15 of the load space 18, the scraper 10 includes a hydraulic pushing cylinder 151 for the load space 18. The mechanical work stages of the scraper 10 will be described in greater detail later on with reference to Figures 5a - 5c.

[0055] The scraper 10 according to the invention also includes an autonomous guidance system 38, which is configured to guide the movements of the scraper 10 according to a predetermined program. Preferably, the autonomous guidance system 38 is a computer implemented by means of a computing unit and a memory 41, wherein the computer is preferably located in the front frame 44 of the scraper 10 in connection with the power unit 26. In addition to the computer, the autonomous guidance system 38 includes geopositioning means 40 for geopositioning the scraper 10 for an autonomous guidance and at least two sensor units 42 pointing in opposite directions relative to each other. The geopositioning means 40 enables the guidance system to detect the position of the scraper 10 on a map while the sensor units 42 enable the guidance system to perceive the environment of the scraper 10 with greater accuracy and to detect an orientation of the scraper 10. Using these, the scraper 10 is able to move in a work area with a precision of 1 - 10 cm, preferably 1 - 5 cm, which is a prerequisite for autonomous guidance.

[0056] Preferably, the guidance system is configured to receive preset guidance rules, for example from a central computer or the like at which a human operator has established guidance rules and a guidance plan, on the basis of which the computer of the autonomous guidance system autonomously guides the scraper 10 using the positional data provided by the geopositioning means 40 and the environmental data provided by the sensor units 42. The environmental data can be, for example, a point cloud set generated by laser scanners that form the sensor unit, from which point cloud set machine vision can be used to detect various objects, for example obstacles, through shape recognition. Preferably, the guidance system includes an Al unit, which is configured to make decisions regarding the guidance of the scraper 10 based on the data generated by the sensor units 41, the guidance rules and the guidance plan. For example, for a second scraper 10 detected from a point cloud set through shape recognition, the Al unit can determine from successive perceptions an expected trajectory of the second scraper 10, determine the trajectory of the scraper 10 in relation thereto, and make a decision whether the scraper 10 must be stopped to avoid a collision or whether it is possible to continue the motion according to the original guidance plan.

[0057] The autonomous guidance system 38 can be implemented using already existing systems, for example the Mobius® Autonomous Vehicle Control guidance system marketed by Autonomous Solutions Inc (ASI ) .

[0058] Figure 4 shows another embodiment of a scraper 10 according to the invention, which includes a spreader plate 80 arranged on the rear frame 48, more specifically behind the wheels 22 of the rear frame 48, i.e. behind the rear wheels. The purpose of the spreader plate 80 is to level earth expelled from the load space 18 to a selected height and angle of inclination. To this end, the lower edge of the spreader plate 80 is flat and the spreader plate 80 includes actuators for adjusting a height and an inclination of the spreader plate 80. The actuators here are two hydraulic lifting cylinders 82 for lifting the spreader plate 80, by means of which the spreader plate 80 is configured to be movable relative to the frame 12, more specifically relative the rear frame 48, with respect to a pivot point 81.

[0059] The spreader plate 80 further includes a control system for operating the actuators, wherein the control system includes geopositioning means 43 for geopositioning the spreader plate 80. Two satellite geopositioning antennas 51 arranged on each end of the spreader plate 80 are employed as geopositioning means 43 here. GPS can be primarily used as the geopositioning means 43, although it can also be implemented by means of some other known satellite geopositioning system such as, for example, Glonass, Galileo, Beidou, IRNSS, QZSS. In this case, the geopositioning means 43 can determine both the position of the spreader plate 80 in the work area and the height and the angle of inclination of the spreader plate 80. The scraper 10 can consequently be programmed to spread and level earth at a location according to selected coordinates and at a selected height and inclination autonomously.

[0060] In an alternative embodiment, the spreader plate 80 can include, instead of or in addition to a second satellite geopositioning antenna 51, a gyroscope for determining the inclination of the spreader plate 80.

[0061] The control system can include manual switches for operating the actuators of the spreader plate 80 manually based on readable positional data provided by the geopositioning means 43. The control system can also include a computer by means of which the control system is configured to receive pre-set control rules, for example from a central computer or the like at which a human operator has established control rules and a control plan, on the basis of which the computer of the autonomous control system autonomously controls the actuators of the spreader plate 80 using the positional data provided by the geopositioning means 43.

[0062] In Figure 4, a pushing bumper 90 is also arranged in connection with the spreader plate 80, via which pushing bumper 90 it is possible to provide additional traction for the performance of work by pushing with either a second scraper 10 or another work machine. The pushing bumper 90 can be attached to the frame 12 either directly or via the spreader plate 80.

[0063] Figures 5a- 5c show work stages of a scraper 10 according to the invention.

[0064] Figure 5a shows a driving position of the scraper 10. In the driving position, the rear frame 48, the load space 18 and a possible spreader plate 80 of the scraper 10 are in a raised position. A hatch 19 of the load space 18 is closed.

[0065] Figure 5b shows a collecting position of the scraper 10. In the collecting position, the hatch 19 of the load space 18 is open, the rear frame 48 and thus the load space 18 is lowered slightly by the lifting means 28 and the load space 18 is tilted by the tilting cylinders 142 of the load space 18 relative to the pivot shaft 143 in such a manner that the scraper blade 17 penetrates the substrate 200. The earth at the surface of the substrate 200 thereby starts to accumulate in the load space 18 as the scraper 10 is driven forward, i.e. to the right in Figure 5b.

[0066] Figure 5c shows a spreading position of the scraper 10. In the spreading position, the rear frame 48 is raised up, the load space 18 is tilted by the tilting cylinders 142 of the load space 18 so as to be inclined slightly downwards relative to the pivot shaft 143, and the hatch 19 of the load space 18 is open. The earth in the load space 18 is pushed out of the load space 18 through the hatch 19 by a pusher plate 15 operated by the pushing cylinder 151, and a possible spreader plate 80 located at the rear of the scraper 10 levels the spread earth to a desired height and angle of inclination.

[0067] The scraper 10 can be configured to switch between the operating modes, i.e. between the driving position, the collecting position and the spreading position, according to the positional data provided by the geopositioning means 40.

[0068] Preferably, the height of the load space 18 from the substrate 200 can be adjusted by the lifting means 28, although a height adjustment is not an obligatory feature, as the collecting position can also be implemented by simply tilting the load space 18 relative to the pivot shaft 143. One way of implementing a height adjustment of the load space 18 of the scraper 10 between the operating modes, i.e. a design with lifting means 28, is described with reference to Figure 7. Figure 7 shows the suspension of the wheels 22 of the rear frame 48 of the scraper 10. Another possible implementation is disclosed in the patent application WO / 2022064104 Al of the Applicant, which discloses a solution using a kind of eccentric shaft. As shown in Figure 7, the wheels 22 of the scraper 10 are suspended in the rear frame 48 in such a manner that the suspension of the wheels 22 includes a supporting arm 160 with a first end 161 and a second end 162. The wheel 22 is attached in an articulated manner to the first end 161 of the supporting arm 160, and the second end 162 is attached in an articulated manner to the frame 12, more precisely to the rear frame 48. The suspension further includes a height-ad ustment cylinder 170 with a first end 171 and a second end 172, wherein the first end 171 is attached in an articulated manner to the frame 12. The suspension further includes a damping element 180 with a first end 181 and a second end 182, wherein the first end 181 is attached in an articulated manner to the first end 161 of the supporting arm 160. The suspension also includes a linking element 190 with a first support point 191, a second support point 192 and a third support point 193. The second end 172 of the height-adjustment cylinder 170 is attached in an articulated manner to the first support point 191 of the linking element 191, the second end 182 of the suspension element 180 is attached in an articulated manner to the second support point 192 of the linking element 190, and the linking element 190 is attached in an articulated manner by the third support point 193 to the supporting arm 160.

[0069] Preferably, the linking element 190 is attached in an articulated manner by the third support point 193 between the first end 161 and the second end 162 of the supporting arm 160, preferably to a central part of the supporting arm 160.

[0070] Preferably, the linking element 190 is triangular and each support point is located at each corner of the linking element 190. A triangular structure is very rigid.

[0071] The frame 12 can include an attachment element 195 with a first attachment point 196 and a second attachment point 197, and the first end 171 of the height-ad ustment cylinder 170 is attached in an articulated manner to the first attachment point 196, and the second end 162 of the supporting arm 160 is attached in an articulated manner to the second attachment point

[0072] 197.

[0073] The damping element 180 can be a mechanical, hydraulic or pneumatic element. Preferably, however, it is a hydraulic cylinder, as shown in Figure 7.

[0074] The height-adjustment cylinder 170 can be a hydraulic or pneumatic cylinder, but preferably it is likewise a hydraulic cylinder .

[0075] As shown in Figure 7, by means of the components of the suspension, preferably using a hydraulic motive force, it is possible for the load space 18 to be lowered downward in the collecting mode (Figure 5b) , so that the scraper blade 17 can penetrate the substrate 200 more effectively.

[0076] Figure 8 schematically shows a scraper 10 according to the invention configured to move along a route 74 defined by preset route points in a work area. The scraper 10 includes geopositioning means 40 for determining a position of the scraper 10 and a guidance system for guiding the scraper 10 based on positional data provided by the geopositioning means 40 and the route points 80 entered into the guidance system. The geopositioning means 40 here includes a satellite geopositioning device, which is in communication with satellites 97 in order to determine the position of the scraper 10.

[0077] The guidance system of the scraper 10 can utilize a separate satellite geopositioning station 100 for generating a geopositioning corrective signal in order to improve a precision of the geopositioning means 62 of the scraper 10. A position of the route points 74 and of the scraper 10 can thereby be determined with a precision of up to + / - 2 cm. A Real-Time Kinematic or RTK positioning is used here, which uses a carrier wave to determine a position. The satellite geopositioning station 100 is in communication with satellites 97 via a geopositioning antenna 95 and transmits the phase of the carrier wave to the geopositioning means of the scraper 10 via a transmitting antenna 96.

[0078] A CAD model created for the work area and based on either measured or calculated data, for example, can be used for the planning of the route points 74. The CAD model can incorporate existing and / or projected shapes of the surface. The projection can be based, for example, on a point cloud model obtained by laser scanning. For example, a flying device such as, for example, a drone, which includes a laser scanner can be used to create a point cloud model. By scanning with a laser scanner, it is possible to create a three-dimensional model that can be used to create a planned route 74 for the scraper 10. An optimal route for the scraper 10 can be generated advantageously using artificial intelligence, wherein the route includes data on differences in elevation of the ground surface by means of which route points from which earth is collected and route points at which the earth is spread out are planned for the route. The scraper 10 can be configured to collect more material from elevations of the ground surface and, conversely, to spread the collected earth in depressions of the ground surface, so that the extent of earth moving is ideally minimized, which reduces the number of trips a scraper 10 makes and consequently its working hours. The plan generated based on the point cloud model can be used to further control the position of the spreader plate 80 of the scraper 10 in such a manner that the earth spread is levelled to a selected height and inclination at a selected location.

[0079] More specifically, in the situation shown in Figure 8, the scraper 10 is configured to change a battery pack 30 autonomously. A charging station 56 is used to charge the battery packs 30 of the scraper 10. In addition, each battery pack 30 includes geopositioning means for determining the position and orientation of the battery pack 30, which geopositioning means can include satellite geopositioning means and / or a gyroscope. This is important for an autonomous operation, as the scraper 10 must approach the battery pack 30 from a certain direction in order to successfully attach the battery pack 30 to the front frame 44 of the scraper 10 owing to the design of the scraper 10 and the battery pack 30. In the system, the scraper 10 according to the invention is configured to move autonomously to the charging station 56 when the charge of the battery pack 30 runs low. Preferably, two battery packs 30 can be used for one scraper 10, so that the scraper 10 can operate continuously, except for during the changing of the battery pack 30, while one battery pack 30 is continuously being charged. In this case, the scraper 10 is thus configured to drive autonomously to the charging station 56, where the scraper 10 first disconnects the first battery pack 30 that it has been using and arranges this battery pack 30 for charging by plugging it into the charging station. The scraper 10 then hooks up the second battery pack 30 for use, which at this point is advantageously fully charged here. For this operation, the scraper 10 operates momentarily without a main battery pack 30; to make this possible, the scraper 10 includes a second, smaller battery pack, possibly arranged in an undetachable manner, which enables an interim operation of the scraper 10. Once the charged battery pack 30 has been hooked up, the scraper 10 can be configured to charge the smaller battery with the energy of the larger battery pack 30. A changing of the battery pack 30 can thus advantageously be implemented in the absence of a human being, although this is not an indispensable feature of the scraper 10 according to the invention, but rather it is also possible for the battery pack 30 to be changed manually by a human being.

[0080] The technology of the charging station 56 can be a technology for the charging of batteries known from the prior art, for example analogous to charging technology for electric cars.

[0081] The charging station 56 can also include, as an additional feature, a connection to a solar-panel or wind-power unit for charging the battery packs 30 of the scraper 10. This connection of the charging station 56 can also include means for supplying power from fully charged battery packs 30 of the scraper 10 via the charging stations 56 to a national or workarea network in order to balance load peaks. An analogous principle can also be employed, for example, in connection with the start-up of equipment of the work area, which causes a high peak in power consumption.

[0082] It is additionally possible to employ, for the guidance of the scraper 10, traffic-management software and hardware that include a route planning, scheduling and optimization, a collision-avoidance system and a digital positioning system for positioning movable vehicles. The traffic-management software and hardware enable an autonomous monitoring and guidance of the scraper 10.

[0083] Preferably, the scraper 10 according to the invention uses a satellite geopositioning system. For the determination of geographic data, the scraper 10 comprises geopositioning means 40, which are shown in Figure la. The geopositioning means preferably utilizes geographic data obtained from satellites 97, although, preferably, it can additionally use a local satellite geopositioning station 75, the exact location of which is known. The local satellite geopositioning station 75 transmits its precise geographic data via a local antenna 76 in the area to the scraper 10. Using both the local geographic data and the data obtained from satellites, the geopositioning means can determine its position with a precision of + / - 2 cm. GPS can be primarily used as the geopositioning means, although it can also be implemented by means of any other known satellite geopositioning system such as, for example, Glonass, Galileo, Beidou, IRNSS, QZSS.

[0084] An ultimate precision for an autonomous operation is achieved by means of the sensor units 42, which are preferably laser scanners 50. While the satellite geopositioning system allows the scraper 10 to be guided to, for example, a charging station 54, the exact position of which is known, an autonomous positioning of the scraper 10 can be achieved with a precision of 1 - 10 cm, preferably 1 - 5 cm, by using the additional data provided by the sensor units 42. Preferably, the scraper 10 has 4 - 6 laser scanners 52, preferably 5 laser scanners 52, for mapping the environment of the scraper 10. The scraper 10 according to the invention preferably comprises 5 laser scanners, so that the scraper 10 can be oriented with precision. Moreover, a sufficient number of laser scanners allows an environment of the scraper 10 to be mapped comprehensively enough so that collisions with the environment and other moving work machines can also be avoided in all circumstances. Preferably, the laser scanners are arranged at the corners of the scraper 10 so as to obtain the best coverage of the entire environment of the scraper 10.

[0085] Instead of laser scanners, the sensor units 42 can also be, for example, camera units utilizing machine vision, radar or other perception means suitable for this application.

[0086] Figure 9 schematically shows a scraper 10 according to the invention that is configured to move along a route 74 defined by pre-set route points 71, 72, 73 in a work area. This is possible as the scraper 10 includes geopositioning means 40 for determining a position of the scraper 10 and a guidance system for guiding the scraper 10 based on positional data provided by the geopositioning means 40 and the route points 71, 72, 73 entered into the guidance system. The scraper 10 can be configured, for example, to collect earth at selected route points 71 and then continue along selected route points 72 and to unload and level the collected earth at selected route points 73.

[0087] One system can include a scraper 10 according to any of the embodiments described in the foregoing, which includes a spreader plate 80, as well as other scrapers 20 which do not necessarily include a spreader plate. In this case, the scraper 10 equipped with the spreader plate 80 is configured to drive, in a selected work stage, over a selected work area last while spreading earth and to level the spread earth to a selected height and inclination with the spreader plate 80. In this case, all scrapers 10, 20 can be any scrapers according to the prior art, whether equipped with an internal combustion engine or an electric motor, whether manned or autonomous. The only thing that is essential in this case is that one scraper 10 includes a spreader plate 80 with its peripheral devices. The control system for controlling the spreader plate 80 can use a separate satellite geopositioning station 100 for generating a geopositioning corrective signal in order to improve a precision of the geopositioning means 43. A position and inclination of the spreader plate 80 can thereby be determined with a precision of up to + / - 2 cm. An RTK positioning can be used here, which uses a carrier wave to determine a position. The satellite geopositioning station 100 is in communication with satellites 97 via a geopositioning antenna 95 and transmits the phase of the carrier wave to the geopositioning means by means of the transmitting antenna 96.

Claims

CLAIMS1. A scraper (10) which includes- a frame (12) including a first end (14) and a second end (16) ,- a load space (18) attached to the frame (12) for earth that is loaded on board the scraper (10) ,- a scraper blade (17) for collecting earth from the ground into the load space (18) ,- a pusher plate (15) for the load space (18) for expelling earth from the load space (18) ,- a hatch (19) of the load space (18) for closing the load space (18) ,- wheels (22) for supporting the frame (12) on a substrate (200) , and- a power unit (26) for transmitting power to the wheels (22) for moving the scraper (10) , wherein the scraper (10) is self-propelled in such a manner that the scraper (10) is configured to move by itself using the power unit (26) of the scraper (10) , characterized in that the power unit (26) in the scraper (10) includes- a battery pack (30) for supplying the power unit (26) with electric current, and- an electric motor (32) for driving the wheels (22) of the scraper (10) by means of the current supplied by the battery pack (30) , and the scraper (10) further includes- an autonomous guidance system (38) for automatically guiding the scraper (10) according to a pre-selected plan, wherein the guidance system (38) includes geopositioning means (40) for geopositioning the scraper (10) for an autonomous guidance and at least two sensor units (42) pointing in opposite directions relative to each other for a positioning ofthe scraper (10) that occurs with a precision of 0.1 - 10 cm, preferably 1 - 5 cm, also in connection with a collecting and spreading of earth.

2. The scraper (10) according to claim 1, characterized in that the battery pack (30) can be attached in a detachable manner to the power unit (26) for the changing of the battery pack (30) .

3. The scraper (10) according to claim 1 or 2, characterized in that the frame (12) includes a front frame (44) and a rear frame (48) attached to the front frame (44) by means of a vertical articulated joint (46) , and the scraper (10) includes steering means arranged between the front frame (44) and the rear frame (48) for an articulated steering of the scraper (10) .

4. The scraper according to claim 3, characterized in that the power unit (26) is arranged on the front frame (44) and the load space (18) is arranged on the rear frame (48) , or vice versa.

5. The scraper according to any one of claims 1 - 4, characterized in that the electric motor (32) is a hub motor.

6. The scraper (10) according to any one of claims 3 - 5, characterized in that the electric motor (32) is a hub motor and one hub motor is arranged on each wheel (22) of the rear frame (48) .

7. The scraper according to any one of claims 1 - 6, characterized in that the sensor unit (42) is a laser scanner.

8. The scraper (10) according to claim 7, characterized in that 4 - 6 laser scanners (50) , preferably 5 laser scanners (50) , are provided to map the environment of the scraper (10) .

9. The scraper (10) according to any one of claims 1 - 8, characterized in that the guidance system (38) includes an artificial intelligence unit (29) that is configured to make a decision regarding a stopping of the autonomously guided scraper (10) based on user-generated guidance rules and a guidance plan entered into the guidance system (38) and using the data generated by the sensor units (42) .

10. The scraper according to any one of claims 1 - 8, characterized in that a height of the load space (18) from the substrate (200) is configured to be adjustable by means of lifting means (28) .

11. The scraper according to claim 10, characterized in that the lifting means (28) includes- a supporting arm (160) with a first end (161) and a second end (162) , wherein the first end (161) is attached in an articulated manner to a wheel (22) , and wherein the second end (162) is attached in an articulated manner to the frame (12) ,- a height-ad ustment cylinder (170) with a first end (171) and a second end (172) , wherein the first end (71) is attached in an articulated manner to the frame (12) ,- a damping element (180) with a first end (181) and a second end (182) , wherein the first end (181) is attached in an articulated manner to the first end (161) of the supporting arm (60) ,- a linking element (190) with a first support point (191) , a second support point (192) and a third support point (193) , wherein the second end (172) of the height-adjustment cylinder (170) is attached in an articulated manner to the first supportpoint (191) of the linking element (191) , the second end (182) of the damping element (180) is attached in an articulated manner to the second support point (192) of the linking element (190) , and the linking element (190) is attached in an articulated manner by the third support point (193) to the supporting arm (160) .

12. The scraper (10) according to any one of claims 1 - 11, characterized in that the scraper (10) includes a spreader plate (80) , actuators for adjusting a height and an inclination of the spreader plate (80) , and a control system for operating the actuators.

13. The scraper (10) according to claim 12, characterized in that the control system for controlling the spreader plate (80) includes geopositioning means (43) for geopositioning the spreader plate (80) .

14. The scraper (10) according to any one of claims 1 -13, characterized in that the scraper (10) includes a pushing bumper (90) arranged on the frame (12) on the rear part of the scraper (10) .

15. The scraper (10) according to any one of claims 1 -14, characterized in that the load space (18) is configured to be tiltable with respect to a pivot point (143) .

16. A system for moving earth, wherein the system includes- at least one scraper (10) according to any one of claims 1 -15,- at least two identical battery packs (30) of the scraper (10) ,- a charging station (56) for charging a battery pack (30) of the scraper (10) ,wherein the scraper (10) is configured to use the battery packs (30) in turns.

17. The system according to claim 16, characterized in that the system includes a satellite geopositioning station (100) for generating a geopositioning corrective signal to improve a precision of the geopositioning means (40) of the scraper (10) .

18. A method for moving earth, wherein in the method- work is performed using at least one scraper (10) according to any one of claims 1 - 15,- at least two detachable battery packs (30) are employed alternately in connection with the scraper (10) ,- each battery pack (30) is charged in turns at a charging station (56) ,- the charge of the battery pack (30) being used by the scraper (20) is monitored remotely, and the guidance system (38) of the scraper (10) is configured to schedule a changing of the battery pack (30) at the charging station (56) in such a manner that the charge of the battery pack (30) being used by the scraper (10) is 10 - 35%, preferably 20 - 30%, when the scraper (10) arrives at the charging station (56) .

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