EP4642664A1

EP4642664A1 - Method for determining a condition of a road

Info

Publication number: EP4642664A1
Application number: EP22843896.6A
Authority: EP
Inventors: Anders Lindkvist
Original assignee: Epiroc Rock Drills AB
Current assignee: Epiroc Rock Drills AB
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2025-11-05
Also published as: AU2022492439A1; WO2024144440A1

Abstract

Method performed by a control unit for determining a condition of a road (1) using a system comprising an electrically powered vehicle (10), a power line (20), a positioning system (30) for determining a geographical position of the vehicle (10), and a current collector assembly (11) having a distance sensor (12) for determining a vertical distance (h) between the vehicle (10) and the power line (20). The method comprises obtaining substantially simultaneously at each time point during a time period a first information on the vertical distance (h) between the vehicle (10) and the power line (20) by means of the distance sensor (12) and a second information on the geographical position of the vehicle (10) by means of the positioning system (30), wherein the first and the second information are processed as an information pair, analyzing the information pairs obtained during the time period, and determining the road condition based on the analysis result of information pairs obtained during the time period.

Description

METHOD FOR DETERMINING A CONDITION OF A ROAD

Technical field

[0001 ] The present disclosure relates generally to a method for determining a condition of a road. The method is performed by a control unit using a system which comprises an electrically powered vehicle, a power line, a current collector assembly and a positioning system wherein the current collector assembly comprises a distance sensor. The present disclosure further relates to a control unit configured to operate in an electrically powered vehicle and an electrically powered mining, constructions, or excavation vehicle.

Background art

[0002] Within mining industry as well as within road safety and other fields, different kind of methods are used to determine and predict when maintenance of the road must be performed. When the ground or the road is used frequently, potholes, bumps and washboard-like areas are developed and makes the road surface uneven. Further, rocks or stones may be dropped and left on the road in random positions along the road. These local irregularities may cause that the vehicle travelling on the road must decrease the speed, in order to maintain comfort and safety as well as minimizing wear of the vehicle. Further, the road may be worn down over time, obtaining a slope in an unwanted way, or the opposite, obtaining an unwanted build-up of material (gravel or the like) on the road surface, which means that the road deviates from a wanted slope or “design”. Some of these issues are not big problems above ground, but within mining industry and for vehicles operating below ground in the mine passages/corridors, this is a problem. Since electrical vehicles, which use a current collector assembly (including attachments, collector arm, connecting means etc.) and a power line for providing electrical power to the vehicle, is dependent on good contact between the power line and the current collector, the distance between the vehicle and the power line must be kept within a certain range to be able to have contact between the power line and the current collector mounted on the vehicle. The power line is normally mounted at a determined distance from the ceiling or wall of the mine passage, and the distance between the road surface, i.e. , the vehicle moving along the road, and the power line thereby is crucial. There is no known method for detecting local objects on the ground, potholes, bumps, wear and unwanted conditions of the road, for determining whether a road must be maintained, for a system comprising an electrically powered vehicle, a power line and a current collector assembly.

[0003] Thus, there is a need for a method for determining a condition of a road, using such system.

Summary of disclosure

[0004] It is an object of the disclosure to address at least some of the problems and issues outlined above. An object of embodiments of the present disclosure is to provide a method for determine a condition of a road, a control unit and an electrically powered vehicle as defined in the attached independent claims.

[0005] According to one aspect, a method performed by a control unit for determining a condition of a road is disclosed. The method is performed by the control unit using a system which comprises an electrically powered vehicle, a power line arranged along the road, and a positioning system for determining a geographical position of the vehicle. The vehicle preferably is an electrically powered mining, constructions or excavation vehicle. The positioning system may be a satellite-based communication system, such as Global Positioning System (GPS), or a ground-based positioning system. In the latter, a mobile communication network based on any known cellular technology such as GSM, 3^rd Generation (3G), Long-Term Evolution (LTE), e.g., 4^th Generation (4G) or 5^th Generation (5G) wireless communication network may be used-. The vehicle comprises communication means for receiving information regarding its position from the positioning system. The system further comprises a current collector assembly, which is securely arranged to the vehicle, and which electrically connects the vehicle with the power line. By that, the electrically powered vehicle is provided with electrical power for its operation. The current collector assembly is in resilient connection to the power line and has a connecting means for keeping the current collector assembly in contact with the power line so that a bearing force between the current collector assembly and the power line is substantially constant as the vehicle moves along the road. The current collector assembly is arranged to increase and decrease its length/height and may have different designs, for example pantograph or other design, well-known in the field. The power line may for example be in the form of a wire, a rigid or flexible rail or the like, and the connecting means may comprise a spring arrangement, an actuator, or the like, which is arranged to make sure that the current collector assembly is in contact with the power line at a substantially constant force, by a pushing force in direction towards the power line such that a contact part of the current collector assembly contacts the power line, independent of the distance between the vehicle and the power line. The connecting means may also be some kind of holding arrangement which instead of a pushing force instead holds the power line. By that, at least a contact part of the current collector assembly “follows” the power line and the current collector assembly expands or de-expands to maintain contact at a substantially constant force. The current collector assembly comprises a distance sensor, which is arranged for determining a vertical distance between the electrically powered vehicle and the power line.

[0006] The method comprises:

- obtaining substantially simultaneously at each time point during a time period a first information on the vertical distance between the vehicle and the power line by means of the distance sensor and a second information on the geographical position of the vehicle by means of the positioning system, wherein the first and the second information are processed as an information pair,

- analyzing the information pairs obtained during the time period, and

- determining the road condition based on the analysis result of information pairs obtained during the time period.

[0007] Such a method solves the problem of determining where a local deviation of the road surface is positioned, i.e. where the distance between the vehicle and the power line changes or deviates from a wanted distance which is preset or in some way pre-determined as an ideal distance. For example, when the vehicle moves along the road and runs over a stone, a bump or into a pothole, the information of the position of the vehicle together with the information of the distance between the vehicle and the power line, is analyzed and may be used for deciding whether the road needs to be maintained in some way. For example, when one or several local potholes are determined, a maintenance operation may be performed at that specific position or along a distance, if the information states a need along a longer distance of the road. Further, if the road along the mine passage is worn down over time, the information of the position and the distance between the power line and the vehicle, may be monitored over time, and maintenance of the road may be planned for a minimum of disturbance of the production of the mine etc.

[0008] According to an embodiment, when the vertical distance of the information pair is above a first threshold value or below a second threshold value, the second threshold value being lower than the first threshold value, the method comprises determining that the road needs to be maintained at the geographical position of the information pair. By that, the distance between the power line and the vehicle is set to be within a range within which the road does not need maintenance, but when the distance is outside the range, locally or over a distance, maintenance of the road should be initiated or planned or at least indicated the there is a need of maintenance of the road. The first threshold value is a limit value for a maximum distance between the electrically powered vehicle and the power line, which by that indicates if the road surface is at a too long distance from the power line, i.e. too low, wherein the road is determined as being worn down or comprises a pot hole or track formations. The second threshold value is a limit value for a minimum distance between the electrically powered vehicle and the power line, which by that indicates if the road surface is at a too short distance from the power line, wherein the road is determined as being too high, by that for example gravel and dirt is accumulated on the road surface.

[0009] According to an embodiment, when the vertical distances at a plurality of consecutive geographical positions of the obtained information pairs are above the first threshold value, the method comprises determining that the road needs to be maintained in a geographical area covering the consecutive geographical positions. By that, the analyzing of the information indicates that the road is worn down along the distance where the distance is above the first threshold value, wherein the road may be determined to be maintained along the consecutive geographical positions of the information pairs. The maintenance may for example be to add a layer of macadam, gravel or the like on top of the road surface to restore the road such that the distance between the road surface and the power line is within the limits, which is then indicated by the distance sensor of the current collector assembly mounted on the vehicle.

[0010] According to an embodiment, when the vertical distances at a plurality of consecutive geographical positions of the obtained information pairs are below the second threshold value, the method comprises determining that the road needs to be maintained in a geographical area covering the consecutive geographical positions. By that, the analyzing of the information indicates that the road has got a layer of gravel, rocks or the like along the distance where the distance is below the second threshold value, wherein the road may be determined to be maintained along the consecutive geographical positions of the information pairs. The maintenance may for example be to remove a layer of macadam, gravel or the like from the top of the road surface to restore the road such that the distance between the road surface and the power line is within the limits, which is then indicated by the distance sensor of the current collector assembly mounted on the vehicle.

[0011 ] According to an embodiment, when a difference between the vertical distances of two or more consecutive geographical positions of the obtained information pairs is above a third threshold value, determine that the road needs to be maintained in a geographical area covering the consecutive geographical positions. By that, local potholes, stones, rocks, bump etc. is positioned, wherein road maintenance may be determined, and the local irregularities fixed.

[0012] According to an embodiment, when the vertical distances at a plurality of consecutive geographical positions of the obtained information pairs present a regular or irregular oscillation during the time period, determining that the road needs to be maintained. By that, so-called washboard-like surface of the road may be positioned, wherein road maintenance may be performed along/at that position.

[0013] According to an embodiment, the method further comprises storing the obtained information pairs. This, to be monitored over time, to see and learn from the data, for planning of road maintenance, and to prevent wear which may vary along the road of for example a mine.

[0014] According to an embodiment, the method further comprises sending, wirelessly to a supervising system, the obtained information pairs for which it is determined that the road needs to be maintained.

[0015] According to an aspect, a control unit configured to operate in an electrically powered vehicle, and operative for determining a condition of a road, is disclosed. The control unit is configured to operative with a system comprising a power line, which is arranged along the road, and a current collector assembly, which is securely arranged to the vehicle and arranged to electrically connect the vehicle with the power line. The current collector assembly has a connecting means arranged for keeping the current collector assembly in contact with the power line so that a bearing force between the current collector assembly and the power line is substantially constant as the vehicle moves along the road. The current collector assembly has a distance sensor which is arranged for determining a vertical distance between the vehicle and the power line. Further, the control unit comprises a processing circuitry and a memory. Said memory contains instructions executable by said processing circuitry, whereby the control unit is operative for:

- obtaining, substantially simultaneously at each time point during a time period a first information on a vertical distance between the electrically powered vehicle and the power line by means of the distance sensor and a second information on a geographical position of the electrically powered vehicle by means of a positioning system, wherein the first and the second information are processed as an information pair,

- analyzing the information pairs obtained during the time period, and - determining the road condition based on the analysis result of information pairs obtained during the time period.

[0016] According to an embodiment, the control unit is operative for performing the method according to above.

[0017] According to an aspect, an electrically powered mining, constructions or excavation vehicle, is disclosed. The electrically powered vehicle may be a haul truck, a loader, a mining truck or any other type of vehicle suitable for mining or construction work. The electrically powered mining, constructions or excavation vehicle comprises a positioning system for determining a geographical position of the vehicle, a current collector assembly securely arranged to the vehicle and arranged to electrically connect the vehicle with a power line arranged along the road, wherein the current collector assembly is arranged to be in connection to the power line and has a connecting means for keeping the current collector assembly in contact with the power line so that a bearing force between the current collector assembly and the power line is substantially constant as the vehicle moves along the road. The current collector assembly comprises a distance sensor for determining a vertical distance between the vehicle and the power line, wherein the vehicle comprises a control unit according to above.

[0018] Such an electrically powered mining, constructions or excavation vehicle solves the problem of determining where a local deviation of the road surface is positioned, i.e. where the distance between the vehicle and the power line changes or deviates from a wanted distance which is preset or in some way predetermined as an ideal distance between the road surface and the power line. For example, when the vehicle moves along the road and runs over a stone, a bump or into a pothole, the information of the position of the vehicle together with the information of the distance between the vehicle and the power line, is analyzed and may be used for deciding whether the road needs to be maintained in some way. For example, when one or several local potholes are determined, a maintenance operation may be performed at that specific position or along a distance, if the information states a need along a longer distance of the road. Further, if the road along the mine passage is worn down over time, the information of the position and the distance between the power line and the vehicle, may be monitored over time, and maintenance of the road may be planned for a minimum of disturbance of the production of the mine etc. This is positive for the operation time of the vehicle, which may minimize the down-time for road maintenance as well as of ergonomic aspects for the driver of the vehicle, since a road in good condition contributes to the working environment of the driver as well as minimizes maintenance of the vehicle.

[0019] Further possible features and benefits of this solution will become apparent from the detailed description below.

Brief description of drawings

[0020] The disclosure is now described, by way of example, with reference to the accompanying drawings, in which:

[0021] Fig. 1 shows an example of an electrically powered vehicle for use in a mine.

[0022] Fig. 2 shows a schematic section along a mine passage and a front portion of the electrically powered vehicle of Fig. 1 , which is in contact with a power line arranged along the ceiling of the mine passage via a current collector assembly.

[0023] Fig. 3a shows a section across a mine passage with a power line installed at the ceiling of the mine passage and Fig. 3b shows a section across the mine passage and the electrically powered vehicle of Fig.1 , which is in contact with the power line via the current collector assembly.

[0024] Fig. 4a shows a schematic section along a mine passage showing a front portion of the electrically powered vehicle of Fig. 1 when in contact with a power line, via the current collector assembly, wherein a vertical distance between the vehicle and the power line is within vertical distance limits of a reach of the current collector assembly. [0025] Fig. 4b shows a similar schematic section as Fig. 4a, wherein a vertical distance between the vehicle and the power line is at a first threshold value, i.e. , a maximum limit value of the reach of the current collector assembly.

[0026] Fig. 4c shows a similar schematic section as Fig. 4a-b, wherein a vertical distance between the vehicle and the power line is at a second threshold value, i.e., a minimum limit value of the reach of the current collector assembly.

[0027] Fig. 5 shows a schematic figure of a control unit configured to operate in an electrically powered vehicle and operative for determining a condition of a road, according to the disclosure.

Description of embodiments

[0028] In the following, different embodiments are described of a method, a control unit and an electrically powered vehicle in which the present disclosure can be used or is incorporated in.

[0029] Fig. 1 shows an example of an electrically powered vehicle 10 for use in a mine. The electrically powered vehicle 10 comprises wheels 12, a chassis 13, an operator’s cabin 14, dump box 15, and other equipment (not visible) such as electrical motor, driving means, controls, control unit etc. For the driving and operation of the electrically powered vehicle, the vehicle 10 is to be supplied with electrical power, wherein the vehicle 10 comprises a current collector assembly 11 , which is arranged for “collecting” current from a power line 2, which is arranged along the road in the mine and above ground.

[0030] Fig. 2 shows a schematic section along a mine passage 200 where a front portion of the electrically powered vehicle 10 of Fig. 1 , when the vehicle 10 is driving along a road 1 , and wherein the current collector assembly 11 is in contact with a power line 20 arranged along the ceiling 201 of the mine passage 200 and along the road 1 . The current collector assembly 11 is securely arranged to the vehicle 10 at a fixation base 11a and the collector assembly 11 is arranged to electrically connect the vehicle 10 with the power line 20 and is in resilient connection to the power line 20. The current collector assembly 11 comprises connecting means 11b which are arranged for keeping the current collector assembly 11 in contact with the power line 20 so that a bearing force between the current collector assembly 11 and the power line 20 is substantially constant as the vehicle 10 moves along the road 1 . The connecting means 11 b of the current collector assembly 11 may be of different kinds depending on the type of power line 20. The power line 20 may for example be in the form of power lines or one or more power guide rails for example, wherein the current collector assembly 11 may comprise spring means or actuator means to make sure that the connecting means 11 b is “pushed” towards the power line 20 or power guide rail 20. In Fig. 2, an actuator 11c is visible, which thus is arranged to adjust the current collector assembly 11 such that the bearing force between the current collector assembly 11 and the power line 20 is substantially constant as the vehicle 10 moves along the road 1 . Another option may be that the connecting means 11 b grips around the power line/power guide rail 20 and thus, the current collector assembly 11 is arranged to “follow” the power line/rail 20 when the vehicle 10 moves along the road 1 .

[0031 ] The power line 20 is normally arranged at predetermined distance from the ceiling 201 of the mine passage 200, and the distance between a road surface 202 of the mine passage 200/the road 1 , and the power line 20 is to be within a determined range such that the distance between the power line 20 and the fixation base 11a of the current collector assembly 11 (i.e. the vehicle, since the fixation base is arranged at the vehicle) not exceeds the maximum reach/distance range of the current collector assembly 11 . The current collector assembly 11 is arranged to be lowered or raised depending on the distance between the fixation base 11a and the power line 20, for example by pivoting a round one or more pivot points and/or by expansion and retraction of the current collector assembly 11 . Since the road 1 , on which the vehicle 10 moves along, may be worn down, incline in different directions, get potholes or bumps and even get a higher road surface due to that material like gravel or is deposited on the road surface 202, the distance between the power line 20 and the road surface 202 (and thus the vehicle 10), the current collector assembly 11 needs to be raised or lowered relative the vehicle 10. It should be mentioned that the power line 20 may be arranged on the wall of the mine passage 200, wherein the current collector assembly 11 may be arranged differently compared to the figures, but in a similar way, cooperate with the current collector assembly 11 .

[0032] Fig. 3a shows a section across the mine passage 200 of Fig. 2 with the power line 20 installed at the ceiling 201 of the mine passage 200, and a dotted line indicating the vehicle 10. Fig. 3b shows the same section as in Fig. 3a, but with the electrically powered vehicle of Fig.1 in contact with the power line 20. The power line 20 is in the figures symbolically exemplified with two parallel power lines 20 hanging from the ceiling 201 in a bracket 21 , at a predetermined distance from the ceiling 201 . An ideal vertical distance between the power line/lines 20 and the road surface 202 is given by vehicle 10 and the current collector assembly 11 arranged on it (see Fig. 3b), such that the current collector assembly 11 may operate within its range (reaching range) such that the vehicle 10 may continuously, without interruption, be provided with power. An actual vertical distance h is determined as a vertical distance between the fixation base 11a of the current collector assembly 11 , which is fixedly arranged on the vehicle. The vertical distance h may instead be a distance between the top of the vehicle 10 and the power line 20 or for example a distance between an optional point of the current collector assembly 11 and the power line 20. The current collector assembly 11 comprises a distance sensor 12 arranged somewhere along the same. The distance sensor 12 is arranged to determine the actual vertical distance h between the vehicle 10 and the power line 20, which is possible since the position of the distance sensor 12 on the current collector assembly 11 is known, and since the distance sensor 112 is arranged to sense the position of the current collector assembly 11 or parts of it, i.e. , how much it is extracted or retraced. This may for example be a sensor arrangement 12, which is arranged to sense how much the current collector assembly 11 is extracted or retraced, or a vision sensor sensing the physical vertical distance between the top of/or a determined position of the vehicle and the power line, or any other sensor arrangement, arranged for in some way determine the actual is extracted or retraced distance h. This will be further explained below. [0033] Fig. 4a-c shows schematic sections along the mine passage and showing a front portion of the electrically powered vehicle 10 of Fig. 1 , when in contact with the power line 20, via the current collector assembly 11. A positioning system 30 is symbolically shown as a mast comprising one or more antennas for wireless communication. The positioning system may be or utilize for example a satellite-based positioning system or a ground-based communication system. The vehicle 10 comprises communication means for wirelessly communicating with the positioning system 30, a control unit and all such arrangements necessary for determine the position the geographical position of the vehicle 10 in the mine and for processing the information of the position as well as the information of the vertical distance h between the power line 20 and the vehicle 10. When in a mine, the communication means of the vehicle may communicate via base stations of a wireless communication network. The base stations are spread out in the mine in order to be able to provide the vehicle with wireless connection to the wireless communication network. The position of the individual base stations may be logged and communicated to the control unit, the control unit may use the information of the position of the individual base stations and information of to which base station it is connected to determine its position, or to obtain information of its position from the wireless communication network. When the communication means of the vehicle is in reach of three or more base stations, triangulation can be used to determine its position.

[0034] In Fig. 4a, the vertical distance h between the vehicle 10 and the power line 20 is within a wanted range of the current collector assembly 11 arranged on the vehicle 10. The range is predetermined such that the actual vertical distance h which is measured/determined by the distance sensor 12, should be between a first threshold value hi and a second threshold value h2, i.e., h2^ h < hi, wherein when the actual vertical distance h is within this range, the road is okay and does not need to be maintained. The vertical distance h may be the distance between the power line and any determined point of the vehicle 10 (like indicated in the figures), or any determined point of the current collector assembly 11 , or any determined point of the distance sensor 12 etc., of importance is that the distance sensor 12 may be able to determine in which position the current collector assembly 11 is. The road 1 with its road surface 202 showed in Fig. 4a is not worn down or comprises any bumps or potholes or the like, which indicates that the road 1 does not need to be maintained at the geographical position in which the electrically powered vehicle 10 is situated at the moment (which is a position the positioning system 30 has information of). By that, the vertical distance h is within a predetermined range.

[0035] Fig. 4b shows a similar schematic section as Fig. 4a, wherein the vertical distance h between the vehicle 10 and the power line 20 is at the first threshold value hi, which is determined as the maximum value of the vertical distance h, which indicates one limit of the range as explained above, within which the road does not need maintenance. The road 1 with its road surface 202 is in Fig. 4b worn down along a short distance, and if the road 1 is worn down a bit more, the actual vertical distance h will exceed the first threshold value hi which indicates that the road 1 needs to be maintained at the geographical position in which the electrically powered vehicle 10 is positioned at the moment, and which position is detected/determined by the positioning system 30.

[0036] Fig. 4c shows a similar schematic section as Fig. 4a-b, wherein the vertical distance h between the vehicle 10 and the power line 20 is at a second threshold value h2, which is determined as a minimum value of the vertical distance h, and which indicates the other limit of the range as explained above, within which range the road does not need maintenance. The road 1 with its road surface 202 is in Fig. 4c not worn down but instead comprises a local hill, gravel deposit or the like, along a short distance, and if gravel or the like gets further deposited on the road surface 202, the actual vertical distance h will decrease even further, and the second threshold value h2 will be passed, which indicates that the road 1 needs to be maintained at the geographical position in which the electrically powered vehicle 10 is positioned at the moment, and which position is detected/determined by the positioning system 30. As indicated by Figs. 4a-c, the vertical distance h may change along the road 1 , but as long as the vertical distance h is within the predetermined or wanted range of the current collector assembly 11 , there is no need of maintenance of the road 1 . Local deviations may be allowed and the information may be treated in any way, to decide if act or not act, plan the maintenance or wait another time period etc. Other types of irregularities like “washboard-pattern”, unwanted slopes or inclines may also be discovered and acted on based on the information pairs and the analyze of the same.

[0037] When the electrically powered vehicle 10 moves along the road 1 , the position of the vehicle 10 in the mine is as mentioned known by the communication with the positioning system 30. Where local deviations or irregularities of the road surface 202 is registered by the monitoring of the vertical distance h between the vehicle 10 and the power line 20, i.e. where the distance between the vehicle 10 and the power line 20 changes or deviates from a wanted distance range as explained above, which is preset or in some way predetermined as an ideal range of the distance, the position is registered and the information pairs/information data is analyzed to determine the road condition and the need of maintenance. Thus, when the vehicle 10 moves along the road 1 and runs over a stone, a bump or into a pothole, the information of the position of the vehicle 10 together with the information of the vertical distance h between the vehicle 10 and the power line 20, is analyzed and may be used for deciding whether the road 1 needs to be maintained in some way. For example, when one or several local potholes are determined, a maintenance operation may be performed at that specific position or along a distance, if the information states a need along a longer distance of the road 1 . Further, if the road along the mine passage is worn down over time, the information of the position and the distance between the power line 20 and the vehicle 10, may be monitored over time, and maintenance of the road 1 may be planned for a minimum of disturbance of the production of the mine. The inventive method comprises obtaining substantially simultaneously at each time point during a time period a first information on the vertical distance h between the vehicle 10 and the power line 20 by means of the distance sensor 12 and a second information on the geographical position of the vehicle 10 by means of the positioning system 30, wherein the first and the second information are processed as an information pair. The method further comprises analyzing the information pairs obtained during the time period and determining the road condition based on the analysis result of information pairs obtained during the time period.

[0038] Fig. 5 shows the control unit 100 of according to the disclosure. The control unit 100 comprises processing circuitry 101. The control unit 100 further comprises a memory 102. The memory 102 containing instructions executable by the processing circuitry 101 , whereby the control unit 100 is operative for performing any of the embodiments of the method for determining a condition of a road using a system comprising an electrically powered vehicle, a power line arranged along the road, and a positioning system for determining a geographical position of the vehicle. The embodiments of the method being described in this disclosure.

[0039] According to other embodiments, the control unit 100 may further comprise a communication unit 104. The communication unit 104 may be considered to comprise conventional means for communication with a supervising system, such as a transmitter for wirelessly sending the determined information pairs. The communication unit 104 may also comprise conventional means for obtaining the information on the position of the vehicle from a positioning system, such as a receiver for wireless communication. The instructions executable by the processing circuitry 101 may be arranged as a computer program 103 stored in said memory 102. The processing circuitry 101 may comprise one or more programmable processor, application-specific integrated circuits, field programmable gate arrays or combinations of these adapted to execute instructions.

[0040] The computer program 103 may be arranged such that when its instructions are run in the processing circuitry, they cause the control unit 100 to perform the steps described in any of the described embodiments of the method for determining the condition of the road along which the electrically powered vehicle operates. The computer program 103 may be carried by a computer program product connectable to the processing circuitry 101. The computer program product may be the memory 102, or at least arranged in the memory. The memory 102 may be realized as for example a Random-access memory (RAM), Read-Only Memory (ROM) or an Electrical Erasable Programmable ROM (EEPROM).

[0041] Although the description above contains a plurality of specificities, these should not be construed as limiting the scope of the concept described herein but as merely providing illustrations of some exemplifying embodiments of the described concept. It will be appreciated that the scope of the presently described concept fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the presently described concept is accordingly not to be limited. Reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." All structural and functional equivalents to the elements of the abovedescribed embodiments that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed hereby. Moreover, it is not necessary for an apparatus or method to address each and every problem sought to be solved by the presently described concept, for it to be encompassed hereby. In the figures, a broken line generally signifies that the feature within the broken line is optional.

Claims

1 . A method performed by a control unit for determining a condition of a road (1 ) using a system comprising: an electrically powered vehicle (10), a power line (20) arranged along the road (1 ), a positioning system (30) for determining a geographical position of the vehicle (10), and a current collector assembly (11 ) securely arranged to the vehicle (10) and electrically connecting the vehicle (10) with the power line (20), the current collector assembly (11) is in resilient connection to the power line (20) and having a connecting means (11 b) for keeping the current collector assembly (11 ) in contact with the power line (20) so that a bearing force between the current collector assembly (11) and the power line (20) is substantially constant as the vehicle (10) moves along the road (1), wherein the current collector assembly (11) has a distance sensor (12) for determining a vertical distance (h) between the vehicle (10) and the power line (20), the method comprising: obtaining substantially simultaneously at each time point during a time period a first information on the vertical distance (h) between the vehicle (10) and the power line (20) by means of the distance sensor (12) and a second information on the geographical position of the vehicle (10) by means of the positioning system (30), wherein the first and the second information are processed as an information pair, analyzing the information pairs obtained during the time period, and determining the road condition based on the analysis result of information pairs obtained during the time period.

2. Method according to claim 1 , wherein when the vertical distance (h) of the information pair is above a first threshold value (hi) or below a second threshold value (h2), the second threshold value (h2) being lower than the first threshold value (hi ), determining that the road (1 ) needs to be maintained at the geographical position of the information pair.

3. Method according to claim 2, wherein when the vertical distances (h) at a plurality of consecutive geographical positions of the obtained information pairs are above the first threshold value (hi ), determining that the road (10) needs to be maintained in a geographical area covering the consecutive geographical positions.

4. Method according to claim 2, wherein: when the vertical distances (h) at a plurality of consecutive geographical positions of the obtained information pairs are below the second threshold value (h2), determining that the road (10) needs to be maintained in a geographical area covering the consecutive geographical positions.

5. Method according to any of the previous claims, wherein when a difference (d) between the vertical distances (h) of two or more consecutive geographical positions of the obtained information pairs is above a third threshold value (hs), determine that the road (1) needs to be maintained in a geographical area covering the consecutive geographical positions.

6. Method according to claim 1 , wherein when the vertical distances (h) at a plurality of consecutive geographical positions of the obtained information pairs present a regular or irregular oscillation during the time period, determining that the road (1 ) needs to be maintained.

7. Method according to any of the previous claims, wherein the method further comprising: storing the obtained information pairs.

8. Method according to any of the previous claims, wherein the method further comprising: sending, wirelessly to a supervising system, the obtained information pairs for which it is determined that the road (1 ) needs to be maintained.

9. A control unit (100) configured to operate in an electrically powered vehicle (10), and operative for determining a condition of a road (1 ), wherein a power line (20) is arranged along the road (1 ) and a current collector assembly (11 ) is securely arranged to the vehicle (10) and electrically connecting the vehicle (10) with the power line (20), the current collector assembly (11 ) is arranged to be in connection to the power line (20) and having a connecting means (11 b) for keeping the current collector assembly (11 ) in contact with the power line (20) so that a bearing force between the current collector assembly (11 ) and the power line (20) is substantially constant as the vehicle moves along the road (1 ), wherein the current collector assembly (11 ) has a distance sensor (12) for determining a vertical distance (h) between the vehicle (10) and the power line (20), and there is a positioning system (30) for determining the geographical position of the vehicle (10), wherein the control unit (100) comprises a processing circuitry (101) and a memory (102), said memory containing instructions executable by said processing circuitry (101 ), whereby the control unit (100) is operative for: obtaining, substantially simultaneously at each time point during a time period a first information on the vertical distance (h) between the vehicle (10) and the power line (20) by means of the distance sensor (12) and a second information on the geographical position of the vehicle (10) by means of the positioning system (30), wherein the first and the second information are processed as an information pair, analyzing the information pairs obtained during the time period, and determining the road condition based on the analysis result of information pairs obtained during the time period.

10. The control unit (100) according to claim 9, operative for performing the method of any of claims 2-8.

11. An electrically powered mining, constructions or excavation vehicle (10), comprising a positioning system (30) for determining a geographical position of the vehicle (10), a current collector assembly (11 ) securely arranged to the vehicle (10) and arranged to electrically connect the vehicle (10) with a power line (20) arranged along the road (1 ), wherein the current collector assembly (11 ) is arranged to be in connection to the power line (20) and having a connecting means (11 b) for keeping the current collector assembly (11 ) in contact with the power line (20) so that a bearing force between the current collector assembly (11 ) and the power line (20) is substantially constant as the vehicle (10) moves along the road (1 ), wherein the current collector assembly (11 ) comprises a distance sensor (12) for determining a vertical distance (h) between the vehicle (10) and the power line (20), wherein the vehicle comprises a control unit (100) according to any of claims 9-10.