Road construction machine and management system

Abstract

To provide a road construction machine capable of suppressing a decrease in construction accuracy.SOLUTION: A road construction machine equipped with a tractor comprises a control device that estimates a current position of the road construction machine and a steering device that steers the tractor based on the current position. The control device is configured to output information regarding the amount of data available for estimating the current position.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to road machinery and a management system.

Background Art

[0002] Conventionally, an asphalt finisher has been known, which includes a tractor, a hopper installed in front of the tractor for receiving paving material, a conveyor for conveying the paving material in the hopper to the rear side of the tractor, a screw for spreading the paving material conveyed by the conveyor in the vehicle width direction on the rear side of the tractor, and a screed for leveling the paving material spread by the screw on the rear side of the screw.

[0003] For example, Patent Document 1 discloses a road paving machine including a paving screed, a GNSS receiver, and an electronic control system, which determines the current position of the road paving machine by the GNSS receiver, automatically controls the compaction performance of the paving screed as a function of the target layer thickness, and paves the paving material with each previous compaction degree.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the road paving machine described in Patent Document 1, when the estimation accuracy of the current position decreases, the construction accuracy may decrease.

[0006] One aspect of the present disclosure aims to provide a road machine capable of suppressing a decrease in construction accuracy.

Means for Solving the Problems

[0007] A road machine according to an aspect of the present disclosure is a road machine including a tractor, and includes a control device that estimates the current position of the road machine, and a steering device that steers the tractor based on the current position. The control device is configured to output information regarding the amount of data available for estimating the current position.

Advantages of the Invention

[0008] According to an aspect of the present disclosure, since the estimation accuracy of the current position can be easily known, a decrease in construction accuracy can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0010] Hereinafter, each embodiment of the present disclosure will be described with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] [Embodiment] One embodiment of the present disclosure is a management system that manages an asphalt finisher, which is an example of a road machine. The asphalt finisher according to this embodiment has an automatic paving function that automatically paves a road surface while performing automatic steering of a tractor and automatic expansion and contraction of a screed.

[0012] In the automatic paving function of the asphalt finisher, it is important to accurately estimate the current position of the vehicle. The controller of the asphalt finisher estimates the current position on the road surface to be constructed based on the positioning data obtained by detecting the vehicle position with a surveying instrument, and realizes the automatic paving function by controlling the steering of the tractor or the expansion and contraction of the screed. Therefore, the estimation accuracy of the current position has a great influence on the construction accuracy.

[0013] The estimation accuracy of the current position depends on the state of the sensor for acquiring the positioning data. The sensors for acquiring the positioning data vary depending on the surveying instrument. Examples of the surveying instrument include a total station or a positioning satellite. Examples of the positioning satellite include GPS (Global Positioning System) or GNSS (Global Navigation Satellite System). When the surveying instrument is a total station, the sensor is a wireless communication device that receives a wireless signal transmitted from the total station. When the surveying instrument is a positioning satellite, the sensor is a radio receiver that receives a satellite signal transmitted from the positioning satellite.

[0014] The higher the estimation accuracy of the current position, the higher the reliability of the estimated current position. The reliability of the current position depends on the amount of positioning data available for estimating the current position. For example, when estimating the current position based on positioning data received from a total station, if the positioning data from the total station is interrupted, the reliability of the current position will decrease. Also, for example, when estimating the current position based on positioning data received from positioning satellites, the more communication-capable satellites there are, the higher the reliability of the current position.

[0015] On the other hand, conventional asphalt finishers have no measures to recover the reliability when the reliability of the current position decreases. Therefore, even when the reliability of the current position decreases, conventional asphalt finishers continue automatic paving based on the current position with low reliability. As a result, there is a risk that the construction accuracy will be low in the range where the reliability of the current position has decreased. On the other hand, if the asphalt finisher can notify that the reliability of the current position is decreasing, the operator can take measures to recover the reliability. Thus, there is a need for an asphalt finisher to have a function of notifying the reliability of the current position.

[0016] <Overall Configuration of the Management System> The overall configuration of the management system SYS according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing an example of the overall configuration of the management system according to the embodiment.

[0017] As shown in FIG. 1, the management system SYS according to the embodiment includes an asphalt finisher 100, a communication terminal 200, and a remote management device 300. The asphalt finisher 100 and the remote management device 300 are connected by a public network NT.

[0018] Further, the management system SYS may perform various settings related to the control of the asphalt finisher 100 at the communication terminal 200, for example, in response to an input from the user or automatically, and transmit them to the asphalt finisher 100. Thereby, various operations of the asphalt finisher 100 can be controlled or monitored from the communication terminal 200.

[0019] Also, the asphalt finisher 100 may transmit information indicating the current situation to one or more of the communication terminal 200 and the remote management device 300. Furthermore, the asphalt finisher 100 may transmit log information indicating the paving result of the road surface to one or more of the communication terminal 200 and the remote management device 300.

[0020] The remote management device 300 is a terminal provided for remotely managing the work site. For example, the remote management device 300 manages the construction status by storing the log information transmitted from the asphalt finisher 100.

[0021] The communication terminal 200 is, for example, a terminal possessed by a user who manages work at the work site or a user who is working at the work site. In this embodiment, the communication terminal 200 is a portable information terminal such as a smartphone or a tablet terminal. The communication terminal 200 receives image information representing the current construction status of the asphalt finisher 100 from the asphalt finisher 100 and displays it on a display device (for example, a liquid crystal panel). Thereby, the user who manages work at the work site can recognize the current construction status of the asphalt finisher 100.

[0022] The number of communication terminals 200 included in the management system SYS may be one or a plurality. Thereby, the management system SYS can provide information regarding the asphalt finisher 100 to a plurality of users who each use a plurality of communication terminals 200.

[0023] The asphalt finisher 100 included in the management system SYS may be one unit or a plurality of units. Thereby, the management system SYS can perform data collection, information provision to users based on the collected data, settings related to the control of the asphalt finisher 100, etc. for the asphalt finisher 100.

[0024] <Overview of Asphalt Finisher> The overview of the asphalt finisher 100, which is an example of the road machinery according to the embodiment, will be described with reference to FIGS. 2 to 4. FIG. 2 is a side view showing an example of the asphalt finisher according to the embodiment. FIG. 3 is a top view showing an example of the asphalt finisher according to the embodiment. FIG. 4 is a rear view showing an example of the asphalt finisher according to the embodiment.

[0025] As shown in FIGS. 2 to 4, the asphalt finisher 100 according to the embodiment mainly includes a tractor 1, a hopper 2, and a screed 3.

[0026] The tractor 1 is a mechanism for driving the asphalt finisher 100. In this embodiment, the tractor 1 rotates two or four wheels using a traveling hydraulic motor to move the asphalt finisher 100. The traveling hydraulic motor rotates by receiving the supply of hydraulic oil from a hydraulic pump driven by a prime mover such as a diesel engine. The two or four wheels may be replaced with crawlers.

[0027] The tractor 1 is equipped with a controller 50, an auxiliary storage device 51, a display device 60, a driver's seat 61, an information acquisition device 62, etc. Specifically, a cab including the display device 60 and the driver's seat 61 is installed at the rear part of the upper surface of the tractor 1, and the information acquisition device 62 is installed at the center of the front end of the upper surface of the tractor 1.

[0028] Hopper 2 is a mechanism for receiving paving materials. Examples of paving materials include asphalt mixtures and the like. In this embodiment, hopper 2 is configured to be openable and closable in the vehicle width direction by a hydraulic cylinder. The asphalt finisher 100 usually receives paving materials from the loading platform of a dump truck with hopper 2 fully open. Also, even when receiving paving materials from the loading platform of a dump truck, the asphalt finisher 100 continues traveling and construction while pushing the dump truck forward via a push roller. The paving materials received in hopper 2 are fed to the front side of screed 3 using conveyor CV and screw SC. When the paving materials in hopper 2 decrease, the asphalt finisher 100 closes hopper 2 and collects the paving materials near the inner wall of hopper 2 at the central part of hopper 2 so that conveyor CV can convey the paving materials to screed 3.

[0029] Conveyor CV is driven by a hydraulic motor that rotates upon receiving supply of hydraulic oil from a hydraulic pump. In this embodiment, conveyor CV is configured to send the paving materials in hopper 2 to the rear side of tractor 1 via a conveyance passage. The conveyance passage is a substantially rectangular parallelepiped-shaped space formed inside tractor 1 and has a substantially rectangular inlet that opens into hopper 2 at the front surface of tractor 1.

[0030] Screw SC is driven by a hydraulic motor that rotates upon receiving supply of hydraulic oil from a hydraulic pump. In this embodiment, screw SC includes a central screw, a left screw, and a right screw. The central screw is installed within the width of tractor 1. The left screw is connected to the left end of the central screw and is installed so as to protrude to the left from the width of tractor 1. The right screw is connected to the right end of the central screw and is installed so as to protrude to the right from the width of tractor 1.

[0031] The screed 3 is a mechanism for leveling the paving material. In this embodiment, the screed 3 is a floating screed towed by the tractor 1 and is connected to the tractor 1 via a leveling arm. In this embodiment, the screed 3 is configured to be vertically movable and telescopically extensible in the vehicle-width direction by a hydraulic cylinder. The width of the screed 3 is larger than that of the tractor 1 when extended in the vehicle-width direction.

[0032] In this embodiment, the screed 3 includes a main screed, a left telescopic screed, and a right telescopic screed. The left telescopic screed and the right telescopic screed are configured to be telescopically extensible in the vehicle-width direction. The left telescopic screed and the right telescopic screed that are telescopically extensible in the vehicle-width direction are arranged with an offset from each other in the traveling direction. Therefore, it can have a width (length in the vehicle-width direction) longer than when not offset, can extend longer in the vehicle-width direction, and can construct a wider newly constructed pavement.

[0033] The controller 50 is an example of a control device that controls the asphalt finisher 100. The controller 50 is a computer provided with, for example, a CPU (Central Processing Unit), a volatile memory, a non-volatile memory, etc. The controller 50 is a computer including a CPU and a RAM (Random Access Memory) and is mounted on the tractor 1. Various functions of the controller 50 are realized, for example, by the CPU executing a program stored in the auxiliary storage device 51.

[0034] The auxiliary storage device 51 is a device for storing various information. In this embodiment, the auxiliary storage device 51 is a non-volatile memory and is integrated with the controller 50. However, the auxiliary storage device 51 may be arranged outside the controller 50 as a structure separate from the controller 50.

[0035] The display device 60 is a device for displaying various types of information. In the present embodiment, the display device 60 is a liquid crystal display, and displays various types of information in response to control commands from the controller 50. Further, the display device 60 may include an input device such as a touch panel that receives operation inputs from the operator of the asphalt finisher 100.

[0036] The information acquisition device 62 is a device for acquiring various types of information used for automatic paving control. In the present embodiment, the information acquisition device 62 acquires positioning data for estimating the current position. Further, the information acquisition device 62 acquires the detection results of detecting objects existing around the asphalt finisher 100. The information acquisition device 62 outputs the acquired various types of information to the controller 50.

[0037] <Computer> The controller 50, the communication terminal 200, and the remote management device 300 of the asphalt finisher 100 are realized by, for example, a computer. FIG. 5 is a block diagram showing an example of the hardware configuration of the computer according to the embodiment.

[0038] As shown in FIG. 5, the computer 500 has a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, an HDD (Hard Disk Drive) 504, an input device 505, a display device 506, a communication I / F (Interface) 507, and an external I / F 508. The CPU 501, the ROM 502, and the RAM 503 form a so-called computer. Each hardware of the computer 500 is interconnected via a bus line 509. Note that the input device 505 and the display device 506 may be connected to the external I / F 508 and used.

[0039] The CPU 501 is an arithmetic unit that realizes the control and functions of the entire computer 500 by reading programs and data from a storage device such as the ROM 502 or HDD 504 onto the RAM 503 and executing processing. The computer 500 may have a GPU (Graphics Processing Unit) in addition to or instead of the CPU 501.

[0040] The ROM 502 is an example of a non-volatile semiconductor memory (storage device) that can hold programs and data even when the power is turned off. The ROM 502 functions as a main storage device that stores various programs, data, etc. necessary for the CPU 501 to execute various programs installed in the HDD 504. Specifically, the ROM 502 stores boot programs such as BIOS (Basic Input / Output System) and EFI (Extensible Firmware Interface) that are executed when the computer 500 starts up, as well as data such as OS (Operating System) settings and network settings.

[0041] The RAM 503 is an example of a volatile semiconductor memory (storage device) in which programs and data are erased when the power is turned off. The RAM 503 is, for example, DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). The RAM 503 provides a working area in which various programs installed in the HDD 504 are expanded when executed by the CPU 501.

[0042] The HDD 504 is an example of a non-volatile storage device that stores programs and data. Programs and data stored in the HDD 504 include an OS, which is basic software that controls the entire computer 500, and applications that provide various functions on the OS. Note that the computer 500 may use a storage device (e.g., SSD: Solid State Drive, etc.) that uses flash memory as a storage medium instead of the HDD 504.

[0043] The input device 505 includes a touch panel used by the user to input various signals, operation keys and buttons, a keyboard and a mouse, a microphone for inputting sound data such as voice, etc.

[0044] The display device 506 is composed of a display such as a liquid crystal or an organic EL (Electro-Luminescence) for displaying a screen, a speaker for outputting sound data such as voice, etc.

[0045] The communication I / F 507 is an interface for connecting to a communication network and enabling the computer 500 to perform data communication.

[0046] The external I / F 508 is an interface with an external device. Examples of the external device include a drive device 510, etc.

[0047] The drive device 510 is a device for setting a recording medium 511. The recording medium 511 here includes media that optically, electrically or magnetically record information, such as CD-ROMs, flexible disks, magneto-optical disks, etc. Also, the recording medium 511 may include semiconductor memories that electrically record information, such as ROMs, flash memories, etc. Thus, the computer 500 can read and / or write to the recording medium 511 via the external I / F 508.

[0048] Note that various programs installed in the HDD 504 are installed, for example, when a distributed recording medium 511 is set in a drive device 510 connected to the external I / F 508 and the various programs recorded on the recording medium 511 are read by the drive device 510. Alternatively, various programs installed in the HDD 504 may be installed by being downloaded from another network different from the communication network via the communication I / F 507.

[0049] <Situation where the reliability of the current position decreases> A situation where the reliability of the current position deteriorates will be specifically described with reference to FIGS. 6 to 8. Here, the description will focus on the situations that can occur when estimating the current position using a total station.

[0050] FIG. 6 is a diagram showing a first example of a situation where the reliability of the current position deteriorates. As shown in FIG. 6, the total station TS is installed at a position separated from the asphalt finisher 100. The total station TS is often installed, for example, within a predetermined distance in the traveling direction of the asphalt finisher 100. The predetermined distance is within the maximum communicable distance of the total station TS.

[0051] A target TG is installed on the asphalt finisher 100. The target TG is, for example, a prism. The target TG is often installed, for example, on the upper part of the screed 3, but it may be at any position as long as it is visible from the total station TS.

[0052] The total station TS irradiates the target TG with laser light and analyzes the reflected light from the target TG to measure the distance and angle between the total station TS and the target TG. The total station TS may have an automatic tracking function for automatically aiming at the target TG.

[0053] At a work site where road paving or the like is being performed, many workers W are working around the asphalt finisher 100. Therefore, when a worker W enters between the total station TS and the target TG, the total station TS becomes unable to measure the positional relationship with the target TG. As a result, the positioning data from the total station TS is interrupted in the information acquisition device 62. Since there are various objects such as work tools at the work site, not limited to the worker W, the same applies if those objects enter between the total station TS and the target TG.

[0054] FIG. 7 is a diagram showing a second example of a situation where the reliability of the current position decreases. When using a plurality of total stations, the amount of data available for estimating the current position increases, so the estimation accuracy of the current position improves. As shown in FIG. 7, when using two total stations TSL and TSR, the total stations TSL and TSR are often installed in a pair on the left and right at positions that are line-symmetric with respect to the traveling direction of the asphalt finisher 100. The total station TSL measures the relative positional relationship with the target TGL installed on the upper part of the left telescopic screed. The total station TSR measures the relative positional relationship with the target TGR installed on the upper part of the right telescopic screed.

[0055] At this time, when the worker W enters between the total station TSL and the target TGL, the total station TSL becomes unable to measure the positional relationship with the target TGL. As a result, in the information acquisition device 62, the positioning data from the total station TSL is interrupted. In this case, the asphalt finisher 100 estimates the current position using only the positioning data from the total station TSR. Since the number of positioning data available for estimating the current position decreases from two to one, the reliability of the current position decreases.

[0056] FIG. 8 is a diagram showing a third example of a situation where the reliability of the current position decreases. When the asphalt finisher 100 travels to the installation position of the total station, it becomes necessary to further move the installation position of the total station in the traveling direction. As shown in FIG. 7, when two total stations TSL and TSR are installed in a pair on the left and right, since it is necessary to move the two total stations TSL and TSR together, construction may be stopped during that time, or the positioning data from both the total stations TSL and TSR may be interrupted.

[0057] Therefore, as shown in FIG. 8, the total station TSL installed on the left side in the traveling direction and the total station TSR installed on the right side in the traveling direction may be installed at positions with different distances from the asphalt finisher 100. In this case, when the asphalt finisher 100 advances to the position of the total station TSL, the total station TSL is moved ahead of the total station TSR. Thereafter, when the asphalt finisher 100 advances to the position of the total station TSR, the total station TSR is moved ahead of the total station TSL. By repeating this, it is possible to prevent the positioning data from both total stations TSL and TSR from being interrupted.

[0058] However, since there is a limit to the measurable distance or the communicable distance of the total station, the positioning data that can be obtained from the total station may be only one. Also, while one of the total stations is being moved, only the positioning data from one of the total stations can be obtained. In this case as well, since the number of positioning data that can be used for estimating the current position decreases from two to one, the reliability of the current position decreases.

[0059] So far, the case of estimating the current position using a total station has been described, but a situation where the reliability of the current position decreases can also occur when estimating the current position using a positioning satellite. For example, in a place where high-rise buildings are built around, the number of positioning satellites that can receive satellite signals may decrease. Also, in a place where there is a structure above a tunnel or an overpass, the number of positioning satellites that can receive satellite signals decreases.

[0060] <Functional Configuration of Asphalt Finisher> The functional configuration of the controller 50 that controls the asphalt finisher 100 will be described with reference to FIG. 9. FIG. 9 is a block diagram showing an example of the functional configuration of the controller according to the embodiment.

[0061] As shown in FIG. 9, an auxiliary storage device 51, a display device 60, an information acquisition device 62, a traveling speed sensor 63, a communication device 64, a steering device 65, and a screed control device 66 are connected to the controller 50.

[0062] The auxiliary storage device 51 stores log information indicating the construction results by the asphalt finisher 100. The log information includes information indicating a range where the reliability of the current position has decreased (hereinafter also referred to as the "low reliability range"). Since the reliability of the current position depends on the amount of positioning data available for estimating the current position, the low reliability range is a range where the amount of positioning data has dropped below a predetermined reference value.

[0063] For example, when estimating the current position using a total station, the low reliability range is the range of the road surface constructed from when the positioning data from the total station is interrupted until it recovers. When using multiple total stations, the low reliability range is the range of the road surface constructed from when the positioning data from any one of the total stations is interrupted until the positioning data recovers at all the total stations. Also, for example, when estimating the current position using positioning satellites, the low reliability range is the range of the road surface constructed from when the number of positioning satellites capable of receiving satellite signals drops below a predetermined number until it recovers to the predetermined number.

[0064] The information acquisition device 62 acquires positioning data for estimating the current position. The positioning data is data indicating the relative positional relationship between the asphalt finisher 100 and a reference object. The reference object is, for example, a surveying instrument. When estimating the current position using a total station, the reference object is the total station, and the positioning data is data indicating the relative positional relationship (distance and angle) between the total station and a target installed on the asphalt finisher 100. When estimating the current position using positioning satellites, the reference object is the positioning satellite, and the positioning data is data indicating the relative positional relationship (azimuth and signal arrival time) between the positioning satellite and a receiver installed on the asphalt finisher 100.

[0065] In this embodiment, the information acquisition device 62 acquires positioning data by receiving the positioning data from the surveying instrument. The information acquisition device 62 includes, for example, at least one of a wireless communication device capable of communicating with a total station and a radio wave receiver capable of receiving satellite signals transmitted from positioning satellites. The wireless communication device includes, for example, at least one of a wireless LAN module, a mobile communication module, and a Bluetooth (registered trademark) module. The radio wave receiver includes, for example, at least one of a GPS receiver and a GNSS receiver.

[0066] The information acquisition device 62 may acquire the detection results of detecting the road surface and objects around the asphalt finisher 100. The information acquisition device 62 includes, for example, at least one of a monocular camera, a stereo camera, a distance image camera, an infrared camera, a distance sensor, and a LIDAR. The distance sensor includes, for example, at least one of a millimeter wave radar, a laser radar, an ultrasonic sensor, and an infrared sensor.

[0067] The traveling speed sensor 63 is configured to detect the traveling speed of the asphalt finisher 100. For example, the traveling speed sensor 63 is an encoder that detects the angular velocity of the rotation axis of the rear wheel traveling motor that drives the rear wheels of the tractor 1. The traveling speed sensor 63 may be composed of a proximity switch or the like that detects a slit formed on a rotating plate.

[0068] The communication device 64 performs wireless communication with a device existing around the asphalt finisher 100 or a server that manages the work site. For example, the communication device 64 performs wireless communication using, as a wireless communication standard, any one or more of Wi-Fi (registered trademark), wireless LAN, and Bluetooth (registered trademark).

[0069] The steering device 65 controls the tractor 1 according to a control command. For example, the steering device 65 performs rotation control (speed control) on the rear wheel traveling motor of the tractor 1 and steering angle control on the front wheels (an example of driving wheels) of the tractor 1 so as to follow the steering angle and speed indicated by the control command.

[0070] The screen control device 66 is configured to control the amount of expansion and contraction of the left and right telescopic screens. For example, the screen control device 66 controls the flow rate of the hydraulic oil flowing into the screen expansion and contraction cylinders that perform the expansion and contraction of the left and right telescopic screens respectively. The screen control device 66 switches the communication or cutoff of the pipeline connecting the rod side oil chamber of the screen expansion and contraction cylinder and the hydraulic pump according to the control command from the controller 50. Thereby, the expansion and contraction of each of the left and right telescopic screens can be realized.

[0071] More specifically, the controller 50 includes a position estimation unit 101, a steering control unit 102, a screen control unit 103, a reliability determination unit 104, a display control unit 105, and a communication control unit 106 as functional blocks configured by software, hardware, or a combination thereof.

[0072] The position estimation unit 101 estimates the current position of the asphalt finisher 100 based on the positioning data acquired by the information acquisition device 62. In the present embodiment, the position estimation unit 101 estimates the position coordinates of the asphalt finisher 100 in the reference coordinate system. The reference coordinate system is, for example, the World Geodetic System. The World Geodetic System is a three-dimensional orthogonal XYZ coordinate system with the center of gravity of the earth as the origin. In the World Geodetic System, the X-axis is in the direction of the intersection of the Greenwich meridian and the equator, the Y-axis is in the direction of 90 degrees east longitude, and the Z-axis is in the direction of the North Pole.

[0073] When estimating the position coordinates of the asphalt finisher 100 in the reference coordinate system, the position estimation unit 101 may utilize the road design data stored in the auxiliary storage device 51. The road design data is the design data of the road to be constructed. The road design data may include information regarding the positions of ground features such as traffic lights, utility poles, and manholes, for example.

[0074] The position estimation unit 101 may estimate the current position of the asphalt finisher 100 based on the detection result acquired by the information acquisition device 62. For example, the position estimation unit 101 recognizes an image that captures the surroundings of the asphalt finisher 100, and estimates the current position of the asphalt finisher 100 based on the positional relationship with the objects captured in the image. When estimating the current position based on the detection result, the position estimation unit 101 may utilize the road design data stored in the auxiliary storage device 51.

[0075] The steering control unit 102 outputs a control command for controlling the operation of the tractor 1 to the steering device 65. In the present embodiment, the steering control unit 102 outputs a control command indicating the steering angle and the traveling speed to the steering device 65 so as to move on the road surface to be constructed based on the current position estimated by the position estimation unit 101. The steering control unit 102 may determine the traveling route based on the road design data stored in the auxiliary storage device 51. The steering control unit 102 may also determine the traveling route based on the detection result of the road surface acquired by the information acquisition device 62. Thereby, the controller 50 performs automatic steering control of the tractor 1 so as to perform the paving process on the road surface to be constructed.

[0076] The screed control unit 103 outputs a control command for controlling the operation of the screed 3 to the screed control device 66. In the present embodiment, the screed control unit 103 outputs a control command indicating the expansion and contraction amounts of the left telescopic screed and the right telescopic screed to the screed control device 66 so as to match the shape of the end portion of the road surface to be constructed. The screed control unit 103 may detect the shape of the end portion of the road surface based on the road design data stored in the auxiliary storage device 51. The screed control unit 103 may also extract the shape of the end portion of the road surface from the detection result of the road surface acquired by the information acquisition device 62. Thereby, the controller 50 performs automatic expansion and contraction control of the screed 3 so as to perform the paving process in accordance with the shape of the end portion of the road surface to be constructed.

[0077] Based on the positioning data acquired by the information acquisition device 62, the reliability determination unit 104 determines the reliability of the current position estimated by the position estimation unit 101. In the present embodiment, the reliability determination unit 104 determines the reliability of the current position based on the data volume of the positioning data. Specifically, the reliability determination unit 104 compares the data volume of the positioning data with a predetermined reference value, and when the data volume is less than the reference value, determines that the reliability of the current position has decreased.

[0078] When the reliability determination unit 104 determines that the reliability of the current position has decreased, it records the position coordinates with decreased reliability in the log information stored in the auxiliary storage device 51. As a result, the log information indicating the low reliability range is stored in the auxiliary storage device 51.

[0079] The display control unit 105 controls to display information regarding the data volume of the positioning data acquired by the information acquisition device 62 on the display device 60. When the reliability determination unit 104 determines that the reliability of the current position has decreased, the display control unit 105 may display information regarding the data volume of the positioning data on the display device 60. At this time, the display control unit 105 may display a warning on the display device 60 indicating that the data volume of the positioning data has decreased.

[0080] The communication control unit 106 controls to transmit and receive information to and from an external device using the communication device 64. In the present embodiment, the communication control unit 106 transmits and receives information to and from the communication terminal 200 and the remote management device 300. The communication control unit 106 transmits information regarding the data volume of the positioning data acquired by the information acquisition device 62 to at least one of the communication terminal 200 and the remote management device 300. Further, the communication control unit 106 transmits the log information stored in the auxiliary storage device 51 to the remote management device 300.

[0081] ≪Recovery method proposal function≫ The management system SYS according to the embodiment has a recovery method proposal function. The recovery method proposal function is a function that proposes a method for recovering the data volume of the positioning data.

[0082] In the recovery method proposal function, the reliability determination unit 104 determines the recovery method of the positioning data according to the situation around the asphalt finisher 100. The display control unit 105 performs control to display, on the display device 60, information indicating the recovery method of the positioning data determined by the reliability determination unit 104.

[0083] For example, when estimating the current position using a total station, when the positioning data from the total station is interrupted, the reliability determination unit 104 proposes, as a recovery method for the positioning data, moving a shielding object or a person existing between the asphalt finisher 100 and the total station. In this case, the reliability determination unit 104 may also propose, as a recovery method for the positioning data, changing the attachment position of the target installed on the asphalt finisher 100.

[0084] Also, for example, when estimating the current position using positioning satellites, when the number of positioning satellites capable of receiving satellite signals decreases, the reliability determination unit 104 proposes, as a recovery method for the positioning data, moving the attachment position of the radio receiver to a position where satellite signals can be easily received. In this case, the reliability determination unit 104 may also propose candidates for positions where satellite signals can be easily received.

[0085] The reliability determination unit 104 records the proposed recovery method for the measurement data in the log information. The reliability determination unit 104 may receive an input of the recovery method implemented by the user via the operation panel and record the recovery method implemented by the user in the log information. The reliability determination unit 104 may also record, in the log information, the position coordinates where the recovery method was proposed or the position coordinates where the recovery method was implemented, together with the recovery method for the measurement data.

[0086] ≪Log confirmation function≫ The management system SYS according to the embodiment has a log confirmation function. The log confirmation function is a function for confirming the construction result by the asphalt finisher 100 based on the log information.

[0087] In the log confirmation function, the communication control unit 106 transmits the log information stored in the auxiliary storage device 51 to the remote management device 300. The remote management device 300 accumulates the log information received from the asphalt finisher 100 in a storage device such as the HDD 504.

[0088] The remote management device 300 displays the past construction results on the display device according to the operations of the user who remotely manages. When the remote management device 300 displays the past construction results, it indicates the low reliability range included in the log information in the construction results. If a recovery method has been implemented by the user, the remote management device 300 indicates the implemented recovery method and the implemented position coordinates in the construction results. Thereby, the user of the remote management device 300 can confirm the low reliability range (that is, the range where the construction accuracy may be low) in the past construction results by the asphalt finisher 100.

[0089] <Management method> The management method executed by the management system SYS will be described with reference to FIG. 10. FIG. 10 is a flowchart showing an example of the management method according to the embodiment. The management method is a method for managing the asphalt finisher 100 having an automatic paving function.

[0090] In step S1, the controller 50 of the asphalt finisher 100 starts automatic paving control. First, the controller 50 reads out the road design data from the auxiliary storage device 51. Next, the controller 50 acquires the range of the road surface to be constructed based on the road design data. Subsequently, the steering control unit 102 of the controller 50 determines a travel route based on the range of the road surface to be constructed, and outputs a control command indicating the steering angle and the travel speed to the steering device 65. In addition, the screed control unit 103 of the controller 50 detects the shape of the end of the road surface from the range of the road surface to be constructed, and outputs a control command indicating the expansion and contraction amounts of the left and right telescopic screeds to the screed control device 66.

[0091] In step S2, the information acquisition device 62 of the asphalt finisher 100 acquires positioning data for estimating the current position. The information acquisition device 62 outputs the acquired positioning data to the controller 50.

[0092] In step S3, the position estimation unit 101 of the controller 50 estimates the current position of the asphalt finisher 100 based on the positioning data acquired in step S2. The position estimation unit 101 sends the estimated current position to the steering control unit 102 and the screed control unit 103. The steering control unit 102 and the screed control unit 103 continue the automatic paving control based on the current position received from the position estimation unit 101.

[0093] In step S4, the reliability determination unit 104 of the controller 50 calculates the data volume of the positioning data acquired in step S2. When estimating the current position using total stations, the data volume of the positioning data is, for example, the number of total stations from which the positioning data could be received. Also, when estimating the current position using positioning satellites, the data volume of the positioning data is, for example, the number of positioning satellites from which satellite signals can be received.

[0094] The reliability determination unit 104 determines the reliability of the current position estimated in step S3 based on the data volume of the positioning data. Specifically, the reliability determination unit 104 determines whether the reliability of the current position has decreased by comparing the data volume of the positioning data with a predetermined reference value. The reference value is set, for example, to a data volume that can obtain sufficient prediction accuracy. For example, if two total stations are used, the reference value can be set to 2. For example, when using GPS satellites, since GPS requires satellite signals from four positioning satellites, the reference value can be set to 4.

[0095] When the data volume is less than the reference value (YES), the reliability determination unit 104 determines that the reliability of the current position is decreasing, and proceeds to step S5 for processing. On the other hand, when the data volume is greater than or equal to the reference value (NO), the reliability determination unit 104 determines that the reliability of the current position is not decreasing, and proceeds to step S7 for processing.

[0096] In step S5, the display control unit 105 of the controller 50 displays information regarding the data volume of the positioning data on the display device 60. The information regarding the data volume of the positioning data may be a warning indicating that the data volume of the positioning data (or the reliability of the current position) is decreasing. The information regarding the data volume of the positioning data may be a numerical value indicating the data volume, a graph showing the transition of the data volume, an icon indicating communication information with a total station or a positioning satellite, or an icon indicating that the data volume is decreasing. Thereby, the operator of the asphalt finisher 100 can immediately recognize that the reliability of the current position is decreasing.

[0097] In addition, when the information acquisition device 62 fails to acquire the positioning data in step S2 (in other words, when the data volume of the positioning data is zero), the asphalt finisher 100 may stop the automatic paving control. Alternatively, the asphalt finisher 100 may stop the automatic paving control and display on the display device 60 that manual construction should be performed. This is because when the positioning data cannot be acquired, the construction accuracy is significantly reduced and there is a possibility that the construction may need to be redone.

[0098] Also, the communication control unit 106 of the controller 50 transmits information regarding the data volume of the positioning data to at least one of the communication terminal 200 and the remote management device 300. The communication terminal 200 or the remote management device 300 displays the information regarding the data volume of the positioning data on the display device 506. Thereby, the user remotely managing the work site, the user managing the work at the work site, and the user working at the work site can immediately recognize that the reliability of the current position is decreasing.

[0099] In step S6, the reliability determination unit 104 of the controller 50 determines a method for recovering the positioning data according to the situation around the asphalt finisher 100. Next, the display control unit 105 displays information indicating the recovery method determined by the reliability determination unit 104 on the display device 60.

[0100] In addition, the communication control unit 106 of the controller 50 transmits information indicating the method for recovering the positioning data to at least one of the communication terminal 200 and the remote management device 300. The communication terminal 200 or the remote management device 300 displays the information indicating the method for recovering the positioning data on the display device.

[0101] Thereby, the operator of the asphalt finisher 100, the user remotely managing the work site, the user managing the work at the work site, or the user working at the work site can quickly take measures to recover the data volume of the positioning data. Once the data volume of the positioning data is recovered, the asphalt finisher 100 can accurately pave the road surface based on the highly reliable current position.

[0102] In step S7, the controller 50 determines whether the construction on the road surface to be constructed has been completed. If the construction is completed (YES), the controller 50 proceeds to step S8. On the other hand, if the construction is not completed (NO), the controller 50 returns the process to step S2.

[0103] After returning the process to step S2, the controller 50 executes the processes from step S2 to step S7 again. Thereby, the asphalt finisher 100 continues the automatic paving control until the construction of the road surface to be constructed is completed.

[0104] In step S8, the controller 50 stores the log information indicating the construction result in the auxiliary storage device 51. The controller 50 records the range (low reliability range) where the reliability of the current position is determined to have decreased in step S4 in the log information. Further, the controller 50 may record the method for recovering the positioning data proposed in step S6 in the log information.

[0105] The communication control unit 106 of the controller 50 transmits the log information stored in the auxiliary storage device 51 to the remote management device 300. The timing of transmitting the log information may be arbitrary. The communication control unit 106 may transmit the log information at any time whenever the log information is stored in the auxiliary storage device 51, or may transmit the untransmitted log information in a lump at a predetermined time interval.

[0106] When the remote management device 300 receives the log information from the asphalt finisher 100, it accumulates the received log information in the storage device. The remote management device 300 displays, on the display device, the construction results in which the low reliability range is indicated in response to the operation of the user who remotely manages. Thereby, the user who remotely manages can confirm the range of the road surface where the construction accuracy may be low based on the past construction results. As a result, the maintenance management of the road surface can be advanced efficiently.

[0107] <Effects of the Embodiment> The asphalt finisher 100 according to the present embodiment estimates the current position of the asphalt finisher 100 and outputs information regarding the amount of data available for estimating the current position. The lower the amount of data available for estimating the current position, the lower the reliability of the estimated current position. When construction is performed based on a current position with low reliability, the construction accuracy decreases. In one aspect, according to the present embodiment, since it is possible to easily know that the reliability of the current position is decreasing and to quickly take measures, it is possible to suppress a decrease in construction accuracy.

[0108] When the asphalt finisher 100 detects that the amount of data available for estimating the current position has dropped below a reference value, it outputs information regarding the amount of data. According to the present embodiment, since the information is output only when the reliability of the current position is decreasing, it is possible to prevent overlooking that the reliability of the current position is decreasing.

[0109] When the asphalt finisher 100 detects that the amount of data available for estimating the current position has dropped below a reference value, it outputs information indicating a method for recovering the amount of data. According to this embodiment, since measures for recovering the amount of data can be carried out promptly, the road surface can be paved accurately based on a highly reliable current position.

[0110] The asphalt finisher 100 stores information regarding the amount of data available for estimating the current position in the auxiliary storage device 51 of the asphalt finisher 100. The asphalt finisher 100 stores log information indicating the position where the amount of data has dropped. According to this embodiment, in the construction results by the past asphalt finisher 100, a low reliability range (that is, a range where the construction accuracy may be low) can be confirmed.

[0111] The asphalt finisher 100 displays information regarding the amount of data available for estimating the current position on the display device 60 of the asphalt finisher 100. According to this embodiment, the operator of the asphalt finisher 100 can immediately recognize that the reliability of the current position has decreased.

[0112] The asphalt finisher 100 transmits information regarding the amount of data available for estimating the current position to the communication terminal 200 or the remote management device 300. According to this embodiment, a user remotely managing the work site, a user managing the work at the work site, and a user working at the work site can immediately recognize that the reliability of the current position has decreased.

[0113] As described above in detail for the embodiments of the present disclosure, the embodiments disclosed this time are illustrative in all respects and not restrictive. The embodiments can be modified and improved in various forms without departing from the scope and gist of the appended claims. The matters described in the above embodiments can also adopt other configurations and can be combined within a non - conflicting range.

Description of Reference Numerals

[0114] 1: Tractor 2: Hopper 3: Screed 50: Controller 51: Auxiliary storage device 60: Display device 61: Driver's seat 62: Information acquisition device 63: Travel speed sensor 64: Communication device 65: Steering device 66: Screed control device 100: Asphalt finisher 101: Position estimation unit 102: Steering control unit 103: Screed control unit 104: Reliability determination unit 105: Display control unit 106: Communication control unit 200: Communication terminal 300: Remote management device CV: Conveyor SC: Screw SYS: Management system

Claims

1. A road machine equipped with a tractor, a control device for estimating the current position of the road machine, and a steering device for steering the tractor based on the current position, comprising: the control device is configured to output information regarding the amount of data available for estimating the current position, a road machine.

2. The amount of data includes the number of positioning data received from a total station or the number of positioning satellites capable of receiving satellite signals, The road machine according to claim 1.

3. The control device outputs information regarding the amount of data only when the amount of data is lower than a reference value, and does not output information regarding the amount of data when the amount of data is equal to or higher than the reference value, The road machine according to claim 1.

4. When the positioning data from the total station is interrupted or the number of positioning satellites capable of receiving satellite signals decreases, the amount of data drops below the reference value, The road machine according to claim 3.

5. When the control device detects that the amount of data has dropped below the reference value, it outputs information indicating the method for recovering the amount of data, The road machine according to claim 3.

6. The recovery method includes moving an object existing between the total station and the road machine, changing the mounting position of a target installed on the road machine, or moving the mounting position of a radio receiver that receives satellite signals from positioning satellites, The road machine according to claim 5.

7. Outputting information regarding the amount of data includes storing information regarding the amount of data in the storage device of the road machine, storing log information indicating the position where the amount of data has dropped, displaying information regarding the amount of data on the display device of the road machine, or transmitting information regarding the amount of data to an external device, The road machine according to any one of claims 1 to 6.

8. A management system in which a road machine equipped with a tractor and an information processing device can communicate with each other via a network, wherein the road machine, a control device for estimating the current position of the road machine, and a steering device for steering the tractor based on the current position, comprising: the control device is configured to transmit information regarding the amount of data available for estimating the current position to the information processing device, the information processing device, comprises a display unit for displaying log information indicating the information regarding the amount of data, a management system.

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