Remote communication system and remote control type construction machine system

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The remote communication system for construction machinery addresses the issue of radio wave shielding and inter-base station handovers by using redundant data transmission across multiple radio lines and a monitoring function to optimize base station arrangement, ensuring stable and high-quality remote communication.

JP2025062220APending Publication Date: 2025-04-14HITACHI CONSTRUCTION MACHINERY CO LTD

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Patent Information

Application Number: JP2023171143
Authority / Receiving Office: JP · JP
Patent Type: Applications
Current Assignee / Owner
Filing Date: 2023-10-02
Publication Date: 2025-04-14

AI Technical Summary

Technical Problem

Existing remote communication systems for construction machinery face challenges in maintaining communication quality due to radio wave shielding by metallic structures on excavators, and they do not effectively handle inter-base station handovers during shovel movement.

Method used

A remote communication system comprising a first and second telecommunications unit, each connected to multiple mobile radio base stations, which replicates and transmits video and operation data redundantly across multiple radio lines to ensure stable communication, and includes a monitoring function to determine the optimal arrangement of radio base stations based on communication quality.

Benefits of technology

The system prevents deterioration in communication quality due to radio wave shielding, ensuring stable transmission of high-quality video and operation signals necessary for remote operation of construction machinery, and optimizes radio base station arrangement for improved communication reliability.

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Abstract

To determine the quality of arrangement of a plurality of radio base stations.SOLUTION: A remote communication system 100 comprises: a first remote communication unit 110 which communicably connected with a mobile radio base station 40-1 and a mobile radio base station 40-2 and loaded on a construction machine; and a second remote communication unit 120 which is communicably connected with the mobile radio base station 40-1 and the mobile radio base station 40-2 and exchanges data with the first remote communication unit 110 via the mobile radio base station 40-1 and the mobile radio base station 40-2. At least one of the first remote communication unit 110 and the second remote communication unit 120 includes a monitoring function for determining the quality of arrangement of the mobile radio base station 40-1 and the mobile radio base station 40-2 based on communication qualities of a radio channel 300 and a radio channel 310.SELECTED DRAWING: Figure 12

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Description

[Technical field]

[0001] The present invention relates to a remote communication system and a remote-controlled construction machine system that transmit and receive data via a plurality of mobile wireless base stations. [Background technology]

[0002] In recent years, due to rising labor costs and a shortage of skilled workers, there is a demand for remote control of excavation and loading operations of construction machinery.

[0003] When remotely operating construction machinery, such as an excavator, high-quality video signals and highly reliable operation signals required for remote operation must be transmitted remotely. If communication quality deteriorates, the image becomes distorted and operation becomes impossible, resulting in a significant drop in productivity. One of the major factors that deteriorates communication quality is the radio wave shielding problem specific to excavators.

[0004] A conventional technique for solving the problem of deterioration in communication quality between a wireless terminal mounted on an excavator and a wireless base station is, for example, the technique disclosed in Patent Document 1. In Patent Document 1, an actuator that rotates an on-board antenna on the remotely operated shovel side and a controller that controls the actuator are provided on the shovel, and the on-board antenna is rotated so as to enter the radiation range of the wireless base station in accordance with the rotation of the shovel.

[0005] Furthermore, Patent Document 2 discloses a technology for controlling the directivity angle of beamforming, which is a wireless technology for providing a directivity angle to a radio wave radiation range. In Patent Document 2, after connecting to a wireless base station to communicate with using an omnidirectional vehicle-mounted antenna, the directivity angle of the radiation range is limited to the direction of the wireless base station antenna by beamforming. Then, the directivity angle of beamforming is controlled so that the wireless base station antenna is kept captured in the radiation range in accordance with the rotation of the excavator. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 07-288753 [Patent Document 2] Patent Publication No. 2022-87604 Summary of the Invention [Problem to be solved by the invention]

[0007] One factor that may degrade the quality of communication between a wireless terminal mounted on an excavator and a wireless base station is that the front equipment of the excavator, such as a metal structure such as a bucket, arm, or boom, may block radio waves between an antenna mounted on the excavator and an antenna of a wireless base station. Furthermore, the effect of radio wave blocking may change depending on the position and turning operation of the excavator. The techniques disclosed in the above Patent Documents 1 and 2 do not provide a method for dealing with such an event. Furthermore, the techniques disclosed in the above Patent Documents 1 and 2 are based on the premise that wireless communication is performed with one wireless base station, and do not support handover between base stations that accompanies movement of the excavator.

[0008] Therefore, the present invention has been made in consideration of the above-mentioned problems, and provides a remote communication system that aims to prevent deterioration of communication quality due to radio wave blocking problems caused by, for example, the front equipment of a shovel, and to stably remotely communicate high-quality video signals and highly reliable operation signals required for remote operation, and a method for judging the suitability of the placement of multiple wireless base stations. [Means for solving the problem]

[0009] A telecommunication system according to the present invention comprises a first telecommunication unit communicatively connected to a first mobile radio base station and a second mobile radio base station, and a second telecommunication unit for transmitting and receiving data to and from the first telecommunication unit via the first mobile radio base station and the second mobile radio base station, The first remote communication unit is mounted on the construction machine, and An imaging device; a first vehicle-mounted wireless terminal communicatively connected to a first mobile wireless base station via a first wireless line; a second vehicle-mounted wireless terminal communicably connected to the second mobile wireless base station via a second wireless line; a first communications platform that copies video data showing an image captured by the imaging device, makes the copied video data redundant using a first vehicle-mounted wireless terminal and a second vehicle-mounted wireless terminal, transmits the duplicated video data to a second remote communications unit via the first mobile wireless base station and the second mobile wireless base station via the first wireless line and the second wireless line, and outputs operation data for operating the construction machine received from the second remote communications unit via the first mobile wireless base station and the second mobile wireless base station via the first wireless line and the second wireless line to the construction machine, The second remote communication unit is provided in a remote operation room for remotely operating the construction machine, and a monitor that displays an image according to the received image data; a second communication platform that copies operation data, makes the copied operation data redundant, transmits the redundant data to a first remote communication unit via the first mobile radio base station and the second mobile radio base station through the first wireless line and the second wireless line, receives video data from the first remote communication unit via the first mobile radio base station and the second mobile radio base station through the first wireless line and the second wireless line, and outputs the video data to a monitor; At least one of the first remote communication unit or the second remote communication unit has a monitoring function for determining whether the placement of the first mobile radio base station or the second mobile radio base station relative to the construction machine is appropriate based on the communication quality of the first radio line and the second radio line.

[0010] Furthermore, a remote-controlled construction machine system according to the present invention includes the above-mentioned remote communication system, construction machine, and remote control room. Effect of the Invention

[0011] According to the remote communication system of the present invention, it is possible to judge whether the arrangement of multiple wireless base stations is appropriate, thereby preventing deterioration of communication quality due to radio wave shielding caused by, for example, the front device of an excavator, and enabling stable remote communication of high-quality video signals and highly reliable operation signals required for remote operation. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an example of the overall configuration of a mine to which a remote communication system for construction machinery is applied. [Diagram 2] 1 is a schematic diagram illustrating an example of communication quality with respect to the position and swing angle of a shovel 10. FIG. [Diagram 3] 1 is a schematic diagram illustrating an example of communication quality with respect to the position and swing angle of a shovel 10. FIG. [Figure 4] FIG. 2 is a schematic diagram illustrating an example in which a plurality of vehicle-mounted antennas are mounted on a shovel 10. [Diagram 5] FIG. 2 is a schematic diagram illustrating an example in which a plurality of vehicle-mounted antennas are mounted on a shovel 10. [Figure 6] 1 shows an example of the arrangement of mobile wireless base stations in a mine to which a remote communication system for construction machines is applied. [Figure 7] 1 shows an example of the arrangement of mobile wireless base stations in a mine to which a remote communication system for construction machines is applied. [Figure 8] 1 is a schematic diagram showing an example of the arrangement of mobile wireless base stations relative to a loading area 30, which is a working area of a shovel 10. FIG. [Figure 9] 1 is a schematic diagram showing an example of the arrangement of mobile wireless base stations relative to a loading area 30, which is a working area of a shovel 10. FIG. [Figure 10] 1 is a schematic diagram showing an example of the arrangement of mobile wireless base stations relative to a loading area 30, which is a working area of a shovel 10. FIG. [Figure 11] 1 is a schematic diagram showing an example of the arrangement of mobile wireless base stations relative to a loading area 30, which is a working area of a shovel 10. FIG. [Figure 12] FIG. 1 is a block diagram showing a configuration of a remote communication system. [Figure 13] 1 is a schematic diagram showing an example of the arrangement of multiple vehicle-mounted antennas mounted on a construction machine. [Figure 14] 1 is a graph for determining whether the placement of mobile radio base stations is good or bad. [Figure 15] 1 is a graph for determining whether the placement of mobile radio base stations is good or bad. [Figure 16] 1 is a graph for determining whether the placement of mobile radio base stations is good or bad. [Figure 17] 1 is a graph for determining whether the placement of mobile radio base stations is good or bad. [Figure 18] 10 is a flowchart showing a method for determining whether the placement of a mobile radio base station 40-1 or a mobile radio base station 40-2 is good or bad. [Figure 19] FIG. 1 is a diagram illustrating an example of the configuration of a remote-controlled construction machine system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be indicated by the same numbers. Note that the accompanying drawings show embodiments and implementation examples according to the principles of the present disclosure, but these are for understanding the present disclosure and are not to be used to interpret the present disclosure in a limiting manner. The description in this specification is merely a typical example and does not limit the scope or application of the present disclosure in any sense.

[0014] In the present embodiment, the description is given in sufficient detail for a person skilled in the art to implement the present disclosure, but it should be understood that other implementations and forms are possible, and that changes in configuration and structure and substitutions of various elements are possible without departing from the scope and spirit of the technical ideas of the present disclosure. Therefore, the following description should not be interpreted as being limited thereto.

[0015] Hereinafter, a remote communication system for a construction machine according to an embodiment will be described in detail with reference to the drawings. The remote communication system for a construction machine is a system for remotely performing excavation work, loading work, traveling, and other operations at a construction site or mine without an operator riding on a shovel, and is a system for remotely communicating video signals and operation signals required for remote operation.

[0016] Fig. 1 is a schematic diagram showing an example of the overall configuration of a mine to which a remote communication system for construction machines is applied. The mine shown in Fig. 1 includes a shovel 10, a dump truck (hereinafter simply referred to as a dump truck) 20, a loading area 30, a mobile wireless base station 40, a fixed wireless base station 50, a remote operation room 60, and a remote operation device 70. For the sake of simplicity of explanation, only the mobile wireless base station 40 (40-1) is shown in Figs. 1 to 5, but the mine according to this embodiment includes multiple mobile wireless base stations 40.

[0017] The shovel 10 is a construction machine that can be remotely operated, and in principle is operated without an operator on board, and is remotely controlled using a remote operation device 70 arranged in a remote operation room 60 and a remote communication system. The remote communication system is configured to be able to perform excavation work, loading work, traveling, and other remote operations of the shovel 10. Details of the remote communication system will be described later. At the loading site 30, the shovel 10 performs loading work of loading the soil and ore excavated by remote control into the dump truck 20.

[0018] When the excavator 10 finishes loading the soil and ore, the dump truck 20 travels along the transport path and discharges the load at the soil discharge site. After completing the soil discharge, the dump truck 20 travels along the transport path and returns to the loading site 30. The dump truck 20 travels back and forth between the loading site 30 and the soil discharge site to transport the load. The dump truck 20 may be a manned dump truck with a driver on board, or an unmanned dump truck that is automatically or remotely operated.

[0019] A mobile wireless base station 40-1 having a movable configuration is placed at the loading site 30. Video signals and operation signals are transmitted via a wireless line 300 between the mobile wireless base station 40-1 and an on-board antenna 12-1 mounted on the excavator 10.

[0020] The fixed wireless base station 50, the remote control room 60, and the remote control device 70 are placed in a location remote from the loading site 30. The remote control room 60 may be placed in a movable container or trailer, or in a control center that manages the entire mine. The remote control room 60 may also be placed in an urban area far away from the mine, rather than in the mine.

[0021] The excavator 10 is remotely controlled for excavation, loading, traveling, and other operations by an operator using devices (levers, switches, panels, etc., not shown) used for various operations in a remote control device 70 arranged in a remote control room 60. Operation signals for remote operation generated by the operator using the remote control device 70 arranged in the remote control room 60 are transmitted from the fixed wireless base station 50 to the mobile wireless base station 40-1 via the fixed wireless line 200. Note that a fixed wireless terminal to be mounted on the mobile wireless base station 40-1 for communicating with the fixed wireless base station 50 is omitted in the figure.

[0022] The operation signal is then transmitted from the mobile wireless base station 40-1 via a wireless line 300 to an on-board antenna 12-1 mounted on the shovel 10. The shovel 10 performs excavation work, loading work, traveling, and other operations in accordance with the operation signal.

[0023] On the other hand, video signals required for the excavation work, loading work, traveling, and other remote operations of the shovel 10 are sent to the vehicle-mounted antenna 12-1 via an imaging device (for example, cameras 1101 to 1104 in FIG. 12) and a video encoder (see FIG. 12) attached to the shovel 10, and are then transmitted from the vehicle-mounted antenna 12-1 to the mobile wireless base station 40-1 via a wireless line 300. The video signals transmitted to the mobile wireless base station 40-1 are transmitted to the fixed wireless base station 50 via the fixed wireless line 200. The video signals transmitted to the fixed wireless base station 50 are transmitted to the remote control device 70 arranged in the remote control room 60 connected by cables 400, and are displayed on a monitor (see FIG. 12) provided on the remote control device 70. The operator remotely controls the excavation work, loading work, traveling, and other operations of the shovel 10 by viewing the images displayed on the monitor provided on the remote control device 70.

[0024] In order to remotely control the excavation work, loading work, traveling, and other operations of the shovel 10, it is necessary to remotely communicate high-quality video signals and highly reliable operation signals. In this case, if the communication quality deteriorates, the image will be distorted and the operation will become impossible, resulting in a significant drop in productivity. One factor that may deteriorate the communication quality is that the front device 11 of the shovel 10, such as a metal structure such as a bucket, arm, or boom, may block radio waves between the vehicle-mounted antenna 12-1 mounted on the shovel 10 and the antenna of the wireless base station (mobile wireless base station 40-1). Furthermore, the influence of radio wave blocking may change depending on the position of the shovel 10 and the turning operation 1000. Therefore, in this embodiment, a remote communication system is provided that aims to prevent communication quality deterioration caused by radio wave blocking between the vehicle-mounted antenna 12-1 mounted on the shovel 10 and the antenna of the wireless base station (mobile wireless base station 40-1) by the front device 11 of the shovel 10, and to stably remotely communicate high-quality video signals and highly reliable operation signals required for remote operation.

[0025] The number of each device is not limited to those shown in the drawings or to a specific number. For example, the number of each of the shovel 10 and the dump truck 20 may be one, or one or both of them may be multiple.

[0026] Here, if the shovel 10 is in the position and rotation angle as shown in Figure 2, the vehicle-mounted antenna 12-1 mounted on the shovel 10 and the mobile wireless base station 40-1 will be in a line-of-sight positional relationship, and the communication quality of the wireless line 300 will be good.

[0027] 3, the vehicle-mounted antenna 12-1 and the mobile wireless base station 40-1 mounted on the shovel 10 are in a positional relationship in which they are shielded from radio waves by the front equipment 11 of the shovel 10, resulting in poor communication quality of the wireless link 300. In other words, it can be seen that the swinging motion peculiar to the shovel causes a radio wave shielding problem between the vehicle-mounted antenna 12 and the mobile wireless base station 40-1 by the front equipment 11.

[0028] Furthermore, as shown in FIG. 4, when multiple vehicle-mounted antennas 12-1, 12-2, 12-3, and 12-4 are provided on the excavator 10 and MIMO (Multi Input Multi Output) transmission or beamforming is performed between the excavator 10 and the mobile wireless base station 40-1, it is not sufficient for MIMO transmission or beamforming to be capable of transmitting and receiving using just one of the multiple antennas; communication must be possible between the vehicle-mounted antennas 12-1, 12-2, 12-3, and 12-4 and the multiple antennas of the mobile wireless base station 40-1 (not shown in the figure).

[0029] 4, the communication quality is different among the wireless link 300-1 between the vehicle-mounted antenna 12-1 and the mobile wireless base station 40-1, the wireless link 300-2 between the vehicle-mounted antenna 12-2 and the mobile wireless base station 40-1, the wireless link 300-3 between the vehicle-mounted antenna 12-3 and the mobile wireless base station 40-1, and the wireless link 300-4 between the vehicle-mounted antenna 12-4 and the mobile wireless base station 40-1. The wireless links 300-2, 300-3, and 300-4 are in good conditions, and the wireless link 300-1 is in bad conditions.

[0030] 5, the communication quality is different among the wireless link 300-1 between the vehicle-mounted antenna 12-1 and the mobile wireless base station 40-1, the wireless link 300-2 between the vehicle-mounted antenna 12-2 and the mobile wireless base station 40-1, the wireless link 300-3 between the vehicle-mounted antenna 12-3 and the mobile wireless base station 40-1, and the wireless link 300-4 between the vehicle-mounted antenna 12-4 and the mobile wireless base station 40-1. The wireless links 300-1, 300-3, and 300-4 are in good conditions, while the wireless link 300-2 is in bad conditions.

[0031] An example of the arrangement of mobile wireless base stations in a mine to which a remote communication system for construction machinery is applied is shown in Fig. 6. In this embodiment, as shown in Fig. 6, a plurality of vehicle-mounted antennas 12-1, 12-2, 12-3, and 12-4 mounted on a shovel 10 are arranged at the vehicle rear of the shovel 10. The vehicle rear of the shovel 10 is, for example, a position rearward of the boom of the front device 11.

[0032] 6, the communication quality is different among the wireless link 300-1 between the vehicle-mounted antenna 12-1 and the mobile wireless base station 40-1, the wireless link 300-2 between the vehicle-mounted antenna 12-2 and the mobile wireless base station 40-1, the wireless link 300-3 between the vehicle-mounted antenna 12-3 and the mobile wireless base station 40-1, and the wireless link 300-4 between the vehicle-mounted antenna 12-4 and the mobile wireless base station 40-1. The wireless links 300-3 and 300-4 are in good conditions, while the wireless links 300-1 and 300-2 are in bad conditions.

[0033] On the other hand, as shown in Fig. 7, the wireless link 310-1 between the vehicle-mounted antenna 12-1 and the mobile wireless base station 40-2, the wireless link 310-2 between the vehicle-mounted antenna 12-2 and the mobile wireless base station 40-2, the wireless link 310-3 between the vehicle-mounted antenna 12-3 and the mobile wireless base station 40-2, and the wireless link 310-4 between the vehicle-mounted antenna 12-4 and the mobile wireless base station 40-2 have the same communication quality. The wireless links 310-1, 310-2, 310-3, and 310-4 are all in good conditions.

[0034] In this way, by arranging mobile wireless base station 40-1 and mobile wireless base station 40-2 on a diagonal outside of loading area 30, which is the working area of shovel 10, and arranging vehicle-mounted antennas 12-1, 12-2, 12-3, and 12-4 at the rear of shovel 10, vehicle-mounted antennas 12-1 to 12-4 can send and receive data to and from either wireless line 300 or wireless line 310, regardless of the position or rotation angle of shovel 10.

[0035] The arrangement of the mobile wireless base stations with respect to the loading area 30, which is the working area of the shovel 10, will be described in detail with reference to Fig. 8. As shown in Fig. 8, it is preferable to arrange the mobile wireless base station 40-1 and the mobile wireless base station 40-2 at two diagonal corners on the outer side of the loading area 30, which is the working area of the shovel 10. Also, the mobile wireless base station 40-1 and the mobile wireless base station 40-2 may be arranged at two other diagonal corners on the outer frame of the loading area 30 as shown in Fig. 9.

[0036] On the other hand, when the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are arranged on two opposing sides, not on the two diagonal corners on the outside of the loading area 30 as shown in Fig. 10, a radio wave shielding problem may occur due to the turning motion specific to the excavator. Also, when the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are arranged on two other opposing sides, not on the two diagonal corners on the outer frame of the loading area 30 as shown in Fig. 11, a radio wave shielding problem may also occur due to the turning motion specific to the excavator.

[0037] Here, Fig. 8, Fig. 9, Fig. 10, and Fig. 11 are merely examples of the placement of mobile wireless base stations in a mine to which the remote communication system for a construction machine according to an embodiment of the present invention is applied. In an actual mine site, there are cases where the loading area 30 has a complex shape or where the mobile wireless base stations cannot be placed at the two diagonal corners on the outside of the loading area 30 due to the surrounding topography such as the face. There are also cases where radio waves are reflected by the surrounding topography such as the face, making it unnecessary to place the mobile wireless base stations at the two diagonal corners on the outside of the loading area 30, and conversely, where it is undesirable to place the mobile wireless base stations at the two diagonal corners on the outside of the loading area 30. Furthermore, there are also cases where the optimal placement of the mobile wireless base stations changes from moment to moment as the topography changes as the excavation work progresses.

[0038] FIG. 12 is a block diagram showing the configuration of the remote communication system 100. The remote communication system 100 in FIG. 12 includes a first remote communication unit 110 and a second remote communication unit 120. The first remote communication unit 110 is disposed in the shovel 10, and the second remote communication unit 120 is disposed in the remote operation room 60. The fixed wireless base station 50, the cables 400, and the remote operation device 70 shown in FIG. 1 to FIG. 11 are omitted in this figure. A remotely operated construction machine system 1900, which is an example of the remotely operated construction machine system of the present invention, includes the remote communication system 100, which will be described in detail below, a construction machine (e.g., the shovel 10), and a remote operation room 60, as shown in FIG. 19.

[0039] The first remote communication unit 110 arranged on the excavator 10 has a first vehicle-mounted wireless terminal 1190, a second vehicle-mounted wireless terminal 1191, a camera 1101, a camera 1102, a camera 1103, a camera 1104, an encoder 1111, an encoder 1112, an encoder 1113, an encoder 1114, an operation signal interface 1120, and a first communication platform 1130.

[0040] The second remote communication unit 120 located in the remote operation room 60 comprises a decoder 1201, a decoder 1202, a decoder 1203, a decoder 1204, a monitor 1211, a monitor 1212, a monitor 1213, a monitor 1214, an operation signal interface 1220, and a second communication platform 1230.

[0041] In the second remote communication unit 120, video signals 1141, 1142, 1143, and 1144 necessary for remote operation of the shovel 10, which are captured by the cameras 1101, 1102, 1103, and 1104, are input to the encoders 1111, 1112, 1113, and 1114, respectively. The video signals 1141, 1142, 1143, and 1144 input to the encoders 1111, 1112, 1113, and 1114 are encoded (for example, video compression encoding and error correction encoding) to become video data 1151, video data 1152, video data 1153, and video data 1154. Video data 1151 , video data 1152 , video data 1153 , and video data 1154 output from the encoder 1111 , encoder 1112 , encoder 1113 , and encoder 1114 are input to a first communications platform 1130 .

[0042] The video data 1151, video data 1152, video data 1153, and video data 1154 input to the first communication platform 1130 are duplicated for transmission via a two-line redundant system of the first in-vehicle wireless terminal 1190 and the second in-vehicle wireless terminal 1191. The video data 1161-1 and 1161-2, video data 1162-1 and 1162-2, video data 1163-1 and 1163-2, and video data 1164-1 and 1164-2 duplicated by the first communication platform 1130 are input to the first in-vehicle wireless terminal 1190 and the second in-vehicle wireless terminal 1191, respectively. Video data 1161-1, video data 1162-1, video data 1163-1, and video data 1164-1 are emitted as radio waves from vehicle-mounted antennas (vehicle-mounted antennas 12-1, 12-2, 12-3, 12-4 (see FIG. 13)) connected to the first vehicle-mounted wireless terminal 1190, and transmitted to mobile wireless base station 40-1 via wireless line 300 (300-1, 300-2, 300-3, 300-4 in the figure). In addition, video data 1161-2, video data 1162-2, video data 1163-2, and video data 1164-2 are emitted as radio waves from an on-board antenna (on-board antennas 13-1, 13-2, 13-3, 13-4 (see Figure 13)) connected to the second on-board wireless terminal 1191, and transmitted to mobile wireless base station 40-2 via wireless line 310 (310-1, 310-2, 310-3, 310-4 in the figure).

[0043] In the second remote communication unit 120, video data 1261-1 and 1261-2, video data 1262-1 and 1262-2, video data 1263-1 and 1263-2, and video data 1264-1 and 1264-2 received from the mobile radio base station 40-1 and the mobile radio base station 40-2 are input to a second communication platform 1230.

[0044] Of the video data 1261-1 and 1261-2, video data 1262-1 and 1262-2, video data 1263-1 and 1263-2, and video data 1264-1 and 1264-2 input to the second communications platform 1230, the video data received first via a wireless line is made valid and the video data received later via a wireless line is made invalid, and a series of video data is restored. Note that when video data is received via only one wireless line, the received video data is necessarily valid.

[0045] The video data 1241, video data 1242, video data 1243, and video data 1244 restored by the second communication platform 1230 are input to the decoder 1201, decoder 1202, decoder 1203, and decoder 1204, respectively. Then, the video data are decoded (for example, video compression decoding and error correction decoding) by the decoder 1201, decoder 1202, decoder 1203, and decoder 1204 to become the video signal 1251, video signal 1252, video signal 1253, and video signal 1254. The video signal 1251, video signal 1252, video signal 1253, and video signal 1254 output from the decoder 1201, decoder 1202, decoder 1203, and decoder 1204 are input to the monitor 1211, monitor 1212, monitor 1213, and monitor 1214, and the video required for remote operation of the excavator 10 is displayed. The operator operates the lever of the remote control device 70 while watching the images on the monitors 1211, 1212, 1213, and 1214 to perform excavation work, loading work, traveling, and other work with the shovel 10.

[0046] Meanwhile, an operation signal input and generated by an operator using the remote operation device 70 is input to the operation signal interface 1220 of the second remote communication unit 120 and becomes operation data 1271. The operation data 1271 is input to the second communication platform 1230.

[0047] The operation data 1271 input to the second communication platform 1230 is duplicated for transmission by the two-line redundant system of the mobile radio base station 40-1 and the mobile radio base station 40-2. The operation data 1281-1 and 1281-2 duplicated by the second communication platform 1230 are input to the mobile radio base station 40-1 and the mobile radio base station 40-2, respectively, and transmitted to the first vehicle-mounted radio terminal 1190 and the second vehicle-mounted radio terminal 1191 via the radio line 300 (300-1, 300-2, 300-3, 300-4 in the figure) and the radio line 310 (310-1, 310-2, 310-3, 310-4 in the figure).

[0048] In the first remote communication unit 110 , the operation data 1181 - 1 and 1181 - 2 received by the first in-vehicle wireless terminal 1190 and the second in-vehicle wireless terminal 1191 are input to the first communication platform 1130 .

[0049] The operation data 1181-1 and 1181-2 input to the first communication platform 1130 are restored by making the operation data of the wireless line received first valid and invalidating the operation data of the wireless line received later. Note that when operation data of only one wireless line is received, the received operation data is necessarily valid.

[0050] The operation data 1171 restored by the first communication platform 1130 is input to the operation signal interface 1120. The operation data 1171 input to the operation signal interface 1120 is converted into an operation signal required for the mechanical operation of the shovel 10 and then sent to an actuator or the like, and the mechanical operation required for the excavation work, loading work, traveling, and other work of the shovel 10 is performed.

[0051] Fig. 13 shows an external view of an example in which cameras and vehicle-mounted antennas are mounted on a shovel. Cameras 1101, 1102, 1103, and 1104 are mounted at positions for capturing images required for remotely operating shovel 10. Vehicle-mounted antennas 12-1 to 12-4 and 13-1 to 13-4 are each mounted at the rear of the vehicle body. Specifically, vehicle-mounted antennas 12-1 to 12-4 and 13-1 to 13-4 are mounted behind front device 11 (dotted line 11a in the figure).

[0052] As described above, according to the remote communication system 100 of the embodiment, it is possible to stably remotely communicate high-quality video signals and highly reliable operation signals required for remote operation.

[0053] Next, the monitoring function for judging whether the placement of the mobile wireless base stations 40-1 and 40-2 is good or bad will be described in detail with reference to the drawings. In the case of a loading site 30 in a mine to which the remote communication system for construction machines shown in FIG. 6 is applied, it is desirable to place the mobile wireless base stations 40-1 and 40-2 at two diagonal corners on the outside of the loading site 30, as shown in FIG. 8 and FIG. 9, with respect to the loading site 30, which is the working area of the excavator 10. However, in an actual mine site, there are cases where the shape of the loading site 30 is complex, cases where the mobile wireless base stations cannot be placed at two diagonal corners on the outside of the loading site 30 due to the surrounding topography such as the face, cases where it is not necessary to place the mobile wireless base stations at two diagonal corners on the outside of the loading site 30, and cases where it is not desirable to place the mobile wireless base stations at two diagonal corners on the outside of the loading site 30. Furthermore, there are also cases where the optimal placement of the mobile wireless base stations changes from moment to moment as the topography changes as the excavation work progresses. In any case, it is important that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are always in a complementary positional relationship with respect to the position and turning angle of the shovel 10.

[0054] The complementary positional relationship between the mobile radio base station 40-1 and the mobile radio base station 40-2 will be described with reference to Fig. 14. Fig. 14 is a graph showing the occurrence of a packet loss ratio PLR (Packet Loss Ratio), which represents the communication quality of the wireless line 300 by the mobile radio base station 40-1 and the communication quality of the wireless line 310 by the mobile radio base station 40-2. The vertical axis of the graph represents the packet loss ratio PLR, and the horizontal axis represents time.

[0055] As can be seen from Fig. 14, if the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are in a complementary positional relationship, packet loss occurs in the wireless line 300 by the mobile wireless base station 40-1 at time 2010 and time 2011, but packet loss does not occur in the wireless line 310 by the mobile wireless base station 40-2. On the other hand, packet loss occurs in the wireless line 310 by the mobile wireless base station 40-2 at time 2110 and time 2111, but packet loss does not occur in the wireless line 300 by the mobile wireless base station 40-1. In this way, Fig. 14 shows that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are in a complementary positional relationship.

[0056] However, when the mobile radio base station 40-1 and the mobile radio base station 40-2 are not in a complementary positional relationship, as shown in Fig. 15, when packet loss occurs in the radio line 300 by the mobile radio base station 40-1 at time 2010 or time 2011, and when packet loss occurs in the radio line 310 by the mobile radio base station 40-2 at time 2110 or time 2111, it can be seen that packet loss occurs partially at the same time. In this way, Fig. 15 shows that the mobile radio base station 40-1 and the mobile radio base station 40-2 are not in a complementary positional relationship.

[0057] Furthermore, as shown in Fig. 16, when packet loss occurs in the wireless link 300 by the mobile wireless base station 40-1 at time 2010 or time 2011, and when packet loss occurs in the wireless link 310 by the mobile wireless base station 40-2 at time 2110 or time 2111, it can be seen that the packet loss occurs almost simultaneously. In this way, Fig. 16 shows that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are not in a complementary positional relationship at all.

[0058] Therefore, a function is provided that constantly monitors the packet loss rate PLR of the wireless line 300 by the mobile wireless base station 40-1 at time 2010 and time 2011 as shown in Figure 17, and the packet loss rate PLR of the wireless line 310 by the mobile wireless base station 40-2 at time 2110 and time 2111, and when packet loss in the wireless line 300 and packet loss in the wireless line 310 occur simultaneously (3000 and 3001 in Figure 17), monitors that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are not in a complementary positional relationship and are not appropriately positioned with respect to the loading area 30.

[0059] At least one of the first remote communication unit 110 and the second remote communication unit 120 has a monitoring function for judging the quality of the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 based on the communication quality of the radio links 300 and 310. In the above-described embodiment, the packet loss rate is used as an index indicating the communication quality, but the index indicating the communication quality may be the throughput value of the radio links 300 and 310 or the delay time of the radio links 300 and 310.

[0060] The method of determining whether the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 is appropriate or not by the above-mentioned monitoring function can be summarized as follows, for example: A method for determining whether the placement of radio base stations is appropriate in a remote communication system 100, the method comprising: a first remote communication unit 110 mounted on a shovel 10, communicatively connected to a mobile radio base station 40-1 and the mobile radio base station 40-1; and a second remote communication unit 120 communicatively connected to a mobile radio base station 40-1 and the mobile radio base station 40-2, transmitting and receiving data to and from the first remote communication unit 110 via the mobile radio base station 40-1 and the mobile radio base station 40-2, the method comprising the steps of: As shown in Figure 18, A step (S1801) in which the cameras 1101 to 1104 of the first remote communication unit 110 mounted on the shovel 10 capture images; A step (S1802) in which encoders 1111 to 1114 encode video signals 1141 to 1144 of captured images; A step (S1803) in which the first communication platform 1130 copies the encoded video data 1151 to 1154; a step (S1804) in which the first in-vehicle wireless terminal 1190 and the second in-vehicle wireless terminal 1191 make each of the copied video data 1161-1 to 1164-1, 1161-2 to 1164-2 redundant and transmit the redundant data from the first remote communication unit 110 to the second remote communication unit 120 via the wireless line 300 and the wireless line 310; a step (S1805) in which the second communication platform 1230 of the second remote communication unit 120 restores the received video data 1261-1 to 1264-1, 1261-2 to 1264-2, and the decoders 1201 to 1204 decode the restored video data 1241 to 1244; a step (S1806) of the monitors 1211 to 1214 displaying images in accordance with the decoded video signals 1251 to 1254; A step (S1807) in which the operation signal interface 1220 receives operation data 1271 for operating the shovel 10 in a remote operation room 60 separated from the shovel 10; A step (S1808) of the second communication platform 1230 replicating the operation data 1271; A step (S1809) in which the second communication platform 1230 makes each of the duplicated operation data 1281-1, 1281-2 redundant and transmits the data from the second remote communication unit 120 to the first remote communication unit 110 via the wireless line 300 and the wireless line 310; A step (S1810) in which the first communication platform 1130 of the first remote communication unit 110 restores the operation data 1181-1, 1181-2, and the operation signal interface 1120 operates the shovel 10 according to the restored operation data 1171; and The method includes a step (S1811) in which at least one of the first remote communication unit 110 or the second remote communication unit 120 determines whether the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 is appropriate based on the communication quality of the wireless link 300 and the wireless link 310.

[0061] In addition, the judgment method may include a step (S1812) of notifying an alarm when at least one of the first remote communication unit 110 or the second remote communication unit 120 judges that the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 is not appropriate as a result of judging whether the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 is appropriate.

[0062] In Figures 15 to 17, when packet loss in wireless line 300 and packet loss in wireless line 310 occur simultaneously or almost simultaneously, it is determined that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are not in a complementary positional relationship, but the present invention is not limited to this.

[0063] For example, even if they are not simultaneous or nearly simultaneous, if the packet loss rate of the wireless line 300 is higher than a preset threshold and the packet loss rate of the wireless line 310 is higher than a preset threshold, it may be determined that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are not in a complementary positional relationship. The packet loss rate of the wireless line 300 or the wireless line 310 may be the average packet loss rate of the wireless lines 300-1 to 300-4 or the average packet loss rate of the wireless lines 310-1 to 310-4, or may be the packet loss rate of a wireless line selected from the wireless lines 300-1 to 300-4 or the packet loss rate of a wireless line selected from the wireless lines 310-1 to 310-4.

[0064] In addition, even if they are not simultaneous or nearly simultaneous, if the packet loss rate of one of the wireless lines 300-1 to 300-4 and the packet loss rate of the corresponding wireless line that transmits duplicated data of the data transmitted by that one of the wireless lines 310-1 to 310-4 are both higher than a preset threshold, it may be determined that the mobile wireless base station 40-1 and the mobile wireless base station 40-2 are not in a complementary positional relationship.

[0065] The data transmitted to wireless lines 300 and 310 to make the above-mentioned determination may be data captured by any of cameras 1101-1104, operation data output by operation signal interface 1220, data transmitted by execution of network command ping, or data transmitted from software performing packet capture.

[0066] A monitoring function for detecting whether the mobile radio base station 40-1 and the mobile radio base station 40-2 are arranged in a complementary positional relationship is implemented in the first communication platform 1130 and the second communication platform 1230 in the remote communication system 100 shown in Fig. 12. Note that the monitoring function may be implemented only in the first communication platform 1130 or only in the second communication platform 1230.

[0067] 12 are duplicated for redundant transmission over two lines, wireless line 300 and wireless line 310. When duplicating the video data, first communication platform 1130 assigns sequence numbers to video data 1161-1 and 1161-2, video data 1162-1 and 1162-2, video data 1163-1 and 1163-2, and video data 1164-1 and 1164-2. When restoring the video data 1261-1 and 1261-2, the video data 1262-1 and 1262-2, the video data 1263-1 and 1263-2, and the video data 1264-1 and 1264-2 transmitted in a two-line redundant system via the wireless line 300 and the wireless line 310, the second communication platform 1230 detects the occurrence of packet loss in the wireless line 300 and the wireless line 310 from the missing sequence numbers using the assigned sequence numbers. Then, when a packet loss in the wireless line 300 and a packet loss in the wireless line 310 occur simultaneously, the second communication platform 1230 notifies the operation signal interface 1220 of an alarm signal 1231. In response to the alarm signal 1231, the operation signal interface 1220 notifies the operator or supervisor that the mobile radio base station 40-1 and the mobile radio base station 40-2 are not in a complementary relationship and are not appropriately positioned with respect to the loading area 30.

[0068] In addition, a method may be used in which the second communication platform assigns a sequence number when duplicating the operation data 1271 for redundant transmission to the wireless line 300 and the wireless line 310, and the first communication platform 1130 notifies as an alarm signal if packet loss occurs simultaneously on the wireless line 300 and the wireless line 310.

[0069] The alarm signal 1231 may be notified by a buzzer sound or a warning light via the operation signal interface 1220 so that the operator or the supervisor can easily understand, or may be displayed on the monitors 1211 to 1214.

[0070] As described above, according to the system of the embodiment, by monitoring whether the wireless line 300 of the mobile wireless base station 40-1 and the wireless line 310 of the mobile wireless base station 40-2 are not in a complementary positional relationship and are not appropriately positioned with respect to the loading area 30, it is possible to provide a remote communication system 100 having a function of preventing image distortion caused by a deterioration in communication quality.

[0071] In this embodiment, the simultaneous occurrence of packet loss in wireless line 300 and packet loss in wireless line 310 detects that the placement is not appropriate for loading area 30. However, it is also possible to use a method that detects this by the simultaneous occurrence of a decrease in throughput or an increase in delay rather than packet loss.

[0072] In this embodiment, two base stations, mobile radio base station 40-1 and mobile radio base station 40-2, are used, but the number of base stations is not limited to two, and may be three or more, and any of the mobile radio base stations may be a fixed radio base station.

[0073] In the present invention, the communication method of the wireless circuits 300 and 310 is not particularly limited. For example, it may be Wi-Fi (registered trademark) or 5G (5th Generation). Furthermore, the communication methods of the wireless circuits 300 and 310 may be different communication methods, for example, the wireless circuit 300 may be Wi-Fi and the wireless circuit 310 may be 5G.

[0074] Furthermore, the vehicle-mounted wireless terminal mounted on the excavator 10 may be configured to mount one terminal, so long as the vehicle-mounted wireless terminal is capable of connecting to a plurality of base stations simultaneously.

[0075] The communication method relating to the fixed wireless base station 50 and the fixed wireless line 200 is not particularly limited in the present invention.

[0076] Note that the cameras 1101, 1102, 1103, and 1104 may all have the same configuration or may have different configurations. The encoders 1111, 1112, 1113, and 1114 may all have the same configuration or may have different configurations. The decoders 1201, 1202, 1203, and 1204 may all have the same configuration or may have different configurations. The monitors 1211, 1212, 1213, and 1214 may all have the same configuration or may have different configurations.

[0077] In this embodiment, the remote control of a shovel working in a mine has been described as an example, but the remote control of a shovel working in a construction site may also be used. The same effect can also be obtained when a wheel loader or a dump truck, which is a construction machine or a work machine other than a shovel, is remotely controlled.

[0078] The present invention is not limited to the above-described embodiment, and includes various modified examples. For example, the above-described embodiment has been described in detail to easily explain the present invention, and is not necessarily limited to those having all the configurations described. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. In addition, each of the above-described configurations, functions, processing units, processing means, etc. may be realized in hardware by designing them as integrated circuits, for example, in part or in whole. In addition, each of the above-described configurations, functions, etc. may be realized in software by a processor interpreting and executing a program that realizes each function. [Explanation of symbols]

[0079] 10... Shovel, 11... Front equipment, 12, 13... Vehicle-mounted antenna, 20... Dump truck, 30... Loading area, 40... Mobile wireless base station, 50... Fixed wireless base station, 60... Remote control room, 70... Remote control device, 100... Remote communication system, 110... First remote communication unit, 120... Second remote communication unit, 200... Fixed wireless line, 300... Mobile wireless line, 400... Cables, 1000... Swinging operation, 1101-1104... Camera, 1111-1114... Encoder, 1120... Operation signal interface, 1141-1144... Video signal, 1151-1154... Video data, 1161-1164... Video data, 1171... Operation data, 1181... Operation data, 1190...first vehicle-mounted wireless terminal, 1191...second vehicle-mounted wireless terminal, 1201-1204...decoders, 1211-1214...monitors, 1220...operation signal interface, 1241-1244...video data, 1251-1254...video signals, 1261-1264...video data, 1271...operation data, 1281...operation data, 1900...remotely operated construction machine system, 2000...packet loss rate of wireless line 300, 2100...packet loss rate of wireless line 310

Claims

1. A telecommunication system comprising: a first telecommunication unit communicatively connected to a first mobile radio base station and a second mobile radio base station; and a second telecommunication unit for transmitting and receiving data to and from the first telecommunication unit via the first mobile radio base station and the second mobile radio base station, the first remote communication unit is mounted on a construction machine; and An imaging device; a first vehicle-mounted wireless terminal communicably connected to the first mobile wireless base station via a first wireless line; a second vehicle-mounted wireless terminal communicably connected to the second mobile wireless base station via a second wireless line; a first communications platform that copies video data showing an image captured by the imaging device, makes the copied video data redundant using the first vehicle-mounted wireless terminal and the second vehicle-mounted wireless terminal, transmits the copied video data to the second remote communication unit via the first mobile wireless base station and the second mobile wireless base station over the first wireless line and the second wireless line, and outputs operation data for operating the construction machine received from the second remote communication unit via the first mobile wireless base station and the second mobile wireless base station over the first wireless line and the second wireless line to the construction machine, The second remote communication unit is provided in a remote operation room for remotely operating the construction machine, and a monitor for displaying an image according to the received image data; a second communication platform that copies the operation data, makes the copied operation data redundant, and transmits the redundant operation data to the first remote communication unit via the first mobile radio base station and the second mobile radio base station by the first wireless line and the second wireless line, and receives the video data from the first remote communication unit via the first mobile radio base station and the second mobile radio base station by the first wireless line and the second wireless line, and outputs the video data to the monitor; At least one of the first remote communication unit and the second remote communication unit has a monitoring function for determining whether the arrangement of the first mobile wireless base station or the second mobile wireless base station relative to the construction machine is good or bad based on the communication quality of the first wireless line and the second wireless line. A telecommunications system comprising:

2. the first vehicle-mounted wireless terminal has one or a plurality of antennas communicably connected to the first mobile wireless base station via the first wireless line; the second vehicle-mounted wireless terminal has one or more antennas communicably connected to the second mobile wireless base station via the second wireless line; The antenna of the first vehicle-mounted wireless terminal and the antenna of the second vehicle-mounted wireless terminal are mounted on the rear of the body of the construction machine.