Remote communication system and remote operation type construction machine system

Abstract

This invention determines the quality of an arrangement of a plurality of wireless base stations. A remote communication system 100 comprises: a first remote communication unit 110 which is communicably connected to a mobile wireless base station 40-1 and a mobile wireless base station 40-2, and is mounted on a construction machine; and a second remote communication unit 120 which is communicably connected to the mobile wireless base station 40-1 and the mobile wireless base station 40-2, and which transmits / receives data to / from the first remote communication unit 110 via the mobile wireless base station 40-1 and the mobile wireless base station 40-2. The first remote communication unit 110 and / or the second remote communication unit 120 has a monitoring function for determining the quality of an arrangement of the mobile wireless base station 40-1 and the mobile wireless base station 40-2 on the basis of the communication quality of a wireless line 300 and a wireless line 310.

Description

Remote communication system and remotely controlled construction machinery system

[0001] The present invention relates to a remote communication system and a remotely operated construction machine system that transmits and receives data via a plurality of mobile wireless base stations.

[0002] In recent years, due to rising labor costs and a shortage of skilled workers, there has been 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 control signals must be transmitted. If communication quality deteriorates, the image will be distorted and the machine will become inoperable, significantly reducing productivity. One of the major factors that deteriorates communication quality is the radio wave shielding problem unique 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 controlled excavator side and a controller that controls the actuator are provided on the excavator, and the on-board antenna is rotated in accordance with the rotation of the excavator so as to enter the radiation range of the wireless base station.

[0005] Furthermore, Patent Document 2 discloses a technology for controlling the directivity angle of beamforming, which is a radio technology for assigning a directivity angle to a radio wave radiation range. In Patent Document 2, an omnidirectional vehicle-mounted antenna is used to connect to a wireless base station with which to communicate, and then beamforming is used to limit the directivity angle of the radiation range to the direction of the wireless base station antenna. Then, the directivity angle of beamforming is controlled so as to keep the wireless base station antenna within the radiation range in accordance with the rotation of the excavator.

[0006] JP 07-288753 A JP 2022-87604 A

[0007] One factor that can 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 the antenna mounted on the excavator and the antenna of the wireless base station. Furthermore, the effect of radio wave blocking may change depending on the position and rotation of the excavator. The technologies disclosed in Patent Documents 1 and 2 do not provide a method for dealing with such phenomena. Furthermore, the technologies disclosed in Patent Documents 1 and 2 are based on the premise of wireless communication with a single wireless base station and do not address handover between base stations that occurs as the excavator moves.

[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 shielding problems caused by, for example, the front device 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 determining whether the placement of multiple wireless base stations is appropriate.

[0009] The remote communication system of the present invention is a remote communication system comprising: a first remote communication unit communicatively connected to a first mobile radio base station and a second mobile radio base station; and a second remote communication unit transmitting and receiving data to and from the first remote communication unit via the first mobile radio base station and the second mobile radio base station, wherein the first remote communication unit is mounted on a construction machine and comprises: an imaging device; a first on-board radio terminal communicatively connected to the first mobile radio base station via a first radio line; and a second on-board radio terminal communicatively connected to the second mobile radio base station via a second radio line, wherein the second remote communication unit is provided in a remote control room for remotely operating the construction machine and comprises a monitor that displays images according to received video data, and at least one of the first remote communication unit or the second remote communication unit has a monitoring function that determines 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 remotely controlled construction machine system according to the present invention includes the above-mentioned remote communication system, construction machine, and remote control room.

[0011] The remote communication system of the present invention can determine whether the placement of multiple wireless base stations is appropriate, thereby preventing degradation 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.

[0012] 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. FIG. 1 is a schematic diagram illustrating an example of communication quality relative to the position and swing angle of a shovel 10. FIG. 1 is a schematic diagram illustrating an example of communication quality relative to the position and swing angle of a shovel 10. FIG. 1 is a schematic diagram illustrating an example of a case where a plurality of on-board antennas are mounted on a shovel 10. FIG. 1 is a schematic diagram illustrating an example of a case where a plurality of on-board antennas are mounted on a shovel 10. FIG. 2 is a diagram illustrating an example of an arrangement of mobile wireless base stations in a mine to which a remote communication system for construction machinery is applied. FIG. 2 is a schematic diagram illustrating an example of an arrangement of mobile wireless base stations relative to a loading area 30, which is the working area of ​​a shovel 10. FIG. 3 is a schematic diagram illustrating an example of an arrangement of mobile wireless base stations relative to a loading area 30, which is the working area of ​​a shovel 10. FIG. 4 is a schematic diagram illustrating an example of an arrangement of mobile wireless base stations relative to a loading area 30, which is the working area of ​​a shovel 10. Fig. 1 is a schematic diagram showing an example of the arrangement of multiple on-board antennas mounted on a construction machine. Fig. 2 is a graph for determining whether the arrangement of a mobile wireless base station is good or bad. Fig. 3 is a graph for determining whether the arrangement of a mobile wireless base station is good or bad. Fig. 4 is a graph for determining whether the arrangement of a mobile wireless base station is good or bad. Fig. 5 is a flowchart showing a method for determining whether the arrangement of a mobile wireless base station 40-1 or a mobile wireless base station 40-2 is good or bad. Fig. 6 is a diagram showing an example of the configuration of a remote-controlled construction machine system.

[0013] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be designated by the same numerals. 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 descriptions in this specification are merely typical examples and are not intended to limit the scope or application of the present disclosure in any way.

[0014] Although the present embodiment has been described in sufficient detail to enable those skilled in the art to practice the present disclosure, 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] A remote communication system for construction machinery according to an embodiment will be described in detail below with reference to the drawings. The remote communication system for construction machinery is a system for remotely performing excavation work, loading work, traveling, and other operations at a construction site or mine without an operator being on board the shovel, and is a system for remotely communicating video signals and operation signals required for remote operation.

[0016] Figure 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. The mine shown in Figure 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 control room 60, and a remote control device 70. For the sake of simplicity, only the mobile wireless base station 40 (40-1) is shown in Figures 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, using a remote control device 70 and a remote communication system located in a remote control room 60. The remote communication system is configured to enable remote operation of the shovel 10, including excavation work, loading work, traveling, and other operations. Details of the remote communication system will be described later. At the loading site 30, the shovel 10 performs loading work by remotely loading excavated earth and sand ore into the dump truck 20.

[0018] When the excavator 10 finishes loading the soil or ore, the dump truck 20 travels along the transport path and dumps the load at the dump site. After dumping is complete, 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 dump 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 driven 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 located in a location remote from the loading site 30. The remote control room 60 may be located in a movable container or trailer, or in a control center that manages the entire mine. The remote control room 60 may also be located in an urban area far away from the mine, rather than within the mine itself.

[0021] The excavator 10 is remotely controlled for excavation work, loading work, 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 the 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 from the drawing.

[0022] The operation signal is then transmitted from the mobile wireless base station 40-1 via the wireless line 300 to the vehicle-mounted 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 a fixed wireless line 200. The video signals transmitted to the fixed wireless base station 50 are transmitted to a remote control device 70 located in a 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] Remotely controlling the excavator 10 for excavation, loading, traveling, and other operations requires remote communication of high-quality video signals and highly reliable operation signals. Degraded communication quality can lead to distorted video images and inoperability, significantly reducing productivity. One factor that can degrade communication quality is the possibility that the front device 11 of the excavator 10, such as a bucket, arm, boom, or other metal structure, may block radio waves between the onboard antenna 12-1 mounted on the excavator 10 and the antenna of a wireless base station (mobile wireless base station 40-1). Furthermore, the effect of radio wave blocking can change depending on the position of the excavator 10 and the swing operation 1000. Therefore, this embodiment provides a remote communication system that aims to prevent degradation of communication quality due to radio wave blocking between the onboard antenna 12-1 mounted on the excavator 10 and the antenna of a wireless base station (mobile wireless base station 40-1) by the front device 11 of the excavator 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 the illustrated number or a specific number. For example, there may be one shovel 10 and one dump truck 20, or there may be multiple of either or both of them.

[0026] Here, if the shovel 10 is positioned and rotates at an 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, which will result in good communication quality for the wireless line 300.

[0027] 3, the vehicle-mounted antenna 12-1 mounted on the shovel 10 and the mobile wireless base station 40-1 are in a positional relationship where radio waves are blocked by the front device 11 of the shovel 10, resulting in poor communication quality for the wireless link 300. In other words, it can be seen that the swinging motion unique to the shovel causes a radio wave blocking problem between the vehicle-mounted antenna 12 and the mobile wireless base station 40-1 due to the front device 11.

[0028] Furthermore, as shown in FIG. 4, when a plurality of on-board 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 able to transmit and receive using just one of the multiple antennas; communication must be possible between the on-board 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 differs among the wireless link 300-1 between the on-board antenna 12-1 and the mobile wireless base station 40-1, the wireless link 300-2 between the on-board antenna 12-2 and the mobile wireless base station 40-1, the wireless link 300-3 between the on-board antenna 12-3 and the mobile wireless base station 40-1, and the wireless link 300-4 between the on-board 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, while the wireless link 300-1 is in poor conditions.

[0030] 5, the communication quality differs among the wireless link 300-1 between the on-board antenna 12-1 and the mobile wireless base station 40-1, the wireless link 300-2 between the on-board antenna 12-2 and the mobile wireless base station 40-1, the wireless link 300-3 between the on-board antenna 12-3 and the mobile wireless base station 40-1, and the wireless link 300-4 between the on-board 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 poor 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 Figure 6. In this embodiment, as shown in Figure 6, a plurality of vehicle-mounted antennas 12-1, 12-2, 12-3, and 12-4 mounted on a shovel 10 are arranged behind the vehicle of the shovel 10. The rear of the vehicle of the shovel 10 means, for example, a position behind the boom of the front device 11.

[0032] 6, the communication quality differs among the wireless link 300-1 between the on-board antenna 12-1 and the mobile wireless base station 40-1, the wireless link 300-2 between the on-board antenna 12-2 and the mobile wireless base station 40-1, the wireless link 300-3 between the on-board antenna 12-3 and the mobile wireless base station 40-1, and the wireless link 300-4 between the on-board 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 poor conditions.

[0033] 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 all 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 line outside loading area 30, which is the working area of ​​shovel 10, and arranging vehicle antennas 12-1, 12-2, 12-3, and 12-4 behind shovel 10, vehicle antennas 12-1 to 12-4 can send and receive data to 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 relative to the loading area 30, which is the work area of ​​the shovel 10, will be described in detail with reference to Fig. 8. As shown in Fig. 8, it is desirable to arrange the mobile wireless base station 40-1 and the mobile wireless base station 40-2 at two diagonal corners on the outside of the loading area 30, which is the work area of ​​the shovel 10. Furthermore, 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, if the mobile radio base station 40-1 and the mobile radio base station 40-2 are arranged on two opposing sides of the loading area 30 instead of on two diagonal corners on the outside as shown in Fig. 10, there is a possibility that a radio wave shielding problem will occur due to the turning motion that is specific to excavators.Furthermore, if the mobile radio base station 40-1 and the mobile radio base station 40-2 are arranged on two other opposing sides of the outer frame of the loading area 30 instead of on two diagonal corners as shown in Fig. 11, there is a possibility that a radio wave shielding problem will occur due to the turning motion that is specific to excavators.

[0037] 8, 9, 10, and 11 merely show one example of the placement of mobile wireless base stations in a mine to which the construction machine remote communication system according to an embodiment of the present invention is applied. At actual mine sites, there are cases where the loading area 30 has a complex shape or where the surrounding terrain, such as the working face, makes it impossible to place mobile wireless base stations at the two diagonal outer corners of the loading area 30. There are also cases where radio waves are reflected by the surrounding terrain, such as the working face, making it unnecessary to place mobile wireless base stations at the two diagonal outer corners of the loading area 30, and conversely, where it is undesirable to place mobile wireless base stations at the two diagonal outer corners of the loading area 30. Furthermore, there are also cases where the optimal placement of mobile wireless base stations changes from moment to moment as the excavation work progresses and the terrain changes.

[0038] FIG. 12 is a block diagram showing the configuration of a remote communication system 100. The remote communication system 100 of 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 control room 60. The fixed wireless base station 50, cables 400, and remote control device 70 shown in FIGS. 1 to 11 are omitted from 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 control room 60, as shown in FIG.

[0039] The first remote communication unit 110 arranged on the shovel 10 has a first on-board wireless terminal 1190, a second on-board 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 control room 60 includes 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 first remote communication unit 110, video signals 1141, 1142, 1143, and 1144 necessary for remotely operating the shovel 10, which are captured by cameras 1101, 1102, 1103, and 1104, are input to encoders 1111, 1112, 1113, and 1114, respectively. The video signals 1141, 1142, 1143, and 1144 input to 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 encoder 1111 , encoder 1112 , encoder 1113 , and encoder 1114 are input to a first communication platform 1130 .

[0042] Video data 1151, video data 1152, video data 1153, and video data 1154 input to the first communication platform 1130 are duplicated for transmission over a two-line redundant system of the first in-vehicle wireless terminal 1190 and the second in-vehicle wireless terminal 1191. 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 an on-board antenna (on-board antennas 12-1, 12-2, 12-3, 12-4 (see Figure 13)) connected to the first on-board 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, 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 received from the mobile radio base station 40-1 and the mobile radio base station 40-2 are input to the 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 communication 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, thereby restoring a series of video data. 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 decoders 1201, 1202, 1203, and 1204, respectively. Then, the video data are decoded (for example, video compression decoding and error correction decoding) by decoders 1201, 1202, 1203, and 1204 to become video signals 1251, 1252, 1253, and 1254. The video signals 1251, 1252, 1253, and 1254 output from decoders 1201, 1202, 1203, and 1204 are input to monitors 1211, 1212, 1213, and 1214, and images required for remote operation of the excavator 10 are displayed. The operator operates the levers 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 excavator 10.

[0046] On the other hand, an operation signal input and generated by the 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 over 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 in-vehicle radio terminal 1190 and the second in-vehicle 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 validating the operation data of the wireless line received earlier 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 shovel 10 to perform excavation work, loading work, traveling, and other work is performed.

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

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

[0053] Next, the monitoring function for determining whether the placement of mobile wireless base stations 40-1 and 40-2 is appropriate will be described in detail with reference to the drawings. In the case of a loading area 30 in a mine to which the remote communication system for construction machinery shown in Figure 6 is applied, it is desirable to place mobile wireless base stations 40-1 and 40-2 at two diagonal corners on the outside of the loading area 30, which is the working area of ​​the excavator 10, as shown in Figures 8 and 9. However, in actual mining sites, there are cases where the shape of the loading area 30 is complex, or where the surrounding terrain, such as the working face, makes it impossible to place mobile wireless base stations at the two diagonal corners on the outside of the loading area 30, cases where it is not necessary to place mobile wireless base stations at the two diagonal corners on the outside of the loading area 30, and cases where it is not desirable to place mobile wireless base stations at the two diagonal corners on the outside of the loading area 30. Furthermore, as excavation work progresses and the terrain changes, the optimal placement of the mobile wireless base stations may change from moment to moment. In any case, it is important that the mobile radio base station 40-1 and the mobile radio base station 40-2 always have a complementary positional relationship with respect to the position and swing 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 packet loss rate PLR ​​(Packet Loss Ratio), which represents the communication quality of the radio link 300 of the mobile radio base station 40-1 and the communication quality of the radio link 310 of the mobile radio base station 40-2. The vertical axis of the graph represents the packet loss rate PLR, and the horizontal axis represents time.

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

[0056] However, if 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 Figure 15, it can be seen that packet loss occurs partially at the same time 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. In this way, Figure 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, it can be seen that packet loss occurs almost simultaneously 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. As can be seen from Fig. 16, 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, as shown in Figure 17, the packet loss rate PLR ​​of the wireless line 300 by the mobile wireless base station 40-1 at time 2010 and time 2011, 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 are constantly monitored, 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), a function is provided to monitor 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 relative 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 determining 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] To summarize the method for determining whether the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 is appropriate using the monitoring function described above, the method is, for example, a method for determining whether the placement of the radio base station is appropriate using a remote communication system 100 including: a first remote communication unit 110 mounted on the shovel 10 and communicatively connected to the mobile radio base station 40-1 and the mobile radio base station 40-1; and a second remote communication unit 120 connected to the mobile radio base station 40-1 and the mobile radio base station 40-2 and 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, and as shown in FIG. 18 , the method includes the steps of: a step (S1801) in which cameras 1101 to 1104 of the first remote communication unit 110 mounted on the shovel 10 capture an image; a step in which the encoders 1111 to 1114 encode the video signals 1141 to 1144 of the captured video (S1802); a step in which the first communication platform 1130 copies the encoded video data 1151 to 1154 (S1803); a step in which the first in-vehicle wireless terminal 1190 and the second in-vehicle wireless terminal 1191 make 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 (S1804); A step 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 (S1805); a step in which the monitors 1211 to 1214 display images according to the decoded video signals 1251 to 1254 (S1806); a step in which the operation signal interface 1220 receives operation data 1271 for operating the shovel 10 in a remote control room 60 separated from the shovel 10 (S1807); a step in which the second communication platform 1230 copies the operation data 1271 (S1808);1281-2 to be redundant and transmitted from the second remote communication unit 120 to the first remote communication unit 110 via the wireless circuit 300 and the wireless circuit 310 (S1809); a first communication platform 1130 of the first remote communication unit 110 restoring the operation data 1181-1, 1181-2, and an operation signal interface 1120 operating the shovel 10 in accordance with the restored operation data 1171 (S1810); and 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 wireless base station 40-1 or the mobile wireless base station 40-2 is appropriate based on the communication quality of the wireless circuit 300 and the wireless circuit 310.

[0061] In addition, this judgment method may include a step (S1812) of issuing an alarm when at least one of the first remote communication unit 110 or the second remote communication unit 120 determines, 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, that the placement of the mobile radio base station 40-1 or the mobile radio base station 40-2 is inappropriate.

[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 mobile wireless base station 40-1 and 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 link 300 is higher than a preset threshold and the packet loss rate of the wireless link 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 link 300 or the wireless link 310 may be the average packet loss rate of the wireless links 300-1 to 300-4 or the average packet loss rate of the wireless links 310-1 to 310-4, or the packet loss rate of a wireless link selected from the wireless links 300-1 to 300-4 or the packet loss rate of a wireless link selected from the wireless links 310-1 to 310-4.

[0064] Furthermore, 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 duplicate 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 to 1104, operation data output by operation signal interface 1220, data transmitted by executing the network command ping, or data transmitted from software that performs 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 telecommunication system 100 shown in Figure 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, video data 1262-1 and 1262-2, video data 1263-1 and 1263-2, and video data 1264-1 and 1264-2 transmitted in the two-line redundant system via the wireless line 300 and the wireless line 310, the second communication platform 1230 uses the assigned sequence numbers to detect the occurrence of packet loss in the wireless line 300 and the wireless line 310 from missing sequence numbers. Then, when packet loss in the wireless line 300 and 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 relative to the loading site 30.

[0068] In addition, a method may be adopted 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 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 relative to the loading area 30, it is possible to provide a remote communication system 100 that has the function of preventing image distortion caused by a deterioration in communication quality.

[0071] In this embodiment, the simultaneous occurrence of packet loss on wireless line 300 and packet loss on wireless line 310 detects that the loading area 30 is not properly positioned, but 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 mobile radio base stations, 40-1 and 40-2, are used, but the number of stations is not limited to two, and three or more stations may be used, and either of the mobile radio base stations may be a fixed radio base station.

[0073] In the present invention, the communication method of the wireless lines 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 lines 300 and 310 may be different communication methods, for example, the wireless line 300 may be Wi-Fi and the wireless line 310 may be 5G.

[0074] Furthermore, the vehicle-mounted wireless terminal mounted on the excavator 10 may be configured to include a single terminal, as long as the vehicle-mounted wireless terminal is capable of connecting to multiple 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] 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 used in a mine has been described as an example, but the remote control of a shovel used in a construction site may also be used. The same effect can be obtained when a wheel loader or dump truck, which is a construction machine or work machine other than a shovel, is remotely controlled.

[0078] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be implemented in hardware, in part or in whole, by designing them as integrated circuits, for example. Furthermore, the above-described configurations, functions, etc. may be implemented in software, in which a processor interprets and executes a program that implements each function.

[0079] 10... Shovel, 11... Front device, 12, 13... On-board 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... Turning 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 controlled construction machine system, 2000...packet loss rate of wireless line 300, 2100...packet loss rate of wireless line 310

Claims

1. A remote communication system comprising a first remote communication unit communicatively connected to a first mobile radio base station and a second mobile radio base station, and a second remote communication unit transmitting and receiving data to and from the first remote communication unit via the first mobile radio base station and the second mobile radio base station, wherein the first remote communication unit is mounted on a construction machine and comprises: an imaging device; a first vehicle-mounted radio terminal communicatively connected to the first mobile radio base station via a first radio line; and a second vehicle-mounted radio terminal communicatively connected to the second mobile radio base station via a second radio line, the second remote communication unit is provided in a remote control room for remotely controlling the construction machine, and has a monitor for displaying images according to the received image data, and at least one of the first remote communication unit or the second remote communication unit has a monitoring function for judging whether the arrangement 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. A telecommunications system comprising:

2. The remote communication system described in claim 1, characterized in that the first vehicle-mounted radio terminal has one or more antennas communicatively connected to the first mobile radio base station via the first radio line, the second vehicle-mounted radio terminal has one or more antennas communicatively connected to the second mobile radio base station via the second radio line, and the antennas of the first vehicle-mounted radio terminal and the antennas of the second vehicle-mounted radio terminal are mounted on the rear of the body of the construction machine.

3. The remote communication system according to claim 1, characterized in that the monitoring function has a function of issuing an alarm if it is determined that the placement of the first mobile radio base station and the second mobile radio base station is not appropriate.

4. The remote communication system according to claim 1, characterized in that the indicator indicating the communication quality is a packet loss rate, and the monitoring function is a function of detecting the packet loss rate of the first wireless line and the packet loss rate of the second wireless line, and determining that the placement of the first mobile wireless base station or the second mobile wireless base station is inappropriate based on the packet loss rate of the first wireless line and the packet loss rate of the second wireless line.

5. The remote communication system according to claim 1, characterized in that the index indicating the communication quality is a throughput value, and the monitoring function is a function of detecting the throughput value of the first wireless line and the throughput value of the second wireless line, and determining that the placement of the first mobile wireless base station or the second mobile wireless base station is inappropriate based on the throughput value of the first wireless line and the throughput value of the second wireless line.

6. The remote communication system according to claim 1, characterized in that the indicator of communication quality is a delay time, and the monitoring function is a function of detecting the delay time of the first wireless line and the delay time of the second wireless line, and determining that the placement of the first mobile wireless base station or the second mobile wireless base station is inappropriate based on the delay time of the first wireless line and the delay time of the second wireless line.

7. A remote-controlled construction machine system comprising the remote communication system according to claim 1, said construction machine, and said remote control room.

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