Work site management system

Abstract

A work site management system 1 comprises a server 600 that communicates with electric work machines at a work site, the work site management system 1 being characterized in that the server 600 comprises: a data transmitting and receiving unit 601 that acquires information relating to intrusion prohibited areas set for a power cable connected to an electric excavator 100 driven by electric power, and transmits an entire map created by an arithmetic function unit 602 to the electric excavator 100 or to a terminal having a display unit; and the arithmetic function unit 602, which creates the entire map, which is a map indicating the intrusion prohibited areas within a construction site, on the basis of the information relating to the intrusion prohibited areas acquired by the data transmitting and receiving unit 601. This makes it possible to provide a work site management system that allows operators to easily identify power cables that are routed at a work site.

Description

Work site management system

[0001] The present invention particularly relates to a work site management system that can be suitably used when using an electric work machine supplied with power via a power cable.

[0002] In recent years, from the perspective of environmental consideration, electric work machines operated by electric power have been increasingly used. As a method of supplying power to an electric work machine, there is a method in which a power cable is connected to the electric work machine, and power obtained from a system power supply or the like is supplied to the electric work machine via the power cable.

[0003] Patent Document 1 discloses that a high-voltage cable for connecting and supplying power between an electric drive means driven by power from a power generation means that generates power by driving an engine or a power storage means that stores power generated by the power generation means, and the power storage means is routed along the side surface of a frame structural member protruding in the vertical direction, whereby the high-voltage cable is suitably protected using the frame structural member as a vertical wall, and the high-voltage cable is suitably protected by the frame structural member even when, for example, a construction machine collides with an obstacle or the like.

[0004] Japanese Unexamined Patent Application Publication No. 2011-122307

[0005] In an electric work machine, a power cable for receiving power supply is required outside the vehicle body. Therefore, attention must be paid not only to power cables routed inside the own machine, but also to power cables routed outside the own machine and other machines. However, at a construction site where a plurality of electric work machines operate, a plurality of power cables are also laid, and there is a problem that it is difficult for an operator to notice power cables connected to other electric work machines. An object of the present invention is to provide a work site management system that allows an operator to easily grasp power cables laid on a work site.

[0006] To solve the above problems, the present invention provides a work site management system equipped with a management server that communicates with electric work machines at a work site, wherein the management server comprises: an acquisition unit that acquires information on restricted areas set for power cables connected to electric work machines that are driven by electricity; an overall map information creation unit that creates an overall map, which is a map showing restricted areas within the work site, based on the restricted area information acquired by the acquisition unit; and a transmission unit that transmits the overall map created by the overall map information creation unit to an electric work machine or a terminal having a display unit. In this case, it is possible to provide a work site management system that enables each electric work machine to be aware of the restricted areas set around the power cables, thereby enabling the electric work machines to be operated more safely.

[0007] Here, for example, the management server includes a receiving unit that receives location information within the work site for each of the electric work machines and the cable containers to which the power cables supplying power to the electric work machines are connected, and a no-entry area setting unit that sets a no-entry area based on the location information received by the receiving unit and transmits the information of the no-entry area to the acquisition unit. In this case, each work machine can first set its own no-entry area. Furthermore, for example, the information of the overall map is transmitted to multiple electric work machines in the work site and displayed on a display device provided on each of the multiple electric work machines. In this case, each work machine can understand its own no-entry area. Moreover, for example, the information of the no-entry area acquired by the acquisition unit is the information of the local map set for each of the multiple electric work machines operating in the work site, and the overall map created by the overall map information creation unit is created by integrating the information of the local maps. In this case, the local map allows the user to first understand the no-entry area around their own work machine.

[0008] According to the present invention, it is possible to provide a work site management system that allows operators to easily identify power cables wired at the work site.

[0009] This figure shows the overall configuration of a work site to which this embodiment is applied. This is a block diagram showing the functional configuration of the work site management system. This is a flowchart showing the processing performed by the work site management system. This figure shows how to correct the position of the device itself. This figure shows a no-entry area. This figure shows a local map created by visualizing the no-entry area map data of the no-entry area calculated by the electric excavator. Figures (a) to (c) show the case where the no-entry area map data received by the server is combined and no-entry area map data for the entire construction site is calculated. This figure shows an example of displaying the no-entry area map data as an image.

[0010] The embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0011] <Explanation of the overall configuration of the work site> Figure 1 is a diagram showing the overall configuration of a work site to which this embodiment is applied. Multiple electric work machines are in operation at the work site. The work site shown is a construction site. The diagram shows the case in which an electric excavator 100 is in operation as an electric work machine at the construction site. Note that the electric work machines operating at the construction site are not limited to the electric excavator 100, but can be construction machines such as wheel loaders, bulldozers, and cranes. Also, the electric work machines operating at the construction site may be trucks that transport gravel, etc. Note that the work site is not limited to a construction site. For example, it can also be an agricultural work site in which agricultural machinery is in operation as an electric work machine. In this case, the agricultural machinery may be a felling machine, a logging machine, a tractor, a forestry work vehicle, a logging machine, etc.

[0012] The illustrated electric excavator 100 is an example of an electric powered work machine. It can also be said that the electric excavator 100 is an example of an electric construction machine. A power cable 200 is connected to the electric excavator 100 to supply power to it. The power cable 200 is, for example, a high-voltage cable capable of transmitting three-phase alternating current. The power cable 200 is connected to the electric excavator 100 and a reel-type cable container 300, supplying power to the electric excavator 100 via the reel-type cable container 300. In other words, one end of the power cable 200 is connected to the electric excavator 100, and the other end is connected to the reel-type cable container 300. The reel-type cable container 300 is an example of a cable container that winds up the power cable 200 and stores the excess length of the power cable 200. The reel-type cable container 300 straightens the power cable 200 by winding it up. In other words, when the electric excavator 100 moves away from the reel-type cable container 300, the wound-up power cable 200 is pulled out from the reel-type cable container 300. Conversely, when the electric excavator 100 moves towards the reel-type cable container 300, the power cable 200 is wound into the reel-type cable container 300. The reel-type cable container 300 provides tension to wind up the power cable 200, thereby maintaining a straight shape between the electric excavator 100 and the reel-type cable container 300.

[0013] The reel-type cable container 300 is supplied with power from the grid power supply 400. The grid power supply 400, also known as the commercial power supply, is electricity generated by a power plant and supplied by a power company. Figure 1 shows that power is supplied from the grid power supply 400 via the switchboard 410 and the cable 420.

[0014] As mentioned above, at a construction site, not only the electric excavator 100 but also other construction machinery is in operation. Therefore, there is a risk that other construction machinery may get between the electric excavator 100 and the reel-type cable container 300. In this case, there is a risk that the construction machinery may come into contact with the power cable 200.

[0015] Therefore, in this embodiment, a work site management system 1 is constructed that creates a map showing the location of the power cable 200 within the entire construction site. The work site management system 1 sets the area that falls within a predetermined width, flanking the straight power cable 200, as a no-entry zone. Each of the multiple electric excavators 100 creates one of these no-entry zones. The electric excavator 100 then creates a local map showing the no-entry zone around itself. Furthermore, the server 600 receives these local maps and creates an overall map showing the no-entry zone for the entire construction site. This overall map is sent to each construction machine within the construction site, and by sharing the overall map of the no-entry zone, the above problem is avoided.

[0016] <Explanation of the Configuration of the Work Site Management System 1> Figure 2 is a block diagram showing the functional configuration of the Work Site Management System 1. The Work Site Management System 1 shown in Figure 2 comprises an electric excavator 100, a reel-type cable container 300, and a server 600. Figure 2 also shows the information exchange between these components. Here, it is indicated that there are n electric excavators 100, numbered from No. 1 to No. n. The configuration of each electric excavator 100 can be the same. Therefore, the following explanation will use one electric excavator 100 as an example.

[0017] The electric excavator 100 includes a vehicle control device 120, a power cable detection unit 125, a position detection unit 126, an inverter 117, a drive motor 118, a hydraulic pump 131, and a data transmission / reception unit 150.

[0018] The vehicle control device 120 comprises a control calculation function unit 121, a data recording unit (memory) 122, a communication function unit 123, and an intrusion restriction area map calculation function unit 124. The control calculation function unit 121 performs calculations to control the operation of the entire electric excavator 100, including the hydraulic circuit 130, power cable detection unit 125, and data transmission / reception unit 150. The control calculation function unit 121 also performs control to stop its own electric excavator 100 if another construction machine enters an intrusion restriction area, based on an overall map showing the intrusion restriction areas of the entire construction site sent from the server 600. Specifically, the vehicle control device 120 outputs a motor stop signal to the control unit (controller) 117C of the inverter 117. The inverter 117 further outputs a motor stop signal to the drive motor 118, controls the hydraulic pressure of the hydraulic pump 131, and stops the hydraulic pump 131. The data recording unit (memory) 122 records programs and data for the control calculation function unit 121 to perform calculations. The communication function unit 123 is a communication interface used to transmit control signals to the hydraulic circuit 130, the power cable detection unit 125, and the data transmission / reception unit 150. The no-entry area map calculation function unit 124 creates a local map, which is a map showing the no-entry area set around the power cable 200, based on the position information of the electric excavators 100 and the reel-type cable containers 300. This local map is created for each electric excavator 100 from No. 1 to No. n. The no-entry area map calculation function unit 124 functions as a no-entry area setting unit, setting the no-entry area based on the position information of the electric excavators 100 and the reel-type cable containers 300 within the construction site, which is received by the data transmission / reception unit 150, and transmitting the no-entry area information to the server 600.

[0019] The power cable detection unit 125 detects whether or not the electric excavator 100 is connected to the power cable 200. The power cable detection unit 125 can be configured to detect the connection by, for example, activating a detection sensor or switch provided on the electric excavator 100 at the connector of the connected power cable 200. Alternatively, the operator of the electric excavator 100 can input the connection status. In this case, after connecting the power cable 200 to the electric excavator 100, the operator inputs the connection status of the power cable 200 using the control panel or a switch that indicates the status.

[0020] The position detection unit 126 detects the position of the electric excavator 100. The position detection unit 126 is, for example, a GNSS device and comprises a GNSS antenna and a GNSS receiver. The GNSS antenna receives radio signals from multiple GNSS (Global Navigation Satellite Systems) satellites (positioning satellites). The GNSS receiver uses the signals received by the GNSS antenna to calculate the position and bearing in a geographic coordinate system (global coordinate system). The position detection unit 126 can also be an automatic tracking total station (TS).

[0021] The data transmission / reception unit 150, and the communication function unit 123, are communication interfaces that exchange data with external devices such as the reel-type cable container 300 and the server 600. The data transmission / reception unit 150 receives individual information such as ID from the connected reel-type cable container 300 as container connection information. It also receives the location of the reel-type cable container 300 as container location information. In other words, the data transmission / reception unit 150 functions as a receiver that receives location information within the construction site for both the electric excavator 100 and the reel-type cable container 300 to which the power cable 200 supplying power to the electric excavator 100 is connected. It also transmits local map information to the server 600 as no-entry area map information. In this embodiment, information is exchanged via wireless communication, but wired communication may also be used, or wireless and wired communication may be used in combination.

[0022] The reel-type cable container 300 comprises a connection calculation function unit 301, a position detection calculation function unit 302, and a data transmission / reception unit 303. The connection calculation function unit 301 detects whether or not it is connected to the electric excavator 100. The position detection calculation function unit 302 detects the position of the reel-type cable container 300. The position detection calculation function unit 302 can be a GNSS device, similar to the position detection unit 126. It can also be an automatic tracking total station (TS). The data transmission / reception unit 303 is a communication interface used to transmit control signals to the connection calculation function unit 301 and the position detection calculation function unit 302. The data transmission / reception unit 303 also exchanges data with external devices such as the electric excavator 100 and the server 600.

[0023] The server 600 is an example of a management server that communicates with the electric excavators 100 at a construction site, and comprises a data transmission / reception unit 601 and a calculation function unit 602. The data transmission / reception unit 601 is an example of an acquisition unit, and acquires local map information as information on the no-entry area set around the power cable 200 for each electric excavator 100. It can also be said that the data transmission / reception unit 601 acquires information on the no-entry area set for the power cable 200 connected to the electric excavator 100, which is driven by electricity. In this case, the no-entry area information acquired by the data transmission / reception unit 601 is local map information set for each of the multiple electric excavators 100 operating within the construction site. Furthermore, the data transmission / reception unit 601 is an example of a transmission unit, and transmits the overall map created by the calculation function unit 602 to the electric excavator 100 or a terminal having a display unit. The display unit is not particularly limited as long as it has the function of displaying images, but examples include liquid crystal displays. The calculation function unit 602 is an example of a whole map information creation unit, and based on the information of the restricted area (in this case, the local map) acquired by the data transmission / reception unit 601, it creates a whole map, which is a map showing the restricted area within the construction site. The whole map created by the calculation function unit 602 is created by integrating the information of the local map.

[0024] The vehicle control device 120 and server 600 are computer devices, comprising a processor such as a CPU (Central Processing Unit) as a means of calculation, main memory as a means of storage, and storage. The processor executes various software such as the OS (operating system) and application programs (application software). The main memory is a storage area that stores various software and data used for its execution. Furthermore, the storage is a storage area that stores input data for various software and output data from various software.

[0025] <Explanation of the processes performed by the work site management system 1> Figure 3 is a flowchart showing the processes performed by the work site management system 1. First, the operator of the electric excavator 100 turns on the key (S301). This turns on the high-voltage circuits such as the inverter 117, and the operator can operate the electric excavator 100.

[0026] Next, the electric excavator 100 detects whether the power cable 200 is connected (S302). As described above, there are methods of detection, such as detection by the power cable detection unit 125 or detection by input from the operator.

[0027] Next, the electric excavator 100 identifies the reel-type cable container 300 connected to the electric excavator 100 (S303). Identification methods include automatic recognition technology such as RFID (Radio Frequency Identification), or pairing using identifiable individual information such as serial number and ID through communication between the reel-type cable container 300 and the electric excavator 100.

[0028] Next, the electric excavator 100 acquires position information of the electric excavator 100 and the reel-type cable container 300 from a position measurement system such as a satellite-based position measurement system (GNSS) or an automatic tracking total station (TS) (S304). This can be acquired using the position detection unit 126 and the position detection calculation function unit 302.

[0029] At this time, the electric excavator 100 corrects its own position. Figure 4 shows a diagram illustrating the method of correcting the position of the electric excavator. The electric excavator 100 corrects its position by using the tip 152 of the cable fixing rod 151 of the electric excavator 100, which is obtained when the attached power cable 200 is wound up and becomes linear, as the position of the electric excavator 100.

[0030] Returning to Figure 3, the electric excavator 100 then calculates the position of the power cable 200 from the positions of the electric excavator 100 and the reel-type cable container 300 (S305). The position of the power cable 200 is in a straight line between the electric excavator 100 and the reel-type cable container 300. Therefore, using the paired position information of the electric excavator 100 and the position information of the reel-type cable container 300, the position of the power cable 200 is determined by drawing a straight line between the electric excavator 100 and the reel-type cable container 300.

[0031] Next, the electric excavator 100 calculates the no-entry zone around the power cable 200 (S306).

[0032] Figure 5 shows the restricted access area Wa. Here, it is shown that the restricted access area Wa is defined as the area with a width L surrounding the power cable 200, as calculated in S306. This width L is set to a predetermined length. Here, the restricted access area Wa is shown for two electric excavators 100 connected to one reel-type cable container 300.

[0033] Returning to Figure 3, the electric excavator 100 then calculates the no-entry area Wa calculated in S306 onto the pre-loaded construction site map data to create the no-entry area map data Wm (S307). This no-entry area map data Wm contains information about the no-entry areas set around the power cable 200 for each electric excavator 100.

[0034] Figure 6 shows a local map of the restricted area map data Wm calculated by the electric excavator 100 for the restricted area Wa. The origin Or, which serves as the reference point in this case, can be set arbitrarily, without being limited to the location information of the electric excavator 100, the location information of the power cable 200, or a map of the construction site. Here, we show the case where two electric excavators 100, as shown in Figure 5, each create the restricted area map data Wm.

[0035] Returning to Figure 3, the electric excavator 100 then transmits the information of the no-entry area map data Wm calculated in S307 to the server 600 (S308). If multiple electric excavators 100 are operating at the construction site (Yes in S309), the server 600 collects all of the no-entry area map data Wm (S310). If multiple electric excavators 100 are not operating at the construction site (No in S309), that is, if only one electric excavator 100 is operating, the process proceeds to S312. By aggregating the no-entry area map data Wm from multiple electric excavators 100 at the server 600, it becomes unnecessary for each electric excavator 100 to process data from multiple units, reducing the processing load on the electric excavator 100.

[0036] Next, the server 600 uses the calculation function unit 602 to calculate the no-entry area map data Wsm for the entire construction site. Figures 7(a) to 7(c) show the case where the server 600 combines the received no-entry area map data Wm to calculate the no-entry area map data Wsm for the entire construction site. Of these, Figure 7(a) shows the no-entry area map data Wm for the two electric excavators 100 shown in Figure 5. Then, as shown in Figure 7(b), the server 600 calculates a position correction for the no-entry area map data Wm within the construction site, using the origin 702 of the construction site, which has been set in advance, as the reference point. The corrected no-entry area map data Wm within the construction site is combined into a single no-entry area map data Wsm with respect to the origin 702, as shown in Figure 7(c) (S311). The combined no-entry area map data Wsm forms an area to prevent construction machinery from approaching the power cable 200 at the construction site.

[0037] Returning to Figure 3, the next step is to transmit the construction machinery access restriction map data Wsm, created above, to the construction machinery operating at the construction site (S312). The received access restriction map data Wsm is used as setting data for the area restriction function and displayed on a display device to alert construction machinery to approach the power cable 200, such as through visual cable location recognition, thereby reducing the risk of approaching the power cable 200. The display device is not particularly limited as long as it has the function to display images, but examples include liquid crystal displays. In this way, the map is created by the server 600 as access restriction map data Wsm, which represents the access restriction area Wa, and transmitted to multiple construction machines within the work site. The multiple construction machines then display this access restriction map data Wsm as an image on their display devices.

[0038] Figure 8 shows an example of displaying the no-entry area map data Wsm as an image. As shown in the figure, the no-entry area map data Wsm displays the no-entry area Wa, allowing operators to easily identify the power cables 200 wired to the construction site and understand the no-entry area Wa within the entire construction site. Multiple operators of construction machinery can work without entering the no-entry area Wa by looking at the map displayed as an image. Furthermore, by setting this map as the setting value for the area restriction function, it is possible to control the operation of the electric excavator 100 by restricting the slewing angle, slewing radius, no-entry surface, etc. As a result, construction machinery can be operated more safely.

[0039] Furthermore, the server 600 is responsible for creating the no-entry area map data Wsm. In other words, if each electric excavator 100 sets a no-entry area Wa and shares this information with the construction machinery on the construction site, the amount of information becomes enormous, and the controller of the electric excavator 100 cannot process it all. Also, in this case, the calculations become complicated, and as the electric excavator 100 moves, the position of the power cable 200 also moves, making it difficult for the calculation of the no-entry area Wa to keep up. Moreover, different calculation results are likely to occur. Therefore, it is difficult for each electric excavator 100 to process the no-entry area Wa of multiple electric excavators 100, which are constantly changing. With the above configuration, by having the server 600, which has superior computational processing capabilities, create the no-entry area map data Wsm and transmit it to each construction machine, these problems are less likely to occur.

[0040] In the configuration described above, the information of the no-entry area Wa set around the power cable 200 for each electric excavator 100 is no-entry area map data Wm (local map information), which is a map showing the no-entry area Wa for each electric excavator 100, and the calculation function unit 602 creates no-entry area map data Wsm (overall map information) based on the information of the no-entry area map data Wm. In the configuration described above, local map information was created by the electric excavator 100, and the no-entry area map data Wsm, which is the overall map information, was created by the server 600 based on this. However, it is also possible to transmit the position information of the electric excavator 100 and the reel-type cable container 300 to the server 600, and the server 600 creates the no-entry area map data Wsm based on this. In this case, the server 600 alone can be considered to have the functions of the work site management system 1. Furthermore, since the location of each construction machine can be sent to the server 600, if another construction machine enters the restricted area Wa of a certain construction machine, the server 600 can issue a command to stop at least one of the construction machines, using the restricted area map data Wsm.

[0041] 1...Work site management system, 100...Electric excavator (electric work machine), 120...Vehicle control device, 124...No entry area map calculation function unit (No entry area setting unit), 125...Power cable detection unit, 126...Position detection unit, 150...Data transmission / reception unit (receiving unit), 300...Reel-type cable container, 600...Server (management server), 601...Data transmission / reception unit (acquisition unit, transmission unit), 602...Calculation function unit (overall map information creation unit), Wa...No entry area, Wm, Wsm...No entry area map data

Claims

1. A work site management system equipped with a management server that communicates with electric work machinery at a work site, wherein the management server comprises: an acquisition unit that acquires information on restricted areas set for power cables connected to electric work machinery driven by electricity; an overall map information creation unit that creates an overall map, which is a map showing the restricted areas within the work site, based on the restricted area information acquired by the acquisition unit; and a transmission unit that transmits the overall map created by the overall map information creation unit to the electric work machinery or a terminal having a display unit.

2. The work site management system according to claim 1, characterized in that the management server comprises: a receiving unit that receives location information within the work site of the electric work machine and the cable container to which the power cable supplying power to the electric work machine is connected; and an entry restriction area setting unit that sets the entry restriction area based on the location information received by the receiving unit and transmits information of the entry restriction area to the acquisition unit.

3. The work site management system according to claim 1, characterized in that the information of the overall map is transmitted to multiple electric work machines within the work site and displayed on a display device provided on each of the multiple electric work machines.

4. The work site management system according to claim 1, characterized in that the information of the restricted area acquired by the acquisition unit is local map information set for each of the multiple electric work machines operating within the work site, and the overall map created by the overall map information creation unit is created by integrating the information of the local maps.

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