JP2002047690A - Remote control device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote control device for a construction machine having excellent operability at a low cost. SOLUTION: This remote control device is provided with general-purpose portable communication terminals 14A and 14B mountable on a hydraulic backhoe and general-purpose portable communication terminals 17A and 17B separable from the hydraulic backhoe, for example. Transmission signals from the terminals 17A and 17B are received by the terminals 14A and 14B to control the operation of the hydraulic backhoe, or the transmission signals from the terminals 14A and 14B are received by the terminals 17A and 17B to collect the operation information of the hydraulic backhoe. The terminals 14A, 14B, 17A and 17B utilize at least a transceiver function for mutual direct communications.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control device for remotely controlling a construction machine such as a hydraulic shovel by radio.

[0002]

2. Description of the Related Art A variety of technologies have been developed for a remote control device for remotely controlling a construction machine such as a hydraulic excavator by radio, and a so-called specific low-power radio using a frequency band of, for example, 429 MHz is used as the radio. Have been. The main reasons are considered as follows. It does not require a user's wireless license, and can be operated only with a vehicle construction machine license. Even if radio interference or interference occurs, it is safe because it has a function of automatically stopping or automatically changing the frequency channel. There are 40 channels in the radio frequency band, and in combination with the above, many units can be operated. Since the frequency is low, even if there is an obstacle, the radio wave relatively easily wraps around due to diffraction.

[0003]

However, when a specific low power radio is used, there are the following problems. Since the frequency is low, there is little data that can be exchanged and the transfer speed is low. For this reason it is generally unidirectional,
Although a command can be issued from the operating device to the construction machine, it is difficult to feed back the state quantity from the construction machine to the operating device. Since the power is as small as 10 mW or less, the radio wave reach is as short as about several 100 m. For this reason, if communication is interrupted beyond the reach, the only way to recover is to reduce the distance.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a remote control device for a construction machine which is inexpensive and has excellent operability.

[0005]

According to the first aspect of the present invention,
A remote control device for a construction machine, comprising: a first communication unit mounted on a construction machine; and a second communication unit capable of wirelessly transmitting and receiving the first communication unit.
The communication means has at least a first communication function for directly communicating with each other.

[0006] According to the above configuration, when the first communication means and the second communication means are within the transmission / reception range of the first communication function, the first communication function is used, so that short-distance communication requires communication cost. The first communication function that cannot be used is used. In this case, bidirectional and multi-data exchange is possible.

[0007] In the first aspect, the first communication means and the second communication means
If the communication means also has a second communication function for communicating via a public communication line (claim 2), the first communication means and the second communication means are outside the transmission / reception range of the first communication function. When the first communication function is used, the first communication function is used.
Even when the transmission / reception range of the communication function is exceeded, communication by the second communication function is ensured. Also in this case, bidirectional and multi-data exchange is possible.

In the first or second aspect, the first communication function may be, for example, a transceiver function of a mobile communication terminal (claim 3).

In any one of the first to third aspects, when there is a period in which transmission and reception are in a suspended state while using the first communication function, a plurality of pairs of the first communication means and the second communication means are provided, If the communication timing of each communication means is shifted by at least the pause time between each pair (claim 4),
Even when the first and second communication means directly communicate with each other, the communication is not interrupted, so that the continuous operation of the construction machine is ensured.

According to a second aspect of the present invention, there is provided an operation means for generating an operation signal for remotely operating a construction machine, and a construction based on the operation signal when the operation signal is transmitted from the second communication means to the first communication means. Providing operation control means for controlling the operation of the machine (claim 5) ensures good operability of the construction machine.

[0011] In claim 5, for example, the operating means includes:
When the operation signal is transmitted from the second communication unit to the first communication unit, a second signal conversion unit that performs signal conversion for using the first communication function or the second communication function is provided. What is necessary is just to provide the 1st signal conversion means which converts the conversion signal received by the communication means into a control signal for controlling the operation of the construction machine (claim 6).

According to a second aspect of the present invention, a detecting means for detecting a feedback signal indicating an operation state of the construction machine, and, when the feedback signal is transmitted from the first communication means to the second communication means, based on the feedback signal, If an operation status presenting means for presenting the operation status on the monitor is provided (claim 7), the operation status of the construction machine can be easily grasped, so that the operability of the construction machine is further improved.

[0013] In claim 7, for example, the detecting means includes:
A third signal conversion unit for performing signal conversion for using the first communication function or the second communication function when transmitting the feedback signal from the first communication unit to the second communication unit;
The operation status presentation means may include a fourth signal conversion means for converting the conversion signal received by the second communication means into an operation information signal for presenting the operation status of the construction machine to the monitor ( Claim 8).

In claim 7 or 8, if the feedback signal includes video data (claim 9), the operating condition of the construction machine can be visually grasped, so that the operability of the construction machine is further improved. Is done.

[0015]

(Embodiment 1) FIG. 1 is an overall configuration diagram of a hydraulic shovel as an example of a construction machine to which a remote control device according to Embodiment 1 is applied. In the figure,
100 is a lower traveling body of a hydraulic shovel, 200 is an upper revolving superstructure, and 300 is an excavation attachment mounted on the front of the upper revolving superstructure 200.

The lower traveling body 100 includes left and right crawler frames 101 and crawlers 10 each having only one side shown.
The two crawlers 102 are individually driven to rotate and run.

The upper revolving unit 200 includes the revolving frame 20.
1. It comprises a cabin 202 and the like, and is rotated by a turning motor 203 to turn on the lower traveling body 100.

The excavation attachment comprises a boom 301, an arm 302, and a bucket 303, each of which is driven to expand and contract by cylinders 304 to 306 to perform an excavation work operation and the like.

FIG. 2 is a block diagram showing a schematic configuration of the remote control device according to the first embodiment. A control system of a hydraulic shovel to be operated by this device is configured by an electric / hydraulic system centered on a controller (corresponding to an operation control unit) 1. That is, the starter relay 3 for starting the engine 2 is controlled by the controller 1, and the stepping motor 4 for controlling the stop or switching of the rotation speed of the started engine 2 is controlled by the controller 1.

Actuators such as the swing motor 203 and cylinder 304 (collectively denoted by reference numeral 5).
Is driven by a main hydraulic pressure supplied through a main control valve 6. The operation of the main control valve 6 is further operated by an electromagnetic proportional valve 7 controlled by the controller 1 or a lever operation of a normal operation room. The control is performed by switching the internal hydraulic spool in accordance with the pilot hydraulic pressure supplied from one of the remote control valves 8 selected by the shuttle valve 9 at a high level. The main hydraulic pressure and the pilot hydraulic pressure are supplied from a hydraulic pump 10 driven by the engine 2.

Various sensors 11 including a rotation sensor and a pressure sensor for detecting the operation of the engine 2 and the like, and a status indicator lamp 12 are connected to the controller 1 so that the controller 1 can perform feedback control and the like.

The controller 1 has two general-purpose portable communication terminals (corresponding to the first communication means and the mobile communication terminal) via a communication controller (corresponding to the first signal conversion means) 13A.
Hereinafter, it is referred to as “terminal”. ) 14A and 14B are connected by wire.

An operating device (corresponding to operating means) 15 is provided for the operator to remotely operate at a position away from the hydraulic excavator. The operating device 15 has a communication controller (corresponding to second signal converting means). 2) Two general-purpose portable communication terminals (corresponding to a second communication means and a mobile communication terminal; hereinafter, referred to as "terminals") 17A and 17B are connected by wire via 16A.

FIG. 3 is a block diagram showing a detailed configuration example of a communication controller of the remote control device according to the first embodiment, FIG. 4 is an explanatory diagram showing an example of a protocol, and FIG. 5 shows an example of joystick arrangement of the operation device. It is a schematic diagram. Hereinafter, the first embodiment
Each element that characterizes is described in detail.

The terminals 14A, 14B, 17A, 17B
A transceiver function (first communication function) for directly communicating with each other and a telephone function (second communication function) for communicating via a public communication line.
Communication function), for example, PHS
(Simplified mobile phone system based on digital cordless phone) is available. In the transceiver function of the PHS, there is an idle state of transmission and reception of 2 seconds every 180 seconds due to laws and regulations.

Here, the terminals 14A, 14B, 17A, 1
If the 7B is to use the transceiver function of the PHS in the case of short-distance use, it is necessary to avoid a situation in which remote control cannot be performed during the above-mentioned pause time. Each operation must be maintained as it is, or the operation of the excavator must be stopped. However, if each operation of the hydraulic shovel is maintained as it is, control is not performed, which may cause an unexpected situation. If each operation of the hydraulic shovel is stopped, work efficiency is reduced. Therefore, in the first embodiment, two sets of terminals are provided so that transmission and reception can be performed simultaneously on two channels of CN1 and CN2 in advance, and further, the suspension time does not overlap.
Power on for 90 seconds between each set (communication timing)
Are shifted from each other. Terminals 13A, 13B,
Wireless communication specifications (protocols) for 17A and 17B
Is based on RS232 which is an interface standard.

As shown in FIG. 5, the operating device 15 includes an ATT lever for a boom, an arm, a bucket, a swing and the like, a running lever, an engine start / stop switch, and a running 1 /.
It is equipped with various control switches such as a 2-speed switch and a light, and outputs these operation signals via communication data. The communication specification (protocol) of the wired connection part is the interface standard. RS422.

The communication controller 16A, as shown in FIG.
A terminal power control section 161 for shifting the power-on timing between the two terminals 17A and 17B by the above 90 seconds.
And operation data (operation signal) input from the operation device 15
Is converted into a protocol (RS42).
2) The protocol for PHS data communication (RS232)
And a data conversion section 161 for converting the same data after the conversion by the terminals 17A and 17B simultaneously for each block.

The communication controller 13A, as shown in FIG.
A terminal power control unit 131 for shifting the power-on timing between the two terminals 14A and 14B by the above 90 seconds.
And abnormalities / normalities of the data received simultaneously by the terminals 14A and 14B (in this case, since the power-on timings of both terminals are shifted, at least one of the same data is not in the sleep state). And a data conversion unit 132 that converts the protocol (RS232) of the data determined to be normal by the determination into a protocol (RS422) recognizable by the controller 1, and sends the converted data (control signal) to the controller 1. Things.

The communication controllers 13A and 16A may be provided with a buffer memory for temporarily storing the data to be converted, if necessary, so as to eliminate the influence of the difference in transfer speed between protocols. Good.

The data format of the communication controller 16A, which has received the data from the operation device 15, before the data conversion by the data converter 162 and the data before the data converted by the communication controller 13A are transmitted to the controller 1. The format is, for example, as shown in FIG. 4, and each is an RS422 output.

Here, the communication conditions are as follows: the transmission system is an asynchronous system, the transfer speed is 96000 bps, the parity is an even number, the stop bit is 1 bit, and the data length is 8 bits.
As shown in the figure, one block is composed of 14 bytes, and the data transmission interval is 80 ms. When the data can be received, the received data is immediately format-converted and output. At this time, if the received data is judged to be abnormal by, for example, a parity check, the abnormal data is discarded. Data is not output.

The A0 to A7 signals, which are the contents of the data, are values corresponding to the inclination of the lever of the joystick in FIG. 5, and are, for example, 0 data at the time of neutral, and when the joystick is tilted right or forward, bit5 = If the value of bits 4 to 0 increases at 0, and the joystick is tilted left or backward, b
When it5 = 1, the values of bits 4 to 0 increase.

FIGS. 6A and 6B are flowcharts showing the operation of the remote control device according to the first embodiment. FIG. 6A shows the operation on the operation device side, and FIG. 6B shows the operation on the controller side. . Hereinafter, the procedure will be described.

First, in (a), two terminals 17
The power of the terminals A and 17B is turned on (step S1). At this time, the power on timing between the terminals 17A and 17B is shifted by 90 seconds by the terminal power control unit 161 of the communication controller 16A. Then, operation data is input from the operation device 15 (step S2), and the input operation data is converted for PHS data communication by the data conversion unit 161 of the communication controller 16A (step S3). The same data is transmitted simultaneously by the two terminals 14A and 14B (step S4).

In (b), step S1
At the same time, the power of the two terminals 14A and 14B is turned on (step S11). At that time, the power-on timing between the two terminals 14A and 14B is shifted by 90 seconds by the terminal power control unit 131 of the communication controller 13A. Thus, the timing between the sets is shifted. Then, the transmission data is simultaneously received by both terminals 14A and 14B (step S12), and the data conversion unit 132 of the communication controller 13A determines whether the received data is abnormal or normal, and the controller 1 can recognize the normal data. It is converted into a protocol (step S13). The controller 1 includes a data conversion unit 13
Each actuator 5 is controlled by the data converted in step 2 (step S14).

At this time, the controller 1 checks the received data and outputs a control signal to the electromagnetic proportional valve 7, the stepping motor 4, etc. according to the data. The stepping motor 4 controls the rotation speed / stop of the engine 2 by controlling the number of steps according to the PWM signal. The electromagnetic proportional valve 7 opens and closes the valve proportionally according to the operation amount of the joystick operated by the operation device 15. Since the remote control valve 8 is neutral in the case of remote control, no hydraulic pressure is generated.

Therefore, the shuttle valve 9 selects the hydraulic pressure generated from the electromagnetic proportional valve 7 at a high level, and opens the passage to the main control valve 6. Main control valve 6
The internal hydraulic spool is switched according to the hydraulic pressure input via the shuttle valve 9, and opens and closes a passage for further supplying the hydraulic oil supplied from the hydraulic pump 10 to each actuator 5.

Thus, various operations in the hydraulic excavator are performed. At this time, the status indicator light 12 turns on the indicator light to visually warn whether the communication is normally performed or the various sensors 11 of the shovel body are normal. For example, if the communication abnormality continues for one second or more, the red rotating light is turned on. If it is normal, the red rotating light is turned off and the blue rotating light is turned off. If the various sensors 11 are normal and the engine 2 is started, the yellow light is turned on. Turn on the rotating light.

According to the first embodiment, the terminals 14A, 14A
This transceiver function can be used when B, 17A, and 17B operate within the transmission / reception range of the transceiver function. In this case, the transfer rate of the specific low-power radio in the conventional example is 2400 bps or less. Since the transfer speed of each terminal can be increased to 32000 bps, a time lag from the transmission by the terminal to the actual operation of the hydraulic shovel can be almost eliminated. In addition, since the data amount is large, the accuracy of the data can be improved, and operation performance without a sense of incongruity can be realized.

Further, if the above-mentioned transceiver function is used, communication is limited to a short distance of about 100 m or less, but no communication fee is required. On the other hand, if the above-mentioned telephone function is used, there is no limit on the communication distance. Therefore, if the operator wants to work in a position where the excavator goes out of the transceiver function transmission / reception range and communication by the function becomes impossible, the operator switches in advance to the telephone function of each terminal, The communication function is not interrupted, and the terminals 14A and 14B and the terminals 17A and 17B
Good remote operation between the user and the user.

(Second Embodiment) FIG. 7 is a block diagram showing a schematic configuration of a remote control device according to a second embodiment, and FIG. 8 is a block diagram showing a detailed configuration example of a communication controller of the remote control device according to the second embodiment. It is. Here, the same elements as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The entire configuration of the hydraulic shovel to which the remote control device is applied is as shown in FIG.

In the right place of the hydraulic shovel of the second embodiment,
A camera 19 (corresponding to detection means) for photographing the periphery of the hydraulic excavator is attached, and this camera 19 is wired to terminals 14A and 14B via a communication controller (corresponding to third signal conversion means) 13B. I have.

The operating device 15 is provided with a monitor 18, which is connected to terminals 17A and 17B via a communication controller (corresponding to operation information presenting means and fourth signal converting means) 16B. It is connected.

The communication controller 13B includes a terminal power control unit 131 and a data conversion unit 132 similar to the communication controller 13A of the first embodiment, and further includes an image data processing unit 16
3 is provided. Here, image data (feedback signal) captured by the camera 19 is converted by the image data processing unit 163 into MPEG-2 or MPEG which is a moving image compression method.
-1 is converted (compressed) into standard data of two terminals 14
A and 14B transmit at the same time. The camera 19 is, for example, a CCD camera, and captures video data as a digital signal. The camera 19 is provided with one or a plurality of fixed or movable cameras.

The communication controller 16B includes a terminal power control section 161 and a data conversion section 162 similar to the communication controller 16A of the first embodiment, and further includes an image data output section 16
3 is provided. Here, the video data received as the MPEG-2 or MPEG-1 standard data (in this case, since the power-on timing of both terminals is shifted, at least one of the same data is not in a pause state). Is converted (decompressed) by the image output unit 163 and reproduced, and the reproduced data (operation information signal) is displayed on the monitor 18.
Output to The monitor 18 is, for example, a liquid crystal panel.

The communication controllers 13B and 16B may be provided with a buffer memory for temporarily storing the data to be converted, if necessary, so as to eliminate the influence of differences in compression / decompression timing. Good. Further, as each element relating to the video data, for example, an element conforming to the NTSC standard is used.

FIG. 9 is a flowchart showing the operation of the remote control device according to the second embodiment, in which (a) shows the operation on the controller side, and (b) shows the operation on the operation device side. Steps S1 to S1 of the first embodiment are performed.
4, S11 to S14 may be performed in parallel with the following procedure also in the second embodiment, but the details are omitted since they are as described above.

First, in (a), two terminals 14
The power of the terminals A and 14B is turned on (step S21). At this time, the power on timing between the terminals 14A and 14B is shifted by 90 seconds by the terminal power control unit 161 of the communication controller 16B. However, this step S21 is skipped when step S11 of the first embodiment is executed. Then, the video data is captured by the camera 19 (step S22), and the captured video data is transmitted to the MPE by the image data processing unit 163 of the communication controller 16B.
The data is defined as G-2 or MPEG-1 standard data (step S23), and this data is simultaneously transmitted from the two terminals 14A and 14B (step S24).

In (b), step S2
At the same time, the power of the two terminals 14A and 14B is turned on (step S31). At this time, both terminals 17A and 17B are turned on.
The power-on timing between the sets is shifted by 90 seconds by the terminal power control unit 161 of the communication controller 16B to shift the timing between the sets. However, step S31 is skipped when step S1 of the first embodiment is executed. Then, the transmitted video data is received (step S32), reproduced by the image data output unit 133 of the communication controller 13B (step S33), and output to the monitor 18 (step S3).
4). As described above, by transmitting the video data on the hydraulic excavator side to the operation side, the operator can operate with realism.

In the second embodiment, the first embodiment is used.
In addition to the above operation, data can be exchanged in both directions, so that excellent operability can be obtained.

Although the hydraulic shovel has been described as a construction machine in the first and second embodiments, it goes without saying that the present invention can be applied to a crane and other construction machines.

In the second embodiment, the video data is fetched and transmitted to the operation side. Instead of the video data or together with the video data, the sound data and other mechanical states of the excavator body are transmitted to the operation side. Thereby, it is possible to easily confirm on the operating side whether the hydraulic shovel is normal or whether the working range of the hydraulic shovel is within a predetermined range.

In the first and second embodiments, two sets of PHSs are provided as general-purpose portable communication terminals to avoid communication interruption due to a transmission / reception pause in the transceiver function of the PHS. It may be provided. In addition, the time difference between the power-on between the terminals is 90 seconds in the above description, but any time can be set as long as the communication interruption due to the transmission / reception suspension state can be avoided. On the other hand, when the transmission / reception pause state does not exist, the setting of the time difference is not required, and thus it is sufficient to provide one set of terminals.

In the first and second embodiments, the general-purpose portable communication terminal has both the transceiver function and the telephone function. However, it is sufficient that the general-purpose portable communication terminal has at least the transceiver function.

In the first embodiment, the switching between the transceiver function and the telephone function is manually performed before the work. However, the switching may be automatically performed by detecting a communication interruption or the like.

[0057]

According to the present invention, when the first communication means and the second communication means are within the transmission / reception range of the first communication function, the first communication function is used to perform short-range communication. The first communication function that does not require communication costs can be used. In this case, bidirectional and multi-data exchange is possible.

Further, when the first communication means and the second communication means are out of the transmission / reception range of the first communication function, the second communication function is used so that the transmission / reception range of the first communication function is exceeded. In this case, communication by the second communication function can be ensured. Also in this case, bidirectional and multi-data exchange is possible.

Therefore, at the time of work by remote control over a short distance, low cost and good operability can be obtained by using the first communication function. Good operability can be obtained by using the communication function.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a hydraulic shovel as an example of a construction machine according to the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a remote control device according to the first embodiment.

FIG. 3 is a block diagram illustrating a detailed configuration example of a communication controller of the remote control device according to the first embodiment.

FIG. 4 is a diagram illustrating a configuration example of a protocol.

FIG. 5 is a diagram illustrating a configuration example of a joystick of the operation device.

FIGS. 6A and 6B are flowcharts showing the operation and the like of the remote control device according to the first embodiment, wherein FIG. 6A shows an operation on the operation device side, and FIG. 6B shows an operation on the controller side.

FIG. 7 is a block diagram illustrating a schematic configuration of a remote control device according to a second embodiment.

FIG. 8 is a block diagram illustrating a detailed configuration example of a communication controller of the remote control device according to the first embodiment.

FIG. 9 is a flowchart showing the operation of the remote control device according to the second embodiment, in which (a) shows the operation on the controller side and (b) shows the operation on the operation device side.

[Explanation of symbols]

1 Controller (corresponding to operation control means) 13A, 13B Communication controller (corresponding to first and third signal conversion means) 131 Terminal power control section 132 Data conversion section 133 Image data processing section 14A, 14B General-purpose portable communication terminal (No. 1 Communication means, corresponding to mobile communication terminal) 15 Operator (corresponding to operating means) 16A, 16B Communication controller (corresponding to second and fourth signal conversion means, operation information presenting means) 161 Terminal power control section 162 Data Conversion unit 163 Image data output unit 17A, 17B General-purpose portable communication terminal (corresponding to second communication means, mobile communication terminal) 18 monitor 19 Camera (corresponding to detection means)

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2D003 AA01 AB01 AB02 AB03 AB04 BA01 BA04 BA06 BA07 BA08 CA03 DA03 DA04 DB02 DB03 5K033 AA04 BA08 CB02 DA01 DA19 DB25 5K048 AA04 BA21 BA41 DB01 DC01 EB02 EB12 FB05 GB05 HA04 HA06

Claims (9)

[Claims] 1. first communication means mounted on a construction machine;
In a remote control device for a construction machine including the first communication means and a second communication means capable of wirelessly transmitting and receiving, the first communication means and the second communication means at least include a first communication for directly communicating with each other. A remote control device for a construction machine having a function. 2. The remote control device for a construction machine according to claim 1, wherein the first communication means and the second communication means also have a second communication function for communicating via a public communication line. 3. The remote control device for a construction machine according to claim 1, wherein the first communication function is a transceiver function of a mobile communication terminal. 4. When there is a time in which transmission and reception are in a suspended state while using the first communication function, the first communication means and the second communication means
The remote control device for a construction machine according to any one of claims 1 to 3, wherein a plurality of pairs of communication means are provided, and communication timing of each communication means is shifted between each pair by at least the pause time. 5. An operation means for generating an operation signal for remotely operating a construction machine, and when the operation signal is transmitted from the second communication means to the first communication means, the operation of the construction machine is performed based on the operation signal. 3. A remote control device for a construction machine according to claim 2, further comprising an operation control means for controlling the operation of the remote controller. 6. The operation means includes a second signal conversion means for performing signal conversion for using the first communication function or the second communication function when transmitting the operation signal from the second communication means to the first communication means. 6. The apparatus according to claim 5, wherein the operation control means includes first signal conversion means for converting the conversion signal received by the first communication means into a control signal for controlling the operation of the construction machine. Control equipment for construction machinery. 7. A detecting means for detecting a feedback signal indicating the operation status of the construction machine, and when the feedback signal is transmitted from the first communication unit to the second communication unit, the operation status of the construction machine is determined based on the feedback signal. 3. The remote control device for a construction machine according to claim 2, further comprising an operation status presenting means for presenting the information on a monitor. 8. The detecting means outputs the feedback signal to the first signal.
A third signal converter for performing signal conversion for using the first communication function or the second communication function when transmitting from the communication means to the second communication means;
A fourth conversion unit that converts the conversion signal received by the communication unit into an operation information signal for presenting the operation state of the construction machine to the monitor;
The remote control device for a construction machine according to claim 7, further comprising signal conversion means. 9. The remote control device for a construction machine according to claim 7, wherein the feedback signal includes video data.