JP6989433B2 - Dump truck bed undulation control system for mines - Google Patents

Description

The present invention relates to a loading platform undulation control system for a dump truck for mining.

As an example of wireless communication technology, Patent Document 1 describes "a history information storage unit that stores information on communication environment, terminal position, and communication quality at the time of past communication with a base station device as history information, and a history information storage unit. Communication quality is improved based on the history information selection unit that selects history information that matches the current communication environment from the history information stored in the history information storage unit and the history information selected by this history information selection unit. A configuration including an improvement information acquisition unit for acquiring improvement information regarding the conditions to be performed and a display unit (summary excerpt) for notifying the user of the improvement information acquired by the improvement information acquisition unit is disclosed.

Japanese Unexamined Patent Publication No. 2017-034635

A mine dump truck is a super-large vehicle that loads and transports a load that is heavier than its own weight, and has a large loading platform. Therefore, if the loading platform is erected during the soil discharge work, the loading platform shields the radio waves and the reception power of the wireless antenna installed in the dump truck for mining decreases, which may cause a wireless communication failure.

When an operator is on board a mine dump truck, he may miss the control command from the control station without knowing that a radio communication failure has occurred. Further, when the dump truck for mining is autonomously driven, if a radio communication failure occurs, the control command for the next operation cannot be received from the control station, and the dump truck for mining may stop. Therefore, in order to operate the dump truck for mining stably, it is necessary to take measures against the wireless communication failure that occurs during the excavation work.

In this regard, Patent Document 1 is a general technique relating to wireless communication, and does not consider any specific problem of wireless communication failure that occurs during the excavation work of a dump truck for mining.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a loading platform undulation control system for a dump truck for mining, which can perform a self-recovery operation against a wireless communication failure that occurs during excavation work.

In order to solve the above problems, the present invention presents a vehicle body frame, a loading platform provided on the vehicle body frame so as to be undulating, a hoist cylinder for undulating the loading platform, and a hydraulic pressure for supplying hydraulic oil to the hoist cylinder. A loading platform for a mining dump truck provided with a pump, a directional control valve provided between the hydraulic pump and the hoist cylinder to control the undulation of the hoist cylinder, and a controller for controlling the directional control valve. The undulation control system, the dump truck for mining, detects whether the loading platform is seated on the vehicle body frame, outputs a seating signal, and receives a radio wave flowing through a wireless communication line in the premises. The controller is composed of a computer connected to each of the radio antenna and the seating sensor, the radio antenna is installed in front of the loading platform, and the height of the upper end of the radio antenna is high. The height is the same as or higher than the upper end of the loading platform when the loading platform is seated, and lower than the upper end of the loading platform when the loading platform is upright. Whether or not the loading platform is seated based on the seated signal and the received power comparison unit that compares the received power of the radio waves received by the wireless antenna with the received power threshold for determining whether or not a wireless communication failure has occurred. It is satisfied that the received power of the received radio wave is less than the received power threshold and the loading platform is upright as the seating state determination unit for determining whether or not the loading platform is forcibly seated. It includes a forced seating condition satisfaction determination unit for determining whether or not the vehicle is seated, and controls the directional control valve so as to force the loading platform to seat when the forced seating condition is satisfied. And.

It is possible to provide a loading platform undulation control system for a dump truck for mining, which can perform a recovery operation by itself in response to a wireless communication failure that occurs during soil discharge work. Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

Schematic configuration of the dump truck according to this embodiment (left side view) Schematic configuration of the dump truck according to this embodiment (front view) Figure showing the positional relationship between the antenna and the loading platform (left side view) Diagram showing the positional relationship between the antenna and the loading platform (top view) Dump truck hardware configuration diagram Functional block diagram of autonomous driving controller In the present embodiment, a flowchart showing a flow of processing for performing a recovery operation from a wireless communication failure that occurred during the dump truck's excavation work.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiment, the members having the same function are designated by the same or related reference numerals, and the repeated description thereof will be omitted. Further, in the following embodiments, the same or similar parts will not be repeated in principle unless it is particularly necessary.

A schematic configuration of a mining dump truck (hereinafter abbreviated as “dump truck”) 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram (left side view) of the dump truck 1 according to the present embodiment. FIG. 2 is a schematic configuration diagram (front view) of the dump truck 1 according to the present embodiment.

The dump truck 1 shown in FIGS. 1 and 2 includes a vehicle frame 2 and a left front wheel 3L, a left rear wheel 4L, a right front wheel 3R (see FIG. 2), and a right rear wheel mounted on the lower part of the vehicle frame 2. It is equipped with 4R (see FIG. 2).

Further, a cab 5 is mounted on the deck 8 and the deck 8 on the front side of the vehicle body frame 2, and a loading platform (vessel) 7 for carrying the load via the hoist cylinder 6 is mounted on the rear side so as to be undulating. The loading platform 7 stands up when the hoist cylinder 6 extends (shown by the two-point chain point in FIG. 1), and sits down when the hoist cylinder 6 contracts (shown by the solid line in FIG. 1).

The deck 8 of the dump truck 1 is provided with a left GPS antenna 9L and a right GPS antenna 9R (see FIG. 2) at intervals along the vehicle width direction of the dump truck 1. Each of the left GPS antenna 9L and the right GPS antenna 9R receives the positioning radio wave from the GNSS satellite, and the position calculation device 220 (see FIG. 5) calculates the absolute position of each antenna installation position based on this, and these Is used to calculate the own vehicle position of the dump truck 1.

Further, in the center of the deck 8 of the dump truck 1, a wireless antenna 10 for connecting to the premises wireless communication line 40 (hereinafter abbreviated as “wireless communication line”; see FIG. 5) installed in the mine is installed. ..

The dump truck 1 is a large dump truck that operates at a large-scale site such as a mine or a quarry site. As an example, the size of the dump truck 1 is such that the vehicle height H1 when the loading platform 7 is seated is about 7 m, the vehicle height H2 when the loading platform 7 is upright is about 15 m, and the vehicle width W is about 8 m. Therefore, the vehicle height H2 with the loading platform 7 upright is about twice as high as the vehicle height H1 with the loading platform 7 seated. This change in vehicle height may affect the communication quality of the wireless antenna 10.

The positional relationship between the wireless antenna 10, the seated loading platform 7, and the standing loading platform 7 will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram (left side view) showing the positional relationship between the antenna and the loading platform. FIG. 4 is a diagram (top view) showing the positional relationship between the antenna and the loading platform.

As shown in FIGS. 3 and 4, the height of the upper end portion 10a of the wireless antenna 10 is the same as or higher than the upper end portion 7a of the loading platform 7 when the loading platform 7 is seated. Therefore, when the loading platform 7 is seated, the upper end portion 10a of the wireless antenna 10 is higher than the upper end portion 7a of the loading platform 7 and is not shielded by the loading platform 7.

On the other hand, when the loading platform 7 is upright, the height of the upper end portion 10a of the wireless antenna 10 is lower than the height of the upper end portion 7b of the loading platform 7. Therefore, the region of the angle θ behind the dump truck 1 and from the line connecting the radio antenna 10 and the left side surface 7L of the upright loading platform 7 to the line connecting the radio antenna 10 and the right side surface 7R of the upright loading platform 7 is , The radio wave from the radio base station located behind the loading platform 7 is shielded by the standing loading platform 7 and does not reach the wireless antenna 10, or the received radio wave can be received only from the outside of the loading platform 7. The strength is low.

Therefore, when the dump truck 1 is an autonomous traveling vehicle that autonomously travels and performs soil discharge work according to a control command from the control server 31 connected via the wireless communication line 40, the loading platform 7 is used to perform the soil discharge work. If you stand up, you will not be able to receive the next control command, for example, an instruction to seat the loading platform 7 or an instruction to restart autonomous driving. As a result, the dump truck 1 is stopped, so that the dump truck 1 that autonomously travels is greatly affected by the wireless communication failure.

In the following, an example in which the dump truck 1 equipped with the autonomous traveling function recovers from a wireless communication failure generated during the excavation work will be described. In the present embodiment, the dump truck 1 forcibly seats the loading platform 7 as a recovery measure from a wireless communication failure. The term "forced seating" as used herein means an operation of seating the loading platform 7 regardless of the remaining amount of the load on the loading platform 7, that is, regardless of whether or not the soil discharge work has been completed.

The function of the dump truck 1 will be described with reference to FIG. FIG. 5 is a hardware configuration diagram of the dump truck 1.

As shown in FIG. 5, the dump truck 1 equipped with the autonomous driving function is connected to an autonomous driving controller 200 that executes autonomous driving control processing according to a control command received from the control server 31 via the wireless communication line 40. It is provided with a traveling drive device 210, a position calculation device 220, a seating sensor 230, a wireless communication device 240, a hydraulic circuit 250, and an operation mode switching device 270.

The autonomous operation controller 200 is a computer including a CPU 201, a RAM 202, a ROM 203, an HDD 204, an I / F 205, and a bus 206, to which the CPU 201, the RAM 202, the ROM 203, the HDD 204, and the I / F 205 are connected via the bus 206. .. The configuration example of the computer is not limited to the above, and for example, an integrated circuit that executes a specific function may be used.

The pilot pressure generator 262 included in the position calculation device 220, the seating sensor 230, the wireless communication device 240, and the hydraulic circuit 250 is connected to the I / F 205.

The traveling drive device 210 includes a brake 211 for decelerating and stopping the dump truck 1, a steering motor 212 for traveling straight or turning the dump truck 1, and a traveling motor 213 for accelerating and traveling the dump truck 1 at a constant speed.

The position calculation device 220 calculates the position coordinates represented by the global coordinate system of the dump truck 1 based on the outputs from the left GPS antenna 9L and the right GPS antenna 9R, and outputs the position information to the autonomous operation controller 200. The position calculation device 220 includes an IMU (Inertial Measurement Unit), and may perform position correction processing based on the momentum of the dump track 1 with respect to the position coordinates of the global coordinate system using the output of the IMU.

The seating sensor 230 is provided between the vehicle body frame 2 and the loading platform 7, and when the loading platform 7 is seated, the seating sensor 230 detects this seating state and outputs a seating signal to the autonomous driving controller 200.

The wireless communication device 240 is connected to the wireless communication line 40 provided in the mine via the wireless antenna 10. The autonomous driving controller 200 is connected to the control server 31 via the wireless communication line 40. Then, the autonomous driving controller 200 receives the control command from the control server 31 and transmits the own vehicle position information of the dump truck 1 to the control server 31.

The hydraulic circuit 250 connects a hydraulic pump 254, which is driven by transmitting the power of the engine 252, which is a power source, via an output shaft, and a hoist cylinder 6, which is a drive target. A directional control valve 260 is interposed between the hydraulic pump 254 and the hoist cylinder 6, and the hoist cylinder 6 expands or contracts when the directional control valve 260 changes the direction of the hydraulic oil flowing through the hydraulic circuit 250. .. The engine 252, the hydraulic pump 254, the directional control valve 260, the hoist cylinder 6, and the hydraulic circuit 250 are collectively referred to as a loading platform drive device 300.

Further, when the autonomous operation controller 200, more specifically, the autonomous driving control unit 201e described later, receives a control command instructing soil release, the hoist cylinder 6 is extended based on this, and the loading platform 7 stands up and is loaded on the loading platform 7. Sediment, which is a cargo, is released. Further, the operation mode switching device 270 switches between an autonomous mode for autonomous travel and a manual mode for traveling by the operator's driving operation according to a command from the autonomous travel control unit 201e. In the manual mode, operations such as the accelerator pedal and the brake pedal are enabled.

The function of the autonomous driving controller 200 will be described with reference to FIG. FIG. 6 is a functional block diagram of the autonomous driving controller 200. The autonomous operation controller 200 is responsible for the function of the loading platform undulation control system.

The autonomous driving controller 200 includes a received power comparison unit 201a, a seating state determination unit 201b, a forced seating condition satisfaction determination unit 201c, a valve switching signal output unit 201d, an autonomous driving control unit 201e, and a discharge amount signal output unit 201f. Each of these parts is configured by a computer constituting the autonomous driving controller 200 executing software that realizes the functions of each part.

Further, a part of the RAM 202 is used as a communication deterioration flag storage area 202a, a standing flag storage area 202b, and a forced seating flag storage area 202c.

Further, in a part of the HDD 204, the receive power threshold storage unit 204a for storing the receive power threshold for determining that the communication quality is guaranteed to the extent that the communication quality is not hindered, and the dump truck 1 autonomously travel. It is used as a map information storage unit 204b for storing the map information of the travel route to be referred to.

The operation mode of the dump truck 1 will be described. When the main power of the autonomous operation controller 200 is OFF, the control command cannot be received from the control server 31. The operation mode when the main power of the autonomous driving controller 200 is ON can be an autonomous mode in which the autonomous driving controller 200 autonomously travels according to a control command received from the control server 31 and an instruction from the control server 31. There is a manual mode in which the vehicle is driven by an operator's driving operation.

A recovery operation from a wireless communication failure that occurred during the excavation work of the dump truck 1 will be described with reference to FIG. 7. FIG. 7 is a flowchart showing a flow of processing in which the dump truck 1 performs a recovery operation from a wireless communication failure that occurs during the soil discharge work.

The dump truck 1 receives a control command from the control server 31 via the wireless communication line 40. The autonomous driving control unit 201e refers to the own vehicle position calculated by the position calculation device 220 and the map information stored in the map information storage unit 204b, and confirms the own vehicle position while checking the own vehicle position to drive the traveling drive device 210 according to the control command. Drive control and autonomous driving. Since the loading platform 7 is seated on the dump truck 1 during the transportation of the load, the dump truck 1 receives the seating signal from the seating sensor 230 during the autonomous traveling control.

When the seating state determination unit 201b receives the seating signal, the seating state determination unit 201b writes the value "0" of the standing flag in the standing flag storage area 202b.

Further, during autonomous operation, when a release command is transmitted from the control server 31, the dump truck 1 receives the command, stops at the instructed release point, and starts the release work. The wireless communication device 240 acquires the output of the received radio wave received by the wireless antenna 10. This output includes received power information indicating the strength of the received radio wave. The received power comparison unit 201a acquires received power information from the wireless communication device 240 (S101).

The received power comparison unit 201a reads the received power threshold value from the received power threshold storage unit 204a and compares it with the received power acquired in S101 (S102). If the acquired received power is equal to or higher than the received power threshold value (S102 / No), the process returns to step S101, and the dump truck 1 continues the autonomous operation including the excavation work. During autonomous operation, when the dump truck 1 receives a control command including a release instruction from the control server 31, the autonomous driving control unit 201e commands the valve switching signal output unit 201d and the discharge amount signal output unit 201f to stand up the loading platform 7. Is output. In response to this, the valve switching signal output unit 201d outputs a valve switching signal to the directional control valve 260.

The seating sensor 230 stops the output of the seating signal. Since the seating signal is interrupted, the seating state determination unit 201b determines that the loading platform 7 has risen, and rewrites the value of the standing flag storage area 202b to "1".

If the acquired received power is less than the received power threshold value (S102 / Yes), the received power comparison unit 201a writes the communication deterioration flag value "1" in the communication deterioration flag storage area 202a.

The forced seating condition satisfaction determination unit 201c multiplies the value of the communication deterioration flag by the value of the standing flag, and if the result of the multiplication is "1", determines that the condition for executing the forced seating is satisfied and the forced seating flag. The value "1" of the forced seating flag is written in the storage area 202c (S103). In the present embodiment, the compulsory seating condition is that the received power of the radio wave received by the wireless antenna 10 is less than the received power threshold value and the two small conditions that the loading platform 7 is raised are satisfied. The order of determining the satisfaction of these two sub-conditions does not matter.

The valve switching signal output unit 201d refers to the value "1" of the forced seating flag, and if the value is "1", outputs a valve switching signal for setting the directional control valve 260 in the contraction direction of the hoist cylinder 6. do. Then, the valve switching signal output unit 201d updates the value of the forced seating flag storage area 202c to “0”.

When the direction control valve 260 is switched in the contraction direction of the hoist cylinder 6, the hoist cylinder 6 contracts and the loading platform 7 is seated. This seating operation corresponds to forced seating because it is seated regardless of whether or not the load on the loading platform 7 remains (S104).

When the loading platform 7 is seated, the seating sensor 230 outputs the seating signal again, and the seating state determination unit 201b acquires it. When the seating state determination unit 201b acquires the seating signal, the value of the standing flag storage area 202b is updated to "0". Then, the directional control valve 260 is switched to a neutral state in which the hoist cylinder 6 is not driven.

As a result of the loading platform 7 being seated, the upper end portion 10a of the wireless antenna 10 protrudes higher than the upper end portion 7a of the loading platform 7, so that the wireless communication failure is restored. The received power comparison unit 201a acquires the received power information from the radio antenna 10 again. Then, the received power is compared with the received power threshold value, and when the received power becomes equal to or higher than the received power threshold value (S105 / Yes), the control command can be stably received via the wireless communication line 40, so that the dump truck 1 is autonomous. The operation is restarted (S106). Further, the received power comparison unit 201a updates the value of the communication deterioration flag storage area 202a to "0".

The dump truck 1 returns to S101 and continues autonomous driving unless a control command for transitioning to the manual mode is received from the control server 31 (S107 / No).

On the other hand, when the forced seating condition is not satisfied (S103 / No), a wireless communication failure has occurred even though the person is seated, and the operation for recovering the failure cannot be performed. Further, when the received power is less than the received power threshold as a result of comparing the received power and the received power threshold again by the received power comparison unit 201a even though the dump track 1 is forcibly seated (S105 / No). The operation to recover from the wireless communication failure cannot be performed. That is, the next command cannot be received in the autonomous mode, and the command continues to stop there.

Therefore, the forced seating condition satisfaction determination unit 201c outputs a mode change instruction to the autonomous travel control unit 201e in order to transition from the autonomous mode to the manual mode. In response to this, the autonomous travel control unit 201e drives the operation mode switching device 270 to transition to the manual mode (S108). Then, the dump truck 1 runs by the operation of the operator.

According to the present embodiment, when the radio wave is shielded by standing the loading platform 7 and the strength of the received radio wave of the wireless antenna 10 is lowered, the loading platform 7 can be forcibly seated to recover from the wireless communication failure. As a result, the dump truck 1 during autonomous traveling cannot receive the control command due to the standing of the loading platform 7, and it is possible to prevent the autonomous traveling function from stopping.

The embodiments are not limited to the present invention, and various modifications that do not limit the present invention are included in the present invention. For example, when it is determined that the autonomous driving controller 200 satisfies the forced seating condition in step S103, the autonomous driving controller 200 transmits the vehicle ID uniquely identifying the dump truck 1 on which the autonomous driving controller 200 is mounted to the control server 31. You may. As a result, when the loading platform 7 is raised for the dumping work in the dumping ground, the area where the wireless antenna 10 is shielded by the loading platform 7 can be notified to the control server 31. As a result, it is possible to provide materials for studying the relocation of radio base stations in the dumping ground.

Further, in the above embodiment, the dump truck 1 for an autonomously traveling mine has been described as an example, but the present invention may be applied to a so-called manned dump truck on which an operator is on board and travels according to the driving operation thereof. Also in this case, it is possible to prevent a problem that the operator does not notice that the wireless communication failure has occurred and misses the instruction from the control server 31.

In the above embodiment, if the reception state is not restored even if the loading platform 7 is forcibly seated, there is no choice but to operate in the manual mode, but in the autonomous traveling dump truck where the operator does not normally board, by the time the operator arrives at the vehicle. It takes time and productivity is significantly reduced. On the other hand, the reception condition depends on the geographical conditions and is often improved by the movement of the vehicle. In addition, the dump truck turns back at a certain point for the soil release work and retreats toward the land release point, so even if it advances to some extent from the land release point, the road surface has already passed while retreating, so safety is ensured. Focusing on this point, even if the reception state is not restored after sitting, that is, even if No is obtained in S105 of FIG. 7, there is a high possibility that the reception state will be restored if the vehicle advances a predetermined distance (for example, 1 m). In order to realize this control, in the case of S105 / No, the step of advancing by a predetermined distance may be stored in the RAM 202 or the like of the autonomous driving controller 200 as a command. After advancing by a predetermined distance, the process returns to S105 again to confirm whether the reception state has been restored. However, it is dangerous to move forward indefinitely, so it is desirable to set the number of times to move forward in advance. After advancing a predetermined distance, the loading platform 7 is raised again and the soil discharge work is performed to complete the soil discharge.

In addition, since the dump truck for mining is generally equipped with a payload sensor 231 (see FIG. 5) for measuring the load amount, a step for measuring the load amount after forced seating (S104) is added, and when the load falls below a predetermined threshold value. It is determined that there is residual soil in the loading platform, and after advancing a predetermined distance, the vehicle proceeds to S105 to check the reception status, then restarts autonomous operation in S106 and raises the loading platform 7 again to release the residual soil. May be good.

1 Dump truck 31 Control server 40 Wireless communication line 200 Autonomous operation controller

Claims (2)

Body frame and
A loading platform provided on the vehicle body frame so as to be undulating,
A hoist cylinder that raises and lowers the loading platform,
A hydraulic pump that supplies hydraulic oil to the hoist cylinder,
A directional control valve provided between the hydraulic pump and the hoist cylinder to control the undulation of the hoist cylinder,
It is a loading platform undulation control system for a dump truck for mining equipped with a controller for controlling the directional control valve.
The dump truck for mining is
A seating sensor that detects whether the loading platform is seated on the vehicle body frame and outputs a seating signal,
Equipped with a wireless antenna that receives radio waves flowing through the premises wireless communication line,
The controller is composed of a computer connected to each of the radio antenna and the seating sensor.
The radio antenna is installed on the front side of the loading platform and is installed.
The height of the upper end portion of the wireless antenna is the same as or higher than the upper end portion of the loading platform when the loading platform is seated, and lower than the upper end portion of the loading platform when the loading platform is upright. And
The controller
A reception power comparison unit that compares the reception power of the radio wave received by the radio antenna with the reception power threshold for determining whether a radio communication failure has occurred.
A seating state determination unit that determines whether or not the loading platform is seated based on the seating signal.
As a compulsory seating condition for forcibly seating the loading platform, it is determined whether or not the received power of the received radio wave is less than the received power threshold value and it is satisfied that the loading platform is upright. Including the condition satisfaction judgment unit,
When the forced seating condition is satisfied, the directional control valve is controlled so as to force the loading platform to be seated.
The loading platform undulation control system for mining dump trucks is characterized by this. The undulation control system for a dump truck for mining according to claim 1.
The controller further includes an autonomous driving control unit that executes driving control according to a control command from a control server connected via the premises wireless communication line.
The received power comparison unit compares the received power of the radio wave received by the radio antenna with the received power threshold after the loading platform is forcibly seated, and the received power after the loading platform is forcibly seated is the received power. If it is less than the threshold value, the autonomous driving control unit switches the operation mode of the autonomous driving control unit from the autonomous mode that operates according to the control command to the manual mode that travels according to the driving operation of the operator.
The loading platform undulation control system for mining dump trucks is characterized by this.

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