Asphalt paver and machine learning device

Abstract

An asphalt finisher (100) includes a tractor (1), a hopper (2) disposed at a front side of the tractor (1) and receiving paving material, a conveyor (CV) that conveys the paving material in the hopper (2) to a rear side of the tractor (1), a screw (SC) that spreads the paving material conveyed by the conveyor (CV) at the rear side of the tractor (1), and a screed (3) that levels the paving material spread by the screw (SC) at a rear side of the screw (SC). The asphalt finisher (100) also includes a space recognition device (CM) that monitors a state in the hopper (2), and a controller (50) that moves the hopper (2) based on an output of the space recognition device (CM).

Description

Technical Field

[0001] This invention relates to an asphalt rolling machine. Background Technology

[0002] An asphalt trolley is known, comprising: a conveyor for conveying paving material stored in a hopper to the rear of a traction machine; a screw for spreading the paving material conveyed by the conveyor to the rear of the traction machine; and a leveling machine for evenly spreading the paving material spread by the screw to the rear of the screw (see Patent Document 1). In this asphalt trolley, the conveyor is configured such that a portion of it is exposed at the center of the bottom surface of the hopper. Therefore, the conveyor can convey the paving material located at the center of the hopper to the rear of the traction machine. When the amount of paving material in the hopper decreases, the operator of the asphalt trolley manually closes the hopper, thereby collecting the paving material located at the bottom end of the hopper to the center of the bottom surface, and the conveyor then conveys the paving material located at the bottom end to the rear of the traction machine.

[0003] Previous technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-160636 Summary of the Invention

[0006] The technical problem to be solved by the invention

[0007] However, if the asphalt trolley operator neglects to manually operate the hopper, the paving material at the bottom end of the hopper will not be conveyed by the conveyor to the rear of the tractor and will remain at the bottom end of the hopper. Even with paving material remaining in the hopper, the conveyor cannot deliver it to the rear of the tractor. In this case, insufficient paving material supplied to the trolley may create depressions in the newly constructed road surface.

[0008] Therefore, it is desirable to move the hopper more reliably when the amount of paving material in the hopper decreases.

[0009] means for solving technical problems

[0010] An asphalt screed according to an embodiment of the present invention includes: a traction machine; a hopper disposed in front of the traction machine and receiving paving material; a conveyor that conveys the paving material in the hopper to the rear of the traction machine; a screw that spreads the paving material conveyed by the conveyor on the rear of the traction machine; and a leveling machine that evenly spreads the paving material spread by the screw on the rear of the screw. The asphalt screed further includes: a spatial recognition device that monitors the state inside the hopper; and a controller that moves the hopper according to the output of the spatial recognition device.

[0011] Invention Effects

[0012] When the amount of paving material in the hopper decreases, the aforementioned asphalt roller can move the hopper more reliably. Attached Figure Description

[0013] Figure 1A This is a left view of an asphalt roller.

[0014] Figure 1B This is a top view of an asphalt roller.

[0015] Figure 2 This is the functional block diagram of the controller.

[0016] Figure 3A This is a left view of an asphalt roller and a dump truck.

[0017] Figure 3B This is a left view of an asphalt roller and a dump truck.

[0018] Figure 3C This is a left view of an asphalt roller and a dump truck.

[0019] Figure 4A This is the front view of an asphalt roller.

[0020] Figure 4B This is the front view of an asphalt roller.

[0021] Figure 4C This is the front view of an asphalt roller.

[0022] Figure 4D This is the front view of an asphalt roller.

[0023] Figure 4E This is the front view of an asphalt roller.

[0024] Figure 5 This is a schematic diagram illustrating an example of decision processing based on the spatial recognition unit. Detailed Implementation

[0025] Figure 1A and Figure 1B This is a schematic diagram of the asphalt roller 100 according to an embodiment of the present invention. Specifically, Figure 1A This is the left view of an asphalt roller 100. Figure 1B It is a top view.

[0026] The asphalt trolley 100 mainly consists of a traction machine 1, a hopper 2, and a leveling machine 3. Figure 1A and Figure 1BIn the example shown, the asphalt roller 100 is configured such that its length direction corresponds to the X-axis direction and its width direction corresponds to the Y-axis direction. Furthermore, the Z-axis is configured to be orthogonal to both the X-axis and Y-axis. Specifically, the front side in the length direction corresponds to the +X side, the rear side in the length direction corresponds to the -X side, the left side in the width direction corresponds to the +Y side, the right side in the width direction corresponds to the -Y side, the upper side in the vertical direction corresponds to the +Z side, and the lower side in the vertical direction corresponds to the -Z side.

[0027] The traction unit 1 is a mechanism used to move the asphalt roller 100. In Figure 1A and Figure 1B In the example shown, the tractor 1 uses a rear-wheel motor to rotate the rear wheel 5 and a front-wheel motor to rotate the front wheel 6, thereby moving the asphalt tumbler 100. The rear-wheel motor and the front-wheel motor are hydraulic motors that rotate by receiving working oil from a hydraulic pump. The tractor 1 may also be equipped with tracks instead of wheels.

[0028] Controller 50 is a control device for controlling the asphalt roller 100. Figure 1A and Figure 1B In the example shown, the controller 50 is a computer including a CPU, volatile memory, and non-volatile memory, mounted on the traction machine 1. Various functions of the controller 50 are implemented, for example, by the CPU executing programs stored in the non-volatile memory. These functions include, for example, controlling the output of a hydraulic pump that discharges working oil for driving the hydraulic actuator; and controlling the flow of working oil between the hydraulic actuator and the hydraulic pump. Furthermore, the hydraulic actuator includes a hydraulic cylinder and a hydraulic motor.

[0029] Hopper 2 is a mechanism for receiving paving materials. Paving materials may be, for example, asphalt mixtures. Figure 1A and Figure 1B In the example shown, the hopper 2 is located in front of the tractor 1 (+X side) and is configured to open or close in the Y-axis direction (vehicle width direction) via the hopper cylinder 24. The asphalt roller 100 typically receives paving material from the dump truck's loading platform with the hopper 2 fully open. Furthermore, while receiving paving material from the dump truck's loading platform, the asphalt roller 100 also continuously travels while pushing the dump truck forward via the push roller 2b. Figure 1A and Figure 1BThis indicates that hopper 2 is fully open. If the paving material in hopper 2 decreases, the operator of the asphalt trolley 100 manually closes hopper 2 and collects the paving material near the inner wall of hopper 2 to the center of hopper 2. This is to allow the conveyor CV, located at the center of the bottom surface of hopper 2, to convey the paving material to the rear of the tractor 1. The paving material conveyed to the rear of the tractor 1 is spread along the vehicle width direction at the rear of the tractor 1 and the front of the screed 3 via the screw SC.

[0030] A spatial identification device (CM) for monitoring the status in front of the traction machine 1 is installed on the traction machine 1. The spatial identification device (CM) can be, for example, a monocular camera, a stereo camera, or a LiDAR. Figure 1A and Figure 1B In the example shown, the spatial recognition device CM is a monocular camera that captures images of the area in front of the traction machine 1. At this time, the controller 50 can determine whether the amount of paving material in the hopper 2 is more or less than the specified amount based on the images captured by the monocular camera, which functions as the spatial recognition device CM.

[0031] The conveyor CV is driven by a hydraulic motor that rotates by receiving working oil from a hydraulic pump. Figure 1A and Figure 1B In the example shown, the conveyor CV is configured to transport paving material from the hopper 2 to the rear of the traction machine 1 via the conveying channel CP. The conveying channel CP is a generally rectangular space formed inside the traction machine 1, and has a generally rectangular inlet OP on the front surface 1FW of the traction machine 1 that opens into the hopper 2.

[0032] The screw SC is driven by a hydraulic motor that rotates by receiving working oil from a hydraulic pump. Specifically, the screw SC includes a central screw SCM, a left screw SCL, and a right screw SCR. The central screw SCM is positioned within the width of the traction machine 1. The left screw SCL is connected to the left end of the central screw SCM and protrudes to the left from the width of the traction machine 1. The right screw SCR is connected to the right end of the central screw SCM and protrudes to the right from the width of the traction machine 1.

[0033] The leveling machine 3 is a mechanism used to spread paving materials evenly. Figure 1A and Figure 1BIn the example shown, the leveling machine 3 mainly includes a main leveling machine 30 and a telescopic leveling machine 31. The telescopic leveling machine 31 includes a left telescopic leveling machine 31L and a right telescopic leveling machine 31R. The main leveling machine 30, the left telescopic leveling machine 31L, and the right telescopic leveling machine 31R are staggered. Specifically, the left telescopic leveling machine 31L is located behind the main leveling machine 30, and the right telescopic leveling machine 31R is located behind the left telescopic leveling machine 31L. The leveling machine 3 is a floating leveling machine towed by the traction machine 1, and it is connected to the traction machine 1 via the leveling arm 3A. The leveling machine 3 moves up and down together with the leveling arm 3A by extending and retracting the leveling machine lifting cylinder 25.

[0034] The telescopic leveler 31 is configured to extend and retract along the vehicle width direction via a telescopic cylinder 60. The telescopic cylinder 60 is supported by a support portion fixed to the rear surface of the frame of the main leveler 30 and is configured to enable the telescopic leveler 31 to extend and retract along the vehicle width direction. Specifically, the telescopic cylinder 60 includes a left telescopic cylinder 60L and a right telescopic cylinder 60R. The left telescopic cylinder 60L causes the left telescopic leveler 31L to extend and retract relative to the main leveler 30 to the left side in the vehicle width direction. The right telescopic cylinder 60R causes the right telescopic leveler 31R to extend and retract relative to the main leveler 30 to the right side in the vehicle width direction.

[0035] The leveling arm 3A is configured to connect the leveling machine 3 to the traction machine 1. Specifically, one end (rear end) of the leveling arm 3A is connected to the leveling machine 3, and the other end (front end) is rotatably connected to the traction machine 1.

[0036] The leveling cylinder 23 is a hydraulic cylinder that moves the front end of the leveling arm 3A up and down to adjust the evenness and thickness of the paving material. Figure 1A and Figure 1B In the example shown, the cylinder part of the leveling cylinder 23 is connected to the traction machine 1, and the rod part is connected to the front end of the leveling arm 3A. Furthermore, the front end of the leveling arm 3A is slidably mounted on the traction machine 1. When the spreading thickness is increased, the controller 50 causes the working oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the leveling cylinder 23, causing the leveling cylinder 23 to contract and the front end of the leveling arm 3A to rise. On the other hand, when the spreading thickness is decreased, the controller 50 causes the working oil in the rod-side oil chamber of the leveling cylinder 23 to flow out, causing the leveling cylinder 23 to extend and the front end of the leveling arm 3A to descend.

[0037] The leveling machine lifting cylinder 25 is a hydraulic cylinder used to lift the leveling machine 3. Figure 1A and Figure 1BIn the example shown, the cylinder of the leveler lifting cylinder 25 is connected to the traction machine 1, and the lever is connected to the rear end of the leveling arm 3A. When the leveler 3 is lifted, the controller 50 causes the working oil discharged from the hydraulic pump to flow into the lever-side oil chamber of the leveler lifting cylinder 25. As a result, the leveler lifting cylinder 25 retracts, the rear end of the leveling arm 3A is lifted, and thus the leveler 3 is lifted. On the other hand, when the lifted leveler 3 is lowered, the controller 50 allows the working oil in the lever-side oil chamber of the leveler lifting cylinder 25 to flow out. As a result, the leveler lifting cylinder 25 extends due to the weight of the leveler 3, the rear end of the leveling arm 3A descends, and thus the leveler 3 descends.

[0038] A side plate 40 is installed at the far end of the telescopic leveler 31. The side plate 40 is a plate-shaped component extending along the length of the vehicle and includes a left side plate 40L and a right side plate 40R. Specifically, the left side plate 40L is installed at the far end (left end) of the left telescopic leveler 31L, and the right side plate 40R is installed at the far end (right end) of the right telescopic leveler 31R.

[0039] Side plate 40 is also installed at the far end of telescopic plow plate 41. Telescopic plow plate 41 is a component used to adjust the amount of paving material that remains in front of telescopic leveler 31 in the paving material spread by screw SC, and it is configured to extend and retract along the width direction together with telescopic leveler 31.

[0040] Specifically, the telescopic plow plate 41 is a plate-shaped component extending along the vehicle width direction, and includes a left telescopic plow plate 41L and a right telescopic plow plate 41R. Furthermore, a left side plate 40L is installed at the far end (left end) of the left telescopic plow plate 41L, and a right side plate 40R is installed at the far end (right end) of the right telescopic plow plate 41R.

[0041] The telescopic plow plate 41 is configured to adjust its height in the Z-axis direction independently of the telescopic leveler 31 and the side plate 40. The asphalt roller 100 adjusts the gap between the lower end of the telescopic plow plate 41 and the roadbed by moving the telescopic plow plate 41 up and down, thereby adjusting the amount of paving material passing through this gap. Therefore, by moving the telescopic plow plate 41 up and down, the asphalt roller 100 can adjust the amount (height) of paving material positioned behind the telescopic plow plate 41 (-X side) and in front of the telescopic leveler 31 (+X side), and further adjust the amount of paving material taken into the lower side of the telescopic leveler 31.

[0042] The leveling machine step 42 is a component that forms the footboard for workers to operate behind the leveling machine 3. Specifically, the leveling machine step 42 includes a left leveling machine step 42L, a central leveling machine step 42C, and a right leveling machine step 42R.

[0043] The fixing plate 43 is a plate-shaped component used to prevent the paving material spread by the screw SC in the vehicle width direction from spreading out in front of the screw SC in order to properly spread the paving material in the vehicle width direction. Figure 1A and Figure 1B In the example shown, the fixing plate 43 includes a left fixing plate 43L and a right fixing plate 43R.

[0044] Next, refer to Figure 2 The supporting functions, which are one of the functions of the controller 50, will be explained. Figure 2 This is a functional block diagram of the controller 50. The support function is used to support the operation of the asphalt roller 100 by the operator of the asphalt roller 100. The support function is mainly realized by the coordinated operation of the spatial recognition device CM, the screw speed sensor 45, the conveyor feed speed sensor 46, the travel speed sensor 47, the auxiliary storage device 48, the controller 50, the screw control device 51, the conveyor control device 52, the hopper control device 53, the travel control device 54, and the output device 55.

[0045] The screw speed sensor 45 is configured to detect the rotational speed of the screw SC. Figure 2 In the example shown, the screw speed sensor 45 is an encoder that detects the angular velocity of the rotating shaft of the hydraulic motor that drives the screw SC. The screw speed sensor 45 can be constructed from a proximity switch or the like that that detects a slit formed in the rotating plate.

[0046] The conveyor feed speed sensor 46 is configured to detect the feed speed of the conveyor CV. Figure 2 In the example shown, the conveyor feed speed sensor 46 is an encoder that detects the angular velocity of the rotating shaft of the hydraulic motor that drives the conveyor CV. The conveyor feed speed sensor 46 can be composed of a proximity switch or the like that that detects a slit formed in the rotating plate.

[0047] The travel speed sensor 47 is configured to detect the travel speed of the asphalt roller 100. Figure 2 In the example shown, the driving speed sensor 47 is an encoder that detects the angular velocity of the rotating shaft of the motor that drives the rear wheels 5. The driving speed sensor 47 can be composed of a proximity switch or the like that that detects a slit formed in the rotating plate.

[0048] The auxiliary storage device 48 is configured to store various types of information. Figure 2 In the example shown, the auxiliary storage device 48 is a non-volatile storage device mounted on the traction machine 1 and stores various information.

[0049] The screw control device 51 is configured to control the rotational speed of the screw SC. Figure 2In the example shown, the screw control device 51 is a solenoid valve that controls the flow rate of the working oil flowing into the hydraulic motor driving the screw SC. Specifically, the screw control device 51 increases or decreases the cross-sectional area, i.e., the flow path area, of the pipe connecting the hydraulic motor and the hydraulic pump of the screw SC, according to control instructions from the controller 50. More specifically, the screw control device 51 increases the flow rate of the working oil flowing into the hydraulic motor of the screw SC by increasing the flow path area, thereby increasing the rotational speed of the screw SC. Alternatively, the screw control device 51 decreases the flow rate of the working oil flowing into the hydraulic motor of the screw SC by decreasing the flow path area, thereby decreasing the rotational speed of the screw SC.

[0050] The conveyor control device 52 is configured to control the feed speed of the conveyor CV. Figure 2 In the example shown, the conveyor control device 52 is a solenoid valve that controls the flow rate of the working oil flowing into the hydraulic motor driving the conveyor CV. Specifically, the conveyor control device 52 increases or decreases the cross-sectional area, i.e., the flow path area, of the pipe connecting the hydraulic motor and the hydraulic pump driving the conveyor CV, according to control instructions from the controller 50. More specifically, the conveyor control device 52 increases the flow rate of the working oil flowing into the hydraulic motor driving the conveyor CV by increasing the flow path area, thereby increasing the feed speed of the conveyor CV. Alternatively, the conveyor control device 52 decreases the flow rate of the working oil flowing into the hydraulic motor driving the conveyor CV by decreasing the flow path area, thereby decreasing the feed speed of the conveyor CV.

[0051] The hopper control device 53 is configured to control the extension and retraction of the hopper cylinder 24. Figure 2 In the example shown, the hopper control device 53 is a solenoid valve that controls the flow rate of working oil flowing into or out of the hopper cylinder 24. Specifically, the hopper control device 53 switches the connection / disconnection of the pipes connecting the hopper cylinder 24 to the hydraulic pump and the pipes connecting the hopper cylinder 24 to the working oil tank according to control instructions from the controller 50. More specifically, the hopper control device 53 is configured to allow working oil to flow into the bottom oil chamber of the hopper cylinder 24 by connecting these pipes, causing the hopper cylinder 24 to extend and automatically close the hopper 2. Alternatively, the hopper control device 53 is configured to connect these pipes according to control instructions from the controller 50, causing working oil to flow out of the bottom oil chamber of the hopper cylinder 24, causing the hopper cylinder 24 to contract and open the hopper 2.

[0052] The travel control device 54 is configured to control the travel speed of the asphalt roller 100. Figure 2In the example shown, the travel control device 54 is a solenoid valve that controls the flow rate of the working oil flowing into the rear wheel travel motor and the front wheel travel motor, respectively. Specifically, the travel control device 54 increases or decreases the cross-sectional area, i.e., the flow path area, of the pipes connecting the rear wheel travel motor and the front wheel travel motor to the hydraulic pump, respectively, according to the control instruction from the controller 50. More specifically, the travel control device 54 increases the flow rate of the working oil flowing into the rear wheel travel motor and the front wheel travel motor by increasing the flow path area, thereby increasing the travel speed of the asphalt roller 100. Alternatively, the conveyor control device 52 decreases the flow rate of the working oil flowing into the rear wheel travel motor and the front wheel travel motor by decreasing the flow path area, thereby decreasing the travel speed of the asphalt roller 100.

[0053] The output device 55 is configured to output information. The information includes visual information and auditory information. Figure 2 In the example shown, output device 55 is configured to transmit information to workers operating around the asphalt roller 100. Workers operating around the asphalt roller 100 include the operator of the asphalt roller 100 and the driver of the dump truck. Specifically, output device 55 is the main monitor 55A (see reference 55A). Figure 1A and Figure 1B ), sound output device 55B (reference) Figure 1A and Figure 1B . ) and indicator 55C (reference) Figure 1A and Figure 1B However, the output device 55 can be one or two of the main monitor 55A, the sound output device 55B, and the indicator 55C.

[0054] The main monitor 55A is configured to display various information. Figure 2 In the example shown, the main monitor 55A is a liquid crystal display (LCD) capable of displaying various information according to control instructions from the controller 50. Furthermore, the main monitor 55A may include input devices such as a touch panel that accepts operational input from the operator of the asphalt tumbler 100.

[0055] The sound output device 55B is configured to output sound to the vicinity of the asphalt tumbler 100. Figure 2 In the example shown, the sound output device 55B is a loudspeaker that outputs sound to the vicinity of the asphalt tumbler 100 and can output an alarm tone according to control instructions from the controller 50. The sound output device 55B can output sound information.

[0056] Indicator 55C is a display device having a display section facing the front of the asphalt roller 100. Figure 2In the example shown, indicator 55C is mounted on the tractor unit 1 so that the driver of the dump truck, seated in the cab, can visually identify it. Specifically, indicator 55C is positioned higher than the upper surface of the tractor unit 1. Indicator 55C is an LED panel capable of displaying various information based on control instructions from the controller 50. For example, it can display a reverse instruction to the driver of the dump truck loaded with paving material, informing the driver that the dump truck can reverse.

[0057] exist Figure 2 In the example shown, the indicator 55C is configured to extend outward from the right side of the tractor 1 when in use. That is, the indicator 55C is configured to fold up within the width of the asphalt trolley 100 when not in use.

[0058] The controller 50 acquires information from the spatial identification device CM, screw speed sensor 45, conveyor feed speed sensor 46, travel speed sensor 47, and auxiliary storage device 48, and performs various calculations. Based on the calculation results, it outputs control instructions to the screw control device 51, conveyor control device 52, hopper control device 53, travel control device 54, and output device 55.

[0059] Specifically, the controller 50 determines whether the specified conditions are met based on information obtained from at least one of the spatial identification device CM, screw speed sensor 45, conveyor feed speed sensor 46, travel speed sensor 47, and auxiliary storage device 48. When the specified conditions are met, the controller outputs a control instruction to at least one of the screw control device 51, conveyor control device 52, hopper control device 53, travel control device 54, and output device 55.

[0060] More specifically, the controller 50 has a space recognition unit 50A and a hopper control unit 50B, which are functional modules consisting of software, hardware or a combination thereof.

[0061] The space recognition unit 50A is configured to identify the state in front of the tractor 1 based on the output of the space recognition device CM. Figure 2 In the example shown, the space recognition unit 50A is configured to recognize the height of the paving material inside the hopper 2. The height of the paving material inside the hopper 2 is, for example, the central portion MP inside the hopper 2 (refer to...). Figure 1B The distance between the bottom surface of hopper 2 and the surface of the paving material. The central part MP of hopper 2 is, for example, the exposed part of conveyor CV.

[0062] Specifically, the spatial recognition unit 50A derives the height of the paving material in the central part MP within the hopper 2 by performing prescribed image processing on images captured by the monocular camera, which functions as a spatial recognition device CM. Furthermore, the spatial recognition unit 50A can derive the volume or weight of the paving material in the central part MP within the hopper 2 by performing prescribed image processing on images captured by the monocular camera, which functions as a spatial recognition device CM. Alternatively, the spatial recognition unit 50A can derive the paving material in the central part MP within the hopper 2 based on the output of the LIDAR, which functions as a spatial recognition device CM.

[0063] Furthermore, the space identification unit 50A determines whether the exported height is greater than a predetermined height. The predetermined height is, for example, a value (height) pre-registered in the auxiliary storage device 48. The predetermined height is, for example, the height of the inlet OP of the conveyor channel CP. In addition, when exporting the volume of paving material in the central part MP within the hopper 2, the space identification unit 50A determines whether the exported volume is greater than a predetermined volume.

[0064] The spatial recognition unit 50A can be configured to determine whether a dump truck is present in front of the asphalt roller 100. Specifically, the spatial recognition unit 50A can be configured to determine whether a dump truck has contacted the asphalt roller 100 via the push roller 2b, whether the dump truck has unloaded its cargo platform, whether the dump truck is close to the asphalt roller 100, or whether the dump truck is far away from the asphalt roller 100 by performing prescribed image processing on the image captured by the monocular camera, which is a spatial recognition device CM. In addition, when the dump truck contacts the asphalt roller 100, the rear wheel tires of the dump truck and the push roller 2b disposed on the front side of the hopper 2 (see reference) Figure 1A and Figure 1B ( ) The dump truck driver then shifts the truck into neutral. The dump truck is then pushed forward by the driving force of the asphalt roller 100, moving forward together with the asphalt roller 100.

[0065] Figures 3A-3C This is a left view of the asphalt roller 100 and the dump truck 200. The dump truck 200 is an example of a transport vehicle that carries paving material supplied to the hopper 2 of the asphalt roller 100.

[0066] Figures 3A-3C This shows three states of the dump truck 200. Specifically, Figure 3A The diagram shows the state of the asphalt roller 100 and the dump truck 200 as paving material loaded on the platform of the dump truck 200 is fed into the hopper 2 of the asphalt roller 100. Figure 3A In the process, the loading platform 200b of the dump truck 200, which is in contact with the asphalt roller 100, is unloaded.

[0067] Figure 3BThis diagram shows the state of the asphalt roller 100 and the dump truck 200 after all the paving material loaded on the platform 200b has been fed into the hopper 2 and the platform 200b has been returned to its unloaded state. Figure 3B In the middle, the dump truck 200 still contacts the asphalt roller 100 via the push roller 2b.

[0068] Figure 3C The diagram shows the state of the asphalt roller 100 and the dump truck 200 when the dump truck 200 moves forward and separates from the asphalt roller 100.

[0069] The spatial recognition unit 50A is capable of performing prescribed image processing on images captured by a monocular camera, which serves as a spatial recognition device CM, to determine the current state of the asphalt roller 100 and the dump truck 200. Figure 3A The state shown, or as Figure 3B The state shown, or as Figure 3C The states shown, etc.

[0070] Furthermore, the spatial recognition unit 50A can be configured to determine whether there is an object entering the hopper 2. Specifically, the spatial recognition unit 50A can be configured to determine whether a worker has entered the hopper 2, or whether there are tools such as rakes or shovels inside the hopper 2, by performing prescribed image processing on images captured by a monocular camera that serves as a spatial recognition device CM.

[0071] Furthermore, the space recognition unit 50A can be configured to determine whether the paving material in the hopper 2 has been used up. Specifically, the space recognition unit 50A can be configured to determine whether the paving material in the hopper 2 has been used up by performing prescribed image processing on the image captured by the monocular camera, which is a space recognition device CM.

[0072] The hopper control unit 50B is configured to close hopper 2 when specified conditions are met. Figure 2 In the example shown, the space recognition unit 50A determines whether the height of the paving material in the central part MP of the hopper 2 is greater than a predetermined height based on the image captured by the monocular camera, which serves as the space recognition device CM. Furthermore, when the space recognition unit 50A determines that the height of the paving material in the central part MP of the hopper 2 is greater than the predetermined height, the hopper control unit 50B sends a closing instruction to the hopper control device 53. Upon receiving the closing instruction, the hopper control device 53 extends the hopper cylinder 24 and closes the hopper 2 by allowing working oil to flow into the bottom oil chamber of the hopper cylinder 24. The hopper control unit 50B can, for example, extend the hopper cylinder 24 until the hopper 2 is completely closed, or it can extend the hopper cylinder 24 only to a predetermined length.

[0073] Furthermore, the hopper control unit 50B can send an output instruction to the output device 55 when the hopper 2 is closed, that is, when the hopper cylinder 24 is extended. Upon receiving the output instruction, the output device 55 can, for example, display text information such as "hopper is closing" on the main monitor 55A to inform the operator of the asphalt roller 100 that the hopper 2 has been automatically closed. Alternatively, the output device 55 can, for example, output audible information such as "hopper is closing" on the sound output device 55B to inform workers around the asphalt roller 100 that the hopper 2 has been automatically closed. Alternatively, the output device 55 can, for example, output text information such as "hopper is closing" on the indicator 55C to inform the driver of the dump truck 200 that the hopper 2 has been automatically closed.

[0074] The hopper control unit 50B can be configured such that when the space recognition unit 50A determines, based on the image captured by the monocular camera (which serves as the space recognition device CM), that the dump truck 200 is in contact with the asphalt roller 100, the hopper 2 will not be closed even if the space recognition unit 50A determines that the aforementioned conditions are met. This is to prevent the hopper wings from contacting the dump truck. At this time, the hopper control unit 50B can be configured not to send a closing instruction to the hopper control device 53, or it can send a stop instruction to the hopper control device 53. Upon receiving the stop instruction, the hopper control device 53 stops the extension of the hopper cylinder 24 by stopping the flow of working oil into the bottom oil chamber of the hopper cylinder 24, thereby stopping the operation of the hopper 2.

[0075] Furthermore, the hopper control unit 50B can be configured such that even when the space identification unit 50A determines that the dump truck 200 is not in contact with the asphalt roller 100, and when the space identification unit 50A determines that the distance between the dump truck 200 and the asphalt roller 100 is less than a predetermined distance, the hopper 2 will not be closed, just as when the space identification unit 50A determines that the dump truck 200 is in contact with the asphalt roller 100.

[0076] Furthermore, the hopper control unit 50B can be configured such that when the space recognition unit 50A determines, based on the image captured by the monocular camera (which serves as the space recognition device CM), that an object is present in the hopper 2, the hopper 2 will not be closed even if the space recognition unit 50A determines that the aforementioned conditions are met. This is to prevent the hopper wings from contacting the object or to prevent the object (e.g., a shovel) from being buried by the paving material inside the hopper 2. In this case, the hopper control unit 50B can be configured not to send a closing instruction to the hopper control device 53, or it can be configured to send a stop instruction to the hopper control device 53.

[0077] Furthermore, the hopper control unit 50B can be configured to reduce the feed speed of the conveyor CV, the rotational speed of the screw SC, and the travel speed of the asphalt roller 100 when the space recognition unit 50A determines, based on images captured by a monocular camera (which serves as a space recognition device CM), that the paving material in the hopper 2 has been exhausted. Moreover, the hopper control unit 50B can be configured to stop the operation of the conveyor CV, the screw SC, the rear wheel 5, and the front wheel 6. This is because when construction continues by the asphalt roller 100 without paving material in the hopper 2, a depression forms on the newly constructed road due to the lack of paving material.

[0078] At this time, the hopper control unit 50B sends deceleration or stop instructions to the screw control device 51, the conveyor control device 52, and the travel control device 54, respectively. Upon receiving the deceleration or stop instruction, the screw control device 51 reduces the flow rate of the working oil flowing into the hydraulic motor driving the screw SC, thereby reducing the speed of the screw SC or stopping the rotation of the screw SC. The same applies to the conveyor control device 52 and the travel control device 54.

[0079] Figures 4A-4E This is the front view of the asphalt roller 100. Figures 4A-4E The five states of the paving material PM in hopper 2 are roughly shown. For clarity, in Figures 4A-4E In the diagram, the paving material PM inside hopper 2 is marked with a dotted shading line. Furthermore, in... Figure 4A The diagram shows the base 1BF of the traction machine 1, the front wheels 6 (left front wheel 6L and right front wheel 6R), and the hopper cylinders 24 (left hopper cylinder 24L and right hopper cylinder 24R). Figures 4B to 4E The text has been omitted. Furthermore, in... Figure 4A , Figure 4C and Figure 4D In the middle, the part of the inlet OP of the transmission channel CP formed on the front surface 1FW of the traction machine 1 that is buried by the paving material PM and is not actually visible is represented by a dashed line.

[0080] Specifically, Figure 4A This shows the state of the paving material PM in hopper 2 immediately after it has been supplied by dump truck 200. Specifically, Figure 4A As shown Figure 3B The state of the paving material PM in hopper 2 after the paving material loaded on the loading platform 200b of the dump truck 200 is supplied into hopper 2, as shown. More specifically, Figure 4A This shows a state in which a sufficient amount of paving material PM is stored in the space within the hopper 2, which is surrounded by the front surface 1FW of the tractor 1 and the hopper wings 2W (left hopper wing 2WL and right hopper wing 2WR).

[0081] Figure 4BThis shows the state when the amount of paving material PM in hopper 2 decreases. Specifically, Figure 4B The diagram shows the state where the paving material PM located in the central part MP of hopper 2 is conveyed by conveyor CV to the rear of traction machine 1, and the height of the paving material PM in the central part MP of hopper 2 is height H1. That is, Figure 4B The height H1 of the paving material PM in the central part MP of hopper 2 is smaller than the specified height Ht. Figure 4B In the example shown, the specified height Ht corresponds to the height of the inlet OP of the conveying channel CP formed on the front surface 1FW of the traction machine 1. On the other hand, Figure 4B The height of the paving material PM at the left and right ends of the hopper 2 is shown as height H2, which is still greater than the specified height Ht.

[0082] exist Figure 4B In the state shown, the space recognition unit 50A can determine, based on the image captured by the monocular camera which is the space recognition device CM, that the height H1 of the paving material in the central part MP inside the hopper 2 is smaller than the specified height Ht.

[0083] When the spatial identification unit 50A determines that the height H1 of the paving material in the central part MP of the hopper 2 is less than the specified height Ht, the hopper control unit 50B sends a closing instruction to the hopper control device 53. Upon receiving the closing instruction, the hopper control device 53 extends the hopper cylinder 24 and closes the hopper 2 by allowing working oil to flow into the bottom oil chamber of the hopper cylinder 24.

[0084] Figure 4C and Figure 4D This shows the state of the paving material PM inside hopper 2 when hopper 2 is closed. Specifically, Figure 4C The diagram shows the state when the left hopper wing 2WL and the right hopper wing 2WR are each closed to about half (when the hopper angle is angle α1). Figure 4D This shows the state when the left hopper wing 2WL and the right hopper wing 2WR are fully closed (when the hopper angle is angle α2). Additionally, Figure 4A and Figure 4B This shows the state when the left hopper wing 2WL and the right hopper wing 2WR are fully open (when the hopper angle is zero). The hopper angle is, for example, the angle formed between the bottom surface of the hopper 2 and a defined imaginary plane. The defined imaginary plane is, for example, the imaginary plane on which the asphalt roller 100 is located, typically an imaginary horizontal plane.

[0085] Figure 4E This shows the state when paving material PM remains at the left and right ends of hopper 2, and when the paving material PM in the central part MP is exhausted. Specifically, Figure 4E Shown in Figure 4BThe state of the paving material PM inside hopper 2 after the state shown is maintained as is when the fully open state of hopper 2 is retained.

[0086] The hopper control unit 50B can automatically close the hopper 2 when the height of the paving material in the central part MP of the hopper 2 falls below a predetermined height Ht, thus collecting the paving material PM from the left and right ends of the hopper 2 into the central part MP. Therefore, the hopper control unit 50B can prevent situations such as... Figure 4E The diagram shows a situation where paving material PM remains at the left and right ends of the hopper 2, while the paving material PM in the central part MP is exhausted. As a result, the hopper control unit 50B can prevent the formation of depressions on the newly constructed road due to insufficient supply of paving material PM to the leveling machine 3.

[0087] As described above, the asphalt roller 100 includes: a traction machine 1; a hopper 2 disposed in front of the traction machine 1 and receiving paving material; a conveyor CV that conveys the paving material in the hopper 2 to the rear of the traction machine 1; a screw SC that spreads the paving material conveyed by the conveyor CV at the rear of the traction machine 1; and a leveling machine 3 that evenly spreads the paving material spread by the screw SC at the rear of the screw SC. Furthermore, the asphalt roller 100 also includes: a spatial recognition device CM that monitors the state inside the hopper 2; and a controller 50 that moves the hopper 2 according to the output of the spatial recognition device CM.

[0088] With this structure, the asphalt roller 100 can reliably move the hopper 2 when the amount of paving material PM in the hopper 2 decreases. Therefore, the asphalt roller 100 can reliably prevent the following situation: even though there is sufficient paving material PM remaining at the end of the hopper 2, the paving material PM supplied to the leveler 3 is insufficient.

[0089] The controller 50 is configured to close the hopper 2 when it is determined that the amount of paving material PM in the hopper 2 is less than a predetermined amount. For example, the controller 50 may be configured to automatically close the hopper 2 when it is determined that the height of the paving material PM in the central part MP of the hopper 2 is less than a predetermined height Ht, indicating that the amount of paving material PM in the hopper 2 is less than a predetermined amount. Furthermore, when the hopper 2 is automatically closed, the controller 50 may be configured to notify the surrounding area of ​​this information.

[0090] Alternatively, the controller 50 can be configured to close the hopper 2 when it is determined that the amount of paving material PM in the hopper 2 has changed from a state greater than a predetermined amount to a state less than a predetermined amount. For example, the controller 50 can be configured to close the hopper 2 when it is determined that the height of the paving material PM in the central part MP of the hopper 2 has changed from a state greater than a predetermined height Ht to a state less than a predetermined height Ht. Furthermore, when the hopper 2 is closed, the controller 50 can be configured to notify the surrounding area of ​​this information.

[0091] With these structures, the asphalt roller 100 can reliably close the hopper 2 when the amount of paving material PM in the hopper 2 is less than the specified amount. Furthermore, the asphalt roller 100 can use the output device 55 to instruct workers around the asphalt roller 100 to close the hopper 2, or to perform a hopper 2 closing operation.

[0092] The controller 50 can be configured to determine whether an object is present in the hopper 2 before or during its movement. For example, the controller 50 can be configured to determine whether a worker has entered the hopper 2 or whether tools such as rakes or shovels are present in the hopper 2 by performing prescribed image processing on images captured by a monocular camera (which serves as a spatial recognition device, CM). Furthermore, when the controller 50 determines that a worker, rake, or shovel is present in the hopper 2, it may not close the hopper 2 even if the amount of paving material PM in the hopper 2 is less than a predetermined amount. This is to prevent the hopper wings 2W from contacting the object or to prevent the object from being buried by the paving material PM in the hopper 2.

[0093] Furthermore, while a hydraulic motor was used in the above embodiment, an electric motor could also be used instead of a hydraulic motor.

[0094] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Various modifications or substitutions can be applied to the above embodiments without departing from the scope of the present invention. Furthermore, the features described separately can be combined as long as they do not create technical contradictions.

[0095] For example, in the above embodiment, the controller 50 is configured to close the hopper 2 when predetermined conditions are met. Furthermore, typically, the controller 50 is configured to stop the extension of the hopper cylinder 24 when the hopper 2 is fully closed. However, when the hopper 2 is fully closed, or when the hopper 2 is about to be fully closed, the controller 50 can extend or retract the hopper cylinder 24 within a predetermined time. That is, the controller 50 can cause the hopper 2 to vibrate. This is to shake off the paving material PM adhering to the inner wall or bottom surface of the hopper wing 2W.

[0096] Furthermore, the controller 50 can be configured to perform feedback control on the hopper angle based on the height of the paving material PM derived by the space recognition unit 50A, so that the height of the paving material PM in the central part MP inside the hopper 2 becomes the desired height.

[0097] Alternatively, the controller 50 can identify the state of the paving material PM in hopper 2 before closing hopper 2 based on images captured by the monocular camera, which serves as a spatial recognition device CM. Furthermore, the controller 50 can infer the state of the paving material PM in hopper 2 when hopper 2 is closed based on its identification result. The state of the paving material PM in hopper 2 is, for example, based on the angle of repose β of the paving material PM (reference). Figure 4B The angle of repose β is typically preset based on the type of paving material PM. In this case, the controller 50 can determine the target hopper angle based on the inference result. That is, the controller 50 can determine the degree to which the hopper 2 should be closed.

[0098] Furthermore, the controller 50 can use the learned model that has learned the control conditions to make various judgments. For example, the spatial recognition unit 50A of the controller 50 can use the learned model that has learned the control conditions of the hopper 2 to make various judgments. Such judgments include, for example, whether the amount of paving material in the hopper 2 is more or less than the specified amount; whether there is a dump truck 200 in front of the asphalt roller 100; whether the dump truck 200 is far away from the asphalt roller 100; whether there is an object entering the hopper 2; whether the height of the paving material in the central part MP of the hopper 2 is greater than the specified height; or whether the paving material in the hopper 2 has been used up.

[0099] Specifically, the spatial recognition unit 50A uses a learned model stored in a non-volatile storage device to make various judgments based on the input image captured by the monocular camera, which is the spatial recognition device CM. Specifically, the spatial recognition unit 50A loads the learned model from the non-volatile storage device into a main storage device such as RAM, and causes the CPU to perform processing based on the learned model, thereby making various judgments based on the input image.

[0100] For example, such as Figure 5 As shown, the learned model can be constructed around a neural network 401. In this example, the neural network 401 is a so-called deep neural network with one or more intermediate layers (hidden layers) between the input and output layers. Figure 5 In the example, there are N intermediate layers (N is a natural number greater than 2). In neural network 401, a weighted parameter representing the connection strength with the lower layers is defined for each of the multiple neurons constituting each intermediate layer. Figure 5 In the example, the number of neurons is L (L is a natural number greater than 2). Furthermore, the neurons in each layer form a neural network 401 by outputting the sum of the values ​​obtained by multiplying the weighted parameters specified for each neuron in the upper layer by the input values ​​from multiple neurons in the upper layer through a threshold function to the neurons in the lower layer.

[0101] Using a 401 neural network as the object, machine learning, specifically deep learning, is performed to optimize the aforementioned weighted parameters. Thus, for example, as... Figure 5 As shown, in neural network 401, an input image can be input as an input signal x, and a predefined list of monitored objects (in this example, the probability of the existence of each type of object (predicted probability)) and a scene (state) based on their positional relationships, etc., can be output as an output signal y. Neural network 401 is, for example, a convolutional neural network (CNN). A CNN is a neural network that applies existing image processing techniques (convolutional processing and pooling processing). Specifically, a CNN outputs feature data (feature maps) that are more compact than the input image by repeatedly performing a combination of convolutional and pooling processing on the input image. Furthermore, the pixel values ​​of each pixel in the output feature map are input into a neural network consisting of multiple fully connected layers, and the output layer of the neural network can, for example, output values ​​representing the state of the paving material within the hopper 2.

[0102] Thus, the neural network 401 can be configured to take an input image as an input signal x and output the position and size of an object in the input image (i.e., the area occupied by the object in the input image) and the type of the object as an output signal y (e.g., a value representing the state of the paving material in the hopper 2). That is, the neural network 401 can be a structure that detects objects in the input image (determines whether there is an object occupying an area in the input image) and classifies the object. Furthermore, the output signal y can be configured as image data with the object's occupying area and classification-related information superimposed on the input image as the input signal x. Therefore, the spatial recognition unit 50A can determine, for example, the state of the paving material in the hopper 2 based on the position and size of the object's occupying area in the input image.

[0103] In the above embodiment, the monocular camera, which serves as the spatial recognition device CM, is fixed to the upper end of the front end of the traction machine 1, and the camera range (field of view) is predetermined (fixed). Furthermore, when the position of an object (paving material in the hopper 2) detected by the learned model is within the monitoring area and is classified as an object in the monitoring object list, the spatial recognition unit 50A can determine that an object being monitored has been detected within the monitoring area. Additionally, the neural network 401 can be a structure having a neural network structure that respectively corresponds to processing for extracting the occupied area (window) of an object in the input image and processing for determining the type of object in the extracted area. That is, the neural network 401 can be a structure that performs object detection and object classification in stages. Furthermore, the neural network 401 can be a structure having a neural network structure corresponding to the following processing: defining the object classification and the object's occupied area (bounding box) for each grid cell that divides the entire area of ​​the input image into a predetermined number of partial regions; and determining the final object's occupied area by connecting the occupied areas of each type of object according to the object classification of each grid cell. That is, the neural network 401 can be a structure that performs object detection and object classification in parallel.

[0104] Furthermore, the controller 50 can be configured to learn control conditions that associate with the open or closed state of the hopper 2. For example, the controller 50 can be configured to learn the relationship (hopper control conditions) between the state of the paving material in the hopper 2 and the open or closed state of the hopper 2, based on a dataset created by combining a combination of a camera image of the paving material in the hopper 2 obtained by the spatial recognition device CM and reference information representing "preferred open or closed state of the hopper 2" as determination data pre-stored in a non-volatile storage device. This learning process can be performed in a management device (machine learning device) that is wirelessly connected to the asphalt roller 100. At this time, the learned model created in the management device (machine learning device) is sent to the asphalt roller 100. The hopper control unit 50B can use the received learned model to determine the preferred open or closed state of the hopper 2 corresponding to the current state of the paving material in the hopper 2, and control the hopper 2 to achieve its preferred open or closed state.

[0105] This application claims priority based on Japanese Patent Application No. 2020-059058, filed on March 27, 2020, the entire contents of which are incorporated herein by reference.

[0106] Symbol Explanation

[0107] 1-Traction machine, 1BF-Base, 1FW-Front surface, 2-Hopper, 2b-Push roller, 2W-Hopper wing, 3-Leveler, 3A-Leveling arm, 5-Rear wheel, 6-Front wheel, 23-Leveling cylinder, 24-Hopper cylinder, 25-Leveler lifting cylinder, 30-Main leveler, 31-Telescopic leveler, 40-Side plate, 41-Telescopic plow plate, 42-Leveler step, 43-Fixed plate, 45-Screw speed sensor, 46-Conveyor feed speed sensor, 47-Travel speed sensor, 48-Auxiliary storage device, 50-Control Device, 50A-Spatial Identification Unit, 50B-Hopper Control Unit, 51-Screw Control Device, 52-Conveyor Control Device, 53-Hopper Control Device, 54-Travel Control Device, 55-Output Device, 55A-Main Monitor, 55B-Sound Output Device, 55C-Indicator, 60-Telescopic Cylinder, 100-Asphalt Roller, 200-Dump Truck, 200b-Platform, CM-Spatial Identification Device, CP-Conveying Channel, CV-Conveyor, MP-Central Section, OP-Entrance, PM-Paving Material, SC-Screw.

Claims

1. An asphalt rolling machine, comprising: Traction machine; A hopper is located at the front of the traction machine and receives paving materials; The conveyor transports the paving material in the hopper to the rear of the traction machine; The screw spreads the paving material conveyed by the conveyor behind the traction machine; and The screed spreads the paving material, which is laid out by the screw, evenly on the rear side of the screw. The asphalt roller also features: A spatial identification device monitors the state inside the hopper; and The controller moves the hopper based on the output of the spatial recognition device. The controller infers the state of the paving material in the hopper when the hopper is closed to any degree, based on the current state of the paving material identified by the output of the spatial identification device. The state of the paving material in the hopper is inferred from the angle of repose of the paving material, and the controller determines the degree to which the hopper should be closed based on the inference result.

2. The asphalt roller according to claim 1, wherein, The controller is configured to close the hopper to a degree determined by the inference result when it is determined that the amount of paving material in the hopper is less than a specified amount.

3. The asphalt roller according to claim 1, wherein, The controller is configured to inform the surroundings of this information when the hopper is moved.

4. The asphalt roller according to claim 1, wherein, The controller is configured to close the hopper to a degree determined by the inference result when it is determined that the paving material in the hopper has transitioned from a state of more than a predetermined amount to a state of less than the predetermined amount.

5. The asphalt roller according to claim 1, wherein, The controller is configured to determine whether there is an object entering the hopper before moving the hopper.

Images