Asphalt finisher

Abstract

To improve work efficiency.SOLUTION: An asphalt finisher according to one aspect of the present disclosure includes: a tractor; a hopper installed on a front side of the tractor, capable of receiving a pavement material, and openable and closable in a vehicle width direction; a conveyor for conveying the pavement material in the hopper to a rear side of the tractor; a screw for spreading the pavement material conveyed by the conveyor on the rear side of the tractor; and a screed connected to a rear part of the tractor in a vertically movable manner and spreading the pavement material spread by the screw on a rear side of the screw. The asphalt finisher also includes a control unit configured to acquire a first amount of the pavement material charged into the hopper, calculate a second amount of the pavement material conveyed from the hopper from a detection result by a detection device, and control the opening and closing of the hopper based on a first amount of the charged pavement material and a second amount of the conveyed pavement material is provided.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an asphalt finisher. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a road machine, such as an asphalt finisher, that includes a tractor, a screed that is disposed behind the tractor for spreading and leveling paving material, and a work implement that supplies paving material in front of the screed.

[0003] Conventionally, in order for an asphalt finisher to spread and level paving material, it is necessary to recognize the remaining amount of paving material. Therefore, for example, a technology has been proposed in which a camera and an image processing device are used to recognize an image of a conveyor captured by the camera, to detect whether or not asphalt mixture is on the conveyor, and to drive a hopper according to the detected remaining amount (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-139372 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, there are cases where a technique other than image recognition would be better for detecting whether or not an asphalt mixture is loaded.

[0006] One aspect of the present invention improves work efficiency by obtaining the amount of paving material put into a hopper and the amount of paving material transported from the hopper, and performing appropriate control over the opening and closing of the hopper based on the obtained results. [Means for solving the problem]

[0007] An asphalt finisher according to one embodiment of the present invention comprises a tractor, a hopper installed in front of the tractor capable of receiving paving material and which can be opened and closed in the vehicle width direction, a conveyor for transporting the paving material in the hopper to the rear of the tractor, a screw for spreading the paving material transported by the conveyor at the rear of the tractor, and a screed connected to the rear of the tractor in a manner that allows it to move up and down and for spreading the paving material spread by the screw at the rear of the screw, and a control device configured to obtain a first amount of the paving material poured into the hopper, calculate a second amount of the paving material transported from the hopper from the detection result by a detection device, and control the opening and closing of the hopper based on the first amount of paving material poured in and the second amount of paving material transported. Effect of the Invention

[0008] According to one aspect of the present invention, the opening and closing of a hopper is appropriately controlled, thereby improving work efficiency. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of the configuration of a construction management system according to an embodiment. [Diagram 2] 1 shows an example of the configuration of an asphalt finisher as a road machine according to an embodiment. [Diagram 3] 2 is a block diagram showing an example of the configuration of a controller of an asphalt finisher according to an embodiment and devices connected to the controller. FIG. [Figure 4] 5A to 5C are explanatory diagrams showing the opening and closing operation of the hopper according to the embodiment. [Diagram 5] FIG. 2 is a diagram showing an opening of a conveyor of an asphalt finisher according to an embodiment. [Figure 6] 4 is a flowchart showing a processing procedure executed by a controller according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is an example, not a limitation of the invention, and all features and combinations described in the embodiment are not necessarily essential to the invention. In addition, the same or corresponding components in each drawing are denoted by the same or corresponding reference numerals, and the description may be omitted.

[0011] [Configuration of construction management system] First, the configuration of a construction management system SYS according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a construction management system SYS according to an embodiment.

[0012] The construction management system SYS is mainly composed of an asphalt finisher 100, a dump truck 200, and a plant 300.

[0013] The asphalt finisher 100 is a machine used for paving roads, etc. Specifically, the asphalt finisher 100 is mainly composed of a tractor 1, a hopper 2, and a screed 3. The specific configuration of the asphalt finisher 100 will be described later.

[0014] The dump truck 200 is an example of a transport vehicle that transports paving material to be supplied into the hopper 2 of the asphalt finisher 100. In the example shown in Fig. 1, the dump truck 200 is a dedicated dump truck for transporting paving material, equipped with a movable bumper. The dump truck 200 has a driver's cab 202 and a loading platform 201.

[0015] When the dump truck 200 approaches the asphalt finisher 100, it lifts the loading platform 201 and discharges the paving material from the loading platform 201 into the hopper 2.

[0016] The plant 300 is an example of a paving material production facility. In the example shown in Fig. 1, the plant 300 mainly includes a mixer 80, a trolley 81, a hot silo 82, and the like.

[0017] The mixer 80 is a device for uniformly mixing aggregate, filler (stone powder), asphalt, etc. The trolley 81 is a device for transporting the mixture discharged from the mixer 80 to the hot silo 82. The hot silo 82 is a device for keeping the mixture produced by the mixer 80 warm and storing it.

[0018] In addition, the plant 300 is provided with a controller C3, a spatial recognition device M3, and a communication device T3.

[0019] The controller C3 is a control device installed in the plant 300. In the example shown in FIG. 1, the controller C3 is a computer including a CPU, a volatile storage device, and a non-volatile storage device, and is placed in a building attached to the plant 300. The controller C3 is configured to be able to control the spatial recognition device M3 and the communication device T3. The various functions of the controller C3 are realized, for example, by the CPU executing a program stored in the non-volatile storage device. The various functions realized by the controller C3 include, for example, a function to control the movements of the mixer 80, the trolley 81, the hot silo 82, and the like.

[0020] Moreover, the various functions realized by the controller C3 include a function of recognizing the dump truck 200 based on the output of the spatial recognition device M3.

[0021] The spatial recognition device M3 is configured to be able to monitor the state of the dump truck 200 on which paving material is loaded in the plant 300. The spatial recognition device M3 is, for example, a monocular camera, a stereo camera, a millimeter wave radar, an ultrasonic sensor, a laser radar, or a LIDAR. When a millimeter wave radar, an ultrasonic sensor, a laser radar, or the like is used as the spatial recognition device M3, the spatial recognition device M3 may be configured to transmit a number of signals (for example, laser light, etc.) toward an object and receive the reflected signals.

[0022] The controller C3 can recognize the amount of paving material loaded onto the dump truck 200 from the monitoring results of the spatial recognition device M3, etc.

[0023] The communication device T3 is configured to control communication between the plant 300 and an external device. In the example shown in Fig. 1, the communication device T3 is configured to control wireless communication with a communication device mounted on the asphalt finisher 100.

[0024] [Outline of Asphalt Finisher] Fig. 2 shows an example of the configuration of an asphalt finisher 100 as a road machine according to this embodiment. Fig. 2(A) shows a side view, and Fig. 2(B) shows a top view.

[0025] The asphalt finisher 100 is mainly composed of a tractor 1, a hopper 2, and a screed 3.

[0026] The tractor 1 is a mechanism for driving the asphalt finisher 100, and tows the screed 3. In the example shown in FIG. 2, the tractor 1 moves the asphalt finisher 100 by rotating the rear wheels 5 using a rear-wheel driving motor and rotating the front wheels 6 using a front-wheel driving motor. The rear-wheel driving motor and the front-wheel driving motor are hydraulic motors that are rotated by receiving a supply of hydraulic oil from a hydraulic pump. The tractor 1 may be equipped with crawlers instead of wheels. A driver's seat 1S and an operation panel 65 are arranged on the upper part of the tractor 1.

[0027] The hopper 2, which is an example of a working device, is a mechanism for receiving paving material (for example, asphalt mixture). The hopper 2 is installed at the front of the tractor 1, and is configured to be openable and closable in the vehicle width direction by a hopper cylinder 2c. The asphalt finisher 100 normally receives paving material discharged from the loading platform 201 of the dump truck 200 with the hopper 2 fully open. In addition, even when receiving paving material discharged from the loading platform 201 of the dump truck 200, the asphalt finisher 100 can continue traveling while pushing the dump truck 200 forward via the push roller 2b. When the paving material in the hopper 2 decreases, the hopper 2 is closed, and the paving material near the inner wall of the hopper 2 is collected in the center of the hopper 2, so that the conveyor CV, which is an example of a working device, can feed the paving material to the screw SC located at the rear.

[0028] The paving material fed to the rear side of the tractor 1 is spread by the screw SC in the vehicle width direction behind the tractor 1 and in front of the screed 3. In this embodiment, the screw SC has extension screws connected to the left and right.

[0029] The screed 3 is provided at the rear of the tractor 1, and is a mechanism for leveling the paving material spread by the screw SC. In this embodiment, the screed 3 is configured to be movable (movable) vertically (up and down) and extendable in the vehicle width direction by a hydraulic cylinder. The width of the screed 3 is greater than the width of the tractor 1 when extended in the vehicle width direction. In this embodiment, the screed 3 includes a main screed 30, a left telescopic screed 31L, and a right telescopic screed 31R. The left telescopic screed 31L and the right telescopic screed 31R are configured to be able to extend and retract in the vehicle width direction (Y-axis direction). The left telescopic screed 31L and the right telescopic screed 31R, which are extendable in the vehicle width direction, are offset from each other in the traveling direction (X-axis direction). Therefore, the screed 3 can have a longer width (length in the vehicle width direction) than when not offset, can be extended longer in the vehicle width direction, and can construct a wider new pavement.

[0030] The controller 50 is a control unit that controls the asphalt finisher 100. The controller 50 is, for example, a computer equipped with a CPU, a volatile memory, a non-volatile memory, etc. The controller 50 is a computer including a CPU and a RAM, and is mounted on the tractor 1. The various functions of the controller 50 are realized, for example, by the CPU executing a program stored in an auxiliary storage device.

[0031] The auxiliary storage device is a device for storing various types of information. In this embodiment, the auxiliary storage device is a non-volatile memory, and is integrated into the controller 50. However, the auxiliary storage device may be disposed outside the controller 50 as a structure separate from the controller 50.

[0032] The display device 52 is a device for displaying various types of information. In this embodiment, it is a liquid crystal display provided on the operation panel 65, and displays various images output by the controller 50.

[0033] The retaining plate 70 is a plate-shaped member that prevents the paving material being sent out in the vehicle width direction by the screw SC from scattering in front of the screw SC, so that the paving material can be properly sent out in the vehicle width direction by the screw SC.

[0034] The side plate 71 is also attached to the distal end of the moldboard 72. The moldboard 72 is a member for adjusting the amount of paving material that remains in front of the left telescopic screed 31L and the right telescopic screed 31R out of the paving material spread by the screw SC, and is configured to be able to extend and retract in the vehicle width direction together with the left telescopic screed 31L and the right telescopic screed 31R.

[0035] Next, the controller 50 mounted on the asphalt finisher 100 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing an example of the configuration of the controller 50 of the asphalt finisher 100 according to this embodiment and devices connected to the controller 50.

[0036] The communication device 42 performs wireless communication with devices present around the asphalt finisher 100, or a server that manages a work site, etc. In this embodiment, the communication device 42 may use, for example, one or more of Wi-Fi (registered trademark), wireless LAN, Bluetooth (registered trademark), etc. as a wireless communication standard.

[0037] The positioning device 43 is configured to detect the position of the asphalt finisher 100. In this embodiment, the positioning device 43 is a GNSS receiver. The position of the asphalt finisher 100 is expressed using a reference coordinate system. That is, the position of the asphalt finisher 100 is specified by coordinates in the reference coordinate system. The reference coordinate system is, for example, the world geodetic coordinate system. The world geodetic coordinate system is a three-dimensional orthogonal XYZ coordinate system that has its origin at the center of gravity of the earth, its X axis in the direction of the intersection of the Greenwich meridian and the equator, its Y axis in the direction of 90 degrees east longitude, and its Z axis in the direction of the North Pole.

[0038] The measuring device 44 is, for example, an ultrasonic sensor, a monocular camera, a stereo camera, or a LIDAR. The measuring device 44 measures the distance to the roadbed before the paving material is spread and the distance to the road surface (surface of the paving material) that has been spread and leveled by the screed 3, and outputs the difference between the measured distances to the controller 50 as the thickness of the paving material.

[0039] The screw rotation speed sensor 45 is configured to detect the rotation speed of the screw SC. In the example shown in Fig. 3, the screw rotation speed sensor 45 is an encoder that detects the angular speed of a rotating shaft of a hydraulic motor that drives the screw SC. The screw rotation speed sensor 45 may be configured with a proximity switch or the like that detects a slit formed in a rotating plate.

[0040] The conveyor feed speed sensor 46 is configured to detect the feed speed of the conveyor CV. In the example shown in Fig. 3, the conveyor feed speed sensor 46 is an encoder that detects the angular speed of the rotating shaft of a hydraulic motor that drives the conveyor CV. The conveyor feed speed sensor 46 may be configured with a proximity switch or the like that detects a slit formed in a rotating plate.

[0041] The traveling speed sensor 47 is configured to detect the traveling speed of the asphalt finisher 100. In the example shown in Fig. 3, the traveling speed sensor 47 is an encoder that detects the angular speed of a rotating shaft of a rear wheel driving motor that drives the rear wheels 5 of the tractor 1. The traveling speed sensor 47 may be configured with a proximity switch or the like that detects a slit formed in a rotating plate.

[0042] The hopper cylinder 2c is configured to open and close the hopper 2 in the vehicle width direction.

[0043] Fig. 4 is an explanatory diagram showing the opening and closing operation of the hopper 2 according to this embodiment. As shown in Fig. 4, the hopper 2 is formed with a storage section 2a, a hopper cylinder 2c, and an opening and closing rotary shaft 2d, which are symmetrically arranged on the left and right. Two conveyors CV are extended between the storage sections 2a arranged symmetrically on the left and right.

[0044] The storage section 2a of the hopper 2 is provided so as to be freely opened and closed with respect to an opening / closing pivot shaft 2d. The storage section 2a is opened and closed by controlling the extension and contraction of a hopper cylinder 2c. The extension and contraction of the hopper cylinder 2c is controlled by a controller 50.

[0045] In the example shown in Fig. 4, when the storage section 2a is open, the paving material discharged from the dump truck 200 is stored in the storage section 2a. When the storage section 2a is closed, the paving material stored in the storage section 2a moves to the conveyor CV. The paving material moved to the conveyor CV is then fed to the screed 3.

[0046] Returning to FIG. 3, the controller 50, more specifically, has, as functional blocks configured by software, hardware, or a combination thereof, an acquisition unit 50a, a calculation unit 50b, a determination unit 50c, a hopper control unit 50d, and an output control unit 50e.

[0047] The acquisition unit 50a acquires various pieces of information. The acquisition unit 50a acquires information received by the communication device 42 or detection information from various sensors.

[0048] The acquiring unit 50a acquires information from an external device via the communication device 42. For example, the acquiring unit 50a acquires information indicating the amount of paving material to be dumped into the hopper 2 from the external device via the communication device 42. For example, the acquiring unit 50a acquires the amount of paving material loaded onto the dump truck 200, received from the controller C3 of the plant 300 via the communication device T3, as information indicating the amount of paving material dumped from the dump truck 200 into the hopper 2.

[0049] The amount of paving material according to this embodiment may be any criterion for determining whether or not it is loaded in the hopper 2, and may be, for example, the volume or weight of the paving material. Furthermore, the controller 50 may hold the density of the paving material in advance, and calculate the weight from the volume or the volume from the weight as necessary.

[0050] The method of acquiring information indicating the amount of paving material is not limited to receiving the information from the controller C3 of the plant 300, and any method may be used. For example, the loading amount of paving material at the time of shipment is described on the shipping slip of the dump truck 200. For this reason, the acquisition unit 50a may read the shipping slip (one example of a medium) of the dump truck 200 with an imaging device (not shown), extract information indicating the loading amount of paving material indicated on the shipping slip, and acquire the extracted information as information indicating the amount of paving material to be put into the hopper 2. Note that the shipping slip may be read by an external device (e.g., a mobile communication terminal). Furthermore, any worker may input the loading amount of paving material indicated on the shipping slip into an external device (e.g., a mobile communication terminal). Then, the acquisition unit 50a may acquire information indicating the loading amount of paving material from the external device as information indicating the amount of paving material to be put into the hopper 2. Furthermore, the object to be read is not limited to the shipping slip. For example, the maximum loading capacity indicated on the automobile inspection certificate (one example of a medium) may be read as the loading capacity of paving materials.

[0051] Further, the dump truck 200 may be provided with a weight meter for detecting the loaded weight. Therefore, the acquisition unit 50a may acquire the loaded weight measured by the weight meter from the dump truck 200 via the communication device 42 as the amount of the input paving material.

[0052] Furthermore, the acquiring unit 50a may acquire the difference between the weight of the dump truck 200 measured by the weight measuring device before discharging the paving material and the weight of the dump truck 200 measured by the weight measuring device after discharging the paving material, as information indicating the amount of paving material dumped from the dump truck 200 into the hopper 2. The weight measuring device of the dump truck 200 may be disposed on the route from the plant 300 to the asphalt finisher 100.

[0053] The acquisition unit 50a may also receive the amount of paving material loaded on the dump truck 200 from an external device capable of communicating with an imaging device at a fixed point installed at the work site. For example, the external device may be a monitoring device that monitors the work site, and may estimate the amount of paving material loaded on the bed 201 of the dump truck 200 shown in the image based on image information captured by an imaging device at a fixed point installed at the work site, and transmit the estimated amount of paving material to the asphalt finisher 100.

[0054] By using the above-mentioned method, the acquisition unit 50a according to this embodiment can acquire the amount of paving material dispensed into the hopper 2 without providing a detection device or the like for detection in the asphalt finisher 100. Therefore, since there is no need to provide a detection device or the like, it is possible to reduce costs, and the amount of paving material dispensed into the hopper 2 can be acquired even if a change occurs in the surrounding situation that makes the detection device unusable. Therefore, the controller 50 according to this embodiment can realize improved accuracy in controlling the opening and closing of the hopper 2 based on the amount of paving material dispensed.

[0055] The acquisition unit 50a may also acquire information indicating the amount of paving material to be dumped into the hopper 2 from the operation panel 65. For example, when the dump truck 200 starts discharging the paving material, the operator inputs information indicating the amount of paving material loaded on the dump truck 200 into the operation panel 65, whereby the acquisition unit 50a acquires the information indicating the amount of paving material to be dumped into the hopper 2 from the operation panel 65. For example, the operator can recognize the amount of paving material loaded on the dump truck 200 by referring to a shipping slip.

[0056] In this way, the acquiring unit 50a acquires information indicating the amount of paving material (first amount) dumped into the hopper 2 based on an input operation from the operator via the operation panel 65 or communication from an external device. In this way, in this embodiment, it is not necessary to provide a detection device or the like for measuring the amount of paving material dumped into the hopper 2, which makes it possible to reduce costs.

[0057] The acquisition unit 50a also acquires the timing at which the paving material is dumped from the dump truck 200. The timing at which the paving material is dumped from the dump truck 200 may be acquired from an input operation by the operator via the operation panel 65. Furthermore, the acquisition unit 50a may acquire the timing at which the dump truck 200 lifts the loading platform 201. For example, the timing at which the dump truck 200 lifts the loading platform 201 may be received from the dump truck 200 via the communication device 42, or may be received from a monitoring device (not shown) that monitors the operation of the dump truck 200. In this way, the acquisition unit 50a can acquire the amount of paving material dumped from the dump truck 200 and the timing at which the paving material is dumped from the dump truck 200.

[0058] The acquisition unit 50a acquires position information of the asphalt finisher 100 from the positioning device 43. The acquisition unit 50a acquires information indicating the thickness of the paving material in the vertical direction (Z-axis direction) from the measuring device 44. The acquisition unit 50a acquires rotation speed information of the screw SC from the screw rotation speed sensor 45. The acquisition unit 50a acquires transport speed information of the conveyor CV from the conveyor feed speed sensor 46.

[0059] The acquisition unit 50a also acquires speed information of the asphalt finisher 100 detected by the traveling speed sensor 47. The acquisition unit 50a also acquires steering angle information from the tractor 1.

[0060] The calculation unit 50b calculates the amount of paving material transported from the hopper 2 (an example of a second amount) from the detection result by the detection device.

[0061] For example, the calculation unit 50b calculates the amount of paving material conveyed from the hopper 2 based on paving material conveying speed information acquired from the conveyor feed speed sensor 46 and the area of ​​the opening of the conveyor CV.

[0062] Fig. 5 is a diagram showing the openings of the conveyors CV of the asphalt finisher 100 according to this embodiment. Fig. 5 shows an example of the cross section A-A' of the asphalt finisher 100 shown in Fig. 2(A) viewed in the +X axis direction. As shown in Fig. 5, openings 401 and 402 are provided corresponding to the two conveyors CV. Each of the openings 401 and 402 has a width Wc and a height H.

[0063] A conveyor CV conveys the paving material to the screed 3 through each of the openings 401, 402 shown in FIG.

[0064] The calculation unit 50b calculates the amount of paving material conveyed from the hopper 2 based on the area of ​​the openings 401, 402 (one example of the opening area) and the conveying speed Vc of the conveyor CV. Specifically, the calculation unit 50b calculates the amount Q of paving material conveyed from the hopper 2 for each of the openings 401, 402 using the following formula (1). The correction coefficient ηa is determined according to the ratio of paving material present in each of the openings 401, 402 of the conveyor CV, the density of the paving material, and the like. As shown in formula (1), the amount (e.g., weight) of the paving material conveyed during the time can be calculated by integrating Vc×Wc×H×ηa over time. In this embodiment, the amount of paving material conveyed for each of the openings 401, 402 can be calculated with high accuracy by performing the above-mentioned calculation. Therefore, the controller 50 can improve the accuracy of the opening / closing control of the hopper 2 based on the amount of paving material conveyed for each of the openings 401, 402.

[0065] Q=∫(Vc×Wc×H×ηa)dt……(1)

[0066] Note that this embodiment is not limited to the method of calculating the amount of paving material conveyed from the hopper 2 based on the conveying speed of the paving material and the area of ​​the opening of the conveyor CV obtained from the conveyor feed speed sensor 46. Therefore, another method of calculating the amount of paving material conveyed from another hopper 2 will be described.

[0067] For example, the calculation unit 50b may calculate the amount of paving material conveyed from the hopper based on the rotation speed of the screw SC for spreading the paving material and the shape of the screw SC (for example, the projected area of ​​the screw SC and the screw pitch of the screw SC). The rotation speed Nsc of the screw SC is indicated in the rotation speed information acquired from the screw rotation speed sensor 45. The projected area Ap of the screw SC (the area projected by the screw diameter (of the blade portion that sends the paving material)) and the screw pitch P are determined in advance. Specifically, the calculation unit 50b calculates the amount (for example, weight) Q of the paving material conveyed from the hopper 2 using the following formula (2). The correction coefficient ηb is determined according to the correspondence between the rotation speed of the screw SC and the amount of paving material spread from the screw SC. In this embodiment, the amount of the paving material conveyed can be calculated with high accuracy by performing the above-mentioned calculation. Therefore, the controller 50 can realize improvement in the accuracy of the opening and closing control of the hopper 2 based on the amount of the paving material conveyed.

[0068] Q=∫(Ap×P×Nsc×ηb)dt……(2)

[0069] As another example, the calculation unit 50b may calculate the amount Q of the paving material transported from the hopper 2 based on the area S of the road surface spread by the screed 3 and the thickness th of the paving material spread on the road surface. Specifically, the calculation unit 50b calculates the amount Q of the paving material transported from the hopper 2 by multiplying the area S of the road surface, the thickness th of the road surface, and the correction coefficient ηc. The thickness th of the paving material is based on the thickness of the paving material in the vertical direction (Z-axis direction) measured by the measuring device 44. The area S of the road surface is calculated based on the road surface width W on which the asphalt finisher 100 works, the moving speed V of the asphalt finisher 100, the moving time T of the asphalt finisher 100, as well as the steering angle of the asphalt finisher 100, in other words, the curvature of the road surface. A method for calculating the area of ​​the road surface based on these pieces of information may be a well-known method, and a description thereof will be omitted. The road surface width W may be obtained from the construction information or may be the width of the screed 3. The correction coefficient ηc is determined according to the ratio of the paving material per unit volume of the road surface and the density of the paving material, etc. Furthermore, the correction coefficient ηc may be adjusted taking into consideration the curvature of the road surface and further the acceleration / deceleration according to the radius of curvature when the asphalt finisher 100 turns.

[0070] The moving speed V of the asphalt finisher 100 is based on the speed information acquired from the travel speed sensor 47. In this embodiment, the method of acquiring the moving speed V of the asphalt finisher 100 is not limited to the speed information acquired from the travel speed sensor 47. For example, the moving speed of the asphalt finisher 100 may be derived based on the wheel speed of the front wheels 6. Furthermore, the moving distance per unit time of the asphalt finisher 100 may be derived based on the change in the position per unit time of the asphalt finisher 100 indicated by the position information acquired from the positioning device 43. In this embodiment, the amount of the paving material discharged can be calculated with high accuracy by performing the above-mentioned calculation. Therefore, the controller 50 can realize an improvement in the accuracy of the opening and closing control of the hopper 2 based on the amount of the paving material discharged.

[0071] The calculation unit 50b further calculates the amount of paving material loaded in the hopper 2 based on the amount of paving material to be dumped into the hopper 2 and the amount Q of paving material transported from the hopper 2 acquired by the acquisition unit 50a.

[0072] The determining unit 50c determines the amount of paving material loaded in the hopper 2.

[0073] The hopper control unit 50d controls the opening and closing of the hopper 2 based on the result of the determination by the determination unit 50c based on the amount of paving material input and the amount of paving material transported. Specifically, in order to control the opening and closing of the hopper 2, the hopper control unit 50d outputs a control command to extend and retract the hopper cylinder 2c.

[0074] For example, the determination unit 50c determines whether the amount (e.g., weight or volume) of paving material loaded in the hopper 2 is equal to or less than a first threshold value. If it is determined that the amount of paving material loaded in the hopper 2 is greater than the first threshold value, the hopper control unit 50d does not particularly control the opening and closing of the hopper 2.

[0075] On the other hand, when the determination unit 50c determines that the amount of paving material loaded in the hopper 2 is equal to or less than the first threshold value, the hopper control unit 50d controls the hopper 2 to gradually close. The speed at which the hopper 2 closes is determined according to the embodiment. By the hopper control unit 50d controlling the hopper 2 to close, the paving material loaded in the storage unit 2a of the hopper 2 is moved to the conveyor CV.

[0076] Thereafter, the determination unit 50c determines whether the amount of paving material loaded in the hopper 2 is equal to or less than a second threshold (second threshold<first threshold). If it is determined that the amount of paving material loaded in the hopper 2 is greater than the second threshold and less than the first threshold, the hopper control unit 50d continues to control the hopper 2 to gradually close.

[0077] On the other hand, when the determination unit 50c determines that the amount of paving material loaded in the hopper 2 is equal to or less than the second threshold value, the hopper control unit 50d repeatedly controls the opening and closing of the hopper 2. By repeatedly performing the control to open and close the hopper 2, the hopper control unit 50d causes the paving material adhering to the storage unit 2a of the hopper 2 to fall onto the conveyor CV.

[0078] Furthermore, when the dump truck 200 approaches the asphalt finisher 100, the hopper control unit 50d performs control to open the hopper 2. This allows the paving material to be discharged from the dump truck 200. The control to open the hopper 2 may be based on an operation by an operator, or may be based on a detection result of the approach of the dump truck 200 detected by a detection device provided in the asphalt finisher 100.

[0079] The output control unit 50e outputs information about the amount of paving material loaded in the hopper 2, calculated based on the amount of paving material put into the hopper 2 and the amount Q of paving material transported from the hopper 2, to the display device 52. The information about the amount (remaining amount) of paving material loaded in the hopper 2 may be in any form, and may be, for example, the weight of the paving material loaded in the hopper 2 or the volume of the paving material. Furthermore, there is also a method in which the output control unit 50e outputs to the display device 52 a numerical value (for example, a %) or an indicator indicating the amount of paving material currently loaded in the hopper 2 relative to the amount of paving material that can be loaded in the hopper 2.

[0080] Furthermore, the output control unit 50e does not limit the output destination of the information regarding the amount of paving material loaded in the hopper 2 to the display device 52. For example, the output control unit 50e may output the information regarding the amount of paving material loaded in the hopper 2 to an external device.

[0081] Next, a process procedure executed by the controller 50 according to this embodiment will be described below. Fig. 6 is a flowchart showing a process procedure executed by the controller 50 according to this embodiment.

[0082] The acquisition unit 50a acquires the amount of paving material dumped into the hopper 2 from the dump truck 200 (S1501). The method of acquiring the amount of paving material dumped into the hopper 2 is the same as that described above, and therefore the explanation thereof will be omitted.

[0083] The acquiring unit 50a acquires, from the detection device, detection information for calculating the amount of paving material conveyed from the hopper 2 (S1502).

[0084] The calculation unit 50b calculates the amount of paving material conveyed from the hopper 2 based on the detection result by the detection device (S1503).

[0085] The calculation unit 50b calculates the amount of paving material loaded in the hopper 2 based on the amount of paving material put into the hopper 2 and the amount of paving material transported from the hopper 2 (S1504).

[0086] Then, the determination unit 50c determines whether the amount of loaded paving material is equal to or less than the second threshold (S1505). If the determination unit 50c determines that the amount of loaded paving material is equal to or less than the second threshold (S1505: YES), the hopper control unit 50d controls the hopper 2 to repeatedly open and close (S1506). After a predetermined time has elapsed, the process proceeds to S1507.

[0087] On the other hand, if the determination unit 50c determines that the amount of loaded paving material is greater than the second threshold (S1505: NO), the determination unit 50c determines whether the amount of loaded paving material is equal to or less than the first threshold (S1507).

[0088] When the determination unit 50c determines that the amount of loaded paving material is equal to or less than the first threshold value (S1507: YES), the hopper control unit 50d controls the hopper 2 to gradually close (S1508). After a predetermined time has elapsed, the process proceeds to S1507. The speed at which the hopper 2 closes is adjusted according to the embodiment, such as the conveying speed of the conveyor CV.

[0089] When it is determined that the amount of loaded paving material is greater than the first threshold value (S1507: YES), the determination unit 50c does not perform any particular control.

[0090] Then, the determination unit 50c determines whether or not the dump truck 200 has approached the asphalt finisher 100 (S1509). This determination may be based on an input operation from the operator indicating that the dump truck 200 has approached, or may be based on a detection result from a detection device provided in the asphalt finisher 100.

[0091] Then, when the determination unit 50c determines that the dump truck 200 is not approaching the asphalt finisher 100 (S1509: NO), the process proceeds to S1511.

[0092] On the other hand, when the determination unit 50c determines that the dump truck 200 is approaching the asphalt finisher 100 (S1509: YES), the hopper control unit 50d performs control to open the hopper 2 (S1510).

[0093] Thereafter, the determination unit 50c determines whether or not paving material has been dumped from the dump truck 200 (S1511). This determination is based on the timing at which paving material has been dumped from the dump truck 200, which is acquired by the acquisition unit 50a. For example, the determination may be based on whether or not a notification that the loading platform 201 has been lifted has been received from the dump truck 200 or the monitoring device, or based on whether or not an input operation to the effect that the paving material has been dumped has been performed via the operation panel 65 by the operator.

[0094] When it is determined that the paving material has not been dumped from the dump truck 200 (S1511: NO), the determination unit 50c performs the process from S1502.

[0095] On the other hand, when it is determined that paving material has been dumped from the dump truck 200 (S1511: YES), the determination unit 50c performs processing from S1501. That is, the subsequent processing is performed based on the amount of paving material newly acquired by the acquisition unit 50a and received or input from an external device. Note that, when paving material remains in the hopper 2, the acquisition unit 50a may add the amount of paving material loaded in the hopper to the amount of paving material received or input from an external device. This updates the amount of paving material at the time when the paving material is dumped from the dump truck 200, thereby improving the calculation accuracy of the amount of paving material loaded in the hopper 2.

[0096] The opening and closing control of the hopper 2 in this embodiment is merely an example, and is not limited to the above-mentioned opening and closing control. For example, when the amount of paving material loaded in the hopper 2 is equal to or less than a predetermined threshold, the controller 50 may perform only one of the following controls: gradually closing the hopper 2 or repeatedly opening and closing the hopper 2, or the other control. In other words, it is sufficient to control the opening and closing of the hopper 2 according to the amount of paving material loaded in the hopper 2.

[0097] (Modification) The above-mentioned embodiment has been described with respect to the case where a correction coefficient corresponding to a calculation pattern is used. However, the above-mentioned embodiment is not limited to the method of using a correction coefficient corresponding to a calculation pattern, and a coefficient that takes into account the situation when the asphalt finisher 100 performs construction in addition to the calculation pattern may be used. Therefore, in this modified example, a case where a correction coefficient that takes into account the situation when the asphalt finisher 100 performs construction is used will be described. Note that this modified example may use any calculation pattern among the calculation patterns of the amount Q of paving material shown in the above-mentioned embodiment.

[0098] For example, the correction coefficient according to this modified example may be adjusted according to the weather, humidity, temperature, road surface conditions, the type of mixture contained in the paving material, and the like when the asphalt finisher 100 performs construction.

[0099] As a method for adjusting the correction coefficient taking into account the situation when the construction is performed, any method may be used, for example, a predetermined function may be used. In this modification, a case where a trained model is used as an example of calculation of the correction coefficient using a function will be described.

[0100] In this modification, a learning device for performing machine learning may be provided as the construction management system SYS. The learning device may be, for example, an on-premise server installed in the plant 300 or a remote monitoring area, or may be a cloud service.

[0101] The learning device performs machine learning using the current situation based on at least one of weather, humidity, temperature, road surface condition, and type of composite material included in the pavement material, and a correction coefficient corresponding to the current situation as training data, to generate a trained model. As machine learning, for example, deep learning can be applied. Specifically, as machine learning, a method of learning by backpropagation using a neural network can be considered, but other methods may also be used.

[0102] The trained model outputs a correction coefficient corresponding to the current situation when information indicating the current situation based on any one or more of the weather, humidity, temperature, road surface condition, and type of mixture contained in the pavement material is input. The information indicating the current situation may be input by the operator or may be received from an external device via the communication device 42.

[0103] The learning device outputs the trained model to the asphalt finisher 100. The output method may be any mode, for example, transmission via a public network, or storage in the auxiliary storage device 48 via a removable non-volatile memory.

[0104] The trained model is then stored in the auxiliary storage device 48 of the asphalt finisher 100.

[0105] The calculation unit 50b of the asphalt finisher 100 of this modified example obtains a correction coefficient by inputting the current situation to the trained model stored in the auxiliary storage device 48. The calculation of the amount Q of paving material using the correction coefficient is the same as in the above-mentioned embodiment, and the explanation will be omitted.

[0106] For example, even if the conveying speed of the conveyor CV does not change, the amount of paving material conveyed by the conveyor CV may change depending on the weather, humidity, temperature, etc. Therefore, in this modified example, a correction coefficient according to the current situation is used.

[0107] In this manner, in this modified example, by using a trained model to identify the correction coefficient, it is possible to improve the calculation accuracy of the amount Q of paving material.

[0108] <effect> In the above-described embodiment, the amount of paving material loaded in the hopper is calculated by a method other than image recognition, and the opening and closing of the hopper is controlled according to the amount of paving material loaded in the hopper. Therefore, by suppressing image recognition and the like to control the opening and closing of the hopper, a reduction in the processing load can be achieved. Furthermore, since the processing load is reduced, there is no need to install a costly arithmetic device, and therefore costs can be reduced.

[0109] Furthermore, when recognizing the amount of paving material loaded from an image as in the past, there are situations such as at night when the amount of light is low and it is difficult to recognize the amount of paving material. In contrast, the controller 50 according to the above-mentioned embodiment can calculate the amount of paving material loaded regardless of changes in the surrounding conditions, and can control the opening and closing of the hopper at an appropriate timing, thereby improving work efficiency.

[0110] Although the embodiment of the asphalt finisher according to the present invention has been described above, the present invention is not limited to the above embodiment. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0111] 100 Asphalt finisher 2 Hopper 2a Storage section 2c Hopper cylinder 2d Opening and closing pivot shaft 3. Screed 42 Communication Equipment 43 Positioning Device 44 Measuring Equipment 45 Screw rotation speed sensor 46 Conveyor feed speed sensor 47 Travel speed sensor 50 Controller 50a Acquisition Department 50b Calculation part 50c Judgment part 50d Hopper control unit 65 Operation Panel CV Conveyor SC screw 200 Dump Truck 300 Plants

Claims

1. A tractor, a hopper that is installed in front of the tractor and is capable of receiving paving material and is openable and closable in the vehicle width direction; a conveyor that conveys the paving material in the hopper to the rear side of the tractor; A screw that spreads the paving material transported by the conveyor behind the tractor; A screed is connected to the rear of the tractor in a vertically movable manner and spreads the paving material spread by the screw on the rear side of the screw, Obtaining a first amount of the paving material deposited in the hopper; Calculating a second amount of the paving material conveyed from the hopper based on a detection result by the detection device; a control device configured to control the opening and closing of the hopper based on a first amount of the paving material input and a second amount of the paving material conveyed; Equipped with Asphalt finisher.

2. The control device is configured to acquire information indicating a first amount of the paving material put into the hopper based on an input operation by an operator or communication from an external device. An asphalt finisher as claimed in claim 1.

3. The information indicating the first amount of paving material is information indicating the difference between the weight of the dump truck measured before discharging the paving material into the hopper and the weight of the dump truck measured after discharging, information indicating the load weight of the dump truck, information extracted from a medium indicating the amount of the paving material loaded on the dump truck, information estimated based on image information from an imaging device that images the dump truck, or information indicating the amount of the paving material loaded on the dump truck by a plant that produces the paving material. An asphalt finisher as claimed in claim 2.

4. The control device outputs information regarding the amount of the paving material present in the hopper based on the first amount and the second amount to a display device or an external device. An asphalt finisher as claimed in claim 1.

5. The control device is configured to calculate a second amount of the paving material conveyed from the hopper based on a conveying speed of the paving material by the conveyor and an opening area of ​​the conveyor. An asphalt finisher as claimed in claim 1.

6. The control device is configured to calculate a second amount of the paving material conveyed from the hopper based on a rotational speed of the screw for spreading the paving material. An asphalt finisher as claimed in claim 1.

7. The control device is configured to calculate a second amount of the paving material conveyed from the hopper based on an area of ​​the road surface spread by the screed and a thickness of the paving material spread on the road surface. An asphalt finisher as claimed in claim 1.

8. The control device uses a correction coefficient when calculating a second amount of the paving material transported from the hopper based on the detection result by the detection device, The correction coefficient is adjusted based on the conditions when the asphalt finisher is working. An asphalt finisher as claimed in claim 1.

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