JP7740800B2 - Road machinery - Google Patents

Description

This disclosure relates to road machinery.

An asphalt finisher is known that includes a conveyor that transports paving material supplied to a hopper toward the rear of the tractor, a screw that spreads the paving material transported by the conveyor behind the tractor, and a screed that evens out the paving material spread by the screw behind the screw (see Patent Document 1). In this asphalt finisher, the conveyor is positioned so that a portion of it is exposed at the center of the bottom of the hopper. This allows the conveyor to transport paving material in the center of the hopper toward the rear of the tractor. This asphalt finisher is equipped with a monocular camera that monitors the inside of the hopper, and is configured to close the hopper when it determines, based on images captured by the monocular camera, that the amount of paving material remaining in the hopper is less than a predetermined amount. This is to collect paving material at the edge of the hopper's bottom in the center, so that the paving material at the edge of the bottom can be transported toward the rear of the tractor by the conveyor.

International Publication No. 2021/193381

However, simply monitoring the inside of the hopper with a monocular camera may not accurately estimate the amount of paving material remaining. This is because smoke rising from the paving material may interfere with monitoring the inside of the hopper.

Therefore, it is desirable to more accurately estimate the amount of paving material in the hopper.

A road machinery according to an embodiment of the present disclosure comprises a tractor, a hopper installed in front of the tractor to receive paving material, a conveyor that transports the paving material in the hopper to the rear of the tractor, a screw that spreads the paving material transported by the conveyor behind the tractor, a screed that evens out the paving material spread by the screw behind the screw, and a calculation device that estimates the volume of paving material discharged from the hopper as a consumed volume , wherein the calculation device is configured to estimate the remaining volume as the volume of paving material remaining in the hopper without detecting the replenished volume by subtracting the value of the consumed volume from the value of the replenished volume as the volume of paving material replenished to the hopper, which is calculated based on a preset additional value as the value of the volume of paving material loaded on the bed of a dump truck, and the additional value is added to the value of the replenished volume during construction .

The road machine described above can more accurately estimate the amount of paving material in the hopper.

FIG. 2 is a left side view of the asphalt finisher. FIG. 2 is a top view of the asphalt finisher. FIG. 2 is a functional block diagram of a controller.

Figures 1 and 2 are schematic diagrams of an asphalt finisher 100, an example of a road machine according to an embodiment of the present disclosure. Specifically, Figure 1 is a left side view of the asphalt finisher 100, and Figure 2 is a top view.

The asphalt finisher 100 is primarily composed of a tractor 1, a hopper 2, and a screed 3. In the example shown in Figures 1 and 2, the asphalt finisher 100 is positioned so that the vehicle length direction corresponds to the X-axis direction and the vehicle width direction corresponds to the Y-axis direction. The Z-axis is positioned so that it is perpendicular to both the X-axis and the Y-axis. Specifically, the front side of the vehicle length direction corresponds to the +X side, the rear side of the vehicle length direction corresponds to the -X side, the left side of the vehicle width direction corresponds to the +Y side, the right side of the vehicle 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.

The tractor 1 is a mechanism for propelling the asphalt finisher 100. In the example shown in Figures 1 and 2, the tractor 1 moves the asphalt finisher 100 by rotating the rear wheels 5 using a rear wheel drive motor and by rotating the front wheels 6 using a front wheel drive motor. The rear wheel drive motor and the front wheel drive motor are hydraulic motors that rotate with hydraulic oil supplied from a hydraulic pump. The tractor 1 may also be equipped with crawlers instead of wheels.

The controller 50 is an example of a computing device. In the example shown in Figures 1 and 2, the controller 50 is a computer including a CPU, a volatile memory device, and a non-volatile memory device, and is mounted on the tractor 1 and configured to control the asphalt finisher 100 by operating various functions. The various functions of the controller 50 are realized, for example, by the CPU executing programs stored in the non-volatile memory device. The various functions realized by the controller 50 include, for example, a function to control the discharge volume of a hydraulic pump that discharges hydraulic oil to drive a hydraulic actuator, and a function to control the flow of hydraulic oil between the hydraulic actuator and the hydraulic pump. The hydraulic actuator includes a hydraulic cylinder and a hydraulic motor.

The hopper 2 is a mechanism for receiving paving material PV. The paving material PV is, for example, an asphalt mixture. In the example shown in Figures 1 and 2, the hopper 2 is installed on the front (+X side) of the tractor 1 and is configured to open and close in the Y-axis direction (vehicle width direction) using a hopper cylinder 24. The asphalt finisher 100 typically receives paving material PV from the bed of a dump truck with the hopper 2 fully open. A dump truck is an example of a vehicle (transport vehicle) that transports paving material PV to be supplied to the asphalt finisher 100. Even while receiving paving material PV from the bed of the dump truck, the asphalt finisher 100 can continue traveling by pushing the dump truck forward via the push roller 2b. Figures 1 and 2 show the hopper 2 in a fully open state. Note that for clarity, the paving material PV received in the hopper 2 is omitted from Figures 1 and 2. When the paving material PV in the hopper 2 decreases, the operator of the asphalt finisher 100 manually closes the hopper 2, allowing the paving material PV that was near the inner wall of the hopper 2 to be collected in the center of the hopper 2. This is so that the conveyor CV at the center of the bottom of the hopper 2 can transport the paving material PV to the rear of the tractor 1. The paving material PV transported to the rear of the tractor 1 is spread in the vehicle width direction by the screw SC behind the tractor 1 and in front of the screed 3.

The tractor 1 is equipped with a spatial recognition device CM for monitoring the situation ahead of the tractor 1. The spatial recognition device CM is, for example, a monocular camera, a stereo camera, or LIDAR. In the example shown in Figures 1 and 2, the spatial recognition device CM is a monocular camera that captures images of the situation ahead of the tractor 1. In this case, the controller 50 can determine whether the amount of paving material PV in the hopper 2 is more or less than a predetermined amount based on the image captured by the monocular camera serving as the spatial recognition device CM.

The conveyor CV is driven by a hydraulic motor that rotates when hydraulic oil is supplied from a hydraulic pump. In the example shown in Figures 1 and 2, the conveyor CV is configured to transport paving material PV in the hopper 2 to the rear of the tractor 1 via a transport path CP. The transport path CP is a roughly rectangular space formed inside the tractor 1, and has a roughly rectangular entrance OP that opens into the hopper 2 at the front face 1FW of the tractor 1. Specifically, the conveyor CV includes a left conveyor CVL and a right conveyor CVR that operate independently of each other. The transport path CP also includes a left transport path CPL for the left conveyor CVL and a right transport path CPR for the right conveyor CVR.

The screw SC is driven by a hydraulic motor that rotates when hydraulic oil is supplied from a hydraulic pump. Specifically, the screw SC includes a left screw SCL and a right screw SCR that operate independently of each other. In the illustrated example, the left screw SCL is installed so that it protrudes to the left from the width of the tractor 1. The right screw SCR is installed so that it protrudes to the right from the width of the tractor 1.

The screed 3 is a mechanism for spreading and leveling the paving material PV. In the example shown in Figures 1 and 2, the screed 3 mainly includes a front screed 30 and a rear screed 31. The rear screed 31 includes a left rear screed 31L and a right rear screed 31R. The front screed 30, left rear screed 31L, and right rear screed 31R are arranged so that they are offset from each other in the front and rear directions. Specifically, the left rear screed 31L is arranged behind the front screed 30, and the right rear screed 31R is arranged behind the left rear screed 31L. The screed 3 is a floating screed towed by the tractor 1 and is connected to the tractor 1 via a leveling arm AM. The screed 3 is moved up and down together with the leveling arm AM by the extension and retraction of the screed lift cylinder 25.

The rear screed 31 is configured to be able to extend and retract in the vehicle width direction by a telescopic cylinder 60. The telescopic cylinder 60 is supported by a support fixed to the housing of the front screed 30, and is configured to be able to extend and retract the rear screed 31 in 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 extends and retracts the left rear screed 31L on the left side of the front screed 30. The right telescopic cylinder 60R extends and retracts the right rear screed 31R on the right side of the front screed 30.

The leveling arm AM is configured so that the screed 3 can be connected to the tractor 1. Specifically, the leveling arm AM includes a left leveling arm AML and a right leveling arm AMR. Each of the left leveling arm AML and the right leveling arm AMR has one end (rear end) connected to the screed 3 and the other end (front end) connected to the tractor 1 (leveling cylinder 23).

The leveling cylinder 23 is a hydraulic cylinder that moves the front end of the leveling arm AM up and down to adjust the spreading thickness of the paving material PV. In the example shown in Figures 1 and 2, the cylinder portion of the leveling cylinder 23 is connected to the tractor 1, and the rod portion is connected to the front end of the leveling arm AM. The front end of the leveling arm AM is attached to the tractor 1 so that it can slide up and down. When increasing the spreading thickness, the controller 50 causes the hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the leveling cylinder 23, contracting the leveling cylinder 23 and raising the front end of the leveling arm AM. When decreasing the spreading thickness, the controller 50 causes the hydraulic oil to flow out of the rod-side oil chamber of the leveling cylinder 23, extending the leveling cylinder 23 and lowering the front end of the leveling arm AM.

The screed lift cylinder 25 is a hydraulic cylinder for lifting the screed 3. In the example shown in Figures 1 and 2, the screed lift cylinder 25 includes a left screed lift cylinder 25L and a right screed lift cylinder 25R. The left screed lift cylinder 25L has a cylinder portion connected to the left rear end of the tractor 1 and a rod portion connected to the rear end of the left leveling arm AML. The right screed lift cylinder 25R has a cylinder portion connected to the right rear end of the tractor 1 and a rod portion connected to the rear end of the right leveling arm AMR. When lifting the screed 3, the controller 50 allows hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the screed lift cylinder 25. As a result, the screed lift cylinder 25 contracts, lifting the rear end of the leveling arm AM and lifting the screed 3. When lowering the lifted screed 3, the controller 50 allows hydraulic oil to flow out of the rod-side oil chamber of the screed lift cylinder 25. As a result, the weight of the screed 3 causes the screed lift cylinder 25 to extend, lowering the rear end of the leveling arm AM and lowering the screed 3. During construction, the screed lift cylinder 25 is in a state where it can extend and retract in response to the up and down movement of the screed 3.

A side plate 40 is attached to the distal end of the rear screed 31. The side plate 40 is a plate-shaped member extending in the vehicle length direction and includes a left side plate 40L and a right side plate 40R. Specifically, the left side plate 40L is attached to the distal end (left end) of the left rear screed 31L, and the right side plate 40R is attached to the distal end (right end) of the right rear screed 31R.

In the illustrated example, the side plate 40 is also connected to the distal end of the moldboard 41. The moldboard 41 is a component for adjusting the amount of paving material PV that remains in front of the rear screed 31 after being spread by the screw SC, and may be configured to be able to expand and contract in the vehicle width direction together with the rear screed 31.

Specifically, the moldboard 41 is a plate-shaped member extending in the vehicle width direction, and includes a left moldboard 41L and a right moldboard 41R. In the illustrated example, the left side plate 40L is connected to the distal end (left end) of the left moldboard 41L, and the right side plate 40R is connected to the distal end (right end) of the right moldboard 41R.

The moldboard 41 is configured so that its height in the Z-axis direction can be adjusted independently of the rear screed 31 and side plate 40. By moving the moldboard 41 up and down, the operator of the asphalt finisher 100 can adjust the size of the gap between the bottom end of the moldboard 41 and the roadbed BC, thereby adjusting the amount of paving material PV passing through that gap. Therefore, by moving the moldboard 41 up and down, the operator of the asphalt finisher 100 can adjust the amount (height) of paving material PV remaining behind the moldboard 41 (-X side) and in front of the rear screed 31 (+X side), and thus adjust the amount of paving material PV taken in below the rear screed 31.

The screed steps 42 are components that form a foothold for workers working behind the screed 3. Specifically, the screed steps 42 include a left screed step 42L, a central screed step 42C, and a right screed step 42R.

The retaining plates 43 are plate-shaped members that prevent the paving material PV being spread in the vehicle width direction by the screws SC from scattering in front of the screws SC, so that the paving material PV can be properly spread in the vehicle width direction by the screws SC. In the example shown in Figures 1 and 2, the retaining plates 43 include a left retaining plate 43L and a right retaining plate 43R.

Next, referring to Figure 3, an example of the support function, which is one of the functions of the controller 50, will be described. Figure 3 is a functional block diagram of the controller 50. The support function is a function for assisting the operator of the asphalt finisher 100 in operating the asphalt finisher 100. The support function is mainly realized through cooperation between the spatial recognition device CM, information acquisition device 45, controller 50, screw control device 51, conveyor control device 52, hopper control device 53, travel control device 54, leveling thickness control device 55, paving width control device 56, and output device 57.

The information acquisition device 45 is a device for acquiring various types of information. In the illustrated example, the information acquisition device 45 is a device for acquiring information that can be used to control the opening and closing of the hopper 2, and includes a spatial recognition device CM, a screw rotation speed sensor 45A, a conveyor feed speed sensor 45B, a travel speed sensor 45C, a steering angle sensor 45D, a screed extension/contraction sensor 45E, a thickness sensor 45F, and an auxiliary memory device 45G.

The screw rotation speed sensor 45A is configured to detect the rotation speed of the screw SC. In the illustrated example, the screw rotation speed sensor 45A is an encoder that detects the angular velocity of the rotation shaft of the hydraulic motor that drives the screw SC. The screw rotation speed sensor 45A may also be configured with a proximity switch that detects slits formed in the rotating plate. Specifically, the screw rotation speed sensor 45A includes a left screw rotation speed sensor that detects the rotation speed of the left screw SCL and a right screw rotation speed sensor that detects the rotation speed of the right screw SCR.

The conveyor feed speed sensor 45B is configured to detect the feed speed of the conveyor CV. In the illustrated example, the conveyor feed speed sensor 45B 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 45B may also be configured with a proximity switch that detects a slit formed in the rotating plate. Specifically, the conveyor feed speed sensor 45B includes a left conveyor feed speed sensor that detects the feed speed of the left conveyor CVL and a right conveyor feed speed sensor that detects the feed speed of the right conveyor CVR.

The traveling speed sensor 45C is configured to detect the traveling speed of the asphalt finisher 100. In the illustrated example, the traveling speed sensor 45C is an encoder that detects the angular velocity of the rotating shaft of the rear wheel traveling motor that drives the rear wheels 5. The traveling speed sensor 45C may also be configured as a wheel speed sensor that detects the rotational speed of the rear wheels 5, or a proximity switch that detects a slit formed in a rotating plate that rotates together with the rotating shaft of the rear wheel traveling motor.

The steering angle sensor 45D is configured to detect the steering angle of the front wheels 6. In the illustrated example, the steering angle sensor 45D is an expansion/contraction sensor that detects the amount of expansion/contraction of the steering cylinder that changes the steering angle of the front wheels 6.

The screed extension/retraction sensor 45E is configured to detect the amount of extension/retraction of the rear screed 31. In the illustrated example, the screed extension/retraction sensor 45E is an extension/retraction sensor that detects the amount of extension/retraction of the telescopic cylinder 60. The controller 50 can derive the amount of extension/retraction of the rear screed 31 based on the information related to the amount of extension/retraction of the telescopic cylinder 60 output by the screed extension/retraction sensor 45E.

Specifically, the screed extension/contraction sensor 45E includes a left screed extension/contraction sensor that detects the amount of extension/contraction of the left rear screed 31L, and a right screed extension/contraction sensor that detects the amount of extension/contraction of the right rear screed 31R.

Based on the output of the screed extension/contraction sensor 45E, the controller 50 can derive the distance between the left end of the left rear screed 31L and the right end of the right rear screed 31R in the vehicle width direction as the paving width (the width of the new pavement NP).

The thickness sensor 45F is configured to detect the thickness of the paving material PV laid by the screed 3. In the illustrated example, the thickness sensor 45F includes a first ultrasonic thickness sensor that detects a first distance between the surface of the roadbed BC, which is the ground before paving, and a reference position (reference height), and a second ultrasonic thickness sensor that detects a second distance between the surface of the new pavement NP, which is the ground after paving, and the reference position (reference height). The thickness sensor 45F outputs the difference between the first and second distances as the laid thickness. The reference position (reference height) is, for example, the position (height) of the first thickness sensor in the vertical direction. The second thickness sensor is preferably attached to the asphalt finisher 100 so that its position (height) is the same as the position (height) of the first thickness sensor.

The auxiliary storage device 45G is configured to store various types of information. In the illustrated example, the auxiliary storage device 45G is a non-volatile storage device installed in the tractor 1 and stores various types of information.

The screw control device 51 is configured to control the rotational speed of the screw SC. In the illustrated example, the screw control device 51 is a solenoid valve that controls the flow rate of hydraulic oil flowing into the hydraulic motor that drives the screw SC. Specifically, the screw control device 51 increases or decreases the flow path area, which is the cross-sectional area of the pipe connecting the hydraulic motor that drives the screw SC and the hydraulic pump, in response to a control command from the controller 50. More specifically, the screw control device 51 increases the flow path area to increase the flow rate of hydraulic oil flowing into the hydraulic motor that drives the screw SC and increase the rotational speed of the screw SC. Alternatively, the screw control device 51 reduces the flow path area to decrease the flow rate of hydraulic oil flowing into the hydraulic motor that drives the screw SC and decrease the rotational speed of the screw SC. The screw control device 51 is also configured to be able to separately control the rotational speeds of the left screw SCL and the right screw SCR.

The conveyor control device 52 is configured to control the feed speed of the conveyor CV. In the illustrated example, the conveyor control device 52 is a solenoid valve that controls the flow rate of hydraulic oil flowing into the hydraulic motor that drives the conveyor CV. Specifically, the conveyor control device 52 increases or decreases the flow path area, which is the cross-sectional area of the pipe connecting the hydraulic motor that drives the conveyor CV and the hydraulic pump, in response to a control command from the controller 50. More specifically, the conveyor control device 52 increases the flow path area to increase the flow rate of hydraulic oil flowing into the hydraulic motor that drives the conveyor CV and increase the feed speed of the conveyor CV. Alternatively, the conveyor control device 52 decreases the flow path area to decrease the flow rate of hydraulic oil flowing into the hydraulic motor that drives the conveyor CV and decrease the feed speed of the conveyor CV. The conveyor control device 52 is also configured to separately control the feed speeds of the left conveyor CVL and the right conveyor CVR.

The hopper control device 53 is configured to control the amount of extension and retraction of the hopper cylinder 24. In the illustrated example, the hopper control device 53 is a solenoid valve that controls the flow rate of hydraulic oil flowing into or out of the hopper cylinder 24. Specifically, in response to control commands from the controller 50, the hopper control device 53 switches between open and closed connections for the lines connecting the hopper cylinder 24 to the hydraulic pump and the lines connecting the hopper cylinder 24 to the hydraulic oil tank. More specifically, the hopper control device 53 is configured to connect these lines, thereby allowing hydraulic oil to flow into the bottom-side oil chamber of the hopper cylinder 24 and extending the hopper cylinder 24 to automatically close the hopper 2. Alternatively, in response to control commands from the controller 50, the hopper control device 53 is configured to connect these lines, thereby allowing hydraulic oil to flow out of the bottom-side oil chamber of the hopper cylinder 24 and retracting the hopper cylinder 24 to open the hopper 2.

The travel control device 54 is configured to control the travel speed of the asphalt finisher 100. In the illustrated example, the travel control device 54 is a solenoid valve that controls the flow rate of hydraulic oil flowing into each of the rear and front drive motors. Specifically, the travel control device 54 increases or decreases the flow path area, which is the cross-sectional area of the pipe connecting each of the rear and front drive motors to the hydraulic pump, in response to control commands from the controller 50. More specifically, the travel control device 54 increases the flow path area to increase the flow rate of hydraulic oil flowing into each of the rear and front drive motors, thereby increasing the travel speed of the asphalt finisher 100. Alternatively, the conveyor control device 52 reduces the flow path area to decrease the flow rate of hydraulic oil flowing into each of the rear and front drive motors, thereby decreasing the travel speed of the asphalt finisher 100.

The leveling thickness control device 55 is configured to control the leveling thickness. In the illustrated example, the leveling thickness control device 55 is a solenoid valve that controls the flow rate of hydraulic oil flowing into or out of the leveling cylinders 23. Specifically, the leveling thickness control device 55 increases or decreases the flow path area, which is the cross-sectional area of the pipe connecting the leveling cylinders 23 and the hydraulic pump, in response to control commands from the controller 50. More specifically, the leveling thickness control device 55 can increase the leveling thickness by allowing the hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the leveling cylinders 23, contracting the leveling cylinders 23 and raising the front ends of the leveling arms AM. The leveling thickness control device 55 can also decrease the leveling thickness by allowing the hydraulic oil in the rod-side oil chamber of the leveling cylinders 23 to flow out, and extending the leveling cylinders 23 to lower the front ends of the leveling arms AM.

The paving width control device 56 is configured to control the paving width. In the illustrated example, the paving width control device 56 is a solenoid valve that controls the flow rate of hydraulic oil flowing into or out of the telescopic cylinder 60. Specifically, the paving width control device 56 increases or decreases the flow path area, which is the cross-sectional area of the pipe connecting the telescopic cylinder 60 and the hydraulic pump, in response to control commands from the controller 50. More specifically, the paving width control device 56 allows hydraulic oil discharged from the hydraulic pump to flow into the bottom-side oil chamber of the telescopic cylinder 60, thereby extending the telescopic cylinder 60 and protruding the rear screed 31, thereby increasing the paving width. The paving width control device 56 also allows hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the telescopic cylinder 60, thereby retracting the telescopic cylinder 60 and retracting the rear screed 31, thereby decreasing the paving width.

The output device 57 is configured to output information. The information includes visual information and auditory information. In the illustrated example, the output device 57 is configured to convey information to workers working around the asphalt finisher 100. The workers working around the asphalt finisher 100 may include the operator of the asphalt finisher 100 and the driver of the dump truck. Specifically, the output device 57 is a main monitor 57A (see Figures 1 and 2), a sound output device 57B (see Figures 1 and 2), and an indicator 57C (see Figures 1 and 2). However, the output device 57 may be one or two of the main monitor 57A, the sound output device 57B, and the indicator 57C.

The main monitor 57A is configured to display various information. In the illustrated example, the main monitor 57A is an LCD display, and can display various information in response to control commands from the controller 50. The main monitor 57A may also include an input device such as a touch panel that receives operational input from the operator of the asphalt finisher 100.

The sound output device 57B is configured to output sound toward the surroundings of the asphalt finisher 100. In the illustrated example, the sound output device 57B is a speaker that outputs sound toward the surroundings of the asphalt finisher 100, and can output an alarm sound in response to a control command from the controller 50. The sound output device 57B may also output a voice message.

Indicator 57C is a display device having a display portion facing forward of asphalt finisher 100. In the illustrated example, indicator 57C is attached to tractor 1 so that it can be seen by the dump truck driver sitting in the driver's seat of the dump truck. Specifically, indicator 57C is installed at a position higher than the top surface of tractor 1. Indicator 57C is an LED panel, and can display various information in response to control commands from controller 50. For example, it can display a reverse instruction to the driver of a dump truck loaded with paving material PV, informing the driver that it is possible to reverse the dump truck.

In the illustrated example, the indicator 57C is configured to be unfoldable so that it protrudes outward from the right side of the tractor 1 when in use. In other words, the indicator 57C is configured to be foldable so that it fits within the vehicle width of the asphalt finisher 100 when not in use.

The controller 50 acquires information from the spatial recognition device CM, screw rotation speed sensor 45A, conveyor feed speed sensor 45B, travel speed sensor 45C, steering angle sensor 45D, screed extension/contraction sensor 45E, thickness sensor 45F, and auxiliary memory device 45G, performs various calculations, and then outputs control commands to the screw control device 51, conveyor control device 52, hopper control device 53, travel control device 54, paving thickness control device 55, paving width control device 56, and output device 57, etc., depending on the calculation results.

Specifically, the controller 50 determines whether predetermined conditions are met based on information obtained from at least one of the spatial recognition device CM, screw rotation speed sensor 45A, conveyor feed speed sensor 45B, travel speed sensor 45C, steering angle sensor 45D, screed extension/contraction sensor 45E, thickness sensor 45F, and auxiliary memory device 45G, and if it determines that the predetermined conditions are met, outputs a control command to at least one of the screw control device 51, conveyor control device 52, hopper control device 53, travel control device 54, leveling thickness control device 55, paving width control device 56, and output device 57.

More specifically, the controller 50 has functional blocks configured using software, hardware, or a combination thereof: a spatial recognition unit 50A, an estimation unit 50B, and a hopper control unit 50C.

The spatial recognition unit 50A is configured to recognize the situation ahead of the tractor 1 based on the output of the spatial recognition device CM. In the illustrated example, the spatial recognition unit 50A is configured to recognize the height of the paving material PV in the hopper 2. The height of the paving material PV in the hopper 2 is, for example, the distance between the bottom of the hopper 2 and the surface of the paving material PV at the center MP of the hopper 2 (see Figure 2). The center MP of the hopper 2 is, for example, the part where the conveyor CV is provided.

Specifically, the spatial recognition unit 50A derives the height of the paving material PV at the center MP within the hopper 2 by applying predetermined image processing to the image captured by the monocular camera serving as the spatial recognition device CM. The spatial recognition unit 50A may also derive the volume or weight of the paving material PV at the center MP within the hopper 2 by applying predetermined image processing to the image captured by the monocular camera serving as the spatial recognition device CM. Alternatively, the spatial recognition unit 50A may derive the height, volume, or weight of the paving material PV at the center MP within the hopper 2 based on the output of a LIDAR serving as the spatial recognition device CM.

The space recognition unit 50A then determines whether the derived height is greater than a predetermined height. The predetermined height is, for example, a value (height) pre-registered in the auxiliary storage device 45G. The predetermined height is, for example, the height of the entrance OP of the conveying path CP. Note that when the space recognition unit 50A derives the volume of the paving material PV in the center MP within the hopper 2, it determines whether the derived volume is greater than a predetermined volume.

The spatial recognition unit 50A may be configured to determine whether or not a dump truck is present in front of the asphalt finisher 100. Specifically, the spatial recognition unit 50A may be configured to perform predetermined image processing on images captured by a monocular camera serving as the spatial recognition device CM to determine whether or not the dump truck is in contact with the asphalt finisher 100 via the push roller 2b, whether or not the dump truck is dumping up its loading platform, whether or not the dump truck is approaching the asphalt finisher 100, or whether or not the dump truck is moving away from the asphalt finisher 100. When the dump truck is in contact with the asphalt finisher 100, the rear tires of the dump truck are in contact with the push roller 2b (see Figures 1 and 2) located in front of the hopper 2. At this time, the driver of the dump truck shifts the gear of the dump truck into neutral. As a result, the dump truck is pushed by the driving force of the asphalt finisher 100 and moves forward together with the asphalt finisher 100.

The asphalt finisher 100 may also be equipped with an object detection device that detects objects present in front of the asphalt finisher 100. The object detection device may be, for example, a millimeter-wave radar, an ultrasonic sensor, or a laser radar, and is attached to the center of the front end of the asphalt finisher 100 or to the center of the front end of the top surface of the tractor 1. The controller 50 may then determine whether or not a dump truck is present in front of the asphalt finisher 100 based on the output of the object detection device.

The spatial recognition unit 50A may also be configured to determine whether or not an object has entered the hopper 2. Specifically, the spatial recognition unit 50A may be configured to perform predetermined image processing on an image captured by a monocular camera serving as the spatial recognition device CM, thereby determining whether or not a worker has entered the hopper 2, or whether or not a tool such as a rake or shovel is inside the hopper 2.

The spatial recognition unit 50A may also be configured to determine whether or not the paving material in the hopper 2 has run out. Specifically, the spatial recognition unit 50A may be configured to determine whether or not the paving material in the hopper 2 has run out by performing predetermined image processing on an image captured by a monocular camera serving as the spatial recognition device CM.

The estimation unit 50B is configured to estimate various values. In the illustrated example, the estimation unit 50B is configured to estimate the volume of paving material PV discharged from the hopper 2 (consumed volume), the volume of paving material PV replenished to the hopper 2 (replenished volume), and the volume of paving material PV remaining in the hopper 2 (remaining volume).

In the illustrated example, the estimation unit 50B is configured to estimate the volume of paving material PV transported from the hopper 2 by the conveyor CV as the volume of paving material PV discharged from the hopper 2 (consumed volume).

Specifically, the estimation unit 50B calculates the volume of paving material PV passing through the conveying path CP by multiplying the width W1 (see Figure 2) of the conveying path CP by the height H1 (see Figure 1) of the conveying path CP and the conveying distance D1 (see Figures 1 and 2). The width W1 and height H1 of the conveying path CP are stored in advance (before construction begins) in the auxiliary memory device 45G. The product of the width W1 and height H1 of the conveying path CP corresponds to the cross-sectional area of the conveying path CP. The volume of the paving material PV passing through the conveying path CP corresponds to the volume of the paving material PV conveyed by the conveyor CV. In the illustrated example, the cross-sectional area of the conveying path CP is the same as the opening area of the entrance OP of the conveying path CP. The conveying distance D1 is the travel distance of the conveyor CV and is derived based on the output of the conveyor feed speed sensor 45B. The conveying distance D1 may be calculated based on the rotational speed of the hydraulic motor that drives the conveyor CV or the flow rate of hydraulic oil flowing into the hydraulic motor that drives the conveyor CV. The conveying distance D1 may also be calculated based on the contents of a control command regarding the conveyor feed speed sent from the controller 50 to the conveyor control device 52. In other words, the conveying distance D1 may be calculated based on the command value rather than the actual measured value of the conveyor feed speed. This is because it is believed that there will be no significant difference between the actual measured value and the command value during operation of the asphalt finisher 100.

The product of the conveying distance D1, which is the distance traveled by the conveyor CV during the first period from time t1 to time t2, and the cross-sectional area of the conveying path CP (width W1 x height H1), corresponds to the volume of paving material PV conveyed by the conveyor CV during the first period, and further corresponds to the volume of paving material PV discharged from the hopper 2 during the first period (consumed volume).

More specifically, the volume of paving material PV discharged from hopper 2 (consumed volume) is the sum of the volume of paving material PV discharged from hopper 2 by the left conveyor CVL and the volume of paving material PV discharged from hopper 2 by the right conveyor CVR. The estimation unit 50B calculates the volume of paving material PV passing through left conveyor path CPL by multiplying the width W1L of left conveyor path CPL by the height H1 of left conveyor path CPL by the left conveyor distance (the distance traveled by the left conveyor CVL). Similarly, the estimation unit 50B calculates the volume of paving material PV passing through right conveyor path CPR by multiplying the width W1R of right conveyor path CPR by the height H1 of right conveyor path CPR by the right conveyor distance (the distance traveled by the right conveyor CVR). In the illustrated example, the estimation unit 50B can calculate the volume per unit time of paving material PV passing through left conveying path CPL by multiplying the width W1L of left conveying path CPL by the height H1 of left conveying path CPL and the feed speed of the left conveyor CVL. The estimation unit 50B can then calculate the volume of paving material PV passing through left conveying path CPL during any given period by integrating the volumes per unit time. The same applies to the volume of paving material PV passing through right conveying path CPR.

The estimation unit 50B may also be configured to estimate the volume of the paving material PV (new pavement NP) laid by the screed 3 as the volume of the paving material PV discharged from the hopper 2 (consumed volume).

Specifically, the estimation unit 50B may calculate the volume of the paving material PV (new paving body NP) laid and leveled by the screed 3 by multiplying the thickness H2 (see Figure 1) of the paving material PV (new paving body NP) laid and leveled by the screed 3 by the width W2 (see Figure 2) of the new paving body NP and the travel distance D2 (see Figures 1 and 2) of the asphalt finisher 100.

In the illustrated example, the thickness H2 of the new pavement NP is calculated based on the output of the thickness sensor 45F, and the width W2 of the new pavement NP is calculated based on the output of the screed extension/contraction sensor 45E. The thickness H2 of the new pavement NP may also be calculated based on the content of a control command related to the leveling thickness sent from the controller 50 to the leveling thickness control device 55. The width W2 of the new pavement NP may also be calculated based on the content of a control command related to the paving width sent from the controller 50 to the paving width control device 56. In other words, the thickness H2 of the new pavement NP may be calculated based on the command value rather than the actual measured value of the leveling thickness. The width W2 of the new pavement NP may also be calculated based on the command value rather than the actual measured value of the paving width. This is because it is believed that there will be no significant difference between the actual measured value and the command value when operating the asphalt finisher 100.

Movement distance D2 of the asphalt paver 100 is calculated based on the output of the travel speed sensor 45C and the output of the steering angle sensor 45D. Specifically, movement distance D2 of the asphalt paver 100 is a straight-line distance calculated based on the output of the travel speed sensor 45C when the asphalt paver 100 is traveling straight, and is a curved distance calculated based on the output of the travel speed sensor 45C and the output of the steering angle sensor 45D when the asphalt paver 100 is traveling a curve. Movement distance D2 may also be calculated based on the content of a control command related to the travel speed transmitted from the controller 50 to the travel control device 54. Movement distance D2 may also be calculated based on the content of a control command related to the travel speed and the content of a control command related to the steering angle. In other words, movement distance D2 may be calculated based on the command values for the travel speed and steering angle rather than the actual measured values of the travel speed and steering angle. This is because it is believed that there will be no significant difference between the actual measured values and the command values during operation of the asphalt paver 100. The control command regarding the steering angle is, for example, a control command sent from the controller 50 to the steering control device.

The product of the travel distance D2, which is the distance traveled by the asphalt finisher 100 during the first period from time t1 to time t2, and the cross-sectional area (width W2 x thickness H2) of the new pavement NP corresponds to the volume of the pavement material PV (new pavement NP) laid by the screed 3 during the first period, and further corresponds to the volume of the pavement material PV discharged from the hopper 2 during the first period. In the illustrated example, the estimation unit 50B multiplies the cross-sectional area (width W2 x thickness H2) of the new pavement NP by the traveling speed of the asphalt finisher 100 to calculate the volume per unit time of the pavement material PV (new pavement NP) laid by the screed 3. The estimation unit 50B then integrates the volumes per unit time to calculate the volume of the pavement material PV (new pavement NP) laid by the screed 3 during any period.

Furthermore, when the estimation unit 50B determines that a predetermined addition condition is met, it may estimate the current replenishment volume by adding an additional value to the value of the volume (replenishment volume) of the paving material PV replenished in the hopper 2. The predetermined addition condition may be, for example, the spatial recognition unit 50A determining that the dump truck has contacted the asphalt finisher 100 via the push roller 2b, or the operation of a predetermined input device such as an add button. The additional value is the value of the volume of the paving material PV loaded on the dump truck bed and is stored in advance (before construction begins) in the auxiliary storage device 45G. The additional value may also be dynamically set. In this case, the estimation unit 50B may receive the additional value (the value of the volume of the paving material PV loaded on the bed) from the dump truck via a communication device, which is another example of the information acquisition device 45. Alternatively, the estimation unit 50B may derive the value of the volume of the paving material PV loaded on the dump truck bed based on an image captured by a monocular camera serving as the spatial recognition device CM. For example, the estimation unit 50B may derive the value of the volume of the paving material PV loaded on the bed of the dump truck by determining the type of dump truck (whether it is a medium-sized dump truck or a large dump truck) based on an image captured by a monocular camera serving as the spatial recognition device CM.

The estimation unit 50B may also estimate the remaining volume by subtracting the consumed volume from the replenished volume. With this configuration, the estimation unit 50B can accurately estimate the remaining volume even if paving material PV is replenished into the hopper 2 while there is still paving material PV remaining in the hopper 2.

The hopper control unit 50C is configured to close the hopper 2 when predetermined conditions are met. In the example shown in FIG. 3, the estimation unit 50B determines whether the volume of the paving material PV discharged from the hopper 2 exceeds a predetermined value based on information acquired by an information acquisition device 45 other than the spatial recognition device CM. In the illustrated example, the predetermined value is set based on the volume of the paving material PV replenished into the hopper 2. Therefore, the larger the volume of the paving material PV replenished into the hopper 2, the larger the predetermined value. Note that the spatial recognition unit 50A may also determine whether the height of the paving material at the center MP in the hopper 2 is greater than a predetermined height based on an image captured by a monocular camera serving as the spatial recognition device CM.

Then, when a predetermined condition is met, such as the estimation unit 50B determining that the volume of the paving material PV discharged from the hopper 2 exceeds a predetermined value, the hopper control unit 50C sends a close command to the hopper control device 53. The predetermined condition may also be the spatial recognition unit 50A determining that the height of the paving material at the center MP within the hopper 2 is greater than a predetermined height.

In the illustrated example, the hopper control unit 50C sends a close command to the hopper control device 53 when the estimation unit 50B determines that the volume of paving material PV discharged from the hopper 2 exceeds a predetermined value. Upon receiving the close command, the hopper control device 53 extends the hopper cylinder 24 by allowing hydraulic oil to flow into the bottom-side oil chamber of the hopper cylinder 24, thereby closing the hopper 2. The hopper control unit 50C may, for example, extend the hopper cylinder 24 until the hopper 2 is completely closed, or may extend the hopper cylinder 24 by a predetermined length.

Furthermore, when closing the hopper 2, i.e., when extending the hopper cylinder 24, the hopper control unit 50C may send an output command to the output device 57. Having received the output command, the output device 57 may notify the operator of the asphalt finisher 100 that the operation to close the hopper 2 is being performed automatically, for example, by displaying a text message such as "Hopper closing" on the main monitor 57A. Alternatively, the output device 57 may notify a worker working around the asphalt finisher 100 that the operation to close the hopper 2 is being performed automatically, for example, by outputting an audio message such as "Hopper closing" from the sound output device 57B. Alternatively, the output device 57 may notify the driver of the dump truck that the operation to close the hopper 2 is being performed, for example, by outputting a text message such as "Hopper closing" to the indicator 57C.

The hopper control unit 50C may be configured not to close the hopper 2 when the spatial recognition unit 50A determines, based on an image captured by the monocular camera serving as the spatial recognition device CM, that a dump truck is in contact with the asphalt finisher 100, even if it determines that the above-mentioned specified conditions are met. In other words, the hopper control unit 50C may be configured to restrict the closing operation of the hopper 2 when a transport vehicle is present in front of the hopper 2. This is to prevent contact between the hopper wings and the dump truck bed. In this case, the hopper control unit 50C may be configured not to send a close command to the hopper control device 53, or may send a stop command to the hopper control device 53. Upon receiving the stop command, the hopper control device 53 stops the flow of hydraulic oil into the bottom-side oil chamber of the hopper cylinder 24, thereby stopping the extension of the hopper cylinder 24 and stopping the movement of the hopper 2.

Furthermore, even if the spatial recognition unit 50A determines that the dump truck is not in contact with the asphalt finisher 100, if the spatial recognition unit 50A determines that the distance between the dump truck and the asphalt finisher 100 is less than a predetermined distance, the hopper control unit 50C may be configured not to close the hopper 2, just as when the spatial recognition unit 50A determines that the dump truck is in contact with the asphalt finisher 100. In this case, the hopper control unit 50C may be configured to open the hopper 2.

Furthermore, the hopper control unit 50C may be configured not to close the hopper 2 when the spatial recognition unit 50A determines, based on an image captured by the monocular camera serving as the spatial recognition device CM, that an intruding object is present in the hopper 2, even if it determines that the above-mentioned specified conditions are met. This is to prevent contact between the hopper wings and the intruding object, or to prevent the intruding object (e.g., a shovel) from being buried in the paving material inside the hopper 2. In this case, the hopper control unit 50C may be configured not to send a close command to the hopper control device 53, or may be configured to send a stop command to the hopper control device 53.

The hopper control unit 50C may also be configured to slow down the feed speed of the conveyor CV, the rotation speed of the screw SC, and the travel speed of the asphalt finisher 100 when the spatial recognition unit 50A determines, based on images captured by the monocular camera serving as the spatial recognition device CM, that there is a shortage of paving material in the hopper 2 or that it has run out. In this case, the hopper control unit 50C may also be configured to stop the movement of the conveyor CV, screw SC, rear wheels 5, and front wheels 6. This is because if construction by the asphalt finisher 100 were to continue when there was no paving material in the hopper 2, a depression would form in the newly constructed road due to the lack of paving material.

In this case, the hopper control unit 50C sends a deceleration command or a stop command to each of the screw control unit 51, conveyor control unit 52, and travel control unit 54. Upon receiving the deceleration command or stop command, the screw control unit 51 reduces the flow rate of hydraulic oil flowing into the hydraulic motor that drives the screw SC, thereby slowing down the rotational speed of the screw SC or stopping the rotation of the screw SC. The same applies to the conveyor control unit 52 and travel control unit 54.

As described above, as shown in Figures 1 and 2, the asphalt finisher 100 comprises a tractor 1, a hopper 2 installed in front of the tractor 1 to receive paving material PV, a conveyor CV that transports the paving material PV in the hopper 2 to the rear of the tractor 1, a screw SC that spreads the paving material PV transported by the conveyor CV behind the tractor 1, a screed 3 that spreads the paving material PV spread by the screw SC behind the screw SC, and a controller 50, which is an example of a calculation device that estimates the volume of the paving material PV discharged from the hopper 2.

In such an asphalt finisher 100, the controller 50 may estimate the volume of paving material PV transported by the conveyor CV as the volume of paving material PV discharged from the hopper 2. Hereinafter, this estimation method will be referred to as the first estimation method. Alternatively, the controller 50 may estimate the volume of paving material PV (new pavement NP) laid and leveled by the screed 3 as the volume of paving material PV discharged from the hopper 2. Hereinafter, this estimation method will be referred to as the second estimation method. When using the first estimation method, the controller 50 can estimate that the remaining volume has fallen below a predetermined value more quickly than when using the second estimation method. This is because the first estimation method is based on the amount of paving material PV moving upstream of the paving material PV's movement path. Therefore, the controller 50 can more reliably prevent a situation in which the paving material PV supplied to the screed 3 is insufficient. Furthermore, when using the second estimation method, the controller 50 can estimate the remaining volume more accurately than when using the first estimation method. This is because voids are less likely to occur in the newly laid pavement NP than in the blocks of paving material PV passing through the transport path CP.

This configuration allows the controller 50 to more accurately estimate the amount of paving material PV in the hopper 2. For example, even if it is difficult to estimate the amount of paving material PV in the hopper 2 based on images captured by a monocular camera serving as the spatial recognition device CM due to environmental issues such as smoke rising from the paving material PV in the hopper 2 or dust floating around at the construction site, the controller 50 can estimate the amount of paving material PV in the hopper 2 based on the output of an information acquisition device 45 other than the spatial recognition device CM. Furthermore, the controller 50 can prevent the amount of paving material PV in the hopper 2 from being overly low or overly high due to environmental issues.

The controller 50 may also calculate the difference between the amount of paving material PV in the hopper 2 estimated based on an image captured by the monocular camera serving as the spatial recognition device CM and the amount of paving material PV in the hopper 2 estimated based on the output of an information acquisition device 45 other than the spatial recognition device CM. The controller 50 may then determine the accuracy of the estimation based on this difference. In this case, the controller 50 may differentiate the content of the processing to be executed when the accuracy of the estimation is high from the content of the processing to be executed when the accuracy of the estimation is low. Alternatively, the controller 50 may be configured not to execute the processing to be executed when the accuracy of the estimation is high when the accuracy of the estimation is low.

The controller 50 may also determine the timing to close the hopper 2 based on the volume of paving material PV discharged from the hopper 2. Alternatively, the controller 50 may determine the amount by which the hopper 2 is closed based on the volume of paving material PV discharged from the hopper 2. In the illustrated example, the amount by which the hopper 2 is closed is the extension amount of the hopper cylinder 24. However, the amount by which the hopper 2 is closed may also be the rotation angle around the rotation axis of the hopper wing.

The controller 50 may also be configured to close the hopper 2 when the volume of the paving material PV discharged from the hopper 2 exceeds a predetermined value. The controller 50 may also be configured to close the hopper 2 by a predetermined closure amount each time the volume of the paving material PV discharged from the hopper 2 increases by a predetermined value.

This configuration allows the controller 50 to reliably move the hopper 2 when the amount of paving material PV in the hopper 2 decreases. Therefore, the asphalt finisher 100 can reliably prevent a situation in which a shortage of paving material PV is supplied to the screed 3 even though sufficient paving material PV remains at the end of the hopper 2. As a result, the controller 50 can suppress or prevent unevenness from forming on the surface of the new pavement NP.

The controller 50 may also notify that the volume of paving material PV discharged from the hopper 2 has exceeded a predetermined value. In the illustrated example, the controller 50 activates the output device 57 to notify workers working around the asphalt finisher 100 that the consumed volume has exceeded the predetermined value (that the remaining volume has fallen below the predetermined value).

With this configuration, the controller 50 can prevent a situation in which a shortage of paving material PV is supplied to the screed 3 even though sufficient paving material PV remains at the end of the hopper 2. When the operator of the asphalt finisher 100 learns that the consumed volume has exceeded a predetermined value (that the remaining volume has fallen below the predetermined value), he or she can take measures to prevent the above-mentioned situation from occurring, such as closing the hopper 2. As a result, the controller 50 can prevent or limit the formation of irregularities on the surface of the new pavement NP. Closing the hopper 2 can be achieved, for example, by tilting a hopper opening/closing lever (not shown) installed near the driver's seat in the closing direction.

The controller 50 may be configured to close the hopper 2 when it determines that the amount of paving material PV in the hopper 2 is less than a predetermined amount. For example, the controller 50 may be configured to determine that the remaining volume has fallen below a predetermined value when it determines that the consumed volume has exceeded a predetermined value, and to automatically close the hopper 2. If the hopper 2 is to be automatically closed, the controller 50 may be configured to notify the surrounding area of this. The controller 50 may be configured to close the hopper 2 when it determines that the consumed volume has exceeded a predetermined value and also determines that the height of the paving material PV at the center MP in the hopper 2 is less than a predetermined height. Alternatively, the controller 50 may be configured to close the hopper 2 when it determines that the height of the paving material PV at the center MP in the hopper 2 is less than a predetermined height.

This configuration allows the asphalt finisher 100 to reliably close the hopper 2 when the consumed volume exceeds a predetermined value (when the remaining volume falls below a predetermined value). Therefore, the asphalt finisher 100 can reliably prevent a situation in which a shortage of paving material PV is supplied to the screed 3 even though sufficient paving material PV remains at the end of the hopper 2. As a result, the controller 50 can suppress or prevent unevenness from forming on the surface of the new pavement NP.

Furthermore, by using the output device 57, the asphalt finisher 100 can notify workers working around the asphalt finisher 100 in advance that the hopper 2 will be closed. Alternatively, by using the output device 57, the asphalt finisher 100 can notify workers working around the asphalt finisher 100 that the hopper 2 is currently being closed. As a result, the asphalt finisher 100 can increase safety when automatically closing the hopper 2. For example, the asphalt finisher 100 can prevent contact between the hopper 2 moving in the closing direction and workers working around the asphalt finisher 100.

Furthermore, the controller 50 may be configured to determine whether a dump truck is approaching the asphalt finisher 100 (hopper 2) or whether an object has entered the hopper 2 before or while the hopper 2 is being moved. For example, the controller 50 may be configured to perform predetermined image processing on an image captured by a monocular camera serving as the spatial recognition device CM to determine whether a dump truck is reversing toward the asphalt finisher 100, whether a worker has entered the hopper 2, or whether a tool such as a rake or shovel is present in the hopper 2. If the controller 50 determines that a dump truck is reversing toward the asphalt finisher 100 or that an object such as a worker, rake, or shovel is present in the hopper 2, it may be configured not to close the hopper 2 even if it determines that the consumed volume has exceeded a predetermined value (the remaining volume has fallen below a predetermined value). This is to prevent contact between the hopper wings and the dump truck bed, to prevent contact between the hopper wings and incoming objects, and to prevent incoming objects from being buried in the paving material PV inside the hopper 2.

Furthermore, in the above-described embodiment, a hydraulic motor is used to drive the hydraulic actuator, etc., but an electric motor may be used instead of a hydraulic motor.

Preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, nor to the embodiments described below. Various modifications or substitutions may be applied to the above-described or below-described embodiments without departing from the scope of the present invention. Furthermore, features described separately may be combined unless technical contradictions arise.

For example, in the above-described embodiment, the controller 50 is configured to close the hopper 2 when a predetermined condition is met. The controller 50 is typically configured to stop the movement of the hopper 2 when the hopper 2 has closed the desired amount. However, the controller 50 may extend and retract the hopper cylinder 24 for a predetermined period of time when the hopper 2 has closed the desired amount, or when the hopper 2 is about to close the desired amount. In other words, the controller 50 may open and close (vibrate) the hopper 2. This is to shake off paving material PV that has adhered to the inner walls or bottom surface of the hopper wings.

The controller 50 may also make various determinations using a trained model that has learned the control conditions. For example, the controller 50 may make various determinations using a trained model that has learned the control conditions of the hopper 2. The various determinations include, for example, determining whether the amount of paving material PV in the hopper 2 is greater than a predetermined amount, determining whether the amount of paving material PV coming out of the hopper 2 is greater than a predetermined amount, determining whether a dump truck is present in front of the asphalt finisher 100, determining whether a dump truck is moving away from the asphalt finisher 100, determining whether an object has entered the hopper 2, determining whether the height of the paving material PV at the center MP in the hopper 2 is greater than a predetermined height, or determining whether the paving material PV in the hopper 2 has run out.

Specifically, the controller 50 may use the trained model stored in the non-volatile storage device to make various determinations based on at least one of the input image, which is an image captured by the monocular camera serving as the spatial recognition device CM, and various information acquired by the information acquisition device 45. More specifically, the controller 50 may load the trained model from the non-volatile storage device into a main storage device such as RAM, and cause the CPU to execute processing based on the trained model, thereby making various determinations based on at least one of the input image and various information.

DESCRIPTION OF SYMBOLS 1...Tractor 1BF...Base part 1FW...Front part 2...Hopper 2b...Push roller 3...Screed 5...Rear wheel 6...Front wheel 23...Leveling cylinder 24...Hopper cylinder 25...Screed lift cylinder 30...Front screed 31...Rear screed 40...Side plate 41...Moldboard 42...Screed step 43...Retaining plate 45...Information acquisition device 45A...Screw rotation speed sensor 45B...Conveyor feed speed sensor 45C...Travel speed sensor 45G...Auxiliary storage device 50...Controller 50A...Spatial recognition part 50C...Hopper control part 51...Screw control device 52...Conveyor control device 53...Hopper control device 54...Travel control device 55...Paving thickness control device 56...Paving width control device 57...Output device 57A...Main monitor 57B...Sound output device 57C...Indicator 60: Telescopic cylinder; 100: Asphalt finisher; AM: Leveling arm; AML: Left leveling arm; AMR: Right leveling arm; CM: Spatial recognition device; CP: Conveyor path; CPL: Left conveyor path; CPR: Right conveyor path; CV: Conveyor; CVL: Left conveyor; CVR: Right conveyor; MP: Center; OP: Entrance; PV: Paving material; SC: Screw; SCL: Left screw; SCR: Right screw.

Claims (8)

A tractor and
a hopper installed in front of the tractor to receive paving material;
a conveyor that transports the paving material in the hopper to the rear of the tractor;
a screw that spreads the paving material transported by the conveyor behind the tractor;
A screed that spreads the paving material spread by the screw behind the screw,
a calculation device that estimates the volume of paving material discharged from the hopper as a consumed volume ;
The calculation device is configured to estimate the remaining volume, which is the volume of paving material remaining in the hopper, without detecting the replenished volume, by subtracting the value of the consumed volume from the value of the replenished volume, which is the volume of paving material replenished to the hopper, calculated based on a preset added value as the value of the volume of paving material loaded on the bed of the dump truck;
The additional value is added to the value of the replenishment volume during construction .
Road machinery. The calculation device estimates the volume of the paving material transported by the conveyor as the consumed volume.
2. A road machine according to claim 1. The calculation device estimates the volume of the pavement laid and leveled by the screed as the consumed volume.
2. A road machine according to claim 1. The calculation device determines a timing to close the hopper based on the consumption volume.
A road machine according to any one of claims 1 to 3. The calculation device determines the closing amount of the hopper based on the consumption volume.
A road machine according to any one of claims 1 to 3. the computing device restricts the closing operation of the hopper when a transport vehicle is present in front of the hopper.
A road machine according to any one of claims 1 to 5. The computing device notifies that the consumption volume has exceeded a predetermined value.
A road machine according to any one of claims 1 to 6. the computing device closes the hopper when the remaining volume falls below a predetermined value;
A road machine according to any one of claims 1 to 7.