JP2023154942A - Road machine - Google Patents

Abstract

To provide an asphalt finisher capable of more appropriately controlling an expansion and contraction amount of a screed.SOLUTION: An asphalt finisher 100 includes a tractor 1, a hopper 2 installed on the front side of the tractor 1 for receiving a pavement material PV, a conveyor CV for conveying the pavement material PV in the hopper 2 to the rear side of the tractor 1, a screw SC for spreading on the rear side of the tractor 1 the pavement material PV conveyed by the conveyor CV, a screed 3 for evenly leveling the pavement material PV spread by the screw SC on the rear side of the screw SC, and a controller 50 which calculates, on the basis of information related to a planimetric feature defining a boundary line of a road of a construction object positioned ahead of the screed 3, a coordinate on the boundary line in a prescribed coordinate system.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD This disclosure relates to road machines.

Conventionally, an asphalt finisher is known that uses a semiconductor laser projector attached to the end of a screed and a CCD camera to detect the boundary line of the road to be paved, and expands and contracts the screed in accordance with the boundary line (patented). (See Reference 1).

This asphalt finisher is configured to expand and contract the screed so that the distance between the end of the screed and the boundary line in the vehicle width direction becomes smaller.

Japanese Patent Application Publication No. 6-294105

However, after recognizing that a gap exists between the end of the screed and the boundary line in the vehicle width direction, the asphalt finisher described above expands and contracts the screed so that the gap becomes smaller. Therefore, the above-described asphalt finisher may not be able to quickly respond to changes in the orientation of the boundary line.

Therefore, by recognizing changes in the direction of the boundary line before the screed reaches areas where the direction of the boundary line changes, such as where the road (construction width) is widened, asphalt can more appropriately control the amount of expansion and contraction of the screed. It is desirable to provide road machinery such as finishers.

A road machine according to an embodiment of the present disclosure includes a tractor, a hopper installed in front of the tractor to receive paving material, a conveyor that feeds the paving material in the hopper to the rear of the tractor, and a conveyor configured to A screw that spreads the fed paving material behind the tractor, a screed that spreads the paving material spread by the screw evenly behind the screw, and a construction target located in front of the screed. and a control device that calculates coordinates on the boundary line in a predetermined coordinate system based on information regarding terrestrial features that define the boundary line of the range.

Since the above-mentioned road machine can utilize the coordinates on the boundary line located in front of the screed, it is possible to more appropriately control the amount of expansion and contraction of the screed.

It is a side view of an asphalt finisher. It is a top view of an asphalt finisher. 1 is a diagram showing a configuration example of an operation support system. It is a schematic perspective view of the formwork for pavement. It is a flowchart which shows an example of the flow of goal setting processing.

FIG. 1 is a side view of an asphalt finisher 100, which is an example of a road machine according to an embodiment of the present disclosure. FIG. 2 is a top view of the asphalt finisher 100. In the illustrated example, the asphalt finisher 100 is a wheel-type asphalt finisher, and mainly includes a tractor 1, a hopper 2, and a screed 3. In the following, the direction of the hopper 2 as seen from the tractor 1 (+X direction) is referred to as the front, and the direction of the screed 3 as seen from the tractor 1 (−X direction) as the rear.

The tractor 1 is a mechanism for moving the asphalt finisher 100. In the illustrated example, the tractor 1 rotates the rear wheels 5 using the hydraulic motor for running the rear wheels, and rotates the front wheels 6 using the hydraulic motor for running the front wheels to move the asphalt finisher 100. The hydraulic motor for running the rear wheels and the hydraulic motor for running the front wheels are supplied with hydraulic oil from the hydraulic pump and rotate. However, the front wheel 6 may be a driven wheel.

Asphalt finisher 100 may be a crawler type asphalt finisher. In this case, the combination of rear wheels 5 and front wheels 6 is replaced with a combination of left crawlers and right crawlers.

Hopper 2 is a mechanism for receiving paving material PV. In the illustrated example, the hopper 2 is installed in front of the tractor 1 and is configured to be opened and closed in the vehicle width direction (Y-axis direction) by a hopper cylinder. The asphalt finisher 100 normally receives the paving material PV (for example, an asphalt mixture) from the bed of a dump truck when the hopper 2 is fully open. A dump truck is an example of a transportation vehicle that transports paving material PV. 1 and 2 show that the hopper 2 is fully open. When the paving material PV in the hopper 2 decreases during construction, the operator of the asphalt finisher 100 closes the hopper 2 and collects the paving material PV near the inner wall of the hopper 2 in the center of the hopper 2. This is to enable the conveyor CV located in the center of the hopper 2 to feed the paving material PV to the rear of the tractor 1. The paving material PV fed to the rear of the tractor 1 by the conveyor CV is spread in the vehicle width direction behind the tractor 1 and in front of the screed 3 by the screw SC. In the illustrated example, the screw SC is in a state where the left extension screw SCL and the right extension screw SCR are connected. In FIGS. 1 and 2, for clarity, the illustration of the paving material PV in the hopper 2 is omitted, and the paving material PV spread by the screw SC is shown in a rough dot pattern, and the paving material PV spread by the screed 3 is shown in a rough dot pattern. The newly constructed pavement NP is shown in a fine dot pattern.

The screed 3 is a mechanism for leveling the paving material PV. In the illustrated example, the screed 3 includes a front screed 30 and a rear screed 31. The front screed 30 includes a left front screed 30L and a right front screed 30R. The rear screed 31 is a screed that can be expanded and contracted in the vehicle width direction, and includes a left rear screed 31L and a right rear screed 31R. Specifically, the rear screed 31 is expanded and contracted by a screed expansion and contraction cylinder 7 installed within the screed 3. More specifically, the screed telescopic cylinder 7 includes a left screed telescopic cylinder 7L and a right screed telescopic cylinder 7R. The left rear screed 31L is expanded and contracted by the left screed telescopic cylinder 7L, and the right rear screed 31R is expanded and contracted by the right screed telescopic cylinder 7R.

Furthermore, the screed 3 is a floating screed that is pulled by the tractor 1, and is connected to the tractor 1 via a leveling arm 3A. The leveling arm 3A includes a left leveling arm 3AL arranged on the left side of the tractor 1 and a right leveling arm 3AR arranged on the right side of the tractor 1. Note that an end leveling device may be disposed at the end of the rear screed 31.

A side plate 41 is attached to the distal end of the rear screed 31. In the illustrated example, a left side plate 41L is attached to the left end of the left rear screed 31L, and a right side plate 41R is attached to the right end of the right rear screed 31R.

A footboard 32 is attached to the rear of the screed 3. Specifically, the footboard 32 is attached to the rear of the screed 3 so that a worker can move back and forth in the vehicle width direction without stepping on the newly installed pavement NP. In the illustrated example, the footboards 32 include a central footboard 32C attached to the rear of the front screed 30, a left footboard 32L attached to the rear of the left rear screed 31L, and a right footboard 32R attached to the rear of the right rear screed 31R. include.

A moldboard 42 is attached to the front part of the screed 3. The mold board 42 is configured to be able to adjust the amount of paving material PV that stays in front of the screed 3. The paving material PV passes through the gap between the lower end of the moldboard 42 and the roadbed BS and reaches under the screed 3. In the illustrated example, the moldboard 42 includes a left moldboard 42L located in front of the left rear screed 31L, and a right moldboard 42R located in front of the right rear screed 31R.

A screw SC is arranged in front of the mold board 42, and a retaining plate 43 is arranged in front of the screw SC. Specifically, the retaining plate 43 includes a left retaining plate 43L disposed in front of the left extension screw SCL and a right retaining plate 43R disposed in front of the right extension screw SCR. Note that the retaining plate 43 may be omitted.

A traveling speed sensor S1, a controller 50, an object detection device 51, an on-vehicle display device 52, a steering device 53, and a screed expansion/contraction device 54 are attached to the tractor 1.

The traveling speed sensor S1 is configured to be able to detect the traveling speed of the asphalt finisher 100. In the illustrated example, the traveling speed sensor S1 is a wheel speed sensor, and is configured to be able to detect the rotational angular velocity and rotational angle of the rear wheels 5, as well as the traveling speed and distance of the asphalt finisher 100.

Controller 50 is a control device that controls asphalt finisher 100. In the illustrated example, the controller 50 is configured with a microcomputer including a CPU, a volatile storage device, a nonvolatile storage device, and the like. Each function of the controller 50 is realized by the CPU executing a program stored in a nonvolatile storage device. However, each function of the controller 50 may be realized not only by software but also by hardware, or by a combination of hardware and software.

The object detection device 51 is configured to acquire information regarding features within a predetermined range of the road to be constructed, and to output the acquired information to the controller 50. That is, the object detection device 51 is configured to monitor a predetermined range of the road to be constructed. The predetermined range on the road is, for example, a range located in front of the screed 3 and including the boundary line of the road. In the illustrated example, the predetermined range on the road is a range having a longitudinal width and a lateral width larger than the width of the paving formwork, and is, for example, a 2 meter square range.

The range located in front of the screed 3 includes, for example, the range located in front of the hopper 2, the range located in front of the axle of the front wheel 6, the range located in front of the axle of the rear wheel 5, and the range located in front of the axle of the rear wheel 5. This is the range located in front of the

The features within the predetermined range include, for example, the roadbed BS and the object AP located outside the roadbed BS. The object AP is a feature used to determine the position of the end face in the width direction of the pavement to be laid. In the example shown in FIGS. 1 and 2, the object AP is a paving formwork having a predetermined thickness (height), and the left object APL is on the left side of the asphalt finisher 100, and the left object APL is on the right side of the asphalt finisher 100. right object APR. Specifically, the left object APL includes a first left object APL1 and a second left object APL2, and the right object APR includes a first right object APR1 and a second right object APR2. The object AP may be an L-shaped gutter block, a curb block, a cut step of an existing pavement, or the like. The cut step of the existing pavement means the step between the surface of the cut part and the surface of the uncut part, which is formed when cutting the old pavement and laying the new pavement. do. The object AP may be a feature with almost no thickness, such as a line drawn on the ground, a tape pasted on the ground, or a thread stretched along the ground. The information regarding the feature includes, for example, the height of the feature, the color of the surface of the feature, the reflectance of the surface of the feature, and the like. Note that in FIG. 1, illustration of the left object APL is omitted for clarity.

In the illustrated example, the object detection device 51 is a stereo camera configured to monitor a predetermined range. Note that the object detection device 51 is a monocular camera configured to monitor a predetermined range, LIDAR, millimeter wave radar, laser radar, laser scanner, distance image camera, laser range finder, ultrasonic sensor, or a combination thereof. It may be.

Further, the stereo camera as the object detection device 51 is preferably configured to have an automatic exposure adjustment function. With this configuration, the object detection device 51 can acquire information regarding terrestrial objects within a predetermined range regardless of day or night, that is, without requiring special lighting or the like.

In the illustrated example, the object detection device 51 includes a left object detection device 51L installed on the left side of the asphalt finisher 100, and a right object detection device 51R installed on the right side of the asphalt finisher 100.

The left object detection device 51L is configured to be able to monitor the ground on the left side of the asphalt finisher 100. In the illustrated example, the left object detection device 51L is a stereo camera that monitors a left monitoring range ZL (range surrounded by a dashed line in FIG. 2) on the ground on the left side of the asphalt finisher 100.

The right object detection device 51R is configured to be able to monitor the ground on the right side of the asphalt finisher 100. In the illustrated example, the right object detection device 51R is a stereo camera that monitors a right monitoring range ZR (range surrounded by a dashed line in FIG. 2) on the ground on the right side of the asphalt finisher 100.

Object detection device 51 may be attached to asphalt finisher 100 via attachment member 60. The attachment member 60 is a member used to attach the object detection device 51 to the asphalt finisher 100. In the illustrated example, the attachment member 60 includes a left attachment member 60L and a right attachment member 60R. In the example shown in FIG. 2, the left object detection device 51L is attached to the left front end of the tractor 1 via the left attachment member 60L, and the right object detection device 51R is attached to the right front end of the tractor 1 via the right attachment member 60R. attached to the section. Note that the left object detection device 51L may be attached to other parts of the asphalt finisher 100, such as the left front end of the hopper 2, via the left attachment member 60L. Similarly, the right object detection device 51R may be attached to other parts of the asphalt finisher 100, such as the right front end of the hopper 2, via the right attachment member 60R.

Further, the object detection device 51 may be configured to be able to monitor the expansion and contraction state of the rear screed 31. For example, the object detection device 51 additionally includes a stereo camera configured to monitor the end of the left rear screed 31L and a stereo camera configured to monitor the end of the right rear screed 31R. may be included in In this case, the object detection device 51 may be arranged on the screed 3. For example, the object detection device 51 may be arranged on the rear screed 31. Further, when an end leveling device is arranged at the end of the rear screed 31, the object detection device 51 may be arranged at the end leveling device.

Further, in the example shown in FIG. 2, the object detection device 51 is attached to the attachment member 60 so as to face vertically downward, but it may be attached to the attachment member 60 so as to face in another direction such as diagonally downward. Good too.

Further, in the example shown in FIG. 2, the left attachment member 60L is composed of an extensible member TA that can be expanded and contracted in the width direction, and a rotation member SB that is rotatably connected to the distal end of the extensible member TA. There is. The rotating member SBa indicated by a broken line in FIG. 2 shows the state when the rotating member SB is rotated. The same applies to the right attachment member 60R.

In this way, the attachment member 60 is configured so that the monitoring range of the object detection device 51 can be moved by the telescopic member TA and the rotating member SB. This is to be able to respond to changes in pavement width, etc. In this case, the controller 50 may be configured to be able to control the expansion and contraction of the expandable member TA so that the object detection device 51 follows the object AP. Thereby, the controller 50 can ensure that the object AP is continuously included within the monitoring range of the object detection device 51 even if the position of the object AP changes in the vehicle width direction.

The attachment member 60 may include at least one of a sensor that detects the amount of expansion and contraction of the expandable member TA, and a sensor that detects the amount of rotation (rotation angle) of the rotation member SB.

Note that at least one of the telescopic member TA and the rotating member SB may be omitted. For example, the attachment member 60 may be configured to be non-extendable and non-rotatable. That is, the attachment member 60 may be a rod-shaped member that is neither extendable nor rotatable.

Further, the object detection device 51 may be directly attached to the asphalt finisher 100 without using the attachment member 60.

Further, the object detection device 51 may be configured as one device that can simultaneously monitor the ground on the left side of the asphalt finisher 100 and the ground on the right side of the asphalt finisher 100. Specifically, the object detection device 51 may be configured as one device that can simultaneously monitor the left object APL and the right object APR. In this case, the object detection device 51 may be attached to the center of the front end of the upper surface of the tractor 1.

The asphalt finisher 100 is also equipped with a steering angle sensor configured to detect the steering angle of the asphalt finisher 100, a screed expansion/contraction amount sensor configured to detect the amount of expansion/contraction of the rear screed 31, etc. It may be.

The in-vehicle display device 52 is configured to display information regarding the asphalt finisher 100. In the illustrated example, the in-vehicle display device 52 is a liquid crystal display installed in front of the driver's seat 1S. However, the in-vehicle display device 52 may include a display device installed on at least one of the left end and right end of the screed 3.

The steering device 53 is configured to be able to steer the asphalt finisher 100. In the illustrated example, the steering device 53 is configured to extend and retract a front wheel steering cylinder installed near the front axle. Specifically, the steering device 53 includes a steering electromagnetic control valve that controls the flow rate of hydraulic oil flowing from the hydraulic pump to the front wheel steering cylinder and the flow rate of hydraulic oil discharged from the front wheel steering cylinder. The steering electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic oil in the front wheel steering cylinders in accordance with the rotation of a steering wheel SH (steering wheel) serving as an operating device. The steering electromagnetic control valve is designed to control the inflow and outflow of hydraulic fluid in the front wheel steering cylinders in response to the operation of an input switch, which is an operating device separate from the steering wheel SH, regardless of the movement of the steering wheel SH. It may be configured as follows. Further, the steering electromagnetic control valve may be configured to be able to control the inflow and outflow of hydraulic fluid in the front wheel steering cylinders in response to a steering command from the controller 50, regardless of the rotation of the steering wheel SH. That is, the controller 50 may be configured to be able to automatically steer the asphalt finisher 100 regardless of whether or not the driver operates the steering wheel SH.

When the asphalt finisher 100 is a crawler-type asphalt finisher, the steering device 53 is configured to be able to separately control a pair of left and right crawlers. Note that the crawler-type asphalt finisher has a left operating lever, which is an operating device for operating the left crawler, and a right operating lever, which is an operating device for operating the right crawler, instead of the steering wheel SH.

Specifically, the steering device 53 includes a left steering electromagnetic control valve that controls the flow rate of hydraulic oil flowing from a hydraulic pump to a left travel hydraulic motor for rotating a left crawler, and a left steering electromagnetic control valve that rotates a right crawler from a hydraulic pump. and a right-hand steering electromagnetic control valve that controls the flow rate of hydraulic oil flowing to the right-hand driving hydraulic motor. The left steering electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic fluid in the left travel hydraulic motor according to the operation amount (inclination angle) of the left operation lever. Similarly, the right steering electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic fluid in the right travel hydraulic motor according to the operation amount (inclination angle) of the right operation lever. The left steering electromagnetic control valve is configured to control the inflow and outflow of hydraulic fluid in the left travel hydraulic motor in response to a steering command from the controller 50, regardless of whether or not the driver operates the left operation lever. may be configured. Similarly, the right steering electromagnetic control valve is configured to control the inflow and outflow of hydraulic fluid in the right travel hydraulic motor in response to a steering command from the controller 50, regardless of whether or not the driver operates the right operation lever. It may be configured as follows.

The screed expansion/contraction device 54 is configured to expand/contract the rear screed 31 in the vehicle width direction (Y-axis direction). In the illustrated example, the screed expansion/contraction device 54 is configured to expand/contract the screed expansion/contraction cylinder 7 installed in the screed 3 . Specifically, the screed expansion/contraction device 54 includes a screed expansion/contraction electromagnetic control valve that controls the flow rate of hydraulic oil flowing from the hydraulic pump to the screed expansion/contraction cylinder 7 and the flow rate of hydraulic oil discharged from the screed expansion/contraction cylinder 7. . The screed expansion/contraction electromagnetic control valve is configured to control the inflow and outflow of hydraulic oil in the screed expansion/contraction cylinder 7 in accordance with the operation of a telescoping button set (not shown) as an operating device provided near the on-vehicle display device 52. It is composed of The telescoping button set typically includes a left telescoping button set for telescoping the left rear screed 31L and a right telescoping button set for telescoping the right rear screed 31R. The screed expansion/contraction electromagnetic control valve may be configured to be able to control the inflow and outflow of hydraulic oil in the screed expansion/contraction cylinder 7 in response to expansion/contraction commands from the controller 50, regardless of the operation of the expansion/contraction button set. That is, the controller 50 may be configured to be able to automatically extend and retract the rear screed 31 regardless of whether or not the driver operates the telescopic button set.

Specifically, the screed expansion and contraction device 54 includes a left expansion and contraction electromagnetic control valve that controls the flow rate of hydraulic oil flowing from the hydraulic pump to the left screed expansion and contraction cylinder 7L for expanding and contracting the left rear screed 31L, and a left expansion and contraction electromagnetic control valve that controls the flow rate of hydraulic oil flowing from the hydraulic pump to the left screed expansion and contraction cylinder 7L for expanding and contracting the left rear screed 31L. It includes a right expansion/contraction electromagnetic control valve that controls the flow rate of hydraulic oil flowing into the right screed expansion/contraction cylinder 7R for expanding and contracting the rear screed 31R. The left telescoping electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic oil in the left screed telescoping cylinder 7L in accordance with the operation of the left telescoping button set. Similarly, the right telescopic solenoid control valve is configured to be able to control the inflow and outflow of hydraulic oil in the right screed telescopic cylinder 7R according to the operation details of the right telescopic button set. The left telescopic solenoid control valve is configured to control the inflow and outflow of hydraulic oil in the left screed telescopic cylinder 7L in response to a telescopic command from the controller 50, regardless of whether or not the driver operates the left telescopic button set. It may be configured as follows. Similarly, the right telescopic solenoid control valve can control the inflow and outflow of hydraulic fluid in the right screed telescopic cylinder 7R in response to a telescopic command from the controller 50, regardless of whether or not the driver operates the right telescopic button set. It may be configured as follows.

Next, with reference to FIG. 3, a configuration example of the operation support system DS installed in the asphalt finisher 100 will be described. FIG. 3 is a block diagram showing an example of the configuration of the operation support system DS.

The operation support system DS mainly includes a controller 50, a left object detection device 51L, a right object detection device 51R, a traveling speed sensor S1, an on-vehicle display device 52, a steering device 53, a screed expansion and contraction device 54, and the like.

In the example shown in FIG. 3, the controller 50 includes a coordinate calculation section 50a, a steering control section 50b, and a screed expansion/contraction control section 50c.

The coordinate calculation unit 50a is configured to calculate coordinates on the boundary line of the construction target range based on information regarding the feature acquired by the object detection device 51. The guide line GD shown by a thick broken line in FIG. 2 is an example of a boundary line of a road to be constructed, and is a virtual line representing a guide surface. The guide surface is a virtual surface that is recognized as a surface on which the end surfaces in the width direction of the pavement to be laid are to be aligned. In the example shown in FIG. 2, the guide line GD is the left guide line GDL representing the left guide surface, which is the surface with which the left end surface of the new pavement NP should be made to match, and the left guide line GDL, which is the surface with which the right end surface of the new pavement NP should be made to match. It includes a right guide line GDR representing a right guide surface.

Specifically, the coordinate calculation unit 50a calculates the coordinates on the guide line GD based on the information regarding the object AP acquired by the object detection device 51. More specifically, the coordinate calculation unit 50a calculates the coordinates of the point VL forming the left guide line GDL based on the information regarding the left object APL acquired by the left object detection device 51L, and also calculates the coordinates of the point VL forming the left guide line GDL. The coordinates of the point VR that constitutes the right guide line GDR are calculated based on the information regarding the right object APR that has been acquired.

For example, as shown in FIG. 4, the coordinate calculation unit 50a uses a virtual The right guide line GDR is generated using image recognition technology so that the line becomes the right guide line GDR. Then, the coordinate calculation unit 50a calculates the coordinates of the intersection of the generated right guide line GDR and the transverse line TL as the coordinates of the point VR. In the example shown in FIG. 4, the transverse line TL is a straight line that is parallel to the vehicle width direction (Y-axis direction) and intersects the center line (optical axis OA) of the right object detection device 51R. Note that FIG. 4 is a schematic perspective view of the paving formwork as the right object APR seen from the rear of the asphalt finisher 100, and schematically shows the positional relationship between the right object detection device 51R and the right object APR. ing.

For example, the coordinate calculation unit 50a uses a distance image related to the right monitoring range ZR generated based on the output of a stereo camera as the right object detection device 51R, and calculates a pixel including the intersection of the right guide line GDR and the transverse line TL. The coordinates of the point VR are calculated as the coordinates of the point VR. The distance image is a data set in which each pixel value of a two-dimensionally arranged pixel group is represented by the distance from the right object detection device 51R.

The coordinates of point VR are one coordinate in a predetermined coordinate system. The predetermined coordinate system is, for example, the world geodetic system. The world geodetic system is a three-dimensional orthogonal XYZ system with its origin at the center of gravity of the Earth, the X-axis pointing toward the intersection of the Greenwich meridian and the equator, the Y-axis pointing toward 90 degrees East longitude, and the Z-axis pointing toward the North Pole. It is a coordinate system. However, the predetermined coordinate system may be a local coordinate system whose origin is a predetermined point on the asphalt finisher 100. That is, the predetermined coordinate system may be a local coordinate system whose origin moves as the asphalt finisher 100 moves. Specifically, the predetermined coordinate system may be, for example, a three-dimensional orthogonal coordinate system whose origin is the center point of the asphalt finisher 100. In this case, the center point of the asphalt finisher 100 may be, for example, the center point of the tractor 1, or the intersection of the axle of the rear wheels 5 and the longitudinal axis AX (see FIG. 2). Further, the predetermined coordinate system may be a local coordinate system in which the origin does not move even if the asphalt finisher 100 moves. In this case, the local coordinate system may be a coordinate system whose origin is the center point of the asphalt finisher 100 at the time of starting construction. Further, the predetermined coordinate system may be a plane orthogonal coordinate system such as a survey plane coordinate system used in a total station or the like.

For example, the coordinate calculation unit 50a extracts a pixel whose difference from the pixel value on the left side is greater than or equal to a predetermined threshold value from among the pixels constituting the distance image, and calculates a single guide line GD from the arrangement of the plurality of extracted pixels. It may be configured to derive the line of the book. A line is a straight line, a curve, or a combination thereof. Any image recognition technique such as Hough transform can be used to derive a single line.

Note that the coordinate calculation unit 50a may perform averaging processing to eliminate the influence of portions where the positions of the extracted pixels vary. Specifically, such variations may occur in a portion of the image where two paving forms are in contact with each other, or in an image portion corresponding to an irregular portion of a cutting step.

In this example, the predetermined threshold is a threshold TH regarding the height of the paving formwork. In this case, the coordinate calculation unit 50a can generate, as the right guide line GDR, a virtual line representing the upper left edge of the right object APR, which is a paving formwork, and has a height H1 greater than or equal to the threshold TH, as shown in FIG. .

Note that the threshold value TH may be configured to be able to be set in advance according to the height of the paving formwork actually used. Utilization of the threshold value TH set according to the height of the paving formwork actually used makes it possible to generate guide lines based on the edges of the thin paving formwork. In addition, when using the threshold value TH set according to the height of the paving formwork actually used, the coordinate calculation unit 50a may incorrectly guide the user based on the shape (edge) of features other than the paving formwork. It is possible to suppress the generation of lines.

Thereafter, the coordinate calculation unit 50a calculates the coordinates of the intersection of the generated right guide line GDR and the transverse line TL as the coordinates of the point VR, as shown in FIG.

The above explanation relates to the process of calculating the coordinates of the point VR on the right guide line GDR from the distance image regarding the right monitoring range ZR, but the coordinates of the point VL on the left guide line GDL from the distance image regarding the left monitoring range ZL The same applies to the process of calculating .

Moreover, when the object detection device 51 is a monocular camera, the "distance image" in the above description can be read as "image". In this case, the "pixel value" is expressed not by distance but by color information or the like. The color information may be luminance.

In this way, the coordinate calculation unit 50a intermittently calculates and stores the coordinates of the points VL and VR. In the illustrated example, the coordinate calculation unit 50a is configured to calculate and store the coordinates of the point VL and the point VR each time the asphalt finisher 100 moves forward by a predetermined distance (for example, 15 cm). Note that the coordinate calculation unit 50a may be configured to calculate and store the coordinates of the point VL and the point VR each time a predetermined time elapses.

FIG. 1 shows how the coordinate calculation unit 50a intermittently calculates and stores the coordinates of a point VL. In FIG. 1, a point VL0 corresponds to a point VL derived by the coordinate calculation unit 50a based on the current output of the left object detection device 51L. Further, the point VL1 corresponds to the point VL derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at a certain point in the past. The same applies to points VL2 to VL4. Furthermore, the point VL11 corresponds to the point VL that the coordinate calculation unit 50a derives based on the output of the left object detection device 51L at a certain point in the future. The same applies to points VL12 to VL14. That is, at this moment, the coordinate calculation unit 50a has already calculated and stored the coordinate values of the point VL0 and the points VL1 to VL4.

Similarly to FIG. 1, FIG. 2 also shows how the coordinate calculation unit 50a intermittently calculates and stores the coordinates of the points VL and VR. In FIG. 2, point VR0 corresponds to point VR derived by the coordinate calculation unit 50a based on the current output of the right object detection device 51R. The same applies to point VL0. Further, the point VR1 corresponds to the point VR derived by the coordinate calculation unit 50a based on the output of the right object detection device 51R at a certain point in the past. The same applies to points VR2 to VR4. Further, the point VL1 corresponds to the point VL derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at a certain point in the past. The same applies to points VL2 to VL4. Furthermore, the point VR11 corresponds to the point VR that the coordinate calculation unit 50a derives based on the output of the right object detection device 51R at a certain point in the future. The same applies to points VR12 to VR14. Furthermore, the point VL11 corresponds to the point VL that the coordinate calculation unit 50a derives based on the output of the left object detection device 51L at a certain point in the future. The same applies to points VL11 to VL14.

The steering control unit 50b is configured to be able to automatically steer the asphalt finisher 100 regardless of operations on an operating device such as a travel speed dial. Note that the steering control unit 50b may be configured to be able to control the traveling speed of the asphalt finisher 100 when automatically steering the asphalt finisher 100. Furthermore, the steering control section 50b may be omitted.

The screed expansion/contraction control unit 50c is configured to automatically expand/contract the left and right expandable rear screeds 31, regardless of operations on operating devices such as a set of expansion/contraction buttons. Note that the screed expansion/contraction control unit 50c may be configured to automatically expand/contract the rear screed 31 according to the traveling speed and steering angle of the asphalt finisher 100 when the asphalt finisher 100 is automatically steered.

In the illustrated example, the screed expansion/contraction control unit 50c generates an expansion/contraction command for the screed expansion/contraction cylinder 7 based on the coordinates on the boundary line calculated and stored by the coordinate calculation unit 50a. The expansion/contraction command is, for example, a command regarding the expansion/contraction speed, a command regarding the amount of expansion/contraction, or a combination thereof.

Specifically, the screed expansion/contraction control unit 50c performs feedforward control of the amount of expansion/contraction of the rear screed 31. More specifically, the screed expansion/contraction control unit 50c expands/contracts the left screed expansion/contraction cylinder 7L so that the coordinates of a predetermined portion (for example, the left front end point) of the left rear screed 31L match the left target coordinates. The left target coordinates are an example of target coordinates, and are, for example, the coordinates of a point VL located at the closest position in front of a predetermined portion (for example, the left front end point) of the left rear screed 31L. Further, the screed expansion/contraction control unit 50c expands/contracts the right screed expansion/contraction cylinder 7R so that the coordinates of a predetermined portion (for example, the right front end point) of the right rear screed 31R match the right target coordinates. The right target coordinates are another example of target coordinates, and are, for example, the coordinates of a point VR located at the closest position in front of a predetermined portion (for example, the right front end point) of the right rear screed 31R. Further, the screed expansion/contraction control section 50c may be configured to determine the expansion/contraction speed according to the traveling speed of the asphalt finisher 100 detected by the traveling speed sensor S1.

Note that the coordinates of a predetermined portion of the rear screed 31, such as the coordinates of the left front end point of the left rear screed 31L and the coordinates of the right front end point of the right rear screed 31R, are the same as the coordinates of the point VL and the point VR. It can be calculated by the coordinate calculation unit 50a. Specifically, the coordinate calculation unit 50a calculates the relative position of the object detection device 51 with respect to the position of a reference point such as the center point of the tractor 1, based on the amount of expansion and contraction of the telescopic member TA that positions the object detection device 51. can. Similarly, the coordinate calculation unit 50a calculates the relative positions of the left front end point of the left rear screed 31L and the right front end point of the right rear screed 31R with respect to the position of the reference point, based on the amount of expansion and contraction of the rear screed 31. It can be calculated. Further, the coordinate calculation unit 50a can calculate the relative position of the reference point at the second time point with respect to the position of the reference point at the first time point based on the outputs of the traveling speed sensor S1, the steering angle sensor, and the like. Therefore, the coordinate calculation unit 50a calculates the points VL, VR, the left front end point of the left rear screed 31L, and the right front end point of the right rear screed 31R at other times with respect to the position of the reference point at the first time point. Relative position can be calculated.

Next, with reference to FIG. 5, a process in which the controller 50 sets a target for expanding and contracting the rear screed 31 (hereinafter referred to as "target setting process") will be described. FIG. 5 is a flowchart showing an example of the flow of goal setting processing. The controller 50 repeatedly executes this target setting process at a predetermined control cycle.

First, the controller 50 acquires vehicle body coordinates (step ST1). The vehicle body coordinates mean the coordinates of a predetermined part of the asphalt finisher 100, and include the coordinates of the left front end point of the left rear screed 31L and the coordinates of the right front end point of the right rear screed 31R. Contains coordinates.

Specifically, the controller 50 stores the center point of the asphalt finisher 100 at a first point in time, such as the start of construction, as a reference point.

During construction, the controller 50 can derive the relative position of the center point of the asphalt finisher 100 and the orientation of the asphalt finisher 100 at any point in time, such as the current moment, based on the outputs of the traveling speed sensor S1 and the steering angle sensor. Note that the relative position of the center point means the relative position of the center point with respect to the reference point. The same applies to the following description.

In the illustrated example, the controller 50 can derive the coordinates of the turning center based on the output of the steering angle sensor. Then, the controller 50 can derive the relative position of the center point of the asphalt finisher 100 and the direction of the asphalt finisher 100 at an arbitrary point in time, such as the current moment, based on the coordinates of the turning center and the output of the traveling speed sensor S1. Note that the controller 50 derives the travel distance or change in attitude based on the output of an IMU (Inertial Measurement Unit), a GNSS (Global Navigation Satellite System), or a surveying device (not shown) mounted on the asphalt finisher 100. It may be configured as follows. Furthermore, the controller 50 adjusts the asphalt finisher at any given time based on the relative position of the center point of the asphalt finisher 100 and the orientation of the asphalt finisher 100 at any given time, and the known dimensions of each member constituting the asphalt finisher 100. The relative positions of 100 predetermined regions can be derived. The relative position of the predetermined portion of the asphalt finisher 100 includes the relative position of the left object detection device 51L and the relative position of the right object detection device 51R.

After acquiring the vehicle body coordinates, the controller 50 acquires the feature coordinates (step ST2). The feature coordinates refer to the coordinates of a feature such as the object AP, and include coordinates on the left boundary line of the road to be constructed, coordinates on the right boundary line of the road to be constructed, and the like.

Specifically, the controller 50 detects the left side of the road to be constructed based on the relative position of the center point of the asphalt finisher 100 and the orientation of the asphalt finisher 100 at any time and the output of the object detection device 51 at any time. The coordinates of point VL, which are the coordinates on the boundary line, and the coordinates of point VR0, which are the coordinates on the right boundary line of the road to be constructed, can be calculated.

After acquiring the vehicle body coordinates and the feature coordinates, the controller 50 sets a target (step ST3). In the illustrated example, the controller 50 calculates a target value for the amount of expansion and contraction of the rear screed 31.

Specifically, based on the relative position of the center point of the asphalt finisher 100 and the orientation of the asphalt finisher 100 at the present time, the controller 50 moves the screed to the position closest to the front of a predetermined portion (for example, the left front end point) of the left rear screed 31L. The distance between a certain point VL and the longitudinal axis AX as the central axis of the asphalt finisher 100 (hereinafter referred to as the "first distance") is derived. Further, the controller 50 determines the relationship between a predetermined portion of the left rear screed 31L (for example, the left front end point) and the longitudinal axis AX of the asphalt finisher 100 based on the relative position of the center point of the asphalt finisher 100 and the orientation of the asphalt finisher 100 at the present time. The distance between them (hereinafter referred to as the "second distance") is derived. Then, the controller 50 sets the difference between the first distance and the second distance as the target expansion/contraction amount. Specifically, when the first distance is larger than the second distance, the controller 50 sets the difference between the first distance and the second distance as the target extension amount, and when the first distance is smaller than the second distance, the controller 50 sets the difference between the first distance and the second distance as the target extension amount. , the difference between the first distance and the second distance is set as the target contraction amount.

The controller 50 also determines the distance in the traveling direction between a predetermined portion (for example, the left front end point) of the left rear screed 31L and the closest point VL in front of the predetermined portion (hereinafter referred to as a “third distance”). ) to determine the expansion/contraction speed. Specifically, the controller 50 causes the expansion/contraction speed to increase as the third distance increases, provided that the target expansion/contraction amount is the same.

Alternatively, the controller 50 predicts the position of a predetermined part (for example, the left front end point) of the left rear screed 31L after a predetermined time (for example, 1 second), and predicts the position of the predetermined part (for example, the front left end point) of the left rear screed 31L after a predetermined time, A line segment connecting the point VL and the closest point VL behind it may be derived. Then, the controller 50 may set the distance between the interpolation point on the line segment (the point at which the two points VL are interpolated) and the longitudinal axis AX as the first distance.

With this configuration, the controller 50 can grasp the position of the boundary line in front of the screed 3, and therefore can extend and contract the rear screed 31 at appropriate timing. Therefore, since the controller 50 can suppress or prevent the expansion and contraction of the rear screed 31 from being delayed when the construction width changes, construction accuracy can be improved.

With the above-described configuration, the screed expansion/contraction control unit 50c moves the left rear screed 31L so that the coordinates of the left front end point of the left rear screed 31L match the coordinates on the guide line GD when the asphalt finisher 100 moves forward by a predetermined distance. can be expanded and contracted. That is, the screed expansion/contraction control unit 50c controls the point VL and the left front end point of the left rear screed 31L when the distance in the traveling direction between the point VL and the left front end point of the left rear screed 31L at any time becomes zero. The amount of expansion and contraction of the left rear screed 31L can be controlled so that the distance in the vehicle width direction between it and the front end point becomes zero.

Similarly, the screed expansion/contraction control unit 50c controls the screed expansion/contraction control unit 50c to move the right rear side so that the coordinates of the right front end point of the right rear side screed 31R match the coordinates of the nearest point VR in front of the asphalt finisher 100 when the asphalt finisher 100 moves forward by a predetermined distance. The screed 31R can be expanded and contracted. That is, when the distance in the traveling direction between point VR and the right front end point of the right rear screed 31R at any time becomes zero, the screed expansion/contraction control unit 50c controls the screed expansion/contraction control unit 50c to The amount of expansion and contraction of the right rear screed 31R can be controlled so that the distance in the vehicle width direction between it and the front end point becomes zero.

As described above, the asphalt finisher 100, which is an example of a road machine according to an embodiment of the present disclosure, includes a tractor 1 and is installed in front of the tractor 1 to receive paving material PV, as shown in FIGS. 1 and 2. hopper 2, a conveyor CV that feeds the paving material PV in the hopper 2 to the rear of the tractor 1, a screw SC that spreads the paving material PV fed by the conveyor CV behind the tractor 1, and a screw SC that spreads the paving material PV fed by the conveyor CV to the rear of the tractor 1; Based on information about the screed 3 that spreads the expanded paving material PV behind the screw SC and the feature (object AP) that defines the boundary line (guide line GD) of the construction target area located in front of the screed 3. and a control device (controller 50) that calculates coordinates on a boundary line (guide line GD) in a predetermined coordinate system.

Furthermore, in the asphalt finisher 100, the screed 3 is configured to be expandable and contractible in the vehicle width direction. Therefore, the controller 50 can expand and contract the screed 3 so that the coordinates on the boundary line (guide line GD) match the coordinates of the end of the screed 3.

With this configuration, the controller 50 can recognize a change in the direction of the boundary line (guide line GD) before the screed 3 reaches the part where the direction of the boundary line (guide line GD) changes. Therefore, compared to the case where the controller 50 recognizes that there is a gap between the end of the screed 3 and the boundary line (guide line GD) and then expands and contracts the screed so that the gap becomes smaller, The amount of expansion and contraction of the screed 3 can be appropriately controlled. In other words, the controller 50 can suppress the occurrence of a gap between the end of the screed 3 and the boundary line (guide line GD).

Furthermore, in the asphalt finisher 100, the controller 50 may be configured to calculate coordinates on the boundary line (guide line GD) every time the tractor 1 moves forward by a predetermined distance. In the example shown in FIG. 2, the controller 50 is configured to intermittently calculate and store the coordinates of the points VL and VR on the boundary line (guide line GD).

This configuration has the effect of suppressing an unnecessarily large computation load regarding calculation of coordinates.

In other words, the controller 50 makes the coordinates on the boundary line (guide line GD) calculated at the first time point the target coordinates of the end of the screed 3 at the second time point after the first time point. The screed 3 is configured to expand and contract as shown in FIG.

With this configuration, the controller 50 can recognize a change in the direction of the boundary line (guide line GD) before the screed 3 reaches the part where the direction of the boundary line (guide line GD) changes. Therefore, this configuration has the effect that the amount of expansion and contraction of the screed 3 can be controlled more appropriately.

The asphalt finisher 100 may also include an object detection device 51 that acquires information regarding a feature (object AP) that defines the boundary line (guide line GD) of the road to be constructed that is located ahead of the screed 3. . The object detection device 51 may be placed further forward than the screed 3. In the example shown in FIG. 2, the object detection device 51 is arranged in front of the tractor 1, which is in front of the screed 3.

With this configuration, before the screed 3 reaches the part where the direction of the boundary line (guide line GD) changes, the object detection device 51 collects information regarding that part (for example, relative position with respect to the vehicle body (tractor 1), distance image, or images, etc.). Therefore, this configuration has the effect that the controller 50 can recognize a change in the direction of the boundary line (guide line GD) before the screed 3 reaches the part where the direction of the boundary line (guide line GD) changes. bring.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above. Various modifications or substitutions may be made to the embodiments described above without departing from the scope of the present invention. Furthermore, the features described with reference to the above-described embodiments may be combined as appropriate unless technically inconsistent.

For example, in the embodiment described above, the object detection device 51 is configured to acquire information regarding the feature (object AP) that defines the boundary line (guide line GD) of the construction target range located in front of the screed 3. ing. However, the controller 50 may be configured to acquire information regarding the feature (object AP) from design data or the like stored in advance in a volatile storage device or a nonvolatile storage device. In this case, acquisition of information regarding the terrestrial feature (object AP) by the object detection device 51 may be omitted.

Further, in the embodiment described above, the object detection device 51 is attached to the asphalt finisher 100, but it may be attached to a moving body other than the asphalt finisher 100, such as a vehicle or a multicopter.

1...Tractor 1S...Driver's seat 2...Hopper 3...Screed 3A...Leveling arm 3AL...Left leveling arm 3AR...Right leveling arm 5...Rear wheel 6...・Front wheel 7...Screed telescopic cylinder 7L...Left screed telescopic cylinder 7R...Right screed telescopic cylinder 30...Front side screed 30L...Left front screed 30R...Right front screed 31...Rear Side screed 31L...Left rear screed 31R...Right rear screed 32...Tread plate 32C...Central tread 32L...Left tread 32R...Right tread 41...Side plate 41L...・Left side plate 41R...Right side plate 42...Mold board 42L...Left mold board 42R...Right mold board 43...Retaining plate 43L...Left retaining plate 43R... Right retaining plate 50... Controller 50a... Coordinate calculation section 50b... Steering control section 50c... Screed expansion/contraction control section 51... Object detection device 51L... Left object detection device 51R... Right object detection device 52... Vehicle-mounted display device 53... Steering device 54... Screed expansion/contraction device 60... Mounting member 60L... Left mounting member 60R... Right mounting member 100... Asphalt finisher AP...Object APL...Left object APL1...First left object APL2...Second left object APR...Right object APR1...First right object APR2...Second right object AX ...Longitudinal axis BS...Roadbed CL...Center line CV...Conveyor DS...Operation support system GD...Guide line GDL...Left guide line GDR...Right guide line NP・...New pavement body PV...Paving material S1...Traveling speed sensor SB, SBa...Rotating member SC...Screw SC...Screw SCL...Left extension screw SCR...Right extension Screw SH... Steering wheel TA... Telescopic member ZL... Left monitoring range ZR... Right monitoring range

Claims (5)

tractor and
a hopper installed in front of the tractor to receive paving material;
a conveyor that feeds the paving material in the hopper to the rear of the tractor;
a screw that spreads the paving material fed by the conveyor behind the tractor;
a screed for leveling the paving material spread by the screw behind the screw;
a control device that calculates coordinates on the boundary line in a predetermined coordinate system based on information about features that define the boundary line of the construction target area located ahead of the screed;
road machinery. The screed is expandable and contractible in the vehicle width direction,
The control device expands and contracts the screed so that the coordinates on the boundary line match the coordinates of the end of the screed.
The road machine according to claim 1. The control device calculates coordinates on the boundary line each time the tractor moves forward by a predetermined distance.
The road machine according to claim 1 or 2. The control device expands and contracts the screed so that the coordinates on the boundary line calculated at the first time point become the target coordinates of the end of the screed at a second time point after the first time point.
The road machine according to claim 1 or 2. comprising an object detection device that acquires information regarding a feature that defines the boundary line of the construction target area located in front of the screed,
The object detection device is arranged ahead of the screed.
The road machine according to claim 1 or 2.

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