Screed Control Device

Abstract

To provide a screed controller capable of controlling screed leveling when evenly laying an asphalt mixture or the like without preparatory work such as setting of a reference line in advance and without requiring cost and labor.SOLUTION: A screed control device 100 for controlling the level (vertical position) of a screed provided behind a leveling vehicle that levels a pavement material of a road, includes: an optical range-finding unit 200 attached to the screed that uses light to detect distance data between a plurality of points; a data processing unit 110 that processes the distance data between the points acquired by the optical range-finding unit 200, estimates two different planes along a traveling direction of a road, and obtains, as a reference line, the line where the two planes intersect; a leveling cylinder that adjusts the level of the screed; and a cylinder control unit 170 that controls the leveling cylinder based on the reference line obtained by the data processing unit 110.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a screed control device that controls a screed in a leveling vehicle. [Background technology]

[0002] Conventionally, in road paving work, the asphalt mixture is loaded onto the bed of a dump truck and transported to the construction site. The dump truck is then coupled to an asphalt finisher and the asphalt mixture is unloaded. The asphalt finisher then spreads the asphalt mixture evenly and compacts it with a roller.

[0003] In order to adjust the level of the paved surface of the asphalt mixture to a predetermined level (vertical position), a reference line is set in advance, and the leveled surface is controlled to be at a predetermined level along the reference line. In other words, the leveled surface is aligned with the reference line, and the distance (distance) between the vertical position (level) of the leveled surface and the reference line is always constant.

[0004] However, particularly in the paving of bridges, there is a problem in that the walls of structures exist at the edges of the road where the asphalt mixture is to be spread, making it difficult to install wires as reference lines.

[0005] Therefore, for example, cited document 1 (JP Patent Publication No. 2008-285962) proposes a technology for controlling an attitude adjustment device (leveling cylinder and arm) that adjusts the attitude of a leveling device 1 (screed) provided at the rear of a traveling vehicle, which includes a reference electric wire 2 extended along the direction in which the leveling device 1 is moved, a power supply unit 4 that supplies power to the reference electric wire 2, and a detector 3 (3b) that moves close to the reference electric wire 2 and detects the magnetic field generated by the current flowing through the reference electric wire 2, and controlling the attitude adjustment device so that the vertical position of the detector 3 relative to the reference electric wire 2 is constant based on the detection results. [Patent Document 1] JP 2008-285962 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional technology proposed in the cited document 1, the reference electric wire 2 must be attached to the side of the balustrade A with adhesive tape 2a, but this work is very time-consuming and places a heavy burden on the workers. In addition, the adhesive tape 2a is easily peeled off from the balustrade A, which is usually made of concrete, and if the tensioned reference electric wire 2 is handled incorrectly, the reference electric wire 2 easily falls off the balustrade A, and the work must be redone. In addition, because the reference electric wire 2 is attached with adhesive tape 2a, there is a risk that it will fall off due to weather conditions such as rain. [Means for solving the problem]

[0007] In order to solve the above problems, the screed control device of the present invention is a screed control device that controls the level (vertical position) of a screed provided behind a paving vehicle that spreads paving material on roads, and includes an optical distance measuring unit that is attached to the screed and detects distance data between multiple points using light, a data processing unit that processes the distance data of the multiple points obtained by the optical distance measuring unit, estimates two different surfaces along the road traveling direction, and determines the line where the two surfaces intersect as a reference line, a leveling cylinder that adjusts the level of the screed, and a cylinder control unit that controls the leveling cylinder based on the reference line determined by the data processing unit. The optical distance measuring unit emits a scanning laser beam in a circumferential direction and receives the returned laser beam to obtain distance data. The optical distance measuring unit is attached to the screed so that the scanning laser beam of the optical distance measuring unit scans a cross section perpendicular to the traveling direction of the vehicle. It is characterized by:

[0008] Further, the screed control device according to the present invention is a screed control device that controls the level (vertical position) of a screed provided behind a paving vehicle that spreads paving material on a road, and includes an optical distance measuring unit that is attached to the screed and detects distance data between a plurality of points using light, an inclination sensor that is attached to the screed and detects inclination angle data of the screed, a data processing unit that processes the distance data of the plurality of points acquired by the optical distance measuring unit and the inclination angle data of the screed detected by the inclination sensor, estimates two different planes along the traveling direction of the road, and determines the line where the two planes intersect as a reference line, a leveling cylinder that adjusts the level of the screed, and a cylinder control unit that controls the leveling cylinder based on the reference line determined by the data processing unit. The optical distance measuring unit emits a scanning laser beam in a circumferential direction and receives the returned laser beam to obtain distance data. The optical distance measuring unit is attached to the screed so that the scanning laser beam of the optical distance measuring unit scans a cross section perpendicular to the traveling direction of the vehicle. It is characterized by:

[0009] The screed control device according to the present invention is characterized in that a LIDAR is used in the optical distance measuring unit. Effect of the Invention

[0010] The screed control device of the present invention processes distance data from multiple points obtained by an optical distance measuring unit, estimates two different surfaces along the road's direction of travel, and obtains the line where the two surfaces intersect as a reference line. Therefore, with this screed control device of the present invention, there is no need for any advance preparation work such as attaching a reference electric wire to the side of the parapet with adhesive tape, and it becomes possible to easily control the leveling of the screed when spreading asphalt mixtures, etc., without incurring any cost or effort. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an asphalt finisher 10 to which a screed control device 100 according to an embodiment of the present invention is applied. [Diagram 2] FIG. 1 is a block diagram of a screed control device 100 according to an embodiment of the present invention. [Diagram 3]1 is a schematic diagram of an asphalt finisher 10 to which a screed control device 100 according to an embodiment of the present invention is applied, viewed from the rear. FIG. [Figure 4] FIG. 1 is a diagram showing an example of a concrete bridge 50. [Diagram 5] FIG. 2 is a diagram showing an example of a flowchart of a control process by the screed control device 100 according to the embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing how a first surface and a second surface are estimated, and how a reference line is extracted as the intersection line of these surfaces. [Figure 7] FIG. 11 is a schematic diagram showing an asphalt finisher 10 to which a screed control device 100 according to a second embodiment of the present invention is applied, as viewed from the rear. [Figure 8] FIG. 4 is a block diagram of a screed control device 100 according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing an example of a flowchart of a control process by the screed control device 100 according to a second embodiment of the present invention. [Figure 10] FIG. 13 is a diagram showing an image of correction of distance data at a plurality of points using tilt angle data. [Figure 11] FIG. 2 is a diagram showing an example of a concrete foundation 80. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing an asphalt finisher 10 to which a screed control device 100 according to an embodiment of the present invention is applied.

[0013] The screed control device 100 according to the present invention can be suitably used in a paving and leveling vehicle equipped with a screed, such as an asphalt finisher, a concrete finisher, etc. In this embodiment, the paving and leveling vehicle will be described using an asphalt finisher 10 as an example, but the scope of application of the screed control device 100 according to the present invention is not limited to this example.

[0014] The asphalt finisher 10, which is a paving and leveling vehicle, comprises a hopper section 13 that loads the asphalt mixture received from a dump truck 30, a traveling section 15 having a traveling device, and a screed 20 that spreads the asphalt mixture. A driver's seat 16 for the operator of the asphalt finisher 10 is provided in the traveling section 15.

[0015] The asphalt finisher 10 also has a leveling arm 23 that supports the screed 20 on the vehicle body, and a leveling cylinder 4 that changes the height of the screed 20. The screed control device 100 according to the present invention is configured to output a control command to the above-mentioned leveling cylinder 25 that changes the level of the screed 20 in order to bring the paving surface to a predetermined level (vertical position).

[0016] Fig. 2 is a block diagram of the screed control device 100 according to an embodiment of the present invention. Also, Fig. 3 is a schematic diagram of an asphalt finisher 10 to which the screed control device 100 according to an embodiment of the present invention is applied, viewed from the rear.

[0017] In Fig. 2, the information processing device 105 in the screed control device 100 can be, for example, a general-purpose notebook computer comprising a CPU, a ROM for holding programs that run on the CPU, a RAM that is the work area of ​​the CPU, a large-capacity storage unit such as an HDD or SSD, a communication unit, etc. Such an information processing device 105 communicates data with each of the components connected in Fig. 2, and is capable of receiving predetermined data from each of the components to perform calculations and outputting the predetermined data as commands, etc.

[0018] The instruction input unit 120 is an input means such as a keyboard or a pointing device provided in the information processing device 105, and the display unit 160 is a display provided in the information processing device 105. The instruction input unit 120 and the display unit 160 function as a user interface for the screed control device 100. This allows the user of the screed control device 100 to specify, for example, the difference between the pavement surface level of the leveling cylinder 25 and a reference line.

[0019] Furthermore, some of the components of the screed control device 100 according to the present invention may be a program that operates on the information processing device 105. The data processing unit 110 calculates a reference line based on a plurality of distance data acquired from the optical distance measuring unit 200, and further operates the cylinder control unit 170 based on this calculated reference line. Such a cylinder control unit 170 may be a program that operates on the information processing device 105. The cylinder control unit 170 outputs a control command to the leveling cylinder 25 that changes the level of the screed 20.

[0020] In this embodiment, a general-purpose laptop is used as the information processing device 105, but the screed control device 100 according to the present invention can also be configured using dedicated hardware.

[0021] For example, a two-dimensional LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) sensor can be used as the optical distance measuring unit 200. In Fig. 3, an enlarged view of the optical distance measuring unit 200 using LIDAR is shown in a dashed line frame.

[0022] The optical distance measuring unit (LIDAR) 200 is composed of a main body 203 and a cover 205 that transmits laser light. A laser light emitting element (not shown) that emits laser light is provided inside the main body 203. A mirror 207 that rotates by a motor (not shown) is provided inside the cover 205, and as the mirror 207 rotates, a laser light for scanning is emitted from the cover 205 in the circumferential direction of 360° of the cylindrical cover 205.

[0023] The laser light, which hits the target from the cover 205, is scattered, and returns to the LIDAR side. It passes through the cover 205, is reflected by the mirror 207, and is detected by a laser receiving element (not shown) provided in the main body 203. The LIDAR sensor receives the laser reflected from the target in this way, and obtains data (point cloud data) related to the distance between the target and the LIDAR sensor, for example, by TOF (Time of Flight). The mirror 207 rotates about 10 times per second to scan the surroundings, and thus, it is possible to obtain hundreds to thousands of pieces of distance data per second. For example, TiM510 manufactured by SICK can be used as the optical distance measuring unit (LIDAR) 200 of the screed control device 100 according to the present invention. A plurality of distance data obtained by the optical distance measuring unit 200 are input to the data processing unit 110, processed, and used for controlling the cylinder control unit 170.

[0024] In this embodiment, a two-dimensional LIDAR sensor is used as the LIDAR sensor of the optical distance measuring unit 200, but a three-dimensional LIDAR sensor may also be used, and a type in which the mirror 207 is not mechanically driven may also be used.

[0025] The optical distance measuring unit 200 as described above is attached to the screed 20, for example, as shown in Figure 3. Figure 3 is a view of the screed 20 viewed from the rear side of the asphalt finisher 10. In the screed control device 100 according to the present invention, the optical distance measuring unit 200 is attached to the screed 20 so that it scans a vertical cross section in the direction of travel of the vehicle (the direction toward the back of the paper in Figure 3). The dotted arrow in Figure 3 is an image of the laser light emitted from the optical distance measuring unit 200.

[0026] Here, a road on which a concrete bridge 50 is used will be described as an example of a road on which an asphalt mixture is laid by an asphalt finisher 10 equipped with a screed control device 100 according to the present invention.

[0027] Fig. 4 is a diagram showing an example of a concrete bridge 50. Fig. 4 shows only one side of a balustrade 55 of the concrete bridge 50. The concrete bridge 50 is manufactured in a factory or the like by a precast method or the like, and after being transported and installed at the site, an asphalt mixture is spread and leveled. The concrete bridge 50 has a deck 53 extending in a horizontal plane, and left and right balustrades 55 erected from the deck 53.

[0028] The deck section 53 is provided with an asphalt laying section 68 where it is expected that an asphalt mixture will be laid and leveled. The parapet section 55 is provided with a parapet top surface 66, and it is conceivable to provide a wire on this parapet top surface 66 as a reference line for bringing the leveling surface to a predetermined level. However, in reality, there are many cases in which a structure such as a soundproof wall is already installed on the parapet top surface 66, making it difficult to provide a reference line for a wire on the parapet top surface 66.

[0029] In the screed control device 100 according to the present invention, a line that is guaranteed to have a certain height and that is aligned with the direction of the lane of the road is extracted as a reference line based on a plurality of distance data acquired by the optical distance measuring unit 200. In general, a first inner wall surface 61 and a second inner wall surface 62 that is provided at a predetermined angle to the first inner wall surface 61 are formed inside the concrete bridge 50. In this embodiment, the first inner wall surface 61 and the second inner wall surface 62 are estimated based on the distance data acquired by the optical distance measuring unit 200, and a line where these surfaces intersect is obtained and used as a "reference line" when adjusting the setting of the leveling cylinder 25. In this embodiment, the reference line is obtained from the intersection line between the first inner wall surface 61 and the second inner wall surface 62, but the reference line can also be obtained using the other two surfaces.

[0030] FIG. 5 is a diagram showing an example of a flowchart of a control process by the screed control device 100 according to the embodiment of the present invention.

[0031] In FIG. 5, when the control process is started in step S100, the process proceeds to step S101, where distance data for a plurality of points is acquired from the optical distance measuring unit 200.

[0032] In step S102, the first surface is estimated from distance data of multiple points acquired from the optical distance measuring unit 200. Fig. 6 is a diagram showing the estimation of the first and second surfaces and the extraction of a reference line as the intersection line of these surfaces. In step S102, the position of the surface indicated by P, which is the first surface, is calculated and estimated from the distance data of multiple points.

[0033] Next, in step S103, the second surface is estimated from the distance data of the multiple points. In this step, the position of the surface indicated by Q, which is the second surface, is calculated and estimated from the distance data of the multiple points.

[0034] Next, in step S104, the line where the first plane P and the second plane Q intersect is extracted as a reference line 70, and in step S105, a control command is output from the cylinder control unit 170 to the leveling cylinder 25 based on the reference line 70.

[0035] In step S106, it is determined whether or not an end instruction has been issued by the user via instruction input unit 120. If the result of this determination is NO, the process returns to step S101 and loops. On the other hand, if the result of the determination is YES, the process proceeds to step S107 and ends the control process.

[0036] As described above, the screed control device 100 of the present invention processes distance data of multiple points acquired by the optical distance measuring unit 200, estimates two different surfaces along the road travel direction, and obtains the line where the two surfaces intersect as the reference line 70. Therefore, with the screed control device 100 of the present invention, there is no need for any advance preparation work such as attaching a reference electric wire to the side of the parapet with adhesive tape, and it becomes possible to easily control the leveling of the screed when spreading asphalt mixtures, etc., without incurring any cost or effort.

[0037] Next, another embodiment of the present invention will be described. In roads where asphalt mixture is laid and leveled, the surface to be leveled may have an inclination, and the inclination may vary depending on the position in the lane direction. In this case, the previous embodiment has a problem that the reference line cannot always be accurately extracted. The screed control device 100 according to the second embodiment described below solves such a problem.

[0038] Fig. 7 is a schematic diagram of an asphalt finisher 10 to which a screed control device 100 according to a second embodiment of the present invention is applied, viewed from the rear. Fig. 8 is a block diagram of the screed control device 100 according to the second embodiment of the present invention. In the figure, components with the same reference numbers as those in the previous embodiment are the same as those in the previous embodiment.

[0039] In the screed control device 100 according to the second embodiment, in addition to the optical distance measuring unit 200, the screed 20 is fitted with an inclination sensor 220 capable of acquiring inclination angle data. The inclination sensor 220 detects the inclination state of the screed 20, i.e., the inclination state of the optical distance measuring unit 200 itself. The inclination angle data acquired by the inclination sensor 220 is transmitted to the data processing unit 110 as shown in Fig. 8 and used for control by the cylinder control unit 170.

[0040] Next, a description will be given of a control example of the screed control device 100 according to the second embodiment configured as above. Fig. 9 is a diagram showing an example of a flowchart of a control process by the screed control device 100 according to the second embodiment of the present invention.

[0041] In FIG. 9, when the control process is started in step S200, the process proceeds to step S201, where distance data for a plurality of points is obtained from the optical distance measuring unit 200, and tilt angle data is obtained from the tilt sensor 220 in step S202.

[0042] Next, in step S203, the distance data for multiple points acquired from optical distance measuring unit 200 is corrected based on the tilt angle data acquired from tilt sensor 220. Figure 10 is a diagram showing an image of correction of distance data for multiple points based on tilt angle data.

[0043] Fig. 10(A) shows distance data for multiple points before correction using tilt angle data. Here, the positions of the x's indicate the measurement points for distance data acquired by optical distance measuring unit 200. Before correction, tilt sensor 220 detects a tilt of α° to the right on the page relative to the horizontal. When such a tilt of α° is detected, the distance data for multiple points is corrected by rotating α° to the left on the page around optical distance measuring unit 200, as shown in Fig. 10(B).

[0044] In step S204, the first surface is estimated from the distance data of the multiple points corrected as described above. Fig. 11 is a diagram showing an example of a concrete foundation 80 on which an asphalt mixture is to be spread evenly. The concrete foundation 80 has an asphalt laying portion 88 that is expected to be spread evenly, and a curbstone 81 provided on both edges (only one is shown in the figure) of the asphalt laying portion 88. The curbstone 81 has an inner surface 83 and a top surface 84. In step S204, the position of the surface indicated by P (inner surface 83), which is the first surface, is calculated and estimated from the distance data of the multiple points corrected.

[0045] Next, in step S205, the second surface is estimated from the corrected distance data of the multiple points. In this step, the position of the surface indicated by Q (top surface 84), which is the second surface, is calculated and estimated from the distance data of the multiple points.

[0046] Next, in step S206, the line where the first plane P and the second plane Q intersect is extracted as a reference line 90, and in step S207, a control command is output from the cylinder control unit 170 to the leveling cylinder 25 based on the reference line 90.

[0047] In step S208, it is determined whether or not an end instruction has been issued by the user via the instruction input unit 120. If the result of this determination is NO, the process returns to step S201 and loops. On the other hand, if the result of the determination is YES, the process proceeds to step S209 and ends the control process.

[0048] The screed control device 100 according to the second embodiment described above provides the same effects as the previous embodiment and, furthermore, in cases where the surface on which the asphalt mixture is to be spread has a slope, it becomes possible to accurately control the leveling of the screed. [Explanation of symbols]

[0049] 10. Asphalt finisher 13 Hopper section 15...Running section 16. Cockpit 20. Screed 25···Leveling cylinder 30···Dump truck 35... Cargo area 50. Concrete bridge 53...floor slab section 55···Balustrade 61...First inner wall surface 62...Second inner wall surface 66....Parapet top 68 Asphalt laying section 70... Reference line 80...Concrete foundation 81...Curb 83...Inner side (first side) 84···Top surface (2nd surface) 88 Asphalt laying section 90... Reference line 100 Screed control device 105 Information processing device 110 Data processing unit 120...Instruction input section 160...Display section 170···Cylinder control section 200...Light distance measurement section (LIDAR) 203 Main body 205···Cover 207...Mirror 220 Tilt sensor

Claims

1. A screed control device for controlling the level (vertical position) of a screed provided behind a paving vehicle that spreads pavement material on a road, An optical distance measuring unit attached to the screed and detecting distance data between a plurality of points using light; a data processing unit that processes distance data of a plurality of points acquired by the optical distance measuring unit, estimates two different planes along a traveling direction of a road, and obtains a line where the two planes intersect as a reference line; A leveling cylinder to adjust the screed level; a cylinder control unit that controls the leveling cylinder based on the reference line obtained by the data processing unit, The optical distance measuring unit emits a scanning laser beam in a circumferential direction and receives the returned laser beam to obtain distance data, A screed control device characterized in that the optical distance measuring unit is attached to the screed so that a scanning laser light of the optical distance measuring unit scans a cross section perpendicular to the traveling direction of the vehicle.

2. A screed control device for controlling the level (vertical position) of a screed provided behind a paving vehicle that spreads pavement material on a road, An optical distance measuring unit attached to the screed and detecting distance data between a plurality of points using light; An inclination sensor attached to the screed for detecting inclination angle data of the screed; a data processing unit that processes distance data of a plurality of points acquired by the optical distance measuring unit and inclination angle data of the screed detected by the inclination sensor, estimates two different planes along the road traveling direction, and determines the line where the two planes intersect as a reference line; A leveling cylinder to adjust the screed level; a cylinder control unit that controls the leveling cylinder based on the reference line obtained by the data processing unit, The optical distance measuring unit emits a scanning laser beam in a circumferential direction and receives the returned laser beam to obtain distance data, A screed control device characterized in that the optical distance measuring unit is attached to the screed so that a scanning laser light of the optical distance measuring unit scans a cross section perpendicular to the traveling direction of the vehicle.

3. The screed control device according to claim 1 or 2, characterized in that a LIDAR is used for the optical distance measuring unit.

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