Work vehicles

Abstract

To provide a work vehicle that can accurately transport goods to a transport vehicle. [Solution] A work vehicle according to one embodiment comprises a vehicle body, a camera mounted on the vehicle body that is located behind the cabin of a transport vehicle that transports the work vehicle and is capable of photographing markers containing multiple symbols, and a controller that identifies the size and shape of the markers from the image captured by the camera and detects the distance between the vehicle body and the transport vehicle's cargo bed, and the position of the vehicle body relative to the cargo bed, from the identification result.

Description

Technical Field

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[0001] The present invention relates to a work vehicle.

Background Art

[0002] Conventionally, a technique for automatically loading and unloading a work vehicle onto a transport vehicle has been known (see, for example, Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described technique, when transporting a work vehicle to a transport vehicle, the work vehicle is automatically driven based on the position information obtained from a satellite positioning device. However, the satellite positioning device has variations in accuracy, and there are also cases where the communication state is unstable, making it difficult to accurately transport the work vehicle to the transport vehicle in some cases.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a work vehicle that can be accurately transported to a transport vehicle.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, a work vehicle (1) according to one embodiment comprises a vehicle body (2), a camera (20) mounted on the vehicle body (2) that is located behind the cabin (300a) of a transport vehicle (300) that transports the work vehicle (1) and is capable of photographing a marker (310) containing a plurality of symbols (310a), and a controller (200) that identifies the size and shape of the marker (310) from the image captured by the camera (20), and detects the distance between the vehicle body (2) and the cargo bed (300b) of the transport vehicle (300), and the position of the vehicle body (2) relative to the cargo bed (300b) from the identification result. [Effects of the Invention]

[0007] According to one embodiment, the product can be accurately transported to the transport vehicle. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic left side view showing a work vehicle according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the control system for a work vehicle according to an embodiment. [Figure 3] Figure 3 is a perspective view showing the tractor and the transport vehicle. [Figure 4] Figure 4 shows an example of a marker installed on a transport vehicle. [Figure 5] Figure 5 shows the positional relationship between the tractor and the transport vehicle. [Figure 6] Figure 6 shows the positional relationship between the tractor and the transport vehicle. [Figure 7] Figure 7 is a flowchart illustrating the transport process in the automated transport control according to the embodiment. [Modes for carrying out the invention]

[0009] The embodiments of the work vehicle disclosed herein will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below.

[0010] First, an overview of the work vehicle 1 according to the embodiment will be described with reference to Figure 1. Figure 1 is a schematic left side view showing the work vehicle 1 according to the embodiment. In the following description, a tractor will be used as an example of the work vehicle 1. Furthermore, the tractor 1, which is the work vehicle, is, for example, an agricultural tractor capable of performing agricultural work in a field while automatically driving in a straight line.

[0011] In addition, the tractor 1, which is a work vehicle, can perform predetermined tasks while being driven around the field with an operator (also called a worker) on board. Furthermore, it can perform predetermined tasks while automatically driving around the field, controlled by a control system centered on the control device 200 (see Figure 2), which will be described later.

[0012] In the following explanation, the forward and backward directions refer to the direction of travel when the tractor 1 or transport vehicle 300 is moving straight, with the front side of the direction of travel defined as "forward" and the rear side as "rear." Specifically, the direction of travel for the tractor 1 is the direction from the driver's seat 8 (described later) towards the steering wheel 9 when the tractor 1 is moving straight.

[0013] Furthermore, the left-right direction is the direction perpendicular to the front-back direction. In the following, left and right are defined with respect to the "front" side. That is, with the pilot seated in the cockpit 8 facing forward, the left side is "left" and the right side is "right". The up-down direction is the vertical direction. The front-back, left-right, and up-down directions are perpendicular to each other in three dimensions.

[0014] As shown in Figure 1, the tractor 1 comprises a vehicle body 2 and an implement 6. The vehicle body 2 is capable of traveling within a field and is equipped with front wheels 3 and rear wheels 4. The front wheels 3 are a pair of steering wheels (steering wheels) provided on the left and right sides. The rear wheels 4 are a pair of drive wheels (drive wheels) provided on the left and right sides. The vehicle body 2 may also be equipped with a crawler system instead of wheels (at least one of the front wheels 3 and rear wheels 4). In this case, the crawler is the drive wheel.

[0015] To the rear wheels 4 which are driving wheels, the rotational power generated by the engine E which is a drive source housed within the bonnet 5 is transmitted after being appropriately decelerated by a transmission 121 (refer to FIG. 2) provided within a power transmission device (transmission case) 12. The rear wheels 4 are driven by the rotational power transmitted from the engine E. The transmission 121 switches the rotational power transmitted from the engine E to any one of a plurality (for example, 1st speed to 8th speed) of shift stages. Note that the drive source may be a motor for running.

[0016] The traveling vehicle body 2 is configured such that the power generated by the engine E and decelerated by the transmission 121 can also be transmitted to the front wheels 3 via a 4WD clutch. In this case, when the 4WD clutch transmits power, the four wheels of the front wheels 3 and the rear wheels 4 are driven by the power transmitted from the engine E. Also, when the 4WD clutch blocks the transmission of power, only the two rear wheels 4 are driven by the power transmitted from the engine E. Thus, the traveling vehicle body 2 is configured to be able to switch between two-wheel drive (2WD) and four-wheel drive (4WD).

[0017] At the rear part of the traveling vehicle body 2, a working machine 6 for performing work in the field is connected, and a PTO device 7 having a PTO shaft 71 for transmitting the power for driving the working machine 6 is provided. At the central part of the traveling vehicle body 2, a driver's seat 8 on which an operator sits when operating the tractor 1 is provided.

[0018] Note that in the example shown in FIG. 1, the case where the working machine 6 is a rotary tiller is illustrated. The rotary tiller tills the field surface (soil) by the tilling claws 61 rotating by the power transmitted from the PTO shaft 71 of the PTO device 7. The working machine 6 is not limited to a rotary tiller, and may be a working machine that performs harrowing or the like.

[0019] In front of the driver's seat 8, a steering wheel 9, which is a handle for steering the front wheels 3, is provided. Note that the steering wheel 9 and a drive unit for driving the steering wheel 9, etc. constitute a steering device 122 (see FIG. 2). The steering wheel 9 is provided at the upper end of a handle post 10. Below the handle post 10 and near the feet of the operator when the operator is seated on the driver's seat 8, various operation pedals 11 (an accelerator pedal, a brake pedal, a clutch pedal) are provided.

[0020] Also, at the rear of the traveling vehicle body 2, a lifting device 13 for raising and lowering the working machine 6 is provided. The lifting device 13 moves the working machine 6 to a non-working position by raising the working machine 6. Also, the lifting device 13 moves the working machine 6 to a ground working position by lowering the working machine 6. The lifting device 13 includes a hydraulic lifting cylinder 131, a lift arm 132, a lift rod 133, a lower link 134, and a top link 135.

[0021] When hydraulic oil is supplied to the lift arm 132, the lift arm 132 rotates around the axis AX to raise the working machine 6, and when the hydraulic oil is discharged from the lift arm 132, the lift arm 132 rotates around the axis AX to lower the working machine 6. Note that a lift arm sensor 114 (see FIG. 2) for detecting the rotation angle of the lift arm 132 is provided at the base of the lift arm 132 (near the axis AX). The height of the working machine 6 is calculated based on the detection value of the lift arm sensor 114.

[0022] Also, the lift arm 132 is connected to the lower link 134 via the lift rod 133. Thus, the lifting device 13 connects the working machine 6 to the traveling vehicle body 2 so that the working machine 6 can be lifted and lowered by the lower link 134 and the top link 135.

[0023] Furthermore, the tractor 1 is equipped with a camera 20. The camera 20 is mounted on the vehicle body 2. The camera 20 is, for example, located above the cabin 2a of the vehicle body 2. Multiple cameras 20 are provided. The cameras 20 are positioned to photograph the front and rear of the tractor 1. The cameras 20 may be positioned to photograph either the front or the rear of the tractor 1. The cameras 20 are positioned to photograph a marker 310 (see Figure 4) located behind the cabin 300a (see Figure 3) of the transport vehicle 300, which will be described later. The camera 20 may be a camera capable of measuring the distance to an object, such as a stereo camera.

[0024] Furthermore, the tractor 1 is equipped with a control device 200 (see Figure 2). The control device 200 controls the engine E and the travel speed of the vehicle body 2. The control device 200 also controls the steering angle of the steering wheel 9. The control device 200 also controls the implement 6.

[0025] Furthermore, the tractor 1 is equipped with a positioning device 150. The positioning device 150 is mounted on the upper part of the vehicle body 2 and measures the position of the vehicle body 2 at predetermined intervals and acquires information on the vehicle body 2's own position (e.g., latitude and longitude). The positioning device 150 is, for example, a GNSS (Global Navigation Satellite System) and can perform positioning and timing by receiving radio waves from navigation satellites S orbiting overhead.

[0026] Next, with reference to Figure 2, the control system 100 of the work vehicle 1 according to the embodiment, that is, the control system of the work vehicle 1 (tractor 1) centered on the control device 200, will be described. Figure 2 is a block diagram of the control system 100 of the work vehicle 1 according to the embodiment. As shown in Figure 2, the control device 200 includes an engine ECU (Electronic Control Unit) 201, a travel system ECU 202, and a work implement lifting system ECU 203.

[0027] The engine ECU 201 controls the rotational speed of the engine E. The driving system ECU 202 controls the speed of the vehicle body 2 (see Figure 1) by controlling the rotation of the drive wheels (rear wheels 4). In addition, the driving system ECU 202 can control the steering angle of the steering wheel 9 by controlling the steering wheel 9 during autonomous driving. The work equipment lifting system ECU 203 controls the lifting device 13 to drive the work equipment 6 up and down.

[0028] The control device 200 is a controller. The control device 200 is capable of controlling each part by electronic control and includes a processing unit having a CPU (Central Processing Unit), and a storage unit that stores various programs, etc., consisting of, for example, a hard disk, ROM (Read Only Memory), RAM (Random Access Memory).

[0029] The control device 200 is connected to a positioning device (GNSS) 150, a rotation sensor 110, a vehicle speed sensor 111, a gear shift sensor 112, a steering angle sensor 113, and other components. The control device 200 is also connected to the engine E, a transmission 121, a steering device 122, a lifting device 13, and other components. Furthermore, the control device 200 is connected to an automatic driving switch 140, an automatic transport switch 142, and other components. The control device 200 acquires various signals (information) from the positioning device 150 and other components.

[0030] The rotation sensor 110 detects the rotation speed of the rear wheel 4. The vehicle speed sensor 111 detects the driving speed (vehicle speed) of the vehicle body 2 (see Figure 1). The gear shift sensor 112 detects which of the multiple gears the transmission 121 is in. The steering angle sensor 113 detects the steering angle of the front wheel 3 (see Figure 1), which is the steering wheel. In other words, the steering angle sensor 113 detects the steering angle of the steering wheel 9.

[0031] The automatic driving selector switch 140 is a switch that toggles whether or not automatic driving is performed. When the automatic driving selector switch 140 is "ON", automatic driving control is enabled and executed. When the automatic driving selector switch 140 is "OFF", automatic driving control is disabled and not executed. In other words, the automatic driving selector switch 140 is a switch that can enable or disable automatic driving control. The automatic driving selector switch 140 is operated by an operator.

[0032] For example, in straight-line driving controlled by automatic driving control, tractor 1 travels in a straight line along a straight-line driving path. The straight-line driving path is, for example, a driving path parallel to a set reference straight line. The reference straight line is set, for example, by setting a reference start point and a reference end point during driving through the operation of a reference line setting switch. For example, the reference straight line includes information about the distance and direction of the reference straight line.

[0033] The tractor 1 may travel along a pre-set route using automatic driving control. The tractor 1 travels along the route based on the position information included in the route and the position information of the tractor 1 detected by the positioning device 150.

[0034] When the control device 200 performs automatic driving control, it steers the steering wheel 9 by controlling the steering cylinder connected to the steering wheel 9 while feeding back the steering angle of the front wheels 3.

[0035] Even if the automatic driving switch 140 is set to "ON," if the specified conditions are not met, the automatic driving control may not be effective and may not be performed.

[0036] The automatic transport changeover switch 142 is a switch that switches whether or not to perform automatic transport to the transport vehicle 300 (see Figure 3). When the automatic transport changeover switch 142 is "ON", the automatic transport control described later is enabled and the automatic transport control is executed. When the automatic transport changeover switch 142 is "OFF", the automatic transport control is disabled and the automatic transport control is not executed. In the automatic transport control, the vehicle body 2 is controlled so that the tractor 1 is transported to the cargo bed 300b of the transport vehicle 300. In the automatic transport control, for example, the engine E and the transmission 121 are controlled so that the vehicle speed of the vehicle body 2 is a predetermined speed set in advance. Also, in the automatic transport control, for example, the engine E of the vehicle body 2 is controlled so that its rotational speed is a predetermined speed set in advance. Also, in the automatic transport control, the steering wheel 9 is steered so that the tractor 1 is transported to the cargo bed 300b of the transport vehicle 300.

[0037] Furthermore, the control device 200 is connected to a lifting lever 160, etc. The lifting lever 160 is a lever that raises and lowers the work implement 6. The lifting lever 160 is, for example, mounted on the handle post 10 and is operated up and down. For example, when the lifting lever 160 is operated upward, the work implement 6 rises. When the lifting lever 160 is operated downward, the work implement 6 lowers.

[0038] Furthermore, the control device 200 is connected to the remote control 170 wirelessly via a network through the communication unit 120. The remote control 170 may be a terminal device. The remote control 170 can remotely control the tractor 1. The network includes communication using Bluetooth®, wireless LAN (Local Area Network), and UWB (Ultra Wide Band), etc.

[0039] When the control device 200 transports the tractor 1 to the cargo bed 300b of the transport vehicle 300 by automatic transport control, as shown in Figure 3, it detects the relative position of the tractor 1 with respect to the transport vehicle 300. The control device 200 also detects the distance between the vehicle body 2 and the cargo bed 300b of the transport vehicle 300, and the position of the vehicle body 2 with respect to the cargo bed 300b. Specifically, the control device 200 detects the distance between the vehicle body 2 and the marker 310, and the position of the vehicle body 2 with respect to the marker 310. Figure 3 is a perspective view showing the tractor 1 and the transport vehicle 300. Although Figure 3 shows an example where the tractor 1 is moved backward to transport it to the cargo bed 300b of the transport vehicle 300, the tractor 1 may also be moved forward to transport it to the cargo bed 300b of the transport vehicle 300.

[0040] As shown in Figure 4, the transport vehicle 300 is equipped with markers 310. Figure 4 is a diagram showing an example of markers 310 provided on the transport vehicle 300. Specifically, the markers 310 are provided behind the cabin 300a of the transport vehicle 300. Two markers 310 are provided. The two markers 310 are identical and are positioned side by side in the left-right direction of the transport vehicle 300. The two markers 310 are positioned at the same height in the vertical direction. The two markers 310 are positioned so that their distances from the center line P1 in the left-right direction of the transport vehicle 300 are equal.

[0041] The marker 310 is, for example, rectangular. The marker 310 has different symbols 310a at each of its four corners. For example, the marker 310 may have round, triangular, square, and protruding symbols 310a at its four corners. Note that the marker 310 shown in Figure 4 is just an example and is not limited to these. The same symbols 310a on two markers 310 are of the same height and size. Note that the symbols 310a on two markers 310 may be arranged symmetrically with respect to the center line P1.

[0042] The information about the marker 310 is stored in the control device 200. The information about the marker 310 includes the size of the marker 310, the shape (type) of the symbol 310a, the size of the symbol 310a, and the mounting information of the marker 310. The mounting information of the marker 310 includes the height at which the marker 310 is mounted and the distance between two markers 310.

[0043] Furthermore, the information of the marker 310 is stored in association with the distance to the vehicle body 2. For example, the size of the marker 310 when photographed by the camera 20 is stored in association with the distance from the cargo bed 300b (marker 310) of the transport vehicle 300 to the vehicle body 2.

[0044] Furthermore, the information of the marker 310 is stored in association with the position of the vehicle body 2 relative to the cargo bed 300b (marker 310) of the transport vehicle 300. Specifically, the size and shape of the symbol 310a of the marker 310 as captured by the camera 20 are stored in association with the position of the vehicle body 2 relative to the cargo bed 300b. The size and shape of the symbol 310a of the marker 310 as captured by the camera 20 and the position of the vehicle body 2 relative to the cargo bed 300b will be described later. Alternatively, the size and shape of the marker 310 as captured by the camera 20 may be stored in association with the position of the vehicle body 2 relative to the cargo bed 300b.

[0045] The control device 200 captures images of the marker 310 using the camera 20, and from the captured images, it detects the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300, as well as the position of the vehicle body 2 relative to the loading platform 300b.

[0046] As shown in Figure 5, when the tractor 1 is in a straight line behind the cargo bed 300b of the transport vehicle 300, specifically when the centerline P1 in the left-right direction of the transport vehicle 300 and the centerline P2 in the left-right direction of the tractor 1 approximately coincide and the tractor 1 is not misaligned with the transport vehicle 300, the tractor 1 can be moved straight backward to climb the ramp 330 attached to the cargo bed 300b and be transported to the cargo bed 300b. Figure 5 is a diagram showing the positional relationship between the tractor 1 and the transport vehicle 300. By moving the tractor 1 straight backward, the tractor 1 can be safely and accurately transported to the transport vehicle 300.

[0047] On the other hand, as shown in Figure 6, if the tractor 1 is not in a straight line behind the cargo bed 300b of the transport vehicle 300, specifically if the center line P1 of the transport vehicle 300 in the left-right direction and the center line P2 of the tractor 1 in the left-right direction do not coincide, and the tractor 1 is offset from the transport vehicle 300, then even if the tractor 1 is reversed straight, it cannot be transported onto the cargo bed 300b. Figure 6 is a diagram showing the positional relationship between the tractor 1 and the transport vehicle 300.

[0048] In automatic transport control, the control device 200 captures a photograph of the marker 310 with the camera 20, determines from the captured image whether the tractor 1 is misaligned with the transport vehicle 300, and transports the tractor 1 to the transport vehicle 300.

[0049] In the following, the transport process in the automated transport control according to the embodiment will be described with reference to Figure 7. Figure 7 is a flowchart illustrating the transport process in the automated transport control according to the embodiment.

[0050] The control device 200 determines whether the automatic transport changeover switch 142 is "ON" or not (S100). If the automatic transport changeover switch 142 is "OFF" (S100: No), the control device 200 terminates the current process.

[0051] If the automatic transport changeover switch 142 is "ON" (S100:Yes), the control device 200 acquires the image captured by the camera 20 from the camera 20 (S101).

[0052] Next, the control device 200 identifies the size and shape of the marker 310 from the image captured by the camera 20 (S102). The control device 200 identifies the size and shape of the marker 310 by performing predetermined image processing on the image captured by the camera 20. Specifically, the control device 200 identifies the size of the marker 310, the size of the symbol 310a of the marker 310, and the shape of the symbol 310a of the marker 310.

[0053] Next, the control device 200 detects the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300, and the position of the vehicle body 2 relative to the loading platform 300b, based on the identification results (S103). The control device 200 detects the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300, for example, based on the sizes of two markers 310. The control device 200 detects the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300 by reading the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300 corresponding to the sizes of the identified markers 310.

[0054] Furthermore, the control device 200 detects the size and shape of the same symbol 310a on the two markers 310. The control device 200 then compares the size and shape of the same symbol 310a on the two markers 310.

[0055] For example, if tractor 1 is in a straight line behind the cargo bed 300b of transport vehicle 300, as shown in Figure 5, and tractor 1 is not offset from transport vehicle 300, then the shapes of the same symbol 310a of the two markers 310 will match. Also, if tractor 1 is in a straight line behind the cargo bed 300b of transport vehicle 300, and tractor 1 is not offset from transport vehicle 300, then the sizes of the same symbol 310a of the two markers 310 will match.

[0056] On the other hand, for example, if tractor 1 is not in a straight line behind the cargo bed 300b of transport vehicle 300, as shown in Figure 6, and tractor 1 is offset from transport vehicle 300, the shapes of the same symbol 310a of the two markers 310 will not match. Also, if tractor 1 is not in a straight line behind the cargo bed 300b of transport vehicle 300, and tractor 1 is offset from transport vehicle 300, the sizes of the same symbol 310a of the two markers 310 will not match.

[0057] Therefore, the control device 200 can detect the position of the vehicle body 2 relative to the cargo bed 300b based on the identification results of the size and shape of the symbol 310a of the marker 310. The relationship between the size and shape of the symbol 310a of the marker 310 and the position of the vehicle body 2 relative to the cargo bed 300b is determined by experiments or simulations and stored in the control device 200. The control device 200 compares the size and shape of the same symbol 310a of two identified markers 310 and detects differences in size and shape. Then, the control device 200 detects the position of the vehicle body 2 relative to the cargo bed 300b by reading out the position of the vehicle body 2 relative to the cargo bed 300b corresponding to the detected differences.

[0058] Next, the control device 200 determines whether the tractor 1 is misaligned with the transport vehicle 300 based on the detection result of the position of the traveling vehicle body 2 relative to the cargo bed 300b (S104). Specifically, the control device 200 determines whether the tractor 1 can be transported onto the cargo bed 300b of the transport vehicle 300 if the tractor 1 reverses straight, based on the detection result of the position of the traveling vehicle body 2 relative to the cargo bed 300b. If the tractor 1 can reverse straight and be transported onto the cargo bed 300b of the transport vehicle 300, the control device 200 determines that the tractor 1 is not misaligned with the transport vehicle 300. If the tractor 1 cannot reverse straight and be transported onto the cargo bed 300b of the transport vehicle 300, the control device 200 determines that the tractor 1 is misaligned with the transport vehicle 300.

[0059] If the tractor 1 is not misaligned with the transport vehicle 300 (S104: No), the control device 200 reverses the vehicle body 2 (S105). For example, the control device 200 controls the engine E and the transmission 121 so that the vehicle speed of the vehicle body 2 is a predetermined speed. The control device 200 also steers the steering wheel 9 so that the vehicle body 2 reverses in a straight line. As a result, the tractor 1 is automatically transported to the cargo bed 300b of the transport vehicle 300.

[0060] If the tractor 1 is misaligned with the transport vehicle 300 (S104: Yes), the control device 200 adjusts the position of the tractor 1 (S106). Based on the detection result of the position of the vehicle body 2 relative to the cargo bed 300b, the control device 200 drives the vehicle body 2 so that it is in a straight line behind the cargo bed 300b of the transport vehicle 300. The control device 200 drives the vehicle body 2 so that the center line P1 in the left-right direction of the transport vehicle 300 and the center line P2 in the left-right direction of the tractor 1 coincide. The control device 200 controls the engine E and the transmission 121, and further steers the steering wheel 9 to drive the vehicle body 2 so that it is in a straight line behind the cargo bed 300b of the transport vehicle 300.

[0061] The control device 200 returns to step S101 and repeats the above process. When the control device 200 automatically drives the vehicle body 2 so that it is in a straight line behind the cargo bed 300b of the transport vehicle 300, it repeats the above process and automatically drives the vehicle body 2 so that the same symbol 310a of the two markers 310 are identified as the same size. The control device 200 also automatically drives the vehicle body 2 so that the same symbol 310a of the two markers 310 are identified as the same shape.

[0062] Furthermore, the control device 200 may stop the vehicle body 2 when it is in a straight line behind the cargo bed 300b of the transport vehicle 300, by automatically driving the vehicle body 2. Also, if the vehicle body 2 is not in a straight line behind the cargo bed 300b of the transport vehicle 300, and the size of the symbol 310a of the marker 310 becomes larger than or equal to a preset stopping size based on the identification result, the control device 200 may stop the vehicle body 2. The stopping size is the size at which the tractor 1 may come into contact with the transport vehicle 300. This makes it possible to suppress contact between the tractor 1 and the transport vehicle 300.

[0063] Some of the transport processes described above are not limited to automatic transport control, but can also be used when the tractor 1 is transported to the transport vehicle 300 by the operator. For example, the control device 200 can improve the safety and transport accuracy of the transport operation of the tractor 1 to the transport vehicle 300 by notifying whether or not the tractor 1 is misaligned with the transport vehicle 300 based on the identification result.

[0064] The tractor 1 comprises a vehicle body 2, a camera 20, and a control device 200. The camera 20 is mounted on the vehicle body 2 and is capable of photographing a marker 310 containing multiple symbols 310a located behind the cabin 300a of the transport vehicle 300 that transports the tractor 1. The control device 200 identifies the size and shape of the marker 310 from the image captured by the camera 20, and from the identification result detects the distance between the vehicle body 2 and the cargo bed 300b of the transport vehicle 300, as well as the position of the vehicle body 2 relative to the cargo bed 300b.

[0065] As a result, when the tractor 1 is transported to the transport vehicle 300 by automatic driving, for example, it is transported to the loading platform 300b of the transport vehicle 300 based on the size and shape of the marker 310 captured by the camera 20. Therefore, the tractor 1 can be transported to the transport vehicle 300 with high precision.

[0066] If the control device 200 determines from the identification result that the vehicle body 2 is not in a straight line behind the cargo bed 300b of the transport vehicle 300, it will automatically move the vehicle body 2 so that it is in a straight line behind the cargo bed 300b of the transport vehicle 300.

[0067] As a result, the tractor 1 automatically travels in a straight line behind the cargo bed 300b of the transport vehicle 300, making it easy to align the tractor 1 with the transport vehicle 300. Therefore, the workload of the operator of the tractor 1 can be reduced. In addition, the tractor 1 can be transported to the transport vehicle 300 with high precision.

[0068] Two identical markers 310 are provided on the left and right sides of the transport vehicle 300. The control device 200 automatically drives the vehicle body 2 so that the same symbol 310a on the two markers 310 are identified at the same size.

[0069] This allows the tractor 1 to travel precisely in a straight line behind the cargo bed 300b of the transport vehicle 300. Therefore, the tractor 1 can be transported to the transport vehicle 300 with precision.

[0070] Each of the four corners of the marker 310 is provided with a different symbol 310a. The control device 200 automatically drives the vehicle body 2 so that the same symbol 310a on two markers 310 are identified at the same size.

[0071] This allows the tractor 1 to travel precisely in a straight line behind the cargo bed 300b of the transport vehicle 300. Therefore, the tractor 1 can be transported to the transport vehicle 300 with precision.

[0072] If the control device 200 determines from the identification result that the vehicle body 2 is not in a straight line behind the cargo bed 300b of the transport vehicle 300, it will automatically move the vehicle body 2 so that the center of the transport vehicle 300 in the left-right direction coincides with the center of the vehicle body 2 in the left-right direction.

[0073] This allows the tractor 1 to accurately align its body 2 with the transport vehicle 300 in the left-right direction. As a result, the tractor 1 can be accurately transported to the transport vehicle 300.

[0074] The transport vehicle 300 may have only one marker 310. In this case, for example, the marker 310 is located at the center of the transport vehicle 300 in the left-right direction. The control device 200 detects the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300, and the position of the vehicle body 2 relative to the loading platform 300b, based on the size and shape of the symbol 310a of the marker 310. The control device 200 pre-stores the relationship between the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300, the position of the vehicle body 2 relative to the loading platform 300b, and the size and shape of the symbol 310a of the marker 310. Then, the control device 200 detects the distance between the vehicle body 2 and the loading platform 300b of the transport vehicle 300, and the position of the vehicle body 2 relative to the loading platform 300b, based on the identification results and the stored information.

[0075] Tractor 1 may have the following variations:

[0076] The control device 200 may detect the height of the cargo bed 300b based on the position of the marker 310 or the symbol 310a of the marker 310 in the image captured by the camera 20, if the tractor 1 is not misaligned with the transport vehicle 300 and the tractor 1 is being transported to the cargo bed 300b of the transport vehicle 300. For example, the control device 200 detects the distance between the vehicle body 2 and the cargo bed 300b (marker 310) of the transport vehicle 300 from the image captured by the camera 20. The control device 200 then detects the height of the cargo bed 300b based on the detected distance and the position of the marker 310 or the symbol 310a of the marker 310 in the image captured by the camera 20. The relationship between the distance between the vehicle body 2 and the cargo bed 300b of the transport vehicle 300 and the position of the marker 310 or the symbol 310a of the marker 310 in the image captured by the camera 20 is stored in the control device 200 beforehand.

[0077] The control device 200 controls the engine E and the transmission 121 based on the detected height of the cargo bed 300b. For example, the control device 200 sets at least one of the vehicle speed, the output (torque) of the engine E, or the rotational speed of the engine E based on the detected height of the cargo bed 300b, and controls the engine E and the transmission 121.

[0078] Furthermore, if the tractor 1 is not misaligned with the transport vehicle 300 and the tractor 1 is being transported to the cargo bed 300b of the transport vehicle 300, the control device 200 may steer the steering wheel 9 so that the sizes of the same symbols 310a of the two markers 310 in the image captured by the camera 20 are the same.

[0079] Furthermore, if the control device 200 determines that the tractor 1 is not misaligned with the transport vehicle 300 and is transporting the tractor 1 to the cargo bed 300b of the transport vehicle 300, and the size of the marker 310 becomes greater than or equal to a preset transport completion size based on the identification result, the control device 200 may stop the vehicle 2. This allows the vehicle 2 to be automatically stopped when the transport of the tractor 1 to the cargo bed 300b of the transport vehicle 300 is complete.

[0080] Furthermore, the control device 200 may calculate the angle of the ramp 330 installed on the loading platform 300b of the transport vehicle 300, that is, the lifting angle when the vehicle body 2 is transported to the loading platform 300b, and set the state of the vehicle body 2 according to the lifting angle. As described above, the control device 200 detects the height of the loading platform 300b of the transport vehicle 300 and calculates the lifting angle from the detected height of the loading platform 300b and the length of the ramp 330. The length of the ramp 330 is stored in the control device 200. The state of the vehicle body 2 includes at least one of the vehicle speed and the rotational speed of the engine E. The state of the vehicle body 2 may also include the output (torque) of the engine E. The state of the vehicle body 2 with respect to the lifting angle is set in advance. The state of the vehicle body 2 with respect to the lifting angle is set so that the tractor 1 can be safely transported to the loading platform 300b of the transport vehicle 300. The lifting angle may be calculated taking into account the angle of the road surface on which the transport vehicle 300 and the tractor 1 are stationary or traveling. The angle of the road surface is detected, for example, by a tilt sensor (for example, a G sensor) installed on the tractor 1.

[0081] Alternatively, the control device 200 may calculate the depth (length in the front-to-back direction) and height (height of the loading platform 300b) of the ramp 330 from the image captured by the camera 20, and then calculate the lifting angle.

[0082] As a result, the control device 200 can safely transport the tractor 1 to the loading platform 300b of the transport vehicle 300 by controlling, for example, the vehicle speed according to the lifting angle.

[0083] The control device 200 may also calculate the distance between the ramps 330 from the image captured by the camera 20. If the distance between the ramps 330 is longer than the tread width of the tractor 1, the control device 200 will stop the vehicle 2.

[0084] Furthermore, when the control device 200 transports the tractor 1 to the cargo bed 300b of the transport vehicle 300, it transports the tractor 1 so that the left-right centerline P2 of the tractor 1 coincides with the left-right centerline P1 of the transport vehicle 300.

[0085] When the control device 200 sets a reference straight line in automatic driving control, it first determines a first reference point, then applies the RANSAC algorithm to a certain number of acquired positional information to estimate a straight line model and set the reference straight line. This eliminates the need to determine a second reference point, and the control device 200 can set a reference straight line that minimizes the influence of outliers.

[0086] Furthermore, the control device 200 does not set the current position when the linear model is estimated as a reference line if it is more than a predetermined distance away from the position where the first reference point was acquired. This allows the control device 200 to suppress false detection of reference lines.

[0087] Furthermore, the control device 200 automatically registers a reference line when the angle of the linear model stabilizes. This prevents the control device 200 from forgetting to register a reference line.

[0088] Furthermore, the control device 200 may detect crops and ridges in the field by performing image processing on the images captured by the camera 20. The control device 200 may also further detect crops and ridges in the field using a LiDAR (Light Detection And Ranging) sensor provided as a detection sensor. The control device 200 detects areas of the same height from the detection results of the detection sensor and detects areas of greater height as ridges. The control device 200 also detects objects of similar height relative to the depth (in front of the vehicle body 2) as crops from the detection results of the detection sensor. In addition, the control device 200 detects ridges and crops by performing image processing on the images captured by the camera 20 to detect the edges of ridges based on the color and shape of the crops.

[0089] Furthermore, the control device 200 may detect crops and ridges in the field, for example, by using a machine learning model. The control device 200 detects ridges and crops by inputting the point cloud data from LiDAR, the images captured by the camera 20, and the machine learning model. For example, the learning parameters for machine learning are the height and elevation difference of the point cloud data, the color in the image, and the shape in the image.

[0090] Furthermore, the control device 200 may, as described above, detect ridges and crops during field management work and correct the driving line for straight-line assistance in automatic driving. The driving line is set in advance, and the vehicle body 2 travels along the driving line in automatic driving mode. If, for example, a detected ridge is at an angle to the driving line, the control device 200 corrects the driving line so that the vehicle body 2 passes through the detected ridge at an appropriate position. The control device 200 performs a correction of the driving line if the deviation between the center of the ridge and the driving line is greater than or equal to a predetermined amount. The predetermined amount is, for example, the amount at which the vehicle body 2 is likely to trample the ridge or crops. For example, the control device 200 corrects the driving line so that the vehicle body 2 passes through the center of the ridge. The control device 200 may also generate a new driving line.

[0091] The work vehicle 1 is not limited to a tractor, but may be, for example, a rice transplanter. The rice transplanter may be equipped with an AI camera behind the seedling tank. The AI ​​camera photographs the seedlings placed in the seedling tank and predicts where the seedlings will be picked. The AI ​​camera then determines which parts of the seedlings to plant along the travel path. The AI ​​camera can also predict and detect missing plants.

[0092] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0093] 1. Tractor (work vehicle) 2. Running vehicle 2a Cabin 6. Work equipment 20 cameras 100 control systems 170 Remote Control 200 Control devices (controllers) 300 transport vehicles 300a Cabin 300b cargo bed 310 markers 310a Symbol 330 Walking board E Engine (power source)

Claims

1. The vehicle body and A camera mounted on the vehicle body is provided to photograph a marker containing multiple symbols located at the rear of the cabin of a transport vehicle that transports work vehicles, A controller that identifies the size and shape of the marker from the image captured by the camera, and detects the distance between the vehicle body and the cargo bed of the transport vehicle, and the position of the vehicle body relative to the cargo bed, from the identification result. A work vehicle equipped with the following features.

2. The work vehicle according to claim 1, wherein the controller, based on the identification result, automatically moves the vehicle so that the vehicle is on the straight line behind the cargo bed of the transport vehicle if the vehicle is not on the straight line behind the cargo bed of the transport vehicle.

3. The aforementioned markers are provided in pairs, with two identical markers positioned in the left-right direction on the transport vehicle. The work vehicle according to claim 2, wherein the controller automatically drives the vehicle body such that the same symbols of the two markers are identified at the same size.

4. The aforementioned marker has different symbols at each of its four corners. The work vehicle according to claim 3, wherein the controller automatically drives the vehicle body so that the same symbols of the two markers are identified at the same size.

5. The work vehicle according to claim 2, wherein the controller, based on the identification result, automatically moves the vehicle so that the left-right center of the transport vehicle coincides with the left-right center of the vehicle body if the vehicle body is not on a straight line behind the cargo bed of the transport vehicle.

6. The aforementioned controller, Based on the identification results, the lifting angle when the vehicle body is transported onto the transport vehicle's cargo bed is calculated based on the height of the transport vehicle's cargo bed and the length of the ramp installed on the transport vehicle's cargo bed. The driving state of the aforementioned vehicle body is set according to the lifting angle, The work vehicle according to claim 1, wherein the aforementioned driving state is at least one of the vehicle speed and the rotational speed of the drive source of the driving vehicle body.

Images