Work vehicles

Abstract

To create elevation distribution maps more efficiently than by driving through the field and creating the elevation distribution map information for the field. [Solution] A positioning device (41) that measures the current position of the vehicle body (1a), an imaging device (31) mounted on the vehicle body (1a) that images the field, and based on the positioning results of the positioning device (41) that elevation information of the field is acquired, and based on the imaging results of the imaging device (31) that the elevation of the soil in the field within the imaging range is determined, and a distribution map of the elevation of the field is created from the elevation information and the determination results of the soil elevation, thereby enabling the creation of elevation distribution map information more efficiently than when driving through the field and creating the elevation distribution map information of the field.

Description

Technical Field

[0001] The present invention relates to a work vehicle that operates in a field.

Background Art

[0002] In work vehicles such as tractors and rice transplanters, when performing leveling work based on map information (height map) of the height distribution in a pre-created field, a work vehicle equipped with a three-dimensional positioning system travels in the field, and the unevenness in the field is measured from the measurement results of the three-dimensional positioning system to create a height map. This technology is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] (Problems of the Prior Art) In the prior art, in order to create a height map of the entire field, it is necessary to drive a work vehicle evenly over the entire field, which takes time and effort to create the height map and results in low work efficiency.

[0005] The technical problem of the present invention is to create map information of the height distribution more efficiently than when traveling in a field to create map information of the height distribution of the field.

Means for Solving the Problems

[0006] To solve the aforementioned technical problems, the invention described in claim 1 is a work vehicle comprising: a positioning device (41) for determining the current position of a vehicle body (1a); an imaging device (31) mounted on the vehicle body (1a) for imaging a field; and a control unit (100) that acquires elevation information of the field based on the positioning result of the positioning device (41), determines the elevation of the soil in the field within the imaging range based on the imaging result of the imaging device (31), and creates an elevation distribution map of the field from the elevation information and the determination result of the soil elevation.

[0007] The invention described in claim 2 is a work vehicle according to claim 1, further comprising a control unit (100) that determines, based on imaging results of a field filled with water, that areas where soil is above the water surface are high, and areas where soil is not above the water surface are low.

[0008] The invention described in claim 3 is a work vehicle according to claim 2, comprising a control unit (100) that determines the level of the soil in the field based on the image of the field after puddling work, and notifies the worker to perform puddling work again if the area of ​​the part of the field where the soil is above the water surface reaches a predetermined area. [Effects of the Invention]

[0009] According to the invention described in claim 1, the elevation of the soil in the field within the imaging range is determined based on the imaging results from the imaging device (31), and an elevation distribution map of the field is created from the elevation information and the determination result of the soil elevation. This makes it possible to create elevation distribution map information more efficiently than when driving through the field to create elevation distribution map information of the field.

[0010] According to the invention described in claim 2, in addition to the effects described in claim 1, the part of the soil that is above the water surface is determined to be high, and the part of the soil that is not above the water surface is determined to be low, making it easier to determine the height of the soil based on the water surface.

[0011] According to the invention described in claim 3, in addition to the effects described in claim 2, when the area of ​​soil exposed above the water surface after puddling reaches a predetermined area, the worker is prompted to perform puddling again, which makes the field more level than when the worker is not prompted. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is an explanatory diagram of a tractor as an example of a work vehicle in the embodiment, and is an explanatory diagram of the state in which the implement has been lowered to the height at which work is performed. [Figure 2] Figure 2 is an explanatory diagram of a tractor as an example of a work vehicle in the embodiment, and is an explanatory diagram of the state in which the implement is raised. [Figure 3] Figure 3 is a functional block diagram of the control means of the embodiment. [Figure 4] Figure 4 is an explanatory diagram of an example of elevation determination in the embodiment, where Figure 4(A) is an explanatory diagram of an example of an acquired image, and Figure 4(B) is an explanatory diagram of an example of a created elevation map. [Modes for carrying out the invention]

[0013] Next, with reference to the drawings, specific examples of embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. In describing the embodiments, the left and right directions relative to the aircraft's forward direction will be referred to as left and right, respectively, the forward direction will be referred to as forward, and the reverse direction as backward. In the following explanation using diagrams, diagrams of components other than those necessary for the explanation have been omitted as appropriate for ease of understanding.

[0014] Figure 1 is an explanatory diagram of a tractor as an example of a work vehicle in the embodiment, and is an explanatory diagram of the state in which the implement has been lowered to the height at which work is performed. Figure 2 is an explanatory diagram of a tractor as an example of a work vehicle in the embodiment, and is an explanatory diagram of the state in which the implement is raised. In Figures 1 and 2, the tilling tractor 1, an example of a work vehicle of the present invention, is equipped with a running body (an example of a vehicle body) 1a, and front and rear wheels 2,2 and rear wheels 3,3, which are an example of a running gear. An engine 4 is mounted inside the bonnet 6 at the front of the running body 1a. The rotational power of the engine 4 is appropriately reduced by a transmission in the transmission case 5 and transmitted to the front wheels 2,2 and rear wheels 3,3. In addition, a working implement such as a tiller (an example of a working implement, a rotary tiller) 18 for tilling the ground (field) behind the tractor 1 is attached to the rear of the tractor body, and power is transmitted via the PTO shaft 9 to drive the working implement. In this specification, the left and right sides of the tractor 1 in the direction of forward movement are referred to as the left and right sides, respectively, the forward direction is referred to as the front side, and the reverse direction is referred to as the rear side.

[0015] A cabin 7 is supported on top of the vehicle body 1a. Inside the cabin 7, a driver's seat 8 is positioned above the transmission case 5, and in front of the driver's seat 8 are a steering wheel 10 and a parking brake (not shown). Also in front of the driver's seat 8 are a display panel (meter panel) such as a speedometer (not shown) and various switches (not shown) for operation. Below and in front of the driver's seat 8 are driving controls such as a brake pedal 12 and an accelerator pedal 13.

[0016] In Figure 1, a hydraulic cylinder case 14 is provided above the rear of the transmission case 5, and lift arms 15, 15 are pivotally attached to both the left and right sides of this hydraulic cylinder case 14. Lift rods 17, 17 are interposed and connected between the lift arms 15, 15 and the lower links 16, 16, and a tiller 18 is connected to the rear of the lower links 16, 16.

[0017] When hydraulic oil is supplied to the hydraulic cylinder 14a housed in the hydraulic cylinder case 14, the lift arms 15, 15 are rotated upward, and the tiller (working machine) 18 is lifted via the lift rod 17, the lower link 16, etc. Conversely, when the hydraulic oil in the hydraulic cylinder 14a is discharged into the transmission case 5 that also serves as a hydraulic tank, the lift arms 15, 15 descend. Note that the working machine attached to the rear part of the traveling vehicle body 1a, that is, the working machine to which drive is transmitted from the PTO shaft 9, is not limited to a rotary tiller for agricultural work, and there are working machines such as a plow, a seeding machine, a seedling transplanter, a fertilizer spreader, a chemical sprayer, etc.

[0018] In the tractor 1 of the embodiment, a camera 31, which is an example of an imaging device and also an example of a detection device, is installed at the front part of the vehicle body 1a. The camera 31 can image the front of the vehicle body 1a. Note that the imaging range of the camera 31 (the horizontal direction and the vertical direction (tilt) with respect to the front of the vehicle body 1a) is predetermined. In the embodiment, the camera 31 is provided with an actuator for changing and adjusting the orientation (shooting direction), that is, a so-called pan function. Therefore, the imaging range of the camera 31 is configured to be changeable. Note that it is also possible to attach a lens such as a wide-angle lens or a fish-eye lens to the camera 31 to adjust and change the width (horizontal direction and / or vertical direction width) of the imaging range (field of view) to an arbitrary width and adopt a mode without a pan function.

[0019] Also, the number of cameras 31 can be such that cameras facing each direction are installed so as to be able to image not only the front but also the front, rear, sides, etc. Furthermore, it is also possible to install a plurality of cameras facing the same direction so as to be able to measure the distance to an object (obstacle, ridge, etc.) by stereo vision with the plurality of cameras.

[0020] Furthermore, the tractor 1 of this embodiment has a GNSS receiver 41 installed on the top surface of the cabin 7 as an example of a positioning device. The receiver 41 can receive signals from GNSS (Global Navigation Satellite System) satellites 42 and measure the current position of the tractor 1. In this embodiment, in addition to the GNSS receiver 41, an IMU (Inertial Measurement Unit) (not shown) is provided. The IMU can measure acceleration and angular velocity to detect the attitude of the tractor 1 (left-right tilt and front-back tilt). Therefore, by correcting the measurement results of the GNSS receiver with the IMU, the current position can be measured with greater accuracy compared to when the current position is measured using only the GNSS method.

[0021] Therefore, the tractor 1 of this embodiment can be driven autonomously (automatic driving, unmanned driving) using GNSS, or it can be driven by an operator riding in the cabin 7 according to the operator's commands (manual driving, manned driving). In addition, when driving autonomously, the operator who operates the tablet terminal (an example of a terminal) 46 that can communicate wirelessly with the tractor 1 can be outside the tractor 1 (outside or inside the field), or can be riding in the cabin 7 while carrying the tablet terminal 46.

[0022] The tractor 1 and the tablet terminal 46 are configured to communicate via a communication line 47. The communication line 47 can be any wireless or wired line, such as a telephone line, internet line, LAN line, or Bluetooth®. A server 48, which is an example of an information processing device, is connected to the communication line 47. The server 48 can send and receive information (communicate) with the tractor 1 and the tablet terminal 46. The server 48 can communicate map information, work information, etc., with the tractor 1 and the tablet terminal 46. It is also possible to configure the system so that the tractor 1 and the tablet terminal 46 can communicate directly without using the communication line 47 (ad hoc network).

[0023] (Description of the control unit) Figure 3 is a functional block diagram of the control means of the embodiment. In the block diagram of Figure 3, elements unrelated to the description of the embodiments of the present invention are omitted from the illustration and description.

[0024] (Description of the control unit of Tractor 1) In Figure 3, the control unit (an example of a control means) 100 of the tractor 1 in this embodiment is composed of a small information processing device, a so-called microcomputer. Therefore, the control unit 100 can realize various functions by executing programs stored in ROM, RAM, etc.

[0025] The control unit 100 of the tractor 1 in this embodiment receives signals from the GNSS receiver 41, the camera 31, other sensors (not shown), various switches, buttons, and other signal output elements. It also receives information and control signals transmitted from the tablet terminal 46 and the server 48. The GNSS receiver 41 receives signals from a GNSS satellite 42 to measure the current position of the vehicle body 1a, and corrects this position using the attitude of the vehicle body 1a measured by an inertial measurement unit (IMU) to determine the current position. Camera 31 captures images of the area outside the vehicle body 1a. Therefore, images including the field are captured.

[0026] The control unit 100 of the combine harvester 1 in this embodiment outputs control signals to controlled elements such as the engine 4, the driving system (front wheels 2, rear wheels 3), the tiller 18, and the actuators of the camera 31. The control unit 100 in this embodiment can also transmit information and signals such as image information to a tablet terminal 46 and a server 48.

[0027] The control unit 100 of this embodiment has the following functional modules (program modules). The positioning means 101 measures the current position of the tractor 1 based on the positioning results of the GNSS receiver 41. The map information acquisition means 102 acquires map information that has been pre-stored in the server 48. In this embodiment, the map information acquisition means 102 acquires map information of the field corresponding to the current position of the tractor 1, which has been positioned by the positioning means 101. In this embodiment, the map information acquired by the map information acquisition means 102 also includes information on the elevation of the field.

[0028] The image acquisition means 103 acquires images captured by the camera 31. In this embodiment, the camera 31 changes its orientation horizontally (pant and turn) using an actuator, and the image acquisition means 103 acquires images of the entire field.

[0029] The elevation determination means 104 includes a water surface detection means 104a and determines the elevation of the soil in the field based on the image captured by the camera 31. The elevation of the soil in the field can be determined using conventionally known image analysis or AI. Specifically, the distribution of soil elevation within the imaging range of the field is determined by performing image analysis based on reference information (training information) that associates (links) the field image and elevation information, or by using AI that has been trained based on training information, taking the image captured by the camera 31 as input and outputting the result of determining the elevation of the soil in the field. The elevation determination means 104 determines the distribution of soil elevation over the entire field imaged by the camera 31.

[0030] Figure 4 is an explanatory diagram of an example of elevation determination in the embodiment, where Figure 4(A) is an explanatory diagram of an example of an acquired image, and Figure 4(B) is an explanatory diagram of an example of a created elevation map. Furthermore, if the field is filled with water (water is present), the water surface is detected by the water surface detection means 104a, and if the field is not filled with water, the water surface detection means 104a determines that there is no water surface. In Figure 4(A), in the image of a field filled with water, the height of the soil is determined based on the detected water surface. Therefore, in the captured image, it is possible to determine that the part of the soil that is above the water surface is high, and the part of the soil that is not above the water surface is low.

[0031] When determining the elevation of the soil using the elevation determination means 104 of the embodiment, it is also possible to exclude from the elevation determination result any areas where the height is higher than a predetermined threshold, i.e., irregularly elevated areas. In other words, if an irregularly elevated result occurs due to an unclear image caused by light reflection, etc., or if the AI's determination result is incorrect, it is possible to exclude such areas from the determination result to ensure the accuracy of the determination. If the area of ​​the irregularly elevated area does not reach the threshold, it is also possible to determine that a clump of soil exists locally in the field and not determine that it is elevated. Furthermore, even if the area of ​​the irregularly elevated area reaches the threshold, if the aspect ratio does not reach a predetermined value (for example, if it is elongated vertically), it is also possible to determine that it may be a clump of soil, etc., and not determine that it is elevated.

[0032] The elevation distribution map creation means 105 creates an elevation distribution map (elevation map) of the field from the elevation information and the results of the soil elevation determination. In this embodiment, the elevation distribution map creation means 105 adds the soil elevation determined by the elevation determination means 104 to the elevation information of the map information to create an elevation map of the field at the time of imaging by the camera 31 (see Figure 4(B)). The created elevation map is displayed on the display panel in the cabin 7 and is also transmitted to the terminal 46 and the server 48.

[0033] The automatic work control means 106 includes an automatic driving control means 106a, a work implement control means 106b, and a puddling work completion determination means 106c, and controls the automatic work. When an automatic work input is received via the operation buttons in the cabin 7 or the terminal 46, the automatic work control means 106 generates a work path in the field based on elevation distribution map information and controls the tractor 1 to perform the work while autonomously driving along the work path.

[0034] The automatic driving control means 106a performs autonomous driving (automatic driving) control, that is, speed control and steering control, based on the current position of the tractor 1 determined by the positioning means 101 and the work path. The implement control means 106b controls the operation and raising / lowering of the tiller 18. In this embodiment, the implement control means 106b operates the tiller 18 during operation and stops the tiller 18 after the work is completed, based on the current position of the tractor 1 and the work path determined by the positioning means 101. In addition, the tiller 18 is lowered during operation (straight-line driving) and raised during turning.

[0035] Furthermore, the implement control means 106b of this embodiment, during puddling operations, increases the tillage depth when passing over high points on the elevation map and decreases the tillage depth when passing over low points, thereby promoting soil movement from high to low points and making the field closer to level. It is also preferable to control the tillage depth to increase in areas with high soil and decrease in areas with low soil during the following year's tillage operations (rough plowing, field tilling) based on the elevation map from the previous year's puddling. In other words, tillage without water is more effective at transporting soil than puddling with water, making it particularly efficient.

[0036] Furthermore, in this embodiment, the tiller 18 is provided with an adjustment shaft 18c for adjusting the pressure of a spring 18b that applies pressure to the rear cover 18a in contact with the soil of the field. The implement control means 106b can adjust the pressure of the rear cover 18a by rotating the adjustment shaft 18c in forward and reverse directions to move the end plate 18d, thereby expanding and contracting the spring 18b. It is also preferable to increase the pressure of the rear cover 18a in areas with higher soil on the elevation map during puddling or tilling operations, making it easier to move the soil from higher to lower areas.

[0037] The puddling completion determination means 106c comprises an exposed area calculation means 106c1 and a rework notification means 106c2, and determines the completion of the puddling work. The exposed area calculation means 106c1 calculates (sums up) the area of ​​the part of the soil that is above the water surface as determined by the height determination means 104. The puddling completion determination means 106c then determines that the puddling work is insufficient (puddling work is not completed) if the area of ​​the part of the soil that is above the water surface reaches a predetermined area (determined area), and determines that the puddling work is sufficient (puddling work is completed) if it does not reach the determined area. If the puddling work is determined to be incomplete, the rework notification means 106c2 will notify the worker to resume the puddling work. The notification can be displayed on the display panel inside the cabin 7, on the display screen of the terminal 46, or by any other notification method such as voice guidance, lamp illumination, or buzzer sound.

[0038] (Operation of the embodiment) In the tractor 1 of the embodiment with the above configuration, the elevation of the soil in the field is determined based on the image from the camera 31, and an elevation map is created. Therefore, when creating the elevation map, it is not necessary for the tractor 1 to travel evenly throughout the field. Thus, compared to conventional techniques that create elevation distribution map information by driving through the field, the elevation map can be created in a short time, the consumption of fuel and other resources of the tractor 1 can be reduced, and the damage to the field caused by the movement of the tractor 1 is also reduced. Therefore, an elevation map (map information of elevation distribution) can be created efficiently.

[0039] Furthermore, in this embodiment, when the field is filled with water, the soil elevation is determined based on the water level. Therefore, when the camera 31 recognizes the soil elevation, the elevation and unevenness of the soil are easier to see. Furthermore, in the tractor 1 of this embodiment, if a large amount of soil is exposed above the water surface after the start of puddling, the operator is prompted to continue puddling until the amount of exposed soil decreases. Therefore, the field can be made more level compared to the case where the operator is not prompted to repeat the puddling work.

[0040] In the tractor 1 of this embodiment, the control unit 100 centrally processes the determination of the elevation of the field and the determination of the completion of the puddling work, but the system is not limited to this. It is also possible to use a distributed processing configuration that utilizes multiple information processing devices connected to a network. Furthermore, although a tractor 1 is used as an example of a work vehicle in this embodiment, the invention is not limited to this. It can be applied to work vehicles such as rice transplanters, cultivators (pest control machines), combine harvesters (harvesting machines), and riding lawnmowers. [Explanation of symbols]

[0041] 1. Work vehicles, 1a Vehicle body, 31 Imaging device, 41 Positioning device, 100 Control unit.

Claims

1. A positioning device (41) that determines the current position of the vehicle body (1a), An imaging device (31) mounted on the vehicle body (1a) and for imaging the field, A control unit (100) acquires elevation information of the field based on the positioning results of the positioning device (41), determines the soil elevation of the field within the imaging range based on the imaging results of the imaging device (31), and creates an elevation distribution map of the field from the elevation information and the soil elevation determination results. A work vehicle equipped with [a specific feature / equipment].

2. Based on the imaging results of the field when it is filled with water, the control unit (100) determines that the parts where the soil is above the water surface are high, and the parts where the soil is not above the water surface are low. A work vehicle according to claim 1, comprising:

3. Based on the imaging results of the field after puddling, the control unit (100) determines the elevation of the soil in the field, and if the area of ​​soil above the water surface reaches a predetermined area, it notifies the worker to perform puddling again. A work vehicle according to claim 2, comprising:

Images