Work vehicle

Abstract

To provide a work vehicle capable of automatically travelling without using positional information, solving a problem with a conventional work vehicle equipped with an automatic travelling mechanism for causing a machine body to automatically travel using positional information by GNSS and capable of automatically travelling along a work passage that when a positional information receiver and a GNSS control program are mounted, the cost increases accordingly, and there occur cases where positional information cannot be received depending on a work environment and a communication state, which makes the automatic travelling mechanism non-functional.SOLUTION: In a work vehicle equipped with an automatic steering device for automatically steering an advancing direction of a travelling vehicle body 2, cameras 73C and 73S are provided for imaging identification bodies LC and LS of a multi-film M laid in a farm field. A controller 60 is provided for recognizing the identification bodies LC and LS from videos of the cameras 73C and 73S, calculating a difference from the center of the videos, and actuating the automatic steering device.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle such as a tractor equipped with a pesticide sprayer for spraying pesticides and a work implement. [Background technology]

[0002] BACKGROUND ART There are work vehicles that are equipped with an automatic driving mechanism that uses position information from GNSS to automatically drive the vehicle, and that can automatically drive along work lines (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-097813 Summary of the Invention [Problem to be solved by the invention]

[0004] However, installing a location information receiving device and a GNSS control program increases costs, and depending on the work environment and communication conditions, location information may not be received, causing the automatic driving mechanism to stop functioning.

[0005] An object of the present invention is to provide a work vehicle that is capable of automatic travel without using position information. [Means for solving the problem]

[0006] The invention described in claim 1 is a work vehicle equipped with an automatic steering device 5a that automatically steers the direction of travel of a traveling body 2, and is provided with cameras 73C, 73S that photograph identifying objects LC, LS of a mulch film M laid in a field, and a controller 60 that recognizes the identifying objects LC, LS from the images of the cameras 73C, 73S, calculates the difference from the center of the image, and activates the automatic steering device 5a.

[0007] According to the invention described in claim 1, by using the identifiers LC and LS of the multi-film M to determine the left-right deviation of the traveling vehicle body 2 and activating the automatic steering device 5a, automatic traveling becomes possible without using position information, thereby reducing the labor of the worker.

[0008] The invention described in claim 2 is a work vehicle described in claim 1, which is provided with a central detection camera 73C that photographs the central identifier LC of the mulch film M that is placed in the center of the ridge, and a side detection camera 73S that photographs the side identifier LS that is placed near the boundary between the ridge and the ridge furrow on the side, away from the center of the mulch film M in the left and right directions.

[0009] According to the invention described in claim 2, even if crops grow on the ridges and cover the central identifier LC, automatic travel is possible by photographing the side identifiers LS on the left and right sides with the side detection camera 73S, thereby improving work accuracy.

[0010] The invention described in claim 3 is the work vehicle described in claim 1, in which the cameras 73C, 73S are provided so that their vertical positions or their photographing distances can be freely adjusted by the adjustment operation device 72a.

[0011] According to the invention described in claim 3, there is no need for the operator to get off the traveling vehicle body 2 to adjust the shooting distance, and automatic traveling is less likely to be interrupted, thereby reducing labor and improving work efficiency.

[0012] The invention described in claim 4 is a work vehicle described in any one of claims 1 to 3, in which a plurality of distance sensors 76 that detect the distance to the field surface are provided on an up-and-down movable frame 71 that can be freely adjusted in the vertical direction, and the position of the plurality of distance sensors 76 can be freely adjusted in the left-right direction, and the shape of the ridges is calculated and recorded based on the distances measured by the plurality of distance sensors 76.

[0013] According to the invention described in claim 4, since the ridge shape can be recorded, it is possible to determine whether the ridges are properly made and cultivate crops in the appropriate ridges. In addition, the memorized ridge shape can be used in subsequent operations for automatic driving and various other operations.

[0014] The invention described in claim 5 is a work vehicle described in claim 4 that is provided with a teaching switch 77 that starts and ends teaching of the distance sensor 76 and erases the teaching information, sets a reference ridge shape from the distance information of the distance sensor 76 between the start and end of teaching, and calculates the range that is considered to be a normal ridge based on the reference ridge shape.

[0015] According to the invention described in claim 5, it is possible to prevent minute changes in vertical height from being considered abnormal while measuring the ridge shape, and by not considering slight changes in the ridge shape due to crop growth, rain, wind, etc. as abnormal, when the recorded ridge shape is used in a subsequent process, it is possible to prevent excessive measures from being taken against abnormal ridges, and to prevent the work time from being extended.

[0016] Teaching information can be erased using the teaching switch 77, so when teaching a new area where the teaching range is inappropriate or the shape or height of the ridges is different, it is possible to prevent the previous information from being used to erroneously recognize an abnormality. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a side view showing a camera of a drug sprayer according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the camera of the same pesticide sprayer. [Figure 3] This is a front view showing the camera of the same pesticide sprayer to explain its operation. [Figure 4] FIG. 2 is a side view showing the distance sensor of the same chemical sprayer. [Figure 5] FIG. 2 is a plan view showing the distance sensor of the same chemical sprayer. [Figure 6] This is a front view showing the distance sensor of the same chemical sprayer to explain its operation. [Figure 7] FIG. 2 is a control block diagram of the same drug sprayer. DETAILED DESCRIPTION OF THE INVENTION

[0018] A chemical sprayer will be described as an embodiment of a work vehicle according to the present invention. However, the present invention is not limited to the embodiment described below.

[0019] <Outline of the chemical sprayer> FIG. 1 is a left side view of a chemical sprayer 1 according to a preferred embodiment of the present invention, FIG. 2 is a plan view of the chemical sprayer 1, and FIG. 3 is a front view of the chemical sprayer 1. As shown in FIG.

[0020] In this specification, as shown by the arrow in Figure 1, the side in the direction of travel of the drug sprayer 1 is referred to as the "front", and unless otherwise specified, the left side in the direction of travel of the drug sprayer 1 is referred to as the "left", and the opposite side is referred to as the "right".

[0021] The chemical sprayer 1 comprises a running body 2, a chemical tank 30 attached to the rear of the running body 2, a center boom 50 provided at the front of the running body 2, and a pair of left and right side booms 51, 52 rotatably provided on the left and right sides of the center boom 50.

[0022] The traveling vehicle body 2 comprises a main frame 8 that forms the skeleton of the vehicle body, a cabin 20 attached to the upper part of the main frame 8, front wheels 6 and rear wheels 7, and a bonnet 12 inside which an engine 3 is installed.

[0023] Inside the cabin 20 in which the operator (operator) sits, there is a steering handle 5 for steering the front wheels 6, a driver's seat 4, a controller 60 for controlling the pesticide sprayer 1, and an operating unit 9 with various operating switches.The pesticide sprayer 1 of this embodiment travels over a field based on the operation of the operator seated in the driver's seat 4, and sprays the pesticide stored in the pesticide tank 30 over the field from the center boom 50 and a pair of left and right side booms 51, 52.

[0024] The power output from the engine 3 is changed in speed in a transmission case (not shown) and then transmitted to the front wheels 6 and rear wheels 7. As a result, the traveling vehicle body 2 moves forward or backward.

[0025] Chemical tank 30 functions as a container for storing a liquid in which pesticides or the like are dissolved, and is substantially U-shaped in plan view so as to surround driver's seat 4.

[0026] The center boom 50 and the pair of left and right side booms 51, 52 each have a number of nozzles 42 for spraying chemicals supplied from the chemical tank 30, and are connected to the front of the traveling body 2 via a lifting link device 13.

[0027] The lifting link device 13 comprises an upper link arm 14 and a lower link arm 15 arranged parallel to each other, a hitch bracket 16 attached to the front of the arms, and a pair of lift cylinders 17 on the left and right, and the rear ends of the upper link arm 14 and the lower link arm 15 are connected to a support 40 provided at the front of the running body 2.

[0028] A support frame 41 to which a center boom 50 is fixed is attached to the front of the hitch bracket 16, and when the front of the upper link arm 14 and the lower link arm 15 are rotated up and down by a pair of left and right lift cylinders 17, the hitch bracket 16, support frame 41, center boom 50 and the pair of left and right side booms 51, 52 are raised and lowered (rotated) up and down as a unit.

[0029] FIG. 4 is a control block diagram of the control system, detection system, input system and drive system of the medicine sprayer 1.

[0030] The control system of the chemical sprayer 1 includes a controller 60 that controls the overall operation of the chemical sprayer 1.

[0031] As shown in Figure 7, the controller 60 includes a processing unit 89 having a CPU and a memory unit 62 having a ROM and RAM, and the memory unit 62 stores various programs and data for controlling the medicine dispenser 1.

[0032] The detection system of the pesticide sprayer 1 includes a steering sensor 58 having an encoder that detects the steering angle of the steering handle 5, an angle sensor 53 that is located near the pivot point 19 at the base of each side boom 51, 52 and detects the rotation angle of each side boom 51, 52 centered on the pivot point 19, and a central detection camera 73C and left and right side detection cameras 73S described below.

[0033] The chemical sprayer 1 is provided with an operation unit 9 that functions as an input system.

[0034] The operating unit 9 is equipped with an up / down switch 90 for operating the extension / retraction of the lift cylinder 17, a left open / close switch 91 and a right open / close switch 92 for extending / retracting the open / close cylinder 18 and switching each of the pair of left and right side booms 51, 52 between the deployed position and the stowed position, and a left up / down switch 93 and a right up / down switch 94 for extending / retracting each of the up / down cylinders 44, 45 as lifting actuators and rotating the free ends (rear ends in Figure 2) of each of the pair of left and right side booms 51, 52 in the up / down direction.

[0035] The drive system of the pesticide sprayer 1 includes a lift solenoid valve 96 that extends and retracts a pair of left and right lift cylinders 17, left and right geared motors 27 that extend and retract each of the left and right opening / closing cylinders 18 that switch each of the pair of left and right side booms 51, 52 shown in Figure 1 between an deployed position and a stored position, left and right solenoid valves 46 that extend and retract the left and right up and down cylinders 44, 45, a steering electric motor 5a (which steers while detecting the steering angle with a steering sensor 58) as an automatic steering device that rotates the steering handle 5 left and right, and a buzzer 75a and lamp 75b described below.

[0036] Here, we will explain the hydraulic system and control configuration that extends and retracts the pair of left and right lift cylinders 17 to raise and lower the lifting link device 13 and thereby raise and lower the hitch bracket 16, support frame 41, center boom 50, and the pair of left and right side booms 51, 52.

[0037] An accumulator 97 and a lift solenoid valve 96 are provided in the center of the left and right of the support frame 41, and are connected by hydraulic hoses 98 to a hydraulic pump provided on the machine body and the left and right lift cylinders 17.

[0038] A lift sensor 54 for detecting the lift position is provided at the base of the lifting link device 13, a pressure sensor 55 is provided in the accumulator 97, a vehicle speed sensor 56 and an inclination sensor 59 are provided on the aircraft body, and an acceleration sensor 57 is provided at the tip, center or base of the side booms 51, 52.

[0039] When the lift sensor 54 detects that the center boom 50 and the left and right side booms 51, 52 are at their lowest positions, the controller 60 activates the lift solenoid valve 96 to close the oil passage of the accumulator 97.

[0040] When the tilt sensor 59 detects frequent changes in the tilt of the machine body within a predetermined short period of time, the controller 60 determines that the machine is traveling on a rough road, and when the vehicle speed sensor 56 detects a vehicle speed above a predetermined level or when the acceleration sensor 57 reaches a predetermined value or higher (when the left and right side booms 51, 52 detect a bending of more than a predetermined level that could cause them to bend up or down and come into contact with the ground), the controller 60 activates the lift solenoid valve 96 to briefly open the oil passage of the accumulator 97, quickly raising the center boom 50 and the left and right side booms 51, 52 for an instant, preventing the tips of the left and right side booms 51, 52 from touching the ground and being damaged.

[0041] The controller 60 can perform the above operation any number of times by reducing the pressure to a predetermined level or less when the pressure sensor 55 detects a pressure increase of the accumulator 97 exceeding a predetermined level.

[0042] Next, the pair of left and right side booms 51, 52 can be rotated and switched independently between a stored position in which they extend rearward along the side of the traveling body 2 and a deployed position in which they extend outward in the vehicle width direction from the traveling body 2, as follows.

[0043] An opening / closing cylinder 18 having a geared motor 27 is attached to each of the left and right upper surfaces of the support frame 41 .

[0044] The tip of each opening / closing cylinder 18 is connected to an attachment arm 23 or 24 provided at both the left and right ends of the support frame 41, and when each of the left and right opening / closing cylinders 18 extends or contracts, each of the left and right attachment arms 23, 24 rotates around a rotation axis 19 extending approximately in the vertical direction.

[0045] Here, the rear of the left mounting arm 23 is fixed to the left support column 43 to which one end of the left side boom 51 is attached, and the rear of the right mounting arm 24 is fixed to the right support column 43 to which one end of the right side boom 52 is attached. Thus, when each opening / closing cylinder 18 is extended, as the mounting arms 23, 24 are rotated, each side boom 51, 52 is rotated outward in the left-right direction integrally with the support column 43 around the rotation shaft 19.

[0046] As a result, each side boom 51, 52 is deployed outward in the left and right directions, so that while traveling through a field, the center boom 50 and the pair of left and right side booms 51, 52 can be used to spray pesticides widely in the width direction of the vehicle body.

[0047] On the other hand, when the left and right opening / closing cylinders 18 are contracted, the mounting arms 23, 24 are rotated, and the side booms 51, 52 are rotated inward in the left-right direction around the rotation shaft 19.

[0048] As a result, each side boom 51, 52 assumes a storage position extending rearward along the side of the traveling body 2, thereby preventing the pair of left and right side booms 51, 52 from becoming bulky on the outside in the width direction of the body when not spraying pesticide.

[0049] Furthermore, in both the stowed posture and the deployed posture, the free ends of each side boom 51, 52 (the ends opposite the ends attached to the support columns 43, which are the rear ends in the stowed posture shown in FIG. 2) can be rotated up and down independently to the left and right as follows.

[0050] As shown in Fig. 1, a pair of left and right vertical movement cylinders 44, 45 are provided to connect the upper parts of the left and right support columns 43 to the side booms 51, 52. When the vertical movement cylinders 44, 45 extend and retract, the free ends of the side booms 51, 52 (the rear ends in the stowed position shown in Fig. 2) are rotated upward or downward.

[0051] In this embodiment, when the vertical movement cylinders 44, 45 are extended and the free ends of the side booms 51, 52 are rotated downward to their limits, the side booms 51, 52 are configured to assume a substantially horizontal posture in which the free ends and the fixed ends fixed to the mounting arms 23 are positioned at substantially the same height. Hereinafter, the posture in which the free ends and fixed ends of the side booms 51, 52 are positioned at substantially the same height will be referred to as the "horizontal posture."

[0052] On the other hand, when each of the up-and-down cylinders 44, 45 is contracted and the free ends of each of the side booms 51, 52 are raised, each of the side booms 51, 52 assumes an oblique position so that its free end side is positioned higher than its fixed end side, and rises up to a vertical position.

[0053] On the other hand, as shown in Figures 1 and 2, boom receivers 80 are provided at the left and right rear parts of the traveling body 2, respectively, to accommodate the side booms 51 or 52 in a storage position (a position in which the booms extend approximately rearward along the side of the traveling body 2).

[0054] Next, we will explain the configuration and control for automatically running along the ridges by detecting the center line LC as a central identifier in the center of the left and right sides of the mulch film M laid on the ridges of a field and the side lines LS as side identifiers on both the left and right sides.

[0055] The mulch film M is entirely black with a white center line LC in the center on both sides and white side lines LS on both sides. When the mulch film M is laid on a ridge in a field, the center line LC is located in the center on both sides of the ridge, and the left and right side lines LS are located at the boundaries of the furrows on both sides of the ridge.

[0056] The rear ends of the left and right camera support frames 70 are fixed to the support frame 41 at the front end of the body of the drug sprayer 1 and are arranged facing forward, and a vertically movable frame 71 that is long in the left-right direction is arranged at the front ends of the left and right camera support frames 70 so that it can be freely adjusted up and down via a rack and pinion mechanism 72b using a vertically movable motor 72 operated by an up-down adjustment dial 72a as an adjustment operating device of the operating unit 9.

[0057] The vertically movable frame 71 is provided with a central detection camera 73C at the center of the left and right sides for detecting a central line LC, and left and right side detection cameras 73S at the left and right ends for detecting left and right side lines LS.

[0058] The vertically movable frame 71 is mounted via a general vibration control device, so that even if the vehicle body 2 tilts when it goes over an obstacle such as a pebble in a field, the central detection camera 73C and the left and right side detection cameras 73S are not affected by the tilt or vibration of the vehicle body, thereby preventing erroneous measurements.

[0059] If it is felt that the vertical position of the central detection camera 73C and the left and right side detection cameras 73S needs to be adjusted during automatic driving, the vertical adjustment dial 72a on the operating unit 9 can be operated while continuing work, thereby activating the vertical movement motor 72 and raising or lowering the vertical movement frame 71, so that the central detection camera 73C and the left and right side detection cameras 73S can be brought closer to the mulch film M laid on the ridges without hitting the crops on the ridges, thereby improving the detection accuracy of the central line LC and the side lines LS.

[0060] Therefore, there is no need for the operator to get out of the cabin 20 (traveling vehicle body 2) to adjust the photographing distance, and automatic travel is less likely to be interrupted, reducing the amount of labor required and improving work efficiency.

[0061] In addition, instead of a configuration in which the vertical positions of the central detection camera 73C and the left and right side detection cameras 73S are adjusted by operating the up / down adjustment dial 72a, a zoom operation dial may be provided on the operation unit 9 as an adjustment operation device for changing the zoom of the central detection camera 73C and the left and right side detection cameras 73S, and the detection accuracy of the central line LC and the side lines LS may be improved by operating the zoom operation dial.

[0062] The operation unit 9 is provided with an automatic travel switching lever 74 for turning automatic travel ON / OFF. Each time the automatic travel switching lever 74 is turned ON, a buzzer 75a that emits a beep and a lamp 75b that lights up to notify the user are provided.

[0063] When the automatic driving switch lever 74 is turned ON, the controller 60 operates the steering electric motor 5a to automatically operate the steering handle 5 based on the image information of the center line LC detected by the center detection camera 73C and the image information of the side line LS detected by the left and right side detection cameras 73S, thereby causing the machine to automatically drive along the furrows.

[0064] That is, based on the image information of the center line LC detected by the center detection camera 73C, the controller 60 activates the steering electric motor 5a to automatically operate the steering handle 5 so that the center line LC is positioned in the center of the center detection camera 73C, thereby causing the machine to automatically travel along the ridges.

[0065] When the center detection camera 73C cannot detect the center line LC due to crops in the ridges, the controller 60 operates the steering electric motor 5a to automatically operate the steering handle 5 based on the image information of the side line LS detected by the side detection camera 73S so that the side line LS is positioned in the center of the side detection camera 73S, and causes the machine to automatically travel along the ridges.

[0066] Therefore, even if crops grow on the ridges and cover the central center line LC (identifier), the side detection camera 73S can detect the side lines LS (identifiers) on the left and right sides, allowing automatic driving and improving work accuracy.

[0067] The vehicle may be configured to automatically travel only by detecting the center line LC by the center detection camera 73C, or may be configured to automatically travel only by detecting the side line LS by the side detection camera 73S.

[0068] If the center detection camera 73C cannot detect the center line LC and the side detection camera 73S cannot detect the side line LS, an alarm is sounded by the buzzer 75a and automatic traveling is stopped.

[0069] In addition, the controller 60 transmits the images from the central detection camera 73C and the left and right side detection cameras 73S to a server of the management system, a management tablet terminal, etc., so that the images can be viewed on the monitor of the server or the management tablet terminal.

[0070] The center line LC and the side lines LS are white lines formed integrally with the multi-film M, but any other identifying element may be used, for example, they may be of a different color or may have a separate element attached (a separate element attached in a straight or dotted line).

[0071] Furthermore, the identifier may be formed of a magnetic material, and detectors for detecting magnetism may be used instead of the central detection camera 73C and the left and right side detection cameras 73S.

[0072] In summary, by using the center line LC and side lines LS (identifiers) of the mulch film M laid in the field to determine the left-right deviation of the traveling vehicle body 2 and then traveling automatically, automatic traveling becomes possible without using position information, thereby reducing the labor of the worker.

[0073] 4 and 5 show an embodiment in which a plurality of distance sensors 76 are arranged side by side in the left-right direction on the vertically movable frame 71 to measure and store the shape of the ridges.

[0074] For ease of understanding, Figures 4 and 5 omit the central detection camera 73C, left and right side detection cameras 73S, and related equipment on the vertically movable frame 71, but by providing the central detection camera 73C, left and right side detection cameras 73S, and distance sensor 76 described below on the vertically movable frame 71, automatic driving and measurement of ridge shape can be performed.

[0075] The vertically movable frame 71, which is elongated in the left-right direction and is provided via a vibration damping device so as not to be affected by the tilt of the traveling vehicle body 2, is provided with a distance sensor 76 consisting of four ultrasonic sensors.

[0076] The vertically movable frame 71 is located further forward on the vehicle body than the center boom 50 and the left and right side booms 51, 52, preventing herbicides and the like sprayed by the center boom 50 and the left and right side booms 51, 52 from coming into contact with the distance sensor 76.

[0077] The vertically movable frame 71 has a number of vertically penetrating fitting sections (hereinafter referred to as masses) arranged in parallel in the left-right direction, into which distance sensors 76 are fitted and attached, and electrical and communication wiring for the distance sensors 76 is provided in these masses.

[0078] Therefore, when the distance sensor 76 is fitted and attached to any of the masses of the vertically movable frame 71 , the distance sensor 76 is energized and the detection information of the distance sensor 76 is transmitted to the controller 60 .

[0079] The inner left and right distance sensor 76 is fitted into the mass of the vertically movable frame 71 so as to be positioned above the left and right ends A of the ridge top surface, and detects the distance between the left and right ends A of the ridge top surface.

[0080] The outer left and right distance sensor 76 is fitted into the mass of the vertically movable frame 71 so as to be positioned above the left and right ends of the bottom of the ridge (left and right ends of the ridge furrow) B, and detects the distance between the left and right ends of the bottom of the ridge (left and right ends of the ridge furrow) B.

[0081] Therefore, the controller 60 recognizes the squares into which the inner left and right distance sensors 76 and the outer left and right distance sensors 76 are fitted, calculates the ridge width, and calculates the ridge shape based on the distances measured by the inner left and right distance sensors 76 and the outer left and right distance sensors 76.

[0082] Therefore, since the ridge shape can be recorded, it is possible to determine whether the ridges are properly formed and cultivate crops in the appropriate ridges. In addition, the memorized ridge shape can be used in subsequent operations for automatic driving and various other tasks.

[0083] Here, a method for calculating the ridge shape by teaching will be described.

[0084] When proceeding along the ridge, the controller 60 acquires the teaching start point of the ridge when the teaching switch 77 provided on the operating unit 9 is turned ON, and acquires the teaching end point of the ridge when the teaching switch 77 is turned OFF.As the controller 60 proceeds from the start point to the end point, it learns the ridge shape using distance information from the inner left and right distance sensors 76 and the outer left and right distance sensors 76, sets the basic ridge shape, and calculates and stores the range that is considered to be a normal ridge from the basic ridge shape.

[0085] After the teaching is completed, the controller 60 judges the ridge shape calculated from the distance information from the left and right distance sensors 76 and the outer left and right distance sensors 76 to be normal if it is within a range that is considered to be a normal ridge from the stored basic ridge shape and stores it, and judges it to be abnormal if it is outside the range that is considered to be a normal ridge from the basic ridge shape and notifies of the possibility of ridge collapse, etc., by sounding a buzzer or the like and stores it.

[0086] Therefore, it is possible to prevent minute changes in vertical height from being considered abnormal while measuring the ridge shape, and by not considering slight changes in the ridge shape due to crop growth, rain, wind, etc. as abnormal, when the recorded ridge shape is used in subsequent processes, it is possible to prevent excessive measures from being taken against abnormal ridges, and to prevent the work time from being extended.

[0087] Then, when the teaching switch 77 is pressed and held, the memory of the start point, end point, and reference ridge shape is erased.

[0088] Therefore, by pressing and holding the teaching switch 77, each piece of information can be erased, so when teaching a new area where the teaching range is inappropriate or the shape or height of the ridges is different, it is possible to prevent the previous information from being used to erroneously identify an abnormality.

[0089] Furthermore, when the ridge shape calculated from the distance information from the left and right distance sensors 76 and the outer left and right distance sensors 76 deviates significantly from the range considered to be a normal ridge from the stored basic ridge shape, the controller 60 determines that the traveling vehicle body 2 has reached the end of the ridge and is therefore unable to proceed, and issues an alarm using a buzzer or the like to stop the traveling vehicle body 2 from proceeding or terminates automatic traveling.

[0090] Furthermore, the vertically movable frame 71 is provided so that it can be freely adjusted up and down via a rack and pinion mechanism 72b using a vertically movable motor 72 operated by an up and down adjustment dial 72a on the operating unit 9. Therefore, by operating the up and down adjustment dial 72a, the left and right distance sensors 76 and the outer left and right distance sensors 76 can be brought close to the ridges to the extent that they do not come into contact with the crops on the ridges, thereby improving detection accuracy.

[0091] At this time, the controller 60 corrects the distance detection in accordance with the amount of vertical movement of the left and right distance sensors 76 and the outer left and right distance sensors 76 . [Explanation of symbols]

[0092] 2 Running vehicle 5a Automatic steering device (steering electric motor) 60 Controller 71 Vertical movement frame 72a Adjustment operation device (up / down adjustment dial) 73C Camera (Central Detection Camera) 73S Camera (Side Detection Camera) 76 Distance Sensor 77 Teaching switch LC identifier (central identifier) LS Identifier (Side Identifier) M Multi Film

Claims

1. The work vehicle is provided with an automatic steering device (5a) that automatically steers the direction of travel of a traveling body (2), and is characterized in that it is provided with cameras (73C, 73S) that photograph identifiers (LC, LS) of a mulch film (M) laid in a field, and a controller (60) that recognizes the identifiers (LC, LS) from the images of the cameras (73C, 73S), calculates the difference from the center of the image, and operates the automatic steering device (5a).

2. The work vehicle according to claim 1, characterized in that it is provided with a central detection camera (73C) that photographs the central identifier (LC) of the mulch film (M) placed in the center of the ridge, and a side detection camera (73S) that photographs the side identifier (LS) that is placed near the boundary between the ridge and the furrow on the side away from the center of the mulch film (M) in the left and right directions.

3. 2. A work vehicle according to claim 1, wherein the cameras (73C, 73S) are provided so that their vertical positions or photographing distances can be freely adjusted by an adjustment operation device (72a).

4. A work vehicle as described in any one of claims 1 to 3, characterized in that a plurality of distance sensors (76) that detect the distance to the field surface are provided on an up-and-down movable frame (71) that can be freely adjusted in the vertical direction, and the shape of the ridges is calculated and recorded based on the distances measured by the plurality of distance sensors (76).

5. A work vehicle as described in claim 4, characterized in that a teaching switch (77) is provided to start and end teaching of the distance sensor (76) and erase the teaching information, a reference ridge shape is set from the distance information of the distance sensor (76) from the start to the end of teaching, and a range to be considered as a normal ridge is calculated based on the reference ridge shape.

Images