Work vehicle

Abstract

To solve the problem that when crops are stored in a container using a harvesting work machine, there is a case where the work is performed while the container is lowered in a farm field, but since a work machine for recovering the container automatically is not available, the recovery work is performed by a human operator who manually runs a transport vehicle.SOLUTION: There is provided a work vehicle with a vehicle body configuration in which a robot arm that grabs containers from a farm field performs expansion and contraction, and movement in a horizontal direction and a vertical direction with respect to the ground so as to catch the containers and stack them to a placing table.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an unmanned work vehicle capable of automatic travel and automatic loading, which collects containers containing harvested crops in a farm field. [Background technology]

[0002] When crops are removed from the field and stored in containers, the containers are large and heavy, so the work must be done while lowering them into the field, necessitating the use of work vehicles that can retrieve the stored containers unmanned. (Patent Document 1) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-121848 Summary of the Invention [Problem to be solved by the invention]

[0004] In the prior art, there is a technique that uses a gate-shaped frame between which the crop storage bags are moved.

[0005] However, the shape of the storage bag is easily deformed, making it difficult to reliably recover it automatically using an imaging device. In particular, it is difficult to automatically detect the hanging part and align the hanging device with that part.

[0006] The present invention aims to provide a work vehicle that is a device for recovering fixed-shaped containers, that shortens the overall length of the work vehicle by stacking the containers, that is sized to allow for easy turning, and that enables efficient unmanned operation by changing the travel speed according to the conditions. [Means for solving the problem]

[0007] The first aspect of the present invention is achieved by the following technical means.

[0008] The work vehicle 1 is provided with a first arm that extends and retracts parallel to the ground and a second arm that extends and retracts perpendicular to the ground, and an imaging device is installed at the intersection of the first arm and second arm facing in a direction to image the ground, and the first arm is used for alignment in a direction parallel to the ground, and the second arm is used for alignment in a height position relationship with the container 100, and angle 106 formed with the long side 105 of the container 100 or angle 107 formed with the short side 104 of the container with respect to a parallel line 50Z formed by the first arm is adjusted to match angle 106 to a predetermined value, or angle 107 to match angle 107 to a predetermined value, thereby performing steering control of the entry angle for the work vehicle 1 to catch the container 100.

[0009] The second invention is solved by the following technical means.

[0010] The robot arm 50 has horizontal arms 52 and 62, which are first arms that can be extended and retracted, inside a U-shaped cylindrical arm 53, and vertical arms 51 and 61, which are second arms that run perpendicular to the extendable first arm and extend downward from the first arm, and is configured so that the attachment angle and distance of the first arm and second arm can be adjusted. [Effects of the Invention]

[0011] The first invention allows the orientation of the container to be recognized and the container to be loaded onto a work vehicle unmanned using a robot arm. Previously, positional relationships could only be recognized by human vision, but now this is possible by adjusting the extension and retraction direction of the arm and the positional relationship of the imaging device.

[0012] The second invention makes it possible to configure a robot arm that can catch a heavy container and transport it to a platform. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an overall perspective view of a work vehicle according to the present invention, seen from the left front. [Figure 2] 1 is an overall perspective view of a work vehicle according to the present invention, seen from the left rear. [Figure 3] FIG. 2 is a left side view of the work vehicle of the present invention. [Figure 4] FIG. 1 is a top view of a work vehicle according to the present invention. [Figure 5] FIG. 2 is an overall perspective view of the work vehicle of the present invention from the front left, showing the robot hand extended. [Figure 6] FIG. 2 is an overall perspective view of the work vehicle of the present invention from the front left, showing a state in which the robot hand is retracted and a container is loaded onto the loading platform. [Figure 7] FIG. 1 is an overall perspective view of the work vehicle of the present invention from the front left, showing the robot hand retracted and containers stacked two-tiered. [Figure 8] FIG. 1 is an overall perspective view of the work vehicle of the present invention from the left front, showing the state in which the long and short sides of the container are recognized by an imaging device and the entry direction is controlled. [Figure 9] Figure 2 is an overall perspective view of the work vehicle of the present invention from the left front, showing the state in which the long and short sides of the container are recognized by an imaging device and the approach direction is controlled. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described below with reference to the embodiments shown in the drawings.

[0015] The work vehicle shown in FIGS. 1 to 9 shows an example of this embodiment.

[0016] The background of the work vehicle of the present invention will be explained.

[0017] The work involves pulling crops from the soil in the field, cutting off roots, stems, and leaves as needed, and placing the fruit in a container. However, small-sized vehicles cannot carry a large number of containers filled with harvested crops due to their small size. Therefore, depending on the size of the vehicle, the work may continue by lowering containers into the field as they fill. During this work, containers filled with crops are scattered throughout the field. This requires workers to retrieve the containers. Therefore, if containers are lowered in the center of the field and then retrieved later, it becomes extremely inefficient. Therefore, considering the efficiency of the work, regardless of the amount of crops in the containers, they are currently replaced in a position close to the road surface, where retrieval is easier.

[0018] However, this method results in variations in the amount of containers that can be filled, and requires many containers. Although the weight per load is reduced, the number of operations increases, making transportation from the field using trucks inefficient.

[0019] Given this current situation, it is considered more efficient to use containers until they are full and then lower them into the field when they are full, taking into account subsequent work. When using this work system, it is necessary to retrieve the containers that have been lowered near the center of the field. The present invention is concerned with the task of retrieving containers containing harvested crops, and requires the configuration of a robotic work machine with an automatic driving function.

[0020] The configuration of the work vehicle of the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG.

[0021] Wheel 13 is attached to the end of link 11 connected to left frame 10, and wheel 14 is attached to the end of link 12, and links 11 and 12 rotate relative to the left frame to prevent vibration. A reinforced coil spring is attached to the rotation axis at the connecting part to reduce shaking in the rotational direction.

[0022] A wheel 23 is provided at the end of a link 21 connected to the right frame 20, and a wheel 24 is provided at the end of a link 22, and the vibration response is similar.

[0023] To drive the wheels, the wheels 13 are equipped with in-wheel motors 15, which are connected to a steering mechanism 17 (not shown), allowing the vehicle to move forward and backward, change speed by changing the rotation speed of the in-wheel motors, stop, and steer left and right. Each wheel is equipped with a device with a similar configuration.

[0024] Wheel 14 is equipped with a wheel-in motor 16, which is connected to a steering mechanism 18, although not shown. Wheel 23 is equipped with a wheel-in motor 25, which is connected to a steering mechanism 27, although not shown. Wheel 24 is equipped with a wheel-in motor 26, which is connected to a steering mechanism 28, although not shown. The steering mechanism is not essential, and steering can also be achieved by changing the rotation speed of each wheel-in motor. The wheel-in motors are powered by a battery 19. Near battery 19 is a battery management system, although not shown, which receives commands from the management system that controls the operation of the work vehicle and supplies the appropriate amount of power at the appropriate time.

[0025] The working mechanism 30 is placed above this traveling section and has a left side surface 31 and a right side surface 33, which are connected by a frame 35 to form a gate-shaped frame. To enable the robot arm 50 to move up and down within this working mechanism 30, the left side surface 31 is provided with a rail 33 and the right side surface 33 with a rail 34, which serve as rails for the up and down movement of the robot arm 50. The up and down movement of the robot arm 50 is achieved by extending and retracting a central cylinder 36.

[0026] The robot arm 50 has an extension and retraction structure to catch a container 100 containing produce, and the extended position in FIG. 5(A) is shown as robot arm 50A. The extended position and shape of robot arm 50A are indicated by the letter A in the symbol. The horizontal arm 62 is made up of a stack of cylinders in several stages, and is shown in the extended state as horizontal arm 62A. Each arm has an electric cylinder inside, and the arms are operated by the extension and retraction of the electric cylinder.

[0027] The position of container 100 in the field is confirmed by imaging device 56 and imaging device 66, and horizontal arm 52 moves to horizontal arm 52A, and horizontal arm 62 moves to horizontal arm 62A. Hand 55 and hand 65 move to hand 55A and hand 65A by extending each arm, and vertical arm 51 and vertical arm 61 reach the positions of vertical arm 51A and vertical arm 61A by being controlled by motor 54A and motor 64A to change the attachment angle and arm dimensions at the joint position of vertical arm 51, vertical arm 61, and horizontal arm 52, horizontal arm 62. This arm control allows hand 55A and hand 65A to move and catch container 100.

[0028] 6 shows the positional relationship when the container 100 is placed above the platform 32 of the work vehicle 1. This is achieved by raising the arm 53 of the main body of the robot arm 50 and moving it to the position of arm 53A, and retracting it to the positions of vertical arm 51B and vertical arm 61B.

[0029] 7 shows the state where containers are stacked in two layers. By further raising arm 53 of the main body of robot arm 50 and moving it to the position of arm 53B, and then retracting it to the position of vertical arm 51C and vertical arm 61C, vertical arm 51C and vertical arm 61C are raised by motors 54C and 64C toward above arm 53B, the position of container 100 is further raised, making it possible to stack containers. When traveling in a stacked state, vertical arm 51C and vertical arm 61C are slightly pressed downward by motors 54C and 64C toward arm 53B, thereby applying a load to container 100.

[0030] In the first invention, in order for a work vehicle to automatically catch containers filled with crops in a harvest field, an arm mechanism that extends and retracts parallel to the direction of travel is required, and in order to stack the containers, they need to be able to be lifted upward from the ground.

[0031] For this reason, the vehicle is provided with a first arm that expands and contracts parallel to the ground and a second arm that expands and contracts perpendicular to the ground, and an imaging device is installed at the intersection of the first arm and the second arm facing in a direction to image the ground, and first arms, horizontal arms 52 and 62, are used for alignment in a direction parallel to the ground, and second arms, vertical arms 51 and 61, extend toward the ground, and alignment of the height positional relationship with the container 100 is confirmed from the vertical direction using the difference in the left and right zoom functions of imaging devices 56 and 57 located at the intersection of the first and second arms, and as shown in Figure 5(B), angle 106 formed with long side 105 of container 100 or angle 107 formed with short side 104 with respect to parallel line 50Z formed by first arms, horizontal arms 52 and 62, is adjusted so that angle 106 matches 0 degrees or angle 107 matches to 90 degrees, thereby steering control of the approach angle for work vehicle 1 to catch container 100.

[0032] In this way, imaging devices 56 and 57 are located on the left and right, and because they function as stereo cameras, it is possible to calculate three-dimensional dimensions, making clear any dimensional or angular deviations in both the horizontal and vertical directions from the ground, and these distance and angle deviations are matched by controlling the steering of the work vehicle and the extension and contraction amount of the robot arm 50. Furthermore, imaging devices 56 and 57 have a wide-angle imaging range, so it is possible to capture images of the inside of the container even if they are fixed in the positions shown in the figure.

[0033] Identifying the long and short sides of a container will be described with reference to Fig. 8. Identifying the long and short sides 105B and 104B of the container 100 is possible by measuring the length using an imaging device.

[0034] Another method is to have the container 100 have letters, shapes, or images that can be recognized by an imaging device, and by making these recognizable letters, shapes, or images different on the long and short sides of the container, it becomes possible to identify them. In this diagram, label 102 indicates the direction of the long side of the container, and label 103 indicates the short side. By recognizing the labels, the imaging device can determine whether the container is on the long side or the short side and determine the direction in which the work vehicle should enter.

[0035] Furthermore, as shown in Figure 9, when determining whether the container 100C is on the long side or the short side, it would be inefficient if the work machine had to drive close to the container and then check the container to find that it was empty. Therefore, if the user could display label 102 or label 103 when crops were placed in the container, the user could confirm that the container contained crops when these labels were displayed. In Figure 9, labels 102A and 103A indicate this content. Each label has a cover that hides the label, and the label can be seen by removing the cover.

[0036] It is possible to check whether such a container contains harvested produce and the orientation of the container, and to match the approach angle for the work vehicle 1 to catch the container. By performing this orientation adjustment, it becomes easier to align the hand with the handle. In addition, the orientation of the container is important for loading, and by having the work vehicle 1 recognize the long and short sides and not confuse them, it is possible to transport it without any problems.

[0037] The movement of robot arm 50 has been explained, but in order for horizontal arms 52 and 62 to extend and retract and maintain sufficient strength, it is preferable to make arm 53, which is the main body of the arm, a cylindrical body in a U-shape as shown in the figure, and insert the extendable arm into the part that is open only at the front.

[0038] In the second invention, robot arm 50 incorporates horizontal arms 52 and 62, which are first arms that can be extended and retracted, inside arm 53, which is a U-shaped cylindrical body, and vertical arms 51 and 61, which are second arms that run perpendicular to the extending first arms and extend downward from the first arms, making it possible to adjust the attachment angle and distance of the first and second arms.

[0039] A feature of the weight balance of the work vehicle 1 is that the cylinders 36 for raising and lowering the robot arm 50 are provided above the rear wheels 14 and 24. In the present invention, the center of gravity moves forward as the robot arm extends and retracts. This is addressed by positioning the cylinders 36 above the rear wheels, which are the rearmost ends, when the vehicle is unladen. Although not shown in this diagram, the battery 19 that serves as the power source for the wheel-in motor is located in a thin shape below the platform 32, and serves to lower the center of gravity.

[0040] Furthermore, when a container is placed on the platform 32, the center of gravity is stabilized at the bottom in the center, ensuring excellent balance during subsequent work. The platform has protrusions in some areas to prevent the loaded container from easily shifting position due to vibration.

[0041] A feature of the hand section of the work vehicle 1 is that the tips of hands 55 and 65 are tapered in the vertical direction and have an arc-shaped curve in the front-to-back direction, making it easy to fit into the handle of a container. Therefore, the work vehicle 1 can approach a container placed in a field so that it faces the front of the machine, and once it is ready to store the container, it can operate the robot arm 50, or it can operate the robot arm 50 while traveling.

[0042] The rails 33 and 34, which also serve as the mast at the rear of the vehicle, have a wider pitch than the lower platform 32 and are almost the same width as the running wheels, so the width of the container can be fully utilized and the width of the vehicle can be made small. Depending on the configuration, only the top plate of the platform can be made wider by overlapping with the running wheels when viewed from above.

[0043] A satellite positioning unit 90 and an inertial measurement unit 91 are placed on the rail 35, which is the uppermost position of the work mechanism 30, to enable automatic operation of the work vehicle 1. Although not shown, by placing a lidar near the satellite positioning unit 90 and the inertial measurement unit 91, which serves the purpose of overlooking the positional relationship between the work vehicle 1 and the field, it is possible to eliminate any difference in position with the satellite positioning unit 90, thereby making it easier to calculate the relationship between the imaging positions. Furthermore, if an ultrasonic or millimeter-wave radar device is placed as a distance measurement device other than a lidar, it can also be used as an obstacle sensor.

[0044] The driving control will now be described.

[0045] This work vehicle is designed for transportation, but because containers filled with crops are scattered throughout the field, in order to improve work efficiency, it runs at high speed when there are no containers loaded, and the speed is controlled to decrease as the load increases. Similarly, acceleration from a stop is controlled to accelerate more slowly as the load increases. The load can be determined by automatically detecting the number of stacked layers, or by installing a weight sensor on one of the axles.

[0046] In addition to loading onto the platform, the robot arm 50 can be extended and the robot can move while holding the container. In this state, the robot can further reduce its travel speed to ensure smooth transportation.

[0047] In addition, travel on an incline can also be accommodated by adjusting the extension and retraction amount of the robot arm 50. When the road ahead is inclined while travelling, the extension and retraction amount of the robot arm 50 can be temporarily extended forward to shift the center of gravity forward, thereby achieving balance.

[0048] The stacking alignment control will be described.

[0049] When loading a second container on top of a first container, if the loading position cannot be aligned, the first container on the loading platform is caught again, the robot arm 50 is raised upward, or extended forward, and then reloading control is performed to load the container on the loading platform again. One cause of the misalignment may be a movement of the container position due to vibration during travel, and this control addresses this by reloading.

[0050] When stacking two layers, if the weight is toward the rear and the balance becomes worse, or if it is not possible to load on the first layer even if a reloading operation is performed, the first layer can be left loaded on the loading platform, and only the second layer can be moved with the robot arm 50 extended forward. [Explanation of symbols]

[0051] 1 Work vehicle 50 Robot Arm 51 Vertical Arm 52 horizontal arm 56 Imaging device 66 Imaging device 100 containers 106 Angle with the long side 105 107 Angle with the short side 104

Claims

1. A first arm that extends and retracts parallel to the ground and a second arm that extends and retracts perpendicular to the ground are provided, An imaging device is installed at the intersection of the first arm and the second arm, facing in a direction to image the ground; The first arm is used to align the position parallel to the ground, and the second arm is used to align the position relative to the height of the container (100), From the angle (106) formed by the first arm and the long side (105) of the container (100) or the angle (107) formed by the short side (104) of the container (100) with respect to the parallel line (50Z) formed by the first arm, A work vehicle that performs steering control of the approach angle for the work vehicle 1 to catch the container 100 by matching the angle (106) to a predetermined value or matching the angle (107) to a predetermined value.

2. 2. The work vehicle of claim 1, wherein the robot arm (50) has horizontal arms (52) and (62) that are first arms that can be extended and retracted inside a U-shaped cylindrical arm (53), and vertical arms (51) and (61) that are second arms that are perpendicular to the extendable first arms and extend downward from the first arms, and wherein the attachment angle and distance of the first arms and second arms can be adjusted.

Images