Work vehicle

Abstract

To solve a problem that, when a head-forming vegetable is harvested using a harvesting work machine, although, in some cases, only root-cutting is performed and the head-forming vegetable is left on a field and is collected by a dedicated work vehicle thereafter, the head-forming vegetable is large and heavy, so that, in a case of using a harvest collection machine adapted for such a head-forming vegetable, the machine becomes large and cannot turn compactly in a field with ridges.SOLUTION: A work vehicle has a compact configuration capable of turning compactly while handling dust or clod since the work vehicle is provided with a dedicated adsorption hand in order to reliably grasp a head-forming vegetable and employs a configuration of a placement table utilizing a conveyor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an unmanned work vehicle capable of automatic travel and automatic loading for harvesting head vegetables in a farm field. [Background technology]

[0002] When collecting and storing heading vegetables from the field, the crops tend to roll and are heavy, making it difficult to transport large quantities at once. This has created a need for unmanned work vehicles that can collect heading crops. (Patent Document 1) [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-113648 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional technology has a harvesting hand for harvesting head vegetables, a conveyor for transporting the harvested vegetables, and a storage facility at the rear. The shape of the conventional harvesting hand is not clearly described, and the handover structure between the harvesting hand and the transport conveyor and the method of transportation are unknown. Furthermore, although it is a robotic configuration, the detection device for detecting vegetables and the movement of the harvesting hand are also unknown.

[0005] The present invention aims to specialize in the configuration of a small recovery machine, which uses an imaging device to reliably grab (catch) head vegetables, transports them backward with a transport device, removes dust and clods of soil, and temporarily stores them using a transport system. [Means for solving the problem]

[0006] The first aspect of the present invention is achieved by the following technical means.

[0007] The mounting tables 141 and 142 are arranged in a V-shape facing the vehicle's longitudinal surface 100, with a mounting table gap 144 between them, the mounting tables 141 and 142 are driven and transported by a belt conveyor, a partition plate 143 is installed behind the mounting tables 141 and 142, the robot arm 50 is arranged above the mounting tables 141 and 142, and the clamping position 110 of the robot arm 50 is arranged in a straight line above the mounting table gap 144, facing the vehicle's longitudinal surface 100.

[0008] The second invention is solved by the following technical means.

[0009] Facing the front-to-rear surface 100 of the vehicle, the suction hands 120 are arranged symmetrically at the clamping positions 110 of the robot arm 50, and the clamping positions 110 of the robot arm 50 are arranged below the imaging device (130). The imaging device 130 switches its imaging direction between two directions: the position of the imaging device 130 that images the front from the center position on the left and right of the vehicle, and the imaging device 130A that images the downward from the center position on the left and right of the vehicle, and moves in conjunction with the direction of movement of the robot arm 50. [Effects of the Invention]

[0010] The first invention allows dust and dirt clumps adhering to the head vegetables to be immediately discharged outside the vehicle, keeping the vegetables clean. In addition, by reducing the space required for temporary storage of the head vegetables, the vehicle can be made into a compact work vehicle.

[0011] According to the second invention, when the imaging device is aligned with the center, the center position of the vehicle body, the center position of the robot arm, and the center position of the loading platform all coincide, and everything is aligned with the center of the imaging device, so that the unmanned work vehicle of the present invention can travel, catch, and store the harvested product with high precision. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall perspective view of a work vehicle according to the present invention, seen from the left front. [Figure 2] FIG. 1 is an overall perspective view of the work vehicle of the present invention from the front left, showing the state in which heading vegetables are being pulled out of a field. [Figure 3] FIG. 10 is a diagram showing the construction of the work vehicle of the present invention, in which the head vegetables it has caught are placed on a platform. [Figure 4] FIG. 1 is a diagram showing the construction of a work vehicle of the present invention equipped with a Mecanum wheel. [Figure 5] FIG. 1 is a side view of a work vehicle of the present invention equipped with a Mecanum wheel. [Figure 6] FIG. 1 is a top view of a work vehicle of the present invention equipped with a Mecanum wheel. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described below with reference to the embodiments shown in the drawings.

[0014] The work vehicle shown in FIGS. 1 to 6 shows an example of this embodiment.

[0015] The background of the work vehicle of the present invention will be explained.

[0016] The work involves pulling crops out of the soil in the field, cutting off the roots, stems and leaves in some cases, and storing the fruit parts of the crop in containers. However, with relatively large head vegetables, there are gaps when they are stored in containers, and the number that can be stored in a container is limited compared to its size, which poses the challenge of limited loading capacity for small vehicles.

[0017] Furthermore, when the vegetables are placed flat on a table without using a container, the vegetables tend to roll around, making it difficult to store them stably.

[0018] Furthermore, the harvesting arm has a hardened surface and is not designed to securely grab (catch) the head vegetables without damaging them.

[0019] Given this current situation, it is clear that there is a need for a dedicated unmanned work vehicle that can reliably catch head vegetables and has a platform to store the harvested head vegetables so that they do not roll away.

[0020] The present invention is a harvester for head vegetables, which are spherical and roll easily. Because the vegetables are large, they are not packed into containers or bags, but are stored on a dedicated platform. This is a robotic work machine with an automatic driving function. For head vegetables with well-rooted roots, the underground roots must be cut. The present invention is a work vehicle that collects head vegetables that have been temporarily placed in the field after cutting the roots. For head vegetables whose roots can be cut simply by catching them with a robotic arm and lifting them out of the ground, it is possible to harvest and collect them directly using the vehicle of the present invention, without using a work vehicle for root cutting.

[0021] The configuration of the work vehicle of the present invention will be described with reference to FIGS.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The robot arm 50 has an extension and retraction structure to catch the head vegetables 150, and in Figure 2 the extended position of the arm 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.

[0028] The positions of the heading vegetables 150 in the field are confirmed by imaging devices 56 and 66, and horizontal arm 52 moves to horizontal arm 52A, and horizontal arm 62 moves to horizontal arm 62A. Hands 55 and 65 move to hands 55A and 65A by extending each arm, and vertical arms 51 and 61 are controlled by motors 54A and 64A to change the mounting angles and arm dimensions at the joints of vertical arms 51 and 61 with horizontal arms 52 and 62, respectively, in order to reach the positions of vertical arms 51A and 61A. This arm control causes hands 55A and 65A to move.

[0029] Hands 55A and 65A are equipped with suction hands 120 specifically designed to catch head vegetables. The tip of suction hand 120 is made of rubber and has a rubber hand 121 shaped like a zabuton cushion, curved and recessed in the center so that it can fit snugly against the surface of the head vegetables. The pressure of the rubber hand can be adjusted using dampers 122, so that the rubber hand 121 can be pressed with the appropriate pressure to catch the head vegetables. When the rubber hand 121 is pressed with the appropriate pressure, air escapes from the recessed area, causing it to fit snugly against the more suction-sensitive surface inside. Even if some vibration occurs and the pressure decreases, the recessed area is decompressed, so the rubber hand will not come off easily.

[0030] In the case of head vegetables that have roots that extend partly underground from the field but are weak and can be pulled out by pulling them out, the suction hand 120 of this work machine is firmly clamped between arms 51 and 61, the head vegetables are pressed down with great force to secure them in place, and the cylinder 36 is extended and retracted to pull the robot arm 50 upward, thereby pulling them out of the ground.

[0031] Other rooted varieties are cut with a special harvesting machine blade (not shown) or by hand with a blade, and only the head vegetables are temporarily placed in the field, and this is also used to collect the temporarily placed head vegetables.

[0032] 2 shows the positional relationship when head vegetables 150 are caught and placed above the loading platforms 141 and 142 of the work vehicle 1. The loading platforms 141 and 142 are conveyors made of rubber belts, and are arranged on the left and right, with the center section lowered and facing the cross section 100 in the fore-and-aft direction of the vehicle, forming a V-shape, with a loading platform gap 144 in the center to allow removal of mud and foreign matter.

[0033] A typical conveying device for removing dust and clods of dirt is a roller conveyor system with multiple rollers connected together. There are gaps between the rollers, and these gaps are used to remove the dust and clods. However, in this configuration, the roller system cannot perform the movements described below. Therefore, the left and right conveyor belts must be configured to transport the vegetables in a continuous conveying system. Furthermore, a continuous system would not allow the dust and clods to fall off, making it impossible to separate them from the vegetables themselves, making it impossible to stack vegetables on top of each other while removing the dust and clods. Here, we will explain how to stack vegetables on top of each other while removing the dust and clods.

[0034] The placing tables 141 and 142 are conveyors, and can be transported slowly. Head vegetables placed in the front move so as to be sent to the rear. Also, in Figure 3, there is a partition board 143 behind the placing tables 141 and 142, and as long as the vegetables do not exceed this height, they will not fall off the placing tables 141 and 142. Therefore, because the placing tables 141 and 142 are conveyors, if they are sent to the rear they are blocked by the partition board, and lighter vegetables rise to the top and are stacked. Because they move slowly, the vegetables come into light contact with each other and are not damaged. These V-shaped conveyor platforms 141 and 142 are not flat platforms but have inclined sides, and are surrounded by a rear partition plate on the back, bottom, left and right sides, with only the front being open, so as explained above, when the conveyor is moved slowly backward, the head vegetables from the front are pushed backward, while the lighter vegetables are pushed upward, which has the advantage of allowing for stacking or cramming. During this transport from front to rear and while vegetables are piled on top of each other, dust and dirt lumps come off at the contact surface with the vegetable thread or transport conveyor and can fall through the gap 144 between the V-shaped conveyor platforms 141 and 142.

[0035] In the first invention, placing tables 141 and 142 are arranged in a V-shape facing the front-to-rear surface 100 of the vehicle, with a placing table gap 144 between them, placing tables 141 and 142 are driven and transported by a belt conveyor, a partition plate 143 is installed behind placing tables 141 and 142, and a robot arm 50 is arranged above placing tables 141 and 142, with the clamping position 110 of the robot arm 50 facing the front-to-rear surface 100 of the vehicle and arranged in a straight line above the placing table gap 144. As a result, the head vegetables caught by the robot arm 50 are separated from the robot arm 50 and placed above the placing table gap 144, which is the gap between the robot arm 50 and the placing table that also serves as the transport conveyor. Therefore, dust and dirt lumps are immediately discharged from the placing table gap 144 when the transport conveyor, which serves as the placing table, starts operating, so the head vegetables do not become covered in mud.

[0036] As shown in Figure 3, by raising arm 53 of the main body of robot arm 50 and moving it to the position of arm 53A, and then moving vertical arm 51A and vertical arm 61A further upward, it is possible to raise suction hand 120A, making it possible to place heading vegetables directly on top of the heading vegetables.

[0037] As explained above, stacking can be done by slowly moving the conveyor backwards and using the pushing force, but it is also possible to raise the robot arm 50 upward and load heading vegetables on top of those already on the conveyor. In this case, it is possible to load vegetables in the desired position.

[0038] The response of the imaging device 130 will now be explained. In Figure 1, the imaging device is pointed in the direction of travel, and accurately detects the position of the heading vegetable ahead. Next, as shown in Figure 2, the suction hand 120 grips the heading vegetable and moves in a direction facing the ground just before lifting it from the ground. This is to ensure that the suction hand 120 is accurately gripping the heading vegetable by capturing an image of the heading vegetable from directly above. If there is a misalignment and there is a risk of losing balance when lifting, the suction hand 120 opens and the vegetable is picked up again.

[0039] The image capture device 130 (130A) is located directly above the center of the suction hand 120, so the work vehicle is moved slightly to place the head vegetable in the center position. After that, the image capture device 130 faces downward to check how well the suction hand 120 is holding the vegetable until the vegetable is stored on the transport conveyor.

[0040] These other imaging devices, imaging device 56 and imaging device 57, are located on the left and right and have stereo camera functions, making it possible to calculate three-dimensional dimensions, making clear any dimensional or angular deviations in both the horizontal and vertical directions relative to the ground, and controlling the steering of the work vehicle and the extension and contraction amount of the robot arm 50 to match these distance deviations and angles.

[0041] In the second invention, the suction hands 120 are arranged symmetrically at the clamping positions 110 of the robot arm 50 facing the front-to-rear surface 100 of the vehicle, and the clamping positions 110 of the robot arm 50 are arranged below the imaging device 130. The imaging device 130 switches its imaging direction between the position of the imaging device 130 that images the front from the center position of the left and right of the vehicle, and the imaging device 130A that images the downward from the center position of the left and right of the vehicle. By linking this with the direction of movement of the robot arm 50, the imaging device 130 is always in the center of the vehicle regardless of the position of the robot arm. When the imaging device is centered, the center position of the vehicle body, the center position of the robot arm, and the center position of the mounting table all coincide, and everything is centered on the imaging device. It can be seen that this unmanned work vehicle of the present invention can travel, catch, and store harvested products with high precision.

[0042] The balance of the vehicle of the present invention will now be explained. A feature of the weight balance of the work vehicle 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 unloaded.

[0043] The rails 33 and 34, which also serve as the mast at the rear of the machine, have a wider pitch than the lower mounting base 32 and have almost the same outer width as the running wheels, so the transport conveyor can be used to its full capacity and the width of the machine body can be made small.

[0044] A satellite positioning unit 90 and an inertial measurement unit 91 are arranged on the frame 35, which is the uppermost position of the work mechanism 30, to enable automatic driving of the work vehicle 1. Although not shown, Lidar is arranged near the satellite positioning unit 90 and the inertial measurement unit 91 to provide an overview of the positional relationship between the work vehicle 1 and the field, eliminating any difference in position with the satellite positioning unit 90 and creating conditions that make it easier to calculate the relationship between the imaging positions. Furthermore, if an ultrasonic or millimeter-wave radar device is arranged as a distance measurement device other than Lidar, it can also be used as an obstacle sensor.

[0045] In this embodiment, the use of Mecanum wheels as another form of running wheels will be described.

[0046] When correcting the center position deviation of the image from the hand camera, it is sometimes desirable for the work vehicle to move left and right in a manner that is close to vertical. However, the wheel configuration must be such that the steering angle can be turned more than 180 degrees relative to the direction of travel, and vertical movement left and right is difficult with four-wheel steering.

[0047] In addition, with a crawler configuration, it is possible to perform rotational travel by rotating the left and right crawlers in opposite directions, but this type of travel can damage the field, so it is not a method of travel that is used in fields where ridges are made for field crops.

[0048] Considering the configuration of these work vehicles and the conditions of the fields, the application of Mecanum wheels, which are omnidirectional wheels with a four-wheel steering configuration, is considered. As shown in Figure 4, Mecanum wheels have a series of barrel-shaped rollers tilted relative to the axle around the outer periphery of the wheel. By changing the rotation direction and speed of each wheel, it is possible to change the direction of movement. In the illustration, the barrel-shaped rollers are omitted as being cylindrical, but the larger the curve of the barrel, the greater the lateral movement possible and the less affected the road surface the configuration will be.

[0049] Generally, Mecanum wheels cannot be used on rough roads or soil because they will slip. In the proposed field, if lanes 171 and 172, on which work vehicles travel other than in the ridge-making area 170, have relatively hard soil, or if hard rubber mats or hard boards such as plywood are laid on lanes 171 and 172, one method of preparing the field would allow Mecanum wheels to travel.

[0050] To deal with the Mecanum wheel itself, a structure has been devised in which a gap is created between the wheel section and the barrel-shaped roller, so that even if soil adheres to the roller, the roller will not be unable to rotate. [Explanation of symbols]

[0051] 56 Imaging device 66 Imaging device 120 Suction Hand 130 Imaging device 141 Mounting table 142 Mounting table 161 Mecanum Wheel 162 Mecanum Wheel

Claims

1. The mounting bases (141) and (142) are arranged in a V-shape facing the front-rear surface (100) of the vehicle, and a mounting base gap (144) is provided between them; The mounting table (141) and the mounting table (142) are driven and transported by a belt conveyor. A partition plate (143) is installed behind the mounting table (141) and the mounting table (142), and a robot arm (50) is arranged above the mounting table (141) and the mounting table (142); The work vehicle is configured such that the clamping position (110) of the robot arm (50) faces the front-rear surface (100) of the vehicle and is arranged in a straight line above the platform gap (144).

2. Facing the front-rear surface (100) of the vehicle, suction hands (120) are arranged symmetrically at clamping positions (110) of the robot arms (50); The clamping position (110) of the robot arm (50) is disposed below the imaging device (130); 2. The work vehicle of claim 1, wherein the imaging device (130) switches its imaging direction between two directions: a position of the imaging device (130) that images the front from the center position of the left and right of the vehicle, and an imaging device (130A) that images the downward from the center position of the left and right of the vehicle, and is linked to the moving direction of the robot arm (50).

Images