JP7810426B2 - Work vehicle, control method, and program - Google Patents

Description

One aspect of the present invention relates to a work vehicle, a control method, and a program.

Mountainous areas are home to many small farm fields, each with large ridges and lands, making it an important task to reduce the labor and effort required for ridge maintenance. Ridge maintenance is an important task for maintaining ridges and preventing weeds from invading farmland and pests and diseases, but with a shortage of workers and an aging workforce, ridge maintenance may become difficult, making it difficult to continue farming. Ridge maintenance is work that is not directly linked to production, so there is a need to reduce the labor required and streamline the work.

Work vehicles for performing tasks such as mowing in relation to levee management are known, such as those described in Patent Documents 1 and 2. Patent Document 1 discloses a work vehicle that uses the tension in a rope body, one end of which is supported by a fixed object, to reel in and unreel the rope body, thereby propelling the vehicle body. Patent Document 2 discloses a vehicle used for mowing on slopes that determines the relative position of a mower from the direction of travel of the mower and the payout angle and amount of two rope bodies.

Patent No. 7120605 JP 2015-167492 A

In the above-described configuration, due to the structure in which the work vehicle is lifted by the rope, an increase in vehicle weight increases the tension in the rope, and the torque required by the motor in the winding section that winds up the rope increases. Generally, high-torque motors are difficult to adopt because they are large or expensive. If a high-torque motor is not adopted, the vehicle must be retrieved manually, without rewinding the rope. For these reasons, there has traditionally been a need to reduce the torque required by the motor in the winding section.

One aspect of the present invention was made in consideration of the above-mentioned situation, and aims to provide a work vehicle, control method, and program that can reduce the required torque of the motor in the winding section.

A work vehicle according to one aspect of the present invention comprises a rope body having one end fixed to a fixed object, a winding section attached to the other end of the rope body and winding the rope body, a first fixed pulley attached near the winding section and guiding the rope body being wound by the winding section, a second fixed pulley guiding the rope body between the fixed object and the first fixed pulley, a vehicle body section that moves on the rope body between the fixed object and the second fixed pulley in the direction in which the rope body extends, and a movable pulley fixed to the vehicle body section, suspended from the rope body between the first fixed pulley and the second fixed pulley, and moving in response to the rope body being wound by the winding section.

In a work vehicle according to one aspect of the present invention, a vehicle body is suspended from a rope body between a first fixed pulley and a fixed object, and a movable pulley fixed to the vehicle body is suspended from a rope body between the first fixed pulley and a second fixed pulley. With this configuration, the gravity acting on the vehicle body can be supported using the portion of the rope body connecting the first fixed pulley to the movable pulley, the portion of the rope body connecting the second fixed pulley to the movable pulley, the portion of the rope body connecting the fixed object to the vehicle body, and the portion of the rope body connecting the second fixed pulley to the vehicle body. With this configuration, the tension in the rope body can be reduced compared to, for example, a configuration in which the vehicle body is simply suspended from a single rope body connecting from a reeling section to a fixed object. This reduces the torque required by the motor in the reeling section that reels in the rope body. As a result, the required torque can be met even with a lower-torque motor.

The system further includes a control unit for controlling the winding unit and the vehicle body unit. The winding unit has a reel that rotates with the rope body wound around it to wind the rope body, a first motor that is a drive source for rotating the reel, a first motor drive control mechanism that controls the drive of the first motor, and a winding amount detection unit that detects information related to the winding amount of the rope body wound by the reel. The vehicle body has a second motor that is a drive source for moving the vehicle body along the extension direction of the rope body, a second motor drive control mechanism that controls the drive of the second motor, and a movement amount detection unit that detects information related to the movement amount of the vehicle body relative to the rope body. The control unit may output a first control signal to the first motor drive control mechanism and a second control signal to the second motor drive control mechanism so that the vehicle body moves to a predetermined position based on the information related to the winding amount of the rope body and the information related to the movement amount of the vehicle body. In this way, the control unit outputs control signals to the first motor drive control mechanism and the second motor drive control mechanism based on specified information, automating the winding of the rope body and the movement of the vehicle body, making it easier to control the work vehicle. Furthermore, by taking into account the amount of winding of the rope body wound by the reel and the amount of movement of the vehicle body relative to the rope body, it is possible to estimate, for example, the current position of the vehicle body. Based on this information, an appropriate control signal can be output to move the vehicle body to a specified position. As described above, the above-described configuration makes it possible to appropriately control the winding unit and the vehicle body, and to move the vehicle body to a specified position with high precision.

The work vehicle may further include a control unit that controls the reeling unit and the vehicle body unit. The reeling unit includes a reel that rotates with the rope body wound around it to reel in the rope body, a first motor that serves as a drive source for rotating the reel, and a first motor drive control mechanism that controls the drive of the first motor. The vehicle body includes a second motor that serves as a drive source for moving the vehicle body along the direction in which the rope body extends, and a second motor drive control mechanism that controls the drive of the second motor. The control unit may output a first control signal to the first motor drive control mechanism and a second control signal to the second motor drive control mechanism based on at least the position of the first fixed pulley relative to the fixed object and the second fixed pulley. In this way, the control unit outputs control signals to the first motor drive control mechanism and the second motor drive control mechanism based on predetermined information, automating the reeling of the rope body and the movement of the vehicle body unit and making it easier to control the work vehicle. Furthermore, while it may be necessary to change the control of the winding unit and vehicle body section depending on the position of the first fixed pulley (i.e., the winding unit), by outputting a first control signal and a second control signal depending on the position of the first fixed pulley relative to the fixed object and the second fixed pulley, it is possible to control the winding unit and vehicle body section appropriately depending on the configuration of the work vehicle.

When the first fixed pulley is provided adjacent to the second fixed pulley, the control unit may perform a first control in which the second motor rotates in a first direction to move the vehicle body in a direction toward the fixed object, and simultaneously outputs a first control signal to cause the rope to be extended by the reel. When the first fixed pulley is provided adjacent to the second fixed pulley, the movement of the vehicle body in the direction toward the fixed object may be restricted due to limitations on the length of the rope connected to the movable pulley. In this regard, by extending the rope by the reel at the same time as the vehicle body moves, the vehicle body can be moved appropriately without being restricted by the length of the rope.

When the first fixed pulley is provided adjacent to the fixed object, the control unit may implement second control by outputting a second control signal so that the second motor rotates in the first direction, causing the body unit to move toward the fixed object, without outputting the first control signal. In this way, when the first fixed pulley is provided on the fixed object side and the body unit can move toward the fixed object without unwinding the rope body, the second control signal is output so that the body unit moves when the first control signal is not output, simplifying control and reducing the amount of processing.

The winding unit further includes a winding length detection unit that detects information related to the winding length of the rope body wound by the reel. When the first fixed pulley is located near the midpoint between the fixed object and the second fixed pulley, the control unit may determine the winding length of the rope body based on the information related to the winding length of the rope body detected by the winding length detection unit, and implement either the first control or the second control depending on the winding length of the rope body. When the first fixed pulley is located near the midpoint between the fixed object and the second fixed pulley, the winding length of the rope body determines whether the movement of the vehicle body moving in the direction toward the fixed object is likely to be restricted or not. In this regard, by switching between control when the movement of the vehicle body is restricted (first control) and control when the movement of the vehicle body is not restricted (second control) depending on the winding length of the rope body, the vehicle body can be moved appropriately while preventing unnecessary stretching of the rope body.

In one aspect of the present invention, a control method for a work vehicle includes a computer controlling the work vehicle, which outputs a first control signal to the winding unit and a second control signal to the body unit so that the body unit moves to a predetermined position based on information related to the amount of winding of the rope body and information related to the amount of movement of the body unit. This control method reduces the torque required by the motor in the winding unit of the work vehicle.

A program for a work vehicle according to one aspect of the present invention causes a computer controlling the work vehicle to output a first control signal to the winding unit and a second control signal to the body unit so that the body unit moves to a predetermined position based on information related to the amount of winding of the rope body and information related to the amount of movement of the body unit. This program reduces the torque required by the motor in the winding unit of the work vehicle.

One aspect of the present invention provides a work vehicle, control method, and program that can reduce the required torque of the motor in the winding section.

1 is a schematic diagram showing an image of a work environment of a work vehicle according to a first embodiment; 1 is a schematic diagram showing an image of a work environment of a work vehicle according to a first embodiment; FIG. 1 is a block diagram illustrating an example of a hardware configuration of a work vehicle according to a first embodiment. FIG. 2 is a block diagram showing the functions of a control unit. FIG. 10 is a schematic diagram showing an image of a work vehicle according to a modified example. FIG. 10 is a schematic diagram showing an image of a work vehicle according to a modified example. 10 is a flowchart showing a processing procedure in a work vehicle according to a second embodiment. 10 is a diagram for explaining a method for estimating the current position of a vehicle body part in a work vehicle according to a second embodiment. FIG. 11 is a flowchart showing a processing procedure in a work vehicle according to a third embodiment.

Embodiments of a work vehicle, a work vehicle control method, and a program will be described below with reference to the drawings. In the description, identical elements or elements with identical functions will be designated by the same reference numerals, and duplicate descriptions will be omitted.

[First embodiment]
1 and 2 are schematic diagrams showing an image of a work image of a work vehicle 1 according to a first embodiment. FIG. 1 is a perspective view of the work vehicle 1 positioned in a work area W on a slope. FIG. 2 is a side view of the work vehicle 1 positioned in the work area W on a slope. As shown in FIGS. 1 and 2, the work vehicle 1 is a vehicle for mowing grass in the work area W on a slope while moving. The work area W is a slope having a top W1 and a bottom W2, and slopes downward from the top W1 to the bottom W2. Specifically, the work area W is, for example, a slope of a ridge in a rice paddy field, but is not limited to this and may also be a slope of a developed land or a levee. The work area W is, for example, a steep slope with a maximum gradient of 30 to 50 degrees or more (see FIG. 2), but is not limited to this and may also be a gentler slope. Hereinafter, the horizontal direction in the work area W is referred to as the X direction, and the direction perpendicular to the X direction in the work area W is referred to as the Y direction.

The work vehicle 1 comprises a wire 2 (rope body), a winding unit 3, a first fixed pulley 4, a second fixed pulley 5, a movable pulley 6, and a vehicle body unit 7. One end of the wire 2 is fixed to a fixed object P1, and the other end is connected to the winding unit 3.

The second fixed pulley 5 and fixed object P1 are provided at the top W1 of the slope near the working area W. The second fixed pulley 5 and fixed object P1 are provided, for example, at both ends of the top W1 in the X direction. The unwinding unit 3 and the first fixed pulley 4 are provided at the top W1 of the slope near the working area W. The unwinding unit 3 and the first fixed pulley 4 are provided so as to be positioned between the second fixed pulley 5 and fixed object P1 in the X direction. The first fixed pulley 4 is provided near the unwinding unit 3. In the example shown in FIG. 1, the first fixed pulley 4 is provided adjacent to the second fixed pulley 5.

The wire 2 is a rope with one end fixed to the fixed object P1, for example, a wire made of woven metal wires. The wire 2 may be a metal wire, a string or cord made of woven natural materials, synthetic fibers, composite materials, or resin materials, or a rope molded from resin. One end of the wire 2 is, for example, loop-shaped and is supported by being hooked onto the fixed object P1, which is fixed to the ground. A snap hook or other support member for hooking onto the fixed object P1 may be connected to one end of the wire 2. The other end of the wire 2 is connected to the winding unit 3. The wire 2 extends from the other end toward the one end, passing through the first fixed pulley 4, the movable pulley 6, the second fixed pulley 5, and the car body unit 7.

The fixed object P1 is, for example, a stake driven into the ground at the top W1 or midway of the work area W or a slope near the work area W. In addition to stakes, the fixed object P1 may also be a guardrail, tree, or other structure. The stake is, for example, a steel rod with reinforcing bars or the like processed into it. The stake is, for example, inserted into a polyvinyl chloride pipe that has been buried in the ground in advance. The stake may also be driven directly into the ground. In addition to steel rods, any other type of stake may be used as long as it is capable of supporting one end of the wire 2.

The winding unit 3 is provided at the other end of the wire 2 and winds the wire 2. Figure 3 is a block diagram illustrating the hardware configuration of the work vehicle 1. As shown in Figure 3, the winding unit 3 has a reel 31, a first motor 32, a first motor driver (first motor drive control mechanism) 33, and a first encoder (winding amount detection unit) 34.

The reel 31 rotates with the wire 2 wound around it, thereby unwinding the wire 2. The other end of the wire 2 is wound around the reel 31. The first motor 32 is a drive source that rotates the reel 31. The first motor driver 33 controls the drive of the first motor 32 under the control of the control unit 8, which will be described later. The first encoder 34 detects information related to the amount of winding of the wire 2 wound by the reel 31. The first encoder 34 may be, for example, a rotary encoder, or may detect the rotation of the first motor 32. The first encoder 34 outputs the detected information related to the amount of winding of the wire 2 to the control unit 8. Note that instead of the first motor driver 33, a motor controller, a motor control IC, or other configuration capable of controlling the drive of the first motor 32 may be used.

Returning to Figure 1, the first fixed pulley 4 is located near the winding unit 3 and is a fixed pulley that guides the wire 2 being wound by the winding unit 3. The first fixed pulley 4 is located, for example, in a position that guides the wire 2 toward the winding unit 3 just before it is wound by the winding unit 3 (i.e., a position that guides the wire 2 just after it has been unwound from the winding unit 3). In the example shown in Figure 1, the winding unit 3 is adjacent to the first fixed pulley 4, but this is not limited to this. The winding unit 3 only needs to be located so that the wire 2 between the winding unit 3 and the first fixed pulley 4 does not interfere with the movement of the movable pulley 6 and the car body unit 7. For example, the winding unit 3 may be located at a position away from the first fixed pulley 4 at the top W1 of the working area W, or may be located outside the space between the second fixed pulley 5 and the fixed object P1, or may be located at another position that does not interfere with the movement of the movable pulley 6 and the car body 7. The second fixed pulley 5 guides the wire 2 between the fixed object P1 and the first fixed pulley 4.

The movable pulley 6 is fixed to the car body 7. The movable pulley 6 is suspended from the wire 2 between the first fixed pulley 4 and the second fixed pulley 5, and moves in response to the winding of the wire 2 by the winding unit 3. Specifically, the movable pulley 6 moves through the working area W together with the car body 7, which will be described later. When the movable pulley 6 moves as the wire 2 is wound by the winding unit 3, the length of the wire 2 between the first fixed pulley 4 and the movable pulley 6, and the length of the wire 2 between the second fixed pulley 5 and the movable pulley 6, changes. The first fixed pulley 4, the second fixed pulley 5, and the movable pulley 6 then rotate so that the wire 2 between the first fixed pulley 4 and the movable pulley 6, and the wire 2 between the second fixed pulley 5 and the movable pulley 6, are of appropriate lengths. At this time, tension is generated in the wire 2 between the first fixed pulley 4 and the movable pulley 6, and in the wire 2 between the second fixed pulley 5 and the movable pulley 6. As a result, the portion of the wire 2 connecting from the first fixed pulley 4 to the movable pulley 6 and the portion of the wire 2 connecting from the second fixed pulley 5 to the movable pulley 6 support the movable pulley 6, thereby supporting the gravity acting on the car body 7.

The vehicle body 7 moves on the wire 2 between the fixed object P1 and the second fixed pulley 5 in the direction in which the wire 2 extends. The vehicle body 7 is suspended, for example, by the wire 2 over a working area W on a slope. The vehicle body 7 is capable of moving over the working area W. The example shown in Figure 1 shows how the wire 2 extends when the movable pulley 6 and vehicle body 7 move to each position along the X direction.

As shown in FIG. 3 , the body 7 includes a second motor 71, a second motor driver (second motor drive control mechanism) 72, and a second encoder (movement amount detection unit) 73. The second motor 71 is a drive source for moving the body 7 along the extension direction of the wire 2. The second motor 71 is configured to move the body 7 relative to the wire 2. The second motor driver 72 controls the drive of the second motor 71 in accordance with control by the control unit 8, which will be described later. This causes the body 7 to move along the wire 2. The second encoder 73 detects information related to the amount of movement of the body 7 relative to the wire 2. The second encoder 73 may be, for example, a rotary encoder or may detect the rotation of the second motor 71. The second encoder 73 outputs information related to the detected amount of movement of the body 7 relative to the wire 2 to the control unit 8. A mowing blade (not shown) for mowing grass is provided on the underside of the body 7. The mowing blade may be, for example, a nylon cord cutter or a metal-free blade. Furthermore, in the first embodiment, the first encoder 34 and the second encoder 73 do not have to be provided on the work vehicle 1. Furthermore, the vehicle body 7 is equipped with a plurality of wheels that movably support the vehicle body as it moves within the work area W. Furthermore, since the vehicle body 7 only needs to be able to move within the work area W, a sled that movably supports the vehicle body as it moves within the work area W may be provided instead of the plurality of wheels.

Referring again to Figure 1, when the work vehicle 1 begins to be used, one end of the wire 2 is unwound from the reel 31. The wire 2 passes through the first fixed pulley 4, movable pulley 6, second fixed pulley 5, and body 7, in that order, before being hooked onto and secured to fixed object P1. At this time, tension is generated in the wire 2. With tension generated in the wire 2, the first motor 32 rotates the reel 31 forward or reverse, thereby adjusting the amount of winding and unwinding (extension) of the wire 2. Furthermore, by rotating the second motor 71 of the body 7 forward or reverse, the body 7 moves over the wire 2 in the direction in which the wire 2 extends. As described above, by winding and unwinding the wire 2 and moving the body 7 relative to the wire 2, the body 7 moves to a predetermined position in the work area W.

Figure 4 is a block diagram related to the functions of the control unit. As shown in Figure 1, control information for the work vehicle 1 is received by the operation unit 300. As shown in Figure 4, the operation unit 300 receives user operations and transmits control information for moving the work vehicle 1 to the control unit 8 via the communication unit 9. The operation unit 300, for example, communicates wirelessly with the communication unit 9. The operation unit 300 is, for example, a general-purpose mobile terminal device with communication capabilities, such as a tablet terminal, smartphone, notebook PC (Personal Computer), or proportional radio. Alternatively, the operation unit 300 may be a desktop PC. The operation unit 300 may, for example, be a PC connected to a wired LAN that connects to the Internet. In this way, the operation unit 300 may be any terminal that can use browser software with communication capabilities. The operation unit 300 may also be configured as a dedicated terminal.

The work vehicle 1 further includes a control unit 8, a communication unit 9, a drive unit 10, and a power supply unit 11. The communication unit 9 communicates between the control unit 8 and external devices. The communication unit 9 transmits control information from the operation unit 300 to the control unit 8. The drive unit 10 is configured to drive a mowing blade (not shown) for mowing grass in accordance with the control of the control unit 8. The power supply unit 11 is a power source that supplies power to various devices in the work vehicle 1.

The control unit 8 controls the drive unit 10 for mowing, and also controls the winding unit 3 and the vehicle body unit 7. The control unit 8 controls the first motor driver 33 and the second motor driver 72 based on control information received from the operation unit 300 via the communication unit 9. As an example, two control units 8 are provided in the first motor driver 33 and the second motor driver 72, respectively. The control units 8 are connected to each other via wireless communication or the like so that they can send and receive information. The operation unit 300 accesses one control unit 8 via wireless communication or the like and sends commands to the other control unit 8 via the one control unit 8. For example, the operation unit 300 may send control information (commands) to the control unit 8 provided in the second motor driver 72 via the control unit 8 provided in the first motor driver 33, or may send control information (commands) to the control unit 8 provided in the first motor driver 33 via the control unit 8 provided in the second motor driver 72. The operation unit 300 and each control unit 8 may be connected to the Internet via a mobile phone line or the like. In this case, the operation unit 300 may send commands (directly) to each control unit 8 via an internet line. Furthermore, each control unit 8 and the operation unit 300 may be connected to each other so that they can send and receive information. For example, each control unit 8 and the operation unit 300 may be connected via the internet, a wide area network (WAN), a local area network (LAN), a wireless network, or short-range wireless communication. Short-range wireless communication includes Bluetooth (registered trademark) or Wi-Fi. Furthermore, similarly to the above, each control unit 8 may be connected to each other so that they can send and receive information.

The control information is information generated based on operations input by the user to the operation unit 300, and is, for example, at least one of information indicating that the first motor 32 should rotate forward or backward and information indicating that the second motor 71 should rotate forward or backward. In other words, the user controls the first motor driver 33 and the second motor driver 72 via the operation unit 300 while actually viewing the vehicle body 7. In this way, the user controls the winding of the wire 2 and the movement of the vehicle body 7 relative to the wire 2, thereby controlling the movement of the vehicle body 7 within the work area W. The user may also control the first motor driver 33 and the second motor driver 72 via the operation unit 300 while checking the vehicle body 7 via a camera or the like.

The control unit 8 may also obtain the amount of winding of the wire 2 wound by the reel 31 from the first encoder 34. In this case, the control unit 8 may determine the amount of winding of the wire 2 based on information related to the amount of winding of the wire 2 wound by the reel 31, and present this amount of winding to the user via the operation unit 300. The control unit 8 may also obtain information related to the amount of movement of the vehicle body unit 7 relative to the wire 2 from the second encoder 73. In this case, the control unit 8 may determine the amount of movement of the vehicle body unit 7 relative to the wire 2 based on information related to the amount of movement of the vehicle body unit 7 relative to the wire 2, and present this amount of movement to the user via the operation unit 300.

As shown in FIG. 3, the control unit 8 is composed of one or more control computers. The control unit 8 has a circuit 190. The circuit 190 includes at least one processor 191, memory 192, storage 193, an input/output port 194, an input device 195, and a display device 196.

Storage 193 has a computer-readable storage medium, such as a hard disk. Storage 193 stores a program that causes control unit 8 to execute processing based on control information received from operation unit 300.

Memory 192 temporarily stores programs loaded from the storage medium of storage 193 and the results of calculations performed by processor 191. Processor 191 executes programs in cooperation with memory 192 to configure the functional modules described above. Input/output port 194 inputs and outputs electrical signals between communication unit 9, power supply unit 11, first motor driver 33, first encoder 34, second motor driver 72, second encoder 73, and drive unit 10 in response to commands from processor 191.

The input device 195 and display device 196 function as a user interface for the control unit 8. The input device 195 is, for example, a keyboard, and acquires information input by the user. The display device 196 includes, for example, an LCD monitor, and is used to display information to the user. The input device 195 and display device 196 may be integrated as a so-called touch panel.

Next, the effects of the work vehicle 1 according to the first embodiment will be described.

The work vehicle 1 according to the first embodiment comprises a wire 2 having one end fixed to a fixed object P1, a winding unit 3 attached to the other end of the wire 2 and winding the wire 2, a first fixed pulley 4 attached near the winding unit 3 and guiding the wire 2 being wound by the winding unit 3, a second fixed pulley 5 guiding the wire 2 between the fixed object P1 and the first fixed pulley 4, a vehicle body 7 that moves on the wire 2 between the fixed object P1 and the second fixed pulley 5 in the direction in which the wire 2 extends, and a movable pulley 6 fixed to the vehicle body 7, suspended from the wire 2 between the first fixed pulley 4 and the second fixed pulley 5, and moving in response to the winding of the wire 2 by the winding unit 3.

In the work vehicle 1 according to the first embodiment, the vehicle body 7 is suspended from the wire 2 between the first fixed pulley 4 and the fixed object P1, and the movable pulley 6 fixed to the vehicle body 7 is suspended from the wire 2 between the first fixed pulley 4 and the second fixed pulley 5. With this configuration, the gravity acting on the vehicle body 7 can be supported using the portion of the wire 2 connecting the first fixed pulley 4 to the movable pulley 6, the portion of the wire 2 connecting the second fixed pulley 5 to the movable pulley 6, the portion of the wire 2 connecting the fixed object P1 to the vehicle body 7, and the portion of the wire 2 connecting the second fixed pulley 5 to the vehicle body 7. With this configuration, the tension in the wire 2 can be reduced compared to, for example, a configuration in which the vehicle body 7 is suspended from a single wire 2 simply connecting the winding unit 3 to the fixed object P1. This reduces the torque required by the first motor 32 at the winding unit 3 that winds the wire 2, allowing a lower-torque motor to meet the required torque. As a result, it is possible to reduce the weight of the work vehicle 1 and improve its mobility (high mobility).

The above-mentioned effects will be explained in detail. The work vehicle according to the comparative example does not have a movable pulley 6 or second fixed pulley 5, and the body section 7 is suspended from the wire 2 between the first fixed pulley 4 and the fixed object P1. Below, the tension of the wire 2 in the work vehicle according to the comparative example is compared with the tension of the wire 2 in the work vehicle 1 according to the first embodiment. The tension of the wire 2 is measured assuming that the weight of the body section 7 is 17.6 kgf. In the work vehicle according to the comparative example, when the distance between the first fixed pulley 4 and the fixed object P1 is 280 cm and the body section 7 is located 140 cm from the first fixed pulley 4 in the X direction and 136.5 cm from the top W1 in the Y direction, the tension of the wire 2 is, for example, 12.3 kgf.

In contrast, in the work vehicle 1 according to the first embodiment, when the distance between the second fixed pulley 5 and the fixed object P1 is 280 cm and the vehicle body 7 is located 0 cm from the second fixed pulley 5 in the X direction (see the left side of Figure 1) and 138 cm from the top W1 in the Y direction, the tension of the wire 2 is, for example, 9.6 kgf. When the vehicle body 7 is located 140 cm from the second fixed pulley 5 in the X direction (see the center of Figure 1) and 136.5 cm from the top W1 in the Y direction, the tension of the wire 2 is, for example, 8.3 kgf. When the vehicle body 7 is located 280 cm from the second fixed pulley 5 in the X direction (see the right side of Figure 1) and 135 cm from the top W1 in the Y direction, the tension of the wire 2 is, for example, 5.5 kgf. The tension of the wire 2 was measured using a force gauge (manufactured by Imada Corporation). Specifically, first, a force gauge is connected to the other end of the wire 2 in place of the winding unit 3. Then, as the force pulling the wire 2 is gradually increased, the maximum value (load) measured by the force gauge before the car body 7 begins to move is taken as the tension in the wire 2.

As a result of the above, the tension in the wire 2 can be reduced in the work vehicle 1 according to the first embodiment compared to the work vehicle according to the comparative example. This reduces the torque required by the first motor 32 in the winding section 3 that winds up the wire 2.

In the work vehicle 1 according to the first embodiment, the winding unit 3 is provided at the top W1 of the working area W, rather than in the vehicle body 7. This allows the vehicle body 7 to be made lighter than when the structure for winding the wire 2 is provided in the vehicle body 7. As a result, the mobility of the vehicle body 7 can be increased.

In the work vehicle 1 according to the first embodiment, the first fixed pulley 4 is arranged adjacent to the second fixed pulley 5, but this is not limited to this. For example, as in the work vehicle 1 according to the modified example shown in FIG. 5, the first fixed pulley 4 may be arranged adjacent to the fixed object P1. In this case, when the distance between the second fixed pulley 5 and the fixed object P1 is 280 cm in the work vehicle 1, the tension of the wire 2 is, for example, 7.3 kgf when the body 7 is located 0 cm from the second fixed pulley 5 in the X direction (see the left side of FIG. 5) and 138 cm from the top W1 in the Y direction. When the body 7 is located 140 cm from the second fixed pulley 5 in the X direction (see the center of FIG. 5) and 136.5 cm from the top W1 in the Y direction, the tension of the wire 2 is, for example, 11.8 kgf. When the vehicle body 7 is located 280 cm from the second fixed pulley 5 in the X direction (see the right side of Figure 5) and 135 cm from the top W1 in the Y direction, the tension in the wire 2 is, for example, 7.8 kgf. As a result, compared to the work vehicle according to the comparative example, the work vehicle 1 according to the modified example shown in Figure 5 can reduce the tension in the wire 2. This reduces the torque required by the first motor 32 in the winding unit 3 that winds up the wire 2.

Also, for example, as in the work vehicle 1 according to the modified example shown in Figure 6, the first fixed pulley 4 may be located near the midpoint between the fixed object P1 and the second fixed pulley 5. In this case, when the distance between the second fixed pulley 5 and the fixed object P1 is 280 cm in the work vehicle 1, if the body 7 is located 0 cm from the second fixed pulley 5 in the X direction (see the left side of Figure 6) and 138 cm from the top W1 in the Y direction, the tension in the wire 2 will be, for example, 7.7 kgf. If the body 7 is located 140 cm from the second fixed pulley 5 in the X direction (see the center of Figure 6) and 136.5 cm from the top W1 in the Y direction, the tension in the wire 2 will be, for example, 9.8 kgf. When the vehicle body 7 is located 280 cm from the second fixed pulley 5 in the X direction (see the right side of Figure 6) and 135 cm from the top W1 in the Y direction, the tension in the wire 2 is, for example, 7.0 kgf. As a result, compared to the work vehicle of the comparative example, the work vehicle 1 of the modified example shown in Figure 6 can reduce the tension in the wire 2. This reduces the torque required by the first motor 32 in the winding unit 3 that winds up the wire 2. Note that "near the midpoint" may be the midpoint between the fixed object P1 and the second fixed pulley 5, or a position offset from the midpoint.

Furthermore, when the first fixed pulley 4 is positioned in the center between the second fixed pulley 5 and the fixed object P1 (see Figure 6), the variation (change) in the tension of the wire 2 at the winding unit 3 when the car body 7 moves is smaller than when the first fixed pulley 4 is adjacent to the second fixed pulley 5 or the fixed object P1 (see Figures 1 and 5). Therefore, by positioning the first fixed pulley 4 in the center between the second fixed pulley 5 and the fixed object P1, the torque required by the first motor 32 at the winding unit 3 to wind the wire 2 can be reduced.

In addition, in the work vehicle 1 according to the first embodiment, one movable pulley 6 is suspended from the wire 2 between the first fixed pulley 4 and the second fixed pulley 5, but the number of movable pulleys 6 is not limited to this. For example, multiple movable pulleys 6 fixed to the vehicle body 7 may be suspended from the wire 2 between the first fixed pulley 4 and the second fixed pulley 5. As an example, a third fixed pulley may be further provided between the first fixed pulley 4 and the second fixed pulley 5. In this case, the first movable pulley may be suspended from the wire 2 between the first fixed pulley 4 and the third fixed pulley, and the second movable pulley may be suspended from the wire 2 between the third fixed pulley and the second fixed pulley 5.

In addition, in the work vehicle 1 according to the first embodiment, the first fixed pulley 4 and the second fixed pulley 5 may be fixed to each support pole as shown in FIG. 1, or may be fixed to a single support pole. In the work vehicle 1 according to the modified example, the first fixed pulley 4 may be fixed to a support pole as shown in FIG. 5, or may be fixed to a fixed object P1.

Second Embodiment
A control unit 8A included in a work vehicle 1A according to the second embodiment will be described. In the second embodiment, descriptions of parts common to the first embodiment will be omitted, and differences from the first embodiment will be mainly described.

The control unit 8A controls the drive unit 10 for mowing control, and also controls the winding unit 3 and the vehicle body unit 7. The control unit 8A outputs a first control signal to the first motor driver 33 and a second control signal to the second motor driver 72. The first control signal is a signal that indicates whether the first motor 32 should rotate forward or backward. The second control signal is a signal that indicates whether the second motor 71 should rotate forward or backward.

Unlike the first embodiment, the control unit 8A automatically controls the winding unit 3 and the vehicle body unit 7. Specifically, the control unit 8A outputs a first control signal to the first motor driver 33 and a second control signal to the second motor driver 33 so that the vehicle body unit 7 moves to a predetermined position based on information related to the amount of winding of the wire 2 and information related to the amount of movement of the vehicle body unit 7.

Figure 7 is a flowchart showing the processing steps in the work vehicle 1A according to the second embodiment. The processing in the work vehicle 1A will be described in detail below. When mowing work in the work area W, the user sets the work vehicle 1A in the work area W. Then, in the work vehicle 1A, when the control unit 8A receives a signal from the operation unit 300 instructing the start of mowing work, the following processing is executed.

First, the control unit 8A acquires various information (step S01). Specifically, the control unit 8A acquires the distance L1 (see FIG. 1) between the second fixed pulley 5 and the fixed object P1 in the working area W. The control unit 8A acquires the distance L2 between the first fixed pulley 4 and the second fixed pulley 5. The control unit 8A acquires the length H of the working area W in the Y direction. The control unit 8A may set the various information described above in advance, or may acquire it from an external source using a sensor or the like. Alternatively, the user may input the various information described above to the operation unit 300, and the input information may be transmitted to the control unit 8A.

Next, the control unit 8A sets a movement path for the vehicle body unit 7 based at least on the distance L1 and the length H (step S02). Specifically, the control unit 8A sets a movement path for the vehicle body unit 7 within the working area W. More specifically, the control unit 8A sets the distance L1 as the movement distance of the vehicle body unit 7 in one movement along the X direction. The control unit 8A sets a descent distance, which is the distance the vehicle body unit 7 moves along the Y direction toward the bottom W2 (see Figure 1) of the working area W. The control unit 8A sets the number of movements of the vehicle body unit 7 in the X direction based at least on the descent distance and the length H. As described above, the control unit 8A sets a movement path so that the vehicle body unit 7 repeatedly moves in the X direction the set number of times, passing through the entire working area W.

For example, the control unit 8 sets a movement path so that movement is performed as follows based on the set number of movements. As one example, the vehicle body unit 7 moving along the movement path performs the above-mentioned single movement along the X direction from one end of the working area W to the other end. At the other end, the vehicle body unit 7 moves a descending distance along the Y direction toward the bottom W2 of the working area W. The vehicle body unit 7 performs the above-mentioned single movement along the X direction from the other end of the working area W to one end. At one end, the vehicle body unit 7 moves a descending distance along the Y direction toward the bottom W2 of the working area W. The vehicle body unit 7 repeatedly performs the above-mentioned movement based on the preset number of movements.

The descent distance may be a distance equal to the width in the Y direction of the mowing area, which is the area where mowing is performed by the vehicle body unit 7. The descent distance may also be a distance shorter than that width. For example, the control unit 8A may acquire overlap information, which is information indicating the degree of overlap of the areas through which the mowing areas pass. In this case, the descent distance may be set to a distance shorter than the width in the Y direction of the mowing area based on the overlap information. The overlap information may be set in advance by the control unit 8A or by the user.

Next, the control unit 8A determines the amount by which the wire 2 is wound (step S03). Specifically, the control unit 8A pre-stores a correspondence between the amount by which the wire 2 is wound around the reel 31 and the amount of rotation of the first motor 32. The control unit 8A acquires the amount of rotation of the first motor 32 from the first encoder 34 as information related to the amount by which the wire 2 is wound. The control unit 8A determines the amount by which the wire 2 is wound based on this amount of rotation.

Next, the control unit 8A determines the amount of movement of the body unit 7 relative to the wire 2 (step S04). Specifically, the control unit 8A pre-stores a correspondence between the amount of movement of the body unit 7 relative to the wire 2 and the amount of rotation of the second motor 71. The control unit 8A acquires the amount of rotation of the second motor 71 from the second encoder 73 as information related to the amount of movement of the body unit 7 relative to the wire 2. The control unit 8A determines the amount of movement of the body unit 7 relative to the wire 2 based on the amount of rotation.

Next, the control unit 8A estimates the current position of the body unit 7 in the working area W (step S05). Specifically, the control unit 8A estimates the current position of the body unit 7 based on the amount of winding of the wire 2 and the amount of movement of the body unit 7 relative to the wire 2. Figure 8 is a schematic diagram for explaining a method for estimating the current position of the body unit 7 by the control unit 8A. In Figure 8, the position of the second fixed pulley 5 is the origin A (0,0), the position of the first fixed pulley 4 is point R (L2,0), the position of the fixed object P1 is point B (L1,0), and the position of the body unit 7 is point P (x,y). Furthermore, the length of the wire 2 between the second fixed pulley 5 and the car body 7 and the length of the wire 2 between the second fixed pulley 5 and the movable pulley 6 (distance between AP) are denoted as a, the length of the wire 2 between the fixed object P1 and the movable pulley 6 (distance between BP) is denoted as b1, and the length of the wire 2 between the first fixed pulley 4 and the movable pulley 6 (distance between RP) is denoted as b2. The amount of movement of the car body 7 relative to the wire 2 is denoted as ENC1, and the amount of stretching of the wire 2 is denoted as ENC2. Note that L1 and L2 are preset constants, and x, y, a, b1, b2, ENC1, and ENC2 are variables. The amount of movement ENC1 of the car body 7 relative to the wire 2 is positive on the side of point B, and the amount of stretching of the wire 2 ENC2 is positive. Additionally, for simplicity of explanation, the length of the wire 2 between the second fixed pulley 5 and the car body 7 and the length of the wire 2 between the second fixed pulley 5 and the movable pulley 6 are approximately the same.

If the initial position of the body 7 is point P(0,0), the distance between APs is a=0, the distance between BPs is b1=L1, and the distance between RPs is b2=L2. Now, suppose the body 7 moves to point P(x,y). At this time, the relationships between the constants and variables are expressed as in the following equations (1) to (5).
b1=L1-ENC1...(1)
2a+b1+b2=L1+L2+ENC2...(2)
x ² +y ² -a ² =0...(3)
(L1-x) ² +y ² -b1 ² =0...(4)
(L2-x) ² +y ² -b2 ² =0...(5)

The control unit 8A previously acquires the distance L1 between the fixed object P1 and the second fixed pulley 5, and the distance L2 between the first fixed pulley 4 and the second fixed pulley 5 (step S01). The control unit 8A can determine the amount of extension ENC1 of the wire 2 and the amount of movement ENC2 of the body unit 7 relative to the wire 2 (steps S03 and S04). From the above, equations (1) to (5) can be considered as five simultaneous equations containing five variables: x, y, a, b1, and b2. Therefore, the solutions for x, y, a, b1, and b2 are uniquely determined. Therefore, point P(x, y), which is the position of the body unit 7, is uniquely determined. From the above, the control unit 8A can estimate point P(x, y), which is the current position of the body unit 7, based on the amount of extension ENC1 of the wire 2 and the amount of movement ENC2 of the body unit 7 relative to the wire 2.

Next, the control unit 8A outputs a first control signal to the first motor driver 33 and a second control signal to the second motor driver 33 so that the body unit 7 moves to a predetermined position (step S06). Specifically, the control unit 8A identifies the predetermined position to which the body unit 7 will move next based on the set movement path of the body unit 7 and the current position of the body unit 7. The control unit 8A outputs a first control signal and a second control signal so that the body unit 7 moves to the predetermined position.

Referring to Figure 8, the control unit 8A sets the movement path of the vehicle body 7 (step S02), thereby identifying a predetermined position P(x, y) to which the vehicle body 7 should next move based on its current position. Since equations (1) to (5) can be considered as five simultaneous equations containing five variables, ENC1, ENC2, a, b1, and b2, the solutions for ENC1, ENC2, a, b1, and b2 are uniquely determined. In other words, once the predetermined position P(x, y) is identified, the amount of movement ENC1 of the vehicle body 7 relative to the wire 2 and the amount of wire 2 extension ENC2 required for the vehicle body 7 to move to the predetermined position can be identified. The control unit 8A outputs a first control signal and a second control signal to achieve the identified amount of movement ENC1 of the vehicle body 7 relative to the wire 2 and the identified amount of wire 2 extension ENC2.

Finally, the control unit 8A determines whether the vehicle body unit 7 has reached the end of the movement path (step S07). Specifically, when the vehicle body unit 7 moves to a predetermined position, the control unit 8A determines whether the predetermined position is the end of the movement path. If the control unit 8A determines that the vehicle body unit 7 has not reached the end of the movement path (step S07: NO), the control unit 8A again determines the amount of winding of the wire 2 and the amount of movement of the vehicle body unit 7 relative to the wire 2 (steps S03 and S04). If the control unit 8A determines that the vehicle body unit 7 has reached the end of the movement path (step S05: YES), the control unit 8A concludes that the mowing operation has ended and terminates the process.

The storage 193 shown in FIG. 3 stores a program for causing the control unit 8A to execute a control method for the work vehicle 1A. The control method for the work vehicle 1A is, for example, a control method in which the computer (control unit 8A) controlling the work vehicle 1A estimates the current position of the vehicle body 7 based on the specified amount of winding of the wire 2 and the amount of movement of the vehicle body 7 relative to the wire 2, and outputs control signals to the first motor driver 33 and the second motor driver 72, taking into account the estimation result, so that the vehicle body 7 is controlled to the desired position by winding the wire 2 and moving the vehicle body 7 relative to the wire 2. The program in this case is a program that causes the computer (control unit 8A) controlling the work vehicle 1A to estimate the position of the vehicle body 7 based on the specified amount of winding of the wire 2 and the amount of movement of the vehicle body 7 relative to the wire 2, and output control signals to the first motor driver 33 and the second motor driver 72, taking into account the estimation result, so that the vehicle body 7 is controlled to the desired position by winding the wire 2 and moving the vehicle body 7 relative to the wire 2.

Next, the effects of the work vehicle 1A according to the second embodiment will be described.

The work vehicle 1A according to the second embodiment further includes a control unit 8A that controls the winding unit 3 and the vehicle body unit 7. The winding unit 3 includes a reel 31 that rotates with the wire 2 wound around it to wind up the wire 2, a first motor 32 that is a drive source for rotating the reel 31, a first motor driver 33 that controls the drive of the first motor 32, and a first encoder 34 that detects information related to the amount of winding of the wire 2 wound up by the reel 31. The vehicle body unit 7 also includes a control unit 8A that controls the winding unit 3A that controls the winding unit 3A that controls the amount of winding of the wire 2 wound up by the reel 31. The control unit 8A has a second motor 71, which is the drive source for moving the body unit 7 along the extension direction of the wire 2, a second motor driver 72 that controls the drive of the second motor 71, and a second encoder 73 that detects information related to the amount of movement of the body unit 7 relative to the wire 2. Based on information related to the amount of winding of the wire 2 and information related to the amount of movement of the body unit 7, the control unit 8A outputs a first control signal to the first motor driver 33 and a second control signal to the second motor driver 72 so that the body unit 7 moves to a predetermined position.

In the work vehicle 1A according to the second embodiment, the control unit 8A outputs control signals to the first motor driver 33 and the second motor driver 72 based on predetermined information, automating the winding of the wire 2 and the movement of the vehicle body 7, making it easier to control the work vehicle 1A. Furthermore, by taking into account the amount of winding of the wire 2 wound by the reel 31 and the amount of movement of the vehicle body 7 relative to the wire 2, it is possible to estimate, for example, the current position of the vehicle body 7. Based on this information, an appropriate control signal can be output to move the vehicle body 7 to a predetermined position. As described above, the above-described configuration makes it possible to appropriately control the winding unit 3 and the vehicle body 7, and to move the vehicle body to a predetermined position with high precision.

In the work vehicle 1A according to the second embodiment, by simultaneously controlling the first motor driver 33 of the winding unit 3 and the second motor driver 72 of the vehicle body unit 7 for a single wire 2 (a continuous rope), it is possible to move the vehicle body unit 7 (work equipment) to any position in two dimensions.

Note that the same control as in the second embodiment may also be performed in the work vehicles according to the modified examples shown in Figures 5 and 6.

[Third embodiment]
A control unit 8B included in a work vehicle 1B according to the third embodiment will be described. In the third embodiment, descriptions of parts common to the second embodiment will be omitted, and differences from the second embodiment will be mainly described.

The control unit 8B automatically controls the winding/unwinding unit 3 and the car body unit 7. Specifically, unlike the second embodiment, the control unit 8B outputs a first control signal and a second control signal depending on the position of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5. As a result, the control unit 8B moves the car body unit 7 along the X direction.

Specifically, as shown in FIG. 1, the control unit 8B performs the first control when the first fixed pulley 4 is disposed adjacent to the second fixed pulley 5. In the first control, when the vehicle body 7 moves from one end of the working area W to the other, the control unit 8B outputs a second control signal so that the second motor 71 rotates in the first direction, causing the vehicle body 7 to move toward the fixed target P1. At the same time, the control unit 8B outputs a first control signal so that the reel 31 stretches the wire 2. In the first control, the control unit 8B outputs the first control signal so that the wire 2 is stretched by an amount that does not restrict the movement of the vehicle body 7. The amount of stretching may be any amount that does not restrict the movement of the vehicle body 7. For example, the amount of stretching may be an amount that causes the vehicle body 7 to move parallel to the X direction. Alternatively, for example, the amount of stretching may be an amount that causes the vehicle body 7 to move in the Y direction, drawing a convex curve toward the bottom W2.

In addition, in the first control, when the vehicle body 7 moves from the other end of the working area W to one end, the control unit 8B outputs a second control signal so that the second motor 71 rotates in the opposite direction to the first direction, thereby moving the vehicle body 7 in a direction away from the fixed object P1. At the same time, the control unit 8B outputs a first control signal so that the wire 2 is wound by the reel 31.

More specifically, as shown in FIG. 5, the control unit 8B performs the second control when the first fixed pulley 4 is provided adjacent to the fixed object P1. In the second control, when the body unit 7 moves from one end of the working area W to the other end, the control unit 8B outputs a second control signal so that the second motor 71 rotates in the first direction, causing the body unit 7 to move in the direction toward the fixed object P1, without outputting the first control signal. In this case, the body unit 7 moves in the Y direction in a convex curve toward the bottom W2.

In addition, in the second control, when the vehicle body 7 moves from the other side to one end of the working area W, the control unit 8B outputs a second control signal so that the vehicle body 7 moves in a direction away from the fixed object P1 by rotating the second motor 71 in the opposite direction to the first direction, without outputting the first control signal.

More specifically, as shown in FIG. 6, when the first fixed pulley 4 is located near the midpoint between the fixed object P1 and the second fixed pulley 5, the control unit 8B determines the amount of winding of the wire 2 based on information related to the amount of winding of the wire 2 detected by the first encoder 34, and performs either the first control or the second control according to the amount of winding of the wire 2. More specifically, the control unit 8B estimates the current position of the car body 7 by determining the amount of winding of the wire 2 based on information related to the amount of winding of the wire 2. The control unit 8B performs the second control when the car body 7 is located closer to the second fixed pulley 5 than the first fixed pulley 4 in the X direction. The control unit 8B performs the first control when the car body 7 is located closer to the fixed object P1 than the first fixed pulley 4 in the X direction. The amount of winding of the wire 2 when the car body 7 is located directly below the first fixed pulley 4 is pre-stored as a threshold value. The control unit 8B can then appropriately switch between executing the first control and the second control by determining whether the amount of winding of the wire 2 exceeds the threshold. The threshold may be set in advance by the control unit 8B or may be input in advance by the user.

Figure 9 is a flowchart showing the processing steps in the work vehicle 1B according to the third embodiment. The processing in the work vehicle 1B will be described in detail below. In the work vehicle 1B, when the control unit 8B receives a signal from the operation unit 300 instructing the start of mowing work, the following processing is executed. First, as in the second embodiment, the control unit 8B receives various information (step S01).

Next, the control unit 8B sets a movement path for the car body unit 7 based on the position and length H of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5 (step S02B). Specifically, in step S02B, the control unit 8B sets the movement of the car body unit 7 along the X direction from one end of the working area W to the other end in accordance with the position of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5 as one movement in the X direction. The control unit 8B sets a descent distance, which is the distance the car body unit 7 moves along the Y direction toward the bottom W2 of the working area W. The control unit 8B sets the number of movements of the car body unit 7 in the X direction based at least on the descent distance and length H. As described above, the control unit 8B sets a movement path such that the car body unit 7 repeatedly moves in the X direction based on the set number of movements, and the car body unit 7 passes through the entire working area W.

In the example shown in FIG. 1, the first fixed pulley 4 is provided adjacent to the second fixed pulley 5, and so the control unit 8B sets the path for the single movement so that the single movement is achieved by implementing the first control. In this case, the path along which the body unit 7 moves in the single movement is a curved line that is convex toward the bottom W2 in the Y direction or a line segment that is parallel to the X direction.

In the example shown in Figure 5, the first fixed pulley 4 is provided adjacent to the fixed object P1, so the control unit 8B sets the path for the single movement so that the single movement is achieved by performing the second control. In this case, the path along which the body unit 7 moves in the single movement is a path that curves convexly toward the bottom W2 in the Y direction.

In the example shown in FIG. 6, the first fixed pulley 4 is located near the midpoint between the fixed object P1 and the second fixed pulley 5, so the control unit 8B sets the path for the single movement so that the single movement is achieved by implementing the first control and the second control. In this case, if the car body 7 is located closer to the second fixed pulley 5 than the first fixed pulley 4 in the X direction, the second control is implemented, and the path along which the car body 7 moves is a path that curves convexly toward the bottom W2 in the Y direction. Also, if the car body 7 is located closer to the fixed object P1 than the first fixed pulley 4 in the X direction, the first control is implemented, and the path along which the car body 7 moves is a path that curves convexly toward the bottom W2 in the Y direction or a line segment parallel to the X direction.

Next, as in the second embodiment, the control unit 8B determines the amount of winding of the wire 2 (step S03), determines the amount of movement of the vehicle body 7 relative to the wire 2 (step S04), and estimates the current position of the vehicle body 7 in the working area W (step S05). At this time, if the control unit 8B has previously performed the second control, it may determine only the amount of winding of the wire 2 (without performing step S04) and estimate the current position of the vehicle body 7. In this case, the second control does not change the amount of movement of the vehicle body 7 relative to the wire 2, so the control unit 8B does not need to newly determine the amount of movement of the vehicle body 7 relative to the wire 2 when estimating the current position of the vehicle body 7.

Next, as in the second embodiment, the control unit 8B outputs a first control signal to the first motor driver 33 and a second control signal to the second motor driver 34 so that the body unit 7 moves to a predetermined position (step S06). Finally, the control unit 8B determines whether the body unit 7 has reached the end of the movement path (step S07). If the control unit 8B determines that the body unit 7 has not reached the end of the movement path (step S07: NO), the control unit 8B again determines the amount of winding of the wire 2 (step S03). If the control unit 8B determines that the body unit 7 has reached the end of the movement path (step S05: YES), the control unit 8B determines that the mowing operation has ended and ends the process.

The storage 193 shown in FIG. 3 stores a program for causing the control unit 8B to execute a control method for the work vehicle 1B. The control method for the work vehicle 1B is, for example, a control method in which the computer (control unit 8B) controlling the work vehicle 1B sets a movement path for the body unit 7 in accordance with the position of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5, and outputs control signals to the first motor driver 33 and the second motor driver 72 so that the body unit 7 moves along that movement path. The program in this case is a program that sets a movement path for the body unit 7 in accordance with the position of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5, and outputs control signals to the first motor driver 33 and the second motor driver 72 so that the body unit 7 moves along that movement path.

Next, the effects of the work vehicle 1B according to the third embodiment will be described.

The work vehicle 1B of the third embodiment further includes a control unit 8B that controls the winding unit 3 and the vehicle body unit 7. The winding unit 3 includes a reel 31 that rotates with the wire 2 wound around it to wind the wire 2, a first motor 32 that is a drive source for rotating the reel 31, and a first motor driver 33 that controls the drive of the first motor 32. The vehicle body unit 7 includes a second motor 71 that is a drive source for moving the vehicle body unit 7 along the extension direction of the wire 2, and a second motor driver 72 that controls the drive of the second motor 71. The control unit 8B outputs a first control signal to the first motor driver 33 and a second control signal to the second motor driver 72 depending on at least the position of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5. The control unit 8B outputs control signals to the first motor driver 33 and the second motor driver 72 based on predetermined information, automating the winding of the wire 2 and the movement of the vehicle body 7, making it easier to control the work vehicle 1B. Furthermore, while it may be necessary to change the control of the first fixed pulley 4 (i.e., the winding unit 3) depending on the position of the first fixed pulley 4, the first control signal and the second control signal are output depending on the position of the first fixed pulley 4 relative to the fixed object P1 and the second fixed pulley 5, allowing the winding unit 3 and the vehicle body 7 to be controlled appropriately depending on the configuration of the work vehicle 1B.

When the first fixed pulley 4 is located adjacent to the second fixed pulley 5, the control unit 8B performs first control by outputting a second control signal so that the second motor 71 rotates in the first direction to move the car body 7 in a direction toward the fixed object P1, and simultaneously outputting a first control signal so that the wire 2 is extended by the reel 31. When the first fixed pulley 4 is located adjacent to the second fixed pulley 5, the movement of the car body 7 in the direction toward the fixed object P1 may be limited due to limitations on the length of the wire 2 connected to the movable pulley 6. In this regard, by extending the wire 2 by the reel 31 at the same time as the car body 7 moves, the car body 7 can be moved appropriately without being restricted by the length of the wire 2.

When the first fixed pulley 4 is located adjacent to the fixed object P1, the control unit 8B performs second control by outputting a second control signal so that the second motor 71 rotates in the first direction, causing the body unit 7 to move toward the fixed object P1, without outputting the first control signal. In this way, when the first fixed pulley 4 is located on the fixed object P1 side and the body unit 7 can move toward the fixed object P1 without unwinding the wire 2, the second control signal is output so that the body unit 7 moves, without outputting the first control signal, simplifying control and reducing the amount of processing.

The winding unit 3 further has a first encoder 34 that detects information related to the amount of winding of the wire 2 wound by the reel 31. When the first fixed pulley 4 is located near the midpoint between the fixed object P1 and the second fixed pulley 5, the control unit 8B determines the amount of winding of the wire 2 based on the information related to the amount of winding of the wire 2 detected by the first encoder 34, and performs either the first control or the second control depending on the amount of winding of the wire 2. When the first fixed pulley 4 is located near the midpoint between the fixed object P1 and the second fixed pulley 5, the amount of winding of the wire 2 determines whether the movement of the vehicle body 7 moving in the direction toward the fixed object P1 is easily restricted or not. In this regard, by switching between control in which the movement of the vehicle body 7 is restricted (first control) and control in which the movement of the vehicle body 7 is not restricted (second control) depending on the amount of stretching of the wire 2, it is possible to appropriately move the vehicle body 7 while preventing the wire 2 from being unnecessarily stretched.

Note that the same control as in the third embodiment may also be performed in the work vehicles according to the modified examples shown in Figures 5 and 6.

1, 1A, 1B...work vehicle, 2...wire (rope body), 3...winding section, 4...first fixed pulley, 5...second fixed pulley, 6...movable pulley, 7...vehicle body section, 8, 8A, 8B...control section, 31...reel, 32...first motor, 33...first motor driver (first motor drive control mechanism), 34...first encoder (winding amount detection section), 71...second motor, 72...second motor driver (second motor drive control mechanism), 73...second encoder (movement amount detection section), P1...fixed object.

Claims (8)

a rope body having one end fixed to a fixed object;
a winding section provided at the other end of the rope body and winding the rope body;
a first fixed pulley provided near the winding section and guiding the rope body being wound by the winding section;
A second fixed pulley that guides the rope body between the fixed object and the first fixed pulley;
A vehicle body portion that moves on the rope body between the fixed object and the second fixed pulley along the extending direction of the rope body;
A work vehicle comprising: a movable pulley that is fixed to the vehicle body portion, suspended on the rope body between the first fixed pulley and the second fixed pulley, and moves in accordance with the winding of the rope body by the winding portion. Further, a control unit is provided to control the winding unit and the vehicle body unit.
The winding unit includes a reel that rotates with the rope body wound around it to wind the rope body, a first motor that is a drive source that rotates the reel, a first motor drive control mechanism that controls the drive of the first motor, and a winding amount detection unit that detects information related to the winding amount of the rope body wound by the reel,
The vehicle body section has a second motor which is a drive source for movement of the vehicle body section along the extension direction of the rope body, a second motor drive control mechanism which controls the drive of the second motor, and a movement amount detection section which detects information related to the movement amount of the vehicle body section relative to the rope body,
2. A work vehicle as described in claim 1, wherein the control unit outputs a first control signal to the first motor drive control mechanism and a second control signal to the second motor drive control mechanism so that the body section moves to a predetermined position based on information related to the amount of winding of the rope body and information related to the amount of movement of the body section. Further, a control unit is provided to control the winding unit and the vehicle body unit.
The winding unit includes a reel that rotates with the rope body wound around it to wind the rope body, a first motor that is a drive source that rotates the reel, and a first motor drive control mechanism that controls the drive of the first motor,
The vehicle body includes a second motor that is a drive source for moving the vehicle body along the extension direction of the rope body, and a second motor drive control mechanism that controls the drive of the second motor,
2. The work vehicle according to claim 1, wherein the control unit outputs a first control signal to the first motor drive control mechanism and a second control signal to the second motor drive control mechanism in accordance with at least a position of the first fixed pulley relative to the fixed object and the second fixed pulley. A work vehicle as described in claim 3, wherein the control unit performs a first control in which, when the first fixed pulley is provided adjacent to the second fixed pulley, the control unit outputs the second control signal so that the second motor rotates in a first direction to move the vehicle body in a direction toward the fixed object, and simultaneously outputs the first control signal so that the rope body is stretched by the reel. A work vehicle as described in claim 4, wherein the control unit, when the first fixed pulley is provided adjacent to the fixed object, performs second control by outputting the second control signal so that the second motor rotates in the first direction to move the vehicle body in a direction toward the fixed object when the first control signal is not output. The winding unit further includes a winding amount detection unit that detects information related to the winding amount of the rope body wound by the reel,
6. A work vehicle as described in claim 5, wherein when the first fixed pulley is provided near the midpoint between the fixed object and the second fixed pulley, the control unit determines the amount of winding of the rope body based on information related to the amount of winding of the rope body detected by the winding amount detection unit, and performs either the first control or the second control depending on the amount of winding of the rope body. A computer for controlling the work vehicle according to claim 1,
A control method for a work vehicle, which outputs a first control signal to the winding section and a second control signal to the body section so that the body section moves to a predetermined position based on information related to the amount of winding of the rope body and information related to the amount of movement of the body section. A computer for controlling the work vehicle according to claim 1,
A program that outputs a first control signal to the winding unit and a second control signal to the body unit so that the body unit moves to a predetermined position based on information regarding the amount of winding of the rope body and information regarding the amount of movement of the body unit.