JP7626191B2 - Work vehicles - Google Patents

Description

The present invention relates to a work vehicle such as a tiller.

A known work vehicle has a route generation unit that sets a travel area and generates a travel route for the vehicle in the travel area, and travels autonomously along the generated route, the travel area including a first area including a work route along which work is performed by a work machine, and a second area set around the first area, and when an instruction to start work is given in the second area, if the difference in angle between the azimuth angle in which the vehicle body is facing and the azimuth angle from the current position to the work start point is within a specified range, the work vehicle travels from the current position to the start position of the work route and then starts work (see Patent Document 1).

Patent No. 6594805

However, with conventional technology, when moving to the starting position for work, it was possible for the machine to make unnecessary sharp turns or reverse, causing unnecessary damage to the field.

An object of the present invention is to provide a work vehicle that can travel smoothly and automatically without damaging farm fields .

A first invention of the present invention is a work vehicle equipped with a traveling body that travels on a reciprocating traveling path that is set inside a farm field and repeats reciprocating traveling, and a headland traveling path that travels along the outer circumferential shape of the reciprocating traveling path, and is equipped with a control unit that, upon receiving an instruction to start automatic work traveling, causes the traveling body to perform automatic travel traveling that does not involve work along the headland traveling path to a work start point on the reciprocating traveling path, and the control unit, when turning during the automatic travel traveling that does not involve work on the headland traveling path, does not perform a reverse operation after turning, and is equipped with a braking device that is capable of applying unilateral braking to each of the left and right rear wheels, the headland traveling path has a plurality of straight lines, and when turning and moving from one side on the headland traveling path to another side, the work vehicle performs a turning without applying the unilateral brake .

In the second aspect of the present invention, a plurality of headland travel routes are set from the inside to the outside in the headland area,
The control unit is a first work vehicle of the present invention that automatically selects the headland traveling route other than the outermost route as a route for movement traveling of the traveling body that does not involve work .

In the third aspect of the present invention, when the traveling vehicle body is automatically rotated and moved to a traveling line substantially parallel to a traveling route during a moving travel not involving work, the control unit performs the turning with the one-side brake,
In the work vehicle of the first or second aspect of the present invention , when turning and transferring from a traveling path to a traveling line that is substantially perpendicular to the traveling path, the turning is performed without applying the single brake .

According to the first aspect of the present invention, while it is necessary to turn and then reverse to fill the working area during work travel in order to perform work evenly, this is not necessary during non-work travel travel, and so by omitting this, it is possible to travel without unnecessarily damaging the field. Also, by suppressing unnecessary braking when traveling on the headland travel route, it is possible to travel without unnecessarily damaging the field.

The second aspect of the present invention makes it possible to suppress deviation from the field area and prevent the machine from stopping.

According to the third aspect of the present invention, when traveling along a route that requires a sharp turn, one-sided braking can be applied to allow the vehicle to move appropriately to the work starting point , and when a gentle turn can be made, unnecessary braking can be suppressed to allow the vehicle to move without unnecessarily damaging the field.

FIG. 1 is a side view of a work vehicle according to an embodiment of the present invention; Configuration diagram of the control unit of the work vehicle FIG. 2 is a simplified plan view showing a travel route of the work vehicle traveling in a farm field. FIG. 1 is a simplified plan view for explaining the travel route of the work vehicle (case 1); FIG. 2 is a simplified plan view for explaining the travel route of the work vehicle (case 2); FIG. 1 is a simplified plan view for explaining the travel route of the work vehicle (Case 3) FIG. 4 is a simplified plan view for explaining the travel route of the work vehicle (Case 4)

The following describes an embodiment of the present invention in detail with reference to the drawings. Figure 1 is a side view of a tractor as an example of a work vehicle according to an embodiment of the present invention.

First, the overall configuration of the tractor 1 will be described with reference to Figure 1.

The tractor 1, which is a work vehicle, is an agricultural tractor that performs work in fields and the like while traveling on its own. In addition to being driven by a driver (also called an operator) and traveling through a field while performing a specified task, the tractor 1 also performs the specified task while traveling automatically through the field, with each part controlled by a control system centered on the control unit 40 (see FIG. 2), which will be described later.

In the following, the forward/rearward direction refers to the direction of travel of the tractor 1 when traveling straight, with the forward side of the traveling direction being defined as "front" and the rear side being defined as "rear." The traveling direction of the tractor 1 refers to the direction from the driver's seat 8 (described later) toward the steering wheel 9 when traveling straight (see Figure 1).

The left-right direction is the direction that is horizontally perpendicular to the front-rear direction. In the following, left and right are defined as facing "forward." In other words, when the operator of the tractor 1 (also called the "operator") is seated in the operator's seat 8 and facing forward, the left hand side is the "left" and the right hand side is the "right."

The up-down direction is the vertical direction. The front-rear direction, left-right direction, and up-down direction are perpendicular to each other. Note that each direction is defined for the convenience of explanation, and the present invention is not limited to these directions. In addition, hereinafter, the tractor 1 may be referred to as the "machine body."

As shown in FIG. 1, the tractor 1 includes a running body 2 and a work implement W. The running body 2 includes a body frame 3, front wheels 4, rear wheels 5, a bonnet 6, an engine E, a steering unit 7, and a transmission case 10. The body frame 3 is the main frame of the running body 2.

The front wheels 4 are a pair, one on the left and one on the right, and are primarily used for steering (steered wheels). The rear wheels 5 are a pair, one on the left and one on the right, and are primarily used for driving (drive wheels). The tractor 1 may be configured to be switchable between two-wheel drive (2WD) in which the rear wheels 5 are driven, and four-wheel drive (4WD) in which both the front wheels 4 and the rear wheels 5 are driven. In this case, both the front wheels 4 and the rear wheels 5 are driven wheels. The traveling body 2 may be equipped with a crawler device instead of the wheels (front wheels 4 and rear wheels 5). In this case, the traveling crawlers are the drive wheels.

The bonnet 6 is provided at the front of the traveling vehicle body 2 so that it can be opened and closed freely. The bonnet 6 can be rotated (opened and closed) in the vertical direction with the rear part as the center of rotation. When closed, the bonnet 6 covers the engine E mounted on the vehicle body frame 3. The engine E is the driving source of the tractor 1, and is a heat engine such as a diesel engine or a gasoline engine.

The control section 7 is provided on the top of the traveling vehicle body 2, and includes a cockpit 8 and a steering wheel 9. The control section 7 may be formed by being covered by a cabin 7a provided on the top of the traveling vehicle body 2. The cockpit 8 is the driver's seat. The steering wheel 9 is operated by the driver when steering the front wheels 4. The control section 7 includes a display section (meter panel) in front of the steering wheel 9 that displays various information.

The control unit 7 also includes various operating levers, such as a forward/reverse lever, an accelerator lever, a main shift lever, and an auxiliary shift lever, as well as various operating pedals, such as an accelerator pedal, a brake pedal, and a clutch pedal.

The transmission case 10 houses the transmission (gear change mechanism). The transmission 10 appropriately reduces the speed of the power (rotational power) transmitted from the engine E and transmits it to the rear wheels 5, which are the driving wheels, and the PTO (Power Take-off) shaft.

A work machine W that performs work in the field is connected to the rear of the traveling body 2, and a PTO shaft that transmits the power to drive the work machine W protrudes rearward from the transmission case 10. The PTO shaft transmits the rotational power that has been appropriately reduced by the transmission to the work machine W that is attached to at least the rear of the traveling body 2.

In addition, a lifting device 12 that raises and lowers the work machine W is provided at the rear of the traveling vehicle body 2. The lifting device 12 moves the work machine W to a non-working position by raising the work machine W. In addition, the lifting device 12 moves the work machine W to a ground work position by lowering the work machine W.

The working machine W is a machine that performs work in a farm field. In the example shown in FIG. 1, the working machine W is a rotary tiller W1 that performs tilling work in a farm field. The rotary tiller W1 tills the farmland (soil) by rotating the tiller tines using power transmitted from the PTO shaft.

The tractor 1 also includes a control unit 40 as shown in FIG. 2. The control unit 40 controls the engine E (40a is an engine ECU) and the traveling speed of the traveling vehicle body 2 (40b is a traveling system ECU). The control unit 40 also controls the work equipment W. 40c is a recording unit that records various data.

The tractor 1 also includes a positioning device 30. The positioning device 30 is provided on the top of the traveling body 2 and measures the position of the traveling body 2. The positioning device 30 is, for example, a Global Navigation Satellite System (GNSS), and can perform positioning and timing by receiving radio waves from a navigation satellite Sa orbiting in the sky.

The tractor 1 also includes an obstacle sensor 20. The obstacle sensor 20 includes a front sensor 21 and a rear sensor 22. The front sensor 21 is disposed at the front of the traveling body 2, for example, by being attached to a sensor mounting stay 13 provided in front of the bonnet 6, and detects objects (obstacles) present in front of the traveling body 2. The rear sensor 22 is disposed at the upper rear of the traveling body 2, for example, by being attached to the top of the cabin 7a, and detects objects (obstacles) present behind the traveling body 2.

Furthermore, both the front sensor 21 and the rear sensor 22 are mid-range sensors, preferably infrared sensors. Infrared sensors emit infrared beams and detect the light reflected from obstacles.

The front sensor 21 and rear sensor 22 can detect the distance to an obstacle by, for example, measuring the time it takes to detect the reflected light from an obstacle after emitting an infrared beam. The front sensor 21 and rear sensor 22 are infrared sensors that detect obstacles two-dimensionally, with a detection range of, for example, several meters to several tens of meters. Note that it is also possible to use other mid-range sensors other than infrared sensors as the obstacle sensor 20, such as ultrasonic sensors. 100 denotes a remote control device (remote controller), and the tractor 1 can be remotely controlled by the operator operating the remote control device 100.

Next, we will provide an overview of how to cultivate a field using the tractor 1.

Figure 3 is a diagram showing a typical travel route of the tractor 1. Here, 50 indicates a farm field, 50a indicates a main range area in the approximate center of the farm field 50 where the tractor travels back and forth, and 50b indicates a headland area outside the main range area 50a. 51 indicates a bank, and 52 indicates an entrance and exit. The headland travel route in the headland area 50b is set up in multiple steps (3 routes), with one revolution being one step.

As shown by the dashed dotted line, the tractor 1 performs automatic work travel back and forth within the main range area 50a, then performs automatic work travel once around the headland area 50b immediately surrounding the outer periphery, and stops at the temporary stop position 50c. R1a indicates the round-trip travel route, and R1a-1 indicates the first travel line in the round-trip travel. R1b is the innermost travel route for one round within the headland area 50b, and is the automatic work travel route as described above.

Such a route is pre-recorded in the recording unit 40c of the control unit 40, and the driving system ECU 40b operates the steering device 9 and the transmission 10 while checking the satellite signals received by the positioning device 30 against the pre-recorded route data to make the tractor 1 drive autonomously for work.

Then, for the remaining area of the headland area 50b, as shown by the solid line, the operator 53 gets on the tractor 1 at the temporary stop position 50c and manually drives the tractor 1 to perform the work. Note that the getting on position can be other than the temporary stop position 50c.

Here, R2a is the outermost circular travel route in the headland area 50b, that is, the travel route adjacent to the bank 51. R2b is the central circular travel route in the headland area 50b. That is, in FIG. 3, three circular travel routes (R1b, R2a, R2b) are set as travel routes in the headland area 50b. Note that even if the two outer travel routes R2a and R2b in the headland area 50b are manual work travel routes, the data of these travel routes R2a and R2b are stored in advance in the recording unit 40c of the control unit 40. For example, they are used to warn if the worker 53 deviates significantly from the travel routes R2a and R2b during manual driving.

When the tractor 1 travels in this manner, S is the starting point of the automatic work travel in the main range area 50a, i.e., the round-trip travel route R1a.

Now, when an instruction to start automatic work driving is received, the control unit 40 will explain in several cases how to automatically move the tractor 1 located at the entrance/exit 52 on the bank 51 to the work start point S in order to make the tractor 1 perform automatic work driving in the main range area 50a where it travels back and forth.

This movement is automatic travel without work being performed. Also, the shape of the field 50 is taken as an example to be approximately rectangular, as shown in Figures 4 to 7, and the "up and down, left and right" indicating the position are defined on those drawings.

(1) As shown in FIG. 4, when the work start point S is diagonally opposite the entrance/exit 52, the control unit 40 causes the tractor 1 to automatically travel in a non-working state as follows.

That is, the tractor 1 located at the entrance/exit 52 automatically travels along the innermost route R1b or the middle route R2b other than the outermost route R2a out of the three travel routes R1b, R2a, and R2b in the headland area 50b. This is because if the tractor 1 travels along the outermost route R2a, it is likely to deviate from the field area and stop frequently. For the same reason, the outermost route R2a is not used in the following cases.

For example, when traveling along the innermost route R1b, the vehicle travels along route R1b-1 on the right side, then makes a further turn RD1 to move to the upper side R1b-2, and then makes a further turn RDS1 to move to the first travel line R1a-1 of the round-trip travel route R1a. This turn RD1 is made at a nearly right angle, so the turning radius is relatively large and gentle control is sufficient. So-called side brakes are not used.

Alternatively, if the middle route R2b is chosen, the vehicle will travel along route R2b-1 on the right side, then make a further turn RD2 to move to the upper side R2b-2, then make a further turn RDS2 to move to the first travel line R1a-1 of the round-trip travel route R1a. This turn RD2 also turns at a nearly right angle, so the turning radius is relatively large and gentle control is sufficient. No so-called side brakes are used.

In these turns RD1 and RD2, unlike the robot travel (turning method) on the headland where normal work is performed, no reverse motion is performed. This avoids disturbing the headland surface and eliminates unnecessary motion, allowing the robot to move quickly to the work start point S. Of course, in order to standardize the control software, it is also possible to perform reverse motion. However, reverse motion is possible after entering the work start point S.

(2) As shown in FIG. 5, when the work start point S is located above on the same side as the entrance/exit 52, the control unit 40 causes the tractor 1 to automatically travel without working as follows.

That is, the tractor 1 located at the entrance/exit 52 automatically travels along the three travel routes R1b, R2a, and R2b in the headland area 50b, selecting the innermost route R1b or the middle route R2b other than the outermost route R2a.

For example, when traveling along the innermost route R1b, the vehicle travels along route R1b-1 on the right side. It then makes a turn RDS3 to move to the first travel line R1a-1 of the round trip travel route R1a. This turn RDS3 is not the right-angle turn described above, but is on a nearly parallel line, so it is necessary to make a sharper turn than the right-angle turn described above, such as a one-point turn. In other words, the vehicle is equipped with a braking device capable of applying single-sided braking to each of the left and right rear wheels 5.5, and a single-point turn is performed using the single brakes.

Alternatively, if the middle route R2b is used, the vehicle travels along route R2b-1 on the right side, then makes a turn RDS4 to move to the first travel line R1a-1 of the round-trip travel route R1a. This turn RDS4 is not a right-angle turn as described above, but is on a nearly parallel line, so it is necessary to make a sharper turn than a right-angle turn, for example by making a one-point turn (using the brakes, for example).

Furthermore, even though they are both single-point turns, when comparing turn RDS4 for the middle route R2b with turn RDS3 for the innermost route R1b described above, the distance to the driving line R1a-1 is different, so turn RDS3 for the innermost route R1b requires a sharper turn.

In other words, when turning to the work start point S from route R2b other than the innermost headland travel route R1b among the route portions of the headland travel route that are set at a parallel angle to the route portion where the work start point S of the round-trip travel route exists, the single-brake braking force is weakened compared to turning to the work start point S from the innermost headland travel route R1b portion.

(3) As shown in FIG. 6, when the work start point S is located at the lower left side of the entrance/exit 52 and the tractor 1 is not facing the work start point S, the control unit 40 causes the tractor 1 to automatically travel in a non-working state as follows.

That is, the tractor 1 located at the entrance/exit 52 automatically travels along the three travel routes R1b, R2a, and R2b in the headland area 50b, selecting the innermost route R1b or the middle route R2b other than the outermost route R2a.

For example, when traveling along the innermost route R1b, the vehicle travels along route R1b-1 on the right side, then makes a turn RD1 to move to the upper side R1b-2, then makes a turn RD3 to move to route R1b-3 on the left side. It then makes a turn RDS5 to move to the first travel line R1a-1 of the round-trip travel route R1a.

The RDS5 does not make right-angle turns, but rather turns on a nearly parallel line, so it is necessary to make sharper turns than right-angle turns, for example by making a one-point turn (using the brakes, for example).

Alternatively, if the middle route R2b is used, the vehicle travels along route R2b-1 on the right side, then turns RD2 to move to the upper side R2b-2, then turns RD4 to move to route R1b-3 on the left side. This route is the same as when the vehicle travels along the innermost route R1b described above. It then turns RDS5 to move to the first travel line R1a-1 of the round-trip travel route R1a. Note that after turning RD4, the vehicle may also use route R2b-3 in the middle on the left side.

These turning RD3 and turning RD4 are made at almost right angles, so they can be made relatively gently. There is no need to use the so-called side brakes.

Furthermore, unlike the robot travel (turning method) on the headland where normal work is performed, no forward or backward movement is performed during these turns RD3 and RD4. This avoids disturbing the headland surface and allows for quick movement to the starting point S, as no unnecessary movement is performed. Of course, in order to standardize the control software, it is also possible to perform a reverse movement. However, reverse movement is possible after entering the work starting point S.

(4) As shown in FIG. 7, when the work start point S is located at the lower left side of the entrance/exit 52, and the direction of the tractor 1 is different from that shown in FIG. 6 and faces the work start point S side, the control unit 40 causes the tractor 1 to perform non-working automatic driving as follows.

In other words, the tractor 1 travels counterclockwise in principle, but if it travels clockwise, the work start point S is in the closest position and the tractor 1 is facing the work start point S.

In this case, the tractor 1 located at the entrance/exit 52 will select the innermost route R1b or the middle route R2b other than the outermost route R2a as the route from among the three travel routes R1b, R2a, and R2b in the headland area 50b, and will automatically travel to the left.

For example, when traveling along the innermost route R1b, the vehicle travels along the lower route R1b-4, turns RDS6, and moves to the first travel line R1a-1 of the round-trip travel route R1a. This turning RDS6 turns at a nearly right angle, so the turning radius is relatively large and gentle control is sufficient.

Alternatively, if the middle route R2b is used, the vehicle travels along the lower route R2b-4, turns RDS7, and moves to the first travel line R1a-1 of the round-trip travel route R1a. This turn RDS7 also turns at a nearly right angle, so the turning radius is relatively large and gentle control is sufficient.

Next, in any of the above four cases, after entering the work start point S, the tractor 1 moves forward a specified distance, then reverses while automatically steering to the work start point S and stops temporarily. At this time, it is also possible to sound a buzzer. This makes it possible to work without leaving any residual tillage. The remote control device 100 causes the temporarily stopped tractor 1 to start work travel on the round trip travel route R1a.

As a further variation, after reversing to the work start point S, the machine reverses further to 1 m before the edge 51 of the field 50, then moves forward in the opposite direction and aligns with the line, pausing temporarily at the work start point S. As a result, the machine enters the work start point S while moving forward, stabilizing the angle of entry and improving straightness when starting work.

Furthermore, after reaching the work start point S as described above, it is also desirable to start the original work drive without pausing. If the vehicle pauses, it will be necessary to operate the remote control to start the drive again, which is inefficient.

Next, we will explain the conditions for starting automatic headland travel to the work start point S described above.

1. When selecting the innermost route R1b other than the outermost route R2a among the three driving routes R1b, R2a, and R2b in the headland area 50b, automatic driving is permitted only when the tractor 1 is located within 1 m of the route R1b.

If the distance is too long, unexpected accidents may occur, and the control specifications for putting the vehicle on the route will be simpler. The 1m setting is a design factor and can be changed.

In addition, if the middle route R2b is selected as the route, tractor 1 must be located within 1 m of route R2b.

2. If the innermost route R1b and the middle route R2b are suitable routes, the route closest to the current position of the tractor 1 (self-position) is automatically selected. For example, if both of these two routes are within 1 m, the closer route is automatically selected and placed on the route. Alternatively, it is also possible to always select the innermost route R1b.

3. When the tractor 1 starts automatic travel to the work start point S, it must be oriented parallel to the line of the nearby bank 51 or within a specified angle. This is to ensure safety.

4. When the tractor 1 starts automatic travel to the work start point S, it is of course not out of the field 50, and it is also required that the tractor 1 does not go out of the field when it advances 3 m from that position. In other words, using the positioning device 30 that measures the position of the work vehicle, the control unit 40 has information on the field area and the work width of the work vehicle, and if it is assumed that the work vehicle will advance a specified distance from its current position, the control unit 40 uses the position of the work vehicle measured by the positioning device 30 to determine whether any part of the work vehicle will deviate from the field area, and only if it will not deviate, automatically moves the traveling vehicle body to the work start point S on the round-trip travel route.

5. If the work start point S is close to the current position of the tractor 1, for example, if the work start point S is close to the entrance/exit 52, automatic driving is prohibited. Since moving manually is more efficient, automatic driving is prohibited.

Regarding the vehicle speed of the tractor 1, the control unit 40 can set the vehicle speed in the headland area up to the work start point S and the vehicle speed during work separately because the driving load is different. By setting the vehicle speed in the headland area faster, time can be saved.

During work, the vehicle speed for the round-trip travel route and for travel in the headland area can be set separately. This eliminates the need to change gears using the tablet when the tractor 1 moves from the round-trip travel route to travel in the headland area.

In addition, when working, the round trip travel route, the front wheel drive setting when turning when traveling in the headland area, and the auto brake setting can be set separately. This eliminates the need to change the settings on the tablet each time the tractor 1 enters the headland area. It also helps to avoid the risk of forgetting to make changes, which can result in poor ground leveling or the tractor leaving the area.

In addition, when working on a round trip route, the front wheel drive and brake settings are set separately for the turning process of adjacent tillage and other processes. For the turning process, strong braking and full turn are applied, while for other processes, no braking and auto 4WD are the default. This eliminates the need to change the settings on the tablet each time. It also avoids the risk of going out of range.

When manually moving the tractor 1 from the entrance/exit 52 to the starting position for automatic headland travel to the above-mentioned work start point S, it is sufficient to move the tractor 1 within 1 m of the innermost route R1b or the middle route R2b. In other words, there is no need to manually place the tractor 1 precisely on those routes.

At that time, it is desirable to show the 1m range on the display, and when the tractor 1 is actually moved manually within that range, a lamp indicating this should light up in green.

The present invention is useful for tractors because it provides a work vehicle that can travel smoothly and automatically to the work starting point without damaging the field.

Reference Signs List 1 Tractor 2 Traveling vehicle body 3 Vehicle frame 4, 5 Wheels 7 Control unit 8 Cab 30 Positioning device 40 Control unit 40c Recording unit 50 Field 50a Main range area (round-trip travel area)
50b Headland area 50c Stop position 51 Bank 52 Entrance/exit 53 Worker 100 Remote control device R1a Round trip travel route R1b, R2a, R2b Headland travel route

Claims (3)

A work vehicle including a traveling vehicle body that travels on a reciprocating travel path that is set inside a farm field and that repeats reciprocating travel, and a headland travel path that travels along an outer circumferential shape of the reciprocating travel path,
a control unit that, when receiving an instruction to start automatic work travel, automatically causes the traveling vehicle body to travel along the headland travel route without performing work to a work start point on the round-trip travel route;
The control unit does not perform a reverse movement operation after a turning operation during a turning operation during automatic travel traveling without work on the headland travel route,
Equipped with a braking device that can brake one side at a time on each rear wheel,
The headland traveling path has a plurality of straight lines, and when turning from one side on the headland traveling path to another side, the work vehicle performs the turning without applying the single brake . A plurality of the headland travel routes are set from the inside to the outside in the headland area,
The work vehicle according to claim 1 , wherein the control unit selects the headland traveling route other than the outermost route as a route for movement traveling of the traveling body automatically not involving work. the control unit performs the turning with one brake when the traveling vehicle body turns and moves to a traveling line that is substantially parallel to a traveling route during automatic travel not involving work,
3. The work vehicle according to claim 1 , wherein when turning from a traveling path to a traveling line that is substantially perpendicular to the traveling line, the turning is performed without applying the single brake .