JP7192667B2 - Autonomous working vehicle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autonomous working vehicle that autonomously travels through fields to perform agricultural work.

Autonomous working vehicles in farm fields include tractors for plowing, seedling transplanters for transplanting seedlings, and combine harvesters for harvesting grains such as rice and wheat.

Patent Literature 1 describes a technology in which a tractor as an autonomous working vehicle, to which a tillage machine is connected, decelerates the traveling speed of the traveling vehicle body to correct the course when it deviates from the planned traveling route during autonomous traveling. there is

JP 2019-41619 A

Autonomous mobile work vehicles that run in fields to perform agricultural work not only deviate from the planned travel route, but also run on muddy terrain, causing the wheels to slip, resulting in excessive plowing and short intervals between seedling transplants. Uniform farming may not be carried out due to unevenness, etc.

SUMMARY OF THE INVENTION An object of the present invention is to enable a work vehicle that autonomously travels in a field to perform uniform farm work even if the travel device slips and the traveling speed slows down.

The above problems of the present invention are solved by the following technical means.

The present invention relates to an autonomous traveling working vehicle in which a working machine is driven by a PTO shaft (392) driven by the output of an engine (321) mounted on a traveling vehicle body (10), and a navigation system (290) provided on the traveling vehicle body (10). ) is compared with the driving speed calculated by the vehicle speed sensor (296) provided in the driving device (220). The autonomous traveling working vehicle is characterized in that the driving of the PTO shaft (392) that drives the working machine is stopped.
A first invention related to the present invention is an autonomous traveling working vehicle in which a working machine is driven by a PTO shaft 392 driven by the output of an engine 321 mounted on the traveling vehicle body 10, and a navigation system 290 provided on the traveling vehicle body 10 calculates The actual traveling speed is compared with the driving traveling speed calculated by the vehicle speed sensor 296 provided in the traveling drive device 220, and when the actual traveling speed is slower than the driving traveling speed by a predetermined amount or more, the traveling load reduction control is performed. Autonomous working vehicle.

A second invention related to the present invention is the autonomous traveling work vehicle according to the first invention related to the present invention, characterized in that the work implement is floated as the running load reduction control.

A third invention related to the present invention is an autonomous traveling work vehicle according to the first invention related to the present invention, characterized in that driving of the PTO shaft 392 that drives the work machine is stopped as running load reduction control. do.

A fourth invention related to the present invention is the autonomous traveling work vehicle according to the first invention related to the present invention, characterized in that the rotation of the engine 321 is reduced as the running load reduction control.

A fifth invention related to the present invention is the autonomous traveling work vehicle according to the first invention related to the present invention, characterized in that the traveling drive device 220 is stopped when the slip traveling state is not resolved.

A sixth invention related to the present invention is the autonomous traveling work according to the fifth invention related to the present invention, characterized in that after the traveling drive device 220 is stopped, the working machine is raised and the drive of the engine 321 is stopped. car.

According to the present invention, by stopping the driving of the PTO shaft 392, the driving load of the working machine is eliminated, and the entire driving force of the engine 321 is transmitted to the traveling drive device 220, thereby recovering the forward driving force and eliminating the slip traveling state.
In the first invention related to the present invention , the work vehicle is supposed to run at the drive travel speed calculated by the vehicle speed sensor 296 provided in the travel drive device 220. If the actual running speed does not reach the drive running speed, it can be determined that the running device such as the wheels and crawlers is slipping, so the running load reduction control is performed and the forward propulsion is restored to drive the vehicle. The drive travel speed of the device 220 approaches the actual travel speed, resulting in uniform agricultural work.

In the second invention related to the present invention, in addition to the effects of the first invention related to the present invention, when the farm work is tillage work, the tillage machine is floated to reduce the tillage resistance and move forward. The propulsive force is recovered and the slip running state can be eliminated, resulting in uniform plowing work.

In the third invention related to the present invention, in addition to the effects of the first invention related to the present invention, stopping the driving of the PTO shaft 392 eliminates the driving load of the work machine and eliminates the total driving force of the engine 321. The forward propulsion force is transmitted to the travel drive device 220 and recovered to eliminate the slip travel state.

In the fourth invention related to the present invention, in addition to the effects of the first invention related to the present invention, the rotation of the engine 321 is reduced to weaken the forward propulsion force of the travel drive device 220. The slip running state can be eliminated by eliminating the slip.

In the fifth invention related to the present invention, in addition to the effects of the first invention related to the present invention, when the slip running state cannot be eliminated, the running can be stopped and the excessive agricultural work can be partially interrupted.

In a sixth invention related to the present invention, in addition to the effects of the fifth invention related to the present invention, the engine 321 is stopped to interrupt the autonomous running and enter the standby state when the slip running state cannot be eliminated. , can wait for the action of the operator.

1 is a schematic side view of a tractor according to this embodiment; FIG. FIG. 2 is an explanatory diagram of a traveling vehicle body; FIG. 4 is a diagram showing a power transmission path of a traveling vehicle body; It is a block diagram showing a control system of a tractor. It is a flow chart explaining automatic travel control of a tractor concerning this embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings. In the description of the embodiments, the left and right directions are referred to as left and right, respectively, the forward direction is referred to as forward, and the backward direction is referred to as rear, but this does not limit the configuration of the present invention.

A configuration of a tractor 1, which is a field work vehicle according to the present embodiment, will be described with reference to FIG. FIG. 1 is a schematic side view of a tractor 1 according to this embodiment.

The tractor 1 includes a traveling vehicle body 10 , a vehicle control section 100 and a communication unit 110 . The tractor 1 is a tractor capable of automatically traveling and working by receiving a signal from a terminal device 2 possessed by a worker, such as a remote controller or a mobile communication terminal, through a communication unit 110 . That is, the tractor 1 is a remotely controllable tractor.

The traveling vehicle body 10 includes a steering handle, operation pedals, and various gauges (not shown), and is configured so that a tillage machine (not shown) can be connected to its rear portion. A DGPS (Differential Global Positioning System) antenna 6 for receiving radio waves transmitted from a plurality of navigation satellites 60 is provided on the ceiling of the traveling vehicle body 10 . It should be noted that a working device other than a tilling machine can be connected to the traveling vehicle body 10 .

The traveling vehicle body 10 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is an explanatory diagram of the traveling vehicle body 10. As shown in FIG. FIG. 3 is a diagram showing a power transmission path of the traveling vehicle body 10. As shown in FIG.

The traveling vehicle body 10 includes various mechanisms including a power transmission mechanism as shown in FIGS. 2 and 3 . That is, as shown in FIG. 2, the traveling vehicle body 10 has front wheels 301L and 301R attached to left and right front axles 406L and 406R, and left and right rear wheels attached to left and right rear axles 405L and 405R. It has wheels 302L and 302R. In the following description, L is attached to the left side and R is attached to the right side to indicate the right side. may be noted.

An engine 321 serving as a power source is mounted on the front portion of the traveling vehicle body 10, and power is transmitted from the engine 321 to the front wheels 301 and the rear wheels 302 via a power transmission mechanism. The tractor 1 according to the present embodiment is provided with a 4WD clutch 324. By switching the 4WD clutch 324, a 2WD system in which only the rear wheels 302 are driven and a 4WD system in which both the front wheels 301 and the rear wheels 302 are driven. can be switched freely.

A power transmission mechanism to the rear wheels 302 includes a main transmission section 323 arranged via a forward/reverse clutch 322 in the rear stage of the engine 321, and an auxiliary transmission section 325 arranged in the subsequent stage. A wheel differential gearing 326 is provided. A brake device 312 is provided at the base of the rear axle 405 that connects the rear wheel differential gear device 326 and the rear wheel 302 .

Also, power is input to transmission shaft 404 via an idle gear provided at the rear stage of auxiliary transmission section 325 , and power is transmitted to front wheels 301 via 4WD clutch 324 and front wheel differential gear device 320 .

The tractor 1 according to the present embodiment includes an automatic traveling unit 160 (see FIG. 4) controlled by the vehicle control section 100 so as to enable automatic traveling. A steering angle detection sensor 304 that detects the steering angle of the front wheels 301 is connected to the vehicle control unit 100. During automatic driving, the vehicle control unit 100 feeds back the actual detected steering angle of the front wheels 301. 100 controls the steering cylinder 303 for steering.

The brake device 312 provided on the rear wheel 302 functions by hydraulically acting on the brake cylinder 311 when the driver steps on the brake pedal 310 provided on the machine body. That is, the left brake device 312L provided at the base of the left rear axle 405L is connected to the left brake cylinder 311L, and the right brake device 312R provided at the base of the right rear axle 405R is connected to the right brake cylinder 311R.

As shown, the left and right brake cylinders 311L and 311R are connected to left and right brake solenoids 330L and 330R connected to the vehicle control unit 100, respectively. Therefore, when a predetermined brake signal is input to vehicle control unit 100, vehicle control unit 100 can drive brake solenoid 330 to operate either one or both of left and right brake devices 312L and 312R. . The brake solenoid 330 forms a hydraulic circuit together with, for example, a hydraulic pump 341, a relief valve 340, and the like.

Next, power transmission paths from the engine 321 of the tractor 1 to the front wheels 301 and the rear wheels 302 will be described with reference to FIG. As illustrated, the output shaft of the engine 321 is connected to the power transmission shaft 401 via a forward/reverse clutch 322 that switches between forward and reverse. Therefore, the tractor 1 can selectively rotate the power transmission shaft 401 forward and backward by switching the forward/reverse clutch 322 .

Also, the power transmission shaft 401 is connected to the main transmission portion 323 and the sub transmission portion 325 . That is, main transmission portion 323 and sub-transmission portion 325 are arranged on a power transmission path for transmitting power from engine 321 to rear wheels 302 (front wheels 301 and rear wheels 302).

The main transmission portion 323 includes a first speed/third speed switching clutch 402 having a first clutch gear 361 and a third clutch gear 363, and a second speed/fourth speed clutch having a second clutch gear 362 and a fourth clutch gear 364. A speed switching clutch 403 is mounted, and the power from the engine 321 can be shifted to 1st to 4th speeds and output.

Further, the main transmission section 323 is equipped with a high/low clutch 365, which enables the 1st to 4th speeds to be switched to a higher speed or a lower speed.

The sub-transmission portion 325 to which the power of the main transmission portion 323 is input includes a first shifter 381 and a second shifter 382 of a double sub-transmission clutch operated by an unillustrated sub-transmission lever, and a plurality of transmission gears. Prepare. Depending on which transmission gear the first shifter 381 and the second shifter 382 are engaged with, the speed can be changed to super low speed, low speed, medium speed and high speed. Then, the rotation of the output shaft of the auxiliary transmission portion 325 is transmitted from the rear wheel differential gear device 326 to the rear wheels 302 via the axle and the rear wheel planetary gear mechanism 391 .

Further, the power input from the main transmission portion 323 to the auxiliary transmission portion 325 is input to the transmission shaft 404 equipped with the 4WD clutch 324 via the idle gear, thereby transmitting the driving force to the front wheels 301 . The action of the 4WD clutch 324 also makes it possible to switch from normal front wheel drive to accelerated front wheel drive. When the 4WD clutch 324 is set to neutral, the drive of the front wheels 301 is cut off and only the rear wheels 302 are driven, that is, 2WD.

Thus, the power transmitted to the rear stage of the 4WD clutch 324 is transmitted to the front wheels 301 via the front wheel differential gear device 320 and the front wheel planetary gear mechanism 390 .

The traveling vehicle body 10 also includes a work power transmission mechanism 360 that transmits power from the engine 321 to the tilling machine without passing through a transmission mechanism such as the main transmission section 323 or the auxiliary transmission section 325 . Specifically, the traveling vehicle body 10 is provided with a PTO (Power Take Off) clutch 366, and by engaging the PTO clutch 366, power is transferred from the engine 321 to the PTO shaft 392 without passing through the main transmission section 323 or the like. can be transmitted.

The PTO shaft 392 is provided with a PTO speed first shifter 371 and a PTO speed second shifter 372 on the front side, and by operating these, the PTO shaft 392 can be rotated forward from low speed to high speed. , can also be reversed.

Next, the control system of the tractor 1 according to this embodiment will be described with reference to FIG. FIG. 4 is a block diagram showing the control system of the tractor.

The tractor 1 according to this embodiment can control each part by electronic control, and includes a vehicle control part 100 that forms the core of the control system. By receiving a command signal from the terminal device 2 via the communication unit 110, the vehicle control unit 100 can control the automatic traveling unit 160 to automatically travel.

A vehicle control unit 100 provided in the tractor 1 includes a storage device 140 configured by a hard disk, a ROM (Read Only Memory), a RAM (Random Access Memory), etc., in which various programs and various necessary data are stored, and a CPU ( It includes a plurality of controllers 120, 130, 150 composed of ROM, RAM, etc., as well as a processing unit having a central processing unit.

Examples of the controllers 120, 130, 150 include a travel system controller 120 that controls the travel system, an engine controller 130 that controls the engine 321, and a work machine system controller 150 that controls a tillage work machine connected to the rear part of the machine body.

Each of the travel system controller 120, the engine controller 130, and the work machine system controller 150 has a processing unit including a CPU, a ROM in which control programs are stored, a storage unit such as a RAM for a work area, and further. are provided with input/output units, and are connected to each other so that signals can be exchanged with each other. Note that the ROM of the storage unit stores control programs and the like corresponding to control targets of the respective controllers 120, 130, and 150, respectively.

In addition, the vehicle control unit 100 includes an emergency stop switch 210, a steering drive motor (not shown), a traveling drive device 220 including the transmission mechanism shown in FIGS. Various travel system sensors 230 including the second obstacle detection sensor 231b and the steering angle detection sensor 304 are connected. Further, the vehicle control unit 100 is connected with a navigation system 290 including the DGPS antenna 6 (see FIG. 1), a direction sensor 295, a vehicle speed sensor 296, and the like.

The first obstacle detection sensor 231a is, for example, an ultrasonic sensor, and is a sensor that detects an obstacle within a first predetermined range in the traveling direction of the traveling vehicle body 10, for example, in front of or on the side of the traveling vehicle body 10. . The second obstacle detection sensor 231b is, for example, an infrared sensor, and is a sensor that detects an obstacle within a second predetermined range in the traveling direction of the traveling vehicle body 10, for example, in front of or on the side of the traveling vehicle body 10. The first predetermined range and the second predetermined range are ranges set in advance, and the second predetermined range is a range narrower than the first predetermined range. Note that the first obstacle detection sensor 231a and the second obstacle detection sensor 231b may be cameras or other sensors that capture images for an image processing determination program for obstacle detection.

The navigation system 290 measures the latitude and longitude of the vehicle body 10 using radio waves received by the DGPS antenna 6, displays the position in the field on the field map, and calculates the actual traveling speed of the vehicle body 10 as it travels.

A direction sensor 295 detects the direction of travel of the traveling vehicle body 10 , and a vehicle speed sensor 296 is incorporated in the power transmission mechanism of the rear wheels 302 to calculate the driving speed from the number of revolutions of the rear wheels 302 . Therefore, the actual running speed calculated by the navigation system 290 and the driving running speed displayed by the vehicle speed sensor 296 match, but when the rear wheels 302 slip, the actual running speed becomes slower than the driving running speed. becomes.
When the slip traveling state occurs, the work machine repeats plowing in the same place, resulting in excessive agricultural work. The controller 130 reduces the rotation of the engine 321, and the work implement system controller 150 executes travel load reduction control such as lifting the work implement.
If the slip traveling state is still not resolved, the traveling drive device 220 is stopped, the working machine is greatly raised, the driving of the engine 321 is stopped, and the communication unit 110 notifies the terminal device 2 held by the worker. Wait for workers to take action.

The vehicle control unit 100 also includes a work machine lifting drive device 240 including a work machine lifting device (not shown), a PTO on/off operation switch 250 for turning on and off the PTO clutch 366, and a plowing machine for controlling the tillage machine. Necessary work machine system/PTO drive sensors 260, an engine drive device 270, engine drive sensors 280, and the like are connected.

In this way, the tractor 1 performs a predetermined work while a worker rides on the body and travels. Predetermined work can be executed while traveling.

When the tractor 1 is caused to travel automatically, for example, a planned travel route corresponding to the content of work is determined in advance for each field, converted into data, and stored in the storage device 140 . The planned travel route is set according to the shape and size of the field, the width, length and number of ridges formed in the field, the type of crop, and the like.

The vehicle control unit 100 detects the position of the traveling vehicle body 10 on the field map using the navigation system 290, and calculates the actual traveling route based on the detected current position. Vehicle control unit 100 then controls steering cylinder 303 and engine 321 so that the actual travel route coincides with the planned travel route.

Note that the automatic traveling of the tractor 1 can be set as appropriate, in addition to being executed by the vehicle control unit 100 via the terminal device 2 as in the present embodiment.

Next, the configuration of the terminal device 2 capable of remotely controlling the tractor 1 will be described. As shown in FIG. 4 , the terminal device 2 is capable of wireless communication with the communication unit 110 of the tractor 1 . The terminal device 2 also includes, as operation units, a forward "on/off" switch 21 and a reverse "on/off" switch 22 for causing the tractor 1 to travel, and an ENG rotation speed switch 24 for switching the rotation speed of the engine 321. , and a vehicle stop switch 26 capable of stopping the tractor 1 in an emergency.

The terminal device 2 also includes a PTO "on/off" switch 23 and a work machine "up/down" switch 25 for operating the tillage machine.

By operating the terminal device 2, the operator can move the tractor 1 forward and backward at a predetermined speed, stop it, and raise and lower the tillage machine to work with a predetermined power. be able to.

Next, automatic travel control of the tractor 1 according to this embodiment will be described with reference to the flowchart of FIG. Here, it is assumed that the tractor 1 is automatically traveling.

The vehicle control unit 100 detects the current position of the traveling vehicle body 10 based on the signal from the navigation system 290 (S100). The vehicle control unit 100 compares the current position and the planned travel route, and calculates the distance between the current position and the planned travel route (S101). Specifically, the vehicle control unit 100 calculates the distance between the planned travel route and the current position of the traveling vehicle body 10 (DGPS antenna 6) as the distance between the current position and the planned travel route.

In addition, the vehicle control unit 100 compares the distance between the current position and the planned travel route with a preset first predetermined value (S102). The first predetermined value is the distance between the planned travel route and the traveling vehicle body 10 (DGPS antenna 6) that allows it to be determined that the traveling vehicle body 10 deviates from the planned traveling route. That is, the vehicle control unit 100 determines whether or not the traveling vehicle body 10 has deviated from the planned travel route during automatic travel.

When the distance between the current position and the planned travel route is equal to or greater than the first predetermined value (S102: Yes), the vehicle control unit 100 determines that the traveling vehicle body 10 has deviated from the planned travel route, and decelerates the traveling vehicle body 10. (S103). Specifically, the vehicle control unit 100 decelerates the traveling vehicle body 10 by downshifting the main transmission unit 323 or the sub transmission unit 325 . Note that the deceleration here does not presuppose that the traveling vehicle body 10 is stopped.

When the distance between the current position and the planned travel route is smaller than the first predetermined value (S102: No), the vehicle control unit 100 determines that the traveling vehicle body 10 has not deviated from the planned travel route. End the process.

The vehicle control unit 100 detects the current position of the traveling vehicle body 10 based on the signal from the navigation system 290 (S104).

The vehicle control unit 100 compares the current position and the planned travel route, and calculates the distance between the current position and the planned travel route (S105).

The vehicle control unit 100 compares the distance between the current position and the planned travel route with a preset second predetermined value (S106). The second predetermined value is a value smaller than the first predetermined value, and is a value with which it can be determined that the current position substantially matches the planned travel route. That is, the vehicle control unit 100 determines whether or not the travel route of the traveling vehicle body 10 has been corrected by automatic travel and substantially matches the planned travel route.

When the distance between the current position and the planned travel route is equal to or less than the second predetermined value (S106: Yes), the vehicle control unit 100 accelerates the traveling vehicle body 10 (S107). Specifically, the vehicle control unit 100 accelerates the traveling vehicle body 10 by upshifting the main transmission unit 323 or the sub transmission unit 325 . The vehicle control unit 100 accelerates the vehicle speed of the traveling vehicle body 10 to the vehicle speed before deceleration.

Note that the vehicle control unit 100 is controlled when a state in which the distance between the current position and the planned travel route is equal to or less than a second predetermined value continues for a preset predetermined time, or when the distance between the current position and the planned travel route becomes the second predetermined value. The traveling vehicle body 10 may be accelerated when the state of being equal to or less than the predetermined value continues for a predetermined traveling distance.

When the distance between the current position and the planned travel route is greater than the second predetermined value (S106: No), the vehicle control unit 100 continues deceleration and detects the current position (S104).

10 traveling vehicle body 220 traveling drive device 290 navigation system (positioning device)
296 vehicle speed sensor 321 engine 392 PTO shaft

Claims (1)

Calculated by a navigation system (290) provided on the traveling vehicle body (10) in an autonomous traveling working vehicle in which a working machine is driven by a PTO shaft (392) driven by the output of an engine (321) mounted on the traveling vehicle body (10) The actual travel speed is compared with the drive travel speed calculated by the vehicle speed sensor (296) provided in the travel drive device (220), and if the actual travel speed is in a slip travel state slower than the drive travel speed by a predetermined amount or more, the work machine is driven. An autonomous working vehicle characterized by stopping the driving of the PTO shaft (392) .

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