Control system for autonomous work vehicles

Abstract

The present invention addresses the challenge of enabling safe work operations when a work machine is attached to a vehicle body and the vehicle operates autonomously, by paying attention to obstacles around the work area and notifying the supervisor of any dangers that may hinder movement. [Solution] In an autonomous work vehicle equipped with a positioning device 30 on a vehicle body 2 fitted with a work machine W, which performs work autonomously while recognizing its position on a topographic map, the management device for the autonomous work vehicle is characterized by the following: Cameras K1, K2, K3, and K4 pointed around the vehicle capture images of the area around the vehicle, and the video unit 40d of the control unit 40 uses these images to create an overhead view of the work machine-equipped vehicle W1. A bird's-eye view of the work machine-equipped vehicle W1 with the work machine W attached is displayed on the monitor 15, and when the vehicle body 2 is moving and it is predicted that the work machine-equipped vehicle W1 will approach an obstacle, an alarm is issued to alert the manager of the work vehicle.

Description

Technical Field

[0001] The present invention relates to a management device for a self-propelled work vehicle that mounts a work implement on a traveling vehicle body and performs work with the work implement.

Background Art

[0002] As a technology that enables a work vehicle to perform work by self-propelled travel, there is a work vehicle described in Japanese Patent Application Laid-Open No. 7363683. This work vehicle is equipped with a positioning device and can perform agricultural work by self-propelled travel along a determined work route while recognizing the position of the vehicle body on a topographic map.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The self-propelled work vehicle performs agricultural work while driving a work implement such as a tillage implement in a field surrounded by ridges. However, when the surrounding of the ridge is surrounded by a high wall, since the tillage implement protrudes greatly to the rear and left and right of the traveling vehicle body, there is a possibility that the rear part of the work implement will protrude greatly from the ridge and collide with the wall when performing a turning operation. Therefore, it is necessary for the traveling manager of the work vehicle to monitor the movement of the work implement mounting body including the work implement and pay attention to safe travel.

[0005] An object of the present invention is to notify a manager of a danger when there is an obstacle around a work site and it hinders travel when mounting a work implement on a traveling vehicle body and performing work by self-propelled travel, so that safe work travel can be performed.

Means for Solving the Problems

[0006] The problems of the present invention are solved by the following technical means.

[0007] The invention of claim 1 is a management device for an autonomous work vehicle that performs work autonomously while recognizing its position on a topographic map by equipping a vehicle body 2 with a work machine W on it with a positioning device 30, wherein cameras K1, K2, K3, and K4 facing the surroundings of the vehicle capture images of the area around the vehicle, and the video unit 40d of the control unit 40 uses these images to create an overhead view of the vehicle body W1 with the work machine W attached, and displays a bird's-eye view on the monitor 15 that includes an image of the vehicle body W1 with the work machine W attached on the overhead view, and issues a warning to alert the operator of the work vehicle when it is predicted that the vehicle body W1 will approach an obstacle as the vehicle body 2 moves.

[0008] The invention of claim 2 is a management device for an autonomous mobile work vehicle according to claim 1, characterized in that the control unit 40 predicts the travel trajectory of the work equipment-equipped machine W1 and, when it predicts that the work equipment-equipped machine W1 is approaching an obstacle, it reduces the travel speed of the mobile vehicle 2.

[0009] The invention of claim 3 is a management device for an automated work vehicle according to claim 1, characterized in that the control unit 40 predicts the trajectory of the work equipment-equipped machine W1 and displays it on the monitor 15.

[0010] The invention of claim 4 is a management device for an autonomous work vehicle according to claim 1, which moves to a pre-set escape area when it detects an oncoming work vehicle with an obstacle sensor 20 facing forward. [Effects of the Invention]

[0011] In the invention of claim 1, the operator uses the control unit 40 to analyze and synthesize images captured by cameras K1, K2, K3, and K4 to create a bird's-eye view on the monitor 15 that includes the machine W1 with the work equipment attached. The monitor 15 monitors for obstacles such as banks and walls in the surrounding area, and if it is predicted that the operator will approach them, it issues an alarm to notify the operator's vehicle manager. This allows the vehicle manager to perform obstacle avoidance maneuvers to avoid the risk of the vehicle 2 or work equipment W colliding with the obstacle.

[0012] In the invention of claim 2, when the work implement mounting body W1 approaches an obstacle, the traveling speed is decelerated, so that the traveling manager of the work vehicle can notice and perform a collision avoidance operation with sufficient margin.

[0013] In the invention of claim 3, when the operator's manager is looking at the monitor 15, the obstacle with a possibility of collision can be quickly discovered on the predicted traveling locus of the work implement mounting body W1, and a collision avoidance operation can be performed.

[0014] In the invention of claim 4, when traveling on a rural road and it is determined by the obstacle sensor 20 that it is difficult to pass by a large work vehicle ahead, it can move to a retreat location and wait for the oncoming work vehicle to pass, so that it can travel safely.

Brief Description of the Drawings

[0015] [Figure 1] It is a right side view of a work vehicle according to an embodiment of the present invention. [Figure 2] It is a control block diagram of the work vehicle. [Figure 3] It is a plan view of a remote control device of the work vehicle. [Figure 4] It is a bird's-eye view of the work implement mounting body shown on the monitor. [Figure 5] It is a view looking forward from inside the cab. [Figure 6] It is a plan view when the work vehicle encounters another work vehicle on a narrow rural road. [Figure 7] It is a side view of the work vehicle with a rotary encoder communicator mounted. [Figure 8] It is a perspective view of a rotary tiller.

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0017] First, referring to FIG. 1, the overall configuration of a tractor as an example of the work vehicle 1 will be described.

[0018] The tractor 1 is an agricultural tractor that performs agricultural work in a field while self-propelling. Also, the tractor 1 is operated by an operator (also referred to as a worker) who rides on it and travels within the field to execute predetermined agricultural work. However, under the control of the control unit 40 (see FIG. 2), it is possible to execute predetermined work while autonomously traveling within the field.

[0019] Also, hereinafter, the front-rear direction is the traveling direction when the tractor 1 is moving straight forward. The front side in the traveling direction is defined as "front", and the rear side as "rear". The traveling direction of the tractor 1 is, when moving straight forward, the direction from the driver's seat 8 described later toward the steering wheel 9 (see FIG. 1).

[0020] The left-right direction is a direction that is horizontally orthogonal to the front-rear direction. Hereinafter, the left and right are defined toward the "front" side. That is, in the state where the operator (also referred to as the "worker") of the tractor 1 is sitting on the driver's seat 8 and facing forward, the left hand side is "left" and the right hand side is "right".

[0021] The up-down direction is the vertical direction. The front-rear direction, the left-right direction, and the up-down direction are orthogonal to each other. Note that each direction is defined for convenience of explanation, and the present invention is not limited by these directions. Also, hereinafter, the tractor 1 may be referred to as the "airframe" in some cases.

[0022] As shown in FIG. 1, the tractor 1 includes a traveling vehicle body 2 and a working machine W. The traveling vehicle body 2 includes a vehicle body frame 3, front wheels 4, rear wheels 5, a bonnet 6, an engine E, a control unit 7, and a transmission case 10. The vehicle body frame 3 is the main frame of the traveling vehicle body 2.

[0023] The front wheels 4 are a pair, left and right, and primarily serve as steering wheels. The rear wheels 5 are a pair, left and right, and primarily serve as drive wheels. The tractor 1 may be configured to switch between two-wheel drive (2WD), where the rear wheels 5 are driven, and four-wheel drive (4WD), where both the front wheels 4 and rear wheels 5 are driven. In this case, both the front wheels 4 and rear wheels 5 are drive wheels. The vehicle body 2 may be equipped with crawler tracks instead of wheels (front wheels 4 and rear wheels 5). In this case, the crawler tracks are the drive wheels.

[0024] The bonnet 6 is provided at the front of the vehicle body 2 so as to be able to be opened and closed. The bonnet 6 can rotate (open and close) vertically with its rear as the pivot point. When closed, the bonnet 6 covers the engine E mounted on the vehicle frame 3. The engine E is the power source for the tractor 1 and is a heat engine such as a diesel engine or a gasoline engine.

[0025] The control unit 7 is located on top of the vehicle body 2 and includes a cockpit 8 and a steering wheel 9. The control unit 7 may also be formed by being covered by a cabin 7a located on top of the 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 unit 7 also includes a display unit (meter panel) in front of the steering wheel 9 that displays various information.

[0026] The control unit 7 is also equipped with various operating levers such as forward / reverse levers, accelerator levers, main transmission levers, and sub-transmission levers, as well as various operating pedals such as accelerator pedals, brake pedals, and clutch pedals.

[0027] The transmission case 10 houses the transmission (speed change mechanism). The transmission 10 appropriately reduces the power (rotational power) transmitted from the engine E and transmits it to the drive wheels, the rear wheels 5, and the PTO shaft to drive the work implement W.

[0028] A work implement W, used for working in the field, is attached to the rear of the vehicle body 2, and a PTO shaft, which transmits power to drive the work implement W, protrudes rearward from the transmission case 10. The PTO shaft transmits rotational power, which has been appropriately reduced by the transmission, to the work implement W mounted on the rear of the vehicle body 2.

[0029] Furthermore, a lifting device 12 for raising and lowering the work implement W is provided at the rear of the vehicle body 2. The lifting device 12 moves the work implement W to a non-working position by raising it. The lifting device 12 also moves the work implement W to a ground-level working position by lowering it.

[0030] Implement W is a machine that performs work in the field. In the example shown in Figure 1, implement W is a rotary tiller that performs tilling work in the field. A rotary tiller tills the field surface (soil) by rotating its tilling tines with power transmitted from the PTO shaft.

[0031] For the sake of explanation, the state in which the implement W is attached to the vehicle body 2 will be referred to as the implement-equipped vehicle body W1.

[0032] The tractor 1 is equipped with a control unit 40 as shown in Figure 2. The control unit 40 consists of an engine ECU 40a that controls the engine E, a driving system ECU 40b that controls the driving speed of the vehicle body 2, a recording unit 40c that records various data, and an image unit 40d that creates a bird's-eye view image by combining images from front and rear cameras K1 and K2 that capture the front and rear directions of the vehicle body 2, and left and right cameras K3 and K4 that capture the left and right lower sides, with images of the implement-equipped machine body 1W with the implement W attached to the tractor 1 that were captured in advance. The control unit 40 also controls the movement of the implement W.

[0033] Furthermore, the tractor 1 is equipped with a positioning device 30. The positioning device 30 is installed in the cabin 7a on top of the vehicle body 2 and determines the position of the vehicle body 2 on a topographic map. The positioning device 30 is, for example, a GNSS (Global Navigation Satellite System) and can determine the topographic position of the vehicle body 2 and time it by receiving radio waves from navigation satellites S orbiting overhead.

[0034] Furthermore, the engine speed sensor ES detects the engine rotation speed, the vehicle speed sensor VS detects the vehicle's speed, and the steering angle sensor AS detects the steering angle of the front wheels 4, all of which are used for control.

[0035] Furthermore, the tractor 1 is equipped with an obstacle sensor 20. The obstacle sensor 20 comprises a front sensor 21 and a rear sensor 22. The front sensor 21 is located at the front of the vehicle body 2, for example, by being mounted on a sensor mounting bracket 13 provided in front of the bonnet 6, and detects objects (obstacles) in front of the vehicle body 2, and together with the front cameras K1 and K2, identifies a work vehicle coming from the front. The rear sensor 22 is located at the upper rear of the vehicle body 2, for example, by being mounted on the top of the cabin 7a, and detects objects (obstacles) in rear of the vehicle body 2.

[0036] Furthermore, both the front sensor 21 and the rear sensor 22 are medium-range sensors, and preferably infrared sensors. The infrared sensor emits an infrared beam and detects reflected light from obstacles.

[0037] The forward sensor 21 and the rear sensor 22 can detect the distance to an obstacle by, for example, measuring the time it takes from emitting an infrared beam until the reflected light from the obstacle is detected. The forward sensor 21 and the rear sensor 22, which are infrared sensors, detect obstacles in two dimensions, with a detection range of, for example, several meters to several tens of meters. It is also possible to use other medium-range sensors besides infrared sensors as the obstacle sensor 20, such as ultrasonic sensors or the aforementioned surveillance cameras.

[0038] The alarm 17 sounds an alarm to notify the operator of the work vehicle when the work machine-equipped machine W1 approaches an obstacle such as the embankment 51. The alarm 17 may be designed to become higher pitched as the distance to the obstacle decreases, and it is recommended that the vehicle slow down as it approaches and stop just before collision.

[0039] Furthermore, while the operator controls the autonomous driving of the tractor 1 from the driver's seat 8, the operator can also remotely control it as described later by operating the remote control device 100 held by the operator, after getting out of the work vehicle 1. Figure 3 is a front view of the remote control device 100. In Figure 3, 100a are two push buttons labeled "A" and "B". 100b is the stop button, 100c is the pause button, 100d is the power button, and 100e is the automatic (autonomous) driving instruction button. The remote control device 100 is equipped with a monitor 15, which displays the machine with the implement attached W1, created by the video unit 40d, in an overhead bird's-eye view. When attaching another implement to the work vehicle 1, a plan view of the machine with the implement attached W1 is prepared in advance.

[0040] Figure 4 is shown on the monitor 15 screen as an overhead view centered on the implement-equipped machine W1 traveling in the field 50. The implement-equipped machine W1 is positioned in the center determined by the forward cameras K1 and K2 pointed forward from the cabin 7a and the left and right cameras K3 and K4 pointed downward to the left and right, forming a bird's-eye view screen.

[0041] The front wheel 4 is equipped with a steering angle sensor AS, and the predicted movement trajectory S1 of the front wheel 4, created by the control unit 40, is also drawn as a dotted line, as is the predicted movement trajectory S2 of the work machine W.

[0042] Furthermore, the control unit 7 inside the cabin 7a has a monitor 15 near the meter panel 11 in front of the steering wheel 9, allowing the operator seated in the cockpit 8 to view a bird's-eye view of the machine W1 with the work equipment attached. In addition, the predicted movement trajectory S1 of the front wheel 4 is projected onto the front window of the cabin 7a (Figure 5).

[0043] Figure 6 shows the response method when the implement-equipped machine W1 detects an oncoming work vehicle 35 ahead on a farm road 34. The forward sensor 21 calculates the relative speed of the machine to calculate the time until encounter, and the front cameras K1 and K2 search for a field adjacent to the farm road 34 where it can safely retreat, and the machine retreats to the nearest available field. In this case, the machine excludes fields with crops in them and selects a field under its own management that is large enough to enter, is uncultivated, and has a gentle slope. If the field is under someone else's management, the machine requests permission to enter from that manager, and enters only if permission is granted. If the field is under someone else's management, the machine searches for the manager in the database, requests permission to enter from that manager's system, and enters to retreat only if permission is granted. If the management system is not digitized, the machine contacts the manager by email, etc., but if there is no reply within a certain time, it is determined that "permission is not granted". Before the day of operation, plan the route according to the work plan and obtain permission to enter the fields along the route from the field management system in advance. When returning to farm road 34 after evacuating, choose a location where you can move forward. However, if the slope of the evacuation location is gentle, evacuate by reversing. Whenever possible, consider evacuation that crosses multiple fields and avoid reversing.

[0044] Furthermore, the width of the oncoming work vehicle 35 is determined using front cameras K1 and K2, and when retreating, this width is taken into consideration, and the vehicle is moved to a position where it will not make contact.

[0045] If the vehicle is traveling on a farm road 34 that is too narrow for two vehicles to pass each other, and it spots another vehicle ahead, the owner of the oncoming tractor is identified from the camera footage, compared with map data, and the destination of the oncoming vehicle 35 is estimated. If it is estimated that the oncoming vehicle 35 will be heading to a field before the encounter, the vehicle stops just before the access road to the estimated target field. The accuracy of estimating which field the vehicle is going to is improved by using camera footage of the implements attached to the oncoming vehicle 35 and the fields managed by the oncoming vehicle 35.

[0046] Furthermore, if the evacuated field is managed by another party, the manager will be searched in the database, permission to enter will be requested from the manager's system, and entry will only be permitted if permission is granted. If the management system is not digitized, the manager will be contacted by email or other means, but if no reply is received within a certain time, it will be assumed that permission has not been granted. However, if there is no other option but to enter the field without permission due to time or geographical constraints, entry will be made without authorization, but permission will be obtained afterward.

[0047] If an oncoming vehicle appears ahead and is not agricultural machinery, take evasive action without hesitation.

[0048] Figure 7 is a side view showing a rotary encoder communication device 42 that wirelessly controls the drive system ECU 40b, which is detachably mounted near the steering wheel 9. The vehicle can be controlled by the remote control device 100 when the steering wheel 9 is in the forward position.

[0049] The mechanism that locks the rotary encoder communicator 42 cannot be unlocked unless the tractor 1 is in the field. Also, if the steering wheel 9 is moved from its normal position, steering can be controlled by the operator's voice. To simplify the system, the patterns are limited to "turn left / right" = full left / right steering lock, "adjust left / right" = 5-degree left / right steering, and "go straight". If there is a conflict between voice input and steering input, the steering input takes priority. Also, when leaving the field, if the steering wheel 9 is not locked in its normal position, the vehicle will stop moving. Furthermore, a switch on the rotary encoder communicator 42 allows for ON / OFF selection of wireless communication. When wireless communication is ON, steering is possible even with the unit removed from its normal position, and when it is OFF, voice control is possible.

[0050] Alternatively, a small-diameter sub-steering wheel may be installed near the driver's hand (left armrest), allowing steering via the sub-wheel only when tractor 1 is in a field.

[0051] Figure 8 shows a rotary tiller as the implement W. The tilling cover that covers the tilling tines from the rear is divided into a left tilling cover 24L and a right tilling cover 24R, which are pivotally supported and pressed against the ground by retaining springs 25L and 25R respectively. By lifting and fixing one side, soil mounding work can be performed.

[0052] Furthermore, the pressing force of the retaining springs 25L and 25R that hold down the left tilling cover 24L and the right tilling cover 24R can be changed. When the front sensor 21 detects depressions in the ground or areas with a lot of weeds or straw, the pressure of the retaining springs 25L and 25R that hold down the left tilling cover 24L or the right tilling cover 24R on the side the rear wheel 5 is passing over will have the effect of leveling the ground. Conversely, in areas where the ground is raised, increasing the pressing pressure of the left tilling cover 24L or the right tilling cover 24R will improve the effect of leveling the ground.

[0053] Furthermore, by installing tillage depth sensors on the left tillage cover 24L and the right tillage cover 24R, it is possible to change and control the pressing force of the retaining springs 25L and 25R based on tillage depth data.

[0054] The tilling cover may be divided into three or more sections, and each section may be designed to be connected as a single unit. [Explanation of Symbols]

[0055] 1 Work vehicle 2. Running vehicle 15 monitors 20 Obstacle Sensors 30 Positioning device 40 Control Unit K1, K2, K3, K4 Cameras W work machine W1 Work equipment mounting unit

Claims

1. A management device for an autonomous mobile work vehicle that performs work autonomously while recognizing its position on a topographic map by equipping a mobile vehicle (2) with a work implement (W) attached to it with a positioning device (30), wherein cameras (K1, K2, K3, K4) pointed around the vehicle capture images of the area around the vehicle, and the video unit (40d) of the control unit (40) creates an overhead view of the mobile vehicle (W1) with the work implement attached on it, and displays a bird's-eye view on the monitor (15) that incorporates the image of the mobile vehicle (W1) with the work implement (W) attached onto the overhead view, and issues a warning to alert the operator of the work vehicle when it is predicted that the mobile vehicle (W1) will approach an obstacle as the mobile vehicle (2) moves.

2. The control unit (40) predicts the travel trajectory of the work equipment-equipped machine body (W1), and when it predicts that the work equipment-equipped machine body (W1) will approach an obstacle, it reduces the travel speed of the vehicle body (2), as described in claim 1.

3. The autonomous mobile work vehicle management device according to claim 1, characterized in that the control unit (40) predicts the trajectory of the work equipment-equipped machine body (W1) and displays this trajectory on a monitor (15).

4. A management device for an autonomous mobile work vehicle according to claim 1, which, when it detects an oncoming work vehicle using an obstacle sensor (20) facing forward, moves to a pre-set escape area.

Images