AU2015347785B9

AU2015347785B9 - Field state detection system

Info

Publication number: AU2015347785B9
Application number: AU2015347785A
Authority: AU
Inventors: Toshifumi HIRAMATSU
Original assignee: Yanmar Power Technology Co Ltd
Current assignee: Yanmar Power Technology Co Ltd
Priority date: 2014-11-13
Filing date: 2015-11-10
Publication date: 2019-10-31
Anticipated expiration: 2035-11-10
Also published as: KR20170081686A; KR102121646B1; AU2015347785A1; AU2015347785B2; AU2015347785A9; WO2016076320A1

Abstract

A camera 42 for imaging a prescribed location such as a machine body step 81 or a rear wheel 10 of an autonomous work vehicle 1 and a field surface G thereunder is attached to a prescribed location on the autonomous work vehicle 1. Field hardness is measured from the amount of sinkage of the machine body with respect to the field at random locations by calculating the height of the step 81 or the rear wheel 10 of the autonomous work vehicle 1 with respect to the field surface G from images that are imaged while traveling. The hardness of the field is detected continuously while traveling and recorded in a storage device. Thereby, the distribution of hardness in the field as a whole can be easily obtained.

Description

(57) Abstract: A camera 42 for imaging a prescribed location such as a machine body step 81 or a rear wheel 10 of an autonomous work vehicle 1 and a field surface G thereunder is attached to a prescribed location on the autonomous work vehicle 1. Field hardness is measured from the amount of sinkage of the machine body with respect to the field at random locations by calculating the height of the step 81 or the rear wheel 10 of the autonomous work vehicle 1 with respect to the field surface G from images that are imaged while traveling. The hardness of the field is detected continuously while traveling and recorded in a storage device. Thereby, the distribution of hardness in the field as a whole can be easily obtained.

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2015347785 16 May 2019

FIELD STATE DETECTION SYSTEM

Technical Field [0001] The present invention relates to a system for detecting a field hardness and a work finish as a field state, and particularly relates to a technique of measuring a field hardness from an amount of sinkage from an image of a work vehicle and a field surface captured by a camera provided to the work vehicle, and detecting an abnormality of a work machine from a change in the field surface.

Background Art [0002] In a conventionally known technique, a sensing unit, a shaft, a clamping unit, and a display unit are used. The sensing unit has a conical shape and has an inserted depth changing in accordance with the hardness of a ground surface. The shaft is fixed to an upper portion of the sensing unit and extends upward. The clamping unit clamps the shaft in a standby state, and releases the shaft when a measurement is performed. The display unit displays the movement amount of the shaft. The shaft is fixed by the clamping unit to be at a level of coming into contact with the ground surface to be measured. Then, the fixing of the shaft is released so that the sensing unit is inserted into the ground with its own weight. The hardness of the ground surface is measured based on the inserted depth (refer to, for example, Patent Literature 1).

Citation List

Patent Literature [0003]

PTL 1: Japanese Unexamined Patent Application Publication No. 11-94723 [0004] When the hardness is measured by the technique, a small field only needs measurement at several positions to roughly figure out the hardness. However, a field for cultivating rice, wheat, potatoes, and the like is large, and requires at least dozens of points to be sequentially measured to figure out the hardness distribution of the entire area. Thus, when the hardness is measured by using the measurement device, the sensing unit needs to be inserted in the ground over and over again, and thus the measurement requires a large amount of labor and time.

[0005] Any discussion of documents, acts, materials, devices, articles or the like which

2015347785 16 May 2019 has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

[0005A] Throughout this specification the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Summary [0006] The present disclosure provides a field state detection system which includes a first camera that is attached to an autonomous work vehicle and configured to capture a first image of a predetermined position of the autonomous work vehicle and a field surface below the predetermined position. The system includes a second camera that is attached to an accompanying work vehicle configured to perform work while traveling in tandem with the autonomous work vehicle and configured to capture an image of the predetermined position of the autonomous work vehicle and the field surface below the predetermined position, A height of the predetermined position of the autonomous work vehicle from the field surface is calculated from at least one of the first image and the second image as an amount of sinkage into the field for measuring a hardness of the field.

[0007] The measured hardness may be sequentially written to a field map, and may be stored as hardness distribution data in a storage device.

[0008] The work vehicle may be provided with a third camera that is connected to a controller and configured to capture an image of a state after the work. The controller may be configured to execute image processing on the image captured with the third camera and a resultant image is compared with a normal work image stored in advance, while the work is in process.

The controller may be connected to a stopping unit configured to stop traveling and the work, may be configured to determine that an abnormality has occurred when image data has a difference between the image after the work captured by the third camera and the normal work image, and to perform control in such a manner that the traveling and the work stop.

2015347785 16 May 2019

The controller may be able to communicate with a management server through a communication line, and may be configured to store the hardness distribution data, the normal work image, and an abnormal work image in a database of the management server.

The controller may be able to communicate with a remote controller through a communication device, and may be configured to notify, upon determining that the abnormality has occurred, the remote controller of the abnormality.

[0008A] The present disclosure also provides a field state detection system comprising: a first camera that is attached to an accompanying work vehicle, the accompanying work vehicle accompanying an autonomous work vehicle configured to perform work while traveling in tandem with the accompanying work vehicle, the first camera configured to capture a first image of a predetermined position of the autonomous work vehicle and a field surface below the predetermined position, wherein a height of the predetermined position of the autonomous work vehicle from the field surface is calculated from the first image as an amount of sinkage into the field for measuring a hardness of the field.

[0009] With an embodiment according to a configuration described above, the hardness can be successively measured while the work vehicle is traveling. Thus, labor and time required for measuring the hardness can be dramatically reduced. Furthermore, the measurement involves almost no operation and thus can be easily conducted.

Brief Description of Drawings [0010] [Fig. 1] Fig. 1 is schematic side view of an autonomous work vehicle provided with a camera for measuring harness.

[Fig. 2] Fig. 2 is a control block diagram.

[Fig. 3] Fig. 3 is diagram illustrating a state where the autonomous work vehicle is working.

[Fig. 4] Fig. 4 is a diagram illustrating a reference length of the autonomous work vehicle.

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PCT-780 [Fig. 5] Fig. 5 is a schematic side view of a configuration where sinkage of the autonomous work vehicle is measured with a camera for measuring the hardness provided to an accompanying work vehicle.

[Fig. 6] Fig. 6 is a similar control block diagram.

[Fig. 7] Fig. 7 is a diagram illustrating a work image captured with a normal work state.

[Fig. 8] Fig. 8 is a diagram illustrating a work image captured with an abnormal work state.

Description of Embodiments [0011] An embodiment is described in which an autonomous work vehicle 1 that can autonomously travel with no people riding is a tractor, and a rotary tiller 24 attached to the autonomous work vehicle 1 is a work machine. In the description, a F direction corresponds to a front side.

[0012] Figs. 1 and 2 illustrate an overall configuration of the tractor as the autonomous work vehicle 1. An engine 3 is disposed in a hood 2, a dashboard 14 is disposed in a cabin 11 on a rear side of the hood 2. A steering wheel 4, as a steering operation unit, is disposed on the dashboard 14. Front wheels 9 and 9 turn in accordance with rotation of the steering wheel 4 via a steering device to have an orientation changed. The steering direction of the autonomous work vehicle 1 is detected by a steering sensor 20. The steering sensor 20 includes an angular sensor such as a rotary encoder, and is disposed in a rotation base portion of the front wheel 9. A configuration of the steering sensor 20 for performing the detection is not particularly limited, and any configuration may be employed as long as the steering direction can be recognized. Specifically, the rotation of the steering wheel 4 may be detected, or an operation amount of a power steering may be detected. A detection value obtained by the steering sensor 20 is input to a controller 30. The controller 30 includes a central processing unit (CPU), a storage device 30m including a RAM and a ROM, and an interface. The storage device 30m stores a program, data, and the like for operating the autonomous work vehicle 1.

[0013] A driver's seat 5 is disposed on the rear side of the steering wheel 4. A

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PCT-780 transmission case 6 is disposed below the driver's seat 5. Rear axle cases 8 and 8 continue to both left and right sides of the transmission case 6. Rear wheels 10 and 10 are supported by the rear axle cases 8 and 8 via an axle. Driving force from the engine 3 is shifted by a transmission (including a main transmission and a sub transmission) in the transmission case 6 and can be used for driving the rear wheels 10 and 10. For example, the transmission includes a hydraulic continuously variable transmission, and can perform the shifting with a movable swash plate in a variable capacity hydraulic pump operated by a speed changing unit 44 such as a motor. The speed changing unit 44 is connected to the controller 30. Rotation speed of the rear wheel 10 is detected by a vehicle speed sensor 27 and is input to the controller 30 as traveling speed. How the vehicle speed is detected and where the vehicle speed sensor 27 is disposed are not limited.

[0014] The transmission case 6 incorporates a PTO clutch and a PTO transmission. The PTO clutch is turned ON and OFF with a PTO ON/OFF unit 45. The PTO ON/OFF unit 45 is connected to the controller 30, and can control connection and disconnection of driving force to a PTO shaft.

[0015] A front axle case 7 is supported by a front frame 13 that supports the engine 3. The front wheels 9 and 9 are supported on both sides of the front axle case 7, in such a manner that the driving force from the transmission case 6 can be transmitted to the front wheels 9 and 9. The front wheels 9 and 9 are steered wheels that can turn in accordance with a rotation operation on the steering wheel 4. The front wheels 9 and 9 can be steered left and right by a steering actuator 40 including a power steering cylinder serving as a driving unit of the steering device. The steering actuator 40 is connected to the controller 30 and is driven while being controlled by an autonomous traveling unit.

[0016] An engine controller 60 serving as an engine rotation control unit is connected to the controller 30. An engine rotation speed sensor 61, a water temperature sensor, a hydraulic sensor, and the like are connected to the engine controller 60, and can detect the state of the engine. The engine controller 60 detects a load from a setting rotation speed and an actual rotation speed, and performs control so that an excessive load is not imposed.

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PCT-780 [0017] A level sensor 29 that detects a liquid level of a fuel is disposed in a fuel tank 15 disposed close to a step 81, and is connected to the controller 30. A fuel meter that displays a remaining amount of fuel is provided on a display unit 49 provided on the dashboard of the autonomous work vehicle 1, and is connected to the controller 30. An engine speed meter, the fuel meter, a monitor for displaying hydraulic pressure, abnormality, and the like, and the display unit 49 that displays a setting value and the like are disposed on the dashboard 14.

[0018] The rotary tiller 24 as a work machine is attached to a rear side of a tractor vehicle body via a work machine attachment device 23, in such a manner as to be able to be lifted and lowered. A lifting and lowering cylinder 26 is provided on the transmission case 6. A lifting and lowering arm as a part of the work machine attachment device 23 is pivoted through an extending/contracting movement of the lifting and lowering cylinder 26, so that the rotary tiller 24 can be lifted and lowered. The extending/contracting movement of the lifting and lowering cylinder 26 is achieved with an operation of a lifting and lowering actuator 25 connected to the controller 30.

[0019] A mobile communication device 33 as a part of a satellite positioning system is connected to the controller 30. A mobile GPS antenna 34 and a data receiving antenna 38 are connected to the mobile communication device 33, and are provided on the cabin 11. The mobile communication device 33 includes a position calculation unit and transmits longitude and latitude to the controller 30 so that the current position can be recognized. Highly accurate measurement can be achieved by using a Global Navigation Satellite System (GNSS), such as a quasi-zenith satellite (Japan) and a GLONASS satellite (Russia) in addition to a GPS (US). Still, the GPS is used in description of the present invention.

[0020] The autonomous work vehicle 1 includes a gyro sensor 31 for obtaining posture change information on the vehicle body and an orientation sensor 32 for detecting a traveling direction. The sensors are connected to the controller 30. It is to be noted that the orientation sensor 32 can be omitted because the traveling direction can be calculated from the position measurement by the GPS.

The gyro sensor 31 detects: an angular velocity of an inclination (pitch) of the vehicle

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PCT-780 body of the autonomous work vehicle 1 in a front and rear direction; an angular velocity of an inclination (roll) of the vehicle body in a left and right direction; and an angular velocity of yawing. The inclination angles of the vehicle body of the autonomous work vehicle 1 in the front and rear direction and the left and right direction, as well as, the yaw angle of the vehicle body can be obtained by calculation involving integrating the three angular velocities. A specific example of the gyro sensor 31 includes a mechanical gyro sensor, an optical gyro sensor, a hydrodynamic gyro sensor, and a vibration gyro sensor. The gyro sensor 31 is connected to the controller 30, and inputs information on the three angular velocities to the controller 30.

[0021] The orientation sensor 32 detects an orientation (traveling direction) of the autonomous work vehicle 1. A specific example of the orientation sensor 32 includes a magnetic orientation sensor. The orientation sensor 32 is connected to the controller 30 and inputs information on the orientation of the vehicle body to the controller 30.

[0022] Thus, the controller 30 calculates signals obtained from the gyro sensor 31 and the orientation sensor 32 with a posture and orientation calculation unit, and obtains the posture of the autonomous work vehicle 1 (the orientation, the inclination in the vehicle body front and rear direction and the vehicle body left and right direction, and the yaw direction).

[0023] Next, how position information on the autonomous work vehicle 1 is obtained by the global positioning system (GPS) is described.

The GPS, which has been developed for supporting navigation for aircrafts, vessels, and the like, includes: 24 GPS satellites (four in each of the six orbital planes) orbiting at the height of approximately 20,000 kilometers; a control station where the GPS satellites are tracked and controlled; and a communication device of a user for which the positioning is performed.

The positioning using the GPS includes various methods such as autonomous positioning, relative positioning, differential GPS (DGPS) positioning, and real time kinematics-GPS (RTK-GPS) positioning, and may employ any one of these methods. The present embodiment employs the RTK-GPS positioning featuring high measurement accuracy, and

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PCT-780 the positioning with this method is described with reference to Figs. 1 and 2.

[0024] The RTK-GPS positioning involves GPS observation simultaneously performed with a base station the position of which has been known and a rover the position of which is to be obtained. The base station performs real time transmission monitored data to the rover through a wireless scheme or the like, and the position of the rover is obtained real time, based on the position monitored by the base station.

[0025] In the present embodiment, the autonomous work vehicle 1 is provided with the mobile communication device 33, the mobile GPS antenna 34, and the data receiving antenna 38 serving as the rover. A fixed communication device 35, a fixed GPS antenna 36, and a data transmission antenna 39 serving as the base station are disposed at a predetermined position that does not hinder any work in the field. In the RTK-GPS positioning according to the present embodiment, the base station and the rover both measure phases (relative positioning), and the fixed communication device 35 in the base station transmits data obtained by the measurement to the data receiving antenna 38 through the data transmission antenna 39.

[0026] The mobile GPS antenna 34 provided in the autonomous work vehicle 1 receives a signal from GPS satellites 37, 37 .... The signal is transmitted to the mobile communication device 33 to be used for the positioning. At the same time, the fixed GPS antenna 36 in the base station receives a signal from the GPS satellites 37, 37 ... to be used for the positioning by the fixed communication device 35. The resultant data is transmitted to the mobile communication device 33, and the position of the rover is determined by analyzing the monitored data. The position information thus obtained is transmitted to the controller 30.

[0027] As described above, the controller 30 in the autonomous work vehicle 1 includes the autonomous traveling unit that achieves autonomous traveling. The autonomous traveling unit receives electric waves transmitted from the GPS satellites 37, 37 .... The position information on the vehicle body is obtained at a set time interval in the mobile communication device 33. Displacement information and orientation information on the

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PCT-780 vehicle body are obtained from the gyro sensor 31 and the orientation sensor 32. The autonomous traveling and work can be achieved with the steering actuator 40, the speed changing unit 44, the lifting and lowering actuator 25, the PTO ON/OFF unit 45, the engine controller 60, and the like controlled based on the position information, the displacement information, and the orientation information so that the vehicle body travels along a set route R set in advance. Position information on an outer circumference of a field H as a work range is set in advance through a known method, and is stored in the storage device 30m.

[0028] The autonomous work vehicle 1 is provided with an obstacle sensor 41 that is connected to the controller 30 and prevents physical contact with an obstacle. For example, the obstacle sensor 41 includes a laser sensor and an ultrasonic sensor, is disposed on a front portion, a side portion, and a rear portion of the vehicle body, is connected to the controller 30, detects whether there is an obstacle in front of, behind, or on the left or right side of the vehicle body, and performs control in such a manner that the traveling stops when the obstacles are within a set distance.

[0029] The autonomous work vehicle 1 is provided with a camera 42F that captures an image of a front side and a camera 42R that captures an image of the work machine provided on the rear side and the state of the field after the work. The cameras are connected to the controller 30. In the present embodiment, the cameras 42F and 42R are disposed on front and rear portions of a roof of the cabin 11. However, the disposed position is not limited to this. The cameras may be provided on front and rear portions in the cabin 11. A single camera 42 may be disposed at the center of the vehicle body and rotated about a vertical axis so that an area of the periphery is captured. Furthermore, a plurality of cameras 42 may be disposed on four corners of the vehicle body and capture an image of the periphery of the vehicle body. The images captured by the cameras 42F and 42R are displayed on a display device 113 of a remote controller 112 provided to an accompanying work vehicle 100.

[0030] The traveling route R and a work step of the autonomous work vehicle 1 can be set with the remote controller 112. The remote controller 112 can be used for remotely controlling the autonomous work vehicle 1, monitoring a traveling state of the autonomous

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PCT-780 work vehicle 1 and a work state of the work machine, and storing work data, and includes a controller (a CPU and a memory) 119, a communication device 111, and the display device 113.

[0031] The remote controller 112 can be detachably attached to an operation unit on the dashboard and the like of the autonomous work vehicle 1. Thus, the remote controller 112 can be operated while being carried outside the autonomous work vehicle 1. An example of the remote controller 112 includes a laptop or a tablet personal computer. In the present embodiment, the tablet computer is used.

[0032] The remote controller 112 and the autonomous work vehicle 1 can wirelessly communicate with each other. The autonomous work vehicle 1 and the remote controller 112 respectively include a communication device 110 and the communication device 111 for the communications. The communication device 111 is integrally formed with the remote controller 112. The communication units can communicate with each other via a wireless LAN such as WiFi for example. The remote controller 112 has a casing with a surface provided with the display device 113 as a touch panel operation screen that can be operated by touching the screen. The casing incorporates the communication device 111, the CPU, the storage device, a battery, and the like.

[0033] In this configuration, the traveling route R is set for the field H as illustrated in Fig. 3 in advance and is stored in the storage device 30m. Thus, the autonomous work vehicle 1 in an autonomous traveling start control mode can travel along the set traveling route R. Map data (information) is referred to for designating a position in the field H, traveling by using the satellite positioning system, and setting the traveling route R. Map data publicly available on the Internet, map data distributed by a map manufacturer, car navigation map data, or the like is used as the map data.

[0034] The rotary tiller 24 performs a tilling work as a work according to the present embodiment. The traveling route R is set for back and forth tilling with the accompanying work vehicle 100 working while traveling in tandem. Thus, each vehicle turns at a headland to skip an adjacent passage to move to the next passage to perform the work. The

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PCT-780 autonomous work vehicle 1 performing the work alone turns at the headland to move to the adjacent passage as the next row to perform the work. The headland in the tilling work performed by the rotary tiller 24 has a length that is double a width W1 of the work machine in the left and right direction.

[0035] An attached position of the GPS antenna 34 and a reference length are input to a storage device 30a of the controller 30 in advance, so that the tilling work can be performed along the set traveling route R. The attached position of the GPS antenna 34 may be above the centroid of the tractor or above the center of the rear axle in the left and right direction as the center of the turning, and thus is not particularly limited. In the present embodiment, the attached position is at the center of the vehicle (tractor) in plan view.

[0036] The sizes (reference length) of the autonomous work vehicle (tractor) 1 and the work machine (rotary tiller 24) are required for achieving the autonomous traveling within the field H and free of collision with an obstacle, and thus is stored in the storage device 30a in advance before the work. As illustrated in Fig. 4, the reference lengths include: an entire length L0 and an entire width W0 of the tractor; a distance LI between the GPS antenna 34 and a front end of the vehicle body in a state where the work machine (rotary tiller 24) is attached to the tractor; a distance L2 between the GPS antenna 34 and a rear end of the work machine; a distance L3 between the GPS antenna 34 and a work position of the work machine; a left and right width W1 of the work machine (when the work machine has a larger width than the tractor); a work overlap amount (overlap width) W2; eccentricity SI (not illustrated) from the center in the left and right direction, when the work machine is eccentrically arranged; and the like. The distances are each obtained from specification sheets of the tractor and the work machine, and are stored in the storage device 30a of the controller 30.

[0037] The distance LI between the GPS antenna 34 and the vehicle body front end is used for calculating the distance to a field end, such as a ridge, on the forward side or an obstacle on the forward side. The distance L2 between the GPS antenna 34 and the work machine rear end is used for calculating the distance to the ridge or the field when the vehicle

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PCT-780 is traveling backward. The distance L3 between the GPS antenna 34 and the work position of the work machine is required for recognizing a work start position and a work end position at the headland. The distance between the front end or the rear end of the vehicle body and the field end or the obstacle and the like may be displayed by the display unit 49 or the display device 113.

[0038] The work position of the work machine differs among the work machines, and is below a tilling claw shaft in the case of the rotary tiller 24. The position is slightly shifted from the center of the rotary tiller 24 in plan view. The work position is below a spray pole in the case of a boom sprayer. The position is not at the center of the boom sprayer (the sprayer device as a whole) in plan view. As described above, the work position of the work machine is not limited to the center in plan view, and is different among the work machines, and thus needs to be set for each work machine.

[0039] The reference length may be input to the storage device 30a through the remote controller 112 or may be input through the display unit 49 including a touch panel. The reference length is a fixed value for each work machine. Thus, a value corresponding to each model and type of a work machine may be stored in the storage device 30m in advance. Thus, the reference length may be set with the value read and selected each time the work machine is replaced.

[0040] The work machine may be provided with a storage unit 271 loading the reference length in advance. Thus, when the work machine is attached to the autonomous work vehicle 1, the reference length may be read from a reading device 64 provided to the autonomous work vehicle 1, or may be read with the storage unit 271 and the controller 30 connected to each other via a cable. In this manner, the reference length may be set in the controller 30. The storage unit 271 may be an IC chip, a magnetic storage medium, a barcode, a two-dimensional code, or the like, and thus is not particularly limited.

[0041] When the autonomous work vehicle 1 performs a work, the autonomous work vehicle 1 is positioned at the work start position of the headland, and a start switch is operated to start the work. The controller 30 of the autonomous work vehicle 1 controls the steering

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PCT-780 actuator 40 as the steering device, in such a manner that traveling along the set traveling route R is achieved. When the vehicle reaches the field end with the work position of the work machine reaching a work start and end position E (Fig. 3), the PTO ON/OFF unit 45 is turned OFF so that the rotary stops rotating, whereby the work machine stops. At the same time, the lifting and lowering actuator 25 is operated in such a manner that the lifting and lowering cylinder 26 is extended, whereby the rotary tiller 24 is lifted.

Then, the vehicle turns at the headland and travels in an opposite direction. When the work position of the work machine reaches the work start and end position E, the PTO ON/OFF unit 45 is turned ON, whereby the rotary starts rotating so that the work machine is driven. At the same time, the lifting and lowering actuator 25 is operated in such a manner that the lifting and lowering cylinder 26 is contracted, whereby the work starts with the rotary tiller 24 lowered. With the work repeated in this manner, the work start and end position E can be made uniform at the headland at the field end. All things considered, neat finishing can be achieved and a higher work efficiency can be achieved.

[0042] As described above, the autonomous work vehicle 1 includes: the position calculation unit configured to measure the position of a vehicle body by using a satellite positioning system; and the controller 30 configured to achieve automatic traveling and work along the set traveling route R. The controller 30 controls the steering device in such a manner that a vehicle body center is arranged along the set traveling route, and performs control in such a manner that the work machine is driven when a work center of the work machine is positioned at the work start position E, and stops when the work center of the work machine is positioned at the work end position E. Thus, the headland is neatly aligned, and the work for the headland can be neatly finished. Furthermore, spraying work involving less overlapping and a planting work and the like requiring no correction can be achieved.

[0043] The work position of the work machine can be set by the remote controller 112, and thus can be easily set at a position remote from the autonomous work vehicle 1.

The work machine includes a work position storing unit for the work machine. The work position storage unit can be connected to a work machine information reading device

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PCT-780 provided to the vehicle body. Thus, when the work machine is attached to the vehicle body of the autonomous work vehicle 1, the reference length can be easily set in the controller 30 simply by connecting the work position storage unit to the work machine information reading device.

[0044] Next, a configuration of detecting the hardness of the field by calculating an amount of sinkage of the vehicle body with the camera 42 as a field state detection device is described. As illustrated in Fig. 1, the autonomous work vehicle 1 includes the camera 42 that captures a field surface G and a predetermined position of the autonomous work vehicle 1. When the hardness is detected as the field state, the camera 32 is arranged to capture the image of the field surface G and the center between the rear wheels 10 as the predetermined position. The center between the rear wheels 10 and the field surface G are photographed at once, and the resultant image is input to the controller 30 to be subjected to image processing. The controller 30 calculates the distance between the center between the rear wheels 10 of the work vehicle and the field surface G to obtain a height LI. The height of the center between the rear wheels 10 in a state where the vehicle body is not sunken is measured in advance as a reference height L0. A difference L2 between the reference height L0 and the measured height LI is calculated, to be obtained as an amount of sinkage L2 into the field. In this manner, the hardness of the field is measured. It is apparent that the amount of sinkage and the hardness of the field are in a relationship that the amount of sinkage increases as the hardness decreases. Thus, a map or the like representing this relationship is stored in the storage device 30m in advance. The predetermined position is not limited to the center between the rear wheels 10 as in the present embodiment, and may be a lower end of the step 81 at substantially the center of the vehicle body in the front and rear direction as illustrated in Fig. 5, or any other portion where the height from the field surface G can be measured. The predetermined position is most preferably at the center of the vehicle body in the front and rear direction and in the left and right direction.

[0045] In this configuration, the camera 42 captures the image of the field surface G and the predetermined position of the autonomous work vehicle 1 while the traveling (work) is in

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PCT-780 process. Thus, the height is obtained and the amount of sinkage L2 is measured. The height of the rotary tiller 24 as the work machine is controlled in accordance with the amount of sinkage L2. Specifically, when the field surface is soft and the amount of sinkage L2 is large, the lifting and lowering actuator 25 is operated in such a manner that the lifting and lowering cylinder 26 is extended so that the rotary tiller 24 is lifted in accordance with the amount of sinkage L2. On the contrary, when the field surface is hard and thus the amount of sinkage L2 is small, the rotary tiller 24 is lowered. Thus, more accurate tilling depth control can be achieved, whereby a uniform tilling depth can be achieved. For example, a uniform seeding depth can be achieved for a seeding operation, a uniform fertilization depth can be achieved for a fertilization work, and a uniform planting depth can be achieved for a transplanting work, whereby a higher work performance can be achieved.

[0046] The amount of sinkage L2 is measured every time the traveling (work) proceeds for a predetermined distance. The measurement value or the hardness calculated from the measurement value is successively written to the measurement positions on the map (field map) of the field H, whereby a hardness distribution is generated. What is written is not limited and may be numbers, points, colors, or the like. The hardness distribution is overlapped with the field map on the display unit 49 or the display device 113 of the remote controller 112 so that soft and hard positions on the field H can be easily recognized. Thus, the soft position can be easily recognized when the work is performed after the rain, whereby stacking can be prevented by circumventing the soft position or the work performed with a smaller depth to reduce the load at the soft position.

[0047] The controller 30 can communicate with a management server 400 through a communication line 401, and transmits the hardness distribution, obtained by the measurement operation after the work (measurement) is terminated (or while the work is in process), to the management server 400 through the communication line 401. Thus, the hardness distribution of the field is stored. The hardness distribution data is stored as field data in a database of the management server 400, to contribute to the works in the future. The field data includes an address, a tilling date, a planted or a harvested date of crops, a type,

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PCT-780 an amount, and sprayed dates of controlling agent and fertilizer.

[0048] As illustrated in Fig. 5 and Fig. 6, the image capturing for the amount of sinkage may be performed as follows. Specifically, the height of the step 81 of the autonomous work vehicle 1 from the field surface G may be measured with the camera 42 attached to the accompanying work vehicle 100 that performs a work while traveling in tandem with the autonomous work vehicle 1, and capturing an image of the step 81 (or the center between the rear wheels 10) as the predetermined position of the autonomous work vehicle 1 and the image of the field surface G. The predetermined position may be the rear wheel 10, a vehicle body frame, or the like as in the case described above.

[0049] The image of the step 81 of the autonomous work vehicle 1 and the field surface G is transmitted to a controller 130 of the accompanying work vehicle 100. The controller 130 calculates the amount of sinkage L2 as the difference between the distance, between the field surface G and the step 81, and the height of the step 81 from the surface without sinking, and thus calculates the hardness. The amount of sinkage L2 is transmitted to the controller 30 of the autonomous work vehicle 1 through a communication device 133 and the communication device 110, to be used for the tilling depth control for the rotary tiller 24.

The amount of sinkage L2 is also transmitted to the remote controller 112, and thus the hardness is written on the field map in accordance with the traveling position of the autonomous work vehicle 1. The harness is also transmitted and written to the management server 400 through the communication line 401 to be stored as the hardness distribution data, as in the case described above.

[0050] As described above, the camera 42 is attached to the autonomous work vehicle 1 and captures the image of the predetermined position and the field surface G therebelow. The predetermined position includes the step 81 of the vehicle body of the autonomous work vehicle 1, the center between the rear wheels 10, or the like. The height of the step 81 or the rear wheel 10 of the autonomous work vehicle 1 from the field surface G is calculated while the traveling is in process, and the hardness of the field is measured from the amount of sinkage of the vehicle body with respect to the field surface G at a certain position. Thus,

PCT/JP2015/081630

PCT-780 the hardness can be sequentially measured while the autonomous work vehicle 1 is traveling, whereby labor and time required for measuring the hardness can be dramatically reduced. Furthermore, the measurement involves almost no operation and thus can be easily conducted. The field hardness obtained by the measurement is applied to the tilling depth control or the like, whereby a higher work accuracy can be achieved.

[0051] The camera 42 is attached to the accompanying work vehicle 100 that performs the work while traveling in tandem with the autonomous work vehicle 1 and captures the image of the predetermined position and the field surface G therebelow. The predetermined position includes the step 81 of the autonomous work vehicle 1, the center between the rear wheels 10, or the like. The height of the step 81 or the center between the rear wheels 10 of the autonomous work vehicle 1 from the field surface G at the certain position is calculated, and the hardness of the field is measured from the amount of sinkage into the field. Thus, the measurement is performed from the side position away from the autonomous work vehicle 1, whereby a smaller error can be achieved so that the height of the predetermined position can be accurately measured.

[0052] The hardness thus measured is sequentially written to the field map to be stored as the hardness distribution data in the storage device 30m of the controller 30. Thus, the height control can be performed for the work machine while the work is in process, whereby a higher work accuracy can be achieved. Furthermore, the hardness distribution of the field can be easily recognized.

[0053] The camera 42R may be used as a field state detection device to capture an image of the field surface after the work. The state thus detected may be compared with a normal state of the field surface after the work, and it may be determined that an abnormality has occurred in the work machine when there is a difference. In the present embodiment, a work performed by the rotary tiller 24 is a flat ridge forming work, and the set traveling route R corresponds to a back and forth work in which the vehicle moves to an adjacent passage at the headland. An image of this work state is captured with the camera 42R. When an abnormality occurs, a stop unit stops the traveling and the work and an operator is notified of

PCT/JP2015/081630

PCT-780 the abnormality by issuing an alert.

[0054] More specifically, the camera 42R is attached to a rear end of the upper portion of the cabin 11, connected to the controller 30. The camera 42R captures an image of a state where the flat ridge forming is normally performed by the rotary tiller 24, and the image is input to the controller 30 as the field state. The camera 42R attached to the accompanying work vehicle 100, which performs the work while traveling in tandem with the autonomous work vehicle 1, may capture the image indicating the field state. In such a case, the image is captured from behind the autonomous work vehicle 1, and thus the image captured position is not hidden by the work machine, depending on the work machine, whereby detection of the work state is guaranteed.

Image data obtained by the image capturing is subjected to image processing, and is stored in the storage device 30m in advance as a normal work image (image indicating the normal state). In a field where work is performed, the normal work image is an image captured when work is performed for the first time, and is successfully completed. This normal work image thus stored is used as a reference to be compared with an image at the time where work is performed, whereby whether an abnormality has occurred is determined. A conventionally used normal work image may be stored as the normal work image.

[0055] For example, as illustrated in Fig. 7, an image in which a tilled portion and an untilled portion have clearly different colors can be obtained, where C is a color indicating a portion immediately after the tilling, D is a color indicating the untilled portion, and K is a color indicating the tilled portion. This image data is obtained when a normal operation is performed. The positions of the work field and the headland in the traveling route R have been recognized with the positioning device. Thus, whether an abnormality has occurred is not determined for the headland, and is only determined for the work field. It is to be noted that the headland is also a work field in final work around the outer circumference.

[0056] When the work is performed, the image data obtained by the camera 42R is compared with the normal work image. When the tilling claw is damaged or detached, a line shaped portion J with a different color is formed in the area C as illustrated in Fig. 8. For

PCT/JP2015/081630

PCT-780 example, in this case, it is determined that an abnormality has occurred when there are pixels, different from the normal portion, of a setting value or more. When there is the different portion J of a setting value or more, the speed changing unit 44, as a stopping unit for stopping the traveling, is switched to neutral to stop the traveling. Furthermore, the PTO ON/OFF unit 45, as a unit for stopping the operation, is turned OFF, so that the work stops. Alternatively, the engine controller 60 may serve as the stopping unit to stop the engine.

At the same time, warning is issued with buzzer or horn emitted or a direction indicator flashed, so that people in the periphery can recognize the abnormality, and with a notification indicating the abnormality displayed on the display device 113 of the remote controller 112 carried around by the operator. Furthermore, the warning may be issued from a speaker of the remote controller 112.

[0057] The controller 30 can communicate with the management server 400 through the communication line 401. The abnormality is transmitted to the management server 400 through the communication line 401 to be stored as abnormality data. In the management server 400, the abnormality is stored as a maintenance record in the database, to be useful against the occurrence of an abnormality or the like in the future. The captured image can be displayed on the display unit 49 on the dashboard 14 or the display device 113 of the remote controller 112.

[0058] The remote controller 112 is provided with a restart button 118 as a work resuming operation unit. The determination of the abnormality can be canceled and the traveling and the work can be resumed by operating the restart button 118. Specifically, the image comparison might lead to erroneously stopping the vehicle even when the work state is actually normal, due to grass and straw being mixed to be a portion different from the peripheral normal portion. When the vehicle is thus stopped without any abnormality, the operator can easily determine that it is normal. In such a case, the determination of abnormality can be canceled and the work can be quickly resumed by operating the restart button 118, without checking the entire work machine, the system, or the like.

[0059] The type of work is not limited to the flat ridge forming work by the rotary tiller

PCT/JP2015/081630

PCT-780

24, and the embodiment may be applied to other types of work. For example, when the embodiment is applied to transplanting work involving plating seedlings on the ridge at a predetermined interval, the normal captured image includes a row of green seedlings, with the seedling planted at a predetermined interval on a predetermined passage. When an abnormality occurs in the planting claws or supplied seedlings, interruption of a row and a missing seedling can be easily determined with image processing. When such an abnormality occurs, the traveling and work stop, and thus the warning is issued. The transplanting work machine may be a rice transplanter.

[0060] The embodiment can be applied to mowing work and harvesting work. For example, when a mower is attached as the work machine, states before and after the mowing have different colors. In the mowing operation, mowing blades might be damaged or detached. When this happens, the mowed area includes a different color portion. Thus, the traveling stops, the work automatically stops and the warning is issued as in the case described above.

[0061] The embodiment can be further applied to spraying work for spaying fertilizer with a lime sower and for spraying agricultural chemicals. In the fertilizer spraying operation, a sprayed portion and an unsprayed portion on the field upper surface have different colors. Thus, when an abnormality such as a clogging of a dropping hole occurs, a corresponding colored row is interrupted. Thus, the controller 30 determines that an abnormality has occurred, and stops the traveling and work and issues a warning as in the case described above.

The embodiment may be applied to mulching. When an abnormality such as ripping or wrinkling of a covering mulch occurs, the abnormal portion has a color different from the mulch film. Thus, the controller 30 determines that the abnormality has occurred, and stops the traveling and work and issues a warning as in the case described above.

[0062] As described above, the autonomous work vehicle 1 includes: a position calculation unit configured to measure the position of the vehicle body by using a satellite positioning system; and the controller 30 configured to achieve automatic traveling and work

PCT/JP2015/081630

PCT-780 along the set traveling route R. The camera 42R configured to capture an image of the work state is provided to the autonomous work vehicle 1 and is connected to the controller 30. The controller 30 is connected to the stopping unit configured to stop the traveling and work. The controller 30 executes image processing on the image captured by the camera 42R while the work is in process, and the image is compared with the normal work image stored in advance. When the image data that has a difference is obtained, the controller 30 determines that an abnormality has occurred, and performs control in such a manner that the traveling and work stops. Thus, when an abnormality occurs in the work state while the autonomous work vehicle 1 is autonomously traveling, the work is quickly stopped. Thus, further damage on the work machine can be prevented, whereby reworking can be prevented with an erroneous work state shortened as much as possible. The cause of the abnormality can be easily determined by watching the image.

[0063] The controller 30 can communicate with the remote controller 112 via the communication device 110, and thus can issue a notification to the remote controller 112 upon determining that the abnormality has occurred. Thus, the operator can recognize the occurrence of the abnormality, and quickly address the abnormality.

[0064] The remote controller 112 is provided with the restart button 118 serving as the work resuming operation unit. Thus, the determination of the abnormality can be canceled and the traveling and work can be resumed by operating the restart button 118. Thus, the work can be easily resumed simply by operating the restart button 118 in a case where the operation has stopped even when the abnormality has not actually occurred or when the abnormality is corrected with a simple operation and a simple repairing.

[0065] The controller 30 can communicate with the management server 400 through the communication line 401, and when the abnormality occurs, stores the abnormality in the database of the management server 400. Thus, the abnormality and data indicating the state where the abnormality has occurred are stored as a maintenance record in the database, to be utilized for correcting an abnormality occurring in the future.

Industrial Applicability

PCT/JP2015/081630

PCT-780 [0066] The present invention can be used for a construction machine, a farming machine, or the like working in a situation where a plurality of work vehicles perform work in a predetermined field or the like by using a satellite positioning system.

Reference Signs List [0067] 1 autonomous work vehicle controller camera

100 accompanying work vehicle

112 remote controller

130 controller

2015347785 16 May 2019

Claims

1. A field state detection system comprising:

a first camera that is attached to an autonomous work vehicle and configured to capture a first image of a predetermined position of the autonomous work vehicle and a field surface below the predetermined position, and a second camera that is attached to an accompanying work vehicle configured to perform work while traveling in tandem with the autonomous work vehicle and configured to capture an image of the predetermined position of the autonomous work vehicle and the field surface below the predetermined position, wherein a height of the predetermined position of the autonomous work vehicle from the field surface is calculated from at least one of the first image and the second image as an amount of sinkage into the field for measuring a hardness of the field.

2. The field state detection system according to claim 1, wherein the measured hardness is sequentially written to a field map, and is stored as hardness distribution data in a storage device.

3. The field state detection system according to claim 1 or claim 2, comprising a third camera provided on the autonomous work vehicle, the third camera being connected to a controller and configured to capture an image of a state after the work, wherein the controller is configured to execute image processing on the image captured with the third camera and a resultant image is compared with a normal work image stored in advance, while the work is in process.

4. The field state detection system according to claim 3, wherein the controller is connected to a stopping unit configured to stop traveling and the work, and the controller is configured to determine that an abnormality has occurred when image data has a difference between the image after the work captured by the third camera and the normal work image, and to perform control in such a manner that the traveling and the work stop.

2015347785 16 May 2019

5. The field state detection system according to claim 4 or 5, wherein the controller is able to communicate with a management server through a communication line, and is configured to store the hardness distribution data, the normal work image, and an abnormal work image in a database of the management server.

6. The field state detection system according to claims 4 or 5, wherein the controller is able to communicate with a remote controller through a communication device, and is configured to notify, upon determining that the abnormality has occurred, the remote controller of the abnormality.

7. A field state detection system comprising:

a first camera that is attached to an accompanying work vehicle, the accompanying work vehicle accompanying an autonomous work vehicle configured to perform work while traveling in tandem with the accompanying work vehicle, the first camera configured to capture a first image of a predetermined position of the autonomous work vehicle and a field surface below the predetermined position, wherein a height of the predetermined position of the autonomous work vehicle from the field surface is calculated from the first image as an amount of sinkage into the field for measuring a hardness of the field.

8. The field state detection system according to claim 7, wherein the measured hardness is sequentially written to a field map, and is stored as hardness distribution data in a storage device.

9. The field state detection system according to claim 7 or 8, comprising an additional camera provided on the autonomous work vehicle, the additional camera being connected to a controller and configured to capture an image of a state after the work, wherein the controller is configured to execute image processing on the image captured with the additional camera and a resultant image is compared with a normal work image stored in advance, while the work is in process.

2015347785 16 May 2019

10. The field state detection system according to claim 9, wherein the controller is connected to a stopping unit configured to stop traveling and the work, and the controller is configured to determine that an abnormality has occurred when image data has a difference between the image after the work captured by the additional camera and the normal work image, and to perform control in such a manner that the traveling and the work stop.

11. The field state detection system according to claim 9 or 10, wherein the controller is able to communicate with a management server through a communication line, and is configured to store the hardness distribution data, the normal work image, and an abnormal work image in a database of the management server.

12. The field state detection system according to claim 10, wherein the controller is able to communicate with a remote controller through a communication device, and is configured to notify, upon determining that the abnormality has occurred, the remote controller of the abnormality.

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