JP2019083703A - Harvesting machine - Google Patents

Abstract

To provide a combine-harvester capable of performing harvesting work, while detecting obstacles without lowering the workability.SOLUTION: The harvesting machine includes: a camera 81 for capturing a field ahead of the travel direction of a machine body in the field; an image acquisition unit 51 for acquiring a captured image by a camera 81; an obstacle detection unit 52 for detecting an obstacle by processing the captured image; a warning area setup unit 53 for setting up an obstacle warning area prescribed on the basis of a position relative to the machine body; and a vehicle speed change command output unit 65 that, when the obstacle detected by the obstacle detection unit is present in the obstacle warning area, changes the vehicle speed according to a physical relationship between the obstacle and the machine body.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a harvester that detects an obstacle in a field using a captured image acquired by a camera.

  In the field, there may be an operator other than the driver or an obstacle such as an electric pole, so as shown in Patent Document 1, the combine for working on the field is an obstacle. Some are provided with ultrasonic obstacle sensors for detection. When an obstacle is detected by the obstacle sensor, the engine or the like is stopped to prevent danger.

  The combine according to Patent Document 2 is equipped with a laser scanner. This laser scanner is configured such that the laser is emitted toward the right side of the reaper in order to detect a person who has entered the area where most of the road surface is exposed by mowing the object to be removed. ing. Moreover, in patent document 2, in order to detect an obstacle, it is described in place of a laser scanner that it is also possible to use a millimeter-wave radar or to use image processing using a camera or the like.

JP-A-9-76850 JP, 2017-176007, A

In crop work of crops such as wheat, rice and soybeans, obstacles such as humans are likely to be partially obscured by crops, and obstacle detection accuracy fluctuates. For this reason, when the vehicle is stopped every time an obstacle is detected and the detected obstacle is confirmed, the workability is reduced.
From such a situation, there is a demand for a combine that carries out a harvesting operation while detecting an obstacle without lowering the workability as much as possible.

  A harvester according to the present invention comprises: a camera for capturing an image of a forward direction of an aircraft in a field; an image acquisition unit for acquiring an image captured by the camera; and an obstacle detection for detecting an obstacle by performing image processing on the captured image. Section, an alert area setting section that sets an obstacle alert area defined based on the position with respect to the machine, and the obstacle detected by the obstacle detection section is present in the obstacle alert area; And a vehicle speed change command output unit configured to change the vehicle speed in accordance with the positional relationship between the obstacle and the vehicle body.

  According to this configuration, when the detected obstacle is considered to be present in the obstacle warning area set based on the position with respect to the aircraft, the vehicle speed is changed according to the positional relationship between the obstacle and the aircraft. . Therefore, the degree of change of the vehicle speed can be made different depending on the positional relationship between the aircraft and the obstacle depending on whether the possibility of interference within a predetermined time is large or not. At that time, for example, the change of the vehicle speed in the case where the possibility of interference within a relatively short time is large due to the positional relationship between the vehicle and the obstacle will change the vehicle speed to zero, that is, stop the vehicle. . As a result, even if the possibility of interference within a relatively short time is small due to the positional relationship between the airframe and the obstacle, the possibility of stopping the airframe and reducing the workability is reduced. Furthermore, since the obstacle warning area is defined based on the position with respect to the airframe, it is possible to almost ignore the possibility that the airframe and the obstacle interfere with each other even in the area within the shooting field of view of the camera. For areas where it is possible, it can be removed from the obstacle warning area. This improves the efficiency of obstacle detection.

  In one of the preferred embodiments of the present invention, the obstacle alert area is divided into a first alert area and a second alert area having different positional relationships with the vehicle, and the vehicle speed change command output unit A second vehicle speed change command that outputs a first vehicle speed change command when an obstacle exists in the first alert area, and a vehicle speed change value is smaller than the first vehicle speed change command when an obstacle exists in the second alert area Output In this configuration, for example, in the obstacle warning area, the first warning area that is considered to have a high possibility of interference between the airframe and the obstacle, and the possibility of interference between the airframe and the obstacle is more than the first warning area. It can be divided into a second alert area that is considered low. Then, when the detected obstacle is present in the first alert area, the vehicle speed is greatly reduced (including the stop) as compared with the case where the detected obstacle is present in the second alert area. This makes it possible to properly balance the workability and the safety.

  The area extending forward in the traveling direction of the airframe at the working width is an area where there is a high possibility of interference between the airframe and the obstacle, and therefore requires more vigilance than other areas. Furthermore, the shorter the distance from the front, the less time it takes for the vehicle to interfere with the obstacle, so more severe alerting is required. From this, it is desirable to determine the alerting distance ahead of the traveling direction of the aircraft, taking this time margin into consideration. Therefore, in one of the preferred embodiments of the present invention, the first alert area includes the working width of the harvester provided at the front of the machine, the angle of view of the camera, and the traveling direction of the machine from the machine. This is an area defined by the forward warning distance.

  It is preferable that the warning distance be changed according to the vehicle speed, since the time margin for the interference between the airframe and the obstacle depends on the vehicle speed when the obstacle is stationary. In this way, workability and safety are compatible.

  In crop operations such as wheat, rice and soybeans in the field, it is difficult to distinguish between an obstacle and a crop, and there is a possibility that a crop may be erroneously detected as an obstacle. In order to reduce such false detections, there is a high probability that crops exist, taking into consideration the average height of humans, which are the obstacles that must be the most important, and the average height of crops that are lower than this. It is also necessary to exclude the target area from obstacle detection. This can be done effectively by masking the space where the crops are present, with the space extending forward in the traveling direction of the airframe in the field as the detection range. By appropriately masking, it is possible to reliably detect an obstacle such as a human being sticking out of a crop. On the other hand, even though the obstacles present above the cropping area are not hidden by the crop, masking the area at the height level of the crop misses the short obstacles It will be. For this reason, in one of the preferred embodiments according to the present invention, the obstacle detection unit detects the obstacle in a three-dimensional coordinate system in which the eyelid scene is one reference plane, and the height from the eyelid scene is high. Function of masking an obstacle detection range by a masking area defined by the data processing means, and the masking process is not performed on the obstacle existing above the scoop scene after harvest There is.

It is a whole side view of a combine. It is a schematic diagram which shows the obstacle detection range by the stereo camera with which the fuselage front part was equipped. It is a top view which shows the 1st caution area | region and 2nd caution area | region which are used for the obstruction detection by a stereo camera. It is a functional block diagram of the control system in a combine. It is a flowchart which shows the flow of obstacle detection control. It is a schematic diagram which shows the obstacle position in the plane coordinate in alignment with the overhead scene derived | led-out from the obstacle detection result in a three-dimensional obstacle detection space coordinate.

  Hereinafter, an embodiment of a combine as an example of a harvester according to the present invention will be described based on the drawings. In this embodiment, when defining the front-rear direction of the aircraft 1, it is defined along the aircraft traveling direction in the working state. The direction indicated by the symbol (F) in FIG. 1 is the front side of the vehicle, and the direction indicated by the symbol (B) in FIG. 1 is the rear side of the vehicle. When defining the left-right direction of the airframe 1, right and left are defined in the state seen in the advancing direction of the airframe. The “upper (upper)” or “lower (lower)” is a positional relationship in the vertical direction (vertical direction) of the airframe, and indicates a relationship in the ground level.

  As shown in FIG. 1, in the combine, the reaper 2 is connected to the front of the machine body 1 including the pair of left and right crawler traveling devices 10 so as to be able to move up and down around the horizontal axis. Due to the difference in speed between the left and right crawler traveling devices 10, the vehicle body 1 can turn left and right. A threshing device 11 and a grain tank 12 for storing grains are provided at the rear of the machine body 1 in a state of being aligned in the machine body width direction. A boarding driver 14 is provided at a front right side portion of the airframe 1, and an engine (not shown) is provided below the boarding driver 14.

  As shown in FIG. 1, the threshing device 11 internally receives the reaping grain crush which has been cut by the reaping section 2 and transported to the rear, and the origin of the grain clump is pinched by the feed chain 111 and the pinching rail 112 While carrying, the tip side is threshed with a threshing cylinder 113. Then, the grain sorting process is performed on the threshing treatment product in the sorting unit provided below the threshing drum 113, and the grain sorted there is transported to the grain tank 12 and stored. Although not described in detail, a grain discharging device 13 for discharging grains stored in the grain tank 12 to the outside is provided.

  The reaper 2 is provided with a hair clipper type cutting device 22 for cutting the origin of the cropped rice straw which has been raised, a grain transportation device 23 and the like. The grain conveying device 23 conveys the cropped grain weir in the vertical posture, in which the stock origin has been cut, to the tip end portion of the feed chain 111 while gradually changing it to the horizontal falling posture.

  A satellite positioning module 80 is also provided on the ceiling of the boarding and driving unit 14. The satellite positioning module 80 includes a satellite antenna for receiving global navigation satellite system (GNSS) signals (including GPS signals). In order to complement the satellite navigation by the satellite positioning module 80, an inertial navigation unit consisting of a gyro acceleration sensor and a magnetic direction sensor may be incorporated into the satellite positioning module 80. Of course, the inertial navigation unit can be located elsewhere.

  As shown in FIG. 2, at the front of the combine, a stereo camera 81, which is a camera for photographing the forward direction of the airframe 1 in the field, is provided for obstacle detection. In obstacle detection using the stereo camera 81, the principle of triangulation is used. Parallax data is generated from images captured by the camera units on the left and right of the stereo camera 81, the distance between the stereo camera 81 and the detected object is calculated, and the three-dimensional coordinate position of the detected object is calculated. In this embodiment, the angle of view which is the extension in the front-rear direction of the imaging field of view of the stereo camera 81 is about 40 °, but a larger angle of view or a smaller angle of view is adopted according to the specification of obstacle detection. It is also possible.

  In obstacle detection using the stereo camera 81, the position of the obstacle can be determined in a three-dimensional coordinate system, but in this embodiment, in the final obstacle detection control, the position of the detected obstacle is It is determined in a two-dimensional coordinate system in the plane along the eyebrow scene. Therefore, as shown in FIG. 3, an obstacle warning area in which an object detected by the stereo camera 81 is detected as an obstacle and control for avoiding interference with the obstacle is performed is a field that extends forward in the traveling direction of the airframe 1. It is defined on a reference plane (XY plane) corresponding to the plane. Here, the obstacle alert area is a first alert area (filled in FIG. 3 with dark color and given the symbol Z1) and a second alert area (light in FIG. 3), which differ in positional relationship with the airframe 1. And Z2).

  The first alert area is a rectangle defined by the working width of the harvesting section 2 which is the harvest section and the alert distance forward of the traveling direction of the airframe 1 from the airframe 1 (indicated by reference symbol L1 in FIG. 3) The blind spot area is a truncated area determined by the angle of view of the stereo camera 81. In other words, the first alert area is one side of the right and left width of the reaper 2 which is substantially the travel path width of the combine, and a rectangle whose other side is a predetermined distance (warning distance) forward from the airframe 1 The blind spot area determined by the angle of view of the stereo camera 81 is cut out. An obstacle existing in the first alert area comes into contact with the combine as the combine progresses. Therefore, the warning distance is preferably changed according to the vehicle speed of the combine, but in this embodiment, the work traveling speed is set to several meters because it is substantially constant.

  The second alert area is an area obtained by cutting off the first alert area from a tip end area in the dead angle area determined by the angle of view of the stereo camera 81 in a plane extending forward in the traveling direction of the airframe 1. The width of the combine in the left and right direction is about three times the width of the first alert area, and the length in front of the forward direction of the airframe 1 is less than twice the length of the first alert area (shown by L2 in FIG. 3) ). The left-right spread of the second alert area is set in consideration of the turning of the combine, and the extension of the second alert area in the advancing direction is the time for the interference between the airframe 1 and the obstacle, but the first alert It is set to be larger than the area.

  FIG. 3 shows a functional block diagram of the control system of the combine. The control system of this embodiment comprises an electronic control unit called a large number of ECUs, various operation devices, sensors, switches, and a wiring network such as a car-mounted LAN for data transmission between them. The notification device 84 is a device for notifying a driver or the like of a warning such as a detection result of an obstacle or a state of work traveling, and is a buzzer, a lamp, a speaker, a display or the like. As for the detection result of the obstacle, when the obstacle exists in the first alert area, a warning sound, a warning light or a warning message indicating an imminent state is notified as an emergency alert notification, and the first alert When it exists in the area, a gentle alert sound, a caution light or a alert message is alerted as an alert alert rather than the emergency alert alert.

  The communication unit 85 is used to exchange data with an external communication device. The control unit 6 is a core element of this control system, and is shown as a collection of a plurality of ECUs. The positioning data from the satellite positioning module 80 and the photographed image from the stereo camera 81 are input to the control unit 6 through the wiring network.

  The control unit 6 includes an output processing unit 6B and an input processing unit 6A as an input / output interface. The output processing unit 6B is connected to the vehicle travel device group 7A and the work device device group 7B. The vehicle travel device group 7A includes control devices related to vehicle travel, such as an engine control device, a shift control device, a braking control device, a steering control device, and the like. The work device group 7B includes power control devices and the like in the reaper 2, the threshing device 11, the grain discharging device 13, and the grain conveying device 23.

  A traveling system detection sensor group 8A, a working system detection sensor group 8B, and the like are connected to the input processing unit 6A. The traveling system detection sensor group 8A includes a sensor that detects the state of an engine speed adjuster, an accelerator pedal, a brake pedal, a gearshift operator, and the like. The working system detection sensor group 8B includes a cutting unit 2, a threshing device 11, a grain discharging device 13, and a device state in the grain conveying device 23 and a sensor for detecting the state of the grain or grain.

  The control unit 6 includes a work travel control module 60, an image processing module 50, a vehicle speed change command output unit 65, a machine position calculation unit 66, and a notification unit 67.

  The notification unit 67 generates notification data on the basis of a request from each functional unit of the control unit 6, and gives the notification data to the notification device 84. The aircraft position calculation unit 66 calculates the aircraft position which is the map coordinates (or field coordinates) of the aircraft 1 based on the positioning data sequentially sent from the satellite positioning module 80.

  The combine according to this embodiment can travel in both automatic travel (automatic steering) and manual travel (manual steering). In addition to the travel control unit 61 and the work control unit 62, the work travel control module 60 is provided with a work travel instruction unit 63 and a travel route setting unit 64. A traveling mode switch (not shown) for selecting one of an automatic traveling mode for traveling by automatic steering and a manual steering mode for traveling by manual steering is provided in the boarding operation unit 14. By operating the travel mode switch, it is possible to shift from manual steering travel to automatic steering travel, or shift from automatic steering travel to manual steering travel.

  The traveling control unit 61 has an engine control function, a steering control function, a vehicle speed control function, and the like, and provides a traveling control signal to the vehicle traveling device group 7A. The work control unit 62 provides a work control device group 7B with a work control signal in order to control the movement of the reaper 2, the threshing device 11, the grain discharging device 13, the grain feeding device 23, and the like.

  The travel route setting unit 64 develops a travel route for automatic travel in the memory. The travel route developed in the memory is sequentially used as a target travel route in automatic travel. Even if this traveling route is manual traveling, it is also possible to use the guidance for the combine to travel along the traveling route.

  The work travel command unit 63 generates an automatic steering command and a vehicle speed command as an automatic travel command, and supplies the command to the travel control unit 61. The automatic steering command is generated by the traveling route setting unit 64 so as to eliminate the azimuth deviation and the positional deviation between the traveling route and the own machine position calculated by the machine position calculating unit 66. During automatic traveling, the vehicle speed command is generated based on a previously set vehicle speed value. During manual traveling, the vehicle speed command is generated based on the manual vehicle speed operation. However, when an emergency such as obstacle detection occurs, vehicle speed change including forced stop, engine stop, etc. are automatically performed.

  When the automatic travel mode is selected, the travel control unit 61 controls the vehicle travel device group 7A related to steering and the vehicle travel device group 7A related to vehicle speed based on the automatic travel command given by the work travel command unit 63. When the manual travel mode is selected, the travel control unit 61 generates a control signal based on the operation by the driver to control the vehicle travel device group 7A.

  The image processing module 50 has a function of performing image processing on an image captured by the stereo camera 81 to detect an obstacle (object) in a field. The image processing module 50 includes an image acquisition unit 51, an obstacle detection unit 52, and a caution area setting unit 53. The image acquisition unit 51 acquires an image captured by the stereo camera 81. The obstacle detection unit 52 detects an obstacle by performing image processing on the captured image. The image processing in the obstacle detection unit 52 includes coordinate conversion, stereo matching, three-dimensional feature point calculation and the like. The alert area setting unit 53 sets an obstacle alert area defined based on the position with respect to the aircraft 1. In this embodiment, the obstacle alert area is divided into a first alert area and a second alert area, as described with reference to FIG. The obstacle detection unit 52 determines whether the detected obstacle is present in the first alert area or the second alert area, and generates obstacle detection information.

  The obstacle detection information generated by the image processing module 50 is sent to the vehicle speed change command output unit 65. The vehicle speed change command output unit 65 outputs a first vehicle speed change command including the vehicle speed change value to the work travel command unit 63, when the obstacle is present in the first alert area, from the received obstacle detection information. If the obstacle is present in the second alert area, a second vehicle speed change command including the vehicle speed change value is output to the work travel command unit 63. The first vehicle speed change command is a command to set the vehicle speed to zero, that is, a command to stop the machine 1. Of course, the first vehicle speed change command may be a command to make the vehicle speed close to zero, or a command to make the vehicle speed zero gradually. The second vehicle speed change command is a deceleration value that decelerates the vehicle speed to a low speed, for example, about 1 km / h. The second vehicle speed change command may be a deceleration value determined at a ratio to the immediately preceding vehicle speed, such as decelerating to a fraction of the immediately preceding vehicle speed. In any case, the first vehicle speed change value by the first vehicle speed change command is larger than the second vehicle speed change value by the second vehicle speed change command, and is a command for emergency evacuation. Based on the vehicle speed change command determined by the vehicle speed change command output unit 65, the work travel command unit 63 gives a control command to the travel control unit 61 to urgently decelerate the machine 1. When the presence of the detected obstacle shifts from the first alert area to the second alert area, the aircraft 1 which has been stopped advances at a low speed defined by the second vehicle speed change command. Furthermore, if an obstacle is not detected in the alert area, the operation returns to normal driving speed.

Next, FIG. 5 shows a flowchart showing an example of control flow of obstacle detection and vehicle speed deceleration in the above-described control system.
When this control starts, initialization such as resetting of flags and variables is performed (# 01). The setting of the alert area, that is, the first alert area and the second alert area is set (# 02). When the first alert area is changed according to the vehicle speed, the current vehicle speed is acquired, and the first alert area is set based on the vehicle speed.

  A photographed image is acquired from the stereo camera 81 (# 03). The two captured images obtained are subjected to distortion correction (# 04), and stereo matching is performed (# 05). Thereafter, coordinate conversion is performed to common space coordinates, and three-dimensional feature point calculation is performed (# 06). The calculated feature points are distributed in a three-dimensional coordinate space as illustrated in FIG. This three-dimensional coordinate space is divided into a large number of rectangular parallelepiped cells. At that time, an area of a predetermined height which is perpendicular to the XY plane (two-dimensional coordinate plane) corresponding to the scene of the eyebrows is a masking area, and this masking area is used to detect the three-dimensional feature point calculated as an obstacle. A masking process to exclude from the target is performed (# 07). When the crop to be harvested is rice or wheat, it has a predetermined height or about 1 m. Therefore, as shown in FIG. 6, the rectangular parallelepiped cell group has a rectangular parallelepiped shape having a height of about 1 m or less, which floats upward from the eyelid scene. When the number of three-dimensional feature points included in each rectangular solid, that is, the point density exceeds a predetermined threshold value, the rectangular solid cell is treated as an obstacle. Of course, the three-dimensional coordinate space may be masked in advance so that detection of three-dimensional feature points in the masking area is not performed.

  In addition, since the harvest machine of this embodiment can calculate a self-machine position, it can grasp | ascertain the positional relationship of the self-machine position and the operation completed area | region in a field. There is no high crop growth in the work area (the post-harvest weir scene), so the heightwise masking described above is not necessary. That is, the masking process in the height direction is not performed in order to reliably detect an obstacle present above the cropped straw scene.

  Next, it is determined whether an obstacle cell has been calculated, that is, whether an obstacle has been detected (# 08). When the obstacle cell is calculated (# 08 Yes branch), the coordinate value on the XY coordinate plane corresponding to the overhead scene of the obstacle cell is calculated, and this coordinate value becomes the two-dimensional position of the obstacle (# 11 ).

  It is checked whether the obstacle is in the first alert area (# 12). If the obstacle is in the first alert area (# 12 Yes branch), the vehicle speed change command output unit 65 gives a stop command to the work travel command unit 63 as a first vehicle speed change command (# 13). Further, the stop flag is turned on (# 14). In step # 14, when the deceleration flag is ON (when an obstacle moves from the second alert area to the first boundary area), the deceleration flag is turned OFF and the stop flag is turned ON. . As a result, the machine 1 is stopped, and the control returns to step # 02.

  If the obstacle is not in the first alert area in the check of step # 12 (# 12 No branch), it is further checked whether it is in the second alert area (# 20). If the obstacle is in the second alert area (# 20 Yes branch), the vehicle speed change command output unit 65 gives a deceleration command to the work travel command unit 63 as a second vehicle speed change command (# 21). Further, the deceleration flag is set to ON (# 22). In step # 22, when the stop flag is ON (when an obstacle moves from the first alert area to the second boundary area), the stop flag is turned OFF and the deceleration flag is turned ON. . Thus, the aircraft 1 travels at a very low speed (about 1 km / hour), and the control returns to step # 02.

  If an obstacle does not enter the second alert area in the check of step # 20 (#No branch), there will be no obstacle in the alert area. As described above, when there is no obstacle in the alert area, or when no obstacle is detected in the first place (No at No. 08), the state of the stop flag and the state of the deceleration flag are checked, and the state is determined accordingly. The flag content is rewritten. Specifically, at that time, if the stop flag is ON (# 30 Yes branch), the stop flag is rewritten to OFF (# 31), and the traveling command becomes valid, and the machine 1 normally travels ( # 32). Control then returns to step # 02. At that time, if the stop flag is not ON (# 30 No branch), the content of the deceleration flag is checked (# 40). If the deceleration flag is ON (# 40 Yes branch), the deceleration flag is rewritten to OFF (# 41), and the traveling command becomes valid, and the vehicle 1 normally travels (# 42). The normal travel is work travel when an obstacle or the like is not detected, and the vehicle speed is higher than the vehicle speed when the obstacle is present in the second alert area. Control then returns to step # 02. If the deceleration flag is OFF (# 40 No branch), of course, the travel command is valid, and the vehicle 1 normally travels (# 43), and the control returns to step # 02.

  When a field worker enters a warning area ahead of the advancing direction of the harvester aircraft 1 by such control of obstacle detection and vehicle speed change, the harvester is stopped or decelerated, and a field worker leaves the warning area. Then, the harvester returns to work at normal vehicle speed.

  The control of the vehicle speed reduction based on the obstacle detection can be performed regardless of whether the harvester is traveling automatically or is traveling manually.

  In the above-described embodiment, the first alert area and the second alert area are set, and when an obstacle exists in each alert area, the vehicle 1 is stopped or the vehicle speed is changed to a slower speed than normal traveling. . Instead of this, three or more warning areas may be provided, and the machine 1 may be stopped or changed to low speed depending on the respective areas. Furthermore, the warning area may be set steplessly, and the stepless change to the vehicle speed slower than normal traveling may be performed depending on the distance between the machine 1 and the obstacle.

  Note that the configurations disclosed in the above-described embodiment (including the other embodiments, and the same hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in the present specification is an exemplification, and the embodiment of the present invention is not limited thereto, and can be appropriately modified without departing from the object of the present invention.

  The present invention is applied to a harvester that carries out work travel in a field.

1: Machine body 2: Reaping unit 50: Image processing module 51: Image acquisition unit 52: Obstacle detection unit 53: Alert area setting unit 6: Control unit 60: Work travel control module 61: Travel control unit 62: Work control unit 63 : Work travel command unit 64: Travel route setting unit 65: Vehicle speed change command output unit 66: Vehicle position calculation unit 67: Notification unit 80: Satellite positioning module 81: Stereo camera (camera)
84: Notification device

Claims (5)

A camera for capturing the forward direction of the traveling direction of the aircraft in the field;
An image acquisition unit that acquires an image captured by the camera;
An obstacle detection unit that detects an obstacle by performing image processing on the captured image;
An alert area setting unit that sets an obstacle alert area defined based on the position with respect to the aircraft;
A vehicle speed change command output unit that changes the vehicle speed according to the positional relationship between the obstacle and the vehicle when the obstacle detected by the obstacle detection unit is present in the obstacle alert area; Harvester. The obstacle alert area is divided into a first alert area and a second alert area having different positional relationships with the airframe,
The vehicle speed change command output unit outputs a first vehicle speed change command when the obstacle is present in the first warning area, and when the obstacle is present in the second warning area, the vehicle speed is determined according to the first vehicle speed change command. The harvester according to claim 1, which outputs a second vehicle speed change command having a small change value.   The first alert area is an area defined by a working width of a harvester provided at the front of the machine, an angle of view of the camera, and an alert distance from the machine to the forward direction of the machine. A harvester according to item 2.   The harvester according to claim 3, wherein the warning distance is changed according to the vehicle speed.   The obstacle detection unit detects the obstacle in a three-dimensional coordinate system in which an eyelid scene is one reference plane, and masks an obstacle detection range with a masking area defined by the height from the eyelid scene The harvester according to any one of claims 1 to 4, wherein the masking process is not performed on the obstacle that has a function to be present and is present above the sown scene after harvest.

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