Field work vehicle

Abstract

To provide a field work vehicle that is equipped with both a contact-type obstacle sensor and a non-contact-type obstacle sensor but can avoid damage to the non-contact-type obstacle sensor.SOLUTION: A field work vehicle comprises: a non-contact object detection sensor 7 mounted on a vehicle body 1 and scanning the surroundings of the vehicle body 1; a sensor guard 40 arranged to contact an object prior to the non-contact object detection sensor 7 contacting the object; a contact detector 49 that detects contact between the sensor guard 40 and the object; and a travel control unit that stops the vehicle body 1 based on an object contact signal from the contact detector 49.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a farm work vehicle having a function of detecting objects around the vehicle body. [Background technology]

[0002] Patent Document 1 discloses a work machine (a type of field work vehicle) that stops the traveling machine by switching the transmission mechanism that transmits power to the traveling device to a neutral state when an obstacle is detected by a contact-type obstacle sensor. Patent Document 2 discloses an autonomously traveling work machine (a type of field work vehicle) that includes a machine position calculation unit that calculates the machine position using satellite positioning, a sonar sensor as an obstacle detection device that detects obstacles around the machine, and a control unit that stops the autonomous traveling in response to the detection of an obstacle during unmanned autonomous traveling. Furthermore, Patent Document 3 discloses a work vehicle (a type of field work vehicle) that includes a bumper that functions as a contact-type obstacle sensor using a limit switch on the front of the machine and an ultrasonic sensor that serves as a non-contact obstacle sensor mounted on the front of the bumper, and that stops autonomous traveling when the contact-type obstacle sensor or the non-contact obstacle sensor detects an obstacle in front of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-167541 [Patent Document 2] Patent Publication No. 2021-108617 [Patent Document 3] Japanese Patent Application Publication No. 62-297909 Summary of the Invention [Problem to be solved by the invention]

[0004] The work vehicle disclosed in Patent Document 3 is equipped with a contact-type obstacle sensor and a non-contact-type obstacle sensor, making it possible to utilize the characteristics of two types of obstacle sensors. However, because the bumper, which serves as the contact body of the contact-type obstacle sensor, is equipped with an ultrasonic sensor as a non-contact-type obstacle sensor, there is a possibility that this ultrasonic sensor may be damaged by the impact of contact (collision) between the bumper and an object.

[0005] For this reason, there is a demand for a farm work vehicle that is equipped with contact-type obstacle sensors and non-contact-type obstacle sensors, but that can avoid damage to the non-contact-type obstacle sensors. [Means for solving the problem]

[0006] The field work vehicle according to the present invention comprises a non-contact object detection sensor attached to a vehicle body that scans the periphery of the vehicle body, a sensor guard that is arranged to come into contact with an object before the non-contact object detection sensor comes into contact with the object, a contact detector that detects contact between the sensor guard and the object, and a travel control unit that stops the vehicle body based on an object contact signal from the contact detector.

[0007] According to this configuration, the sensor guard is positioned to come into contact with (collide with) an object (obstacle or boundary object) existing around the vehicle body before the non-contact obstacle sensor comes into contact with (collides with) the object, and the behavior of the sensor guard accompanying contact between the sensor guard and the object is detected by the contact detector. In other words, the sensor guard functions as a contact-type obstacle sensor that detects an object before the non-contact object detection sensor comes into contact with the object. As a result, the field work vehicle according to the present invention is equipped with both contact-type and non-contact obstacle sensors, but is able to avoid damage to the non-contact obstacle sensors (such as sonar or laser), which are relatively expensive and have a delicate structure. Furthermore, while the non-contact obstacle sensor determines the distance to the object (an obstacle such as a bank), the vehicle can approach the obstacle, such as a bank, until the vehicle is stopped by contact between the sensor guard, which functions as a contact-type obstacle sensor, and the obstacle. At this time, if the sensor guard comes into contact with the obstacle, the vehicle is stopped, ensuring safety.

[0008] In order not to interfere with object detection by the non-contact object detection sensor that scans the periphery of the vehicle body, it is preferable that the sensor guard not be located within the scanning range of the non-contact object detection sensor. Since the scanning range of many non-contact object detection sensors expands in the left-right and up-down directions (especially upward), a location below the non-contact object detection sensor is suitable for the location of a contact-type obstacle sensor. Furthermore, the sensor guard must come into contact with the object before the non-contact object detection sensor comes into contact with the object. For this reason, in the present invention, the height of the sensor guard above ground is lower than that of the non-contact object detection sensor, and the sensor guard is positioned so as to surround the non-contact object detection sensor in a plan view.

[0009] The sensor guard prevents the non-contact object detection sensor from coming into contact with any object as the vehicle body travels, and therefore does not need to surround the entire peripheral area of ​​the non-contact object detection sensor. Since it is sufficient for the sensor guard to come into contact with an object before the non-contact object detection sensor as the vehicle body travels, it is advantageous for the sensor guard to be arc-shaped with a portion open. For this reason, in the present invention, the sensor guard is a semicircular, curved member that surrounds the outer area of ​​the peripheral area of ​​the non-contact object detection sensor.

[0010] A suitable method for detecting contact between an object and the sensor guard is to detect the behavior of the sensor guard that occurs when it comes into contact with the object. In particular, it is suitable to configure the sensor guard as a swinging body and detect the swinging displacement of the sensor guard that occurs when it comes into contact with the object using a contact detector, such as a limit switch, reed switch, or proximity switch. For this reason, in the present invention, the sensor guard is a swinging body that swings from a predetermined posture when it comes into contact with the object, and the contact detector is a switch that detects the swinging displacement of the sensor guard.

[0011] The possibility of a field work vehicle coming into contact with a boundary object such as a bank increases when turning near the boundary of a field. In this case, even if the vehicle body approaches the boundary object from various directions, it is preferable that the sensor guard surround the non-contact object detection sensor so that the sensor guard can reliably contact the object before the non-contact object detection sensor comes into contact with the object. Furthermore, in order for the sensor guard to behave in such a way that it is smoothly detected by the contact detector upon such contact, it is preferable and structurally simple to configure the sensor guard to swing around a vertical swing axis. For this reason, in the present invention, the sensor guard has an arch-shaped shape in a plan view that surrounds the non-contact object detection sensor and swings around the vertical swing axis upon contact with the object.

[0012] In order to suppress vibration of the sensor guard due to vibration of the vehicle body while the vehicle is traveling, it is preferable to maintain the position using an elastic body. The inclusion of such an elastic body is also advantageous in terms of absorbing vibrations while traveling and shocks during a collision. For this reason, in the present invention, the sensor guard is maintained in the predetermined position by the biasing force of the elastic body.

[0013] In fields where crops are grown, the vehicle body approaches or comes into contact with the crops. It is necessary to prevent the sensor guard from being displaced in a manner that would activate the contact detector due to such contact with the crops. For this reason, in the present invention, the biasing force applied to the sensor guard by the elastic body is adjusted by a biasing force adjuster. The biasing force adjuster adjusts the biasing force applied to the sensor guard so that contact with the crops does not result in a displacement that would be detected by the biasing force adjuster.

[0014] The sensor guard is unnecessary when driving in places where there is no possibility of contact with obstacles or when parking in a barn, etc. When the sensor guard is not needed, the sensor guard protruding from the vehicle body becomes an obstacle. To solve this problem, in the present invention, the sensor guard is stored near the vehicle body by swinging around the vertical swing axis.

[0015] Because the non-contact object detection sensor is used to avoid collisions with obstacles, it is assumed that the vehicle body travels in the direction of the scanning area of ​​the scanning-type non-contact object detection sensor. Therefore, a preferred form of the sensor guard is proposed in which the sensor guard surrounds the non-contact object detection sensor in an arch shape over the scanning range angle of the non-contact object detection sensor in a plan view, and the sensor guard is displaced upon contact with the object. A sensor guard of this form is positioned between the non-contact object detection sensor and the object even when the vehicle body approaches the object in various traveling directions, and therefore can reliably function as a sensor guard.

[0016] Object detection using a non-contact object detection sensor is essential for autonomous driving, particularly unmanned autonomous driving. For this reason, the present invention is suitable for a field work vehicle that includes a vehicle body position calculation unit that calculates the vehicle body position based on positioning data, and the travel control unit that automatically drives the vehicle body based on a target travel route and the vehicle body position. For this reason, a configuration in which the sensor guard is removed may be adopted when the driver drives the vehicle while visually checking the distance to an object, as in manual driving. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a side view of an automatically traveling rice transplanter. [Figure 2] FIG. 2 is a schematic diagram showing the arrangement of sonar units. [Figure 3] FIG. 2 is a plan view showing the relationship between the sonar unit and the sensor guard. [Figure 4] FIG. 2 is a front view showing the relationship between the sonar unit and the sensor guard. [Figure 5] FIG. 1 is a schematic diagram illustrating the travel path of a rice transplanter in a field. [Figure 6] FIG. 2 is a functional block diagram showing a control system of the rice transplanter. DETAILED DESCRIPTION OF THE INVENTION

[0018] In this specification, unless otherwise specified, "front" means the front in the longitudinal direction of the vehicle body, and "rear" means the rear in the longitudinal direction of the vehicle body. In other words, the longitudinal direction of the vehicle body is the traveling direction, with the forward direction indicated by arrow F in FIG. 1 and the backward direction indicated by arrow B in FIG. 1. Furthermore, the left-right direction or lateral direction means the transverse direction of the vehicle body (vehicle body width direction) that is perpendicular to the longitudinal direction of the vehicle body. "Up" or "down" refers to the positional relationship in the vertical direction (perpendicular direction) of the vehicle body, and indicates the relationship regarding the height above the ground.

[0019] Next, one specific embodiment of a field work vehicle according to the present invention will be described with reference to the drawings. Figure 1 is a side view of a transplanter (hereinafter simply referred to as a rice transplanter) that automatically travels in a field, which is an example of a field work vehicle.

[0020] [Overall structure] As shown in Figure 1, the rice transplanter is a ride-on four-wheel drive vehicle. A four-parallel link type lifting mechanism 13 is provided at the rear of the vehicle body 1, and is connected so that it can be raised and lowered and swung. A seedling planting device 3 is attached to the rear end region of the lifting mechanism 13 and is connected so that it can roll. In addition, the vehicle is equipped with a fertilizer applicator 4 that spans from the rear end region of the vehicle body 1 to the seedling planting device 3, and a chemical sprayer 30 that is provided in the rear end region of the seedling planting device 3. The seedling planting device 3, fertilizer applicator 4, and chemical sprayer 30 are examples of ground work devices.

[0021] The vehicle body 1 is equipped with wheels 12 as a mechanism for traveling, an engine 2 as a power unit, and a hydraulic continuously variable transmission 9 as a main transmission. The continuously variable transmission 9 is, for example, an HST (Hydro-Static Transmission), and changes the driving force (rotation speed) output from the engine 2 by adjusting the angles of a motor swash plate and a pump swash plate. The wheels 12 include left and right front wheels 12A that can be steered, and left and right rear wheels 12B that cannot be steered. The engine 2 and the continuously variable transmission 9 are mounted at the front of the vehicle body 1. Power from the engine 2 is supplied to the front wheels 12A, rear wheels 12B, ground work equipment, etc. via the continuously variable transmission 9 and the like.

[0022] As an example, the seedling planting device 3 is configured for eight rows of planting. The seedling planting device 3 includes a seedling loading table 21, eight rows of planting mechanisms 22, etc. The seedling planting device 3 can be changed to two-row, four-row, six-row, etc. planting by clutch control.

[0023] The seedling tray 21 is a base on which eight rows of mat-shaped seedlings can be placed. The seedling tray 21 moves back and forth in the left-right direction at a constant stroke corresponding to the left-right width of the mat-shaped seedlings, and the vertical feed mechanism 23 vertically feeds each mat-shaped seedling on the seedling tray 21 toward the bottom end of the seedling tray 21 at a predetermined pitch each time the seedling tray 21 reaches the left-right stroke end. The eight planting mechanisms 22 are rotary type and are arranged in the left-right direction at constant intervals corresponding to the spacing between the planting rows. Each planting mechanism 22 receives driving force from the engine 2 when the seedling planting clutch is engaged, and cuts one seedling (also referred to as a planted seedling) from the bottom end of each mat-shaped seedling placed on the seedling tray 21 and plants it in the muddy soil after leveling.

[0024] The fertilizer application device 4 includes a horizontally long hopper 25, a delivery mechanism 26, an electric blower 27, multiple fertilizer application hoses 28, and a furrow former 29 provided for each row. The hopper 25 stores granular or powdered fertilizer. The delivery mechanism 26 delivers a predetermined amount of fertilizer from the hopper 25 at a time, enough for two rows.

[0025] The blower 27 generates a conveying wind that carries the fertilizer dispensed by each dispensing mechanism 26 toward the muddy surface of the field. The fertilizer applicator 4 also has a clutch mechanism that switches between an operating state in which the fertilizer stored in the hopper 25 is supplied to the field in predetermined amounts, and a non-operating state in which the supply is stopped.

[0026] The vehicle body 1 is provided with a driver's section 14 in its rear side area. The driver's section 14 is equipped with a steering wheel 10 for steering the front wheels, an on-board terminal 6 that displays (announces) various information to the operator and notifies (outputs) it, and has the function of accepting input of various information, and a driver's seat 16 for the operator (driver / worker). The driver's section 14 is also equipped with manual operating devices. The manual operating devices include a main speed change lever that adjusts the vehicle speed by operating the continuously variable transmission 9, an auxiliary speed change lever that enables the auxiliary speed change operation, an operation operation lever that enables the raising and lowering operation and switching of the operating state of the seedling planting device 3, and a driving mode selector that selects between automatic and manual driving.

[0027] The steering wheel 10 is connected to the front wheels 12A via a steering mechanism (not shown), and during manual driving, the steering angle of the front wheels 12A is adjusted by rotating the steering wheel 10.

[0028] A spare seedling storage device 15 for storing spare seedlings is supported on a spare seedling support frame 17 in front of the operating unit 14. The spare seedling support frame 17 has a two-tiered structure consisting of a base frame and an arched upper frame attached to the upper end of the base frame.

[0029] The positioning unit 8 is attached to the upper frame of the spare seedling support frame 17. In order to use the positioning unit 8 as a satellite positioning unit, the satellite positioning module 8A (see Figure 7) provided in the positioning unit 8 adopts the network-type RTK-GNSS positioning method (VRS method), and therefore a virtual reference point data receiving unit used in the VRS method is also included in the positioning unit 8. As one of the notification device group 1C (see Figure 7), a stacked light 19 that notifies the driving status, such as automatic driving or manual driving, is attached to the spare seedling support frame 17.

[0030] This rice transplanter can be driven manually, remotely controlled, or automatically. Automatic driving is when the rice transplanter performs work while automatically driving along a preset driving route. Automatic driving also includes manned automatic driving, which requires a driver on board, and unmanned automatic driving, which does not require a driver on board. In manned automatic driving, the driver performs some operations according to guidance provided by the rice transplanter, while the rice transplanter automatically performs other operations related to driving and work. In unmanned automatic driving, a driver does not need to be on board, but a driver may be on board during unmanned automatic driving. In remote control driving, the rice transplanter is operated externally using a remote control 90 (see Figure 7).

[0031] As shown in Figure 2, sonar units 7 serving as non-contact detection sensors that scan the periphery of the vehicle body 1 are mounted on the lower part of the vehicle body 1 and on the rear part of the seedling planting device 3. In this embodiment, two sonar units 7 are located in the center of the front area of ​​the vehicle body 1, one sonar unit 7 on each of the left and right ends of the front area of ​​the vehicle body 1, and two sonar units 7 at the rear end of the seedling planting device 3. As shown in Figures 3 and 4, the sonar unit 7 is composed of a sonar main body 7a and a sonar mounting member 7b for mounting the sonar main body 7a on the vehicle body 1.

[0032] A sensor guard 40 is disposed around the sonar unit 7, and contacts an object such as a bank before the sonar unit 7 comes into contact with the object. Figures 3 and 4 show the relative positions of the sonar unit 7, which is disposed at the left end of the front region of the vehicle body 1, and the sensor guard 40. The sensor guard 40 is positioned lower above ground than the sonar main body 7a, and is disposed so as to surround the sonar main body 7a in a plan view. The sensor guard 40 is configured as a swinging body that swings around a vertical swing axis from a predetermined posture upon contact with an object. Furthermore, a contact detector 49 is disposed near the swing axis of the sensor guard 40, and detects contact between the sensor guard 40 and an object based on the swing displacement of the sensor guard 40. While sonar units 7 and sensor guards 40 disposed in other locations are not shown, they have substantially the same positional relationship.

[0033] The sensor guard 40 has an arm-shaped guard main body 40a and an oscillating shaft 40b with a vertical oscillation axis fixed to the base end of the guard main body 40a. The sensor guard 40 is attached to the vehicle body 1 by a guard mounting member 41. The guard mounting member 41 has a bearing base 42 and a support 43. The bearing base 42 receives the oscillating shaft 40b and supports it so that it can oscillate. This allows the guard main body 40a to function as an oscillating body. The bearing base 42 is supported on the vehicle body 1 by the support 43. Furthermore, a detection arm 48 that rotates in conjunction with the oscillating displacement of the sensor guard 40 is fixed to the oscillating shaft 40b. A limit switch that turns ON / OFF in response to the rotation of the detection arm 48 is attached to the bearing base 42 as a contact detector 49. This limit switch is an example of a switch that detects the oscillating displacement of the sensor guard 40, and can be replaced with other proximity switches.

[0034] A coil spring 47 is attached to the swing shaft 40b as an elastic body that biases the guard main body 40a with a predetermined biasing force to a predetermined position (home position). The predetermined position is determined by a stopper (not shown). In addition, a biasing force adjuster 46 that adjusts the biasing force of the coil spring 47 is also attached. The biasing force adjuster 46 can also release the biasing force of the coil spring 47. When the biasing force is released by the biasing force adjuster 46, the guard main body 40a can be swung back to near the inside of the vehicle body 1 (near the vehicle body), and can be locked in that swing position (retracted position) by a locking member (not shown).

[0035] Although the sensor guard 40 is shown schematically in Figures 3 and 4, it can be realized in various shapes and forms. For example, the guard body 40a can be constructed of a wire structure, a mesh structure, a thin plate structure, or a combination thereof, and the guard mounting member 41 can be constructed of a bearing base 42 and a support 43 of any shape. The behavior of the guard body 40a upon contact with an object can be not only a swinging displacement but also a sliding displacement, and even a combination of swinging displacement and sliding displacement is possible. For swinging displacement, it is also possible to adopt a left-right swinging displacement structure that swings to either the left or right upon contact with an object. Furthermore, the guard body 40a can be constructed of a rod or thin plate, and the contact detector 49 can be a strain sensor that detects the distortion of the guard body 40a that occurs upon contact. Furthermore, in the above-described embodiment, the guard body 40a is positioned outside the scanning range of the sonar unit 7, but if the guard body 40a has a wire structure or the like that does not adversely affect sonar performance, or if sonar performance can be maintained by masking alone, the guard body 40a can be positioned within the scanning range of the sonar unit 7.

[0036] As described above, the sensor guard 40 surrounds the sonar unit 7 in an arch shape in a plan view, at least over the scanning range angle of the sonar unit 7. As a result, when the front end portion of the rice transplanter approaches an object that forms a field boundary, such as a bank, in the traveling direction of the rice transplanter, the sensor guard 40 comes into contact with the object before the sensor guard 40 comes into contact with the object. The displacement of the sensor guard 40 due to this contact between the sensor guard 40 and the object is detected by the contact detector 49. In response to the detection result (object contact signal) sent from the contact detector 49, the control system of the rice transplanter performs at least one of the following: an alarm of contact with an object (acoustic alarm, visual alarm), stopping the rice transplanter, or switching the traveling mode (from automatic driving to manual driving, etc.).

[0037] [Route] FIG. 5 shows the travel path of a rice transplanter traveling through a field while planting seedlings and applying fertilizer. This field is surrounded by a boundary line SH, which is a boundary object such as a ridge, and the boundary line SH is set as the field's edge. In the example of FIG. 5, the field is rectangular, and the field's edges consist of a base edge SH0 (bottom edge) and three remaining edges. The remaining edges are a left edge SH1, a top edge SH2, and a right edge SH3. The base edge SH0 is adjacent to a farm road, and an entrance / exit for the field work machine is formed in its end area. For this reason, the base edge SH0 is used as a supply edge for supplying seedlings and fertilizer, and hereinafter the base edge SH0 will also be referred to as the supply edge. The rice transplanter travels substantially along this travel path at a predetermined working width to complete work on the entire field (such as planting seedlings, applying fertilizer, and spraying chemicals).

[0038] The field is divided into an outer peripheral area OA and an inner area IA located inside the outer peripheral area OA. In Figure 5, two circular travel routes CR are set up for the rice transplanter to travel around and work. Work in the inner area IA is carried out using a round-trip travel route IR consisting of multiple inner routes IRS parallel to the left side SH1, one of the remaining edges, and a turning route IRT connecting the two inner routes IRS. Travel on the round-trip travel route IR starts at a start point S and ends at an end point G. The inner route IRS is also called a straight route, but it does not necessarily have to be a straight line; for example, it may be a large arc or may have a bend along the way. The turning route IRT is essentially a 180° turn route and is located in the outer peripheral area OA.

[0039] To actually generate the travel routes shown in Figure 5, i.e., the circular travel route CR and the round-trip travel route IR, it is necessary to calculate the accurate field shape and map coordinates of the boundary line SH. For example, the field shape is calculated based on the basic edge travel trajectory obtained during the basic edge travel, which is non-work travel along the basic edge SH0, and the remaining edge travel trajectory obtained during the remaining edge travel, which is work travel along the remaining edge. In the example of Figure 5, the outermost circular travel route OC consisting of the basic edge travel and the remaining edge travel, and the first circular travel route C1 inside the outermost circular travel route OC are set as the outer periphery area OA. The number of circular travel routes CR is determined by the required space for the turning route IRT of the round-trip travel route IR, i.e., the space required for the rice transplanter to turn. In Figure 5, the number of circular driving routes CR is two, but if the number of circular driving routes CR is set to three, in the outer peripheral area OA, in addition to the outermost circular driving route OC and the first circular driving route C1 inside this outermost circular driving route OC, a second circular driving route is set inside the first circular driving route C1.

[0040] In actual field work, when the rice transplanter enters the field, the driver first manually steers the rice transplanter along the basic side SH0 of the outermost circular travel path OC without performing any work, thereby obtaining a basic side travel trajectory. Next, the driver manually steers the rice transplanter along the remaining sides SH1, SH2, and SH3 of the outermost circular travel path OC while performing work, thereby obtaining a remaining side travel trajectory. The field shape is calculated based on the basic side travel trajectory, which is the travel trajectory during the outermost circular travel, and the remaining side travel trajectory.

[0041] Once the field shape is calculated, the number of circular travel routes CR is determined based on the space required for turning travel on the round-trip travel route IR or based on the intentions of the work manager. In the example of Figure 5, the number of circular travel routes CR excluding the outermost circular travel route OC is one. Therefore, the outer peripheral area OA is an area in which two circular travel routes CR are set. The inner area IA is set inside the outer peripheral area OA. Once the inner area IA is set, a round-trip travel route IR is generated for automatic round-trip work travel within this inner area IA from the start point S to the end point G.

[0042] During circular travel along the outermost circular travel route OC, during 90-degree turns during circular travel, and during supply travel in which the vehicle body 1 approaches the base side SH0 to supply seedlings or fertilizer, the vehicle body 1 may come into contact with an object such as a bank that forms the boundary line SH. In this case, to avoid damage to the sonar unit 7, the guard body 40a of the sensor guard 40 comes into contact with the object before the sonar unit 7, and the resulting displacement is detected by the contact detector 49. The detection result of the contact detector 49 is used by the rice transplanter's control system and serves as a control trigger for issuing an alarm about the risk of contact between the vehicle body 1 and the object, stopping the vehicle body 1, switching the travel mode, and so on.

[0043] [Control system] Next, the control system of this rice transplanter will be explained using FIG.

[0044] The control system of the rice transplanter includes a control unit 5 that controls various operations of the rice transplanter, and an on-board terminal 6 that can exchange data with the control unit 5. Signals are input to the control unit 5 from a positioning unit 8, a manual operation tool sensor group 31, a travel sensor group 32, a work sensor group 33, a sonar unit 7, a contact detector 49, etc. Control signals are output from the control unit 5 to the travel equipment group 1A and the work equipment group 1B.

[0045] The positioning unit 8 includes a satellite positioning module 8A that receives radio waves from satellites of the Global Navigation Satellite System (GNSS), and an inertial measurement module 8B that detects the inclination and acceleration of the three axes of the vehicle body 1. The control unit 5 obtains positioning data for calculating the position and orientation (forward / backward orientation of the vehicle body) of the vehicle body 1 from the satellite positioning module 8A of the positioning unit 8, and obtains inertial measurement data relating to the inclination and acceleration of the three axes of the vehicle body 1 from the inertial measurement module 8B. Here, it is assumed that the positioning data received by the positioning unit 8 also includes the inertial measurement data.

[0046] The group of traveling devices 1A includes a steering device and a transmission device. Based on control signals from the control unit 5, various devices are controlled, and the traveling of the vehicle body 1 is controlled.

[0047] The work equipment group 1B includes various operating equipment, adjusting equipment, clutch control equipment, and the like included in the seedling planting device 3.

[0048] The notification device group 1C includes the above-mentioned stacked lights 19, headlights for notifying the material supply reservation, turn signals, speakers, notification lamps, and notification buzzers. Note that the in-vehicle terminal 6 and the remote control 90 also function as notification devices.

[0049] The manual operation tool sensor group 31 includes sensors and switches that detect the operating status of various manual operation tools. The travel sensor group 32 includes various sensors that detect the steering angle, gear position, engine RPM, etc. The work sensor group 33 includes various sensors that detect the status of the lifting mechanism 13, seedling planting device 3, fertilizer applicator 4, etc.

[0050] In this embodiment, the control unit 5 is equipped with a driving control unit 50, an operation control unit 51, an obstacle detection unit 52, a vehicle body position calculation unit 53, a contact detection unit 54, a vehicle body orientation calculation unit 55, a vehicle body deviation calculation unit 56, a driving route setting unit 57, a notification control unit 58, and a remote control control unit 59.

[0051] The travel control unit 50 is equipped with an automatic travel control unit 50A, a manual travel control unit 50B, a remote control travel control unit 50C, and a travel mode switching unit 50D. The travel of this rice transplanter can be switched between an automatic travel mode for automatic travel, a remote control travel mode for remotely controlled travel, and a manual travel mode for manual travel, and the switching of travel modes is managed by the travel mode switching unit 50D. The travel mode switching unit 50D selects one of the automatic travel mode (it is also possible to distinguish between unmanned automatic travel mode and manned automatic travel mode), the remote control travel mode, and the manual travel mode based on the state of a travel mode switching operating tool (not shown) and commands from the control unit 5, the remote control 90, and the in-vehicle terminal 6.

[0052] The automatic driving control unit 50A used in the automatic driving mode performs steering control so that the vehicle body 1 travels along the target driving route set in the driving route setting unit 57. In this steering control, the vehicle body position calculated by the vehicle body position calculation unit 53 and the vehicle body orientation calculated by the vehicle body orientation calculation unit 55 are used to calculate the position deviation of the vehicle body 1 from the target driving route (lateral deviation from the target driving route) and the orientation deviation of the vehicle body 1 (deviation angle of the vehicle body orientation from the orientation of the target driving route), and steering control (automatic driving control) is performed so that the position deviation and orientation deviation become small.

[0053] The manual driving control unit 50B used in the manual driving mode controls the steering equipment based on the amount of operation of the steering wheel 10, and also controls the transmission equipment based on the operation of manual operating tools such as the main shift lever and the sub shift lever.

[0054] The remote control traveling control unit 50C issues commands to the traveling control unit 50 and the work control unit 51 based on operation commands from the remote control 90 received by the remote control receiving unit 9A, and operates the traveling device group 1A and the work device group 1B.

[0055] In automatic driving, the work control unit 51 automatically controls the work equipment group 1B based on a program given in advance, in manual driving it controls the work equipment group 1B based on the operation of the driver, and in remote control driving it controls the work equipment group 1B based on operation commands from the remote control 90.

[0056] The obstacle detection unit 52 detects an object based on the scanning signal from the sonar unit 7, measures the distance from the vehicle body 1 to the detected object, and provides the distance to the traveling control unit 50. The traveling control unit 50 inhibits the vehicle body 1 from stopping or starting based on the positional relationship between the vehicle body 1 and the object and the traveling direction of the vehicle body 1.

[0057] The vehicle position calculation unit 53 calculates the map coordinates (vehicle position) of the vehicle 1 based on the satellite positioning data and inertial navigation data successively sent from the positioning unit 8. These map coordinates may be coordinates in not only latitude and longitude but also in a field coordinate system or a specific coordinate system.

[0058] As described above, the contact detection unit 54 commands the driving control unit 50 to decelerate or stop the vehicle body 1 and change the driving mode based on the detection result from the contact detector 49. Furthermore, the contact detection unit 54 issues a request to the notification control unit 58 to notify the vehicle body 1 that contact with an object has been detected. If contact with an object is detected while the vehicle is traveling in the automatic driving mode, the vehicle body 1 can be stopped and the driving mode can be changed to the manual driving mode. The time it takes for the object detected by the contact detector 49 to come into contact with the sonar unit 7 varies depending on the vehicle speed. Therefore, a distance between the sonar unit 7 and the sensor guard 40 is secured enough to allow the vehicle body 1 to stop before the detected object comes into contact with the sonar unit 7 at the expected driving speed for work (e.g., maximum speed). To ensure safety when the driving speed is too high and a sufficient distance cannot be secured, a non-contact sensor may be provided at the tip region of the sensor guard 40, and the vehicle body 1 may be decelerated based on the detection result of the non-contact sensor.

[0059] The vehicle body direction calculation unit 55 calculates and outputs the vehicle body direction (direction of vehicle body travel direction) based on a direction vector determined from two vehicle body positions calculated over time.

[0060] The vehicle body deviation calculation unit 56 calculates the amount of deviation of the vehicle body 1 from the target driving route based on the vehicle body position. The amount of deviation of the vehicle body 1 includes an orientation deviation, which is the intersection angle between the target driving route and the longitudinal center line of the vehicle body 1 indicated by the vehicle body orientation, and a position deviation, which is the distance between the target driving route and a reference point of the vehicle body 1 in a transverse direction perpendicular to the target driving route.

[0061] The driving route setting unit 57 receives and manages the driving routes generated by the in-vehicle terminal 6, and sequentially sets the driving routes that are targets for automatic driving control as target driving routes.

[0062] The notification control unit 58 receives notification requests from the respective functional units of the control system, generates control signals to be output to the notification device group 1C, and performs necessary notifications through the respective notification devices.

[0063] The in-vehicle terminal 6 is a communication terminal equipped with a touch panel 6A, and can be detached from the vehicle body 1 and used as a remote control device for operating the vehicle body 1. The in-vehicle terminal 6 has a graphical interface, and has the function of displaying and inputting information through the touch panel 6A, as well as the function of acting as a data input / output interface for the control unit 5.

[0064] In this embodiment, the vehicle-mounted terminal 6 is equipped with a supply edge setting unit 61, a field shape calculation unit 62, a driving trajectory management unit 63, an area setting unit 64, and a driving route generation unit 65, which are essentially applications installed on the vehicle-mounted terminal 6.

[0065] The on-board terminal 6 has a data communication function, and acquires and stores information about the farm field through data communication. The information about the farm field includes the location of the farm field, the name of the farm field, the location of the entrance (exit) of the farm field, and places that can be used to replenish seedlings and fertilizer.

[0066] The supply edge setting unit 61 sets the supply edge automatically or manually. The supply edge is an edge used for supplying, and the basic edge SH0 is usually selected.

[0067] The traveling trajectory management unit 63 operates in cooperation with the vehicle body position calculation unit 53. The traveling trajectory management unit 63 generates and stores a traveling trajectory of the vehicle body 1 based on the vehicle body position calculated by the vehicle body position calculation unit 53. The field shape calculation unit 62 operates in cooperation with the traveling trajectory management unit 63. When the field shape is unknown, the field shape calculation unit 62 calculates the field shape using the method described with reference to FIG. 5. The area setting unit 64 sets an outer periphery area OA including the basic side traveling trajectory and the remaining side traveling trajectory, and an inner area IA inside the outer periphery area OA, based on the field shape.

[0068] The travel path generation unit 65 has a circular travel path generation function that generates a circular travel path CR for automatically traveling around the outer peripheral area OA for work, and a round trip travel path generation function that generates a round trip travel path IR (consisting of a turning path IRT and an internal path IRS) for automatically traveling back and forth for work in the internal area IA.

[0069] The control unit 5 and the in-vehicle terminal 6 are essentially configured as computer systems. Each functional unit configured in these computer systems can be realized by the cooperation of hardware associated with each computer system and programs installed in each computer system. Of course, the function of a specific functional unit may be realized only by hardware or programs, or may be realized in cooperation with an external application server.

[0070] [Another embodiment] (1) In the above-described embodiment, the sensor guard 40 includes an arm-shaped guard body 40a. However, the shape of this guard body 40a may be a semicircular arc or a curved member curved in any desired manner. For example, the sensor guard 40 is preferably a curved member curved two-dimensionally or three-dimensionally in a semicircular arc that surrounds the outer area of ​​the peripheral area of ​​the sonar unit 7. Of course, the sensor guard 40 may also have an angular bent shape.

[0071] (2) In the above-described embodiment, the sensor guard 40 is a swinging body that swings around a vertical swing axis when it comes into contact with an object. However, other displacement structures may be employed. For example, a sliding structure, an elastic deformation structure, a link structure, etc. Depending on the displacement structure, the contact detector 49 may be a detector that detects the direction of the displacement, or a detector that converts the direction of the displacement into another direction using a link or the like for detection.

[0072] (3) In the above-described embodiment, the resistance force in the displacement direction (swing direction) of sensor guard 40 (adjustment of the detection sensitivity of contact detector 49) was adjusted by adjusting the biasing force, but instead, a mechanism (for example, frictional force) may be employed that suppresses displacement of sensor guard 40. Furthermore, the resistance force may be adjusted by an additional elastic body other than the elastic body that maintains sensor guard 40 in a predetermined posture.

[0073] (4) In the above-described embodiment, one sensor guard 40 is provided for each sonar unit 7. However, a configuration may be adopted in which multiple sensor guards 40 are provided to prevent erroneous detection. Conversely, a configuration may be adopted in which a common sensor guard 40 is used for multiple sonar units 7.

[0074] (5) In the above-described embodiment, the sonar unit 7 is used as the non-contact object detection sensor. However, instead of this, a laser sensor, an infrared sensor, or even a camera may be used.

[0075] (6) The functional blocks constructed in the control unit 5 and the in-vehicle terminal 6 shown in Fig. 6 can be subdivided into any functional blocks, or conversely, can be integrated into one functional block. In addition, any functional block may be made into an ECU, and they may be interconnected via an in-vehicle LAN.

[0076] (7) In the above embodiment, a rice transplanter has been described as an example, but the present invention can be applied to field work vehicles such as direct seeding machines, fertilizer applicators, chemical sprayers, harvesters, and tractors.

[0077] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction arises. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0078] The present invention is applicable to a farm work vehicle equipped with a non-contact object detection sensor that scans the periphery of the vehicle body. [Explanation of symbols]

[0079] 1: Body 5: Control unit 7: Sonar unit (non-contact object detection sensor) 7a: Sonar body 7b: Sonar mounting element 40: Sensor Guard 40a: Guard body 40b: Oscillating shaft 41: Guard mounting member 42: Bearing stand 43:Support 46:Biasing force adjuster 47: Coil spring 48: Detection arm 49: Contact detector 50: Driving control unit 52: Obstacle detection unit 53: Vehicle position calculation unit 54: Contact detection unit 58: Notification control section

Claims

1. a non-contact object detection sensor attached to a vehicle body and configured to scan the periphery of the vehicle body; a sensor guard arranged to come into contact with an object prior to contact between the non-contact object detection sensor and the object; a contact detector that detects contact between the sensor guard and the object; a travel control unit that stops the vehicle body based on an object contact signal from the contact detector.

2. 2. The field work vehicle according to claim 1, wherein the height of the sensor guard from the ground is lower than that of the non-contact object detection sensor, and the sensor guard is disposed so as to surround the non-contact object detection sensor in a plan view.

3. 3. The farm work vehicle according to claim 2, wherein the sensor guard is a semicircular curved member that surrounds an outer area of ​​the peripheral area of ​​the non-contact object detection sensor.

4. 2. The farm work vehicle according to claim 1, wherein the sensor guard is a swinging body that swings from a predetermined position when it comes into contact with the object, and the contact detector is a switch that detects the swing displacement of the sensor guard.

5. 5. The farm work vehicle according to claim 4, wherein the sensor guard has an arch-like shape in a plan view that surrounds the non-contact object detection sensor, and swings about a vertical swing axis when the sensor guard comes into contact with the object.

6. 5. The farm work vehicle according to claim 4, wherein the sensor guard is maintained in the predetermined position by being biased by an elastic body.

7. 7. The farm work vehicle according to claim 6, wherein the biasing force applied to the sensor guard by the elastic body is adjusted by a biasing force adjuster.

8. 6. The farm work vehicle according to claim 5, wherein the sensor guard is stored near the vehicle body by swinging about the vertical swing shaft.

9. 2. The field work vehicle according to claim 1, wherein the sensor guard surrounds the non-contact object detection sensor in an arch shape over a scanning range angle of the non-contact object detection sensor in a plan view, and the sensor guard is displaced upon contact with the object.

10. 10. The field work vehicle according to claim 1, further comprising a vehicle body position calculation unit that calculates a vehicle body position based on positioning data, and the travel control unit automatically travels the vehicle body based on a target travel route and the vehicle body position.

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