JP2023124936A - Communication system for work vehicle - Google Patents

Abstract

To provide a communication system for a work vehicle that can be used in automatic driving of a retrofitted automatic driving system, in which information in an on-vehicle network related to control of a work facility etc. of a retrofitted work vehicle can be obtained relatively easily in the automatic driving system, while focusing on providing the automatic driving system that can be easily retrofitted to the work vehicle.SOLUTION: A CAN gateway is provided that is connected to a CAN bus that constructs an on-vehicle network and an automatic driving network and relays an exchange of information in the two networks. This CAN gateway is configured to be able to acquire the information even if it is in the other network, and to be used for automatic driving or control of a work facility etc. in one network.SELECTED DRAWING: Figure 9

Description

The present invention relates to a communication system for a work vehicle mainly used for agricultural purposes, and more particularly to a communication system for a work vehicle that includes an on-vehicle network and an automatic driving network.

Agricultural work vehicles, such as tractors and riding rice transplanters, steer the front wheels by manually rotating a steering wheel installed in the control section, or vehicles equipped with a crawler-type traveling device. In this case, by giving a difference in the rotational speed of the left and right crawler traveling devices, the traveling direction of the traveling machine can be corrected to perform work traveling, turning the traveling machine on a headland, etc.

In addition, in order to perform efficient and waste-free work in the field, such as ridge-building and tilling work, planting seedlings, and fertilizing work, these work vehicles drive in a straight, straight line without meandering. Therefore, it is desired that adjacent travel trajectories be equally spaced. In addition, when turning a traveling aircraft, it is desirable to make a quick and accurate turn based on an appropriate course without losing timing, and even when this work is performed by an inexperienced worker, it is necessary to make a quick and accurate turn without losing timing. It is desirable to be able to perform work efficiently without change.

Therefore, in recent years, with the aim of creating straight and evenly spaced ridges, a processor has been using images taken by a monocular camera installed on the tractor's traveling body to acquire deviations in the traveling direction of the tractor's traveling body during straight-travel and following work. In addition, an instruction to eliminate this misalignment is sent to the automatic steering device installed later on the traveling aircraft, and upon receiving this steering instruction, the automatic steering device rotates the steering shaft using an electric motor to automatically adjust the traveling direction of the traveling aircraft. We provide an assist system that allows you to make corrections.

In addition, in order to realize autonomous driving with a worker on board, which is proposed in the midst of calls for smart agriculture, or unmanned autonomous driving under manned supervision, a satellite positioning system will be used to improve the We provide an automatic driving system that acquires position and orientation information of the vehicle and automatically travels along a linear work route created in advance based on this information (see Patent Document 1), and further develops this system. The present inventors aim to provide an automatic driving system that includes not only working driving routes but also turning driving routes that do not involve work.

Note that agricultural work vehicles are equipped with a plurality of electronic control units (ECUs) to perform various automatic controls in order to increase the efficiency and accuracy of the work. In addition, information exchange between each electronic control unit in this case uses CAN (Controller Area Network), which is a serial communication protocol commonly used in automobiles, etc. The number of signal lines has been reduced to simplify harness routing.

Then, a positioning device using the above-mentioned satellite positioning system and an automatic driving control unit that causes the tractor to automatically travel based on the positioning information etc. are installed in the in-vehicle network constructed using the communication network such as CAN. It has been proposed to incorporate and provide it (see Patent Document 2).

JP 2021-11139 Publication JP 2021-108439 Publication

As mentioned above, in agricultural work vehicles, satellite positioning systems are used to acquire the position and direction information of the traveling vehicle, and the vehicle is operated by a manned or When an unmanned traveling machine runs automatically, it is possible to efficiently carry out highly accurate work with no waste, and the burden on the operator can be reduced because there is no need for the operator to operate the steering wheel.

When actually introducing these automatic driving systems into work vehicles, it is relatively easy to install GNSS receivers and steering units by easily retrofitting them to existing work vehicles, as described in Patent Document 1. This has the advantage of being able to provide an automatic driving system at a low cost and making it easier for users to quickly introduce it.

However, since the automatic driving system is developed with the focus on not selecting work vehicles that can be retrofitted, the automatic driving system is developed without using any information related to the work vehicle's original equipment control, etc. We are building an automated driving system that can be completed simply by using this information. Therefore, there is a problem in that, in a sense, there is a limit to the control content of automatic driving, and it becomes difficult to further expand and develop the control content of automatic driving.

On the other hand, in a work vehicle such as the tractor described in Patent Document 2, which is equipped with a positioning device, an automatic driving control unit, etc. in its in-vehicle network from the beginning to enable automatic driving, the automatic driving system is installed on the vehicle. Information related to work machine control etc. on the network can be easily used, and thereby the control contents of automatic driving can be expanded and developed relatively easily.

However, if an automatic driving system is embedded in a work vehicle from the beginning in this way, users who do not use the automatic driving system will end up needlessly purchasing an expensive work vehicle. Furthermore, even if such an embedded automatic driving system is required and attempted to be retrofitted, there is a problem in that it requires major modification of the work vehicle and cannot be substantially retrofitted.

Therefore, in view of the above-mentioned problems, the present invention focuses on providing an automatic driving system that can be easily retrofitted to a work vehicle, and also provides a system for controlling work machines, etc. of the work vehicle to be retrofitted. It is an object of the present invention to provide a communication system for a work vehicle that can relatively easily acquire information on a related in-vehicle network in an automatic driving system and that can be used in automatic driving of an automatic driving system installed afterwards.

In order to solve the above-mentioned problems, the communication system for a work vehicle of the present invention includes an existing in-vehicle network constructed by connecting an electronic control unit provided for controlling work equipment, etc. to a CAN bus that follows the CAN communication protocol; An electronic control unit installed for automatic driving using a satellite positioning system is connected to an optional automatic driving network constructed by connecting it to a CAN bus that also follows the CAN communication protocol, and to a CAN bus installed in these networks. By installing a CAN gateway that relays the exchange of information on each network, even if it is information on the other network, this information can be acquired and used for automatic driving or control of work equipment, etc. that is responsible for one network. Configure it for use.

Further, in the work vehicle communication system of the present invention, the electronic control unit provided in the CAN gateway is provided with a short-range wireless communication function, and information regarding automatic driving or control of work equipment etc. on the network is transmitted to a nearby mobile device. An electronic control unit provided in the CAN gateway receives information that can be wirelessly transmitted to a terminal or wirelessly transmitted from a mobile terminal, and transmits the received information on an autonomous driving network or an in-vehicle network to enable automatic driving. , or configured to be usable for controlling work machines, etc.

Further, in the communication system for a work vehicle of the present invention, a branch cable is provided in the main cable of the CAN bus that constructs the in-vehicle network or the automatic driving network, and an end of the branch cable and an end of the cable connected to the CAN gateway are connected. Either connect them via a connector, or provide a relay connector on the main cable of the CAN bus, and connect the cables that branch into two from the cable connected to the CAN gateway to each disconnected connector of this relay connector. Connectors provided at the ends are connected to connect the CAN gateway to each CAN bus.

In the communication system for a work vehicle of the present invention, the CAN gateway bundles a waterproof housing case with a board on which electronic components such as the electronic control unit are attached together with the CAN bus cable and other wiring. Attach it to the wire harness with a cable tie.

According to the communication system for a work vehicle of the present invention, an existing in-vehicle network constructed by connecting an electronic control unit provided for controlling work equipment etc. to a CAN bus according to the CAN communication protocol and a satellite positioning system are used. An optional automatic driving network is constructed by connecting an electronic control unit installed for automatic driving to a CAN bus that also follows the CAN communication protocol, and an optional automatic driving network is constructed by connecting an electronic control unit installed for automatic driving to a CAN bus that also follows the CAN communication protocol. A CAN gateway is installed to relay the exchange of information between the two networks, and this information can be acquired even if it is on the other network, so that it can be used for automatic driving or control of work equipment, etc. in one network. .

Therefore, by providing a CAN gateway that relays each other's networks, information on the in-vehicle network related to the control of the work equipment of the work vehicle can be relatively easily acquired by the automatic driving system installed afterwards. It can be used for automatic driving of the automatic driving system attached. Conversely, information on the automatic driving network can be used as necessary to control work equipment of work vehicles.

In addition, as long as the CAN communication protocol used here is followed, the CAN bus that connects the electronic control unit of the in-vehicle network and the CAN bus that connects the electronic control unit of the automated driving network must be connected at both ends to prevent signal reflection. It is necessary to provide a terminating resistor to prevent deterioration of communication quality. Therefore, for example, one terminal resistor is provided in the CAN bus of each electronic control unit connected to both ends of the CAN bus of the in-vehicle network and the automatic driving network.

In this case, if the in-vehicle network and the autonomous driving network's CAN bus were to be connected as is, four terminating resistors would be provided for the entire CAN bus, which would violate the CAN communication protocol. Problems arise, such as the electronic control unit not being able to communicate. Therefore, in order to eliminate this situation, a large number of signal lines are used to connect the electronic control unit of the in-vehicle network and the sensors used in this electronic control unit, so that the electronic control unit of the autonomous driving network can use the information from the electronic control unit of the in-vehicle network and the sensors used in this electronic control unit. If the vehicle is connected to a vehicle, a large-scale harness must be routed, and an automated driving system cannot be easily retrofitted.

However, if a CAN gateway is installed that connects to the CAN bus provided in these networks and relays the exchange of information on each other's networks, it will be possible to transfer information on the other network according to the CAN communication protocol described above. The information can be acquired and used for automatic driving in one network or for controlling work equipment, etc., and although there is a slight increase in costs, the overall benefit is that the automatic driving system can be easily retrofitted. Far more than that.

Further, according to the communication system for a work vehicle of the present invention, the electronic control unit provided in the CAN gateway is provided with a short-range wireless communication function, so that information regarding automatic driving on the network or control of a work machine, etc. can be transmitted nearby. or an electronic control unit provided in the CAN gateway receives information wirelessly transmitted from the mobile terminal, and transmits the received information on an automatic driving network or an in-vehicle network, It is configured to be usable for automatic travel or control of work equipment, etc.

Therefore, highly accurate position and direction information of the work vehicle obtained using the satellite positioning system, or driving route information, etc., which is transmitted on the autonomous driving network, and information such as vehicle speed, work content, fuel and agricultural information, etc., which are transmitted on the in-vehicle network, are collected. Material consumption information, etc. can be linked as necessary and transmitted wirelessly to a mobile terminal in a unified format, and the transmitted information can be sent to a personal computer, farm management server, or cloud service provider's server, etc. It can be transferred and managed. Furthermore, it is possible to transmit driving route instructions based on the above-mentioned information stored in a server or the like via a reverse route so as to be useful on the work vehicle side.

Further, according to the communication system for a work vehicle of the present invention, a branch cable is provided in the main cable of the CAN bus that constructs the in-vehicle network or the automatic driving network, and the end of the branch cable and the end of the cable that connects to the CAN gateway. or connect them via a connector, or provide a relay connector on the main cable of the CAN bus, and connect the cable that branches into two from the cable connected to the CAN gateway to each disconnected connector. Since the CAN gateway is connected to each CAN bus by connecting the connectors provided at each end, it is possible to connect the CAN gateway to the CAN bus of the automatic driving network and the in-vehicle network in a short time and very easily. .

According to the communication system for a work vehicle of the present invention, the CAN gateway has a housing case that is waterproofed and has a board on which electronic components such as the electronic control unit are attached, and is connected to the CAN bus cables and other wiring. Since it is attached to the wire harness bundled together with a cable tie, it is possible to maintain its function for many years without malfunctioning even if rainwater falls on the CAN gateway, and it is also possible to maintain the function of the CAN gateway for many years without any damage. By directly fastening and attaching the housing case to the main wire harness etc. provided on the work vehicle side with a cable tie, it is possible to eliminate the need to prepare a special space for installing the CAN gateway on the work vehicle side.

FIG. 1 is a side view of a tractor to which the present invention is applied. It is a perspective view of a steering system. It is a perspective view of a control part. FIG. 2 is an explanatory diagram of an in-vehicle network. FIG. 2 is an explanatory diagram of an automatic driving network. FIG. 2 is a perspective view showing a state in which a GNSS unit is attached to a tractor. FIG. 3 is a perspective view showing a state in which the drive unit is attached to the steering wheel. FIG. 3 is an exploded view showing the procedure for attaching the drive unit to the steering wheel. It is a wiring diagram of a CAN gateway. FIG. 3 is a perspective view showing the installed state of the CAN gateway. This is the guidance screen of the navigation system. This is a screen for setting the mounting position of the GNSS antenna.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A mode for carrying out the present invention will be described based on the drawings. As shown in FIG. 1, an agricultural tractor 1 as a working vehicle has an engine 2, a clutch housing 3, a transmission case 4, etc. integrally connected from the front to form a vehicle body (traveling body). Further, near the front of the vehicle body, a bonnet 5 and a side cover 6 are provided to cover the engine 2 and auxiliary equipment for the engine 2, and the bonnet 5 is configured to be able to be opened and closed on the front side via a hinge provided at the rear.

Further, a front bracket 7 fixed to the engine 2 and extending forward supports a front axle case 8 so as to be swingable from side to side, as shown in FIG. A king pin case 9 and a final case 10 are attached to the left and right ends of this front axle case 8. Further, a front wheel 12 is attached to a front axle 11 that is pivotally supported by the final case 10.

On the other hand, a rear axle case connected to the left and right sides of the transmission case 4 is provided near the rear of the vehicle body, and left and right rear wheels 14 are attached to a rear axle 13 pivotally supported by the rear axle case. In addition, a well-known three-point link mechanism consisting of a top link 15 and left and right lower links 16, and a connecting device such as a drawbar are installed at the rear of the vehicle body, and these connecting devices include a rotary tiller, a furrow machine, or a seed-seeding device. A working machine such as a machine or a transplanter is connected, and engine power is transmitted to the working machine from a PTO shaft (power take-off shaft) supported at the rear of the transmission case 4.

Furthermore, a cabin 17 is mounted on the vehicle body behind the engine 2 to cover the control section via vibration-proof rubber. Here, the cabin 17 includes a front pillar 18 which is a pair of left and right front pillars, a rear pillar 19 which is a pair of left and right rear pillars, and a mid pillar 20 which is a middle pillar between the left and right pillars. A rectangular frame-shaped upper frame 21 connects and fixes the upper ends of each of the six columns 18, 19, 20 extending in the vertical direction, and a lower frame 22 connects and fixes the lower ends of each of the columns 18, 19, 20. The cabin frame is constructed by

The left and right door glasses 23 are attached to the cabin frame so that they can be opened and closed via hinges 24 provided on the rear side, and a windshield 25 is attached to the front side and a rear glass 26 is attached to the rear side via hinges. Furthermore, a side glass 28 is attached between the mid pillar 20 and the rear pillar 19 via a hinge 27 so as to be openable and closable. Furthermore, a fender 30 is provided extending from the lower ends of the left and right rear pillars 19 toward the floor 29 diagonally downward in front and covering the upper front side of the rear wheel 14. Further, a roof 31 is provided on the upper frame 21 to cover the upper part of the control section.

Further, the driver's seat 32 provided in the cabin 17 is located in the center between the left and right fenders 30. As shown in FIG. 3, on the right and left sides of the driver's seat 32, there are provided a main shift lever 33 and an auxiliary shift lever 34 for shifting the traveling transmission provided in the transmission case 4, as well as a position control lever for raising and lowering the work equipment. Operation tools related to automatic control such as a lever 35, a depth setting volume 36, a PTO switch 37, an automatic switch for the depth and inclination of the working machine, a volume for tilting and raising height, and a plowing lamp are provided.

Furthermore, a steering wheel 38 is provided in front of the driver's seat 32 for steering the left and right front wheels 12 to change the traveling direction of the tractor 1. The steering wheel 38 is fastened to the upper part of a steering shaft 41 covered by a steering column 40 which is rotatably provided on a steering frame 39 erected at the front of the cabin 17 (see FIG. 2), and is mounted below the steering shaft 41. Tilt adjustment can be performed by depressing a tilt pedal 42 provided.

Further, in front of the steering wheel 38, a panel cover 43 and a rear panel cover 44 are provided to cover the periphery of the steering frame 39. Of these, the panel cover 43 has a meter panel 45 equipped with a tachometer, a fuel gauge, a liquid crystal display, etc. In addition to the engine control lever 46 and an operation switch group 47 for turning on and off various automatic controls of the tractor 1, an operation switch for a liquid crystal display provided on the meter panel 45, an automatic all-in-one switch, etc. are provided.

Further, the bracket provided on the aforementioned steering column 40 is provided with a forward/reverse lever 48 of the traveling transmission, a combination switch lever 49, or a quick up lever 50 for raising and lowering the working machine. The steering column 40, bracket, etc. are covered with a column cover 51, and further, a main clutch pedal 52, left and right brake pedals 53, a PTO shift lever 54, etc. are provided below the steering wheel 38.

As shown in FIG. 2, the lower part of the steering shaft 41 rotated by the steering wheel 38 is connected to the input shaft of a fully hydraulic power steering unit 56 via a joint shaft and a yoke 55. The power steering unit 56 operates a double-acting hydraulic cylinder 57 provided in the front axle case 8, and the double-acting hydraulic cylinder 57 rotates the left and right knuckle arms 59 via the tie rods 58 to rotate the left and right front wheels 12. to steer. Therefore, when the steering wheel 38 is rotated, the operating force is reduced using hydraulic pressure, and the left and right front wheels 12 can be smoothly steered to change the traveling direction of the aircraft.

The tractor 1 is equipped with a variety of automatic controls in order to maximize the capabilities of the work equipment connected to the traveling body. A control unit (ECU: Electronic Control Unit) is used. In addition, these electronic control units are distributed in various locations on the vehicle body, and by building a network using CAN (Controller Area Network), a serial communication protocol, signal lines used by multiple electronic control units can be connected. This reduces the number of harnesses and simplifies the wiring of the harness.

Therefore, as shown in FIG. 4, the tractor 1 includes a main electronic control unit (MAC unit provided in the side console on the right side of the driver's seat 32) 60 provided for controlling the work equipment, etc., and the aforementioned operation switch group 47. a front unit 61 that controls the automatic control, a meter panel unit 62 that controls the liquid crystal display etc. provided on the meter panel 45, and a side panel unit 63 that controls automatic control related operating tools provided on the side console on the right side of the driver's seat 32. A first in-vehicle network is constructed by connecting each to a 1-channel CAN bus (CAN1 bus).

In addition, the aforementioned main electronic control unit 60, the traveling unit 64 that performs speed change control of the traveling transmission, and the engine ECU 65 that controls the rotation speed of the engine 2, etc. are respectively connected to the 0 channel CAN bus (CAN0 bus), Build a second in-vehicle network.

Note that each CAN bus is constituted by a closed communication line with terminal resistors R provided at both ends of a CAN high bus line CAN_H and a CAN low bus line CAN_L. In the first in-vehicle network, this terminating resistor R is provided in the main electronic control unit 60 and the front unit 61 (see FIG. 9), and in the second in-vehicle network, this terminating resistor R is provided in the main electronic control unit 60 and the front unit 61, respectively (see FIG. 9). They are provided in the main electronic control unit 60 and the travel unit 64, respectively.

In addition, these electronic control units 60 to 65 connect various sensors, operation switches, volumes, etc. to their input ports, while connecting hydraulic electromagnetic switching valve solenoids, electric motors, lamps, and buzzers to their output ports. For example, if the main electronic control unit 60 is connected to the main electronic control unit 60, these input/output devices can be used to control the position, automatic depth control, tilt control, draft control, front wheel double speed/auto brake for raising and lowering the work equipment. Performs well-known automatic controls such as control and PTO control.

The outline of tractor 1 has been explained above. Next, we will explain the automatic driving system provided as an option. This automatic driving system uses GNSS (Global Navigation Satellite System) based on RTK (Real Time Kinematic). By acquiring the position, direction, or time, the tractor 1 is automatically driven along a straight work route, a turning route, etc. in the field without bothering the worker sitting in the driver's seat 32. It is something.

Therefore, as shown in FIG. 5, this automatic driving system captures radio waves emitted from positioning satellites such as GPS of the United States, GLONASS of Russia, and Galileo of the European Union with two antennas 66 for position and direction. A receiver 67 that acquires position information etc., a base station 68 that acquires correction information to supplement the position information acquired by this receiver 67, and a base station 68 that creates work travel routes, turning travel routes, etc. based on map data etc. , a tablet terminal 69 that calculates a steering amount to guide the tractor 1 to the traveling route based on the deviation from the traveling route, and an automatic controller that controls the steering of the front wheels 12 to match the steering amount instructed by the tablet terminal 69. It includes a steering device 70 and the like.

The automatic driving system can be retrofitted to the existing tractor 1 relatively easily, and includes, for example, the aforementioned GNSS antenna 66, the wireless antenna 71 that communicates with the base station 68, the receiver 67, and the like. The GNSS unit 74 is equipped with a controller (GNSS-ECU) 72 that supervises the entire system, a steering ECU 73 composed of a microcomputer unit of the automatic steering system 70, and the like, as shown in FIG. It is installed and provided together. Furthermore, the base station 68 is installed in a stable location with good visibility and within 300 meters from the field where the tractor 1 is working, and there are no surrounding obstacles such as mountains, trees, or tall buildings.

Furthermore, the tablet terminal 69, which is a thin and lightweight computer equipped with a liquid crystal display with a touch panel and pre-installed with navigation software essential for autonomous driving, can be placed in the hands of the operator sitting in the driver's seat 32. The mobile terminal can be placed in a holder 43a provided on a panel cover 43 provided in front of the driver's seat 32 (see FIG. 3), and if the tablet terminal 69 needs to charge itself, It is also possible to remove it from the holder 43a and carry it to your home or the like.

The remaining drive unit 76 of the automatic steering system 70 will be explained. This drive unit 76 is retrofitted below the steering wheel 38 provided in the control section, and is driven by the electric motor 77 provided in the drive unit 76 from the aforementioned steering ECU 73. When an instruction is issued, the electric motor 77 rotates the steering shaft 41 via the steering wheel 38, and further, the power steering unit 56 and double-acting hydraulic cylinder 57 steer the left and right front wheels 12 to adjust the direction of movement of the tractor 1. change.

To explain in more detail, as shown in FIGS. 7 and 8, the electric motor 77 is constituted by a brushless DC electric motor, and the output shaft of the electric motor 77 is equipped with a large number of rotatable rollers 78 supported by bearings. A pinion 79 is attached and provided. Further, a large diameter rotor 80 made of resin and having a trochoidal tooth profile on the outer peripheral side that meshes with the roller 78 of the pinion 79 is configured to be able to be divided into three parts in the circumferential direction. Further, the pinion housing 81 and rotor housing 82 made of resin that cover the outer peripheral side of the pinion 79 and the rotor 80 can be connected and integrated by two pins 83.

Therefore, when installing the drive unit 76 below the steering wheel 38, first attach each part of the rotor 80 divided into three parts to the three parts of the steering wheel 38 so that the drive unit 76 can be installed without removing the steering wheel 38 from the steering shaft 41. They are joined together below the book spokes 38a. Next, the three connectors 84 are attached to the upper part of the rotor 80, and the tips of the connectors 84 are brought down to the center above the hub 38b, and the three connectors 84 are integrally connected using an annular metal fitting 85. Once fixed, the rotor 80 can be mounted below the steering wheel 38 so as to rotate together with it.

Moreover, by engaging the outer periphery of the rotor 80 attached below the steering wheel 38 with the rollers 86 rotatably provided in the three bulges 82a of the rotor housing 82, the rotor 80 can be attached to the rotor housing 82. The rotor housing 82 is covered and installed while supporting the rotor housing 82. Further, by aligning both ends of the pinion housing 81 to which the electric motor 77 and pinion 79 are attached to both ends of the rotor housing 82 attached to the rotor 80 and connecting them with pins 83, the drive unit 76 to the steering wheel 38 is connected. installation is complete.

Note that the rotor housing 82 is provided with a pin (not shown) protruding downward, and this pin is provided by being attached to the steering column 40 in advance when the rotor housing 82 is attached to the rotor 80. Fit it into the slit in the metal fittings. Therefore, the rotor housing 82 and pinion housing 81 are prevented from rotating due to the driving reaction force when the electric motor 77 rotates the pinion 79 and the rotor 80 rotates the steering wheel 38 accordingly, and the steering wheel 38 is prevented from rotating. To ensure that the traveling direction of a tractor 1 can be changed by rotating the tractor 1 reliably.

Furthermore, although the explanation will be given later, the electric motor 77, which is the main body of the drive unit 76, is integrally provided with an absolute type rotary encoder 87 at its lower part to detect its own rotation. Since this rotary encoder 87 outputs the absolute rotation angle of the electric motor 77 to the steering ECU 73 that controls the electric motor 77, the steering ECU 73 controls the electric motor 77 by feedback control so as to match the instructed steering amount. By rotating it, the traveling direction of the tractor 1 can be quickly corrected.

Furthermore, the GNSS-ECU 72 that controls the entire GNSS unit 74 and the steering ECU 73 are connected to both electronic control units by exchanging information using CAN, which is a serial communication protocol, similar to the in-vehicle network of the tractor 1. The number of signal lines used in 72 and 73 is reduced to simplify harness routing. Note that the terminating resistor R of the CAN bus used here is provided in each of the two electronic control units 72 and 73 (see FIG. 9).

The automatic driving system using the satellite positioning system has been described above, but in such an automatic driving system, the GNSS-ECU 72 and the steering ECU 73 are used to construct a narrowly defined automatic driving network using CAN, and the GNSS-ECU 72 is connected to a tablet terminal. 69, or specific low-power wireless communication with the RTK base station 68, thereby constructing an automated driving network in a broad sense. However, if we try to complete automatic driving of tractor 1 using only the information obtained from such a limited network, there will naturally be a limit to the control content, and it will be necessary to expand the automatic driving control content beyond that. It becomes difficult to develop.

Therefore, in order to solve this problem, by relaying the automatic driving network and the in-vehicle network that the tractor 1 already has using the CAN gateway 88, the electronic control units 72, 73 or the tablet terminal 69 on the automatic driving system side can The information on the in-vehicle network is used to expand the control content of automatic driving, or conversely, the information on the automatic driving network is used by the main electronic control unit 60 etc. provided for controlling the work equipment of the tractor 1, etc. It can be so.

Therefore, the electronic control unit 89 constituting the newly provided CAN gateway 88 connects the two CAN bus connection ports 89a and 89b to the middle of the 1-channel CAN1 bus that constructs the in-vehicle network shown in FIG. The intermediate points of the CAN buses that construct the automatic driving network shown in the figure are connected. To explain in more detail, as shown in FIG. 9, a relay connector 91 (male 91a, A knife 91b) is provided.

An in-vehicle network is constructed by connecting the male 91a and female 91b of the relay connector 91 to each other, but the connection between the male 91a and female 91b is once removed here. In addition, cables 92 (H line 92a, L line 92b, 12V power line and ground line) connected to the CAN bus connection port 89a of the electronic control unit 89 of the CAN gateway 88 are connected to the male 91a and female 91b of the removed connector 91. A female 94b and a male 94a of a connector 94 provided at the ends of a cable 93 that branches into two (H line 93a, L line 93b) are connected.

On the other hand, the main cable 95 (H line 95a, L line 95b, 12V power line and ground line) of the CAN bus that constructs the automatic driving network and the branch cable 96 (H line 96a, L line 96b, 12V power line and ground line) has been established. Therefore, the end of this branch cable 96 and the end of the cable 97 (H line 97a, L line 97b, 12V power line and ground line) connected to the CAN bus connection port 89b of the electronic control unit 89 of the CAN gateway 88, When connected via the connectors 98 (male 98a, female 98b) provided at each end, the CAN gateway 88 can be connected (connected) to the CAN bus of the in-vehicle network and the automatic driving network in a short time and very easily. can.

By the way, the electronic control unit 89 constituting the CAN gateway 88 described above is provided with a short-range wireless communication device 99 that has a communication protocol that allows data to be sent and received using a serial port (see FIG. reference). Therefore, the electronic control unit 89 utilizes this short-range wireless communication function to communicate information related to automatic driving on the network or control of work equipment, etc. on the network in a unified format by associating the information as necessary. The information can be wirelessly transmitted to a mobile terminal 100, such as a tablet terminal, a smartphone, or a notebook computer, provided near the machine 99.

Alternatively, the electronic control unit 89 provided in the CAN gateway 88 receives the information wirelessly transmitted from the mobile terminal 100 via the short-range wireless communication device 99, and the electronic control unit 89 automatically transmits the received information. It can be streamed onto a driving network or an in-vehicle network to be useful for automatic driving or, if necessary, for controlling working machines and the like.

Furthermore, this mobile terminal 100 can transfer and manage the information transmitted from the electronic control unit 89 to a personal computer used by an individual, a farming management server owned by an agricultural corporation, a server of a cloud service provider, etc. Or, create a new travel route based on information accumulated in a server, etc., and send instructions to the tractor 1 to perform work travel based on this travel route by sending an instruction in the opposite direction. This can be useful for autonomous driving, etc., and as a result, the tractor 1 can be equipped with an even more expanded network and can handle various types of control that realize the smart agriculture that has been proposed in recent years.

In the CAN gateway 88 described above, a board to which electronic components such as an electronic control unit 89 and a short-range wireless communication device 99 are attached is housed in a housing case 101 as shown in FIG. Further, urethane resin or the like is injected into the housing case 101 to improve the waterproofness and vibration-proofing properties of the electronic components. Furthermore, this storage case 101 is fastened using a cable tie 103 to a wire harness 102 that is the backbone for connecting the main electronic control unit 60 and the front unit 61, etc., which are arranged below the cover provided below the driver's seat 32.

Therefore, the CAN gateway 88 can be installed in an empty space sandwiched between the lower transmission case 4 and the upper removable cover, etc., where it is difficult for rainwater to splash onto the space. There is no need to keep it. In addition, when the relay connector 91 is pulled out from the CAN1 bus main cable 90 of this wire harness 102 and the cable 93 connected to the CAN gateway 88 is connected to the main cable 90 as described above, the CAN gateway 88 is installed and the cables 93 and 90 are connected. You can complete the connection work at once.

Now, to explain a part of the specific control contents in automatic driving using the communication system provided with the CAN gateway 88 described above, the tractor 1 is used as a working machine with a rotary tiller connected to its rear part to perform cultivation work in a field. When doing this, the rotary tiller is grounded on the field and one stroke of tilling work is carried out. Further, when the tractor 1 reaches the headland, it once raises the rotary tilling device to make direction corrections such as turning, and then lowers the rotary tilling device again to perform the next stroke of tilling work.

Therefore, automatic straight-travel control, which controls the process of performing this tilling work so that the tractor 1 travels straight, uses, for example, the direction of the rotary tiller, based on the reference direction for work travel acquired through teaching travel performed in advance, etc. A working travel route parallel to the reference direction with a predetermined stroke interval obtained by subtracting the overlapped plowing width from the tilling width is created, and the automatic steering device 70 is used so that the tractor 1 follows this work travel route. to automatically steer the steering wheel 38.

In this case, the automatic straight-ahead control is started and ended by the operator tapping the start/stop button 104 on the guidance screen displayed on the liquid crystal display of the tablet terminal 69 on which the navigation software is installed, as shown in FIG. It is assumed that this is done by

Therefore, after completing one stroke of work travel, the worker taps the start/stop button 104 to end the automatic straight-ahead control, and also operates the quick-up lever 50 provided on the control section upward to raise the rotary tiller. Then, the steering wheel 38 is manually operated to turn the tractor 1. Furthermore, when the next work step is reached, the worker operates the quick-up lever 50 downward to lower the rotary tiller to start tilling work, and taps the start/stop button 104 again to activate automatic straight-travel control. This requires a cumbersome operation such as starting it.

However, if the control program is modified so that the automatic straight-ahead control starts and ends in conjunction with the lowering and raising operations of the rotary tiller, the operator will be freed from some of the troublesome operations and the burden will be reduced. can do. Therefore, in order to achieve this, the front unit 61 detects the upward or downward operation of the quick-up lever 50 by turning on/off the quick-up switch 105 (see FIG. 4).

Further, the front unit 61 transmits the information to the main electronic control unit 60 via the in-vehicle network, and on the other hand, the main electronic control unit 60 controls the work machine that it executes based on the information from the front unit 61. In elevating and lowering control, current is passed through the raising solenoid 106 and lowering solenoid 107 of the hydraulic electromagnetic switching valve that operate the hydraulic lift cylinder that constitutes the elevating device of the working machine, and the rotary tiller is raised and lowered by the expansion and contraction operation of the hydraulic lift cylinder.

Therefore, the GNSS-ECU 72 on the automatic driving system side transmits the above-mentioned lifting/lowering command information for the work equipment transmitted from the front unit 61 in the in-vehicle network to the main electronic control unit 60 between the in-vehicle network, the CAN gateway 88, and the automatic driving network. Acquired via CAN bus. Furthermore, the GNSS-ECU 72 instructs the tablet terminal 69 to start or end the automatic straight-ahead control via the short-range wireless communication device 107 based on the information, and the tablet terminal 69 instructs the tablet terminal 69 to start or end the automatic straight-ahead control based on this. , or execute termination.

Therefore, by providing the CAN gateway 88 that relays the in-vehicle network and the automatic driving network, information on the in-vehicle network related to the control of the work equipment of the tractor 1, etc., can be transferred relatively easily in the automatic driving system retrofitted, as in the above example. It is possible to obtain this information in a timely manner, and it can be appropriately utilized in the automated driving of the automated driving system that will be installed afterwards. Furthermore, when the CAN gateway 88 allows information on the automatic driving network to flow onto the in-vehicle network, information such as the position, direction, or time of the tractor 1 flowing on the automatic driving network can be transmitted to the work equipment of the tractor 1, etc. It also becomes possible to utilize it in control as needed.

Note that the two antennas 66 for position and orientation provided in the above-mentioned automatic driving system are such that the antenna 66 provided on the left side in the forward direction of the tractor 1 in FIG. 6 is used as a reference antenna, and the antenna 66 provided on the right side is used as an azimuth antenna. The positioning of the tractor 1 is performed. However, these antennas 66 may be provided in a straight line at predetermined intervals in the forward direction of the tractor 1. When changing the installation position of the antenna 66 in this way, it is necessary to tap the document button 108 displayed on the liquid crystal display of the tablet terminal 69 to change the setting of the installation position of the antenna 66, as shown in FIG. There is.

Therefore, in this case, based on the displayed illustration of the tractor 1, coordinate axis display, explanatory text, and recommended setting values, for example, the actually measured installation of the reference antenna 66 from the left and right center of the rear axle 13, which is the reference position R, is performed. Write the position in the X, Y, and Z input fields. Furthermore, since the azimuth antenna 66 is installed in front of the reference antenna 66, by writing "0" in the azimuth offset input field, the satellite positioning information can be converted into body position information of the tractor 1 without error.

Note that the GNSS unit 74 includes an inertial measurement device 109 consisting of a three-axis gyro and three-direction accelerometers that detect the attitude of the tractor 1. Therefore, even if the tractor 1 tilts in the left-right direction, front-back direction, etc., the body position information at the reference position R of the tractor 1 can be corrected correctly based on the measurement results of the inertial measurement device 109. In addition, when setting the installation information for the inertial measurement device 109 on the tractor 1, it is also possible to write the values without error if the illustration of the tractor 1, coordinate axis display, explanatory text, recommended setting values, etc. are displayed. I can do it.

In addition, if the use of maps (aerial photographs, topographic maps) or information such as field brush polygons shown on the agricultural data collaboration platform, which is being operated mainly by the National Agriculture and Food Research Organization (NARO), will become possible, it will be possible to view fields on personal computers. The field to be worked on with the tractor 1 is specified from an aerial photograph, etc., the outline of the field is extracted by image processing based on this, and the latitude and latitude corresponding to the coordinates of this outline are associated or matched with the map. If the data can be obtained in a file format, the travel route of the tractor 1 can be studied on a desk based on this information.

Then, if the travel route of the tractor 1 created here is finally sent to the tablet terminal 69 via the mobile terminal 100, the tractor 1 will automatically travel in the designated field following the travel route created on the desk. For example, it is possible to save the effort of actually measuring latitude and longitude by driving the tractor 1 along a ridge in a field for teaching purposes.

Furthermore, the electronic control unit 89 of the CAN gateway 88 obtains position information from the in-vehicle network and the automatic driving network when the tractor 1 lowers its working equipment and actually travels in the field, and transmits this information to the mobile The information is finally saved in a personal computer or the like via the terminal 100 along with the field address, work contents, work date and time, etc. This information can be used at a later date, for example, as reference information for creating a travel route when performing rice planting, transplanting seedlings, or harvesting.

In other words, if the tractor 1 is traveling straight in a certain section of the field, taking into consideration the positional information where the tractor 1 is traveling during actual work, the longitude and latitude information and azimuth information of the starting position of that section are recorded, and the section is recorded. If the vehicle travels along another straight line, the travel route for the entire field is created as a series of line segments while recording the longitude, latitude, and azimuth information of the starting position of this section in the same way. . By automatically driving a rice transplanter, a combine harvester, or a tractor along this created travel route, it is possible to reduce the burden on the worker.

In addition to the work route where actual work is performed, if the tractor 1 is to automatically travel unmanned even on the turning route at the headland, there should be a worker in the direction of travel of the tractor 1 in consideration of safety. The tractor 1 is configured to detect the entry of an auxiliary worker or an auxiliary worker using an obstacle sensor (stereo camera, sonar, millimeter wave radar, lidar) and stop the tractor 1 from moving. Therefore, in order to eliminate losses due to such interruptions in work, it is necessary for auxiliary workers and the like to always retreat from the direction in which the tractor 1 is moving.

However, if the tractor 1 is traveling straight on the work route, it can be evacuated in advance from the front in the direction of travel, but when it approaches a turning route, the direction of the turn will be to the right or to the left. There are cases where it is difficult to predict, and in such cases, the tractor 1 is often stopped. Therefore, in order to solve this problem, a travel route is created by adding information indicating the turning direction when the tractor 1 reaches the turning route to the work route information a predetermined distance before reaching the turning route of the tractor 1. do.

When the tractor 1 passes through the working route a predetermined distance before reaching this turning route, the turn signal lamp 110 that indicates the turning direction and the lamps that display the automatic operation of the three-color light separately provided on the tractor 1 flash in a blinking pattern. The lamp is changed to notify an auxiliary worker and the like, and the lamp is turned off when the tractor 1 exits the turning route. Therefore, once the direction in which the tractor 1 is about to turn is known, the auxiliary worker can evacuate with enough time to avoid entering the front of the tractor 1 in the direction of movement, thereby preventing the tractor 1 from interrupting its work. It can be eliminated.

1 Tractor (work vehicle)
60 Main electronic control unit 61 Front unit 69 Tablet terminal 72 GNSS-ECU
73 Steering ECU
76 Drive unit 88 CAN gateway 89 Gateway ECU
90 CAN bus main cable 91 Relay connector 92 Cable connected to CAN gateway 88 95 Main cable of CAN bus that constructs an automated driving network 96 Branch cable 97 Cable connected to CAN gateway 88 100 Mobile terminal

Claims (4)

The existing in-vehicle network is constructed by connecting an electronic control unit installed for controlling work equipment, etc. to a CAN bus that follows the CAN communication protocol, and an electronic control unit installed for autonomous driving using a satellite positioning system. , an optional automated driving network built by connecting to a CAN bus that also follows the CAN communication protocol, and a CAN gateway that connects to the CAN bus and relays the exchange of information on each other's networks. A communication system for a work vehicle that is configured to acquire information even if it is on the other network and use it for automatic driving on one network or for controlling a work machine or the like. The electronic control unit provided in the CAN gateway is provided with a short-range wireless communication function, so that information regarding automatic driving on the network or control of work equipment, etc. can be wirelessly transmitted to a nearby mobile terminal, or can be transmitted from the mobile terminal. The electronic control unit provided in the CAN gateway receives the wirelessly transmitted information, and the received information is sent to the automatic driving network or the in-vehicle network, so that it can be used for automatic driving or control of work equipment, etc. 2. The communication system for a work vehicle according to claim 1. A branch cable is provided in the main cable of the CAN bus that constructs the in-vehicle network or autonomous driving network, and the end of the branch cable and the end of the cable connected to the CAN gateway are connected via a connector, or the CAN bus A relay connector is provided on the main cable of the CAN gateway, and connectors provided at each end of the cable that branches from the cable connected to the CAN gateway into two are connected to each disconnected connector of the relay connector. The communication system for a work vehicle according to claim 1 or 2, wherein the communication system is connected to each CAN bus. The above-mentioned CAN gateway is attached by fastening a waterproof housing case with a board on which electronic components such as the electronic control unit are attached to a wire harness bundled with CAN bus cables and other wiring using cable ties. A communication system for a work vehicle according to item 3.

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