JP7108499B2 - automatic driving system - Google Patents

Description

The present invention relates to an automatic travel system that automatically travels a work vehicle along a target travel route.

The automatic traveling system described above automatically travels the work vehicle along a target travel route generated in advance based on positioning information of the work vehicle acquired using a satellite positioning system or the like. 1).
When performing agricultural work in a field with an unmanned work vehicle using such an automatic driving system, when danger occurs such as when another person accidentally enters the field, the unmanned vehicle during automatic driving It is necessary to stop the work vehicle by remote control. Therefore, the automatic traveling system described in Patent Literature 1 includes a remote control device (an example of a communication terminal) that controls the automatic traveling of the work vehicle through wireless communication.

JP 2016-168883 A

In the automatic traveling system described in Patent Document 1, a user or the like can remotely stop an unmanned work vehicle that is automatically traveling by operating a remote control device. However, due to interference with wireless communication used by external equipment such as others, communication interruption occurs in wireless communication between the remote control device and the work vehicle, and the work vehicle is emergency stopped by remote control when necessary. It is conceivable that an impossible situation may arise.

In view of this situation, a main object of the present invention is to provide an automatic traveling system capable of more reliably controlling traveling of a work vehicle by remote control.

A first characteristic configuration of the present invention is an automatic travel control unit provided in a work vehicle for automatically traveling the work vehicle along a target travel route;
a remote control communication terminal capable of transmitting a control signal for controlling travel of the work vehicle by wireless communication;
a vehicle-side receiving unit provided in the work vehicle for receiving the control signal transmitted from the communication terminal by wireless communication and transmitting the control signal to the automatic travel control unit;
a channel setting unit that sets a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit from a plurality of communication channels;
and a communication state storage unit that stores the past communication state of each of the plurality of communication channels.

According to this configuration, a user or the like owns a communication terminal and can transmit a control signal for controlling travel of the work vehicle from the communication terminal by wireless communication. A vehicle-side receiving unit provided in the work vehicle receives the control signal transmitted from the communication terminal by wireless communication and transmits it to the automatic travel control unit, so that the travel of the work vehicle can be controlled by remote control. can be done.
In this configuration, since the communication state storage section for storing the past communication state of each of the plurality of communication channels is provided, the past communication of each of the plurality of communication channels stored in the communication state storage section is provided. Considering the state, the channel setting unit can set a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit from among a plurality of communication channels.
Therefore, for example, among a plurality of communication channels, it is possible to set an appropriate communication channel, such as one with a small number of communication interruptions in the past, as a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit. It is possible to more reliably control the travel of the work vehicle by remote control.

A second characteristic configuration of the present invention is provided with a channel selection unit that selects a use candidate communication channel from a plurality of communication channels based on the communication state stored in the communication state storage unit,
The channel setting unit sets a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit from among the use candidate communication channels selected by the channel selection unit.

According to this configuration, the channel selection unit selects a candidate communication channel for use from a plurality of communication channels based on the past communication state of each communication channel stored in the communication state storage unit, and the channel setting unit , a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit can be set from the use candidate communication channels.
Therefore, it is possible to automatically set an appropriate communication channel from among a plurality of communication channels as a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving section.

In a third characteristic configuration of the present invention, the channel selection unit is configured to select a plurality of use candidate communication channels from a plurality of communication channels,
a communication confirmation unit that performs communication confirmation processing for confirming at predetermined time intervals whether wireless communication between the communication terminal and the vehicle-side reception unit is established,
When wireless communication between the communication terminal and the vehicle-side receiving unit is not established in the communication confirmation process, the channel setting unit changes the setting of the communication channel from the currently set communication channel to another use candidate communication channel. at the point of switching.

According to this configuration, the channel selection unit selects a plurality of use candidate communication channels from a plurality of communication channels, and the channel setting unit selects one of the use candidate communication channels for wireless communication between the communication terminal and the vehicle-side receiving unit. Can be set to the communication channel used for communication. By performing communication confirmation processing in the communication confirmation unit, it is possible to confirm at predetermined time intervals whether or not wireless communication is established on the communication channel in use. can automatically switch from the current communication channel on which wireless communication is not established to another use candidate communication channel in the channel setting unit.
Therefore, even if a communication interruption occurs in which radio communication is not established between the communication terminal and the vehicle-side receiving section, the communication interruption can be resolved early and the radio communication between the communication terminal and the vehicle-side receiving section can be continued. .

Diagram showing schematic configuration of automated driving system Block diagram showing the schematic configuration of the automated driving system A diagram showing the work area in the state where the target travel route is generated Block diagram showing schematic configuration of emergency stop remote control Block diagram showing a schematic configuration of a remote control receiver Flowchart showing operation when executing remote control receiver start-up processing Flowchart showing the operation when performing activation processing of the remote control for emergency stop Flowchart showing operation after start-up processing of remote control receiver Flowchart showing operation after activation processing of remote control for emergency stop Time chart of communication channel switching operation in wireless communication between emergency stop remote control and remote control receiver

An embodiment of an automatic driving system according to the present invention will be described based on the drawings.
As shown in FIG. 1, this automatic driving system employs a tractor 1 as a work vehicle. Also, an unmanned working vehicle such as an unmanned lawn mower can be applied.

As shown in FIGS. 1 and 2, this automatic traveling system includes an automatic traveling unit 2 mounted on a tractor 1 and a mobile communication terminal 3 set to communicate with the automatic traveling unit 2 . As the mobile communication terminal 3, a tablet-type personal computer, a smartphone, or the like having a touch-operable display unit 51 (for example, a liquid crystal panel) or the like can be adopted.

The tractor 1 includes a traveling body 7 having left and right front wheels 5 functioning as drivable steering wheels and left and right drivable rear wheels 6 . A bonnet 8 is arranged on the front side of the traveling machine body 7 , and an electronically controlled diesel engine (hereinafter referred to as an engine) 9 having a common rail system is provided in the bonnet 8 . A cabin 10 forming a boarding-type operating section is provided on the rear side of the bonnet 8 of the traveling body 7 .

A rotary tillage device, which is an example of a working device 12, is connected to the rear portion of the traveling machine body 7 via a three-point link mechanism 11 so as to be able to move up and down and roll, thereby configuring the tractor 1 for rotary tillage. can. A working device 12 such as a plow, a sowing device, a spreading device, or the like can be connected to the rear portion of the tractor 1 instead of the rotary tillage device.

As shown in FIG. 2, the tractor 1 includes an electronically controlled transmission 13 for shifting the power from the engine 9, a fully hydraulic power steering mechanism 14 for steering the left and right front wheels 5, and the left and right rear wheels 6. Left and right side brakes (not shown) for braking, an electronically controlled brake operation mechanism 15 that enables hydraulic operation of the left and right side brakes, and a work clutch (see FIG. (not shown), an electronically controlled clutch operating mechanism 16 that enables hydraulic operation of a work clutch, an electrohydraulically controlled lifting drive mechanism 17 that drives the work device 12 such as a rotary tillage device to move up and down, automatic traveling of the tractor 1, and the like. vehicle speed sensor 19 for detecting the vehicle speed of the tractor 1, steering angle sensor 20 for detecting the steering angle of the front wheels 5, and the current position and current direction of the tractor 1 A positioning unit 21 and the like are provided.

The engine 9 may be an electronically controlled gasoline engine with an electronic governor. A hydromechanical continuously variable transmission (HMT), a hydrostatic continuously variable transmission (HST), a belt-type continuously variable transmission, or the like can be adopted as the transmission 13 . As the power steering mechanism 14, an electric power steering mechanism 14 or the like having an electric motor may be employed.

Inside the cabin 10, as shown in FIG. 1, a steering wheel 38 that enables manual steering of the left and right front wheels 5 via a power steering mechanism 14 (see FIG. 2), a driver's seat 39 for passengers, a touch panel A formula display and various operating tools are provided.

As shown in FIG. 2, the in-vehicle electronic control unit 18 includes a shift control unit 181 that controls the operation of the transmission 13, a braking control unit 182 that controls the operation of left and right side brakes, and a working device 12 such as a rotary tillage device. A work device control unit 183 that controls the operation, a steering angle setting unit 184 that sets target steering angles of the left and right front wheels 5 during automatic travel and outputs the target steering angles to the power steering mechanism 14, and a pre-generated target travel for automatic travel. It has a non-volatile in-vehicle storage unit 185 or the like that stores the route P (see FIG. 3, for example).

As shown in FIG. 2, the positioning unit 21 includes satellites for measuring the current position and current azimuth of the tractor 1 using GPS (Global Positioning System), which is an example of a satellite positioning system (NSS: Navigation Satellite System). A navigation system 22, and an inertial measurement unit (IMU) 23, which has a triaxial gyroscope, a tridirectional acceleration sensor, and the like, and measures the attitude, orientation, and the like of the tractor 1, and the like are provided. Positioning methods using GPS include DGPS (Differential GPS: relative positioning method), RTK-GPS (Real Time Kinematic GPS: interferometric positioning method), and the like. In this embodiment, RTK-GPS suitable for positioning of mobile units is adopted. Therefore, as shown in FIGS. 1 and 2, reference stations 4 that enable positioning by RTK-GPS are installed at known positions around the field.

As shown in FIG. 2, the tractor 1 and the reference station 4 are provided with positioning antennas 24 and 61 for receiving radio waves transmitted from a positioning satellite 71 (see FIG. 1), and an antenna between the tractor 1 and the reference station 4. Communication modules 25, 62, etc. are provided to enable wireless communication of various information including positioning information in the. Thereby, the satellite navigation device 22 receives the positioning information obtained by the positioning antenna 24 on the tractor side receiving the radio wave from the positioning satellite 71, and the positioning antenna 61 on the base station side receives the radio wave from the positioning satellite 71. Based on the obtained positioning information, the current position and current azimuth of the tractor 1 can be measured with high accuracy. Further, the positioning unit 21 includes a satellite navigation device 22 and an inertial measurement device 23 to measure the current position, current azimuth, and attitude angle (yaw angle, roll angle, pitch angle) of the tractor 1 with high accuracy. can be done.

The positioning antenna 24, the communication module 25, and the inertial measurement device 23 provided in the tractor 1 are accommodated in the antenna unit 80, as shown in FIG. The antenna unit 80 is arranged at an upper position on the front side of the cabin 10 .

As shown in FIG. 2, the mobile communication terminal 3 includes a terminal electronic control unit 52 having various control programs for controlling the operation of the display unit 51, etc., and positioning information between the communication module 25 on the tractor side and A communication module 55 or the like is provided to enable wireless communication of various information including. The terminal electronic control unit 52 includes a travel route generation unit 53 that generates a target travel route P (see, for example, FIG. 3) for automatically traveling the tractor 1, and various input information entered by the user and a travel route generation unit It has a non-volatile terminal storage unit 54 and the like for storing the target travel route P and the like generated by 53 .

When the travel route generating unit 53 generates the target travel route P, a user such as a driver or manager follows the input guidance for setting the target travel route displayed on the display unit 51 of the mobile communication terminal 3, and the user such as the work vehicle or the work vehicle. Vehicle information such as the type and model of the working device 12 is input, and the input vehicle information is stored in the terminal storage unit 54 . The work area S (see FIG. 3) for which the target travel route P is to be generated is an agricultural field, and the terminal electronic control unit 52 of the mobile communication terminal 3 acquires the agricultural field information including the shape and position of the agricultural field, 54 is stored.

When the user or the like drives the tractor 1 to actually run, the terminal electronic control unit 52 acquires the shape and position of the farm field from the current position of the tractor 1 acquired by the positioning unit 21 and the like. It is possible to acquire location information for specifying such as. The terminal electronic control unit 52 specifies the shape and position of the farm field from the acquired position information, and acquires the farm field information including the specified work area S from the specified shape and position of the farm field. FIG. 3 shows an example in which a rectangular work area S is specified.

When the field information including the shape and position of the specified field is stored in the terminal storage unit 54, the travel route generation unit 53 uses the field information and the vehicle body information stored in the terminal storage unit 54 to generate the target A travel route P is generated.

As shown in FIG. 3, the travel route generator 53 divides and sets the work area S into a central area R1 and an outer peripheral area R2. The central area R1 is set in the central part of the working area S, and serves as a reciprocating working area in which the tractor 1 automatically travels in the reciprocating direction in advance to perform a predetermined work (for example, work such as tillage). . The outer peripheral region R2 is set around the central region R1, and serves as a direction changing region in which the tractor 1 changes direction. The traveling route generation unit 53 determines, for example, the turning radius required for turning the tractor 1 along the ridge of the field, based on the turning radius, the front-rear width and the left-right width of the tractor 1 included in the vehicle body information. I am looking for The travel route generator 53 divides the work area S into a central area R1 and an outer area R2 so as to secure the space obtained in the outer area R2.

As shown in FIG. 3, the travel route generating unit 53 generates the target travel route P using vehicle information, field information, and the like. For example, the target travel path P is a plurality of linear work paths P1 that have the same straight distance in the central region R1 and are arranged and set in parallel with a certain distance corresponding to the work width, and adjacent in the outer peripheral region R2. It has a connection path P2 that connects the starting end and the terminal end of the working path P1. The plurality of work paths P1 are paths for performing predetermined work while the tractor 1 is traveling straight. The connection path P2 is a U-turn path for changing the traveling direction of the tractor 1 by 180 degrees without performing a predetermined work, and connects the end of the work path P1 and the beginning of the next adjacent work path P1. ing. Incidentally, the target travel route P shown in FIG. 3 is merely an example, and the type of target travel route to be set can be changed as appropriate.

The target travel route P generated by the travel route generation unit 53 can be displayed on the display unit 51, and is stored in the terminal storage unit 54 as route information associated with vehicle information, field information, and the like. The route information includes the azimuth angle of the target travel route P, the set engine rotation speed, the target travel speed, and the like, which are set according to the travel mode of the tractor 1 on the target travel route P and the like.

In this way, when the travel route generation unit 53 generates the target travel route P, the terminal electronic control unit 52 transfers the route information from the mobile communication terminal 3 to the tractor 1, so that the in-vehicle electronic control unit 18 of the tractor 1 can get route information. The in-vehicle electronic control unit 18 automatically travels the tractor 1 along the target travel route P while acquiring its own current position (current position of the tractor 1) with the positioning unit 21 based on the acquired route information. can be done. The current position of the tractor 1 acquired by the positioning unit 21 is transmitted from the tractor 1 to the mobile communication terminal 3 in real time (for example, at intervals of several milliseconds). I understand.

Regarding the transfer of the route information, the entire route information can be transferred from the terminal electronic control unit 52 to the vehicle-mounted electronic control unit 18 at once before the tractor 1 starts automatic traveling. Further, for example, the route information including the target travel route P can be divided into a plurality of route portions each having a small amount of information and having predetermined distances. In this case, only the initial route portion of the route information is transferred from the terminal electronic control unit 52 to the in-vehicle electronic control unit 18 before the tractor 1 starts automatically traveling. After the start of automatic driving, each time the tractor 1 reaches a route acquisition point set according to the amount of information, etc., the route information only for the subsequent route portion corresponding to that point is sent from the terminal electronic control unit 52 to the in-vehicle electronic control unit. It may be transferred to unit 18 .

When the automatic traveling of the tractor 1 is started, for example, when the user or the like moves the tractor 1 to the start point and various automatic traveling start conditions are satisfied, the user displays the display unit 51 on the mobile communication terminal 3. is operated to instruct the start of automatic traveling, the mobile communication terminal 3 transmits the automatic traveling start instruction to the tractor 1 . As a result, in the tractor 1, the in-vehicle electronic control unit 18 receives the instruction to start automatic travel, so that the positioning unit 21 acquires the current position of the tractor 1 (the current position of the tractor 1), and moves to the target travel route P. Automatic travel control is started to automatically travel the tractor 1 along the road. Automatic travel control in which the vehicle-mounted electronic control unit 18 automatically travels the tractor 1 along the target travel route P within the work area S based on the positioning information of the tractor 1 acquired by the positioning unit 21 using the satellite positioning system. It is configured as an automatic travel control unit that performs

The automatic travel control includes automatic transmission control for automatically controlling the operation of the transmission 13, automatic braking control for automatically controlling the operation of the brake operation mechanism 15, automatic steering control for automatically steering the left and right front wheels 5, and a rotary tillage device. automatic control for work, which automatically controls the operation of the work device 12, and the like.

In the automatic shift control, the shift control unit 181 controls the movement of the tractor 1 on the target travel route P based on the route information of the target travel route P including the target travel speed, the output of the positioning unit 21, and the output of the vehicle speed sensor 19. The operation of the transmission 13 is automatically controlled so that the vehicle speed of the tractor 1 can be obtained as the target traveling speed set according to the traveling mode or the like.

In the automatic braking control, the braking control unit 182 controls the left and right side brakes in the braking region included in the route information of the target travel route P based on the target travel route P and the output of the positioning unit 21. The operation of the brake operating mechanism 15 is automatically controlled so that the wheels 6 are properly braked.

In the automatic steering control, the steering angle setting unit 184 controls the target positions of the left and right front wheels 5 based on the route information of the target travel route P and the output of the positioning unit 21 so that the tractor 1 automatically travels along the target travel route P. A steering angle is obtained and set, and the set target steering angle is output to the power steering mechanism 14 . Based on the target steering angle and the output of the steering angle sensor 20, the power steering mechanism 14 automatically steers the left and right front wheels 5 so that the steering angle of the left and right front wheels 5 is obtained as the target steering angle.

In the automatic work control, the work device control unit 183 controls the tractor 1 to perform work such as the starting end of the work route P1 (see, for example, FIG. 3) based on the route information of the target travel route P and the output of the positioning unit 21. When the work device 12 reaches the start point, a predetermined work (for example, plowing work) is started, and when the tractor 1 reaches the work end point such as the end of the work path P1 (see, for example, FIG. 3). Accordingly, the operations of the clutch operating mechanism 16 and the lifting drive mechanism 17 are automatically controlled so that the predetermined work by the working device 12 is stopped.

Thus, in the tractor 1, the transmission 13, the power steering mechanism 14, the brake operation mechanism 15, the clutch operation mechanism 16, the elevation drive mechanism 17, the vehicle electronic control unit 18, the vehicle speed sensor 19, the steering angle sensor 20, the positioning The automatic traveling unit 2 is composed of the unit 21, the communication module 25, and the like.

In this embodiment, not only can the tractor 1 automatically travel without a user or the like in the cabin 10, but it is also possible to automatically travel the tractor 1 with a user or the like in the cabin 10. Therefore, not only can the tractor 1 automatically travel along the target travel route P by the automatic travel control by the in-vehicle electronic control unit 18 without the user or the like boarding the cabin 10, but also the user or the like can board the cabin 10. Even in this case, the tractor 1 can be automatically traveled along the target travel route P by the automatic travel control by the in-vehicle electronic control unit 18 .

When a user or the like is in the cabin 10, the vehicle electronic control unit 18 switches between an automatic running state in which the tractor 1 runs automatically and a manual running state in which the tractor 1 runs based on the operation of the user. be able to. Therefore, the automatic travel state can be switched to the manual travel state while the target travel route P is being automatically traveled in the automatic travel state. state can be switched to automatic driving state. For switching between the manual driving state and the automatic driving state, for example, a switching operation unit for switching between the automatic driving state and the manual driving state can be provided near the driver's seat 39, and the switching operation unit can be carried. It can also be displayed on the display unit 51 of the communication terminal 3 . Further, when the user operates the steering wheel 38 during automatic driving control by the in-vehicle electronic control unit 18, the automatic driving state can be switched to the manual driving state.

As shown in FIGS. 1 and 2, the tractor 1 is equipped with an obstacle detection system 100 for detecting obstacles around the tractor 1 (running body 7) and avoiding collisions with the obstacles. ing. The obstacle detection system 100 includes a plurality of lidar sensors 101 and 102 that can three-dimensionally measure the distance to the measurement object using lasers, and a plurality of lidar sensors that can measure the distance to the measurement object using ultrasonic waves. Sonar units 103 and 104 having sonar, an obstacle detection section 110, and a collision avoidance control section 111 are provided.

The objects to be measured by the lidar sensors 101 and 102 and the sonar units 103 and 104 are objects, people, and the like. The lidar sensors 101 and 102 include a front rider sensor 101 for measuring the front side of the tractor 1 and a rear rider sensor 102 for measuring the rear side of the tractor 1 . The sonar units 103 and 104 include a right sonar unit 103 for measuring the right side of the tractor 1 and a left sonar unit 104 for measuring the left side of the tractor 1 .

Based on the measurement information from the lidar sensors 101 and 102 and the sonar units 103 and 104, the obstacle detection unit 110 performs obstacle detection processing to detect objects, people, and other measurement targets within a predetermined distance as obstacles. is configured to The collision avoidance control unit 111 is configured to perform collision avoidance control to decelerate the tractor 1 or stop the tractor 1 when an obstacle is detected by the obstacle detection unit 110 . In the collision avoidance control, the collision avoidance control unit 111 not only decelerates the tractor 1 or stops the tractor 1, but also operates the notification device 26 such as a notification buzzer and a notification lamp to notify the presence of an obstacle. I am reporting. In the collision avoidance control, the collision avoidance control unit 111 communicates with the mobile communication terminal 3 from the tractor 1 using the communication modules 25 and 55 and causes the display unit 51 to display the presence of the obstacle. It is possible to notify that

The obstacle detection unit 110 repeatedly performs obstacle detection processing based on measurement information from the lidar sensors 101 and 102 and the sonar units 103 and 104 in real time, and appropriately detects obstacles such as objects and people. The collision avoidance control unit 111 performs collision avoidance control for avoiding collisions with obstacles detected in real time.

The obstacle detection section 110 and the collision avoidance control section 111 are provided in the in-vehicle electronic control unit 18 . The in-vehicle electronic control unit 18 is communicably connected to the engine electronic control unit, lidar sensors 101 and 102, sonar units 103 and 104, etc. included in the common rail system via a CAN (Controller Area Network). there is

When performing agricultural work in the work area S with the unmanned tractor 1 using such an automatic traveling system, when danger occurs such as when another person accidentally enters the work area S, the user etc., the unmanned tractor 1 that is automatically traveling needs to be brought to an emergency stop by remote control.
Therefore, in this automatic traveling system, as shown in FIGS. 1 and 2, an emergency stop control signal for controlling traveling of the tractor 1, such as an emergency stop command for emergency stopping of the tractor 1, can be transmitted by wireless communication. A remote control 200 (an example of a communication terminal for remote control) and a remote control receiver 300 (vehicle side reception) that receives a control signal transmitted from the emergency stop remote control 200 by wireless communication and transmits the control signal to the in-vehicle electronic control unit 18 part) and are provided.

The emergency stop remote controller 200 is owned by a user or the like, and the remote controller receiver 300 is mounted on the tractor 1 . Further, the emergency stop remote control 200 and the remote control receiver 300 are configured to perform wireless communication in a different system from the wireless communication with the mobile communication terminal 3 and the base station 4 using the communication module 25 of the tractor 1. is configured to

A user or the like who owns the emergency stop remote controller 200 operates the emergency stop remote controller 200 at a necessary timing, thereby transmitting an emergency stop command for emergency stopping the tractor 1 by wireless communication. Then, when an emergency stop command is transmitted by radio communication from the emergency stop remote control 200, the remote control receiver 300 of the tractor 1 receives the control signal and transmits it to the onboard electronic control unit 18. performs automatic braking control to stop the tractor 1.

In this automatic driving system, as communication channels for performing wireless communication between the emergency stop remote control 200 and the remote control receiver 300, seven (a plurality of examples) line channels are settable. When the emergency stop remote control 200 and the remote control receiver 300 are started, considering the past communication state of each line channel, three (one example of a plurality) of the seven line channels are used as candidates for use. It is configured to select and establish wireless communication using any one of the selected three (one example of a plurality of) use candidate wire channels.

During activation, the emergency stop remote controller 200 and the remote controller receiver 300 perform communication confirmation processing for confirming whether or not wireless communication is established at predetermined time intervals. Even if it does not hold, if a predetermined condition (in this example, the communication channel is being used by an external device, etc.) that is considered to be caused by the communication channel being used holds, then three (one example of a plurality of) use It is configured to automatically switch to another communication channel among the candidate communication channels, continue wireless communication between the emergency stop remote control 200 and the remote control receiver 300, and continue automatic travel of the tractor 1.

That is, as shown in the time chart of FIG. 10, the emergency stop remote controller 200 and the remote controller receiver 300, for example, when wireless communication is established on communication channel A, a confirmation signal (heartbeat Signal h) and response signal (answerback signal a) are transmitted and received (thin line arrows in the figure) at predetermined time intervals, and it is confirmed at predetermined time intervals whether or not wireless communication is established. At this time, even if the communication waiting time in the communication confirmation process has passed and the wireless communication is not established, if it is because the external device is using the communication channel A (during communication), it will be used for emergency stop. The remote control 200 and the remote control receiver 300 switch the communication channel to be used to the communication channel B, establish wireless communication, and perform wireless communication on the communication channel B. FIG.

Note that the emergency stop remote control 200 and the remote control receiver 300 do not establish wireless communication in the communication confirmation process, and it is assumed that this is not caused by the communication channel being used (in this example, the external device is When the communication channel is not in use, etc.) is established, the communication disruption is confirmed, and the communication disruption information is transmitted to the vehicle-mounted electronic control unit 18 of the tractor 1, and the user or the like is notified of the communication disruption. ing.

As shown in FIG. 4, the emergency stop remote control 200 includes a communication module 202 connected to an antenna 201, a non-volatile remote control storage unit 203 for storing the ID of a remote control receiver with which communication is to be performed, and a battery ( not shown), an emergency stop button 204 for the user to perform an operation to send an emergency stop command (an example of a control signal), a notification device (buzzer) for notifying the state of the tractor 1 and the state of wireless communication such as communication interruption 206A, an alarm device (LED) 206B, a remote controller 210 for controlling the operation of each part in the emergency stop remote controller 200, and the like. Incidentally, as shown by the dashed line in FIG. 4, an operation by a user or the like to temporarily stop the automatic traveling of the tractor 1 or to transmit a pause/resume command (an example of a control signal) for restarting the automatic traveling from there. The emergency stop remote control 200 can also be provided with a pause button 205 for performing

The remote control unit 210 includes a communication confirmation unit 211 that performs communication confirmation processing such as transmission of confirmation signals and reception of response signals, and a channel setting unit 212 that performs processing such as communication channel setting and switching. Furthermore, the remote controller control unit 210 is provided with a radio wave state determination unit 213 that determines the radio wave state of the communication channel in use. The radio wave state determination unit 213 compares the radio wave intensity of the communication channel in use obtained by carrier sense, which is performed when transmitting a confirmation signal or the like to check whether there is another device currently in communication, with a threshold value. , determines the radio wave condition of the communication channel in use.

As shown in FIG. 5, the remote control receiver 300 stores a communication module 302 connected to an antenna 301, an ID of an emergency stop remote control to be a communication partner, past communication states of a plurality of communication channels to be described later, and the like. A non-volatile receiver storage unit 303 (corresponding to a communication state storage unit), a CAN interface 304 for transmitting control signals for controlling travel of the tractor 1 such as an emergency stop command to the in-vehicle electronic control unit 18 via CAN, It is configured with a receiver control section 310 and the like for controlling the operation of each section in the remote control receiver 300 . The antenna 301 is arranged, for example, inside the cabin 10 (see FIG. 1).

The receiver control unit 310 includes a communication confirmation unit 311 that performs communication confirmation processing such as reception of confirmation signals and transmission of response signals, and a channel setting unit 312 that performs processing such as communication channel setting and switching. there is Further, the receiver control unit 310 includes a communication state recording unit 313 for writing the past communication state of each communication channel into the receiver storage unit 303, A channel selection unit 314 that selects a communication channel to be used as a candidate based on the communication state, a radio wave state acquisition unit 315 that acquires the radio wave state of the communication channel in use, and a radio wave state determination unit 316 that judges the acquired radio wave state are provided. ing.

The communication status recording unit 313 is configured to write, as the past communication status for each communication channel, the number of past communication interruptions for each communication channel, radio wave status confirmation results at startup, and the like in the receiver storage unit 303 . For example, when communication interruption occurs, the communication state recording unit 313 writes to the receiver storage unit 303 so as to increase the number of communication interruptions of the communication channel in use. Incidentally, since the communication state of the communication channel changes depending on the surrounding environment, it differs for each work area S. Therefore, the communication state recording unit 313 counts the past communication state for each communication channel for each work area S. It can also be written.

The channel selection unit 314 selects a plurality of (in this example, seven) prepared communication channels based on the past communication state for each communication channel stored in the receiver storage unit 303 in the activation process or the like, which will be described later. A plurality (three in this example) of use candidate communication channels are selected from the channels.

For example, the radio wave state acquisition unit 315 performs carrier sense on the communication channel in use and acquires the radio wave state such as the radio wave intensity of the communication channel. The radio wave state determination unit 316 compares the radio wave intensity of the communication channel in use acquired by the radio wave state acquisition unit 315 with a threshold, for example, and determines the radio wave state of the communication channel in use.

The communication confirmation unit 211 of the emergency stop remote controller 200 and the communication confirmation unit 311 of the remote control receiver 300 correspond to the communication confirmation unit of the automatic driving system. corresponds to the channel setting unit of the automatic driving system.

Next, referring to FIGS. 6 and 7, operations of emergency stop remote control 200 and remote control receiver 300 when wireless communication is established by activating emergency stop remote control 200 and remote control receiver 300 are described. explain.

(Operation of remote control receiver 300)
As shown in the flowchart of FIG. 6, the receiver control unit 310 of the remote control receiver 300 starts a start-up process and turns on the power when a predetermined start condition such as the start of the engine 9 of the tractor 1 is satisfied. (step #11). Then, the channel selection unit 314 executes channel selection processing to select a plurality (three in this example) of use candidate communication channels from a plurality of (seven in this example) communication channels (step #12).

As channel selection processing, the channel selection unit 314 acquires past communication states for each of a plurality of (seven in this example) communication channels stored in the receiver storage unit 303, and obtains a plurality of (seven in this example) A plurality of (three in this example) communication channels with high priority are selected as use candidate channels from the communication channels. The order of priority for channel selection can be changed as appropriate, but in this embodiment, it is set in order of decreasing number of times of communication interruption within a predetermined period in the work area S, or the like.

When a plurality (three in this example) of use candidate communication channels are selected in the channel selection process, the radio wave state acquisition unit 315 executes the radio wave state acquisition process and selects one of the plurality of use candidate communication channels. is used to perform carrier sense, and the radio wave intensity of the communication channel in use is acquired as the radio wave state (step #13).

The radio wave condition acquiring unit 315 repeatedly executes the radio wave condition acquiring process of the communication channel until acquisition of the radio wave condition of one communication channel as a candidate for use reaches a predetermined number of times (for example, three times) (step #14). If No, step #13).
The radio wave state acquisition unit 315 completes the acquisition of the radio wave state of the communication channel when the acquisition of the radio wave state of one communication channel expires a predetermined number of times, and completes the acquisition of the radio wave state of all of the plurality of use candidate communication channels. If not, the communication channel is switched to another candidate communication channel for which acquisition of the radio wave condition has not been completed, and the radio wave condition acquiring process is executed in the communication channel after switching (if Yes in step #14, step #15). No, step #16, step #13).

When the acquisition of the radio wave conditions for all of the plurality (three in this example) of use candidate communication channels is completed, the channel setting unit 312 executes channel determination processing, A communication channel in good condition (a communication channel with high radio wave intensity) is determined as a communication channel to be used, and set as the communication channel to be used (if Yes in step #15, step #17). Thus, the activation process of the remote control receiver 300 is completed. The radio wave state (radio wave state confirmation result) for each communication channel that is a candidate for use acquired by the radio wave state acquisition unit 315 is written by the communication state recording unit 313 to the receiver storage unit 303 as one of the past communication states. .

(Operation of emergency stop remote controller 200)
As shown in the flowchart of FIG. 7, the remote control unit 210 of the emergency stop remote controller 200 starts the startup process when a predetermined startup condition is satisfied, such as the emergency stop button 204 being operated before the power is turned on. When the power is turned on, the channel setting unit 212 executes a temporary channel setting process and sets one communication channel from a plurality of (seven in this example) communication channels as a communication channel to be used for wireless communication (step #21). , step #22). In the channel temporary setting process, the channel setting unit 212 sets the communication channel used immediately before as a communication channel to be used for wireless communication, or performs communication using one communication channel selected in a prescribed order or at random for wireless communication. Channels can be set.

When the communication channel is set in the channel provisional setting process, the communication confirmation unit 211 executes confirmation signal transmission process and establishes wireless communication using the communication channel (whether or not wireless communication is established). A confirmation signal for confirmation is transmitted (step #23). If no response signal is received from the remote control receiver 300 within the communication standby time in response to the confirmation signal, the channel setting unit 212 executes channel switching processing to switch the communication channel to another communication channel. 211 again executes the confirmation signal transmission process using the communication channel after switching (if No in step #24, steps #26 and #23).

When a response signal is received from the remote control receiver 300 in response to the confirmation signal within the communication standby time, the channel setting unit 212 executes channel determination processing, and selects the communication channel that transmitted the confirmation signal for wireless communication. The channel is determined and set (if Yes at step #24, step #25). Thus, the activation process of the emergency stop remote controller 200 is completed, and wireless communication between the emergency stop remote controller 200 and the remote controller receiver 300 is established.

Next, with reference to FIGS. 8 and 9, the emergency stop remote controller 200 and the remote control receiver 300 and the remote control receiver 300 and the remote control receiver 300 and the remote control receiver 200 and the remote control receiver 200 when wireless communication is not established and a communication interruption occurs while the emergency stop remote controller 200 and the remote controller receiver 300 are activated are shown in FIG. The operation of each of the machines 300 will now be described.

(Operation of remote control receiver 300)
As shown in the flowchart of FIG. 8, the communication confirmation unit 211 of the remote control receiver 300 executes communication confirmation processing during activation, and upon receiving a confirmation signal from the emergency stop remote controller 200, the emergency stop remote controller 200 (if Yes at step #31, step #32). This response signal includes information specifying the next candidate (switching destination) line channel to switch to when communication is interrupted, and the emergency stop remote controller 200 that has received the response signal is included in the response signal. Information for specifying the next candidate line channel is stored in the remote controller storage unit 203 .

If the confirmation signal is not received from the emergency stop remote control 200 even after the communication standby time has passed, the radio wave state acquisition unit 315 executes the radio wave state acquisition process and performs carrier sense using the communication channel in use. and obtains the radio wave intensity of the communication channel in use as the radio wave state (if No at step #31 and Yes at step #33, step #34).

After acquiring the radio wave state of the communication channel in use by the radio wave state acquisition process, the radio wave state determination unit 316 executes the radio wave state determination process to determine whether or not the communication channel is being used by an external device. (Step #35). In the radio wave state determination process, the radio wave state determination unit 316 compares the radio wave intensity acquired by the radio wave state acquisition unit 315 with a threshold value, and if the radio wave intensity value is greater than the threshold value, determines that the communication channel is not being used by an external device. If the radio wave intensity is smaller than the threshold, it is determined that the communication channel is being used by an external device.

When it is determined in the radio wave state determination process that the communication channel is being used by an external device, the channel setting unit 312 executes channel switching processing to switch the communication channel in use to the next candidate communication channel (step # 35, step #36).

After executing the channel switching process, if a confirmation signal is received from the emergency stop remote controller 200 before the communication standby time elapses, the communication confirmation unit 311 transmits a response signal to the emergency stop remote controller 200, and the communication state is changed. The recording unit 313 executes the communication state recording process and writes information on the failure of the original communication channel before switching (the number of communication interruptions, duration, etc.) in the receiver storage unit 303 (if Yes in step #37, step #38, step #39).

On the other hand, if the confirmation signal from the emergency stop remote controller 200 is not received even after the communication standby time has elapsed after the channel switching process is executed, the receiver control unit 310 determines the communication interruption and uses the CAN interface. Then, the communication interruption information is transmitted to the in-vehicle electronic control unit 18 of the tractor 1 . Then, the communication state recording unit 313 executes the communication state recording process, writes information on the communication channel failure after switching (number of communication interruptions, duration, etc.) to the receiver storage unit 303, and also writes the original information before switching. Information on the failure of the communication channel (the number and duration of communication interruptions) is written in the receiver storage unit 303 (if No at step #37 and Yes at step #41, steps #42, #43, and #39).
In this way, even if the communication waiting time has elapsed after the execution of the channel switching process, if the confirmation signal from the emergency stop remote controller 200 is not received, the channel switching process is repeated by confirming the interruption of communication. It is designed to prevent the communication interruption time from being prolonged due to

Further, when it is determined in the radio wave state determination process that the communication channel is not being used by an external device, the receiver control unit 310 confirms the communication interruption, and uses the CAN interface to notify the in-vehicle electronic control unit 18 of the tractor 1. Send loss of communication information. Then, the communication state recording unit 313 executes the communication state recording process and writes information on the failure of the original communication channel before switching (the number of communication interruptions and time) to the receiver storage unit 303 (No in step #35). If so, step #40, step #39).
Incidentally, the on-vehicle electronic control unit 18 of the tractor 1 performs automatic braking control to stop the tractor 1 when receiving the communication disruption information.

(Operation of emergency stop remote controller 200)
As shown in the flowchart of FIG. 9, during activation, the communication confirmation unit 211 of the emergency stop remote controller 200 executes communication confirmation processing, and the remote controller receiver 300 receives a predetermined time interval less than the communication waiting time. is transmitting a confirmation signal (step #41). The communication confirmation unit 211 of the emergency stop remote control 200 performs carrier sense immediately before transmitting the confirmation signal to the remote control receiver 300, and stores the radio wave intensity obtained by the carrier sense as the radio wave state in the remote control storage unit 203. remembered in

If no response signal is received from remote control receiver 300 even after the communication standby time has passed after the confirmation signal is transmitted to remote control receiver 300, radio wave state determination section 213 executes the radio wave state determination process and performs remote control storage. Based on the radio wave condition of the communication channel in use stored in the unit 203, it is determined whether or not the transmission of the confirmation signal has failed (if No at step #42 and Yes at step #43, step #44).
In the radio wave state determination process, the radio wave state determination unit 213 compares the radio wave intensity when the confirmation signal is transmitted with a threshold value. If it is determined that the transmission of the confirmation signal has succeeded, and if the radio wave intensity is weaker than the threshold, it is determined that the transmission of the confirmation signal has failed because the external device is using the communication channel.

If it is determined in the radio wave state determination process that the transmission of the confirmation signal has failed, the radio wave state determination unit 213 further determines whether or not the state of the transmission failure has continued for a predetermined period of time. If so, the channel setting unit 212 executes channel switching processing to switch from the communication channel in use to the next candidate communication channel stored in the storage unit (Yes in step #44, step #45). If Yes, step #46). Then, the process returns to step #41, and communication confirmation section 211 transmits a confirmation signal to remote control receiver 300 on the communication channel after switching. If a response signal is not received from the remote control receiver 300 within a predetermined time in response to the confirmation signal transmitted on the switched communication channel, the notification devices 6A and 6B notify the user of the interruption of communication.

[Another embodiment]
Another embodiment of the present invention will be described.
It should be noted that the configuration of each embodiment described below is not limited to being applied alone, but can also be applied in combination with the configuration of other embodiments.

(1) The configuration of the work vehicle can be modified in various ways.
For example, the work vehicle may be configured as a hybrid specification including the engine 9 and an electric motor for traveling, or may be configured as an electric specification including an electric motor for traveling instead of the engine 9. .
For example, the work vehicle may be configured as a semi-crawler specification that includes left and right crawlers instead of the left and right rear wheels 6 as the traveling unit.
For example, the work vehicle may be configured with a rear wheel steering specification in which the left and right rear wheels 6 function as steering wheels.

(2) In the above embodiment, the emergency stop remote controller 200 is shown as an example of a communication terminal for remote control, but a tablet personal computer, a smartphone, or the like may be used. The mobile communication terminal 3 provided in the system may also be used.

(3) In the above embodiment, the channel selection unit 314 is configured to select a plurality (three) of use candidate communication channels. It may be configured to select.

(4) In the above embodiment, the channel setting units 212 and 312 automatically set the communication channel to be used based on the past communication state for each channel stored in the communication state storage unit 303. However, the communication channel to be used may be set manually by the user or the like in consideration of the past communication state for each channel stored in the communication state storage unit 303 .

(5) In the above-described embodiment, as communication confirmation processing, transmission and reception of a confirmation signal (heartbeat signal) and a response signal (answerback signal) (the A thin line arrow) is performed at predetermined time intervals as an example, but various methods can be used to check whether or not wireless communication is established at predetermined time intervals.

1 tractor (work vehicle)
18 In-vehicle electronic control unit (automatic driving control unit)
200 Emergency stop remote control (communication terminal)
211, 311 communication confirmation unit 212, 312 channel setting unit 300 remote control receiver (vehicle side receiving unit)
303 receiver storage unit (communication state storage unit)
314 channel selection unit P target travel route

Claims (3)

an automatic travel control unit provided in a work vehicle and configured to automatically travel the work vehicle along a target travel route within a work area ;
a remote control communication terminal capable of transmitting a control signal for controlling travel of the work vehicle by wireless communication;
a vehicle-side receiving unit provided in the work vehicle for receiving the control signal transmitted from the communication terminal by wireless communication and transmitting the control signal to the automatic travel control unit;
a channel setting unit that sets a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit from a plurality of communication channels;
and a communication state storage unit that stores a past communication state of each of a plurality of communication channels for each of the work areas . an automatic travel control unit provided in a work vehicle and configured to automatically travel the work vehicle along a target travel route within a work area;
a remote control communication terminal capable of transmitting a control signal for controlling travel of the work vehicle by wireless communication;
a vehicle-side receiving unit provided in the work vehicle for receiving the control signal transmitted from the communication terminal by wireless communication and transmitting the control signal to the automatic travel control unit;
a channel setting unit that sets a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit from a plurality of communication channels;
a communication state storage unit that stores past communication states of each of a plurality of communication channels;
a channel selection unit that selects a use candidate communication channel from a plurality of communication channels for each work area based on the communication state stored in the communication state storage unit;
The automatic driving system, wherein the channel setting unit sets a communication channel to be used for wireless communication between the communication terminal and the vehicle-side receiving unit from among the use candidate communication channels selected by the channel selection unit. The channel selection unit is configured to select a plurality of use candidate communication channels from a plurality of communication channels,
a communication confirmation unit that performs communication confirmation processing for confirming at predetermined time intervals whether or not wireless communication between the communication terminal and the vehicle-side reception unit is established;
When wireless communication between the communication terminal and the vehicle-side receiving unit is not established in the communication confirmation process, the channel setting unit changes the setting of the communication channel from the currently set communication channel to another use candidate communication channel. 3. The automatic driving system according to claim 2, wherein the switching is performed.

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