JP6879896B2 - Satellite positioning system for work platforms - Google Patents

Description

The present invention relates to a satellite positioning system for a work vehicle capable of automatically traveling by mounting a positioning unit that calculates the position of the own vehicle using radio waves from a satellite and correction information.

This satellite positioning system belongs to the Global Navigation Satellite System (GNSS) that measures the position of the vehicle on the earth based on the received information of radio waves from multiple satellites, and belongs to the ground. It is composed of a base station unit installed at a predetermined position of the above and an in-vehicle positioning unit mounted on a moving body such as a vehicle. This system is a method in which correction information sent from a base station unit is used in a positioning calculation using satellite radio waves in an in-vehicle positioning unit, and higher positioning accuracy can be obtained as compared with a single positioning method. This method includes real-time kinematic GPS (hereinafter, abbreviated as RTK-GPS), differential GPS (hereinafter, abbreviated as DGPS), and the like. An example of applying RTK-GPS to an autonomous vehicle is disclosed in, for example, Patent Document 1. In the operation of the positioning method using RTK-GPS, a satellite positioning base station unit is installed near the work site where the autonomous vehicle is to travel. When the self-driving vehicle works at the next work site far away, the satellite positioning base station unit is removed, transported to the next work site, and installed in the appropriate place.

Japanese Unexamined Patent Publication No. 2016-31649

In the positioning calculation using satellite radio waves such as RTK-GPS, the satellite positioning method that uses the correction information sent from the base station unit can calculate the position of the own vehicle with high accuracy. In order to realize RTK-GPS, it is necessary to install an RTK base station near the work site to be worked. This installation is a troublesome task, and there is a problem that if the preset base station position mark or the like disappears, the base station position must be obtained again. Further, if the periphery of the work area is a slope or the like and the reception condition of the base station unit is poor, there is a problem that sufficient positioning accuracy cannot be obtained.
Therefore, there is a demand for a satellite positioning system capable of highly accurate positioning using satellite radio waves and correction information without installing a conventional base station unit at a predetermined location.

In the satellite positioning system according to the present invention for an automatically traveling work vehicle, positioning information received from satellites belonging to a plurality of global positioning satellite systems is combined to generate first satellite information and second satellite information. A positioning unit mounted on the work vehicle and calculating the position of the work vehicle using the second satellite information and correction information, and a terminal radio unit capable of wireless data communication with the in-vehicle communication unit mounted on the work vehicle. and a portable communication terminal having a preparative, the portable communication terminal includes a first calculator for calculating an absolute position based on the first satellite information, based on the second satellite information and the absolute position The second satellite information includes a second calculation unit that generates the correction information, and the second satellite information is information generated from the positioning information of the global positioning satellite system of more types than the first satellite information .

According to this configuration, the portable communication terminal has a function of calculating an absolute position based on the first satellite information (first calculation unit) and a correction for transmitting to a mobile station based on the absolute position and the second satellite information. It has a function to generate information (second calculation unit). Therefore, this portable communication terminal functions as a base station that gives correction information to the positioning unit mounted on the work vehicle as a mobile station. Since the first calculation unit of the portable communication terminal can calculate the position of the communication terminal with high accuracy based on the first satellite information, the position is when the second calculation unit creates the correction information. It can be used as an absolute position. Since the first calculation unit can always calculate the position of the communication terminal, even if the portable communication terminal moves, the absolute position of the moving place is calculated. That is, the portable communication terminal can be used as a non-fixed, mobile base station. Therefore, unlike the conventional RTK-GPS, it is not necessary to put a stake or the like as a mark at the installation location of the RTK base station. Further, depending on the situation, the base station can be arranged in the place where the reception condition of the satellite radio wave is the best each time.
Further, in the present invention, the combination of satellite information from a plurality of types of satellite positioning systems such as GPS, GLONASS, Galileo, BEIDOU (BeiDou satellite navigation system), and QZSS (quasi-zenith satellite) is combined with the first satellite information and the second satellite. It can be used as information. In a preferred embodiment of the present invention, the second satellite information is information generated from the positioning information of a larger variety of global positioning satellite systems than the first satellite information. Since the decrease in the number of satellites that can be received directly affects the positioning accuracy, it is important to always secure the number of satellites that enable accurate positioning. However, increasing the types of satellite information used is a factor in increasing costs. The second satellite information needs to be constantly used to calculate the position of the work platform as a mobile station. Furthermore, since the work vehicle moves in a wide area, it often enters the mountain shadow or the forest shadow, and at that time, the number of satellites that can be received decreases. From this, it is a preferable solution to this problem that the second satellite information is information from a larger number of types of global positioning satellite systems than the first satellite information. Similarly, the second calculation unit that uses the second satellite information can also calculate the correction information with high accuracy.

In one of the preferred embodiments of the present invention, the first calculation unit uses a virtual reference point method (abbreviated as VRS) real-time kinematic (abbreviated as RTK), that is, VRS-RTK. Is used to calculate the absolute position. In the virtual reference point method, a state is created as if there is a reference point in the immediate vicinity of the positioning point (position of the portable communication terminal), and positioning is performed by the principle of real-time kinematics, so the position accuracy is cm. Become a class. The first calculation unit can give the position calculated by using the virtual reference point method to the second calculation unit as the absolute position of the portable communication terminal as the base station of the RTK-GPS.

Specifically, the first satellite information is satellite information generated from the positioning information of two types of global positioning satellite systems, and the second satellite information is generated from the positioning information of three types of global positioning satellite systems. it is proposed that the satellite information. For example, the first satellite information may be information from two types of global positioning satellite systems, GPS and GLONASS, and the second satellite information may be information from three types of global positioning satellite systems, GPS, GLONASS, and BEIDOU. it can.

The satellite positioning system according to the present invention is suitable for calculating the position of an agricultural work vehicle that automatically travels in a field formed in a mountain shadow, a forest shadow, or a valley bottom. The field manager owns multiple types of farm work vehicles such as tractors, rice transplanters, and combines for field management, but it is convenient because one portable communication terminal can be used for these farm work vehicles. is there. From this, in one of the preferred embodiments of the present invention, the work vehicle is a farm work vehicle that automatically travels in a field, and the portable communication terminal monitors the automatic travel of the farm work vehicle from outside the vehicle. Brought by a person, the portable communication terminal executes at least a part of the control functions related to the work running of the farm work vehicle. The scope of application of the present invention also includes a work vehicle using the satellite positioning system according to the present invention.

It is a side view of a tractor which is an example of a work vehicle which adopted a satellite positioning system. It is a schematic diagram which shows the traveling route for the tractor which works and travels in the field as a work place. It is a functional block diagram for demonstrating the function of the control system of a tractor and a portable communication terminal in a satellite positioning system. It is a schematic diagram which shows the flow of information in a satellite positioning system.

Next, using the drawings, an aerial work platform, which is an example of an automatically traveling work vehicle adopting the satellite positioning system according to the present invention, will be described. Here, the farm vehicle is a tractor. FIG. 1 is a side view of a tractor cultivating a field as a work site. In the satellite positioning system of this embodiment, three types of global positioning satellite systems, that is, GPS, GLONASS, and BEIDOU, are the first global positioning satellite system G1, the second global positioning satellite system G2, and the third global positioning satellite system, respectively. It is used as G3.

The tractor is equipped with a rotary type tilling device 30 as a working device for performing ground work via a hydraulic lifting mechanism 31 at the rear portion of the vehicle body 10. The front wheel 11 functions as a steering wheel, and the traveling direction of the tractor is changed by changing the steering angle thereof. The steering angle of the front wheels 11 is changed by the operation of the steering mechanism 13. The steering mechanism 13 includes a steering motor 14 for automatic steering. During manual driving, the front wheels 11 are steered by operating the steering wheel 22 arranged in the driver's cab 20. A general-purpose terminal 23 is installed in the driver's cab 20. The general-purpose terminal 23 is provided with a touch panel 23a so that various commands can be input by the driver (which serves as a monitor during automatic driving) and various information is notified to the driver.

In this tractor, an in-vehicle satellite positioning unit 80 as a positioning unit is mounted on the upper part of the cabin 21 of the tractor in order to realize the own vehicle position detection function. The in-vehicle satellite positioning unit 80 can receive signals from satellites AS belonging to the first global positioning satellite system G1, the second global positioning satellite system G2, and the third global positioning satellite system G3. An inertial navigation unit incorporating a gyro acceleration sensor or a magnetic direction sensor may be provided to supplement the vehicle position and vehicle body direction calculated based on the positioning data from the vehicle-mounted satellite positioning unit 80.

Since the in-vehicle satellite positioning unit 80 generates positioning data using a real-time kinematic method, the portable communication terminal 6 (hereinafter, simply abbreviated as the communication terminal 6) that functions as a mobile base station is used in the field. It is placed around. In FIG. 1, since the observer brings the portable communication terminal 6, he / she can move to a place where the radio wave condition from the satellite AS is good. Since the communication terminal 6 has a function as a base station in the real-time kinematic system, the calculated correction information (correction data) is transmitted to the in-vehicle satellite positioning unit 80 using wireless communication (WiFi).

This tractor can automatically travel along a travel path generated based on the shape of the field. The travel route illustrated in FIG. 2 is a travel route that is often used in field tillage work, and is substantially an inner travel route consisting of a straight route SL and a U-turn route TL connecting the straight routes to each other. It is composed of a circuit traveling path CL that orbits the boundary region of the field including the U-turn path TL. The field is divided into an outer peripheral region HA and a central region CA located inside the outer peripheral region, a straight path SL is set in the central region CA, and a U-turn path TL and a circuit traveling path CL are set in the outer peripheral region. Set. The outer peripheral region is an region for securing the space required for the U-turn path TL, and the width thereof is determined based on the working width of the work vehicle and the minimum turning radius. The interval of the straight route in the inner traveling route is the working width of the work vehicle, specifically, the working width considering the overlap. A non-working run is performed in which the tiller 30 is raised until the tractor enters from the doorway and reaches the first straight path SL in the inner run path set in the central region CA. When entering the straight route SL, a working run in which the tilling device 30 is lowered is performed, and a non-working running in which the tilling device 30 is raised is performed only while traveling on the U-turn route TL. When the work run of the central region CA is performed, the work run of the outer peripheral region HA is performed along the orbital travel path CL.

FIG. 3 shows a functional block diagram of the satellite positioning system and the control system of the tractor. The control unit 5, which is a core element of the control system of the tractor, includes an output processing unit 7 and an input processing unit 8 as input / output interfaces. In order to perform wireless communication with different types of wireless communication devices, an in-vehicle wireless unit 70 as an in-vehicle communication unit capable of operating in a plurality of communication methods is connected to the control unit 5. The in-vehicle wireless unit 70 can also perform wireless data communication with the terminal wireless unit 6D of the communication terminal 6. Further, the control unit 5 is connected to the in-vehicle satellite positioning unit 80.

The output processing unit 7 is connected to the input interfaces of the vehicle traveling equipment group 71, the working equipment group 72, and the general-purpose terminal 23. The vehicle traveling device group 71 includes control devices related to vehicle traveling, such as an engine control device, a shift control device, a braking control device, and a steering control device. In this embodiment, the working device group 72 includes a power control device such as a PTO clutch that turns on and off the power transmission to the cultivating device 30, an elevating cylinder control device of the elevating mechanism 31 that raises and lowers the cultivating device 30 and the like. ing.

A traveling system detection sensor group 81, a working system detection sensor group 82, a traveling mode switch 83, an output interface of a general-purpose terminal 23, and the like are connected to the input processing unit 8. The travel mode switch 83 is a switch that selects either an automatic travel mode in which the vehicle travels by automatic steering or a manual steering mode in which the vehicle travels by manual steering. For example, by operating the traveling mode switch 83 while traveling in the automatic steering mode, the vehicle can be switched to traveling by manual steering, and by operating the traveling mode switch 83 while traveling in the manual steering mode, the vehicle can be automatically steered. Can be switched to running. The traveling system detection sensor group 81 includes sensors that detect the engine speed, the accelerator position, the brake position, the steering position, and the like. The work system detection sensor group 82 includes a sensor that detects the driving state and the posture of the tilling device 30.

The control unit 5 includes a work travel control module 50, a vehicle position calculation unit 57, and an external terminal management unit 58. The own vehicle position calculation unit 57 calculates the own vehicle position, which is the coordinate position (map coordinates or field coordinates) of the vehicle body 10, based on the positioning data sequentially sent from the vehicle-mounted satellite positioning unit 80. The external terminal management unit 58 exchanges data with the general-purpose terminal 23 and the communication terminal 6 and executes necessary processing. In addition, the external terminal management unit 58 generates information to be notified to the driver and the observer, and notifies the driver or the observer by a visual method or an auditory method through the general-purpose terminal 23.

The work travel control module 50 includes a travel control unit 51, a work control unit 52, an engine control unit 53, an automatic work travel command unit 54, and a travel route setting unit 55. The travel control unit 51 controls the vehicle travel equipment group 71 such as the steering motor 14. This tractor can travel in both automatic driving (automatic steering) and manual driving (manual steering). Therefore, the travel control unit 51 has a manual travel control function and an automatic travel control function. When the manual driving control function is executed, the vehicle traveling device group 71 is controlled based on the operation by the driver. When the automatic travel control function is executed, the travel control unit 51 controls the vehicle travel equipment group 71 based on the automatic steering command given from the automatic work travel command unit 54. The work control unit 52 gives a work control signal to the work device group 72 in order to control the movement of the tilling device 30. The engine control unit 53 gives an engine control signal to the operating equipment of the engine.

The travel route setting unit 55 sequentially selects and sets a target travel route portion in automatic travel from the travel routes developed in the memory. The travel route set by the travel route setting unit 55 can be used for guidance for the work vehicle to travel along the travel route even in manual travel.

The automatic work travel command unit 54 calculates the directional deviation and the positional deviation between the traveling route and the own vehicle position calculated by the own vehicle position calculation unit 57 by the traveling route setting unit 55, and the directional deviation and the positional deviation are calculated. An automatic steering command for eliminating the above is generated and given to the traveling control unit 51. Further, the automatic work travel command unit 54 generates a set vehicle speed command based on a vehicle speed value set in advance and gives the set vehicle speed command to the travel control unit 51. Further, the automatic work travel command unit 54 can also give a work device operation command to the work control unit 52 according to the position of the own vehicle and the travel state of the own vehicle.

The communication terminal 6 is substantially a computer having a wireless communication function such as a tablet computer, and is provided with a touch panel 6C, a terminal wireless unit 6D, and the like as standard functions. Further, the communication terminal 6 is provided with a satellite positioning module 6A and an automatic traveling management module 6B.

As shown in FIG. 4, the satellite positioning module 6A includes a terminal satellite positioning unit 60, a first calculation unit 61, and a second calculation unit 62. In this embodiment, the terminal satellite positioning unit 60 is a first satellite which is positioning information from two types of global positioning satellite systems, GPS (first global positioning satellite system G1) and GLONASS (second global positioning satellite system G2). Information and positioning information from three types of global positioning satellite systems: GPS (1st global positioning satellite system G1), GLONASS (2nd global positioning satellite system G2), and BEIDOU (3rd global positioning satellite system G3). 2 Has a function of receiving satellite information. The first calculation unit 61 has a function of calculating the absolute position which is the current map coordinate position of the communication terminal 6 as a base station based on the first satellite information. Since the first calculation unit 61 calculates the absolute position using the real-time kinematic of the virtual reference point method, data is exchanged with the VRS-RTK center 100 via the terminal radio unit 6D. The first calculation unit 61 receives VRS data by sending a VRS request to the VRS-RTK center 100. Since the VRS data includes the coordinate position of the virtual reference point, the absolute position of the communication terminal 6 is calculated from the coordinate position of the virtual reference point and the first satellite information and given to the second calculation unit 62.

The second calculation unit 62 has a function of calculating correction information based on the absolute position from the first calculation unit 61 and the second satellite information. The calculated correction information is given to the vehicle-mounted satellite positioning unit 80 via the terminal radio unit 6D and the vehicle-mounted radio unit 70. The in-vehicle satellite positioning unit 80 generates positioning data (indicating the position of the antenna of the in-vehicle satellite positioning unit 80) by the RTK-GPS method based on the received second satellite information and the correction information, and owns the vehicle. It is given to the position calculation unit 57. The own vehicle position calculation unit 57 calculates the own vehicle position (arbitrary position of the vehicle body 10) from the positioning data.

The automatic travel management module 6B includes a field management unit 63, a work management unit 64, a travel route generation unit 65, and a remote control control unit 66.

The field management unit 63 manages map data indicating the location on the map of the field to be worked, field outline data indicating the outer shape of the field, and entrance / exit position data indicating the position and shape of the entrance / exit of the field. These data are input via communication, portable memory, or the like. The work management unit 64 stores work history information related to the work performed on the field so far so that it can be extracted. The work history information includes the travel route and travel locus used in the work, and the radio wave reception status from each satellite AS of the global positioning satellite system.

The travel route generation unit 65 generates a straight route SL, a U-turn route TL, and a circuit travel route CL based on the field outline data and the entrance / exit position data indicating the position and shape of the entrance / exit of the field.

The travel route generation unit 65 reads out the external shape data of the field from the input field information, generates an appropriate travel route in this field, and manages it. At that time, it is also possible to generate a traveling route based on the basic initial parameters input by the driver. Further, the travel route generation unit 65 can download and manage the travel route generated by another computer instead of generating a new travel route. In any case, the travel route managed by the travel route generation unit 65 is sent to the control unit 5 of the tractor, expanded in the memory, and used by the travel route setting unit 55.

The remote controller control unit 66 is an application for using the communication terminal 6 as a remote controller for controlling a tractor. As a result, the observer holding the communication terminal 6 can perform an emergency stop of the tractor, a temporary stop of the running, a start of running, and the like from a position away from the tractor.

[Another Embodiment]
(1) In the above-described embodiment, GPS, GLONASS, and BEIDOU are used as the first global positioning satellite system G1, the second global positioning satellite system G2, and the third global positioning satellite system G3, respectively, but other than that. A global positioning satellite system, such as QZSS, may be used. Further, the first satellite information and the second satellite information may be any combination of satellite information from satellite AS belonging to various global positioning satellite systems.

(2) In the above-described embodiment, the communication terminal 6 (portable communication terminal) is a tablet-type communication terminal, but it may be a communication terminal such as a smartphone, or a combination of a satellite receiving unit and a communication terminal. But it may be. Further, the communication terminal 6 may be mounted on a vehicle instead of being brought by a person.

(3) The division of each functional part in the functional block diagram shown in FIG. 3 is an example for making the explanation easy to understand, and various functional parts may be integrated or a single functional part may be divided into a plurality of parts. You are free to do it.

(4) In the above-described embodiment, the tractor equipped with the tilling device 30 as the working device is taken up as the work vehicle, but the tractor equipped with the working device other than the tilling device 30 and further, the agricultural work such as the combine harvester and the rice transplanter. The present invention can also be applied to machines, lawnmowers, construction machines and the like.

The configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

The present invention is applicable to a satellite positioning system for calculating the own vehicle position of a work vehicle capable of automatically traveling.

5: Control unit 57: Own vehicle position calculation unit 6A: Satellite positioning module 6: Portable communication terminal (communication terminal)
60: Terminal satellite positioning unit 61: 1st calculation unit 62: 2nd calculation unit 6B: Automatic travel management module 63: Field management unit 64: Work management unit 65: Travel route generation unit 66: Remote control control unit 6D: Terminal radio unit 70: In-vehicle wireless unit (communication unit)
80: In-vehicle satellite positioning unit AS: Satellite G1: 1st global positioning satellite system G2: 2nd global positioning satellite system G3: 3rd global positioning satellite system 100: VRS-RTK center

Claims (4)

A satellite positioning system for self-driving work platforms
Positioning information received from satellites belonging to a plurality of global positioning satellite systems is combined to generate first satellite information and second satellite information.
A positioning unit mounted on the work vehicle and calculating the position of the work vehicle using the second satellite information and correction information.
A portable communication terminal equipped with an in-vehicle communication unit equipped on the work vehicle and a terminal wireless unit capable of wireless data communication is provided.
The portable communication terminal includes a first calculator for calculating an absolute position based on the first satellite information, and a second calculation unit that generates the correction information based on the absolute position and the second satellite information Prepare ,
The second satellite information is a satellite positioning system that is information generated from the positioning information of the global positioning satellite system of more types than the first satellite information. The satellite positioning system according to claim 1, wherein the first calculation unit uses a virtual reference point method real-time kinematic to calculate the absolute position. The first satellite information is information generated from the positioning information of two types of global positioning satellite systems , and the second satellite information is information generated from the positioning information of three types of global positioning satellite systems. Item 2. The satellite positioning system according to Item 1 or 2. The work vehicle is an agricultural work vehicle that automatically travels in a field, the portable communication terminal is brought by a monitor who monitors the automatic travel of the agricultural work vehicle from outside the vehicle, and the portable communication terminal is an automatic operation of the agricultural work vehicle. The satellite positioning system according to any one of claims 1 to 3 , which executes at least a part of a driving control function.

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