JP2020144014A - Working machine - Google Patents

Abstract

To suppress lowering of positioning accuracy by a GNSS receiver, even if reducing the number of satellites to be used when generating correction data.SOLUTION: A controller 70 of a hydraulic shovel 1: calculates a mask range 58 where a working device may be an obstacle when two antennas 50 receive satellite signals from a plurality of positioning satellites, on the basis of attitudes of a working machine 6 and a revolving superstructure 3 detected by attitude sensors 75 and 23, and position coordinates and an azimuth angle calculated by a receiver 51; selects the number Nd of transmittable positioning satellites out of a plurality of positioning satellites excluding positioning satellites located at the mask range 58 to create a positioning satellite list Ld; and transmits the positioning satellite list Ld to a reference station. The correction data is generated by the reference station using satellite signals of a plurality of positioning satellites on the positioning satellite list Ld, and the receiver 51 calculates the position coordinates and azimuth angle based on the satellite signals of the plurality of positioning satellites on the positioning satellite list Ld and the correction data.SELECTED DRAWING: Figure 4

Description

The present invention relates to a working machine equipped with a GNSS receiver.

For work machines (for example, hydraulic excavators) equipped with an articulated front work device configured by connecting multiple front members such as booms, arms, and buckets, for Global Navigation Satellite System (GNSS). The machine guidance function that calculates the tip position of the front work device using the receiver and attitude sensor of the above and displays the tip position of the front work device together with the target construction surface on the monitor in the cab, and the tip position of the front work device. Some have a machine control function that controls the operation of the front work device (that is, the operation of the actuator that drives the front member) so that the stool does not enter below the target construction surface.

In this type of hydraulic excavator, RTK (Real Time Kinematic) -GNSS positioning is often used because it is necessary to measure the vehicle body position with high accuracy by GNSS. In this positioning method, correction data is wirelessly transmitted from a GNSS reference station installed at a point (known point) whose position coordinates are known, and the mobile station that receives the correction data calculates the relative position from the reference station, and the coordinates of the known point. In addition, the coordinates of the mobile station are obtained with high accuracy. Here, if the mobile station is mounted on the work machine, the position of the work machine can be measured. Also, instead of setting GNSS reference points at known points, use the VRS (Virtual Reference Station) service that generates virtual reference points based on data from multiple electronic reference points and distributes correction data. Similarly, highly accurate positioning is possible.

As a technique using RTK-GPS, Patent Document 1 describes communication between a plurality of satellite positioning means as a fixed station for transmitting correction data and a plurality of other satellite positioning means as a mobile station for receiving correction data. A server is installed in the IP-VPN communication network, and each satellite positioning means is a satellite positioning unit that receives radio waves from artificial satellites, a communication unit that communicates between each satellite positioning unit, and a satellite. It is equipped with at least a control unit that controls the positioning unit and the communication unit, and the control unit of the mobile station receives the obstacle information registered in the control unit of each satellite positioning means of the fixed station and receives the obstacle information of the plurality of fixed stations. An RTK-GPS surveying system that makes it possible to select a fixed station that transmits optimal correction data is disclosed.

JP-A-2007-309667

By the way, the content of correction data transmitted wirelessly from a reference station is standardized, and the RTCM (Radio Technical Commission for Maritime Services) method is often used. This correction data includes the observation results of each GNSS satellite received by the reference station, and the amount of correction information data increases as the number of satellites increases. Initially, the only GNSS satellites were GPS satellites, but in recent years the number of satellites has been increasing due to the increase in systems such as GLONASS, Galileo, Hokuto, and Michibiki.

In addition, since data communication services that use mobile phone networks provide best-effort services, the amount of data that can be communicated can fluctuate per unit time. Therefore, if the work machine exists in a place where the communication environment is poor and the radio waves are hard to reach, the amount of data that can be transmitted may be significantly reduced. In addition, the amount of data that can be transmitted by the radio that transmits the correction data is also decreasing. The technical background is that radios with almost the same wireless specifications and capable of voice calls such as transceivers use voice compression technology and narrow the band from the viewpoint of effective use of frequencies.

Here, if the amount of correction data exceeds the amount of data that can be transmitted by the radio, there arises a problem that the correction data cannot be transmitted in time and position measurement becomes impossible.

To solve this problem, a method of limiting the number of satellites used to generate correction data to a predetermined value can be considered. However, even if the number of satellites is limited to a predetermined value, the amount of corrected data does not always fall within the amount that can be transmitted. In addition, since it is generally possible to perform positioning using a large number of satellites with higher accuracy, there is also a demand to avoid extremely reducing the number of satellites.

Furthermore, in GNSS positioning, the accuracy deteriorates when an obstacle exists between the satellite and the GNSS antenna. When a GNSS antenna is installed on a work machine, the boom or arm, which is the operating part, may be located higher than the GNSS antenna and become an obstacle. For this reason, when the number of satellites used to generate correction data at the reference station is limited, if the signal from a small number of satellites after the limit is blocked by the boom or arm, compared to before the limit on the number of satellites. Accuracy can be significantly reduced.

The present invention has been made in view of the above problems, and an object of the present invention is a work machine capable of suppressing a decrease in positioning accuracy due to a GNSS receiver even if the number of satellites used for generating correction data is reduced. Is to provide.

The present application includes a plurality of means for solving the above problems. For example, a working device attached to a swivel body, an attitude sensor for detecting the posture of the working device and the swivel body, and an attitude sensor for detecting the posture of the working device and the swivel body. Two antennas for receiving satellite signals from a plurality of positioning satellites, a radio for receiving correction data generated by a reference station based on satellite signals received from the plurality of positioning satellites, and the two antennas. Based on the received satellite signal and the correction data received by the radio, the receiver that calculates the position coordinates of at least one of the two antennas and the azimuth angle of the swivel body, and the receiver In a work machine including a controller that calculates the position coordinates and azimuth angle of the work device based on the calculated position coordinates of at least one antenna and the azimuth angle of the swivel body, the controller is operated by the attitude sensor. Based on the detected postures of the working device and the swivel body, the position coordinates of the at least one antenna calculated by the receiver, and the azimuth angle of the swivel body, the at least one antenna performs the plurality of positionings. A list of first positioning satellites that calculates the range in which the working device can be an obstacle when receiving a satellite signal from the satellite, and excludes the positioning satellites located in the range in which the working device can be an obstacle from the plurality of positioning satellites. Is created, and from a plurality of positioning satellites listed in the first positioning satellite list, a number of positioning satellites capable of generating correction data for the amount of data that the reference station can transmit to the radio by wireless communication is selected. This creates a second positioning satellite list, transmits the second positioning satellite list to the reference station via the radio, and the correction data received by the radio is included in the second positioning satellite list. It is generated using satellite signals transmitted from a plurality of positioning satellites, and the receiver is a satellite signal transmitted from a plurality of positioning satellites on the second positioning satellite list and the radio. Based on the correction data received in, the position coordinates of the at least one antenna and the azimuth angle of the swivel body are calculated.

According to the present invention, the correction data is generated by excluding the signal from the satellite at the position where the working device can be an obstacle, so that stable positioning can be performed even in a situation where positioning is impossible or accuracy is deteriorated in the past. It will be possible.

It is a side view of an example of the work machine and the GNSS reference station which concerns on 1st Embodiment. It is a functional block diagram of the vehicle-mounted controller 70 mounted on the hydraulic excavator of FIG. 1 and the reference station controller 82 installed on the GNSS reference station. This is a processing flow of the vehicle-mounted controller 70 (working machine position / posture calculation unit 53) according to the first embodiment. This is a processing flow of the vehicle-mounted controller 70 (satellite selection calculation unit 52) according to the first embodiment. A table summarizing an example of the contents of the turning flag, the number of satellites flag, and the satellite number output from the radio 7 of the hydraulic excavator 1 to the reference station 8 when passing through the three STEPs 129, 130, and 131 of FIG. This is an example of the receiving satellite list La according to the first embodiment. This is a processing flow of the reference station controller 82 when a signal (swivel flag, number of satellite flags, satellite number) from the radio 7 is received by the radio 87. This is a processing flow of the reference station controller 82 when data is received from the GNSS receiver 81. This is an example of a display screen of a monitor 60 that displays the positional relationship between the hydraulic excavator 1 and the construction target surface 91. This is an example of a display screen of a monitor 60 that displays the positional relationship between the bucket 6C and the construction target surface 91. It is a side view which looked at the hydraulic excavator 1 at the time of execution of STEP 102 from the direction orthogonal to the operation plane of the front work apparatus 6. It is a figure which showed the mask range 58 when the azimuth angle of the front working apparatus 6 seen from the GNSS antenna 50B is 125 degrees, and the elevation angle θ50B is 30 degrees. This is a processing flow of the vehicle-mounted controller 70 (satellite selection calculation unit 52) according to the second embodiment. In the third embodiment, it is a processing flow of the reference station controller 82 when the signal (swivel flag, number of satellite flags, satellite number) from the radio 7 is received by the radio 87. In the third embodiment, it is a processing flow of the reference station controller 82 when data is received from the GNSS receiver 81. This is an example of the celestial sphere display of the GNSS satellite. It is a detailed processing flow of STEP131 in FIG. 4 which concerns on 1st Embodiment. It is a detailed processing flow of STEP131 in FIG. 4 which concerns on 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiment applies the present invention to a crawler type hydraulic excavator as a work machine, and has a machine guidance function for displaying the positional relationship between the bucket tip and the construction target surface on a monitor in the cab. .. In each figure, the same parts are designated by the same reference numerals, and duplicate explanations are omitted as appropriate.

(First Embodiment)
<Target machine>
FIG. 1 is a side view of the hydraulic excavator 1 and the GNSS reference station 8 according to the first embodiment. The hydraulic excavator 1 shown in this figure has a crawler type traveling body (lower traveling body) 2, a swivel body (upper swivel body) 3 rotatably attached to the upper part of the traveling body 2, and one end (base end). It is provided with a front working device (sometimes referred to simply as a "working device") 6 including an articulated link mechanism attached to the swivel body 3.

The front working device 6 has a boom 6A having one end connected to the swivel body 3, an arm 6B having one end connected to the other end of the boom 6A, and a bucket 6C having one end connected to the other end of the arm 6B. Each of these front members 6A, 6B, and 6C is configured to rotate in the vertical direction. Further, boom cylinders 11A, arm cylinders 11B, and bucket cylinders 11C are provided as drive actuators for rotating the front members 6A, 6B, and 6C. The swivel body 3 is swiveled around the swivel center axis O by a swivel motor (not shown).

The swivel body 3 includes an operating device (not shown) operated by an operator, a driver's seat 4 provided with a monitor 60 for displaying the positional relationship between the bucket 6C and the construction target surface, and a plurality of positioning satellites (GNSS). Two GNSS antennas 50A and 50B for receiving satellite signals from (satellite), and radios 7 and 2 for receiving GNSS correction data generated by the reference station 8 based on satellite signals received from a plurality of positioning satellites. Based on the satellite signal received by the two GNSS antennas 50A and 50B and the GNSS correction data received by the radio 7, the position coordinates of the two GNSS antennas 50A and 50B in the geographic coordinate system (global coordinate system) and the swivel body. Based on the position coordinates of the GNSS receivers 51 (51A, 51B) that calculate the azimuth angle of 3 and the two GNSS antennas 50A and 50B calculated by the GNSS receivers 51A and 51B, and the azimuth angle of the swivel body 3. An in-vehicle controller 70, which is a computer that calculates the position coordinates of the front members 6A, 6B, and 6C constituting the front work device 6, is provided. In this embodiment, two GNSS receivers 51A and 51B corresponding to the two GNSS antennas 50A and 50B are mounted, but the positions of the two GNSS antennas 50A and 50B and the azimuth angle of the swivel body 3 are one. A configuration may be adopted in which calculation is performed by a GNSS receiver.

<GNSS Standard Station>
Next, the GNSS reference station 8 that wirelessly transmits the GNSS correction data to the radio 7 of the hydraulic excavator 1 will be described. The GNSS reference station 8 whose coordinate position in the geographic coordinate system is known includes a GNSS antenna 80 for receiving satellite signals from a plurality of positioning satellites (GNSS satellites) and a GNSS based on the satellite signals received by the GNSS antenna 80. A GNSS receiver 81 that calculates the position coordinates of the antenna 80 in the geographic coordinate system, and a reference station controller 82 that generates GNSS correction data for wireless transmission to the radio 7 based on the satellite signal received by the GNSS antenna 80. A list of positioning satellites used when the reference station controller 82 generates GNSS correction data while transmitting the GNSS correction data generated by the reference station controller 82 to the radio 7 (satellite list Ld (second positioning satellite list) described later). ) Is received from the radio 7, the radio 87 is provided. The GNSS receiver 81 connected to the GNSS reference station antenna 80 wirelessly transmits GNSS correction data from the radio 87 via the reference station controller 82. Further, the satellite list Ld received by the radio 87 from the radio 7 includes a plurality of GNSS satellites suitable for GNSS positioning, and the satellite list Ld is output to the reference station controller 82.

<In-vehicle controller, reference station controller>
FIG. 2 is a functional block diagram of the vehicle-mounted controller 70 mounted on the hydraulic excavator of FIG. 1 and the reference station controller 82 installed on the GNSS reference station.

The in-vehicle controller 70 includes an arithmetic processing unit (for example, a CPU (not shown)), a storage device (for example, a semiconductor memory such as a ROM or RAM) 71, and an interface (input / output device (not shown)) for storage. The program (software) stored in advance in the device 71 is executed by the arithmetic processing unit, and the arithmetic processing unit performs arithmetic processing based on the data specified in the program and the data input from the interface, and from the interface. Output a signal (calculation result) to the outside. The reference station controller 82 and the GNSS receivers 51A, 51B, 81 can also be provided with the same type of hardware as the in-vehicle controller 70.

The in-vehicle controller 70 is connected to the GNSS receivers 51A and 51B, the attitude sensors 75A, 75B, 75C, 23, the monitor 60, and the radio 7 via an interface.

<Posture sensor>
The hydraulic excavator 1 is provided with a plurality of posture sensors 75A, 75B, 75C, 23 for detecting the postures of the front working device 6 and the swivel body 3. In this embodiment, an inertial measurement unit (IMU) capable of detecting an angle (or angular velocity) and acceleration is used for each attitude sensor. Among these posture sensors, the boom 6A is equipped with the boom posture sensor 75A, the arm 6B is equipped with the arm posture sensor 75B, and the bucket 6C is equipped with the bucket posture sensor 75C (see FIG. 1). Further, a swivel body posture sensor 23 is attached to the swivel body 3 (see FIG. 1), whereby the tilt angle, the swivel speed, and the swivel angle of the swivel body 3 are measured. The outputs of the attitude sensors 75A, 75B, 75C, and 23 are input to the vehicle-mounted controller 70 via the connection line. As the posture sensor of the front work device 6, an angle sensor that detects the rotation angle of each front member may be used.

<Car body GNSS device>
The two GNSS receivers 51A and 51B measure the positions of the GNSS antennas 50A and 50B by using the satellite signals of a plurality of positioning satellites which are the basis of the GNSS correction data received by the radio 7 from the reference station 8. .. That is, the positioning satellites used by the GNSS receivers 51A and 51B on the hydraulic excavator 1 side for positioning and the positioning satellites used by the GNSS receiver 81 on the reference station 8 side for generating correction data match.

In the present embodiment, of the two GNSS receivers 51A and 51B, the GNSS correction data received by the radio 7 from the reference station 8 is sent from one GNSS receiver 51B to the other GNSS receiver 51A, and is called a moving base RTK. The relative position between the two GNSS antennas 50A and 50B is calculated by the method. As a result, the direction and distance (that is, vector) from one GNSS antenna 50B to the other GNSS antenna 50A can be calculated. Since the positions where the two GNSS antennas 50A and 50B are fixed to the swivel body 3 are the default positions and the coordinate values in the vehicle body coordinate system are known, the azimuth angle of the swivel body 3 can be calculated. If the moving base RTK is used, the azimuth angle of the swivel body 3 can be calculated by calculating the position of one of the two GNSS antennas 50A and 50B.

The radio 7 wirelessly receives GNSS correction data from the reference station 8 (radio 87) outside the vehicle body. The GNSS correction data received by the radio 7 is sent to one of the GNSS receivers 51B. The GNSS receiver 51B uses a technique called RTK to travel from the GNSS receiver 51B to the reference station GNSS antenna 80 based on the GNSS correction data received from the radio 7 and the satellite signal received by the GNSS antenna 50B. And calculate the distance. Since the GNSS correction data includes the position information (coordinate position) of the GNSS antenna 80 in the geographic coordinate system, the position (coordinate position) of the reference station GNSS antenna 50B can be measured with high accuracy by the GNSS receiver 51B.

Needless to say, the two GNSS antennas 50A and 50B may be arranged in reverse, and the same applies to the two GNSS receivers 51A and 51B. Further, the GNSS receivers 51A and 51B may be integrated as a receiver.

The storage device 71 of the vehicle-mounted controller 70 stores the construction target surface data 55 that defines the position of the construction target surface that is the construction target of the hydraulic excavator 1.

The in-vehicle controller 70 functions as a satellite selection calculation unit 52 and a work machine position / attitude calculation unit 53 by executing a program stored in the storage device 71.

The work machine position / attitude calculation unit 53 includes the coordinate positions of the two GNSS antennas 50A and 50B in the geographic coordinate system obtained from the calculation results of the GNSS receivers 51A and 51B, the azimuth angle of the swivel body 3, and each attitude sensor. Based on the information input from 75A, 75B, 75C, 23, the coordinate position of the hydraulic excavator 1 in the site coordinate system (plane orthogonal coordinate system) in which the construction target surface data is defined, and each front in the same coordinate system. The coordinate positions of the members 6A, 6B, 6C (attitude information of each front member 6A, 6B, 6C in the field coordinate system) are calculated. If the construction target surface data of the storage device 71 is cut by the surface passing through the toe position of the bucket 6C, the shape of the construction target surface to be excavated by the bucket 6C can be acquired. Then, if the shape of the acquired construction target surface and the positional relationship of the bucket 6C are displayed on the monitor 60, the machine guidance function can be exhibited.

The satellite selection calculation unit 52 works with the position information of each positioning satellite acquired from the satellite signals by the GNSS receivers 51A and 51B (that is, the azimuth and elevation angles of the positioning satellites based on the two GNSS antennas 50A and 50B). The azimuth angle of the front work device 6 (swivel body 3) calculated by the machine position / attitude calculation unit 53 and the coordinate positions of the front members 6A, 6B, 6C (the attitudes of the front members 6A, 6B, 6C in the world coordinate system). Information) is acquired, and while considering the acquired information and the conditions described later, a positioning satellite suitable for GNSS positioning is selected from a plurality of positioning satellites capable of receiving satellite signals by the two GNSS antennas 50A and 50B. Select multiple. The plurality of positioning satellites selected here are specified by satellite numbers (identification information) preset for each positioning satellite. The positioning satellite selected by the satellite selection calculation unit 52 is transmitted to the reference station 8 via the radio 7.

<Position and posture calculation processing of work machine by in-vehicle controller 70>
FIG. 3 is a processing flow of the vehicle-mounted controller 70 (working machine position / posture calculation unit 53) according to the first embodiment. The in-vehicle controller 70 (working machine position / posture calculation unit 53) repeatedly executes the flow shown in FIG. 3 at a predetermined control cycle.

When the process is started, the work machine position / attitude calculation unit 53 acquires the coordinate position of the GNSS antenna 50B calculated by the GNSS receiver 51B and the azimuth angle of the swivel body 3 calculated by the GNSS receiver 51A (STEP 100). ), The boom posture sensor 75A, the arm posture sensor 75B, the bucket posture sensor 75C, and the swivel posture sensor 23 obtain their detected values (STEP101).

In STEP 102, the work machine position / attitude calculation unit 53 receives the position information and attitude information of the front members 6A, 6B, 6C in the field coordinate system and the position information of the GNSS antenna 50B based on the information acquired in STEP 100, 101. Is calculated, and based on the calculation results, the elevation angle θ50B when the uppermost part of the front working device 6 is viewed from the position of the GNSS antenna 50B is calculated. The elevation angle θ50B will be described with reference to FIG. FIG. 11 is a side view of the hydraulic excavator 1 during execution of STEP 102 from a direction orthogonal to the operation plane of the front work device 6. As shown in this figure, the elevation angle θ50B is an angle formed by the horizontal line 20 and the tangent line 21. The horizontal line 20 is a horizontal line passing through the GNSS antenna 50B, and the tangent line 21 is a straight line having the largest angle with the horizontal line 20 among the straight lines passing through the GNSS antenna 50B and in contact with the front working device 6 in FIG. In the range where the elevation angle with respect to the GNSS antenna 50B is θ50B or less (shaded portion in FIG. 11), the front working device 6 may become an obstacle when the GNSS antenna 50B receives satellite signals from a plurality of positioning satellites.

In STEP 103, the work machine position / attitude calculation unit 53 calculates the turning speed of the turning body 3 based on the azimuth angle of the turning body 3 acquired in STEP 100 and the measured value of the turning body posture sensor 23 acquired in STEP 101. To do. Here, the turning speed of the turning body 3 can be calculated from the time change of the azimuth angle of the turning body 3, and the turning body posture sensor 23 can also output the turning speed. In this embodiment, either one of the turning speeds may be used, or the turning speed may be averaged to obtain the turning speed.

In STEP 104, the work machine position / attitude calculation unit 53 outputs the azimuth angle of the swivel body 3, the turning speed calculated in STEP 103, and the value of the elevation angle θ50B calculated in STEP 102 to the satellite selection calculation unit 52.

In STEP 105, the work machine position / attitude calculation unit 53 reads the construction target surface data 55 from the storage device 71 and combines the calculated attitude information and position information of the front members 6A, 6B, and 6C with the construction target surface. The positional relationship of the bucket 6C is output to the monitor 60. An example of the output of the STEPU 105 is shown in FIGS. 9 and 10. FIG. 9 is an example of a display screen of the monitor 60 that displays the positional relationship between the hydraulic excavator 1 and the construction target surface 91. In the example of FIG. 9, the construction target data terrain 90 in the vicinity of the hydraulic excavator 1 is extracted from the construction target data 55, and the cross section of the extracted construction target data terrain 90 cut by the operation plane of the front work device 6 is the construction target surface 91. It is displayed as. The construction target surface 91 is the target locus of the bucket toe. FIG. 10 is an example of a display screen of the monitor 60 that displays the positional relationship between the bucket 6C and the construction target surface 91. In FIG. 10, only the construction target surface 91 in the vicinity of the bucket 6C is extracted and displayed, and the construction target data terrain 90 is not displayed.

In the above description, the process (STEP100-104) of calculating and outputting the elevation angle θ50B when the uppermost part of the front working device 6 is viewed from the position of the GNSS antenna 50B has been described. Similarly, from the position of the GNSS antenna 50A. It is assumed that the elevation angle θ50A when the uppermost portion of the front working device 6 is viewed is also calculated.

<Satellite list creation process on the in-vehicle controller 70>
FIG. 4 is a processing flow of the vehicle-mounted controller 70 (satellite selection calculation unit 52) according to the first embodiment. The in-vehicle controller 70 (satellite selection calculation unit 52) repeatedly executes the flow shown in FIG. 4 at a predetermined control cycle.

When the processing is started, the satellite selection calculation unit 52 acquires the azimuth, turning speed, and elevation angle θ50B of the swivel body 3 output from the work machine position / attitude calculation unit 53 in STEP 104 of FIG. 3 (STEP 120). It is determined whether or not the obtained turning speed is larger than the set value Va (STEP121). Here, when it is determined that the value is larger than the set value Va, a swivel flag indicating that the swivel body 3 is in the “swivel state” to the reference station controller 82 via the radio 7 (initial value is not). The 0) indicating the turning state is changed to 1 and the transmission is performed (STEP129). In this case, the swivel flag: 1, the number of satellite flags: Null, and the number of satellites (the number of satellite numbers): Null are transmitted to the reference station 8.

On the other hand, when the turning speed is less than or equal to the set value Va in STEP121, the number and position (azimuth and elevation) of the positioning satellite (receiving satellite) on which the GNSS antennas 50A and 50B received the satellite signal and the CN value of the satellite signal are used. Is obtained from the GNSS receivers 51A and 51B (STEP122). The CN value (C / N value) is the quality of the satellite signal transmitted from the positioning satellite, and the larger the value, the higher the quality.

In STEP123, the satellite selection calculation unit 52 creates a receiving satellite list La based on the data acquired in STEP122. The receiving satellite list identifies the positioning satellite by the identification number (satellite number) assigned to each positioning satellite in advance. FIG. 6 is an example of the receiving satellite list La, the position of each satellite is defined by the elevation angle and the azimuth angle from each GNSS antenna 50A and 50B, and the CN value of the satellite signal of each satellite is also included as information.

In STEP124, the satellite selection calculation unit 52 creates a receiving satellite list Lb excluding satellites whose CN value of the satellite signal is a predetermined value Rb (for example, 38) or less from the positioning satellites on the receiving satellite list La. As a result, only the satellite number of the positioning satellite that outputs a high-quality satellite signal remains in the receiving satellite list Lb. In addition, since the CN values of GNSS antennas located at almost the same location are usually almost the same, if the CN values of the satellite signals received by the two GNSS antennas 50A and 50B are significantly different, multipath etc. can be used with either GNSS antenna. It is presumed that the failure has occurred. Therefore, an operation is added to compare the CN values of the two GNSS antennas 50A and 50B, select only the positioning satellites whose difference between the two is smaller than the predetermined value (for example, a value within 4), and update the receiving satellite list Lb. You may.

In STEP 125, the satellite selection calculation unit 52 uses the elevation angles θ50A and θ50B of the two GNSS antennas 50A and 50B, the azimuth angle of the swivel body 3 calculated by the receiver 51A, and the shape of the front work device 6 (this shape is mounted on the vehicle). Based on the fact that the two GNSS antennas 50A and 50B receive satellite signals from a plurality of positioning satellites, the front working device 6 can be an obstacle (mask range) based on the storage device of the controller 70. (Sometimes referred to as) 58 is calculated. The mask range 58 is defined by the elevation angle and the azimuth angle with respect to each of the two GNSS antennas 50A and 50B, and the satellite signal of the positioning satellite located in the mask range 58 is not used for positioning. Here, the case where the mask range 58 of the GNSS antenna 50B is calculated out of the two GNSS antennas 50A and 50B is described.

The calculation process of the mask range 58 of the GNSS antenna 50B will be described with reference to FIG. The satellite selection calculation unit 52 calculates the mask range 58 as shown in FIG. 12 based on the azimuth angle of the swivel body 3 acquired in STEP 120. FIG. 12 is a diagram showing a mask range 58 when the azimuth angle of the front working device 6 viewed from the GNSS antenna 50B is 125 degrees and the elevation angle θ50B is 30 degrees. The mask range 58 is an azimuth angle of 110 to 140 degrees and an elevation angle of 45 degrees or less to which a predetermined value is added based on the azimuth angle and the elevation angle of the front working device 6. The mask range 58 of FIG. 12 is set wider than the shape of the front working device 6 for the purpose of responding to turning and tilt change. In general, if a satellite with a small elevation angle is used, the position accuracy will decrease, so it is not used. Specifically, in the present embodiment, positioning satellites located at an elevation angle of 15 degrees or less do not use positioning.

In STEP126, the satellite selection calculation unit 52 creates a receiving satellite list Lc (first positioning satellite list) excluding the positioning satellites existing in the mask range 58 calculated in STEP125 from the receiving satellite list Lb.

In STEP 127, the satellite selection calculation unit 52 performs DOP (Dilution Of) for each combination of positioning satellites capable of acquiring a FIX solution with the GNSS receiver 51A (51B) from among a plurality of positioning satellites listed in the receiving satellite list Lc. Precision) The value is calculated, and the combination of the positioning satellites having the smallest DOP value from the calculated multiple DOP values is set as the receiving satellite list Lc', and the number Nc'of the positioning satellites belonging to the list is calculated. The DOP calculation formula is known and details are omitted, but it can be calculated from the elevation and azimuth angles of the four GNSS satellites. In addition, the combination of one satellite in the zenith direction and the azimuth difference between the low elevation angles is a good small value.

In STEP 128, the satellite selection calculation unit 52 calculates the number of satellites in STEP 127 rather than the number of positioning satellites (number of satellites that can be transmitted) Nd of the amount of data that the reference station 8 can transmit from the radio 87 to the radio 7 by wireless communication. It is determined whether or not Nc'is large.

When it is determined in STEP 128 that the number of satellites Nc'is larger than the number of satellites Nd that can be transmitted by the radios 7 and 87, the satellite selection calculation unit 52 refers to the reference station controller 82 via the radio 7 in STEP 130. , The number of satellite flags indicating that "the number of satellites is excessive" (the initial value is Null, and 0 when it is determined that the correction data can be transmitted) is changed to 1 for transmission. Further, the satellite selection calculation unit 52 sets the receiving satellite list Lc'as the final receiving satellite list Ld for wirelessly transmitting to the reference station 8. Further, the satellite selection calculation unit 52 transmits the Nc'positioning satellite numbers (satellite numbers) listed in the receiving satellite list Ld to the radio 7 in STEP 132. In this case, the swivel flag: 0, the number of satellites flag: 1, and the number of satellites (the number of satellite numbers): Nc'are transmitted to the reference station 8.

Further, when it is determined in STEP128 that the number of satellites Nc'is equal to or less than the number of satellites that can be transmitted by the radios 7 and 87 (the number of satellites that can be transmitted), the satellite selection calculation unit 52 performs the number of satellites Nc in STEP131. A positioning satellite is added to the receiving satellite list Lc'so that'= Nd', and the receiving satellite list Ld is created.

Here, an example of a method for selecting a positioning satellite to be added in STEP 131 will be described with reference to FIGS. 16 and 17. FIG. 16 is a celestial sphere display of the GNSS satellite. Here, the satellites 90 to 95 are selected satellites, and the values required when calculating the evaluation value of the satellite 99 as the next satellite candidate to be selected are the elevation angle θ and the azimuth angle φ of the satellite 99, and the satellite 99. The azimuth φR of the satellite 92 having an elevation angle of 60 degrees or less and the azimuth φL of the satellite 93 counterclockwise.

FIG. 17 shows a detailed processing flow of STEP131 in FIG. 4, and the evaluation value is evaluated from the unselected satellites by the evaluation formula until the selected number of satellites Nc (initial value is Nc') becomes the number of transmittable satellites Nd. Add higher satellites one by one. The flow will be explained below.

First, the satellite selection calculation unit 52 determines in STEP 220 whether or not the selected number of satellites Nc is equal to the number of transmittable satellites Nd. If they are equal, the satellite selection is finished and the process proceeds to STEP 132.

If the number of transmittable satellites Nd has not been reached, the satellite selection calculation unit 52 determines in STEP 222 whether or not there are unrated satellites in order to obtain the evaluation value of the unselected satellites. If there are unrated satellites, the evaluation satellite is selected (STEP 224), and it is determined whether or not the elevation angle of the selected satellite is equal to or higher than a predetermined value (for example, 60 degrees) (STEP 225). If the elevation angle is equal to or greater than a predetermined value, a low evaluation value (for example, 0) is set for the corresponding satellite, and STEP 222 is executed again.

If the elevation angle is equal to or less than a predetermined value, the satellite selection calculation unit 52 calculates the azimuth evaluation value Δφ and the elevation angle evaluation value Δθ based on the equation 226 in FIG. 17 (STEP 226). Further, the satellite evaluation value Vφn is calculated based on the equation 227 in FIG. 17 (STEP 227). Then, STEP222 is executed again.

When it is determined in STEP222 that the evaluations of all unselected satellites have been calculated, the satellite selection calculation unit 52 adds the positioning satellite having the maximum satellite evaluation value Vφn to the receiving satellite list Ld in STEP223. Next, return to STEP220 and carry out the flow in the environment where one satellite is added. A satellite having the number of transmittable satellites Ld is selected by the above method. When the above processing of STEP 131 is completed, the satellite selection calculation unit 52 proceeds to STEP 132 and transmits the satellite number code of the satellite list Ld to the radio 7. In this case, the swivel flag: 0, the number of satellites flag: 0, and the number of satellites (the number of satellite numbers): Nd are transmitted to the reference station 8.

FIG. 5 shows the contents of the turning flag, the number of satellites flag, and the satellite number output from the radio 7 of the hydraulic excavator 1 to the reference station 8 (reference station controller 82) when passing through the three steps 129, 130, and 131 of FIG. A table summarizing an example is shown. In the case of FIG. 5, the number of transmittable satellites Nd is set to 5.

<Correction data generation control processing in the reference station controller 82>
The processing flow of the reference station controller 82 of the GNSS reference station 8 is shown in FIGS. 7 and 8.

FIG. 7 shows a processing flow of the reference station controller 82 when the signal (swivel flag, number of satellite flags, satellite number) from the radio 7 is received by the radio 87, and the signal from the radio 7 is received by the radio 87. It is executed each time. When the process is started, the reference station controller 82 receives the signals (turning flag, number of satellites flag, satellite number) from the above-mentioned radio 7 described with reference to FIG. 4 from the radio 87.

In STEP 141, the reference station controller 82 determines whether or not the hydraulic excavator 1 is in the swivel state based on the swivel flag of the signal received by the radio 87 (STEP 141).

When it is determined in STEP 141 that the rotation is in progress, the reference station controller 82 sends a command (for example, 2 seconds) to the GNSS receiver 81 to make the correction data transmission interval larger than a predetermined value (first transmission interval increase command). ) And a command to release the satellite restriction to generate correction data (satellite restriction release command) (STEP142). The former command increases the interval at which correction data is transmitted from the GNSS receiver 81 to a preset value, and the latter command limits the number of satellites used when the GNSS receiver 81 generates correction data. It is canceled and the usual correction data (for example, correction data generated based on a plurality of positioning satellites that can receive satellite signals from both the GNSS receivers 51A and 51B and the GNSS receiver 81) is generated and output. .. Further, the reference station controller 82 confirms whether the two commands in STEP 142 have been completed normally, and if not completed normally, executes command processing for retransmitting the two commands (STEP 143).

If it is determined in STEP 141 that the vehicle is not turning, the reference station controller 82 determines in STEP 144 whether or not the number of satellites is excessive based on the satellite number flag of the signal received by the radio 87.

When it is determined in STEP 144 that the number of satellites is excessive, the reference station controller 82 sends a command (for example, the current value + 1 second) to the GNSS receiver 81 to make the correction data transmission interval larger than the current value (for example, the current value + 1 second). 2 Transmission interval increase command) is transmitted (STEP 145). As a result, the interval at which the correction data is transmitted from the GNSS receiver 81 becomes larger than the current value. When STEP 145 is completed, the reference station controller 82 executes the same command processing as STEP 143 (STEP 146), and proceeds to STEP 147.

If it is determined in STEP 144 that the number of satellites is not excessive, the process proceeds to STEP 147.

In STEP 147, the reference station controller 82 transmits a command (satellite restriction command) for limiting the satellite that generates correction data to the satellite number transmitted from the radio 7 to the GNSS receiver 81. As a result, the GNSS receiver 81 generates correction data based on the satellite signals transmitted from the plurality of positioning satellites on the receiving satellite list Ld received by the radio 87. For example, when the number of satellites in the receiving satellite list Ld received by the radio 87 matches Nd, the amount of correction data generated by the GNSS receiver 81 is limited to the amount capable of wireless transmission. When STEP 147 is completed, the reference station controller 82 executes the same command processing as STEP 143 (STEP 148), and ends the processing.

<Correction data transmission processing in the reference station controller 82>
FIG. 8 shows a processing flow of the reference station controller 82 when data is received from the GNSS receiver 81, and is executed each time the reference station controller 82 receives data from the GNSS receiver 81. When the processing is started, the reference station controller 82 receives the data from the GNSS receiver 81 (STEP 160) and determines whether or not the data is correction data (STEP 161).

When it is determined in STEP 161 that the correction data is correct, the reference station controller 82 transmits the correction data received in STEP 160 to the hydraulic excavator 1 via the radio 87 in STEP 163, and ends the process. As a result, the GNSS receivers 51A and 51B on the hydraulic excavator 1 side receive satellite signals transmitted from a plurality of positioning satellites on the receiving satellite list Ld (second positioning satellite list) and correction data received by the radio 7. Based on the above, the position coordinates of the GNSS antennas 50A and 50B and the azimuth angle of the swivel body 3 are calculated.

On the other hand, when it is determined in STEP 161 that the data is not the correction data, the reference station controller 82 indicates in STEP 162 that the command transmitted immediately before in any of STEP 142, 145, 147 in the flow of FIG. 7 is incomplete. It is determined that the data has been received, and the process of FIG. 8 is terminated. When this data is received, the reference station controller 82 considers that the processing specified by the command transmitted in STEP 142, 145, 147 of the flow of FIG. 7 immediately before is not completed normally, and STEP 142 of the flow of FIG. 7 immediately before. , 145,147 will be retransmitted in STEP143,146,148.

<Effect of the first embodiment>
As described above, in the hydraulic excavator 1 according to the present embodiment, when the two GNSS antennas 50A and 50B receive satellite signals from a plurality of positioning satellites, the front working device 6 can be an obstacle (mask range). ) 58 is calculated (S125 in FIG. 4), and the positioning satellites located in the mask range 58 are excluded from the satellite list (received satellite list) used by the reference station 8 to generate the correction data (S126 in FIG. 4). As a result, positioning satellites located in the direction of the front work device 6 (boom 6A, arm 6B, etc.), which causes an error due to multipath when positioning with the GNNS receivers 51A and 51B on the hydraulic excavator 1 side, are excluded from the correction data. This makes it possible to prevent deterioration of the positioning accuracy of the GNNS receivers 51A and 51B. That is, according to the present embodiment, the correction data is generated by excluding the signal from the satellite at the position where the front work device 6 can be an obstacle, so that even in a situation where positioning is impossible or the accuracy is lowered in the past Stable positioning is possible.

In particular, in the present embodiment, the number of satellites included in the correction data transmitted from the reference station 8 is limited to the number of transmittable satellites Nd of the radios 7 and 87 (S131 and 17 in FIG. 4). Even when the radio is used in an environment where the amount of data transfer is small or the amount of data transfer is limited, it is possible to avoid the phenomenon that the GNNS receivers 51A and 51B on the hydraulic excavator 1 side cannot perform positioning.

Further, in the present embodiment, when the turning speed of the turning body 3 is high and the processing for excluding the positioning satellite located in the direction of the front working device 6 such as the boom 6A and the arm 6B from the correction data is not in time, the correction data By increasing the transmission interval of (S142 in FIG. 7) to a predetermined value, it is possible to prevent all the correction data from becoming untransmissible. As a result, it is possible to avoid the phenomenon that positioning is not possible with the GNNS receivers 51A and 51B on the hydraulic excavator 1 side. The transmission interval of the correction data is preferably determined according to the data transferable amount of the radios 7 and 87.

Further, in the present embodiment, when the number of satellites included in the correction data exceeds the number of transmissionable satellites Nd, the transmission interval of the correction data is made larger than the current value (S145 in FIG. 7), so that all the correction data cannot be transmitted. Can be prevented. Further, in the above embodiment, when the number of satellites of the correction data exceeds the number of transmittable satellites Nd, the process of STEP 145 in FIG. 7 is executed, but the data transfer amount of the radios 7 and 87 is monitored. When the decrease in the transfer amount can be grasped, the correction data transmission interval may be increased.

Further, in the present embodiment, when the final receiving satellite list Ld (second positioning satellite list) is created from a plurality of positioning satellites on the receiving satellite list Lc'(first positioning satellite list), the receiving satellite list is created. The DOP value is calculated for each combination of positioning satellites that can acquire the FIX solution with the GNSS receivers 51A and 51B from among the plurality of positioning satellites listed in Lc', and the DOP value is calculated from the calculated multiple DOP values. The final receiving satellite list Ld is created so as to include a plurality of positioning satellites belonging to the combination of positioning satellites having the smallest value. As a result, the positioning satellite with the highest positioning accuracy can be included in the final receiving satellite list Ld, so that the positioning accuracy by the GNSS receivers 51A and 51B can be improved.

Further, by excluding the positioning satellites located in the direction of the front work device 3 which causes an error and then limiting the number of satellites used for the correction data, the data transfer amount of the radios 7 and 87 can be efficiently used. ..

Further, in the present embodiment, the azimuth of the vehicle body is measured by using two sets of GNSS antennas 50A and 50B and the GNSS receivers 51A and 51B, but the azimuth may be measured by using a geomagnetic sensor.

Further, in the present embodiment, when the turning speed of the turning body 3 is detected by the speed sensor and the turning speed exceeds a predetermined threshold value Va, the cycle of transmitting correction data from the reference station 8 to the radio 7 is increased. An example of transmitting a command to the reference station 8 (GNSS receiver 81) has been described. However, when the traveling speed of the traveling body 2 is detected by the speed sensor and the traveling speed exceeds a predetermined threshold value, it is corrected in the same manner as turning. It may be configured to increase the data transmission cycle. That is, it is possible to adopt a configuration in which the transmission cycle of the correction data is increased when the moving speed of the hydraulic excavator 1 exceeds a predetermined threshold value.

(Second Embodiment) Changing the number of transmittable satellites according to the delay time Next, the second embodiment of the present invention will be described with reference to FIG. FIG. 13 is a processing flow of the vehicle-mounted controller 70 (satellite selection calculation unit 52) according to the second embodiment, and is executed between STEP122 and STEP123 in the processing flow of FIG.

In the first embodiment, the case where the number of transmittable satellites Nd in the radios 7 and 87 is fixedly determined has been described. In the second embodiment, a case where the number of satellites Nd that can be transmitted by the radios 7 and 87 is unknown or uncertain will be described.

When the processing of STEP 122 in FIG. 4 is completed, the satellite selection calculation unit 52 acquires the delay time (acquired value) of the correction data output from the GNSS receiver 51B (STEP 160). This correction data delay time may be acquired from data output in a predetermined format (for example, NMEA (National Marine Electricals Association) format) output from the GNSS receiver 51B, for example.

In STEP161, the satellite selection calculation unit 52 uses the correction data delay time (acquisition value) acquired in STEP160 from the minimum value Tmin of the correction data delay time acquired after starting the in-vehicle controller 70 (satellite selection calculation unit 52). Determine if it is small. (STEP161)
When the correction data delay time (acquisition value) acquired in STEP 160 is smaller than the minimum value Tmin, the satellite selection calculation unit 52 sets the correction data delay time (acquisition value) to the new minimum value Tmin to set the minimum value. Update Tmi (STEP 162) and proceed to STEP 163. On the other hand, when the correction data delay time (acquired value) acquired in STEP 160 is equal to or greater than the minimum value Tmin, the process proceeds to STEP 163 without updating the minimum value Tmi.

In STEP163, the satellite selection calculation unit 52 determines whether or not the correction data delay time (acquired value) acquired in STEP160 matches the minimum value Tmin. Here, when it is determined that the correction data delay time matches the minimum value Tmin, that is, when the correction data delay time (acquired value) acquired in STEP 160 is the minimum value Tmin from the start of the controller 70, transmission is performed. Increase the number of possible satellites Nd by one (STEP164). Then, the number of transmittable satellites Nd is updated with the increased value (STEP 168), and the process proceeds to STEP 123 in FIG.

On the other hand, when it is determined in STEP163 that the correction data delay time does not match the minimum value Tmin, the satellite selection calculation unit 52 sets the correction data delay time (acquired value) acquired in STEP160 to the minimum value Tmin to a predetermined value T1 ( (For example, 3 seconds) It is determined whether or not it is larger than the added value (STEP165). When it is determined in this STEP 165 that the correction data delay time is larger than the minimum value Tmin + T1, the satellite selection calculation unit 52 reduces the number of transmittable satellites Nd by one (STEP 166), and the value after the reduction is used. The number of transmittable satellites Nd is updated (STEP168), and the process proceeds to STEP123 in FIG.

If it is determined in STEP 165 that the correction data delay time is equal to or less than the minimum value Tmin + T1, the satellite selection calculation unit 52 does not change the number of transmittable satellites Nd (STEP 167, 168), but in STEP 123 in FIG. move on.

With such a processing flow, the number of transmittable satellites Nd can be changed according to the communication state of the radios 7 and 87.

<Effect of the second embodiment>
According to the present embodiment configured as described above, the number of transmittable satellites Nd changes based on the delay time of the correction data, so that the user does not need to know the amount of data that can be transmitted by the radios 7 and 87. There is an advantage in that the same effect as that of the first embodiment can be exhibited. The specifications of radios 7 and 87 differ depending on the regulations of each country's radio law and the contents of the radio license that can be obtained by the user. Therefore, the radios 7 and 87 used for the correction data communication are configured in accordance with the actual situation that the user often selects them according to the site. Further, when the selection is made by trial and error according to the site, it is difficult to select the radios 7 and 87 and the value of the number of transmittable satellites Nd by trial and error, as in the present embodiment. It can be said that the utility of the hydraulic excavator equipped with the automatic adjustment function of the number of transmissionable satellites Nd is very high.

(Third Embodiment) Correcting data is generated by the reference station controller Next, the third embodiment of the present invention will be described with reference to the processing flows of FIGS. 14 and 15. These processing flows are processing flows executed by the reference station controller 82 of the GNSS reference station 8 and replaces FIGS. 7 and 8 of the first embodiment. In the first embodiment, the satellites used for generating the correction data and the satellites not used are determined, and the correction data generated by the GNSS receiver 81 based only on the former satellite signal is transmitted to the hydraulic excavator 1. On the other hand, in the present embodiment, correction data is first generated by the GNSS receiver 81, and unnecessary satellite data is deleted from the generated correction data to transmit correction data equivalent to that in the first embodiment. It will be realized. The processing flow will be described below.

FIG. 14 is a processing flow of the reference station controller 82 when the signal (swivel flag, number of satellite flags, satellite number) from the radio 7 is received by the radio 87, and the signal from the radio 7 is received by the radio 87. It is executed each time it is received. When the reference station controller 82 receives data from the radio 87 (STEP180), the reference station controller 82 executes a process of extracting parameters (turning flag, number of satellites flag, satellite number) from the received data (STEP181), and ends the processing flow. To do.

FIG. 15 shows a processing flow of the reference station controller 82 when data is received from the GNSS receiver 81, and is executed each time the reference station controller 82 receives data from the GNSS receiver 81. When the reference station controller 82 receives data from the GNSS receiver 81 (STEP200), the reference station controller 82 determines whether or not the received data is correction data (STEP201). If the received data is not the correction data, the reference station controller 82 ends the process. On the other hand, when the data received in STEP 200 is correction data, the reference station controller 82 determines whether the hydraulic excavator 1 is in a swirling state or the number of satellites can be transmitted based on the data received in the processing flow of FIG. It is determined whether or not the state is excessive (excessive) exceeding several Nd (STEP203). In STEP 203, if the hydraulic excavator 1 is not in the swivel body and the number of satellites is Nd or less, the process proceeds to STEP 205.

On the other hand, when it is determined in STEP 203 that the hydraulic excavator 1 is in a swirling body, or when it is determined that the number of satellites exceeds the number of transmittable satellites Nd, the reference station controller 82 receives the data from the GNSS receiver 81. Set the transmission frequency limit state to limit the frequency of transmitting the correction data to the radio 87 to once every two times (STEP204), and proceed to STEP205.

In STEP 205, the reference station controller 82 determines whether or not the transmission frequency is limited in the correction data transmission frequency, and if it is in the transmission frequency limitation state, proceeds to STEP 206, and if the correction data transmission frequency is not restricted. To STEP208.

In STEP 206, the reference station controller 82 determines whether or not the correction data received this time does not need to be transmitted. Specifically, since the transmission frequency is once every two times while the transmission frequency is restricted, it is judged that transmission is unnecessary when transmitting in the latest processing flow, and when transmission is not performed in the latest processing flow. Judge that transmission is required. If it is determined in STEP 206 that transmission is unnecessary, the reference station controller 82 ends the process, and if it is determined in STEP 206 that transmission is necessary, the process proceeds to STEP 208.

In STEP208, the reference station controller 82 extracts the information corresponding to the satellite number indicated by the parameter extracted in STEP181 of FIG. 14 from the correction data received in STEP200, and excludes the information corresponding to other satellite numbers. By doing so, the correction data is reconstructed.

In STEP 209, the reference station controller 82 transmits the reconstructed correction data to the radio 87, whereby the correction data is transmitted to the hydraulic excavator 1.

With the above processing flow, the reference station controller 82 can appropriately reduce the satellite data included in the correction data by a method different from that of the first embodiment. Further, in the present embodiment, since the satellite data from the GNSS receiver 81 is processed, the time required for changing the setting in the GNSS receiver 81 becomes unnecessary, and it becomes possible to quickly react to the state change of the hydraulic excavator 1.

(Fourth Embodiment) A large number of satellites located around the mask range are selected. Next, the fourth embodiment of the present invention will be described with reference to FIGS. 12 and 18. In the fourth embodiment, the satellite at the position (elevation angle / azimuth angle) corresponding to the range 59 set on the outer peripheral portion of the mask range 58 not used for positioning set around the front work device 6 in FIG. 12 is given priority. The receiving satellite list Ld is created by selecting. The range 59 is a region adjacent to the outside of the mask range 58 and existing in a predetermined range from the mask range 58.

FIG. 18 is a process corresponding to STEP131 of FIG. 4 in the first embodiment, and in this embodiment, the process of FIG. 18 is executed instead of STEP131.

In STEP 240, the satellite selection calculation unit 52 first determines whether or not there is a satellite in the satellite list Lc'selected in STEP 125 as a combination having the best DOP value in the range 59 of elevation and azimuth. judge.

If there is no positioning satellite included in the range 59, the satellite selection calculation unit 52 proceeds to STEP241 and selects one satellite by the evaluation method A (described later), and the selected number of satellites becomes the number of transmittable satellites Nd. The process of STEP241 is repeated until (STEP242). Here, the evaluation method A corresponds to the process of STEP222-STEP227 in FIG.

If there are positioning satellites included in the range 59, the satellite selection calculation unit 52 proceeds to STEP 243, first selects the satellites in the range 59 by the evaluation method A (STEP 243), and then all the satellites. The satellites in the range are selected by the evaluation method A (STEP245). Then, the satellites located in the range 59 are preferentially selected by alternately selecting the satellites in the two ranges according to STEP243 and 245 until the selected number of satellites reaches the number of transmittable satellites Nd (STEP244,246). it can.

In GNSS positioning, a certain amount of time is required from the detection of a new satellite until it becomes available for positioning. Therefore, if the satellite hides within the mask range 58 that is not used for positioning due to the turning of the swivel body 3 or the operation of the front work device 6, the positioning accuracy deteriorates until a substitute satellite is captured and positioned. There was a possibility that accurate positioning could not be performed. In response to such a problem, in the fourth embodiment, even if the satellite enters the mask range 58 due to the turning of the swivel body 3 at a relatively small angle or the operation of the front working device 6, the mask range 58 Since there are many alternative satellites in the outer peripheral range 59, there is a high possibility that positioning can be continued.

(Other)
The present invention is not limited to the above-described embodiment, and includes various modifications within a range that does not deviate from the gist thereof. For example, the present invention is not limited to the one including all the configurations described in the above-described embodiment, and includes the one in which a part of the configurations is deleted. Further, it is possible to add or replace a part of the configuration according to one embodiment with the configuration according to another embodiment.

In addition, each configuration related to the controllers 70 and 82 and the functions and execution processing of each configuration are part or all of them by hardware (for example, the logic for executing each function is designed by an integrated circuit). It may be realized. Further, the configuration related to the controllers 70 and 82 may be a program (software) that realizes each function related to the configuration of the controllers 70 and 82 by being read and executed by an arithmetic processing unit (for example, a CPU). Information related to the program can be stored in, for example, a semiconductor memory (flash memory, SSD, etc.), a magnetic storage device (hard disk drive, etc.), a recording medium (magnetic disk, optical disk, etc.), or the like.

Further, in the above description of each embodiment, the control lines and information lines are understood to be necessary for the description of the embodiment, but not all control lines and information lines related to the product are necessarily used. Does not always indicate. In reality, it can be considered that almost all configurations are interconnected.

1 ... work machine, 2 ... traveling body, 3 ... swivel body, 4 ... driver's seat, 6 ... front work device, 7 ... radio, 8 ... GNSS reference station, 11 ... cylinder, 20 ... horizon, 23 ... swivel body attitude sensor , 30 ... ground, 50 ... GNSS antenna, 51 ... GNSS receiver, 52 ... satellite selection calculation unit, 53 ... work machine position / attitude calculation unit, 60 ... monitor, 75 ... front work device attitude sensor, 80 ... reference station GNSS antenna , 81 ... GNSS receiver, 82 ... satellite selection calculation unit, 87 ... radio

Claims (5)

The work equipment attached to the swivel body and
A posture sensor for detecting the posture of the work device and the swivel body, and
Two antennas for receiving satellite signals from multiple positioning satellites,
A radio for receiving correction data generated by the reference station based on satellite signals received from the plurality of positioning satellites, and
A receiver that calculates the position coordinates of at least one of the two antennas and the azimuth angle of the swivel body based on the satellite signal received by the two antennas and the correction data received by the radio. ，
In a work machine including a controller that calculates the position coordinates and the azimuth angle of the work device based on the position coordinates of the at least one antenna calculated by the receiver and the azimuth angle of the swivel body.
The controller
Based on the postures of the work device and the swivel body detected by the posture sensor, the position coordinates of the at least one antenna calculated by the receiver, and the azimuth angle of the swivel body, the at least one antenna When receiving satellite signals from the plurality of positioning satellites, the working device calculates the range in which it can be an obstacle.
A first positioning satellite list was created by excluding the positioning satellites located in the range where the working device could be an obstacle from the plurality of positioning satellites.
The second positioning satellite is selected from the plurality of positioning satellites listed in the first positioning satellite list by selecting a number of positioning satellites capable of generating correction data for the amount of data that the reference station can transmit to the radio by wireless communication. Create a positioning satellite list and
The second positioning satellite list is transmitted to the reference station via the radio.
The correction data received by the radio is generated using satellite signals transmitted from a plurality of positioning satellites on the second positioning satellite list.
The receiver has the position coordinates of the at least one antenna and the position coordinates of the at least one antenna based on the satellite signals transmitted from the plurality of positioning satellites on the second positioning satellite list and the correction data received by the radio. A work machine characterized by calculating the azimuth angle of the swivel body. In the work machine of claim 1,
The controller
When the delay time of the correction data output from the receiver is the minimum value of the delay time of the correction data acquired after starting the controller, the amount of data that can be transmitted to the radio. Increase the number of correction data that can be generated by one,
When the delay time of the correction data output from the receiver is larger than the minimum value of the delay time of the correction data plus a predetermined value, the correction data of the amount of data that can be transmitted to the radio is used. A work machine characterized by reducing the number that can be generated by one. In the work machine of claim 1,
Further equipped with a speed sensor that detects either the traveling speed or the turning speed of the work machine.
The controller is a work machine that transmits a command to increase the cycle of transmitting the correction data to the radio when the speed detected by the speed sensor exceeds a predetermined threshold value to the reference station. In the work machine of claim 1,
When creating the second positioning satellite list from a plurality of positioning satellites listed in the first positioning satellite list, the controller selects positioning satellites located within a predetermined range from a range in which the working device can be an obstacle. A work machine characterized by preferential selection. In the work machine of claim 1,
When the controller creates the second positioning satellite list from a plurality of positioning satellites listed in the first positioning satellite list, the controller selects the receiver from among the plurality of positioning satellites listed in the first positioning satellite list. The DOP value is calculated for each of the combinations of positioning satellites that can be acquired in the above-mentioned second, and the plurality of positioning satellites belonging to the combination of the positioning satellites having the smallest DOP value among the calculated multiple DOP values are included. A work machine characterized by creating a positioning satellite list.

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