JP7016297B2 - Work machine - Google Patents

Description

The present invention relates to a work machine including an upper swing body and a lower traveling body such as a hydraulic excavator.

In recent years, with the response to information-oriented construction, a machine that displays the position and posture of a work device (front work device) that is configured by connecting multiple front members such as booms, arms, and buckets to the operator. Some have guidance and machine control functions that control the position of the work equipment so that it moves along the target construction surface. As a typical example, the position and angle of the bucket tip of the hydraulic excavator are displayed on the monitor, and when the tip of the bucket approaches the target construction surface, the work device operates so that the tip of the bucket does not enter below the target construction surface. It is known that there are restrictions on the pressure.

In this type of computerized construction compatible work machine, an inertial measurement unit (IMU) may be used as a sensor to detect the posture of each front member and the posture of the upper swivel body.

Some of these types of information-oriented construction-compatible work machines are equipped with two satellite positioning systems, so-called GNSS (Global Navigation Satellite System) antennas, on the upper swivel body. By using the positioning result of each GNSS antenna, the direction (direction) of the upper swivel body can be calculated, and thereby the direction (direction) of the working device can also be calculated. Since this configuration is equipped with a GNSS antenna on the upper swivel body, it is a suitable configuration for the problem of performing "excavation operation by matching the direction of the working device (upper swivel body)" with respect to a specific plane. It can be said that.

However, since the GNSS antenna is provided on the upper swivel body, the direction of the lower traveling body cannot be determined from the positioning result of the GNSS. That is, "a posture in which only the upper swing body is rotating without rotating the lower traveling body" (see FIG. 17a) and "a posture in which only the lower traveling body is rotated and the upper turning body is not rotating" (see FIG. 17a). Since the orientations of the working devices are the same in both cases (see FIG. 17b), these two postures are regarded as the same posture when only the positioning result by GNSS is referred to. However, these two postures are clearly different postures.

As an example of the inconvenience caused by not knowing the orientation of the lower traveling body, consider the case of constructing a large work surface. If the lower traveling body is also facing the work surface as shown in FIG. 18a, the lower traveling body is once moved by changing the direction after the excavation work, and after the movement, the work device is made to face the working surface again. become. On the other hand, as shown in FIG. 18b, if the lower traveling body is in a horizontal state with respect to the work surface, the work device always faces the work surface even when traveling, so that the position is as in the case of FIG. 18a. No matching operation is required, and work efficiency can be improved. When performing such work, not only the orientation of the upper swivel body but also the orientation of the lower traveling body is important. However, as described above, it is not easy to know the direction of the lower traveling body only from the positioning result of GNSS.

To solve such a problem, Patent Document 1 shows a swivel joint provided with a rotation angle sensor capable of detecting the rotation angle of the upper swing body.

If the orientation of the upper swing body is detected by two GNSSs and the relative angle between the upper swing body and the lower traveling body is detected by the rotation angle sensor of Patent Document 1, the orientation of the lower traveling body can be calculated immediately. it is conceivable that. Further, if the rotation angle sensor is provided on the rotation rotation shaft as in Patent Document 1, it is possible to accurately detect the relative angle between the upper rotation body and the lower traveling body without being affected by the mechanism backlash and the mounting error. Is.

However, with such a configuration, the rotation angle sensor has to be mounted on the rotation rotation shaft, so that it is extremely difficult to repair or replace the sensor when the rotation angle sensor fails. In addition, if a sensor failure occurs in a mountainous area where it is difficult to bring in repair equipment such as a mobile crane, it may not be possible to repair or replace it, and the process at the construction site may be delayed.

In response to such a problem, in Patent Document 2, the lower traveling body with respect to the upper turning body is provided based on the change in the horizontal component in the positioning result of the GNSS attached to the upper turning body without attaching the sensor to the turning shaft. A method of calculating the posture is presented.

Japanese Unexamined Patent Publication No. 2017-82494 Japanese Unexamined Patent Publication No. 2006-214236

Patent Document 2 does not provide specific details regarding "changes in horizontal components". However, those skilled in the art will consider calculating the relative angle between the upper swivel body and the lower traveling body by, for example, the following calculation method.

<Calculation example>
First, the GNSS positioning result is converted into the Cartesian coordinates of a specific geodetic system (for example, the world geodetic system), and the x, y, z coordinates of the GNSS antenna position are obtained. Consider the case where only the lower traveling body is driven (forward / backward) without rotating the upper swivel body by using this coordinate system.

Here, as shown in FIG. 19, if the "horizontal change" is regarded as a combination of the change of the change amount Δx in the x-coordinate and the change of the change amount Δy in the y-coordinate, the “horizontal change” is an excavator. Is equal to the moving direction of. Then, assuming that the moving direction of the excavator and the angle θrn of the lower traveling body are equal, the angle θrn of the lower traveling body can be calculated by the following equation (1).

According to the above calculation method, it can be said that the angle of the lower traveling body can be calculated without providing the angle sensor on the turning axis. Although the x-axis is set to θrn = 0 degrees in FIG. 19 for the sake of simplicity, it should be noted that the embodiment of the present invention described later is not limited to “the x-axis is set to 0 degrees”. It should be noted that the following figures also emphasize the ease of explanation, and the method of taking the angle does not always follow that of FIG. (<Calculation example> End)

However, in a hydraulic excavator having a crawler type lower traveling body, even if the hydraulic excavator is tried to run straight (for example, parallel to the x-axis in FIG. 19), the hydraulic excavator may be caused by slip due to the road surface or the pressure difference of the traveling hydraulic motor. Will meander. That is, even if the lower traveling body is operated to run straight, the angle of the lower traveling body changes before and after the running (in this paper, the difference in the angles of the lower running body that occurs before and after this running is referred to as the "deviation angle". "). That is, the assumption that the moving direction of the shovel and the angle θrn of the lower traveling body are equal does not hold. Therefore, it is not possible to calculate the angle of the lower traveling body with high accuracy simply by using the equation (1). Patent Document 2 does not provide a solution to this problem.

Further, it is known that in positioning using GNSS, an error of about ± 2 cm occurs even if RTK (Real Time Kinematics), which is a highly accurate positioning method using correction data, is used.

Here, taking the case where the angle θrn of the lower traveling body is 0 degrees as an example, the influence of this positioning error on the above equation (1) will be considered. As described above, Patent Document 2 does not mention "horizontal change", but let us assume that the difference in positioning results for each sampling cycle (for example, 1 second) of a general positioning system is "horizontal change". Further, since the maximum speed of the traveling operation of a general hydraulic excavator (for example, a vehicle weight of 20 tons class) is about 5 km / h, the vehicle advances by about 1.4 m (140 cm) in one cycle (1 second). Here, assuming that the errors in the y direction before and after the movement are -2 cm and +2 cm, respectively, the angle calculated by the equation (1) is about 1.6 degrees from the equation (2).

As can be seen from Eq. (2), the longer the travel distance (the larger the absolute value of the denominator of the inverse tangent function), the more the influence of the positioning error (the molecule of the inverse tangent function) is suppressed. This principle is as shown in FIGS. 20a and 20b, and the influence of the error is relatively smaller in FIG. 20b having a long travel distance than in FIG. 20a having a short travel distance. Therefore, in order to reduce the influence of the positioning error of GNSS, it is conceivable to extend the moving distance.

However, the above discussion is limited to the case where RTK positioning is performed accurately (in the case of FIX solution), and in the case of Float solution when RTK positioning does not work, the positioning error (absolute value of the molecule of the inverse tangent function). ) Becomes larger (for example, about ± 20 cm), and the traveling angle θrn calculated by Eq. (2) changes greatly. Patent Document 2 does not mention this problem at all.

Therefore, it is not easy for those skilled in the art to accurately calculate the angle of the lower traveling body by using the positioning result of GNSS in an actual hydraulic excavator.

The present invention has been made in view of the above-mentioned problem of Patent Document 2, and an object thereof is to turn upward by an existing sensor configuration provided in a work machine for information-oriented construction, that is, information obtained from GNSS. The purpose of the present invention is to provide a work machine capable of calculating the relative angle between the body and the lower traveling body.

The present application includes a plurality of means for solving the above problems, for example, a crawler type lower traveling body, an upper rotating body rotatably attached to the upper portion of the lower traveling body, and the upper portion. A positioning terminal that calculates the positions of the first antenna and the second antenna attached to the swivel body, the positions of the first antenna and the second antenna, respectively, and a controller that calculates the relative angle between the upper swivel body and the lower traveling body. In the work machine provided with, the controller has the positions of the first antenna and the second antenna calculated by the positioning terminal at the first time, and the lower traveling body operates after the first time. From the storage device that stores the positions of the first antenna and the second antenna calculated by the positioning terminal at the second time after the above, and the positions of the first antenna and the second antenna at the first time. The first time based on the position of the vehicle body angle calculation unit that calculates the first vehicle body angle, which is the angle of the upper swivel body at the first time, and the first antenna at the first time and the second time. A traveling displacement angle calculation unit that calculates a traveling displacement angle, which is an angle formed by a straight line passing through the position of the first antenna at the second time, and the first at the first time and the second time. A deviation angle calculation unit that calculates a deviation angle, which is the difference between the angle formed by the lower traveling body with the reference line and the traveling displacement angle at the first time, based on the positions of one antenna and the second antenna. The traveling displacement angle correction unit that adds the deviation angle to the traveling displacement angle to correct the traveling displacement angle, the traveling displacement angle corrected by the traveling displacement angle correction unit, and the first vehicle body angle. A relative angle calculation unit for calculating the relative angle between the upper swivel body and the lower traveling body at the first time is provided.

According to the present invention, the relative angle between the upper swivel body and the lower traveling body can be calculated from the positioning result of GNSS. Unlike the configuration in which the rotation angle sensor is provided on the turning shaft, GNSS has the advantage that it is very easy to replace or repair even if a failure should occur.

It is a perspective view of the hydraulic excavator which concerns on embodiment of this invention. It is a side view of the hydraulic excavator which concerns on embodiment of this invention. It is a functional block diagram of the controller which concerns on 1st Embodiment. It is a schematic diagram explaining the calculation content of the upper swing body angle calculation unit of 1st Embodiment. It is a schematic diagram explaining the calculation content of the front posture calculation unit of 1st Embodiment. It is a functional block diagram of the relative angle calculation part of 1st Embodiment. This is an example of a time chart when performing an operation by the relative angle calculation unit. It is a figure which represented the calculation content of the relative angle calculation part schematically. It is a figure which represented the calculation content of the relative angle calculation part schematically. It is a schematic diagram which shows the coordinate change of the GNSS antenna when the lower traveling body slips. It is a schematic diagram explaining an example of the calculation content of a deviation angle. It is a schematic diagram explaining an example of the calculation content of a deviation angle. It is a schematic diagram explaining an example of the calculation content of a deviation angle. It is a schematic diagram explaining an example of the calculation content of a deviation angle. It is a functional block diagram of the relative angle calculation part of 2nd Embodiment. It is a functional block diagram of the relative angle calculation part of 3rd Embodiment. It is a schematic diagram explaining the calculation content of the traveling displacement angle calculation unit when a turning operation is performed. It is an example of the flowchart of the controller of the 3rd Embodiment. It is a schematic diagram which shows the problem of the direction calculation using GNSS. It is a schematic diagram which shows the problem of the direction calculation using GNSS. It is a schematic diagram which shows the procedure of efficient slope work. It is a schematic diagram which shows the procedure of efficient slope work. It is a schematic diagram explaining the method of calculating the azimuth angle using GNSS. It is a schematic diagram explaining the influence which the positioning error of GNSS has on the angle calculation. It is a schematic diagram explaining the influence which the positioning error of GNSS has on the angle calculation. It is a figure explaining the relationship between the deviation angle δφ and the calculated values θc, θd.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, as an example of a work machine, a hydraulic excavator having a bucket as a work tool at the tip of a front device (front work device) will be described as an example.

FIG. 1 is a diagram schematically showing the appearance of a hydraulic excavator, which is an example of a work machine according to the present embodiment. In FIG. 1, the hydraulic excavator 100 is an articulated front device (front work) configured by connecting a plurality of front members (boom 4, arm 5, bucket (working tool) 6) that rotate in each vertical direction. The device) 1 and the upper swivel body 2 and the lower traveling body 3 constituting the vehicle body are provided, and the upper swivel body 2 is rotatably attached to the upper part of the lower traveling body 3. The lower traveling body 3 is a crawler type traveling body and is also called an endless track.

The base end of the boom 4 of the front device 1 is rotatably supported by the front portion of the upper swing body 2, and one end of the arm 5 is perpendicular to the end portion (tip) different from the base end of the boom 4. It is rotatably supported in the direction, and the bucket 6 is rotatably supported in the vertical direction at the other end of the arm 5. The boom 4, arm 5, bucket 6, upper swivel body 2, and lower traveling body 3 are hydraulic actuators such as a boom cylinder 4a, an arm cylinder 5a, a bucket cylinder 6a, a swivel motor 2a, and left and right traveling motors 3a (however, the left and right traveling motors 3a). Only one traveling motor is driven by (shown).

The boom 4, arm 5, and bucket 6 operate on a plane including the front device 1, and this plane may be referred to as an operating plane below. That is, the operating plane is a plane orthogonal to the rotation axis of the boom 4, arm 5, and bucket 6, and can be set at the center of the boom 4, arm 5, and bucket 6 in the width direction.

In the driver's cab (cab) 9 on which the operator is boarded, operation signals for operating the hydraulic actuators 2a to 6a based on the operation input from the operator, that is, front device 1, upper swivel body 2 and lower traveling body 3 Operation levers (operation devices) 9a, 9b, 9c, 9d for outputting an operation signal for operating the above are provided.

The operating levers 9a and 9b can be tilted back and forth and left and right, respectively, and operations of the hydraulic actuators 2a, 4a, 5a and 6a are assigned to the operating levers 9a and 9b in the front-back direction or the left-right direction, respectively. On the other hand, the operation levers (travel levers) 9c and 9 can be tilted in the front-rear direction, respectively. It is assigned to the forward / backward movement of the motor 3. Further, the operating levers 9a, 9b, 9c, and 9d include sensors (not shown) that electrically detect the tilting direction and tilting amount of the lever, that is, the lever operating direction and operating amount, respectively, and these sensors detect them. The lever operation direction and operation amount are output as operation signals to the controller 16 which is a control device via electrical wiring.

Hereinafter, an operator such as a sensor for detecting the lever operation direction and operation amount of these operation levers 9a, 9b, 9c, 9d, and a sensor for detecting the operation content of the operator for an input device such as a console panel installed in the cab 9. Sensors that detect the operation of are collectively referred to as an operation detection device C05.

Operation control of the boom cylinder 4a, arm cylinder 5a, bucket cylinder 6a, swivel motor 2a, and left and right traveling motors 3a is supplied from the hydraulic pump device 7 driven by a prime mover such as an engine or an electric motor to each hydraulic actuator 2a to 6a. This is done by controlling the direction and flow rate of the hydraulic oil to be operated by the control valve 8. The control valve 8 is operated by a drive signal (pilot pressure) output from a pilot pump (not shown) via an electromagnetic proportional valve. The operation of each hydraulic actuator 2a to 6a is controlled by controlling the electromagnetic proportional valve with the controller 16 based on the operation signals from the operation levers 9a and 9b.

The operating levers 9a, 9b, 9c, 9d may be hydraulic pilot type, and the pilot pressure according to the operating direction and operating amount of the operating levers 9a, 9b, 9c, 9d operated by the operator, respectively, is controlled by the control valve. It may be configured to supply to 8 as a drive signal and drive each hydraulic actuator 2a to 6a.

The upper swivel body 2 includes an inertial measurement unit (IMU) 12 which is an attitude sensor for detecting the tilt angle of the upper swivel body 2 with respect to a predetermined plane (for example, a horizontal plane), and two GNSS antennas 13 shown in FIG. 14 is attached.

The inertial measurement unit 12 measures the angular velocity and the acceleration. For example, considering the case where the upper swivel body 2 to which the inertial measurement unit 12 is attached is stationary, the direction of the gravitational acceleration in the IMU coordinate system set in the inertial measurement unit 12 (that is, the vertical downward direction) and the inertial measurement. The tilt (pitch angle) of the upper swivel body 2 in the front-rear direction can be detected based on the mounting state of the device 12 (that is, the relative positional relationship between the inertial measurement unit 12 and the upper swivel body 2). ..

A potentiometer, an inertial measurement unit, or a cylinder stroke sensor is installed at an appropriate position on the boom 4, arm 5, and bucket 6 which are the constituent members of the front device 1 as posture sensors for measuring their respective postures. There is. Hereinafter, the sensors that measure and calculate the posture of the front device 1 are collectively referred to as the posture measuring device C02.

FIG. 2 is a schematic view of the hydraulic excavator 100 of FIG. 1 as viewed from the side surface, and as shown in this figure, two GNSS antennas 13 and 14 are mounted on the upper swing body 2. For convenience of explanation, the GNSS antenna 13 may be referred to as a main antenna (first antenna), and the GNSS antenna 14 may be referred to as a sub-antenna (second antenna).

A positioning terminal (position measuring device) 15 mounted in the structure of the driver's cab 9 or the upper swing body 2 based on satellite signals (preferably signals from four or more satellites) received by each of the GNSS antennas 13 and 14. Performs positioning calculations for the two antennas 13 and 14. The positioning terminal 15 has a processing device (for example, a CPU) and a storage device in which a program for the processing device to measure the positions of the two antennas 13 and 14 from the satellite signals received by the two antennas 13 and 14 is stored. It is a controller for positioning. The positioning terminal 15 outputs the positioning results of the two antennas 13 and 14 in the NMEA format including the latitude, longitude and geoid height of the respective GNSS antennas 13 and 14. Positioning of two antenna positions may be performed by one positioning terminal, or each antenna may be equipped with a positioning terminal. Hereinafter, for the sake of simplicity, the positioning system composed of the two GNSS antennas 13 and 14 and the positioning terminal 15 is collectively referred to as a position measuring device C01.

Similar to the positioning terminal 15, the controller 16 is arranged in the structure of the driver's cab 9 or the upper swing body 2. The controller 16 has a processing device (for example, a CPU) and a storage device (for example, a semiconductor memory such as a ROM or RAM) in which a program executed by the processing device is stored. The controller 16 of the present embodiment receives signals from various sensors (inertial measurement unit 12, attitude measurement device C02 and operation detection device C05) and a positioning terminal 15 in the position measurement device C01, and performs various calculations related to the operation of the excavator 100. Is going.

FIG. 3 is a functional block diagram showing an outline of the processing function of the controller 16 according to the embodiment of the present invention. The results detected by the position measuring device C01 including the GNSS antennas 13 and 14 and the positioning terminal 15, the inertial measuring device 12, the attitude measuring device C02, and the operation detecting device C05 are input to the controller 16. Based on this information, the controller 16 has a machine guidance function for displaying instructions on a display device C03 such as a display provided in the driver's cab 9, a control valve 8 for controlling the movement of the front device 1, and each of them. It is equipped with a machine control function that controls the hydraulic control device C04 that drives the hydraulic actuators 2a to 6a. Although various functions for controlling the shovel 100 are mounted on the controller 16, the description of the functions not directly related to the present invention is omitted.

The specific calculation contents of each part in the controller 16 of FIG. 3 will be described. The controller 16 includes an upper swing body angle calculation unit C10, a relative angle calculation unit C11, a front posture calculation unit C12, an operation determination unit C20, a vehicle body posture calculation unit C13, an operation instruction calculation unit C14, and a work support calculation unit. It is equipped with C15.

The upper swivel body angle calculation unit C10 calculates the swivel center coordinates and the orientation of the front device 1 in the upper swivel body 2 according to the detection values of the position measuring device C01 and the inertial measuring unit 12. Specifically, as shown in FIG. 4, the angle of the straight line passing through the positions of the two GNSS antennas 13 and 14 in the plane coordinates is calculated from the coordinates of the main antenna 13 and the sub antenna 14 calculated by the positioning terminal 15. Further, the angle θ of the front device 1 is calculated from the geometrical relationship between the antennas 13 and 14 and the front work device 1.

When the hydraulic excavator 100 is performing a turning operation, the front is integrated by integrating the angular velocity ω detected by the inertial measurement unit 12 from the angle θ ₀ obtained from the positions of the above-mentioned GNSS antennas 13 and 14. The angle θ may be calculated according to the equation (3).

The relative angle calculation unit C11 calculates the relative angle α formed by the upper swivel body 2 and the lower traveling body 3. The detection value of the position measuring device C01 (positions of the main antenna 13 and the sub-antenna 14 before and after the traveling operation by the lower traveling body 3) is used for the calculation of the relative angle α. It is also possible to use the detection value of the inertial measurement unit 12 and the output of the operation determination unit C20. Since the calculation content of the relative angle calculation unit C11 is the main feature of this embodiment, the detailed content thereof will be described later.

The front posture calculation unit C12 calculates the posture of the front device 1 based on the detected value of the posture measuring device C02. The posture of the front device 1 includes the postures of the front members 4, 5 and 6 as well as the position of the claw tip of the bucket 6 which is the tip of the front device 1. For example, as shown in FIG. 5, in the coordinate system (xb, yb, zb) with the boom foot pin, which is the center of rotation of the boom 4, as the origin, the boom 4, the arm 5, and the bucket 6 (to be exact, the boom length L). _Assuming that the angles (posture angles) of _bm , arm length Lam, and bucket length L _bk are θ _bm , θ _am , and θ _bc , respectively, the claw tip positions of the bucket 6 are set to the following equations (4) and It can be obtained from the equation (5).

When the potentiometer is used as the attitude measuring device C02, each attitude angle θ _bm , θ _am , and θ _bc can be obtained directly, but when using the inertial measurement unit or the cylinder stroke sensor, the detected value is the attitude angle. An operation to convert to θ _bm , θ _am , and θ _bk is also required.

The vehicle body posture calculation unit C13 integrates information on the posture of the hydraulic excavator 100 based on the calculation results of the upper turning body angle calculation unit C10, the relative angle calculation unit C11, and the front posture calculation unit C12. More specifically, the coordinates of the boom foot pin in the world coordinate system can be calculated according to the turning center coordinates calculated by the upper turning body angle calculation unit C10, the orientation of the front device 1, and the dimensional information of the hydraulic excavator 100. After that, when the bucket claw tip position calculated by the front attitude calculation unit C12 is integrated with the coordinates of the boom foot pin as the origin, the bucket claw tip position in the world coordinate system can be calculated. Further, by using the relative angle α of the upper swivel body 2 and the lower traveling body 3 calculated by the relative angle calculating unit C11 with reference to the turning center coordinates calculated by the upper turning body angle calculation unit C10, the lower traveling body It is possible to calculate the direction (absolute angle) of 3.

The operation support calculation unit C14 performs a calculation related to machine guidance that supports the operator's operation based on the calculation result of the vehicle body posture calculation unit C13 and the operation content determined by the operation judgment unit C20, and displays the instruction content. Output to C03. The support contents include displaying the positional relationship between the predetermined target surface and the bucket, and according to the bucket coordinates calculated by the vehicle body posture calculation unit C13 so that the tip of the bucket 6 does not slip below the target surface. A display prompting the operation of the boom raising lever, a display prompting the operation of the traveling lever so that the direction of the lower traveling body is aligned with the work surface for the work shown in FIG. 18 and the like can be mentioned. The operation instruction calculation unit C14 may be provided with a guidance function for other work, but the description thereof will be omitted because it is not directly related to the present embodiment.

The work support calculation unit C15 performs a calculation related to machine control that automatically or semi-automatically controls the operation of the hydraulic excavator 100 based on the calculation result of the vehicle body posture calculation unit C13 and the operation content determined by the operation determination unit C20. Then, the command value for executing this operation is output to the hydraulic control device C04. The hydraulic pressure control device C04 controls the operation of the hydraulic excavator 100 including the front device 1 based on the input command value. As an example of semi-automatic control of the operation of the hydraulic excavator 100, the front device 1 (more specifically, the claw tip of the bucket 6) is located on or above the target surface when the operating devices 9a and 9b are operated. There is a device that limits the speed at which 1 approaches the target surface to a predetermined speed limit or less.

Next, the configuration of the relative angle calculation unit C11 will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 6 is an example of an embodiment of the relative angle calculation unit C11. In FIG. 6, consider a case where only the detection value of the position measuring device C01 is used as the input of the relative angle calculation unit C11. For convenience of explanation, the coordinates (position) of the main antenna 13 calculated by the position measuring device C01 at the time t1 (first time) are the coordinates 13a, the coordinates (position) of the sub-antenna 14 are the coordinates 14a, and the time t2 ( The coordinates (position) of the main antenna 13 calculated by the position measuring device C01 at the second time) are referred to as coordinates 13b, and the coordinates (position) of the sub-antenna 14 are referred to as coordinates 14b.

The relative angle calculation unit C11 of FIG. 6 includes a first position information storage unit A01, a second position information storage unit A02, a first vehicle body angle calculation unit A03, a second vehicle body angle calculation unit A04, and a traveling displacement angle calculation. A unit A05, a deviation angle calculation unit A06, a traveling displacement angle correction unit A07, and a relative angle calculation unit A08 are provided.

The first position information storage unit A01 and the second position information storage unit A02 are configured in the storage area of the storage device in the controller 16.

The first position information storage unit A01 stores the main antenna position 13a and the sub antenna position 14a at time t1 (first time). The first position information storage unit A01 refers to information on positioning accuracy such as DOP (Dilution Of Precision) and position identification quality output from the positioning terminal 15, and performs positioning with the accuracy required for subsequent calculations. Memorize the location information of the time. For example, when using RTK, the location identification quality is "RTK-FIX", that is, the quality of "GGA" in the NMEA message, which is the standard format of GNSS, is 4. By confirming that and storing the position information, the error of the positioning result can be reduced to about 2 cm. It is desirable that the shovel 100 is not operated from the time t1 onward until the above-mentioned position information is stored.

The second position information storage unit A02 stores the main antenna position 13b and the sub antenna position 14b at time t2 (second time). Like the first position information storage unit A01, the first position information storage unit A02 also stores the position information when the desired positioning accuracy is guaranteed. Similarly, it is desirable not to operate the excavator 100 until the position information is stored.

The relationship between time t1 and time t2 will be described with reference to the time chart of FIG.

First, the operation of the excavator 100 is not restricted before the time t1. The storage of the position information output from the position measuring device C01 is started at the time t1, and the excavator 100 is stopped until the time ta where the desired accuracy (for example, 2 cm of RTK-FIX) is guaranteed. Then, the storage of the position information is finished at the time ta.

After the storage of the position information is completed at the time ta, the operation of the excavator 100 is permitted again. However, as will be described later, it is desirable not to perform any operation other than running from time ta onward to time t2.

When the storage of the position information output from the position measuring device C01 is started again at the time t2, the operation of the excavator 100 is stopped until the time tb where the position accuracy is guaranteed. Similarly, the storage of the position information is finished at the time tb.

By executing the above operation, it is possible to suppress the calculation error of the relative angle α between the lower traveling body 3 and the upper turning body 2 due to the positioning error due to the GNSS. In the following, for the sake of simplicity, it is assumed that the accuracy of "RTK-FIX" is guaranteed even at times t1 and t2.

The first vehicle body angle calculation unit A03 is the direction (angle) of the upper swivel body at time t1 based on the main antenna coordinates 13a and the sub-antenna coordinates 14a stored in the first position information storage unit A01 at time t1. The first vehicle body angle θ ₁ is calculated. The specific calculation is based on FIG. 4, but for the sake of simplicity, it is assumed that the hydraulic excavator 100 is arranged on a sufficiently smooth plane (there is no displacement in the height direction z). Then, assuming that the plane coordinates 13a of the main antenna 13 at time t1 are (x1, y1) and the plane coordinates 14a of the sub-antenna 14 are (x2, y2), a straight line passing through the antennas 13 and 14 at time t1 is predetermined. The angle θ ₁ formed with the reference line (horizontal line in FIGS. 8 and 9) can be given by the following equation (6).

The second vehicle body angle calculation unit A04 is the direction (angle) of the upper swivel body at time t2 based on the main antenna coordinates 13b and the sub antenna coordinates 14b stored in the second position information storage unit A02 at time t2. The second vehicle body angle θ ₂ is calculated. Assuming that the plane coordinate 13b of the main antenna 13 at time t2 is (x3, y3) and the plane coordinate 14b of the sub antenna 14 is (x4, y4), the straight line passing through the antennas 13 and 14 at time t2 is a predetermined reference line. The angle θ ₂ (see FIGS. 8 and 9) formed with (horizontal line in FIGS. 8 and 9) can be given by the following equation (7).

The traveling displacement angle calculation unit A05 is based on the position of one of the two antennas 13 and 14 at times t1 and t2 stored in the first position information storage unit A01 and the second position information storage unit A02. , The traveling displacement angle ψ (φ), which is the angle formed by the straight line passing through the position of one of the antennas at time t1 and time t2 with the predetermined reference line, is calculated. The traveling displacement angle ψ (φ) is an angle of the GNSS antenna generated by the traveling operation of the lower traveling body 3 performed between the time ta and the time t2 after the time t1.

Here, the traveling displacement angle ψ is calculated from the position of the main antenna 13 at times t1 and t2. Assuming that the operator only operates the traveling lever between the time ta and the time t2 in FIG. 7, the angle ψ formed by the straight line passing through the main antenna coordinates 13a before traveling and the main antenna coordinates 13b after traveling is as follows. Calculate with equation (8).

An example of the above operation is shown in FIG. If the locus of the lower traveling body 3 is completely straight, the x-coordinates of the main antenna coordinates 13a and 13b before and after traveling are the same, so that the traveling displacement angle ψ = 0 as shown in FIG. Further, θ1 = θ2 also holds.

Further, FIG. 9 shows an example of a posture in which the relative angles α of the lower traveling body 3 and the upper turning body 2 are different from those of FIG. Similarly to FIG. 8, if the locus of the lower traveling body 3 is completely straight, θ1 = θ2 is established.

As can be seen from FIGS. 8 and 9, the angle ψ calculated by Eq. (8) is equal to the absolute angle of the lower traveling body 3. However, it should be noted that this is limited to the case where the trajectory of the lower traveling body 3 during the traveling operation is completely straight. That is, since it usually meanders due to slipping or the like, the locus of the lower traveling body 3 does not become a straight line.

The deviation angle calculation unit A06 travels the lower traveling body 3 based on the information stored in the first position information storage unit A01 and the second position information storage unit A02 and the calculation result of the first vehicle body angle calculation unit A03. The deviation angle δφ, which is the angle caused by meandering during operation, is calculated.

Here, FIG. 10 shows an example of the change in the coordinates of the GNSS antenna when the deviation angle δφ occurs. To simplify the explanation, consider the case where the coordinates 13a and 14a of the main antenna 13 and the sub-antenna 14 at the time t1 stored in the first position information storage unit A01 are on the X'coordinates (two points 13a, It may be considered that the X'axis is taken so as to connect 14a). From FIG. 10 onward, for the sake of simplicity, the traveling displacement angle of the lower traveling body 3 will be described using φ with the X'axis as 0 degree instead of the above-mentioned ψ. Since the relationship of "ψ + φ = 90 degrees" holds between ψ and φ in Fig. 8.9, it can be easily converted.

First, assuming that the lower traveling body 3 can travel straight along the initial angle of the lower traveling body 3 (the angle of the lower traveling body 3 at t1) φ', the coordinates of the antennas 13 and 14 at time t2 are shown in FIG. It becomes 13c and 14c in. Note that if the vehicle can run straight, the vector connecting the main antenna coordinates 13c and the sub-antenna coordinates 14c will be parallel to the X'axis (the vector connecting the two coordinates 13a and 14a).

However, in the actual running operation, the crawler type lower running body 3 slips between the foot and the ground and meanders, so that each antenna 13 at time t2 stored in the second position information storage unit A02, The coordinates of 14 are, for example, 13b and 14b. In such a case, the angle φ obtained by performing the calculation of Eq. (8) using the coordinates of 13b and 14b becomes a value different from the initial angle (φ'in FIG. 10) of the lower traveling body 3. Will end up. In the present application, the difference in angles generated in this way is referred to as a deviation angle δφ. As is clear from FIG. 10, the deviation angle δφ is the difference (δφ = φ'−φ between the angle φ ′ formed by the lower traveling body 3 with the predetermined reference line (X'axis) and the traveling displacement angle φ at time t1. ).

(1) Approximation of deviation angle δφ by angle θc 1
An example of the calculation method of the deviation angle δφ will be described with reference to FIGS. 11a and 11b. This example is accurate when the deviation angle δφ is sufficiently small.

First, as shown in FIG. 11a, the moving distance of the main antenna 13 between the time t1 and the time t2 is l1, and similarly, the moving distance of the sub-antenna 14 between the time t1 and the time t2 is l2, and the main antenna 13 and the sub. Assuming that the distance between the antennas 14 is H, each value can be calculated by the following equations (9), (10), and (11) using the coordinate values of the two antennas 13 and 14 at times t1 and t2.

In the equation (11), the main antenna coordinates 13a and the sub-antenna coordinates 14a at the time t1 stored in the first position information storage unit A01 are used, but the time t2 stored in the second position information storage unit A02. The respective coordinates 13b and 14b in the above may be used.

Here, paying attention to the fact that the trajectory change due to the slip of the foot and the ground can be approximated as a rotational motion around the far point CO, the moving distance l1 of the main antenna 13 is a part of the outer circumference of the circle of radius (H + R), the sub. The moving distance l2 of the antenna 14 can be regarded as a part of the outer circumference of the circle having the radius R. At this time, the respective moving distances l1 and l2 can be approximated by the following equation.

Since the unknown variables in (12) and (13) are two variables, R and θc, R and θc can be calculated numerically by combining (12) and (13). That is, in this example, the moving distances l1 and l2 of the two antennas 13 and 14 are fan-shaped arcs (however, the radii are R + H and R) having the same center and having a deviation angle δφ as a central angle θc. Calculate the deviation angle δφ.

Consider the sub-antenna coordinates 14a and 14b stored in the first position information storage unit A01 and the second position information storage unit A02 at the times t1 and t2 and the triangle having the far point CO as the apex, and obtain the following from the cosine theorem ( 14) Equation may be added.

However, although the equation (14) is an equation when the sub-antenna coordinates are used, the main antenna coordinates 13a and 13b may be used instead.

(2) Approximation of deviation angle δφ by angle θc 2
Further, consider the case where the X'-Y'coordinate system is taken so as to connect the coordinates 13a and 14a of the main antenna 13 and the sub-antenna 14 at the time t1 stored in the first position information storage unit A01 (FIG. 10). , As shown in FIG. 11b, the angle formed by the straight line passing through the coordinates 13b and 14b of the main antenna 13 and the sub-antenna 14 at time t2 is θc, and therefore the inverse tangent defined by the following equation (15). You can also find θc with a function.

Note that (x3', y3') and (x4', y4') in the above equation (15) are the main antenna coordinates at time t2 stored in the second position information storage unit A02 in the X'-Y' coordinate system. 13b and sub-antenna coordinates 14b.

(3) Approximation of deviation angle δφ by angle θd If the deviation angle δφ is sufficiently small, it can be regarded as δφ = θc, but if not, the approximation accuracy may not be high. Next, an example of a method for improving the approximation accuracy as compared with the case of approximating with θc will be described with reference to FIG.

First, as shown in FIG. 12a, the coordinates 14d of the virtual sub-antenna at the second time t2 are calculated by using the angle φ before and after the movement of the main antenna 13 calculated by the equation (8). The coordinates 14d are the sub-antenna 14 at time t2 on the assumption that the lower traveling body 3 can travel straight along the traveling displacement angle φ due to the traveling operation performed between the time ta and the time t2 after the time t1. Indicates a virtual position. Assuming that the coordinates 14d of the virtual sub-antenna 14 are (xp, yp), it can be specifically given by the following equations (16) and (17).

That is, xp and yp can be defined based on the moving distance l1 of the main antenna 13 between the time t1 and the time t2, the coordinates 14a (x2, y2) of the sub-antenna 14 at the time t1, and the traveling displacement angle φ.

Further, since the distance between the main antenna 13 and the sub-antenna 14 at the same time is constant (the distance is given by H in the equation (11)), the sub-antenna coordinates at the time t2 stored in the second position information storage unit A02. The 14b and the virtual sub-antenna coordinates 14d at the time t2 are arranged on the circumference of the radius H centered on the main antenna coordinates 13b at the time t2 stored in the second position information storage unit A02. This situation is shown in FIG. 12b.

In this example, a straight line passing through the sub-antenna coordinate 14a at time t1 and the virtual sub-antenna coordinate 14d at time t2, and a straight line passing through the sub-antenna coordinate 14b at time t2 and the virtual sub-antenna coordinate 14d at time t2. The deviation angle δφ is approximated by the angle θd formed. θd can be calculated by using the cosine theorem on the triangle consisting of the three sides a, b, and c shown in FIG. 12b, which has three coordinates 14a, 14b, and 14d at the vertices. The side a is the side connecting the two vertices 14a and 14b, the side b is the side connecting the two vertices 14a and 14d, and the side c is the side connecting the two vertices 14d and 14b.

When the deviation angle δφ is small, θd gradually approaches 0 as the sub-antenna coordinate 14b approaches the virtual sub-antenna coordinate 14d along the circumference in FIG. 12b. Similarly, it can be confirmed that the above-mentioned θc also approaches 0 as the sub-antenna coordinate 14b approaches the virtual sub-antenna coordinate 14d along the circumference. This is the reason for the above-mentioned "when the deviation angle is sufficiently small, it can be regarded as δφ = θc".

By the way, FIG. 21 shows the relationship between the deviation angle δφ and its approximate calculated values θc and θd.
First, θc is calculated as a rotation angle around the X'axis using the coordinate values of the two points 13b and 14b at the time t2 that can be actually measured, as shown in the equation (15).

On the other hand, θd is the coordinate values of the two points 14a and 14b at the actually measurable times t1 and t2 and the coordinate values of the virtual positioning points 14d obtained by calculation, as shown in the equations (18) to (21). That is, it is calculated as an angle formed by two straight lines 14a-14d and 14b-14d using the coordinate values of three points.

Here, the straight line 14d-14b is extended, and the coordinates of the intersection with the X'axis are defined as 14e. If the mileage of the lower traveling body 3 is sufficiently long, the straight lines 14a-14c and the straight lines 14d-14e have an approximately parallel relationship. Using this parallel relationship, it can be confirmed that θd and δφ match. This is the reason why δφ can be accurately approximated by θd.

Focusing on the geometrical relationship of each point in FIG. 21, it seems that there is no clear relationship between the deviation angles δφ and θc. However, as shown in FIG. 12b, the values of θc and θd gradually approach each other as the deviation (deviation angle δφ) of the lower traveling body 3 becomes smaller (that is, when 14b and 14d become closer). This relationship between θc and θd is the reason why it is quite appropriate to use θc in the calculation of the deviation angle δφ. However, it should be noted that θc is only an approximate value of “θd, which is an approximate value of δφ”, and is often inferior to θd in terms of accuracy.

The traveling displacement angle correction unit A07 corrects the traveling displacement angle φ in consideration of the deviation angle generated during traveling based on the calculation results of the traveling displacement angle calculation unit A05 and the deviation angle calculation unit A06. Calculate the traveling displacement angle φ'.

More specifically, the correction is made by the following equation. That is, the value obtained by adding the deviation angle δφ to the traveling displacement angle φ is defined as the corrected traveling displacement angle φ'. The corrected traveling displacement angle φ'is the angle (direction) of the lower traveling body 3 before the traveling operation (for example, time t1).

As shown in FIGS. 8 and 9, when the lower traveling body is completely moved straight, the deviation angle δφ = 0 holds, so φ'= φ.

The relative angle calculation unit A08 calculates the relative angle α formed by the upper turning body 2 and the lower traveling body 3 based on the calculation results of the first vehicle body angle calculation unit A03 and the traveling displacement angle correction unit A07. Specifically, the calculation may be performed according to "α = θ ₁ − φ'". That is, the value obtained by subtracting the corrected traveling displacement angle φ'from the first vehicle body angle θ ₁ is the relative angle α between the upper turning body 2 and the lower traveling body 3 at time t1.

As described above, in the work machine provided with the crawler type lower traveling body 3, for example, the angle of the lower traveling body 3 is φ'(FIG. 10) at the time t1 before traveling, and the lower traveling body 3 is held in that state. Even if an operation to make the vehicle go straight is input, the lower traveling body 3 will meander due to slipping during traveling, and the angle of the lower traveling body 3 at time t2 after traveling is a value φ different from the angle before traveling (FIG. 10). ). Therefore, even if the movement direction φ is calculated from the change in the position of either of the two GNSS antennas 13 and 14 installed on the upper swing body 2 before and after running, the angle φ'of the lower running body 3 before running is accurate. It was difficult to calculate.

However, since the work machine of the present embodiment includes the controller 16 having the relative angle calculation unit C11 for executing the above calculation, the deviation angle δφ (δφ) generated as a result of the lower traveling body 3 meandering during the traveling operation. By accurately approximating = φ'-φ) with other angles θc and θd, the angle φ'of the lower traveling body 3 at time t1 can be calculated. As a result, the relative angle α between the upper swivel body 2 and the lower traveling body 3 at time t1 can be calculated. The relative angle α of the body 3 can be calculated. In particular, the present embodiment has an advantage that a series of angles θc, θd, and α can be calculated only from the positioning results of the two GNSS antennas 13 and 14. The method of using the positioning result of GNSS is different from the configuration in which the rotation angle sensor is provided on the turning shaft shown in Patent Document 2, and even if the GNSS (position measuring device C01) should break down, it is very easy to replace or repair it. Is. In recent years, the number of hydraulic excavators equipped with two GNSS antennas has increased due to the progress of computerized construction, and the application to such hydraulic excavators is superior in terms of initial cost compared to the configuration equipped with a dedicated rotation angle sensor. There is.

Further, if the relative angle α calculated as described above is displayed on the display device C03 in the driver's cab 9, for example, the display device is displayed even if the operator forgets the direction of the lower traveling body 3 during the work by the front device 1. Since the relative angle between the upper swing body 2 and the lower traveling body 3 can be grasped at any time by referring to C03, it is possible to prevent the front device 1 from moving forward in an erroneous direction when starting the traveling operation after the work is completed. The use of the relative angle α is not limited to this, and it can be used in various forms in the machine guidance function and the machine control function.

<Second Embodiment>
FIG. 13 is a functional block diagram of the relative angle calculation unit C11 in the second embodiment. The relative angle calculation unit C11 of the present embodiment is characterized in that the output of the inertial measurement unit (IMU) 12 is input to the deviation angle calculation unit D06, and the output is used for the calculation content in the deviation angle calculation unit D06. There is. Except for the contents described below, the same processing as that of the first embodiment shall be executed for the other parts having the same names as those of the first embodiment, and the description thereof will be omitted.

The inertial measurement unit 12 can detect the sum (ω = ωu + ωb) of the angular velocity ωu of the upper swing body 2 and the angular velocity ωb of the lower traveling body 3. Here, if the condition that the upper swing body 2 is not rotated (ωu = 0) is imposed between the time t1 and the time t2, the detection value of the inertial measurement unit 12 is the angular velocity ω = ωb of the lower traveling body. Therefore, if this angular velocity is used, the above-mentioned angle θc can be calculated by the following equation (23). The integration interval in the equation (23) can be set from time t1 to time t2, for example.

That is, the deviation angle calculation unit D06 of the present embodiment calculates the integrated value of the angular velocity detected by the inertial measurement unit 12 from the time t1 to the time t2 as the deviation angle δφ. Even if the deviation angle δφ is calculated in this way, the relative angle α between the upper swing body 2 and the lower traveling body 3 can be calculated. However, when a highly accurate inertial measurement unit (IMU) 12 is used to detect the angular velocity ωb of the lower traveling body 3 as in the present embodiment, θc is based on the GNSS positioning results and equations (14) and (15). It is possible to obtain a more accurate value than the method of the first embodiment for calculating. Further, in recent years, with the progress of computerized construction, the number of hydraulic excavators equipped with an inertial measurement unit (IMU) 12 for detecting the inclination angle of the upper swivel body 2 has increased, and this embodiment is applied to such hydraulic excavators. In this case, there is an advantage in terms of initial cost as compared with a configuration provided with a dedicated rotation angle sensor.

In the present embodiment, the inertial measurement unit 12 attached to the upper swing body 2 acquires the angular velocity ωb of the lower traveling body, but if the sensor can acquire the angular velocity ωb of the lower traveling body 3, another angular velocity detection sensor is used. It doesn't matter. Further, the inertial measurement unit 12 may be attached to the lower traveling body 3 to detect the angular velocity ωb.

<Third Embodiment>
FIG. 14 is a functional block diagram of the relative angle calculation unit C11 in the third embodiment. In this embodiment, in addition to the configuration of the second embodiment, the output of the operation determination unit C20 is input to the relative angle calculation unit C11 and used for the calculation in the deviation angle calculation unit E06 and the traveling displacement angle calculation unit E05. .. Except for the contents described below, the same processing as that of the second embodiment shall be executed for the other parts having the same names as those of the second embodiment, and the description thereof will be omitted.

The operation determination unit C20 inputs a signal output from the operation detection device C05, monitors, for example, the operation direction and the operation amount of the operation levers 9a, 9b, 9c, 9d, and what kind of operation the operator has with respect to the excavator 100. Determine if you have entered an operation. Further, the operation determination unit C20 inputs not only the operation levers 9a, 9b, 9c, and 9d but also the signals output from the input devices including the console panel in the cab 9, and the operation contents (operation contents () are input to these input devices. It is configured so that the input contents) can also be acquired.

The deviation angle calculation unit E06 performs a calculation using the output of the operation determination unit C20 in addition to the calculation performed by the deviation angle calculation unit D06 of the second embodiment. For example, if the turning operation is performed during the running operation of the lower running body 3, the upper turning body 2 rotates (ωu ≠ 0), so that θc cannot be calculated by the equation (19). Therefore, when the deviation angle calculation unit E06 determines that the turning operation is being performed by the operation determination unit C20, the deviation angle calculation unit E06 stops the calculation of θc by the equation (19).

The traveling displacement angle calculation unit E05 also performs not only the calculation of the contents described above but also the calculation using the output of the operation determination unit C20. Assuming that the deviation angle δφ is sufficiently small, the integrated value of the angular velocity detected by the inertial measurement unit (angular velocity detection sensor) 12 coincides with the angle change Δθ of the upper swing body 2 as shown by the following equation (24). ..

By using Δθ in Eq. (24), the traveling displacement angle φ can be calculated even when the turning operation is performed during the traveling operation between the time t1 (first time) and the time t2 (second time). Can be done. Specifically, as shown in FIG. 15, when the right turn operation is performed, the angle θ ₂ calculated by the second vehicle body angle calculation unit A04 is calculated from the angle θ ₁ calculated by the first vehicle body angle calculation unit A03. Also causes a change in Δθ. Therefore, the main antenna coordinates and the sub-antenna coordinates at time t2 are rotated by Δθ with respect to the turning center, respectively, in the direction opposite to the turning operation (that is, the left turning direction) (coordinate conversion). The main antenna coordinates and the sub-antenna coordinates at time t2 obtained after the rotation operation are set as (x3c, y3c) and (x4c, y4c), respectively, and these coordinates are regarded as the coordinates 13b and 14b of the first embodiment, and the first The relative angle α can be calculated by performing the same calculation as in the embodiment.

Since the above calculation is based on the premise that the deviation angle δφ is sufficiently small, the calculation accuracy of the relative angle α tends to decrease when the turning operation is performed. Therefore, to prevent the operator from performing the turning operation, a display is output to the display device C03 to warn the operator that the turning operation is not performed during the calculation of the relative angle α (during the traveling operation by the lower traveling body 3). Is desirable.

An example of the calculation flow of the controller 16 of the present embodiment including the relative angle calculation unit C11 configured as described above will be described with reference to FIG. In the calculation flow of the controller 16 of the first and second embodiments, the processes (S01, S02, S07, S08a, S08b) related to the operation determination unit C20 and the inertial measurement unit 12 may be omitted.

When the power is set from the OFF state to the ON state, the controller 16 starts the process of FIG. First, in S1, the operation determination unit C20 determines whether the operator intends to calibrate the relative angles of the upper swing body 2 and the lower traveling body 3 based on the operation content of the console in the driver's cab 9. .. A calibration start button (input device) is provided on the console to output a calibration instruction for instructing the controller 16 to calibrate the relative angle between the upper swivel body 2 and the lower traveling body 3 based on the input from the operator. When this calibration start button is pressed by the operator, a calibration instruction is output to the controller 16 (operation determination unit C20). When this calibration instruction is input, the operation determination unit C20 determines that the operator intends to calibrate the relative angle.

If the calibration start button is not pressed and the operation determination unit C20 determines in S01 that the calibration of the relative angle is not required, the process is shifted to S02 and normal operation is performed. Normal operation means, for example, performing guidance and control (machine control) operations necessary for performing excavation operation.

When the calibration start button is pressed and the operation determination unit C20 determines that the relative angle calibration is required in S01, the process shifts to S03. In S03, the operation instruction calculation unit C14 displays on the display device C03 that the “calibration mode” is currently selected. When the calibration mode is selected, the operation instruction calculation unit C14 keeps displaying the message "Please do not perform the turning operation" on the display device C03 to urge the operator not to perform the turning operation. It is desirable to ensure calibration accuracy.

Next, in S04, the relative angle calculation unit C11 sets the position identification quality to "RTK-FIX" as to whether or not the positioning results of the main antenna 13 and the sub antenna 14 by the positioning terminal 15 are performed with sufficient accuracy. Judge by whether or not it is. This judgment may be made based on the value of DOP or the like as described above. If the accuracy is insufficient, the operation instruction calculation unit C14 displays on the display device C03 that the display device C03 waits without operation until accurate positioning is performed. If the GNSS reception environment is poor and positioning cannot be performed with the desired accuracy even after a predetermined time has passed, a message or figure prompting the user to change the calibration location (move to another location by running operation) is displayed. It may be displayed on the display device C03. Note that S04 can be omitted.

When it is confirmed that high-precision positioning has been performed in S04, the process is shifted to S05. In S05, the relative angle calculation unit C11 stores the positioning result in the first position information storage unit A01 as the position information of the two antennas 13 and 14 at the time t1 (first time) (first position storage process). .. When the position information of the two antennas 13 and 14 at time t1 is stored, the transition to S06 occurs.

In S06, the operation instruction calculation unit C14 displays, for example, a message "Please input a straight-ahead operation" on the display device C03, and causes the operator to perform a straight-ahead operation on the lower traveling body 3 via the operation levers 9c and 9d (specifically). The two operating levers 9c and 9d are tilted in the same direction by the same amount). At this time, in order to improve the accuracy of the relative angle calculation by improving the approximation accuracy of θc and θd mentioned above, the minimum mileage suitable for calibration is displayed or the mileage after inputting the straight-ahead operation is displayed. Is also good. The mileage of the lower traveling body 3 can be calculated from, for example, a change in the positioning result of GNSS. Further, the calculation may be performed by detecting the rotation speed of the traveling hydraulic motor 3a or the drive wheel of the crawler belt with a sensor.

Next, in S07, the operation determination unit C20 determines whether or not the turning operation has been performed by the operator during the straight-ahead operation. If it is determined that the turning operation has not been performed, the process shifts to S09. When it is determined that the turning operation has been performed, the processes of S08a and S08b are executed.

In S08a, the traveling displacement angle calculation unit E05 integrates the angular velocity ω detected by the inertial measurement unit 12 during the turning operation over time in order to calculate the angle change Δθ during the turning operation. The Δθ calculated here is used in S12 described later to rotate the main antenna coordinates and the sub-antenna coordinates at time t2 by Δθ with respect to the turning center in the direction opposite to the turning operation (coordinate conversion). To. As described with reference to FIG. 15, the main antenna coordinates and the sub-antenna coordinates at time t2 obtained after the rotation operation are set as (x3c, y3c) and (x4c, y4c), respectively, and these coordinates are set as the first embodiment. The relative angle α can be calculated by performing the same calculation as in the first embodiment by regarding the coordinates 13b and 14b of.

In S08b, the operation instruction calculation unit C14 displays, for example, a message on the display device C03, for example, "There is a possibility that the relative angle may be low accuracy because the turning operation was performed during traveling." As a result, the operator is notified that the calculation result of the relative angle may be low accuracy because the turning operation is performed during the traveling operation of the lower traveling body 3. Instead of this type of message, the display device C03 may display a message prompting the operator to press the calibration start button again to perform the calibration operation again.

Next, in S09, the operation instruction calculation unit C14 hides the straight-ahead travel instruction displayed on the display device C03 from S06, and urges the operator to stop the travel operation by the operation levers 9a and 9b. Instead of this, a display instructing to stop the straight-ahead operation may be displayed on the display device C03. For the purpose of improving the approximation accuracy of θc and θd, it may be set that a predetermined time has elapsed from the start of input of the traveling operation as a condition for executing S09 after S06, and the positioning result of GNSS is predetermined. It may be set that the change is equal to or greater than the distance. As a result, a sufficient mileage can be secured, so that the approximation accuracy of θc and θd is improved, and as a result, the accuracy of the relative angle α is also improved.

When the running operation is stopped, the positioning accuracy of GNSS is determined in S10 in the same manner as in S04. After confirming that positioning with sufficient accuracy has been performed, the process proceeds to S11.

In S11, the relative angle calculation unit C11 stores the positioning result in the second position information storage unit A02 as the position information of the two antennas 13 and 14 at the time t2 (second time) (second position storage process). .. When the position information of the two antennas 13 and 14 at time t2 is stored, the transition to S12 occurs. When reaching S11, all the inputs of the relative angle calculation unit C11 in FIG. 14 are aligned, so the process proceeds to the "relative angle calculation" process of S12, and the calculation of the relative angle α is performed. Since the calculation of the relative angle α is as described above, the description thereof will be omitted.

As described above, in the present embodiment, the calibration mode is entered by pressing the calibration start button provided in the driver's cab 9, and the processing sequentially performed by the relative angle calculation unit C11 for the calculation of the relative angle α is performed. Among them, it was decided to display a display instructing the start of the running operation at the timing when the running operation is required (S06) and a display instructing the end of the running operation at the timing when the running operation is no longer necessary (S09). .. As a result, it is promoted that the operator who sees these displays starts and ends the running operation at an appropriate timing, so that smooth calibration is possible and improvement in calibration accuracy can be expected.

Further, in the controller 16 of the present embodiment, the positions of the main antenna 13 and the sub-antenna 14 calculated by the positioning terminal 15 when the calibration instruction is input via the calibration start button on the console in the driver's cab 9 are set at time t1. The main antenna 13 and the sub-antenna 14 are stored in the first position information storage unit A01 as the positions 13a and 14a (S01), and after inputting the calibration instruction, the traveling operation is input via the operating devices 9c and 9d, and then the traveling operation is input. The positions of the main antenna 13 and the sub-antenna 14 calculated by the positioning terminal 15 when the input of the operation is stopped are stored in the second position information storage unit A02 as the positions 13b and 14b of the main antenna 13 and the sub-antenna 14 at time t2. (S11). As a result, the position information of the main antenna 13 and the sub-antenna 14 required for the calculation of the relative angle can be automatically acquired at appropriate timings before and after the start of the traveling operation by the lower traveling body 3.

The timing for storing the positions of the two antennas 13 and 14 in the controller 16 is when the position identification quality is "RTK-FIX" as determined in S04 and S10 of the flow of FIG. 16, that is, the positioning terminal 15. It is preferable that the variation in the positioning result due to the above is equal to or less than a predetermined value. If the controller 16 is configured in this way, the accuracy of the relative angle α can be improved.

Further, in the controller 16 of the present embodiment, the operation levers 9a, 9b, 9c, from the input of the calibration instruction by the calibration start button (S03) to the stop of the input of the traveling operation by the operation levers 9c and 9d (S09). As the display of the operation instruction using 9d, it was decided to display only the travel operation instruction via the travel operation levers 9c and 9d (S06). That is, the operation permission by the display was limited to the running operation. As a result, it is possible to prevent the approximation accuracy of the relative angle α from being lowered due to the input of a turning operation which is another operation during the traveling operation. If a message prompting that the turning operation is not input during the same period (S03-S09) is displayed on the display device C03, it is possible to suppress the turning operation during the calibration operation (including the running operation). Ensuring the accuracy of corner calibration is promoted. However, this display may be limited to the period of S06-S09 where the running operation is required.

<Others>
In FIG. 10 above, the posture of the shovel (upper swivel body 2) at time t2 is rotated to the right as compared with the posture at time t1 (that is, when it meanders to the right while traveling). As an example, it goes without saying that there is a case of rotating counterclockwise (that is, a case of meandering to the left), and in this case as well, the relative angle φ can be calculated by the same method as described above.

The present invention is not limited to the above-described embodiment, and includes various modifications within the scope not deviating 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.

Even if each configuration related to the controller 16 and the functions and execution processes of each configuration are realized by hardware (for example, designing the logic for executing each function with an integrated circuit) in part or all of them. good. Further, the configuration related to the controller 16 may be a program (software) that realizes each function related to the configuration of the controller 16 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.

1 ... front work device (front device), 2 ... upper swivel body, 3 ... lower traveling body, 9c ... traveling operation lever (operating device), 12 ... inertial measuring device (angle speed detection sensor), 13 ... main antenna (first Antenna), 14 ... Sub-antenna (second antenna), 15 ... Positioning terminal, 16 ... Controller, A01 ... First position information storage unit (storage device), A02 ... Second position information storage unit (storage device), A03 ... 1st vehicle body angle calculation unit, A04 ... 2nd vehicle body angle calculation unit, A05 ... Traveling displacement angle calculation unit, A06 ... Deviation angle calculation unit, A07 ... Traveling displacement angle correction unit, A08 ... Relative angle calculation unit, C03 ... Display device , C20 ... Operation judgment unit, θ ₁ ... First vehicle body angle (vehicle body angle), ψ, φ ... Traveling displacement angle, δφ ... Deviation angle, φ'... Corrected traveling displacement angle, θc ... Approximate angle of deviation angle, θd ... Approximate angle of deviation angle

Claims (7)

A crawler-type lower traveling body, an upper swivel body rotatably attached to the upper part of the lower traveling body, a first antenna and a second antenna attached to the upper swivel body, the first antenna and the first antenna. In a work machine equipped with a positioning terminal that calculates the position of each of the two antennas and a controller that calculates the relative angle between the upper swing body and the lower traveling body.
The controller is
The positioning terminal moves at the positions of the first antenna and the second antenna calculated by the positioning terminal at the first time, and at the second time after the lower traveling body performs the traveling operation after the first time. A storage device that stores the calculated positions of the first antenna and the second antenna, and
A vehicle body angle calculation unit that calculates a first vehicle body angle, which is an angle of the upper swing body at the first time, from the positions of the first antenna and the second antenna at the first time.
Based on the positions of the first antenna at the first time and the second time, a straight line passing through the positions of the first antenna at the first time and the second time is an angle formed by a predetermined reference line. A traveling displacement angle calculation unit that calculates the displacement angle, and
Based on the positions of the first antenna and the second antenna at the first time and the second time, the difference between the angle formed by the lower traveling body with the reference line and the traveling displacement angle at the first time. A deviation angle calculation unit that calculates a certain deviation angle, and
A traveling displacement angle correction unit that corrects the traveling displacement angle using the deviation angle, and a traveling displacement angle correction unit.
A relative angle calculation unit for calculating the relative angle between the upper turning body and the lower traveling body at the first time based on the traveling displacement angle corrected by the traveling displacement angle correction unit and the first vehicle body angle is provided. A work machine characterized by that. In the work machine of claim 1,
The deviation angle calculation unit is
Based on the positions of the first antenna and the second antenna at the first time and the second time, the moving distance of the first antenna and the second antenna between the first time and the second time. , Calculate the distance between the first antenna and the second antenna,
A working machine characterized in that the moving distances of the first antenna and the second antenna are each regarded as a fan-shaped arc having the same center and having the deviation angle as a central angle, and the deviation angle is calculated. In the work machine of claim 1,
The deviation angle calculation unit is
Based on the positions of the first antenna at the first time and the second time, the moving distance of the first antenna between the first time and the second time is calculated.
It is assumed that the lower traveling body can travel straight along the traveling displacement angle by the traveling operation based on the moving distance of the first antenna, the position of the second antenna at the first time, and the traveling displacement angle. The virtual position of the second antenna at the second time is calculated in the case of
A straight line passing through the position of the second antenna at the first time and the virtual position of the second antenna at the second time, the position of the second antenna at the second time, and the second at the second time. The angle formed by the straight line passing through the virtual position of the two antennas is defined as the deviation angle, and the deviation angle is defined as the position of the second antenna at the first time and the second time and the second antenna at the second time. A work machine characterized in that it calculates based on the virtual position of. In the work machine of claim 1,
The position of the first antenna and the position of the second antenna at the first time and the second time stored in the storage device are the positions of the first antenna and the position of the second antenna by the positioning terminal. A work machine characterized in that it is data when the variation of the calculation result becomes a predetermined value or less. In the work machine of claim 1,
An input device that outputs a calibration instruction for instructing the controller to calibrate the relative angle between the upper swing body and the lower traveling body based on the input from the operator.
Further provided with an operating device for inputting a running operation for the lower traveling body.
The controller is
The positions of the first antenna and the second antenna calculated by the positioning terminal when the calibration instruction is input via the input device are set as the positions of the first antenna and the second antenna at the first time. Store in the storage device
After the input of the calibration instruction, the traveling operation is input via the operating device, and then when the input of the traveling operation is stopped, the positions of the first antenna and the second antenna calculated by the positioning terminal are set. A work machine characterized by storing in the storage device as the positions of the first antenna and the second antenna at a second time. In the work machine of claim 5,
Further equipped with a display device for instructing the operator of the operation content via the operation device.
The display device is characterized in that it displays an instruction to the operator to input only the traveling operation via the operating device from the input of the calibration instruction to the stop of the input of the traveling operation. Working machine to do. In the work machine of claim 1,
Further equipped with an angular velocity detection sensor attached to the upper swing body,
The deviation angle calculation unit is a work machine characterized in that the integral value of the angular velocity detected by the angular velocity detection sensor from the first time to the second time is calculated as the deviation angle.

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