Swinging work machine and direction detection method for swinging work machine

Abstract

To provide a rotation work machine detecting an orientation of a rotation base with a single position detection device.SOLUTION: A rotational work machine is provided with: a rotational base rotatable around a rotational axis center extending in a vertical direction; a work device arranged on the rotational base; a position detection device arranged on the rotational base and detecting a position; and a calculation section calculating an orientation of the rotational base based on a detected position detected with the position detection device, wherein the calculation section calculates an axis center position of the rotational axis center based on a plurality of detected positions at the time when the rotational base rotates around the rotational axis center and calculates an orientation of the rotational base based on the axis center position and the detected position.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a swivel work machine and a method for detecting the direction of the swivel work machine. [Background technology]

[0002] BACKGROUND ART A loading machine disclosed in Patent Document 1 is known in the prior art. The loading machine disclosed in Patent Document 1 is, for example, a backhoe such as a hydraulic excavator equipped with a working implement that is rotatable up and down relative to the machine body, and has a loading machine orientation sensor that measures the orientation of the loading machine. The loading machine orientation sensor is, for example, a dual-antenna GPS that has two antennas and measures the orientation from the relative positions of the antennas acquired by each antenna. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-75200 Summary of the Invention [Problem to be solved by the invention]

[0004] In the loading machine of Patent Document 1, the direction of the loading machine can be measured by a loading machine direction sensor configured with a dual antenna GPS. In order to improve the measurement accuracy of the direction of the loading machine, it is conceivable to use a device such as a GNSS receiver with high position detection accuracy as a position detection device constituting a dual antenna GPS. However, since GNSS receivers and the like are relatively expensive, there is a problem in that providing multiple GNSS receivers and the like as a dual antenna GPS increases the manufacturing cost of the loading machine.

[0005] The present invention has been made to solve the problems of the prior art, and aims to provide a swivel work machine and a method for detecting the orientation of a swivel work machine that can detect the orientation of a swivel base using a single position detection device. [Means for solving the problem]

[0006] A swivel work machine according to one aspect of the present invention includes a swivel base that can rotate around a rotation axis that extends in a vertical direction, a work device provided on the swivel base, a position detection device that is provided on the swivel base and detects a position, and a calculation unit that calculates the orientation of the swivel base based on the position detected by the position detection device. an inclination detection device for detecting an inclination angle of the swivel base; wherein the calculation unit calculates an axis position of the swivel shaft based on the plurality of detected positions when the swivel base rotates around the swivel shaft, and calculates an orientation of the swivel base based on the axis position and the detected positions. In the rotating work machine, the calculation unit has a filter processing unit that filters the multiple detected positions when the rotating base rotates, and the filter processing unit corrects an approximately arc-shaped area including an arc whose radius is the length from the rotation axis center to the position detected by the position detection device based on the tilt angle detected by the tilt detection device, and eliminates detected positions located outside the area. [Effects of the Invention]

[0007] According to the above-described swivel work machine and orientation detection method for a swivel work machine, the orientation of the swivel base can be detected by a single position detection device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic side view showing the swing work machine. [Figure 2] FIG. 2 is a schematic plan view showing the swing work machine. [Figure 3] FIG. 2 is a diagram illustrating a system of a swing work machine. [Figure 4] FIG. 10 is a plan view showing the case where the swivel base rotates around the swivel axis. [Figure 5] FIG. 10 is a plan view showing the detection position when the swivel base rotates around the rotation axis. [Figure 6A] FIG. 1 is a first diagram illustrating an example of filtering by a filter processing unit. [Figure 6B] FIG. 2 is a second diagram illustrating an example of filtering by the filter processing unit. [Figure 7A]FIG. 1 is a first diagram showing an example of an approximation line calculated by a second calculation unit. [Figure 7B] FIG. 2 is a second diagram showing an example of an approximation line calculated by the second calculation unit. [Figure 8] 10 is a diagram showing an example of a reference direction calculated by a third calculation unit and a current direction calculated by a fourth calculation unit. FIG. [Figure 9] FIG. 10 is a diagram illustrating a series of steps by which the calculation unit calculates the azimuth. [Figure 10] 10A and 10B are diagrams illustrating calculation of the position of an oscillator. [Figure 11] FIG. 10 is a diagram illustrating the calculation of a direction in the first modified example. [Figure 12] FIG. 10 is a diagram illustrating a part of a series of steps in which a calculation unit calculates a direction in the first modified example. [Figure 13] FIG. 10 is a diagram illustrating a system of a swing working machine according to a first modified example. [Figure 14] FIG. 10 is a diagram illustrating a part of a series of steps in which the calculation unit calculates the azimuth in the second modified example. [Figure 15] FIG. 10 is a diagram illustrating a system of a swing working machine in a third modified example. [Figure 16] FIG. 10 is a diagram illustrating a part of a series of steps in which the calculation unit calculates the azimuth in the third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the overall configuration of the swivel work machine 1 will be described. Fig. 1 is a schematic side view showing the swivel work machine 1. Fig. 2 is a schematic plan view showing the swivel work machine 1. As shown in Figs. 1 and 2, the swivel work machine 1 is, for example, a backhoe or the like that includes a swivel base 2, a cabin 5, a lower traveling body 10, and a working device 20. A driver's seat 6 is provided on the swivel base 2.

[0010] Hereinafter, the direction in which the worker (operator) seated in the driver's seat 6 of the rotating work machine 1 faces (the direction of arrow A1 in Figures 1, 2, etc.) will be referred to as the forward direction, and the opposite direction (the direction of arrow A2 in Figures 1, 2, etc.) will be referred to as the rearward direction. Also, the left side of the worker (the near side in Figure 1, the direction of arrow B1 in Figure 2) will be referred to as the left side, and the right side of the worker (the far side in Figure 1, the direction of arrow B2 in Figure 2) will be referred to as the right side. Also, the horizontal direction perpendicular to the fore-and-aft direction will be referred to as the width direction (see Figure 2).

[0011] The swivel base 2 is rotatable around a rotation axis (vertical axis) X that extends in the up-down direction. The swivel base 2 has a swivel base plate 17 and a weight 18. The swivel base plate 17 is supported on the lower running body 10 via a rotation bearing 3 so that it can rotate freely left and right. The center of the rotation bearing 3 is the rotation axis X, and a rotation motor MT is attached to the swivel base plate 17. The rotation motor MT is a hydraulic device driven by hydraulic oil discharged from a hydraulic pump (not shown) provided on the swivel base plate 17, and is a motor that rotates the swivel base plate 17 around the rotation axis X. The weight 18 is provided at the rear of the swivel base 2.

[0012] The lower traveling body 10 has a traveling frame (track frame) 11 and a traveling mechanism 12. The traveling frame 11 is a structure to which the traveling mechanism 12 is attached and which supports the swivel base 2 on its upper portion. The traveling mechanism 12 is, for example, a crawler-type traveling device. The traveling mechanism 12 has an idler 13, a drive wheel 14, a plurality of rollers 15, an endless crawler belt 16, and traveling motors ML and MR that are driven by hydraulic oil discharged from a hydraulic pump. The traveling motors ML and MR are composed of hydraulic motors, and drive the drive wheel 14 to cause the crawler belt 16 to travel in a circumferential direction. A dozer device 29 is provided in front of the traveling mechanism 12.

[0013] A support bracket 7 is provided at the front of the swivel base 2. A swing bracket 8 is attached to the support bracket 7. The swing bracket 8 is supported so as to be swingable around a vertical axis relative to the support bracket 7. The swing bracket 8 swings by extension and contraction of a swing cylinder (not shown) attached to the swivel base 2. In the example shown in FIGS. 1 and 2, as shown in FIG. 2, the support bracket 7 is provided at a position offset to the right from the center in the width direction of the swivel base plate 17 (on a straight line SL that passes through the swivel axis X and extends in the front-to-rear direction).

[0014] As shown in Fig. 1, the working device 20 is provided on a swivel base 2. The working device 20 has a swinging body and a bucket 25. In this embodiment, the swinging body has a boom 21 and an arm 23. The bucket 25 is attached to the tip of the swinging body, the arm 23, in a manner that allows its position to be changed. A bracket 27 is provided at the base end of the bucket 25. The bucket 25 is attached to the tip of the arm 23 via the bracket 27. The bucket 25 has side walls 25A, a bottom wall 25B, and a bucket claw 25C. The side walls 25A include a left side wall and a right side wall. The bottom wall 25B connects the left side wall and the right side wall. The bucket claw 25C is provided at the tip of the bucket 25.

[0015] The work device 20 has a boom cylinder 21a, an arm cylinder 23a, and a bucket cylinder 25a as drive mechanisms (hydraulic actuators or the like) for the boom 21, the arm 23, and the bucket 25. The boom cylinder 21a, the arm cylinder 23a, and the bucket cylinder 25a are configured by hydraulic cylinders. The base end of the boom 21 is pivotally supported by the swing bracket 8 so as to be swingable about a first rotation shaft 22. The base end of the arm 23 is pivotally supported by the tip of the boom 21 so as to be swingable about a second rotation shaft 24. The base end of the bucket 25 is pivotally supported by the tip of the arm 23 so as to be swingable about a third rotation shaft 26. The boom 21 swings up and down by the extension and contraction of the boom cylinder 21a. The arm 23 swings up and down by the extension and contraction of the arm cylinder 23a. The bucket 25 performs scooping and dumping operations by the extension and contraction of the bucket cylinder 25a.

[0016] A control valve (not shown) and the like are mounted on the right side of the swivel base 2, and the control valve controls the supply of hydraulic oil to hydraulic actuators for rotating the swivel base 2, driving the traveling mechanism 12, driving the work device 20, and the like. A prime mover 4, a hydraulic pump (not shown), and the like are mounted on the rear of the swivel base 2. The prime mover 4 is an internal combustion engine such as a diesel engine or a gasoline engine, or an electric motor, or the like. The prime mover 4 may be a hybrid type having both an internal combustion engine and an electric motor.

[0017] A cabin 5 is mounted on the upper part of the swivel base 2. The cabin 5 is a driver's seat protection device that protects a driver's seat 6. A canopy may be mounted instead of the cabin 5 as the driver's seat protection device. Around the driver's seat 6, operating devices 40 are provided, including a rotation lever for rotating the swivel base 2, a travel lever for operating the traveling mechanism 12, and an operating lever for operating the working device 20 (all not shown).

[0018] Fig. 3 is a diagram illustrating the system of the rotating work machine 1. As shown in Fig. 3, the rotating work machine 1 is equipped with a control device 30, a storage device 34, and a display device 35. The control device 30, the storage device 34, and the display device 35 can communicate with each other via an in-vehicle communication network N such as a Controller Area Network (CAN) or FlexRay. The control device 30 is a device that controls various devices possessed by the slewing work machine 1. The control device 30 is composed of electric and electronic components, programs, etc. The storage device 34 is a non-volatile memory or the like that stores an operating system and various application software, and can store various programs and various information related to the slewing work machine 1.

[0019] The display device 35 has a display screen 35a that displays various information about the revolving work machine 1, such as information about the revolving work machine 1. For example, the revolving work machine 1 has a vehicle speed detection device (vehicle speed sensor) 53 that detects the speed (vehicle speed) of the traveling mechanism 12, and the display device 35 can display the vehicle speed detected by the vehicle speed detection device 53 on the display screen 35a. The vehicle speed detection device 53 is connected to the control device 30 and outputs a signal related to the detected vehicle speed (vehicle speed signal) to the control device 30. The control device 30 causes the display device 35 to display the vehicle speed based on the vehicle speed signal. The display screen 35a of the display device 35 is disposed in a position visible to an operator seated in the driver's seat 6 inside the cabin 5 (for example, forward, diagonally forward, or to the side of the driver's seat 6). It should be noted that the display screen 35a may be capable of performing various settings related to the revolving work machine 1.

[0020] The swivel work machine 1 can calculate the orientation D of the swivel base 2 based on position information of the detected position Pd detected by the position detection device 50 provided on the swivel base 2. Furthermore, the swivel work machine 1 can calculate the position Pw of the swing body based on the calculated orientation D of the swivel base 2. Here, the orientation D of the swivel base 2 is, for example, the direction in a horizontal plane to which the working implement 20 on the swivel base 2 faces, and is the direction pointed by the tip end of the working implement 20 (the bucket 25 side) of a straight line SL that extends in the front-to-rear direction and passes through the rotation axis X. Note that the orientation D of the swivel base 2 may be any direction in a horizontal plane that points to a specific point on the swivel base 2, based on the rotation axis X, and is not limited to the direction pointed by the tip end of the working implement 20 of the straight line SL.

[0021] The following describes in detail how the swivel work machine 1 calculates the orientation D of the swivel base 2. As shown in Fig. 3, the swivel work machine 1 includes a position detection device 50, an inclination detection device 51, an angle detection device 52, and a calculation unit (orientation calculation unit) 31. The position detection device 50 is a device that detects its own position, that is, a detection position Pd. The position detection device 50 outputs position information of the detection position Pd (positioning information including latitude and longitude, and position coordinates in this embodiment) as a signal (position signal) to the control device 30. In this embodiment, the position detection device 50 detects the detection position Pd using the well-known GPS (Global Positioning System), which is an example of a Global Navigation Satellite System (GNSS). As shown in FIGS. 1 and 2, the position detection device 50 is disposed at a position away from the turning axis X.

[0022] Fig. 4 is a plan view showing the case where the swivel base 2 rotates around the rotation axis X. As shown in Fig. 4, when the lower traveling body 10 is stopped traveling and the swivel base 2 rotates around the rotation axis X, the position P' of the position detector 50 corresponding to the detection position Pd traces an arc-shaped locus with a radius R1 equal to the distance L1 between the rotation axis X and position P'. Fig. 5 is a plan view showing the detection position Pd when the swivel base 2 rotates around the rotation axis X.

[0023] 5 and the like, the x-axis direction coincides with the longitude direction, and the y-axis direction coincides with the latitude direction. For convenience of explanation, FIG. 5 and the like illustrate a case where the traveling direction (front-rear direction) of the lower running body 10 is oriented in the y-axis direction, and the width direction of the lower running body 10 is oriented in the x-axis direction. 1 and 2, in this embodiment, the position detection device 50 is attached to the upper rear part of the cabin 5 via a bracket 50a. In the example shown in FIG. 2, the position detection device 50 is provided at the center of the swivel base plate 17 in the width direction.

[0024] The mounting position of the position detection device 50 is not limited to the position shown in Figures 1 and 2, etc., as long as it can detect a predetermined position on the swivel head 2 that is horizontally distant from the rotation axis X. For example, the position detection device 50 may be attached to the roof 5a of the cabin 5, or may be attached to a weight 18, a frame (not shown), or an exterior cover 9 provided on the swivel head 2. However, to improve the reception accuracy of the GNSS positioning signal, it is preferable to mount the position detection device 50 at a relatively high position on the swivel head 2. Furthermore, to improve the detection accuracy of the direction D, it is preferable to mount the position detection device 50 at a position that is far from the rotation axis X in the horizontal direction.

[0025] For convenience of explanation, the following description will be given taking as an example a case where the position detection device 50 is attached to the upper rear part of the cabin 5, rearward of the turning axis X, and in the center in the width direction, as shown in Figure 2. The tilt detection device 51 detects the tilt angle of the swivel base 2 relative to a horizontal plane. The tilt detection device 51 outputs the detected tilt angle of the swivel base 2 as a signal (tilt signal) to the control device 30. In this embodiment, the tilt detection device 51 is an inertial measurement unit (IMU). The IMU has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. The IMU is installed on the swivel base 2, for example, below the driver's seat 6, and can detect the roll angle, pitch angle, yaw angle, and the like of the swivel base 2. Note that the tilt detection device 51 is not limited to the above-mentioned inertial measurement unit as long as it can detect the roll angle and pitch angle as the tilt angle of the swivel base 2, and may be a two-axis tilt sensor.

[0026] The angle detection device 52 is a device that detects the rotation angle θ of the swivel base 2 around the rotation axis X relative to the lower traveling structure 10. The angle detection device 52 outputs the detected rotation angle θ as a signal (angle signal) to the control device 30. In this embodiment, the angle detection device 52 is a rotary encoder. In this embodiment, the rotation angle θ is the angle formed by a straight line SL when the swivel base 2 is in an initial position (for example, the position of the swivel base 2 when the front of the working device 20 and the front of the lower traveling structure 10 are aligned) and a straight line SL in a position after the swivel base 2 has rotated.

[0027] The angle detection device 52 is an incremental rotary encoder. Therefore, the angle detection device 52 outputs pulses corresponding to the amount of rotational displacement of the shaft as an angle signal indicating the rotation angle θ to the control device 30. The angle detection device 52 is not limited to an incremental rotary encoder, but may be an absolute rotary encoder. In such a case, the angle detection device 52 outputs a code corresponding to the rotation angle, which is the absolute position from the origin, to the control device 30 as an angle signal indicating the rotation angle θ.

[0028] The angle detection device 52 is not limited to a rotary encoder as long as it can detect the rotation angle θ. The angle detection device 52 may be provided on the swivel base 2 or on the lower traveling body 10. The calculation unit 31 is composed of electric and electronic components provided in the control device 30, and a program installed in the storage device 34. The calculation unit 31 calculates the orientation D of the swivel base 2 based on the detected position Pd detected by the position detection device 50. More specifically, when the lower traveling body 10 travels and then stops, and the swivel base 2 first rotates around the rotation axis X, the calculation unit 31 calculates an approximation line AL of a circle or ellipse based on a plurality of detected positions Pd from when the swivel base 2 starts to rotate until the rotation stops (ends). The calculation unit 31 calculates the axis position Px of the rotation axis X (position coordinate of the rotation axis X) based on the approximation line AL. The calculation unit 31 also calculates the orientation D of the swivel base 2 (a reference orientation D1 which is the direction indicated by the tip of the working implement 20 on a straight line SL2 extending in the front-to-rear direction and passing through the rotation axis X when the swivel base 2 stops rotating) based on the axis position Px and the detection position Pd (any of the detection positions Pd used to calculate the axis position Px). In this embodiment, the calculation unit 31 calculates the reference orientation D1 based on the axis position Px and a reference position Pp which is the average of any of the detection positions Pd used to calculate the axis position Px and indicates the position of the swivel base 2 when it stopped rotating. Then, the calculation unit 31 calculates the current orientation D2 of the swivel base 2 (the direction indicated by the tip of the working device 20 on a straight line SL3 extending in the forward / backward direction passing through the rotation axis X) based on the rotation angle θ from the rotation position corresponding to the reference orientation D1 to the current rotation position (the difference between the rotation angle θ when the swivel base 2 stopped rotating and the current rotation angle θ) and the reference orientation D1.

[0029] 3, the calculation unit 31 includes a first acquisition unit 31a, a second acquisition unit 31b, a third acquisition unit 31c, a fourth acquisition unit 31d, a first calculation unit 31e, a filter processing unit 31f, a second calculation unit 31g, a third calculation unit 31h, and a fourth calculation unit 31i. The first acquisition unit 31a, the second acquisition unit 31b, the third acquisition unit 31c, the fourth acquisition unit 31d, the first calculation unit 31e, the filter processing unit 31f, the second calculation unit 31g, the third calculation unit 31h, and the fourth calculation unit 31i are configured by electric and electronic components provided in the control device 30, and programs installed in the storage device 34, etc.

[0030] The first acquisition unit 31a acquires the vehicle speed of the undercarriage 10 based on a vehicle speed signal output from the vehicle speed detection device 53 to the control device 30. The first acquisition unit 31a acquires the vehicle speed based on the vehicle speed signal and an arithmetic expression, an arithmetic map, or the like stored in the storage device 34. For example, of the vehicle speeds detected by the vehicle speed detection device 53, the first acquisition unit 31a acquires the vehicle speed when the undercarriage 10 is moving forward as a positive value and the vehicle speed when the undercarriage 10 is moving backward as a negative value.

[0031] The second acquisition unit 31b acquires position information (position coordinates) of the detection position Pd based on the position signal acquired by the position detection device 50 through the control device 30. The second acquisition unit 31b acquires the detection position Pd detected by the position detection device 50 as position coordinates based on the position signal and an arithmetic expression or the like stored in the storage device 34. The second acquisition unit 31b stores the position information and the time when the position detection device 50 detected the detection position Pd in ​​the storage device 34 in association with each other.

[0032] The third acquisition unit 31c acquires the roll angle and pitch angle of the swivel base 2 based on the tilt signal output from the tilt detection device 51 to the control device 30. The third acquisition unit 31c acquires the roll angle and pitch angle based on the tilt signal and an arithmetic expression stored in the storage device 34. The fourth acquisition unit 31d acquires the rotation direction and the rotation angle θ of the swivel base 2 based on the rotation signal output from the angle detection device 52 to the control device 30. The fourth acquisition unit 31d acquires the rotation direction and the rotation angle θ of the swivel base 2 based on the rotation signal and an arithmetic expression stored in the storage device 34.

[0033] For example, the fourth acquirer 31d acquires the rotation direction of the swivel head 2 based on the output timing of the A-phase pulse and the B-phase pulse input from the angle detector 52. The fourth acquirer 31d acquires the rotation angle θ by counting the pulses input from the angle detector 52, with the value set to zero when the swivel head 2 is positioned at a predetermined initial position. Therefore, the fourth acquirer 31d can redefine the initial position by initializing (resetting) the count. The initial position is a predetermined position, which is the rotation position of the swivel head 2 when the fourth acquirer 31d initializes the count at any timing. The fourth acquirer 31d also acquires the rotation angle θ as a positive value when the swivel head 2 is rotating counterclockwise in a plan view, and as a negative value when the swivel head 2 is rotating clockwise in a plan view, with the rotation angle θ at the initial position set to zero.

[0034] The first calculation unit 31e extracts a detection position Pd that satisfies a predetermined condition from the detection positions Pd detected by the position detection device 50 as a detection position Pd (candidate position Pc) to be used in calculating the direction D. In this embodiment, the candidate position Pc is a detection position Pd from the start of rotation to the stop of rotation when the lower traveling body 10 travels and then stops, and the swivel base 2 rotates for the first time.

[0035] The first calculation unit 31e determines that the lower traveling structure 10 is in a traveling state (a traveling state) when the absolute value of the vehicle speed acquired by the first acquisition unit 31a exceeds a predetermined first threshold value (for example, zero). Furthermore, the first calculation unit 31e determines that the lower traveling structure 10 is in a stopped state (a traveling-stopped state) when the absolute value of the vehicle speed acquired by the first acquisition unit 31a is equal to or less than the predetermined first threshold value.

[0036] Here, when performing work using the swivel work machine 1, the worker operates the swivel work machine 1, drives the lower running body 10 to move to the work site, and then first rotates the swivel base 2. Therefore, the first calculation unit 31e can extract a candidate position Pc that satisfies the above-mentioned conditions while the worker is performing his or her usual work, without any special operations being performed before performing the work. The first calculation unit 31e determines that the swivel bed 2 is rotating (in a rotating state) when the absolute value of the amount of change in the swivel angle θ acquired by the fourth acquisition unit 31d exceeds a predetermined second threshold. The first calculation unit 31e determines that the lower traveling structure 10 is stopped (in a stopped rotation state) when the absolute value of the amount of change in the swivel angle θ acquired by the fourth acquisition unit 31d is equal to or less than the predetermined second threshold. In this embodiment, the second threshold is zero, and the first calculation unit 31e determines that the swivel bed 2 is rotating when a pulse is input from the angle detection device 52, and determines that the swivel bed 2 is in a stopped rotation state when no pulse is input from the angle detection device 52.

[0037] Therefore, the first calculation unit 31e determines that the swivel bed 2 has started rotating when the lower running structure 10 transitions from a rotation-stopped state to a rotational state and a pulse is input from the angle detection device 52. On the other hand, the first calculation unit 31e determines that the swivel bed 2 has stopped rotating when the lower running structure 10 transitions from a rotation-stopped state to a rotational state and a pulse is no longer input from the angle detection device 52.

[0038] The conditions for the candidate position Pc are not limited to the above-mentioned conditions, and the first calculation unit 31e may calculate the detected position Pd within a predetermined time before the swivel base 2 starts rotating, and the detected position Pd within a predetermined time after the swivel base 2 stops rotating as the candidate position Pc. In the following description, when the first calculator 31e calculates the candidate position Pc, the amount of change in the rotation angle θ from when the swivel base 2 starts to rotate until the rotation stops may be referred to as the "reference angle θb." In other words, as shown in Fig. 5, the reference angle θb is the angle formed by a line SL1 and a line SL2 that extend in the front-to-rear direction and pass through the rotation axis X when the swivel base 2 starts to rotate.

[0039] In addition, in the following description, the detected position Pd acquired by the second acquisition unit 31b at the time when the first calculation unit 31e determines that the swivel base 2 has stopped rotating may be described as the "stop position Pe." Furthermore, in the example described above, the first calculation unit 31e determines whether the undercarriage 10 has transitioned from a running state to a stopped state based on the vehicle speed acquired by the first acquisition unit 31a, but if the control device 30 can acquire operation information of the operation device 40, the first calculation unit 31e may determine the state (running state and stopped state) of the undercarriage 10 based on the operation information. Furthermore, the first calculation unit 31e determines whether the swivel base 2 has started to rotate and whether the rotation has stopped based on a rotation signal output from the angle detection device 52 to the control device 30, but if the control device 30 can acquire operation information of the operation device 40, the first calculation unit 31e may determine the state (rotating state and stopped state) of the swivel base 2 based on the operation information.

[0040] The filter processing unit 31f filters (filters) a plurality of candidate positions Pc (detected positions Pd) when the swivel base 2 rotates. The filter processing unit 31f eliminates candidate positions Pc that are located outside a predetermined area E. FIG. 6A is a first diagram illustrating an example of filtering by the filter processing unit 31f. FIG. 6B is a second diagram illustrating an example of filtering by the filter processing unit 31f.

[0041] Area E is an area of ​​position coordinates indicated by latitude and longitude, and as shown in Fig. 6A, is a substantially arc-shaped area including an arc with a radius equal to the length R1 from the turning axis X to position P' detected by position detection device 50. In Figs. 6A and 6B, candidate positions Pc located within area E are indicated by black dots, and candidate positions Pc located outside area E are indicated by white dots. Furthermore, the size of the central angle θe of area E corresponds to the reference angle θb. Note that the size of the central angle θe of area E only needs to correspond to the reference angle θb, and may be larger than the reference angle θb by a predetermined value. The radial length (width W) of area E is a size defined according to the error in the detection position Pd detected by the position detection device 50. For example, the width W is twice the size of the error in the detection position Pd detected by the position detection device 50.

[0042] The width W is preferably a value according to the magnitude of the error in the detected position Pd, and is not limited to twice the value. The width W may be a value pre-stored in the storage device 34, and may be arbitrarily changed by the operator operating the display device 35 or the like. Therefore, the width W can be set to improve the accuracy of calculation of the axial center position Px by the operator operating the display device 35 or the like to reduce the width W.

[0043] The filter processing unit 31f calculates the area E based on an arithmetic expression (first arithmetic expression) stored in the storage device 34 and various parameters (length R1, width W, reference angle θb, etc.). The arithmetic expression is a mathematical expression defined based on the equation of a circle or ellipse and various parameters. The filter processing unit 31f also corrects the area E based on the tilt angle (roll angle and pitch angle) detected by the tilt detection device 51. The filter processing unit 31f corrects the area E based on an arithmetic expression (second arithmetic expression) stored in the storage device 34 and the tilt angle.

[0044] Therefore, when the swivel base 2 is horizontal and the tilt angle acquired by the third acquisition unit 31c is zero, area E is surrounded by a circle (outer circle) C1 whose radius R2 is greater than the length R1 by half the width W, and a circle (inner circle) C2 whose radius R3 is less than the length R1 by half the width W, and the central angle θe is equal to the reference angle θb, as shown in Fig. 6A. The outer circle C1 and the inner circle C2 are arranged concentrically and each describes a perfect circle.

[0045] The filter processing unit 31f sets the area E when the swivel base 2 is horizontal as the reference area Eb, and corrects this reference area Eb based on the tilt angle. Therefore, when the swivel work machine 1 is located on a slope, the swivel base 2 is tilted, and the tilt angle (roll angle and pitch angle) acquired by the third acquisition unit 31c is other than zero, the filter processing unit 31f corrects the reference area Eb to an area tilted by the tilt angle. In other words, the outer circle C1 and the inner circle C2 are arranged concentrically and each describe an ellipse.

[0046] Furthermore, the filter processing unit 31f moves the calculated area E so that more candidate positions Pc are located within the area E, and performs sweeping by eliminating candidate positions Pc located outside the area E. In the above-described embodiment, the filter processing unit 31f calculates the reference area Eb based on the first calculation formula and various parameters, and corrects the reference area Eb based on the second calculation formula and the tilt angle. However, the storage device 34 may store a single calculation formula that combines the first calculation formula and the second calculation formula, and the filter processing unit 31f may calculate the area E based on the single calculation formula and various parameters (length R1, width W, reference angle θb, and tilt angle).

[0047] The second calculation unit 31g calculates (computes) a circular or elliptical approximation line AL based on the multiple candidate positions Pc (detection positions Pd) filtered by the filter processing unit 31f. The second calculation unit 31g calculates the approximation line AL using an approximation formula in a coordinate system represented by latitude and longitude. Fig. 7A is a first diagram showing an example of the approximation line AL calculated by the second calculation unit 31g. Fig. 7B is a second diagram showing an example of the approximation line AL calculated by the second calculation unit 31g.

[0048] The second calculation unit 31g calculates an approximation line AL using the least squares method of a circular or elliptical equation for multiple detection positions Pd when the swivel base 2 rotates. The model function of the least squares method is an arithmetic formula obtained by correcting the elliptical equation based on the tilt angle, and is used by substituting various parameters (length R1, tilt angle). Therefore, when the swivel base 2 is horizontal and the tilt angle acquired by the third acquisition unit 31c is zero, the approximation line AL calculated by the second calculation unit 31g is a perfect circle with a radius of length R1, as shown in Fig. 7A. On the other hand, when the swivel base 2 is tilted and the tilt angles (roll angle and pitch angle) acquired by the third acquisition unit 31c are other than zero, the approximation line AL calculated by the second calculation unit 31g is an ellipse obtained by correcting the perfect circle with a radius of length R1 by the tilt angle, as shown in Fig. 7B.

[0049] Based on the approximation line AL calculated by the second calculation unit 31g, the third calculation unit 31h calculates (computes) the position (center position) Po of the center of the approximation line AL as the axis position Px of the rotation axis X. Furthermore, based on the calculated axis position Px and the reference position Pp, the third calculation unit 31h calculates a straight line SL2 that passes through the axis position Px and the reference position Pp as the orientation D (reference orientation D1) of the swivel base 2. Fig. 8 is a diagram showing an example of the reference orientation D1 calculated by the third calculation unit 31h and the current orientation D2 calculated by the fourth calculation unit 31i.

[0050] The third calculation unit 31h calculates the reference direction D1 using a mathematical formula in a coordinate system expressed by latitude and longitude. The third calculation unit 31h extracts a detected position Pd (end position Pa) that includes at least the stop position Pe from the detected positions Pd detected by the position detection device 50, and calculates a reference position Pp based on the detected position Pd. The end position Pa is a plurality of detected positions Pd acquired by the second acquisition unit 31b within a predetermined time before and after the first calculation unit 31e determines that the swivel base 2 has stopped rotating. The third calculation unit 31h calculates the reference position Pp based on the average value of position information of the plurality of end positions Pa.

[0051] In FIG. 8, the end position Pa is indicated by a white dot, and the reference position Pp is indicated by a black dot. Furthermore, in this embodiment, the third calculation unit 31h calculates the average value of multiple pieces of position information as the reference position Pp, but the third calculation unit 31h only needs to calculate the reference position Pp based on the detection position Pd that includes at least the stop position Pe, and the detection position Pd (end position Pa) that the third calculation unit 31h refers to may be only the stop position Pe, or may be two or more detection positions Pd that include the stop position Pe.

[0052] After calculating the reference orientation D1, the third calculation unit 31h initializes the count of the fourth acquisition unit 31d and redefines the initial position. That is, at the redefined initial position, the line passing through the turning axis X and extending in the front-to-rear direction is the line SL2. The fourth calculation unit 31i calculates (computes) the current orientation D2 of the swivel head 2 based on the reference orientation D1 and the swivel angle θ. The fourth calculation unit 31i calculates the current orientation D2 of the swivel head 2 based on the swivel angle θ from the swivel position corresponding to the reference orientation D1 to the current swivel position (the difference between the swivel angle θ when the swivel head 2 stopped rotating and the current swivel angle θ) and the reference orientation D1. Note that in this embodiment, the third calculation unit 31h initializes the count of the fourth acquisition unit 31d and redefines the initial position, so the swivel angle θ when the swivel head 2 stopped rotating is zero.

[0053] The fourth calculation unit 31i calculates the current orientation D2 of the swivel base 2 using a formula in a coordinate system expressed by latitude and longitude based on the current swivel angle θ and the reference orientation D1. In this embodiment, the current swivel angle θ is the angle formed by a line SL3 that extends in the front-to-rear direction and passes through the swivel axis X at the current position, and a line SL2. The current orientation D2 of the swivel base 2 is calculated using a formula in a coordinate system expressed by latitude and longitude based on the current swivel angle θ and the reference orientation D1. In other words, if the swivel angle θ acquired by the second acquisition unit 31b is a positive value, the fourth calculation unit 31i calculates the current orientation D2 by tilting the reference orientation D1 counterclockwise by the change amount around the axis position Px. On the other hand, if the turning angle θ acquired by the second acquisition unit 31b is a negative value, the fourth calculation unit 31i calculates the current orientation D2 by tilting the reference orientation D1 clockwise around the axis position Px by the amount of change.

[0054] Fig. 9 is a diagram illustrating a series of steps performed by the calculation unit 31 to calculate the direction D. Below, a series of steps will be described with reference to Fig. 9, including extraction of candidate positions Pc by the first calculation unit 31e, filtering of the candidate positions Pc by the filter processing unit 31f, calculation of the approximation line AL by the second calculation unit 31g, calculation of the axis center position Px and the reference direction D1 by the third calculation unit 31h, and calculation of the current direction D2 by the fourth calculation unit 31i.

[0055] First, the first calculation unit 31e determines whether the lower traveling structure 10 is in a traveling state based on the vehicle speed acquired by the first acquisition unit 31a (S10). If the first calculation unit 31e determines that the lower traveling structure 10 is in a traveling state (S10, Yes), the first calculation unit 31e determines whether the lower traveling structure 10 has transitioned from a traveling state to a traveling-stopped state based on the vehicle speed acquired by the first acquisition unit 31a (S11). If the first calculation unit 31e determines that the lower traveling structure 10 has not transitioned from a traveling state to a traveling-stopped state (S11, No), the first calculation unit 31e continues the processing of S11. If the first calculation unit 31e determines that the lower traveling structure 10 has transitioned from a traveling state to a traveling-stopped state (S11, Yes), the first calculation unit 31e determines whether the swivel base 2 has started to rotate based on the rotation signal acquired by the fourth acquisition unit 31d (S12).

[0056] If the first calculation unit 31e determines that the swivel base 2 has not started rotating (S12, No), it continues the processing of S12, and if it determines that the swivel base 2 has started rotating (S12, Yes), the position detection device 50 detects the detection position Pd (S13). The second acquisition unit 31b stores the position information detected by the position detection device 50 in the storage device 34. The first calculation unit 31e determines whether the swivel base 2 has stopped rotating based on the rotation signal acquired by the fourth acquisition unit 31d (S14).

[0057] If the first calculation unit 31e determines that the swivel base 2 has not stopped rotating (S14, No), that is, until the swivel base 2 stops rotating, the first calculation unit 31e executes the process of S13. On the other hand, if the first calculation unit 31e determines that the swivel base 2 has stopped rotating (S14, Yes), the first calculation unit 31e extracts the position information acquired by the second acquisition unit 31b from the storage device 34 during the period (swivel period) from when the first calculation unit 31e determines that the swivel base 2 has started rotating (S12, Yes) to when the first calculation unit 31e determines that the swivel base 2 has stopped rotating (S14, Yes), and calculates the extracted position information as a candidate position Pc (S15). Therefore, the first calculation unit 31e can calculate the candidate position Pc by the swivel base 2 rotating when the undercarriage 10 stops after traveling.

[0058] In the following description, steps such as S12 to S14 in which the swivel base 2 is rotated around the rotation axis X and a plurality of detection positions Pd are detected by the position detector 50 may be referred to as the first step. After the first calculation unit 31e performs the process of S15, the filter processing unit 31f calculates the area E based on the first calculation formula and various parameters (S16). After calculating the area E (S16), the filter processing unit 31f moves the area E so that more candidate positions Pc are located within the area E (S17). The filter processing unit 31f performs a sweep by excluding candidate positions Pc located outside the area E (S18).

[0059] After the filtering processing unit 31f performs the process of S18, the second calculation unit 31g calculates an approximation line AL for the plurality of candidate positions Pc filtered by the filtering processing unit 31f using the least squares method of a circle or ellipse equation (S19). After the second calculation unit 31g performs the process of S19, the third calculation unit 31h calculates the center position Po of the approximation line AL as the axial position Px of the rotation axis X based on the approximation line AL calculated by the second calculation unit 31g (S20). In other words, S20 is a step (second step) of calculating the axial position Px of the rotation axis X based on the multiple detected positions Pd detected by the position detection device 50 in the first step (S13). In addition, the third calculation unit 31h extracts a detected position Pd (end position Pa) that includes at least the stop position Pe from the detected positions Pd detected by the position detection device 50, and calculates a reference position Pp based on the detected position Pd (S21).

[0060] Based on the axis position Px calculated in S20 and the reference position Pp calculated in S21, the third calculation unit 31h calculates a straight line passing through the axis position Px and the reference position Pp as the orientation D (reference orientation D1) of the swivel head 2, and stores the reference orientation D1 in the storage device 34 (S22). In other words, S22 is a step of calculating the orientation D of the swivel head 2 based on the axis position Px and the reference position Pp calculated in the second step (third step).

[0061] When the third calculation unit 31h calculates the reference direction D1 (S22), it initializes the count of the fourth acquisition unit 31d and redefines the initial position (S23). When the third calculation unit 31h stops the process of S23, the first calculation unit 31e executes the process of S10. Furthermore, when the first calculation unit 31e determines that the lower traveling structure 10 is in a stopped state (S10, No), the fourth calculation unit 31i determines whether the axis position Px and the reference orientation D1 are stored in the storage device 34 (S24).When the fourth calculation unit 31i determines that the axis position Px and the reference orientation D1 are stored in the storage device 34 (S24, Yes), it calculates the current orientation D2 based on the axis position Px and the reference orientation D1 stored in the storage device 34 and the turning angle θ acquired by the fourth acquisition unit 31d (S25).

[0062] When the fourth calculation unit 31i calculates the current direction D2 (S25), the series of processes is stopped. Note that, when the fourth calculation unit 31i determines that the axis center position Px and the reference direction D1 are not stored in the storage device 34 (S24, No), the first calculation unit 31e executes the process of S10. Therefore, when the lower running structure 10 enters a running state (S10, Yes), the reference orientation D1 is redefined by the processes of S11 to S22. On the other hand, when the lower running structure 10 remains stopped (S10, No) and the axis position Px and the reference orientation D1 are stored in the storage device 34 (S24, Yes), the fourth calculation unit 31i calculates the current orientation D2 based on the reference orientation D1 calculated by the processes of S11 to S22 (S25).

[0063] This makes it possible to calculate the orientation D of the swivel 2 even when the swivel working machine 1 is equipped with a single position detection device 50. This makes it possible to introduce a function for calculating the orientation D of the swivel 2 (swivel working machine 1) at low cost. Furthermore, because the current orientation D2 is calculated based on the reference orientation D1 and the rotation angle θ, no detection error occurs in the position detection device 50 after calculation of the reference orientation D1, and the calculation unit 31 can calculate the current orientation D2 with higher accuracy.

[0064] Next, the calculation of the position Pw of the oscillating body in the swivel working machine 1 will be described in detail. As shown in FIG. 3, the swivel working machine 1 has a position calculation unit 32. The position calculation unit 32 is composed of electric and electronic components provided in the control device 30, and a program installed in the storage device 34. The position calculation unit 32 can calculate the position Pw of the oscillating body based on a signal detected by a sensor provided in the swivel working machine 1 and the orientation D of the swivel base 2 calculated by the calculation unit 31 (current orientation D2). The position Pw of the oscillating body calculated by the position calculation unit 32 is displayed on the display device 35, for example. Furthermore, the swivel working machine 1 may be configured to perform work autonomously based on the position Pw of the oscillating body calculated by the position calculation unit 32 and the position information stored in the storage device 34.

[0065] Fig. 10 is a diagram illustrating the calculation of the position Pw of the swinging body. As shown in Fig. 10, in this embodiment, the position calculation unit 32 calculates the position (working position) Pw at which the work device 20 performs work as the position Pw of the swinging body. In particular, the position calculation unit 32 calculates the position coordinates of the bucket claw 25C of the swinging body as the working position Pw. Note that the working position Pw calculated by the position calculation unit 32 is not limited to the position coordinates of the bucket claw 25C, and may be the center of the bottom wall 25B of the bucket 25, for example.

[0066] For example, the work implement 20 is provided with angle sensors 54 (a boom angle sensor 54a, an arm angle sensor 54b, a work implement angle sensor 54c, and a swing angle sensor 54d) that detect the rotation angles of the first rotation shaft 22, the second rotation shaft 24, and the third rotation shaft 26. The angle sensors 54 are, for example, potentiometers that are connected to the control device 30 and output the detected rotation angles to the control device 30 as signals.

[0067] Specifically, the boom angle sensor 54a detects the swing angle (rotation position) of the boom 21, and the arm angle sensor 54b detects the swing angle (rotation position) of the arm 23. The work tool angle sensor 54c detects the swing angle (rotation position) of the bucket 25 relative to the tip side of the arm 23, and the swing angle sensor 54d detects the swing angle (rotation position) of the swing bracket 8 relative to the support bracket 7.

[0068] The position calculation unit 32 calculates the length (length L2 in the front-to-rear direction and length L3 in the width direction) from the rotation axis X to the work position Pw based on the rotation angle detected by the angle sensor 54 and an arithmetic expression stored in the storage device 34. The position calculation unit 32 calculates the work position Pw based on the calculated lengths L2 and L3, the tilt angle acquired by the third acquisition unit 31c, an expression indicating the current orientation D2, and the axis position Px.

[0069] It should be noted that the position calculation unit 32 is only required to be able to calculate the working position Pw, and the angle sensor 54 is not limited to a potentiometer, and may, for example, detect the strokes (extended positions) of the boom cylinder 21a, arm cylinder 23a, bucket cylinder 25a, and swing cylinder, and calculate the swing angles of the boom 21, arm 23, bucket 25, and swing bracket 8 from the detection results. Also, the configuration may be such that the swing angles of the boom 21, arm 23, bucket 25, and swing bracket 8 are detected using an imaging device (camera) that images the periphery of the work implement 20.

[0070] In the above-described embodiment, when the lower traveling structure 10 enters a traveling state (S10, Yes), the calculation unit 31 redefines the reference orientation D1 through the processes of S11 to S22. However, if a predetermined condition is met, the reference orientation D1 may not be initialized. Fig. 11 is a diagram illustrating the calculation of the orientation D in a first modified example. As shown in Fig. 11, when the lower traveling structure 10 transitions from a stopped state to a traveling state and travels straight forward or backward from the position when the calculation unit 31 calculated the reference orientation D1, if the rotation angle θ of the swivel base 2 is maintained, the calculation unit 31 may correct the axis center position Px without updating the reference orientation D1.

[0071] Fig. 12 is a diagram illustrating a part of a series of steps in which the calculation unit 31 calculates the direction D in the first modified example. As shown in Fig. 12, during the period (movement period) from when the first calculation unit 31e determines that the lower traveling body 10 is in a traveling state in S10 until when it determines that the lower traveling body 10 has transitioned from the traveling state to a stopped traveling state (S11, Yes), if the lower traveling body 10 continues to move forward or backward in a straight direction and does not perform a turning operation, the calculation unit 31 executes processing to correct the axis center position Px.

[0072] Fig. 13 is a diagram illustrating the system of the swivel work machine 1 in the first modified example. As shown in Fig. 13, the calculation unit 31 has a correction unit 31j. When the swivel base 2 does not rotate during a movement period and the lower traveling structure 10 continues to travel straight ahead, the correction unit 31j corrects the axis center position Px based on the position information of the detected position Pd detected by the position detection device 50 at the start point S and the end point G of the movement period.

[0073] The correction unit 31j determines whether the rotation angle θ of the swivel base 2 is being maintained based on the rotation angle θ acquired by the fourth acquisition unit 31d. The correction unit 31j also determines whether the lower traveling structure 10 is maintaining straight-line traveling or is turning based on operation information from the operation device 40. The correction unit 31j acquires position information of a detection position Ps at a start point S of the movement period and position information of a detection position Pg at an end point G, based on the position information of the detection position Pd acquired by the second acquisition unit 31b.

[0074] The correction unit 31j also calculates the distance traveled by the lower traveling structure 10 during the movement period (longitude travel distance Lx and latitude travel distance Ly) based on position information of the detection position Ps at the start point S and position information of the detection position Pg at the end point G. The correction unit 31j then corrects the axial center position Px by offsetting the axial center position Px by the same amount as the travel distances Lx and Ly traveled by the lower traveling structure 10. The correction unit 31j overwrites the axial center position Px stored in the storage device 34 with the corrected axial center position Px and stores it.

[0075] Hereinafter, the correction of the axial center position Px by the corrector 31j will be described with reference to FIG. 12, when the first calculation unit 31e determines that the lower traveling structure 10 is in a traveling state (S10, Yes), the correction unit 31j determines whether the rotation angle θ of the swivel base 2 is being maintained based on the rotation angle θ acquired by the fourth acquisition unit 31d (S31).When the correction unit 31j determines that the rotation angle θ of the swivel base 2 is being maintained (S31, Yes), the correction unit 31j determines whether the lower traveling structure 10 is traveling straight ahead based on the operation information of the operation device 40 (S32).

[0076] When the correction unit 31j determines that the lower traveling structure 10 is traveling straight ahead (S32, Yes), it determines whether the lower traveling structure 10 has transitioned from a traveling state to a stopped state based on the vehicle speed acquired by the first acquisition unit 31a (S33). When the correction unit 31j determines that the lower traveling structure 10 has not transitioned from a traveling state to a stopped state (S33, No), it executes the process of S31. On the other hand, when the correction unit 31j determines that the lower traveling structure 10 has transitioned from a traveling state to a stopped state (S33, Yes), it acquires position information of a detection position Ps at a start point S of the movement period and position information of a detection position Pg at an end point G of the movement period based on the position information acquired by the second acquisition unit 31b and stored in the storage device 34 (S34).

[0077] The correction unit 31j calculates the movement distances Lx, Ly traveled by the lower traveling structure 10 during the movement period based on the position information of the detection position Ps at the start point S and the position information of the detection position Pg at the end point G, and corrects the axial center position Px by offsetting the axial center position Px by the same amount as the movement distances Lx, Ly traveled by the lower traveling structure 10 (S35). After the correction unit 31j corrects the axial center position Px (S35), the fourth calculation unit 31i executes the process of S24.

[0078] In addition, if the correction unit 31j determines that the rotation angle θ of the swivel base 2 is not maintained (S31, No), and if the correction unit 31j determines that the lower running body 10 is running in a rotating motion (S32, No), the first calculation unit 31e executes the processing of S11. 12, in S31, it is determined whether the rotation angle θ of the swivel base 2 is maintained, but it is sufficient that the rotation angle θ at the start point S of the movement period and the rotation angle θ at the end point G are the same value, and the corrector 31j may determine whether the rotation angle θ at the start point S of the movement period and the rotation angle θ at the end point G are the same value between S33 and S34 instead of S31. In this case, if the corrector 31j determines that the rotation angle θ at the start point S of the movement period and the rotation angle θ at the end point G are the same value, the corrector 31j executes the process of S34, and if it determines that the values ​​are not the same, the first calculator 31e executes the process of S11.

[0079] The calculation unit 31 calculates the reference orientation D1 by the rotation of the swivel base 2 when the lower traveling body 10 stops after traveling, but may redo the calculation process of the reference orientation D1 if the amount of change in the rotation angle θ of the swivel base 2 (reference angle θb) is equal to or less than a predetermined third threshold. Fig. 14 is a diagram illustrating part of the series of steps by which the calculation unit 31 calculates the orientation D in the second modified example. The processing of the first calculation unit 31e in the second modified example will be described below with reference to Fig. 14.

[0080] 14, the lower traveling structure 10 travels and then stops (S11, Yes), the swivel base 2 starts rotating (S12, Yes), and even if the swivel base 2 stops rotating (S14, Yes), if the first calculation unit 31e determines that the absolute value of the reference angle θb is equal to or less than the third threshold value (S41, No), the process returns to S12. In such a case, the control device 30 may notify the operator to redo the calculation of the reference orientation D1.

[0081] On the other hand, if the swivel base 2 stops rotating (S14, Yes) and the first calculation unit 31e determines that the absolute value of the reference angle θb exceeds the third threshold value (S41, Yes), the process proceeds to S15. The third threshold value is a value pre-stored in the storage device 34, such as 5° or 10°. The third threshold value may be configured to be changeable by the operator by operating the display device 35 or the like.

[0082] The notification device is, for example, a device connected to the control device 30, and is a display device 35 in this embodiment. As shown in FIG. 3, the calculation unit 31 has a notification control unit 33. When the first calculation unit 31e determines that the absolute value of the reference angle θb is equal to or less than the third threshold value (S41, No), the notification control unit 33 acquires the determination result and controls the notification device to issue a notification to the operator. The notification control unit 33 is composed of electric and electronic components provided in the control device 30 and a program installed in the storage device 34. For example, the notification control unit 33 displays a notification screen (not shown) on the display device 35 to notify the operator that the calculation of the reference orientation D1 should be redone. More specifically, the notification screen displays a message (notification message) urging the operator to operate the operation device 40 to rotate the swivel base 2.

[0083] In the above-described embodiment, the notification device is the display device 35. However, the notification device is not limited to the display device 35 and may be a speaker that issues a notification by voice or warning sound, or a lamp that issues a notification by lighting or flashing. In such a case, when the first calculation unit 31e determines that the absolute value of the reference angle θb is equal to or less than the third threshold value (S41, No), the notification control unit 33 outputs a notification message from the speaker or flashes the lamp.

[0084] The swivel work machine 1 may also include an operating device 41 that accepts operations, and the calculation unit 31 may redefine (initialize) the reference orientation D1 by performing processing similar to S11 to S12 instead of or in addition to S11 to S22 in response to the operation of the operating device 41. FIG. 15 is a diagram illustrating the system of the swivel work machine 1 in a third modified example. As shown in FIG. 15, the operating device 41 is a switch that is communicably connected to the control device 30 and accepts operations. Upon accepting an operation, the operating device 41 outputs an instruction signal to the control device 30 instructing the control device 30 to rotate the swivel base 2 by a predetermined rotation angle θ (e.g., 5° or more, or 10° or more). The operating device 41 is, for example, a push switch that can be pressed. Note that the operating device 41 is not limited to a push switch, and may be a display image such as an icon displayed on the display device 35 if the display device 35 is a touch panel that accepts operations.

[0085] The calculation unit 31 also has a swivel control unit 31k. The swivel control unit 31k controls a control valve in response to the operation of the operating tool 41, and rotates the swivel base 2 by a predetermined swivel angle θ using the swivel motor MT. The direction in which the swivel control unit 31k rotates the swivel base 2 in response to the operation of the operating tool 41, and the swivel angle θ may be stored in advance in the storage device 34 as setting information and may be changed at will by an operator operating the display device 35 or the like. Note that the swivel control unit 31k may rotate the swivel base 2 by the predetermined swivel angle θ in the predetermined direction based on an instruction signal input from the operating tool 41, and then maintain the swivel angle θ. Alternatively, after completing the process of S54 (described later), the swivel control unit 31k may rotate the swivel base 2 in the direction opposite to the predetermined direction to return it to the original swivel angle θ.

[0086] Fig. 16 is a diagram illustrating part of a series of steps in which the calculation unit 31 in the third modified example calculates the direction D. Hereinafter, the calculation of the direction D by the calculation unit 31 when the operating tool 41 is operated will be described with reference to Fig. 16. When the first calculation unit 31e determines in S10 that the lower traveling structure 10 is in a stopped state (S10, No), the slewing control unit 31k determines whether or not an instruction signal has been input from the operating device 41 (S51). When the slewing control unit 31k determines that an instruction signal has been input from the operating device 41 (S51, Yes), it controls the slewing motor MT based on the setting information stored in the storage device 34, and starts rotating the swivel base 2 in a predetermined direction (S52).

[0087] When the swivel control unit 31k starts rotating the swivel base 2 (S52), the position detection device 50 detects the detection position Pd (S53). The second acquisition unit 31b stores the position information detected by the position detection device 50 in the storage device 34. The first calculation unit 31e determines whether the swivel base 2 has stopped rotating based on the swivel signal acquired by the fourth acquisition unit 31d (S54). If the first calculation unit 31e determines that the swivel base 2 has not stopped rotating (S54, No), that is, until the swivel base 2 stops rotating, it executes the process of S53. On the other hand, if the first calculation unit 31e determines that the swivel base 2 has stopped rotating (S54, Yes), it extracts the position information acquired by the second acquisition unit 31b from the storage device 34 during the period (swivel period) from when the swivel control unit 31k started rotating the swivel base 2 (S52) until it determines that the swivel base 2 has stopped rotating (S54, Yes), and calculates the extracted position information as a candidate position Pc (S55). Therefore, the first calculation unit 31e can calculate the candidate position Pc by having the swivel control unit 31k rotate the swivel base 2 in response to the operation of the operating tool 41. After the first calculation unit 31e executes the process of S55, the filter processing unit 31f executes the process of S16.

[0088] Furthermore, when the turning control unit 31k determines that an instruction signal has not been input from the operation tool 41 (S51, No), the fourth calculation unit 31i executes the process of S24. Note that S52 to S54 can be considered the first step because the swivel base 2 is rotated around the rotation axis X and a plurality of detection positions Pd are detected by the position detector 50. The above-mentioned swivel working machine 1 comprises a swivel base 2 that can rotate around a rotation axis X that extends in the vertical direction, a working device 20 mounted on the swivel base 2, a position detection device 50 mounted on the swivel base 2 and that detects its position, and a calculation unit 31 that calculates the orientation D of the swivel base 2 based on the detected position Pd detected by the position detection device 50.The calculation unit 31 calculates the axial position Px of the rotation axis X based on the multiple detected positions Pd when the swivel base 2 rotates around the rotation axis X, and calculates the orientation D of the swivel base 2 based on the axial position Px and the detected position (reference position) Pp.

[0089] According to the above configuration, even if the swivel working machine 1 is equipped with a single position detection device 50, it is possible to calculate the orientation D of the swivel base 2. Therefore, it is possible to introduce the function of calculating the orientation D of the swivel base 2 (swivel working machine 1) at low cost. The calculation unit 31 also calculates the axis position Px of the rotation axis X based on a plurality of detected positions Pd from when the swivel base 2 starts to rotate until when the rotation stops.

[0090] According to the above configuration, among the detection positions Pd when the swivel base 2 rotates, many detection positions Pd are used for calculation, and the distance between each detection position Pd can be increased, so the calculation unit 31 can calculate the axis position Px of the rotation axis X with high accuracy. The swivel work machine 1 also has an angle detection device 52 that is provided on the swivel base 2 and detects the rotation angle θ of the swivel base 2 around the rotation axis X, and the calculation unit 31 uses the orientation D of the swivel base 2 calculated based on the axis position Px and any of the detection positions Pd used to calculate the axis position Px as a reference orientation D1, and calculates the current orientation D2 of the swivel base 2 based on the reference orientation D1 and the rotation angle θ from the rotation position corresponding to the reference orientation D1 to the current rotation position.

[0091] According to the above configuration, the current direction D2 is calculated based on the reference direction D1 and the turning angle θ. Therefore, even if an error occurs in the position detection by the position detection device 50 after the calculation of the reference direction D1, the current direction D2 is not affected, and the calculation unit 31 can calculate the current direction D2 with higher accuracy. In addition, the calculation unit 31 calculates the axis position Px of the rotation axis X based on multiple detected positions Pd from when the swivel base 2 starts to rotate until it stops rotating, and calculates the current orientation D2 of the swivel base 2 based on the difference between the rotation angle θ when the swivel base 2 stops rotating and the current rotation angle θ and the reference orientation D1.

[0092] According to the above configuration, the calculation unit 31 can calculate the current direction D2 with high accuracy through relatively simple processing. The calculation unit 31 also has a filter processing unit 31f that filters multiple detection positions Pd when the swivel base 2 rotates, and the filter processing unit 31f excludes detection positions Pd that are located outside an approximately arc-shaped area E that includes an arc whose radius is the length from the rotation axis X to the position detected by the position detection device 50.

[0093] According to the above configuration, it is possible to eliminate the detected positions Pd where an error has occurred in the position detection from among the detected positions Pd detected by the position detection device 50. Therefore, it is possible to improve the calculation accuracy of the direction D. The swivel work machine 1 also includes an inclination detection device 51 that detects the inclination angle of the swivel base 2, and the filter processing unit 31f corrects the area E based on the inclination angle detected by the inclination detection device 51.

[0094] According to the above configuration, the filter processing unit 31f can improve the accuracy of filtering even when the rotating work machine 1 is located on a slope. Furthermore, the calculation unit 31 calculates an approximation line AL of a circle or an ellipse based on a plurality of detected positions Pd when the swivel base 2 rotates, and calculates the axis position Px based on the approximation line AL. According to the above configuration, the calculation unit 31 can calculate the axis position Px of the rotation axis X with high precision.

[0095] Furthermore, the calculation unit 31 calculates an approximation line AL for a plurality of detection positions Pd when the swivel base 2 rotates, using the least squares method of a circle or ellipse equation. According to the above configuration, the calculation unit 31 can calculate the axis position Px of the rotation axis X with high accuracy by a relatively simple process. In addition, the swivel work machine 1 supports the swivel base 2 around the rotation axis X and is equipped with a lower running body 10 that is capable of running, and the calculation unit 31 calculates the axis position Px based on multiple detected positions Pd when the swivel base 2 first rotates when the lower running body 10 runs and then stops.

[0096] According to the above configuration, when work is normally performed with the swivel work machine 1, the swivel base 2 is first rotated after traveling to the work site, so the axis center position Px can be calculated during normal work without any special operations being performed before carrying out the work. The position detector 50 is disposed at a position horizontally spaced apart from the axis of rotation X. According to the above configuration, the position detection device 50 can detect a distant position, and therefore the calculation unit 31 can calculate the direction D with higher accuracy.

[0097] The position detection device 50 is disposed at the end of the swivel base 2 . According to the above configuration, the position detection device 50 can detect a distant position, and therefore the calculation unit 31 can calculate the direction D with even higher accuracy. In addition, the orientation detection method for the swivel work machine 1 includes a first step of rotating the swivel base 2 on which the work device 20 is mounted around the rotation axis X extending in the vertical direction and detecting multiple detection positions Pd using a position detection device 50 mounted on the swivel base 2, a second step of calculating the axial position Px of the rotation axis X based on the multiple detection positions Pd detected by the position detection device 50, and a third step of calculating the orientation D of the swivel base 2 based on the axial position Px calculated in the second step and a reference position Pp.

[0098] Although the present invention has been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0099] 1. Rotating work machine 2 Swivel table 10 Undercarriage 20 Work equipment 31 Arithmetic section 31f Filter processing section 50 Position detection device 51 Tilt detection device 52 Angle detection device AL approximation line D direction D1 Reference direction D2 Current direction E Area Pd detection position Px axis center position X rotation axis θ rotation angle

Claims

1. A rotating table that can rotate around a rotation axis extending in the vertical direction, a working device provided on the swivel base; a position detection device provided on the swivel base and detecting a position; a calculation unit that calculates an orientation of the swivel base based on the position detected by the position detection device; an inclination detection device for detecting an inclination angle of the swivel base; Equipped with The calculation unit calculating an axis position of the swivel axis based on the plurality of detected positions when the swivel base rotates around the swivel axis; In a swivel work machine that calculates the orientation of the swivel base based on the shaft center position and the detected position, the calculation unit has a filter processing unit that filters the plurality of detected positions when the swivel base rotates, The filter processing unit corrects an approximately arc-shaped area including an arc whose radius is the length from the rotation axis to the position detected by the position detection device based on the tilt angle detected by the tilt detection device, and eliminates detected positions located outside the area.

2. A swivel base that can rotate around a rotation axis extending in the vertical direction; a working device provided on the swivel base; a position detection device provided on the swivel base and detecting a position; a calculation unit that calculates an orientation of the swivel base based on the position detected by the position detection device; Equipped with The calculation unit calculating an axis position of the swivel axis based on the plurality of detected positions when the swivel base rotates around the swivel axis; In a swivel work machine that calculates the orientation of the swivel base based on the shaft center position and the detected position, the calculation unit has a filter processing unit that filters the plurality of detected positions when the swivel base rotates, The filter processing unit is a rotating work machine that moves an approximately arc-shaped area that is defined based on the length from the rotation axis to the position detected by the position detection device, and includes an arc with the radius of that length, so that more detection positions are located within the area, and eliminates detection positions that are outside the area after the movement.

3. 3. The swivel working machine according to claim 1, wherein the calculation unit calculates the axis position of the swivel axis based on a plurality of detected positions from when the swivel base starts to rotate until when the swivel base stops rotating.

4. an angle detection device that is provided on the swivel base and detects a rotation angle of the swivel base about the rotation axis; The calculation unit The azimuth of the swivel calculated based on the shaft center position and any one of the detected positions used in the calculation of the shaft center position is set as a reference azimuth, 3. A swivel working machine according to claim 1, wherein the current orientation of the swivel base is calculated based on the reference orientation and a swivel angle from a swivel position corresponding to the reference orientation to a current swivel position.

5. the calculation unit calculates an axis position of the rotation axis based on a plurality of the detected positions from when the rotation of the swivel base starts to when the rotation of the swivel base stops, 5. The swivel working machine according to claim 4, wherein the current orientation of the swivel base is calculated based on the difference between the rotation angle when the swivel base stopped rotating and the current rotation angle, and the reference orientation.

6. The rotating work machine according to claim 1 or 2, wherein the calculation unit calculates an approximation line of a circle or an ellipse based on the plurality of detected positions when the rotating base rotates, and calculates the axis center position based on the approximation line.

7. The swivel working machine according to claim 6 , wherein the calculation unit calculates the approximation line using a least squares method for a circle or ellipse equation for the plurality of detected positions when the swivel base rotates.

8. a lower traveling body that supports the swivel base around the rotation axis and is capable of traveling; The rotating work machine according to claim 1 or 2, wherein the calculation unit calculates the axis center position based on the multiple detected positions when the swivel base first rotates when the lower traveling body stops after traveling.

9. 3. A swivel working machine according to claim 1, wherein the position detection device is disposed at a position horizontally spaced apart from the swivel axis.

10. 10. A swivel working machine according to claim 9, wherein the position detection device is disposed at an end of the swivel base.

11. a first step of rotating a swivel base on which a working device is provided about a rotation axis extending in a vertical direction and detecting a plurality of detection positions by a position detection device provided on the swivel base; a second step of calculating a substantially arc-shaped area including an arc having a radius equal to the length from the rotation axis to the position detected by the position detection device, and correcting the area based on the tilt angle detected by an inclination detection device that detects the tilt angle of the swivel base; a third step of filtering out detection positions located outside the area from among the plurality of detection positions detected in the first step; a fourth step of calculating an axis position of the pivot axis based on the plurality of detected positions filtered in the third step; a fifth step of calculating an orientation of the swivel head based on the shaft center position calculated in the fourth step and the current detected position; A method for detecting the direction of a rotating work machine comprising:

12. A first step of rotating a swivel base on which a work device is mounted around a rotation axis extending in the vertical direction and detecting a plurality of detection positions using a position detection device mounted on the swivel base; a second step of calculating a substantially arc-shaped area that is defined based on a length from the rotation axis center to a position detected by the position detection device and includes an arc having a radius equal to the length; a third step of moving the area so that more detection positions are located within the area; a fourth step of filtering out, from the plurality of detected positions detected in the first step, detected positions that are located outside the area after the movement; a fifth step of calculating an axis position of the pivot axis based on the plurality of detected positions filtered in the fourth step; a sixth step of calculating an orientation of the swivel head based on the shaft center position calculated in the fifth step and the current detected position; A method for detecting the direction of a rotating work machine comprising:

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