Control method for a slewing work vehicle

Abstract

To provide a technology useful for operation support of a construction work such as digging of a side ditch.SOLUTION: A control method of a revolving work vehicle provided with a display device includes: displaying the revolving work vehicle and a virtual line side by side in plan view on a screen of the display device; and displaying a bucket of a work machine, in front of an upper revolving body of the revolving work vehicle, reflecting a movement position by a revolving motion of the upper revolving body and a rotating motion of the work machine, in accordance with operation amounts of the revolving motion and the rotating motion, together with the virtual line on the screen.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a control method for a swing work vehicle.

Background Art

[0002] In a swing work vehicle such as a backhoe, by detecting the position of the working end of the working machine, high-precision control becomes possible, and it can be used for work automation and ensuring the safety of the surroundings. Patent Documents 1 to 3 describe a hydraulic excavator as a swing work vehicle equipped with means for detecting the position of the working end of a working machine having a bucket (that is, the cutting edge of the bucket).

[0003] Also, especially in a mini excavator, in order to improve workability in a narrow space, there may be a function that can offset the working machine horizontally with respect to the upper swing body. The offset of the working machine is realized, in one aspect, by swinging the working machine left and right with respect to the upper swing body, and in another aspect, by moving the working machine left and right in parallel with respect to the upper swing body.

[0004] Patent Document 1 describes a technique for detecting the position of the working end based on the output from a plurality of position sensors installed on the working machine and the position information from two GPS antennas installed on the construction machine body. However, when applied to a swing work vehicle that can offset the working machine horizontally as described above, since the relative relationship between the output from the position sensor and the position information from the antenna changes according to the offset of the working machine, the position of the working end cannot be detected.

[0005] Patent Document 2 describes a technique for detecting the swing center position of the arm based on the position information from a GPS antenna installed at the working end of the arm and the position information from a GPS antenna installed on the construction machine body, and further detecting the position of the working end based on the output from a plurality of position sensors. However, since it is necessary to install an antenna at the working end where large vibrations and impacts are applied during work, it is inconvenient for detecting the position of the working end with high precision.

[0006] Patent Document 3 describes a technique for displaying target rotation information on a screen, which is determined so that the tip of the bucket faces the target surface. However, when applied to a slewing work vehicle that can offset the work machine horizontally as described above, it is not possible to reflect the bucket's position information that has changed due to the offset. Furthermore, in construction work such as digging drainage ditches, it is necessary to align the side of the bucket with the side edge of the area to be excavated, but this technique does not take into account the offset of the work machine or the side of the bucket, and requires a high level of skill from the operator. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2002-181538 [Patent Document 2] Japanese Patent Publication No. 2002-181539 [Patent Document 3] International Publication No. 2015 / 173936 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] This invention has been made in view of the above circumstances, and its purpose is to provide a technology useful for assisting in construction operations such as digging drainage ditches. [Means for solving the problem]

[0009] The control method for a slewing work vehicle according to the present invention is a control method for a slewing work vehicle equipped with a display device, comprising: displaying the slewing work vehicle and a virtual line side by side on the screen of the display device in a plan view; and displaying the bucket of the work machine, whose movement position due to the slewing motion of the upper slewing body of the slewing work vehicle and the rotational motion of the work machine in front of the upper slewing body is reflected in accordance with the amount of operation of the slewing motion and the rotational motion, together with the virtual line on the screen. [Brief explanation of the drawing]

[0010] [Figure 1] Perspective view showing an example of a swivel work vehicle according to the present invention [Figure 2] Right side view of the swivel work vehicle in Figure 1. [Figure 3] Block diagram showing the control system of a slewing work vehicle. [Figure 4] A left side view conceptually showing the coordinate system and the slewing work vehicle. [Figure 5] A plan view conceptually showing the coordinate system and the slewing work vehicle. [Figure 6] A plan view conceptually showing the coordinate system and the slewing work vehicle. [Figure 7] A flowchart showing an example of operation guidance during construction. [Figure 8] A diagram showing an example of a display screen used during the construction of a drainage ditch. [Figure 9] A diagram showing an example of a display screen used during the construction of a drainage ditch. [Figure 10] A diagram showing an example of a display screen used during the construction of a drainage ditch. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described with reference to the drawings.

[0012] [Overview of the swing work vehicle] As shown in Figures 1 and 2, the slewing work vehicle 1 comprises a lower traveling body 2, an upper slewing body 3 that is rotatably mounted above the lower traveling body 2, and a work implement 5 that can be offset horizontally relative to the upper slewing body 3. In this embodiment, the slewing work vehicle 1 is configured as an excavator (backhoe) with a boom swing function, and the offset of the work implement 5 is performed by swinging the work implement 5 left and right relative to the upper slewing body 3. Generally, the boom swing function is equipped on mini excavators where work efficiency in confined spaces is required.

[0013] The lower traveling body 2 is driven by the power from the engine 30 to run and turn the swing work vehicle 1. The lower traveling body 2 includes a pair of left and right crawlers 21, 21 and a pair of left and right traveling motors 22, 22 for driving them. Between the pair of crawlers 21, 21, a base 23 for supporting the upper swing body 3 rotatably is provided. Further, the lower traveling body 2 is provided with a pair of blade arms 24, 24, a blade 25 as an earth discharging plate extending in the left - right direction between the tip ends thereof, and a blade cylinder 26 for vertically rotating the blade 25.

[0014] The upper swing body 3 is configured to be capable of swinging around an axis extending in the vertical direction at its central portion. In FIGS. 1 and 2, a Z - axis coinciding with the axis is drawn. The upper swing body 3 is formed in a substantially disk shape in plan view that can swing within the lateral width of the lower traveling body 2 (the distance between the outer edge of the left crawler 21 and the outer edge of the right crawler 21). On the upper swing body 3, an engine 30, a counterweight 31, a cabin 32, etc. are arranged. The driving part surrounded by the cabin 32 is equipped with a driver's seat (not shown) for the operator to sit on, an operating device 33 (see FIG. 3) for the operator to operate, a display device 37 (see FIG. 3) for displaying various information, etc.

[0015] The swing work vehicle 1 includes a boom bracket 4 which is a swing body horizontally rotatably supported by the upper swing body 3. The boom bracket 4 is attached to the front end of the upper swing body 3 via a stay 33. The stay 33 is provided with a pivot pin 40 with an axis a (see FIG. 4) directed in the vertical direction. The boom bracket 4 is supported so as to be horizontally rotatable (i.e., swingable left and right) around the pivot pin 40. The boom bracket 4 rotates on a horizontal plane orthogonal to the axis a (for example, the XY plane shown in FIG. 5). Between the upper swing body 3 and the boom bracket 4, a swing cylinder 41 that expands and contracts in the front - rear direction is provided. The horizontal rotation of the boom bracket 4 operates according to the expansion and contraction of the swing cylinder 41.

[0016] The working machine 5 is driven by receiving power from the engine 30 and performs earth excavation work and the like according to operations at the operation unit. The working machine 5 is supported by the boom bracket 4 so as to be vertically rotatable. The boom bracket 4 is provided with a pivot pin 60 whose axis is oriented in the horizontal direction. The base end portion of the working machine 5 (the base end portion of the boom 6 described later) is supported so as to be vertically rotatable about the pivot pin 60. The working machine 5 rotates on a vertical plane (for example, the XZ plane shown in FIG. 4) orthogonal to the axis of the pivot pin 60. The working machine 5 performs a swinging operation in conjunction with the horizontal rotation of the boom bracket 4, thereby relatively horizontally moving (offsetting in the horizontal direction) with respect to the upper swing body 3.

[0017] The working machine 5 includes a boom 6, an arm 7, and a bucket 8 which is an attachment for excavation. The boom 6 is attached to the boom bracket 4 so as to be vertically rotatable. The boom 6 extends vertically from the base end portion supported by the boom bracket 4 and is bent in a boomerang shape in side view. A boom cylinder 6a that is movable in a telescopic manner is provided between the boom bracket 4 and the middle portion of the boom 6. The vertical rotation of the boom 6 with respect to the boom bracket 4 operates according to the extension and contraction of the boom cylinder 6a.

[0018] The arm 7 is attached to the boom 6 so as to be vertically rotatable. A pivot pin 70 whose axis is oriented in the horizontal direction is provided at the tip portion of the boom 6. The base end portion of the arm 7 is supported so as to be vertically rotatable (fore-and-aft rotatable) about the pivot pin 70. An arm cylinder 7a that is movable in a telescopic manner is provided between the middle portion of the boom 6 and the base end portion of the arm 7. The vertical rotation of the arm 7 with respect to the boom 6 operates according to the extension and contraction of the arm cylinder 7a.

[0019] Bucket 8 is mounted on arm 7 so as to be able to rotate up and down. A pivot pin 80 with its axis oriented horizontally is provided at the tip of arm 7. The base end of bucket 8 is supported so as to be able to rotate up and down (forward and backward) around the pivot pin 80. A bucket link 81 is interposed between the tip of arm 7 and bucket 8. The bucket link 81 is configured as a link that transmits driving force to bucket 8. A bucket cylinder 8a that is able to extend and retract is provided between the bucket link 81 and the base end of arm 7. The up and down rotation of bucket 8 relative to arm 7 is operated in accordance with the extension and retraction of the bucket cylinder 8a. Bucket 8 includes a cutting edge 8E which is the work end and a lateral portion 8S formed by a side plate.

[0020] [Control system for a slewing work vehicle] An example of the control system of the slewing work vehicle 1 will be briefly described. As shown in Figure 3, the slewing work vehicle 1 includes an operating device 33, a main unit controller 34 which is a vehicle control device, a work equipment control device 35, a display controller 36 which is a display control device, and a display device 37. The operating device 33 includes levers, switches, pedals, an operation panel, etc. The operation panel may also serve as the display device 37. The main unit controller 34 controls the travel operation of the lower traveling body 2 and the slewing operation of the upper slewing body 3 based on control signals from the operating device 33. The main unit controller 34 also controls the work equipment control device 35 and the display controller 36 based on control signals from the operating device 33.

[0021] The work equipment control device 35 controls the operation of the work equipment 5. This operation includes not only the vertical rotation of the boom 6, arm 7, and bucket 8, but also the swinging motion (offset) of the work equipment 5 due to the horizontal rotation of the boom bracket 4. The display controller 36 comprises a storage device 36a, an arithmetic unit 36b, and a safety device 36c. The storage device 36a is composed of RAM, ROM, etc., and stores various data, which will be described later. The arithmetic unit 36b performs predetermined calculation processing based on the data stored in the storage device 36a and detection signals from the position detection devices 11 and 12. The display controller 36 can display the results of the calculation processing on the screen of the display device 37.

[0022] The display system 50 is used in a slewing work vehicle 1 that can offset the work machine 5, which has a bucket 8, horizontally relative to the upper slewing body 1, and provides the operator with information useful for assisting construction operations in excavation work such as digging drainage ditches. The display system 50 comprises the above-described calculation device 36b and display device 37. The calculation device 36b calculates the position of the bucket 8 based on the detection results from the position detection devices 11 and 12 installed on the slewing work vehicle 1, and also calculates the required slewing amount of the upper slewing body 3 and the required offset amount of the work machine 5 necessary to align the side portion 8S of the bucket 8 with the side edge of the planned excavation area 90 (see Figure 8). The display device 37 displays the positional relationship between the bucket 8 and the planned excavation area 90.

[0023] [Bucket location detection] Next, the method for detecting the position of the bucket 8 will be described. More precisely, the position of the cutting edge 8E of the bucket 8 is detected, and the position of the lateral portion 8S is calculated based on that. As shown in Figure 3, the slewing work vehicle 1 is equipped with a position detection device 11 (first position detection device) and a position detection device 12 (second position detection device). The position detection device 11 detects the horizontal position of the boom bracket 4 relative to the upper slewing body 3. The position detection device 12 detects the vertical position of the work machine 5 relative to the upper slewing body 3. Based on the detection results from these position detection devices 11 and 12, the calculation device 36b calculates the position of the cutting edge 8E.

[0024] In this embodiment, the position detection device 11 is composed of a position sensor installed on the boom bracket 4 as shown in Figure 2. The position sensor detects the movement of the boom bracket 4 on its movable surface, more specifically, its movement on a horizontal plane perpendicular to the axis a of the pivot pin 40. By installing such a position sensor on the boom bracket 4, the horizontal position of the boom bracket 4 relative to the upper slewing body 3 can be detected relatively easily. In this embodiment, an example is shown in which an acceleration sensor is used as the position sensor constituting the position detection device 11 to detect the swing angle θ2 of the boom bracket 4 relative to the upper slewing body 3.

[0025] The position sensor constituting the position detection device 11 can also be installed on the swing cylinder 41. While inertial sensors such as acceleration sensors can be used as position sensors as described above, the system is not limited to these; for example, gyro sensors, angle sensors (tilt sensors), and cylinder sensors (stroke sensors) can also be used. When a cylinder sensor is used, the swing angle θ2 can be detected based on the extension / retraction amount (stroke amount) of the swing cylinder 41, and the horizontal position of the boom bracket 4 relative to the upper slewing body 3 can be detected.

[0026] In this embodiment, the position detection device 12 includes a position sensor 12a installed on the boom 6, a position sensor 12b installed on the arm 7, and a position sensor 12c installed on the bucket link 81, as shown in Figure 1. Position sensors 12a to 12c each detect the movement of the work machine 5 on its movable surface, more specifically, the movement on a vertical plane including the axis a of the pivot pin 40. In this embodiment, an example is shown in which acceleration sensors are used as position sensors 12a to 12c to detect angles α, β, and γ, which will be described later. Similar to the position detection device 11, the position sensors constituting the position detection device 12 are not limited to inertial sensors such as acceleration sensors.

[0027] Figure 4 is a left side view conceptually illustrating the coordinate system and the slewing work vehicle 1. This coordinate system is a Cartesian coordinate system defined by the horizontal X-axis extending left and right in Figure 4, the horizontal Y-axis perpendicular to the plane of the paper in Figure 4 (see Figure 5), and the vertical Z-axis extending up and down in Figure 4. The X-axis extends in the front-rear direction of the lower traveling body 2, and the Y-axis extends in the left-right direction (width direction) of the lower traveling body 2. The Z-axis coincides with the axis that serves as the pivot center of the upper slewing body 3. The XY plane containing the origin O is located at the height of the axis of the pivot pin 60, and the axis a of the pivot pin 40 is perpendicular to this XY plane.

[0028] Figure 5 is a plan view conceptually showing the coordinate system and the slewing work vehicle 1. The position of the work implement 5 shown in Figure 4 is represented by a dashed line in Figure 5. In Figures 4 and 5, the axis a of the pivot pin 40 is located on the X-axis. The slewing angle θ1 of the upper slewing body 3 relative to the lower traveling body 2 (see Figure 6) is zero in Figures 4 and 5, based on this state. Also, in Figure 4, the work implement 5 is located on a vertical plane (XZ plane) that includes the axis a of the pivot pin 40 and the Z-axis. The swing angle θ2 of the boom bracket 4 relative to the upper slewing body 3 is zero in Figure 4, based on this state.

[0029] In Figure 4, the work machine 5 is in a movable state on the XZ plane, meaning that the boom 6, arm 7, and bucket 8 can each rotate vertically (forward and backward) on the XZ plane. Angle α is the tilt angle (rotation angle) of the boom 6 with respect to the axis a of the pivot pin 40. Angle β is the tilt angle (rotation angle) of the arm 7 with respect to the extension direction of the boom 6 (direction of length L1). Angle γ is the tilt angle (rotation angle) of the bucket 8 with respect to the extension direction of the arm 7 (direction of length L2). As previously described, these angles α, β, and γ can be detected by the position sensors 12a to 12c that constitute the position detection device 12.

[0030] Length L1 is the length from the base end to the tip of the boom 6, and more specifically, it corresponds to the straight-line distance from the axis of pivot pin 60 to the axis of pivot pin 70. Length L2 is the length from the base end to the tip of the arm 7, and more specifically, it corresponds to the straight-line distance from the axis of pivot pin 70 to the axis of pivot pin 80. Length L3 is the length from the base end to the tip of the bucket 8, and more specifically, it corresponds to the straight-line distance from the axis of pivot pin 80 to the cutting edge 8E. The data for lengths L1 to L3 are stored in advance in the storage device 36a.

[0031] The slewing work vehicle 1 of this embodiment is equipped with two GPS antennas 9,9. The three-dimensional position information of the antennas 9,9 is received by a receiving device 19 (see Figure 3). The antennas 9,9 are fixed at predetermined positions on the slewing work vehicle 1. In this embodiment, the antennas 9,9 are arranged on a horizontal plane parallel to the XY plane. The relative position of the axis that forms the pivot center of the upper slewing body 3 (i.e., the Z axis) with respect to the antennas 9,9, and consequently the relative position of the origin O (global coordinates), is known in advance based on the specifications of the slewing work vehicle 1 or based on prior measurements, and this data is stored in the storage device 36a.

[0032] Figure 6 is a plan view conceptually showing the coordinate system and the slewing work vehicle 1, similar to Figure 5, but differs from Figure 5 in that the upper slewing body 3 is slewing. In Figure 6, the position of the work machine 5 when the swing angle θ2 is zero is shown by the dashed line. The slewing radius r of axis a can be known in advance, and this data is stored in the memory device 36a. The slewing angle θ1 of the upper slewing body 3 relative to the lower traveling body 2 can be calculated based on the three-dimensional position information of the antennas 9,9 and the data stored in the memory device 36a, and this processing is performed by the arithmetic unit 36b. As long as the information necessary for calculating the slewing angle θ1 can be obtained, the installation locations of the antennas 9,9 on the slewing work vehicle 1 are not particularly limited.

[0033] First, as shown by the dashed lines in Figures 4 and 5, when the upper rotating body 3 is not rotating and the work implement 5 is not swinging (i.e., θ1=0, θ2=0), if the three-dimensional coordinates of the cutting edge 8E with respect to the position of axis a on the XY plane are (Xa, Ya, Za), then these coordinates (Xa, Ya, Za) can be determined by the following formula. Xa=L1sinα+L2sin(α+β)+L3sin(α+β+γ) Ya=0 Za=L1cosα+L2cos(α+β)+L3cos(α+β+γ)

[0034] Next, as shown by the solid line in Figure 5, in a state where the work machine 5 is swung without rotating the upper rotating body 3 (θ1=0, θ2≠0), if the three-dimensional coordinates of the cutting edge 8E with the position of axis a on the XY plane as the base point are (Xa1,Ya1,Za1), then those coordinates (Xa1,Ya1,Za1) can be determined by the following formula. Xa1 = Xa·cosθ2 ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}cosθ2 Ya1 = Xa·sinθ2 ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}sinθ2 Za1=Za =L1cosα+L2cos(α+β)+L3cos(α+β+γ)

[0035] Furthermore, as shown in Figure 6, when the upper rotating body 3 is rotated (θ1≠0), if the three-dimensional coordinates of axis a, starting from the origin O on the XY plane, are (Xo0,Yo0,Zo0), and the rotation radius of axis a is r, then the coordinates (Xo0,Yo0,Zo0) can be calculated by the following formula. X₀=r·cosθ1 Yo0 = r·sinθ1 Zo0=0

[0036] Then, as shown by the dashed line in Figure 6, when the upper rotating body 3 is rotated and the work implement 5 is not swinging (θ1≠0, θ2=0), if the three-dimensional coordinates of the cutting edge 8E with respect to the origin O on the XY plane are (Xo1,Yo1,Zo1), then those coordinates (Xo1,Yo1,Zo1) can be determined by the following formula. Xo1 = Xa·cosθ1 + Xo0 ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}cosθ1+r·cosθ1 Yo1 = Xa·sinθ1 + Yo0 ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}sinθ1+r·sinθ1 Zo1 = Za + Zo0 =L1cosα+L2cos(α+β)+L3cos(α+β+γ)

[0037] Furthermore, as shown by the solid line in Figure 6, when the upper rotating body 3 is rotated and the work machine 5 is swung (θ1≠0, θ2≠0), if the three-dimensional coordinates of the cutting edge 8E, starting from the origin O on the XY plane, are (Xo2,Yo2,Zo2), then these coordinates (Xo2,Yo2,Zo2) can be determined by the following formula. Xo2 = Xa·cos(θ1+θ2)+Xo0 ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}cos(θ1+θ2)+r·cosθ1 Yo2 = Xa·sin(θ1+θ2)+Yo0 ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}sin(θ1+θ2)+r·sinθ1 Zo2 = Za + Zo0 =L1cosα+L2cos(α+β)+L3cos(α+β+γ)

[0038] Therefore, when the global coordinates of the origin O are (A, B, C), the global coordinates (Xg2, Yg2, Zg2) of the cutting edge 8E can be obtained by transforming the three-dimensional coordinates (Xo2, Yo2, Zo2) of the cutting edge 8E using the following formula. Xg² = Xo² + A ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}cos(θ1+θ2)+r·cosθ1+A Yg2 = Yo2 + B ={L1sinα+L2sin(α+β)+L3sin(α+β+γ)}sin(θ1+θ2)+r·sinθ1+B Zo2 = Zo2 + C =L1cosα+L2cos(α+β)+L3cos(α+β+γ)+C

[0039] In this embodiment, the horizontal position of the boom bracket 4 relative to the upper slewing body 3 (and thus the swing angle θ2) is detected by the position detection device 11, and the vertical position of the work implement 5 relative to the upper slewing body 3 (and thus the angles α, β, and γ) is detected by the position detection device 12. Based on these detection results, the position of the cutting edge 8E is calculated. This calculation process is performed by the calculation device 36b, appropriately referring to data stored in the storage device 36a and information transmitted from the receiving device 19. The calculation result can be notified to the operator, for example, by displaying it on the display device 37.

[0040] As described above, according to this embodiment, the position of the cutting edge 8E, which is the work end of the work implement 5, can be detected with high precision in the slewing work vehicle 1 having a boom swing function. Based on the detected position of the cutting edge 8E and the relative positional relationship between the cutting edge 8E and the lateral part 8S, the calculation device 36b can calculate the position of the lateral part 8S. The relative positional relationship between the cutting edge 8E and the lateral part 8S is known in advance based on the specifications of the work implement 5 or based on prior measurements, and this data is stored in the storage device 36a.

[0041] [Operation Guidance During Installation] Next, we will explain the operational guidance during construction for digging drainage ditches. Figure 7 is a flowchart of the operational guidance during construction. Figures 8 to 10 show the screens of the display device 37 during construction, respectively. On this screen, the upper slewing body 3, the work machine 5, and the bucket 8 are represented by icons 93, 95, and 98, respectively. In this embodiment, the left side of the screen is configured as a display area C1 showing the slewing work vehicle in plan view. The slewing work vehicle is schematically represented by the upper slewing body 3 and the work machine 5 including the bucket 8. The right side of the screen is configured as a display area C2 showing the upper slewing body 3 and the work machine 5 separately in plan view.

[0042] First, information regarding the current position and orientation of the slewing work vehicle 1 is acquired (step S1). This information can be obtained, for example, from the three-dimensional position information of the antennas 9,9 and the relative positional relationship between the antennas 9,9 and the axis that serves as the pivot center of the upper slewing body 3. Next, the position information of the bucket 8, specifically the position information of the cutting edge 8E of the bucket 8, is determined (step S2). As described above, this information can be calculated by the calculation device 36b based on the detection results from the position detection devices 11,12 installed on the slewing work vehicle 1. Then, the planned excavation area 90 where the trench will be excavated is set (step S3). This setting is done, for example, on the screen using the operation panel of the operation device 33.

[0043] Figure 8 shows the state before the guidance display. Display area C1 reflects the current position and orientation of the slewing work vehicle 1, which was determined in step S1, and the position of the bucket 8, which was determined in step S2. When performing wall excavation, it is preferable to display the wall surface W as shown in Figure 8. Information regarding the position and shape of the wall surface W is acquired or created in advance, and this data is stored in the storage device 36a. Alternatively, the wall surface W may be set on the screen using the operation panel. Display area C2 shows the upper slewing body 3 and the work machine 5 in the initial state when the planned excavation area 90 is set, each facing upwards on the screen.

[0044] The display area C1 shows the planned excavation area 90 set in step S3. In this embodiment, the side edge of the planned excavation area 90 is shown by a virtual line VL extending in the direction of extension of the planned excavation area 90 (up and down direction in Figure 8). This side edge refers to the side edge located on the outside in the width direction of the slewing work vehicle 1, out of a pair of side edges that define the planned excavation area 90. By displaying the side edge of the planned excavation area 90 in this way, the operator's operation can be effectively supported. However, the system is not limited to this; the center line of the planned excavation area 90 may be displayed, or the planned excavation area 90 may be displayed as a strip-shaped area with a predetermined width.

[0045] As shown in Figure 8, the display device 37 shows the positional relationship between the bucket 8 and the planned excavation area 90. In this embodiment, this positional relationship is indicated by an icon 98 and a virtual line VL. To excavate a trench in the planned excavation area 90, the bucket 8's side portion 8S must be aligned with the virtual line VL, which is the side edge of the planned excavation area 90 (hereinafter referred to as the "set state"), and then the work machine 5 must be operated to excavate. To transition from the initial state in Figure 8 to the set state, the operator must change the posture of the slewing work vehicle by making full use of the slewing movement of the upper slewing body 3 and the swing movement of the work machine 5, requiring advanced operating skills from the operator.

[0046] Therefore, in this display system 50, the calculation device 36b calculates the required rotation amount of the upper slewing body 3 and the required offset amount of the work machine 5 necessary to align the side portion 8S of the bucket 8 with the side edge of the planned excavation area 90, in order to assist in construction operations (step S4). The required rotation amount can be rephrased as the rotation angle of the upper slewing body 3 required to transition to the set state. Also, the required offset amount can be rephrased as the swing angle of the work machine 5 required to transition to the set state in this embodiment. In this way, the calculation device 36b calculates the rotation angle of the upper slewing body 3 and the swing angle of the work machine 5 that are suitable for digging a side ditch.

[0047] The display device 37 displays information to teach the operator the amount to operate the upper slewing body 3 according to the required slewing amount and the amount to operate the work implement 5 according to the required offset amount (step S5). Figure 9 is an example of a guidance screen displaying such information. Display area C1 shows icons 93s and 95s indicating the upper slewing body 3 and work implement 5 in the set state. Display area C2 shows icon 93g for the upper slewing body 3 and icon 95g for the work implement 5, indicating the slewing required to transition to the set state. In this example, the operator is taught that the upper slewing body 3 needs to be slewing to the right and the work implement 5 needs to be swung to the left.

[0048] Icon 93g in display area C2 shown in Figure 9 reflects the rotation angle θ3, which is the amount of manipulation for the upper rotating body 3 according to the calculated required rotation amount, and similarly, icon 95g reflects the swing angle θ4, which is the amount of manipulation for the work implement 5 according to the calculated required offset amount. The operator can visually recognize how much the upper rotating body 3 should rotate to the right based on the positional relationship between icons 93 and 93g. The operator can also visually recognize how much the work implement 5 should swing to the left based on the positional relationship between icons 95 and 95g. The numerical values ​​for rotation angle θ3 and swing angle θ4, and the display of arrows A3 and A4 may be omitted as appropriate. Visual effects may also be enhanced using light, and sound effects may be added using sound.

[0049] When the operator rotates the upper slewing body 3 and / or swings the work implement 5, the position information of the bucket 8 (and its cutting edge 8E) corresponding to the movement is obtained (step S6), and it is determined whether the bucket 8 has come into contact with the virtual line VL (step S7). If the bucket 8 has not come into contact with the virtual line VL, the positions of the upper slewing body 3 and the work implement 5 are displayed on the screen (display area C1) (step S8), and the position information of the bucket 8 is obtained again. If the bucket 8 has come into contact with the virtual line VL, further rotation of the upper slewing body 3 is prohibited (step S9).

[0050] Figure 10 shows an example of the screen when the bucket 8 is in contact with the virtual line VL. If the upper slewing body 3 were to slewing to the right from this state, the bucket 8 would collide with the wall surface W, so the rightward rotation of the upper slewing body 3 is restricted to prevent this. For the same reason, the rightward swinging motion of the work machine 5 can also be restricted. The display system 50 is equipped with a safety device 36c that restricts the rotation of the upper slewing body 3 and the offset (swing in this embodiment) of the work machine 5 so that the bucket 8 does not exceed the side edge of the planned excavation area 90 (see Figure 3). The safety device 36c sends a signal to the machine controller 34 when the bucket 8 is in contact with the virtual line VL, causing the above-mentioned restriction of rotation and offset to be executed. In addition to prohibiting rotation, the operator may be notified that the bucket 8 is in contact with the virtual line VL by flashing the screen or playing a sound effect.

[0051] When the bucket 8 makes contact with the virtual line VL, the display device 37 displays information indicating that the rotation of the upper slewing body 3 is restricted and the swing angle of the work implement 5 required to transition to the set state, as shown in Figure 10 (step S10). By operating the upper slewing body 3 and the work implement 5 according to these instructions on the screen, the bucket 8 can be set to a state where its side portion 8S is aligned with the virtual line VL without colliding with the wall surface W. In this way, the display system 50 indicates in which direction and by how much the upper slewing body 3 should be rotated, and the swing angle of the work implement 5 It provides operators with useful information for ditch digging, such as which direction and how much to swing the tool.

[0052] In this embodiment, the display device 37 displays the upper rotating body 3 and the work machine 5 extending from the front end of the upper rotating body 3, but is not limited to this, and other screen configurations can be adopted. However, it is preferable that the display device 37 displays at least the bucket 8 and the planned excavation area 90 in a plan view. This plan view may be a view from above along the axial direction of the rotational axis of the upper rotating body 3. In addition, the display of the planned excavation area 90 may be shown only by its side edges.

[0053] In this embodiment, an example is shown where the offset of the work implement is performed by swinging the work implement left and right relative to the upper slewing body, but it is not limited to this, and may also be performed by moving the work implement (its arm or boom) in parallel left and right relative to the upper slewing body. Such slewing work vehicles are disclosed, for example, in Japanese Patent Publication No. Hei 8-326086 and Japanese Patent Publication No. 2011-184965 by the present applicant. In such cases, instead of the swing angle of the work implement (swing angle of the boom bracket) described above, the bucket position can be calculated based on the amount of operation of the actuator that moves the work implement in parallel left and right (for example, the amount of extension and retraction of the cylinder), and the required offset amount of the work implement can be calculated.

[0054] In this embodiment, an example of calculating the three-dimensional position of the bucket's cutting edge is shown, but the method is not limited to this, and the two-dimensional position may also be calculated. For example, the position of the bucket's cutting edge when the planned excavation area is set may be used as the starting point of the work, and the required rotation amount and required offset amount may be calculated based on the relative positional relationship between the cutting edge position and the planned excavation area, as described above. In this case, it is not necessary to use global coordinates, and therefore the GPS antenna can be omitted. In such a case, the rotation angle of the upper rotating body relative to the lower traveling body may be configured to be detected by a position sensor (e.g., an angle sensor) installed on the upper rotating body.

[0055] The display system for a slewing work vehicle according to this embodiment is used in a slewing work vehicle in which a work machine having a bucket can be offset horizontally with respect to an upper slewing body. The system comprises a calculation device that calculates the position of the bucket based on the detection results from a position detection device installed on the slewing work vehicle, and calculates the required amount of rotation of the upper slewing body and the required amount of offset of the work machine necessary to align the side portion of the bucket with the side edge of the planned excavation area, and a display device that displays the positional relationship between the bucket and the planned excavation area. With this configuration, a slewing work vehicle in which a work machine can be offset horizontally can be used to assist in the operation of construction work such as digging drainage ditches.

[0056] Preferably, the display device displays information for instructing the operator on the amount of operation of the upper slewing body corresponding to the required slewing amount and the amount of operation of the work machine corresponding to the required offset amount. This allows the operator to receive operational guidance regarding the slewing of the upper slewing body and the offset of the work machine in order to align the side portion of the bucket with the side edge of the planned excavation area.

[0057] It is preferable to provide a safety device that restricts the rotation of the upper rotating body and the offset of the work machine so that the bucket does not exceed the side edge of the planned excavation area. This prevents the bucket from colliding with the wall when excavating near a wall.

[0058] The offset of the work implement may be performed by swinging the work implement from side to side relative to the upper rotating body.

[0059] Preferably, the display device shows at least the bucket and the planned excavation area in a plan view. This allows the operator to accurately understand the positional relationship between the bucket and the planned excavation area, which is useful for aligning the side of the bucket with the side edge of the planned excavation area.

[0060] Preferably, the display device displays the side edges of the planned excavation area using virtual lines extending in the direction of the planned excavation area. Displaying the position of the side edges of the planned excavation area can effectively support the operator's operation.

[0061] The slewing work vehicle according to the present invention comprises the above-described slewing work vehicle display system, a lower traveling body, an upper slewing body rotatably mounted above the lower traveling body, and a work machine that can be horizontally offset relative to the upper slewing body. With such a slewing work vehicle, the above-described display system is provided to assist in the operation of construction work such as digging drainage ditches.

[0062] The display method for a slewing work vehicle according to the present invention is used in a slewing work vehicle in which a work machine having a bucket can be offset horizontally with respect to an upper slewing body. Based on the detection results from a position detection device installed on the slewing work vehicle, the position of the bucket is calculated, and the required amount of rotation of the upper slewing body and the required amount of offset of the work machine necessary to align the side portion of the bucket with the side edge of the planned excavation area are calculated, and the positional relationship between the bucket and the planned excavation area is displayed on the screen of the display device. This method is useful for assisting in the operation of construction work such as digging drainage ditches in a slewing work vehicle in which the work machine can be offset horizontally.

[0063] The present invention is not limited in any way to the embodiments described above, and will not depart from the spirit of the present invention. Various improvements and modifications are possible within the given range.

[0064] [Note] An exemplary control method for a slewing work vehicle of the present invention is a control method for a slewing work vehicle equipped with a display device, wherein the slewing work vehicle and a virtual line are displayed side by side on the screen of the display device in a plan view, and the bucket of the work machine, whose movement position due to the slewing motion of the upper slewing body of the slewing work vehicle and the rotational motion of the work machine in front of the upper slewing body is reflected in accordance with the amount of operation of the slewing motion and the rotational motion, is displayed on the screen together with the virtual line (first configuration).

[0065] In the control method for the slewing work vehicle according to the first configuration described above, the virtual line on the screen may be positioned to the side of the slewing work vehicle (second configuration).

[0066] In the control method for the slewing work vehicle according to the first or second configuration described above, the bucket may be positioned to the side of the virtual line on the screen (third configuration).

[0067] In the control method for a slewing work vehicle according to any of the first to third configurations described above, the virtual line on the screen may be configured to extend in the vertical direction of the screen (fourth configuration).

[0068] In the control method for a slewing work vehicle according to any of the first to fourth configurations described above, the screen may be configured to display the slewing center of the upper slewing body fixed in place from an initial state (fifth configuration).

[0069] In a control method for a slewing work vehicle according to any of the first to fifth configurations described above, when the bucket is shown in contact with the virtual line, a control is performed (sixth configuration) that permits only operations in the direction in which the bucket is shown away from the virtual line for both the slewing and rotational movements. [Explanation of Symbols]

[0070] 1. Swivel work vehicle 2 Lower running body 3. Upper rotating body 4. Boom Bracket 5. Work equipment 6 Boom 7 Arms 8 buckets 8a Bucket Cylinder 8E cutting edge 8S Lateral part 11. Position detection device 12 Position detection device 36 Display Controller 36a Storage device 36b Arithmetic unit 36c safety equipment 37 Display device 50 Display Systems 90 Planned drilling area C1 display field (first display field) C2 display field (second display field) VL virtual line

Claims

1. A control method by the control unit of a slewing work vehicle equipped with a display device and a control unit, The display device screen will show an image of the slewing work vehicle in a plan view, along with a dashed line, The image showing the bucket of the work machine, whose position is reflected in the amount of operation of the rotation and pivot movements, is displayed on the screen along with the dashed lines, and the position resulting from the rotation of the upper pivot body of the pivot work machine and the rotation of the work machine in front of the upper pivot body is also displayed on the screen. When the image representing the bucket touches the virtual line and is displayed, the rotational movement is restricted, and information on the rotational movement necessary to implement the restriction of the rotational movement and transition to a state where the side of the bucket is aligned with the virtual line is displayed. A control method having

2. The control method according to claim 1, wherein in the aforementioned screen, the virtual line is positioned to the side of the image showing the swivel work vehicle.

3. The control method according to claim 2, wherein in the screen, the image representing the bucket is positioned to the side of the virtual line.

4. The control method according to claim 3, wherein in the aforementioned screen, the virtual line extends in the vertical direction of the screen.

Images