Dredging support system

Abstract

In a dredging support system attached to a backhoe dredger, the seabed of the dredging area is dredged more efficiently and with greater precision. [Solution] The guidance information displayed on the monitor screen 30 includes a closing operation line 45 that indicates the start timing for closing the grab bucket 8. With this, by simply starting the closing operation of the grab bucket 8 when the closing operation line 45 and the cutting edge of the shell related to the bucket position and orientation information 40 coincide on the monitor screen 30, the lowest point position of the cutting edge of the shell 18 and the dredging depth position can be matched. Therefore, even in dredging operations using a clamshell-type grab bucket 8 in which the cutting edge of the shell 18 traces an arc-shaped trajectory when in the opening and closing position, it is possible to prevent incomplete digging or over-digging.

Description

Technical Field

[0001] The present invention relates to a dredging support system that is installed on a backhoe dredger and transmits guidance information regarding the position information of a bucket, the dredging depth of the seabed, etc. to an operator to assist the dredging work by the operator.

Background Art

[0002] In dredging work using a backhoe workboat equipped with a working machine consisting of a backhoe on a pontoon, the operator of the working machine cannot directly visually observe the dredging status of the seabed by a bucket installed at the tip of the backhoe. For this reason, it is known to attach a dredging support system for transmitting guidance information such as the position information of the bucket and the dredging status of the seabed to an operator to a backhoe dredger. For example, in Patent Document 1, there is provided a turning angle detection device for detecting the turning angle of a backhoe, a front angle detection device for detecting the turning angles of a boom, an arm, a bucket, etc. at the front, and a sonar sensor for exploring the terrain of the excavation surface. Each signal output from the turning angle detection device and the sonar sensor is processed to obtain the terrain of the excavation surface, and a digging trajectory is obtained from the signals output from the turning angle detection device and the front angle detection device, and the terrain of the excavation surface and the digging trajectory are displayed together on the monitor screen in the cab. Patent Document 2 discloses that terrain data measured in advance, a preset target dredging line, and a boom, an arm, and a bucket of a backhoe are drawn and displayed on a monitor screen installed in the cab of the backhoe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described in Patent Document 2, if the posture of the backhoe's boom, arm, and bucket is constantly displayed on a monitor screen installed in the cockpit, the operator can proceed with the dredging work while keeping track of the position and movement of the bucket's tip on the monitor screen. For example, by operating the bucket so that the tip of the bucket aligns with the target dredging line on the monitor screen, dredging can be performed to the target dredging height relative to the seabed. However, even if the bucket's posture is displayed on the monitor screen, it is not easy to actually move the tip of the bucket smoothly and horizontally along the target dredging line. Therefore, even with the configuration described in Patent Document 2, it must be said that it is practically impossible to perform dredging work efficiently and with high precision.

[0005] The inventors are considering applying a dredging support system to dredging operations using a backhoe equipped with a clamshell-type grab bucket having a pair of left and right shells attached to the end of its arm. However, the above-mentioned problems also occur in dredging operations using such a clamshell-type grab bucket. That is, even if the position and attitude of the shell in the water, in addition to the target dredging line, are displayed on the monitor screen in the control room, it is extremely difficult to move the cutting edge of the shell horizontally along the target dredging line, making it impossible to perform dredging work efficiently and with high precision. This is especially true for a typical clamshell-type grab bucket having a pair of left and right shells, where the cutting edge of the shell traces an arc-shaped trajectory when moving from an open position to a closed position, with the center in the left-right direction being lower and both ends in the left-right direction being higher. Therefore, it is practically impossible to move the cutting edge of the shell accurately and horizontally along the target dredging line running horizontally from left to right.

[0006] In addition, with such a common clamshell-type grab bucket, as described above, the tip of the shell traces an arc-shaped trajectory. Therefore, if dredging is performed so that the lowest point of the shell's tip coincides with the target dredging line, it is unavoidable that unexcavated areas higher than the target dredging line will be formed at both ends of the excavated area on the seabed. To remove these unexcavated areas, it is necessary to proceed with the dredging while partially overlapping the excavation areas (the area of ​​the seabed excavated by a single closing motion of the grab bucket). However, determining the extent of the overlapping area, while imagining the seabed condition and excavation state which cannot be seen visually, is greatly influenced by the operator's skill level. In reality, it is impossible to carry out dredging work efficiently and accurately without a skilled operator. Furthermore, if the unexcavated areas are not reflected in the dredging support system, the reliability of the construction history data is reduced.

[0007] The object of the present invention is to provide a dredging support system attached to a backhoe dredger, in which a clamshell-type grab bucket is mounted on the tip of the arm, the cutting edge of the shell traces an arc-shaped trajectory when in the open and closed position, and which enables more efficient and highly accurate dredging of the seabed of the area to be dredged. [Means for solving the problem]

[0008] The present invention relates to a dredging support system in which, during dredging operations by a backhoe dredger, terrain data information 44 obtained from surveys conducted prior to the dredging operation and guidance information including the real-time position of the grab bucket 8 are displayed on a monitor screen 30 installed in the cockpit 5 of the backhoe 2. The grab bucket 8 is a non-horizontal excavation type clamshell grab bucket, comprising a pair of left and right shells 18-18, and when moving from an open position to a closed position, the cutting edges of these shells 18-18 trace an arc-shaped trajectory in which the central part in the left-right direction is lower and both ends on the left and right are higher. This dredging support system comprises a plurality of sensors 19-24 installed on the backhoe 2 for the purpose of detecting the position information and attitude information of the grab bucket 8, a control unit 27 that calculates the position information of the grab bucket 8 based on the detection data of these plurality of sensors 19-24, and the monitor screen 30 on which the position information of the grab bucket 8 calculated by the control unit 27 is displayed. Guidance information is displayed on the monitor screen 30, including terrain data information 44 obtained from prior surveying, bucket position and orientation information 40 showing the real-time position and orientation of the grab bucket 8, a target dredging line 41 indicating a pre-set dredging depth position in the dredging area, and a closing operation line 45 positioned above the target dredging line 41 to indicate the start timing of the closing operation of the grab bucket 8. The closing operation line 45 is defined based on the lowest point position of the trajectory of the cutting edge of the shell 18 and the dredging depth position, and the grab bucket 8 is closed when the closing operation line 45 and the cutting edge of the shell in the open position related to the bucket position and orientation information 40 coincide on the monitor screen 30, so that the lowest point position of the cutting edge of the shell 18 coincides with the dredging depth position.

[0009] The guidance information is drawn below the target dredging line 41 on the monitor screen 30 and includes an over-excavation line 42 indicating the dredging limit.

[0010] The guidance information includes excavation track information 44b and 44c determined by the trajectory of the cutting edge of the shell 18. [Effects of the Invention]

[0011] In the dredging support system of the present invention, the guidance information displayed on the monitor screen 30 includes a closing operation line 45 that indicates the start timing of the closing operation of the grab bucket 8, which is defined based on the lowest point position of the trajectory of the cutting edge of the shell 18 and the dredging depth position. Furthermore, in the present invention, the closing operation line 45 is defined based on the lowest point position of the trajectory of the cutting edge of the shell 18 and the dredging depth position, and the system is configured such that the lowest point position of the cutting edge of the shell 18 and the dredging depth position coincide when the grab bucket is closed while the closing operation line 45 and the cutting edge of the shell related to the bucket position and attitude information 40 coincide on the monitor screen 30. With the dredging support system of the present invention, which has the above configuration, by simply starting the closing operation of the grab bucket 8 when the closing operation line 45 and the cutting edge of the shell related to the bucket position and attitude information 40 coincide on the monitor screen 30, the lowest point position of the cutting edge of the shell 18 and the dredging depth position can be made to coincide. Therefore, even in dredging work using a clamshell-type grab bucket 8 in which the cutting edge of the shell 18 traces an arc-shaped trajectory when in the opening and closing position, it is possible to reliably prevent "under-excavation" where the lowest point position of the cutting edge of the shell 18 is excessively above the target dredging depth position, resulting in a shallower dredged surface than planned, and "over-excavation" where the lowest point position of the shell 18 is excessively below the target dredging depth position, resulting in a deeper dredged surface than planned. As described above, according to the present invention, the dredging work can be carried out appropriately simply by the operator starting the closing operation of the grab bucket 8 when the tip of the shell related to the bucket position and attitude information 40 drawn on the monitor screen 30 coincides with the closing operation line 45, thereby enabling more efficient and highly accurate dredging of the seabed of the area to be dredged. Furthermore, regardless of the operator's skill level, the dredging work can be carried out efficiently and highly accurately simply by the operator starting the closing operation of the grab bucket 8 when the tip of the shell related to the bucket position and attitude information 40 drawn on the monitor screen 30 coincides with the closing operation line 45.

[0012] If the guidance information is drawn below the target dredging line 41 on the monitor screen 30 and includes the over-excavation line 42 indicating the dredging limit, an estimate of the over-excavation width can be drawn on the monitor screen 30, allowing the operator to clearly recognize the over-excavation location in the design calculations. Therefore, over-excavation can be minimized, and excessive over-excavation can be prevented.

[0013] If the guidance information displayed on the monitor screen 30 includes excavation track information 44b and 44c determined by the trajectory of the shell 18's cutting edge, the area A1 where the dredging work has been completed can be clearly depicted on the monitor screen 30, allowing the dredging work to proceed more efficiently. In addition, in dredging operations using a non-horizontal excavation type clamshell grab bucket 8, in which the cutting edge of the shell 18 traces an arc-shaped trajectory with a lower central part in the left-right direction and higher at both ends when moving from an open to a closed position, it is unavoidable that unexcavated portions 48 will be created at both ends in the left-right direction of the excavation area during the excavation work associated with the closing operation of the grab bucket 8. However, as in the present invention, if the guidance information displayed on the monitor screen 30 includes excavation track information 44b and 44c determined by the trajectory of the cutting edge of the shell 18, the unexcavated portions 48 can be clearly indicated, making it easier to optimize the overlapping areas of each excavation area (the area of ​​the seabed excavated by the closing operation of the grab bucket 8 in one go), and in this respect as well, the seabed can be dredged more efficiently and with higher precision. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows an example of the display state of the monitor screen of a dredging support system according to an embodiment of the present invention. [Figure 2] This figure shows an example of the display state of the monitor screen of the system. [Figure 3] This is a block diagram of the system. [Figure 4] This is a side view illustrating the main components of a backhoe dredger equipped with the system. [Figure 5](a) and (b) are diagrams illustrating the trajectory of the shell of a clamshell-type grab bucket. [Modes for carrying out the invention]

[0015] (Embodiment) Figures 1 to 5 show an embodiment of the dredging support system according to the present invention. Figure 4 shows a backhoe dredger to which the dredging support system according to this embodiment is attached. As shown in the figure, the backhoe dredger consists of a barge 1 and a backhoe 2 mounted on its stern. The backhoe 2 includes a crawler-type running body 3, a slewing body 4 provided on the upper part of the running body 3, a control room 5 provided at the front of the slewing body 4, a boom 6 configured to swing vertically relative to the slewing body 4, an arm 7 attached to the tip of the boom 6, and a clamshell-type grab bucket 8 attached to the tip of the arm 7. The slewing body 4 is configured to be rotatable by a slewing mechanism 9 provided on the running body 3. The boom 6 is configured to swing vertically around an axis 12 provided on the slewing body 4 by a boom cylinder 11. The arm 7 is configured to swing vertically around an axis 14 located at the tip of the boom 6, via an arm cylinder 13. A bucket link 16 is attached to the tip of the arm 7 so as to be able to swing around an axis 15, and a grab bucket 8 is attached to the tip of this bucket link 16. A bucket cylinder 17 is attached to the bucket link 16, and this bucket cylinder 17 opens and closes the pair of left and right shells 18-18 that make up the grab bucket 8.

[0016] As shown by the dashed line in Figure 5(a), the trajectory of the shells 18-18 that make up the grab bucket 8 during opening and closing operations is higher in the left-right direction and lower in the center. Therefore, for example, when the grab bucket 8 in the open position is dropped onto a flat seabed, as shown in Figure 5(b), in the excavation work associated with closing the grab bucket 8 (the operation from the open position to the closed position), unexcavated portions 48 are formed at both ends in the left-right direction of the excavation area. Note that the position of the grab bucket 8 and shells 18-18 shown in Figure 5(a) is the "open position", and the position of the grab bucket 8 and shells 18-18 shown in Figure 5(b) is the "closed position".

[0017] As shown in Figure 4, the slewing body 4 is equipped with a first GNSS receiver (sensor) 19 for measuring the three-dimensional coordinates of the backhoe 2 and a second GNSS receiver (sensor) 20 for detecting the orientation of the backhoe 2 (the rotation angle of the slewing body 4). In addition, a vehicle tilt sensor (sensor) 21 for detecting the tilt angle of the slewing body 4 is installed on the upper part of the control room 5. The boom 6 is equipped with a boom attitude sensor (sensor) 22 for detecting the attitude position of the boom 6 as changed by the boom cylinder 11, and the arm 7 is equipped with an arm attitude sensor (sensor) 23 for detecting the attitude position of the arm 7 as changed by the arm cylinder 13. The bucket link 16 is equipped with a bucket attitude sensor 24 for detecting the attitude position of the grab bucket 8.

[0018] As shown in the block diagram of FIG. 3, the dredging support system includes, in addition to the previous first GNSS receiver 19, second GNSS receiver 20, vehicle body tilt sensor 21, boom attitude sensor 22, arm attitude sensor 23, and bucket attitude sensor 24, a control unit 27 responsible for controlling the entire system, a bucket opening / closing switch 28, a transceiver unit 29 responsible for data transmission and reception, a monitor screen 30 on which various information such as construction information is displayed, and a management terminal device (management terminal) 31, etc. The bucket opening / closing switch 28 is operated by an operator for the purpose of opening and closing the grab bucket 8. When the switch 28 is pressed from a state where the grab bucket 8 is in the open position, the cylinder constituting the bucket cylinder 17 extends downward and the grab bucket 8 becomes the closed position. When the switch 28 is pressed again from this closed position state, the grab bucket 8 returns to the open position. The transceiver unit 29 performs data transmission and reception with the management terminal 31. The control unit 27, bucket opening / closing switch 28, transceiver unit 29, and monitor screen 30 are installed in the cab 5.

[0019] Using FIGS. 1 and 2, the content displayed on the monitor screen 30 installed in the cab 5 will be described. On the monitor screen 30, two screens are arranged side by side: a screen (first screen) showing the dredging state from the side as shown in FIG. 1 and a screen (second screen) showing the dredging state in the planar direction as shown in FIG. 2. The operator can proceed with the dredging work while viewing both of these screens.

[0020] The control unit 27 stores, in addition to the underwater terrain data information obtained by prior surveying and sent from the management terminal 31, information related to a target depth indicating a preset target dredging depth position, information related to the over-dredging depth calculated based on the target depth, information related to the start timing of the closing operation of the grab bucket calculated based on the target depth, and the like. Further, based on the detection values from the various sensors 19 to 24, the control unit 27 calculates in real time information indicating the dredged planar direction area already dredged, information related to the position and posture of the grab bucket 8 and the shells 18, 18 constituting the grab bucket, information related to the position and posture of the dredger, and the like, and draws these various types of information on the monitor screen 30 as shown in FIGS. 1 and 2.

[0021] In FIG. 1, reference numeral 40 is a diagram (bucket position and attitude information) showing the position and attitude state of the grab bucket 8 drawn on the monitor screen 30. This bucket position and attitude information 40 is drawn on the monitor screen 30 in real time based on the position information and attitude information of the grab bucket 8 calculated by the control unit 27 based on the detection values detected by various sensors such as the bucket attitude sensor 24. Further, when the actual position and attitude of the grab bucket 8 in water are changed, the bucket position and attitude information 40 on the monitor screen 30 of the first screen is configured to change according to those positions and attitudes. That is, when the position and attitude of the grab bucket 8 change, the bucket position and attitude information 40 on the monitor screen 30 of FIG. 1 is configured to change so as to faithfully reproduce those positions and attitudes. Note that the bucket position and attitude information 40 in FIG. 1 is always drawn on the monitor screen 30 in a state as if the grab bucket 8 is viewed from the side.

[0022] In Figure 1, the horizontal line corresponding to the dashed line symbol 41 indicates the target dredging line, which shows the target dredging depth position, and the horizontal line corresponding to the dashed line symbol 42 indicates the over-excavation line, which shows the over-excavation limit. These lines, along with the horizontal line 43 indicating the water depth, are drawn on the monitor screen 30. Furthermore, the solid line in Figure 1 is the seabed line (topographic data information) 44, mainly consisting of line 44a, which relates to the height position of the seabed according to the topographic data information. This seabed line 44 also includes lines 44b and 44c, which show the trajectory of the shell 18 (excavation track information determined by the trajectory of the cutting edge of the shell 18). In other words, the seabed line 44 is composed of lines 44b and 44c, which relate to the excavation track information showing the seabed after excavation, determined by the trajectory of the tip of the shell 18, and line 44a, which relates to the height position of the seabed according to the topographic data information obtained from prior surveying, and depicts the actual seabed condition with almost perfect fidelity. Furthermore, the horizontal line corresponding to reference numeral 45, shown as a dashed line in Figure 1, is a closing operation line indicating the start timing of the closing operation of the grab bucket 8. When the closing operation line 45 and the cutting edge of the grab bucket shell, corresponding to the bucket position and orientation information 40, coincide on the monitor screen 30, the system is configured such that the lowest point position of the cutting edge of the shell 18 coincides with the dredging depth position.

[0023] In Figure 2, reference numerals 50 and 51 indicate the position and attitude of the barge 1 and backhoe 2, which are plotted on the monitor screen 30. These plots 50 and 51 relating to the barge 1 are plotted in real time on the second screen of the monitor screen 30 based on the position and attitude information of the barge 1 calculated by the control unit 27 based on detection values ​​supplied from various sensors such as the first GNSS receiver 19. Furthermore, when the actual position and attitude of the barge 1 change, the plots 50 and 51 relating to the barge 1 on the monitor screen 30 in Figure 2 also change accordingly. In other words, when the position and attitude of the barge 1 or backhoe 2 change, the plots 50 and 51 relating to the barge 1 or backhoe 2 on the monitor screen 30 in Figure 2 also change to faithfully reproduce those positions and attitudes. In Figure 2, reference numeral 52 denotes a diagram showing the positional and orientation information of the grab bucket 8 in a plan view (hereinafter referred to as the "diagram relating to the planar position of the bucket"), where the region of the grab bucket 8 in a plan view in the open position (see Figure 5) (the maximum region of the grab bucket 8 in a plan view) is drawn as a diagram.

[0024] In the second screen of Figure 2, symbol A1 indicates the area where dredging work has been completed, symbol A2 indicates the area where dredging work is in progress, and symbol A3 indicates the area before dredging work. More specifically, the area where dredging work has been completed, symbol A1, refers to the region (46a) in the first screen of Figure 1 where the line relating to the shell trajectory related to the bucket position and attitude information 40 is located between the target dredging line 41 and the over-excavation line 42. The area where dredging work is in progress, symbol A2, refers to the region (46b) in the first screen of Figure 1 where the line relating to the shell trajectory related to the bucket position and attitude information 40 is located between the line 44a, which represents the seabed height position before dredging work obtained by prior surveying, and the target dredging line 41. The area designated as A3, which is the area before the dredging operation, refers to the region (46c) in the first screen of Figure 1 where the line 44a, which represents the height position of the seabed before the dredging operation obtained from the prior survey, has not changed. These areas A1 to A3, which are drawn on the second screen of Figure 2, also change in real time as the dredging operation by the grab bucket 8 progresses.

[0025] The operator proceeds with the dredging work while viewing the first screen (Figure 1) and the second screen (Figure 2) displayed on the monitor screen 30. Specifically, as shown in Figure 2, the operator displaces the position and orientation of the grab bucket 8 so that the diagram 52 relating to the planar position of the bucket overlaps with area A2 during dredging or area A3 before dredging, and then lowers the grab bucket 8. As the grab bucket 8 is lowered in this way, height information 47 from the water surface is displayed on the monitor screen 30, as shown in Figure 1. This height information displayed in Figure 1 also changes in real time according to the displacement of the grab bucket 8.

[0026] On the first screen of Figure 1, when the closing operation line 45 coincides with the cutting edge of the shell related to the bucket position and orientation information 40, the operator presses the bucket opening / closing switch 28 to close the grab bucket 8. As a result, the shells 18 of the grab bucket 8 move closer together, and the grab bucket 8 eventually assumes a closed position. At this time, since the closing operation line 45 indicates the start timing of the closing operation of the grab bucket 8, by starting the closing operation of the grab bucket 8 when the closing operation line 45 coincides with the cutting edge of the shell related to the bucket position and orientation information 40 as described above, the lowest point position of the cutting edge of the shell 18 can be made to coincide with the dredging depth position. Furthermore, as the grab bucket 8 displaces from the open position to the closed position in this way, it is possible to excavate sediment from the seabed and take the sediment into the shell 18. Once the grab bucket 8 is in the closed position and one excavation operation is complete, the operator lifts the grab bucket 8 out of the water and moves it onto a soil transport vessel (not shown in the diagram). There, the grab bucket 8 is displaced to the open position, and the soil taken into the shell 18 is transferred to the soil transport vessel.

[0027] Thus, when the first excavation operation by the grab bucket 8 is completed, the semi-circular trajectory of the shell (excavation track information 44c) resulting from the excavation operation is drawn on the monitor screen, as shown in Figure 1. In addition, the area where the height position after the first excavation operation is located below the dredging depth position is drawn on the second screen as area A1 where the dredging operation has been completed. For the next (second) excavation operation, the operator moves the grab bucket 8 horizontally, referring to the shell trajectory (excavation track information 44c) on the first screen in Figure 1, so that the line diagram 52 relating to the planar position of the bucket overlaps with the boundary between area A1 where the dredging operation has been completed and area A2 where the dredging operation is in progress, on the second screen in Figure 2, and then moves the grab bucket 8 vertically (lowers it). Then, in the first screen of Figure 1, when the closing operation line 45 and the cutting edge of the shell related to the bucket position and orientation information 40 coincide, the bucket opening / closing switch 28 is pressed to close the grab bucket 8.

[0028] More specifically, as shown in Figure 5(a), the trajectory of the shells 18-18 that make up the grab bucket 8 during opening and closing operations is higher in the left-right direction and lower in the center. Therefore, the line (excavation information) 44b relating to the shell's trajectory on the monitor screen 30 in Figure 1, which faithfully reproduces the position and movement of the shells 18, is also higher in the left-right direction and lower in the center. In addition, during the excavation work associated with the first closing operation of the grab bucket 8, an unexcavated area is created at the end in the direction of excavation progress (to the right in Figure 1), as indicated by reference numeral 48 in Figure 5(b). Therefore, in the second excavation work, the grab bucket 8 is positioned above this unexcavated area 48 to excavate it, and the excavation work is performed. In this embodiment, since lines (excavation information) 44b related to the shell's trajectory and diagrams corresponding to the unexcavated areas 48 are drawn on the monitor screen 30, it becomes easy to optimize the overlapping portions of each excavation area (the area of ​​the seabed excavated by a single closing operation of the grab bucket), making it possible to dredge the seabed more efficiently and with higher precision.

[0029] Subsequent steps, such as lifting the grab bucket 8 from the water and transferring it to the soil transport vessel, are the same as in the first excavation operation. The excavation operation described above is repeated to expand area A1, where dredging has been completed. Information regarding the dredging status, including area A1 where dredging has been completed, is recorded as construction history data in the recording area of ​​the control unit 27 at predetermined intervals, and this construction history data is transmitted to the management terminal 31 at predetermined intervals.

[0030] As described above, with the dredging support system of this embodiment, the operator can align the lowest point of the shell's cutting edge with the dredging depth simply by starting the closing operation of the grab bucket 8 while the cutting edge of the shell, related to the bucket position and orientation information 40 drawn on the monitor screen 30, coincides with the closing operation line 45. Therefore, even in dredging operations using a clamshell-type grab bucket 8 in which the cutting edge of the shell 18 traces an arc-shaped trajectory when opened and closed, it is possible to reliably prevent "under-excavation," where the lowest point of the shell's cutting edge is excessively above the target dredging depth, resulting in a shallower dredged surface than planned, and "over-excavation," where the lowest point of the shell 18 is excessively below the target dredging depth, resulting in a deeper dredged surface than planned. Therefore, this dredging support system allows for more efficient and accurate dredging of the seabed of the area to be dredged. Furthermore, regardless of the operator's skill level, the dredging work can proceed while preventing "incomplete dredging" or "over-dredging" simply by having the operator start closing the grab bucket 8 when the cutting edge of the shell, related to the bucket position and attitude information 40 displayed on the monitor screen 30, coincides with the closing operation line 45.

[0031] The guidance information includes an over-excavation line 42, which is drawn below the target dredging line 41 on the monitor screen 30 and indicates the dredging limit. This allows the operator to clearly recognize the over-excavation location in the design calculations by displaying an estimate of the over-excavation width on the monitor screen 30. Therefore, it is possible to minimize over-excavation and prevent excessive over-excavation.

[0032] Since the guidance information displayed on the monitor screen 30 includes excavation track information 44b and 44c determined by the trajectory of the shell 18's cutting edge, the area A1 where dredging work has been completed can be clearly depicted on the monitor screen 30, allowing dredging work to proceed more efficiently. In addition, in dredging operations using a non-horizontal excavation type clamshell grab bucket 8, in which the cutting edge of the shell 18 traces an arc-shaped trajectory with a lower central part in the left-right direction and higher at both ends when moving from an open to a closed position, it is unavoidable that unexcavated portions 48 will be created at both ends in the left-right direction of the excavation area during the excavation work associated with the closing operation of the grab bucket 8. However, as in this embodiment, if the guidance information displayed on the monitor screen 30 includes excavation track information 44b and 44c determined by the trajectory of the cutting edge of the shell 18, the unexcavated portions 48 can be clearly indicated, making it easier to optimize the overlapping areas of each excavation area (the area of ​​the seabed excavated by the closing operation of the grab bucket 8 in one go), and in this respect as well, the seabed can be dredged more efficiently and with higher precision.

[0033] The sensors installed on the backhoe 2 for the purpose of detecting the position and attitude information of the grab bucket 8 are not limited to those described in the above embodiment. The shape of the clamshell-type grab bucket is not limited to those described in the above embodiment. [Explanation of symbols]

[0034] 2 Backhoe 5. Cockpit 8 grab buckets 18 shells 19. Sensor (First GNSS receiver) 20. Sensor (Second GNSS receiver) 21. Sensor (Vehicle tilt sensor) 22 Sensors (Boom attitude sensors) 23. Sensor (Arm posture sensor) 24. Sensor (Bucket attitude sensor) 27 Control Unit 30 Monitor Screens 40 Bucket position and attitude information 41 Target dredging line 42 Over-excavation line 44. Topographic data information (submarine lines) 44b Excavation Site Information 44th century excavation site information 45 Open operation line

Claims

1. A dredging support system in which, during dredging operations using a backhoe dredger, topographic data information (44) obtained from surveys conducted prior to the dredging operation and guidance information including the real-time position of the grab bucket (8) are displayed on a monitor screen (30) installed in the cockpit (5) of the backhoe (2), The grab bucket (8) is a non-horizontal digging type clamshell grab bucket, comprising a pair of left and right shells (18, 18), wherein when moving from an open position to a closed position, the cutting edges of these shells (18, 18) trace an arc-shaped trajectory, with the center in the left-right direction being lower and both ends being higher. For the purpose of detecting the position and attitude information of the grab bucket (8), the backhoe (2) is equipped with a plurality of sensors (19-24), a control unit (27) that calculates the position information of the grab bucket (8) based on the detection data of the plurality of sensors (19-24), and a monitor screen (30) on which the position information of the grab bucket (8) calculated by the control unit (27) is displayed. On the monitor screen (30), guidance information is displayed, including terrain data information (44) obtained from prior surveying, bucket position and orientation information (40) showing the real-time position and orientation of the grab bucket (8), a target dredging line (41) indicating a pre-set dredging depth position in the dredging area, and a closing operation line (45) positioned above the target dredging line (41) to indicate the start timing of the closing operation of the grab bucket (8). A dredging support system characterized in that the closing operation line (45) is defined based on the lowest point position of the trajectory of the cutting edge of the shell (18) and the dredging depth position, and the grab bucket (8) is closed when the closing operation line (45) and the cutting edge of the shell in the open position according to the bucket position and attitude information (40) coincide on the monitor screen (30), so that the lowest point position of the cutting edge of the shell (18) coincides with the dredging depth position.

2. The dredging support system according to claim 1, wherein the guidance information is drawn below the target dredging line (41) on the monitor screen (30) and includes an over-excavation line (42) indicating the dredging limit.

3. The dredging support system according to claim 1 or 2, wherein the guidance information includes excavation information (44b, 44c) determined by the trajectory of the cutting edge of the shell (18).

Images