EP0125736A1 - Drague - Google Patents
Drague Download PDFInfo
- Publication number
- EP0125736A1 EP0125736A1 EP84200678A EP84200678A EP0125736A1 EP 0125736 A1 EP0125736 A1 EP 0125736A1 EP 84200678 A EP84200678 A EP 84200678A EP 84200678 A EP84200678 A EP 84200678A EP 0125736 A1 EP0125736 A1 EP 0125736A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- depth
- excavation
- tidal level
- tidal
- excavated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/88—Dredgers; Soil-shifting machines mechanically-driven with arrangements acting by a sucking or forcing effect, e.g. suction dredgers
- E02F3/90—Component parts, e.g. arrangement or adaptation of pumps
- E02F3/907—Measuring or control devices, e.g. control units, detection means or sensors
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
- E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
- E02F3/435—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like
- E02F3/437—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/26—Indicating devices
- E02F9/264—Sensors and their calibration for indicating the position of the work tool
- E02F9/265—Sensors and their calibration for indicating the position of the work tool with follow-up actions (e.g. control signals sent to actuate the work tool)
Definitions
- This invention relates to a dredging excavator, such as hydraulic backhoe ship or grab dredge ship, useful in excavating and dredging a sea or river floor to a prescribed depth.
- a dredging excavator such as hydraulic backhoe ship or grab dredge ship, useful in excavating and dredging a sea or river floor to a prescribed depth.
- dredge a sea floor or a river floor located near an estuary (hereinafter represented by "sea floor”).
- dredge a sea floor or a river floor located near an estuary
- FIG. 1 is a side view illustrating the approximate structure of a hydraulic backhoe ship.
- a hydraulic backhoe ship 1 a sea floor 2, spuds 3 driven in the sea floor 2, a sea level 4 and a pontoon 5 floating on the sea level 4.
- the pontoon 5 is held on the spuds 3 in such a way that the pontoon 5 is slidable up and down along the spuds 3 but is restrained from moving horizontally over the sea level 4.
- the pontoon 5 ascends along the spuds 3 as the tidal level arises, but it descends along the spuds 3 as the tidal level lowers.
- Numeral 6 indicates a swivel cab of the backhoe, which swivel cab is mounted on the pontoon 5.
- An excavating mechanism is constructed of the boom 7, arm 8 and bucket 9.
- Numeral 13 designates the present excavation-finished floor to which the excavation has proceeded by the excavating mechanism.
- each target excavation depth is not given as a depth from the sea level 4 at that particular time point but is determined in relation to a preselected standard level (for example, the lowest tidal level at low tide).
- numerals 4, 14 and 15 indicate the present sea level, the lowest tidal level and the intended excavation-finished surface, respectively.
- the target excavation depth is therefore a depth h O as depicted in the drawing. Accordingly, it is always required to know ,as the present depth of excavation, the distance h between the lowest tidal level 14 and the present excavation-finished floor 13 and then to compare the depth h with the above-described target excavation depth h o .
- the tidal level varies moment by moment. Such a change may reach as much as 1 m - 2 m where the tidal level undergoes a great variation.
- the following means is employed to determine the excavated depth h between the lowest tidal level 14 and the excavation-finished floor 13 while overcoming such drawbacks as mentioned above. Namely, a worker who is different from the backhoe operator measures the depth h 1 by providing a weight (lead) with a graded fishing line and lowering the fishing line until the weight reaches the excavation-finished floor 13. He then obtains a tidal level at that particular time point from a tide table so that the depth oh is determined. Thereafter, he subtracts the depth ⁇ h from the depth h 1 so as to determine whether the resulting value h has reached the target excavation depth h O .
- this method requires not only a great deal of time but also an additional worker for the measurement.
- the above method is accompanied by another drawback that the accuracy of measurement is low due to slack of the fishing line and the like. Furthermore, it has also been proposed, as a method for knowing the tidal level at each specific time point without involving the above-mentioned cumbersome of referring to the tide table, to provide a float-type tide indicator on a quay, to convert each measurement result of the tide indicator into an electric signal, to transmit the signal by means of an FM transmitter, and then to receive the signal by a receiver installed on the pontoon 5 so that the operator can know the tidal level.
- This method is disclosed in "WORLD DREDGING & MARINE CONSTRUCTION", March, 34(1978). The facilities required in the above method are however very costly. Moreover, almost no contribution will be made to the solution of the above-mentioned drawbacks even if this method is employed.
- An object of this invention is therefore to overcome the drawbacks of the above-described prior art techniques and to provide a dredging excavator which permits the prompt and accurate determination of the excavated depth from a standard level to a present excavation-finished floor and facilitates the excavation to a target depth on the basis of the thus-determined excavated depth.
- a dredging excavator which comprises:
- the dredging excavator of this invention is equipped with the computing means adapted to compute an excavated depth and means to obtain a tidal level at the excavation site, whereby to correct the excavated depth in accordance with the tidal level and to output the thus-corrected value. Therefore, the dredging excavator permits the prompt and accurate determination of the excavated depth from the standard level to the present excavation-finished floor and facilitates the excavation to the intended depth on the basis of the thus-determined value.
- h 0 , h, h 1 and &h mean the depth between the lowest tidal level 14 and the target excavation-finished floor, the depth between the lowest tidal level 14 and the present excavation-finished floor 13, the depth between the sea level 4 and the present excavation-finished floor 13 and the height of the tide between the sea level 4 and the lowest tidal level 14, respectively.
- Designated at h 2 is a distance between the sea level 4 and the fulcrum A.
- the excavated depth h 1 from the sea level 4 is expressed by the following equation: Since the lengths l 1 , l 2 and l 3 and the distance h 2 have already been known, the excavated depth h 1 from the sea level 4 to the excavation-finished floor 13 can be determined when one detects the relative angles a, 8 and Y by suitable angle detector and performs an operation in accordance with Equation (1).
- the draft of the pontoon 5, namely, the distance h 2 remains constant at any time point of measurement.
- the excavation depth which is to always to be compared with the target excavation depth h 0 is the depth h between the lowest tidal level 14 and the present excavation-finished floor 13.
- This depth h is a value obtained by subtracting the height ⁇ h of the tidal level from the excavated depth h 1 which is a distance from the sea level 4 and has been obtained in accordance with Equation (1), namely, is given by the following equation: Therefore, the depth of each excavation can be controlled by always precisely knowing the excavation depth h and governing the excavation so as to allow the excavation depth h to reach the target excavation depth h 0 .
- FIG. 3 in which there are illustrated angle detectors 16,17,18 provided at desired locations of the excavating mechanism and adapted to measure angles a, 6 and Y and output signals E ⁇ , E ⁇ , E ⁇ in accordance with the angles, a computing and controlling unit 19 composed of a micro-computer or the like and adapted to perform prescribed operations and controls, a clock counter 20 adapted to generate an output counted at each prescribed time point, a memory unit 21 adapted to store tidal levels, and a display unit 22 adapted to display a signal E h corresponding to the excavated depth h computed at the computing and controlling unit 19.
- the clock counter 20 is equipped for example with a standard clock-pulse generator. It counts down clock pulses so as to count signals once every hour and outputs the count number (the elapsed time).
- the memory unit 21 there is stored an hourly tide table for a harbor, where the hydraulic backhoe ship is operated, after a desired day.
- the clock counter 20 is actuated to start the counting when it has reached the desired day.
- a digital signal corresponding the initial count "0" is output from the clock counter 20 to the computing and controlling unit 19.
- a value for example, a numeral 0.1 which has been stored at an address corresponding to the count "0” is withdrawn from the memory unit 21.
- This value is the tidal level oh to be corrected.
- the clock counter 20 output a count "1" and a value (e.g., a tidal level 0.25) stored at an address corresponding to the count "1" is withdrawn from the memory unit 21.
- the clock counter 20 Upon an elapsed time of further one hour, the clock counter 20 outputs a count "2" and a value (for example, a tidal level 0.5) stored at an address corresponding to the count "2" is withdrawn from the memory unit 21. Thereafter, the same operation is repeated.
- a value for example, a tidal level 0.5
- the power supply of the computing and controlling unit 19 may be turned on to actuate the computing and controlling unit 19 when the excavation work by the hydraulic backhoe ship is started.
- the clock counter 20 continues its counting operation irrelevant to the computing and controlling unit 19 and outputs a count corresponding to the present day and time.
- a backup-type clock counter may be used as the clock counter 20.
- the computing and controlling unit 19 receives the signals E a , E ⁇ , E ⁇ corresponding to the angles ⁇ , ⁇ , ⁇ from the angle detectors 16,17,18 and then computes the depth h 1 in accordance with the above-described equation. Then, based on an output signal of the clock counter 20, the signal E ah corresponding to the tidal level ⁇ h at the present time point is obtained from the memory unit 21. The thus-obtained tidal level oh is thereafter subtracted from the above-computed depth h 1 so as .to obtain the corrected excavated depth h.
- the thus-determined depth h is output to the display unit 22, so that a value corresponding to the depth is displayed there.
- the operator of the hydraulic backhoe ship can proceed with the excavation work while watching values h to be displayed, whereby allowing him to control the depth of excavation without failure.
- the clock counter in such a way that its power supply is not turned off and to assemble it in the computing and controlling unit 19.
- the time interval of the tide table stored in the memory unit may be set at a time interval other than one hour. If one wants to improve the accuracy of the tidal level, which is used in an operation, by using a time interval shorter than that of an actually-available tide table, the following linear correction may be carried out.
- the tidal level b h at a time point between the time points is given by the following equation so as to perform a correction.
- each display at the displaying unit is not necessarily limited to a corrected excavated depth but may show a remaining depth to be excavated.
- the remaining depth to be excavated can be displayed if the target excavation depth is preset and the display unit is provided with means to subtract the corrected excavated depth from the preset value.
- an alarm device either in combination with the display unit or separately so that a warning sound may be produced when the remaining depth of excavation has reached 0 (zero).
- hourly tidal levels at the working site of the hydraulic backhoe ship are stored in advance.
- the tidal level at the present time which has been determined by the clock counter, is withdrawn so that the depth excavated from the sea level - which depth has been obtained as a result of an operation - may be corrected by the tidal level.
- the thus-corrected value namely, the excavated depth form the lowest tidal level to the excavation-finished floor is always displayed.
- the hydraulic backhoe ship can determine, without need for any extra man power, the excavated depth from the lowest tidal level to the excavation-finished floor promptly and precisely.
- the operator of the hydraulic backhoe ship is thus allowed to complete readily the excavation to the target excavation depth while watching the display.
- the work efficiency has also been improved because the excavation work is not interrupted by measurement of each excavated depth.
- FIG. 19a Designated at numeral 19a is a computing and controlling unit which is composed of a micro-computer or the like and is adapted to perform prescribed operations and controls.
- the computing and controlling unit 19a is equipped with comparator means in which a target depth h 0 has been stored as a preset value.
- a hydraulic pump P 1 adapted to drive the boom cylinder 10
- a directional control valve 23 interposed between the boom cylinder 10 and hydraulic pump P 1 so as to control the actuation of the boom cylinder 10
- an auxiliary hydraulic pump P 21 pilot valves 25a,25b
- an operation level 26 adapted to switch over the pilot valves 25a,25b
- a pilot circuit 27 adapted to communicate the working oil from the auxiliary hydraulic pump P 2 to the directional control valve 23.
- Figure 4 also shows a pilot-operated directional control valve 28 incorporated in the pilot circuit 27 and connecting the pilot valve 25a with one (the right-hand one as seen in the drawing) of the pilot.ports of the directional control valve 23, and a switch 29 incorporated in an electric circuit between an electromagnetic solenoid of the pilot-operated directional control valve 28 and the power supply 30.
- the switch 29 is ON-OFF controlled by signals output from the computing and controlling unit 19a.
- the computing and controlling unit 19a receives the signals E ,E ⁇ , E ⁇ corresponding to the angles a,6,y respectively from the angle detectors 16,17,18 and then computes the depth h 1 in accordance with the above-described equation (1). Then, based on a signal output from the clock counter 20, the signal E ⁇ h corresponding to the tidal level ⁇ h at the present time point is taken out from the memory unit 21.
- the thus-obtained tidal level A h is subtracted from the above-computed depth h 1 so as to determine a corrected excavated depth h.
- the thus-determined depth h is next compared with the preset target depth h O of excavation.
- the comparison result indicates that the thus-corrected depth h is shallower than the target depth h O of excavation, in other words, when h ⁇ h 0 , no signal will be output from the computing and controlling unit 19a so as to keep the switch 29 in an opened state.
- the corrected depth h is equal to or deeper than the target depth h O of excavation on the other hand, in other words, when h > h 0 , the computing and controlling unit 19a outputs a signal so as to close the switch 29.
- the switch 29 When h > h 0 on the other hand, the switch 29 is closed and the pilot-operated directional control valve 28 is correspondingly switched over. Accordingly, the pilot valve 25a is disconnected from the pilot circuit 27 which is connected to the right-hand (as seen in Figure 4) pilot port of the directional control valve 23. The pilot circuit 27 is in turn connected to the reservoir. Even if the operator of the hydraulic backhoe ship operates the operation lever 26 to switch over the pilot valve 25a in the above state, the directional control valve 23 cannot be switched to the right-hand position as seen in the drawing.
- the switching of the directional control valve 23 to the right-hand position connects the hydraulic pump P i to the rod-side compartment of the boom cylinder 10 and the bottom-side compartment of the same boom cylinder 10 to the reservoir, thereby actuating the boom cylinder 10 in the contracting direction and thus lowering the boom 7.
- the thus-lowered boom 7 enables to excavate a still deeper sea floor.
- the depthwise movement of the boom 7 is restrained and any further excavation is hence avoided when the present excavation-finished floor 13 has reached the target excavation-finished floor 15.
- the operator wants to excavate a place closer to the hydraulic backhoe ship, he is required to withdraw the arm 8 toward the hydraulic backhoe ship and then to raise the leading edge of the bucket 9. This operation establishes the situation h ⁇ h 0 and cause the pilot-operated directional control valve 28 to regain its original position, thereby permitting a further lowering of the boom 7.
- the excavation can be carried out by the so-lowered boom 7 when such a closer place has not reached the depth hoe
- the clock counter in the computing and controlling unit by making its power supply free from turning-off, to suitably set the time interval of the tide table to be stored, and in this case to employ the linear correction method.
- hourly tidal levels at the working site of the hydraulic backhoe ship are stored in advance.
- the tidal level at the present time point, which has been determined by the clock counter, is obtained, whereby correcting the excavated depth from the sea level which depth has been obtained by an operation.
- the thus-corrected value namely, the excavated depth from the lowest tidal level to the excavation-finished floor is always compared with the target depth of excavation.
- the above hydraulic backhoe ship permits prompt and precise determination of the excavated depth from the lowest tidal level to the excavation-fished floor without need for any extra man power and at the same time, can avoid any excavation beyond the target depth of excavation and thus possible need for reburying work, thereby facilitating excavation work to a prescribed depth.
- the above hydraulic backhoe ship can improve the work efficiency because the excavation work is not interrupted by measurement of excavated depths.
- the operator of the hydraulic backhoe ship is not required to exercise any special attention as to the depth of excavation. His fatigue can thus be reduced to a significantly low level in this connection.
- Numeral 36 indicates a tidal level computing unit adapted to compute a tidal level ⁇ h at a given time point on the basis of a prescribed function (which will be described later).
- the tidal level computing unit 36 outputs a signal E ⁇ h corresponding to the thus-computed tidal level ⁇ h.
- Numeral 37 indicates an excavated-depth computing unit which receive the signals E ⁇ , E ⁇ , E ⁇ corresponding to the boom angle a, arm angle s and bucket angle y depicted in Figure 2 and the signal E ⁇ h and computes the excavated depth h in accordance with the equations (1) and (2).
- the excavated-depth computing unit 37 outputs a signal E h corresponding to the thus-computed excavated depth h.
- the angles a,s, Y are detected respectively by the angle detectors 16,17,18.
- the angle detectors 16,17,18 output the signals E ⁇ , E ⁇ ,E ⁇ which correspond respectively to the angels ⁇ , ⁇ , ⁇ .
- Designated at numeral 38 is a display device, which receives the signal E h from the excavated-depth computing unit 37 and then displays the excavated depth h.
- the value ⁇ h in the equation (2) is obtained by an operation at the tidal level computing unit 36 in accordance with a predetermined function without relying upon any tide table.
- a function useful in obtaining the value ⁇ h will hereinafter be described with reference to Figure 6.
- variations in tidal level are handled approximately as a cosine function.
- the tidal level ah is plotted along the vertical axis whereas the time t is plotted along the horizontal axis.
- the tidal level ⁇ h is set at 0 when it is at low tide (i.e., at the lowest tidal level) and is set at H when it is at the highest tidal level.
- the tidal level Ah at the time point T' can be expressed by the following equation:
- numeral 40 indicates a starting-time signal setting unit.
- a time interval t 1 from a time point at which the tidal-level computing unit has been actuated (which corresponds to the time point T shown in Figure 6) to another time point at which the tidal level is lowest is set at the starting-time signal setting unit 40.
- the starting-time signal setting unit 40 generates a signal E t1 in response to the time point t 1
- Numeral 41 indicates an amplitude signal setting unit which sets the value H/2 in the equation (4) and generates a signal E H/2 corresponding to the value H/2.
- Designated at numeral 42 is an elapsed-time signal generator which outputs a signal E t2 corresponding to the time t 2 elapsed after the time point set by the starting-time signal setting unit 40.
- the signals E t1 and E t2 are summed up at an adder 43 into a signal E t1 + t2 .
- the signal E tl + t2 is multiplied with a coefficient 360/t 0 at a coefficient multiplier 46.
- a signal obtained for an angle 180° from a memory 45 is then subtracted from the thus-multiplied signal at a subtracter 46, thereby obtaining a signal
- This signal is then converted at a trigonometric function generator 47 to a signal corresponding to the cosine of the angle
- an output E H/2 from an amplitude signal generator 41 is multiplied at a multiplier 48, followed by an addition of a signal E H/2 at an adder 49 to obtain a signal namely, a signal E ⁇ h corresponding to the tidal level at that time point.
- the boom angle signal E ⁇ is converted to a signal E cos ⁇ corresponding to the cosine of the angle a at a trigonometric function generator 50, to which a coefficient K l1 corresponding to the length a 1 between the fulcrum A and fulcrum B is multiplied at a coefficient multiplier 51 to obtain a signal E l1 cos ⁇ .
- the arm angle signal E is added with the signal E ⁇ at an adder 32.
- the resulting signal is then converted at a trigonometric func- ti on generator 53 to a signal E COS( ⁇ + ⁇ ) which corresponds to the cosine of the angle (a + B), to which a coefficient K l2 corresponding to the length l 2 between the fulcrum B and fulcrum C is multiplied at a coefficient multiplier 54.
- E COS( ⁇ + ⁇ ) which corresponds to the cosine of the angle (a + B)
- K l2 corresponding to the length l 2 between the fulcrum B and fulcrum C is multiplied at a coefficient multiplier 54.
- From a subtracter 54 there is generated a signal E l 1 cos a - l 2 cos( ⁇ + B) l 1 COS as a result of subtraction of the output signal from the coefficient multiplier 54 from the output signal from the coefficient multiplier 51.
- the bucket angle signal E ⁇ is added with the output signal from the adder 52 at an adder 56, followed by its conversion at a trigonometric function generator 57 to a signal E cos ( ⁇ + ⁇ + y ) corresponding to the cosine of the angle (a + ⁇ + ⁇ ).
- a coefficient K l3 corresponding to the length l 3 between the fulcrum C and the leading edge D is multiplied at a coefficient multiplier 58.
- the output signal from the adder 55 and that obtained from the coefficient multiplier 58 are added together at an adder 59. Then, a signal corresponding to the depth h 2 from a memory 61 is subtracted at a subtracter 60.
- the output signal E ⁇ h from the tidal-level computing unit 36 is further subtracted at a subtracter 62 to obtain a signal: namely, a signal E h corresponding to the excavated depth h.
- This signal E h is then input to the display , device 38 as illustrated in Figure 5.
- the display device 38 then displays the excavated depth h.
- the operator of the hydraulic backhoe ship inputs, at a suitable time point preceding the initiation of an excavation, the time point to the starting-time signal setting unit 40 of the tidal-level computing unit 36. Since the time point of the lowest tidal level at the work site has already been known from a tide table, the starting-time signal setting unit 40 outputs the time t 1 from the lowest tidal level to the preset time point. Thereafter, time t 2 elapsed from the preset time point is output from the elapsed-time signal generator 42. On the other hand, time (t l + t 2 ) passed after the lowest tidal level is output from the adder 43.
- the operator of the hydraulic backhoe ship also adjusts the amplitude signal setting unit 41 so as to preset the amplitude H/2, thereby outputting the signal E H/2 .
- the difference H between the lowest tidal level and the highest tidal level has already been known for each working site.
- the operator can automatically compute and display excavated depths h, which have been corrected by their corresponding tidal levels, at the display device 38 only by adjusting the starting-time signal setting unit 40 and amplitude signal setting unit 41 prior to starting the excavation work. Since this display device 38 is provided at a location which is readily visible by the operator, the operator can proceed with the excavation work while watching excavated depths h displayed on the display device 38.
- the cosine function to be stored in the trigonometric function generator 47 it is possible to choose not only the single period of from a lowest tidal level to the next lowest tidal level but also many other functions such as the single period of from a highest tidal level to the next highest tidal level, the single period of from a lowest tidal level to the second next lowest tidal level and so on.
- the hydraulic backhoe ship is used at a plurality of working sites and the amplitude change to a small extent from one working site to another, it is unnecessary to adjust the amplitude signal generator.
- tidal-level computing unit and excavated-depth computing unit may also be composed of a micro-computer instead of the analog-type computing unit employed in the above embodiments.
- the display device may show remaining depths to be excavated. In this case, such remaining depths to be excavated may be displayed provided that the display device is additionally provided with means adapted to store a target excavation depth and to subtract each corrected excavated depth from the target excavation depth. It is also possible to provide an alarm device either in combination with the display device or separately from the display device so that a warning sound can be produced when the remaining depth of excavation has reached 0.
- an excavated depth corrected in view of its corresponding tidal level is computed by means of the tidal level computing unit and excavated -depth computing unit, and it is then displayed. Therefore, the above hydraulic backhoe ship can determine excavated depths promptly and precisely without need for any extra man power. The thus-determined excavated depths are then displayed to the operator, whereby facilitating the excavation work. Furthermore, the operator is not required to spend any time for measuring excavated depths. The work efficiency has hence been improved. Since excavated depths can be displayed accurately, it is possible to minimize over-excavated volumes. In addition, variations in tidal level are stored as a cosine function, it is possible to use the hydraulic backhoe ship according to this embodiment in almost all working sites without need for any large memory capacity.
- FIG. 9 the excavated-depth display and control unit of the hydraulic backhoe ship according to the fourth embodiment of this invention is illustrated in the form of a block diagram.
- the same numerals and characters designate the same elements of structure as those employed in Figure 5. Explanation of such elements is thus omitted.
- Numeral 36a indicates a tidal level computing unit adapted to compute a tidal level h at a given time point on the basis of a predetermined function (which will be described later).
- the tidal level computing unit 36a outputs a signal E oh corresponding to the thus-computed tidal level bh.
- the fourth embodiment is different from the third embodiment in that the fourth embodiment makes use of a different function as a basis for operations at the tidal level computing unit and the structure of its tidal level computing unit is hence different from that employed in the third embodiment.
- the curve F in Figure 10 is a curve representing variations in tidal level.
- Time t is plotted along the horizontal axis, whereas the depth from a standard plane in the sea floor to the sea level is plotted along the vertical axis.
- Any plane may be chosen as the standard plane.
- an intended excavated floor may be chosen as the standard plane.
- h 0 indicates a tidal plane which serves as a standard for the target depth of excavation.
- the tidal level lowest in the year may be chosen as h o .
- T 1 is the time at low tide immediately before the excavation.
- h 1 is the depth from the standard plane at that time.
- T 2 is the time at high tide immediately after the excavation.
- h 2 is the depth from the standard plane at that time.
- h x is the depth from the standard plane at that time.
- FIG. 11 is a block diagram showing the specific example of the tidal level computing unit depicted in Figure 9.
- setting units 65,66 adapted to set the depths h l ,h 2 respectively
- setting units 67,68 for setting the times T 2 , T 1 respectively
- a setting unit 69 at which time points are set one after another with a predetermined interval adapted to set the depth h 0 .
- Numeral 71 designates an adder for adding signals E h1 , F h2 corresponding respectively to the depths h l ,h 2 set in the setting units 65,66, while numeral 72 indicates a coefficient multiplier adapted to multiply each output from the adder 71 by 1/2.
- Designated at numeral 73 is a subtracter adapted to subtract the signal E h2 from the signal E h1 .
- Numeral 74 is a coefficient multiplier for multiplying each output from the subtractor 73 by 1/2.
- Numeral 75 is a subtracter adapted to subtract a signal E T2 corresponding to the time T 1 set at the setting unit 67 from a signal E T1 corresponding to the time T 1 set at the setting unit 68.
- Designated at numeral 76 is a subtracter for subtracting the signal E Tl from a signal E Tx corresponding to a time point T x set at the setting unit 69.
- Numeral 77 indicates a divider for dividing a signal E Tx-T1 from the subtracter 76 by a signal E T2-T1 from the subtracter 75.
- Designated at numeral 78 is a coefficient multiplier adapted to multiply each output from the divider 77 by w(180 0 ).
- Numeral 79 is a function generator which receive a signal from the coefficient multiplier 78 and then outputs a signal corresponding to the cosine of the thus-received signal.
- Designated at numeral 80 is a multiplier for multiplying a signal output from the coefficient multiplier 74 by a signal output from the function generator 79.
- Numeral 81 indicates an adder for adding a signal from the coefficient multiplier 72 to a signal from the multiplier 80.
- Each output of the adder 81 becomes a signal E hx corresponding to the depth h x determined by the above equation (5).
- Designated at numeral 82 is a subtracter adapted to a signal E hO corresponding to the depth h O set at the setting unit 70 from the signal E hx output from the adder 81.
- the output signal of the subtracter 82 becomes a signal E ⁇ h corresponding to the tidal level A h, and the signal E ⁇ h becomes a signal to be output from the tidal level computing unit 36a.
- the operator of the hydraulic backhoe ship sets, at a suitable time point prior to starting an excavation, the time point at the setting device 69 of the tidal level computing unit 36a. Thereafter, times are set one after another with a predetermined time interval at the setting device 69. Signals E Tx corresponding to the thus-set time points are to be output from the setting device 69.
- the present embodiment represents the relationship between a low tide (or high tide) immediately before the time point and a high tide (or low tide) immediately after the time point by the equation (5).
- An operation is performed in accordance with the equation (5) at the tidal level computing unit 36a depicted in Figure 11.
- the tidal level computing unit and excavated-depth computing unit may be composed of a micro-computer instead of the above-described analog-type computing device.
- the display of the display device is not limited to the display of corrected excavated depths. It may be designed to show remaining depths to be excavated. Furthermore, the display device may produce an alarm sound.
- excavated depths which have been corrected by their corresponding tidal levels are calculated by the tidal level computing unit and excavated-depth computing unit and are then displayed.
- the above embodiment can bring about the same effects as the aforementioned third embodiment.
- the fourth embodiment is able to calculate still more correct excavated depths.
- the detection of the relative angles may be effected in accordance with the strokes of their corresponding cylinders instead of relying upon the angle detectors.
- the dredging excavator of this invention may be applied not only to sea floors but also river floors. Needless to say, the present invention may be applied not only to hydraulic backhoe ships but also to simple winch-equipped grab dredge ships and the like.
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Paleontology (AREA)
- Component Parts Of Construction Machinery (AREA)
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP85122/83 | 1983-05-17 | ||
JP85123/83 | 1983-05-17 | ||
JP8512383A JPS59213825A (ja) | 1983-05-17 | 1983-05-17 | 水底掘削作業船 |
JP8512283A JPS59213824A (ja) | 1983-05-17 | 1983-05-17 | 水底掘削作業船 |
JP8512483A JPS59213826A (ja) | 1983-05-17 | 1983-05-17 | 水底掘削作業船 |
JP85124/83 | 1983-05-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0125736A1 true EP0125736A1 (fr) | 1984-11-21 |
Family
ID=27304772
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84200678A Withdrawn EP0125736A1 (fr) | 1983-05-17 | 1984-05-11 | Drague |
Country Status (1)
Country | Link |
---|---|
EP (1) | EP0125736A1 (fr) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1996015326A1 (fr) * | 1994-11-16 | 1996-05-23 | Shin Caterpillar Mitsubishi Ltd. | Procede et dispositif permettant de piloter le bras articule d'un engin de chantier |
EP1835079A1 (fr) * | 2006-03-17 | 2007-09-19 | Qinghua He | Excavatrice commandée électro-mécaniquement et procédé de commande de l'excavatrice commandée électro-mécaniquement. |
CN106168991A (zh) * | 2016-06-24 | 2016-11-30 | 珠江水利委员会珠江水利科学研究院 | 一种基于水动力数值模拟的感潮河网潮位预报方法 |
JP2016223184A (ja) * | 2015-06-01 | 2016-12-28 | あおみ建設株式会社 | 浚渫装置及び該浚渫装置の管理装置 |
CN112922074A (zh) * | 2021-01-28 | 2021-06-08 | 三一重机有限公司 | 动臂浮动的自适应启动方法及装置 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
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DE893630C (de) * | 1951-08-01 | 1953-10-19 | Friedrich Koester | Geraet zur Stromraeumung |
DE2413738A1 (de) * | 1973-03-23 | 1974-10-03 | Billiton Research Bv | Vorrichtung zum einstellen der arbeitstiefe eines unterwasser-baggerelements |
DE2620809A1 (de) * | 1976-05-11 | 1977-11-17 | Orenstein & Koppel Ag | Einrichtung zur positionsanzeige und zur automatischen positionsregulierung des grabgefaesses fuer hydraulisch betaetigte erdbewegungsmaschinen |
GB2000326A (en) * | 1977-06-23 | 1979-01-04 | Poclain Sa | Device for automatic stoppage of a hydraulic motor |
EP0009516A1 (fr) * | 1978-09-29 | 1980-04-16 | Ballast-Nedam Groep N.V. | Méthode et dispositif pour maintenir des outils à un niveau au-dessous d'une surface d'eau |
WO1981002904A1 (fr) * | 1980-04-11 | 1981-10-15 | Digger Meter Corp | Systemes de controle de profondeur |
-
1984
- 1984-05-11 EP EP84200678A patent/EP0125736A1/fr not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
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DE893630C (de) * | 1951-08-01 | 1953-10-19 | Friedrich Koester | Geraet zur Stromraeumung |
DE2413738A1 (de) * | 1973-03-23 | 1974-10-03 | Billiton Research Bv | Vorrichtung zum einstellen der arbeitstiefe eines unterwasser-baggerelements |
DE2620809A1 (de) * | 1976-05-11 | 1977-11-17 | Orenstein & Koppel Ag | Einrichtung zur positionsanzeige und zur automatischen positionsregulierung des grabgefaesses fuer hydraulisch betaetigte erdbewegungsmaschinen |
GB2000326A (en) * | 1977-06-23 | 1979-01-04 | Poclain Sa | Device for automatic stoppage of a hydraulic motor |
EP0009516A1 (fr) * | 1978-09-29 | 1980-04-16 | Ballast-Nedam Groep N.V. | Méthode et dispositif pour maintenir des outils à un niveau au-dessous d'une surface d'eau |
WO1981002904A1 (fr) * | 1980-04-11 | 1981-10-15 | Digger Meter Corp | Systemes de controle de profondeur |
Non-Patent Citations (1)
Title |
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DE INGENIEUR, vol. 87, no. 27, July 1975, pages 545-557, Den Haag, NL; W.H.A. VAN OOSTRUM: "Geprogrammeerd baggeren" * |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1996015326A1 (fr) * | 1994-11-16 | 1996-05-23 | Shin Caterpillar Mitsubishi Ltd. | Procede et dispositif permettant de piloter le bras articule d'un engin de chantier |
US5784944A (en) * | 1994-11-16 | 1998-07-28 | Shin Caterpillar Mitsubishi Ltd. | Device and method for controlling attachment of construction machine |
EP1835079A1 (fr) * | 2006-03-17 | 2007-09-19 | Qinghua He | Excavatrice commandée électro-mécaniquement et procédé de commande de l'excavatrice commandée électro-mécaniquement. |
JP2016223184A (ja) * | 2015-06-01 | 2016-12-28 | あおみ建設株式会社 | 浚渫装置及び該浚渫装置の管理装置 |
CN106168991A (zh) * | 2016-06-24 | 2016-11-30 | 珠江水利委员会珠江水利科学研究院 | 一种基于水动力数值模拟的感潮河网潮位预报方法 |
CN106168991B (zh) * | 2016-06-24 | 2019-03-15 | 珠江水利委员会珠江水利科学研究院 | 一种基于水动力数值模拟的感潮河网潮位预报方法 |
CN112922074A (zh) * | 2021-01-28 | 2021-06-08 | 三一重机有限公司 | 动臂浮动的自适应启动方法及装置 |
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