JPH01271395A - Initial swing suppressive control for suspended load - Google Patents

Abstract

PURPOSE:To surely suppress and dissolve the initial swing without impairing the cargo handling efficiency by setting a trolley in the movable state in the lateral direction during the preset period immediately after the start of cargo hoisting and moving the trolley on the vertical line of a hoisted cargo. CONSTITUTION:An operation control device 46 releases the mechanical brake 48 of a traverse drum 26 during the fixed time period from the start of winding until a grab bucket 20 is removed from the surface of a cargo after the closing action of the grab bucket 20 to grab the cargo based on the grounding judgement of the grab bucket 20 and applies a command to reduce or negate its function to a traverse speed control device 50. Both a main trolley 10 and an auxiliary trolley 12 are set to the unrestricted state, the main trolley 12 is moved on the vertical line of the grab bucket 20. The initial swing of the grab bucket 20 is suppressed and dissolved, the traverse speed of the main trolley 10 can be controlled in this state. The initial swing is surely suppressed and dissolved without impairing the cargo handling efficiency, the safe and quick unloading work can be performed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention is used to control the sway of a suspended load by controlling the acceleration/deceleration during traversing in a cargo handling/transporting machine such as an unloader according to a predetermined acceleration/deceleration pattern, thereby suppressing the initial sway when lifting a load. The present invention relates to a control method for suppressing the initial swing of a suspended load, which is suitable for the following.

[Conventional technology]

When unloading cargo (stones, etc.) loaded on a ship, an unloader is used that grabs the cargo with a grab bucket, lifts it up, and transports it by moving sideways. As shown in FIG. 5, for example, such an unloader includes a main trolley 10, a sub-trolley 12, a supporting row 114, an opening/closing rope 16, and a traversing row 118, which can be moved vertically and horizontally by these loads. A grab bucket 20 for grasping a load such as ore, and a hopper 2 for charging ore etc. lifted onto land by the grab bucket 2o.
There are some that are mainly composed of 2. In the above-mentioned unloader, the grab bucket 20 is suspended by a support row 114 via a main trolley 10 and a sub-trolley 12 which are movable at a predetermined distance. Further, the support row 114 is wound up and unwound by the support drum 24, so that the support row 1
The grab bucket 20 can freely move up and down and traverse, in combination with the change in the length of the rope 14 and the traverse movement of the main trolley 10 and the sub-trolley 12 as the traverse row 118 is wound up and unwound by the traverse drum 26. It has become. In addition, the reference numeral 28 in the figure is an opening/closing drum for winding up and unwinding the opening/closing row 116 to open and close the grab bucket, and two are the hulls of ships on which cargo is loaded. The positional relationship of the grab bucket 20, each trolley 10.12, and each rope 14.16.18 is shown in FIG. 6, as shown in FIG. from the sheave 30B in the main trolley, and further to the sheave 3 of the grab bucket 20.
It is fixed at a predetermined position on the main trolley 10 via 0C. Furthermore, even if the position of the main trolley 10 changes during traversing, the change in the rope lengths of the support rope 14 and opening/closing row 116 is absorbed by the traversing of the sub trolley 12. Grab bucket 2 from main trolley 10
The rope length 1 up to 0 remains unchanged. In addition, in FIG. 6, the symbols 32, 34, and 36 are respectively,
This is a sheave for guiding the traversing rope 8, the support lower 14, and the opening/closing loader 16. Even in unloaders, etc., which are required to operate with complex movements such as those mentioned above, contact with the suspended load at the end of traversal acceleration/deceleration must be prevented and suppressed from the perspective of improving the safety of lifting work and work efficiency. . In order to meet such demands, various proposals and reports have been made regarding techniques related to steady rest prevention. Among these, for example, presetting the main trolley speed to minimize contact at the target point;
A program control method that operates according to the settings, and a feedback control method that detects the deflection angle (angular velocity, angular acceleration) of the suspended load and controls the traverse speed of the main trolley 10 to eliminate contact (for example, Japanese Patent Application Laid-Open No. 57-107392, JP-A-58-2185>, a clamp method for mechanically fixing the suspended load itself (JP-A-6O-248592), and each has its own advantages and disadvantages. The general theory that should be considered when performing this control will be explained below. First, considering the equation of motion of the crane, in the schematic diagram of the crane shown in Fig. 7, the position of d nitro, v nitro speed, degree of adjustment of α-nitroly, mass of M-nitroly, F: tension of traversing rope, m: mass of hanging load + lifting equipment, ℃: hoisting rope length (distance between center of gravity between rope fulcrum and 1), T: tension of the hoisting rope, The equation of motion of the load in the horizontal and vertical directions is as follows: rey= rag −T −cosθ −・−−
---= (1) I! X= T −sinθ
・−・−−−−−−(2) Here, x and y can be expressed as in equations (3) and (4), respectively. y=f・COSθ (3
)x=d-1・sinθ ・・・・・・・・・(
4) Therefore, by differentiating equations (3) and (4), we get (5), (
It becomes as shown in equation 6), and when further differentiated, it becomes as shown in equations (7) and (8). Ω=1・cosθ−1・θ・sinθ・・・・・・・・・
・(5) Uke=d-λ-sinθ-ffl・θ-CQS
θ-(6)y = (ffl-12(A)') c
os t9-(2βθ10lθ) sinθ・・・・・・
...<7) x = d - (ffl-fl (θ)
2) sinθ−<2J2 immersion+βθl cos θ・
・・・・・・・・・(8) These Y and X are expressed by the above formulas (1) and (2
)2 and rearranging, it becomes the equation (9>), and the equation (10) regarding runout is obtained. d-CO3θ-21θ-(θ=g・sinθ-(9)θ
=(d-cosθ-22θ-g-sinθ)/β...
・・・・・・(10) Now, assuming that the deflection angle θ is small, sinθkiθ
, COSθΦ1, and since d=α, (1
0) becomes the following equation (11). θ-(α-2; xi-gθ)/u ・・・・・・・・・
(11) As is clear from equation (11), in order to control the swinging of the suspended load, it is sufficient to control the acceleration α of the trolley. If the rope length is constant in equation (11), then )-0 will be obtained, so that the value will be as shown in equation (12) below. θ-(α-Qθ)/λ ・・・・・・・・・(12
) Also, the angular velocity ω in the swing-out motion is ω−C

When Equation 12) is controlled using this angular velocity ω, the following Equation (13) is obtained. θ−ω2 ・((α/(lI)−θ)・・・・・・・
(13) If both sides of this equation (13) are integrated and rearranged, the following equation (14) is obtained. $ 2 / (1) 2 + (θ-<a/g) ) '
=const・・・・・・・・・(14) From this equation (14), between θ and θ/ω, (α/v
, O), it can be seen that there is a relationship that results in circular motion around the circumference at a constant angular velocity ω. Here, Fig. 8 and Fig. 9 respectively show a typical traverse acceleration/deceleration pattern in steady rest control and a phase diagram of runout during that pattern. Fig. 8 shows a combination of Takara front deceleration + constant speed. , the 9th section is based on a combination of only Hozen deceleration. That is, in FIGS. 8 and 9 (A> shows acceleration/deceleration patterns according to these methods, Tj and Tj in FIG.
4, Ts is deceleration time, T2. 'rs represents constant speed time, and Tj represents maximum speed Vmax time. In addition, <8) in FIGS. 8 and 9 means that the above equation (11) is
It is a phase diagram showing the relationship between θ and δ/ω when controlling as ω′=g/12 and θ=(d−x)/fl. Note that the origins a, d, e, and h in these figures correspond to a state with no shake. Each of these traverse acceleration/deceleration patterns is characterized by returning to the origin of the runout phase diagram at the end of acceleration (indicated by the code d) and at the end of deceleration (indicated by the code), and the runout changes relative to the traverse distance. Therefore, if the period of maximum speed is changed according to the desired traverse pressure type, the unloader can be traversed without wobbling. [Problems to be Solved by the Invention] By the way, in the steady rest control by the program control, the steady rest control of the suspended load can be executed according to the phase plane circuits shown in FIGS. 8(B) and 9(B). is a case where the runout starts from the origin of the same phase plane diagram at the start of traversing, that is, the initial runout is 0, and when the initial runout occurs, the runout starts away from the origin, so the runout at the end of traverse. will remain. In other words, even if the steady rest control described above is used to prevent the vehicle from wobbling during traversing, the steady rest cannot be completely prevented as long as the initial wobbling still exists. For example, in the case of an unloader, as shown in FIG. 10, the position of the main trolley 10 may vary depending on the surface condition of the thin layer in the hull 29, such as the surface of ore, the way the grab bucket 20 swings when it lands on the surface, etc. grab bucket 20
In many cases, the relative position with respect to the wire is not located on a substantially vertical line, and if the wire is wound up in that state, initial runout will certainly occur. Further, in order to eliminate the initial swing that has occurred in this way, it is conceivable that the operator manually operates the unloader to prevent the grab bucket 20 from swinging while hoisting it up. However, such manual steady rest control by the operator diminishes the significance of automatically performing steady rest control without human intervention through program control. is requested. Furthermore, in reality, when lifting a load in the condition shown in Figure 10, it is difficult to completely eliminate the initial swing by manual operation.
There was a need for control technology to suppress this as much as possible. On the other hand, even in conventional steady rest control other than program control, the presence of initial runout is an obstacle to reliably execute steady rest control during traversing, and the initial runout can be suppressed and eliminated. Technology is required.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and can reliably suppress and eliminate the initial swing that occurs when hoisting a load with an unloader, etc., without impairing cargo handling efficiency. An object of the present invention is to provide an initial swing suppression control method for a suspended load that can safely and effectively perform steady control.

[Means to solve the problem]

The present invention is a control method for suppressing the initial swing of a suspended load that occurs when lifting a load via a rope supported by a trolley in an unloader, etc. The above object is achieved by moving the trolley along the vertical line of the suspended load while allowing free movement in the transverse direction.

[Effect]

The present invention will be explained in detail below. For example, in the unloader shown in FIG. 2, the grab bucket 20 descends and lands on the surface of the load, performs the closing operation and hoisting operation, and leaves the surface of the load, that is, the grab bucket 20 is fixed or partially It is assumed that the main trolley 10 is fixed in the transverse direction during the fixed state. At this time, if the main trolley is on the vertical line of the grab bucket 2o as shown in Fig. 2, no initial swing will occur even if the suspended load is hoisted, but as shown in Fig. 10 above, for example, If the grab bucket 20 and trolley 10 do not exist substantially vertically, initial swing will occur when hoisting up the suspended load. The present invention was devised in order to suppress the initial swing during hoisting of a suspended load that occurs as described above. For example, if the present invention is explained using the unloader shown in FIG. 2, the main trolley 1
0, each row 114, 16, 18 and sheave 30A so that the sub trolley 12 can move freely without being restrained.
, 30B and through both trolleys 10.12, the main trolley 10 is moved vertically above the grab bucket 20 to suppress and eliminate the initial swing of the suspended load. This is what I did. Next, the principle of making the trolley freely movable in the transverse direction and moving the trolley along the vertical line of the suspended load will be explained. First, in FIG. 2, for example, in an unloader, from when the grab bucket 20 lands on the image surface to when the load (indicated by reference numeral 37 in the figure) is grabbed by the closing operation and the load is hoisted, the grab bucket 20 is fixed or semi-fixed. It shows the balance of forces when the opening/closing row 116 or the support row 114 is in a fixed state and under tension in a winding state. As shown in the figure, when the main trolley 10 and the grab bucket 20 are located on a vertical line, the sheave 30B is attached to the main trolley 10.
The horizontal force F1 acting on the auxiliary trolley 12 through the sheave 30A and the horizontal force F2 acting on the sub trolley 12 through the sheave 30A are in opposite directions and equal in magnitude, so they are balanced through the transverse row 118. ing. Therefore, even if the main trolley 10 and the sub trolley 12 are not fixed in the transverse direction and can move freely at this time, both these trolleys 10
．． 12 does not move in the transverse direction. Next, consider the case where the main trolley 10 and the grab bucket 20 do not align on the vertical line. The state of the unloader in this case is shown in FIGS. 3 and 4. FIG. 3 shows a case where the trolley 10 is positioned squarely in the direction of the sub-trolley 12 with respect to the vertical line of the grab bucket 20. In the case of FIG. The tension FO acting on the opening/closing rope 16 has a predetermined angle with respect to the direction along the vertical line, and due to this influence, it acts on the main trolley 10 more than the tension F3 on each rope 14.16 between both trolleys 10.12. The force F1 becomes smaller, and eventually the force F1 is applied to the sub-trolley 1.
The force F2 acting on F2 is smaller than the force F2 acting on F2. Here, since both trolleys 10.12 are connected by the transverse rope 18, if both trolleys 10.12 are not fixed in the transverse direction and are allowed to move freely, the difference between each force F+ and F2 is canceled out. Main trolley 10 and secondary I-lorry 12
moves to the left in the figure, and when the difference between the above-mentioned forces F+ and F2 is eliminated, that is, the positional relationship as shown in Figure 2 is reached, and the main trolley 10
When it is located on the vertical line of the grab bucket 20, its movement stops. Further, in the case of FIG. 4, contrary to the case shown in FIG. 3, the first main trolley 10 is located in the opposite direction of the sub trolley 12 from the vertical line of the grab bucket 20. In the case of the figure, the tension Fo acting on the support row 114 and opening/closing row 116 between the main trolley 10 and the Gura and Tsubagetsu I/20
Under the influence of this, the force F1 applied to the main I trolley 10 becomes larger than the tension F3, and eventually the two forces become larger than the force F2 acting on the sub trolley 12. Therefore, the main trolley 10 and the auxiliary I-RO 1-RU 12 have these forces F+-F
2 moves to the right in Figure 4, and the corresponding forces F7 and F
2 has been canceled out, i.e. the main trolley 10. The secondary trolley 12 is in the state shown in FIG. 2, and the main trolley 1
0 is located on the vertical line of the grab bucket 20, its movement will stop. The present invention has been made based on the above principle, and is capable of reliably suppressing the initial swing of the grab bucket from hoisting up to the start of traversing. In addition, the control according to the present invention can be performed during the normal operation steps of an unloader, etc., such as lowering → landing → stopping lowering → closing the grab bucket → hoisting, so there is no reduction in efficiency in terms of cargo handling efficiency. Initial runout can be suppressed without causing such problems. In addition, when the present invention is employed in an unloader as shown in FIG. 2, it is desirable that the grab bucket 20 is sufficiently heavy with respect to the main trolley, and that the rolling friction of the wheels of the main trolley 10 and the sub-trolley 12 is small. This is because by doing so, the main trolley 10 can quickly move vertically above the grab bags.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. This embodiment has a configuration as shown in FIG. For lifting or loading cargo onto the hull 29,
In FIG. 0, reference numeral 38 indicates an initial runout control device applied to an unloader whose traversing speed is program-controlled according to a predetermined traversing acceleration/deceleration pattern as shown in FIG. 8(A). A fixed sheave 40 guides the row 114 to the opening/closing drum 28.
A fixed sheave, 42, for guiding each rope 14.16 is attached to a predetermined one of each fixed sheave 38.40.
a strain gauge for converting and detecting the load applied to the grab bucket 16 (corresponding to the weight of the grab bucket 20) into an electrical signal;
44 is an amplifier for amplifying the electrical signal of the strain gauge 42; 46 is an unloader operation control device mainly composed of a sequencer; 48 is an unloader operation control device that prohibits the operation of the traversing drum 26 and controls each trolley 10. ．． ．． 12 is a trough mechanical brake for inhibiting traversing, and 50 is a traversing speed control device for controlling the traversing speed of each trolley 10.12. The configuration of the pond is shown in FIGS. 5 and 6 above, and is substantially the same as that of Tachino, so similar parts are given the same numbers and explanations thereof will be omitted. The effects of the embodiment will be explained below. In this embodiment, in the unloader having the configuration shown in FIG. 1, as shown in FIGS. 2 to 4, the following points are taken into consideration to suppress the initial swing when the grab bucket 20 grabs and lifts the load. and execute it. That is, in order to bring the main trolley 10 and the sub trolley 12 into an unrestrained state in the traverse direction, both trolleys 10 and 12 are brought into an unrestrained state after it is detected that the grab bucket 20 has landed on the surface of the load. That is important. This is because when the grab bucket 20 has not yet landed on the cargo inside the hull 29, the grab bucket 20 may be swinging in the air, and at this time, both the trolleys 10
．． This is because the grab baguette 12 is moved by the swinging of the grab baguette I-20, causing a serious operational problem.9 The operation control device 46 determines whether or not the grab baguette 22 has landed on the load. That is, the strain gauge 42 converts the tension of the support row 114 and the opening/closing rope 16 into an electrical signal via each fixed sheave 38, 40, and this electrical signal is sent to the amplifier 4.
4 is input to the operation control device 46 with a width Fa, and the operation control device 46 determines whether the grab bucket 22 has landed based on this input signal. This determination is based on the electric signal from the strain gauge 42 when the grab bucket 20 lands on the surface of the load and the load is almost gone, versus the electric signal from the strain gauge 42 when the grab bucket 20 is loaded. This is done by determining the difference in the strain amount of the strain gauge 42 from the difference in the target signals, and determining that the grab bucket 20 has landed when this difference is less than a predetermined value (usually 100 to 150 μs (micro strain)). . Based on the landing determination of the grab bucket 20 performed as described above, the operation control device 46 performs a closing operation of the grab bucket 20 to grab the load, and after a certain period of time after the grab bucket 20 starts hoisting, that is, the grab bucket 20 closes the load. , the mechanical brake 48 of the traverse drum 26 is released and a command is transmitted to the traverse speed control device 50 to reduce or eliminate the traverse speed control function. This allows the main I.
Since both the trolley 10 and the sub-trolley 12 are in an unrestricted state, the main trolley 10 can move on the vertical line of the grab bucket 20, suppressing the initial swing of the grab bucket 20, and controlling the traverse speed of the main trolley 10 while eliminating the initial swing. m(#f
iJ (according to a predetermined acceleration/deceleration pattern). Furthermore, as a countermeasure against malfunction in detecting the landing of the grab bucket 20, if the landing detection signal is masked by the operation # control device 46 when the support row 114 is outside the tool during lowering.
Safe and reliable control operations can be performed. In the above embodiments, ore is used as an example of the load, but the load is not limited to ore, and may be of various types depending on the scope of application of the unloader or the like. Further, in the above embodiment, the present invention is applied to an unloader for unloading cargo from a ship's hull, but the present invention can also be applied to various other loading devices, such as an overhead traveling lane. It is possible. Furthermore, the unloader adopting the present invention is not limited to one having a sub-trolley as shown in FIG. The present invention can be applied to any type of unloader, etc., in which the trolley naturally moves sideways and can be positioned on the vertical line of the suspended load. Furthermore, the unloader etc. to which the present invention is adopted include:
It is not limited to those with steady rest control by program control, and may be adopted in unloaders with other control methods, and in this case, the initial vibration can be reliably suppressed and eliminated to ensure operation using that method. This will enable it to be implemented without any problems.

【Effect of the invention】

As explained above, according to the present invention, the initial vibration that occurs when hoisting a load with an unloader or the like can be reliably suppressed and eliminated without impairing cargo handling efficiency. Therefore, when hoisting a load, there is almost no initial clinging, and in combination with the steady rest control during traversing, an excellent effect can be obtained in that the load can be hoisted safely and quickly.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram including a partial block diagram showing the configuration of an embodiment of the present invention, and Figs. 2 to 4 show the main trolley when carrying a load, for explaining the present invention in detail. FIG. 5 is a layout diagram that schematically shows the overall configuration of a conventional unloader, and FIG. 6 is a diagram showing the area around the trolley of the conventional unloader. FIG. 7 is a schematic diagram showing the dynamic relationship between the suspended load and the trolley; FIGS. 8 and 9 are line diagrams showing examples of traverse acceleration/deceleration patterns and phase diagrams of deflection; FIG. 10 is a layout diagram, including a partial top view, showing an example of a state in which the grab bucket has landed. 8... Load, 10... Main trolley 51
2... Sub-trolley, 14... Support rope, 16... Opening/closing rope, 18... Traverse rope, 20... Grab bucket, 22... Hopper, 24... Support drum, 26... ...traversing drum, 28...opening/closing drum, 3OA, 30B, 30C...sheave, 37...load (
38. 40... Fixed sheave, 42... Strain gauge, 44... Amplifier (amplifier), 46... Operation control device, 48... Mechanical brake, 50... Traverse speed #Control device.

Claims (1)

[Claims] (1) A control method for suppressing the initial swing of a suspended load that occurs when lifting a load via a rope supported by a trolley in an unloader, etc., which involves moving the trolley sideways for a predetermined period immediately after the start of lifting the load. 1. A control method for suppressing initial swing of a suspended load, characterized in that the trolley is moved along a vertical line of the suspended load in a state where it can freely move in the direction of the suspended load.