JPH0218293A - Condition detecting method for lifting load - Google Patents

Abstract

PURPOSE:To improve safety with transportation efficiently performed by compar atively calculating a detection value of tension of a hanging rope to be converted into an indicating value showing a deflecting angle and an eccentric degree of a load, in the case of detecting the deflecting angle or the like of the lifting load transported by a container crane or the like. CONSTITUTION:In a lifting load moved and transported, a pendulum-shaped deflection such as with the center of a trolley 9 serving as the vertex is generated in addition to a fine movement displayed as a component by swiveling (deflecting angle thetax, thetay, thetaz) about three axes (x, y, z) passing through the center of gravity O. These deflecting conditions appear in aged deterioration of tension values T1, T2, T3, T4 detected in each sheave 6. While the pendulum-shaped deflection appears as the unevenness of tension, and the center of gravity O of the lifting load comes to be deflected to a front side in the advance direction A, increasing the tension values T2, T4. Accordingly, a change of tension is generated in accordance with a change of these deflections. The two kinds of these deflections, being different in their period, can be easily extracted respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for detecting the condition of a suspended load, and more particularly to a method for detecting the swing angle of a suspended load, which is data on the operation of a crane.

[Prior Art 1] In general, cargo transported by a container crane or the like is suspended by being supported at two or four points by a rope from a running or traversing trolley, and 2 moves vertically according to the amount of the rope. It is now possible to do so.

[Problems to be Solved by the Invention] By the way, when a suspended load is accelerated or decelerated during sideways driving, pendulum-like vibrations occur, which adversely affects driving efficiency and safety6. The system was designed to visually grasp the condition and perform regular operation to correct the situation based on experience or intuition. However, this operation requires skill and there is a problem in that if the situation is not accurately grasped, appropriate corrections cannot be made.

In addition, in recent years, various proposals have been made to operate cranes by automatic control that does not require skill or the like. 17 to perform arithmetic processing and drive the operating device. However, there is no definitive method for detecting this state, and it has been a challenge to find a method that can accurately detect it.

In view of the above circumstances, the present invention was devised to provide a method that can accurately detect the condition of a suspended load.

Further means and effects for solving the problem are as follows:
It detects the tension of the hanging rope, compares and calculates these detected values that change over time, and converts them into index values that indicate the swing angle and load eccentricity of the suspended load.

Further, it is preferable that the above-mentioned index values are extracted according to the length of the vibration period.

The above-mentioned hanging rope may support the suspended load at four points, and the respective detected values may be added or subtracted from each other and converted into three-axis components.

Furthermore, it is preferable that the detected value is increased or decreased depending on the amount of winding of the hanging rope.

Swinging of bulk loads due to sideways driving and 1a
The first part of the mental load jl is TFEF (f, 6=:).

[Example 1 Embodiments of the present invention will be described below with reference to the accompanying drawings.

According to No. 11-71, the suspended load state detection method i, /: according to the present invention is applied, and t-, ri l...-7/7
) Describe one embodiment of the automatic control device 4, 2-85 1 is the second (') detector 37+17: cell) that detects the tension of the hanging D~7゛:2, and based on that information. Is it possible to omit calculations? It is mainly achieved by the operation device 5 which transmits the rotational force from the power source to the appropriate device (11), etc. I-
I'm here.

This example C, -1 ri) - E (J, one hanging - 12,
Separate Ghibli Tenatsu at the gate, hanging 7: Tin 1 in container 7. The detector 3 is connected to the four corners of the trolley 9 through the legs 8, that is, supports the suspension tη at four points. 9 and a sheave block 10 for support.

The arithmetic processing device 4 receives information from the detector 3, and compares and calculates this information as appropriate to indicate the swing angle and load eccentricity of the suspended load. It is designed to obtain index values. Further, based on this index value, a runout signal and a face center signal are output, and the operating device 5 is made to perform an operation that eliminates runout and load eccentricity.

The driving device 5 receives a signal from the arithmetic processing device 4 (when it is 1, increases or decreases the acceleration or deceleration of the trolley 9 that is traveling sideways).
It is designed to drive a known tilting device (not shown), adjust the amount of winding of I'1 reloaf, etc.

Next, an embodiment of the present invention will be described as the effect of the above-mentioned tree formation.

A suspended load that is being transported and moved has a swing (swing angle θx1) around three axes (x, y, z) passing through the center of gravity 0 as shown in
In addition to the microtremor whose components are represented by θy, θl), as shown in Figures 2 and 3, the center (P) of the trolley 9 is
A swing-like runout (runout angles αy, αX) that appears to be in the middle of the season occurs. These swing states are determined by the tension value (T, ,'f"2.'T", , '' detected in each jeep 6).
It appears in the change over time of I'a). That is, as the load rotates around the axis, the load on the deflected side is reduced, and the load is increased or decreased at a frequency according to the natural frequency of the product.

For example, when vibration occurs around the y-axis, 1゛1 and '1
'3, T2 and T4 increase and decrease in opposite phases.

In addition, the swing 7-shaped runout appears as an imbalance in tension, and the second
In terms of the deflection position in the figure (indicated by the - dotted chain line), the center of gravity of the suspended load is 0. will be 1 load on the front side in the direction of travel A, and 1
'2, T4 increases. Therefore, the increase or decrease in tension is
This will be done according to the increase or decrease of these runouts.6 And since these two types of runouts have different periods,
Each can be easily extracted. This tension change is also affected by the eccentric load of the lifted cargo.

The above can be expressed numerically as follows.

TI +1'2 +Ts +'r"<2W("F +
+Ts ) −<T2 +T, )X
; (θ■, αy, εX) (T"+ 172) (Ti 1i'4)Y;
(θX, αX, εy) (Tl +74) −(T2 +73) =z,
; (θl) here W; Weight of suspended load ; X component of load eccentricity εy; Y component of load concentricity As for the concentricity of the load, the change over time 1 can be ignored.

It is expressed by the following formula.

εX = X = (X1+X2+-・-X11)/n
t: V = Y = fYI+Y2+ −
・Yn)/n and the runout is calculated using the following formula6 θY=F(X) αyGoG (X) θx −F (Y) αx = G (Y)θz=F(
Z) Here F: Extraction process of short-period changes G: Extraction process of long-period changes Therefore, the arithmetic processing unit 11 outputs °′θ as the vibration tL signal.
It outputs `` and αpa, and outputs ``ε as a concentric signal.

The operating device 6 performs adjustment operation based on this signal.

When α PA is received, the acceleration or deceleration is changed to attenuate the vibration, and traversing operation is performed. The amount of winding of the re-rope 2 can be adjusted, or the tilting device provided in the re-rope 2, the rope 8, etc. can be driven.

Don't you want to detect tension like this? Since the state of hanging 6jF can be grasped by -1, the detector toss of the song, for example, Il! It can detect the deflection angle more accurately than the deflection angle detector of Zhi Ni. Furthermore, since it is designed to detect rocking around the center of gravity and severe G, it contributes to improving the safety of suspended loads during transportation or landing.

Note that in order to have the processing functions represented by 'FJ' and GJ, the arithmetic processing unit 4 may be provided with a rectifier circuit (low-pass filter, bypass filter, etc.). Alternatively, an A/D converter may be conveniently used.

Furthermore, since the detected value varies depending on the length of the hanging row 12, an arithmetic circuit that inputs information from the winding amount sensor may be incorporated so that it can be increased or decreased depending on the winding.

FIG. 11 shows detection data obtained according to this example.
The figure shows a comparison of changes in speed over time during traverse operation of the trolley 2.

The tension values ('1 to T4) show small vertical fluctuations as well as large fluctuations with 172 cycles in (a) to (b) in the figure.As shown in (C) and (d). When the suspended load was compared with the state obtained at that time by T6111PJ, there was good agreement, proving that the detection method of the present invention is practical.

Although the above embodiments have been described in the case of being applied to an automatically controlled container crane, they can also be applied to other cranes or cranes in which part of the stroke is performed manually.

Furthermore, even if the number of tension sensors is 2 ffAl, it cannot be applied to detect the deflection angle. For example, at T1 and T2, θy, αy
If we can understand this, we can achieve traversal control with less vibration), and it can also be applied to detect the amount of vibration of a single-hung crane.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

(1) Detects the tension of the hanging rope, compares and calculates these detected values that change over time, and converts them into index values that indicate the swing angle and load eccentricity of the suspended load, so you can accurately grasp the condition of the suspended load. It is possible to improve the efficiency and safety of transportation by crane.

(2) In the method of extracting index values according to the length of the vibration period, it is possible to grasp the deflection angle that occurs during traversing operation, which contributes to the realization of damped operation.

(3) According to the method of adding and subtracting the detected values to each other, 1. Applicable to large container cranes, etc. 6. (4) The method of correcting the detected values by the amount of winding of the hanging rope allows for more accurate state detection. .

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of an automatic control device for a crane to which the suspended load state detection method according to the present invention is applied; FIGS. 2 and 3 are diagrams for explaining FIG. 1; 5th 4th
The figure is a graph showing detected data and comparing changes in tension and speed over time. In the figure, T to T4 are tensions, and θ and α are deflection angles. Patent applicant: Patent attorney representing Ishikawajima-Harima Heavy Industries Co., Ltd.
Nobuo Kinutani Figure 2 Figure 3

Claims (1)

[Claims] 1. A suspension characterized by detecting the tension of a suspension rope, comparing and calculating these detected values that change over time, and converting them into index values indicating the swing angle and load eccentricity of the suspended load. How to detect the condition of a load. 2. The method for detecting the condition of a suspended load according to claim 1, wherein the index value is extracted according to the length of the vibration period. 3. The above-mentioned hanging rope supports the hanging load at four points, and
3. The method for detecting the state of a suspended load according to claim 1, wherein the respective detected values are added or subtracted from each other and converted into three-axis components. 4. The method for detecting the condition of a suspended load according to any one of claims 1 to 3, wherein the detected value is increased or decreased depending on the amount of winding of the suspended rope.