JPH0592891A - Grab quantity control method for unloader - Google Patents

Abstract

PURPOSE:To correct sinkage quantity according to the surface shape of bulk material onto which a grab bucket is landed so as to get the grab quantity to approach the target set grab quantity. CONSTITUTION:The landing of a grab bucket 1 onto the surface of bulk material is detected by a landing detector 14 to stop the grab bucket 1, and the present sinkage quantity S is computed by a sinkage quantity computing element 25 from the relation between the grab quantity W and sinkage quantity S by the description of the bulk material and also by the surface shape in the landing position of the grab bucket 1, on the basis of control deviation E between the actual grab quantity W up to the preceding time and the target set value WO. A support wire 5 is then delivered by the specified quantity by a sunk position controller 12 so as to sink the grab bucket 1 into the bulk material by the sinkage quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work of unloading a bulk material by a grab bucket unloader, and more particularly to a method of controlling a gripping amount of a grab bucket when lifting the bulk material to a target set value.

[0002]

2. Description of the Related Art Conventionally, as a method for controlling the grasping amount of a loose material to a target set value in the operation of unloading a loose material with a grab bucket unloader, for example, Japanese Patent Laid-Open No. 58-1
Those described in JP-A-77888 and JP-A-59-36095 are known.

These detect the current when the wire is fed out in the drum driving motor of the drum around which the supporting wire that hangs the grab bucket so that it can be moved up and down is detected. Detects landing on the surface of bulk material. Then, the supporting wire is loosened by a predetermined amount on the basis of the time when the landing is detected, the sinking amount of the grab bucket into the bulk is adjusted, and the gripping amount of the bulk by the grab bucket is controlled to the target installation value. ..

At this time, the amount of subsidence of the grab bucket and the amount of gripping are linearly proportional to each other to calculate the amount of subsidence.
The relationship between the amount of sinking and the amount of gripping is calculated in advance for each brand of bulk material, and the amount of sinking is calculated from the relationship, and further, the actual amount of gripping up to the previous time is compared with the target set amount of gripping,
Feedback control for adjusting the sinking amount of the grab bucket is also performed by obtaining the slack length of each wire at the next gripping according to the deviation.

[0005]

However, in the conventional gripping amount control method for the unloader, the sinking amount of the grab bucket is calculated only from the relationship between the brand and the gripping amount. Is not always flat, for example, if the surface of the loose object on which the grab bucket is landed is concave, the amount of grip will be small, and if it is inflated, the amount of grip will be large. It fluctuates, and thus the actual grasped amount varies. For this reason,
It becomes necessary to set the upper limit of the target setting grip amount small,
There is a problem that the average value of the actual grip amount by the grab bucket becomes small.

The present invention has been made by paying attention to the above problems, and corrects the sinking amount in accordance with the surface shape of the loose material on which the grab bucket lands, and sets the gripping amount as the target setting gripping amount. The purpose is to get closer to.

[0007]

In order to achieve the above-mentioned object, the unloader rated gripping amount control method of the present invention detects landing of a grab bucket on the surface of a bulk object as a load,
Further, based on the brand of the bulk and the deviation of the actual grasped amount up to the previous time from the target set value, the sinking amount of the grab bucket from the landing point into the bulk is adjusted to adjust the grab bucket. In the gripping amount control method of the unloader for controlling the actual gripping amount, when the sinking amount of the grab bucket is obtained, the sinking amount is corrected by the surface shape of the loose material at the position where the grab bucket is landed. ..

[0008]

The relationship between the sinking amount and the gripping amount of the grab bucket according to the brand of the bulk material is obtained in advance for each surface shape. For example, the surface shape is classified into three states of a flat state, a convex state, and a concave state, and the relationship between the grasping amount and the sinking amount corresponding to the three states is obtained in advance, and the surface shape of the loose material on which the grab bucket lands. Correct the amount of sinking according to.

As a result, when the surface shape is convex, the sinking amount is small, and when the surface shape is concave, the sinking amount is large, and the actual gripping amount in the grab bucket approaches the target set gripping amount. The amount variation is smaller than in the past.

[0010]

Embodiments of the present invention will be described with reference to the drawings.
First, to explain the configuration, a crane garter forming a horizontal beam horizontally projects a predetermined height toward the ship side from a body or a vertical column standing on the quay. A trolley is reciprocally provided on the crane garter, and a grab bucket is hung from the trolley via a support wire.

As shown in FIG. 1, the grab bucket 1 includes a pair of left and right shells 1a, a pivotal attachment member 1b for pivotally pivoting opposing portions of the shells 1a, and both shells 1a. It is composed of a connecting member 1c which is supported by. One end of an opening / closing wire 2 is connected to a pivot member 1b of the grab bucket 1, and the opening / closing wire 2 is wound around a drum 2b via a guide sheave 2a.
The opening / closing motor 3 is connected to the shaft portion of the shaft, and the driving of the opening / closing motor 3 allows the pivot member 1b to move up and down relative to the connecting member 1c.
The shell 1a can be opened and closed. The opening / closing motor 3 is connected to the opening / closing motor control device 4.

Further, one end of a supporting wire 5 is connected to a connecting member 1c of the grab bucket 1, the supporting wire 5 is wound around a drum 5b via a guide sheave 5a, and a shaft of the drum 5b is provided with a lifting motor. 6 is connected, and the grab bucket 1 can be moved up and down by driving the lifting motor 6. The lifting motor 6 is connected to a lifting motor control device 7.

A pulse oscillator 8 is connected to the shaft portion of the lifting motor 6, and a position detector 9 is connected to the output side of the pulse oscillator 8. The position detector 9 is a pulse oscillator. The feeding length L of the support wire 5 can be calculated by the pulse signal from 8. The output side of the position detector 9 has a landing position detector 10, a deceleration position controller 11,
Also, it is connected to the input side of the sinking position controller 12 and can supply a length signal according to the payout length L of the support wire 5.

Further, the deceleration position controller 11 and the sink position controller 12 are respectively connected to a lifting motor control device 7 to drive the lifting motor 6 in forward and reverse directions to move the grab bucket 1 up and down. To control. Further, a strain gauge 13 for detecting a load applied from the grab bucket 1 is installed on a support portion of the guide sheave 5 a for the support wire 5, and the strain gauge 13 is connected to a landing detector 14. The landing detector 14 can detect the landing of the grab bucket 1 from the change in the voltage supplied from the strain gauge 13.

The output side of the landing detector 14 is connected to the landing position detector 10, and the landing position detector 10 inputs the landing signal from the landing detector 14, and the support wire 5 at that time is input. The feeding length L1 can be detected by inputting it from the position detector 9. Further, the output side of the landing detector 14 is also connected to a landing stop controller 15, and the landing stop controller 15 inputs the landing detection signal from the landing detector 14 to raise and lower the motor controller. A stop command is supplied to 7.

The output side of the landing position detector 10 is connected to the sinking position calculator 16 and the deceleration position calculator 17, and the feeding length L of the support wire 5 corresponding to the landing position is L.
1 can be supplied. The deceleration position calculator 17 is connected to the deceleration position setter 18 that stores the distance to the deceleration position, and decelerates from the input support wire feeding length L and the set deceleration position data from the deceleration position setter 18. It is possible to obtain the start point and supply the signal to the deceleration position controller 11.

The output sides of the two motor control devices 4 and 7 are respectively connected to a gripping amount calculator 19, and the gripping amount calculator 19 receives the currents input from the two motor control devices 4 and 7. By multiplying the value by a proportional constant, it is possible to calculate the grip amount in the grab bucket 1 as a load value. The output side of the gripping amount calculator 19 is connected to the average value calculator 20 and the data analysis device 30 so that a signal corresponding to the actual gripping amount W1 can be supplied.

The data analysis device 30 sets the relationship between the sinking amount of the glag bucket 1 and the actual grip amount as initial data for each brand and for each surface shape, and accumulates the data of the actual grip amount W1. The relationship between the sinking amount of the grag bucket 1 and the actual gripping amount is re-analyzed and updated when data is collected for a certain amount or more. The data analysis device 30
It is known that the grasping amount and the sinking amount have a linear relationship in the above-described analysis process in FIG. 2. As shown in FIG. 2, when the grasping amount is W and the sinking amount is S, W = A1. It is represented by S + B1 (A1 and B1 are proportional constants). Based on this,
The proportional constants A1 and B1 are obtained and initialized for each surface shape and for each brand, and the actual grasped amount W of the collected data W
When 1 is a predetermined number, for example, 30 are collected, the analysis is performed again and the proportional constants A1 and B1 are updated. In the present embodiment, the surface shape is classified into four states: convex, concave, flat, and inclined.

Further, the data analysis device 30 derives the following equation for each gradient classification from the above equation. S = −α · A · Ε + B where α is a correction coefficient, A is a control parameter proportional gain, B is a control parameter basic manipulated variable, and Ε is a control deviation described later. Also, the average value calculator 20
The output side of is connected to the control deviation calculator 21, and it is possible to calculate the average value of the actual grip amount W1 up to the previous time and supply a signal according to the value W to the control deviation calculator 21.

The control deviation calculator 21 is also connected to a gripping load setting device 22 in which a target set amount gripping amount W0 is set, and control is performed from the input average actual gripping amount W and the target set gripping amount W0. Calculate the deviation E1. The output side of the control deviation calculator 21 is connected to a signal controller 23, which, as shown in FIG.
Correction for the upper and lower limits of 1 and dead zone processing are performed to obtain the corrected control deviation E.

The output side of the signal controller 23 is connected to the control parameter setting device 24. The control parameter setter 24 is composed of four setting blocks 24a to 24d which are selected in synchronization with an output limiter 26 which will be described later, and one of which can be selected by a synchronization switch SW. In the blocks 24a to 24d, the control parameter proportional gain A and the control parameter basic operation amount B corresponding to the concave, convex, flat, and inclined surface shapes are input from the data analyzer 30 and the sinking amount calculator is input. 25 can be supplied.

The sinking amount calculator 25 converts the input control deviation E into the sinking amount S1 by the following equation. S1 = −α · A · Ε + B (1) Further, the output side of the sinking amount calculator 25 is connected to an output limiter 26, which is selected by the operator via the synchronous switch SW. The upper limit value SH and the lower limit value SL (see FIG. 2) of the sinking amount S1 corresponding to the surface shape are input from the data analyzer 30 and the sinking amount S1 is set.
To correct.

The output side of the output limiter 26 is connected to the sinking position calculator 16 and the sinking amount S can be supplied to the data analyzer 30. The subsidence position calculator 16 can add the calculated subsidence amount S and the landing position detection amount L1 to calculate the subsidence position LS, and can supply the value LS to the subsidence position detector 12. In the grab bucket unloader having the above-mentioned configuration, the grab bucket 1
The trolley suspending the ship is traversed from the standby position to the sea side and stopped at the working position above the relevant hatch of the ship. At this time, the shell 1a of the grab bucket 1 is in an open state.

From this state, the grip amount control in the grab bucket unloader is started. First, the glove bucket 1 is allowed to fall naturally in the open state. At this time, the position detector 9 constantly calculates the payout length L of the support wire 5 via the pulse transmitter 8 connected to the lifting motor 6, and the payout length signal is always given to the deceleration position controller 1
1, supplied to the landing position detector 10.

When the deceleration position controller 11 detects that the feeding length L has reached a preset predetermined length, the deceleration position controller 11 supplies a deceleration signal to the lifting motor controller 7. Then, the rotation of the lifting motor 6 is decelerated, and the descending speed of the grab bucket 1 is decelerated.
Further, when the grab bucket 1 descends and lands on the surface of the load, the landing detector 14 detects the landing through a voltage change from the strain gauge 13, and the landing detector 14 controls the landing detection signal to landing stop. Device 15 and landing position detector 10
Supply to.

Then, the landing stop controller 15 receives the landing stop signal and stops the lifting motor 6 via the lifting motor control device 7 to stop the descent of the grab bucket 1. Further, when the landing detection signal is input, the landing position detector 10 detects the payout length L1 of the support wire 5 at that time.

At this time, the operator visually confirms the surface shape of the bulk material that is the load at the landing position of the grab bucket 1 and sets the synchronous switch SW corresponding to the surface shape. Further, for the control deviation calculator 21,
Average value W of the actual grip amount from the average value calculator 20 to the previous time
Is supplied, and a preset target set gripping amount W0 is supplied from the gripping load setter 22. Then, the control deviation calculator 21 subtracts the set gripping amount W0 from the actual gripping amount W to obtain the control deviation E1 of the gripping amount, corrects the control deviation signal E1 by the signal limiter 23, and then the control deviation E2. Is supplied to the sink amount calculator 25 via the control parameter setter 24.

In the control parameter setting device 24, the data analysis device 30 obtains the control parameter proportional gain A and the control parameter basic manipulated variable B corresponding to the predetermined blocks 24a to 24d selected according to the surface shape of the bulk goods to be loaded.
Is input to the sink amount calculator 25 and supplied. The sinking amount calculator 25 calculates the sinking amount S based on the input parameters.
1 is calculated by the equation (1), and is corrected by the output limiter 26, and then the sinking amount calculator 16 calculates the sinking amount S.
To supply.

In the sinking position calculator 16, the sinking position L is obtained by adding the input sinking amount S to the feeding length L1 of the support wire 5 corresponding to the landing position of the grab bucket 1.
S is calculated and the value LS is supplied to the sinking position controller 12. The sinking position controller 12 drives the drive motor 6 via the lifting motor controller 7 while inputting the payout length L of the support wire 5 from the position detector 9, and the payout length L is the sink position. The support wire 5 is extended until it becomes equal to LS, and thus the grab bucket 1 is submerged in the bulk by the subduction amount S.

After that, the opening / closing motor 3 is driven through the opening / closing motor control unit 4 to close the pair of shells 1a of the grab bucket 1, and the loose object is grabbed in the glove bucket 1 and supported in that state. The wire 5 is wound up and the grab bucket 1 is raised. During the winding, the current values from both the motor control devices 4 and 7 are supplied to the grip amount calculator 19, and the actual grip amount W1 is calculated by the following formula. W1 = K1 * (J1 + J2) + K2 Here, K1 and K2 are regression coefficients, J1 is a current value from the lifting motor control device, and J2 is a current value from the opening / closing motor control device.

The calculated grasping amount W1 is calculated by the average value calculator 2
0 and supplied to the data analysis device 20. Average value calculator 2
At 0, the average gripping amount W is calculated from the gripping amount W1 supplied and the gripping amount up to the previous time. In the data analysis device 30, the current preset brand and operator are the synchronization switch S.
The current gripping amount W1 is stored as the gripping amount corresponding to the surface shape classification set via W, and the sinking amount S and the gripping amount W of the corresponding brand and the corresponding surface shape are stored each time 30 pieces of corresponding data are accumulated. The relationship is analyzed, and the parameters A and B in the above equation (1) are updated.

The raised grab bucket 1 traverses overland and fully opens above the hopper to load the grabbed bulk into the hopper. When the gripping amount by the grab bucket is controlled as described above, for example, as shown in FIG.
When trying to grab 1 with the grab bucket 1 in the order of the numbers in the figure, conventionally, for example, with the convex surface shape of the numbers 5 and 6, the amount of grip is larger than the target set amount of grip, and the inclined states of the numbers 4 and 7 are gripped. In the surface shape of No. 3, the amount of grip is smaller than the target set amount of grip, and the variation in the actual amount of grip becomes large. The amount approaches the target set gripping amount and the variation becomes small.

As a result of actual measurement, a comparison between the conventional average gripping amount ignoring the surface shape and the average gripping amount according to the present embodiment showed that the average gripping amount increased by about 0.2 t and The ability had improved.

[0034]

As described above, in the grasping amount control method of the unloader of the present invention, the grasping amount of the grab bucket is corrected by correcting the sinking amount of the grab bucket according to the shape of the surface of the loose material on which the grab bucket lands. The variation with respect to the target set value becomes small, and it is possible to grip with a value close to the target set value, and it is possible to increase the average grip amount without changing the upper limit over ratio of the grip amount, thus improving the unloading ability.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a method of controlling a grip amount of an unloader according to the present invention.

FIG. 2 is a diagram showing a relationship between a sinking amount and a gripping amount.

FIG. 3 is a diagram showing a relationship between a control deviation and a corrected control deviation.

FIG. 4 is a diagram showing an example of the shape of the surface of a bulk material.

[Explanation of symbols]

 1 grab bucket 2 open / close wire 3 open / close motor 5 support wire 6 lifting motor 9 position detector 10 landing position detector 11 deceleration position controller 12 sinking position controller 14 landing stop controller 16 sinking position calculator 17 Deceleration Position Calculator 19 Grip Amount Calculator 21 Control Deviation Calculator 24 Control Parameter Setter 25 Sinking Calculator 30 Data Analysis Device Ε Control Deviation A Control Parameter Proportional Gain B Control Parameter Basic Operation Amount W Actual Grip Amount S Sinking Amount

Claims (1)

[Claims] 1. The landing point of a grab bucket on the surface of a bulk material that is a load is detected, and the landing point is determined based on the brand of the bulk material and the deviation from the target set value of the actual grip amount up to the previous time. In the gripping amount control method of the unloader for controlling the actual gripping amount by the grab bucket by adjusting the sinking amount into the bulk of the grab bucket from, depending on the surface shape of the bulk at the position where the grab bucket lands. A method for controlling a gripping amount of an unloader, which comprises correcting the sinking amount.