JP2000219482A - Crane control method and control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To suppress a run-out when a load is moved by a crane, a state of a run-out of a load, specifically, a run-out state of a wire hanging a suspended load is detected. Sensors,
For example, an acceleration sensor is required, but such a sensor generally has a built-in gyro, is relatively expensive, and has a complicated structure. SOLUTION: The swing cycle (angular angular velocity) of a crane's suspended load.
Because of the principle of the pendulum, it depends only on the length of the wire suspending the suspended load, so that the crane body 1 is once moved at a constant speed during the acceleration period from the stop state to the original constant speed movement. Thus, the suspended load 2 precedes the crane main body 1 and causes a swing in a certain period during the subsequent constant speed movement, but the suspended load 2 swings in the backward direction with respect to the crane main body 1. , The crane body 1 is accelerated again to cancel the amplitude of the load swing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method and an apparatus for suppressing a swing (load swing) of a suspended load during crane operation.

[0002]

2. Description of the Related Art When a suspended load is conveyed by a crane and simple control is performed without considering load fluctuation, the control is performed as shown in a timing chart of FIG. First, time TA
In FIG. 4, the crane body is started and acceleration is started, and the vehicle is accelerated for a time t1 until a time TB at which the vehicle is accelerated to the maximum speed Vmax. Thereafter, the crane body moves at a constant speed until the deceleration start time TC at the maximum speed Vmax, starts deceleration at the time TC, decelerates for a time t2, and stops at the time TD.

When such simple control is performed,
If the maximum speed Vmax, acceleration and deceleration of the crane body are always constant, the acceleration time t1, the deceleration time t2, and the deceleration start time TC can be easily determined if the current position and the movement target position of the crane body are known. I can do it.

FIG. 2 is a schematic diagram showing a relative motion state of a suspended load with respect to the crane main body when the simple control as described above is performed. When the simple control as described above is performed, when the crane body is started, as shown in FIG. 2 (a), the load 2 moves in the moving direction of the crane body 1 (rightward in the figure). Is relatively opposite direction (left direction in the figure)
To be late. In this state, while the crane main body 1 continues accelerating, the crane main body 1 is temporarily stabilized in a state of dragging a suspended load, but at the time TB when the crane main body 1 shifts from the acceleration state to the constant speed moving state. As shown in FIG. 2 (b), the suspended load 2 precedes in the same direction relative to the moving direction of the crane main body 1, and thereafter swings back and forth with respect to the crane main body 1. As a result, the suspended load 2 remains swinging with respect to the crane main body 1 at the stop time TD, so that the unloading, that is, the suspended load 2 cannot be landed until the vibration stops.

As described above, if the crane is controlled without considering the load swing, the total work ending time until unloading becomes long, and the suspended load cannot be accurately lowered to the target position. There was a problem. Further, if the crane moves with the suspended load swinging, there is a danger to surrounding workers, and the suspended load itself and surrounding structures may be damaged.

[0006] With respect to the movement of the suspended load and the unloading of the load by the crane, the above-mentioned problem of the load swing basically exists. Therefore, various measures have been conventionally taken to suppress the load swing. In recent years, the state of the load swing is detected by a sensor, and the moving speed of the crane body is controlled by a computer according to the detection result, in other words, by adjusting the relative moving speed between the crane body and the suspended load. In general, a technique for suppressing the swing of a suspended load is used. Hereinafter, the basic concept of such a conventional technique will be described with reference to the schematic diagram of FIG.

First, as shown in FIG. 3 (a), during the constant speed movement after the crane main body 1 is started from a stopped state and accelerated, as shown in FIG. 3 (b). If the sensor detects that the suspended load 2 is delayed with respect to the crane body 1 (the suspended load 2 swings in the direction opposite to the moving direction of the crane body 1), the crane body 1 at that time is detected. The crane body 1 is decelerated for a certain period of time in consideration of the speed of the crane body, the length of the wire, and the like, so that the relative movement speed between the crane body 1 and the suspended load 2 is adjusted to be “0”. The deflection of the load 2 is suppressed.

On the other hand, as shown in FIG. 3C, while the crane body 1 is moving at a constant speed, the suspended load 2 is ahead of the crane body 1 (movement of the crane body 1). When the sensor detects that the suspended load 2 swings in the same direction, the crane body 1 is accelerated for a certain period of time to reduce the relative moving speed between the crane body 1 and the suspended load 2 to “0”. The swing of the suspended load 2 is suppressed by making the adjustment to "."

Further, even when the crane body 1 is decelerated, the moving speed of the crane body 1 is controlled by controlling the moving speed of the crane body 1 so that the relative speed between the crane body 1 and the suspended load 2 becomes "0" as described above. The swing is suppressed, and finally, even when the crane main body 1 is stopped, the minute control is performed to unload at a predetermined stop position.

[0010]

Conventionally, when a load is moved by a crane, the state of the load swing is detected by a sensor as described above, and based on the result, the moving speed of the crane body is controlled to control the relative speed between the two. Is set to "0" to suppress the swing of the suspended load. However, such a conventional technique requires a sensor for detecting the state of the load swing, specifically, the state of the swing of the wire suspending the suspended load, for example, an acceleration sensor. Such a sensor generally has a built-in gyro, is relatively expensive, and has a complicated structure.

Further, when controlling the moving speed of the crane body based on the detection result of such a sensor, a calculation is performed by a computer from the time when the swing of the suspended load is detected by the sensor, and the control output is actually obtained. It takes some time to output to Therefore, the swing cannot be immediately suppressed in the swing cycle at the time when the swing of the suspended load is detected by the sensor, and the prediction control for the next swing cycle must be performed. For this reason, strict control could not be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and it is possible to suppress swing of a suspended load and unload a cargo at an accurate position without requiring extra hardware such as a sensor. It is an object of the present invention to provide a crane control method and apparatus capable of performing the control.

[0013]

According to the principle of the pendulum, the swing period (angular angular velocity) of the load of the crane depends only on the length of the wire hanging the load. Therefore, after starting from the stop state and transiting to the constant speed movement after acceleration, the suspended load precedes the crane main body, and the load fluctuates at a certain period during the subsequent constant speed movement. Immediately after the crane main body 1 transitions to the constant speed movement, when the suspended load swings in the reverse direction with respect to the crane main body, the crane main body is moved at that time and the length of the wire suspending the suspended load. It is possible to absorb (cancel) the amplitude of the deflection of the load by accelerating again for a certain period of time at an acceleration corresponding to. In this case, since the crane main body is not decelerated to absorb the amplitude of the load swing, the working time does not increase.

Therefore, during the acceleration period from when the crane main body is started up to the state where the crane moves to the original constant speed, at least one is set.
It is possible to reduce or eliminate the amplitude of the load swing during the original constant-speed movement by performing the constant-speed movement at an intermediate speed and then re-acceleration. This is also true during deceleration, in which the crane body performs at least one intermediate-speed constant-speed movement during the deceleration period from the constant-speed movement state to the stop state, and then decelerates again. In addition, it is possible to reduce or eliminate the amplitude of the load swing at the time of stop.

The method for controlling a crane according to the present invention includes an acceleration period in which the crane body, in which a suspended load is suspended by a wire, is started from a stopped state and accelerated, and a constant speed movement period in which the crane body is moved at a constant speed after the acceleration period. A crane control method including a deceleration period of decelerating and stopping at a target position after the constant speed movement period, wherein the crane body is accelerated at a predetermined acceleration during the acceleration period, and thereafter the crane body is accelerated. Is moved at a constant speed for a predetermined time, and then accelerated again at the predetermined acceleration.During the deceleration period, the crane main body is decelerated at a predetermined deceleration. After the high speed movement, control is performed so as to decelerate again at the predetermined deceleration, and the relative forward movement of the suspended load with respect to the crane body generated during the constant speed movement during the acceleration period is the same. The acceleration during the acceleration period and the time for constant speed movement during the acceleration period are determined so as to be canceled during the acceleration period, and the relative load to the crane body of the suspended load generated during the constant speed movement during the deceleration period The deceleration during the deceleration period and the time for constant speed movement during the deceleration period are determined so that the target reverse movement is canceled during the subsequent deceleration period.

Further, the control device for a crane according to the present invention comprises:
Acceleration control for starting and accelerating the crane body from which the load suspended by the wire is suspended from a stopped state, constant speed movement control for moving at a constant speed after the acceleration period, and target position for decelerating after the constant speed movement period. A crane control device that performs deceleration control to stop the crane body, the crane body is accelerated at a predetermined acceleration during the acceleration period, and then the crane body is moved at a constant speed for a predetermined time, and then the crane body is moved to the predetermined speed. Control to accelerate again with acceleration, during the deceleration period, decelerate the crane body at a predetermined deceleration, and then move the crane body at a constant speed for a predetermined time, and then decelerate again at the predetermined deceleration. And a forward movement of the suspended load relative to the crane body occurring during the constant speed movement during the acceleration period is canceled during a subsequent acceleration period. The predetermined acceleration during the acceleration period and the time of constant speed movement during the acceleration period, and the relative backward movement of the suspended load with respect to the crane body occurring during the constant speed movement during the deceleration period is performed during the subsequent deceleration period. Storage means for storing a predetermined deceleration of the deceleration period and a time of constant speed movement during the deceleration period, so that the control circuit is stored in the storage means. The control is performed according to the acceleration during the acceleration period and the time of constant speed movement during the acceleration period, and the deceleration during the deceleration period and the time of constant speed movement during the deceleration period. And

In the crane control method and control device according to the present invention, the crane body is moved at a constant speed for a predetermined time during the acceleration period up to the original constant speed movement, and then accelerated again at a predetermined acceleration. The acceleration and the time of the constant speed movement during the acceleration period at that time, the relative forward movement of the suspended load with respect to the crane body generated during the constant speed movement during the acceleration period is performed during the subsequent acceleration period. It is set to be canceled. Therefore, the load swing during the period of the original constant speed movement is reduced or eliminated. Also, during the deceleration period until the vehicle stops, the crane body is controlled to move at a constant speed for a predetermined time and then decelerated again at a predetermined deceleration. The time of the high speed movement is set such that the relative backward movement of the suspended load with respect to the crane body that occurs during the constant speed movement during the deceleration period is canceled during the subsequent deceleration period.
Therefore, the load swing at the time of stoppage is reduced or eliminated.

The above-described constant-speed movement is performed during the acceleration period from the start of the stop state to the original constant-speed movement after acceleration and the deceleration period from the original constant-speed movement state to the stop. Is repeated a plurality of times, it is possible to more effectively suppress the load swing.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments.

First, an outline of a crane to which the present invention is applied will be described with reference to a schematic side view of FIG. 4 and a schematic plan view of FIG. 5 together with a warehouse provided with the crane. Here, a case where a coil made of a thin steel plate (hereinafter, simply referred to as a coil) is used as a suspended load will be described.

Reference numeral 1 denotes a crane body.
It moves on the traveling girder 11 in the left-right direction in FIG. 4 and in the up-down direction in FIG. The traveling girder 11 moves on the traveling rails 12 and 12 in the depth direction in FIG. 4 and in the left and right direction in FIG. In the following description, the movement of the crane body 1 on the traveling girder 11 is referred to as traversing, and the movement of the crane body 1 due to the movement of the traveling girder 11 on the traveling rails 12 is referred to as traveling. Accordingly, the crane body 1 is moved in two orthogonal directions so that the traveling rails 12,
It is possible to arbitrarily move the range sandwiched between the twelve.

The coil 2 to be suspended is a crane body 1
Are arranged in a matrix in the moving range of four in the transverse direction and six in the running direction. As shown in FIG. 5, an address is assigned in advance to the position where each suspended load 2 is to be placed, and a target position where the suspended load should be moved or a position where the suspended load should be taken out (movement start). Position) can be specified.

A coil hacker 13 for suspending the coil 2 as a suspended load is suspended from the crane body 1 by a wire 14. The coil hacker 13 moves up and down by extending the wire in the crane main body 1, and also holds / releases the coil 2 as a suspended load according to an instruction from the crane main body 1.

The general operation of the crane in such a warehouse is as follows. When the coil 2 is carried in, the trolley or the like carries the coil 2 into the warehouse from the carry-in entrance 20, is gripped and lifted by the coil hacker 13 lowered from the crane body 1, and is moved by the crane body 1 to the position of the designated address. After being moved, the coil is removed by releasing the coil hacker 13 to release the coil. on the other hand,
When the coil 2 is unloaded from the warehouse, first, the crane body 1 moves to the address where the coil 2 to be unloaded is placed, lowers the coil hacker 13 and removes the target coil 2.
And lifted it, then moved to the exit 20
By lowering the coil hacker 13 and releasing the coil 2, the coil 2 is unloaded onto a truck or the like.

It is an object of the present invention to control the movement of the coil 2, that is, the suspended load when the coil 2 is conveyed by the crane as described above, and the procedure will be described in detail below.

FIG. 6 is a timing chart showing an operation speed pattern when the crane is operated by the method of the present invention. Note that, in the embodiment of the present invention, an example is shown in which two constant-speed movements are performed during an acceleration period and a deceleration period described later.

First, at time TA, the crane main body 1 is started and acceleration is started (first acceleration period). At time TB, the crane moves to constant speed movement at the speed VL and moves at a constant speed as it is until time TC ( (First constant speed moving period). In the following description, the speed VL during the first constant speed movement period is referred to as a low speed, and a period from the time TA at which the vehicle is started from the stop state to the end time TC of the first constant speed movement period is referred to as the low speed operation.

After the first constant speed movement period from the time point TB to the time point TC, acceleration is started again at the time point TC (second acceleration period). It moves at a constant speed to TE as it is (second constant-speed movement period). In the following description, the speed VM during the second constant speed movement period is referred to as a medium speed, and a period from the time point TC at which the vehicle is reaccelerated to the end time point TE of the second constant speed movement period is referred to as a medium speed operation.

After the second constant speed movement period from the time point TD to the time point TE, acceleration is started again at the time point TE (third acceleration period). The vehicle moves at a constant speed to the TG as it is (third constant speed movement period). In the following description, the speed VH during the third constant speed movement period is referred to as high speed, and the period from the point of time TE at which re-acceleration is performed to the end point TG of the third constant speed movement period is referred to as high speed operation.

After the third constant speed movement period from the time point TF to the time point TG, deceleration is started at the time point TG (first deceleration period).
The vehicle moves at a constant speed to TI as it is (fourth constant speed movement period).
Medium speed operation is performed from the time point TG at which deceleration is started to the time point TI at which the fourth constant speed movement period ends.

After the fourth constant speed movement period from the time point TH to TI, the deceleration is started again at the time point TI (second deceleration period), and at the time point TJ, the low speed constant speed movement period is changed to the time point. Move at a constant speed until TK (fifth constant speed movement period). The low-speed operation is performed from the time point TI at which the re-deceleration is started to the time point TK at the end of the fifth constant speed movement period. Then, after the fifth constant speed movement period from time TJ to TK, deceleration is started again at time TK and stopped at time TL (third deceleration period).

The swing cycle (angular angular velocity) of the crane's suspended load depends only on the length of the wire suspending the suspended load due to the pendulum principle. Therefore, after starting from the stopped state and transiting to the constant speed movement after acceleration, the suspended load precedes the crane main body, and during the subsequent constant speed movement, the load swings at a cycle corresponding to the wire length. Immediately after the crane main body 1 transitions to the constant speed movement, when the suspended load swings in the reverse direction with respect to the crane main body, the crane main body is moved at that time and the length of the wire suspending the suspended load. It is possible to absorb the amplitude of the deflection of the load by accelerating again for a certain period of time at an acceleration corresponding to.

Therefore, by setting the moving speed and time in each constant speed moving period other than the third constant speed moving period, which is the original constant speed moving period, such that the amplitude of the swing of the suspended load is canceled. It is possible to reduce or eliminate the amplitude of the load swing during the third constant speed movement period, which is the constant speed movement period, and further reduce or eliminate the amplitude of the load swing during stoppage. It is possible.

From the above viewpoints, the crane body 1 when the acceleration during the acceleration period, the deceleration during the deceleration period, and the times during the first, second, fourth, and fifth constant speed movement periods are appropriately set. FIGS. 7A to 7 show the relative movement of the suspended load 2. FIG.
A schematic diagram of (k) is shown. 7 (a) to 7 (k), white circles and broken lines indicate the positions of the suspended load 2 and the wire at the start of each period, and solid circles and solid lines represent the suspended load 2 and the wire. Each position at the end of the period is shown, and arrows indicate the relative movement direction and the relative movement amount of the suspended load 2 with respect to the crane body 1 in each period.

First, during the first acceleration period from the time point TA to the time point TB, as shown in FIG. 7A, the suspended load 2 is relatively delayed with respect to the crane body 1. Swings backward in the traveling direction as viewed from the crane body 1.

Then, in the first constant-speed movement period up to time TC after transition to low-speed constant-speed movement at speed VL at time TB, as shown in FIG. The suspended load 2 moves relative to the crane main body 1 and moves forward in the traveling direction when viewed from the crane main body 1.

In the second acceleration period from the next time point TC to TD, the suspended load 2 moves in a direction relatively delayed with respect to the crane body 1 as shown in FIG. 7B, the swing of the crane main body 1 in the traveling direction is different from the first acceleration period, and is different from the crane main body 1 in the traveling direction of the crane main body 1 in the first constant speed moving period shown in FIG. The amplitude of the suspended load 2 is canceled.

Next, during the second constant speed movement period up to time TE after the transition to the middle speed constant speed movement at the speed VM at time TD, as shown in FIG. The suspended load 2 moves in the direction of advance relative to the crane main body 1 and swings forward in the traveling direction as viewed from the crane main body 1, but unlike the first constant speed period, as shown in FIG. During the second acceleration period, the swing of the suspended load 2 swinging backward in the traveling direction of the crane body 1 is reduced.

In the third acceleration period from the next time point TE to TF, the suspended load 2 moves in a direction relatively delayed with respect to the crane main body 1 as shown in FIG. As seen from the crane main body 1, it swings backward in the traveling direction.
In the second constant speed movement period shown in (d), the amplitude of the suspended load 2 swinging forward in the traveling direction of the crane main body 1 is canceled again.

Next, in the third constant speed movement period up to time point TG after transition to high speed constant speed movement at the speed VH at time point TF, as shown in FIG. The suspended load 2 moves in the traveling direction relative to the crane body 1 and swings forward in the traveling direction as viewed from the crane body 1;
In the third acceleration period shown in (e), the swing of the suspended load 2 swinging backward in the traveling direction of the crane main body 1 further decreases, and the crane main body 1 is almost stopped relative to the crane main body 1.

After the crane body 1 is moved at a constant speed VH for a while in a state where the suspended load 2 is almost stopped relative to the crane body 1 as shown in FIG. In the first deceleration period from TG to TH, as shown in FIG.
, And swings forward in the traveling direction as viewed from the crane body 1.

Next, in the fourth constant speed movement period up to time TI after the transition to the middle speed constant speed movement at the speed VM at time TH, as shown in FIG. , The suspended load 2 moves in a direction relatively delayed with respect to the crane body 1,
When viewed from the crane main body 1, it swings backward in the traveling direction.

In the second deceleration period from the next time point TI to TJ, as shown in FIG. 7 (i), the suspended load 2 moves in a direction to advance relatively to the crane body 1. Swinging forward in the traveling direction as viewed from the crane main body 1, but different from the first deceleration period, in the first deceleration operation period shown in FIG. The amplitude of the suspended load 2 is canceled.

Next, during the fifth constant speed movement period up to time point TK after transition to low speed constant speed movement at speed VL at time point TJ, as shown in FIG. The suspended load 2 moves in a direction relatively delayed with respect to the crane body 1,
Although it swings backward in the traveling direction when viewed from the crane body 1, the fourth
In the second deceleration operation period shown in FIG. 7 (i), the swing of the suspended load 2 swinging forward in the traveling direction of the crane main body 1 is reduced.

In the third deceleration period from the next time point TK to TL, as shown in FIG. 7 (k), the suspended load 2 moves in a direction to advance relatively to the crane body 1. Swinging forward as viewed from the crane body 1 as shown in FIG. 7 (j).
In the fifth constant-speed movement period shown in (1), the swing of the suspended load 2 swinging forward in the traveling direction of the crane main body 1 is further reduced and the crane main body 1 is almost stopped.

By controlling the crane main body 1 to stop just when the suspended load 2 almost stops relative to the crane main body 1 as shown in FIG. In this case, the suspended load 2 can be unloaded to the target position accurately and quickly without performing steadying control when the crane stops.

Next, an example of the configuration of a control circuit for performing the above-described control is shown in the block diagram of FIG. However, FIG.
In the block diagram of FIG. 5, a circuit for moving the coil hacker 13 up and down and a circuit for the coil hacker 13 to hold / release the coil are omitted.

The CPU 31 sends an operation instruction from the operation instruction input device 32, specifically, the current position of the suspended load 2 and the position of the transport destination (the address of the current position of the suspended load 2 shown in FIG. The address of the transfer destination position) is input. In addition, the condition table 35 includes a suspended load (a thin steel coil in the present embodiment).
7 together with data such as weight, size, length from the fulcrum of the wire 4 to the center of gravity when the wire 4 is suspended, and acceleration and reduction to realize the state shown in FIG. The data of the speed and the time of each constant speed movement period are stored in advance. When these data are empty (in this case, the coil hacker 13 is a suspended load), a plurality of sets are stored in advance in the condition table 35 in accordance with each of the objects to be suspended, and the actual It is also possible to use properly according to the suspended load.

The traveling position sensor 41 indicates the traveling position of the crane body 1, in other words, the position of the traveling girder 11, and the traversing position sensor 42.
Detects the traversing position of the crane main body 1, in other words, the position on the traveling girder 11 of the crane main body 1, and inputs it to the CPU 31.

The specific configuration of the position sensors 41 and 42 can be of various types. For example, a mark fixedly installed on the traveling girder 11 and the rail 12 is read to detect the absolute position. There are a method and a method of detecting the relative position with respect to the reference position by measuring the rotation speed of both motors M1 and M2. In any case, the position of the crane main body 1 in the traveling direction and the traverse direction can be determined at any time. Good.

The CPU 31 supplies control signals to the traveling motor control circuit 51 and the traversing motor control circuit 52 to
The crane body 1 is moved by driving the traversing motor M2. Running motor control circuit 51 from CPU 31
And the control signal given to the traversing motor control circuit 52 is:
Based on the detection results of the traveling position sensor 41 and the traversing position sensor 42, and in order to execute the driving instruction given from the driving instruction input device 32, the above-described procedure is performed according to the procedure shown in the flowcharts of FIGS. 6 is generated according to the driving speed pattern as shown in FIG.

Reference numeral 33 denotes a low-speed operation timer, which starts measuring a predetermined time when the low-speed operation is started. Reference numeral 34 denotes a medium speed operation timer, which starts measuring a predetermined time when the medium speed operation is started. The data set as the time in these timers is read from the condition table 35 described above.

Hereinafter, the crane control method of the present invention will be described with reference to the flowcharts shown in FIGS. 9 and 10.
Control when traveling on 11 and traveling control, that is, control when traveling girder 11 travels on rails 12 and 12 are basically the same, and when only one of them is performed alone,
Both may be performed simultaneously. Below is the running girder
Only the traveling control when the 11 moves on the rails 12, 12 will be described.

The acceleration, deceleration, time of the first, second, fourth, and fifth constant speed movement periods, and movement speeds VL, VM, VH of each constant speed movement period are stored in the condition table 35 in advance. It is set based on the data that has been set. Of these, the first
And the time of the second constant speed movement period is determined by the measured value and acceleration of the low speed operation timer 33 and the medium speed operation timer 34, the speed VL of the first constant speed movement period, and the speed VM of the second constant speed movement period. Is determined. The times of the fourth and fifth constant-speed movement periods are relative positions to the target position detected by the traveling position sensor 41 and the traversing position sensor 42 which are set as the start times of the first and second deceleration periods, respectively. It is determined by the data, the deceleration, and the moving speeds VM and VL in the fourth and fifth constant speed moving periods.

First, the CPU 31 acquires the current position data of the traveling girder 11 on the rails 12, 12 (step S11). Specifically, the CPU 31 inputs the detection value of the traveling position sensor 41 and acquires the absolute position (traveling position) of the traveling girder 11 on the traveling rail 12. However, acquisition of the current position data of the traversing position is performed by inputting the detection value of the traversing position sensor 42 and acquiring the absolute position (traversing position) of the crane body 1 on the traveling girder 11.

Next, the CPU 31 obtains the data of the target position of the travel position to which the traveling girder 11 should move from the data of the drive instruction input to the drive instruction input device 32 (step S12), and obtains the current data acquired in step S11. The relative position data is obtained by calculating the difference from the position data (step S13).
However, the target position of the traversing position is also acquired at the same time.

The CPU 31 first starts a low-speed operation for acceleration, that is, an operation for performing constant-speed movement at the low speed VL (step S14). Specifically, the CPU 3 moves the crane body 1 at a constant speed at a low speed VL.
1 supplies a control signal to the traveling motor control circuit 51 to activate the traveling motor M1. As a result, the traveling girder 11 starts on the traveling rail 12 from a stopped state and starts accelerating at a predetermined acceleration (first acceleration period). At this time, the low-speed operation timer 33 starts measuring time at the same time (step S15).

Thereafter, the CPU 31 determines from the detected value of the traveling position sensor 41 whether the traveling girder 11 has reached the position of the relative position data D0 (the position where the traveling girder 11 can be stopped at the target position while traveling at a constant speed at the low speed VL). It is determined whether the relative position data has become equal to or less than the first predetermined value D1 and whether the low-speed operation timer 33 has finished measuring the predetermined time T1 (step S16).
, Step S17, Step S18). However, step S16
The control in steps S17 and S17 is normally performed during deceleration, and only the processing in step S18 is involved during acceleration.

In the first acceleration period after the low-speed operation is started, when the traveling speed of the traveling girder 11 accelerates to the low speed VL, the low-speed operation timer 33 ends the measurement of the predetermined time T1. Until (“N” in step S18
O "), the traveling girder 11 moves at a constant speed at the speed VL (first constant speed movement period). When the low-speed operation timer 33 finishes counting the predetermined time T1 (" YES "in step S18), the CPU 31 Starts the medium speed operation for acceleration, that is, the operation for performing the constant speed movement at the medium speed VM (step S19) .Specifically, the crane body 1 is moved at the medium speed VM. In order to move at a constant speed, the CPU 31 provides a control signal to the traveling motor control circuit 51 to accelerate the traveling motor M1.This causes the traveling girder 11 to further accelerate at a predetermined acceleration from the constant speed traveling state at the speed VL. (Second acceleration period) At this time, the medium-speed operation timer 34 simultaneously starts measuring time (step S20).

Thereafter, the CPU 31 determines whether or not the relative position data has become equal to or less than the first predetermined value D1 based on the detection value of the traveling position sensor 41, and whether or not the medium speed operation timer 34 has finished measuring the predetermined time T2. Is determined (step S21, step S22). However, the control in step S21 is normally performed during deceleration, and only the processing in step S22 is involved during acceleration.

In the second acceleration period after the start of the medium speed operation, when the moving speed of the traveling girder 11 accelerates to the speed VM which is the medium speed, the medium speed operation timer 34 thereafter sets the medium speed operation timer 34 to the predetermined time T2. Until the timing ends ("N" in step S22)
O "), the traveling girder 11 moves at a constant speed at the speed VM (second constant speed movement period). When the medium speed operation timer 34 finishes counting the predetermined time T2 (" YES "in step S22), The CPU 31 determines whether or not the relative position data falls within a range that is equal to or more than the first predetermined value D1 and less than the second predetermined value D2 (step S23).
However, the control in step S23 is normally performed at the time of deceleration, and is not relevant at the time of acceleration.

Next, the CPU 31 starts a high-speed operation for acceleration, that is, an operation for performing constant-speed movement at the high speed VH (step S24). Specifically, the speed that is fast
In order to move the crane body 1 by VH, the CPU 31 gives a control signal to the traveling motor control circuit 51 to accelerate the traveling motor M1. As a result, the traveling girder 11 starts accelerating at a predetermined acceleration from the constant speed moving state at the speed VM (third acceleration period).

Thereafter, the CPU 31 determines whether or not the relative position data has become equal to or less than the second predetermined value D2 based on the detection value of the traveling position sensor 41 (step S25).

In the third acceleration period after the high-speed operation is started, when the traveling speed of the traveling girder 11 is accelerated to the high speed VH, the relative position data is thereafter changed to the second speed VH.
Until it becomes less than the predetermined value D2 (“YES” in step S25).
The traveling girder 11 moves at a constant speed at the speed VH (third constant speed movement period).

When the constant speed movement at the high speed VH is performed for a while, the relative position data eventually becomes less than the second predetermined value D2 ("NO" in step S25).
At this point, the CPU 31 returns the process to step S19 to start the medium speed operation for deceleration, that is, the operation for performing the constant speed movement at the medium speed VM. Specifically, in order to move the crane main body 1 at the middle speed VM, the CPU 31 supplies a control signal to the traveling motor control circuit 51 to cause the traveling motor to rotate.
Decelerate M1. As a result, the traveling girder 11 starts to decelerate at a predetermined deceleration from the constant speed movement state at the speed VH (first deceleration operation period). At this time, the medium-speed operation timer 34 simultaneously starts measuring a predetermined time T2 (step S20).

Thereafter, the CPU 31 determines whether or not the relative position data has become equal to or less than the first predetermined value D1 based on the detection value of the traveling position sensor 41, and whether or not the medium speed operation timer 34 has finished measuring the predetermined time T2. Is determined (step S21, step S22). If the medium speed operation timer 34 has finished measuring the predetermined time T2 ("YES" in step S22), the CPU 31 proceeds to step S2.
The process proceeds to 3 to determine whether the relative value data is greater than or equal to the first predetermined value D1 and less than the second predetermined value D2, but the relative value data is already greater than or equal to the second predetermined value D2 in S25. Is not (less than)
In step 1, the process returns from step S23 to step S21 to continue the medium speed operation. Therefore, during the first deceleration operation, the relative position data in step S21 is changed to the first predetermined value D1.
Only the determination of whether or not the following is significant.

As described above, during the first deceleration period after the start of the medium speed operation for deceleration, when the traveling speed of the traveling girder 11 is eventually reduced to the medium speed VM, thereafter, as described above. The traveling girder 11 moves at a constant speed VM at a middle speed until the relative position data becomes equal to or less than the first predetermined value D1 (second constant speed movement period). When the relative value data becomes equal to or less than the first predetermined value D1 ("YES" in step S21), the CPU 31
Returns the process to step S14.

When the process returns to step S14, the CPU 31
Starts a low speed operation for deceleration, that is, an operation for performing a constant speed movement at a low speed VL. Specifically, in order to move the crane body 1 at a low speed VL, the CP
U31 supplies a control signal to the traveling motor control circuit 51 to further decelerate the traveling motor M1. As a result, the traveling girder 11 starts to decelerate at a predetermined deceleration from the constant speed movement state at the speed VM (second deceleration operation period). At this time, the low-speed operation timer 33 simultaneously starts counting the predetermined time T1 (step S1).
Five).

Thereafter, the CPU 31 determines whether or not the vehicle has arrived at the position of the relative position data D0 (the position where the vehicle can stop at the target position during the constant speed traveling at the low speed VL) based on the detection value of the traveling position sensor 41, It is determined whether or not the position data has become equal to or less than the first predetermined value D1 (step S16, step S1).
7). However, in this case, since the relative position data has already been determined to be equal to or less than the first predetermined value D1 in step S21, the result of determination in step S17 is always "YES", so that the processing from step S17 must be performed. The process returns to step S16, and the low-speed operation is continued. Therefore, this second
In the deceleration operation of, only the determination as to whether or not the vehicle has arrived at the relative position D0 in step S16 has significance.

As described above, in the second deceleration period after the low-speed operation for deceleration is started, when the traveling speed of the traveling girder 11 is eventually reduced to the low speed VL, thereafter, as described above, the target The traveling girder 11 moves at a constant speed at the low speed VL until it reaches the position of the relative value data D0 before the position (fifth constant speed movement period). When the vehicle arrives at the relative position D0 ("YES" in step S16), the CPU 31 performs control for stopping (step S26). Specifically, in the state where the vehicle is moving at a constant speed at the low speed VL, the CPU 31 supplies a control signal to the traveling motor
Decelerate M1 further. As a result, the traveling girder 11 starts to decelerate at a predetermined deceleration from the constant speed moving state at the speed VL (third speed).
During the deceleration operation period, the vehicle stops after moving a predetermined distance while decelerating.

In the above-described embodiment, the constant speed movement during the acceleration period and the constant speed movement during the deceleration period are respectively repeated twice, but may be performed only once or three or more times. Further, the number of constant-speed movements during the acceleration period and the number of constant-speed movements during the deceleration period may not be the same, and the constant-speed movement may be performed only during either the acceleration period or the deceleration period. Good.

Further, in the above embodiment, the traveling control of the crane main body 1 has been described, but basically the same control is performed for the traversing control.

[0073]

As described above in detail, according to the crane control method and the control apparatus according to the present invention, the crane is controlled during the acceleration period from the stop state to the original constant speed movement period after starting. After moving the main body at a constant speed for a predetermined time, it is controlled to accelerate again at a predetermined acceleration,
The acceleration and the time of the constant speed movement during the acceleration period are set so that the relative forward movement of the suspended load with respect to the crane body occurring during the constant speed movement during the acceleration period is canceled during the subsequent acceleration period. ing. Therefore, the load swing during the period of the original constant speed movement is reduced or eliminated. Also,
During the deceleration period from the original constant speed movement period to the stop, the crane body is controlled to move at a constant speed for a predetermined time and then decelerate again at a predetermined deceleration. The time of the constant speed movement during the period is set such that the relative backward movement of the suspended load with respect to the crane body that occurs during the constant speed movement during the deceleration period is canceled during the subsequent deceleration period. Therefore, the load swing at the time of stoppage is reduced or eliminated.

As described above, according to the present invention, a crane control method and a control apparatus capable of sufficiently suppressing the load swing of the crane without using extra hardware such as an acceleration sensor are realized. .

If the constant speed movement during the acceleration period and the deceleration period is repeated a plurality of times, the amplitude of the load swing can be further reduced.

[Brief description of the drawings]

FIG. 1 is a timing chart showing a state in which a simple control is performed without considering a load swing when a suspended load is conveyed by a crane.

FIG. 2 is a schematic diagram showing a relative motion state of a suspended load with respect to a crane main body when a simple control as shown in FIG. 1 is performed.

FIG. 3 is a schematic diagram for explaining a basic concept of a conventional technique for suppressing a swing of a suspended load.

FIG. 4 is a schematic side view showing a crane to which the present invention is applied, together with a warehouse provided with the crane.

FIG. 5 is a schematic plan view showing a crane to which the present invention is applied, together with a warehouse provided with the crane.

FIG. 6 is a timing chart showing an operation speed pattern when a crane is operated according to the method of the present invention.

FIG. 7 is a schematic diagram showing a state of relative movement of a suspended load with respect to a crane main body when the crane is operated according to the method of the present invention.

FIG. 8 is a block diagram showing a configuration example of a control circuit of the crane of the present invention.

FIG. 9 is a flowchart showing a control procedure by the control circuit of the crane of the present invention.

FIG. 10 is a flowchart showing a control procedure by the control circuit of the crane of the present invention.

[Explanation of symbols]

 1 Crane body 2 Lifting load 31 CPU 35 Condition table 41 Travel position sensor 42 Traverse position sensor

Claims (2)

[Claims] An acceleration period for starting and accelerating a crane body from which a load is hung by a wire from a stopped state, a constant speed movement period for moving at a constant speed after the acceleration period, and after the constant speed movement period. A crane control method including a deceleration period for decelerating and stopping at a target position, wherein during the acceleration period, the crane body is accelerated at a predetermined acceleration, and thereafter the crane body is moved at a constant speed for a predetermined time. Controlling to accelerate again at the predetermined acceleration, during the deceleration period, the crane main body is decelerated at a predetermined deceleration, and then the crane main body is moved at a constant speed for a predetermined time, and then the predetermined deceleration is performed. So that the forward movement of the suspended load relative to the crane main body that occurs during the constant speed movement during the acceleration period is canceled during the subsequent acceleration period. The acceleration of the acceleration period and the time of constant speed movement during the acceleration period are defined, and the relative backward movement of the suspended load with respect to the crane body occurring during the constant speed movement during the deceleration period is performed during the subsequent deceleration period. A method for controlling a crane, wherein a deceleration during the deceleration period and a time for constant-speed movement during the deceleration period are determined so as to be canceled during the deceleration period. 2. An acceleration control for starting and accelerating a crane main body from which a load is hung by a wire from a stopped state, a constant speed movement control for moving at a constant speed after the acceleration period, and after the constant speed movement period. In a crane control device that performs deceleration control for decelerating and stopping at a target position, after accelerating the crane body at a predetermined acceleration during the acceleration period, and thereafter moving the crane body at a constant speed for a predetermined time, The crane body is controlled to accelerate again at the predetermined acceleration, and the crane body is decelerated at a predetermined deceleration during the deceleration period. And a control circuit that controls the vehicle to decelerate again during the acceleration period. As described above, the predetermined acceleration of the acceleration period and the time of constant speed movement during the acceleration period, and the relative backward movement of the suspended load with respect to the crane body that occurs during the constant speed movement during the deceleration period are reduced. Storage means for storing a predetermined deceleration of the deceleration period and a time of constant-speed movement during the deceleration period so as to be canceled during the subsequent deceleration period; The control is performed in accordance with the acceleration of the acceleration period and the time of constant speed movement during the acceleration period, and the deceleration of the deceleration period and the time of constant speed movement during the deceleration period, which are stored in A control device for a crane, comprising: