JP2832661B2 - Deflection angle detector for suspended loads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection angle detector for detecting a deflection angle of a suspended load suspended on a bogie by a hoisting rope.

[0002]

2. Description of the Related Art As one type of a crane, a crane for carrying a suspended load suspended by a hoisting rope on a bogie is known. In this type of crane, the bogie is driven by a motor whose speed is controlled by a speed controller.

[0003] Generally, a suspended load is suspended from a bogie by a hoisting rope, so that when the bogie moves, it swings with it. Therefore, when the bogie stops at a predetermined target stop position, it is necessary to control so that the suspended load does not swing. Such control is referred to as crane steadying control.

[0004] In order to perform the steadying control of the crane, it is necessary to accurately detect the swing angle of the suspended load. Here, the swing angle of the suspended load is the link between the fulcrum of the pendulum and the suspended load center.
We have things挾角of the line and the vertical line, on the winding of the time deflection there is no
The angle between the rope and the vertical line, and the hoisting rope at some point
It is approximated by the difference of the included angle with the vertical line .

[0005] A conventional swing load deflection angle detector comprises a deflection angle sensor attached to a rope end of a hoisting rope.

[0006]

As is well known, a crane carries a suspended load while accelerating and decelerating a bogie by driving an electric motor. Generally, the deflection angle sensor described above is
The swing angle of the suspended load can be accurately detected only while the bogie is stopped or while moving at a constant speed. In other words, at the time of acceleration / deceleration of the bogie, the shake angle sensor is affected by the acceleration / deceleration of the bogie due to the detected shake angle due to the characteristics of the shake angle sensor. That is, the deflection angle sensor detects the deflection angle of the suspended load under the influence of the acceleration and deceleration of the bogie, and outputs a deflection angle detection signal indicating the deflection angle of the suspended load including an error.

If the anti-sway control of the crane is performed based on the swing angle of the suspended load including such an error, naturally,
Its performance cannot be good. That is, a residual vibration having a large amplitude remains, or it takes a long time to stop the vibration of the suspended load.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a swing angle detector for a suspended load that can accurately detect the swing angle of a suspended load even when the bogie is accelerated or decelerated.

[0009]

SUMMARY OF THE INVENTION A swing angle detector for a suspended load according to the present invention is for detecting the swing angle of a suspended load suspended on a bogie by a hoisting rope.

According to the present invention, the swing angle detector for a suspended load is attached to a rope end of a hoisting rope, and detects a swing angle of the suspended load under the influence of acceleration and deceleration of the bogie. A first deflection angle sensor for outputting a first detection signal including an acceleration / deceleration state of the truck and a deflection angle of the suspended load; and a first deflection angle sensor mounted on the truck and having the same characteristics as the first deflection angle sensor. having a second deflection angle sensor for outputting a second detection signal which detected the state of the acceleration and deceleration of the carriage; it is connected to the first and second deflection angle sensor, the first detection signal a second It characterized by having a; subtracts the detection signal, a subtracter which outputs the true deflection angle detection signal indicative of the deflection angle of the true of the suspended load by removing the acceleration state of the carriage.

[0011]

According to the present invention, the deflection angle detector for a suspended load includes two deflection angle sensors having the same characteristics, that is, a first and a second deflection angle sensor. The first deflection angle sensor is attached to the rope end of the hoisting rope and detects the deflection angle of the suspended load. The first deflection angle sensor is affected by acceleration and deceleration of the bogie. Therefore, the first deflection angle sensor is of the bogie pressure
A first detection signal including a deceleration state and a swing angle of the suspended load is output. In order to cancel this error (acceleration / deceleration state of the truck) , a second deflection angle sensor is attached to the truck. This second
The deflection angle sensor detects the acceleration / deceleration state of the bogie .
And outputs a detection signal. Then, by the subtractor, the first
By the detection signal subtracting the second detection signal,
A true deflection angle detection signal representing the true deflection angle of the suspended load from which the error (acceleration / deceleration state of the bogie) has been removed is obtained.

Therefore, the swing angle detector of the present invention can always accurately detect the swing angle of the suspended load regardless of whether the bogie is accelerated or decelerated. As a result, when the swing angle detector of the present invention is used to perform the steadying control of the crane, the performance thereof can be improved.

[0013]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a steadying control device for a crane including a swing angle detector of a suspended load according to an embodiment of the present invention.

The crane shown is for carrying a suspended load W suspended by a hoisting rope to a carriage 4. In this crane, the truck 4 is transported by driving the truck drive wheels 5 with the electric motor 3.

Also, the illustrated anti-sway control device of the crane is different from the anti-sway angle detector of the suspended load except that
The applicant of the present application has already disclosed in Japanese Patent Application No. 346,766, entitled "Swing-stopper for hoisting and transporting" (hereinafter referred to as the prior application), filed on December 27, 1991. Is the same as

Accordingly, the detailed configuration and operation of the suspended load according to the present invention other than the swing angle detector will be briefly described with reference to the specification of the above-mentioned prior application, and the suspended load according to the present invention will be described. The deflection angle detector will be described in detail.

The crane steadying control device includes a speed commander 13 for generating a first speed command signal, a first speed command signal, and a true deflection angle detection signal and a speed detection signal to be described later. Performs the fuzzy operation described later,
And a speed controller 2 for controlling the speed of the electric motor 3 in response to the second speed command signal.

The control device of the crane has two detectors described below. One of them is a speed detector 6 for detecting the moving speed of the carriage 3, which is attached to the electric motor 3. The speed detector 6 sends a speed detection signal indicating the detected moving speed to the fuzzy control unit 1. The other one is a swing load swing angle detector (described later) according to the present invention for detecting the swing angle of the hoisting rope (hanging load) W. The deflection angle detector sends a true deflection angle detection signal representing the deflection angle of the true suspended load W to the fuzzy controller 1 as described later.

Next, a swing angle detector for a suspended load according to the present invention will be described. The swing angle detector of the suspended load has two shake angle sensors having the same characteristics, that is, first and second shake angle sensors 7 and 14 and a subtractor 15. The first deflection angle sensor 7 is attached to the rope end (hanging portion) of the hoisting rope, and detects the deflection angle of the suspended load.

As described above, the conventional swing angle detector of the suspended load includes only the first swing angle sensor 7. First
The deflection angle sensor 7 is affected by the acceleration and deceleration of the truck 4.
Therefore, the first deflection angle sensor 7 detects the acceleration / deceleration of the carriage 4.
And outputting a first detection signal including the state and the swing angle of the suspended load. This first detection signal is supplied to the subtractor 15.

In the present invention, this error (the acceleration / deceleration
In order to cancel the condition , the second deflection angle sensor 14 is attached to the carriage 4. This second deflection angle sensor 14
A second detection signal for detecting the state of acceleration / deceleration of the cart 4 is output. This second detection signal is also supplied to the subtractor 15.

The subtractor 15 subtracts the second detection signal from the first detection signal to obtain the error (addition of the bogie 4).
A true deflection angle detection signal representing the true deflection angle of the suspended load from which the deceleration state has been removed is obtained. This true deflection angle detection signal is supplied to the fuzzy control unit 1.

Accordingly, the swing angle detector of the suspended load according to the present invention can always detect the swing angle of the suspended load W accurately regardless of whether the bogie 4 is accelerated or decelerated. As a result, when the swing angle detector of the present invention is used to perform the steadying control of the crane, the performance thereof can be improved.

Next, the fuzzy controller 1 will be described. The fuzzy control unit 1 includes an angular velocity calculator 8, a positioning fuzzy inference unit 9, and a steady-state fuzzy inference unit 10
, A crisping operation unit 11 and an integrator 12.

The angular velocity calculator 8 calculates the shake angular velocity by differentiating the true shake angle detection signal, and outputs a shake angular velocity signal representing the calculated shake angular velocity.

A first speed command signal from the speed command device 13 and a speed detection signal from the speed detector 6 are supplied to the positioning fuzzy inference device 9. When the first speed command signal and the speed detection signal are given, the positioning fuzzy inference unit 9 performs the positioning fuzzy inference using a positioning fuzzy control rule as described later, thereby obtaining a positioning fuzzy inference device. The fitness of the fuzzy set relating to the acceleration (hereinafter, simply referred to as positioning acceleration fitness) is calculated.

As is well known, generally, the fuzzy control rules are divided into an antecedent part represented by an "if sentence" and a consequent part represented by a "then sentence". In the positioning fuzzy control rules, the possible values of the first speed command signal are represented by a speed command fuzzy set with a language label described later, and the possible values of the speed detection signal are also the speed detection fuzzy labels with a language label. Expressed as a set. Here, the language label for each of the first speed command signal and the speed detection signal is, for example,
With a given value as the reference (center), "quite slow"
There are seven types: "Medium slow", "Slightly slow", "Center", "Slightly fast", "Medium fast", and "Quite fast". In this case, since there are seven speed command fuzzy sets and seven speed detection fuzzy sets, the number of positioning fuzzy control rules is 49. Seven language labels of fuzzy set for speed command and seven language of fuzzy set for speed detection
A positioning matrix in which one of the two language labels is a row and the other is a column is formed, and the consequent part of the positioning fuzzy control rule, that is, the above-described positioning acceleration conformity, is assigned to 49 elements of the positioning matrix. Assign.

The positioning fuzzy inference unit 9 determines which combination of the actually input first speed command signal and speed detection signal is represented by any of the antecedents of the 49 positioning fuzzy control rules. Judgment is made, and the consequent part (positioning acceleration suitability) corresponding to the determined antecedent part of the positioning fuzzy control rule is output.

The true shake angle detection signal from the shake angle detector and the shake angular velocity signal from the angular velocity calculator 8 are supplied to the shake preventing fuzzy inference unit 10. The steady-state fuzzy inference device 10 performs a steady-state fuzzy inference using a steady-state fuzzy control rule as described later when a true shake angle detection signal and a steady-state angular velocity signal are given. The fitness of the fuzzy set relating to the steady-state acceleration (hereinafter, simply referred to as the steady-state acceleration fitness) is calculated.

According to the fuzzy control rules for steadying, the possible values of the true swing angle detection signal are represented by a fuzzy set for swing angle detection with a language label described later, and the possible values of the shake angular velocity signal are also labeled with a language label. It is represented by a fuzzy set for the shake angular velocity. Here, the language label for each of the true shake angle detection signal and the shake angular velocity signal is, for example, “swaying considerably backwards” or “slightly middle swinging with a certain value as a reference (center)”. , "Slightly swinging back,""center,""slightly swinging forward,"
There are seven types: "swaying forward" and "swaying forward". In this case, since there are seven fuzzy sets for shake angle detection and seven for fuzzy set for shake angular velocity, the number of fuzzy control rules for shake prevention is 49. Forming one of the seven language labels of the fuzzy set for the deflection angle detection and the seven language labels of the fuzzy set for the deflection angular velocity as a row, and forming the other as a column to form a steadying matrix;
The consequent part of the steady-state fuzzy control rule, that is, the steady-state acceleration adaptability is assigned to each of the 49 elements of the steady-state matrix.

In the steady-state fuzzy inference device 10, the combination of the true shake angle detection signal and the shake angular velocity signal which are actually input is represented by any one of the antecedents of the 49 steady-state fuzzy control rules. Is determined, and the consequent part (steadiness acceleration conformity) corresponding to the antecedent part of the determined steady-state fuzzy control rule is output.

The positioning fuzzy inference unit 9 and the steady-state fuzzy inference unit 10 are supplied to the crispization computing unit 11 with the positioning acceleration suitability and the steady-state acceleration suitability, respectively. The crisping calculator 11 performs a crisping operation on the positioning acceleration conformity and the steady-state acceleration conformity to determine the output acceleration. Here, the crispization means that each of the adaptations such as the acceleration adaptability for positioning and the acceleration adaptation for steadying is an ambiguous instruction, so that the output represented by a numerical value interpreting the ambiguous instruction is output. It means to convert to acceleration.
This crispization is also called defuzzification. As the crisping method, for example, the center of gravity method or Sugano's simplified method is used. The crisp operation unit 11 outputs an output acceleration signal representing the output acceleration obtained by the crisp operation.
Anyway, the crisping arithmetic unit 11 coordinates the positioning adaptation suitability and the steady rest acceleration suitability by a crisping technique such as the center of gravity method or the Sugano's simplified method, so that the optimal acceleration signal for the crisped steady rest is obtained. As an output acceleration signal.

The integrator 12 integrates the output acceleration signal supplied from the crisp calculator 11 and outputs a signal obtained as a result of the integration as a second speed command signal. This second speed command signal is supplied to the speed controller 2.

[0035]

As described above, according to the present invention, the second deflection angle mounted on the bogie is determined by the subtractor from the first detection signal obtained by the first deflection angle sensor mounted on the rope end. By subtracting the second detection signal obtained by the sensor, a true swing angle detection signal representing the true swing angle of the suspended load without error is obtained, regardless of whether the bogie is accelerated or decelerated. The swing angle of the suspended load can always be detected accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a steadying control device for a crane including a swing angle detector of a suspended load according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuzzy control part 2 Speed controller 3 Electric motor 4 Dolly 5 Dolly drive wheel 6 Speed detector 7 First deflection angle sensor 8 Angular velocity calculator 9 Fuzzy inference device for positioning 10 Fuzzy inference device for steadying 11 Crisping calculator 12 Integrator 13 Speed commander 14 Second deflection angle sensor 15 Subtractor

Claims (1)

(57) [Claims] 1. A swing angle detector for detecting a swing angle of a suspended load suspended on a bogie by a hoisting rope, wherein the swing angle of the suspended load is attached to a rope end of the hoisting rope. Detected in a state affected by the acceleration and deceleration of the bogie, the acceleration and deceleration of the bogie and the swing angle of the suspended load
A first deflection angle sensor that outputs a first detection signal including: a first deflection angle sensor mounted on the bogie, having the same characteristics as the first deflection angle sensor, and detecting an acceleration / deceleration state of the bogie .
A second deflection angle sensor that outputs a second detection signal, and a second deflection angle sensor that is connected to the first and second deflection angle sensors, subtracts the second detection signal from the first detection signal , And a subtractor for outputting a true swing angle detection signal representing a true swing angle of the suspended load from which the acceleration / deceleration state has been removed.