JP2522020B2 - Control method of steadying operation of suspended load - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for controlling a steady motion of a suspended load, and more particularly to a method for controlling a steady motion of a suspended load in a crane that performs a traveling operation of a suspended load by automatic control. Regarding

[Prior Art] Generally, in a container crane or the like, after hoisting a load, it accelerates to the maximum speed as quickly as possible,
It is necessary to reduce the work time for traverse operation.

However, with this acceleration, the suspended load vibrates like a pendulum, which adversely affects the safety of the suspension movement, and this vibration does not subside even when it reaches above the predetermined unloading position,
It will take a long time to work. For this reason, conventionally, the driver performs an adjustment operation based on his experience and intuition so as to damp this shake, and performs a traverse operation so that the shake angle becomes as small as possible when the maximum speed is reached.

[Problems to be Solved by the Invention] By the way, recently, various proposals have been made to try to improve work efficiency by automatically operating a crane.

However, it was difficult to appropriately damp the vibration of the suspended load that occurs when the vehicle is accelerated. For example, even if the deflection angle of a suspended load is detected and an acceleration corresponding to that angle is set, the operating conditions change depending on the weight of the suspended load and the length of the suspension rope, and it is not always possible to perform appropriate control. could not.

Therefore, in view of the above circumstances, the present invention was devised to provide a control method for performing an operation that appropriately damps the vibration of a suspended load that occurs during acceleration.

[Means and Actions for Solving the Problem] The present invention quantifies the empirical adjustment operation such that the swing angle of the suspended load becomes approximately 0 when the trolley that started traversing reaches a constant speed, It is set as an empirical rule for each of various operating conditions, and based on this empirical rule, the acceleration suspension speed and the re-acceleration start deflection angle are determined from the detected weight of the suspended load and the hanging rope length to accelerate the operation. When the trolley reached the acceleration stop speed, it switches to constant speed operation to maintain that speed, the deflection angle of the suspended load is detected by the detection means during the constant speed operation, and the detected value starts reacceleration. When the deflection angle is reached, the acceleration operation that reaches a predetermined maximum transverse speed is restarted. Further, when the weight of the suspended load and the length of the hanging rope are operating conditions that are not empirical rules, it is preferable to determine the acceleration stop speed and the reacceleration start deflection angle by fuzzy reasoning from empirical rules that are close to the operating conditions.

In this way, when the acceleration stop speed is reached, the motion is switched to constant-velocity motion, and when the deflection angle reaches the re-acceleration start deflection angle, the acceleration is restarted, so that the suspended load deflection caused by the acceleration at the start of traverse Are dampened until the maximum traverse speed is reached.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

First, referring to FIG. 2, an embodiment of an automatic control device for a crane to which the steadying operation control method for a suspended load according to the present invention is applied will be described.

The apparatus 1 includes a detecting unit 3 for detecting the state of the suspended load 2, an arithmetic processing unit 4 for performing an arithmetic operation based on the information, and a trolley 5 for appropriately applying a driving force from a power source (not shown).
And the like.

The arithmetic processing unit 4 performs various adjustment operations that the driver has conventionally performed, that is, an operation in which the swing angle θ of the suspended load 2 becomes approximately 0 when the trolley 5 that has started to traverse reaches a constant speed. It is digitized for each operating condition and is input in advance as a rule map that is an empirical rule, and it can be taken out as operating data when necessary.
A known fuzzy controller (not shown) is mounted.

The detecting means 3 includes a tension sensor for detecting the tension of the suspension rope, a winding amount sensor for detecting the winding amount, and a known deflection angle sensor for detecting the deflection angle of the suspended load. By inputting these tension and winding amount into the arithmetic processing unit 4, the load M of the suspended load and the length L ₁ of the suspended rope are calculated.

The driving device 6 is formed such that when receiving signals from the arithmetic processing device 4 and the deflection angle sensor, the driving device 6 performs an appropriate comparison operation to perform a desired operation. From the driving device 6,
The signal is output in the form of an electric signal, and is sequentially transmitted to the trolley 5 via the electric motor 7, the speed reducer 8, and the drum 9.

Next, an embodiment of the present invention will be described as an operation of the above configuration.

As shown in FIG. 1 and FIG. 3, when the maximum traverse speed Vmax is selected by the cargo handling data and the traverse start command is input to the driving device 6, the control of the present invention is started.

First, from the cargo handling data, the winding target rope length L ₂ is input to the arithmetic processing unit 4, and the load M of the suspended load, the rope length L ₁ at the start of traverse, and the initial suspended load deflection angle θ ₀ are also input. It The arithmetic processing unit 4 determines the acceleration stop speed V ₁ and the reacceleration start deflection angle θ ₁ based on these pieces of information.
Then, when the traverse operation is started, the operation device 6 compares the speed V of the trolley 5 with the acceleration stop speed V _1, and when V = V ₁ , the operation device 6 performs the constant speed operation in which the speed is maintained. Switch.

After that, when the deflection angle θ detected by the deflection angle sensor reaches the re-acceleration start deflection angle θ ₁ , the acceleration operation is switched to again,
A predetermined maximum transverse speed Vmax is set. That is, in FIG.
The speed changes as shown in (a) to (d). Then, as shown in FIG. 1, the deflection angle θ of the suspended load
Occurs on the rear side in the transverse direction, increases by inertia even after switching to the acceleration stop speed V ₁ , reaches a peak, and then swings back to the front side in the transverse direction. The deflection angle at this time becomes 0 when the maximum transverse velocity Vmax is reached, that is, the deflection to the rear side in the transverse direction due to the re-acceleration operation and the deflection in the opposite direction due to inertia cancel each other out. , Will be re-accelerated.

In this way, not only the cargo handling data and the swing angle of the suspended load but also the rope length and the load are taken into consideration to determine the operation data, so that the swing can be surely performed. This also makes it possible to handle safely and smoothly even when there is a change in the suspension rope length such as when straddling an obstacle during traverse operation. Then, in determining the driving data, the rule of thumb is used so that it is extremely practical.

Here, the procedure for determining the acceleration stop speed V ₁ and the re-acceleration start deflection angle θ ₁ in this embodiment will be described with reference to FIG.

The prepared rule map has a certain maximum traverse speed Vmax.
Of the appropriate acceleration stop speed V ₁ corresponding to the rope length L ₁ at the start of traverse, the target rope length L _{2 for} winding, and the suspended load M under
And the re-acceleration start deflection angle θ ₁ are set in advance. For example,
Set L ₁ and L ₂ every 5m and M every 10Ton and combine
In each case, what value of V ₁ and angle θ ₁ should be used to set the deflection angle θ to 0 when Vmax is reached is written based on the driver's experience and computer simulation.

Then, when the data in the actual traverse operation is input, the rule close to the set numerical value related to the data is extracted, and the fitness μ is calculated by the membership function. As the membership function, for example, one that approximates the goodness of fit of the values before and after the set value in each rule by a triangular straight line is used. As a result of this calculation, as shown in FIG. 4 (f), the goodness of fit μ _b is obtained with respect to the output value (θ _b ) of the rule whose driving condition is closer, and the rule of the driving condition farther than that is used. Low fitness μ for output value (θ _a ).
_a . Then, as shown in FIG. 4 (g), correction (on the figure, truncated processing) is performed according to the calculated goodness of fit μ, the “center of gravity” of these unions is detected, and the fixed value “θ ₁ ” is obtained. To do.

With this, the rule of thumb can be extracted as continuous data.

Note that, in FIG. 4, the re-acceleration start deflection angle θ ₁ is illustrated, but the acceleration stop speed V ₁ is also determined by the same procedure.

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

(1) According to the method described in claim 1, the vibration of the suspended load can be reliably attenuated by the adjustment operation based on the empirical rule based on the acceleration stop speed and the reacceleration start deflection angle until the maximum traverse speed is reached. Therefore, appropriate control can be realized in the automatic operation of the crane.

(2) According to the method of claim 2, the rule of thumb can be extracted as continuous data.

[Brief description of drawings]

FIG. 1 is a comparison diagram of speed and deflection angle showing an embodiment of a steadying operation control of a suspended load according to the present invention, and FIG. 2 is a diagram showing a configuration for carrying out the method, FIG. Figure 3 is the first
FIG. 4 is a flow chart for explaining the application of fuzzy inference. In the figure, V ₁ is the acceleration stop speed, V max is the maximum traverse speed, and θ ₁ is the reacceleration start deflection angle.

Claims (2)

(57) [Claims] 1. An empirical adjustment operation in which a swing angle of a suspended load becomes substantially 0 when a trolley that has started traversing reaches a constant speed is quantified and set as an empirical rule for each of various operating conditions. Based on the empirical rule, the acceleration suspension speed and the reacceleration start deflection angle are determined from the detected weight of the suspended load and the hanging rope length, and the trolley that has been accelerated operates reaches the acceleration suspension speed. At that time, the operation is switched to a constant speed operation to maintain the speed, the deflection angle of the suspended load is detected by the detecting means during the constant speed operation, and when the detected value reaches the reacceleration start deflection angle, a predetermined value is determined. A method for controlling the steady motion of a suspended load, which comprises restarting an acceleration operation that reaches the maximum traverse speed of. 2. When the weight of the suspended load and the length of the hanging rope are operating conditions that are not empirical rules, the acceleration stop speed and re-acceleration start deflection angle are determined by fuzzy reasoning from empirical rules that are close to the operating conditions. The method for controlling the steady motion of a suspended load according to claim 1.