JP6684442B2 - Control method and control device for suspension crane - Google Patents

Description

  The present invention relates to a control device and a control method for a suspension crane that carries out cargo handling work by traversing a trolley in a harbor, a steel mill, various factories, etc. Control technology for this.

Generally, in cargo handling work using a suspended crane, steady rest control is required to make the suspended load accurately reach the target position in a short time and to reduce the swing of the suspended load during traveling or when the trolley is stopped. .
In order to perform the above steady rest control, various control methods have been developed so far, and particularly in recent years, electric steady rest control by computer control has attracted attention.

  The electric steady rest control calculates a speed pattern that makes the swing of the suspended load zero at the end of acceleration / deceleration of the trolley, drives the trolley according to this speed pattern, and the swing amount (distance) of the suspended load. There is a method of detecting the deflection angle and performing feedback control on the drive system of the trolley.

Here, FIG. 6 shows the steady rest control device described in Patent Document 1 as an example of the former method based on the speed pattern.
This steady rest control device drives the trolley device 70 in accordance with a predetermined speed pattern so as to set the swing angle θ of the suspended load 70d to zero while the traveling trolley 70b is running and stopped, and starts the suspended load 70d at the starting point position in the shortest time. It is intended to be transported to the target position from.

Hereinafter, an outline of the steady rest control according to this conventional technique will be described.
6, the input device 20 is input with travel conditions such as the length l of the rope 70c supporting the suspended load 70d, the travel distance L of the trolley 70b, the maximum acceleration α _max of the trolley 70b, and the maximum speed V _max . To the output side of the input device 20, a speed pattern calculation device 30, a load shake angle calculation device 40, and an evaluation reference calculation device 80 are connected.

  The speed pattern calculation device 30 includes, for example, five kinds of speed pattern calculation units 30a to 30e. The calculation unit 30a has a speed pattern 1 and the calculation unit 30b has a speed pattern 2, for example, the calculation units 30a to 30e. , The speed patterns 1 to 5 of the trolley 70b are set. These calculation units 30a to 30e calculate the acceleration switching time and the acceleration change amount according to the traveling conditions such as the rope length 1 and the traveling distance L output from the input device 20 for each speed pattern.

FIG. 7 shows an example of speed patterns 1 to 5.
The speed patterns 1 and 2 are so-called trapezoidal speed patterns. V _c is a general set speed, V _max is a maximum speed, t ₁ and t ₂ are acceleration switching times, and t ₃ is a stop time. The speed pattern 3-5, the acceleration in the acceleration section and the deceleration section, deceleration, an example of combining a constant velocity appropriate, t _af the acceleration change time, the t _f shows the stop time.

Returning to FIG. 6, the load shake angle calculation device 40 includes load shake angle calculation units 40a to 40e corresponding to the speed patterns 1 to 5 (speed pattern calculation units 30a to 30e), respectively.
These load deflection angle calculation units 40a to 40e apply the state transition method using the acceleration switching time and the acceleration change amount of the speed patterns 1 to 5 immediately before the operation of the trolley 70b, thereby accelerating and decelerating sections and constants. The deflection angle θ in the high speed section is calculated.

The evaluation reference calculation device 80 calculates the speed pattern 1 based on the acceleration output from the speed pattern calculation device 30, the acceleration change amount, the acceleration switching time, the traveling time, and the deflection angle θ output from the load deflection angle calculation device 40. By evaluating 5 to 5, a speed pattern having a small deflection angle θ and capable of traveling to the target position in the shortest time is determined, and a selection signal indicating the speed pattern is output to the speed pattern selection device 50.
The speed pattern selection device 50 outputs one speed pattern selected according to the selection signal to the speed control device 60.

  The speed control device 60 operates the difference circuit 60a, the compensation circuit 60b, and the amplification circuit 60c to feed back the electric motor 60d so that the speed detection value by the speed detector 60e follows the input speed pattern (speed command). The trolley 70b is driven by controlling and transmitting the driving force of the electric motor 60d to the gear mechanism 70a of the trolley device 70. As a result, the trolley 70b is allowed to reach the target position while suppressing the deflection angle θ of the suspended load 70d during traveling and when the trolley 70b is stopped.

  In this prior art, the rope length l is constant during traverse of the trolley 70b, the traveling is started from the time when the acceleration of the trolley 70b is zero, and the run-out friction and run-out angle θ are sufficiently small. It is a condition for analysis.

Japanese Patent Publication No. 2-44757 (Page 2, right column, line 23 to page 3, right column, line 24, FIG. 2, FIG. 3, etc.)

Now, hanging hoisting height of the load 70d X _h, when the amount of movement of the trolley 70b and X _t, the cargo handling operation by hanging crane, in order to reach the target position in a short time the suspended load 70d, FIG. 8 ( As shown in b), it is desirable to control the suspended load 70d so that the suspended load 70d follows the locus of the starting point O → A → B → C → D → E while simultaneously performing the lifting and lowering of the suspended load 70d and the traverse of the trolley 70b.
However, in the steady rest control device according to Patent Document 1, the rope length l is constant during the traverse of the trolley 70b, and therefore the vertical movement and the transverse movement are not planned to be performed at the same time. As a result, the suspended load 70d is forced to follow a locus of starting points O → F → G → E as shown in FIG. 8A, resulting in extremely inefficient operation.

Here, even if the rope length l during traverse is constant, as shown in FIG. 9A, when the operation is interrupted during constant speed traveling in which the speed v _{T of the} trolley 70b is constant, If the trolley 70b is decelerated and stopped using the speed pattern of the technique, the swing angle θ of the suspended load 70d at the time of stop can be converged to zero.
However, as shown in FIG. 9B, when the traveling operation is interrupted while the suspended load 70d is largely swinging during acceleration of the trolley 70b, if the above-described speed pattern is applied, the precondition is not satisfied, and thus the swing angle is increased. θ may not converge to zero and may oscillate.

  Therefore, a problem to be solved by the present invention is to provide a suspension system capable of suppressing the swing of the suspended load when the trolley is stopped even when an operation interruption request is generated while simultaneously performing the lifting of the suspended load and the traverse of the trolley. A crane control method and a control device are provided.

In order to solve the above-mentioned problems, the control method according to claim 1 is a control method for a suspension crane that conveys a suspended load suspended from a trolley by a rope from a starting point position to a target position. In a control method of a suspension crane capable of lifting operation of the suspended load,
While stopping the lifting operation of the suspended load when the operation suspension signal of the crane is generated during traveling of the trolley,
A swing amount of the suspended load and an amount obtained by dividing the swing speed of the suspended load by the natural angular velocity of the suspended load are provided on each axis, and the first circular orbit during constant speed traveling of the trolley and the A phase plane having a second circular orbit during acceleration / deceleration of the trolley,
The deceleration start timing of the trolley and the deceleration of the trolley are obtained from the locus on the phase plane so that the shake amount and the shake speed become zero when the trolley is stopped, and according to the deceleration start timing and the deceleration. The deceleration of the trolley is started.

  The control method according to claim 2 is the control method for a suspended crane according to claim 1, wherein the deceleration is performed at one of intersections of the first circular trajectory and the second circular trajectory in the phase plane. This is the start timing.

  The control method according to claim 3 is the control method for the suspension crane according to claim 1 or 2, wherein the deceleration is based on the natural angular velocity, the trolley velocity, and the phase on the phase plane. It is what you want.

The control device according to claim 4 is a control device for a suspension crane that conveys a suspended load suspended from a trolley by a rope from a starting point position to a target position, the traverse device for traversing the trolley, and the suspended load. In a suspension crane control device having a lifting device for lifting and lowering,
At least a trolley target speed, a trolley acceleration, and a rope length, and a speed command generation unit that generates a sequential speed command of the trolley,
An operation-interruption speed command generation unit that generates an operation-interruption speed command for the trolley when an operation-interruption signal for the crane is generated at any timing;
A speed command switching unit that switches and outputs the sequential speed command to the speed command at the time of operation interruption when the operation interruption signal is generated,
A speed control unit that generates a speed control signal according to the sequential speed command or the speed command at the time of operation interruption;
A trolley mechanical system including the lifting device, the traverse device, and the trolley driven according to the speed control signal;
A shake sensor for detecting a shake amount of the suspended load,
When the operation interruption signal is generated during traveling of the trolley, while stopping the lifting operation of the suspended load via the speed control unit,
The speed command generation unit at the time of operation interruption,
A deflection plane of the suspended load and an amount obtained by dividing the deflection velocity of the suspended load by the natural angular velocity of the suspended load constitute a phase plane having each axis, and the deflection amount and the deflection speed when the trolley is stopped. So as to be zero, the deceleration start timing of the trolley and the deceleration of the trolley are obtained from the locus on the phase plane, and the speed command for starting the deceleration of the trolley is started according to the deceleration start timing and the deceleration. It is generated as a speed command during interruption.

  According to the present invention, even when a crane operation interruption request is generated while simultaneously performing lifting and lowering of a suspended load and traverse of the trolley, the timing and deceleration at which the deceleration of the trolley is started are set as the swing amount of the suspended load. Also, by obtaining it based on the trajectory on the phase plane regarding the shake velocity, it is possible to control so that the shake amount of the suspended load when the trolley is stopped becomes zero.

It is a block diagram showing a control device concerning an embodiment of the present invention. It is a conceptual block diagram of the trolley mechanical system in FIG. It is a figure for demonstrating the function of the shake sensor in FIG. FIG. 7 is a phase plan view regarding the shake amount x _L of a suspended load and (d / dt) (x _L / ω). FIG. 7 is a phase plan view regarding the shake amount x _L of a suspended load and (d / dt) (x _L / ω). It is a block diagram of the steady rest control apparatus described in patent document 1. It is explanatory drawing of the speed pattern in the prior art shown in FIG. It is a figure which shows the locus | trajectory of the suspended load in crane cargo handling operation. It is a figure which shows the relationship between the trolley speed at the time of the traveling operation interruption of a trolley, and the swing load swing angle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a control device for a suspended crane according to this embodiment. This control device is composed of a speed command generation unit 1, a speed command generation unit during operation interruption 2, a speed command switching unit 3, a speed control unit 4, a trolley mechanical system 5, and a shake sensor 6.

The speed command generator 1 receives the trolley target speed V _T , the trolley acceleration α _T , and the rope length 1 as inputs, and generates and outputs a trolley sequential speed command v ′ _T. During acceleration of the trolley, the trolley acceleration α _T is adjusted to sequentially change the speed command v ′ _T until the trolley speed v _T reaches the trolley target speed V _T.
At this time, the speed command generation unit 1 determines the natural angular velocity (natural angular frequency) ω of the rope and the loading system from ω = √ (g / l) (g is the gravitational acceleration) from the rope length 1 as in Patent Document 1. ), And generate a speed pattern (sequential speed command v ′ _T ) combining the acceleration / deceleration section and the constant speed section of the trolley, the swing of the suspended load at the time when the trolley reaches the target speed V _T is zero. Can be

The operation-interruption speed command generation unit 2, the speed command switching unit 3, and the speed control unit 4 will be described later. Next, the configurations and functions of the trolley mechanical system 5 and the shake sensor 6 will be described.
FIG. 2 is a conceptual configuration diagram of the trolley mechanical system 5.
In FIG. 2, 7 is a trolley that travels along a traverse path 8, 9 is a suspended load (including a spreader for holding the suspended load, a head block, etc.), 12 is a rope, and 10 is a lift for moving the suspended load 9 up and down. A device (hoisting / lowering device) 11 is a traverse device for traversing the trolley 7. The elevating device 10 and the traversing device 11 are mainly composed of an electric motor, a speed reducer, a rope winding drum, and the like.

FIG. 3 is a diagram for explaining the function of the shake sensor 6.
The shake sensor 6 has, for example, an optical detection means arranged on the trolley 7, and detects the shake amount (distance) x _L or the shake angle θ of the hanging load 9 with reference to the vertical line. In this embodiment, the description will be continued assuming that the shake sensor 6 detects the shake amount x _L.

Returning to FIG. 1, the speed command generator 2 at the time of motion interruption includes the sequential speed command v ′ _T output from the speed command generator 1, the crane motion interrupt signal S generated at an arbitrary timing, and the shake sensor 6. Based on the shake amount x _L of the suspended load 9 detected by the above, the speed command v ′ _S during operation interruption is generated.

Next, generation of the speed command v ′ _S at the time of operation interruption will be described.
The shake amount x _L of the suspended load 9 changes according to Formula 1 based on the pendulum motion equation when the trolley 7 is moving at acceleration α _T.

In addition, when Formula 1 is expanded, it becomes a circle equation shown in Formula 2.

Here, in FIG. 4, the deflection amount x _L of the suspended load 9 is taken as the vertical axis, and the deflection velocity (dx _L / dt) is divided by the angular velocity ω (d / dt) (x _L / ω) FIG. 3 is a phase plan view with an axis, conceptually showing the locus of the suspended load 9.
In FIG. 4, when the trolley acceleration α _T is zero (when traveling at a constant speed), the locus of the suspended load 9 follows the circular orbit A centered at the origin (0, 0) in the polar coordinate system and has a declination θ. = Ωt, the vehicle moves at an angular velocity ω, and when the trolley acceleration α _T is constant, it moves along a circular orbit B centered on the point (0, α _T / ω ² ).

When the operation interruption signal S is generated during acceleration of the trolley 7, the route a → b → c is followed, and when the operation interruption signal S is generated while the trolley 7 is traveling at a constant speed, b → Follow the route c. In any case, in order to set the shake amount x _L of the suspended load 9 to zero, the trolley acceleration (deceleration) α _T is given at a predetermined timing so that the locus passes through the origin (0, 0), and , It is necessary that the trolley speed v _T becomes zero at the origin (0,0).

Here, it will be described at what timing the zero or a constant value is given as the trolley acceleration α _T to make the shake amount x _L zero. Since it is premised that the lifting / lowering operation of the suspended load 9 is stopped when the operation interruption signal S is generated, the change in the rope length 1 can be ignored.

It is known that if only the trolley 7 is allowed to traverse without raising or lowering the suspended load 9, the acceleration α _T that should be applied during deceleration should be equal to that during acceleration, but the trolley 7 should be raised while the suspended load 9 is being rolled up. It may be moved.
Therefore, as shown in FIG. 4, it is assumed that the trolley 7 is traveling at a constant speed v _T and the operation interruption signal S is generated when the locus on the phase plane is the circular orbit A. In this case, The deceleration α _T and the deceleration start timing to be given to No. 7 will be described. In FIG. 4, (π-z) is the phase when the deceleration start timing is viewed in polar coordinates, and z = ωv _T / 2α _T.

First, Expression 3 is established from the triangle having the origin (0, 0), the point (0, α _T / ω ² ) and the deceleration start timing (the intersection of the circular trajectories A and B) as vertices in FIG.

If ωv _T / 2α _T = z is set in Expression 3, Expression 4 is obtained, and z needs to satisfy Expression 5.

In the range of z = 0 to π, (sinz / z) in Equation 5 is a monotonically decreasing function. Therefore, a function for obtaining this inverse function is prepared, z is calculated, and further, the deceleration to be given to the trolley 7. α _T is calculated by ω v _T / 2α _T = z.

Next, regarding the deceleration start timing of the trolley 7, as shown in FIG. 5, while the phase is (π-z) or less, the vehicle travels at a constant speed according to the trajectory b, and when the phase reaches (π-z). It is understood that it is sufficient to shift to the locus c and switch to deceleration.
When the operation interruption signal S is generated at an arbitrary timing during acceleration of the trolley 7, it is observed around the origin (0, 0) using the shake amount x _L and the shake velocity (dx _L / dt) immediately before that. The initial phase θ ₀ and the radius r are obtained, the acceleration of the trolley 7 is interrupted, the vehicle is run at a constant speed by the natural angular velocity ω until the phase reaches (π-z), and then the phase reaches (π-z). Just switch to deceleration at that point.

Further, when the gravitational acceleration is g, the natural angular velocity ω can be sequentially calculated by the following equation 6 using the rope length 1 as described above even when the height of the suspended load 9 changes. Is. Accordingly, even when the operation interruption signal S is generated while the lifting load 9 is being raised and lowered and the trolley 7 is being traversed at the same time, the deceleration α _T and the deceleration start timing to be given to the trolley 7 can be appropriately obtained. .

The speed command switching unit 3 in FIG. 1 outputs the speed command v ′ _T as the speed command v ′ as it is during normal operation, but when the crane operation interruption signal S is input, the speed command switching unit 3 outputs the speed command v ′ sequentially. Instead of _T , the speed command v ′ _S at the time of operation interruption is selected and output as the speed command v ′. The speed command v'corresponds to the speed pattern including information such as the deceleration of the trolley 7 and the deceleration start timing described above. When the operation interruption signal S is input, the operation of the lifting device 10 is stopped as described above.

The speed control unit 4 generates a speed control signal for controlling the lifting device 10 and the traverse device 11 of the trolley mechanical system 5 in accordance with the speed command v ′ input from the speed command switching unit 3.
In particular, when the operation interruption signal S is generated, the operation of the lifting device 10 is stopped, and the speed control signal is generated according to the deceleration α _{T of the} trolley 7 and the deceleration start timing included as information in the operation interruption speed command v ′ _S. Then, the operation of the traverse device 11 is controlled by this speed control signal to decelerate and stop the trolley 7.

Regarding the deceleration α _T and the deceleration start timing of the trolley 7, the locus on the phase plane passes through the origin (0, 0) in FIGS. 4 and 5, and the trolley velocity v _T becomes zero at the origin (0, 0). Therefore, the shake amount x _L of the suspended load 9 when the trolley 7 is stopped can be made zero.

Although the above-described embodiment is a combination of constant speed traveling (a state of waiting for deceleration timing) and deceleration traveling, the trajectory on the phase plane passes through the origin and the trolley speed v is set at the origin. _{As long as T} is zero, constant speed traveling, deceleration traveling, and acceleration traveling may be combined as appropriate.

1: Speed command generation unit 2: Speed command generation unit during operation interruption 3: Speed command switching unit 4: Speed control unit 5: Trolley mechanical system 6: Shake sensor 7: Trolley 8: Traverse track 9: Suspended load 10: Lifting device 11: Traverse device 12: Rope

Claims (4)

A control method for a suspension crane that conveys a suspended load suspended from a trolley by a rope from a starting point position to a target position, in a control method for a suspended crane capable of traversing operation of the trolley and lifting operation of the suspended load. ,
While stopping the lifting operation of the suspended load when the operation suspension signal of the crane is generated during traveling of the trolley,
A swing amount of the suspended load and an amount obtained by dividing the swing speed of the suspended load by the natural angular velocity of the suspended load are provided on each axis, and the first circular orbit during constant speed traveling of the trolley and the A phase plane having a second circular orbit during acceleration / deceleration of the trolley,
The deceleration start timing of the trolley and the deceleration of the trolley are obtained from the locus on the phase plane so that the shake amount and the shake speed become zero when the trolley is stopped, and according to the deceleration start timing and the deceleration. A method for controlling a suspension crane, comprising decelerating the trolley. The method for controlling a suspended crane according to claim 1,
A method for controlling a suspended crane, wherein one of the intersections of the first circular orbit and the second circular orbit on the phase plane is set as the deceleration start timing. The control method for the suspension crane according to claim 1 or 2,
A method for controlling a suspended crane, wherein the deceleration is obtained based on the natural angular velocity, the velocity of the trolley, and the phase on the phase plane. A control device of a suspension type crane that conveys a suspended load suspended from a trolley by a rope from a starting point position to a target position, of a suspension type crane having a traverse device that traverses the trolley and an elevating device that elevates and lowers the suspended load. In the control device,
At least a trolley target speed, a trolley acceleration, and a rope length, and a speed command generation unit that generates a sequential speed command of the trolley,
An operation-interruption speed command generation unit that generates an operation-interruption speed command for the trolley when an operation-interruption signal for the crane is generated at any timing;
A speed command switching unit that switches and outputs the sequential speed command to the speed command at the time of operation interruption when the operation interruption signal is generated,
A speed control unit that generates a speed control signal according to the sequential speed command or the speed command at the time of operation interruption;
A trolley mechanical system including the lifting device, the traverse device, and the trolley driven according to the speed control signal;
A shake sensor for detecting a shake amount of the suspended load,
When the operation interruption signal is generated during traveling of the trolley, while stopping the lifting operation of the suspended load via the speed control unit,
The speed command generation unit at the time of operation interruption,
A deflection plane of the suspended load and an amount obtained by dividing the deflection velocity of the suspended load by the natural angular velocity of the suspended load constitute a phase plane having each axis, and the deflection amount and the deflection speed when the trolley is stopped. So as to be zero, the deceleration start timing of the trolley and the deceleration of the trolley are obtained from the locus on the phase plane, and the speed command for starting the deceleration of the trolley is started according to the deceleration start timing and the deceleration. A suspension crane control device, which is generated as a speed command during interruption.

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