JP3355616B2 - Crane steady rest control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-sway control method for a suspension crane having a trolley and a hoist.

[0002]

2. Description of the Related Art A suspended crane generally has a trolley truck 1 traveling on rails 3 by wheels 2 as shown in FIG. 8, and the wheels 2 are mounted on a traveling motor mounted on the trolley truck 1. 11 is driven to rotate via a speed reducer 12. An electromagnetic brake 13 and a speed detector 14 for detecting the speed of the traveling motor 11 are attached to a rotating shaft of the traveling motor 11. A hoisting machine 4 having a hoisting drum 41 is installed on the trolley 1.
The hoisting drum 41 is rotationally driven by a hoisting motor 42 via a speed reducer 43. Hoisting motor 42
The rotating shaft has an electromagnetic brake 44 and a speed for detecting the motor speed.
A degree detector 45 is attached. A rope 5 is wound around the hoisting drum 41, and a suspended load 6 is suspended by the rope 5 via a hanging tool 51. The traveling speed control of the trolley 1 controls the traveling electric motor 11 by a traveling drive control device (not shown ). FIG.
Is a block diagram of the traveling drive control device. The speed command signal of the speed command device 21 is input to the linear command device 22 and detected by the ramp-shaped speed command _NRF and the speed detector 14 obtained therefrom. Motor generated through the element filter 26
The deviation from the machine speed signal N _MFB is input to a speed controller 23 having an integrator having a proportional gain A and a time constant τ _I , amplified, and outputs a torque command signal _TRF . Furthermore, input to the motor torque controller 24 which controls the motor torque a torque command signal T _RF at a primary delay time constant tau _T, controls the torque T _M of the driving motor 11, controls the speed of the moving electric motor 11 I do. The motor speed signal N _MFB is a driving motor.
11 is generated through a first-order lag element. 25 is a block representing the mechanical time constant tau _M of the driving motor 11, the N _M is the speed of the moving electric motor 11 (p.u). 27 is a block representing a dynamic model of the suspended load, and 28 is a block representing a model of the load torque T _L (pu) of the electric motor. In block 27, θ is the deflection angle (rad) of the rope 5. In the travel drive control unit in FIG. 10, the speed commander 21 controls the traveling speed of the trolley carriage 1 according to the ramp-like acceleration or deceleration speed command N _RF obtained by inputting a high-speed or low-speed speed command signal to the linear commander 22 by Is performed, a periodic swing of the suspended load occurs in accordance with the acceleration and deceleration of the trolley 1. The swing angle of the rope 5 increases as the traveling acceleration / deceleration of the trolley 1 increases. As a solution to this problem, conventionally, during acceleration / deceleration of the trolley cart, the operator manually changes the traveling speed of the trolley cart in accordance with the swing state of the suspended load to stop the periodic swing of the suspended load. Was. FIG. 11 shows the relationship between the speed command, the motor speed, the swing angle of the rope, and the motor torque. During the trolley bogie traveling acceleration / deceleration operation, a periodic swing of the suspended load occurs, and the trolley bogie becomes unstable. The variable speed characteristics are shown. The swing angle θ of the rope is represented by (°).

[0003]

However, in the above configuration, in order to stop the periodic swing of the suspended load, the operator of the crane performs the acceleration / deceleration operation of the traveling of the trolley truck while observing the state of the swing of the suspended load. Therefore, in order to perform remote operation or automatic operation, the traveling acceleration and deceleration of the trolley cart must be made very slow, and there is a drawback that the transport capacity of the crane is significantly reduced. SUMMARY OF THE INVENTION It is an object of the present invention to suppress a periodic swing of a suspended load caused by a traveling acceleration / deceleration operation of a trolley truck, and to enable automatic operation of a crane while maintaining a traveling speed of the trolley truck high.

[0004]

Means for Solving the Problems The present invention includes a driving motor for moving and driving the trolley carriage, proportional from the deviation signal of the speed command signal of the driving motor (N _RF0) and the motor speed signal (N _MFB) and A travel drive control device that calculates a torque command by an integrator or a speed controller having only a proportional gain, controls the torque of the travel motor by the torque command to control the speed of the travel motor, and a trolley truck. a hoisting motor for driving the hoisting machine has a hanger for suspending the suspended load to the tip of the rope winding up by the hoist, the suspension crane and a drive control device of the hoisting motor, suspended Of the suspended load directly
The traveling direction of the velocity V _LE of the suspended load as determined by the travel direction speed detector for determining the speed, and the set damping factor ([delta]), and the speed command signal (N _RF0), said motor speed signal (N _MFB) If, because the hoisting drum obtained from the speed detector of the hoisting motor rope length measurements up a suspended load and (L _E), the following _{equation, E RR1 = (N RF0 -N} MFB) V R / _{s- (2δ / ω E) V} LE _{However, ω E = (g / L} E) 1/2, V R is the trolley carriage speed corresponding to the driving motor rated speed, g is the gravitational acceleration, s
Calculates the position error (E _RR1 ) by the operation of the Laplace operator, amplifies it by a proportional integration amplifier or a proportional amplifier, and adds the obtained speed correction signal (N _RFDP ) to the speed command signal (N _RF0 ). Then, the speed of the traveling motor is controlled in accordance with the obtained traveling speed command signal (N _RF1 ).

[0005]

Next, the operation of the control device according to the method of the present invention for suppressing the periodic swing of the suspended load and the principle of suppressing the swing of the rope will be described. In FIG. 9, the traveling speed of the trolley cart is V ₁ (m / sec), and the length of the rope is L.
Assuming (m), a known equation of motion for determining the deflection angle θ (rad) of the rope is as shown in the following equation (1).

[0006]

(Equation 1)

[0007] relationship shown in the following equation (2) between the speed N _M of the trolley carriage travel speed V ₁ and the electric motor for running.

[0008]

(Equation 2)

By substituting equation (2) into equation (1), the following equation (3) is obtained.

[0010]

(Equation 3)

When the equation (3) is expressed by using the Laplace operator s, the following equation (4) is obtained.

[0012]

(Equation 4)

When θ (s) is obtained from equation (4), the following equation (5) is obtained.

[0014]

(Equation 5)

Equation (5) shows that the motion model of the swing angle of the rope in the block 27 in FIG. 1 is equivalent. t
= 0 and θ = 0, constant acceleration α (pu / sec)
When θ (t) for accelerating the traveling electric motor is calculated by the equation (4), the following equation (6) is obtained.

[0016]

(Equation 6)

Equation (6) shows that the deflection angle θ oscillates. When the trolley truck starts accelerating, the vibration starts, and even after the acceleration ends, the force for attenuating the periodic rope swing of the suspended load is air resistance or the like, and it takes a considerable time until the swing stops. The traveling position of the suspended load in the traveling direction is x (m) with the trolley bogie traveling start point as the origin, and the swing angle θ (rad) of the rope is small, so if it approximates sin θ ≒ θ, Equation (7) holds.

[0018]

(Equation 7)

Here, L is the length of the lifting rope.
(7) of the θ is substituted into the equation (4), if organized about the x, equations for the position x of the suspended load in the running direction is obtained as the following equation (8).

[0020]

(Equation 8)

Here, it is assumed that ω = (g / L) ^1/2 .
Equation (8) shows that the position X of the suspended load in the traveling direction is also a function that changes periodically. To dampen such a movement where the position of the suspended load changes periodically,
(8) Since the right side may be controlled trolley carriage traveling motor speed N _M to contain the function of -sx of formula, the right-hand side of (8), divided as the right side of the following equation (9) .

[0022]

(Equation 9)

[0023] However, [delta] is the damping coefficient setting value of movement of deflection of the suspended load, N _M0 is the velocity component proportional to the speed command N _RF0 output by the speed command unit in the motor speed N _M. When N _M0 in Expression (9) is replaced with N _RF0 , the following Expression (10) is obtained.

[0024]

(Equation 10)

Sx in the third term on the left side of the equation (10) is a differential signal of the position x of the suspended load, and is equal to the moving speed V _{L of the} suspended load. Therefore, sx is replaced with V _L , and the left side is E _RR. Then, the following equation (11) is obtained.

[0026]

[Equation 11]

The first term on the right side of the equation (11) indicates a position command value because the speed command signal of the traveling motor is integrated over time. The second term on the right-hand side indicates the position of the trolley cart because the speed of the traveling motor is integrated over time. The third term on the right side is a signal proportional to the moving speed of the suspended load. E _RR of the left side indicates the position error from the optimum position condition of suppressing the trolley carriage runout suspended load shown in (10). In (11), replacing the N _M of the second term on the moving electric motor feedback signal N _MFB, replacing the V _L of the third term to the moving speed detection signal V _LE of the suspended load, further, the third term from length measurements of the lifting rope omega L _E and the gravitational acceleration g, replacing the vibration of the angular velocity omega _E of suspended load computed by the following equation (12), (11) formula is shown in (13) The position error E _RR1 from the optimal position condition of the trolley truck that suppresses the swing of the suspended load is obtained by rewriting as in the expression.

[0028]

(Equation 12)

[0029]

(Equation 13)

In order that the position error signal E _RR1 approaches 0,
If the traveling speed command signal is corrected to control the speed of the traveling electric motor, a damping element is generated in the movement of the swing of the suspended load,
Periodic swing of the suspended load can be suppressed.

[0031]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 is a block diagram of a traveling drive control device for a trolley having a speed controller according to the present invention. Note that the same components as those in FIG. 10 described in the description of the conventional example have the same names and the same reference numerals, and description thereof will be omitted. First, a first embodiment of the present invention will be described with reference to FIG. Introduction speed commander 2
A signal N _RF0 that is output through the linear command device 22
In addition the damping control speed command correction signal N _RFDP to give al
Filter 2 having a first-order lag element from signal N _RF1
Subtract the motor speed signal N _MFB via 6 . When the deviation between the speed command N _RF1 and the motor speed signal N _MFB is input to the speed controller 23, a signal obtained by multiplying the deviation signal by a proportional gain A and a signal obtained by integrating the signal with a time constant τ _I are added. The output signal is output as a torque command signal _TRF . When the speed controller 23 has only the proportional gain A, a signal obtained by multiplying the deviation signal by A is output to the torque controller 24 as a motor torque command signal _TRF . The torque controller 24 controls the motor torque T _M with the first-order lag element τ _T according to the torque command signal T _RF . 30 is the angular frequency ω _E of the swing of the suspended load
An angular velocity computing unit of the shake calculates the speed detector 45
The angular frequency ω _E is calculated by the equation (12) from the measured length (L _E ) of the rope from the hoisting drum to the suspended load obtained from the above.

Next, the operation of the damping controller 29 will be described. The damping controller 29 calculates the equation (13) based on the signal N _RF0 , the motor speed signal N _MFB , the angular frequency calculation signal ω _E , the speed V _{LE in} the traveling direction of the suspended load attached to the hanging tool 51, and the damping coefficient set value δ. According to the position error E
Calculate _RR1 . The traveling direction speed V _LE of the suspended load is
The traveling direction speed that directly determines the speed of the suspended load
Determined by the detector. The position error E _RR1 is a position error from an optimal position of the trolley truck for suppressing the shake.
When this position error E _RR1 is amplified by a proportional integration amplifier constituted by a proportional gain G and an integration time constant τ _DP , a speed correction signal N _RFDP is obtained. A traveling speed command signal N _RF0 output from the speed command device 21 via the linear command device 22
The driving speed command signal N _RF1 (pu) is obtained by adding the correction signal N _RFDP to (pu) and the motor speed signal N _MFB.
If you enter a deviation (p.u) to the speed controller 23, the speed controller 23, the motor speed N _M performs speed control so as to follow to the traveling speed command signal N _RF1. By this control, the swinging motion of the suspended load is damped by the set damping coefficient δ, and the periodic swinging of the suspended load is suppressed.

Next, a second embodiment will be described with reference to FIG. This embodiment, in place of the running direction of the velocity V _LE of the suspended load in the first embodiment, acceleration in the traveling direction of the suspended load
acceleration alpha _VLE by the suspended load speed calculator 36 by using the alpha _VLE
Is calculated, and the position error E _RR1 is calculated using the obtained traveling direction speed V _LE1 of the suspended load, and is controlled in the same manner as in the first embodiment.

Next, a third embodiment will be described with reference to FIG. This embodiment is based on the traveling of the suspended load in the first embodiment.
Instead of the speed _VLE of the speed, the motor of the traveling speed control device
Speed signal N _MFB rope length measurements L _E and the trolley on the dolly in
The deflection angle detected by the deflection angle detector 33 of the provided rope
From the signal θ _E , the traveling direction of the suspended load according to the following equation (14)
_Is obtained and the position error E _RR1 is calculated and controlled using the obtained speed V _LE2 in the same manner as in the first embodiment.

[0035]

[Equation 14]

Next, a fourth embodiment will be described with reference to FIG. In the crane steady rest control method shown in the first embodiment , a plurality of damping coefficient set values δ _{1 to} δ are set by the damping coefficient switch 34 in accordance with the operating state of the traveling motor.
It switches the switch SW ₁ to SW _n from among _n, selects and outputs any one of the damping coefficient setting value signal.
When the damping coefficient setting signal selected by the damping coefficient switch 34 is input to the damping coefficient switching controller 35, a damping coefficient setting value δ is generated via the primary delay element by the selected damping coefficient setting signal .
For example, when the output signal of the damping coefficient switch 34 is switched from δ ₁ to δ ₂ , the output signal of the damping coefficient switch 34 changes instantaneously from δ ₁ to δ _2. As a result of the gradual change of the signal on the side, the _steadying control of the crane can be stably performed without a direct delay in the calculation of the speed correction signal _NRFDP of the damping control by the damping controller 29. As shown in FIGS. 5 and 6 as the fifth and sixth embodiments, the damping coefficient switch 34 and the damping coefficient switch adjuster 35 described in the fourth embodiment are added to the second and third embodiments. Is provided by the damping coefficient switch 34 from among a plurality of damping coefficient setting values δ _{1 to} δ ₂ .
The switches SW _{1 to} SW _n are switched to select any one damping coefficient set value signal, and the damping coefficient set signal selected by the damping coefficient switch 34 is input to the damping coefficient switch adjuster 35, and the selected signal is selected. The damping coefficient set value signal may be generated as a damping coefficient set value δ via a first-order lag element. FIG. 7 shows the driving characteristics of the trolley truck when the vibration suppression method of the present invention corresponding to FIG. 11 of the conventional example is applied. Here, it can be seen that the swing of the suspended load is sufficiently suppressed and the trolley bogie has a stable variable speed characteristic as compared with the characteristic of the conventional example shown in FIG.

[0037]

As described above, according to the present invention, since the periodic swing of the suspended load generated during the acceleration and deceleration of the trolley truck is suppressed, the swing can be reduced by the manual operation of the crane operator. There is no need to stop the trolley, so that the trolley truck can run at high speed, and there is an effect that the transfer capacity by the automatic operation of the crane can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a traveling drive control device according to the present invention.

FIG. 2 is a block diagram showing a second embodiment of the traveling drive control device of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the traveling drive control device of the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the traveling drive control device of the present invention.

FIG. 5 is a block diagram showing a fifth embodiment of the traveling drive control device of the present invention.

FIG. 6 is a block diagram showing a sixth embodiment of the traveling drive control device of the present invention.

FIG. 7 is an acceleration / deceleration characteristic diagram of the traveling drive control device for the trolley truck according to the present invention.

FIG. 8 is a configuration explanatory view of a suspended crane that runs a trolley truck on which a hoist is mounted.

FIG. 9 is an explanatory diagram showing a mechanical relationship that the trolley carriage traveling device receives due to the load of the suspended load.

FIG. 10 is a block diagram showing a conventional traveling drive device.

FIG. 11 is an acceleration / deceleration characteristic diagram of a traveling drive device of a conventional example.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 trolley cart, 11 traveling motor, 14 speed detector, 2 wheels, 3 rails, 4 hoisting machine, 41 hoisting drum, 42 hoisting motor, 45 speed detector, 21
Speed commander, 22 linear commander, 23 speed controller,
24 motor torque controller, 25 mechanical time constant of traveling motor, 26 filter , 29 damping controller,
30 run-out angular velocity calculator , 31 traveling load speed detector, 32 load traveling direction acceleration detector, 33 run-out
Angle detector , 34 Damping coefficient switch, 35 Damping coefficient switch adjuster, 36 Lifting speed calculator

Claims (4)

(57) [Claims] 1. A traveling motor for driving a trolley truck, and has only a proportional and integrator or a proportional gain from a deviation signal between a speed command signal (N _RF0 ) and a motor speed signal (N _MFB ) of the traveling motor. calculates a torque command signal (T _RF) by the speed controller, the torque command signal (T _RF)
A traveling drive control device that controls the torque of the traveling electric motor by controlling the torque of the traveling electric motor, and a hoisting electric motor that drives a hoisting machine provided in the trolley cart;
In a suspension crane having a suspender for suspending a suspended load at the tip of a rope wound by the hoist and a drive control device for the hoisting motor , the speed of the suspended load is directly obtained by attaching to the suspender. Travel direction speed
Speed V in the traveling direction of the suspended load obtained by the degree detector
_LE , the set damping coefficient (δ), the speed command signal (N _RF0 ), the motor speed signal (N _MFB ), and the load from the hoist drum obtained from the speed detector of the hoisting motor. since up to the rope length measurements (L _E), the following _{equation, E RR1 = (N RF0 -N} MFB) V R / s- (2δ / ω E) V LE _{However, ω E = (g / L} E ) ^1/2, V _R is the trolley carriage speed corresponding to the driving motor rated speed, g is the gravitational acceleration, s is the Laplace operator, the calculation of the position error from the optimum running position of the trolley carriage ( E _RR1 ), the position error (E _RR1 ) is amplified by a proportional integration amplifier or a proportional amplifier, and the amplified speed correction signal (N _RFDP ) is added to the speed command signal (N _RF0 ). control the speed of the traveling motor in accordance with the addition to the resulting running speed command signal (N _RF1) Steadying control method of the crane which is characterized in that. 2. A speed signal (V _LE1 ) obtained by time-integrating a detection signal (α _VL ) of the acceleration of the suspended load in the traveling direction instead of the speed (V _LE ) of the suspended load in the traveling direction. 2. The method according to claim 1, wherein the position error (E _RR1 ) is calculated using the following equation. 3. A motor speed signal (N _MFB ), a swing angle signal (θ _E ) detected by a rope swing angle detector, and the winding speed, instead of the speed (V _LE ) in the traveling direction of the suspended load. length measurement value of the rope from the hoist drum obtained from the speed detector of the above electric motor to said suspended load from (L _E), the following _{calculation, V LE2 = V R N MFB} -sL E θ E And calculating the position error (E _RR1 ) using the obtained velocity signal V _LE2.
The method for controlling the steady rest of the crane as described in the above. 4. A signal which is arbitrarily switched to any one of a plurality of damping coefficient setting values according to an operation state of the traveling motor and is selected via a first-order lag element. The method according to any one of claims 1 to 3, wherein the signal is a final damping coefficient set value.