JPH08324961A - Swing and position control method for crane - Google Patents

Abstract

PURPOSE: To improve an influence of disturbance, reduction of a calculating load and bracing controllability, by representing a relational expression, between a speed at acceleration/deceleration and the lapse of time after starting, by a circular arc formula, and performing speed control in accordance with a pattern expressed by the circular arc formula at acceleration/deceleration time. CONSTITUTION: In an encoder 5, a rotational speed of a driven wheel 4 is converted into a pulse, to detect a position of a crane. A detected actual position is compared with a target position, to input this position deviation to a time axis arithmetic block 10. Further a command speed, output to be based on a speed pattern output from a calculation pattern block 11, is corrected to be input as a speed command to an inverter 1. By differentiating an actual position output from the encoder 5, an actual speed is obtained to be fed back to the speed command in the inverter 1 through a PID controller 12. That is, a residual distance with the target position is measured to be based on an output of the encoder 5, and in accordance with this measuring, a circular arc formula is correction calculated in real time, to execute positioning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the runout and position of a suspended wire crane equipped with a traverse and traveling device equipped with a variable speed control mechanism such as an inverter.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 1-281293 discloses that, while hoisting or lowering a rope for suspending a load when operating a suspension crane, the crane is run to steady a suspended load. During acceleration, acceleration-deceleration-
There is disclosed a method of performing steady rest by repeating a plurality of traveling patterns of acceleration and deceleration-acceleration-deceleration during deceleration.

Japanese Patent Laid-Open No. 1-281294 discloses a target speed and an allowable acceleration / deceleration speed during traveling and traversing, a target hoisting or lowering speed, a wire length at the time of starting traveling and traversing, and a hanging speed. Based on the position of the center of gravity of the load,
A steady rest control method for calculating an operation pattern by linear control by calculating a phase locus is disclosed.

FIG. 8 is an explanatory view of the linear control, where m is the mass of the load [kg], l is the wire length [m], θ is the wire deflection angle [rad], and g is the gravitational acceleration [m]. / Sec
² ]

The equation of motion is expressed by the following equation. However, “′” represents the first derivative of time, and “″” represents the second derivative of time.

(L ₀ + l′ t) θ ″ + 2l′θ ′ + g θ = −x ″ Initial and final conditions during acceleration x ′ (0) = 0, θ (0) = 0, θ ′ (0) = 0 → x '(0) = v, θ (0) = 0, θ' (0) = 0 Initial and final conditions during deceleration x '(0) = v, θ (0) = 0, θ' ( 0) = 0 → x ′ (0) = 0, θ (0) = 0, θ ′ (0) = 0 There are two methods to solve this equation, the method based on the phase plane trajectory and the method based on the maximum principle. According to the method using the phase plane locus, which is easy to understand and a solution can be easily obtained, the following relationship is obtained.

(Θ + x ″ / g) ² + (θ ′ / ω) ² = (x ″ / g) ² The phase plane locus obtained by this method is shown in FIG.

Since the change in the rope length l becomes non-linear, the values of acceleration (x ") and switching time (t) required for steady rest operation are derived by convergence calculation by creating a simulator on a personal computer. Is shown in FIG.

[0009]

However, when these motion equations based on linear control are used, the acceleration / deceleration is delayed with respect to the speed command based on the calculated value of acceleration / deceleration due to the response delay of the drive system especially at the time of speed switching. , The residual shake occurs due to the error from the calculated value.

Further, since the calculation formula is complicated, the calculation load becomes large and real-time feedback control becomes difficult. Further, since the control is based on the theoretical formula, there is a problem that it is weak against disturbance.

The problem to be solved by the present invention is to provide a method for controlling the runout and position of a crane, in which the influence of disturbance is smaller, the calculation load is smaller, and the steadying control is good.

[0012]

In order to solve the above problems, a first method for controlling the runout and position of a crane according to the present invention is a suspension type system having a traverse and traveling device equipped with a variable speed control mechanism such as an inverter. In the automatic operation method of the wire crane, the relational expression between the speed during acceleration and deceleration and the elapsed time after starting is represented by a circular arc type, and the speed is controlled according to the pattern represented by the circular arc during acceleration and deceleration. Is.

A second crane deflection and position control method according to the present invention is an automatic operation method for a suspension wire crane equipped with a traverse and traveling device equipped with a variable speed control mechanism such as an inverter. The relational expression between the speed during deceleration and the elapsed time after starting is represented by a circular arc type, during acceleration, speed control is performed based on the circular arc type, and during deceleration, the deceleration pattern represented by the circular arc type is predetermined. Based on the difference between the target position and the position at that time, correction calculation is performed in real time for correction, and positioning is performed based on the corrected deceleration pattern.

[0014]

In the present invention, the arc type is used for the acceleration / deceleration pattern to reduce the shock during crane operation, realize smooth control, perform steady rest, and use the arc type to reduce the calculation load. Feedback control by small real-time calculation is performed to enable highly accurate positioning.

The control by the circular arc and the circular control will be described. FIG. 1 shows an outline of circular control, in which the vertical axis represents speed and the horizontal axis represents time. This has each pattern of a first acceleration section with an arc, a second acceleration section with an arc, a constant speed section (T ₁ sec), a first deceleration section with an arc, and a second deceleration section with an arc.

Here, the connection angle θ [rad] = (2π / 360 °) × 45 ° =
π / 4 current angle θ _t [rad] = (2θ [rad] / Tθ [s
ec] × t (sec) (where 2 [Theta]: target angle, t: time to progression, T.theta: arrival time) switching speed _{v 0 = v 3/2 (} v 3: constant-speed Speed [m / se
c]) Assuming that the speed parameter (correction value for v ₀ at the angle θ) is A = {v ₀ / (1-cos θ)}, the speed command is as follows in each section to.

Section A × (1-cos θ _t ) Section v ₃ − (A × (1-cos (θ−θ _t ))) Section v ₃ Section v ₃ − (A × (1-cos θ _t )) Section A × (1-cos (θ−θ _t )).

Therefore, if the three items of Tθ, T ₁ and v ₃ are set, the speed command in each section can be obtained.

As described above, by using the circular arc type for acceleration / deceleration, smooth acceleration / deceleration is performed. Also, since the method is simple, the feedback system is easy to configure. Furthermore, since complicated calculation is unnecessary, real-time calculation can be performed.

Next, the positioning control method of the present invention will be described.

FIG. 2 shows a speed pattern of the positioning control method. Acceleration / deceleration time is Tθ, constant speed time is T ₁ ,
It is assumed that the constant speed is v ₃ and the acceleration / deceleration is performed in a pattern represented by a circular arc formula having a downward convex shape and a pattern having an arc shape having a convex upward shape. In the figure, indicates a triangular portion, indicates a quadrangular portion, and Z indicates a portion sandwiched between the hypotenuse and the arc of the triangle.

[0022] + area = 3v ₃ · Tθ / 8, of the area = v ₃ · Tθ / 8, where the arc AB, segment AC, the area of a figure surrounded by CB and triangles ACB 3 When the ratio with the area of is k, k is expressed by the following equation.

K = (r ² θ−y · x) / (sin θ · r ² −y · x) = θ · tan θ− (sin θ) ² / {sin θ (tan θ−sin θ)} = {2θ−sin (2θ )} / {2sin θ-sin (2θ)} Using this relationship, the areas of the portions Z, A, and B in FIG. 2 are expressed as follows.

Z = (v ₃ · Tθ / 8) × (k−1) A = 3v ₃ · Tθ / 8 + Z B = v ₃ · Tθ / 8-Z The area of each part in FIG. 2 is the product of time and speed. , That is, the distance, the areas Z, A, B obtained by the above equation
By performing control so that the circular arc control is switched at the distance represented by, the circular control can be positioned.

The above is the control method at the time of acceleration, but when stopping, in order to stop at a predetermined position, the actual value (actual distance k ₁ ) with respect to the calculated value (calculated distance k ₀ , calculated speed v ₀ ). ，
It is necessary to monitor the actual speed v ₁ ) and make a correction if there is a deviation between the two. FIG. 4 shows the state. _Assuming that the target point is k _M0 , the time Tθ / 2 from the actual value measurement time t _c to the stop can be obtained by the following formula.

Tθ / 2 = {2 (k _M0 ± k ₁ )} / {v ₁ (2-k)} The sign of k _M0 ± k ₁ means that it changes depending on the operation direction.

FIG. 5 is a diagram for explaining the method of real-time calculation, and the area of the section represents the remaining distance B ₁ .

The switching speed calculated value v ₀ = v _3/2 [mm / sec] angle correction value _{θ t = (2θ / Tθ)} × t remaining distance B ₁ = k _M0 ± k ₁ remaining time T _x [sec] = 2B ₁ / {v ₁ (2-k)}, the angle advance value is θ _t = θ _t0 (previous angle) + θ _tx
Since the formula (angular increments coefficient), where _{θ t = θ t0 + (θ} -θ t0) / (T x) × Δt, (θ-θ t0) is the remaining angle, Delta] t is the elapsed time (last - This time).

However, T _x is an absolute value, θ _t = θ _t0 + Σθ _tx
Is. This Σθ _tx indicates the averaging process of θ _tx .

Then, by performing control so as to stop when the relationship of θ _t > T θ is satisfied, real-time positioning control can be realized.

[0031]

EXAMPLES The present invention will be specifically described below based on examples.

FIG. 6 is a block diagram for implementing the method of the present invention. In the figure, 1 is an inverter, 2 is a crane traveling motor, 3 is a drive wheel, 4 is a driven wheel, and 5 is an encoder mounted on the shaft of the driven wheel 4.

The encoder 5 is for converting the rotation angle of the driven wheel 4 into a pulse and detecting the position of the crane. The detected actual position is compared with the target position, and the position deviation thereof is a time axis calculation block. 10 and the speed pattern output from the calculation pattern block 11 (see FIG. 1,
Command speed output based on (see FIG. 2),
The speed command is input to the inverter 1. Also, the actual speed is obtained by differentiating the actual position output from the encoder 5, and is fed back to the speed command in the inverter 1 via the PID controller 12.

FIG. 7 is a flow chart showing the steady rest and positioning control procedure of the present invention. When a stop command is issued in step 100, in step 110, acceleration (first acceleration) is performed based on a downwardly convex arc type. Next, at step 120, acceleration (second acceleration) based on the upwardly convex arc type is performed. As a result, constant speed operation is performed (step 1
30). Next, at step 140, deceleration (first deceleration) is performed based on the upward convex arc type based on the stop command. In step 150, deceleration (second deceleration) based on the downwardly convex arc type is performed. In step 150, as described above, the remaining distance from the target position is measured based on the output of the encoder 5, and based on this, the arc type is corrected and calculated in real time to perform positioning. When the positioning is completed, the operation is completed (step 160).

[0035]

As described above, the present invention has the following effects.

Since the circular control is adopted, the impact at the time of crane operation is small, the shake is minimized, and the accuracy of the steady rest can be improved.

Since the calculation formula is simple, the calculation in real time, that is, the feedback calculation of the position control can be performed.

Since the control method is easy, it is highly flexible against external disturbances, and it is possible to perform simultaneous running / traversing and winding operations, that is, diagonal suspension.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an outline of steady rest control of the present invention.

FIG. 2 shows a speed pattern of a positioning control method.

FIG. 3 is an explanatory diagram for deriving a positioning control method.

FIG. 4 is an explanatory diagram for deriving a method of positioning control.

FIG. 5 is a diagram for explaining a method of real-time calculation in positioning control.

FIG. 6 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 7 is a flowchart showing a steadying and positioning control procedure.

FIG. 8 is an explanatory diagram of conventional linear control.

FIG. 9 is a diagram of a phase plane locus, which is one of the solutions of linear control.

FIG. 10 is a time chart of a conventional steady rest pattern.

[Explanation of symbols]

1 inverter, 2 crane traveling motor, 3 driving wheels, 4 driven wheels, 5 encoder, 10 time axis calculation block, 11 calculation pattern block, 12 PID controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoji Shimogasa 1-1 Tobata-cho, Tobata-ku, Kitakyushu City Nippon Steel Corporation Yawata Works Co., Ltd.

Claims (2)

[Claims] 1. In an automatic operation method of a suspension wire crane equipped with a traversing and traveling device equipped with a variable speed control mechanism such as an inverter, the relational expression between the speed during acceleration and deceleration and the elapsed time after starting is an arc. A method for controlling the shake and position of a crane, which is characterized by performing speed control in accordance with a pattern expressed by a formula and expressed by the circular arc formula during acceleration and deceleration. 2. In an automatic operation method of a suspension wire crane equipped with a traverse and traveling device equipped with a variable speed control mechanism such as an inverter, the relational expression between the speed during acceleration and deceleration and the elapsed time after starting is an arc. Expressed by a formula, during acceleration, speed control is performed based on the circular arc formula, and during deceleration, the deceleration pattern represented by the circular arc formula is based on the difference between the predetermined target position and the position at that time, A method for controlling the deflection and position of a crane, which comprises performing correction calculation in real time and making corrections, and then performing positioning based on the corrected deceleration pattern.