KR100206497B1 - Swing prevention position control device in a crane - Google Patents

Abstract

The present invention relates to a control device for unmanned ceiling cranes that are frequently used in factories or production sites, and in particular, three-axis to quickly move the ceiling crane to the desired position, while preventing the shaking of the transfer occurring during the movement of the ceiling crane The present invention relates to an anti-shake position control device of a ceiling crane, comprising: an anti-shake control device that receives a shake angle measured by a two-dimensional angle measuring device as a girder or a trolley moves to compensate a reference position input signal of a girder or a trolley, and a reference position An anti-shake position servo controller comprising a first accelerometer to add a compensation signal to an input signal and a first position controller to control the speed of the driving motor of the girder or the trolley according to the compensated signal, respectively, independently of the girder and the trolley. Control to subtract the height output signal from the reference height input signal A position servo controller configured to include a two-winder and a second position controller for controlling the speed of the driving motor so that the conveyed material reaches a target height according to the subtracted height control signal. It is characterized in that the movement of the conveyance in any direction occurring during the movement of the three-axis ceiling crane can be prevented, and at the same time, it is possible to move the crane to the desired position quickly and precisely, which greatly increases the productivity. There is.

Description

Anti-shake position control device of 3-axis ceiling crane

The present invention relates to a control device of an unmanned overhead crane (many overhead crane), which is frequently used in factories and production sites, in particular, to prevent the movement of conveyances generated during the movement of the long crane, and at the same time to quickly move the ceiling crane to the desired position It relates to an anti-swing position control device of a three-axis ceiling crane.

FIG. 1 is a schematic view of a triaxial ceiling crane which is frequently used for transporting heavy materials. As shown here, the girders 4 and the trolley 5 of the ceiling crane move with acceleration and deceleration, so that the rows 10 of the trolley 5 move. Conveyed material is transported.

In addition, the absolute coordinate system defined in the fixed frame 3 and the relative coordinate system defined in the angle measuring device 6 below the trolley 5 are used to properly indicate the position of the ceiling crane. (relative coordinate) (2) is shown. Here, the travel axis (X axis) is the moving axis of the girder 4, and the transverse axis (Y axis) is the moving axis of the trolley 5. The Z axis is also the lifting / lowering axis of the conveyed material.

In addition, the distance measuring devices 11 and 12 or the laser distance sensors 13 and 14 and the laser distance sensor reflectors 15 and 16 may be used to determine the reference position of the girder 4 and the trolley 5 and determine the moving distance. For this purpose, only one of the distance measuring devices 11 and 12 or the laser distance sensors 13 and 14 and the distance sensor reflecting plates 15 and 16 may be used. If both are used, the distance measuring devices 11 and 12 may be initialized using the laser distance sensors 13 and 14 at arbitrary positions. When the distance measuring devices 11 and 12 include a device that can be initialized by itself, only the distance measuring devices 11 and 12 may be used.

The string 9 is for two-dimensional angle measurement, and the grab 7 is provided with a tension adjusting device 17 which gives a constant tension regardless of the length of the string. The string 10 is a support string of the grab 7. This row 10 is adapted to be adjustable in length in the trolley 5.

FIG. 2 is a plan view showing an installation state of the distance measuring device by expanding a1 (or a2) in FIG. 1, and FIG. 3 is a front view of FIG. In general, an incremental encoder connected to a driving motor of a ceiling crane has a problem that accurate distance measurement is impossible because the wheel of the ceiling crane slides due to inertia during acceleration and deceleration. 2 and 3 is a device for solving the above problems, the frame 34 is attached to the ceiling crane body, the other frame 36 is fastened by welding to the frame 34, bearing ( 23, a frame 37 rotatable about the frame 36, an encoder 21 fastened to the frame 37, a traveling wheel 22 for distance measurement, and a furnace fastened to the shaft of the encoder 21. A no-slip pulley 26, a no-slip pulley 28 fastened to a distance measuring wheel, and a no-slip belt 27 connecting two pulleys 26 and 28 are shown.

In addition, regardless of the road surface condition of the trolley and girder rails 18 and 19, the outer circumferential surface of the driving wheel 22 is attached to the ceiling crane body so that the trolley and girder rails 18 and 19 are always in constant contact with the trolley and girder rails 18 and 19. The distance measuring device with a spring 30 installed between the frame 34 and the rotating frame 37 is shown. Here, a bolt 38 and a double nut 29 were mounted to adjust the compression force of the spring 30.

The bolt 38 is not fixed to the rotating frame 37 and can freely move in relative motion.

In addition, the distance measurement traveling wheel 22 consisted of the urethane resin 32 in the outer peripheral surface which contacts the trolley and the girder rails 18,19. In order to remove the foreign matter on the rails (18) and (19), a foreign matter removing device (31) was installed. The position output signal from this distance measuring device is input to a control unit count board not shown and used in the position control device.

Details, uses and effects of the distance measuring device are described in more detail in Korean Patent Application (Application No. 96-67655).

4 is an enlarged view of a portion b of FIG. 1 and is a schematic view of a two-dimensional angle measuring device attached to the lower portion of the trolley 5. FIG. As shown here, rotation angle sensors 41 and 42 are connected to both ends of one lever 48 of the cross lever. The cross levers 48 and 49 are integral. One sensor 41 is connected in the axial direction to detect the x direction rotation angle and the other sensor 42 is connected / fixed to the lever 48 to detect the y direction rotation angle. A U-shaped lever 47 is connected to one end of the lever 49 to which the sensor is not connected, and the pulley 45 is fixed to the U-shaped lever 47. The U-shaped lever 47 and the pulley 45 may rotate about the lever 49. The U-shaped lever 47 rotates around the cross lever 48 and the cross lever 48 centers the bearing 44 as the feed 8 connected through the rope 9 rotates in the x-axis direction. The rotation angle in the x direction of the conveyed object is detected by the rotation angle sensor 41. When the feed 8 rotates in the y-axis direction, the pulley 45 and the U-shaped lever 47 rotate about the lever 49, and a no-slip belt according to the rotation of the pulley 45 is rotated. The y-axis rotation angle is detected by the fixed rotation angle sensor 42 connected by 46.

Therefore, the shake angle of the conveyed material in any direction can be measured.

The shake angle output signal from the angle measuring device is input to a control unit analog input board (not shown) and used in the shake prevention control device. The details, uses and effects of the angle measuring device are shown in Korean Utility Model Registration Application (Application No. 94-39349).

FIG. 5 shows the relationship between the absolute coordinate system 1 and the relative coordinate system 2 defined in FIG.

Arbitrary positions xo and yo from the world coordinate system can be obtained from the traveling and transverse axis distance measuring devices. In Fig. 5, the arbitrary swing angle θ can be decomposed into θx and θy, and these θx and θy can be measured using an angle measuring device. Here, θx represents the shake angle in the traveling axis direction in which the shake angle θ is projected onto the relative coordinate system xz plane, and θy represents the shake angle in the transverse axis direction as the minimum shake angle measured from the relative coordinate system xz plane.

As described above, when the three-axis ceiling crane carries the conveyed material, shaking of the conveyed material occurs due to the acceleration and deceleration of the girder 4 and the trolley 5, which makes it difficult to control the ceiling crane. There is a danger. Therefore, for unmanned operation of the overhead crane, it is necessary to develop an anti-shake control device and a precise position control device that can quickly and accurately transfer the conveyed material to the target point while minimizing the shaking of the conveyed material during the movement of the crane.

In accordance with the needs as described above, the anti-shake and position control device has been developed in various forms, the most commonly used method is the velocity profile (velocity) by calculating the acceleration and deceleration section is minimized according to the moving distance of the crane profile) and feedback control to eliminate shaking and position error while driving the crane according to this profile. Korean Patent Application (Application No. 95-17145) provides a position and anti-shake control device that can perform the control of one axis (driving axis or transverse axis).

However, the conventional control devices still shake after the end of the control due to the inaccuracy of the shake angle measuring device and the distance measuring device, the experimental determination of the grain acceleration / deceleration section, and the problem of the control logic itself.

Meanwhile, in British Patent Publication No. 2280045 (A), a control rule for measuring and using a shake angle and an angular velocity is configured as fuzzy logic. However, since the control rule is only when the shake angle is 0, only a part of the total control time performs feedback control, and there is a problem that the shake is present even after the control ends, resulting in a decrease in productivity.

The object of the present invention is to solve the above problems and to minimize the shaking of the conveyed material generated during the movement of the three-axis crane (driving, transverse and hoisting / lowering shaft), to prevent the shaking of the conveyed material at the target point and at the same time to speed up the crane To provide an anti-shake control device and a position control device for a three-axis ceiling crane that can be moved to the desired position.

In addition, another object of the present invention, when fixed to the transverse axis of the three-axis ceiling crane becomes a two-axis crane (driving and hoisting / hoisting shaft), so the anti-shake control device for the three-axis ceiling crane that can be applied to the two-axis crane as it is; It is to provide a position control device.

1 is a schematic diagram of a triaxial ceiling crane.

FIG. 2 is a plan view showing an installation state of the distance measuring device by expanding a1 (or a2) in FIG.

3 is a front view showing an installation state of the distance measuring device of FIG.

4 is an enlarged view of part b of FIG. 1 and is a schematic diagram of a two-dimensional angle measuring device attached to the lower part of the trolley.

5 defines coordinates and shake angles θ and its x-axis components θx and y-axis components θy of the workpiece at any position from the origin, and sets any shake angle θ by using the angle measuring device shown in FIG. 4. And θy.

6 is a block diagram of an anti-shake position servo controller with respect to a travel axis (X axis) (or a transverse axis (Y axis)) according to the present invention.

7 is a block diagram of the position servo controller with respect to the traveling axis (or the transverse axis or the hoisting / lowering axis (Z axis)) according to the present invention.

FIG. 8 is an equivalent block diagram of the anti-shake position servo controller shown in FIG.

FIG. 9 is a modified block diagram of the anti-shake position servo controller shown in FIG.

10 is a speed profile according to the present invention, which is a speed profile according to a moving distance in one-axis control, (a) is a speed profile when the moving distance is long, and (b) is a speed profile when the moving distance is short. .

* Explanation of symbols for main parts of the drawings

1: Absolute coordinate system 2: Relative coordinate system

3: crane fixed frame 4: traveling shaft girder

5: transverse shaft trolley 6: angle measuring device

7; Grab 8: Conveying Material (Load)

9: Cable for angle measuring device 10: Grab attachment string

11, 12: distance measuring device 13, 14: laser distance sensor

15, 16: laser distance sensor reflector 17: tension control device

18, 19: trolley and girder rail 21: encoder

22: Distance measuring wheel 26: Encoder-side loose slip poly

27: no slip belt 28: driving wheel side no slip pulley

32: urethane resin 41, 42: rotation angle sensor

43: fixed point 44: bearing

47: shake transmission element 63: shake prevention controller

66: position controller 67: speed book view

69: Integrator 71: Transport Kinetic Model

74: Reverse speed display 75: Position servo controller

77: designed position servo controller 78: new anti-shake controller

The present invention as a technical means for achieving the above object is provided with a distance measuring device, a driving motor and a motor controller in the girder traveling in the X-axis and the trolley running in the Y-axis, respectively, 3-axis ceiling with distance measuring device, hoisting / unwinding motor and motor controller for Z-axis and 2-dimensional angle measuring device for measuring the swing angle of conveyance suspended in Z-axis at the bottom of trolley In the anti-shake position control device of the crane, a first position that compensates the reference position input signal of the girder or trolley to receive the angle measured by the two-dimensional angle measuring device as the girder or trolley moves to give a stable and optimal attenuation An anti-shake controller 63 for generating a compensation signal and a first compensation signal are added to the reference position input signal and the girder of the distance measuring device A first retarder for generating a position control signal by subtracting the output position signal of the trolley and a first speed control signal for controlling the speed of each driving motor so that the girder or the trolley reaches the target position according to the position control signal; An anti-shake position servo controller comprising a first position controller 66 and a first speed servo 67 for driving the drive motor to drive the drive motor in accordance with the first speed control signal includes: A second retarder which independently controls the trolley of the Y axis and generates a height control signal by subtracting the height output signal from the reference height input signal of the conveyed object, and the speed of the drive motor so that the conveyed object reaches the target height according to the height control signal. The second position controller 66 for outputting a second speed control signal for controlling the drive speed and the drive motor to drive the Z-axis drive motor of the conveyed object following the second speed control signal. A second gear BookView 67 position servo controller is configured to include the features to control the height of feed water suspended in the direction of the Z axis.

As another technical means for achieving the above object, the present invention is provided with a distance measuring device, a driving motor and a motor controller are respectively installed on a girder traveling on the X axis and a trolley transverse to the Y axis, A distance measuring device, hoisting / reeling motor, and motor controller are installed on the Z axis for the unloading, and a two-dimensional angle measuring device is installed on the lower part of the girder and the trolley to measure the swing angle of the conveyed object suspended in the direction of the Z axis. In the anti-shake position control device of a three-axis ceiling crane, the first retarder for generating a position control signal by subtracting the position output signal of the girder or the trolley from the reference position input signal, and the girder or the trolley in accordance with the position control signal A first position controller 66 for outputting a first speed control signal for controlling the speed of each drive motor to reach A new anti-shake controller 78 which generates a first compensation signal for compensating the speed of the driving motor of the girder or the trolley so as to receive the angle measured by the two-dimensional angle measuring device as the Raleigh moves to provide stable and optimal damping of the shaking. And a second retarder for generating a second speed control signal for controlling the speed of the girder or trolley by adding the first compensation signal and the first speed control signal, and the driving motor to drive the driving motor following the second speed control signal. The anti-shake position servo controller configured to include a first speed servo (67) for driving the independently control the girder of the X axis and the trolley of the Y axis, respectively, and control the height by subtracting the height output signal from the reference height input signal of the conveyed object. Outputs a third speed control signal for generating a signal and a third speed control signal for controlling the speed of the drive motor so that the conveyed object reaches the target height according to the height control signal. A position servo controller comprising a second position controller 66 and a second speed servo 67 for driving the drive motor such that the driving motor in the Z-axis direction of the conveyed object is driven in accordance with the third speed control signal. It characterized in that for controlling the height of the suspended object suspended in the direction of the axis.

Hereinafter, with reference to the accompanying drawings, the present invention will be described.

6 is a block diagram of an overall control system for a travel shaft according to the present invention. This block diagram can also be used in common for the transverse axis control. The feedback servo angle 72 (θx) is input to the anti-shake controller 63, and the position servo controller in which the sum 64 of the output value and the reference position input signal 65 (Xr) 64 (Uxa) is indicated by a dotted line ( 75). The position servo controller 75 is described in FIG. The position output 70 of the position servo controller 75 is input to the feed dynamics G _L (s) 71 to be the shake angle 72. dx (68) is a velocity disturbance that is added to the output of the velocity report.

The symbols used in FIGS. 6 and 7 will be described. The crane is mostly driven by a motor. In the case of automatic cranes, the speed is controlled using a speed controller of the motor. To move the crane, enter the speed command in the speed report of the crane motor. The crane then starts to move and follows the speed command. The speed report 67 shows the dynamic function relationship of the speed output of the crane with respect to the speed command of the crane. Velocity readings can be obtained from experiments or theory, and can be defined as a function of the Laplace variable S with Gvs (s) = V (s) / Vr (s). V (s) represents the Laplace transformation of the crane speed and Vr (s) represents the Laplace transformation of the crane speed command. Integrator 69 1 / s is inserted to convert the speed of the crane to the position of the crane and is not an actual crane device. Reverse speed reading 74 means the inverse dynamics of the crane speed reading and is defined as Gvs ^-1 (s) = Vr (s) / V (s) and is a function of the Laplace variable s.

The feed dynamics 71 shows the shake dynamics of the feed relative to the movement of the crane. When the crane moves and the position X (s) changes, the swing angle θ (s) changes. X (s) and θ (s) are Laplace transforms of the crane position and swing angle, respectively.

The swing dynamics of the conveyance represent the dynamic functional relationship of the swing angle θ (s) with respect to the crane position X (s) and can be defined as G _L (s) = θ (s) / X (s). G _L (s) is defined in the text below.

The position controller 66, the reverse speed monitor 74, and the anti-shake controller 63 all represent a computer system and implement control logic K _XP (s), G _VS ^-1 (s), and Kxa (s), respectively. . Each control computer system has an input device for receiving an input signal. If the input signal is a digital signal, a digital input board is used. If the input signal is an analog signal, an analog-digital conversion board is used to input the digital signal. After receiving various input signals as digital signals according to sampling signals in the control computer system, control logic K _XP (s), G _VS ^-1 (s), K _xa from the CPU board of the control system. will implement (s). This calculation result is digital value and is output through the digital-to-analog conversion board. In some cases, the digital output board is used to output digital values directly. At this time, the appropriate sequence control signal is output together with the operation state of the crane. Here, the position controller, reverse speed display and anti-shake controller may be implemented in each control computer system, but control logic K _XP (s), G _VS ^-1 (s), and Kxa (s) can be implemented in one control computer system. It can also be implemented. How to implement control logic in a control computer system is described in the text below.

7 shows the position servo controller 75, which is indicated by a dotted line when the output of the anti-shake controller 63 is 0 in FIG. 6, can also be used for position control of the hoisting / lowering shaft. The result 76 (x _e ) of the subtraction of the position output 70 (x) fed back from the Xr 65 is input to the position controller 66. Since the output of the anti-shake controller 63 is 0, the Uxa 64 of FIG. 6 and the Xr 65 of FIG. 7 are the same. The feedforward reference speed input signal 73 is input to the reverse speed view 74, and the addition result of the output of the reverse speed view 74 and the output of the position controller 66 is displayed in the speed view Gvs (s) ( 67). The feedforward reference speed input signal 73 is used to increase the command followability of the x 70 relative to the xr 65 of the position servo controller 75 and need not be used. The girder speed 61 is integrated by 1 / s 69 and converted to position 70.

8 is an equivalent block diagram of an anti-shake position servo controller including a position servo controller designed in the present invention. Reference numeral 77 denotes the position servo controller 75 shown in dotted lines when v _ref = 0 and d _x = 0 in FIG.

9 is equivalent to FIG. The new anti-shake controller 78 is equal to the product of the position controller 66 and the anti-shake controller 63 in FIG. Kna (s) = Kxa (s) Kxp (s). In Fig. 6, the control output of the anti-shake controller is fed back to the position controller Kxp (s). In Fig. 9, the control output of the anti-shake controller is fed directly to the speed servo.

10 is a profile in the form of a trapezoid 101 as a velocity profile according to the present invention, and a profile in the form of a triangle 103 is a profile when the movement distance is short. T is described in detail below as the acceleration / deceleration time. In Fig. 10B, S ₁ and S ₂ each represent a moving distance by the area of an isosceles triangle. Vmax represents the physical maximum travel speed of travel, traverse and hoisting / lowering axes and can have different values for each axis.

Hereinafter, the operation of the present invention will be described in detail.

Crane operation in most cases changes the length of the rope slowly and keeps the swing angle small during the movement of the crane for safety reasons and to protect the feed. At this time, the acceleration of the crane is much smaller than the acceleration of gravity. For most industrial ceiling cranes, the reduction ratio is large, allowing trolley and girder position to be controlled regardless of load. In this case, the eye equation of the girder 4 and the trolley 5 shown in FIG. 1428-1431, 1996).

First, the equation of motion in the direction of travel axis is as follows.

The equation of motion in the transverse axis direction is

The meanings of variables and constants used here are as follows:

Mx: Girder (4) and trolley including motor, gear and pulley inertia taking into account the reduction gear ratio

Mass of 5

My: Mass of the trolley (5) including the motor, gear, and pulley inertia considering the reduction ratio

Dx: Viscous friction coefficient in the direction of travel axis including rotational viscous friction coefficient of rotating part

Dy: Viscous friction coefficient in the transverse axis direction including the rotational viscous friction coefficient of the rotating part

m: mass of conveyed material, L: string length, g: gravitational acceleration

θx: shake angle in x direction, θy: shake angle in y direction

θx: shake angle acceleration in x direction, θy: shake angle acceleration in y direction

fx: external force acting in x direction, fy: external force acting in y direction

Since the equations 1, 2, 3, and 4 are independent of the travel axis and the transverse axis, the motion equations Equation 1, Equation 2, and Equation 4 can be designed independently. Therefore, the controller for the traveling axis is designed using the equations (1) and (2). The anti-shake controller and the position controller for the transverse axis can also be designed in the same manner using the equations (3) and (4).

The speed report Gvs (s) (= [girder speed output] / [girder speed command]) defined in FIG. 6 may be modeled as a secondary or tertiary system through a step response method and a frequency response method.

In the present invention, the independent variable s of the various controllers represents a Laplace complex variable.

The procedure for designing a position controller and an anti-shake controller for a mathematically modeled system as described above is as follows. Since the same design method can be applied to the traveling axis and the transverse axis when designing the position controller, the design method for the traveling axis will be described here. The controller design sequence first designs the position controller and then the anti-shake controller. The block diagram of the position servo controller of FIG. 7 is a structure that can be commonly applied to driving, traversing, and hoisting / lowering axes. In Fig. 7, the position controller Kxp (s) is designed using a loop type method or a phase lead / lag method. In order to minimize the influence of velocity disturbance dx on position x in the low frequency region and to increase the command followability, the size of the open-loop transmission function Kxa (s) Gvs (s) / s is sufficiently large, and the model uncertainty and the sensor in the high frequency region are high. In order to minimize the influence of noise, the size of the open-loop transfer function is set to -20dB / dec to minimize the size of the open-loop transfer function and to ensure stability at the crossover frequency. The basic structure of the designed position controller is as follows.

Where Rpp and Rpt are proportional control gain and integral control gain of the position controller, respectively.

In the high frequency and low frequency region, the performance of the position controller (Equation 5) can be improved somewhat by the lead / lag method. In addition, when using integral control, it is necessary to perform anti-windup control in order to prevent an integrator windup phenomenon.

The feedforward reference speed input signal 73 is used to increase the command followability of the position servo controller and is not necessarily used. Here, the inverse dynamics 74 is an inverse dynamics model of the speed differential 67.

)보다 작으므로, 흔들림방지 제어기를 설계할 때 위치서보제어기의 동특성을 반드시 고려하여야 한다. 본 발명에서 흔들림 방지 제어기는 근궤적법을 이용하여 설계한다. 개루프 전달함수 G_oθ(s) =Kxa(s)Gx(s)G_L(s)에서 Gx(s)G_L(s)의 극점(pole)과 영점(zero)의 수와 위치를 고려하여 설계한 흔들림방지제어기의 기본구조는 다음과 같다.Anti-shake controller is designed as follows. 8 shows an anti-shake position servo controller, which is equivalent to FIG. 6 when V _ref = 0 and d _x = 0. FIG. In FIG. 8, Gx (s) is a position servo controller designed when V _ref = 0 and d _x = 0, and shows a portion 75 indicated by a dotted line in FIG. The bandwidth of the position servo controller designed above is the load swing frequency (

Less than), the dynamic characteristics of the position servo controller must be taken into account when designing an anti-shake controller. The anti-shake controller in the present invention is designed using the root locus method. Considering the number and positions of the poles and zeros of the open loop transfer function G _oθ (s) = Kxa (s) Gx (s) G _L (s), Gx (s) G _L (s) The basic structure of the anti-shake controller is as follows.

Here, k _ap > 0, k _ad > 0, k _p > 0, k _i > 0 are control constants, and the values are determined so that the representative poles of the anti-shake control system closed loop always have optimum attenuation. In addition, the anti-shake controller (Equation 6) can slightly improve the performance in the high frequency and low frequency region by the phase forward / delay method.

If you set K _p = k _pp and Ki = k _pi in the anti-shake controller (Equation 6), s / (K _pp s + k _pi ) of the anti-shake controller (Equation 6) is the position controller (Equation 5). Offset from (k _pp s + k _pi ) / s, the control input of the speed report Gvs (s) by the shake angle measurement value θx in FIG. 6 becomes PD (proportional / differential) control. In other words

Where Kna (s) is a new anti-shake controller fed back to speed monitor Gvs (s) and k _ap and k _ad are the proportional control gain and derivative control gain of anti-shake controller. In addition, the anti-shake controller (Equation 7) can slightly change and improve the performance in the high frequency and low frequency region by the phase forward / delay method. In this case, it is simpler to directly feed the control inputs by the measurement of the swing angle directly to the speed view. This controller structure is shown in FIG. However, it is not necessary to limit the pole of the anti-shake controller (Equation 6) to -k _pi / k _pp .

If the line length changes, the gain value of the anti-shake controller is adjusted in the following way. Equations 6 and 7 can be written as follows, respectively.

k _{ad /} k _ap sets a value such that the representative poles of the anti-shake control system closed loop poles always have optimum attenuation regardless of the line length. K _{ad /} k _ap obtained as described above can be obtained so that the representative pole points of the anti-shake control system are always in the optimum attenuation position for a given line length. When the line length of the _ap k from L _o k _apo d, k _ap value of books to any line length L can be determined as follows:

If the gain value of the anti-shake controller is changed according to the change in the string length, the optimum damping can be always obtained in the anti-shake control system. Therefore, the gain value of the traveling and anti-axis anti-shake controller in the three-axis simultaneous control is adjusted according to the above method. Optimal damping of the movement of the feed is always possible during the feedback control time. The gain value (Equation 10) of the anti-shake controller can be adjusted somewhat in the experiment and can be expressed in a table form.

In the present invention, the position controller (Equation 5) and the anti-shake controller (Equations 6, 7, 8, and 9) are represented as a function of Laplace variation s. However, the controllers (logics) are implemented in the control computer system after Z conversion. When converting the controllers (logics) of the Laplace function to Z, trapezoidal transformation s = 2 (z-1) / (Ts (z + 1)), backward rectangular rule s = (z-1) / Taz, forward rectangular rule s This can be accomplished by substituting = (z-1) / Ts for the Laplace function. Where z is the independent variable in the Z transform and Ts is the sampling period. Other methods may be used, such as pole-to-zero mapping.

In most cases, a motor with a large reduction ratio is used for the hoisting / lowering shaft so that the influence of the mass of the feed on the position control can be ignored. Therefore, the hoisting / lowering position controller of the conveyed material can be designed in the same manner as the position controller of the traveling shaft and the transverse shaft described above, and a position controller (Equation 5) can be used. In addition, the position controller performance can be somewhat improved by using the phase advance / delay method in the high frequency and low frequency regions.

On the other hand, the reference speed input signal and the reference position input signal of the travel shaft or the transverse shaft are obtained by the following method. The velocity profile of FIG. 10 can be obtained by solving the optimal control problem with the boundary condition that the shaking angular velocity and the shaking angle are zero at the starting point and the arrival point while minimizing the transfer time in the equation (2) or (4). Where Vmax is the maximum physical speed of each axis of the crane. The velocity profile is first divided into long and short travel distances as shown in FIG. This velocity profile is used as the feedforward reference velocity input signal of 73. The reference position input signal is obtained by integrating this velocity profile. If the moving distance is larger than the area S ₁ of the isosceles triangle 102 shown in FIG. 10 (b), a reference position input signal is generated through the speed profile shown in FIG. If it is smaller than the isosceles triangle area S ₁ shown in Fig. 10 (b), the maximum speed is lowered so that the moving distance is equal to the trivalent area S ₂ , and the reference position input signal is obtained by integrating this velocity profile. . Here, the acceleration / deceleration time T is defined below.

When driving the driving, traversing and hoisting / lowering axes simultaneously, the speed profile for obtaining the reference speed input signal and the reference position input signal of each axis may vary depending on obstacles or loading status of the load to be transported by the crane. The combination of the trapezoidal velocity profile of (a) and the triangular profile of (b) of FIG. 10 is obtained.

Acceleration and deceleration time T is the period of the workpiece shake with respect to the line length at the beginning of the acceleration and deceleration section of the trolley and girder, and one cycle of the workpiece shake with respect to the line length at the end of Ts. When Tr is the time that reaches 90% of the maximum speed when the maximum speed step input is applied to step 67), the acceleration / deceleration time T is set as follows in the present invention.

(초)이고, 0≤α≤1, 0≤η≤1(피드포워드 기준속도입력신호(73)가 사용될 때 η=0), n은 T〉0을 만족시키는 최소 자연수이다.Here, one period of feed shake for any line length L

(Sec), 0 ≦ α ≦ 1, 0 ≦ η ≦ 1 (η = 0 when the feedforward reference speed input signal 73 is used), and n is the minimum natural number satisfying T >

In position control of hoisting / lowering shaft, acceleration / deceleration time can be adjusted in the range allowed by driving motor torque according to the working situation separately from acceleration and deceleration time T of trolley and girder.

As described above, the present invention can prevent the movement of the conveyance generated during the movement of the three-axis ceiling crane, and at the same time can move the crane to the desired position quickly and precisely, there is a great effect in improving the productivity.

Claims (16)

The distance measuring device, the driving motor and the motor controller are installed in the girder traveling in the X axis and the trolley running in the Y axis, respectively, and the distance measuring device, the hoisting / reeling motor and motor with respect to the Z axis for lifting and unloading the conveyed material. A controller is provided, and the girder or the troll in the anti-shake position control device of the three-axis ceiling crane is provided with a two-dimensional angle measuring device for measuring the shaking angle of the conveyance suspended in the Z-axis direction at the bottom of the trolley An anti-shake controller for generating a first compensation signal for compensating for the reference position input signal of the girder or the trolley so as to receive the angle measured by the two-dimensional angle measuring device according to the movement of the li, and to give a stable and optimal damping of the shaking; The first compensation signal is added to the reference position input signal, and the girder or the trolley of the distance measuring device Outputting a first acceleration control unit for generating a position control signal by subtracting an output position signal, and a first speed control signal for controlling the speed of each driving motor so that the girder or the trolley reaches a target position according to the position control signal; An anti-shake position servo controller comprising a first position controller and a first speed servo for driving the driving motor to drive the driving motor in accordance with the first speed control signal. A second rewinder which independently controls the trolley and generates a height control signal by subtracting the height output signal from the reference height input signal of the conveyed object, and the speed of the driving motor so that the conveyed object reaches a target height according to the height control signal; A second position controller for outputting a second speed control signal for controlling the speed and the Z-axis driving motor of the conveyed object following the second speed control signal Position servo controller including a second speed servo for driving the drive motor to be driven to control the height of the suspended object in the direction of the Z-axis, the gain value of the anti-shake controller as the line length in the Z-axis direction changes Anti-shake position control device of a three-axis crane characterized in that it is adjusted. According to claim 1, wherein the first speed control to receive a reference speed input signal fed forward between the first position controller and the first speed monitor to improve the followability of the drive motor of the girder or the trolley A first reverse speed view for outputting a second compensation signal for compensating a signal; and a third accelerometer for adding the second compensation signal and the first speed control signal of claim 1 and outputting the first speed control signal to the first speed report. Anti-shake position control device of a three-axis crane, characterized in that configured to. The second speed control signal of claim 1, wherein the second speed control signal is input to receive a reference speed input signal fed forward between the second position controller and the second speed monitor to improve the followability of the Z-axis driving motor of the feeder. And a fourth reverse speed readout for outputting a third compensation signal for compensating the signal, and a fourth adder / rewinder for adding the third compensation signal and the second speed control signal of claim 1 to output the speed compensator. Anti-shake position control device of a three-axis crane, characterized in that. The reference speed input signal according to claim 2 or 3, wherein the feed forward reference speed input signal is generated with respect to the traveling, traversing and hoisting / retraction axes by combining a trapezoidal speed profile and a triangular speed profile. And generate the reference position input signal of claim 1 by integrating and generate the reference height input signal of claim 1 by integrating the reference speed input signal of claim 3. The acceleration / deceleration time of the reference position input signal of the girder or the trolley or the reference speed input signal of the girder or the trolley according to claim 1 is a conveyance for the row length at the start of the acceleration / deceleration section of the trolley and the girder. One cycle of oscillation is Ts, one cycle of conveyance oscillation with respect to the line length at the end of Te, and the time to reach 90% of the maximum velocity when Tr, 0≤ When α≤1, 0≤η≤1 (η = 0 when the feedforward reference speed input signal is used, n is the minimum natural number satisfying T> 0)

Anti-shake position control device of a three-axis crane, characterized in that made using. The method of claim 1, wherein the first position controller and the second position controller,

Where k _pp and k _pi are control constants An anti-shake position control device for a three-axis crane, which is based on having a transfer function of a form and is a controller modified by a phase forward / delay method in a high frequency and low frequency region. According to claim 1, The anti-shake controller,

Where k _ad , k _ap , k _p , and k _i are control constants An anti-shake position control apparatus for a three-axis crane, characterized in that it has a transfer function of the form and is a controller modified by a phase forward / delay method in a high frequency and low frequency region. The method according to claim 7, wherein when the length in the Z-axis direction is changed, a value is set so that the representative poles of the anti-shake closed loop always have optimum attenuation regardless of the Kad / Kap length.

(Where k _apo is a gain value when the length of the line L _o ), k _ap is calculated and k _ad from k _ad / k _ap to calculate k _ad from the anti-shake position control device. A distance measuring device, a driving motor and a motor controller are installed, respectively, and a girder traveling in the X axis and a trolley running in the Y axis, and the distance measuring device and the hoisting / lowering motor and the motor controller with respect to the Z axis for lifting and unloading the conveyed material. In the anti-shake position control device of the three-axis ceiling crane is installed, the two-dimensional angle measuring device for measuring the shaking angle of the conveyance suspended in the direction of the Z axis in the bottom of the girder and the trolley, the reference position input Controlling the speed of each driving motor which subtracts the position output signal of the girder or the trolley from the signal to generate a position control signal, and causes the girder or the trolley to reach a target position according to the position control signal. A first position controller for outputting a first speed control signal and the two-dimensional angle as the girder or the trolley moves; An anti-shake controller for generating a first compensation signal for compensating the speed of the driving motor of the girder or the trolley so as to receive the shaking angle of the conveyed object measured by the stationary device and to give a stable and optimal damping of the shaking, and the first compensation signal And a second retarder for generating a second speed control signal for controlling the speed of the girder or the trolley by adding a first speed control signal, and driving the drive motor to drive the driving motor following the second speed control signal. An anti-shake position servo controller configured to include a first speed servo is configured to independently control the girder of the X axis and the trolley of the Y axis, and to generate a height control signal by subtracting the height output signal from the reference height input signal of the conveyed object. A third speed for controlling the speed of the driving motor so that the conveyed object reaches a target height according to a third rewinder and the height control signal; The position servo controller includes a second position controller for outputting a control signal and a second speed servo for driving the driving motor such that the driving motor in the Z-axis direction of the conveyed object is driven in accordance with the third speed control signal. Controlling the height of the suspended object in the direction of the Z-axis, the anti-shake position control device of the three-axis crane, characterized in that the gain value of the anti-shake controller is adjusted according to the length of the line when the length of the Z-axis direction changes. 10. The method of claim 9, wherein the first speed controller receives a feedforward reference speed input signal between the first position controller and the first speed monitor to improve the followability of the driving motor of the girder or the trolley. And a first reverse speed monitor for outputting a second compensation signal for compensating a control signal to the second accelerometer, wherein the second accelerometer includes the second compensation signal, the first speed control signal, and the first compensation. Anti-shake position control apparatus for a three-axis crane characterized in that the output to the first speed monitor by adding a signal. 10. The method of claim 9, wherein the third speed control signal is input to receive the reference speed input signal fed forward between the second position controller and the second speed monitor to improve the followability of the Z-axis driving motor of the conveyed object. And a second reverse speed readout for outputting a compensating third compensation signal, and a fourth accelerometer for adding the third compensated signal and the third speed control signal of claim 7 to output the second speed readout. Anti-shake position control device of a three-axis crane characterized in that it is. The reference speed input signal according to claim 10 or 11, wherein the feedforward reference speed input signal is generated for driving, traversing and hoisting / retraction axes by combining a trapezoidal speed profile and a triangle speed profile. The anti-shake control device of claim 3, wherein the reference position input signal of claim 9 is generated by integrating and the reference height input signal of claim 9 is generated by integrating the reference speed input signal of claim 11. The acceleration / deceleration time of the reference position input signal of the girder or the trolley and the reference speed input signal of the girder or the trolley according to claim 10 is set to the line length at the start of the acceleration and deceleration section of the trolley and the girder. One cycle of the workpiece shake is Ts, and one cycle of the workpiece shake with respect to the line length at the end is Te, and when the maximum speed step input is applied to the speed servo 67, the speed is 90% of the maximum speed. When the time to reach is Tr, 0≤α≤1, 0≤η≤1 (η = 0 when the feedforward reference speed input signal is used, n is the minimum natural number satisfying T> 0),

Anti-shake position control device of a three-axis crane, characterized in that made using. The method of claim 9, wherein the first position controller and the second position controller.

An anti-shake position control device of a three-axis crane, which is based on a shape having a cutting function and is a controller modified by a phase forward / delay method in a high frequency and low frequency region. The anti-shake controller of claim 9,

Where k _ad and k _ap are control constants An anti-shake position control device of a three-axis crane, which is based on a transmission function of a form and is a controller modified by a phase forward / delay method in a high frequency and low frequency region. 16. The method according to claim 15, wherein if the length in the Z-axis direction is changed, Kad / Kap is determined so that the representative poles of the anti-shake closed loop always have optimum attenuation regardless of the length of the string, and for the varying length of the string L,

(Where k _apo is the gain value for the row length L _o ) is the gain value for the row length Lo) using the anti-shake of the three-axis crane characterized in that Kap is calculated and Kad is calculated from Kad / Kap Position control device.

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