JPH11335069A - Suspension type elevating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively perform vibration control by preventing oscillation at the time of vibration control, caused by an eleastic vibration component mixed into a signal in accordance with the vibration velocity of an elevating part elevatingly suspended via a suspension material, by an oscillation preventing means, and changing setting the oscillation preventing means at every positioning place. SOLUTION: In a suspension type elevating device, providing positioning actuator 1 and an upper plate 2 on the lower part of a mobile dolly 53 moving along a ceiling rail 52, and arranging an elevating part 55 having a hand 55a for gripping a cargo 56 on the lower end part of a suspension material 54 suspended by the upper plate 2; a vibration position sensor 3, for detecting a relative vibration position to the upper plate 2 of the elevating part 55, is provided. In an elevating part position control part 10, positioning is made while controlling the vibration of the elevating part 55 based on the relative vibration position. At that time, the component of elastic vibration mixed into a relative vibration position signal is suppressed by a notch filter NF to change the center frequency of the filter NF at every positioning place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension type elevating device, and more particularly, to a suspension type elevating device for performing vibration suppression control for suppressing the vibration of an elevating part suspended from a movable carriage via a suspension member. It concerns the device.

[0002]

2. Description of the Related Art As a transport device for transporting a load, a lift with a hand is suspended by a suspension material from a movable truck running on a rail arranged near a ceiling so as to be able to move up and down. There is a suspended lifting device (so-called crane) for transporting. The suspension type lifting device is generally used for transferring heavy objects, but in recent years, its use as a transfer device such as a wafer cassette in a semiconductor manufacturing plant has been particularly noted. A problem with such a suspension type lifting device is the swing of the suspended lifting table. Since the lift platform is a pendulum with the movable platform as a fulcrum, for example, when the movable platform is stopped, a swing occurs on the lift platform in accordance with the natural frequency determined by the length of the suspension member. While the lift platform is shaking greatly, for example, immediately after the movable trolley stops, it is not possible to accurately grasp the luggage placed at the predetermined position, or to move the luggage being gripped to the predetermined position accurately. Can not be placed. In a semiconductor manufacturing plant, various processing equipment is often installed close to each other, and the mechanical strength of the conveyed members is weak. Therefore, the swing of the elevating table is a particularly important problem, such as a dynamic vibration absorber and a damper. In many cases, passive steady rests using are not sufficient. Therefore, it is necessary to perform vibration suppression control for positively attenuating the swing of the elevator. FIG. 4 shows an example of a suspension type lifting device capable of performing the above-described vibration suppression control. As shown in FIG. 4, the suspension type lifting device includes a movable carriage 53 moving along a rail 52 provided on a ceiling 51, a positioning actuator 1 and an upper plate 2 attached to a lower portion of the movable carriage 53. A suspension member 54 suspended from the upper plate 2; and a hand 5 attached to the lower end of the suspension member 54 and capable of gripping a load 56.
A lifting / lowering portion 55 to which the upper / lower portion 5a is integrally attached, a deflection position sensor 3 for detecting a relative deflection position of the lifting / lowering portion 55 with respect to the upper plate 2, and a relative deflection position of the lifting / lowering portion 55 with respect to the upper plate 2; A position control unit 10 that controls the position and speed of the positioning actuator 1 to control the position and speed of the positioning actuator 1 and controls the position of the lifting unit 55 while controlling the vibration of the lifting unit 55. Is provided. In the suspension type lifting device, when the movable carriage 53 reaches a predetermined position (station) on the rail 52, the suspension member 5 is attached to the upper plate 2 by a winding device (not shown).
4. The unwinding / rewinding of No. 4 is performed, whereby the elevating unit 55 is lowered / raised. At this time, the swing generated in the elevating unit 55 is suppressed by operating the positioning actuator 1. The positioning actuator 1 holds the upper plate 2 in a horizontal plane with the movable carriage 5
3 and moves in accordance with a thrust command output from the lifting / lowering unit position control unit 10.
Here, FIG. 5 shows an example of a control block diagram of the lifting / lowering unit control unit 10. The actual position and actual speed of the positioning actuator 1 are detected by a sensor (not shown). In the suspension type lifting / lowering device, when the movable carriage 53 stops at the target position, the positioning actuator 1 is moved to, for example, a predetermined origin position (the movable carriage 53 and the upper plate 2 with respect to the lifting / lowering unit position controller 10). (Determined from the relative positional relationship of the above). The deviation between the position command and the actual displacement of the positioning actuator 1 is input to the position compensator 11. The position compensator 11 outputs a speed command to make the position deviation zero. The deviation between the speed command and the actual speed of the positioning actuator 1 is input to the speed compensator 12. The speed compensator 12 outputs a thrust command that makes the speed deviation zero. At the same time, the relative shake speed of the elevating unit 55 with respect to the upper plate 2 is input to the steady rest compensation unit 4. The relative shake speed is determined based on the relative shake position of the elevating unit 55 with respect to the upper plate 2 detected by the shake position sensor 3. In the steady rest compensator 4, a thrust corresponding to the swing speed of the elevating unit 55 is output by the proportional element 4a, and further output as a vibration suppression signal via the filter 4b. The vibration damping signal output from the steady rest compensator 4 is added to the thrust command output from the speed compensator 12 after phase inversion, and the thrust command is input to the positioning actuator 1 and given a predetermined value. The operation is performed.
According to the above control, when there is a run-out in the elevating unit 55, the positioning actuator 1 is equivalently proportional to the run-out speed of the elevating unit 55 when the run-out frequency is sufficiently lower than the speed control frequency. And displace. Here, when a relative displacement occurs between the upper plate 2 and the elevating unit 55, the elevating unit 5
5, a force proportional to its own swing speed is given to the lifting unit 55 as a damping force, and the vibration of the lifting unit 55 is attenuated in a short time.

[0003]

When the vibration suppression control is performed based on the relative vibration position as described above, a signal corresponding to the relative vibration position includes a rail vibration or a signal between the positioning actuator and the sensor. A signal related to the generated elastic vibration may be mixed. In this case, if the vibration suppression control is performed by using the proportional element 4a having a large value in order to enhance the vibration suppression effect, oscillation occurs at the frequency related to the elastic vibration as shown in FIG. There was a problem. In addition, the frequency of the elastic vibration changes depending on the position of the rail on which the movable trolley runs, the state of the ceiling on which the rail is provided, and the like. In order to solve the problems in the prior art, the present invention has improved a suspension type elevating device, and a movable bogie uses an oscillation related to vibration suppression control generated by elastic vibration mixed in a signal corresponding to a relative swing speed. It is an object of the present invention to provide a suspension type lifting device which can be suitably suppressed for each moving station.

[0004]

Means for Solving the Problems In order to achieve the above object, according to the first aspect of the present invention, a movable trolley moving on a predetermined track and a movable trolley suspended from the movable trolley via suspension materials. An elevating unit, positioning means for positioning the suspension member in a horizontal plane, and vibration damping control means for operating the positioning means based on the swing speed of the elevating unit to perform vibration suppression control for suppressing the swing of the elevating unit. In the suspension type lifting device provided, the oscillation preventing means for preventing the oscillation related to the vibration suppression control caused by the elastic vibration component mixed in the signal corresponding to the swing speed of the elevating unit, and the setting of the oscillation preventing means are set. And a setting change means for changing the position for each position to be positioned by the positioning means. According to a second aspect of the present invention, in the suspension lifting device according to the first aspect, the oscillation preventing means is a suppression filter that suppresses the elastic vibration component from a signal corresponding to a swing speed of the lifting unit. The gist is that the setting change means changes the setting of the suppression frequency band to be suppressed by the suppression filter. The invention according to claim 3 is:
3. The suspension type lifting device according to claim 2, wherein the oscillation preventing means is a notch filter, and the setting changing means changes the setting of the center frequency of the notch filter. . Claims 1-3
According to the suspension type elevating device described in any one of the above, for example, an elastic vibration component is mixed into a signal corresponding to the swing speed of the elevating unit due to generation of elastic vibration in the positioning actuator or vibration of the rail. Even in the case where the vibration changes at each position where the positioning is performed by the positioning actuator, the oscillation preventing means can prevent the oscillation related to the vibration suppression control. Here, the prevention of the oscillation related to the vibration suppression control by the oscillation prevention means is performed by suppressing the elastic vibration component using a notch filter or the like from a signal corresponding to the shake speed of the elevating unit. Also,
The invention according to claim 4 is the invention according to any one of claims 1 to 3 above.
In the suspension type elevating device described in the paragraph, there is provided storage means for storing the setting of the oscillation preventing means in correspondence with each position to be positioned by the positioning means, and the setting change means is stored in the storage means. The gist is that the setting of the oscillation preventing means is changed based on the setting of the oscillation preventing means. According to the suspension type lifting device according to the fourth aspect, by providing a simple storage means such as a nonvolatile memory, the setting of the oscillation preventing means can be changed. According to a fifth aspect of the present invention, in the suspension type elevating device according to any one of the first to third aspects, the predetermined track is provided on the predetermined track side corresponding to each position to be positioned by the positioning means. Or output means for outputting information on the elastic vibration component of the member in the vicinity thereof to the setting changing means, wherein the setting changing means controls the oscillation prevention based on the information on the elastic vibration component output from the output means. The gist is that the setting of the means is changed. According to the suspension type lifting device according to the fifth aspect, by providing the output means on the predetermined track side, the configuration of the suspension type lifting device can be simplified.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The following embodiment is a specific example of the present invention and does not limit the technical scope of the present invention. First, FIG. 1 shows a schematic configuration of a suspension type lifting device A1 according to an embodiment of the present invention. The suspension type lifting device A1
Is a transfer device used, for example, in a semiconductor manufacturing plant and the like, and its configuration is almost the same as that described in the prior art. That is, as shown in FIG. 1, the suspension type lifting / lowering device A1 includes a movable carriage 53 that moves along a rail 52 provided on a ceiling 51, and a positioning actuator 1 (positioning) attached to a lower portion of the movable carriage 53. And an upper plate 2 and a suspension 5 suspended from the upper plate 2
4 and attached to the lower end of the suspension
A lifting / lowering portion 55 integrally provided with a hand 55a capable of holding the gripper 6, a vibration position sensor 3 for detecting a relative vibration position of the lifting / lowering portion 55 with respect to the upper plate 2, and an upper / lower plate 2 of the lifting / lowering portion 55; The vertical movement controlling the position and speed of the positioning actuator 1 by controlling the position and speed of the positioning actuator 1 while controlling the vibration of the lifting unit 55 based on the relative vibration position with respect to the vertical movement of the lifting unit 55 to control the position of the lifting unit 55 Unit position control unit (corresponding to vibration suppression control means) 10
And The suspension type lifting device A1 is particularly different from the conventional one in that the component of the elastic vibration of the upper plate 2 mixed in the relative swing position signal of the lifting portion 55 with respect to the upper plate 2 is converted to a notch filter NF (oscillation prevention). Means, an example of a suppression filter).
The center frequency omega ₀ of a point to be changed for every predetermined position (station) for positioning by the positioning actuator 1. Next, the suspension type lifting device A1 will be described in detail. Here, FIG. 2 is a diagram showing an example of a control block diagram of the suspension type lifting device A1. As shown in FIG. 2, the elevating / lowering unit position control unit 10 comprises: a position control loop for outputting a speed command by a position compensating unit 11 based on a deviation between a position command for the positioning actuator 1 and an actual position; A speed control loop for outputting a thrust command to the positioning actuator 1 by the speed compensating unit 12 based on a deviation between the speed command for the positioning actuator 1 output from the unit 11 and the actual speed, and the optical position sensor 3 A notch filter NF for suppressing the elastic vibration component of the upper plate 2 and the like from the relative deflection displacement of the elevating unit 55 output from the
A vibration damping signal for the positioning actuator 1 is output based on the vibration speed of the lifting / lowering unit 55 determined based on the relative vibration position in which the elastic vibration component is suppressed by F. Compensation unit 1
Anti-sway compensator 4 to be added to the thrust command output from 2
And The steady rest compensator 4 includes a proportional element 4a.
And a filter 4b. The proportional element 4a
Is set according to the stop height of the elevating unit 55.
The filter 4b is a low-pass filter provided for removing observation noise and preventing oscillation of the servo system due to the observation noise.

The control operation of the positioning actuator 1 by the above-described elevator position control unit 10 will be described. When the mobile trolley 53 stops at the station,
The positioning actuator 1 is moved, for example, to a predetermined origin position (the moving carriage 5
(Determined from the relative positional relationship between the upper plate 2 and the upper plate 2). In the position command, a deviation from the actual displacement of the positioning actuator 1 is obtained.
It is input to the position compensator 11. Position compensator 11
Outputs a speed command to make the position deviation zero, and further calculates the deviation of the speed command from the actual speed of the positioning actuator 1 and inputs the deviation to the speed compensator 12. The speed compensator 12 outputs a thrust command that makes the speed deviation zero. At the same time, the relative shake velocity obtained by differentiating the relative shake position of the elevating unit 55 output from the optical position sensor 3 by the differentiator is input to the shake compensation unit 4. In the suspension type lifting device A1, the elastic vibration component generated in the upper plate 2, the rail 52, and the like mixed in the relative swing position is suppressed by the notch filter NF. The notch filter NF is realized by, for example, a digital filter using a DSP or the like. Its frequency transfer function is G (s) = s ² + ω ₀ ² / (s ² + 2ζω ₀ s +
ω ₀ ² ) (where ω ₀ is the center frequency of the notch filter NF, ζ
Is a constant. ). FIG. 3 shows a gain curve of the notch filter. The horizontal axis is frequency ω
, The vertical axis is the logarithmic axis of the gain G. As shown in FIG. 3, the notch filter NF is intended to attenuate only the center frequency omega ₀ near the component. The center frequency ω ₀ is set to a frequency of the elastic vibration component measured in advance. When the constant ζ is set to be large, the frequency width Δ for attenuating the signal is widened, and when the constant ζ is set to be small, the frequency width Δ is narrowed. When the notch filter NF is constituted by a digital filter, it is easy to change the center frequency ω ₀ and the constant ζ. The frequency of the elastic vibration component is stored in a storage means such as a non-volatile memory (not shown), and every time it reaches the station, the center frequency ω ₀ of the notch filter NF is added to the frequency of the elastic vibration component corresponding to the station. Be updated. Note that a computing unit such as a CPU or a DSP that performs this updating process corresponds to a setting updating unit in the present invention. Thereby, even when the frequency of the elastic vibration of the ceiling 51, the rail 52, or the like changes for each station, the elastic vibration component can be easily suppressed from the relative vibration position signal. Then, the relative shake position signal in which the elastic vibration component is suppressed by the notch filter NF is differentiated by a differentiator, converted into a shake relative speed, and input to the shake compensation unit 10. In the steady rest compensator 4, the proportional element 4a
As a result, a thrust corresponding to the swing speed of the elevating unit 55 is output, and further output as a vibration suppression signal via the filter 4b. The vibration damping signal output from the steady rest compensator 4 is added to the thrust command output from the speed compensator 12 after phase inversion, and the thrust command is input to the positioning actuator 1 and given a predetermined value. The operation is performed.
According to the above control, when there is a runout in the elevating unit 55, the positioning actuator 1 is equivalently displaced in proportion to the runout speed of the elevating unit 55. Here, when a relative displacement occurs between the upper plate 2 and the elevating unit 55, the elevating unit 55
Since a force proportional to the applied force acts on the lifting / lowering unit 55, a force proportional to its own swing speed is given to the lifting / lowering unit 55 as a damping force, and the vibration of the lifting / lowering unit 55 is attenuated in a short time. In addition, even when the upper plate 2 or the like is elastically vibrated, only the elastic vibration component is suppressed from the vibration speed of the elevating unit 55. Therefore, even if the vibration suppression control for suppressing the vibration of the elevating unit 55 is performed. As shown in FIG. 6B, occurrence of oscillation due to the elastic vibration is prevented. As described above, according to the above-mentioned suspension type elevating device, an elastic vibration component is mixed into a signal corresponding to the swing speed of the elevating unit due to, for example, generation of an elastic vibration on the upper plate. Even in the case where the vibration changes, the oscillation preventing means can prevent the oscillation related to the vibration suppression control.

[0007]

In the above embodiment, the vibration direction of the elevating section 55 is limited to the direction perpendicular to the rail, but the vibration parallel to the rail and the vibration of the suspension member 54 in the torsion direction will be described. This can also be applied by performing similar control using a positioning actuator that can move in a direction parallel to the rail and around a vertical axis. In the above-described embodiment, the positioning actuator 1 is used as an example of the positioning means. However, the moving carriage 53 itself may be used as the positioning means. That is, the movement of the movable carriage 53 on the rail may be used to perform the steadying and positioning of the elevating unit. However, in that case, it is possible to cope only with vibration parallel to the rail. In the above embodiment,
The frequency stored in the memory is read and the center frequency ω ₀ of the notch filter is updated for each station. However, the present invention is not limited to this. For example, at the location on the rail 52 side corresponding to each station, the rail 52 or the ceiling near the same may be used. Notch filter NF
Output means for outputting the notch filter N by an arithmetic means such as a CPU (another example of a setting updating means) based on the information on the elastic vibration component output from the output means.
The center frequency ω _{0 of} F may be updated. Further, in the above-described embodiment, the notch filter NF is constituted by a digital filter, but may be constituted by an analog filter. Further, not only a notch filter but also a low-pass filter, for example, can be used. In the above embodiment, the elastic vibration component mixed in the relative shake position measured by the optical position sensor 3 is suppressed. However, the present invention is not limited to this. For example, the notch filter NF May be inserted to suppress the elastic vibration component of the vibration suppression signal. Such a suspension type lifting device is also an example of the suspension type lifting device in the present invention. In the above-described embodiment, the relative shake speed is obtained by using the optical position sensor 3, but the present invention is not limited to this.

[0008]

As described above, the above claims 1 to 5 are described.
According to the suspension type elevating device described in any one of the above, for example, an elastic vibration component is mixed into a signal corresponding to the swing speed of the elevating unit due to generation of elastic vibration in the positioning actuator or vibration of the rail. Even in the case where the vibration changes at each position where the positioning is performed by the positioning actuator, the oscillation preventing means can prevent the oscillation related to the vibration suppression control.

[Brief description of the drawings]

FIG. 1 shows a suspension type lifting device A according to an embodiment of the present invention.
FIG. 1 is a schematic diagram showing a schematic configuration of No. 1.

FIG. 2 is a block diagram showing a schematic configuration of a lifting / lowering unit position control unit 10 of the suspension type lifting / lowering device A1.

FIG. 3 is a diagram showing a gain curve of a notch filter.

FIG. 4 is a schematic diagram showing a schematic configuration of a conventional suspension type lifting device.

FIG. 5 is a block diagram showing a schematic configuration of a lifting / lowering unit position control unit of a conventional suspension type lifting / lowering device.

FIG. 6 is a diagram for explaining oscillation caused by elastic vibration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Positioning actuator (an example of a positioning means) 3 ... Optical position sensor 4 ... Anti-sway compensating part 4a ... Proportional element 4b ... Filter 10 ... Elevating part position control part 11 ... Position compensating part 12 ... Speed compensating part 52 ... Rail 53 … Moving trolley 54… suspension material 55… elevator

Claims (5)

[Claims] 1. A moving truck that moves on a predetermined track, a lifting unit suspended from the moving truck via a suspension member, a positioning unit that positions the suspension member in a horizontal plane, and the lifting unit. A signal corresponding to the swing speed of the lifting / lowering unit, comprising: a suspension type lifting / lowering device comprising: a vibration suppression control unit for operating the positioning means based on the swing speed of the lift to control the swing of the lifting / lowering unit. An oscillation preventing means for preventing oscillation caused by the elastic vibration component mixed in the vibration damping control, and a setting changing means for changing the setting of the oscillation preventing means for each position to be positioned by the positioning means. A suspension type elevating device. 2. The apparatus according to claim 1, wherein said oscillation preventing means is a suppression filter for suppressing said elastic vibration component from a signal corresponding to a swing speed of said lifting / lowering part, and said setting change means is a suppression frequency band for suppressing said suppression filter. The suspension type elevating device according to claim 1, wherein the setting is changed. 3. The suspension lifting device according to claim 2, wherein said oscillation preventing means is a notch filter, and said setting change means changes a setting of a center frequency of said notch filter. 4. A storage means for storing the setting of the oscillation preventing means corresponding to each position to be positioned by the positioning means, wherein the setting change means stores the setting of the oscillation preventing means stored in the storage means. 4. The method according to claim 1, wherein the setting of the oscillation preventing means is changed based on the setting.
The suspension type lifting device according to the paragraph. 5. An output means for outputting information on the elastic vibration component of the predetermined track or a member near the predetermined track to the setting change means is provided on the predetermined track corresponding to each position to be positioned by the positioning means. 4. The suspension type lifting device according to claim 1, wherein said setting changing means changes the setting of said oscillation preventing means based on information on an elastic vibration component outputted from said output means. .