JPH11343096A - Suspension type elevating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform constantly stable vibration control even when the load of a suspended cargo is changed, when hanging materials having rigidity in the direction of swaying are used. SOLUTION: In a suspended type elevating-lowering device A1 in which an elevating- lowering part 57 is suspended from a movable carriage 53 by means of hanging materials 56' such as a wide belt which have rigidity in the direction of swaying, and which is provided with an anti-swaying compensating part 61 composed of an proportional element for outputting vibration control signals in response to the swaying speed of the elevating-lowering part 57 and a low pass filter, and a positioning actuator 54 for positioning the hanging materials 56' horizontally based on the vibration control signals, the load of a cargo W held by the elevating-lowering part 57 is detected by a load sensor 3, and the size of the proportional element constituting the anti- swaying compensating part 61 is adjusted by an adjustment part 1 based on a reference table 2 in which optimum values of the proportional element which correspond to the load of the cargo are previously stored, and the load of the cargo. Further, the filter frequency of the low pass filter is adjusted in response to the load of the cargo. Thus, even when the load of the cargo is changed to change the natural frequency of a pendrum spring, constantly stable vibration control can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension type lifting apparatus in which a lifting unit is suspended from a base (for example, a movable carriage) by a suspension member having a predetermined rigidity in a swing direction such as a wide belt. More particularly, the present invention relates to a suspension type elevating device in which the suspension member is positioned in a horizontal direction based on a vibration control signal corresponding to a swing speed of the elevating portion, thereby controlling the vibration of the elevating portion. is there.

[0002]

2. Description of the Related Art For example, in a factory or the like, as an apparatus for transporting luggage, a lifting unit with a hand is suspended by a suspending member from a movable trolley running on a rail disposed near a ceiling so as to be able to move up and down. In recent years, a suspension-type lifting device (so-called crane) that grips and transports a sheet has attracted particular attention. The biggest problem of such a suspension type lifting device is the swing of the suspended lifting portion. While the elevating unit is shaking greatly, for example, immediately after the movable trolley is stopped, it is not possible to accurately grasp the luggage placed at the predetermined position, or the luggage held at the predetermined position is not accurately moved. Can not be placed. However, after waiting for the natural decay of the swing of the lift,
The work efficiency would be extremely poor if the work was carried out. Therefore, it is effective to perform vibration suppression control for positively damping the swing of the elevating unit. A suspension elevating device for performing such vibration suppression control has already been filed by the present applicant (Japanese Patent Application No. 10-088743). Hereinafter, a transfer device A0, which is an example of the suspension type lifting device, will be briefly described with reference to FIGS. As shown in FIG. 5, the transfer device A0 includes a movable carriage 53 that moves along a rail 52 provided on a ceiling 51, a positioning actuator 54 attached to a lower portion of the movable carriage 53, and an upper plate 5.
5, a suspending member 56 suspended from the upper plate 55, and a lifting / lowering portion 57 attached to a lower end of the suspending member 56 and integrally attached with a hand 57a capable of gripping a load W.
And the light emitted from above the elevating section 57 is
An optical position detecting device 58 for detecting the relative position of the elevating unit 57 with respect to the movable carriage 53 based on the light receiving position of the optical position detecting device 58;
8 to control the operation of the positioning actuator 54 on the basis of the output of the control unit 8 to control the positioning of the positioning actuator 54 and control the vibration of the lifting unit 57.
The suspension member 56 is wound / unwound by, for example, a winding drum (not shown) attached to the upper plate 55 side, whereby the elevating unit 57 is moved up / down. The positioning actuator 54 moves the upper plate 55 relative to the movable carriage 53 in a horizontal direction and around a vertical axis, and operates according to a thrust command from the elevation unit position control device 60. As shown in FIG. 6, the lifting / lowering unit position control device 60 includes the positioning actuator 54, a positioning controller 63, a differentiator 61, and a steady rest compensating unit 62. The positioning controller 63 further outputs a speed command based on a deviation between a position command (target position value) and an actual displacement (actual position) for the positioning actuator 54, and a position compensating unit 63a. A speed compensator 63b that outputs a thrust command to the positioning actuator 54 based on the output deviation between the speed command and the actual speed for the positioning actuator 54, and a vibration suppression signal output from the steady rest compensator 62. Is added to the thrust command output from the speed compensator 63b. The steady rest compensator 62 includes a proportional element 62a.
And the filter 62b, and the shake position (horizontal position xc, yc, and rotation angle θ about the vertical axis) of the elevation unit 57 output from the optical position detection device 58.
A vibration damping signal is output based on the shake speed obtained by differentiating s) with the differentiator 61. The filter 62b
Is a low-pass filter provided to remove the observation noise and prevent the oscillation of the servo system due to the observation noise.

A description will now be given of the operation of positioning and damping control with respect to the elevating unit 57 by the elevating unit position controller 60 as described above. When the movable carriage 53 stops at the target position, the positioning actuator 54 is moved to, for example, a predetermined origin position (determined by the relative positional relationship between the movable carriage 53 and the upper plate 55) with respect to the lifting / lowering unit position control device 60. Is given a position command for control. The position command has a deviation (position deviation) from the actual displacement of the positioning actuator 54, and is input to the position compensator 63a. The position compensator 63a outputs a speed command to make the position deviation zero, and the speed command is used to calculate a deviation (speed deviation) from the actual speed of the positioning actuator 54. 63b. From the speed compensator 63b, the speed deviation is set to 0.
Is output. At the same time, a shake speed obtained by differentiating the shake position of the elevating unit 57 obtained by the optical position detection device 58 with the differentiator 61 is input to the shake prevention compensator 62. . In the steady rest compensator 62, the proportional element 62a outputs a thrust corresponding to the shake speed of the elevating unit 57, and the filter 62b removes observation noise, and outputs the thrust to the positioning controller 63 as a damping signal. Is output. The vibration damping signal output from the steady rest compensator 4 is added to the thrust command output from the speed compensator 63 b after the phase inversion in the positioning controller 63, and the thrust command is added to the positioning actuator 54. Is input to The positioning actuator 54 performs an operation according to the input thrust command. According to the above control, when there is a run-out in the elevating unit 57, the positioning actuator 54 is equivalently proportional to the run-out speed of the elevating unit 57 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 55 and the lifting / lowering portion 57, a force proportional to the relative displacement acts on the lifting / lowering portion 57, so that a force proportional to its own swing speed is applied to the lifting / lowering portion 57. Thus, the vibration of the elevating unit 57 is attenuated in a short time. Further, since the vibration suppression signal output from the steady rest compensator 62 is added in the form of a disturbance to the thrust command output from the speed compensator 63b, the positioning actuator 54 is controlled by the position compensator 63a. By the position control loop, the vibration is attenuated at the target position with the attenuation of the vibration of the elevating unit 57.

[0004]

In the transfer device A0, if the suspension member 56 is made of a wire having little rigidity in the direction of its swing,
If the suspension length is the same, the frequency is constant regardless of the load of the load W gripped by the hand 57a. This is because the rigidity of the pendulum spring is proportional to the load. Therefore, in this case, if a predetermined value is used for each suspension length as the proportional element 62a of the steady rest compensator 62, the load W
Even if the load changes, the vibration suppression control is performed accurately. However, for example, when the suspension member 56 has a predetermined rigidity in the swing direction, for example, is formed of a wide belt or the like, even if the suspension length is the same, the suspension member 56 has a specific rigidity according to the load of the load W. The frequency changes. This is because the rigidity of the pendulum spring is obtained by adding the rigidity of the suspension member, and the rigidity of the pendulum spring and the load do not have a proportional relationship. As is clear from the root locus shown in FIG.
If the magnitude of “a” is constant, the vibration suppression control tends to become unstable as the natural frequency increases. Specifically, when the natural frequency of the pendulum spring is relatively low, as shown in FIG. 8A, the swing of the elevating unit 57 is stably damped by the stable operation of the positioning actuator 54, When the natural frequency increases, the operation of the positioning actuator 54 becomes unstable as shown in FIG. 8 (b), and the decay time of the vibration of the elevating unit 57 also becomes unstable. As described above, when a wide belt or the like having a predetermined rigidity in the deflection direction is used as the suspension member 56, the natural frequency changes depending on the magnitude of the load. There is a problem that the vibration suppression control does not work effectively depending on the magnitude of the load. The present invention has been made in view of the above circumstances, and its purpose is to
An object of the present invention is to provide a suspension type elevating device capable of always performing stable vibration suppression control even when a load of a suspended load changes when a suspension material having rigidity in a swing direction is used.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a suspension type lifting apparatus in which a lifting member capable of gripping a load is suspended from a base by a suspension member having a predetermined rigidity in a swing direction. A vibration compensation device for outputting a vibration suppression signal corresponding to a vibration speed of the lifting / lowering portion; and a positioning device for horizontally positioning the suspension member based on the vibration suppression signal from the vibration compensation device. And a load detecting means for detecting the load of the load, and the swing speed constituting the steady rest compensating means based on the load of the load obtained by the load detecting means. The present invention is configured as a suspension type elevating device comprising a proportional element adjusting means for adjusting the size of the proportional element. At this time, the proportional element adjusting means is:
For example, the adjustment of the proportional element may be performed based on a proportional element table in which an optimum value of the proportional element according to the load of the load is stored in advance. Further, it is desirable to have a filter frequency adjusting means for adjusting the frequency of the noise removal filter constituting the steady rest compensating means based on the load of the load obtained by the load detecting means. At this time, the filter frequency adjusting means can be configured to adjust the filter frequency based on a filter frequency table in which an optimum value of the frequency of the noise removal filter according to the load of the load is stored in advance. In addition to the load detecting means for directly detecting the load of the load held by the elevating section, the load detecting means detects the load of the load based on, for example, a current value of a drive motor for driving the elevating section up and down. It may be configured as follows.

[0006]

According to the suspension type lifting device according to the present invention, for example, the proportional element table in which the optimum value of the proportional element according to the load of the load is stored is used to respond to the load of the load obtained by the load detecting means. The optimal proportional element size is set,
Based on this, the vibration suppression control is performed. Therefore, when a suspension having a predetermined rigidity in the swing direction is used, optimal vibration suppression control can always be performed even if the load of the load changes and the natural frequency of the pendulum spring changes. Further, for example, using a filter frequency table in which the optimum value of the frequency of the noise removal filter according to the load of the load is stored in advance, the optimum filter frequency is set according to the load of the load obtained by the load detecting means. If the vibration suppression control is performed by using the filter, an optimum filter frequency according to the magnitude of the noise can be set, and the optimum vibration suppression control can always be performed. Note that the optimal value of the filter frequency is set to a lower value as the load on the load increases, and a higher value as the load on the load decreases, so that the filter frequency is set lower as the natural frequency becomes lower. The adverse effect of the setting on the vibration suppression control can be ignored.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the present invention will be described below with reference to the accompanying drawings to facilitate understanding of the present invention. The following embodiments and examples are mere examples embodying the present invention, and do not limit the technical scope of the present invention. Here, FIG. 1 is a schematic diagram showing a schematic configuration of a transport device A1 according to an embodiment of the present invention, FIG. 2 is a block diagram showing a schematic configuration of a lifting / lowering portion position control device 60 'of the transport device A1, and FIG. Is a correspondence table showing the relationship between the magnitude of the load and the natural frequency, the proportional element, the noise, and the filter frequency. FIG. 4 is a vibration damping time chart of the lifting / lowering unit when the vibration control is performed by the transfer device A1. 7 is a graph showing the operation history of the positioning actuator.

The transfer apparatus A1 according to this embodiment is an example in which the suspension type lifting apparatus according to the present invention is embodied in the same manner as the above-mentioned conventional transfer apparatus A0. Are denoted by the same reference numerals, and detailed description is omitted in principle. The transport device A1 according to the present embodiment includes:
It has a schematic configuration as shown in FIGS. First, a suspension member 56 ′ suspending the elevating unit 57 from the upper plate 55.
Is constituted by a belt which is wide in a direction perpendicular to the rail 52 (the left-right direction in FIG. 1). Therefore, the suspension member 56 '
Has a predetermined rigidity against deflection in the direction perpendicular to the rail 52. A load sensor 3 (an example of a load detecting unit) that detects a load of the load W held by the hand 57a is installed in the elevating unit 57. Further, the optimal value of the proportional element 62a and the optimal value of the frequency of the low-pass filter 62b (an example of a noise removing filter) are stored in the lifting / lowering unit position control device 60 'in accordance with the load of the load W held by the hand 57a. Based on the reference table 2 (an example of a proportional element table and a filter frequency table) stored in advance and the load of the load W detected by the load sensor 3, the size of the proportional element 62a and the An adjustment unit 1 (an example of a proportional element adjustment unit and a filter frequency adjustment unit) that extracts the optimum value of the frequency of the low-pass filter 62b and adjusts the proportional element 62a and the low-pass filter 62b based on these optimum values. I have. The optimum values of the proportional element and the filter frequency stored in the reference table 2 are set based on the relationship as shown in FIG. First, with respect to the proportional element, the natural frequency increases as the load W becomes lighter. Therefore, the optimal value of the proportional element is set to a smaller value as the load of the load W becomes smaller. Note that the optimum value of the proportional element can be obtained from the root locus. For the filter frequency,
As the size of the proportional element increases, the value is set to a lower value to prevent the noise from expanding. In addition, since the filter frequency is set lower as the natural frequency becomes lower by such setting, the adverse effect on the vibration suppression control by setting the filter frequency lower can be ignored.

The procedure of the vibration suppression control by the transfer device A1 will be described. When starting the vibration suppression control, first, the load W held by the hand 57a by the load sensor 3 is loaded.
(0 if not gripped) is detected. The adjusting unit 1 extracts the size of the proportional element and the optimum value of the frequency of the low-pass filter from the look-up table 2 based on the load of the load W detected by the load sensor 3. The values of the proportional element 62a and the low-pass filter 62b are set to optimal values according to the load. Adjustment of the magnitude of the proportional element and the frequency of the low-pass filter according to the load of the load is based on only the components relating to the deflection in the direction perpendicular to the rail 53 in which the suspension member 56 'has rigidity and the direction of the torsion. A constant value for each suspension length is used for the component in the direction parallel to the rail 53 where the suspension member 56 'has no rigidity. After the adjusting unit 1 sets the values of the proportional element 62a and the low-pass filter 62b of the steady rest compensating unit 62, the vibration suppression control is started in the same manner as in the conventional transport device A0. FIG. 4 shows an example of the displacement decay time calendar of the elevating unit 57 obtained as a result of performing the vibration damping control by the transfer device A1. The conditions (the initial displacement of the lifting unit, the suspension length, the load of the load, the start time of the vibration suppression control, etc.) are the same as those in the case of FIG. In the case of the conventional transport device A0 (FIG. 8)
It can be seen that the operation of the positioning actuator 54 is more stable than in the case of (b)), and the swing of the elevating unit 57 is attenuated in a short time. As described above, in the present transfer apparatus A1,
On the basis of the reference table 2 and the load of the load W obtained by the load sensor 3 as described above, the proportional element 62a and the low-pass filter 62b are
Since the optimal value is set according to the load of the load W gripped in 7a, stable vibration suppression control can be always performed even if the load of the load W changes.

[0010]

[Embodiment] In order to minimize adverse effects on vibration suppression control due to rapid changes in the proportional element and the filter frequency,
The updating of the proportional element and the filter frequency by the adjusting unit 1 is desirably performed when the swing speed of the elevating unit 57 is 0 or close to it. The low-pass filter 62
b, or the low-pass filter 6 by the adjusting unit 1
Adjustment of 2b is not essential. For example, when the effect of noise is negligible or when a sufficient effect is obtained with a constant filter frequency, the low-pass filter 62b is omitted, or the adjustment of the low-pass filter 62b by the adjustment unit 1 is omitted. You can also. In the above embodiment, the adjusting unit 1 controls the proportional element 62a.
Is adjusted, but this is only an example. For example, the differentiator 61 is omitted by omitting the proportional element 62a.
May be adjusted. As the load detecting means for detecting the load of the load, in addition to the load sensor 3 for directly detecting the load of the load as in the load sensor 3, for example, a drive motor for driving a winding drum for winding and unwinding the suspension member 56 '. It is also conceivable to detect the current value (the square of the current value is a function of the load). Further, the control block diagram shown in FIG. 2 is merely an example, and it goes without saying that, for example, the configuration of the positioning controller 63 can be appropriately changed.

[0011]

As described above, the present invention relates to a suspension type lifting device in which a lifting portion capable of gripping a load is suspended from a base by a suspension member having a predetermined rigidity in a swing direction. A suspension comprising: a steady rest compensating means for outputting a vibration damping signal corresponding to a swing speed of the elevating unit; and a positioning means for positioning the suspension material in a horizontal direction based on the vibration damping signal from the steady rest compensating means. A load detecting means for detecting the load of the load, and a magnitude of a proportional element applied to the shake speed constituting the steady rest compensating means based on the load of the load obtained by the load detecting means. And a proportional element adjusting means for adjusting the height of the pendulum spring, the natural frequency of the pendulum spring changes due to a change in the load of the suspended load. It is possible to also perform always stable damping control. Further, by providing a filter frequency adjusting means for adjusting the frequency of the noise removing filter constituting the steady rest compensating means based on the load of the load obtained by the load detecting means, an optimum frequency corresponding to the magnitude of the noise is provided. The filter frequency can be set, and optimal vibration suppression control is always possible. Note that the optimal value of the filter frequency is set to a lower value as the load on the load increases, and a higher value as the load on the load decreases, so that the filter frequency is set lower as the natural frequency becomes lower. The adverse effect of the setting on the vibration suppression control can be ignored.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a transport device A1 according to an embodiment of the present invention.

FIG. 2 is a vertical position control device 6 of the transport device A1.
FIG. 2 is a block diagram showing a schematic configuration of 0 ′.

Fig. 3 Size of load, natural frequency, proportional element,
6 is a correspondence table showing a relation between noise and a filter frequency.

FIG. 4 is a graph showing a vibration damping time history of a lifting / lowering unit and an operation history of a positioning actuator when vibration suppression control is performed by the transfer device A1.

FIG. 5 is a schematic diagram illustrating a schematic configuration of a transport device A0 according to a conventional technique.

FIG. 6 is a vertical section position control device 60 of the transport device A0.
FIG. 2 is a block diagram showing a schematic configuration of FIG.

FIG. 7 is a root locus when the natural frequency of the pendulum spring is changed.

FIG. 8 is a graph showing a vibration damping time history of the elevating unit and an operation history of the positioning actuator when the vibration suppression control is performed by the transfer device A0 (when the natural frequency is low (a)).
(B).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Adjustment part (an example of a proportional element adjusting means and a filter frequency adjusting means) 2 ... Reference table (an example of a proportional element table and a filter frequency table) 3 ... Load sensor (an example of a load detecting means) 53 ... An example of a base) 54 ... Positioning actuator (an example of positioning means) 56 ... Suspension member 57 ... Elevating part 57a ... Hand 58 ... Optical position detecting device 62 ... Sway compensator W ... Luggage

Claims (5)

[Claims] 1. A suspension type lifting device in which a lifting member capable of gripping a load is suspended from a base by a suspension member having a predetermined rigidity in a swinging direction. A suspension type lifting / lowering device comprising: a steady rest compensating means for outputting a swing signal; and a positioning means for positioning the hanging material in a horizontal direction based on the vibration damping signal from the steady rest compensating means. Load detecting means for detecting the load, and proportional element adjusting means for adjusting the magnitude of the proportional element relating to the shake speed constituting the steady rest compensating means based on the load of the load obtained by the load detecting means. A suspension type lifting apparatus characterized by comprising: 2. The apparatus according to claim 1, further comprising a proportional element table preliminarily storing an optimum value of said proportional element according to a load of said luggage, wherein said proportional element adjusting means adjusts said proportional element based on said proportional element table. The suspension type lifting device according to claim 1. 3. A filter frequency adjusting means for adjusting a frequency of a noise removing filter constituting the steady rest compensating means based on the load of the load obtained by the load detecting means. Suspension type lifting device. 4. A filter frequency table in which an optimum value of a frequency of the noise removing filter according to a load of the load is stored in advance, and the filter frequency adjusting means includes:
4. The suspension type lifting device according to claim 3, wherein said filter frequency is adjusted based on said filter frequency table. 5. The suspension type lifting device according to claim 1, wherein said load detecting means detects the load of said load based on a current value of a drive motor for driving the lifting portion up and down.