JP4123566B2 - Suspended lifting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has an elevating part suspended from a base (for example, a movable carriage) via a suspension member so that the elevating part can be raised and lowered, and optical position detection of the position of the elevating part is performed for position adjustment of the elevating part The present invention relates to a suspension type lifting device that can prevent trouble when the light beam of the optical position detector is blocked by a human hand or the like.
[0002]
[Prior art]
For example, in a factory or the like, a transport device equipped with a suspended lifting device (a so-called crane) is often used as a load transport device. An example of such a transport apparatus is shown in FIGS.
4 includes a moving carriage 53 that moves along a rail 52 disposed on a ceiling 51, a positioning actuator 1 and an upper plate 2 that are attached to the lower portion of the moving carriage 53, and the upper plate. 2 is attached to the lower end portion of the suspension material 54, and a lifting / lowering portion 55 integrally attached with a hand 55a capable of gripping the load 59, and is provided on the lifting / lowering portion 55. A lifting part position control device 10 (see FIG. 5, which will be described in detail later) that controls vibration of the lifting part 55 by controlling the positioning operation of the positioning actuator 1 is provided. The suspension material 54 is taken up / unwinded by a winding device (not shown) attached to the upper plate 2 side, for example, and the raising / lowering portion 55 is raised / lowered.
The positioning actuator 1 moves the upper plate 2 relative to the movable carriage 53 in the horizontal direction perpendicular to the rail 52, and operates in accordance with a thrust command from the elevator position control device 10. The actual position (actual movement amount) and actual speed of the positioning actuator 1 are detected by a sensor (not shown) provided in the positioning actuator 1. The relative position of the elevating unit 55 as viewed from the upper plate 2 is observed by receiving a light beam from the light projecting unit 56 provided on the elevating unit 55 by the light receiving unit 57 provided on the upper plate 2.
Next, the configuration and control operation of the lift unit position control device 10 will be described with reference to the control block diagram shown in FIG.
As shown in FIG. 5, the elevating unit position control device 10 outputs a speed command from the position compensation unit 11 based on the deviation between the position command (position target value) for the positioning actuator 1 and the actual displacement (actual position). And a speed control for outputting a thrust command to the positioning actuator 1 by the speed compensation unit 12 based on a deviation between a speed command for the positioning actuator 1 output from the position compensation unit 11 and an actual speed. A damping signal for the positioning actuator 1 is output based on the loop and the shaking relative speed obtained by differentiating the shaking relative displacement of the lifting / lowering part 55 with respect to the upper plate 2 from the light receiving part 57 by the differentiator 58. An anti-sway compensation unit 4 (anti-sway compensation means) that adds the thrust signal output from the speed compensation unit 12 after phase inversion of the shake signal. Is constructed out with equivalent).
The steady-state compensation unit 4 includes a proportional element 4a and a filter 4b. The proportional element 4a is set according to the stop height of the elevating part 55. The filter 4b is a low-pass filter provided to remove observation noise and prevent servo system oscillation due to the observation noise.
[0003]
In the elevating part position control device 10 as described above, when the movable carriage 53 stops at the target position, the positioning actuator 1 is moved to the elevating part position control apparatus 10 by, for example, a predetermined origin position (with the moving carriage 53 and the above). A position command for control is given (determined from the relative positional relationship with the upper plate 2). The position command takes a deviation (position deviation) from the actual displacement of the positioning actuator 1 and is input to the position compensation unit 11. The position compensation unit 11 outputs a speed command that makes the position deviation zero, and the speed command is further deviated from the actual speed of the positioning actuator 1 (speed deviation). 12 is input. The speed compensator 12 outputs a thrust command that sets the speed deviation to zero.
At the same time, a shake relative speed composed of a differential value of the shake relative displacement from the light receiving unit 57 is input to the shake compensation unit 4. In the anti-sway compensation unit 4, a thrust according to the oscillation speed of the elevating unit 55 is output by the proportional element 4a, and further output as a vibration suppression signal through the filter 4b.
The vibration suppression signal output from the steady rest compensation unit 4 is added to the thrust command output from the speed compensation unit 12 after phase inversion, and the thrust command is input to the positioning actuator 1 to obtain a predetermined value. Operation is performed.
With the above control, when there is a swing in the lifting / lowering section 55, the positioning actuator 1 is equivalently proportional to the swing speed of the lifting / lowering section 55 when the swing frequency is sufficiently lower than the speed control frequency. To be displaced. Here, when a relative displacement occurs between the upper plate 2 and the lifting / lowering part 55, a force proportional to the lifting / lowering part 55 acts on the lifting / lowering part 55. Therefore, a force proportional to its own swing speed is applied to the lifting / lowering part 55. The vibration of the elevating part 55 is attenuated in a short time. Further, since the vibration suppression signal output from the steady rest compensation unit 4 is added to the thrust command output from the speed compensation unit 12 in the form of a disturbance, the positioning actuator 1 is controlled by the position control loop. It is accurately positioned at the target position together with the vibration attenuation of the elevating part 55.
[0004]
[Problems to be solved by the invention]
In the conventional suspension type lifting device described above, since an optical position sensor is used to measure the deflection displacement of the lifting unit 55, a human hand or the like is temporarily placed between the upper plate 2 of the positioning actuator 1 and the lifting unit 55. If the light is accidentally entered, the detection light beam is blocked, and the detection value by the light receiving unit 57 changes rapidly. For this reason, the relative shake speed, which is the differential value of the displacement value, also changes suddenly. In response to this, the positioning actuator 1 operates suddenly and gives a shock to the load 59.
[0005]
[Means for Solving the Problems]
The present invention was made for the purpose of solving the problems of the prior art as described above, and the gist of the invention of claim 1 is that the suspension material is provided from the support portion attached to the base. A suspension type lifting device that is suspended and suspended by the suspension member so as to be movable up and down, and an actuator that moves the support portion relative to the base in a horizontal direction in accordance with an input thrust command A positioning control device for positioning the elevating unit by outputting a thrust command corresponding to the displacement and speed of the support unit to the actuator to adjust the position of the suspension member, and the elevating unit with respect to the support unit A vibration speed detection unit that detects a vibration speed of a part, and a vibration prevention compensation unit that outputs a vibration suppression signal corresponding to the vibration speed detected by the speed sensor. Device, the positioning control device, a signal from the light receiving portion of the optical position sensor including a light receiving portion provided on the light projecting portion and the other provided on one of said base or elevating unit When not changing suddenly, the damping signal output from the steadying compensation unit is added to the thrust command, and when the signal from the light receiving unit changes suddenly, the damping signal is A suspension type lifting device characterized in that the addition to the thrust command is stopped .
Further, in the invention 請 Motomeko 2, in accordance with a change in the output from the light receiving portion after the discontinuation of the addition to the thrust command of the damping signal, returning an addition to the thrust command of the damping signal It is understood as suspended, lifting apparatus was composed claim 1, wherein the. In addition, as described in claim 3 , by detecting only a long-cycle change in the output from the light receiving unit , the inconvenience of returning due to noise is avoided.
Further, the determination may be made based on the output from the light receiving unit subjected to the square process.
[0006]
Embodiment
Subsequently, an embodiment in which the present invention is embodied will be described for the understanding of the present invention. Here, FIG. 1 is a control hardware block diagram of a suspension type lifting apparatus used in one embodiment of the present invention, FIG. 2 is a hardware block diagram showing a part thereof, and FIG. 3 is a signal from a position sensor, its differential It is a time chart which shows a signal waveform when the value, the presence or absence of a position control output, and the square of the differential value are passed through a low-pass filter.
This embodiment is different from the suspension type lifting device shown in the prior art in that an opening / closing switch is provided on a path for transmitting a damping signal from the steadying compensation unit 4 to the output of the speed compensation unit 12 as shown in FIG. SW is provided so that the insertion of the vibration suppression signal as a disturbance can be stopped if necessary, the differential value by the differentiator 58 of the shake relative displacement of the lift unit 55 from the light receiving unit 57, and the differential value The signal passing through the low-pass filter 60 is input to the overdetermination unit 61, and the open / close switch SW is turned off by a determination signal issued when the overdetermination unit 60 determines that an excessive shake has occurred. .
With the above configuration, in a state in which a vibration suppression signal from the steady rest compensation unit is introduced and a normal positioning operation is performed, for example, a human hand is suddenly inserted between the light receiving unit 57 and the light projecting unit 56 to perform projection. When the light beam from the light unit 56 is blocked, the differentiator 58 introduces a waveform including a large fluctuation to the overdeterminer 61. At the same time, the signal from the differentiator 58 is introduced into the low pass filter 60 and is introduced into the overdeterminer 61 as a signal with suppressed fluctuations. The overdetermination unit 61 is a comparator, which compares the shake relative speed signal from the differentiator 58 with a signal in which fluctuation from the low-pass filter 61 is suppressed, and the difference exceeds a predetermined value. In such a case, an excessive determination signal is output and the open / close switch SW is opened on the assumption that the fluctuation is excessive, that is, a problem such as blocking of the light beam from the light projecting unit 58 has occurred. As a result, the introduction of a vibration suppression signal with sudden fluctuations is prevented, the rapid operation of the positioning actuator 1 is suppressed, and the light from the light projecting unit 57 is blocked by a hand or the like, so that an excessive impact is applied to the load. The problem of hanging is solved. Naturally, when the fluctuation of the speed signal from the differentiator 58 is not so large, since the excessive determination signal is not output, the introduction of the vibration suppression signal is continued.
[0007]
【Example】
The circuit shown in FIG. 2 is obtained by adding a return function to the above embodiment. In this case, the shake relative speed signal V output from the differentiator 58 is squared by the squaring circuit 62 and then introduced into the overdetection circuit 63. At the same time, the signal output from the squaring circuit 62 is smoothed by the low-pass filter 64 and then introduced into the under-detection circuit 65. The outputs of the over-detection circuit 63 and the under-detection circuit 65 are both transmitted to the relay circuit. The output of the relay circuit 66 drives the open / close switch SW.
Consider a case in which a relative velocity signal with a large fluctuation caused by blocking the light beam from the light projecting unit 56 is input to this circuit. In this case, the relative speed signal becomes a signal that fluctuates greatly as shown in FIG. 3 because the displacement signal is indefinite. This signal is converted to a positive number by passing through the squaring circuit 63, and the excessive detection circuit 63 determines whether or not the signal includes excessive fluctuation. As described above, by squaring the speed signal, it is only necessary to determine the excessive value in the positive direction, the circuit is simplified, and the output range is increased. improves.
If it is determined that the fluctuation is excessive, the relay circuit 66 is driven, the open / close switch SW is opened, the introduction of the vibration suppression signal is stopped, and the rapid movement of the positioning actuator 1 is suppressed.
In this state, if the inserted hand escapes to a region where it does not block the light beam, the fluctuation in speed is drastically reduced. If it is determined that the fluctuation has passed through the low-pass filter 64 and then the under-detection circuit 65 and the fluctuation is sufficiently small, a determination signal is sent to the relay circuit 66, and the relay circuit 66 Is driven in a direction to close the open / close switch SW, and returns to a state where the vibration suppression signal is introduced.
In this way, when the light beam from the light projecting unit 56 is temporarily blocked, the vibration suppression signal that greatly fluctuates due to the rapid fluctuation of the light beam is not introduced into the control loop. In addition to avoiding damage to the baggage due to unintentional movements, the introduction of the vibration suppression signal is automatically restored when there is no significant fluctuation caused by the light ray being blocked.
In each of the above examples, the light projecting unit 56 is provided on the elevating unit 55 side and the light receiving unit 57 is provided on the upper plate 2 which is an example of the base, but the light projecting unit 56 is provided on the upper plate 2 side. Of course, the light receiving unit 57 may be provided in the lifting unit 55.
[0008]
【The invention's effect】
As described above, the present invention is a suspension type lifting device in which a suspension member is suspended from a support portion attached to a base, and the lifting portion is suspended by the suspension member so as to be lifted and lowered. In response to the command, the actuator moves the support portion relative to the base in the horizontal direction, and outputs a thrust command corresponding to the displacement and speed of the support portion to the actuator to position the suspension material. A positioning control device for positioning the elevating part by adjusting, a shake speed detecting part for detecting a swing speed of the elevating part with respect to the support part, and a vibration control according to the shake speed detected by the speed sensor it comprises a and steadying compensation unit for outputting a signal, the positioning control device, and a light receiving portion provided on the light projecting portion and the other provided on one of said base or elevating unit When the signal from the light receiving portions of the histological position sensor does not change rapidly, the damping signal output from the steadying compensator is added to the thrust command, the signal from the light receiving portion The suspension type lifting device is characterized in that, when it changes suddenly, the addition of the vibration suppression signal to the thrust command is stopped. The light beam of the light receiving unit for detecting the position of the lifting unit is for some reason. When the light is temporarily interrupted or the amount of light is reduced, the degree of adjustment of the position of the elevating part is adjusted, so that the rapid operation of the positioning actuator that occurs when the light is interrupted is prevented. Problems that cause damage to the lowered luggage are avoided.
Further, in accordance with a change in the output from the light receiving portion after the discontinuation of the addition to the thrust command above SL damping signal, if so to return the sum to said thrust command of the damping signal, a temporary If the obstacle that has blocked the light beam does not block the light beam, it can return to normal vibration control immediately.
Furthermore, by detecting only the long-cycle change in the output from the light receiving unit , it becomes possible to make a judgment based on the smoothed signal and does not recover due to an instantaneous speed reduction. It is something that can be done.
Furthermore, if the speed signal is squared, it is only necessary to determine an excessive value in the positive direction, the circuit is simplified, and the output range becomes large. The accuracy of the determination is improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a schematic configuration of a suspension type lifting apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram of a modification of a part of the control circuit of the suspension type lifting device.
FIG. 3 is a time chart showing signal waveforms in the example shown in FIG. 2;
FIG. 4 is a schematic diagram showing a schematic configuration of a conventional suspension type lifting device A0.
FIG. 5 is a block diagram showing a schematic configuration of a control circuit of a conventional suspension type lifting apparatus A0.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Positioning actuator 4 ... Stabilization compensation part 4a ... Proportional element 4b ... Filter 10 ... Lifting part position control apparatus 11 ... Position compensation part 12 ... Speed compensation part 53 ... Moving carriage (base)
54 ... Suspended material 55 ... Elevating / lowering part 56 ... Light projecting part 57 ... Light receiving part 58 ... Differentiator 60 ... Low pass filter 61 ... Over-determining circuit 62 ... Square circuit 63 ... Over-detecting circuit 64 ... Low-pass filter 65 ... Under-detecting circuit

Claims (4)

A suspension type lifting device in which a suspension material is suspended from a support portion attached to a base, and the elevation portion is suspended by the suspension material so as to be movable up and down,
An actuator for moving the support portion relative to the base in a horizontal direction according to an input thrust command;
A positioning control device for positioning the elevating unit by outputting a thrust command corresponding to the displacement and speed of the support unit to the actuator and adjusting the position of the suspension member;
A swing speed detection unit that detects a swing speed of the lifting unit with respect to the support unit;
An anti-sway compensator that outputs a vibration suppression signal corresponding to the shake speed detected by the speed sensor;
When,
Comprising
In the positioning control device, a signal from the light receiving unit of an optical position sensor including a light projecting unit provided on one of the base and the lifting unit and a light receiving unit provided on the other changes rapidly. when you are not, the damping signal output from the steadying compensator is added to the thrust command, when the signal from the light receiving portion changes rapidly, the aforementioned thrust command of the damping signal Suspended lifting device characterized by stopping addition of Depending on the change in the output from the light receiving portion after the discontinuation of the addition to the thrust command of the damping signal, the damping signal is the return of the addition to the thrust command comprising claim 1, wherein the suspended, lift device. The suspended lifting device according to claim 2, wherein only a long-cycle change is detected from the output from the light receiving unit . The suspension type lifting device according to any one of claims 1 to 3 , wherein the output from the light receiving unit is determined based on a square process.

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