JPS60197180A - Deceleration braking method in induction motor drive device - Google Patents

Abstract

PURPOSE:To control to drive a driven unit with respect to a target position in high positioning accuracy by performing a braking operation while restricting the reverse rotation of a rotational shaft. CONSTITUTION:Main and auxiliary coils 2, 3 of an induction motor 1 are connected through bidirectional switching elements 5, 6 with an AC power source AC, and outputs of power source frequency detector 20, 21 connected between both electrodes of the elements 5, 6 are input to an electronic controller 10. The output of a tachometer generator 7 is input to the controller 10 through a low pass filter 8 and a waveform shaper 9. The controller 10 controls the conducting angles of the elements 5, 6 to brake while restricting the reverse rotation of a rotational shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a braking system for a capacitor running induction motor.

(b) Conventional technology The present applicant is Japanese Patent Application No. 59-24154, Japanese Patent Application No. 59-2
No. 4155, Japanese Patent Application No. 59-24156 and Japanese Patent Application No. 1983
-Each f of the interaction motor in No. 24157 etc.
! We proposed a control device, etc. In these systems, when the driven body is moved to the slow-down starting position, only the bidirectional switching element corresponding to the opposite phase is allowed to flow in a half-wave, thereby braking and decelerating the induction motor.

(c) Problems to be solved by the invention However, the above ili! The I control device has a problem in that when the actual moving speed of the driven body decreases and the braking operation by reverse phase excitation is continued, the induction motor is driven to rotate in reverse. For this reason, the positioning accuracy of the driven body to reach the target position was poor.

(d) Means for Solving the Problems In view of the above-mentioned conventional drawbacks, the object of the present invention is to perform a braking operation while regulating the reverse rotation of the rotating shaft by a simple means, and to improve the positioning accuracy of the driven body to the target position. An object of the present invention is to provide a deceleration braking method for an interaction motor drive device with high performance.

゛And the present invention detects the actual moving speed of the driven object and first and second bidirectional switching elements that flow AC power to the main coil and auxiliary coil of an interaction motor to which capacitors are connected in parallel. The first detection device uses the actual moving speed of the driven object calculated based on the input cycle of No. 8 and each speed data stored in the memory and corresponds to the actual moving distance of the driven object. Alternatively, the flow angle of the second bidirectional switching element can be controlled by digital control.
In the interaction motor drive device, the control device is equipped with a control device that calculates speed change and reversible drive control of an induction motor, and the control device adjusts the actual travel distance of the driven object or the slow town start position stored in the register. When the gravel is reached, the memory storage area is switched to a slowdown table in which speed data multiplied by 18 to the deceleration traveling of the driven object is written, and based on the speed data written in the slowdown table, the The second bidirectional switching element and the twelfth bidirectional switching element are simultaneously subjected to a half-wave flow at a flow angle corresponding to the phase angle of the capacitor, and the rotating shaft is constrained to direct current, thereby rapidly controlling the driven body to a predetermined low speed.

(e) Effect of the Invention In the present invention, when the actual moving distance of the driven body reaches the slowdown start position, the fi 41 and the second bidirectional switching element are subjected to half-wave flow substantially at the same time. Since the flow angle is set according to the phase angle of the capacitor, substantially equal current is applied to the soil coil and the auxiliary coil, and the rotating shaft is braked and decelerated by DC restraint. Furthermore, due to the above action, even when the first and second bidirectional switching elements are made to flow at the same time, the main coil and the auxiliary coil are supplied with current during half-wave flow, so that burning out of these coils can be prevented. is possible.

(f) Effects of the Invention The present invention can perform a braking operation while controlling the reverse rotation of the rotary shaft by using the above-described simple means, and can drive and control the driven body to the target position with high positioning accuracy.

(g) Examples An embodiment will be described below with reference to one drawing.

First Embodiment In FIGS. 1 to 3, one ends of the main coil 2 and the auxiliary coil 3 of the induction motor 1 are commonly connected to one terminal of an alternating current power source AC. 1111 main coil 2
A capacitor 4 is connected in parallel to the other end of the auxiliary coil 3, and is also connected to one electrode of first and second bidirectional switching elements 5 and 6, such as Trihook (trade name), respectively. These first and second bidirectional switching elements 5.
The other electrode of 6 is connected to the AC voltage i'l! The other terminals of iAc are commonly connected. Further, power frequency detection devices 20 and 21 are connected between the electrodes of the first and second bidirectional switching elements 5 and 6, respectively.

i1'i1 A driven body (not shown) is connected to the rotating shaft of the induction motor 1 via an appropriate speed reduction mechanism as necessary.
but! Drive connected. Further, for example, a tacho sensor 7 as a detection device is attached to the non-output side of the rotating shaft. This tachosenerator 7 outputs a detection signal having a period corresponding to the rotational speed of the rotating shaft. The detection signal is then input to the electronic control unit eL10 via the low-pass filter 8 and the waveform shaping circuit 9.

This controller 1rl (control device 10 is mainly composed of a microprocessor and a storage member (ROM-RAM), and performs speed/JF control 0ρ operation and ff1IJ operation, which will be described later).

The ROM II stores binary speed data regarding the traveling distance and traveling pattern (accelerating traveling, constant speed traveling, and decelerating traveling) of the driven body shown in FIG. 2(A). Note that the storage area in the storage area of the ROMII in which various speed data related to deceleration traveling are written is called a slowdown table. The distance register 12 stores the set distance data from the traveling origin of the driven object to the specified target position a. It stores the actual travel distance. Also, register 14
Stored therein is position data relating to a slowdown start position at which the driving pattern of the driven body changes from constant speed driving to slow speed driving.

When the start switch is operated, the electronic control device 10
calculates the actual moving speed of the driven body based on the six-point cycle of the detection signal, and sequentially increments the pointer 13 to store the actual moving distance of the driven body. Further, the electronic control unit 10 sets a PID constant (P is a proportional constant, For example, in the case of positive phase excitation during forward movement, the pulse width of the timing signal that determines the flow angle of the first bidirectional switching element 5 is determined by PID by digital control. calculate. Then, the electronic control unit 1o sets the phase angle counter 15 based on the above PID calculation result, and then crosses nw (n is an arbitrary integer) of the AC power supply AC detected by the power supply frequency 20 and 21.
However, when the count value of the phase angle counter 15 reaches 0, a timing signal consisting of a pulse width up to the next zero cross ((n4-1).tau.) is output to the drive circuit 16. This drive circuit 16 is 4'
6>X gate l- of the first bidirectional switching element 5
The gate current consisting of the pulse width of the above timing signal is l
:IJ is added and the first bidirectional switching element 5 is made to flow.

When the driven body is accelerated, the electronic control device 1
If the speed data is set higher than the actual moving speed of the driven body, and the PIDf4 calculation result is, for example, greater than a positive predetermined value, o operates the first bidirectional switching element 5, m1, at a large flow angle. A large electric power fJ' is supplied to the induction motor 1 by circulating the electric power. - When moving a driven object at a constant speed, the electronic control unit 10 sets the speed data and the actual moving speed to be approximately equal, so that if the PID calculation result is within the constant range of j91, the electronic control unit 10 First bidirectional switching element 5
A small horn is supplied to the interaction motor 1 by circulating it at a small flow angle. These operations generate electronic illumination.
The control device IO controls the driven body one movement at a variable speed.

Then, when the actual travel distance of the driven object reaches the slowdown start position stored in the register 14 according to the above-mentioned constant speed running, the electronic control & control unit moves the driven object to ili! Decelerate f motion. That is, similar to the operation described in step 111j, the electronic control unit 10 uses the speed data based on the actual moving speed of the driven object and the actual moving distance of the driven object to generate digital iti! PID operation JX is performed under the I control, and when the PID calculation result is greater than a predetermined negative value, the second bidirectional switching element 6 for anti-phase excitation is caused to flow in a half wave. In addition to the above operation, the electronic control device 10 causes the first bidirectional switching element 5 to flow in a half-wave for positive phase excitation. The half-wave flow angles of the first bidirectional switching element 5 and the second bidirectional switching element 6 are PID calculated based on the phase angle of the capacitor 4.

As a result, the first bidirectional switching element 5 and °
When the second bidirectional switching element 6 is passed through the half #JAE at the same time, the direct IA is applied to the main coil 2) 3L and the auxiliary coil 3.
I electric current L is supplied, and as a result, the rotating shaft is braked and decelerated in a state where reverse rotation is regulated.

When the actual moving speed of the driven object reaches a predetermined low speed, the electronic IJ control device 10 sends the driven object at a very low speed by passing half a wave through the first bidirectional switching element 5 (n11). and travel to the target position a. When the actual moving distance of the driven object and the required distance data stored in the distance register match during this suction speed feeding, the electronic i1i'l a JII device 10 operates the first bidirectional switching element. 5 li;t
By interrupting XIII! 1i, the moving object is stopped at the target position a. Incidentally, the electronic control & If the detection number 1d is not panned for J9i9 hours later, it is determined that the driven body has stopped at the target position a.

Note that if the actual moving distance of the driven object does not match the set distance data stored in the distance register 12 due to overrun or shoot stop of the driven object, the electronic control device 10 changes the set distance data to the pointer 13. Based on the difference from the stored actual travel distance, the slow-down start position recorded in the register 14 is corrected by the above subtraction result, and the driven body is moved from the corrected slow-down start position during the next run. Make it swim faster. Furthermore, in the above description, the operation of moving the driven body forward by circulating the first bidirectional switching element 5 has been mainly explained, but mainly by circulating the bidirectional switching element 6 of fi42, the driven body is moved forward. The same applies to the backward movement, and detailed explanation thereof will be omitted.

2nd Embodiment In the description of the second embodiment, common members with those of the first embodiment will be given common numbers and their explanation will be omitted.

4 to 6, a two-phase rotary encoder 30 is attached to the rotation shaft of the interaction motor 1. As shown in FIGS. This rotary encoder 30 faces a detection disk 31 with a large number of slits 31a bored at predetermined pitches on the outer circumferential side via the detection disk 31, and is arranged in the rotation direction at every 1/2 of the pitch in 6ii. Two pairs of light emitting parts 32a and 32b and light receiving RIs 133a and 33
It is composed of b. As the detection disk 31 rotates, the rotary encoder 30 opens the slit 31a.
Electrical No. 16 KSI and KS2 are output from the light emitting parts 33a and 33b based on the light that has passed through. This ゛Electric F3 K
SI/KS2 is output at a period corresponding to the rotational speed of the rotational shaft and in an order of Iiii'l according to the rotational direction of the rotational shaft.

Thereby, the rotary encoder 30 detects the rotational speed and moving direction of the driven body.

Then, when the actual moving distance of the driven body reaches the slowdown start position 1αb stored in the register 14 after the driven body is accelerated and traveled at a constant speed in accordance with the operation described in No. 111, the electronic control unit 10 The ROMII is switched to the slowdown table and the driven body is made to run at a braking speed. This braking operation corresponds to the phase angle of the capacitor 4 by the first bidirectional switching element 5 for positive phase Mh magnetization and the second bidirectional switching element 6 for negative phase excitation, similar to the above-mentioned operation. Half-wave circulation is carried out at the given circulation angle. When the driven body reaches a predetermined low speed, the electronic control device 10 causes the first bidirectional switching element 5 to flow in a half-wave, thereby causing the driven body to move at a slow speed. Then, the electronic control unit IO refers to the count (+tJ'Et) of the pointer 13 and the set distance data stored in the distance register 12, and interrupts the flow of the first bidirectional switching element 5 when the two match. Then, the driven body is stopped at the target position 1δa.

On the other hand, as shown in FIG. 6, if the count value of the pointer 13 and the set distance data do not match when the driven body is stopped due to fluctuations in the load inertia of the driven body, the electronic control unit 1O changes the data of both. Based on this, the deviation data indicating that the driven body overran or short-stopped from the target position a and the correction direction for the target position ff1a are determined. Then, the electronic control device 10 moves the first direction in the determined correction direction.
The actual moving distance of the driven body and the set distance +4I are calculated while passing a half wave through the two-way switching element 5 and the second two-way switching element 6.
The driven body is fed at a slow speed until the data match. As a result, the position iα of the driven body is corrected relative to the target position tFta.

Note that the first and second embodiments used the running pattern shown in the 21st threshold (A), but the present invention uses the running pattern shown in FIGS. 7(^) and (B).
As shown in , after the driven body is temporarily stopped at the temporary stop position at the target position a hand...I, 1] target position i&
For a, the driven object is fed at a slow speed or at a medium speed.
After that, the inertia of the driven body becomes zero at the temporary stop position, so the drive is performed at a slow speed while stopping once. It is possible to inquire.

[Brief explanation of drawings]

Figure 1 is the 1'j! Example electronic block 1 distribution, 2nd distribution
Figure (A) is a tire diagram showing the running pattern, and (8) is the current waveform 1ff1. FIG. 3(A) shows the voltage 1! of the first bidirectional switching element. IL waveform diagram, (B) is the current waveform diagram of the second bidirectional switching element, (C) is the if tM waveform diagram of the main coil, (D) is the current waveform diagram of the auxiliary coil, and Figure 4 is the current waveform diagram of the second bidirectional switching element. An electronic block diagram of the embodiment, FIG. 5 is an explanatory diagram of the detection device,
Fig. 6 is an explanatory diagram showing the position correction operation, and Fig. 7 (A).
B) is an explanatory diagram showing an example of changing the running pattern. In the figure, 1 is an induction motor, 2 is a main coil, 3 is an auxiliary coil, 4 is a capacitor, 7 is a tacho generator as a detection device, 10 is a control device, and 11 is R as a memory.
OM, 30 is a rotary encoder as a detection device,
AC is an alternating current power source. Patent author Taichik Co., Ltd. Star Seiki Co., Ltd. Agent Patent attorney Ken Ito - Figure 5 32a Figure 6ll-+? $- 2.1

Claims (1)

[Claims] 1. A first and m2 bidirectional switching element that distributes AC IAE power to the main coil and auxiliary coil of an induction motor to which capacitors are connected in parallel, and a detection device that detects the actual moving speed of the driven object, 01j The first or second speed of 1111 is calculated based on the actual moving speed of the M driving body calculated based on the human power period of No. The flow angle of the bidirectional switching element is calculated by PID using digital control,
Control for variable speed and reversible drive control of induction motors! In the induction motor drive device equipped with a position A, the control device described in ++ij sets the memory storage area to decelerate the driven body when the driven body reaches the moving distance or the slowdown start position stored in the register. The first and second bidirectional switching elements can be connected to the slowdown table in which speed data written in the slowdown table is written. Half wave 1f at the same time with the flow angle according to the angle
tMJ, special feature is to brake and decelerate the driven body to a predetermined low speed by DC restraining the rotating shaft.
A deceleration braking method for an interaction motor drive device.