JPS5858885A - Constant speed controller for motor - Google Patents

Abstract

PURPOSE:To accurately control a motor in a wide speed range by detecting the phase difference between the motor speed and the desired set speed with a digital calculator, a timing signal generator, a detector, a photodetector and a photodetector controller. CONSTITUTION:The speed of a motor 1 is detected by a speed detector which has a timing signal generator 9 and a detector 10. The set speed timing signal is oututted in response to the detector output, thereby increasing or decreasing the quantity of light of a light emitting element 10a. The phase difference between the motor speed and the desired set speed is detected by the difference of the output from the increase or decrease of the quantity of light and the speed detector, the motor operating amount is determined by a digital calculator 19 with the predetermined varied amount based on the phase difference, thereby controlling the speed of the motor 1 and maintaining the motor the desired set speed.

Description

[Detailed Description of the Invention] The present invention detects the difference between the motor speed and a desired set speed,
The present invention relates to a constant speed control device for a motor that controls the rotational speed of a motor to a predetermined value.

Conventionally, this Hinoki device detects the motor rotation speed by counting the feed signals obtained by the timing signal generator and detector attached to the motor, and calculates the detected rotation speed and the desired set speed (desired setting speed). i-microprocessor, which performs constant speed control by comparing the motor rotational speed) and changing the amount of operation to the motor (armature current, power frequency, etc.) based on the results. A digital speed control method using, etc. is known.

With the above speed control method, it is necessary to set a counting time when counting timing signals, but as shown in the first diagram, even if the counting time t1 is the same, in the case of the first timing signal R1. In the case of the second timing signal R1, the count is ``3'', and in the case of the second timing signal R1, the count is ``4'', resulting in an error of only ``1'' in the count number, resulting in an error from the desired set speed. In FIG. 1, R1 is a counting timing signal, which reduces speed accuracy.

The error in this count is determined by the resolution and counting time of the timing generator, and the error can be reduced by increasing the resolution and counting time.

but,! Increasing the resolution of the counting generator increases the cost, and increasing the counting time deteriorates the speed control accuracy due to hardware or software speed control. It is undesirable for the rotation to vibrate or resonate.

'On the other hand, the timing belt and detector detect the phase difference between the shifted timing signal and the reference signal (the same signal as the timing signal predicted when the motor is rotating at the reference setting speed). A so-called phase synchronization control method is known, in which the motor is controlled at a constant speed by changing the amount of operation to the motor so that the phase differences become equal (so that they are synchronized).

Since this phase synchronization control method can change the manipulated variable at any time using an analog value called phase difference as a reference value, it is possible to perform highly accurate speed control.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a constant speed control device for a motor that is inexpensive and can provide highly accurate speed control over a wide speed range. .

The present invention will be described in detail below with reference to FIG. 2 and subsequent figures.

Figure 2 is an explanatory diagram of the overall configuration, and the output shaft of motor 1 is 1 m long.
is connected to the drive pulley 5 via the pulley 2, the timing belt 3, and the boot 94, and a load 8 is provided on the cable 7 wound around the drive pulley 5 and the secondary rainbow pulley 6, so that the motor 1 rotates in forward and reverse directions. The cable 7 is rotated in the directions of arrows ``a'' and ``ro'' to cause the load 8 to reciprocate.

This is a 9-digit timing signal generator, which is installed on the rotating shaft 1b of the motor 1, detects the timing signal with the detector 10, and outputs a feedback signal (timing signal) as shown by R4.

FIG. 3 shows an example of a speed control device, in which the timing signal detector 10 is an optical detector (photointerlang) consisting of a light emitting part 10a and a light receiving part Job.In general usage, the light emitting part IOa is The light is emitted at all times, and the optical path FOE formed between it and the light receiving unit Job is continuously connected by a timing signal generator 9 such as a slit plate rotated by a motor 1.
Feedback signal R4 shown in FIG. 2 from the light receiving unit +ob
This signal R4 is input to the speed control device and used as a reference for counting or for comparing the phase difference with the reference pulse signal.

On the other hand, in the present invention, the controller 16 of the light emitting unit log includes:
t5 (signal having the same pulse width as the signal obtained from the light receiving section 10b when the motor 1 rotates at the desired set speed)
In other words, the timing at which the timing signal generator 9 passes through the optical path (setting speed timing signal) (motor rotational speed)
It is input in synchronization with R7 to reduce the light sensitivity of the light emitting section 10a, thereby obtaining the phase comparison timing signal R6 from the light receiving section +ob through the light receiving section controller 17.

As a result, the phase difference ratio *3. Digital arithmetic processing device using a microprocessor etc. without using a device 19
and timing signal generator 9, detector 10, light emitting jfls
, and the light receiving S controllers 16 and 17 can detect the phase difference between the motor speed and the desired set speed.

20 is an input processing device that inputs input signals such as desired set speed, motor operation mode, start, stop, etc. to the digital processing device 19 as a control signal Re based on the calculation command of the digital processing device 19; The bag [19] gives the calculation result to the motor drive device 1118 as a control signal R1, and the motor drive 1Atil18 receives the te control signal R? is converted into a motor drive operation amount RIO to drive the motor l.

When speed control is to be performed, the desired set speed and the like are input to the digital arithmetic processing unit 19 through the input processing bag [20].

As a result, the set speed timing signal Ri and the basic control signal R9 are calculated and determined by the digital arithmetic processing unit 119e, and the initial operation amount of the device is set.

Then, when the control start signal is passed through the input processing bag #20 and inputted to the digital arithmetic processing unit 19, the start time t2 and the drive device 1i18 are selectively calculated based on the calculation command.
Starting characteristics (Fig. 8A)

mouth, c) are selected. Number 2 in Figure 8 is maximum operation 111'
These are the motor characteristics when L+o is given.

2g5, 6, and 7 are tables showing the change t (gain) of the manipulated variable over time with respect to the initial value obtained by the fiIJ phase comparison timing signal R6,
Figure 5 shows the proportional relationship, Figure 6 shows the integral relationship, and Figure 7 shows the integral relationship (+1. (-1).

Next, the operation will be explained based on the timing chart shown in FIG.

When the control start (!!) signal is input, the set speed timing signal Rs (hereinafter referred to as signal R5) is not output during the startup time t! until the motor reaches a certain rotation speed and continues rotating, and the light emitting unit lOa is A feedback signal R4, that is, a timing signal R7 (hereinafter referred to as signal R7) for the timing generator 9 to pass through the optical path 10c, is output from the light receiving section Ob as in the general usage method. Ru.

The first phase comparison timing signal R4 (
Detect the leading edge of the signal (hereinafter referred to as signal R4),
The light emitting unit 10a outputs a signal Rs having a constant period r1.
The amount of light is reduced by the period r1.

At this time, if the motor speed is lower than the desired set speed, the period r2 of the time R7 during which the slit of the timing generator 9 passes the optical detector 10 becomes longer than the period r1 of the signal R8, and the timing signal is detected. Before the light path 10c is blocked, the device 9 detects an increase in the amount of light from the light emitting unit log and outputs the signal R4, and when the light is blocked, the signal R4 is stopped, so the output cycle of the signal R4 is 1) The phase difference between the motor speed and the desired set speed can be detected, and the digital processing unit 19 calculates based on the phase difference.
A control signal R9 is input to the drive device 18 according to the gains shown in FIGS. 5, 6, and 7, and the operating amount Rh to the motor 1 is
By changing the initial value of o, the motor speed is trap-controlled to the desired set speed.

In addition to the initial operation amount set by the signal r1, the operation is performed as shown in any one of the tables shown in Figs. 5 to 7 according to the passage of time until the next pulse signal r4 is output. amount is changed.

Also, if the motor speed matches the desired set speed, the cycle of signal R7! 01r'2 is the same as the period r1 of the signal Rs, and at the rising edge of the signal R7, the signal FLs is output and the light amount of the light emitting section 101 is reduced, so the signal R6 is not output and the signal R7 is stopped (timing signal The generator 9 is the optical path f
At the same time as the fg signal Rs is stopped and the amount of light emitted increases, the signal R4 is not output and the phase difference does not occur, so the manipulated variable R+o is maintained at that time t.

Furthermore, if the motor speed is faster than the desired set speed, the period r' of the signal R7! is r'z<r+, and the signal R5 is output at the rising edge of the signal R1. Therefore, even if the optical path 10c is opened, the signal R4 is not output, and while the light emission @IOa is attenuated, the optical path 10ct-8 light is Therefore, the light receiving unit +ob detects the change in the amount of light, and outputs a signal r'i based on the logical value of this light amount change signal and the signal r1. Therefore, the signal R4 is a pulse signal r'i (t's - r 1- r
'z).

Therefore, the phase difference between the motor speed and the desired set speed can be detected, and based on the phase difference, the motor speed is controlled and maintained at the desired set speed in the same manner as described above.

To summarize the above operation, the speed of the motor (2) is detected by a speed detector consisting of a timing signal generator 9 and a detector 10, and a set speed timing signal is outputted in response to the output of the speed detector, and a set speed timing signal is outputted to the light emitting section 10. The phase difference between the motor speed and the desired set speed is detected based on the difference between the increase and decrease in the light amount and the output from the speed detector, and the motor is adjusted by a predetermined amount of change based on the phase difference. The operating wear is determined by the digital processing unit 19, and the speed of the motor is thereby controlled and maintained at the desired set speed.

By controlling the motor speed in the manner described above, the speed can be controlled with higher accuracy than the conventional digital speed control method, and the cost can be lowered compared to the case where one digital speed control method is highly accurate. Furthermore, resonance and vibration between the control device and the controlled side can be prevented.

Furthermore, compared to the phase synchronization method, the speed controllable range can be widened.

This is because the digital arithmetic processing unit 19 can perform calculations no matter what speed the motor is at, and at the same time, as shown in Figure 8, the control characteristics can be freely selected using input signals, increasing versatility. Highly accurate speed control is possible.

In the above embodiments, optical detectors are used as the timing signal generator 9 and the detector 10, but other detectors such as magnetic detectors may also be used.

In addition, digital speed control devices using V microprocessors, etc. do not need to have a single input/output; it is possible to perform multiple speed controls, and it is also possible to control multiple speeds in synchronization. It is.

However, when changing the manipulated variable during one speed control, synchronization can be achieved by correcting the manipulated variable in the state of another speed control system that you want to synchronize with.

Therefore, according to the speed control device described above, it is possible to control a plurality of motors at once at desired speeds individually, at different speeds, or synchronized to obtain highly accurate, low cost, and highly versatile speed control.

As described above, the present invention provides a constant speed speed control device for a motor that is inexpensive and can provide highly accurate speed control over a wide speed range.

[Brief explanation of the drawing]

gt diagram is a timing signal table diagram for explaining the counting error of the digital speed control system, Figure 2 and subsequent figures are the bookmarks showing embodiments of the present invention, Figure 2 is a schematic explanatory diagram of the overall configuration, and Figure 3 4 is an explanatory diagram of the control device, FIG. 4 is an operation timing table, and FIG. 5 is an explanatory diagram of the control device. Figures 6 and 7 show the characteristics of the motor operation amount set by the output pulse width (changes in the operation amount that are added or subtracted from the initial setting value until the next operation amount is measured);
FIG. 8 is a control characteristic table. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto Figure 1

Claims (1)

[Claims] In a constant speed control device that detects a difference between a motor speed and a desired set speed and controls the speed of the motor to a desired set speed, the desired set speed signal is generated in response to an output from a speed detector of the motor. a first middle stage for outputting, a second means for detecting a difference between the output of the first means and the output from the speed detector, and a first middle stage for detecting a difference between the first means and the output from the speed detector; a third means for controlling the speed of the motor according to the amount of change in the speed of the motor;