JPH0421381A - Speed controller - Google Patents

Abstract

PURPOSE:To realize stabilized starting and to shorten the time to be elapsed before starting by providing means for storing an output from a control means to a motion element at the previous starting time of the motion element and outputting thus stored content, as an initial value of the control means, at next starting time. CONSTITUTION:When a motor is restarted, a corrected digital amount G (threshold level 1 for starting the motor) stored in a latch circuit 13 is provided, as an initial value, to an integrator 10. Since a motor 1 is winding a tape, the motor 1 requires additional winding torque as compared with initial starting time, and the corrected digital value G initiates with a value (threshold level 2 for starting the motor) higher than the initial value. At this time, the corrected digital value G (threshold level 2 for starting the motor) is held in the latch circuit 13 again by a start detection result signal and provided, as an initial value, at the next starting time.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention recognizes the speed of a moving body based on an electrical output signal proportional to the speed of the moving body, and detects the difference from the set value. The present invention relates to a speed control device that provides feedback and controls the speed of a moving body.

[Prior art] Figure 3 shows, for example, a digital speed control device as a conventional speed control device.
FIG. 2 is a block diagram applied to a tape drive reel device of an audio tape recorder.

In FIG. 3, numeral 1 is a motor as a moving body that drives a belt hung on a reel, and numeral 2 is a frequency generator that operates in conjunction with this motor 1.

The output of the frequency generator 2 is amplified by an amplifier 3, which outputs a pulse train P proportional to the number of revolutions of the motor 1, and sends it to a counter 7 and a launch circuit 8.

On the other hand, 4 is an oscillator that generates a reference counter clock, and the output of this oscillator 4 is sent to a branching unit 6.

A frequency division ratio B for setting the frequency division value set by the setter 5 is input to the frequency divider 6. This setting device 5 is for setting the speed of the moving body.

Based on the frequency division ratio B set by the second setter 5, the frequency divider 6
divides the frequency of the reference counter clock output from the oscillator 4. The output of the frequency divider 6 is output to the counter 7 and the frequency divider 9.

The set speed of the motor 1 set by the setting device 5 and the counter clock A output from the frequency divider 6 are also input to the counter clock.

As a result, the counter 7 starts counting the counter clock A output from the frequency divider 6 using the pulse train P output from the amplifier 3, and latches the count value C up to that point when the next pulse train P is input. At the same time as outputting to circuit 8,
The value of the counter 7 is returned to the initial value and counting is started anew.

The latch circuit 8 compares the count value C with the set speed of the motor 1, and outputs the difference between the actual speed and the set speed as an error amount E.

Further, the frequency divider 9 further divides the frequency of the counter clock A divided by the frequency divider 6 at a constant rate, and sends the frequency-divided integral clock F to the integrator 10.

The integrator 10 integrates the error amount E output from the latch circuit 8 based on the integrator clock F, and outputs a corrected digital amount G as an output.

The corrected digital amount G and the error amount E are added together, and the addition result is input to a digital/analog (hereinafter referred to as D/A) converter 11. The D/A converter 11 converts the sum of the error amount E and the correction digital amount G into an analog value, and outputs an output for controlling the speed change of the motor 1.

Next, the operation will be explained with reference to FIG.

FIG. 4 is a timing chart of main parts and output signals of the conventional example shown in FIG.

The speed of the motor 1 is input into the setting device 5. Based on this input, the mechanism from when the motor 1 starts moving from a stationary state until it reaches the set speed will be explained by dividing it into the following three stages.

(1) 1st stage This first stage is from the speed setting until the motor l starts moving, and the reference counter clock from the oscillator 4 is activated based on the command of the frequency division ratio B from the setter 5 corresponding to the set speed. The frequency is divided by the frequency divider 6, and the counter clock A shown in FIG. 4(b) is outputted from the frequency divider 6 to the counter 7 and the frequency divider 9.

As shown in FIG. 4(C), the counter 7 counts the counter clock A up to a set value greater than the set speed, and then returns to the initial value. This operation is repeated until the motor 1 starts moving, and the counter 7 outputs the count value C.

The latch circuit 8 that receives this count value C outputs the set speed as an error amount E as shown in FIG.

Further, the frequency divider 9 divides the frequency of the counter clock A by a predetermined fixed frequency division ratio, and outputs an integrator clock F as shown in FIG. 4(e).

In the integrator 10, the error amount E is accumulated for the number of integrator clocks, and as shown in FIG. 4(f), the corrected digital amount G is
Output.

The sum of this corrected digital amount and the error amount E is input to the D/A converter 11, where it is converted into an analog value and becomes the driving energy for the motor 1. Until this drive energy reaches a certain value, that is, the amount at which the motor l starts to move,
The value of the correction digital quantity G continues to increase.

In this way, the ratio of the error amount E to the accumulated drive energy of the motor 1 is kept low, and the motor 1 is set to start moving slowly.

(2) Second stage This second stage is from when the motor 1 starts moving until it reaches the set speed.
Based on the frequency emitted from the frequency generator 2 connected to the amplifier 3, the pulse train P is generated as shown in FIG.
is emitted.

The counter 7 returns to its initial value due to the pulses of this pulse train P, and counts the counter clock A until the next pulse train P arrives, and at the time the pulse arrives, the counter 7 returns to its initial value, and at the same time it returns to its initial value. Output count value C.

The latch circuit 8 outputs the difference between this count value C and the set speed as an error amount E. This error amount E is accumulated in the integrator 10 for the number of integrator clocks F, and is added to the output value of the first stage.

When this operation is repeated and the error amount E becomes zero, the speed of the motor 1 has reached the set speed of the setting device 5.

(3) Third stage This third stage is to maintain the set speed, and since the speed of the motor 1 has reached the set speed, the error amount E! =:
O, correction digital amount Gζ is the amount for maintaining the set speed.

Here, due to load fluctuations of motor 1, power supply fluctuations, etc.
The error amount E fluctuates by becoming positive or negative. This fluctuation is (error amount E + correction digital amount G)
This is converted by the D/A converter 11 and supplied as drive energy to the motor 1 to continue maintaining speed control.

Perform speed control using the steps above, or if you change the speed midway through, please follow step 1 above. Since this can be easily understood as an application of the third stage, the explanation will be omitted.

Since the conventional speed control device is configured as described above, the frequency division ratio of the frequency divider 6 is set in relation to the speed setting of the motor 1, and the gain of the speed control loop is kept almost constant. In devices designed to stabilize control in response to speed changes, the division ratio becomes thicker as the speed setting becomes lower.
The value of counter clock A becomes a low frequency.

The integrator clock F, which is further divided by the frequency divider 9, has a lower frequency, resulting in a problem that it takes a longer time to obtain the integrator output necessary for starting the motor 1.

This problem has been resolved and the motor setting speed is high.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A conventional speed control device that allows a motor to start operating at a fixed time regardless of low speed will be explained based on the drawings.

FIG. 5 is a block diagram showing its configuration. In FIG. 5, when explaining the configuration, the same parts as those in FIG. 3 are given the same reference numerals, and the parts different from those in FIG. 3 will be mainly described. In this FIG. 5, symbols 1 to 11 and A-
C and P are exactly the same as in FIG.

12 is a start detector, which has been newly added in the example shown in FIG. There is.

Further, H is a frequency division rate that is instructed from the setter 5 to the frequency divider 9 until the motor 1 starts moving.

Note that the amplifier 3 constitutes the main body of the speed detection means, and the frequency divider 6
, 9 constitute a counter clock generation means, the launch circuit 8 serves as a holding means, and the integrator 1O1 D/A converter 1
1 constitutes a control means.

Next, the operation will be explained with reference to FIG.

FIG. 6 is a timing chart showing important input/outputs in FIG. 5. The operation of this embodiment after the moving body starts moving is exactly the same as the operation of the conventional example shown in Fig. 3 and Part 4, so it will be omitted here. The parts will be explained below.

The output from the frequency divider 9 is the integrator Cronk F (see Fig. 6).
e)) When the motor 1 is running, the counter clock A (Fig. 6 (b3 ”)) is the output from the frequency divider 6.
The frequency is divided at a constant frequency division ratio, but until the motor 1 starts moving, the start detector 12 operates and the frequency is not set at a fixed frequency division ratio, but from the setter 5 set as described below. The frequency divider 9 converts the counter clock A according to the indicated frequency division ratio H.
Divide the frequency.

The integrator clock F, which is the output of this result, is designed so that the motor l starts moving at a constant time regardless of the set speed of the moving body.

That is, within the set startup time, the product of the set speed and the integrator clock F is set to a constant value, that is, a value that is the amount of input energy necessary for the motor to start moving.

In other words, the difference between the conventional example shown in FIG. 3 and the conventional example shown in FIG. . In addition, Fig. 6(a) shows the pulse train P, Fig. 6(C) shows the counting bond, and Fig. 6(c) shows the pulse train P.
Figure (f) shows the corrected digital quantity.

[Problem to be solved by the invention]

As described above, the conventional speed control device uses the activation detection means 12.
Since the structure is configured to control the time until the moving body starts, the moving body starts from a stop slowly by changing the value of the correction digital quantity G, and the time until it starts moving can be adjusted to the set speed. However, in cases where the load on the moving body changes and starting and stopping are repeated frequently, the time it takes for the moving body to start moving becomes relatively long, and this stability There was a problem in that the start-up control that was performed actually worsened controllability.

This invention was made to solve the above-mentioned problems, and even when the load on the moving object changes and starting and stopping are frequently repeated, stable starting can be performed. Another object of the present invention is to obtain a speed control device that can shorten the time required to start moving.

[Means to solve the problem]

The speed control device according to the present invention is provided with a storage means for holding the output from the control means to the moving body at the time of the previous activation of the moving body and outputting the held content as the initial stage of the control means at the next activation. It is something.

[For production]

In the case where the moving body is repeatedly started and stopped, the storage means in this invention retains the output of the control means at the time of the previous startup, gives the retained value as the initial value of the control means at the next startup, and loads the control means during that time. The speed error is accumulated by the amount of change, which acts to speed up the startup.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment.

In FIG. 1, when describing the configuration, parts that are the same as those in FIG. 5 are given the same reference numerals, and parts that are different from those in FIG. 5 will be mainly described. In this FIG. 1, numbers 1 to 12
and A to H and P are exactly the same as in FIG.

Further, 13 is a latch circuit, which is newly added in this embodiment.
It is held and output based on the activation detection result signal. The output (2) of the latch circuit 13 is given as the initial value of the integrator 10 when the motor 1 is once stopped and then started again.

Next, the operation will be explained with reference to FIG.

FIG. 2 is a timing chart showing important inputs and outputs of FIG. 1. The operation of this embodiment after the motor 1 starts moving is exactly the same as the operation of the conventional example shown in FIGS. Some parts will be explained below.

A case will be described in which the motor 1 drives a tape reel, drives from the beginning of winding to the end of winding, and stops and starts many times in the middle.

First, when starting for the first time, the motor 1 is started in the same manner as the conventional example shown in FIG. 5, and the motor 1 reaches the set speed. At this time, the correction digital amount G at the time of starting the motor 1 is held in the latch circuit 13 based on the starting detection result signal.

Next, when starting again after a -degree stop, the corrected digital position G (motor starting threshold level 1) held in the latch circuit 13 is integrated as shown in FIG. 2(f). It is given to this integrator 10 as an initial value of the integrator 1o.

Since the motor 1 is winding the tape, a winding torque is required compared to when it is first started, and the corrected digital amount G is started with a value higher than the initial value (motor starting threshold level 2).

At this time, the corrected digital amount C (motor activation threshold level 2) is held in the latch circuit 13 again according to the activation detection result signal and is given as an initial value at the next activation. When starting and stopping are performed many times, these operations are repeated.

Therefore, there is no need for the value of the corrected digital amount G to change between zero and the motor starting threshold level every time the motor is started and stopped, unlike in the conventional example, and the change in the winding torque due to the change in the tape winding amount is eliminated. You can start it with just

In the above embodiment, the case of a drive/motor for a tape reel has been described, but it is sufficient if the load on the moving body changes uniformly, and the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, in controlling a motor that repeats starting and stopping many times, the information obtained at the previous starting is retained and given as an initial value at the next starting, so that the motor is controlled repeatedly. Even when the load on the body changes and the starting and stopping of the moving body is frequently repeated, the time required for starting can be shortened, stable starting is possible, and controllability is improved. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a speed control device according to an embodiment of the present invention, FIG. 2 is a timing chart of main parts and outputs of the same embodiment, FIG. 3 is a block diagram of a conventional speed control device, and FIG. The figure is an input/output timing chart of the main parts of the speed control device shown in FIG. 3, FIG. 5 is a block diagram showing another example of a conventional speed control device, and FIG. 6 is a diagram of the speed control device shown in FIG. This is a timing chart of input/output of main parts. 1... Motor, 3... Amplifier, 5... Setting device, 6
．． 9... Frequency divider, 7... Counter, 8.13...
Latch circuit, 10... Integrator, 11... D/A converter. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa 1, special request to display the incident lol! r2 No. 121849, Name of the invention Speed control device 3, Person making the amendment Representative: Tsuya Shiki 4, Agent Q 5, Detailed description of the invention in the specification subject to amendment 6, Contents of the amendment (1) In the specification, page 6, line 2, "in rD/A converter 11" is corrected to "in rD/A converter 11." (2) Correct line 12i7 “as initial” to “J as initial value”. that's all

Claims (1)

[Claims] pulse generating means for outputting a pulse train proportional to the motion speed of the moving body; means for increasing the amount of force applied to the moving body when the moving body is stopped; and the movement body being started by increasing the amount of force applied. a detection means for detecting the above-mentioned force using the pulse; a storage means for storing the force amount in response to the detection result by the detection means; A speed control device comprising: a control means for controlling the increasing means to apply a force to the moving body, and controlling an amount of force based on a speed error with respect to a target speed after the moving body is started.