JPH02118808A - Speed control device - Google Patents

Abstract

PURPOSE:To realize a smooth transient response by quantizing the period of a rotation detecting signal, in which the period is changed in accordance with the rotation speed of the rotor to be controlled, with a clock pulse and detecting the error for the reference period with a digital quantity. CONSTITUTION:A clock gate pulse, a latch pulse and a presetting pulse are generated by a rotating detecting signal FG inputted from a terminal 10. In a figure H in which the counting initial value stored in a data register 5 is in an analog way expressed, first, NP0 is set to a presetting pulse PR and by a second clock pulse CLK2 of Fig.G, the counted value is counted up in the sequence of NP1 NP2 . Each time a rotating detecting signal arrives, a counting initial value is also made variable and the rotation speed is smoothly changed as shown in the figure H. Until the counted value of a counter 6 becomes the value set by a counted value detecting circuit 7, the value is counted up and for the rotor, the speed rises up to the set speed. When the set speed is switched, the hunting phenomenon is not generated and the smooth transient response can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention detects an error in the rotation period of a rotating body with respect to a reference period as a binary number, and controls the speed of the rotating body using an output based on the error. Regarding a control device.

BACKGROUND ART FIG. 4 is a block diagram showing the configuration of a digital speed control device that has already been proposed.
A counter 1 that counts K, a latch 2 that receives the counting output, and various timing pulses that are synchronized to a 7° CLK clock based on a rotation detection signal FG whose period changes depending on the rotation speed of the rotating body. A timing generator 3 that outputs clock pulses CI and A that masks clock pulses CI and K
It is composed of an ND gate circuit 4 and a data register 5 that supplies an initial count value to the counter 1.

The operation of the speed control device configured as described above will be briefly explained using the block diagram shown in FIG. 4 and the timing chart of the main parts shown in FIG.

The clock pulse CI in FIG. 5 is inputted from the terminal 9 in FIG. 4, and is the clock signal of the counter 1, that is, the basic unit of the reference period, and is also a synchronization signal for various timing pulses. FIG. 5B is a rotation detection signal input from the terminal 10 in FIG.
Create the latch pulse shown in the figure and the preset pulse shown in Figure 5E. Data register 5 by preset pulse
Presect the initial count value stored in counter 1,
Immediately after that, the clock pulse that had been cut off in the AND gate circuit 4 by the clock gate pulse is supplied to the counter 1, and the counter 1 starts counting.

FIG. 5F shows an analog representation of the counting operation, and the count value of the counter 1 is taken into the latch 2 by the latch pulse generated by the arrival of the next rotation detection signal. Here, the clock gate pulse is used to stop the counting operation of the counter 1 when presetting the initial count value to the counter 1 and when taking the count value of the counter 1 into the latch 2, thereby ensuring stable operation. The data taken into latch 2 is digital-to-analog converted and the drive circuit (
It is supplied to a motor (not shown) that drives a rotating body via a motor (not shown). Therefore, in order to keep the operating point constant in a steady state, the count value taken into latch 2 when the rotating body is rotating at a set speed is set to a predetermined value (defined as IF).
The initial count value (referred to as NPo) to be stored in the data register 6 is determined so that . That is, when the set speed (base cycle) of the rotating body is To and the frequency of the clock pulse is fCK, the initial count value NPo is obtained by the following equation.

NPo-NF-fcKXT.

Therefore, when changing the set speed of the rotating body, either the initial count value stored in the data register 6 is changed, or the rotation detection signal input to the timing generator 3 is frequency-divided and input.

Problems to be Solved by the Invention However, in order to achieve a smooth transient response when switching the speed of a rotating body, the latter method requires integer frequency division of the rotation detection signal, so the switching steps are rough and incomplete, and the former method In this case, it is necessary to set a large number of initial count values to be stored in the data register 6, resulting in a problem that the circuit becomes complicated.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a speed control device that has a simple configuration and performs a smooth transient response without causing a notching phenomenon when changing the set speed of a rotating body.

Means for Solving the Problems In order to achieve the above object, the present invention quantizes the period of a rotation detection signal whose period changes according to the rotational speed of the rotating body to be controlled using clock pulses, and converts the error with respect to the reference period into a digital quantity. This is a device for detecting the reference period, and includes a modulation means for modulating the reference period.

According to the present invention, with the above-described configuration, it is possible to obtain a speed control device that realizes a smooth transient response when switching the set speed of the rotating body.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition to the configuration, the initial count value of the data register 5 is input from the terminal 13 (received by the pulse PR, and the up-count and down-count are switched by the addition/subtraction switching signal U/D input from the terminal 11, and the count is input from the terminal 12. A second counter 6 counts the input second clock pulse CLK2 and supplies the counted value to the counter 1 as a new count initial value; a count value detection circuit 7 that detects whether the count value has reached 0, and an AND gate circuit 8 whose output is input to one input terminal and a second clock pulse CLK2 is input to the other terminal.
It is composed of.

The operation of the speed control device configured as described above will be explained with reference to the block diagram shown in FIG. 1 and the timing chart of the main parts shown in FIG. 2.

The timing chart from the person to E in FIG. 2 is the same as the timing chart from the person to E in FIG. 6 explained in the conventional example in FIG. A pulse is created.

FIG. 2H is an analog representation of the initial counting value stored in the data register. Initially, NPo was set by the preset pulse PR, but the second value O- ) Coupals 01. In 2, the count value is incremented as MP, → NP2 → NP3 → NP4. Therefore, the initial count value preset in the counter 1 every time a rotation detection signal arrives is also IP, →NP2→
As a result, the rotational speed of the rotating body changes smoothly as shown in FIG. 2H. Then, the count value of the counter θ is determined by the count value detection circuit 7.
The amps are counted until the count value set in is reached.
The speed of the rotating body increases to a reference speed corresponding to the set count value.

In this embodiment, a speed increase has been described, but if the second counter 6 is caused to perform a cedar run count using an addition/subtraction switching signal, deceleration can be similarly achieved.

Incidentally, in recent years, a speed control device for a rotating body based on software software program using a microprocessor has already been proposed, and FIG. This is a flowchart.

A branch 30 in FIG. 3 determines whether or not a rotation detection signal has arrived, and if it has arrived, a processing block 31
Then move on to calculate the speed error.

Here, the speed error calculation calculates the difference between the arrival time of the rotation detection signal and the expected arrival time based on the basic clock cycle, and the detection of the arrival time of the rotation detection signal is based on the basic clock pulse built in the microprocessor. This can be realized by latching the count value of a time pace counter that counts in free run to a register using a rotation detection signal. The expected arrival time will be explained later.

Next, in branch 32, it is determined whether or not the obtained velocity error is within the measurement range, and processing block 33 or 34
If it is within the measurement range, it outputs as is, and if it is outside the measurement range, it outputs the maximum or minimum output. Then, in processing block 35, the expected arrival time of the next rotation detection signal is calculated. That is, it is determined by adding the count value corresponding to the reference period and the value for speed modulation to the arrival time of the current rotation detection signal. If no in branch 30,
The process moves to a processing block 36, and if the rotation detection signal has not arrived for a predetermined time period or more according to the time pace counter, an acceleration command is outputted in a processing block 37 to solve the problem when starting the rotating body. Next, in branch 38, it is determined whether an external speed modulation command is received or not.
If yes, the process moves to branch 40, where it is determined whether the modulation value exceeds a predetermined value, and if no, in processing block 41, a certain constant value α is added or subtracted from the modulation value. . In said branch 38, if not, a processing block 39 clears said modulation value.

Through the above-described flow, the same operation as the speed control device of the present invention shown in FIG. 1 described above can be realized.

Effects of the Invention As described above, the speed control device of the present invention realizes a smooth transient response without causing any hunting phenomenon when changing the set speed of a rotating body by modulating the basic cycle with a simple circuit configuration. can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a speed control device in one embodiment of the present invention, FIG. 2 is a timing chart explaining the circuit operation of FIG. 1, and FIG. 3 is a speed control device in another embodiment of the present invention. FIG. 4 is a flowchart of the control device, FIG. 4 is a block diagram of a conventional speed control device, and FIG. 5 is a timing chart for explaining the operation of FIG. 4. 1... Counter, 2... Latch, 3...
・River・Timing generator, 4, 8... Song AND gate circuit, 6... Data register, θ...
...Second counter...Count value detection circuit. Name of agent: Patent attorney Shigetaka Awano (1 person)

Claims (1)

[Claims] A speed control device that quantizes the period of a rotation detection signal whose period changes according to the rotational speed of a rotating body to be controlled using clock pulses, and detects an error with respect to a reference period as a digital amount, and modulates the reference period. A speed control device equipped with modulation means.