JPH01278279A - Motor-driven positioner with linearizing function - Google Patents

Abstract

PURPOSE:To easily alter linearizing characteristic by converting a set value signal by a nonvolatile memory in which its content can be altered by an external unit. CONSTITUTION:The linearizing characteristic of a nonvolatile memory 14 is altered by an external communication terminal 16 and a communication circuit 15. A set value signal (a) is converted to a digital code C in response to the linearizing characteristic of the memory 14. On the other hand, a feedback signal (b) from a potentiometer 4 is converted by an A/D converter 12 to a digital code D. A discriminator 7 controls the rotating direction of a reversible motor 2 in response to the comparison result of the code C with the code D. Thus, the alternation of the linearizing characteristic can be facilitated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electric positioner with a linear rice function built into an actuator that continuously sets the position and angle of a controlled object using an analog set value signal. .

[Prior art]

FIG. 3 is a block diagram showing an example of the configuration of a conventional actuator of this type.

In the figure, 1 is a positioner unit, 2 is a reversible motor, 3 is a phase advance capacitor attached to the reversible motor 2, and 4 is a mechanically connected rotary output shaft of the reversible motor 2, either directly or via a deceleration mechanism, etc. A potentiometer is coupled to detect angle or position.

The positioner unit 1 includes a set value input circuit 5 that receives a set value signal a, a feedback input circuit 6 that receives a feedback signal output from the potentiometer 4, an output signal C of the set value input circuit 5, and an output of the feedback input circuit 6. A determination circuit 7 that determines whether to rotate the reversible motor 2 forward, reverse, or stop based on the signal d, and a forward rotation instruction signal e outputted by the determination circuit 7.

Reception of the readiness instruction signal r is a relay 9.10 that drives the reversible motor 2, and both ends 41.43 of the potentiometer 4.
A constant voltage circuit 8 is provided to supply a constant voltage to.

In FIG. 3, when the output signal C of the set value input circuit 5 is larger than the output signal d of the feedback input circuit 6, the judgment circuit 7 outputs the forward rotation instruction signal e, the relay 9 is turned ON, and the reversible motor 2 is Rotate forward. As the reversible motor 2 rotates forward, the slider of the potentiometer 4 moves upward, the feedback signal rises, and the output signal d of the feedback input circuit 6 becomes the output signal C.
When it becomes equal to , the determination circuit 7 stops outputting the forward rotation instruction signal e and turns off the relay 9, thereby stopping the reversible motor 2. Similarly, when the output signal C is smaller than the output signal d, the relay 10 is ONL and the reversible motor 2 is rotated in reverse until the output signal d becomes equal to the output signal C. When the output signal d becomes equal, the relay 10 reaches 0FFt and stops.

FIG. 4 is a diagram showing the structure of the potentiometer 4 shown in FIG. 3, in which 40 is a resistor, and 44 is a slider that rotates in conjunction with the shaft of the potentiometer and moves in contact with the resistor 40. , 42 is a slider terminal, 4
1 is a terminal connected to one end of the resistor 40, and 43 is a terminal connected to the other end of the resistor 40. Here, the resistor 40
As shown in FIG. 4, the resistance value between the terminal 43 and the slider terminal 42 can be changed by changing the width or thickness depending on the rotation angle θ of the slider 44. can be made non-linear as shown in FIG. At this time, the relationship between the feedback signal and the rotation angle θ of the potentiometer 4 is the same as the curve in FIG. 5, so the relationship between the set value signal a and the mechanical output j is as shown in FIG. This is a characteristic of an inverse function.

In this way, in the conventional actuator having the configuration shown in FIG. 3, the positioner unit 1, which is a motor servo controller, does not have a linear rice function, but by changing the characteristics of the potentiometer 4, the range in which the potentiometer 4 can be manufactured is can have arbitrary linear rice characteristics.

As a second conventional example, for example, "Instrumentation" 1985
There is also one described in Vol. 28 No. 12 pages 31 to 37 (particularly the structure shown in FIG. 6 on page 34). Instead of adding a linear rice characteristic using a potentiometer, this characteristic is given by an opening feedback correction circuit, and the operating principle is the same.

[Problem to be solved by the invention]

However, the first conventional device having the above configuration has the disadvantage that it is difficult to improve the precision of the characteristics of the potentiometer 4 due to manufacturing technology, resulting in poor yield and high cost.

Furthermore, in order to change the linear rice characteristic, it is necessary to remake the potentiometer 4, which makes it difficult to change. Furthermore, the hunting phenomenon caused by excessive rotation of the reversible motor 2 after the relays 9 and 10 are turned off is also a problem. In order to prevent this, a dead zone is provided in the judgment circuit 7.
Since the feedback path and nonlinear characteristics of the first and second conventional examples are involved, it is necessary to set a dead zone that moves stably at a point where the feedback gain is minimum, which causes a problem that the overall accuracy deteriorates.

The present invention has been made in view of the above-mentioned points, and eliminates the above-mentioned problems, allows the linear rice characteristics to be easily changed without using parts with a special structure, and eliminates the deterioration of accuracy due to the linear rice characteristics. The purpose of the present invention is to provide an electric positioner with a linear rice function.

[Means to solve the problem]

In order to solve the above problems, the present invention provides an electric positioner with a linear rice function, as shown in FIG. A communication circuit 15 that performs data communication with an external communication terminal 16, and a first A/D converter 11 that digitizes a setting signal received by the setting value input circuit 5. , a second A/D converter 12 for digitizing the feedback signal, and an EE
A means for writing data from an external communication terminal 16 received by a communication circuit 15 into the nonvolatile memory 14, and a first A/D converter 11.
The data digitized by the non-volatile memory 1
The reversible motor 2 is rotated in the forward direction by means of reading the data written in the address 4 and the data read from the nonvolatile memory 14 and the data digitized by the second A/D converter 12. , and a determination circuit 7 that determines stoppage and controls the output circuit.

[Effect]

By configuring the electric positioner with linear rice function as described above, the linear rice characteristic can be realized by the contents of the non-volatile memory 14, and by changing the contents of the non-volatile memory 14 from the external communication terminal 16 using the communication circuit 15. Since the linear rice characteristics can be changed, it is easy to optimize the characteristics according to the operating conditions after installation, and since the set value signal a is converted and the linear rice characteristics are added, there is no dead zone for stable operation. Since the width can be constant, a highly accurate electric positioner can be realized.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of an actuator equipped with an electric positioner with a linear rice function according to the present invention. In the figure, 1 is a positioner unit, 2 is a reversible motor, 3 is a phase advance capacitor attached to the reversible motor 2, and 4 is a potentiometer. Unlike the conventional example shown in FIG. 4, this potentiometer 4 has a uniform resistor, and the resistance value between the terminal 43 and the slider terminal 42 changes in proportion to the rotation angle θ of the slider. . 16 is an external communication terminal such as an external personal computer or a handy terminal.

In addition to a set value input circuit 5, a feedback input circuit 6, a judgment circuit 7, a constant voltage circuit 8, and relays 9 and 10, the positioner unit 1 includes a first A/D converter 11, a second A/D converter 11, and a
The configuration includes a /D converter 12, a data selector 13, a nonvolatile memory 14, and a communication circuit 15.

The set value signal a has its zero point and span width adjusted by the set value input circuit 5, and is converted into a digital code C by the first A/D converter 11. The data selector 13 normally outputs a digital code C, and the nonvolatile memory 14 uses the digital code C as an address and stores the contents of the address specified by the address in the digital code C'.
Output as .

The contents of the nonvolatile memory 14 are written by outputting address data g and conversion seed data h and strobing the selector switching signal i when the communication circuit 15 receives address information and conversion code information from the external communication terminal 16. I can be hatched. If the relationship between the address value of the nonvolatile memory 14 and the conversion code data value stored at the address specified by the address is set as shown in FIG. 2, the value of the digital code C and the value of the digital code C' during normal operation The relationship is also the same as in Figure 2.

Next, the feedback input circuit 6 adjusts the zero point span width of the feedback signal, and the second A/D
It is converted into a digital hood D by a converter 12.

The judgment circuit 7 compares the digital hood C' and the digital code D, and when the digital code C' is larger than the digital code D, outputs a forward rotation instruction signal e, and the relay 9 turns ONL and the reversible motor 2 rotates forward. do. The rotational output shaft of the reversible motor 2 becomes a mechanical output j directly or via a reduction mechanism, and is coupled to the potentiometer 4. When the reversible motor 2 rotates forward, the slider of the potentiometer 4 moves as shown in FIG. As the motor moves upward, the feedback signal rises, and when the digital code D becomes equal to the digital hood C', the relay 9 goes to 0FFL and the reversible motor 2 stops.

Conversely, when the digital hood C' is smaller than the digital code D, the judgment circuit 7 outputs the reversal instruction signal f, the relay 10 is turned on, the reversible motor 2 is reversed, and the digital code C' is smaller than the digital code D. When the digital code D becomes equal to the digital code C' due to the reverse operation when the value is large, the relay 10 is turned off and the reversible motor 2 is stopped.

In this way, in this embodiment, the value of digital code C' and the angle or position of mechanical output j are proportional, so the relationship between set value signal a and mechanical output j is the same as in FIG. 2, and the linear rice function is realizable.

Note that in the present invention, the first A/D converter 11, the second A/D converter 11
/D converter 12, communication circuit 15, nonvolatile memory 14,
Although we have described an example in which separate hardware is used for the data selector 13, recently microprocessors have been introduced that incorporate these A/D converters, communication circuits, EEPROM (electrically erasable programmable ROM), etc. as nonvolatile memory in one chip. Since this EEPROM can also be developed, the judgment function, communication function, etc. can be realized by processing by a program.

〔Effect of the invention〕

As explained above, according to the present invention, the following excellent effects can be obtained.

■Linear rice characteristics can be realized depending on the contents of the nonvolatile memory, and the contents of the nonvolatile memory, that is, the linear rice characteristics can be changed from an external device using communication means.
Advanced tasks such as optimizing the characteristics according to the operating conditions after installation can be easily accomplished, and since the set value signal is converted and linear rice characteristics are added, the dead band width for stable operation is constant. A highly accurate device can be realized.

(2) Furthermore, the A/D conversion means, communication means, nonvolatile memory, etc. can be integrated into one chip as peripheral circuits and programs of the microprocessor, which has great advantages in terms of cost, space, and reliability.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of an actuator equipped with an electric positioner with a linear rice function according to the present invention, Figure 2 is a diagram showing the contents of a nonvolatile memory, and Figure 3 is a diagram showing a conventional electric positioner with a linear rice function. 4 is a diagram showing the structure of the potentiometer 4 in FIG. 3, FIG. 5 is a diagram showing the characteristics of the potentiometer 4 in FIG. 3, and FIG. 6 is a diagram showing the mechanical output j. FIG. 3 is a diagram showing the relationship between the set value signal a and the set value signal a. In the figure, 1...positioner unit, 2...reversible motor, 3...phase advance capacitor, 4...
・Potentiometer, 5...Set value input circuit, 6.
...Feedback input circuit, 7...Judgment circuit,
8... Constant voltage circuit, 9... Relay, 10...
・Relay, 11... First A/D converter, 12...
...Second A/D converter, 13...Data selector, 14...Nonvolatile memory, 15...Communication circuit, 16...External communication terminal. Applicant: Oki Electric Industry Co., Ltd. (1 other person) Agent: Patent attorney Takashi Kumagai (1 other person)

Claims (2)

[Claims] (1) In an electric positioner that is equipped with an output circuit that controls a motor capable of forward and reverse rotation and an input circuit that receives a set value signal and a feedback signal, a communication means that performs data communication with an external device and a set value that is received by the input circuit. A first A/D conversion means for digitizing a signal, a second A/D conversion means for digitizing a feedback signal, and a non-volatile memory, the data being received from an external device by the communication means. means for writing into the non-volatile memory;
means for converting the data digitized by the first A/D conversion means into an address of the non-volatile memory and reading the data written to the address; An electric positioner with a linear rice function, comprising means for determining forward rotation, reverse rotation, or stoppage of the motor based on data digitized by a D conversion means and controlling the output circuit. (2) The electric positioner with a linear rice function according to claim (1), characterized in that an EEPROM is used as the nonvolatile memory.