KR910001292B1 - High speed high precision linear method of linear compensator - Google Patents

Abstract

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Description

High speed high precision linear method of linear compensator

1 is a circuit diagram according to the present invention.

2 is an output state graph of memory storage data for sensor detection of FIG.

3 is an input signal to output data table of an analog-to-digital converter.

4 is a data table for the address of the FIG. 1 memory.

* Explanation of symbols for main parts of the drawings

TC: Thermal Coupler 10: Operational Amplifier

20: analog / digital converter 30: memory

40: timing controller 60: display unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for linearly controlling the output signal of an analog device having a nonlinear output with high speed and high precision data in a system for automatically controlling a control element.

In general, in the system for automatically controlling various data acquisition systems and control elements such as temperature, pressure, and flow rate, the output signals of analog devices having nonlinear outputs are linearized as follows. Three methods are mainly used.

First, a method of using a signal compensating amplifier suitable for the output characteristics of an input device, second, a method of converting an input signal into a digital signal and substituting it into a linearization equation to process the software. A method of converting an input signal into a digital signal and performing a calculation process using hardware logic prepared in advance is used. However, when linearizing the input signal in the above manner, the following problem occurs.

In the first case, a separate amplification circuit must be made and manufactured, which makes the device complicated, thereby causing a failure due to an increase in price and complexity of the circuit.

In the case of the second method, there is an inconvenience in that a program must be created by processing an input signal as software, and an inconvenience in that a long time of several tens of msec to several hundred msec is required.

Even in the third case, high-precision hardware is required to process the input signal by hardware, which has caused the price of the system to increase.

Accordingly, an object of the present invention is to provide a method of storing high-precision linearized digital data at high speed with respect to an output change value of a sensing element by storing a correction value of an output of an input of an element outputting a sensing value in a memory. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram according to the present invention, a thermal coupler (TC) for sensing a temperature and outputting a predetermined electrical signal, an operational amplifier (10) for amplifying a predetermined output of the thermal coupler (TC), Analog-to-Digital Converter (hereinafter referred to as A / D converter) which inputs the output analog signal of the operational amplifier 10 to an analog signal input terminal (AIN) and converts it into a digital signal. (20), a memory (30) for inputting output data of the A / D converter (20) as an address signal, thereby accessing and outputting the linearized data stored in advance, and the A / D converter (40). A timing controller 40 for outputting a clock for controlling an analog / digital conversion time of the controller and an enable signal for outputting data of the memory 30, and outputted from the memory 30; Decode the linearized data to visually It is composed of a display unit 50 for displaying the data, wherein the memory 30 is a value of the data stored as a permanent memory (Read Only Memory) chart of the correction value of the output side with respect to the input of the sensor TC It is inputted. The display unit 50 includes a 7-segment driver that decodes binary code data or hexadecimal code data to display 7-segments.

Second turn as a graph of the correction value on the output side to the input of the case, given by the sensor element (TC) a particular equation is Y = X ^2/2 a, Y side and the actual sensing output of the thermal couple (TC), X side This is a correction value for the input signal on the Y side.

First, referring to FIG. 2, since the equation of the input-to-output is known for each nonlinear element such as a sensor or a transducer of the sensor, the correction value on the output side of the input can be easily charted. Can be.

Accordingly, when the analog signal output from the nonlinear device is converted into a digital signal, digital data (number) corresponding to the sensing signal level can be obtained. At this time, the above-mentioned digital data (number) is a value in which the signal outputted by the nonlinear element is directly expressed as a digital number. Since this is a value before being linearized, it is output by substituting the characteristic equation of the nonlinear element or using a comparison chart. You get the actual measurements for the numbers.

Therefore, if the characteristic equation of the non-linear device is given by Y = X ^2/2 at the same time can be seen that the film value line for the output Y of the nonlinear device as expression to when La X (1) characteristic curve is that, as the second assist Able to know.

Y = 0-10 (Full Scale: Pull Scale)

At this time, if the A / D converter for converting and outputting the output value Y of the nonlinear element into digital is an 8-bit (Bit) changer, the resolution (resolution) can be written as in the following Equation (2).

Therefore, the linearized data corresponding to the output value of the nonlinear element should be stored by the resolution of the second equation.

The third turn is the output Y of a nonlinear device having the characteristic equation Y = X ^2/2 as described above a tabulated output at the time when digital by an 8-bit A / D converter.

In FIG. 3, the actual value is the output Y of the nonlinear element, and the decimal ADDR and the hexadecimal ADDR are output data (8 bits) of the A / D converter for digitally converting the actual value (analog signal) of the output value Y of the nonlinear element. Data is written in decimal and hexadecimal addresses.

The count that the basis of the equation (1) described above the value X linearized with respect to the output Y of the nonlinear device, and the result memory 30. If the characteristic equation of the non-linear element having a Y = X ^2/2 turns 4 Tableed in

In the fourth diagram, ADDRESS is a decimal address, which is output data of the A / D converter 20, which is an address of the memory 30.

MEMORY is data stored in a storage area designated by ADDRESS and is a linearized value calculated based on Equation (2).

Hereinafter, the operation of one embodiment of the present invention will be described.

When a predetermined signal sensed and output by the thermal coupler TC is input to the operational amplifier 10, the operational amplifier 10 amplifies the predetermined signal to the analog signal input terminal AIN of the A / D converter 20. Output At this time, if the actual value Y signal output from the thermal coupler TC is "2", the A / D converter 20 is the actual value Y according to the second equation at the speed of the clock output from the timing controller 40. Data hexadecimal ADDR "34H" (52 for decimal ADDR) (see Table 3) (where "H" means hexadecimal number) converted from digital signal to address of memory 30 Output to (30).

The memory 30 inputting the address signal hexadecimal ADDR "34H" (decimal ADDR "52") output from the A / D converter 20 is enabled by the enable signal periodically output from the timing controller 40. The linearization data 2.015564 (refer to FIG. 4 table) stored at the designated address is outputted to the display unit 50. That is, the memory 30 having inputted the output data "34H" of the A / D converter 20 as an address has the linearized data "2.0155" recorded in accordance with the above-described first equation (refer to the characteristic curve in FIG. 2 and FIG. 4). "Is read by the control signal of the timing control part 40, and it outputs to the display part 50. FIG.

In this case, the display unit 50 is visually displayed by decoding the linearized data output from the memory 30 into display data and driving a 7-segment indicator. At this time, it can be seen that the linearization time of the nonlinear signal output from the thermal coupler (TC) is output at high speed because it is within several tens of microseconds from several hundred nsec. Can be used as a Data Acquisition System.

As described above, according to the present invention, the actual output value of the nonlinear element which outputs the correction value data on the output side with respect to the input of the nonlinear element stored in the memory from the analog / digital converter acts as an address of the memory and linearizes it. Since the data is output from the memory, it is easy to obtain linearized data without a complicated program.

Claims (1)

In the high-speed, high-precision linear method of the linear compensator, an amplifier 10 for inputting and amplifying and outputting the output of the thermal coupler TC which senses temperature and outputs it as a predetermined electrical signal, and an output terminal of the amplifier 10 An analog / digital converter 20 connected to an input terminal and outputting an address signal for outputting linearized data by converting the amplified analog signal into a digital signal; and the analog / digital converter 20 A memory 30 for connecting an input address terminal to an output terminal of the input terminal and inputting the digital conversion output data as an address signal to access and output the linearized data preset in the input address storage region when a predetermined control signal is input; Outputs a clock and data of the memory 30 to control the analog / digital conversion time of the analog / digital converter 20 A timing controller 40 for outputting an enable signal for outputting the signal, and a display unit 50 connected to an output terminal of the memory unit 30 for decoding and displaying linearized data output from the memory 30 into display data. And converting the output value of the thermal coupler TC, which is a nonlinear sensor, into a digital signal and displaying the linearized data using the value as an address of the memory 30 in which the linearization value for correction of the output side with respect to the input of the sensor is stored. High speed, high precision linear scheme of linear compensators.

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