TEMPERATURE ESTIMATION APPARATUS AND METHOD IN THERMOCOUPLE INPUT MODULE OF PLC

• US 20120219035A1
• Filed: 02/17/2012
• Published: 08/30/2012
• Est. Priority Date: 02/28/2011
• Status: Abandoned Application

• Current Assignee: LSIS Co. Ltd. (LS Corporation)
• Original Assignee: LSIS Co. Ltd. (LS Corporation)
• Inventors: KWON, JAE IL
• Application Number:
  US13/399,959
• Publication Number:
  US 20120219035A1
• Time in Patent Office: Days
• US Class Current: 374/170
• CPC Class Codes: G01K 7/021 Particular circuit arrangements G01K7/026, G01K7/12, G01K7/14 take precedence
• CPC Class Codes: G05B 19/054 Input/output

Abstract

Disclosed is a temperature estimation apparatus and a method in thermocoupler input module of PLC, wherein the estimation according to the present invention is performed in such a manner that an analogue signal corresponding to a thermo-electromotive force is converted to a digital data, and the estimation is performed using a predetermined temperature estimation function corresponding to the thermo-electromotive force converted to the digital data.

Claims

1. A temperature estimation apparatus estimating a temperature of thermo-electromotive force inputted from a plurality of thermocoupler input units, the apparatus comprising:

a converter converting an analogue signal corresponding to the thermo-electromotive force to a digital data; and

a controller estimating a temperature corresponding to the thermo-electromotive force converted to the digital data.

2. The apparatus of claim 1, further comprising a multiplexer selecting any one of a plurality of analogue signals corresponding to the thermo-electromotive force inputted from the plurality of thermocoupler input units.

3. The apparatus of claim 1, further comprising an amplifier amplifying an analogue signal corresponding to the thermo-electromotive force.

4. The apparatus of claim 3, wherein the amplifier is an operational amplifier.

5. The apparatus of claim 1, further comprising an insulation unit interposed between the converter and the controller to insulate the digital data transmitted to the controller.

6. The apparatus of claim 5, wherein the insulation unit is a photodetector.

7. The apparatus of claim 1, wherein the controller estimates a temperature corresponding to the thermo-electromotive force using a predetermined temperature estimating function.

8. The apparatus of claim 7, wherein the predetermined temperature estimating function is defined by the following equation:

T(x)=ax⁴+bx³+cx²+dx+e, 

 

[Equation 1]

where T(x) is a temperature based on a thermo-electromotive force (x).

9. The apparatus of claim 8, wherein the ‘

a’

to ‘

e’

are variables in the predetermined temperature estimating function, and determined by type and temperature range of the thermocoupler input units inputted by the thermo-electromotive force.

10. The apparatus of claim 8, further comprising storage storing the variables.

11. A temperature estimation method, the method comprising:

converting an analogue signal corresponding to a thermo-electromotive force to a digital data; and

estimating a temperature corresponding to the thermo-electromotive force converted to the digital data.

12. The method of claim 11, further comprising selecting any one analogue signal from a plurality of analogue signals corresponding to a plurality of thermo-electromotive forces.

13. The method of claim 11, further comprising amplifying the analogue signal corresponding to the thermo-electromotive force.

14. The method of claim 11, wherein the step of estimating the temperature includes estimating a temperature corresponding to the thermo-electromotive force, using a predetermined temperature estimating function.

15. The method of claim 14, wherein the predetermined temperature estimating function is defined by the following equation:

T(x)=ax⁴+bx³+cx²+dx+e, 

 

[Equation 1]

where T(x) is a temperature based on a thermo-electromotive force (x).

16. The method of claim 15, wherein the ‘

a’

to ‘

e’

are variables in the predetermined temperature estimating function, and determined by type and temperature range of the thermocoupler input units inputted by the thermo-electromotive force.