Jeong Wan Lee

1
Lecture 3 ????? ??? ??

• Jeong Wan Lee
• ?????

2
?? ??

• ????? ??? ??
• Interfering/Modifying ??? ??5?? ????
• Method of inherent insensitivity (???)
• Method of high gain feedback (??? ???)
• Method of calculated output correction (???? ???)
• Method of signal filtering (?????)
• Method of opposing inputs (????)
• HW
• Read carefully Sec. 2.5 with attention to the
  examples provided
• Problems 2-9, 2-10,

3
????? ??? ??
interfering input
FI
iI
FM.I
modifying input

iM
FM,D
output
desired input
FD
iD
4

• desired input ????? ?? ?
• FD static or dynamic ????
• interfering input ??? ?? ??? ?? ??
• FI static or dynamic ????
• modifying input I/O ???? (FI,FD)? ??? ?? ?gt
  ?? ??? iI? iM ? ? ??? ???

5
?- Mercury Manometer

• desired input and output
• input p_1, p_2, output x
• interfering input
• ???? ??? p_1p_2????, x? ?????.
• ???? ???? ?? q? ??
• modifying input
• ????, ????? ??
• I/O relation? ??? ??.

6
?- Strain gauge Measurement

• ???? ?? ?? ??
• ???? ???? ?? gt ???? ??
• ???? ????

• Interfering input60Hz EMI, ??? ??
• modifying input??(GF? ??? ?), ??? ??

7
Interfering/Modifying ??? ?? 5?? ???
1. ???

• FI,FM,D ---gt 0? ??? ??
• ??? ??? ??? gt ?? ??? ?? ??
• ? ??? ? ??? ??? ???? ??? ??
• ???? ?? shilding ??? ??

8
2. ??? ?? ???

• Open Loop System
• ?? modifying input? ???, KMO, KSP ? ??? ?? gt ???
  ??? ??

iM,2
iM,1
ei
xo
KMO
KSP
voltage
displacement
torque
spring
motor
9
Feedback Closed Loop System
iM,3
iM,2
iM,1
ei
xo

KAM
KMO
KSP
-
spring
amplifier
motor
eo
KFB
feedback

• IF ,
  i.e.THEN KMO ,
  KSP? ? ????
• modifying input? ???? ????
• ? ???? ??, Stability ?? ??

10
3. ???? ???
Input, iD,

Transducer
output
-
iM,i,I
Correction Table
microprocessor

• interfering input? modifying input? ??? ??? ? ?,
  ?? ???? ????? ??
• micro processor? ??? look-up table??
• ? ???? ?? ??, off-set ??

11
4. ?? ???

• ??? ??? filtering?? ??
• input filtering
• output filteringdesired signal? ? ?????
  filtering?? ?? ??
• ?? ??? ?? ??? ????.

iM , iD
0
input filter
oD
oM oDoI
output filter
12
???? ?

• thermal insulation
• magnetic shielding

• ??????
• ???? ????

13

• ???? ????output low-pass filtering
• Chopped Radiometer

14
5. ????

• ?? ??? ?? ?? ??? ????.

15
?- Millivoltmeter
16
?-Static pressure probe