低通滤波器系数计算
-----Vicho
-----2013.03.16
1. 低通滤波器表达式：
() ( )
(
)
(
)
1 LowPassFreqScaler LowPassFreqScaler 1yn xn yn=− × + × −
2. 系数计算：
Step1:
c
cpwm
LowPassFreqScaler
Time
τ
τ
=
+
Step2:
c
1
2 Freqcutoff
τ
π
=
××
1
Timepwm =
Freqpwm
Step3:
Timecutoff
2
LowPassFreqScaler
Timecutoff 1
2 Freqpwm 1000
π
π
×
=
+
××
Timecutoff Freqpwm 1000
LowPassFreqScaler
Timecutoff Freqpwm 1000 2
π
×
×
=
×
×+×
Step4:
Step3 中的 Timecutoff 的时间为(s)，若 Timecutoff 的单位为(ms)，则 Step3 中的表
达式为：
Timecutoff Freqpwm 1000
LowPassFreqScaler
××
=
1000
Timecutoff Freqpwm 1000××
1000
2
Timecutoff Freqpwm
Timecutoff Freqpwm 2
π
π
+
×
×
=
×+×
Step5:
