0x2023 Notch filter

Implemented as IIR 2nd order filter configured by the center frequency and the bandwidth around it. Filter is placed on the output of the velocity controller so it filters the torque demand value. Frequency prewarping is applied. Filter formula in discrete domain

yk = a0 xk + a1 xk-1 + a2 xk-2 + b1 yk-1 + b2 yk-2

where  a0 = K, a1 = -2Kcos(2pi*f), a2 = K, b1 = 2Rcos(2pi*f), b2 = -R2 

and K = (1 - 2Rcos(2pi*f) + R2) / (2-2cos(2pi*f))

       R = 1 - 3 * BW

f - center frequency and BW - bandwidth expressed relative to the sampling frequency, where f,BW = [0, 0.5]

 

Name Index:Sub Type Bit Size Options Unit Access PDO Mapping
Enabled 0x2023:1 BOOL 1
Disabled 0
Enabled 1
readwrite
Name Index:Sub Type Bit Size Min Data Max Data Default Data Unit Access PDO Mapping
Center frequency 0x2023:2 UINT 16 10 2000 100 Hz readwrite
Name Index:Sub Type Bit Size Min Data Max Data Default Data Unit Access PDO Mapping
Rejection band 0x2023:3 UINT 16 1 4000 1 Hz readwrite