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 |
|
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 | |||||