Table 1.
Results gathered for signal A.
| Filter Type | Std. Dev. (mV) | Std. Dev. (mV) | (DM) THR = 1.60 V | (DM) THR = 1.20 V | (DM) THR = 0.95 V | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| AXL 1 | ST1 | ST2 | AXL 1 | ST1 | ST2 | AXL 1 | ST1 | ST2 | |||
| None | 29.48 | 30.28 | 1 | 0 | 13 | 1 | 1 | 28 | 1 | 6 | 61 |
| MAA (Nw = 32) | 17.76 | 19.61 | 0 | 0 | 3 | 0 | 0 | 4 | 0 | 0 | 6 |
| MAA (Nw = 64) | 14.28 | 15.42 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 |
| MAG (Nw = 32) | 19.90 | 20.35 | 0 | 0 | 0 | 0 | 0 | 4 | 0 | 0 | 4 |
| MAS (Nw = 32) | 19.91 | 22.60 | 0 | 0 | 4 | 0 | 0 | 6 | 0 | 0 | 8 |
| MAS (Nw = 64) | 16.65 | 19.62 | 0 | 0 | 0 | 0 | 0 | 4 | 0 | 0 | 6 |
| MF (Nw = 32) | 16.92 | 17.28 | 0 | 0 | 0 | 0 | 0 | 4 | 0 | 0 | 4 |
| MF (Nw = 64) | 14.76 | 13.01 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| SG (31, 3) | 22.29 | 25.13 | 0 | 0 | 4 | 0 | 0 | 8 | 0 | 13 | 10 |
| SG (63, 3) | 18.81 | 20.99 | 0 | 0 | 4 | 0 | 0 | 4 | 0 | 0 | 5 |
1 AXL expected value is zero. MAA: moving average arithmetic filter; MAG: moving average geometric filter; MAS: moving average arithmetic square filter; MF: median filter; SG: Savitzky-Golay; THR: threshold level in (V); AXL: number of counted axles; ST1: status of operation, cumulated number of detected errors. Expected value = 0, ST2: accumulated number of incorrect transitions in the state machine. Value 0 means that there was a clear passage detected (expected). Hence, the lower value → the higher efficiency of filtration.