Update the scheduled knock signal filtering parameters for a cylinder for the HIP901x family of engine knock signal processors.
None (Main library). (See Section 2.3, “Licensed Features”.)
The pan_KnockFilter_Hip901x block sets the HIP901x device signal processing parameters to be applied to the knock transducer signal when it is sampled. The sensor sampling region is set by the application using the pan_KnockDetectionWindow block. The result of the filtering is provided by the pan_KnockFeedback block.
A simplified view of the knock signal processing stages is given in the following block diagram:
The knock signal to process is first selected from two differential inputs, as selected by the application using the pan_KnockConfig block. The device responsible for detecting knock can process just one sensor at a time.
The knock signal is then passed through a 3rd order anti-aliasing filter. This filter is required to have no more than 1dB attenuation at 20kHz (highest frequency of interest) and a minimum attenuation of 10dB at 180kHz.
The knock signal is then passed through a gain stage to compensate knock energies if needed.
The knock signal is then passed through a band-pass filter to detect the frequencies of interest. The filter frequency is established by the characteristics of the particular engine and transducer.
The knock signal is then passed through a full wave rectifier before being passed into an integrator stage, the output of which can be monitored for knock. Integration is towards the positive supply when a knock signal is present.
Knock signal processing is active in full engine synchronisation mode and disabled in other modes. When the ECU is not in full engine synchronisation mode, the knock processing result is forced to zero.
The cylinder to set the knock filter parameters.
Range: [1, n] where n is the number of cylinders specified by the pan_EngineConfig block.
Value type: Integer Gain applied to the knock transducer signal for a specific cylinder.
Range: [0.111, 2] unitless
Value type: Real Bandpass centre frequency applied to the knock transducer signal for a specific cylinder.
Range: [1.22, 19.98] kHz
Value type: Real Integration time constant applied to the knock transducer signal for a specific cylinder.
Range: [40, 600] microseconds
Value type: Real
The values of the gain, bandpass and integrator inports are quantised by the knock processing as given in the table below. Input values are rounded to the nearest available discrete value. Out of range input values are clipped to range.
| Gain | Bandpass | Integrator |
|---|---|---|
| kHz | microseconds | |
| 2.000 | 1.22 | 40 |
| 1.882 | 1.26 | 45 |
| 1.778 | 1.31 | 50 |
| 1.684 | 1.35 | 55 |
| 1.600 | 1.40 | 60 |
| 1.523 | 1.45 | 65 |
| 1.455 | 1.51 | 70 |
| 1.391 | 1.57 | 75 |
| 1.333 | 1.63 | 80 |
| 1.280 | 1.71 | 90 |
| 1.231 | 1.78 | 100 |
| 1.185 | 1.87 | 110 |
| 1.143 | 1.96 | 120 |
| 1.063 | 2.07 | 130 |
| 1.000 | 2.18 | 140 |
| 0.944 | 2.31 | 150 |
| 0.895 | 2.46 | 160 |
| 0.850 | 2.54 | 170 |
| 0.810 | 2.62 | 180 |
| 0.773 | 2.71 | 200 |
| 0.739 | 2.81 | 220 |
| 0.708 | 2.92 | 240 |
| 0.680 | 3.03 | 260 |
| 0.654 | 3.15 | 280 |
| 0.630 | 3.28 | 300 |
| 0.607 | 3.43 | 320 |
| 0.586 | 3.59 | 360 |
| 0.567 | 3.76 | 400 |
| 0.548 | 3.95 | 440 |
| 0.500 | 4.16 | 480 |
| 0.471 | 4.39 | 520 |
| 0.444 | 4.66 | 560 |
| 0.421 | 4.95 | 600 |
| 0.400 | 5.12 | |
| 0.381 | 5.29 | |
| 0.364 | 5.46 | |
| 0.348 | 5.66 | |
| 0.333 | 5.90 | |
| 0.320 | 6.12 | |
| 0.308 | 6.37 | |
| 0.296 | 6.64 | |
| 0.286 | 6.94 | |
| 0.276 | 7.27 | |
| 0.267 | 7.63 | |
| 0.258 | 8.02 | |
| 0.250 | 8.46 | |
| 0.236 | 8.95 | |
| 0.222 | 9.50 | |
| 0.211 | 10.12 | |
| 0.200 | 10.46 | |
| 0.190 | 10.83 | |
| 0.182 | 11.22 | |
| 0.174 | 11.65 | |
| 0.167 | 12.10 | |
| 0.160 | 12.60 | |
| 0.154 | 13.14 | |
| 0.148 | 13.72 | |
| 0.143 | 14.36 | |
| 0.138 | 15.07 | |
| 0.133 | 15.84 | |
| 0.129 | 16.71 | |
| 0.125 | 17.67 | |
| 0.118 | 18.76 | |
| 0.111 | 19.98 |