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extract sampling class

This commit is contained in:
Matthew Kennedy 2023-06-20 17:09:44 -07:00
parent e2791d8099
commit 6ebbe939ad
1 changed files with 81 additions and 55 deletions
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136
firmware/sampling.cpp
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@ -11,16 +11,6 @@
#include <rusefi/interpolation.h>
// Stored results
struct measure_results {
float nernstAc;
float nernstDc;
float pumpCurrentSenseVoltage;
float internalBatteryVoltage;
};
static struct measure_results results[AFR_CHANNELS];
// Last point is approximated by the greatest measurable sensor resistance
static const float lsu49TempBins[] = { 80, 100, 150, 200, 250, 300, 350, 400, 450, 550, 650, 800, 1000, 1200, 2500, 4500 };
static const float lsu49TempValues[] = { 1030, 972, 888, 840, 806, 780, 761, 744, 729, 703, 686, 665, 642, 628, 567, 500 };
@ -31,6 +21,45 @@ static const float lsu42TempValues[] = { 1199, 961, 857, 806, 775, 750, 730, 715
static const float lsuAdvTempBins[] = { 53, 96, 130, 162, 184, 206, 239, 278, 300, 330, 390, 462, 573, 730, 950, 1200, 1500, 1900, 2500, 3500, 5000, 6000 };
static const float lsuAdvTempValues[] = { 1198, 982, 914, 875, 855, 838, 816, 794, 785, 771, 751, 732, 711, 691, 671, 653, 635, 614, 588, 562, 537, 528 };
struct Sampler {
public:
void ApplySample(AnalogChannelResult& result, float virtualGroundVoltageInt);
float GetNernstDc() const {
return nernstDc;
}
float GetNernstAc() const {
return nernstAc;
}
float GetPumpNominalCurrent() const {
// Gain is 10x, then a 61.9 ohm resistor
// Effective resistance with the gain is 619 ohms
// 1000 is to convert to milliamperes
constexpr float ratio = -1000 / (PUMP_CURRENT_SENSE_GAIN * LSU_SENSE_R);
return pumpCurrentSenseVoltage * ratio;
}
float GetInternalBatteryVoltage() const {
// Dual HW can measure heater voltage for each channel
// by measuring voltage on Heater- while FET is off
// TODO: rename function?
return internalBatteryVoltage;
}
private:
float r_2 = 0;
float r_3 = 0;
float nernstAc;
float nernstDc;
float pumpCurrentSenseVoltage;
float internalBatteryVoltage;
};
static Sampler samplers[AFR_CHANNELS];
constexpr float f_abs(float x)
{
return x > 0 ? x : -x;
@ -40,9 +69,6 @@ static THD_WORKING_AREA(waSamplingThread, 256);
static void SamplingThread(void*)
{
float r_2[AFR_CHANNELS] = {0};
float r_3[AFR_CHANNELS] = {0};
chRegSetThreadName("Sampling");
SetupESRDriver(GetSensorType());
@ -57,46 +83,53 @@ static void SamplingThread(void*)
// Toggle the pin after sampling so that any switching noise occurs while we're doing our math instead of when sampling
ToggleESRDriver(GetSensorType());
for (int ch = 0; ch < AFR_CHANNELS; ch++) {
measure_results &res = results[ch];
float r_1 = result.ch[ch].NernstVoltage;
// r2_opposite_phase estimates where the previous sample would be had we not been toggling
// AKA the absolute value of the difference between r2_opposite_phase and r2 is the amplitude
// of the AC component on the nernst voltage. We have to pull this trick so as to use the past 3
// samples to cancel out any slope in the DC (aka actual nernst cell output) from the AC measurement
// See firmware/sampling.png for a drawing of what's going on here
float r2_opposite_phase = (r_1 + r_3[ch]) / 2;
// Compute AC (difference) and DC (average) components
float nernstAcLocal = f_abs(r2_opposite_phase - r_2[ch]);
res.nernstDc = (r2_opposite_phase + r_2[ch]) / 2;
res.nernstAc =
(1 - ESR_SENSE_ALPHA) * res.nernstAc +
ESR_SENSE_ALPHA * nernstAcLocal;
// Exponential moving average (aka first order lpf)
res.pumpCurrentSenseVoltage =
(1 - PUMP_FILTER_ALPHA) * res.pumpCurrentSenseVoltage +
PUMP_FILTER_ALPHA * (result.ch[ch].PumpCurrentVoltage - result.VirtualGroundVoltageInt);
#ifdef BATTERY_INPUT_DIVIDER
res.internalBatteryVoltage = result.ch[ch].BatteryVoltage;
#endif
// Shift history over by one
r_3[ch] = r_2[ch];
r_2[ch] = r_1;
for (int ch = 0; ch < AFR_CHANNELS; ch++)
{
samplers[ch].ApplySample(result.ch[ch], result.VirtualGroundVoltageInt);
}
#if defined(TS_ENABLED)
/* tunerstudio */
SamplingUpdateLiveData();
#endif
}
}
void Sampler::ApplySample(AnalogChannelResult& result, float virtualGroundVoltageInt)
{
float r_1 = result.NernstVoltage;
// r2_opposite_phase estimates where the previous sample would be had we not been toggling
// AKA the absolute value of the difference between r2_opposite_phase and r2 is the amplitude
// of the AC component on the nernst voltage. We have to pull this trick so as to use the past 3
// samples to cancel out any slope in the DC (aka actual nernst cell output) from the AC measurement
// See firmware/sampling.png for a drawing of what's going on here
float r2_opposite_phase = (r_1 + r_3) / 2;
// Compute AC (difference) and DC (average) components
float nernstAcLocal = f_abs(r2_opposite_phase - r_2);
nernstDc = (r2_opposite_phase + r_2) / 2;
nernstAc =
(1 - ESR_SENSE_ALPHA) * nernstAc +
ESR_SENSE_ALPHA * nernstAcLocal;
// Exponential moving average (aka first order lpf)
pumpCurrentSenseVoltage =
(1 - PUMP_FILTER_ALPHA) * pumpCurrentSenseVoltage +
PUMP_FILTER_ALPHA * (result.PumpCurrentVoltage - virtualGroundVoltageInt);
#ifdef BATTERY_INPUT_DIVIDER
internalBatteryVoltage = result.BatteryVoltage;
#endif
// Shift history over by one
r_3 = r_2;
r_2 = r_1;
}
void StartSampling()
{
adcStart(&ADCD1, nullptr);
@ -105,7 +138,7 @@ void StartSampling()
float GetNernstAc(int ch)
{
return results[ch].nernstAc;
return samplers[ch].GetNernstAc();
}
float GetSensorInternalResistance(int ch)
@ -141,22 +174,15 @@ float GetSensorTemperature(int ch)
float GetNernstDc(int ch)
{
return results[ch].nernstDc;
return samplers[ch].GetNernstDc();
}
float GetPumpNominalCurrent(int ch)
{
// Gain is 10x, then a 61.9 ohm resistor
// Effective resistance with the gain is 619 ohms
// 1000 is to convert to milliamperes
constexpr float ratio = -1000 / (PUMP_CURRENT_SENSE_GAIN * LSU_SENSE_R);
return results[ch].pumpCurrentSenseVoltage * ratio;
return samplers[ch].GetPumpNominalCurrent();
}
float GetInternalBatteryVoltage(int ch)
{
// Dual HW can measure heater voltage for each channel
// by measuring voltage on Heater- while FET is off
// TODO: rename function?
return results[ch].internalBatteryVoltage;
return samplers[ch].GetInternalBatteryVoltage();
}