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HAL_SITL: use baro atmospheric tables

This commit is contained in:
Andrew Tridgell 2024-04-29 09:30:55 +10:00 committed by Peter Barker
parent 67c506e75c
commit b4ebae5e1b
1 changed files with 1 additions and 22 deletions
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23
libraries/AP_HAL_SITL/sitl_airspeed.cpp
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@ -24,27 +24,6 @@ using namespace HALSITL;
#define VOLTS_TO_PASCAL 819 #define VOLTS_TO_PASCAL 819
#define PASCAL_TO_VOLTS(_p) (_p/VOLTS_TO_PASCAL) #define PASCAL_TO_VOLTS(_p) (_p/VOLTS_TO_PASCAL)
// return current scale factor that converts from equivalent to true airspeed
// valid for altitudes up to 10km AMSL
// assumes standard atmosphere lapse rate
static float get_EAS2TAS(float altitude)
{
float pressure = AP::baro().get_pressure();
if (is_zero(pressure)) {
return 1.0f;
}
float sigma, delta, theta;
AP_Baro::SimpleAtmosphere(altitude * 0.001, sigma, delta, theta);
float tempK = C_TO_KELVIN(25) - ISA_LAPSE_RATE * altitude;
const float eas2tas_squared = SSL_AIR_DENSITY / (pressure / (ISA_GAS_CONSTANT * tempK));
if (!is_positive(eas2tas_squared)) {
return 1.0;
}
return sqrtf(eas2tas_squared);
}
/* /*
convert airspeed in m/s to an airspeed sensor value convert airspeed in m/s to an airspeed sensor value
*/ */
@ -52,7 +31,7 @@ void SITL_State::_update_airspeed(float true_airspeed)
{ {
for (uint8_t i=0; i<AIRSPEED_MAX_SENSORS; i++) { for (uint8_t i=0; i<AIRSPEED_MAX_SENSORS; i++) {
const auto &arspd = _sitl->airspeed[i]; const auto &arspd = _sitl->airspeed[i];
float airspeed = true_airspeed / get_EAS2TAS(_sitl->state.altitude); float airspeed = true_airspeed / AP_Baro::get_EAS2TAS_for_alt_amsl(_sitl->state.altitude);
const float diff_pressure = sq(airspeed) / arspd.ratio; const float diff_pressure = sq(airspeed) / arspd.ratio;
float airspeed_raw; float airspeed_raw;