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Added PerformanceModel for fixed wing (#22091)

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* created a Performance Model for fixed wing vehicle
- added compensation for maximum climbrate, minimum sinkrate, minimum airspeed and trim airspeed based on weight ratio and air density
- added atmosphere lib to standard atmosphere calculations


---------

Signed-off-by: RomanBapst <bapstroman@gmail.com>
Co-authored-by: Thomas Stastny <thomas.stastny@auterion.com>
This commit is contained in:
Roman Bapst
2023-11-21 17:13:50 +01:00
committed by GitHub
co-authored by Thomas Stastny
parent 70cd224236
commit dd2322d622
40 changed files with 800 additions and 474 deletions
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src/lib/atmosphere/atmosphere.cpp
+3 -6
View File
@@ -41,19 +41,16 @@
namespace atmosphere
{
static constexpr float kTempRefKelvin = 15.f - CONSTANTS_ABSOLUTE_NULL_CELSIUS; // temperature at base height in Kelvin
static constexpr float kTempGradient = -6.5f / 1000.f; // temperature gradient in degrees per meter
static constexpr float kPressRefSeaLevelPa = 101325.f; // pressure at sea level in Pa
float getDensityFromPressureAndTemp(const float pressure_pa, const float temperature_celsius)
{
return (pressure_pa / (CONSTANTS_AIR_GAS_CONST * (temperature_celsius - CONSTANTS_ABSOLUTE_NULL_CELSIUS)));
return (pressure_pa / (kAirGasConstant * (temperature_celsius - kAbsoluteNullCelsius)));
}
float getPressureFromAltitude(const float altitude_m)
{
return kPressRefSeaLevelPa * powf((altitude_m * kTempGradient + kTempRefKelvin) / kTempRefKelvin,
-CONSTANTS_ONE_G / (kTempGradient * CONSTANTS_AIR_GAS_CONST));
-CONSTANTS_ONE_G / (kTempGradient * kAirGasConstant));
}
float getAltitudeFromPressure(float pressure_pa, float pressure_sealevel_pa)
{
@@ -70,7 +67,7 @@ float getAltitudeFromPressure(float pressure_pa, float pressure_sealevel_pa)
* h = ------------------------------- + h1
* a
*/
return (((powf(pressure_ratio, (-(kTempGradient * CONSTANTS_AIR_GAS_CONST) / CONSTANTS_ONE_G))) * kTempRefKelvin) -
return (((powf(pressure_ratio, (-(kTempGradient * kAirGasConstant) / CONSTANTS_ONE_G))) * kTempRefKelvin) -
kTempRefKelvin) / kTempGradient;
}
src/lib/atmosphere/atmosphere.h
+11
View File
@@ -44,6 +44,17 @@ namespace atmosphere
// NOTE: We are currently only modelling the first layer of the US Standard Atmosphere 1976.
// This means that the functions are only valid up to an altitude of 11km.
static constexpr float kAirDensitySeaLevelStandardAtmos = 1.225f; // kg/m^3
// [kg/m^3] air density of standard atmosphere at 11000m above mean sea level (this is the upper limit for the standard
// atmosphere model we are using, see atmosphere lib used)
static constexpr float kAirDensityStandardAtmos11000Amsl = 0.3639;
static constexpr float kAirGasConstant = 287.1f; // J/(kg * K)
static constexpr float kAbsoluteNullCelsius = -273.15f; // °C
static constexpr float kTempRefKelvin = 15.f - kAbsoluteNullCelsius; // temperature at base height in Kelvin
static constexpr float kTempGradient = -6.5f / 1000.f; // temperature gradient in degrees per meter
static constexpr float kPressRefSeaLevelPa = 101325.f; // pressure at sea level in Pa
/**
* Calculate air density given air pressure and temperature.