private static void ConversionIntegrityTest(float altitude)
{
float derivedPressure = StaticPressureHelper.GetPressure(altitude, SeaLevelStaticPressure);
float derivedAltitude = StaticPressureHelper.GetAltitude(derivedPressure, SeaLevelStaticPressure);
AssertWithin(derivedAltitude, altitude, 0.001f);
}
public override void Update(PhysicalHeliState startState, PhysicalHeliState endState, JoystickOutput output, TimeSpan totalSimulationTime, TimeSpan endTime)
{
PhysicalHeliState stateToMeasure = endState;
float trueAltitude = stateToMeasure.Position.Y;
if (IsPerfect)
{
Altitude = trueAltitude;
}
else
{
float simulatedPressure = _pressureProvider.GetSimulatedStaticPressure(trueAltitude);
Altitude = StaticPressureHelper.GetAltitude(simulatedPressure, SeaLevelStaticPressure);
}
}
public void GetPressureTest()
{
float altitude, expected, actual;
// All expected values are taken from a lookup table
altitude = 11000f;
expected = 22632f;
actual = StaticPressureHelper.GetPressure(altitude, SeaLevelStaticPressure);
AssertWithin(actual, expected, 100);
altitude = 0f;
expected = 101325f;
actual = StaticPressureHelper.GetPressure(altitude, SeaLevelStaticPressure);
AssertWithin(actual, expected, 100);
altitude = 5000f;
expected = 54019f;
actual = StaticPressureHelper.GetPressure(altitude, SeaLevelStaticPressure);
AssertWithin(actual, expected, 100);
}
public float GetSimulatedStaticPressure(float trueAltitude)
{
float truePressure = StaticPressureHelper.GetPressure(trueAltitude, SeaLevelStaticPresure);
// If we assume the pressure is rising linearly (although it is not) we would want to further distort the
// measured pressure by applying non-linearity to the readings.
Vector2 lowestPressurePlot = GetPressurePlot(StaticPressureHelper.MinAltitude);
Vector2 highestPressurePlot = GetPressurePlot(StaticPressureHelper.MaxAltitude);
var pressurePlot = new Vector2(trueAltitude, truePressure);
// float nonLinearPressure = NonLinearity.SinusOffset(pressurePlot, lowestPressurePlot, highestPressurePlot).Y;
float nonLinearPressure =
NonLinearity.SinusOffset(pressurePlot, lowestPressurePlot, highestPressurePlot, 5f, 100).Y;
// Noise amplitude is selected to give a few meters of variation, both positive and negative
const float pressurePerMeter = 11.989f;
const float noiseAmplitudeMeters = 0.5f;
const float noiseAmplitudePressure = noiseAmplitudeMeters * pressurePerMeter;
return(Noise.WhiteNoise(nonLinearPressure, noiseAmplitudePressure));
}
public void GetAltitudeTest()
{
float pressure, expected, actual;
// All expected values are taken from a lookup table
pressure = 22632;
expected = 11000;
actual = StaticPressureHelper.GetAltitude(pressure, SeaLevelStaticPressure);
AssertWithin(actual, expected, 100);
pressure = 101325;
expected = 0;
actual = StaticPressureHelper.GetAltitude(pressure, SeaLevelStaticPressure);
AssertWithin(actual, expected, 100);
pressure = 54019;
expected = 5000;
actual = StaticPressureHelper.GetAltitude(pressure, SeaLevelStaticPressure);
AssertWithin(actual, expected, 100);
}
private Vector2 GetPressurePlot(float altitude)
{
return(new Vector2(altitude, StaticPressureHelper.GetPressure(altitude, SeaLevelStaticPresure)));
}
