public SensorEstimatedState(SensorModel sensorModel, PhysicalHeliState initialState)
{
_sensors = sensorModel;
_initialState = initialState;
_estimated = new PhysicalHeliState();
Log = new List<HelicopterLogSnapshot>();
}
public override void Update(PhysicalHeliState startState, PhysicalHeliState endState, JoystickOutput output, TimeSpan startTime, TimeSpan endTime)
{
// Note: The sonic range finder is concerned with measuring at the new position in the timestep,
// so always use endState here.
PhysicalHeliState stateToMeasure = endState;
Vector3 worldDirection = Vector3.Transform(_relativeRangeDirection, stateToMeasure.Orientation);
worldDirection.Normalize();
// Line equation, how long must line be to reach ground at y=y0 at given angle?
// y = ax + b
// y0 = worldDirection.Y * u + state.Position.Y =>
// u = (y0-state.Position.Y)/worldDirection.Y
Vector2 mapPosition = VectorHelper.ToHorizontal(stateToMeasure.Position);
float y0 = _map.GetAltitude(mapPosition);
if (stateToMeasure.Position.Y <= y0)
FlatGroundHeight = stateToMeasure.Position.Y - y0; // This will only be the case if we can fly through the terrain.. usually this should never happen
else
{
const float maxRange = 10f;
const float minDelta = 0.001f; // Search resolution, returns distance when searching further does not improve the distance accuracy more than this
float rayDistanceToGround = BinarySearchTerrainRayIntersection(0, maxRange, minDelta, stateToMeasure.Position, worldDirection);
if (float.IsNaN(rayDistanceToGround))
FlatGroundHeight = float.NaN;
else
{
// A vector from the current position to the ground
Vector3 rangeVectorToGround = worldDirection*rayDistanceToGround;
// Invert vector and take its Y component to give flat ground height
FlatGroundHeight = Vector3.Negate(rangeVectorToGround).Y;
}
}
}
public void GetState(out PhysicalHeliState estimated, out PhysicalHeliState observed, out PhysicalHeliState blindEstimatedState)
{
estimated = new PhysicalHeliState(_currentState.Result.Orientation, _currentState.Result.Position,
_currentState.Result.Velocity,
_currentState.StartingCondition.Acceleration);
observed = new PhysicalHeliState();
blindEstimatedState = new PhysicalHeliState();
}
public SimulationStepResults(PhysicalHeliState startState, TimeSpan startTime)
{
StartingCondition = new TimestepStartingCondition(startState.Position, startState.Velocity,
startState.Acceleration, startState.Orientation, startTime);
Result = new TimestepResult(startState.Position, startState.Velocity, startState.Orientation, startTime);
StartTime = startTime;
EndTime = startTime;
Duration = TimeSpan.Zero;
}
public override void Update(PhysicalHeliState startState, PhysicalHeliState endState, JoystickOutput output, TimeSpan startTime, TimeSpan endTime)
{
PhysicalHeliState stateToMeasure = endState;
// TODO Fill XYZ magnetic readings
// TODO Simulate sensor lag, inaccuarcy, noise..
_sampleHistory.Add(stateToMeasure.Axes);
CurrentMeasuredAxes = IsPerfect ? stateToMeasure.Axes : ComputeMeanAxes();
}
public HelicopterLogSnapshot(PhysicalHeliState trueState, PhysicalHeliState observedState,
PhysicalHeliState estimatedState, PhysicalHeliState blindEstimatedState,
ForwardRightUp accelerometer, float groundAltitude, TimeSpan time)
{
True = trueState;
Estimated = estimatedState;
Observed = observedState;
Time = time;
Accelerometer = accelerometer;
BlindEstimated = blindEstimatedState;
GroundAltitude = groundAltitude;
}
public HelicopterLogSnapshot(PhysicalHeliState trueState, PhysicalHeliState observedState,
PhysicalHeliState estimatedState, PhysicalHeliState blindEstimatedState,
ForwardRightUp accelerometer, float groundAltitude, TimeSpan time)
{
True = trueState;
Estimated = estimatedState;
Observed = observedState;
Time = time;
Accelerometer = accelerometer;
BlindEstimated = blindEstimatedState;
GroundAltitude = groundAltitude;
}
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);
}
}
/// <summary>Calculates the input and external forces.</summary>
/// <returns>The new orientation and the total acceleration for this orientation in this timestep.</returns>
public SimulationStepResults PerformTimestep(PhysicalHeliState prev, JoystickOutput output, TimeSpan stepDuration,
TimeSpan stepEndTime)
{
if (!_isInitialized)
{
// startCondition.Acceleration = CalculateAcceleration(startCondition.Orientation, startCondition.Velocity, input);
_prevTimestepResult = new TimestepResult(prev.Position, prev.Velocity, prev.Orientation,
stepEndTime - stepDuration);
_isInitialized = true;
}
// If the number of substeps is 0 then only the state at the end of the timestep will be calculated.
// If the number is greater than 1, then the timestep will 1 then a substep will be calculated in the middle of the timestep.
const int substeps = 0;
if (substeps < 0)
throw new Exception("The number of substeps is invalid.");
TimeSpan substepDuration = stepDuration.Divide(1 + substeps);
Vector3 initialAcceleration = CalculateAcceleration(prev.Orientation, prev.Velocity, output);
var initialState = new TimestepStartingCondition(_prevTimestepResult, initialAcceleration);
//_prevTimestepResult.Result;
// var substepResults = new List<SubstepResults> {initialState};
// We always need to calculate at least the timestep itself, plus any optional substeps.
// Substeps are used to provide sensors with a higher frequency of data than the simulator is capable of rendering real-time.
// const int stepsToCalculate = substeps + 1;
// SubstepResults prevSubstep = initialState;
// for (int i = 0; i < stepsToCalculate; i++)
// {
// prevSubstep.Acceleration = CalculateAcceleration(prevSubstep.Orientation, prevSubstep.Velocity, input);
// SubstepResults r = SimulateStep(prevSubstep, prevSubstep.Acceleration, input, substepDuration, stepEndTime);
//
// substepResults.Add(r);
// prevSubstep = r;
// }
TimestepResult result = SimulateStep(initialState, output, substepDuration, stepEndTime);
//new SimulationStepResults(stepDuration, substepDuration, substepResults);
_prevTimestepResult = result;
// DebugInformation.Time1 = stepEndTime;
// DebugInformation.Q1 = result.Orientation;
//
// DebugInformation.Vectors["Pos"] = result.Position;
// DebugInformation.Vectors["Vel"] = result.Velocity;
// DebugInformation.Vectors["Acc"] = initialAcceleration;
return new SimulationStepResults(initialState, result, stepEndTime - stepDuration, stepEndTime);
}
public override void Update(PhysicalHeliState startState, PhysicalHeliState endState, JoystickOutput output, TimeSpan startTime, TimeSpan endTime)
{
var dt = (float) ((endTime - startTime).TotalSeconds);
_rate.Pitch = output.Pitch*PhysicsConstants.MaxPitchRate;
_rate.Roll = output.Roll*PhysicsConstants.MaxRollRate;
_rate.Yaw = output.Yaw*PhysicsConstants.MaxYawRate;
// Note it is important to explicitly calculate the delta and not reuse the _rate values multiplied by dt
// See http://stackoverflow.com/questions/2491161/why-differs-floating-point-precision-in-c-when-separated-by-parantheses-and-when
// and QuaternionPrecisionTest.Test() for more information about precision.
_delta.Pitch = output.Pitch*PhysicsConstants.MaxPitchRate*dt;
_delta.Roll = output.Roll*PhysicsConstants.MaxRollRate*dt;
_delta.Yaw = output.Yaw*PhysicsConstants.MaxYawRate*dt;
// TODO Handle IsPerfect == false
}
/// <summary>
/// Returns a new physical state where the values represent the error in the estimated state to
/// the given true state. I.e. position = estimatedPosition - truePosition.
/// </summary>
/// <param name="trueState"></param>
/// <param name="estimatedState"></param>
/// <returns></returns>
public static PhysicalHeliState GetError(PhysicalHeliState trueState, PhysicalHeliState estimatedState)
{
var axesError = new Axes
{
Forward = estimatedState.Axes.Forward - trueState.Axes.Forward,
Right = estimatedState.Axes.Right - trueState.Axes.Right,
Up = estimatedState.Axes.Up - trueState.Axes.Up
};
// var rotationError = new Matrix {Forward = axesError.Forward, Right = axesError.Right, Up = axesError.Up};
// TODO Verify this works, since axes were originally used to compute state instead of orientation (but should equivalent)
return new PhysicalHeliState(
Quaternion.Identity, // TODO Not sure how to represent rotation error in quaternion representation
estimatedState.Position - trueState.Position,
estimatedState.Velocity - trueState.Velocity,
estimatedState.Acceleration - trueState.Acceleration);
}
/// <summary>
/// TODO Temporary. We might later distinguish between physical state and navigation state.
/// </summary>
/// <param name="s"></param>
/// <param name="heightAboveGround"></param>
/// <param name="waypoint"></param>
/// <param name="output"></param>
/// <returns></returns>
public static HeliState ToHeliState(PhysicalHeliState s, float heightAboveGround, Waypoint waypoint, JoystickOutput output)
{
// Update state
var r = new HeliState
{
HeightAboveGround = heightAboveGround,
Orientation = s.Orientation,
Forward = s.Axes.Forward,
Up = s.Axes.Up,
Right = s.Axes.Right,
Output = output,
Position = s.Position,
Velocity = s.Velocity,
Acceleration = s.Acceleration,
Waypoint = waypoint,
HPositionToGoal = VectorHelper.ToHorizontal(waypoint.Position - s.Position),
};
// Update angles from current state
var radians = new Angles
{
PitchAngle = VectorHelper.GetPitchAngle(s.Orientation),
RollAngle = VectorHelper.GetRollAngle(s.Orientation),
HeadingAngle = VectorHelper.GetHeadingAngle(s.Orientation),
};
// Velocity can be zero, and thus have no direction (NaN angle)
radians.BearingAngle = (s.Velocity.Length() < 0.001f)
? radians.HeadingAngle
: VectorHelper.GetHeadingAngle(s.Velocity);
//GetAngle(VectorHelper.ToHorizontal(s.Velocity));
radians.GoalAngle = VectorHelper.GetAngle(r.HPositionToGoal);
radians.BearingErrorAngle = VectorHelper.DiffAngle(radians.BearingAngle, radians.GoalAngle);
// Store angles as both radians and degrees for ease-of-use later
r.Radians = radians;
r.Degrees = ToDegrees(radians);
return r;
}
private void UpdatePhysicalState(GameTime gameTime, JoystickOutput output, out PhysicalHeliState trueState)
{
_simulationState = _physics.PerformTimestep(_physicalState, output, gameTime.ElapsedGameTime,
gameTime.TotalGameTime);
TimestepResult final = _simulationState.Result;
// We need to use the second last simulation substep to obtain the current acceleration used
// because the entire substep has constant acceleration and it makes no sense
// to use the acceleration calculated for the state after the timestep because no animation will occur after it.
// TODO Support substeps
Vector3 currentAcceleration = _simulationState.StartingCondition.Acceleration;
trueState = new PhysicalHeliState(final.Orientation, final.Position, final.Velocity, currentAcceleration);
}
public override void Update(GameTime gameTime)
{
if (_playEngineSound && _engineSoundInst != null && _engineSoundInst.State != SoundState.Playing)
_engineSoundInst.Play();
long totalTicks = gameTime.TotalGameTime.Ticks;
JoystickOutput output = GetJoystickInput(totalTicks);
// Invert yaw because we want yaw rotation positive as clockwise seen from above
output.Yaw *= -1;
// Update physics and sensors + state estimators
PhysicalHeliState trueState, observedState, estimatedState, blindEstimatedState;
UpdatePhysicalState(gameTime, output, out trueState);
UpdateStateEstimators(_simulationState, gameTime, output, out estimatedState, out blindEstimatedState, out observedState);
float trueGroundAltitude = GetGroundAltitude(trueState.Position);
float estimatedGroundAltitude = GetGroundAltitude(trueState.Position);
float trueHeightAboveGround = GetHeightAboveGround(trueState.Position);
float gpsinsHeightAboveGround = GetHeightAboveGround(estimatedState.Position);
float rangefinderHeightAboveGround = _sensors.GroundRangeFinder.FlatGroundHeight;
float estimatedHeightAboveGround;
if (!_testConfiguration.UseGPS)
throw new NotImplementedException();
else if (!_testConfiguration.UseINS)
throw new NotImplementedException();
if (_testConfiguration.UseGPS && _testConfiguration.UseINS)
{
if (!_testConfiguration.UseRangeFinder)
estimatedHeightAboveGround = gpsinsHeightAboveGround;
else
{
// The range finder may be out of range (NaN) and typically requires <10 meters.
// In this case we need to fully trust INS/GPS estimate.
// Note GPS is easily out-bested by range finder, so no need to weight
estimatedHeightAboveGround = float.IsNaN(rangefinderHeightAboveGround)
? gpsinsHeightAboveGround
: rangefinderHeightAboveGround;
// : 0.2f*gpsinsHeightAboveGround + 0.8f*rangefinderHeightAboveGround;
}
}
else
throw new NotImplementedException();
// Override Kalman Filter estimate of altitude by the more accurate range finder.
// However, there is a problem that the estimated map altitude depends on the estimated horizontal position; which is inaccurate.
estimatedState.Position.Y = estimatedHeightAboveGround + estimatedGroundAltitude;
_physicalState = trueState;
_trueState = StateHelper.ToHeliState(trueState, trueHeightAboveGround, Autopilot.CurrentWaypoint, output);
_estimatedState = StateHelper.ToHeliState(estimatedState, estimatedHeightAboveGround, Autopilot.CurrentWaypoint, output);
// _observedState = observedState;
// Calculate current error in estimated state
_estimatedStateError = StateHelper.GetError(_physicalState, StateHelper.ToPhysical(_estimatedState));
// Add current simulation step to log
ForwardRightUp accelerometerData = _sensors.IMU.AccelerationLocal;
Log.Add(new HelicopterLogSnapshot(trueState, observedState, estimatedState, blindEstimatedState, accelerometerData, trueGroundAltitude, gameTime.TotalGameTime));
// Update visual appearances
UpdateEffects();
UpdateSound(output);
// If we have disabled Jitter we must detect collisions ourselves for test scenarios
if (!UseTerrainCollision)
{
if (IsCollidedWithTerrain())
if (Crashed != null) Crashed(gameTime);
}
// Handle crashes, user input etc.. that cause the helicopter to reset
HandleResetting(gameTime);
base.Update(gameTime);
}
public void GetState(out PhysicalHeliState estimated, out PhysicalHeliState observed, out PhysicalHeliState blindEstimatedState)
{
if (!Ready) throw new Exception("Can't call GetNextState() when Ready is false.");
estimated = _currentEstimate;
observed = _currentObservation;
blindEstimatedState = _currentBlindEstimate;
}
public void Update(SimulationStepResults trueState, long elapsedMillis, long totalElapsedMillis,
JoystickOutput currentOutput)
{
#if XBOX
// TODO Xbox equivalent or fix the GPSINSFilter dependency on Iridium Math.Net
_isInitialized = true;
#else
// TODO If sensors are not ready we cannot produce an estimated state
// However, currently the helicopter starts mid-air so we have no time to wait for it to initialize.. so this is cheating.
// When the helicopter starts on the ground we can properly implement this process.
if (!_isInitialized)
{
if (!_sensors.Ready) return;
_estimated.Position = _initialState.Position;
_estimated.Velocity = _initialState.Velocity;
_estimated.Acceleration = _initialState.Acceleration;
_estimated.Orientation = _initialState.Orientation;
_prevGPSPos = _sensors.GPS.Output.Position;
_gpsins = new GPSINSFilter(
TimeSpan.FromMilliseconds(totalElapsedMillis - elapsedMillis),
_initialState.Position,
_initialState.Velocity,
_initialState.Orientation,
_sensors.Specifications);
_isInitialized = true;
}
TimeSpan totalTime = TimeSpan.FromMilliseconds(totalElapsedMillis);
// Setup observations
var observations = new GPSINSObservation();
observations.Time = totalTime;
observations.RangeFinderHeightOverGround = _sensors.GroundRangeFinder.FlatGroundHeight; // TODO Update frequency? Noise?
if (_sensors.GPS.IsUpdated)
{
observations.GotGPSUpdate = true;
observations.GPSPosition = _sensors.GPS.Output.Position;
observations.GPSHVelocity = _sensors.GPS.Output.Velocity;
}
// Setup input to filter's internal model
var input = new GPSINSInput
{
AccelerationWorld = _sensors.IMU.AccelerationWorld,
Orientation = _sensors.IMU.AccumulatedOrientation,
// PitchDelta = _sensors.IMU.AngularDeltaBody.Radians.Pitch,
// RollDelta = _sensors.IMU.AngularDeltaBody.Radians.Roll,
// YawDelta = _sensors.IMU.AngularDeltaBody.Radians.Yaw,
// PitchRate = _sensors.IMU.Output.AngularRate.Radians.Pitch,
// RollRate = _sensors.IMU.Output.AngularRate.Radians.Roll,
// YawRate = _sensors.IMU.Output.AngularRate.Radians.Yaw,
};
// Estimate
StepOutput<GPSINSOutput> gpsinsEstimate = _gpsins.Filter(observations, input);
// Vector3 deltaPosition = gpsinsEstimate.PostX.Position - _currentEstimate.Position;
// if (deltaPosition.Length() > 40)
// deltaPosition = deltaPosition;
// var trueState = CheatingTrueState.Result;
GPSINSOutput observed = gpsinsEstimate.Z;
GPSINSOutput estimated = gpsinsEstimate.PostX;
GPSINSOutput blindEstimated = gpsinsEstimate.X;
_currentEstimate = new PhysicalHeliState(estimated.Orientation, estimated.Position, estimated.Velocity,
input.AccelerationWorld);
_currentBlindEstimate = new PhysicalHeliState(blindEstimated.Orientation, blindEstimated.Position, blindEstimated.Velocity,
input.AccelerationWorld);
_currentObservation = new PhysicalHeliState(observed.Orientation, observed.Position, observed.Velocity,
Vector3.Zero);
#endif
}
public abstract void Update(PhysicalHeliState startState, PhysicalHeliState endState, JoystickOutput output, TimeSpan totalSimulationTime, TimeSpan endTime);
public override void Update(PhysicalHeliState startState, PhysicalHeliState endState, JoystickOutput output, TimeSpan startTime, TimeSpan endTime)
{
_accelerometer.Update(startState, endState, output, startTime, endTime);
_gyroscope.Update(startState, endState, output, startTime, endTime);
// Make sure we use orientation at start of timestep to transform to world, since IMU should be able to calculate accumulated position
// by this world acceleration, and according to my physics simulation the position is calculated before rotation is.
AccelerationWorld = _accelerometer.AccelerationWorld;
AccelerationLocal = new ForwardRightUp(_accelerometer.Forward, _accelerometer.Right, _accelerometer.Up);
AngularRateBody = AngularValues.FromRadians(_gyroscope.Rate);
AngularDeltaBody = AngularValues.FromRadians(_gyroscope.Delta);
PitchRollYaw delta = AngularDeltaBody.Radians;
AccumulatedOrientation =
VectorHelper.AddPitchRollYaw(AccumulatedOrientation, delta.Pitch, delta.Roll, delta.Yaw);
}
private void InitHelicopters(SunlightParameters skyParameters, NavigationMap heightmap)
{
// TODO 1 or more helicopters?
if (_scenario.HelicopterScenarios == null || _scenario.HelicopterScenarios.Count == 0)
throw new Exception("Could not find helicopter scenario.");
HelicopterScenario heliScenario = _scenario.HelicopterScenarios[0];
var startVelocity = new Vector3(); //new Vector3(-0.5f, 0, -1.0f)
var startState = new PhysicalHeliState(
Quaternion.Identity,
heliScenario.StartPosition,
startVelocity,
Vector3.Zero);
_helicopter = new HelicopterBase(this, _testConfiguration, _terrainCollision, this, _basicEffect, skyParameters, heliScenario,
heliScenario.EngineSound, heliScenario.PlayerControlled, DrawText);
// If testing then we will continue to the next waypoint as soon as the true position is within
// the radius of the waypoint. If not testing (non-simulated scenarios), we typically want to
// progress only if the estimated state is belived to be within the radius.
_helicopter.Autopilot.IsTestMode = IsTestMode;
_helicopter.Autopilot.IsTruePositionWithinRadius = false;
_helicopter.Autopilot.MaxHVelocity = _testMaxHVelocityIter.Current;
// Optionally a PID setup may have been provided to use with the helicopters.
// If not a default setup is used.
if (_initialPIDSetup.HasValue)
SetPIDSetup(_initialPIDSetup.Value);
// InitFormationHelicopters(startPos, skyParameters);
_helicopter.Autopilot.Map = heightmap;
}
public void Update(PhysicalHeliState tartState, PhysicalHeliState endState, JoystickOutput output, TimeSpan startTime, TimeSpan endTime)
{
if (!_isInitialized)
{
_initStartTime = startTime;
_isInitialized = true;
}
PhysicalHeliState stateToMeasure = endState;
// Only update GPS readout as often as SecondsPerUpdate says
if (_useUpdateFrequency && startTime < _prevUpdate + TimeSpan.FromSeconds(SecondsPerUpdate))
return;
// It takes some time for a GPS to connect and produce positional values
if (!Ready && startTime >= _initStartTime + _setupDuration)
Ready = true;
// Update the GPS information if the device is ready
if (Ready)
{
_prevUpdate = startTime;
Vector3 position = stateToMeasure.Position;
Vector3 velocity = stateToMeasure.Velocity;
if (!_isPerfect)
{
position += VectorHelper.GaussRandom3(_sensorSpecifications.GPSPositionStdDev);
velocity += VectorHelper.GaussRandom3(_sensorSpecifications.GPSVelocityStdDev);
}
Output = new GPSOutput(position, velocity);
}
}
private void UpdateStateEstimators(SimulationStepResults simulationState, GameTime gameTime, JoystickOutput output,
out PhysicalHeliState estimatedState,
out PhysicalHeliState blindEstimatedState,
out PhysicalHeliState observedState)
{
var dtMillis = (long)gameTime.ElapsedGameTime.TotalMilliseconds;
var totalMillis = (long)gameTime.TotalGameTime.TotalMilliseconds;
// TimeSpan totalSimulationTime = gameTime.TotalGameTime;
// Update sensors prior to using the state provider,
// because they are typically dependent on the state of the sensors.
Sensors.Update(_simulationState, output);
// Update states
((SensorEstimatedState)_estimatedStateProvider).CheatingTrueState = simulationState; // TODO Temp cheating
_estimatedStateProvider.Update(simulationState, dtMillis, totalMillis, output);
// TODO Separate physical and navigational states
_estimatedStateProvider.GetState(out estimatedState, out observedState, out blindEstimatedState);
}
public void Reset(TimeSpan totalGameTime, HelicopterScenario scenario, NavigationMap heightmap)
{
Console.WriteLine(@"Resetting helicopter.");
_scenario = scenario;
// TODO We would rather want to do Autopilot.Reset() than this fugly code
Autopilot.IsAtDestination = false;
Autopilot = Autopilot.Clone();
Autopilot.Task = scenario.Task.Clone();
Autopilot.Map = heightmap;
Vector3 startPosition = scenario.StartPosition;
Vector3 startVelocity = Vector3.Zero;
Vector3 startAcceleration = Vector3.Zero;
Quaternion startOrientation = Quaternion.Identity;
if (Task.HoldHeightAboveGround > 0)
startPosition.Y = Autopilot.Map.GetAltitude(VectorHelper.ToHorizontal(startPosition)) + Task.HoldHeightAboveGround;
var startPhysicalState = new PhysicalHeliState(
startOrientation, startPosition, startVelocity, startAcceleration);
var initialState = new SimulationStepResults(startPhysicalState, totalGameTime);
_physicalState = startPhysicalState;
// Re-create the state provider when resetting because some sensors will have to re-initialize.
_physics = new HeliPhysics(_collision, UseTerrainCollision);
_sensors = new SensorModel(_sensorSpecifications, Autopilot.Map, startPosition, startOrientation);
_perfectStateProvider = new PerfectState();
_estimatedStateProvider = new SensorEstimatedState(_sensors, startPhysicalState);
// Wait for state to become stable.
// while (!_perfectStateProvider.Ready)
// {
// TODO GPS will require N seconds of startup time
// _perfectStateProvider.Update(initialState, 0, 0, new JoystickOutput());
// Sensors.Update(initialState, new JoystickOutput());
// Thread.Sleep(100);
// }
// When resetting, use perfect state as starting point.
// TODO It should not be necessary to create this waypoint since it should never be used for navigation! Delete if safe.
// Use start position and start orientation instead.
const float defaultWaypointRadius = 5;
var startWaypoint = new Waypoint(startPosition, 0, WaypointType.Intermediate, defaultWaypointRadius);
_trueState = StateHelper.ToHeliState(startPhysicalState, GetHeightAboveGround(startPhysicalState.Position), startWaypoint, new JoystickOutput());
_estimatedState = _trueState;
Log.Clear();
}
public void Update(SimulationStepResults step, JoystickOutput output)
{
// TODO Use substeps in physics simulation when sensors require higher frequency than the main-loop runs at
// Currently we simply use the state at the start of the timestep to feed into the sensors, so they read the state
// that was before any motion took place in that timestep.
// Later we may need to update sensors multiple times for each timestep.
TimestepStartingCondition start = step.StartingCondition;
TimestepResult end = step.Result;
var startPhysicalState = new PhysicalHeliState(start.Orientation, start.Position, start.Velocity,
start.Acceleration);
var endPhysicalState = new PhysicalHeliState(end.Orientation, end.Position, end.Velocity,
new Vector3(float.NaN));
// Update all sensors
foreach (ISensor sensor in _sensors)
sensor.Update(startPhysicalState, endPhysicalState, output, step.StartTime, step.EndTime);
}