Can JSBSim add a air disturbance when autopilot?

[theorynice]

JSBSim brings me great help. I have developed an autopilot controller in JSBSim, but I want to test its ability by adding some air disturbance. How can I do that?

[seanmcleod]

JSBSim has a couple of turbulence models available -

jsbsim/src/models/atmosphere/FGWinds.h

Lines 56 to 67 in 375f5be

	/** Models atmospheric disturbances: winds, gusts, turbulence, downbursts, etc.
	<h2>Turbulence</h2>
	Various turbulence models are available. They are specified
	via the property <tt>atmosphere/turb-type</tt>. The following models are
	available:
	- 0: ttNone (turbulence disabled)
	- 1: ttStandard
	- 2: ttCulp
	- 3: ttMilspec (Dryden spectrum)
	- 4: ttTustin (Dryden spectrum)

[theorynice]

Thank you. It helps me much!

[theorynice]

Excuse me, when I set the turbulence type as 3 (ttMilspec) and the other two parameters: 'atmosphere/turbulence/milspec/windspeed_at_20ft_AGL-fps' as 50
'atmosphere/turbulence/milspec/severity' as 3
The flight result shows it really works.
But when I plot the wind information, including 'atmosphere/psiw-rad' and 'atmosphere/wind-mag-fps', their values are invariant from beginning to end. So, how can I show this turbulence signal?

[theorynice]

Sorry, it's my mistake, I should plot total wind information instead, rather than steady constant wind information.

[seanmcleod]

Read the documentation in FGWinds.h, i.e. continue reading below the snippet I posted above. There is more documentation regarding the options and even some examples.

[seanmcleod]

Take a look at:

jsbsim/src/models/atmosphere/FGWinds.cpp

Lines 561 to 564 in 375f5be

	// Total, calculated winds (local navigational/geographic frame: N-E-D). Read only.
	PropertyManager->Tie("atmosphere/total-wind-north-fps", this, eNorth, (PMF)&FGWinds::GetTotalWindNED);
	PropertyManager->Tie("atmosphere/total-wind-east-fps", this, eEast, (PMF)&FGWinds::GetTotalWindNED);
	PropertyManager->Tie("atmosphere/total-wind-down-fps", this, eDown, (PMF)&FGWinds::GetTotalWindNED);