Error !!!!!!!!

[ArbabKhan-sudo]

I am getting this error, I am using pre-built F-35B jsbsim.xml model to calculate Gamma angle & G-Force

     JSBSim Flight Dynamics Model v1.2.1 Aug  8 2024 19:02:38
            [JSBSim-ML v2.0]

JSBSim startup beginning ...

Attempt to divide by zero in method     FGColumnVector3::operator/(const double scalar),     object 0 , 0 , 0

  A proper axis type has NOT been selected. Check your aerodynamics definition.
Traceback (most recent call last):
  File line 91, in <module>
    observation, reward, done, info = env.step(action)                          
    self.sim.run()                                     
  File "_jsbsim.pyx", line 1435, in jsbsim._jsbsim.FGFDMExec.run
jsbsim._jsbsim.BaseError:   A proper axis type has NOT been selected. Check your aerodynamics definition.

[agodemar]

@ArbabKhan-sudo I guess this is an error coming from the RL environment you are using. Probably you should double-check the environment settings before throwing an "Error !!!!!!!!" to this forum.

[seanmcleod]

@ArbabKhan-sudo do you think this is the most useful subject line for a discussion?

Have you looked into the error message that JSBSim is giving you?

Check the 6 axes in the aerodynamics section, since JSBSim is telling you that one of them isn't valid.

jsbsim/src/models/FGAerodynamics.cpp

Lines 233 to 239 in 8e4803b

	default:
	{
	FGLogging log(FDMExec->GetLogger(), LogLevel::DEBUG);
	log << "\n A proper axis type has NOT been selected. Check "
	<< "your aerodynamics definition.\n";
	throw BaseException(log.str());
	}

jsbsim/src/models/FGAerodynamics.cpp

Lines 279 to 285 in 8e4803b

	default:
	{
	FGLogging log(FDMExec->GetLogger(), LogLevel::DEBUG);
	log << "\n A proper axis type has NOT been selected. Check "
	<< "your aerodynamics definition.\n";
	throw BaseException(log.str());
	}

Can you provide a link to the F-35 model you're using? If you want someone else to also take a look at the aerodynamics section.

[bcoconni]

FWIW this error generally means your FDM is lacking an <aerodynamics> section. The easiest way to make JSBSim stop complaining is to add an empty aerodynamics section with <aerodynamics/> (mind the slash before the closing bracket).