Integrating Catapult launch in PX4 SITL using JSBSim

PX4 Autopilot
1

Hi @Jaeyong-Lim, i am trying to integrate a catapult launch for the fixed wing (Rascal) aircraft in PX4 SITL using JSBSim.
I have tried editing the initialization file LSZH.xml located in /PX4-Autopilot/Tools/jsbsim_bridge/scene by adding
ubody unit=“FT/SEC” 40.0 /ubody
vbody unit=“FT/SEC” 0.0 /vbody
wbody unit=“FT/SEC” 0.0 /wbody
phi unit=“DEG” 0.0 /phi
theta unit=“DEG” 40.0 /theta
psi unit=“DEG” 40.0 /psi

The problem i am facing is that the launch occurs as soon as i Run the sitl (make px4_sitl jsbsim_rascal) so there is no time to arm or upload a mission from QGC to the aircraft.
My objective is to Simulate a catapult launch and have the aircraft follow a mission similar to gazebo_plane_catapult.
Thank you.

2

@Sai_Shravanth I don’t think setting the initial conditions with an initial velocity is the right approach, since we also need time for the EKF to initialize on the vehicle.

In gazebo, the plugin is implemented that the catapult is only triggered when the vehicle is armed: https://github.com/PX4/PX4-SITL_gazebo/blob/master/src/gazebo_catapult_plugin.cpp

3

@Jaeyoung-Lim Is there anything similar in line for JSBSim?
I am fairly new to this so If you could guide me through any possible steps to achieve a solution or provide any resources which i can refer to it would be of great help.

Thank you.