JSBSim outputs time‑step data to x1_taxi.csv . Alex plots yaw vs time. Works perfectly – the aircraft turns, gear compresses, no oscillation.
<flight_control name="FCS"> <channel name="pitch"> <pid name="elevator_pid"> <kp> 0.8 </kp> <ki> 0.05 </ki> <kd> 0.2 </kd> <input> aero/qbar-psf </input> <!-- dynamic pressure --> <output> fcs/elevator-cmd-norm </output> </pid> </channel> </flight_control> He runs a quick test using JSBSim’s command‑line tool: jsbsim tutorial
Alex opens the drive. Inside: x1_fdm.xml , a blank JSBSim configuration file. No UI. Just XML. JSBSim outputs time‑step data to x1_taxi
Output: pitch oscillation increases. Diverges. Crash. Just XML
Maya smiles. “You don’t fly it. You build the laws of physics for it. JSBSim is a library—a simulation engine. It takes an XML model and outputs time‑step states: position, orientation, velocities. You visualize separately.”
The Python interface is key for iterative testing, Monte Carlo runs, or coupling JSBSim with external autopilots, sensor models, or wind fields. No need for XML scripts once you learn the property system. Part 7: The Handoff – Debugging the Real Thing Morning. Maya reviews Alex’s model.