Jsbsim Tutorial 【Android】

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.csv . Alex plots yaw vs time. Works perfectly – the aircraft turns, gear compresses, no oscillation.

Alex launches FlightGear: fgfs --fdm=jsbsim --aircraft=x1 . The X‑1 appears on the runway, virtual sun glinting. He takes off, and for the first time, the simulation looks and feels alive .

JSBSim has no built-in graphics. It’s a flight dynamics model (FDM) meant to be driven by a simulator like FlightGear, or controlled via scripts. The aircraft is defined entirely in one XML file (or split into metric/units/aero/propulsion files). Part 2: Skeleton of an Aircraft Alex opens a template from the JSBSim aircraft folder. Copies c172.xml as a base. Renames it x1.xml . jsbsim tutorial

The first section: <?xml version="1.0"?> followed by <fdm_config> .

Alex fixes everything, re‑runs the full envelope: stalls, spins, engine‑out, crosswind landing. All pass.

<ground_reactions> <contact type="BOGEY" name="nose_gear"> <location unit="IN"> 80 0 -30 </location> <spring_coeff unit="LBS/FT"> 15000 </spring_coeff> <damping_coeff unit="LBS/FT/SEC"> 1500 </damping_coeff> </contact> </ground_reactions> And the propeller: Alex opens the drive

jsbsim --script=scripts/x1_test.xml The script: set prop/engine[0]/running 1 , set fcs/throttle-cmd-norm 0.7 , run 30 .

import jsbsim fdm = jsbsim.FGFDMExec() fdm.load_model('x1') fdm['propulsion/engine[0]/running'] = 1 fdm['fcs/throttle-cmd-norm'] = 1.0 for t in range(1000): fdm.Run() if t == 200: fdm['fcs/elevator-cmd-norm'] = -0.3 # pitch up print(fdm['position/h-sl-ft'], fdm['attitude/theta-deg'])

At 5 PM, Maya hands him a FlightGear configuration file that references x1.xml . “Now go see your aircraft fly for real.” Just XML

<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 includes a simple autopilot and PID controllers, but you must model the entire control loop, including actuator delays, limits, and hinge moments. Use <actuator> with time constants. Part 5: Ground and Propulsion – Taxi Test Maya: “Before flying, prove it can taxi.”