johan-kallstrom / j6dof-flight-sim

A high fidelity 6DOF flight simulation that the user can fly themselves or run to analyze an aircraft's flight dynamics

Java Flight Simulator

A Six Degree of Freedom (6DOF) Flight Simulator Written in Java by Chris Ali

This program was written to apply my knowledge and background in Flight Dynamics to build my Java language skills. It can run as a simple analysis tool for flight dynamics, as well as a real time simulation for pilot-in-the-loop use. When configured as a pilot in the loop simulation, a LWJGL out-the-window display opens and the user can control the simulation using a joystick or keyboard.

One day I'd like to tie objectives or a scoring element into the simulation to make it a game as well.

Assumptions and Simplifications

• JavaFlightSim assumes a non-rotating Earth.

• The aircraft is a rigid body, with a constant mass.

• A simple ground reaction model is implemented, but is unstable while on the ground stationary and on hills

• Only a simple propeller engine model is implemented for now. No engine effects (fuel burn, propeller effects) are modeled yet

Future Ideas

• Selectable starting locations (in air or on ground)

• Configurable weather and time of day

• Use of USAF Digital DATCOM to calculate stability derivatives for creating custom and/or more accurate aircraft

Libraries

• The Apache Commons Math libraries perform the numerical integration (Runge-Kutta) necessary to make the program tick.

• jFreeChart libraries are used to graph the aircraft's response.

• LWJGL is used to create the out the window display and sounds using OpenGL through GLFW and OpenAL

Reference

• The 6DOF state equations come from Small Unmanned Aircraft: Theory and Practice by Beard, R.W. and McLain, T.W.

• Trimming method and other simulation strategies come from Principles of Flight Simulation, Allerton David

Building and Development

• Maven is required to build project and generate natives

• When setting up your IDE to develop, add the VM argument:

  -Djava.library.path=natives/

  and one of the two following command line arguments to run using JavaFX or Swing GUIs:

  LWJGL_SWING LWJGL_JAVAFX

• Currently being developed with Java 11, but should be compatible with Java 14 and Java 8

• Running the build script ./buildJavaFlightSim.sh will execute the Maven package task and package all required dependencies and natives

• buildJavaFlightSim.sh should work in Windows if run through WSL shell or Cygwin