Stability assessment using Lyapunov's first method

An analytical "loss of stability" indicator is presented which can be applied to nonlinear systems of arbitrary order. The authors propose the use of the Lyapunov Exponent as a "departure index" which can be especially useful in flight control systems as a warning of instability. Testing of the approach has begun using specialized version of the flight simulation package called SLIM (Space Launch Initiative Maveric, where Maveric stands for Marshall Aerospace Vehicle Representation In C) developed at Marshall Space Flight Center for 6-DOF high fidelity reusable launch vehicle guidance and control system simulations. Simulation results obtained using SLIM are presented in this paper which show significant promise.