Autonomous parafoil precision landing using convex real-time optimized guidance and control

To overcome the limitations of current parafoil precision landing capabilities, an efficient real-time convex optimized guidance and control strategy is presented. The parafoil guidance problem is non-convex in essence and it can be solved with a sequence of convex problems, each of those converging in polynomial time to a feasible solution of the approximated original problem. Our approach shows reliable and fast numerical convergence through in-flight recalculation of time of flight and a new optimal trajectory to cope with time-varying dynamics. The efficiency of our strategy is demonstrated via a comparative analysis of the existing X-38 in-flight demonstrated guidance and control system. Exhaustive Monte Carlo simulations show performance improvements of about one order of magnitude. The concept proposed is simple, yet general, as it scales to any atmospheric parafoil landing system and allows efficient implementation relying only on the turn rate saturation information for the parafoil model.