Long-Endurance, Autonomous Vehicle Control

The work proposed here is the development of a prototype autonomous flight control system for the MDA High Altitude Airship (HAA). This large, unmanned airship will maintain station at up to 70,000 ft over a fixed point on earth for up to a year as a military or commercial sensor and telecom platform. Flight control design challenges include high sensitivity to the wind and limited power available for control effectors. The critical problem of station keeping at altitude has been partitioned into the Sub Thrust Limit (STL) regime where winds are low enough to maintain station with available thrust and the Post Thrust Limit (PTL) regime at higher wind levels. Phase I developments of a PTL control strategy that seeks to exploit features of the wind field will be further developed and assessed. This will involve the development of a "wind estimator" that fuses off-board forecasts and onboard wind sensor data. The wind estimator will interface with trajectory optimization algorithms configured to minimize energy consumption and station keeping error while enforcing control power and other constraints. These control, guidance and navigation system features will be extended to other mission phases including ascent, cruise, and descent.