Autonomous Shipboard Landing of VTOL UAV
Abstract
Unmanned Combat Air Vehicles (UCAVs) will be required to operate autonomously with a great degree of stability and performance robustness, especially in adverse combat environments. Barron Associates developed a reliable reconfigurable control and guidance system for a UCAV executing a shipboard-landing maneuver with improved performance and safety.
Problem
The utility and importance of Unmanned Combat Air Vehicles (UCAVs) is becoming increasingly apparent for both reconnaissance and combat roles. However, significant technological hurdles still need to be overcome for successful implementation and wide use of UCAVs by the military. Development of a reliable, low cost vehicle is a driving goal of most UCAV programs. Further, these vehicles will be required to operate autonomously with a great degree of stability and performance robustness - especially in adverse combat environments. Because of this, the importance of developing reconfigurable control and guidance systems for UCAVs is evident. Such systems should be able to autonomously adapt to plant parameter modeling errors, and to slowly time varying changes in the dynamics as the vehicle transitions from one operating condition to the next. Furthermore, these systems should be able to reconfigure rapidly to sudden catastrophic changes in the vehicle due to, for example, actuation failure or battle damage. Successful development and implementation of reconfigurable control/guidance systems will significantly increase the reliability of the vehicle and probability of safe recovery, and decrease development, implementation and operating costs by reducing the need for multiple actuation redundancy.
Solution
Barron Associates addressed the needs of the Navy by developing a reconfigurable control and guidance system for a UCAV executing a shipboard-landing maneuver. Preliminary algorithm development was completed in Phase I and tested on a nonlinear simulation model based on linear simulations developed by Texas A&M. In Phase II, Barron Associates further developed and integrated the technologies with a high fidelity simulation model of the Bell Helicopter Textron, Inc. (BHTI) Eagle Eye tilt-rotor UCAV. Several Monte-Carlo experiments were performed using the various simulation models over the course of both program phases. The vehicle was subjected to a range of Sea States, starting conditions and single and multiple effector impairments. The reconfigurable control system was shown to achieve quite acceptable landing performance for the majority of runs, even under severe impairments that would otherwise result in a highly unstable vehicle. Without control reconfiguration capabilities, these impairments often resulted in poor targeting performance or complete loss of the vehicle.