Safety-Guaranteed Flight Test Environment for Micro Air Vehicles

Abstract

This paper proposes a novel safety-guaranteed flight test environment for more efficient free-flight testing of micro air vehicles. The magnetic suspension and balance system, which has up to now only been employed for sting-free aerodynamic coefficient measurement during wind-tunnel testing, has the potential to be developed as a free-flight test rig. The magnetic suspension and balance control system can be adjusted so that magnetic constraint forces or moments can be removed for certain degrees of freedom, so that a micro air vehicle model inside the magnetic suspension and balance system can move freely in those degrees of freedom. At the same time, the removed magnetic constraint forces or moments can be regenerated when the position or attitude of the model changes beyond designated ranges. In this way, the model can be exposed to free-flight conditions for those degrees of freedom while falling is prevented, even if the model has inherently unstable dynamics. This is the basic idea for the safety guaranteed flight test environment which is herein named the “pseudoflight environment.” The pseudoflight environment allows to conduct some iterative free-flight tests to tune the flight control system in a safe way. It is important to note that a synthetic force or moment can be applied to the micro air vehicle model under the pseudoflight environment for quantitative evaluation of the flight control system because the magnetic forces and moments of the magnetic suspension and balance system can be generated at will. This is another unique feature of the pseudoflight environment that cannot be obtained through existing wind-tunnel tests using mechanical-type balances or real flight tests. The advantages of the proposed idea were experimentally demonstrated with the yaw attitude control systems of a micro air vehicle model.