Fly Micro Research Articles

Free-Wing Unmanned Aerial Vehicle as a Microgravity Facility

A conceptual study is presented on the dynamics of a proposed unmanned aerial vehicle (UAV), which is designed as a testbed for studying the influence of micro- (or partial) gravity on various biological or physical phenomena. The design option of a torque-controlled wing, free to rotate about a spanwise axis, is evaluated in terms of gust sensitivity and automatic settling at a certain g-setpoint. The complete set of nonlinear equations of motion of such a free-wing UAV are derived using Lagrange’s equations. A linear aerodynamic model of the UAV is used to investigate its flight dynamics, gust sensitivity, and ability to fly micro- and partial gravity flights. Comparison to a similar fixed-wing UAV shows considerably decreased gust sensitivity. Nomenclature Cm = dimensionless moment coefficient about the center of gravity of the fuselage c = cosine ¯ c = mean aerodynamic chord F = generalized force f = position of the fuselage center of mass g = Earth’s gravitational acceleration H = transfer function h = position of the intersection of the hinge lines of both wing halves L = Lagrangian function lw = position of the left wing half center of mass M = moment m = mass n = load factor p = angular velocity component of the fuselage along the x f axis q = angular velocity component of the fuselage along the y f axis q = column vector of generalized coordinates R = transformation matrix between two reference frames r = angular velocity component of the fuselage along the z f axis rw = position of the right wing half center of mass S = power spectral density s = angular velocity component of the wing halves along their hinge axes s = sine T = kinetic energy t = tangent t = time u = geodetic velocity component of the center of mass of the fuselage along the x f axis V = potential energy v = geodetic velocity component of the center of mass of the fuselage along the y f axis v = velocity