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Ancil Marshall

Ancil Marshall

Senior Guidance Navigation and Controls Engineer

Guidance Navigation and Controls
Aircraft, Spacecraft, Orbital Dynamics
Modeling and Simulation
48 years old
Boston (02108) United States (Massachusetts)
Employed Open to opportunities
Senior Guidance, Navigation and Controls (GNC) Engineer with over fifteen years of experience specializing in aircraft, missiles, launch vehicles, space vehicles and commercial drones. Expert in a wide-range of GNC responsibilities such as the modeling of aerospace vehicles, the design and analysis of feedback control laws, the development of guidance algorithms, the analysis of mission performance via simulations, the support of vehicle integration tests and on-site, in-field flight activities.

Strong project management skills demonstrated by leading various programs and heading up small multi-disciplinary teams for diverse projects. Firmly believes in team development through collaboration, training and mentoring.

Open to new opportunities in a GNC flight controls group where I can leverage my experience to ensure the success of challenging projects.
Feedback controllers for the stabilization of the angular velocity vector of a rigid
spacecraft using a single-gimbal Variable Speed Control Moment Gyro (VSCMG) are
presented. Linearization of the equations of motion show that complete attitude stabilization
is not possible via linear methods. Nonetheless, it is shown that the linearized
angular velocity equations are controllable, and a simple LQR control law is used to
locally asymptotically stabilize the angular velocity vector. A Lyapunov-based approach
is subsequently used to derive a state feedback control law that globally asymptotically
stabilizes the nonlinear angular velocity system.

AIAA Guidance, Navigation & Control Conference, Austin, TX, 2003
Creation date
13 Aug 2003