A Novel Aircraft Center of Gravity and Gross Weight Estimation Method Solely Using Standard Aircraft Measurement Sensors Navy SBIR FY2011.2 Sol No.: Navy SBIR FY2011.2 Topic No.: N112-114 Topic Title: A Novel Aircraft Center of Gravity and Gross Weight Estimation Method Solely Using Standard Aircraft Measurement Sensors Proposal No.: N112-114-0693 Firm: Impact Technologies, LLC 200 Canal View Blvd Rochester, New York 14623 Contact: Liang Tang Phone: (585) 424-1990 Web Site: www.impact-tek.com Abstract: Impact Technologies, in collaboration with Rochester Institute of Technology proposes to develop and demonstrate a novel algorithm for estimating aircraft gross weight and center-of-gravity location using an innovative nonlinear real-time filter based method. The proposed algorithm uses known physics-based kinematic relationships between aircraft states for the estimation process and requires only traditional sensor measurements typically employed by aircraft. The physics-based kinematic relationships are used to derive the aircraft's imposed loading estimates. Once the imposed load is determined the algorithm quickly isolates the vehicle's gross weight and center-of-gravity. Estimation of the aircraft's aerodynamic parameters is not required in the new approach. The new real-time filtering algorithm is based on an augmented version of the Sliding Mode Control algorithm which guarantees stable convergence (using Lyapunov's Direct Method) of the aircraft's gross weight and center-of-gravity estimates within known bounds. Preliminary simulation studies have demonstrated fast convergence of the aircraft's gross weight and center-of-gravity location within a high degree of accuracy. While Phase I will focus on proof-of-concept software-in-the-loop demonstration and refinement to the current algorithms, a flight worthy algorithm will be developed and demonstrated using a relevant Navy aircraft vehicle platform for a mission profile in Phase II. Benefits: The proposed device incorporated for estimation of center-of-gravity and gross weight provides significant improvement over current technology. The device has both military and commercial applications, fixed-wing and rotary-wing aircraft platforms, providing near instantaneous updates of gross weight and center-of-gravity. The technology can remove the dependence on tedious calculations which introduce a high probability of human error. The parameters obtained can be used to update flight control algorithms, significantly improving flight controls and efficiency of the control system. Situations where updated information might be desired could include cargo drop off or pick up, shifts in payload location, passenger drop off or pick up, and many others. The updated parameters can also take into account fuel consumption for calculation of both gross weight and center-of-gravity. Improvements can also be made for airframe fatigue life analysis, where incorporation of updated values to the health monitoring system can relax conservative loading estimates. The system is robust in that it does not require advanced aerodynamic models of the vehicle, and as such can be implemented to any new vehicle without acquiring advanced aerodynamic data. The successful completion of this project would allow an aircraft to have the most up to date and accurate estimates available for center-of-gravity and gross weight, which are necessary when determining flight control inputs to the vehicle, stability of the aircraft, and ensuring the safety of passengers and payload. Return