# SURF 2012: Aircraft electric power system modeling in SIMULINK/Stateflow

**2012 SURF project description**

- Mentor: Richard Murray
- Co-mentor: Ufuk Topcu, Mumu Xu and Necmiye Ozay

The electric power system (EPS) of an aircraft provides electric power to all of its subsystems and typically consists of a combination of generators, switches, and loads. Electric power is distributed via one or more buses, and connection of generators to loads is routed by way of a series of electronic control switches (contactors). In current practice, the (discrete) control logic that opens and closes these contactors is designed by hand and its correctness is assured by exhaustive testing. As an alternative, automatic embedded controller synthesis methods can be used. In particular, our group investigates use of the Temporal Logic Planning Toolbox, TuLiP [1], to synthesize control logic for contactors that react the health conditions of different components of the system. A sample power system model for a traditional aircraft is available from MATLAB SimPowerSystems toolbox [2]. The first part of this project aims at developing a simulation model in Simulink for a more complex power system and combining it with TuLiP controllers in order to run mixed simulations (with both continuous evolution and discrete decisions). A second goal of the project is to investigate---using the model developed in the first phase---sensor placement and design trade-offs between the number of sensors used versus reliability of fault diagnosis. A working copy of a high-level description of EPS challenge problem can be obtained from one of the co-mentors.

Possible steps of the project include:

- Developing a SIMULINK model for the electric power system starting from a fairly complete single line diagram (SLD). Exporting TuLiP automata that implement the control logic to this simulation model to enable mixed analog discrete simulations. Designing an input file for the simulation where one can easily specify and test different dynamic fault scenarios.
- Searching different sensors and sensing modalities used for diagnostics in aircraft electric power systems (voltage, current measurements, etc) and modeling them in Simulink (if such models do not already exist). Developing mathematical models for such sensors and investigating how these sensors should be placed within the power system to reliably (e.g., with high probability) diagnose possible faults within the system.

*Required Skills:* This project requires programming experience, in particular familiarity with MATLAB and Simulink. Knowledge of basic circuit theory would be useful. Some working knowledge of continuous/discrete optimization tools is a plus.

**References**

- T. Wongpiromsarn, U. Topcu, N. Ozay, H. Xu, and R.~M. Murray, TuLiP: a software toolbox for receding horizon temporal logic planning. International Conference on Hybrid Systems: Computation and Control, 2011 (software available at http://tulip-control.sourceforge.net).
- Aircraft Electrical Power Generation and Distribution, http://www.mathworks.com/products/simpower/demos.html?file=/products/demos/shipping/powersys/power_aircraft_distribution.html.