An Integrated, Modular Simulation System for Education ... - Cal Poly

Impulse ResponseRoll Angle32.5Amplitude21.510.5State Space6 DOF00 5 10 15 20 25 30Time (sec.)Figure 23 Roll Angle ResponseStandard AtmosphereA C MEX S-function block was created (Figure 24) to replace the hardwiredatmosphere function. The original function estimated the atmosphere up to the firstisothermal layer. Thislimited the functionConstant459.67to altitudes less than36,090 ft the cruising1.8to Rankineto F1Temperature Faltitude ofcommercial airliners.1Alt ft3.281To metersstd_atmsSFunctionDemux.00014503To psi019403To psi12Pressure lb/in^23Density slug/ft^3The S-functionstandard atmospherefunction calculates3.281To ft/secDemuxFigure 24 Atmosphere Conversion from SI to English Units4a ft/secthe pressure, temperature, density, and speed of sound up to 47 kilometers or about155,000 ft. using altitude as an input. Using the altitude output from the 6-DOF functionrequired including a unit delay block in the Simulink model to avoid a algebraic loop.The delay and initial condition must be set to match the models starting altitude and timestep. The C MEX S-function does the calculations using SI units, the conversion to64