Open-loop example systems

The FDC toolbox contains three open-loop example systems, which demonstrate how the Beaver model can be used in practice: OLOOP1, OLOOP2, and OLOOP3. These systems have been included in the FDC directory EXAMPLES; they can be opened by typing oloop1, oloop2, or oloop3 at the Matlab command line.

OLOOP1 and OLOOP2

OLOOP1 and OLOOP2 demonstrate how the system Beaver can be used in practice for non-linear, off-line, open-loop simulations of the 'Beaver' aircraft. OLOOP1 computes responses to control inputs to the elevator, ailerons, rudder, engine RPM, or manifold pressure of the engine, while OLOOP2 computes non-linear aircraft responses to atmospheric turbulence.

Before running a simulation, it is necessary to define the parameters for the aircraft model, by loading them into the workspace using DATLOAD. In addition, it is necessary to load trimmed-flight initial conditions with TRILOAD, or compute trimmed-flight conditions with the ACTRIM utility. These routines can all be started by double-clicking the initialization buttons on top of the OLOOP1 or OLOOP2 models.

OLOOP3

OLOOP3 demonstrates how to create open-loop simulations of aircraft responses to control inputs using a linearized aircraft model which is derived from the non-linear model Beaver.

The system matrices of the linear state-space model must be defined in the Matlab workspace before it is possible to start a simulation. These matrices can be determined for a user-specified operating point with the linearization routine ACLIN (double-click the appropriate button-block in the block-diagram of OLOOP3 to start this program). They can also be loaded from file (for instance a *.LIN file, created by ACLIN), which can be done conveniently with the utility LINLOAD. Both ACLIN and LINLOAD can be started by double-clicking the initialization buttons on top of the OLOOP3 model.