RotorGen2 Minimal-Complexity Helicopter Math Models Home

Robert Heffley Engineering has applied RotorGen2 minimal-complexity models to a variety of helicopters.

• Minimal-complexity air-vehicle modeling is based on a scheme outlined in an Army-sponsored program more than 20 years ago (Manudyne Report 83-2-3).

• The original concept was to devise a helicopter math model that embodies the first-principles of rotary-wing aerodynamics while requiring a minimum of model parameters and computing power.

• The main objectives were to minimize computational delay (frame time), to simplify adaptation to a specific aircraft, and to minimize the engineering labor in implementation and checkout.

• RotorGen was an implementation of the original minimal-complexity model applied to a series of handling-qualities studies by the U.S. Army on the NASA Ames VMS large-amplitude motion simulator facility.

• RotorGen2 is a second-generation development of the original "minimal-complexity" math model form.

• The advantages of RotorGen2 is its implementation in Matlab and Simulink form as well as C++ code, its capability to run in the TPV modeling environment, and the array of RHE development tools for adapting RotorGen2 to specific rotary-wing vehicles.

• Because RotorGen2 depends on analytic functions to describe aerodynamics, it can be molded to match a minimal amount of available data, much of which may be basic geometrical and mass data.

• RotorGen2 provides a simulation solution for many applications requiring basic helicopter dynamical modes without higher-order/high-frequency blade dynamics.

• RotorGen2 provides correct non-linear behavior over a large range of airspeeds and wing-body aerodynamics for the full range of angle of attack and sideslip.

• While the basic RotorGen2 model models only the normal working state, it can be augmented to include the autorotation (windmill) state.

• Other effects can be added, including higher-order tip-path-plane dynamics, ground effect, ground contact, blade stall onset, etc.

• RotorGen2 provides the user with control over the tradeoff between complexity and model accuracy, hence, engineering cost, computer performance, and simulator fidelity.