Global Linear Modeling of Small Scale Helicopter

Abstract

The establishment of global helicopter linear model is indispensable for the design of an onboard autonomous control system by using linear control laws. To date, however, it has never been afforded in the literatures. In the first principle approach, the mathematical model is developed using basic helicopter theory accounting for particular characteristic of the miniature helicopter. In this approach, no formal system identification procedures are required for the proposed model structure. The relevant published references however did not present rigorous linear models development required for the design of linear control laws. This chapter presents a step by step development of linear model for small scale helicopter based on first-principle approach. Beyond the previous work in literatures, the calculation of the stability derivatives is presented in detail. A computer program is used to solve the equilibrium conditions and then calculate the change in aerodynamics forces and moments due to the change in each degree of freedom and control input. The detail derivation allows the comprehensive analysis of relative dominance of vehicle states and input variables to force and moment components. The procedure can be implemented for various flight conditions. Hence it facilitates the development of global small scale helicopter dynamics model.