Control of rotor speed for a model helicopter: a design cycle

In rotary wing aircraft it is desirable to hold the rotor speed constant, since varying rotor speed causes nonlinearities that complicate identification and control. In this paper we discuss the design of a tachometer to measure the rotor speed of a model helicopter. We then identify a SISO model and synthesize and implement a control law that regulates the rotor speed. We compare different control laws and highlight the problems resulting from an essentially discrete valued measurement.