Investigation of Small Scale Helicopter Servo-Actuator Performance Using Frequency Sampling Filters

Abstract

This paper addresses the performance of electric servo-actuators as part of a helicopter control linkage system. The development of a helicopter flight control system initially requires a non-linear model capable of accurately predicting the aircraft dynamics. The first step of this non-linear model represents the servo-actuator system, which transmits the pilots control inputs to the main rotor system. A series of system identification experiments were performed on a cyclic system servo-actuator under different operating conditions, and the servo-actuator step responses were estimated using a Frequency Sampling Filter. A performance comparison is made for a zero load bench test and the aircraft load condition in order to determine the most accurate representation of the servo-actuator dynamics for helicopter flight applications.