Development and flight test verification of the differential-pressure-based two-dimensional low-airspeed sensor integrated with rotors of small helicopters

Abstract

This paper describes the development and the flight test verification results of the differential-pressure-based low-speed air-data sensors (ADS) mounted on the rotor of small helicopters.Referring to the low-speed sensor technologies for large-scale helicopters, newly-developed small and light-weight sensor, rotating with the main rotor of the small helicopter, integrates two probes at the both ends of the arm, a differential pressure sensor, a rotary encoder with one magnet and two sensors, a microcomputer, a wireless data link, and a battery.This can measure the static or total pressure at each rotor angle, and the airspeed of the fuselage can be calculated by using the differential pressure and the encoder from low speed.Flight test results show that the magnitude of the airspeed can be calculated precisely from low speed, on the other hand, the angle of the airspeed has static error about thirty to forty degrees.