Research And Development Of Dual-redundancy Ice Detection System

Icing occurs when aircraft is sailing,which seriously threatens flight safety.Chinese Air Police-200 early warning aircraft crashed because of the icing of the aircraft.It was the most serious air disaster in the history of the Chinese Air Force.Since the invention of airplanes,people gradually began to pay attention to relevant research on airplane icing detection.Aircraft icing detection is an important part of the anti-deicing system.Small failures can cause catastrophic consequences.The way to improve the reliability of a system is to use redundancy technology.In order to be able to develop an aircraft wing surface icing detection system with high reliability,this thesis separately studied the complex impedance icing detection technology and the optical fiber icing detection technology and then carried out the dual-redundancy system based on this.Research and development of ice detection system.First of all,this thesis carried out the principle research of the complex impedance icing detection technology and the optical fiber icing detection technology,and used the above two principles to carry out the icing wind tunnel exploration test,and found that the complex impedance icing detection technology cannot be used in ice.The thickness of icing is measured in the state of water mixing,and there is a problem of serious temperature drift;the optical fiber icing detection technology has the problem that the signal response will be affected by the ice type.Then,this thesis conducts an in-depth study on the complex impedance icing detection technology.The detection method of complex impedance icing considering the influence of temperature and the mixed state of ice and water is explored,and the theoretical model of the complex permittivity of ice at different temperatures and the temperature drift correction model is established.Through simulation analysis of the dispersion interval of ice and water under different frequency electric fields,the classification method and measurement model of ice state,water state and ice-water mixed state are summarized.For fiber-optic icing detection technology,this thesis analyzes the microscopic differences between bright ice,frost ice,and mixed ice,and the mechanism of the influence of pores on fiber-optic icing detection,and summarizes a plan to weaken the influence of porosity.Finally,in accordance with the requirements of non-similar redundancy technology,this thesis uses different software,hardware,and detection technologies to design and develop a dual-redundancy icing detection system,and verify the icing detection ability of the dual-redundancy icing detection system through experiments.reliability.The doubleredundant icing detection system has high accuracy and good stability in measuring icing thickness,and it can be installed flush with the wing and has a good application prospect.