This paper deals with the problem that the signals of the force sensor of an aircraft＇s electric braking sys- tem are superimposed with high-amplitude interference. The analysis of the electric braking system shows that the three-phase current of its motor and the pulse width modulation （PWM） wave output by the electro-mechanical ac- tuator controller （EMAC） are the primary sources of interference and that the coupling interference between cable lines is the main cause of the interference of signals of the force sensor. The mathematical model of coupling inter- ference between cable lines is established, according to which the transmission cable is designed and the line cou- pling was reduced by using electromagnetic shielding, line twisting and effective grounding. A passive electromag- netic interference （EMI） filter is designed for the output end of the EMAC. Through these improvements, the inter- ference superimposed on the force sensor is greatly reduced. The paper also improves the electromagnetic ＇, compati-bility of the electric braking system and ensures that the braking force servo system works normally.
Journal of Northwestern Polytechnical University
aircraft, braking, brushless DC motors, design, design of experiments, efficiency, electromagnetic shielding, fast Fourier transforms, interference suppression, mathematical models, pulse width modu- lation, sensors, schematic diagrams, topology, （EMI）, EMI filter, transmission cable electric braking system, electromagnetic interference