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With the development of science and technology, position and orientation system (POS) technology has become an important tool for airborne earth observation system, and plays an important role in both military and civil fields. The calibration of the device directly affects the accuracy of inertial navigation. Therefore, the paper designs a compact dual mode navigation system with high and low precision, which can be used in distributed POS system. Firstly, the status of IMU calibration technology is introduced. Then it introduces the working principle, structure design and layout design of fiber optic gyroscope (FOG) combination. Finally, the calibration experiment verifies that the designed FOG combination system meets the performance index.

This paper discusses the influence of pH value, temperature and current density on the crystalline and amorphous structure of Ni-W alloy coatings during the electroplating process. The relationship between the corrosion resistance of Ni-W alloy coating and its crystal structure is discussed. In addition, the most common types of ternary systems and composite coatings for electrodeposited Ni-W alloy coatings are introduced. The effects of element types and contents on the hardness, wear resistance, corrosion resistance and thermal stability of Ni-W alloy coatings are analyzed. Finally, the current problems and development directions of Ni-W alloy coatings are proposed.

In order to provide higher accuracy for transfer alignment on aircraft, a surface-attached FBGs is designed for distributed deformation measurement of aircraft wing. To verify the measurement accuracy of the surface-attached FBGs, a strain calibration method of the surface-attached FBGs applied with the wing strain measurement is proposed. Two Aluminium Alloy Test Plates(AATP) with different sizes were designed as the matrix material for tensile test. The test results show that AATP-A has better test effect. Through the two sets of tensile tests, the change of wavelength measured on the surface-attached FBGs is in good agreement with the change of strain value of strain gauge.The experimental results prove that the method based on surface-attached FBGs is feasible for the strain measurement of aircraft wing. The method is simple and reliable, which lays a foundation for the follow-up study of the full-field deformation measurement of aircraft wing.

Ceramic coatings were prepared on the surface of AZ91D magnesium alloy by microarc oxidation technology. The effects of different voltages on morphology, phase composition and thickness of the coatings were characterized by SEM and XRD. The corrosion resistance of the coatings was measured by electrochemical workstation. Results indicated that the microarc oxidation coatings prepared in sodium silicate electrolyte exhibited porous surface and mainly comprised MgO, Mg2SiO4 and a small amount of MgAl2O4. The thickness of the oxide coatings increased rapidly with the increase of voltage. The coating prepared at 400V voltage had good electrochemical corrosion resistance in 3.5wt% NaCl solution.