Design And Research On Aviation Scene Simulator

Aviation scene simulator is used in simulate a flying scene of real target in laboratory. It includes synthesis technique such as optics, mechanism, electronics and control. Simulated functions are spectrum feature, target distance, approaching velocity, approaching acceleration, visual angle, separating velocity of different targets etc. The simulator is a load of the flight table, and is limited in volume, weight. But it needs good property of anti-impact, anti-vibration and heat-resisting.This thesis is about the research of design of the simulator. Three types of target are simulated. The first is the target which is fixed in the centre of the field of view. The second target can be separated from the centre of the field. The third is a group of targets aligned in a row. Upon our design scheme, radiant source is imaging first, and the field diaphragm is located at the image place. The distance variation in near range is simulated by changing the aperture of the field diaphragm. In the mean time, a light energy modulator is settled by the image place and the distance simulation in far range is operated by attenuate the intensity of the light signal. Besides, the separating from the centre of the field is simulated by a scanning mirror.We design three optical paths for different fields of these target types. They are combined into one beam which is projected to the optical system of the receiver by a telescope projector. In this thesis, we analyzed the imaging quality of the projector, the three imaging sub-systems and the three combinations of the sub-systems and the projector, both before scanning and after scanning to the maximum. Results show that the imaging quality of optical system satisfies the requirement of the simulation. Furthermore, we analyze of the tolerance of the optical system to ensure that the manufacture error does not affect the imaging quality much.The expression of the received radiant energy of the real target is deduced, and the radiant brightness of the radiant source is demonstrated. Xenon lamp is used as the radiant source in the simulator, and the radiant brightness distribution in the spectrum is detected in experiment. The radiant brightness expression of in both near and far distance range is deduced according to the principle of light energy transmission in the simulator. Infrared polarizers combination is used as the modulator of light energy in the simulator. The attenuation ratio expression of two polarizers combination is deduced. It is verified by experiment that in low transmittance state, the expression presents a more precise extinction ratio than Malus's Law does. Attenuation ratio of three polarizers combination is deduced according to this algorithm, and change rule of the attenuation ratio in different rotation modes. Furthermore, attenuation ratio of combination of two polarizers with different extinction ratios is deduced, and it is extended to the states of more than three pieces. In this simulator, we combine three same polarizers and rotating the middle one to enlarge attenuation range by the premise of guaranteeing its dynamic performance.Simulation mathematical model of different moving components is demonstrated based on the optical structure and parameters. Accordingly, relations between the moving velocity and acceleration of simulated target signal versus those of the moving components are demonstrated. According to the manufacture error and the control error of the servo motor, the error of the simulated moving parameters is analyzed.Analyze the response of retaining plate by modeling the both physical fields of motion of the flight table and the heat transmission in the simulator. Besides, analyze the response of the retaining plate under power spectrum density in vibrating circumstance. According to the results, deformation of the retaining plate is small so that the simulator can be regarded firm enough and reliable.