As the input parameters more and not easy to measure accurately,it is difficult to get the high-precision simulation model of thermoelectric cooler.A method of model establishment and modification was proposed.At first,the thermal model of thermoelectric cooler was established.Then,the sensitivity of thermal model parameters is analyzed by the Spearman rank correlation.It is aimed to determine the strong correlation parameters and weak correlation parameters that affect the simulation accuracy.Taking the measured temperatures as the targets,the multi-island genetic algorithm was used to correct the strong correlation parameters firstly.Then the weak correlation parameters are corrected.Based on above results,the Hooke-Jeeves Direct Search Method was used to modify the parameters for obtaining the accurate values when the current is 3.6 A.Similarly,the corrected values are obtained when the current is varyed from 0 A to 3.9 A.The accurate thermal model of thermoelectric cooler can be established at different current.The results show that the maximum error between simulation value and experiment value is less than 4.9 ℃ (-5℃ to 100.5 ℃) when the current is changed from 0 A to 3.9 A.In conclusion,the modified method of thermal model is reasonable and accurate.

To improve the optical axis stabilization ,the static unbalance torque of airborne photo-electric platform must be minimized with the help of balancing weight in assembling stage .An effective layout optimization method of multiple sensors in the airborne photoelectric platform in two-axis four-gimbal form was proposed to reduce the static unbalance torque in the design stage .The finite circle method was employed to establish the module overlap constraint and the optimization algorithm of globally convergent method of moving asymptotes was used to solve the layout optimization problem fast .Results show that this method succeeds in reducing the static unbalanced torques of the inner azimuth and pitch axes by 45% and 68% ,respectively , which effectively reduces the balancing weight and improves the performance of EO platform .

In structural dynamic simulation analysis,the accuracy and efficiency are affected greatly by the model of screwed fittings. Aiming at the complexity and precision deficiency of current models,a modeling method for screwed fittings based on model updating was presented to use rigidity elements to replace bolts. Firstly,according to the presented method,an equivalent FE model of two shells connected with four screws was built and the relationship between the system's natural frequency and screw tightening torque was studied with modal tests. Then the model's stiffness parameters were updated based on the test results. The updating results showed that the errors between the calculated modal frequencies and the test ones are less than 2. 5% in a large tightening torque range. It was demonstrated that the presented modeling method is feasible and effective.

Fast-steering mirror(FSM) is a device used for controlling the direction of a light beam precisely.This article proposed a method to compensate the residual error of a coarse stabilized platform with FSM driven by PZT to improve line-of-sight stabilization accuracy greatly.The high precision line-of sight(LOS) stabilization system was simulated.The results of simulation showed that the stability error of coarse stabilized platform is 110 μ rad,and the stability error after FSM compensation is less than 8 μ rad.This method can improve the stabilization accuracy at least one order of magnitude.