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As object detection is widely adopted in aerial images, scene texts and other fields, rotating object detection plays an important role and draws attention since it can provide highly accurate orientation and scale information. In this article, we propose a novel and simple baseline to effectively conduct rotating object detection. First, we design a brand-new representation for rotating objects by using a circle cut horizontal rectangle (CCH). The CCH ensures that the regression parameters will not exceed the defined domain and avoids vertex sorting, thus solving some problems in current common representations, including the boundary problem and order problem, and improving the robustness. Second, we design a lightweight head based on the CCH to add the rotating regression to classic benchmark in an almost cost-free manner and propose a single-stage anchor-free rotating (SAR) object detection convolutional neural network. Finally, we demonstrate the details of our method by applying it to data sets with different scenarios. The experiments confirm that our method achieves competitive accuracy and state-of-the-art speed in aerial image and scene text detection.

In order to improve the geo-location accuracy of the airborne optoelectronic platform and eliminate the influence of assembly systematic error on the accuracy, a systematic geo-location error correction method is proposed. First, based on the kinematic characteristics of the airborne optoelectronic platform, the geo-location model was established. Then, the error items that affect the geo-location accuracy were analyzed. The installation error between the platform and the POS was considered, and the installation error of platform’s pitch and azimuth was introduced. After ignoring higher-order infinitesimals, the least square form of systematic error is obtained. Therefore, the systematic error can be obtained through a series of measurements. Both Monte Carlo simulation analysis and in-flight experiment results show that this method can effectively obtain the systematic error. Through correction, the root-mean-square value of the geo-location error have reduced from 45.65 m to 12.62 m, and the mean error from 16.60 m to 1.24 m. This method can be widely used in systematic error correction of relevant photoelectric equipment.

Endoplasmic reticulum (ER) stress-mediated apoptosis has been reported to be involved in the noise-induced hearing loss (NIHL). Glucocorticoid-induced leucine zipper (GILZ) protein has been reported to have different regulatory effects on apoptosis according to cell types. However, whether GILZ regulates apoptosis in cochlear cells is unclear. Our study aimed to investigate the mechanism by which GILZ protected ER stress-mediated cochlear apoptosis induced by noise exposure. In our trials, forty-eight male Spraque-Dawley rats were randomized into the noise, OE-GILZ-rLV + noise (ON), shRNA-GILZ-rLV + noise (SN), and control group. Rats in noise and control groups were pre-treated by administration of Blank-rLV. Before and on days 1, 4, 14 after noise exposure, auditory brainstem response (ABR) and cochlear apoptosis were detected. Changes in GILZ, GRP78, CHOP, Bcl-xL, Bax, and cleaved caspase-3 levels were investigated. Noise exposure increased ABR threshold shifts and cochlear apoptosis in parallel with downregulation of Bcl-xL and upregulation of GRP78, CHOP, Bax and cleaved caspase-3. GILZ overexpression significantly reduced ABR threshold shifts and apoptotic cochlear cells owing to noise exposure. GILZ overexpression in the cochlea further increased GRP78 elevation, decreased expression of CHOP, Bax and cleaved caspase-3, and increased expression of Bcl-xL. GILZ silencing demonstrated the opposite effect on these effects. GILZ protects cochlea from ER stress-mediated apoptosis induced by noise exposure through reduction of CHOP and regulation of ER stress-associated apoptotic proteins.

Intratympanic corticosteroid (IC), intravenous batroxobin (IB) as the treatment for sudden sensorineural hearing loss (SSNHL) has been reported. However, the data on combination therapy (CT) was scarce.The aim of this retrospective study was to compare the efficacy of IC, IB, and CT in the treatment of SSNHL with diabetes.A total of 212 SSNHL patients with diabetes, who were initially treated within 14 days of onset of disease, were divided into three groups by treatment modality. The hearing recovery was evaluated by the results of pure-tone test after completion of treatment. The prognostic factors, including age, severity of initial hearing loss, duration to onset of treatment, and audiometric curve type, were further compared.There was a significant difference in hearing recovery by the treatment (p .05). Recovery rates in the CT group were significantly higher in patients with early treatment than with delayed treatment (p = .021). However, duration and recovery rate was not significantly correlated in IC and IB group (p .05). In patients recieving early treatment, the recovery rate in CT group was significantly higher than that in IC (p = .013) and IB group (p = .029). Regardless of treatment, the recovery rates were higher in patients with flat and ascending audiograms (p .05).Patients receiving combined therapy, especially in the early stage of SSNHL, could achieve significantly superior recovery in the treatment of SSNHL with diabetes, compared with those using IC or IB alone.

This paper addresses the aerodynamic modeling, observer-based state-feedback robust control and sensor fault detection for a laboratory ducted coaxial-rotor UAV (DCUAV). First, by introducing the main model elements of this novel unmanned vehicle, the detailed nonlinear mathematical model of the hovering flight UAV is presented. Second, through introducing a weighting matrix and a new form of change-of-variables, a new method is proposed by designing two different systems simultaneously as detector and controller. An observer-based controller is proposed to achieve the control objective and finite-frequency sensor fault detection objective simultaneously. The observer-based controller design method is derived from a new formulation of linear matrix inequality (LMI), which can achieve the prescribed H∞ performance, H- performance and the stability of the closed-loop system. By constructing a new matrix decomposition form, the simultaneous design of detector parameters and controller parameters is solved. Finally, simulations are conducted for the hover flight with disturbances and sensor faults, the results show the satisfactory control performance and fault detection performance.

The reconfigurability metric of distributed control torque gyro (CMG) of Jilin-1 super agile satellite is studied, and a reconfigurability metric of CMG under energy constraints is proposed in this paper. According to the design requirements for the attitude control system of Jilin-1 super agile satellite, the linear attitude dynamics and kinematic equations expressed in the form of state space are established, and the Gram matrix reconfigurability measurement scheme is designed. The minimum eigenvalue of the Gram matrix is used as a criterion for evaluating the reconfigurability of CMG. Finally, a reconfigurable simulation experiment is performed on the distributed CMGs, and the simulation results verify the validity of the metric, which will provide reference that research on the reconstruction and reuse of the actuator of the Jilin-1 super agile satellite.

Feature-based remote sensing image registration methods have achieved great accomplishments. However, they have faced some limitations of applicability, automation, accuracy, efficiency, and robustness for large high-resolution remote sensing image registration. To address the above issues, we propose a novel instance segmentation based registration framework specifically for large-sized high-resolution remote sensing images. First, we design an instance segmentation model based on a convolutional neural network (CNN), which can efficiently extract fine-grained instances as the deep features for local area matching. Then, a feature-based method combined with the instance segmentation results is adopted to acquire more accurate local feature matching. Finally, multi-constraints based on the instance segmentation results are introduced to work on the outlier removal. In the experiments of high-resolution remote sensing image registration, the proposal effectively copes with the circumstance of the sensed image with poor positioning accuracy. In addition, the method achieves superior accuracy and competitive robustness compared with state-of-the-art feature-based methods, while being rather efficient.

To investigate the aerodynamic complexities involved in the combination of freestream and propeller’s suction flow field of ducted coaxial rotors system in forward flight, an orthogonal L16(43) test design has been applied to optimize the design parameters including forward speed, pitch angle, and axial spacing between rotors. Multiblock grids and Multiple Frame of Reference (MFR) method are adopted for calculating aerodynamic performance of the system, hover characteristic was compared with experimental data obtained from the test stand, and the thrust performance is well predicted for various rotor spacing and a range of rpm. This solution approach is developed for the analytical prediction of forward flight and the simulation results indicated that the design parameters influenced lift, drag, and torque reduced in the order: wind speed > rotor spacing > pitch angle, wind speed > pitch angle, and rotor spacing > wind speed > pitch angle, respectively. The optimal rotor spacing and pitch angle were determined to maximize the aerodynamic performance considering high lift, low drag, and trimmed torque.

Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existing point spread function (PSF) models in the literature corresponding to lens aberrations and defocus are either parameterized and spatially invariant or spatially varying but discretely defined. In this paper, a parameterized model is developed and presented for a PSF which is spatially varying due to lens aberrations and defocus in an imaging system. The model is established from the Seidel third-order aberration coefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometry structure. The accuracy of the model is demonstrated with simulations and measurements for a defocused infrared camera and a single spherical lens digital camera. Compared with optical software Code V, the visual results of two optical systems validate our analysis and proposed method in size, shape and direction. Quantitative evaluation results reveal the excellent accuracy of the blur kernel model.

The performance of MEMS-SINS/GPS integrated system degrades evidently during GPS outage due to the poor error characteristics of low-cost IMU sensors. The normal EKF is unable to estimate SINS error accurately after GPS outage owing to the large nonlinear error caused by MEMS-IMU. Aiming to solve this problem, a hybrid KF-UKF algorithm for real-time SINS/GPS integration is presented in this paper. The linear and nonlinear SINS error models are discussed, respectively. When GPS works well, we fuse SINS and GPS with KF with linear SINS error model using normal EKF. In the case of GPS outage, we implement Unscented Transform to predict SINS error covariance with nonlinear SINS error model until GPS signal recovers. In the simulation test that we designed, an evident accuracy improvement in attitude and velocity could be noticed compared to the normal EKF method after the GPS signal recovered.

Roll–pitch seeker is currently applied in particular missiles. There is a stubborn problem called zenith pass problem while roll–pitch seeker is used. Analysis of the zenith pass problem which always results in loss of target is presented in this paper. Based on the analysis result, tracking strategy is carried out to deal with zenith pass problem. To prove the validity of tracking strategy, a practical roll–pitch seeker was accomplished. Model identification and common PID controllers for the physical roll–pitch seeker are taken on, after that, both disadvantages derived from zenith pass problem in tracking process and meliorated phenomenons by the tracking strategy are shown. It is concluded that the tracking strategy designed for solving the zenith pass problem is efficient.

A new mini-spectrophotometer is developed by adopting micro-silicon-slit and micro-silicon-fixer, which are based on micro electro-mechanical systems (MEMS) technology. Both the micro-silicon-slit and the micro-silicon-fixer have their own features, such as small volume and high precision, which are laid out and analyzed later. Meantime, through the analysis of the sample cell’s optical characteristics that have some impacts on the linearity of the spectrophotometer, a relationship equation, which is about the impact of the refractive index of the sample cell and the tested medium on the variety of the transmitted light intensity and the absorbency, is put forward. When the water and the air are taken as the referenced medium, the experiments demonstrate that the difference of the refractive index of the references does not influence the correlation coefficient r and the slope of the absorbency-concentration curve. The final results show that the new mini-spectrophotometer with micro-silicon-slit and micro-silicon-fixer is worked out, its correlation coefficient r > 0.999, and its refractive index resolving power is better than 0.01.

Aiming at the problem that the strapdown imaging seeker cannot measure line-of-sight (LOS) rate directly, this paper presents an effective algorithm for LOS rate estimation. To address the problem, the reference frames and angles are defined. According to the relative kinematics and attitude relationship between missile and target, the nonlinear state equations and measurement equations of LOS rate are derived, and the estimation algorithm based on unscented Kalman filter (UKF) is proposed. Considering the estimation accuracy mainly depends on body LOS (BLOS) angle accuracy and gyro accuracy, the paper is unprecedented to research how these two factors impact the LOS angle and rate accuracy by simulation. Semiphysical simulation experiment verifies the correctness and accuracy of the algorithm, and the result shows that the estimation algorithm can meet the accuracy and real-time requirements of guidance system simultaneously. Thus LOS rate estimation algorithm based on UKF provides a theoretical basis for engineering applications of strapdown imaging seeker.

In this paper, a kind of wind tunnel experiment will be discussed. This wind tunnel experiment is used for conformal dome design. Wind tunnel experiments are done with different speed and attack angles. The results together with the simulation results got before will be used for coupling simulation FEA software. After analyzing and computing the data, the conformal dome's aero-optical effects are studied.

MEMS Gyroscope mathematical model is needed while an electric-optical control system is designed, because MEMS gyroscope is used as angular rate component and its error is also added into the servo loop. To compose the mathematical model, three parameters, damping ratio, scale factor and natural frequency are identified. First a gyroscope mathematical model is presented. Second a MEMS gyroscope is selected to be tested according to the particular standard to get the above mentioned three parameters and the gyroscope frequency response characteristics. Third with the identified parameters, a whole gyroscope mathematical model is composed. Finally, the mathematical model frequency response characteristics is compared to the tested frequency response characteristics. The tested parameters result is that the damping ratio is 0.7149, the bandwidth is 122Hz and the scale factor is 8mv/°/s. In the gyroscope bandwidth, the compared result is that the maximum magnitude attenuation error is 0.98dB while the maximum phase lag error is 0.88°. It is concluded that the three parameters attach to the mathematical model are conveniently tested and the model is easily to be composed. The composed mathematical model frequency characteristics is almost same with the tested frequency characteristics. The model is helpful to the designation the electric-optical servo system.

Conformal optical dome can induce the drag of the missile. The conformal dome test is an important way to make the dome perfect for imaging. This paper shows a interference test of elliptical conformal dome's inside surface. First, the test system is designed by zero position method. The test system is composed by two parts: the focal lens and the spherical mirror. The interferometer used is operating in 632.8nm. The ideal test system's resolution is 0.0065waves in PV(peak to valley) value and 0.004 waves in RMS(root mean square) value. The next step is tolerance analysis. According to the optical and mechanical manufacture level, the tolerance analysis is done by optical software ZEMAX. The results are 1.219 waves in PV value and 0.249 in RMS value. The working wavelength is 4.2μm for conformal dome. After calculation, the PV value is 0.179 waves and the RMS value is 0.0366 waves. Finally, the bolster is designed, and for the key structure the topology optimizing is simulated

This paper create a full aircraft flight simulation model for accurately analyzing the performance and influence of landing gear system. The use of multi-domain modeling technology enables detailed modeling of the flight dynamic and landing gear dynamic. The simulation results show that the aircraft landing gear system mathematical model established appropriately reflects the change of force and moment in the process of taking off and landing, and it is actual in the physical process. The parameter design space is easily searched by considering a number of different landing scenarios to optimize the design.

Frame motion form of roll-pitch seeker is introduced in this paper. There is corresponding relationship between the frame angle of the roll-pitch seeker and the traditional yaw-pitch seeker. The discrepancy of line-of-sight (LOS) rate of the two seekers is caused by the different frame motion forms. LOS rate reconstruction method of roll-pitch seeker is deduced. Compared to the pure proportional navigation guidance law, the true proportional navigation guidance law is more suitable for the roll-pitch seeker missile guidance.

In order to realize the real-time state data monitor of the electromechanical actuator(EMA), the EMA and other subsystem establish a ground half physical experiment simulation platform based on the CAN bus. The CANoe software decodes the received EMA CAN data and showes the result in the image window. The decoding data contains the EMA current, motor operation state, EMA angle and etc. Through these real-time display data, the EMA operation state could be monitored and the EMA failure could be located fastly.

Because the underwater velocity of supercavitating projectile is very high, its structure undergo high longitudinal force. It is necessary to perform structure buckling reliability analysis because the randomicity of structural own parameters and flow parameters should be considered. Critical buckling load of supercavitating projectile is calculated by Galerkin method. The partial matrixes of critical buckling load implicit function to each random variable are deduced, and structural buckling reliability index is calculated by limit step length iteration method. Numerical results show that the critical buckling load and structural buckling reliability index increase with the increase of the ratio of base diameter to cavitator diameter. And structural buckling reliability index increase with the decrease of velocity coefficient.

Vibration of the support is an important factor to the accuracy of strapdown inertial navigation. To get vibration characteristics of the support, FEM model of the support was created with Ansys, and then response characteristics were analyzed on the support under the separated random loads during carrier flight, including the phases of subsonic and subsonic. To validate the analysis method, wide band random vibration test was done on the points of the support, which are used for mounting inertial instruments. The comparison of the analysis and the test data shows that the relative error of analysis result is not more than 13%. According to the two results the support structure was improved. Finally random vibration analysis was carried out on the improved one. The result shows that the acceleration response was largely reduced than before. This research can be a reference of performance improvement of the strapdown inertial support and navigation system precision.

While the high-precision simulation is widely used in science and technology, Design of Experiment (DOE) based on Response Surface (RS) method can be employed in surrogate model to reduce the cost and error. In order to illustrate the relationship between parameters and response features, several DOE methods and Response Surface (RS) method are studied. The author used polynomial regression and RBF neural network based on orthogonal array to build a rocket aerodynamic discipline surrogate model respectively which proved their feasibility. From the results of the test case, conclusion is drawn that characteristic as well as acclimatization of DOE methods and different approximation should be considered for different issues, so the factors of cost and accuracy could reach a balance synthetically.

The paper introduce structured grid division, use CFD numerical simulation and FLUNET software to conduct the simulation calculation for flow field of high-speed vehicle, which study the clamps of high-speed vehicle control helms how to affect the lift-drag characteristics of it. To better illustrate the problem, we use the canard configuration vehicle that efficiency of control is higher. This paper calculate lift-drag characteristics of outer surface of canard helm that with or without clamps in the condition of subsonic transonic and supersonic, then compare the lift-drag characteristics of in different conditions and analyze from the perspective of flow field.

In order to accurately analyze the performance and influence of landing gear system, this paper presents a high fidelity plant model of an aircraft landing gear to inclusion into a full aircraft flight simulation. The use of domain specific modeling software enables detailed modeling of the physics and facilitates accurate computational simulation of the flight dynamic, aerodynamic, landing gear dynamic and mechanical loads that occur when the landing gear are deployed and retracted during landing and take-off operations. The parameter design space is easily searched by considering a number of different landing scenarios including touching down on one wheel first, to optimize the design. The simulation results show that the aircraft landing gear system mathematical model established appropriately reflects the change of force and moment in the process of taking off and landing, and it is improve the precision of flight simulation.

Hinge in mechanical systems exist small clearance and contact deformation, cause the system to the wear and tear, noise, vibration, reliability reduce or even failure[1]. Therefore, the hinge clearance and the impact of flexible components in kinetic models should be considered. In this paper, a nonlinear spring-damper hinge clearance model is considered to establish mechanical system structure of dynamic equations[4∼6], through a four-bar linkage hinge with multi-clearance rotation of ADAMS dynamic simulation for dynamics simulation study. Simulation results show that hinge clearance and link flexible in Four-link mechanism dynamics have a great impact on performance: connection with the clearance lead to pin holes to produce a series of collisions, and a larger initial impact force; After consideration of flexible components, impact force reduced at the clearance, contact time increased, contact-impact areas expand and clearance also caused disturbance of the rod angular velocity of the linkage.

Missiles play a more and more important role in the modern wars. The seeker is the most important sub-system of a guided missile. As long as the development of optics, most missiles use optical-electrical seekers. This kind of seeker has plenty of benefits such as high resolving power, anti-camouflage and low cost. Optical guided missile has a optical dome which plays a very important role on the seeker system. The seeker’s dome has two jobs: first, it is the first element of the imaging system, so the dome should have good optical performance; second, it protects the sensitive optical, detector, and processor components of the missile seeker from hostile environments such as rain, sand, or large temperature gradients. When missile flies at supersonic, the aero load has serious impacts on seeker’s dome. These loads mainly include aerodynamic, aero-thermodynamic, turbulence around the dome and aero vibration. The aerodynamic and aero-thermodynamic make the dome’s shape change. The aero-thermodynamic causes heat barrier. And the turbulences and aero vibration make the image dithering and blur. Because all of the above effects are important for dome design, the study of this chapter is necessary. The study of domes has begun for many years, scientists got a lot of achievement in this field. The research is mainly divided into three parts: materials and fabrication[1,2], test and measurement[3,4], aerodynamic and aerothermal[5,6]. For recent years, there is a new branch of optics : conformal optics[7]. Conformal optical systems are characterized as having external optical surfaces that are optimized for non-optical system requirements. This typically implies blending smoothly with a host platform to achieve an optimum shape. Although the open literature provides extensive discussions on current developments in conformal system design, little information is available to study the conformal seeker’s dome wind tunnel experiments. This chapter describes a method for researching the supersonic dome’s aero-optical phenomena and theirs influents on optical image by wind tunnel experiments. Combined with thrice wind tunnel experiments and CFD (computational fluid dynamics) numerical simulation, this chapter studies the aerodynamic, aero-thermodynamic and the turbulent of the dome’s out surface when it flies at supersonic speed. Then, by using the wind tunnel experiments results, the seeker’s image which is affected by missile flies at supersonic speed is studied. After analyzing the results, the conclusion will be the fundamentals to design future domes. The straight matter describes the methods of wind tunnel experiments, and it is divided into three parts.

Studied the transient thermal transfer analysis method due to a kind of supersonic ellipsoidal dome, which is a conformal dome. Illuminated the principle of transient thermal transfer analysis. Accomplished the transient thermal analysis based on the model of ellipsoidal dome, and studied the influence about the different material and the different velocity. Considered three materials consist of MgF 2 , Al 2 O 3 , and ZnS, and meanwhile, the velocity was Mach2.5, and the time consists of 10s, 20s and 60s. The temperature initial loads were from FLUENT thermal simulation. The thermal conduction analysis and the thermal convection analysis were finished in software ANSYS, in which the entire transient thermal analysis consists of modeling, meshing element, calculating and getting the results. The different temperature distributions based on varied time were gotten about the different materials. The results from analysis showed the temperature distribution of the structure of ellipsoidal dome, which could help the following coupled thermal-structure analysis.

There are mainly two kind of structures for a missile two-axes seeker, which is always mentioned as elevate-azimuth and roll-pitch. The elevate-azimuth structured seeker has been studied for a long time, and it is applied in all sort of missiles. Not only structure design but also control algorithm of the elevate-azimuth seeker are deeply developed. But for elevate-azimuth seeker there are several disadvantages such as big size and large abaxial angle blind. So the elevate-azimuth seeker gimbal angle is designed up to ±65° according to relative references. In modern air war, it is important for a missile to have the ability of “first recognize” and “first attack”. That means the air to air missile seeker is required to be a system with large gimbal angle and large abaxial launch angle. With the mentioned requirement, roll-pitch seeker with its advantages smart size and large gimbal angle is studied widely and deeply. The pitch angle of roll-pitch is up to ±90° while its roll angle up to n × 360 ° . But there are also some disadvantages for the roll-pitch seeker, the most troublesome one is the zenith pass problem. The zenith pass problem is brought about from the gimbal kinematics, it is said that when target moves in the center of image plane, roll servo command gotten from the kinematics algorithm will go to infinite. Math model of zenith pass problem is proposed in this paper and two ways to solve the problem are brought forward.

In order to meet the requirement of inertial navigation components and minimizing the system's weight, topological optimization and size optimization were conducted under conditions of random vibration and impact. Firstly, the structure of inertial navigation support was designed according to types of missile connection and space arrangement of electronic components; and topological optimization was conducted. Then, according to the dynamic characteristics of missile and requirement of inertial navigation system, the method of transforming multi-loading cases to multi-loading constraints was used to optimizing the size of the support under conditions of random vibration and impact. Comparing to the original support structures, the weight of optimal structures reduced by 28.1%; RMS accelerations in installed points reduced by 25.2% under random vibration; the structures also met the requirement of inertial navigation system under condition of impact. The support structure shows improvements in both dynamic characteristic and light weight comparing with the original one.

Based on the kinematics of semi-strapdown seeker, the framework coordinate of the semi-strapdown seeker is established and the optical axis stabilization equation of semi-strapdown seeker is deduced based on product of exponential (POE) formula. The stabilization control principle block diagram of semi-strapdown seeker is shown based on the stabilization equation. The main influence factors of the stability precision are pointed out, such as friction disturbance, velocity measurement noise and missile disturbance. For the sake of improving the stabilization precision and tracking precision, disturbance observer was proposed in the inner loop of semi-strapdown seeker servo-control system. The low frequency external disturbance and high frequency velocity measurement noise are effectively restrained by the disturbance observer as shown in hardware-in-loop simulation, and optical axis stabilization precision and tracking precision are greatly improved.

In order to research the attitude algorithm with angular rate input under the conical motion, a optimal three-sample rotation vector algorithm based on single-step Newton backward interpolation is proposed. Using the principle of limited rigid body rotation and the characteristic of angular rate input, three-sample rotation vector algorithm is derivated. To minimum attitude errors, three-sample rotation vector algorithm is optimized. Three angular rate extraction methods of single-step entire sample recursion, multi-step entire sample and single-step Newton backward interpolation are proposed. Under the condition of conical motion with semi-cone angle 3° and angular frequency 2πrad/s, simulation is done. The simulation results show that single-step Newton backward interpolation is superior to the other two methods, and its maximum error peak is 0.01°, error drift rate is 0.036°/h. Experiments in three-axis flying turntable with the same parameters are carried out, and the results show that error drift rates of three-channels are less than those of traditional quaternion, which are 13.53%, 12.08% and 23.68% lower respectively. It also verified that the new algorithm can perform a high accuracy under the conical motion.

In this paper, a strong coupled CFD-CSD method is developed to simulate the aeroelastic phenomena. The CFD solver is based on the finite-volume algorithm for the Navier-Stokes equations on unstructured grid. The CSD solver solves the aeroelastic governing equations in the modal space. Their coupling is realized by a dual-time method. The spring-based smoothing method is adopted to deform and regenerate the aerodynamic grid. Two test cases are selected to validate the authors' method for static and dynamic aeroelastity. The results of the simulation for the static aeroelastic problems of a missile wing show that the Lift Coefficient and Drag Coefficient are severally 7% and 5% lower than those don't consider the elasticity of the wing. The results for the flutter boundary prediction of the AGARD 445.6 wing have been proved much closer to the experiment than using the DLM. This method can describe the effects of fluid viscosity more exactly for highly nonlinear transonic flight conditions. The calculation has proved reliable in the subsonic regime, but not accurate enough in the supersonic regime.

Based on the kinematics of semi-strapdown seeker, the framework coordinate of the seeker is established. The optical axis stability equation of semi-strapdown seeker is deduced by using attitude transformation matrix. Then, the stability control principle block diagram of semi-strapdown seeker is shown based on the stability equation. The main factors that influence the stabilization precision are pointed out, such as friction disturbance, velocity-measuring noise and missile disturbance. In order to improve the stabilization precision, disturbance observer was proposed in semi-strapdown seeker stability control. The low frequency external disturbance and high frequency velocity measurement noise are effectively restrained by the disturbance observer as shown in hardware-in-loop simulation, and optical axis stabilization precision is improved nearly 20 times and 5 times due to two different frequencies with same amplitude.

Mathematical models of structural optimization were established for the cam wave generator, by integrally taking its static and dynamic performance into consideration, while the dynamic optimum design was carried out. The topology optimization of the cam wave generator was performed based on artificial material density method; then a conceptual model, which satisfied the model acted by four concentrated forces, was obtained. And the size optimization of the cam wave generator was also executed based on the zero-order method in software Ansys after setting up its parameterized model. The optimized results indicate that its final volume declines to 1284.217mm3 from its 1397.830mm3, which reduced by 42.18% than the original volume of cam (2221.224mm3). Simultaneously, the static analysis and modal analysis were implemented, and the results show that the static and dynamic performance complies with the design requirements, proving that the results of dynamic optimum design are reasonable. The optimized results in paper are realizable in engineering. And the study method provides not only a reference to decreasing design mass and lowering inertia of the cam wave generator, but also an important basis of lightweight design of harmonic gear drive.