The sixth generation fighter is important equipment for USAF to re-establish its first-generation strategic advantage. We should fully recognize the leading position of USAF in the development of a series of related technologies and the important position of systematic warfare in future wars. It is important to increase the research on relevant concepts and supporting technologies. For this reason, the development trend of the sixth generation fighter of USA, Russia and European is analyzed to obtain the understanding of the equipment capacity of the sixth generation fighter from the technical perspective.

In recent years, lasers in visible wavelength have attracted many attentions in the fields of laser color display, bio-optics and holography, etc. The energy level of Pr3+ ions determines it can realize the energy level transitions of multiple visible wavelengths such as blue, green, orange, red and deep red light. With the maturity and commercial application of blue laser diode (LD) technology, the visible wavelength Pr3+-doped lasers directly pumped by blue LD pumped have gradually become a research hotspot. The domestic and international research progress and trends of Pr3+-doped all-solid-state lasers in recent years are summarized, including continuous, pulsed and single longitudinal mode lasers.

Research on starlight level wide spectrum full color imaging technology is aimed at the current demand of obtaining the real color image in the low ambient light for other technical methods such as traditional visible light imaging, laser imaging and thermal imaging, which can only obtain the target grayscale imaging information not the target true color information. According to statistics, color images contain 30 times information than that of grayscale images, and spectral information is extremely critical in target recognition. An imaging method with super large pixels, ultra-thin process micro lens collection and large-diameter light transmission is adopted. Based on this, a deep learning image processing algorithm is designed to enlighten and enhance the physics true color of the devices, and the signal-to-background ratio of images is increased further. Lastly, the sensitivity of the device is increased by 50~100 times and the minimum illumination of color night vision is 0.000 4 Lux@25 Hz, F1.0, thereby wide spectrum full color imaging is realized, which provides technical bases for target inspection, recognition and application.

The generation, development, technical characteristics and key technologies of computational imaging technology are introduced. And the advantages and disadvantages of the technology are analyzed. The development trends of the technology are summarized. The technology is not isolated from traditional lens imaging, some problems in traditional imaging are solved by the technology. Computational environment is introduced to traditional optical method or imaging process, and the gain or loss should be balanced considered.

In order to realize target searching of large field of view and target observation of small field of view of coastal photoelectric equipments, based on the research and analysis of the zoom optical system design model and theory parameters, four zoom optical structure of optical compensation method is chosen, and a coastal surveillance infrared optical system of hybrid refractive-diffractive two zoom is proposed. After adjusting the initial structure and optimizing with ZEMAX software, a two zoom infrared optical system is designed, which has 150~300 mm focal length, 100 mm diameter. At the space frequency of 30 lp/mm, the modulation transfer function (MTF) reaches 0.6, the speckle in the full field of view is controlled within 25 μm, and the non-thermal sensitization is realized within the working temperature range of -30℃~+50℃. The system is simple in structure, and the number of lenses is reduced to 5 by using aspheric surface and diffraction surface, and the design results meet various task indexes. It is important to the development of coastal infrared surveillance optical system.

The influence of speaker's emotional factors on speech features is studied. The speech features of the same person such as voice formant frequency characteristics, formant trend characteristics, syllable transition characteristics, fundamental frequency curve characteristics and amplitude curve characteristics under six emotions such as anger, fear, happiness, neutrality, surprise and sadness are chosen. The similarities and differences of voice acoustic characteristics of different emotions are analyzed and compared. The results show that the similarity of formant orientation characteristics of the same person's speech acoustic characteristics under different emotions is high, and there are some differences in formant frequency, fundamental frequency curve and amplitude curve characteristics, which are non-essential differences, and are individual differences. Acoustic characteristics analysis of speech with different emotions can lay a foundation for speech emotion recognition.

The problem of extracting the target speaker speech from multiple speaker speech is researched. In order to improve the accuracy of multi-speaker speech segmentation and clustering, a speech segmentation and clustering algorithm based on Mel frequency cepstral coefficient (MFCC) and Gammatone frequency cepstral coefficient (GFCC) hybrid features is proposed, which can effectively avoid problems such as poor robustness of noisy speech segmentation and clustering. For the superimposed pink noise and factory noise speech, a comparative analysis is made based on the conventional algorithm and the improved segmentation clustering algorithm respectively. The results show that the proposed segmentation clustering algorithm based on mixed features is more accurate in extracting target human speech.

The image taken by the unmanned aerial vehicle (UAV) patrol power channel line has more salt and pepper noise. For the shortcoming of traditional median filtering and adaptive median filtering algorithm to filter out the high concentration of salt and pepper noise and preserve the image edge details, a median filtering algorithm based on partial differential is proposed. The algorithm analyzes whether the original pixel point is a suspected noise point by calculating whether the derivative value of the four pixels in the four directions from the original pixel point is greater than a set threshold, and if one of the derivative value is greater than the set threshold, it is determined to be a suspicious noise point, and the window is moved to if the derivative value is larger than the threshold, it is determined as a noise point. After the noise point is determined, the weighted convolution is performed with the field window of the mask and the noise point that has been set to obtain a new pixel value. The original noise point is replaced by a new pixel value. The final result shows that the algorithm has higher peak signal noise than that of the adaptive median filtering algorithm, and the denoising effect is better.

The reciprocating compressor is an important equipment for petrochemical production, and its safe and stable operation is closely related to the operation states of the gas valve. For realizing the rapid diagnosis of the gas valve fault of the reciprocating compressor, the wavelet packet decomposition is used to extract the fault characteristics. Based on support vector machine (SVM) method, the gas valve fault is identified. The grid search method is used to optimize the parameters. The model for fault diagnosis of compressor gas valve is built, which is combined with wavelet packet decomposition and SVM. And the effectiveness of SVM in fault diagnosis of the compressor gas valve is verified, which simplifies the traditional process of judging the type of gas valve fault by experienced personnel, and provides a theoretical basis for practical problems such as compressor gas valve fault analysis, maintenance and replacement.

In recent years, 3D point cloud registration has a very important role in medical diagnosis and surgical planning, and the accuracy of registration has always been the focus of attention. Several common registration algorithms and performs multiple sets of registration experiments on Bunny, Dragon and Hippo 3D point cloud models in third-party 3D model libraries are introduced. The registration accuracy is verified. Experimental results show that the Super-4pcs algorithm has different angles and low overlap rate for 3D point cloud model, and better registration results can be obtained comparing with several general registration algorithms. At a low overlap rate, a high precision registration effect of 0.001 m can still be achieved. It provides some theoretical guidance for doctors to more effectively apply the point cloud registration algorithm to medical diagnosis and surgical planning.

A static balance detection system for aircraft propellers is designed for the imbalance of aircraft propellers in actual production or maintenance. The size and position of the propeller imbalance can be detected. The test system removes the differential degree of rotation in the X and Y directions of the system through the balance part of the balance table, and uses the sensor to detect the unbalanced moment in its direction. The signal acquisition circuit consisting of stm32f103 and tm7711 is transmitted to the host computer, and is processed in the host computer software to display the final result. The accuracy of the system is verified by experiments.

The characteristic analysis of a class of nonlinear circuit and the synchronization transmission mechanism of the signal are researched, and the results are in agreement with the experimental phenomena. Firstly, the dynamical characteristics of the nonlinear circuit are analyzed. And then, based on the experimental parameters of synchronization transmission signals from two nonlinear circuits, the principle of synchronization transmission signal from nonlinear circuits is analyzed theoretically. Finally, using Hurwitz stability theorem, the value range of coupling coefficients is calculated when two nonlinear circuits transmit signals synchronously, and the results are in agreement with the experimental results.

The problem of projectile attitude control with inertial rotor gyroscope as actuator is studied. In order to better study the influence of the rotor gyroscope mechanism on the projectile, firstly, the gyroscope approximation theory is used to analyze the influence of the gyroscope moment on the flying attitude of the projectile. Secondly, the dynamic model of rotor gyroscope is established, and the control scheme is theoretically feasible from the moment of momentum theorem of gyroscope. Finally, the influence of precession performance of rotor gyroscope on ballistic characteristics is verified. The attitude dynamics model of the projectile controlled by the rotor is established and the numerical simulation is carried out. The simulation results show that the range and deviation of the projectile can be affected by the rotor gyroscope as the actuator. Therefore, it is proved that the research on the attitude control of projectiles by inertial rotor gyroscope is feasible.

Aiming at the complex surface of impeller, a rotary file is selected to process it on the basis of the platform of robotic automatic machining system. The coordinate transformation of F-type rotary file is theoretically deduced to facilitate the calibration of robot tool coordinate system. The finite element analysis of impeller material is carried out by ANSYS Workbench software, and the rules of workpiece deformation, stress and strain, tool deformation are obtained.