In a concealed environment, the long term high accuracy navigation of vehicles is a challenging problem. The performance of traditional navigation methods, such as satellite navigation, inertial navigation and optical imaging navigation, is limited when navigation signals are obstructed or missions are prolonged. In order to cope with this problem, the neutrino navigation technology is studied, which involves a new principle to achieve motion state information of vehicles using natural neutrino signals where electromagnetic signals are denied. The necessity of neutrino navigation research for underwater or underground vehicles is explained. The research status of neutrino navigation technology is outlined, including neutrino radiation characteristics, neutrino detection methods and positioning algorithms. Furthermore, key technologies in the research of neutrino navigation are discussed. Finally, considering the research status and the application requirement, future trend and recommendation for the development of neutrino navigation technology are presented.

The low orbital altitude of the near Earth satellite makes the satellite have higher detection accuracy. However, the service life of the satellite is restricted by the drag caused by the satellite not completely leaving the atmosphere. The air breathing electric propulsion system is used to extend the life of the satellite. The direct simulatiou Monte Carlo (DSMC) calculation method is used to simulate a two dimensional air breathing electric propulsion model. The wall impact model is set as completely diffuse reflection. On the premise that the inlet diameter of the inlet is maintained at a constant value, the inlet long to longitudinal ratio, outlet cone angle, grid length and grid layer number are changed to explore the inlet performance variation rule under the single action of these influencing factors. Under the premise of single influence rule, genetic algorithm is used to carry out multi objective optimization, and the design parameters of high performance inlet meeting the design requirements are obtained, and the optimal design method of inlet at typical height is studied.

The in orbit positioning accuracy of spacecraft is susceptible to the influence of low frequency micro vibrations in the environment and internal disturbances caused by payloads. This study designed a series of piezoelectric actuators with high stiffness for vibration isolation. Firstly, the dynamic model of the piezoelectric isolator and a dual sensor feedback control method were established, and the merits and demerits of the feedback control parameters and anti disturbance characteristics were compared. The feasibility of the piezoelectric isolator proposed was verified through simulation models. Finally, experiments were conducted to confirm the accuracy of the aforementioned design and simulation. The results show that the proposed piezoelectric isolator can provide a basic vibration attenuation capability of -15dB in the 1~25Hz range, and attenuate the resonance peak by -25dB, while also possessing high stiffness characteristics; it can offer excellent low frequency vibration isolation performance and inertial stability, and effectively resist internal disturbances caused by payloads.

Due to the removal of the slotted structure, the winding of the slotless permanent magnet synchronous motor (PMSM) is directly exposed to the high speed alternating air gap magnetic field, and a large amount of eddy current loss is induced inside. For the slotless PMSM, the winding eddy current loss is one of the important sources of the total loss of the slotless PMSM, and the analysis and calculation of the winding eddy current loss is very important. However, the analysis and calculation methods of winding eddy current loss proposed at present are all based on the straight conductor winding, and the calculation principle is based on the shape and distribution of the eddy current loop in the straight conductor. However, the hexagonal winding contains both the straight conductor and the inclined conductor, and the eddy current distribution is different from the straight winding. The traditional calculation method of the eddy current loss of the straight winding is no longer applicable to the hexagonal winding. Therefore, this paper studies the distribution shape and distribution law of eddy current in hexagonal conductor. Based on the hexagonal winding structure flexible printed circuit board (FPCB) winding structure, a three dimensional semi analytical calculation model of eddy current loss of hexagonal FPCB winding structure is proposed. The correctness and effectiveness of the proposed three dimensional semi analytical calculation method for eddy current loss of hexagonal winding are verified by three dimensional finite element calculation and prototype test.

To address the issues of flat curves, multi peaks, and misjudgments in traditional sharpness evaluation methods, a gradient threshold based sharpness evaluation method combining multiple region windows is proposed. The method utilizes the contrast and weighted variance of the gradient image to calculate a segmentation threshold and extract edge points. An improved energy gradient function is then applied to evaluate the sharpness of the region image at the edge points. Different weights are assigned to the evaluation values of various regions to obtain the final evaluation result for the entire image. Comparing this method with traditional approaches, the results show that when using the same evaluation function, the multi region window produces a unimodal evaluation curve without misjudgments, in contrast to the traditional window. The sensitivity factor of this method is, on average, 55.6% higher, and the steepness is 58.3% higher than the optimal results from traditional methods. Therefore, the proposed method can provide an effective reference for automatic focusing applications in space optical sensors.

The lightcurve of an asteroid includes information such as shape and spin state. For the China asteroid exploration mission, it is necessary to obtain the a priori properties of the target through on orbit photometric observations. To meet this demand, we construct a lightcurve observation simulation system, which combines the photoelectric link based point source target simulator and computer graphics scene simulator. After getting simulation images, the target lightcurve is calculated, and then inversion is performed. After experiments, the inversion results of the simulated lightcurves are very close to the inverse results obtained from the real observation data, which can be used in the study of in orbit lightcurve observations of spacecraft. Finally, we analyze the influence of different lightcurve observing orbit for the 2016 HO3 detection mission, providing some ideas for the planning of spacecraft lightcurve observation tasks.

The Control Moment Gyroscope (CMG) frame servo system is often affected by multi source disturbance such as external disturbance and internal parameter perturbation, which leads to the reduction of its control performance. This paper focuses on the influence of parameter perturbation on the frame servo system, and puts forward a perturbation suppression method for CMG frame servo system based on H2/H∞ composite control. Firstly, the motor parameter perturbation is introduced into the conventional H∞ robust control method, which improves the suppression ability of the internal parameter perturbation on the basis of the robustness of external torque perturbation. Secondly, combined with the H2 control strategy, the state feedback based H2/H∞ composite control method is proposed, which ensures the steady state performance and further improves the dynamic response speed of the system. Simulation results show that the proposed H2/H∞ composite control method can effectively reduce the speed fluctuation caused by multisource disturbances and improve the dynamic response speed of the system.

An adaptive simulated annealing particle swarm optimization (ASAPSO) algorithm is introduced to solve the problem of Lambert dual pulse orbital interception, which aims to achieve the minimum fuel consumption by optimizing the sum of the speed increments of the two pulses. First, a mathematical model of orbit change interception is constructed based on Lambert's fixed time flight theorem. Assuming that the spacecraft maneuvers to pursue the target within one week of its initial orbit flight, the time of two pulse orbit changes is set as the decision variable, the fuel consumption is taken as the fitness function, and the ASAPSO hybrid algorithm is adopted as the optimization strategy. Secondly, in order to verify the effectiveness of ASAPSO algorithm, traditional particle swarm optimization (PSO)，simulated annealing particle swarm optimization (SAPSO) and reinforcement learning particle swarm optimization (RLPSO) are used to optimize the same model. The comparison shows that ASAPSO algorithm can quickly converge to the global optimal solution in less iterations, which greatly reduces the computation amount and time to deal with the orbital interception problem. The algorithm combines the global search capability of PSO and the local optimization characteristics of SA to provide a more efficient and accurate solution to the Lambert double pulse orbit change interception problem.

In order to efficiently and safely fulfill the task, this paper proposes a coordinated compliance control strategy for dual arm robots. Firstly, based on the structural characteristics of the holes and pegs, a task plan that completes the assembly in one attempt is designed to meet the requirements of small tolerances. Implementing the idea of dual arm master slave coordination, the task plan is decomposed and assigned to two manipulators. Then, with the goal of eliminating pose deviations between the hole part and the peg part, a smooth motion trajectory is planned. In addition, considering the requirement of compliant contact between the hole part and the peg part, an adaptive impedance controller is constructed. In order to avoid control instability caused by the reciprocating oscillation of contact forces, an adaptive law for the stiffness coefficient is introduced to the controller. Finally, an experimental platform for the peg in hole is built based on the UR10e robotic arm, and the effectiveness of the proposed coordination compliance control strategy for dual arm robots is verified through experiments.

In terms of collision probability calculation in space debris threat assessment, the traditional calculation methods are divided into whether to consider the uncertainty of spacecraft and space debris velocity, and the variances of the initial status of two space objects considered in both cases are small. It will produce a large error in the case of large uncertainty of two space objects orbit determination. In order to calculate the collision probability accurately with the situation of nonlinear relative motion process of two space objects and large initial uncertainty, a collision probability calculation method based on adaptive Gaussian mixture model is proposed, which uses the adaptive Gaussian mixture model to approximate the uncertainty propagation process of spacecraft and space debris orbits, and calculates the collision probability according to the propagation results. The simulation results in the two body environment show that the method achieves well calculation accuracy when the relative motion process is nonlinear, and the calculation accuracy is better than other collision probability calculation methods when the initial uncertainty of the object is large.

On orbit optical observations are not affected by factors such as clouds, atmosphere and daylight, and are superior to traditional ground based measurements in terms of temporal and spatial range and cost of use. Based on the needs of on orbit detection and tracking of non cooperative space targets, the paper proposes a method for on orbit detection of space multi targets. This method first uses Delaunay triangulation matching to achieve stellar background differentiation, and then integrates the target photometric, morphological and kinematic features to perform trajectory association, and finally performs trajectory recognition to achieve robust detection of space targets. In the simulation data set of dense star field multi target observations and field target observation experiments, the multiple object tracking accuracy is greater than 95%, and it can effectively output multi target trajectories without relying on star catalogs for attitude solution, camera calibration parameters and target prior information. Compared with traditional algorithms, it reduces the amount of calculation and improves the onorbit detection capability of space targets.

Unit testing is used to verify the functionality of individual software modules, making it a crucial step in the software development process. It helps in identifying defects in the code in a timely manner, thereby improving the quality and reliability of the software. Manually writing unit tests is time consuming and labor intensive, often missing important code logic. To address this, researchers have proposed techniques for automatic generation of unit tests. Recently, pre trained large language models (LLM) have been widely applied to tasks related to code generation, and there has been work on generating unit tests for languages such as Java and JavaScript. However, in safety critical domains such as aerospace, C language programs are predominantly used. To fill this gap, we designed and implemented an LLM based multi agent interaction method for generating unit tests for C programs, named LLM4CUTCG. To verify the effectiveness of this method, we constructed 125 target programs without data leakage risks and generated tests for these programs. Experimental results show that the line coverage of the tests generated by LLM4CUTCG is 91.71%, and the assertion correctness rate is 50.05%. The coverage rate outperforms traditional methods such as symbolic execution and fuzz testing.