TDOA (Time Difference of Arrival) is a widely used passive positioning technology with high precision, strong ability of collaborating, high robustness. The issues of computational complexity and slow accuracy convergence for the positioning of moving target are addresses. Based on the positioning model in LOS (Line of Sight) environment, a positioning method suitable for a multi-station TDOA system is provided. After linearizing collaboration TDOA positioning relationship equations into a statistical estimation problem, this method online converges iteratively to solutions of targets' locations. A multiplatform collaborative positioning algorithm for different motion characteristics of the targets. Simulations results demonstrate that the provided method can achieve precise positioning. Moreover, the impact of motion patterns on positioning accuracy is analyzed, and simulation results provide guidance for system engineering design.

The hypersonic vehicle needs to separate from the booster stage in an environment with low altitude and high dynamic pressure. The current prediction of separation and attitude control based on limit deviation method is not real enough and the design is heavily redundant. For inserted separation with long stroke and small gap, the collision detection of two stages cannot be carried out during the attitude control design process. To solve the above problems, a coupling calculating method of separation and attitude control is proposed, which introduces the attitude control model into separation dynamic model. Design redundancy is reduced and the level of refine is improved. Also, collision detection can be realized in the whole process, providing support for ensuring the safety of the separation and attitude control process. The method provides a basis for the time to start attitude control of the upper stage, and has guiding significance for optimization design of separation time sequence.

Iron loss occupies a large proportion of the losses of in-wheel motor for special vehicle, which directly affects the efficiency and temperature rise of the drive system. In order to accurately calculate the iron loss, time-stepping finite element analysis is adopted to analyze the flux density waveforms at different regions of the stator core by taking the in-wheel motor with rated power of ${70}\mathrm{\;{kW}}$ for example. Harmonic analysis of radial and tangential flux density waveforms at different regions of the stator core is carried out. The impact of rotating magnetic field and harmonic component on the stator iron loss is further studied. Three different iron loss calculation methods are adopted to calculate the stator iron loss after the flux density waveforms and harmonic analysis are carried out. The stator iron loss values separated from the efficiency and loss test of the in-wheel motor are compared with the calculation values of different calculation methods. The results show that the calculation method in consideration of the effect of rotating magnetic field and harmonic component has the highest accuracy and its calculation result is the closest to the test result, which verifies the validity of the calculation method.

Aiming at the rotor axis of PIGA with a zero bias, the transverse acceleration will be coupled to the direction of the input axis to form a cross-coupling error. For the decoupled nonlinear PIGA output expression, the influence of a time-varying input acceleration and the transverse acceleration which is applied to the output are considered, the computing method of PIGA’s output analytic expression relying on the base acceleration of three orthogonal direction and angles of outer axis and rotor shaft as input information is given. On this basis, the model parameters are calibrated by recursive iteration method, in addition to which, the output value compensation method of gyro accelerometer is given. By comparing the error results before and after parameter compensation, the input acceleration error is reduced from ${0.05}\mathrm{\;g}$ to ${0.002}\mathrm{\;g}$, which verifies the effectiveness of the cross coupling error compensation in the output model in the way of improving the measurement accuracy.

An improved ACO is proposed for two-dimensional path planning of flight vehicles to solve the problems such as slow convergence speed, easy to fall in stagnation and zigzag path with large angles in basic ACO. First, the improved algorithm optimizes extend method to accelerate convergence. Then, a new pheromone strategy is put forward to increase the utilization of pheromone information while preventing ant from falling into stagnation. At last, local optimization method is introduced to reduce the twists and turns in the searched path. According to the simulation results, the improved ACO has superiority in convergence, iteration number and quality of path. The result proves that the improved algorithm can increase the rate of convergence and path quality compared with basic ACO.

To address the reentry missions with different path constraints and range requirements, a conic based bank angle is designed to enhance the lateral maneuverability, and the predictor-corrector guidance method is used to revise the bank angle profile to satisfy the range requirements. The improved artificial potential field method is used to design the lateral guidance method to satisfy the path constraints. Finally, the guidance parameters are optimized by particle swarm optimization algorithm to obtain the trajectory with the best performance. Simulation results verify that the algorithm can adapt various range requirements and path constraints, and meet the terminal constraints with high accuracy.

Focusing on the development of missile intelligent cooperation, the application of missiles in Unmanned Aerial Vehicle (UAV) swarms is focused on. The respective application characteristics of UAV swarm and missile systems are introduced, the application modes of missiles in UAV swarm are explored, the requirement on developing intelligent missile swam is analyzed. Based on the issues of observation, interaction, and collaboration in swarm intelligence, current challenges and key support technologies for missiles application in UAV swarm are analyzed. With the analysis on "MSET" and "Golden Horde" projects, the current situation and development of missiles in swam are analyzed, and the ability doubling points for the actualization of missile-UAV application are pointed out, which provides exploration for future research on intelligent missile system.

The on-orbit refueling technologies of cryogen can reduce the total mass of propellants required in rocket vehicles, allowing a significant increase in the amount of payload delivered beyond low Earth orbit. It has great potential benefits in complex space transportation systems and deep space exploration tasks. A literature investigation on the key techniques of cryogenic propellant on-orbit refueling is conducted. The existing lab-scale and full-scale experimental studies are reviewed in detail. Moreover, advantages of using on-orbit refueling techniques comprehensive analysis in future space tasks are provided. Technical suggestions on the developments for on-orbit refueling of cryogenic propellants are proposed based on this research.

The Model based Definition (MBD) technology digital process verification approach is examined. A process verification system for Design for Manufacture (DFM) is introduced. The system uses PMI, or product and manufacturing information, as a vehicle to express product processing information and dimensional information. In the concept design phase, the auto-matic process testing of the product geometry model is realized, and the viability of the product process is examined, thanks to the development of the model testing tool. The test's outcome is evaluated in accordance with the guidelines for producing liquid rocket engines. The designer can adjust and enhance the sketch of the geometry for the liquid rocket engine in light of the outcome. By using DFM, the process accessibility of the product in the design phase is improved, the design and process changes in the product manufacturing process are reduced, and the product development cycle is shortened.

As an important component of aircraft guidance system, non-metal radomes have multiple functions such as heat protection, wave transmission and load bearing. It is connected to the aircraft body through high-temperature resistant adhesive agent. Radome is frequently subjected to harsh mechanical and thermal loads during the period of service, and the joint structure is often the weakness of strength design. Therefore, accurate simulation for mechanical behavior of the joint structure and achieving accurate prediction of load-carrying capacity are crucial for the structural design and optimization of radome. Based on bilinear cohesive model, the failure behavior of radome adhesive interface is numerically described by ABAQUS. And then the damage evolution of adhesive layer is simulated, and the accurate prediction of bearing performance of radome joint structure under flight thermo-mechanical environment is achieved. The corresponding experimental study is carried out. The experimental results are in good agreement with the simulated ones, verifying the validity of numerical method. It provides an effective way to solve bearing problem of aircraft-level radome joint structure.