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For fault problems of micro-nano satellite attitude control system using pulsed plasma thruster as the actuator, the support vector machine technology was used to detect and isolate two kinds of common faults of pulsed plasma thruster. The wavelet kernel function parameters of Mexico hat were optimized by adaptive genetic algorithm (AGA). Combined with wavelet analysis, the hyperplane optimization efficiency and generalization ability of SVM classifier were improved by these methods. Finally, the experimental results prove that the method can accomplish fault diagnosis tasks quickly and accurately, and also prove the superiority and effectiveness of wavelet kernel function support vector machines in fault diagnosis. [ABSTRACT FROM AUTHOR]

In order to solve the problem of the lack of station in Beidou Global Navigation Satellite System, a route optimization method was proposed to quickly transmit the overseas satellite data to the domestic satellite by using the inter-satellite link. Firstly, the problem of fast data transmission in the case of limited number of ground stations was described, and the optimization objective, rules and constraints of data transmission routing were defined. Then, based on the genetic algorithm, the routing optimization method and the minimum data transmission scheme were proposed. Finally, the validity of the algorithm was verified. The results show data transmission is completed within 2 skips (6 seconds) in the Beidou system constellation with two domestic station conditions. This optimized result can meet the requirements of overseas data fast transmit. [ABSTRACT FROM AUTHOR]

The optimal placement of the actuators and the active vibration suppression of I he constrained gyroelastic body is studied. By simplifying the model of a single gyroelastic body with variable-speed control moment gyros,the linearized dynamic model of the constrained gyroelastic body is obtained. A new method is proposed for the optimal placement of the actuators. This method is directly based on the vibration responses and vibration energy to determine I he optimal placement of the actuators. The objective function is chosen as the optimal value of the linear quadiatic regulator control. The optimal placement of the actuators is formulated in the frame of the combinatorial integer optimization problem. The genetic algorithms (GAs) are used to solve the combination problem of the constrained gyroelastic body with a fixed number of actuators. The optimal placement of the actuators with different installation directions is studied. The optimized configurations are used to realize the active vibration suppression. The effectiveness and feasibility of the optimized results by the proposed method are validated by the numerical simulations. [ABSTRACT FROM AUTHOR]

Most of current researches about variable geometry truss (VGT) motion planning only focus on the situation that each bay has single degree of freedom. Motion planning of VGT whose each bay are variable multiple links were investigated. Kinematic model was set up based on the geometrical relationship. Considering momentum conservation of the freefloating system, velocity kinematic model was formulated. A method of designing moving sequence and moving time separately was proposed for motion planning of single bay VGT. Additionally, multi-bay VGT motion planning problem was solved by energy optimum. Simulation results show that the algorithm is effective, and the optimizing index is 0.8798. The method has practical benefits to the space operation system with VGT. [ABSTRACT FROM AUTHOR]

The on-board radiant calibration methods based on observed stellar has become one of the main calibration methods of infrared camera in recent years. The key of the method is to determine the observed stellar and the irradiance in the camera's detection band. In order to study the irradiance in different bands, first of all, the mathematic model of stellar irradiance was built as a point source. Then the Taylor series and genetic algorithm (GA) was used to calculate the stellar temperature T and the irradiance of stellar based on different irradiance in several bands of stellar in WISE catalog was extrapolated. As a result, the proportion of the stellar whose extrapolation accuracy < 3% is 68. 34%, which satisfies the project s requirements. Finally the spectrum feature of the calibration stellar was ananlyzed in different accuracy to validate the methods. [ABSTRACT FROM AUTHOR]

This paper provides an optimal entry trajectory of the winged Mars probe, right after it changed the orbit into the Martian atmosphere braked by reverse thrust engine. This paper establishes Martian atmosphere model and gravitational field model corresponding on the density of the Martian atmosphere and gravitational field parameters, and determined the dynamic equations of the Mars probe. Within all the constraint conditions in the entering process, this paper designs an optimal entry trajectory based on the genetic algorithm. In addition, this paper provides different thrust engine scheme through comparing them. The results show that the second scheme can achieve the optimal performance index and the landing speed is 13.6 m/s, ultimately realizing the minimum consumption of energy and aerodynamic heat emission structure quality in the process of entering and soft landing. [ABSTRACT FROM AUTHOR]

For the problem of trajectory modeling in ascent phase of launch vehicle, free-node spline model is proposed to represent the change of this trajectory. The trajectory parameter estimation is converted to spline function coefficient estimation for trajectory determination, thus effectively improving accuracy by reducing the number of estimated parameters. Furthermore, an algorithm for optimization of measurement elements is obtained to improve accuracy of the trajectory determination by using chromosome encoding of measurement elements, constructing fitness function based on weighted ranking and designing the improved proportion selecting operator in basic genetic algorithm frame. Then the combinatorial space of measurement elements is sufficiently searched for optimization. The results of simulation based on the classical trajectory of ascent phase and distribution of stations show that accuracy of ascent trajectory determination is effectively improved. Compared with traditional methods, position determination accuracy of this method is improved from 92.0% to 94.4%. In the case of using free-node spline model, the position determination accuracy is also enhanced to 16.4% ~ 88.6%. [ABSTRACT FROM AUTHOR]

Based on the analysis of the output of lunar soil principle and the (resistance moment) output of lunar soil resistance of spiral drill stem, the impact of lunar soil in the spiral groove regolith on drill stem driving torque, the valued field of helix angle and axial drilling power drill stem are considered, and models of drill stem driving torque, axial loading force and power consumption model are established, then effects of structural parameters such as the outer diameter of drill stem, the depth of spiral groove, groove width ratio and helix angle on the driving torque and the axially loading force of drill stem are analyzed by using the above models, and the rule of effect of structure parameters on the driving torque and the loading axially force of drill stem is obtained. Both mass and power consumption of drill stem are selected to be two, objective optimization, outer diameter of drill stem, depth of spiral groove, groove width ratio, helix angle and other parameters are taken as design variables, and the structure parameters of drill stem are optimized by using genetic algorithm. The power consumption is reduced by 31.8% and the mass of drill stem is reduced by 23.3% after optimizations, thus reducing the risk of drilling and providing a theory basis for the design of automatic drill sampling mechanism. [ABSTRACT FROM AUTHOR]