For issues that external uncertain disturbances and parameters perturbation can result in low guidance accuracy as well as poor robustness in traditional terminal phase, an optimal sliding mode guidance law with impact angle constraint was proposed. Firstly three-dimensional mathematical model of missile-target relative motion was established based on point mass assumption, then linear quadratic regulator with differential Riccati equations was adopted to meet the terminal impact angle while sliding mode control used to augment guidance robustness. The proof of Lyapunov stability and simulation results show that the combined three-dimensional optimal sliding mode guidance law can satisfy desired performance index and ensure high accuracy as well as strong robustness.
As a complex engineering technique, reverse engineering is dependent on the high precision measuring equipment. As to special aircraft configuration with complex free-form surfaces, traditional direct CAD constructing method is inefficient. By analyzing the technical characteristics of reverse engineering, a new design approach for special aircraft shape with complex free-form surface is proposed. Finally, the comparison between the traditional method and the new approach is made, and the feasibility of the new design approach is discussed.
A bstract-Considering the dynamic unbalance problem of rolling aircraft which will to some extent lead to a larger distribution of trajectory and instability of flight, the studies of this paper focus on the modeling and simulation problem of dynamic unbalance. Firstly, by introducing the dynamic unbalance angle to the characterization of the dynamic unbalance, the rotating dynamics equations around centroid based on the theory of rigid body motion is established under certain simplifying assumptions. Sequentially, the relationship between two forms of description of dynamic unbalance is deduced with significance of integrating the theoretical model with actual measurement of the dynamic unbalance through dynamic balancing machines. At last, a simulation experiment is given to demonstrate the influence of dynamic unbalance on the flight of rolling aircraft. Simulation results have verified the validity of the model and provide meaningful references for the stability and control design of the rolling aircraft.
A dynamic inverse based controller is designed for the longitudinal dynamics of a generic hypersonic vehicle. This model is strong nonlinear, multivariable coupling and includes uncertain parameters based on its high speed, lager aerodynamic load and rapid changing flight area. After feedback linearization of original model to get dynamic inverse linear model, optimal control method is used to develop controller to follow height and velocity commands. Simulation studies demonstrate that this controller is capable to follow height and speed change commands rapidly and accurately with certain robustness.
In order to improve the efficiency of parameter adjustment in aerodynamic configuration design of flight vehicle, the influences of the main configuration parameters on the aerodynamic coefficients, dynamic coefficients and dynamic characteristic parameters are analyzed based on the integrated design concept and parameter sensitization analysis method. A new idea of aerodynamic optimization taking the dynamic characteristic parameters as the objectives is proposed, and the major configuration parameters are optimized based on the idea and immune clonal selection algorithm. damping coefficient M , etc. For the thrust vector control flight vehicles, there are thrust vector transfer coefficient to flight vehicle K MT and thrust vector coefficient to attack angle K T . Expressions of the aerodynamic characteristic parameters are shown in table 2. 2 2 z z z z M m V SL a J J 2 2 z z z z z z M m VSL a J J 2 2 z z z z z z M m V SL a J J zT
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