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According to the fact that the linear imaging model cannot explain the lens distortion, and to overcome the problem that the ordinary calibration methods are not. suit for the change of height and angle, based on the pin-hole model and the previous distortion correction, this paper builds up a mirror coordinates system to study the reflection relation of pixel and angle. By using trigonometric functions and distortion coefficient, the height parameter and angle parameter are introduced into the model, and then the non-linear model is obtained. Finally, under different kinds of situation, comparing with Tsai's method, the algorithm validity is verified. After changing the camera angle and height, the algorithm, which does not require re-calibration, is still with good accuracy and robustness. Thus, the algorithm can be applied to the engineering field. [ABSTRACT FROM AUTHOR]

This paper constructs a continuous and smooth extended state observer and disturbance rejection cascade decoupling control technology, which is aimed at the nonlinear attitude model with strong coupling, aerodynamic parameter perturbations and uncertainties in the process of hypersonic vehicle without power reentry. An ADRC attitude controller is presented for hypersonic vehicle in convenient to the practical application of engineering, and a continuous and smooth extended state observer is designed by constructing qin function to avoid high-frequency chatter during ADRC application process, which solves the problem of ignoring the coupling impact on outer loop that is caused by inner loop in the inner and outer loop controller, and also solves the problems of charged aircraft model, aerodynamic parameters and perturbation boundaries which are difficult to obtain accurately and precisely. Simulation results show the effectiveness of the method. [ABSTRACT FROM AUTHOR]

Research on design and implementation of data interfaces in the desktop testing platform for a certain satellite was introduced in this paper. Firstly, to satisfy the engineering requirements, general structure of the platform was designed with the real-time simulator and the on-board computer as its core components, and the interfaces among various components in the platform was described. Then, topic focused on researching problems including constitution of the real-time simulator, programming on interfaces using xPC Target, sample time of the interfaces, encoding double precision floating point number for transmission through interfaces, and design of CAN bus protocol on the application layer. Finally, by analyzing results of. the testing experiment, effectiveness and practicality of the data interfaces solution were proved. [ABSTRACT FROM AUTHOR]

Considering influence factor of rotation of moon and geostrophic force, a precise three-dimensional dynamics model for lunar probe returning from the moon was presented. To realize the minimal fuel consumption, an optimal open-loop control law in the propulsion direction of the engine was Pontryagin's maximum principle. The optimal orbit of returning from the moon was obtained when the velocity and position restrictions were considered. The design in this paper is favorable for engineering application. [ABSTRACT FROM AUTHOR]

Detailed theoretical analyses are performed on dimensional synthesis of a 5 - DOF parallel mechanism with topological structure of 4 - UPS/UPU in this paper for providing the theoretical supports for engineering applications. Based on the kinematics analysis, a comprehensive method for the dimensional synthesis of such mechanism is developed for obtaining the optimal kinematics performance within the prescribed task workspace. Firstly, the independent design variables are divided into two categories: structural angles and geometrical parameters. Then the effects of dimensional parameters on the kinematics performance are reviewed through a thorough monotonous analysis, and the optimal solution set of structural angles is defined. Subsequently, the geometrical parameters of such mechanism are achieved by optimizing a compound objective index subjected to a set of appropriate mechanical constraints. A numerical example shows that the proposed method is effective and is significant for some other similar parallel mechanisms. [ABSTRACT FROM AUTHOR]

During the process of modeling and simulation for hydromechanical systems, the model precision can be affected directly by the choice of liquid density and fluid bulk modulus. The traditional method, in which these two parameters are taken as constants based on engineering experience, often lowers the modeling precision. A new method to calculate the liquid density and the fluid bulk modulus has been proposed in this paper, and the formula and algorithm for simplifying these parameters are summarized. A case widely used in the aerospace systems is thoroughly explained with this method. Results indicate that the pressure in positive stage has a little effect on the liquid density and fluid bulk modulus, whereas it must be taken the influence of gas content and pressure on these parameters into account during the stage of negative pressure. [ABSTRACT FROM AUTHOR]