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Kang Y.-M.,Beihang University | Xie W.-D.,Beihang University | Hu J.,Beijing Institute of Computer Application | Huang Q.,Beihang University
Binggong Xuebao/Acta Armamentarii | Year: 2011

The traditional Mean-Shift tracking algorithm is not applied to track a size-changing target effectively due to the fixed band-width of its kernel function. For this reason, a new algorithm is proposed. In each frame, Mean Shift tracking algorithm is employed to get the target location, and then the affine structure between frames is calculated to re-correct the position and size of the target. Different experiments prove that the present method has better stability and robustness than the traditional algorithm.


Zhu M.,Harbin Institute of Technology | Chen Y.,Harbin Institute of Technology | Yang C.,Harbin Institute of Technology | Zhao D.,Beijing Institute of Computer Application
Proceedings - 2012 International Conference on Intelligent Systems Design and Engineering Applications, ISDEA 2012 | Year: 2012

A D-PL ( Digital-PL) chaotic model was proposed to construct ATPG (Automatic Test Pattern Generation) of BIST (Built in Self Test) in this paper. The D-PL chaotic model is improvement of the traditional continuous PL chaotic model. The coefficient of power of 2 was used for traditional PL chaos discrete processing. This approach is conducive to the realization of hardware. Shift registers and accumulator adopted to implement iteration avoiding the direct use of the multiplier. This method can effectively reduce the circuits area After parameters optimization, the D-PL chaotic model ATPG was applied for testing digital circuits. Experiment results show that the proposed D-PL chaotic model ATPG has good randomness and ergodicity. The test pattern of D-PL Model has no correlation. It can effectively improve the digital circuits fault detection rate in BIST. © 2012 IEEE.


Wang Z.,Beijing Institute of Technology | Chen L.,Beijing Institute of Computer Application | Guo S.,Cranfield University
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering | Year: 2013

This article presents a study on the flow field and aerodynamic characteristics of the propellers and rudders for the design of a small ducted fan aircraft. In the analysis, an equivalent actuation disk was created as a simplified model of the propellers. A momentum source is determined by equivalent actuation disk numerical simulation using ANSYS CFX software based on vortex theory. In addition, the momentum source distribution function for the equivalent actuation disk model is improved by using experimental data. The computational fluid dynamics method in the ANSYS CFX software is then used to simulate the flow field of the propellers slipstream and determine the key aerodynamic and design parameters for the built-up rudders of the aircraft. The improved equivalent actuation disk method is validated by using the mixing plane method and their results show a good comparison. The simulation and analysis results provide the basis for optimal design of the built-up rudder arrangement and layout for a small ducted fan aircraft. © IMechE 2012.


Cai G.,Beijing Institute of Technology | Song J.,Beijing Institute of Technology | Chen X.,Beijing Institute of Computer Application
Journal of Aerospace Engineering | Year: 2015

This paper addresses the command tracking control system (CTCS) design problem for plants involving input quantization and input saturation. A novel approach is proposed and demonstrated to the angle of attack (AOA) CTCS and bank angle CTCS of hypersonic reentry vehicles (HRV) driven by a reaction control system (RCS). First, the six-degree-of-freedom (6-DOF) nonlinear dynamic model of HRV and the mathematical model of RCS are established, and dynamic analysis is conducted based on the linearized model of HRV. Second, a general CTCS for plants involving input quantization and saturation is designed by solving a convex optimization problem based on linear matrix inequalities (LMIs). Formulations of the domains of attraction and convergence of the closed loop CTCS are derived. Furthermore, input to state stability (ISS) of the closed loop system is analyzed. Finally, the proposed approach is applied to design the longitudinal AOA CTCS and lateral-directional bank angle CTCS of HRV driven by an RCS. Validation simulations are conducted by using the linear model and the 6-DOF nonlinear dynamic model of HRV, which indicate that the proposed LMIs based approach is well suited for CTCS design for static-unstable plants and multiaxis coupling plants driven by actuators with quantization and saturation. © 2014 American Society of Civil Engineers.


Gaohua C.,Beijing Institute of Technology | Jianmei S.,Beijing Institute of Technology | Xianxiang C.,Beijing Institute of Computer Application
Aircraft Engineering and Aerospace Technology | Year: 2014

Purpose - The purpose of this paper is to design a robust angle-of-attack (AOA) tracking control system for the hypersonic reentry vehicle (HRV) based on the linear parameter varying (LPV) theory, as the aerodynamic coefficients of the hypersonic vehicle vary quickly during the reentry phase. Design/methodology/approach - First, longitudinal moment trim is done along the desired flight trajectory. The linearized system at each trim point is built and the dynamic characteristics analysis is made. Then the LPV control law with parameter-dependent quadratic Lyapunov function (PDQLF-LPV) is applied to design the AOA tracking autopilot at each trim point. Frequency performance of the autopilot is assessed and the step response simulation is conducted to validate the effectiveness of the control system. Finally, actual AOA command tracking simulations based on the time-varying nonlinear model are carried out to test the correctness and robustness of the PDQLF-LPV autopilot. Findings - Analysis results demonstrate that the PDQLF-LPV control system can track the AOA command perfectly during the whole flight envelop with dynamics parameter variation or disturbances, which indicates that it is effective to integrate the PDQLF-LPV control theory with a parameter-varying reference model for control system design of HRV. Originality/value - A reference model with varying parameters is utilized to guarantee the transient performance of the autopilot, and induced L2-norm analysis is introduced to describe and guarantee the robust stability of the autopilot. © 2014 Emerald Group Publishing Limited.


Cai G.,Beijing Institute of Technology | Song J.,Beijing Institute of Technology | Chen X.,Beijing Institute of Computer Application
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering | Year: 2014

An angle-of-attack tracking control system is designed for the hypersonic reentry vehicle, whose aerodynamic parameters vary dramatically during reentry phase. The linear parameter-varying (LPV) theory based on linear fractional transformation (LFT) model (named as LPV-LFT method) is applied to design the controller for hypersonic reentry vehicle. Longitudinal moment trim of the hypersonic reentry vehicle is made along the desired flight trajectory, and a damping feedback loop is firstly designed to improve the system's damping and static stability. Then, the linear dynamics model with damping feedback loop is established in LFT structure and treated as the controlled plant, and a parameter-varying reference model is utilized to guarantee the transient performance. The effectiveness of the proposed angle-of-attack tracking control system is validated through the frequency domain analysis and step response simulations. Finally, the actual angle-of-attack command tracking simulations using the nonlinear time-varying mathematical dynamics model are carried out to verify the accuracy and robustness of the hypersonic reentry vehicle control system. © IMechE 2013 Reprints and permissions: sagepub.co.uk/ journalsPermissions.nav.


Cao J.-Y.,Beijing Institute of Technology | Chai W.-Y.,Beijing Institute of Technology | Wang B.,Beijing Institute of Computer Application | Guo Y.-H.,Beijing Institute of Computer Application
Binggong Xuebao/Acta Armamentarii | Year: 2013

In order to overcome the shortcomings of traditional EJB, CORBA, and publish/subscribe middleware software architecture, an efficient software component framework suitable for embedded distributed computing environment is proposed. The software architecture is based on the open service gateway initiative(OSGi)standard, and can be used in multi-communications protocol environment by adding a transmission abstraction layer. It is characterized by versatility, high stability and less memory footprint. The experimental results show that the software is superior to the traditional software architecture in memory footprint, startup time and service interface response time. It can meet the harsh conditions of the embedded environment.


Zhao X.,Beijing Institute of Computer Application | Qian Y.,Beijing Institute of Computer Application | Zhang M.,Beijing Institute of Computer Application | Niu J.,Beijing Institute of Technology | Kou Y.,Beijing Institute of Technology
2011 IEEE International Conference on Mechatronics and Automation, ICMA 2011 | Year: 2011

Navigation technology plays an important role in the designing of advanced robot. An advanced robot navigation system based on GPS/INS is modeled in this paper. According to the model, the causes of the errors in measurement equation are analyzed, concluding that HDOP (Horizontal Dilution of Precision) and VDOP (Vertical Dilution of Precision) provided by GPS receiver are the crucial factors for the change of measurement noise in the mathematical model. Based on the above conclusion, this paper proposes a novel second order fuzzy self-adaptive filter design. Choosing the differences of location and velocity information provided by GPS receiver and INS device as the inputs, this filter modifies the regulation factor based on the residual sequence statistical information and PDOP (Position Dilution of Precision) provided by GPS receiver to correct the outputs of INS device using fuzzy logic. The experimental results demonstrate that the improved adaptive Kalman filtering algorithm proposed in this paper has a strong adaptability to time-varying measurement noises, which improves precision of the advanced robot navigation. © 2011 IEEE.


Guan X.,Beijing Institute of Technology | Zhao X.,Beijing Institute of Computer Application
Proceedings of the World Congress on Intelligent Control and Automation (WCICA) | Year: 2015

The sensor and the information processing technologies are the basis for intelligent robots. At present, pressure sensor is widely used in the robotics. In order to overcome the shortcomings of traditional pressure sensors, a novel legged robot foot tip pressure sensor based on FSR and embedded system is proposed. The sensing circuit, the A/D convector circuit and data transmission circuit and the digital filtering based on wavelet is studied. Experimental results demonstrate that the designed sensor and filtering algorithm have good linear relationship between the input and output, high resolution, quick response and strong anti-noises performances. © 2014 IEEE.


Cai G.,Beijing Institute of Technology | Song J.,Beijing Institute of Technology | Chen X.,Beijing Institute of Computer Application
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering | Year: 2015

The paper addresses the command-tracking-control-system (CTCS) design problem for plants involving continuous and discrete control input simultaneously. A novel approach based on linear matrix inequalities (LMIs) is proposed and demonstrated to the angle-of-attack (AOA) CTCS of hypersonic reentry vehicle (HRV) driven by a hybrid actuator composed of aerosurfaces and reaction control system (RCS). Firstly, the longitudinal nonlinear dynamics model of HRV and the mathematical model of RCS are established, and then the model of the hybrid actuator is described. Secondly, a general command tracking problem is converted to a regulation problem by constructing a deviation system. And the characteristics of the hybrid actuator is considered and modeled definitely based on some modified sector conditions. Then, the CTCS with hybrid actuator is designed by solving a LMIs-based convex optimization problem. Furthermore, the stability performance of the closed-loop CTCS is evaluated and the formulation of the domain of attraction is derived. And the relationship between the size of stability domain and the magnitude of reference command is also discussed. Finally, the proposed approach is applied to the AOA-CTCS of HRV driven by aerosurfaces and RCS, and different sizes and locations of the stability regions are illustrated with different magnitudes of AOA reference command. Validation simulations are carried out by using the longitudinal nonlinear dynamics models of HRV. The research results demonstrate that the proposed LMIs-based approach is well suited for the AOA-CTCS design for HRV driven by aerosurfaces and RCS. © 2014 IMechE.

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