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第三十四届中国控制会议

作者： Xujun Zhou Xianxia Zhang Bingfei Zhang Shanghai Key Laboratory of Power Station Automation Technology College of Mechatronics Engineering and Automation Shanghai University

ISBN: (纸本)9781467374439

Consider the time complexity and newly added samples, an incremental convex hull algorithm based online Support Vector Regression(ICH-OSVR) is proposed in this paper, which can significantly reduce the time consuming and realize fast online learning when added a new sample. There are two steps, called offline step and online step. Firstly, the convex hull vertices of training samples are selected by using convex hull offline algorithm and then regard the vertices of convex hull as the training samples, which are prepared for training. Secondly, when a new sample comes and it is out of the previous convex hull, update the vertices of convex hull and then the previous SVR model will be updated by the new convex hull, but if the new sample is within the previous convex hull, discard it and do not need to update the model. The effectiveness of our proposed methods has been confirmed according to the artificial data sets and real data sets.

关键词： time complexity,convex hull,support vector regression,online learning

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3D path following control for UAVs using L1 adaptive method

3D path following control for UAVs using L1 adaptive method

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Chinese automation Congress (CAC)

作者： Yongchang Zhang Jie Li Ning Xu Yifeng Niu Huayong Zhu College of Mechatronics Engineering and Automation National University of Defense Technology Changsha China

ISBN: (纸本)9781467371902

This paper considers the 3D path following problem of an Unmanned Aerial Vehicle (UAV), the objective is to steer the UAV along a given reference path, while the desired transient and steady performance is satisfied. To solve the problem, we make use of the typical multi-loop control structure in which the guidance loop controller directs the aircraft to the desired path, while the inner loop controller stabilizes the nonlinear dynamics and tracks the command generated by outer loop. By introducing a virtual target, the proposed Lyapunov based kinematic controller for outer loop can make the UAV asymptotically approach the defined path with smooth movements. Moreover, the developed inner loop controller is based on L 1 adaptive control method, which can provide guaranteed transient performance and guaranteed robustness in the presence of fast adaptation, without introducing or enforcing persistence of excitation, without any gain scheduling in the controller parameters, and without resorting to high-gain feedback. Finally, the controllers are validated by simulation.

关键词： Three-dimensional displays Yttrium

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Mathematical modeling and analysis of thermodynamic processes in a twin-rotor piston engine

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Journal of Central South University 2014年第11期21卷 4163-4171页

作者：邹腾安徐海军潘存云徐小军陈虎 College of Mechatronics Engineering and Automation National University of Defense Technology

In order to study the major performance indicators of the twin-rotor piston engine(TRPE), Matlab/simulink was used to simulate the mathematical models of its thermodynamic processes. With consideration of the characteristics of the working processes in the TRPE, corresponding differential equations were established and then simplified by period features of the TRPE. Finally, the major boundary conditions were figured out. The changing trends of mass, pressure and temperature of working fuel in the working chamber during a complete engine cycle were presented. The simulation results are consistent with the trends of an actual working cycle in the TRPE, which indicates that the method of simulation is feasible. As the pressure in the working chamber is calculated, all the performance parameters of the TRPE can be obtained. The major performance indicators, such as the indicated mean effective pressure, power to weight ratio and the volume power, are also acquired. Compared with three different types of conventional engines, the TRPE has a bigger utilization ratio of cylinder volume, a higher power to weight ratio and a more compact structure. This indicates that TRPE is superior to conventional engines.

关键词： twin-rotor piston engine mathematic model thermodynamic process simulation utilization ratio of cylinder volume

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Self-excited vibration problems of maglev vehicle-bridge interaction system

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Journal of Central South University 2014年第11期21卷 4184-4192页

作者：李金辉李杰周丹峰余佩倡 College of Mechatronics Engineering and Automation National University of Defense Technology

The self-excited vibration problems of maglev vehicle-bridge interaction system were addressed, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, the coupled model containing the quintessential parts was built, and the mechanism of self-excited vibration was explained in terms of energy transmission from levitation system to bridge. Then, the influences of the parameters of the widely used integral-type proportion and derivation(PD) controller and the delay of signals on the stability of the interaction system were analyzed. The result shows that the integral-type PD control is a nonoptimal approach to solve the self-excited vibration completely. Furthermore, the differential-type PD controller can guarantee the passivity of levitation system at full band. However, the differentiation of levitation gap should be filtered by a low-pass filter due to noise of gap differentiation. The analysis indicates that a well tuned low-pass filter can still keep the coupled system stable.

关键词： maglev vehicle-bridge interaction system self-excited vibration energy

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Adaptive backstepping control for levitation system with load uncertainties and external disturbances

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Journal of Central South University 2014年第12期21卷 4478-4488页

作者：李金辉李杰余佩倡王连春 College of Mechatronics Engineering and Automation National University of Defense Technology

To explore the precise dynamic response of the levitation system with active controller, a maglev guide way-electromagnet-air spring-cabin coupled model is derived firstly. Based on the mathematical model, it shows that the inherent nonlinearity, inner coupling, misalignments between the sensors and actuators, load uncertainties and external disturbances are the main issues that should be solved in engineering. Under the assumptions that the loads and external disturbance are measurable, the backstepping module controller developed in this work can tackle the above problems effectively. In reality, the load is uncertain due to the additions of luggage and passengers, which will degrade the dynamic performance. A load estimation algorithm is introduced to track the actual load asymptotically and eliminate its influence by tuning the parameters of controller online. Furthermore,considering the external disturbances generated by crosswind, pulling motor and air springs, the extended state observer is employed to estimate and suppress the external disturbance. Finally, results of numerical simulations illustrating closed-loop performance are provided.

关键词： maglev backstepping control nonlinearity mass variation adaptiveness extended state observer

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ZMP preview control based compliance control for a walking quadruped robot

ZMP preview control based compliance control for a walking q...

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International Conference on Information and automation (ICIA)

作者： Jiaqi Xu Ligang Ge Jian Wang Qing Wei Hongxu Ma College of Mechatronics Engineering and Automation National University of Defense Technology Changsha China

In this paper, a compliance control strategy based on ZMP preview control for quadruped walking gait locomotion under unperceived disturbances is proposed. The preview control is designed to plan the CoM trajectory to realize the desired ZMP. When the robot suffers from interference of environmental disturbances, we introduce an adjusted expected ZMP to suppress the change of the ZMP. The force distribution module calculate desired contact force by eliminating interaction force between the stance legs and the force controller make the contact force track the desired force. Simulation results demonstrate the effectiveness of our compliance control strategy based on ZMP preview control as the quadruped robot successfully walking under unperceived disturbances.

关键词： Legged locomotion Force Trajectory Mathematical model Robot kinematics Dynamics

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Assessment of Zero-Velocity Detectors for Pedestrian Navigation System Using MIMU

Assessment of Zero-Velocity Detectors for Pedestrian Navigat...

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新型导航技术及应用研讨会

作者： CHEN Chang-hao CHEN Ze PAN Xian-fei HU Xiao-ping College of Mechatronics1 Engineering and Automation National University of Defense Technology

A design of pedestrian navigation system based on EKF and ZUPT is proposed in this study. Three different zero-velocity detectors are assessed by the position accuracy calculated through PNS with different choice of detectors and selections of parameters. The trajectories of the pedestrian using MIMU are illustrated which allows to see the validity of algorithm and the impact of zero-velocity detectors on the whole system. The final results show that a position accuracy of 0.39% can be achieved and the detectors using the information of gyroscope signals such as SHOE Detector prove to be more reliable in the detection of time epochs when the MIMU is stationary.

关键词： pedestrian navigation system zero-velocity detector MIMU EKF

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A FAST AND ROBUST VISION-BASED HORIZON TRACKING METHOD

A FAST AND ROBUST VISION-BASED HORIZON TRACKING METHOD

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International Copmputer Conference on Wavelet Active Miedia Technology and Information Processing

作者： HAO GUO YI-MENG ZHANG JING ZHOU YUE-QIANG ZHANG College of Mechatronics Engineering and Automation National University of Defense Technology Changsha 410073 China

ISBN: (纸本)9781467382670

In order to achieve accurate attitude measurement and smooth navigation controlling of unmanned surface vehicle (USV), a visual horizon tracking method based on Kalman filter has been proposed. Firstly, the approximate parameters of the visual horizon are estimated according to the predictive camera attitude, and the candidate image pixels are obtained in a small region of interest around the predicted horizon location. Then, within the candidate image pixels, the candidate line segments are determined by repeated interior points selecting and least squares fitting, and the final visual horizon is picked out according to geometric properties of the candidate line segments. Lastly, the optimal prediction of the camera attitude is updated by Kalman filter. As the horizon detection is only performed in a local region, compared with traditional horizon detection method, the proposed method takes a short time and performs robust to the false alarms. To validate the performance of our method, an experiment is performed based on the frames captured by the camera which is fixed on an USV. The experimental results indicate that our method has higher tracking accuracy and speed.

关键词： Machine Vision Image Measurement Horizon Detection Prediction Kalman Filter

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SIBA: A fast frequent item sets mining algorithm based on sampling and improved bat algorithm

SIBA: A fast frequent item sets mining algorithm based on sa...

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Chinese automation Congress (CAC)

作者： Ying Wei Jian Huang Zhongjie Zhang Jiangtao Kong College of Mechatronics Engineering and Automation National University of Defense Technology Changsha Hunan CN

The adaptability of the classical top-k frequent item sets mining algorithms is unsatisfied when being applied to some large datasets with both large scales of transactions and items. In this work, an algorithm called SIBA (sampling, improved bat algorithm (BA)) is proposed to solve this problem. SIBA applies BA and improves it by cloud model to search frequent item sets from a large number of items rapidly, and builds the sub-dataset in every iteration to reduce the scanning cost. Based on four open access datasets, it is compared with Apriori, FP-growth, and other heuristic algorithm such as PSO (Particle swarm optimization) and GA (Genetic algorithm). The experimental results show that when being applied to frequent item sets mining, SIBA is faster than Apriori and FP-growth, and meanwhile, it is more robust than PSO and GA.

关键词： Heuristic algorithms Reactive power Particle swarm optimization Genetic algorithms Data mining Sociology Statistics

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Prediction method on the impact point of the cluster bomb based on off-line simulation

Prediction method on the impact point of the cluster bomb ba...

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Chinese automation Congress (CAC)

作者： Hongwu Guo Yanbo Huang Shuai Guo College of Mechatronics Engineering and Automation National University of Defense Technology Changsha Hunan China

ISBN: (纸本)9781467371902

Aiming at covering the target area and destroying the target, large amounts of sub-munitions need loading on the cluster bomb. In this paper, the on-line prediction method of the sub-munitions dispersion center which could be used for missile-borne computer is studied. First the method uses off-line simulation to calculate each impact point of sub-munitions. Then the statistical method is used to calculate the sub-munitions dispersion impact point center. Finally, the correspondence between impact point dispersion center and parent shell of the cluster bomb is established. In that way, the missile-borne computer, according to the actual flight status, can predict the location of sub-munitions dispersion centers online. This method improves the cluster bombs impact point prediction accuracy through a large number of off-line calculation. The simulation shows the effectiveness of the method.

关键词： Weapons Computers Computational modeling Interference Monte Carlo methods

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