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Zhang X.-Y.,Tianjin University | Zhang X.-Y.,Tianjin Electronic Information Vocational Technology College | Sun J.-Q.,University of California
JVC/Journal of Vibration and Control | Year: 2014

This paper presents a stability study of linear time-invariant and periodic systems with time delay. The methods of semi-discretization, continuous time approximation and Lyapunov stability theory are used to study the stability of two benchmark systems. It is found that for linear time-invariant systems, the Lyapunov method is usually conservative leading to a much smaller domain of stability in a parameter space than the true solution, with the exception of the complete Lyapunov functional due to Gu, which gives highly accurate predictions with little conservatism. For periodic systems, it is difficult to find appropriate Lyapunov-Krasovskii functionals. Numerical methods such as semi-discretization and continuous time approximation are more appealing, and can compute geometrically complex stability boundaries in the parameter space with high accuracy. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. Source


Cao J.,Tianjin Electronic Information Vocational Technology College | Jia G.,Tianjin University | Zhang C.,Tianjin University
Proceedings of 2010 International Conference on Intelligent Control and Information Processing, ICICIP 2010 | Year: 2010

This paper introduces a soft starter of asynchronous electromotor which is based on magnetically controllable reactor, and analyzes the working principle, function and application. This system optimized the traditional voltage-ramp technique and current-limited technique. The new mode of intelligent torque closed-loop control is proposed, which can start pump loads more smoothly and prevent system from impact. It can also reduce the water hammer and the vibration of pipeline. At last, we make a certification test. © 2010 IEEE. Source


Yu X.L.,Tianjin Electronic Information Vocational Technology College
Advanced Materials Research | Year: 2013

This paper presents analysis and experiments for Generalized Predictive Control (GPC) algorithm based on software simulation. First, we illustrate the time invariant GPC algorithm in detail. Then, we describe the principle for the control parameter selection of GPC based on empirical results. The Recursive Least Square (RLS) algorithm will be used to identify model parameters in the self-tuning GPC. The performance of GPC algorithm is validated by simulation results, which show that the algorithm has rapid and accurate dynamic responses for input signals, such as step signal and square wave. When the model parameters are unknown, with the assistance of RLS, the self-tuning GPC algorithm also presents good performance and robustness capability, even when white Gaussian noise exists. © (2013) Trans Tech Publications, Switzerland. Source


Zhang X.,Tianjin University | Zhang X.,Tianjin Electronic Information Vocational Technology College | Sun J.,University of California at Merced | Ding Q.,Tianjin University
Hsi-An Chiao Tung Ta Hsueh/Journal of Xi'an Jiaotong University | Year: 2013

An approach to analyze kinematics of a five-degree of freedom (5-DOF) robotic manipulator is proposed. The effect of the time delay in control on the stability of the motor control system is considered. The time delayed differential equations are converted into differential equations without delay by using the lowpass filter-based continuous-time approximation (LPCTA). The optimal control method is adopted to design the controller. Experimental results show that the proposed kinematics algorithm is accurate with less computational cost, and is suitable for real-time control application of 5-DOF manipulator. The time delayed control system of 5-DOF manipulator can accurately track the desired trajectory. Source


Zhang C.H.,Tianjin Electronic Information Vocational Technology College | Zhao N.,Tianjin University of Technology and Education | Zhao N.,Tianjin University | Shao H.Y.,Tianjin University
Applied Mechanics and Materials | Year: 2013

It is valuable for supply chain management to analyze and evaluate the operation performance of supply chain, and use timely and accurate operation state feedback to adjust the system to keep smooth running. Aiming at the complexity and uncertainty of supply chain, this thesis put forward a heterogeneous selective ensemble principle component analysis (PCA) algorithm based on fuzzy integral via Bagging ensemble learning. Besides, by using dimension reduction on high-dimensional data set, it realizes to extract the key factors of supply chain performance and breaks the bottleneck that problems in supply chain management cannot be recognized rapidly or analyzed by traditional performance evaluation method. According to the empirical research on survey data of supply chain performance at C Group, the algorithm is proved be effective. © (2013) Trans Tech Publications, Switzerland. Source

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