Tianjin Electronic Information Vocational Technology College

Tianjin, China

Tianjin Electronic Information Vocational Technology College

Tianjin, China
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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.


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.


Li J.,Tianjin University of Technology and Education | Li G.-H.,Tianjin University of Technology and Education | Hou L.-J.,Tianjin University of Technology and Education | Zhang X.-L.,Tianjin Electronic Information Vocational Technology College
Proceedings - 5th International Conference on Intelligent Networks and Intelligent Systems, ICINIS 2012 | Year: 2012

This paper introduces the design method of variable frequency power based on IGBT and SPWM inverter technology. The drive signal of IGBT is SPWM wave produced by MCU, and then a undistorted sine signal can be obtained through the low pass filter. LED digital tube displays the voltage value for watching. The sine wave with stably frequency and high precision could be produced by this design. © 2012 IEEE.


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.


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.


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

Three Lyapunov-Krasovskii (L-K) functionals for stability of time-delayed linear dynamical systems are compared. A benchmark second order linear system under delayed PD feedback controls is considered. The stability domains in the feedback gain parameter space are computed from the LMIs of different L-K functionals, and are compared with that calculated from the characteristic equation of the linear system. The results show that while most L-K functionals provide sufficient conditions for stability, which are conservative, Gu's complete L-K functional is the least conservative and the most accurate, and provides a necessary and sufficient condition for stability. Gu's complete L-K functional involves implicitly infinite number of matrices, hence, with a huge computational effort. When the Lyapunov stability theory is adopted for control design, the conservative stability conditions may be used, while Gu's complete L-K functional is more favorable to the design of controller.


Zhang C.H.,Tianjin Electronic Information Vocational Technology College | Zhao N.,Tianjin University | Niu Z.W.,Tianjin University | Guo W.,Tianjin University
Advanced Materials Research | Year: 2013

Aimed at the complexity and uncertainty of the diagnosis analysis of supply chain performance, this paper proposes a kind of diagnosis method of supply chain performance based on Bayesian network (BN). Based on the self-adaptive fuzzy interpretive structural model proposed in this paper, effective information could be provided to the structural learning of BN to enhance the modeling precision and reliability. Finally, according to investigating supply chain performance data of C Group, BN diagnosis model of supply chain operational cost is established. The consistent empirical analytical result and management practice prove the validity and feasibility of the method in this paper. © (2013) Trans Tech Publications, Switzerland.


Zhang W.,Tianjin Electronic Information Vocational Technology College | Zhang W.,Tianjin University | Li Z.,Tianjin University | Liu C.,Tianjin Electronic Information Vocational Technology College | And 2 more authors.
Applied Mechanics and Materials | Year: 2013

A CA3GA2 lean combustion gasoline engine one dimensional model was built by AVL BOOST software. The relationship between air-to-fuel ratio (A/F) and emission characteristic and fuel economy was simulated. Simulation shows that: (1) CO emission decreases as the A/F ratio increases; (2) HC emission reaches its lowest point at A/F=16~18; (3) NOX emission reaches its highest point at A/F=16~18; (4) the engine lean combustion limit is A/F=22, the brake secific fuel consumption (BSFC) decreases as the A/F ratio increases within the lean combustion limit. © (2013) Trans Tech Publications, Switzerland.


Xu S.,Hebei University of Technology | Xu S.,Tianjin Electronic Information Vocational Technology College | Zhang L.,Hebei University of Technology | Wang J.,Hebei University of Technology
IET Conference Publications | Year: 2012

Reliability analysis of low-voltage switchgear is of great significance to the safety and high efficiency of power system and its equipment. However, this analysis cannot use the conventional reliability estimation method based on large sample theory. In this thesis, the author introduces Bayes theory into the reliability analysis of low voltage switchgear. Firstly, reliability growth model and expert information method are used to obtain prior information of unknown parameters. Secondly, data from the first step is transformed and converted to gain compatibility with field samples. Finally, we form a low-voltage switchgear's prior information credibility test and multiple sources of prior information fusion method.


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.

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