Papers by Author: Chao Wu

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Authors: Jian Hu Jiang, Chao Wu, Gang Zhang
Abstract: In this paper, fuzzy self-tuning controller is introduced first. The fuzzy model is built according to the experience of PID parameter tuning with fuzzy set theory. Parameter tuning is achieved by use of fuzzy ratiocination and decision according to actual response, which is applied for control towards robot. Mathematical model of two-link robot has been built as well as its geometric and dynamical equations through coordinate transformation and matrix operation. Finally, fuzzy PD controller with self-tuning method is applied to realize control towards robots. Simulation in Matlab has been carried out whose result shows that the control method proposed in this paper has better performance than the traditional ones.
Authors: Chao Wu, Mai Dun Shao, Dong Bin Ai
Abstract: With requirements to air quality for human’s living, energy conservation and emission reduction, motorcycle emission in our country is in strict accordance with Euro III standard, while use of EFI (Electronic Fuel Injection) control system is one of the main measures to achieve the emission requirements. In this paper, 51-series MCU is applied as the core control unit for EFI control system of 950 (ml) large displacement motorcycles, which improves the dynamics and fuel economy of 950 (ml) gasoline engines. Hardware and software designs are proposed. Hardware design covers input signal processing circuit and driver circuit for EFL and software design analyzes the software control strategy in four aspects: engine work modes, fuel injection, ignition and idle speed control. The design in this paper has advantages of low cost and optimal control system performance. It not only fulfills the requirement of energy conservation and emission reduction, but also improves the performance of control system. Simulations carried out are presented to demonstrate that air-fuel ratio is controlled around ideal value, which is of great significance to large displacement motorcycle industry.
Authors: Jian Hu Jiang, Chao Wu, Ting Bu
Abstract: In this paper, an open-loop frequency domain analysis based on system identification is introduced. Using model identification tools in Matlab, the open-loop frequency domain characteristic could be derived accurately with the open-loop step response. Then, the closed-loop regulator could be designed with the open-loop frequency domain characteristic to fulfill the steady and dynamic requirements. This method is suitable for most of the systems. An example of Buck converter is proposed to represent the analysis process. Simulation model is built in Matlab software, and some factors which affect the precision of model identification and frequency domain analysis are taken into consideration. Finally, both open- and closed-loop experimental results verify the feasibility of the proposed scheme.
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