Applied Mechanics and Materials Vols. 241-244

Abstract: In this paper, the descriptor system based concept is applied to the stabilization for a discrete T-S fuzzy system. The control input vector and state vector are combined to the descriptor system form which leads to fewer Lyapunov inequalities (lower computation demand) than traditional T-S fuzzy stability criteria. Also, the non-parallel distributed compensation (non-PDC) and slack variables are adapted to relax the proposed stability conditions. Finally, the computation effectiveness the proposed stability criterion is demonstrated by a numerical example.

Abstract: A novel pressurized stripper with side-draw has been implemented successfully in coal-gasification industry and oil-refining industry. In this complex stripping process, ammonia and sour gas can be removed effectively from wastewater with ammonia and sour gas. However, compared to simple strippers, the complex pressurized strippers have rarely been considered for dynamic optimization before. In this paper, the dynamic simulation and optimal control of the novel stripper are proposed to improve the overall cost-effectiveness of the whole process. First of all, sensitivity analysis is proposed to find the sensitive plates in stripper with steady state simulation. Based on the sensitivity analysis, two control schemes are built up. And then, the rejecting disturbance capabilities of the two control schemes are compared and testified by using dynamic simulation. Finally, the optimal control scheme is implemented in industry with distributed control system (DCS). A real industrial application demonstrates that relies on the installed control system, the new stripping process can run steadily, consume less energy and satisfy the product quality requirements even though an uncertain disturbance occurs.

Abstract: In order to obtain accurate prediction model and avoid solving nonlinear programming problem, a direct adaptive predictive control (DAPC) method is proposed. Firstly, a nonlinear system was described based on Takagi-Sugeno (T-S) fuzzy models. Assuming that that the antecedent parameters of T-S models were kept, the consequent parameters were identified on-line by using the weighted recursive least square (WRLS) method. Secondly, the identified parameters of fuzzy model were used to directly receive the model predicted output with direct iterative for the T-S model. Finally, the application results for continuous stirred tank reactor (CSTR) process show that the proposed algorithm is an effective control strategy with excellent tracing ability. The proposed algorithm is a good way to resolve the two major problems, modeling and optimization, and provides a guarantee for high-precision control of nonlinear systems.

Abstract: The influence of electromagnetic coupling and mechanical coupling on control property in dynamic emulation system is analyzed. the coupled system is a dual-input dual-output system.The load torque changes will cause the variation of speed in the system and the speed changes also affect the variation of load torque. The mathematic model of the system based on decoupling control are given. The compensation module can be installed to the system in order to make subsystems almost independent of each other. Simulation and comparison is taken by MATLAB / Simulink software between decoupled system and original system. Result shows that the coupling control method can improve the precision of the control system and fasten response.

Abstract: By applying CC-Link field bus theory and technique, the shortcoming of complex cabling and the problem of signal attenuation are solved in order to realize distributed control and centralized control. The CC-Link field bus structure characteristics and communication mode are detailed, the method of network hardware configuration, parameter setting and software configuration are given. Using the touch screen, the system can achieve real-time monitoring and fault alarming, as well as partial-area remote debugging. The application proves the correctness and feasibility. This control system is easy to install and maintain, saving cost and improving the reliability of the complete system.

Abstract: This paper is to demonstrate an improving PID control with changing integration rate approach, and it was validated and researched by applying to the 2- water tank system. Analyzed the control principle of variable speed integral PID in this research, and optimized the variable speed function of variable speed integral PID control to improve the design. Deduced the improved variable speed integral PID control algorithm, and it was applied to the 2- water tank system. And then made a simulation system to value it. The results show that the improved variable speed integral PID control enables the system to improve the rapidity and accuracy, also shows that the correctness and superiority of the control method. It really a useful method to provide a advanced way for the control system.

Abstract: NAND flash would generate invalid blocks during its manufacturing and using, and the invalid block management is a key point of NAND flash. By studying the structure and storage rules of NAND flash, this paper put forward a wear-levelling algorithm against the invalid blocks of NAND flash based on FPGA. This algorithm use invalid block table and logical-physical address mapping table to manage the invalid blocks and do wear-levelling. The design is implemented by VHDL, and successfully realized the wear-levelling and the reading and writing operations of NAND flash.

Abstract: This article takes the natural gas hot-dip galvanizing kiln as the research object, designing a set of networked control system based on PROFIBUS, introducing the combustion system design of the natural gas kiln and the general structure of control system, and developing PLC control program and human-computer interface of the upper computer, and realizing network monitoring. It has been found that the stably running system provides powerful tools for product quality control and optimal operation management.

Abstract: Brief description is given of existing appraising methods for the performance of cooling tower and their shortcoming firstly. Then the mathematics model of cooling tower operation performance is given by means of relative perfect RBF neural network. Comparing with the usual linearity and non-linearity cooling tower mathematics model, the RBF neural networks mathematics can more truly reflect cooling tower operation performance. This conclusion is valuable for giving a more true and simple method for appraising the operation performance of cooling tower. In this text, we consider that cross-wind effect operation efficiency, the complex process of heat and mass transfer between gas and water is easily effected by the air temperature of surroundings,humidity and the influence of cross-wind.

Abstract: The desktop-based thread force feedback system is divided into three logical parts. They are mechanical device, controller and data processing center. All kinds of interactive behaviors will be limited in the interactive space of the system. There exist two spaces of force feedback in the system. They are partial force space and entire force space. Operation vibrations will happen when the endpoints of threads enter from entire force space to partial force space. The vibrations will affect thread tension calculation. The quadratic program algorithm of thread tension can decrease vibrations and increase stability of thread force feedback when the tolerance coefficient is joined in the equations. It is a global optimization algorithm. The experiments have confirmed that threads tension changes will be smooth when the tolerance coefficient is not equal to zero.