Applied Mechanics and Materials Vols. 336-338

Abstract: Active Disturbances Rejection Controller (ADRC) is applied to pressurizer (PZR) water level control system. Pressurizer is very important to the safety and the economic operation of nuclear power plant, and is a highly complex, nonlinear, and time-varying system. A traditional PID regulator is usually adopted to control water level of pressurizer in majority reactors. But there are large overshoot and low stability, and the control effect is not ideal. In order to obtain satisfactory control effects, ADRC is introduced to the water level control of pressurizer in this paper. This nonlinear control strategy is appropriate for the subject which has the characteristics of large-delay and multi-disturbance. The simulink results illustrate that the improvements are significant for its little overshoot, better stability, advanced anti-interference and strong robustness. Therefore, this new method based on ADRC is feasible and effective.

Abstract: Using MATLAB to establish emulation model of variable rate fertilization control system, using the Z-N method to setting the system of PID parameters, emulation of the system has without PID controller and PID controller, analysis and evaluation of the system dynamic performance index and steady-state performance index. The emulation results shows that the system with PID controller, the maximum overshoot reduce, adjusting time short, improve the time domain dynamic index; phase margin increase, magnitude increase, improved the performance index of the frequency domain.

Abstract: In order to equilibrate the influence of bus priority induction signal control in non-priority phases, signal timing should be optimized in the intersection. Equilibrium methods are proposed for three bus priority strategies: green extension, red truncation and phase insertion. The unsaturated intersection delay is analyzed for a single bus priority request based on linear vehicle flow arrival process, procedures of green loss and loss offset are considered to infer intersection delay formulation. The signal-planning optimal model with total passengers delay minimum and other phase vehicles passing intersection normally for restraint condition is suggested.

Abstract: Firstly, the inventory control models were studied, considering of the cost of store and lack of stock. Secondly, both the models of the distribution centre and supplier were presented. Finally, a numeric example was analyzed by applying the models. The results show that the models are easily to be carried out in engineering field, and it is useful to control the inventory and raise the store efficiency.

Abstract: In this paper, we deal with the robust minimum variance filtering problem for discrete time-varying systems with observation losses. The system under consideration is subjected to time-varying norm-bounded parameter uncertainties in both the state and output matrices, and the observation losses are described by a Bernoulli process with a known probability. An upper bound on the variance of the state estimation error is first found under certain probability of missing observations and admissible parameter uncertainties. Then, a robust filter is derived by minimizing the prescribed upper bound in the sense of the matrix norm. It is shown that the desired filter can be obtained in terms of the solutions to two discrete Riccati difference equations.

Abstract: Base on the parameter of actuator failure the model of aircraft with failure is founded. After that a Hinf reconfiguration controller is designed with LMI to rescue for aircraft when some failure occurs at actuator. At the last the simulation is done about the Hinf reconfiguration controller figures how to work. And the figures about that is given.

Abstract: Mathematical model of pipeline pressure is built according to mass conservation. Aiming at solving the poor adaptability of routine PID algorithm and the disturbance of inlet steam, adaptive fuzzy-PID algorithm and Feed-forward controller are proposed in the control system. System simulation is conducted by MATLAB, and parameter self-tuning rules determined by different errors are studied. Simulation results show that the pressure control system has better static and dynamic performance such as quicker response, smaller overshoot and better capacity of resisting disturbance.

Abstract: This article has proposed a nonlinear decoupling control method based on differential geometry and variable structure control theory according to the nonlinear and strong coupling characteristics of missile with high angle of attack. The affine nonlinear model of missile with high angle of attack was firstly established, the accurate linearization and input/output decoupling of system were then performed by differential homeomorphism and feedback transformations. On the basis of this, the variable structure controller was designed to reduce the influence of parameter variation and disturbance. Simulation results indicate that nonlinear decoupling of missile with high angle of attack can be realized through this control method, which is superior due to its good static and dynamic characteristics.

Abstract: Full-color LED display-Screen is widely used as a new information display device in all aspects of life, but its flat and static display could not cater to peoples dynamic visual change ,and its lack of intelligence capability makes it a defect not to respond timely with special outside change. ARM and FPGA With high speed and programmable features having been used widely in applications of the embedded development and we provide the method to design of Intelligent Full-Color LED display-screen system based on ARM and FPGA. The control system employs Cortex-M3 core-based ARM as its mail controller, the temperature and humidity sensor, microwave sensor, an infrared sensor are adopted for outside information, and FPGA scan control unit for the color data display. Brushless Direct Current Motor (BLDCM) possessing Superior performance in control unit is widely well applied. The experiments show that the reasonable modular design of the program enables its smooth rotation within the range of 45°-135°, and it timely response to various changes on the outside. Thus LED can display 256 data intelligently which ensures the market prospects. Key words: IntelliSense ; ARM ;FPGA; Full-color LED display-Screen ; Cortex-M3;BLDC motor

Abstract: With the development of smart grid, regional grid automatic voltage control (AVC) system has been widely used in power systems, but the effect is uneven, and there are not relating tools to evaluate its performance. The paper proposes a Closed-loop test method combining Real Time Digital Simulation system (RTDS) with reactive optimization procedures to simulate and optimization the status of actual grid. An optimal control scheme of the actual grid from the new method can be used to judge the advantages and disadvantages of actual AVC system. Simulation tests show online RTDS-based power system reactive power and voltage control simulation is good. It can be regard as reference to evaluate the control effectiveness of the actual AVC system.