Applied Mechanics and Materials Vols. 380-384

Abstract: This report compares traditional PID controller and fuzzy PID controller with simulink on the basis of the control theories of traditional PID and fuzzy PID. In order to reduce the numbers of attempts, the simulation deduces one appropriate range of quantitative factor and proportionality factor under given object function through simulink. Simultaneously, this paper makes conclusion of influence of quantitative and proportionality factor to the system. In addition, this paper analyses the performance of quantitative factor and proportionality factor under specific external interference. The results of simulation show that appropriate quantitative and proportionality factors which have important affect on steady and dynamic characteristic of fuzzy PID controller.

Abstract: in the process of refining petroleum, the gasoline-final boiling point and the steam pressure 10% point, which are major indicators of gasoline quality, can not be real time measured online. This paper introduces the designing thoughts and the realization method of computer optimization control for gasoline quality as well as its reliance on the coupling of parameter identification and on-line simulation for modeling. Also includes the techniques of comprehensive evolution of multi-optimal strategies. By means of soft-meter [1] monitoring and optimizing techniques, along with setting up the dynamic mathematics model of gasoline-final boiling point online, the complicated technologies of computer monitoring and optimal controlling of gasoline quality for the catalytic cracking unit can be carried out.

Abstract: An improved control algorithm of repetitive controller based on virtual resistance was proposed to solve the problem of the slow dynamic response and the high total harmonic distortion (THD). The proportional-integral controller (PI controller) can not only adjust rapidly but also eliminate residual error effectively and the repetitive controller can eliminate periodic interference signal effectively. The double loop control combined with PI control and repetitive control. The controller has been used to control the inverter in grid-connected section which can improve the regulating speed and system stability. It can also achieve fairly good control effect under the circumstances of mutations of voltage and load. By designing the parameters of the controller, THD of the grid-connected current is lower than 0.61%. The simulation result shows that the algorithm is correct and feasible.

Abstract: Most variable speed wind turbines have pitch angle control mechanisms and one of their objectives is to protect turbines when the wind speed is too high. Pitch angle control is the most common means for adjusting the aerodynamic torque of the wind turbine when wind speed is above rated speed. The paper deals with optimal tuning of a PID controller for pitch angle control in wind turbines using particle swarm optimization (PSO) algorithm. The particle swarm optimization is used for achieving the correction coefficient values of deviation which are sent to the controller so that the control effect of chlorination system is improved. Simulation results prove the effectiveness of proposed control strategy. System can eliminate the wind speed disturbance and provide good transient and robust performance.

Abstract: Combined with the brake working principle of Permanent magnet synchronous motors, the three-phase PWM rectifier mathematical model and Simulink simulation model are set up. On this basis, according to the design requirements of energy feedback system, the voltage current double-loop control is applied in this system. The space voltage vector tracking is achieved by the use of space voltage vector PWM algorithm. The system modeling and simulation study is conducted in the MATLAB simulation environment, and the correctness of the proposed program is verified, which provides the corresponding theoretical basis for the future product design.

Abstract: The switching system is one of the important models which describe the hybrid dynamical systems. Different models and the switching rules are adopted to better describe the motion of the actual complicated systems. Combined with advantages of the PMSM and BLDCM, the paper proposed the switching control strategy for Brushless PM Motor with the rule of output feedback based on switching system theory. Then the linear model of the switching control system was obtained and the stability of it was analyzed. The results of the simulation and the experiment show that the switching control strategy is stable and could effectively improve the efficiency and reduce the torque ripple of the motor in full speed range.

Abstract: The design of a LED illumination control system based on ARM, infrared technology and ZigBee is described. With the core of S3C44B0X and the infrared sensor collecting the temperature information, the system uses ZigBee technology to do real time monitoring. Through the experiment, the system can make the safe, real time and effective control. It is meaning for the development of the future LED illumination.)

Abstract: With the growing surge of network control system research results, the study of stability analysis aspect of network control system is diversified. This paper introduces the concept of packet loss and equivalent network-induced delay, the stochastic stability of network control model is studied, the use of network control system modeling is transformed into the concept of a discrete time based on jump linear system, and the stochastic stability some conditions of networked control systems are proposed. At the same time, the state feedback controller related to solve the problem will also translated into linear matrix inequality problems, which carries out the study of the stochastic stability of networked control systems. Finally, through the simulation examples, they are given to demonstrate the validity of the study method in application, which use the modeling method to study the problem, and also have certain significance in related fields in a certain extent.

Abstract: This study is concerned with the robust H control for a class of uncertain discrete Networked Control Systems (NCSs). The NCSs with bounded network-induced delay and data packet dropout are modeled as closed-loop systems with time-varying input delay. By using new Lyapunov-Krasovskii function and combining Jessen inequality and reciprocal convex technique, a sufficient condition which asymptotically robust stabilizes closed-loop systems and satisfies H performance index is derived. This study needs fewer Linear Matrix Inequality (LMI), compared with the existing literature. Therefore, the result obtains lower conservativeness. Finally, the robust H controller is obtained with an improved cone complementarity linearization (ICCL).Simulation results show the effectiveness of the proposed method.

Abstract: Testing and commissioning process for intelligent injection process of production engineering monolayer segment flow have strong non-linear, interlayer interference, time-varying, complex model and other characteristics, using the traditional model-based control strategy can not meet the control requirements, puts forward the new dual-core structure variable spacing of the self-adaptive fuzzy control strategy, the rate of change of flow error and flow error as the controller input, through the sub-fuzzy The Controller Online amend the main fuzzy controller input and output dilation factor of the universe, and the universe with the amount of control variable parameters to variable space adjustment, and simplify the design and implementation of a variable universe fuzzy controller. Simulation results show that the proposed control strategy used in intelligent injection wells in the monolayer segment flow control system, allowing the system to obtain better control performance, and shorten the response time and reduce the overshoot.