Applied Mechanics and Materials Vols. 541-542

Abstract: According to the idea of the system identification, 2-DOF PID based on the desired dynamic equation (DDE-PID) has been improved. The DDE-based PID is applied to the integrating system. This method only needs the step response information of the plant, which is easy to be obtained. According to the physical meaning of parameters, the tuning is also convenient to meet the requirement of the dynamic performance. The simulations show that the method has the low overshoot and the short setting time on the integrating system.

Abstract: Servo pneumatics is a mechatronic approach that enables accurate position control of pneumatic drives with high speed. The current study presents a comparison of two servo techniques for position control of pneumatic cylinders. One method uses a proportional valve and another method uses PWM controlled solenoid valves. Mathematical models of the system including the nonlinearities such as mass flow rate, pressure in cylinder chambers and frictional forces are presented in this paper. Using the simulation model created in Matlab-Simulink software, the two systems are analyzed for tracking performances. From the responses it is observed that the proportional valve technique has better tracking characteristics than PWM control technique.

Abstract: PI control strategy was introduced into rotor side converter of DFIG control with the mathematical models and the structure of stator flux-oriented vector control. As the main problem of conventional PID controller with parameters fixed in the whole control process, and influence of three PID control parameters can not be distinguished between different stages, so, the adaptive fuzzy PID control was introduced into RSC control system. The parameters were tuned by adaptive fuzzy control, the design of membership was designed and the control feature was verified with simulation.

Abstract: This paper expatiated a system that was irregular wave maker in wave flume. It was the first time to apply ROCKWELL companys products and motion control technology into the wave-maker system. Firstly, We designed a series of function modules for control system. Then gave the relevant programming flowchart. Secondly, we intruduced the ROCKWELLs softlogix5800 series controller and Ultra3000 series driver in the application of make-wave system. Finally, the system had been successfully applied to the test of scientific research.Compared with the method of simulation control , this servo motor-driven irregular wave machine system have high precision, stable operation, wiring simple. Generally speaking, it provides the practical significance with certain practical foundation and experience for future projects.

Abstract: In various kinds of feedback control, delayed control is an important topic for chaos control, which deserves more thorough researches. However, only a few researchers take in to account that whether the delayed feedback control (DFC) can be employed to control chaotic systems with time-delay. To investigate the control strategy, a stabilization problem of unstable fixed points in the discrete time-delay system is taken into considerations in this paper. Based on our conclusion, it is obvious that the odd number limitation property existing in the system without delay also exists in the time-delay one while the DFC is employed to stabilize the unstable fixed points. Second, based on the property of the root-locus diagram, a developed DFC strategy is proposed to release the limitation. The numerical simulation results validate the effectiveness of our design and are in agreement of our analysis.

Abstract: An adaptive fuzzy controller for dynamic positioning (DP) system is designed. The controller utilizes Backstepping algorithm as the adaptive law and uses a fuzzy system for approximating the disturbances and uncertainties. The proposed adaptive fuzzy controller is proven to be uniform bounded in the sense of Lyapunov. Simulation results show that DP vessel with the adaptive fuzzy controller would be more adaptive with environmental interference and ship parametric uncertainty.

Abstract: . Biomass energy transforms solar energy into chemical energy and the energy is stored in the organisms internally with the help of the photosynthesis. In the biomass boiler combustion system, the boiler drum water level is an important parameter and it is a sign to measure regardless of whether boiler steaming water system is in balance. For a nonlinear process as water level control in boilers, conventional control theory is not an appropriate choice. In this study, a neural network based predictive controller is designed and implemented through simulation in MATLAB software for biomass boilers drum water level control. Performance of neural network controller is compared with conventional PID (Proportional + Integral + Derivative) controller for boiler drum water level control system and it is observed that the neural network based approach is more efficient than conventional PID controller.

Abstract: The proportional flow control valve is not only one of the key competent of vane damp,but also the execution unit of shock absorber damping force's regulation .The proportional flow control valves self-designed will combine the structural design of proportional control valve and crate CFD model . The thesis analyzes its distribution of flow field by CFD and acquires experimental validation .It analyzes dynamic characteristics and determine the relationship of flow and opening and drive current. The proportional control valve test verifies the correctness, finally. It is basis for analyzing of damping characteristics about vane damp, which can be used other proportional control valve CFD study.

Abstract: The circulating fluidized bed boiler (CFB) power unit with its energy-saving and environmental protection has broad application prospects, but the problem of CFB unit automatic control has not been solved satisfied, so automatic generation control (AGC) can not be stabilized input. Through the improvement of the unit automatic control strategy by the method of intelligent predictive multivariable decoupling control and optimization of parameters, the AGC tests achieved approving results in CFB unit.

Abstract: Nowadays, the short of water resource has been a problem. To make the use of water resource more effectively, especially the underground water, we designed the IC card paid water wells Remote Monitoring System. The system consists of 3 parts--water wells terminal control unit, the data transmission network and supervisory and trade center. The process includes hardware design and software design. The core point consists of the IC card reading and writing processes and RS485 multi-device communication using MODBUS protocol. After testing, the basic function is completed, and it will be in the future having broad prospects for development in many fields.