Advanced Materials Research Vols. 816-817

Abstract: The numerical simulation and experimental method are adopted to analyze the piezoelectric vibration control of the simplified autobody beam structure. The autobody beam structure is simplified as a beam fixed at both ends. The finite element model of beam structure with piezoelectric patches is established. The static analysis and modal analysis is conducted by the piezoelectric analysis of the finite element analysis software. The proportional and proportional-derivative control methods are studied in the piezoelectric active vibration control analysis for the simplified beam structure. The experimental system is established to obtain the vibration control effectiveness of the beam structure. The experimental results show that the type of two ends patching beam has more effective vibration control ability than the central patched beam.

Abstract: DFIG (Double Fed Induction Generator) becomes a competitive wind power form due to it needs small capacity converter and the controllable of system efficiency and power factor. Aiming at back to back three-phase voltage-type PWM converter of the doubly-fed VSCF wind turbine, the nonlinear mathematical model of the controller of rotor side and network side is constructed, the strategy of feedback linearization of nonlinear control is proposed, the decoupling control of active and reactive power of DFIG is achieved. The simulation results indicate that: this control strategy has good dynamic characteristics, and the quality of power supply of DFIG is improved.

Abstract: A new fuzzy adaptive sliding mode controller based on fuzzy compensation for robot is proposed. The control architecture employs fuzzy systems to compensate adaptively for plant uncertainties to distinguish different disturbance compensation terms and approximate each of them respectively. By analyzing and comparing the simulation results, it is obviously shown that the control system can lighten the effect on the control system caused by different disturbance factors and eliminate the system chattering than that of traditional SMC.

Abstract: Because its pilot stage is a two-position tree-way valve, the previously research piezoelectric type pneumatic digital valve also constantly works in on or off state even in the case of output stable pressure, which makes the valve with pressure fluctuation, waste gas and other shortcomings. In order to overcome the above problem, a novel pneumatic digital valve driven by dual piezoelectric is presented in this thesis. And its simulation model is built based on the AMESim and Matlab/simulink joint simulation platform. On this basis, its control method is researched by the simulation. The simulation shows that the Bang-Bang and the PWM control algorithm can basically achieve the digital proportional control of the valve, but the valve has overshoot. For this, the compound control algorithm with PID plus PWM is proposed to control the valve. The simulation results show that this algorithm is effective which can reduce the pressure overshoot.

Abstract: Comfortable, healthy, and energy-saving indoor environments can be obtained via a dynamic thermal comfort control. Difficulties to design an optimal control system for a dynamic thermal environment arise due to the lack of coordinative control evaluation methods for conflicting comfort and energy-saving indices. An improved multi-objective algorithm based on discrete PSO (Particle Swarm Optimization) is proposed to calculate the optimal values of parameters in the dynamic comfort control system based on users balance between the comfort and energy conservation. No a priori information or physical indoor environment model is needed. Experiment results demonstrate the effectiveness of the proposed control method.

Abstract: This paper presents a vector control scheme of doubly-fed motor based on stator flux orientation. The scheme achieves decoupled flux and torque component of stator current through directional control of the rotor current vector. It is suitable for both motor sub synchronous operating condition and super synchronous operating condition. Simulation experiment based on the scheme is carried out by Matlab/Simulink and simulating waveforms are given to prove the correctness of the scheme.

Abstract: In hydraulic robots, single-rod electro-hydraulic actuator is widely employed for fast response, small size-to-power ratio, large output force and compact size. The differences of open loop gains and other parameters make the dynamic characteristics of two moving directions asymmetric in symmetric valve controlled asymmetric cylinder system. To ensure robots moving smoothly and improve control precision, a novel pressure compensation based symmetric control scheme is proposed. Pressure feedback algorithm is mathematically proved feasible. Therefore, a displacement and pressure signals fused fuzzy PID controller is designed. Simulation results verify the feasibility and validity for compensating the asymmetric problems.

Abstract: An approach to actively control the low frequency linear spectrum in vessel navigation noise is proposed. The approach relies on the introduction of a secondary noise-cancellation source which is fixed aboard and whose signal generation uses the estimated location knowledge of the receiver. Loss of underwater acoustic transmission is modeled and Monte Carlo simulations are conducted to analyze the noise-reduction effects under different location estimation errors. Simulation results show that bearing estimation error is the predominant factor affecting the radius of the effective noise-reduction region, while distance estimation error has considerable effect only when the perpendicular distance from the receiver to vessels course is quite small. Besides, when bearing estimation error is less than 1.2° and distance estimation error is less than 80%, satisfactory noise reduction region can be obtained using the approach.

Abstract: A high-altitude multi-parameter environmental simulation system can simulate a high-altitude flying environment for aircraft on ground. It has a very important effect on researching aircraft Environment Control System (ECS) and testing its working performance. However, it is very difficult for a traditional experimental system to realize a pressure decoupling control in a real multi-parameter simulation because the pressure control is strongly coupling with the temperature and humidity control. Therefore, a multi-parameter environmental simulation experiment is not very fast and precise currently. In order to meet the high-altitude experimental requirements, it needs to develop a new experimental method and the corresponding strategy. In this paper, an experimental method is used and it controls the pressure in the environmental simulation cabin only by using an air exhaust valve. Further, a two-degree-of-freedom PID pressure control strategy with a nonlinear compensation is also presented to control the air exhaust valve. The control strategy can realize a pressure decoupling control from the temperature and humidity control. The nonlinear flow character of the air exhaust valve can be compensated by introducing a nonlinear compensation part and the pressure control overshoot can be overcome by the two-degree-of-freedom PID controller. Simulation results show that this presented control strategy can realize a real-time environmental control and improve the control precision and respond speed greatly.

Abstract: The remote control of controller is a main trend of development for control system. The lots of work in them all mainly regards internet as the base of frames in the network. There are many levels of technologies for the remote control of controller. Its implements are important technologies among these levels. So, a remote PID controller is completed physically using ARM-based microprocessors. In this paper, how it is built is proposed. The realizations of the control algorithms are focused on specially. The physical prototype was implemented and proved that Embedded ARM control architecture for remote PID controller is correct and effective.