作者: Zdzisław Gosiewski, Maciej Henzel

摘要: Highly maneuverable aircraft has redundant electrohydraulic actuators that generate the
forces to drive the aircraft control surfaces. Two problems are important in these actuators. First,
during reconfiguration of the actuator channels the hydraulic system works in the full range of its
parameters. It leads to strongly nonlinear models of the redundant servo. Second, the frequency
bandwidth of elements, which are located in the feedback loop of the servo, should be as wide as
possible. Therefore, it is necessary to choose proper control method for actuator, where the
controller of control system adjusts the set point signal. The advanced control methods can ensure
the new quality of the systems.
The new, advanced methods can cope with such problem in practical applications. There are
available: adaptive methods, predictive methods, etc. and first of all, the robust control methods.
These methods are robust on external disturbance. The causes of disturbances are very different: the
inaccuracy in the mathematical and simulation model, the change of the operation point, the
weather and temperature conditions, etc. We have designed such models in the Matlab/Simulink
environment and we divided the full actuator into small subsystems.

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摘要: Quasi-static equations are presented for a magnetostrictive medium where mechanical and magnetic fields interact with each other. Finite element method is used in conjunction with the Hamilton's principle to deduce equations for the dynamic behavior of the magnetostrictive material. These equations form the basis for the magnetostrictive material to be utilized as a sensor or as an actuator. When used as an actuator, the material can provide enough power to actuate mechanical systems for vibration control. In this work, a cantilever beam with a magnetostrictive actuator is taken to demonstrate the modeling and use of the magnetostrictive actuator in attenuating structural vibrations. The position of the actuator is changed to observe its effect on the response of the system. This is important because it is a well-known fact that the actuator location has impact, sometimes big, on its performance.

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作者: Ji Jie Ma, Jian Ming Wen, Guang Ming Cheng, Ning Li, Yong Hua Jiang

摘要: Based by controlling the orderly changes of friction force between the PZT rotary actuator and supporting faces in mechanical way, a novel kind of inertial piezoelectric rotary actuator is proposed. the dynamic simulation model of the actuator based on karnopp friction model is established, by using matlab software, Four ordered Runge-Kutta calculation method is used to carry out kinematics simulation of the actuator, the curve of driving signal frequency、voltage and dynamic characteristics is conducted, the prototype of rotary actuator is designed and manufactured, the performance of the actuator is tested，The experimental results show that the developed actuator is characterized by large travel (360º) , good resolution (15µrad) , high speed (0.26rad/s) , and work stability. The motion theory and dynamic formulation of the actuator are proved through comparing the results of simulation and experiment.

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作者: Da Peng Wang, Shi Zhu Tian

摘要: In order to accelerate the velocity and improve the accuracy of the pseudo-dynamic testing，the external displacement control method is put forward based on the hardware control. The internal displacement sensor of the actuator is invalid on control and substituted by the LVDT displacement sensor connected with the specimen. The process of the feedback displacement and command error compensation is quickly implemented by the internal closed-loop control of the actuator. Compared with the iteratively approximate load control, this method not only makes the testing velocity fast, but also enables the error between command and feedback to be “zero”. The fast pseudo-dynamic testing about a cantilever beam is carried out by applying appropriate PID parameters of the actuator. The testing result shows that although this method has rather high requirements in the control system and electro-hydraulic servo load device, and the risk to some extent, the fast response of the actuator can be firmed by applying appropriate PID control parameters. This method provides a fast testing technology for velocity-dependent structures or specimens.

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作者: Yaw Jen Chang, Yun Wei Chung, Ting An Chou, Min Fen Huang

摘要: In this paper, a micropump with electromagnetic actuation is presented. The micropump mainly consists of coil actuators and a PDMS micropump layer. The microcoil was fabricated using the printed circuit board (PCB) with the conventional PCB treatment and the PDMS layer was formed by casting technique. A control circuit was designed using microcontroller to produce square waves to control coil actuator. Due to the simple fabrication process, the micropump can be incorporated in a disposable PDMS lab-on-a-chip device as a fluid actuation component. However, the coil actuator is reusable. In addition, the control circuit makes the micropump portable. The experiment results show that this proposed micropump is capable of delivering a flow rate of 470 μL/min using one coil actuator.

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