Advanced Control of Piezoelectric Actuators.

168 p.A lo largo de las últimas décadas, la ingeniería de precisión ha tenido un papel importante como tecnología puntera donde la tendencia a la reducción de tamaño de las herramientas industriales ha sido clave. Los procesos industriales comenzaron a demandar precisión en el rango de nanómetros a micrómetros. Pese a que los actuadores convencionales no pueden reducirse lo suficiente ni lograr tal exactitud, los actuadores piezoeléctricos son una tecnología innovadora en este campo y su rendimiento aún está en estudio en la comunidad científica. Los actuadores piezoeléctricos se usan comúnmente en micro y nanomecatrónica para aplicaciones de posicionamiento debido a su alta resolución y fuerza de actuación (pueden llegar a soportar fuerzas de hasta 100 Newtons) en comparación con su tamaño. Todas estas características también se pueden combinar con una actuación rápida y rigidez, según los requisitos de la aplicación. Por lo tanto, con estas características, los actuadores piezoeléctricos pueden ser utilizados en una amplia variedad de aplicaciones industriales. Los efectos negativos, como la fluencia, vibraciones y la histéresis, se estudian comúnmente para mejorar el rendimiento cuando se requiere una alta precisión. Uno de los efectos que más reduce el rendimiento de los PEA es la histéresis. Esto se produce especialmente cuando el actuador está en una aplicación de guiado, por lo que la histéresis puede inducir errores que pueden alcanzar un valor de hasta 22%. Este fenómeno no lineal se puede definir como un efecto generado por la combinación de acciones mecánicas y eléctricas que depende de estados previos. La histéresis se puede reducir principalmente mediante dos estrategias: rediseño de materiales o algoritmos de control tipo feedback. El rediseño de material comprende varias desventajas por lo que el motivo principal de esta tesis está enfocado al diseño de algoritmos de control para reducir la histéresis. El objetivo principal de esta tesis es el desarrollo de estrategias de control avanzadas que puedan mejorar la precisión de seguimiento de los actuadores piezoeléctricos comerciale

A Review of Modeling and Control of Piezoelectric Stick-Slip Actuators

Piezoelectric stick-slip actuators with high precision, large actuating force, and high displacement resolution are currently widely used in the field of high-precision micro-nano processing and manufacturing. However, the non-negligible, non-linear factors and complexity of their characteristics make its modeling and control quite difficult and affect the positioning accuracy and stability of the system. To obtain higher positioning accuracy and efficiency, modeling and control of piezoelectric stick-slip actuators are meaningful and necessary. Firstly, according to the working principle of stick-slip drive, this paper introduces the sub-models with different characteristics, such as hysteresis, dynamics, and friction, and presents the comprehensive modeling representative piezoelectric stick-slip actuators. Next, the control approaches suggested by different scholars are also summarized. Appropriate control strategies are adopted to reduce its tracking error and position error in response to the influence of various factors. Lastly, future research and application prospects in modeling and control are pointed out

Advanced Mobile Robotics: Volume 3

Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective

The design and control of an actively restrained passive mechatronic system for safety-critical applications

Development of manipulators that interact closely with humans has been a focus of research in fields such as robot-assisted surgery and haptic interfaces for many years. Recent introduction of powered surgical-assistant devices into the operating theatre has meant that robot manipulators have been required to interact with both patients and surgeons. Most of these manipulators are modified industrial robots. However, the use of high-powered mechanisms in the operating theatre could compromise safety of the patient, surgeon, and operating room staff. As a solution to the safety problem, the use of actively restrained passive arms has been proposed. Clutches or brakes at each joint are used to restrict the motion of the end-effector to restrain it to a pre-defined region or path. However, these devices have only had limited success in following pre-defined paths under human guidance. In this research, three major limitations of existing passive devices actively restrained are addressed. [Continues.

Bilaterally controlled micromanipulation by pushing in 1-D with nano-Newton scale force feedback

In this thesis the focus is on mechanical micromanipulation which means manipulation of micro objects using mechanical tools. Pushing is a type of motion of the micro parts and pushing ability on micro scale is inevitable for many applications such as micro assembly of systems or characterization of tribological properties of micro scale things. The aim of the work in this thesis was to obtain an improved performance in 1-D pushing of micrometer scaled objects in the sense of giving more control to human operator where it allows human intervention via bilateral control with force feedback in nano-Newton scale. For this purpose a system which can practice 1-D pushing of micrometer scaled objects by human operator is built. A bilateral architecture which is composed of master and slave sides has been used in the system. The micrometer scaled object is pushed by the piezoactuator which constitutes the slave side and the master side is a DC motor where the shaft is turned by the human operator via a rectangular prism rod. This system can be considered as an improved system comparing with the ones in literature, since it has a number of different advantages together. One of them is the ability to calibrate the relation between the movement of the slave system and the cycle that is made by the DC motor shaft which is controlled by the operator. This gives the availability to decide how sensitive will the slave side motion be to the master side motion. Moreover, thanks to the nano-Newton scale force sensing ability of the system user has the chance to use this as a force feedback within the bilateral structure, where by the way the operator will understand when the piezoresistive cantilever beam touched the object that is going to be pushed by it. The operator also understands when there is an obstacle or opposite force that keeps the object from continuing on its track

Design and control of a smart fin using piezoelectric actuators

The objective of this research work is to design and implement control algorithms for smart fin of a projectile, which is currently under development in the Army Research Laboratory (ARL). The smart fin is used to maneuver small aerial vehicles by controlling the rotation angle of the fin. The fin is activated by a composite laminated plate that has two active piezoelectric layers. The prototype of the smart fin is assembled using Macro Fiber Composite (MFC actuator model M8557, Smart Material Co); Control algorithms for rotating the fin when subject to external aerodynamic forces are proposed. These controllers use a finite element model of the system. The three controllers are designed using Integral, Adaptive and Fuzzy Logic techniques respectively. Effects of Aerodynamic forces and uncertainties are included in these controllers; An experimental setup of the fin and actuator has been made for verifying and implementing the controllers with a real-time controller (dSPACE DS1102 controller board), which can be interfaced with the code developed in MATLAB and Simulink. Final tuning of the model is done using experimental data

Discrete-Time Control Design for Piezo-Actuated Positioning Systems

芝浦工業大学2018年