نتایج جستجو برای: piezoelectric actuators
تعداد نتایج: 24956 فیلتر نتایج به سال:
The local atomic structure of high performance piezoelectric materials is currently being investigated computationally. These materials are expected to play an important role in the next generation of sensors and actuators, used for example, in aircraft for active vibration and noise control. Many sensors and actuators are composed of piezoelectric materials, since they can transform mechanical...
Composite materials are a very important class of engineering materials with great properties and applications in a variety of complex structures. The correct design of such structures requires adequate analysis and, in particular, adequate and accurate models for simulation with numerical tools. Piezoelectric materials can convert mechanical energy into electric energy and vice-versa and are b...
This paper presents the design of a vibration control mechanism for a beam with bonded piezoelectric sensors and actuators and an application of the arising smart structure for vibrations suppression. The mechanical modeling of the structure and the subsequent finite element approximation are based on Hamilton’s principle and classical engineering theory for bending of beams in connection with ...
Piezoelectric diaphragms are used as synthetic jets because of their size, rapid time response, and relatively low power consumption. Among the piezoelectric diaphragms used are unimorphs and Bimorphs. In this study, a bimorph diaphragm, a thin Unimorph pre-stressed device and a Radial Field Diaphragm (RFD) are compared. A bimorph consists of two bonded PZT discs, a thin Unimorph pre-stressed d...
Piezoelectric actuators are widely used in micro manipulation applications. However hysteresis nonlinearity limits accuracy of these actuators. This paper presents a novel approach utilizing a piezoelectric nano-stage as slave manipulator of a teleoperation system. The Prandtl-Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. A pas...
Certain materials produce electric charges on their surfaces as a consequence of applying mechanical stress. The induced charges are proportional to the mechanical stress. This is called the direct piezoelectric effect and was discovered in quartz by Piere and Jacques Curie in 1880. Materials showing this phenomenon also conversely have a geometric strain proportional to an applied electric fie...
Piezoelectric materials are widely used in the design of smart structures. It is thus of major technological interest to provide efficient modelings of such structures. In the case of thin piezoelectric plates, classical studies generally lead to two different models. These two models can be linked to the distinction between sensors and actuators. Here, we extend these results to the second ord...
Actuators remain a limiting factor in robotics, especially in microrobotics where the power density of actuators is a problem. A 3 × 3 × 8.7 mm 3-axis piezoelectric ultrasonic micromotor system is described here in an effort to help solve this problem. Formed from 4 bulk lead zirconate titanate (PZT) thickness-polarized elements placed around the periphery of a rectangular rod, the stator is de...
Feedforward Controller of Ill-Conditioned Hysteresis Using Singularity-Free Prandtl–Ishlinskii Model
Piezoelectric, magnetostrictive, and shape memory alloy actuators are gaining importance in high-frequency precision applications constrained by space. Their intrinsic hysteretic behavior makes control difficult. The Prandtl–Ishlinskii (PI) operator can model hysteresis well, albeit a major inadequacy: the inverse operator does not exist when the hysteretic curve gradient is not positive defini...
Piezoelectricity is the ability of some materials (notably crystals and certain ceramics) to generate an electric potential in response to applied mechanical stress and vice versa. Whenever this kind of materials produce an electric signal proportional to their deformation, it is said that they work as sensors, and conversely, when they convert electrical energy into mechanical one, as actuator...
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