| A structronic system synergistically integrates electronics, sensor/actuator, control, and structures, which is a structural application of the mechatronic systems. Structronic systems are used in many applications, for example, adaptive wings, integrated sensors or actuators in vibration/noise control systems, actively controlled variable-geometry structures, etc. An ultrasonic piezoelectric motor is also one of structronic actuator applications, which is often regarded as a precision mechatronic system as well. The objectives of this research are (1) to analyze the electromechanical response and micro-control actions when piezoelectric material is applied to a spherical shell as distributed sensors and actuators and (2) to apply the fundamental electromechanics to an application of precision ultrasonic piezoelectric spherical motor.; In the first part, distributed sensing and actuation of spherical shell is studied. It is based on the thin shell vibration theory. Responses and microscopic sensing/control actions of a distributed piezoelectric sensor and actuator layer bonded on spherical shells are investigated. The mathematical models of the hemispherical shell laminated with the distributed sensor and actuator layers are defined. The distributed modal voltages and sensing signals are analyzed and reported. Then, the control forces contributing components and normalized control effects are observed when the design parameters (i.e., actuator patch locations, shell thickness, and shell radius of curvature) are changed.; In the second part, the ultrasonic piezoelectric spherical motor is introduced and studied. The operation objective is to achieve a continuous rotary motion with respect to any given orientation axis on a spherical surface. The spherical motor consists of two major activities. There are (1) to provide orientation to a specific point in the spherical coordinate that can be achieved by the positional stator and (2) to provide continuous rotation about a spin axis which can be attained by the driving stator. Accordingly, dynamic response of a piezoelectric positional stator and driver stator will be analyzed. Their equations of motion are defined. The free and forced vibration responses are estimated and compared with the finite element analysis results. Then, the system design, implementation, and evaluation are reported and discussed. |
