Positive real vibration control using the adaptive piezoelectric sensoriactuator.

摘要

Passive control techniques have proven a reliable alternative to complicated, often expensive, active systems and are devoid of the common stability concerns that preclude active systems from implementation without a skilled background in controls engineering. However, passive systems sometimes suffer in terms of attainable level of performance. This work addresses these concerns through the development of a control methodology that is designed to be simple enough for the average engineer to implement and guaranteed to be stable for any level of tuning. Additionally, the performance and performance robustness of the technique is shown greater than its strictly passive counterparts.; The inherent benefit of collocation offered by the adaptive piezoelectric sensoriactuator in its ability to yield a minimum phase system, provides a platform amenable to implementing positive real control laws. Such controllers guarantee theoretic stability regardless of the level of tuning or system gain. Controllers meeting the positive real criterion are developed for use with the adaptive piezoelectric sensoriactuator. These controllers intentionally draw their inspiration from passive mechanical and electrical devices and, as a result, take advantage of widely known tuning laws. Controllers are developed for two different types of sensoriactuator signal outputs, position and rate, adding flexibility to the possible design configurations of the actual sensoriactuator circuit used.; In addition to the stability robustness offered by this type of control system, the performance can be theoretically greater than similar passive techniques, since removal of the capacitance gives full recovery of the structural dynamics. This allows a controller designed as an electrical stiffness or impedance that functions in a manner which modifies the coupling and dissipates energy as desired. Another benefit offered through the use of this type of structural control system is its high degree of performance robustness. Because the piezoelectric capacitance is continually tracked and its effects eliminated, it no longer serves as a source for detuning and therefore hindering controller performance as in the case of the resonant shunted piezoelectric.; The resonant shunted piezoelectric serves as a benchmark for comparison. Performance and performance robustness of the positive-real control filters are studied and quantified based upon the 2-norm and the infinity-norm. These quantifications are made both analytically as well as verified experimentally on a cantilevered steel beam test article. The implementation feasibility of this type of control system is also studied and qualitatively compared both among the various controllers and to the existing technologies of resonant shunted piezoelectrics and tuned proof mass vibration absorbers.