Investigating distributed sensor/point actuator testbeds by using differential laser Doppler interferometer

The design principles, optical configurations, and capabilities of a newly developed advanced vibrometer/interferometer device railed AVID are present ed. The fundamental principles of this metrology instrument that enables it to have a dc to 20-MHz bandwidth and nanometer resolution are also detaile d, The applicability of using laminated one-dimensional piezoelectric plate s as testbeds to study some of the fundamental characteristics of piezoelec tric actuators and sensors is also examined, Taking advantages of the linea r and angular displacement/velocity measurement modes of the vibrometer/int erferometer, the performance of distributed piezoelectric sensors, which ra n measure bending angle and bending displacement at any point of the testbe d, is characterized. In addition, the corresponding piezoelectric actuator that can exert bending moment on the testbed is also evaluated. The hystere sis effect and feedback vibration control potential of both piezoelectric p olymer polyvinylidene fluoride (PVF2) and piezoelectric ceramic lead, zirco nate, and titarate (PZT) are investigated by using a bimorph configuration testbed. Experimental results show that PVF2 acts more linearly than PZT du ring sensing. Furthermore, the influence of the driving sources on the piez oelectric actuators can be verified experimentally. It ran he shown that dr iving PZT by using a current source will have a less severe hysteresis effe ct than driving it with a traditional voltage source.