A potential problem that could possibly restrict the application of dielectric electro-active polymer (DEAP) actuators for active vibration damping is highlighted in this contribution. If a periodic electric field is applied to a DEAP actuator to counteract a periodic vibratory disturbance, a very common vibration attenuation problem, then the mechanical output will be the square of the periodic input. This will result in an actuator output with several harmonics. Therefore from a vibration damping perspective not only does the first harmonic of the periodic disturbance need to be considered but also additional harmonics, introduced by the actuator itself. Feedforward active damping of periodic vibratory disturbances using a tubular DEAP actuator is addressed in this contribution. Initially the addition of a d.c. bias offset to the periodic voltage signal applied to the actuator is investigated to try and reduce the effect of the higher harmonics. The use of a linearizing gain schedule is then also examined. Using a comparatively large d.c. bias voltage offset has a linearizing affect on the voltage-strain characteristics of the tubular actuator thereby reducing the influence of the higher harmonics on the resulting vibration damping characteristics. The disadvantage of this approach is that the operating range, in terms of the actuator stroke that can be achieved, is decreased. The use of a linearizing gain schedule also reduces the influence of the higher harmonics but provides less of a constraint on the operating range of the actuator.

Date Published: 9 April 2010
PDF: 12 pages
Proc. SPIE 7642, Electroactive Polymer Actuators and Devices (EAPAD) 2010, 76422Q (9 April 2010); doi: 10.1117/12.845764

Published in SPIE Proceedings Vol. 7642:
Electroactive Polymer Actuators and Devices (EAPAD) 2010
Yoseph Bar-Cohen, Editor(s)