Session: 04-07: Novel Actuators

Paper Number: 112125

112125 - A Hybrid Piezoelectric-Hydraulic Actuator Model and Prototype With Large Stroke and Force Parameters 

This paper reports the development of a hybrid piezo-hydraulic actuator. Piezoelectric stacks provide quick and precise response, when used as actuators. However, their small stroke limits their use to micro- and nano-actuation systems. Mechanical levers are most commonly used to amplify the displacement of a piezo stacks, but they sacrifice a significant amount of the blocked force. For the research presented here, a hydraulic lever is used to magnify the displacement of piezoelectric stacks, while generating a large blocked force (on the order of kN). This allows the actuator to achieve displacements on the scale of tens of millimeters. Three piezo stacks push on a piston that moves a hydraulic fluid through a narrowing, which amplifies the stroke of the stacks by the ratio of the wide channel area to the narrow channel area. Since this process decreases the output blocking force by the same ratio, at least three high-force piezo stacks are required to obtain a kN-range blocking force. Hysteresis of the piezo stacks is modelled using a non-symmetrical Bouc-Wen model. The piezo stacks and the hydraulic amplification mechanism are first tested separately to determine any potential loss factors in the design. Then, a prototype of the actuator is manufactured and presented. The prototype is tested by applying an elastic load in the form of a cantilever beam. This is used as verification for a Simulink model of the actuator. Final response characteristics of the proposed actuator as well as drawbacks are also discussed.

Presenting Author: Yan Borden University of Michigan

Presenting Author Biography: Aerospace Engineering Ph.D. Student at University of Michigan – Ann Arbor
Adaptive Intelligent Multifunctional Structures Laboratory
Advisor: Dr. Daniel Inman