Development of Elevator Control Surface for Small Air Robot Using Piezoceramic Actuator

There have been persistent interests in high performance actuators suitable for the actuation of control surfaces of small aircraft and helicopter blades and for active vibration control of aerospace and submarine structures that require high specific force and displacement. What really needed for active actuation is a large-displacement actuator with a compact source, i.e., much higher strain. A lot of effort has been made to develop better actuators with large displacement at a high force. LIPCA was introduced by Yoon et al as an improved actuator with enhanced performance. The LIPCA design offers the advantages to be applied as actuator for the small aerial vehicle comparing with any other actuators. The weight is one of the main concerns for aerospace field, and since LIPCA has lighter weight than any other piezo-actuator thus it is suitable as actuator for small air robot (SAR) control surface. In this paper, a conceptual design of LIPCA-actuated control surface is introduced. A finite element model was constructed and analyzed to predict the deflection angle of the control surface. The hinge moment that produced by the aerodynamic forces was calculated to determine the optimum position of the hinge point, which could produce the deflection as high as possible with reasonable hinge moment. To verify the prediction, a prototype of SAR control surface was manufactured and tested both in static condition and in the wind tunnel. The prediction and test results showed a good agreement for the control surface deflection angle.