Closed-loop active shape control actuator

Abstract

Today, ecology and CO2 emissions are at the centre of many debates. Because the aviation sector is a large emitter of CO2, the main manufacturers of the industry are trying to reduce the fuel consumption of the aircraft and thus the CO2 emissions. One of the technologies studied is the Hybrid Laminar Flow Control system, a combination of Natural Laminar Flow and Laminar Flow Control. Sonaca, being one of these manufacturers, is developing a Natural Laminar Flow profile leading edge. To do so, Sonaca in collaboration with Micromega Dynamics has to correct the wrong shape of a leading edge using an active control mechanism during its manufacturing process.

A description and comparison of actuators, sensors, guiding mechanisms and architecture controls that can be used in an active shape control mechanism are performed. Based on this analysis, two active shape control mechanisms are studied. The first mechanism is composed of three actuators that activate (push or pull) a rigid body attached to the skin of the leading edge. The second mechanism acts directly on the skin by pushing or pulling perpendicularly to the desired skin shape.

Since the correction using the first mechanism requires large forces, two methodologies of optimization are developed. After some investigation, this mechanism did not allow to correct properly the local errors appearing on the skin. This mechanism is therefore abandoned. The characteristics required for the second mechanism favour the choice of an electromechanical actuator connected to a jackscrew and controlled with a LVDT sensor.