Type synthesis and kinematics of a modular variable geometry truss mechanism for aircraft wing morphing

Abstract

Recently there has been a trend in developing morphing airborne structures to positively affect the aerodynamics, flight performance and stability of aircraft, and act as replacements for control surfaces. Most wing level morphing projects focus on variable sweep, dihedral, wing twist or span, but very few combine more than one of these morphing methodologies to achieve greater morphing functionality. Also the methods used for actuation differ significantly from one morphing method to the next. Presented is the type synthesis of a modular variable geometry truss mechanism for aircraft wing morphing. Each truss module resembles a Gough-Stewart platform which is augmented with a central leg. The structural truss members are replaced with active and passive prismatic joints to achieve 1-, 2-, 3-, and 4-DOF morphing for individual or simultaneous wing sweep, dihedral, twist and span. Kinematic requirements are outlined for each truss module and are related to the architecture of the central leg. The wings of a robotic bird are modelled as an example of the modular VGTM morphing wing.