This paper describes the concept of a four-bar linkage mechanism for flapping wing micro air vehicles and outlines its design, implementation, and testing. Micro air vehicles (MAVs) are defined as flying vehicles ca. 150 mm in size (handheld), weighing 50–100 g, and are developed to reconnoiter in confined spaces (inside buildings, tunnels, etc.). For this application, insectlike flapping wings are an attractive solution and, hence, the need to realize the functionality of insect flight by engineering means. Insects fly by oscillating (plunging) and rotating (pitching) their wings through large angles, while sweeping them forward and backward. During this motion, the wing tip approximately traces a figure eight and the wing changes the angle of attack (pitching) significantly. The aim of the work described here was to design and build an insectlike flapping mechanism on a 150 mm scale. The main purpose was not only to construct a test bed for aeromechanical research on hover in this mode of flight, but also to provide a precursor design for a future flapping-wing MAV. The mechanical realization was to be based on a four-bar linkage combined with a spatial articulation. Two instances of idealized figure eights were considered: (i) Bernoulli’s lemniscate and (ii) Watt’s sextic. The former was found theoretically attractive, but impractical, while the latter was both theoretically and practically feasible. This led to a combination of Watt’s straight-line mechanism with a drive train utilizing a Geneva wheel and a spatial articulation. The actual design, implementation, and testing of this concept are briefly described at the end of the paper.

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Micro air vehicles (MAVs) are defined as flying vehicles ca. 150 mm in size (hand-held) weighing 50–100 g, and are developed to reconnoitre in confined spaces (inside buildings, tunnels, etc.). For this application insect-like flapping wings are an attractive solution and hence the need to realize the functionality of insect flight by engineering means. Insects fly by oscillating (plunging) and rotating (pitching) their wings through large angles, while sweeping them forwards and backwards. During this motion the wing tip approximately traces a figure-of-eight and the wing changes the angle of attack (pitching) significantly. This paper presents some aspects of aerodynamic modelling and mechanical design pertinent to engineering realization of insect-like flapping wings on the MAV scale. The aerodynamic modelling uses an indicial Polhamus approach which is implemented in a modular manner. Comparisons are presented with experimental force data from a dynamically scaled insect model and generally show good agreement. The design is then described of a four-bar linkage mechanism to drive an insect-like flapping-wing motion. The indicial Polhamus aerodynamic model was used as part of the design process to predict wing loading. This highlighted some interesting interactions between the position of the wing pitch axis and its loading. The paper concludes with some directions for future work in this challenging field.