A piezo‐driven flapping wing mechanism for micro air vehicles

2006). Flapping wing MAVs (FWMAVs) are a class of new conceptual MAVs that take design cues from flying insects in order to achieve a small size (<3–5 cm), high maneuverability and super remote ability (Yan et al. 2015). A FWMAV is expected to work in a variety of confined spaces such as urban canyons, caves, indoors, and jungles that large flying robots can’t be serviceable. To achieve such tasks, FWMAVs must be designed with small volume and light weight (Karpelson et al. 2008; Yan et al. 2015; Anderson et al. 2011; Conn et al. 2006). The component most responsible for size and weight of FWMAVs is the actuation mechanism for flapping motion. Therefore, selection of an actuation scheme is one of the critical challenges in FWMAV design. Generally, there are two major categories for wing flapping actuators: rotary and linear (Anderson et al. 2011; Conn et al. 2006). The most popular rotary actuators used in FWMAVs are DC electric motors (Nguyen et al. 2014; De Croon et al. 2009; Conn et al. 2007; Khan et al. 2009). However, FWMAVs driven by DC electric motors always require gearboxes to reduce the motor speed to an appropriate level. Therefore, the additional gearboxes and smaller size limitation of the motor seriously hinder the potential for a reduction in scale for FWMAVs. To avoid size limitations of FWMAVs, linear actuators are thought to be a good choice due to their simple design and low weight (Anderson et al. 2011; Conn et al. 2006). The most popular linear actuators include electroactive polymers (EAP), shape memory alloy (SMA), solenoid, and piezoelectric elements (PZTs). However, an EAP actuator always requires large voltages (over 1000 V) and the power electronics for generating such a large voltage from a 5 V battery are large and heavy. SMAs and solenoids are limited by their low bandwidth and cannot operate fast enough to drive FWMAVs. Finally, PZTs are considered to be suitable for miniaturization of FWMAV Abstract In this paper, a novel flapping wing mechanism driven by a linear actuator is proposed. The linear actuator consists of a piezoelectric element and a permanent magnet. Based on the principle of impact drive mechanism, the linear actuator can move a reciprocating linear motion with a long travel range, which can be directly converted to a flapping motion via a crank-slider mechanism. In comparison with conventional flapping wing mechanisms driven by a rotary motor with a crank-rocker mechanism, no gearbox is needed in our design. Therefore, the proposed flapping wing mechanism can be made with small volume and light weight. A prototype was designed and constructed and experiments were carried out to test the performance of the flapping wing mechanism. The experimental results confirm that the designed flapping wing mechanism can obtain a continuous flapping motion by moving the linear actuator reciprocatingly.