Micro Air Vehicle Design

Designing the Wing System of a Micro Air Vehicle – spring 2009

The goal for the project was to design and create an ornithopter MAV that is capable of remotely-controlled flying and maneuverability. There were several aspects of this MAV design. They were consisting of Lever system, wing system, and materials selection. Aluminum was used as veins and pet film was used as the membrane for the wings. Piezoelectric actuator system was considered in order to achieve high frequency like dragonfly. Although weight is a concern for the MAV, the weights of these pieces are very small due to small volumes and to the low density of aluminum.

 

MAV Design team – Winter 2010

The goal was to produce an assembly with a dragonfly’s range of motion as much as mechanically possible. Care must be taken when increasing the range no to cause mechanical binding in the crank arm assembly or induce interference between the left and right sides. Other methods such as making the wings lighter and shorter are being considered to reduce the inertia causing mechanical malfunction in the drive system. Gear modeling was an initial challenge. Originally the gears had too many teeth and did not provide the desired frequency. Some equations used to theoretically calculate torque and angular velocity are seen below. GearTeq software has significantly helped in this process and the gear design improved.

 

Actuator Design Team Winter-Spring 2010

Dragonfly has unique flight capabilities. Also it has many degrees of freedom during his wing motion. It’s hard to incorporate many degrees freedom in to a micro size mechanical system to mimic real dragonfly motion. In this senior design project main focus of the actuator design team was to make a mechanical quad wing flapping device which can independently control the phase difference between front and back pairs of wings. Right and left arms of each pairs of wings kept fixed. The actuator shown in the movie weighs 4.7g.

 

Control System Design Team Winter-Spring 2010

The first goal of the control system design team was to develop a new method of bio-inspired flight control for a micro air vehicle.  Several ideas were considered to achieve this including a center of gravity change and new tail designs.  The team focused on creating the most effective tail modification of a commercially available micro air vehicle toy.  Several tail designs were created and actuated by a micro servo.  The most effective tail was a flexible carbon fiber tissue tail resembling that of a flying fish.  It greatly increased the stability of the toy by eliminating phugoid flight modes and also decreased the turning radius of the vehicle.  The second goal of the control team was to control the frequency of the two motors of the actuator design created by the actuator team.  This was achieved by using a receiver from a coaxial radio controlled helicopter.  The coaxial helicopter has two independently controlled rotors that eliminate the need for a tail rotor to keep the helicopter stable.  This receiver controls the two motors of the actuator to achieve the frequency difference between the two pairs of wings.  Linear actuators on the receiver were used to flex a small version of the carbon fiber tissue tail developed previously.

 

Wing  Design Team Winter-Spring 2010

The characteristics of a dragonfly’s wing differ from other insects in nature.  The dragonfly will create a camber during the upstroke and downstroke as well as flap its wings in a figure eight motion.  This creates a great design challenge when trying to create a mechanical wing that emulates the dragonfly.  Using a combition of hardener, resin, and carbon fiber tow vein like structures can be created and pet film is used for the rest of the wing.  These materials created the flexibility needed to emulate the wing, and the vein structure can be altered to change the camber in the wing.  The programs ANSYS, SolidWorks, and MAYA were used to determine properties of the wing design and determine what changes are needed.  Four wings are attached to an actuator in the video shown.

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