1. Average Orientation Performance by Axis
Exploring maneuvering capabilities of the Robo Raven micro air vehicle Andrew Wood Mentored by John Gerdes
Introduction
The Robo Raven is a micro air vehicle (MAV) that is unique in its ability to mimic the behavior of a bird through the use of two independent flapping wings. In this early stage of development there is little analytical understanding of this form of flight. While flight physics can be measured and predicted through complex fluid dynamics calculations, controlled experimental analysis would be comparably easier and more cost effective (Torenbeek & Wittenberg, 2009). A telemetry unit was required to record in-flight data in place of these inefficient calculations so that flight performances could be more efficiently compared to each other. To test this new procedure, two different flight turn maneuvers were developed and compared. Each of these flight turn maneuvers were expected to perform differently. Experimental analysis of this concept helped determine the most efficient turning maneuvers. The purpose of this project was to develop a procedure by which the flapping wing MAV model could be tested through telemetric analysis of in-flight orientation.
Results
Results (cont’d)
Based on the paired t-test model, the differences between the performances in the yaw, pitch, and roll planes of rotation (Graphs 1, 2, and 3) yielded p-values less than In the three planes of rotation (Figure 2), there is statistically significant evidence that the average performances between the two turn maneuvers are not the same, thus rejecting the null hypothesis that the average performances should be the same.
Average Orientation Performance by Axis
Angle (Degrees)
Conclusion
This project’s purpose was to explore the mechanics and capabilities of a flapping wing MAV through the use of orientation telemetry in order to develop a procedure by which future MAVs and flight maneuvers can be compared. The results show a clear difference in flight performance between the two turn maneuvers, as well as provide insight on the orientation behavior of the MAV in-flight. While the low p-value from all the tests provides ample confidence in these results, there were still some experimental constraints. Predicted areas of design failure include flight testing in an unideal environment and component inconsistency. In an effort to prevent external forces from acting on the MAV, all flight tests took place indoors. This limited airspace required all flight maneuver testing to be confined to two seconds per turn with no possibility of post maneuver recovery analysis. In addition, many parts were damaged throughout testing but were not replaced due to time restraints. The Robo Raven has been in development for years, and until recently, work has only been done to make it attain flight. Now, projects like this are the next step in understanding and expanding upon flapping wing flight. This project will enhance the future of MAVs by providing the first attempt at experimentally measuring the in-flight performance of flapping wing flight, and will be the basis of future MAV flight maneuvers and prototypes.
Seconds
Angle (Degrees)
Materials and Methods
The Robo Raven MAV is a carbon fiber framed, radio controlled pilotless aircraft. It is controlled by a single Arduino Nano microcontroller that is directed from the ground via radio control (Figure 1). The Arduino performs each turn maneuver as a pre-programmed macro. The macros function by taking control of the MAV from the pilot and following the predetermined turn maneuver. Two different two second pre-programmed macros called Aileron and No Wing were compared. An inertial measurement unit (IMU) was mounted on the tail of the frame. The IMU continuously collected orientation data, which was stored by a Micro SD card logger via serial communication. Time intervals were provided by the Arduino in the form of data discontinuities in the data stream. These discontinuities were delivered as carriage returns interjected directly into the serial data stream. Data was post processed using Microsoft Excel®.
Seconds
Angle (Degrees)
Seconds
Graphs 1-3 (above): Average yaw, pitch, and roll of the MAV for each turn maneuver. Averages attained across eleven separate tests for each turn maneuver.
References
Langley Flight School (2015). Attitudes and Movements. Retrieved from
Torenbeek, E., & Wittenberg, H. (2009). Flight Physics: Essentials of Aeronautical Disciplines and Technology, with Historical Notes: 6.9 Horizontal Steady Turn. Springer Science & Business Media
Figure 1 (right): Shown is the Robo Raven MAV. The IMU is mounted at the rear, just under the tail. The SD card logger and the Arduino are mounted in the central frame. The two turn maneuvers that were tested utilized both the wings and the tail, and the tail alone. These maneuvers were labeled aileron and no wing, respectively.
SD card logger
Aileron Maneuver
No Wing Maneuver
Arduino Nano
Yaw axis
Pitch axis
Roll axis
IMU
Figure 2 (left): The three axes of orientation are similar for all aircraft (Langley Flying School, 2015).
Wingspan: 55 in.