February 28, 2014
Team Palladian Design Concept: The RhinoHawk
1. Aircraft (fixed wing, rotary wing, blimp, etc.)
Out aircraft is a custom designed fixed wing with a delta wing planform. It has twin engines mounted to pylons on the leading edges of the wings. The pylons extend aft to created attach points for the elevons. This increased the distance aft between the elevons and the CG to increase pitch authority and stability. The pylons also have fixed rudders at the training edge.
2. Launch & Recovery Mode (hand-toss, bungie, net, etc.)
Our aircraft has the ability to take off and land vertically from a fixed point on the ground. This benefit reduces the space and time for launch while allowing us to have a larger vehicle to increase endurance, stability, and payload. This also opens up possibilities for autonomous landing and takeoff for perch and stare capabilities as well as automated charging for continued operation without human in-the-loop requirements.
3. Avionics (autopilot, servos, linkages, etc.)
The system uses Common Off The Shelf (COTS) stability, guidance, and control hardware to minimize cost and allow for an open architecture. The hardware is commonly available and can be updated easily as well as optimized for our specific airframe. The system has an additional flight sensor package which uses optical flow and ultrasonic distance measuring to enable GPS denied flight as well as constant ground level flight. This will make the system more robust to GPS loss as well as ensure that obstacles like elevation change, trees and mountains do not cause a collision.
4. Sensors (daytime video, nighttime video, magnetic, etc.)
We are exploring several sensor hardware configurations. Our current design uses an EO or IR camera to take high resolution video well as a high zoom camera to allow for detailed still images which can be further analyzed on the ground by the system operator or using image recognition software. We have opted not to have streaming video as the high framerate reduces the video quality and makes ground surveillance much more difficult.
5. Stabilization (platform, electronics, etc.)
The stabilization is controlled by the IMU which is part of the autopilot computer. The airframe has large wings and control surfaces to minimize the effects of wind gusts. The payload will be on a gimbal to allow for additional image stabilization as well as create the potential for scanning a larger area than a fixed camera.
6. Communications (cellular, satellite, radio, etc.)
Communications are sent through an XBee transmitter using a directional antenna to increase range and bandwidth. Our selected hardware is capable of a range of between 20 and 50 km depending on line of sight obstructions.
7. Embedded Systems (computers, graphical processors, operating system, applications, etc.)
We are currently working with Open CV software to develop an image recognition capability to identify moving objects as well as targets of interest. We will be using an integrated mapping software in the ground station to record the time and location of identified objects for further analysis.
8. Extra Features
We have designed the airframe to be modular and low cost. This will enable a damaged airframe to be easily replaced in the event of damage in little time and for low cost. We are currently evaluating the cost/benefit of a folding wing to allow for better transportability. The images processing software and human interaction requirements for this system are still under development. We intend to have as little human interaction with the system as possible in order to create a system that operates with minimal additional manpower requirements. We are also exploring the capability for data to be sent using cell phone service to allow for rangers in the field to have immediate access to the system information. Finally, we are exploring the concept of a docking station for the air vehicle which would allow for autonomous charging and re-launching using solar to enable refueling at remote locations to extend the range of the vehicle beyond the endurance limit from the home base.
Prototype design process:
We are currently testing the payloads and software on a commercial RC aircraft. We will build a full size RhinoHawk for final integration of the selected payloads and software.
Payload Options: Long-wavelength infrared (LWIR) imager with 9° horizontal FOV (HFOV) at 134 g (left); LWIR imager with 40° HFOV at 45 g (center); and continuous-zoom EO imager at 140 g with high definition and <2° HFOV in narrow (right).
http://www.fpvflying.com/products/FPV%252d10X-zoom-camera.html
http://www.foxtechfpv.com/fh10z-pal10x-optical-zoom-rc-controlled-camworld-smallest-p-166.html
http://www.flytron.com/camera-transmitter-shutter/218-fm-36x-mini-zoom-camera-with-infrared-sensitive-ccd.html
http://www.flytron.com/camera-transmitter-shutter/267-fm10x-micro-700tvl-zoom-camera.html
Image zoom capability: A large scanning camera and a high zoom camera allow for bot large area surveillance as well as detailed close-ups of identified targets.
Optical flow and ultrasonic sensor: This component is low cost yet adds a significant capability for sense and avoid of terrain as well as GPD denied navigation.
Open CV: This software can identify and track motion. This will be used to create a photo album of close-ups of identified targets. The targets will be GPS tagged and timestamped for further evaluation.
Computer capability will be split between autopilot and image processor. The flight controls will use an ardupilot due to the robust nature and rich user database. The image and software processing will be done on Udoo board. This board has high functionality and a broad range of open source software.
http://shop.udoo.org/usa/educational-bundles/edu-dual-usa.html