Eclipse Ballooning Project

Transcription

1 Senior Design II, Slide 1 Eclipse Ballooning Project The Parliament Team: Abigail Sydnes, Dmitriy Yarmaliuk, Edward MacMurchy & Michael Mazzanti Faculty Advisor: Dr. John J. Helferty

2 Senior Design II, Slide 2 Introduction

3 Introduction Senior Design II, Slide 3

4 Senior Design II, Slide 4 Introduction Iridium Modem communicates with ground laptop via Internet and satellite communication. Video payload and ground station communicate using Ubiquiti Rocket M5 Modems. OCCAMS Cut Down payload receives commands from Iridium Modem.

5 Senior Design II, Slide 5 Introduction - Proposed Deliverables Reliable means of video capture Sensor and Tracking data from full launch 360 Video Capture Capability Extensive testing to guarantee project success

6 Senior Design II, Slide 6 Problem Statement

7 Senior Design II, Slide 7 Problem Statement Launch Date: August 21, 2017 Trigg County High School, Cadiz, Kentucky Test Launch: April 11, 2017 Purpose Roundtop Mountain Resort Lewisberry, PA Stream stable, targeted video of solar eclipse to the NASA Stream website for entirety of event 360 Video Camera recording entire flight Coordinate nationally with other schools to make recording of historic eclipse

8 Senior Design II, Slide 8 Design Constraints

9 Senior Design II, Slide 9 Design Constraints Maximum weight of HAB (including 2000 gram balloon) of 12lbs. Environmental temperatures as low as -55 C. Robust payload design able to pass through jetstream unscathed. Launch location avoiding any inclement weather. Additionally, avoidance of any airports or similar restricted airspace.

10 Senior Design II, Slide 10 Safety and FAA Regulations Weight Requirements 12 lbs maximum system weight, including balloon 6 lbs maximum payload item weight 2 methods of flight termination Notify FAA between 24 h and 30 m of launch

11 Senior Design II, Slide 11 Evolution of Design

12 Evolution of Design - Montana State University Workshop Senior Design II, Slide 12

13 Senior Design II, Slide 13 Evolution of Design - Inclusion of 360 Camera On top of having a streamed tracking video, a 360 video would provide a full environment view upon recovery of the HAB. Mounting options and low weight (7 oz) of 360 camera allow for easy inclusion in any payload design. In the event of complications with video payload streaming or tracking, eclipse is guaranteed to be captured.

14 Senior Design II, Slide 14 Evolution of Design - Removal of Still Image Payload Weight of payload prevented additional devices from being added without surpassing 12lbs. Live video feed along with still images would be redundant. Quality of streamed video is slightly lower in resolution. Video payload stores camera feed on-board and uninterrupted video may be obtained after recovery. 360 video camera Nikon KeyMission 360 provides high quality, full environment view. KeyMission does not allow for streaming.

15 Senior Design II, Slide 15 Proposed Solution

16 Senior Design II, Slide 16 Proposed Solution Software Design - Autonomous System Raspberry Pi utilized for image processing and manual control of camera positioning. Pi camera used for the purpose of capturing video footage. Made use of the OpenCV library that is aimed at real-time computer vision. Allowed for analyzing the captured video frame by frame. Made use of the WiringPi Python library. Utilized to manage and alter the PWM clock frequency of the Raspberry Pi.

17 Senior Design II, Slide 17 Proposed Solution Software Design - Autonomous System Each frame is converted to monochrome and then blurred. The magnitudes of the darkest and brightest pixels within the frame are identified. A light intensity value is determined for each frame using binary thresholding. A Python dictionary is used to store light intensity/brightness values and their corresponding positions.

18 Senior Design II, Slide 18 Proposed Solution Software Design - Autonomous System A thresholded image is generated using the blurred image and the previously outlined brightest pixel value. The Canny edge detection algorithm is applied to the thresholded image. Light contours identified Each contour is a NumPy array of (x,y) coordinates associated with the boundary points of the object. Contours sorted based on the radius of a minimum enclosing circle around the identified brightest object. The position of the brightest object is outlined in terms of pixels.

19 Senior Design II, Slide 19 Proposed Solution Software Design - Autonomous System Each video frame is set up to be 400 by 300 pixels. Pixel deviation of the brightest object from the center of the frame in terms of the x axis is converted to a degree value. Horizontal field of view associated with the Raspberry Pi camera is The deviation value in degrees is then converted to a step count. Stepper motor makes 513 steps per revolution.

20 Senior Design II, Slide 20 Proposed Solution Software Design - Autonomous System Pixel deviation of the brightest object from the center of the frame in terms of the y axis is converted to a degree value. Vertical field of view associated with the Raspberry Pi camera is The deviation value in degrees is then converted to a PWM signal required to move the servo motor to the required position. Servo motor has 180 degrees of motion.

21 Senior Design II, Slide 21 Proposed Solution Software Design - Manual System (Stepper motor control) Each stroke of the left or right arrow key is mapped to 25 steps of the stepper motor. Current position of stepper is updated and stored with every change in position. If the next required position of the motor exceeds 180 degrees the stepper spins back on itself moving to the required position from the opposite side. Prevents damage of cables during flight.

22 Senior Design II, Slide 22 Proposed Solution Software Design - Manual System (Servo motor control) Each stroke of the up or down arrow key is mapped to 10 degrees of movement for the servo motor. Current position of servo is updated and stored with every change in position. Subdivided the Raspberry Pi PWM clock which has a base frequency of 19.2 MHz. Provided a stable means of setting up pulse width modulation at 50 Hz.

23 Senior Design II, Slide 23 Proposed Solution Hardware Design Coil A1 = Pin 31 Coil A2 = Pin 33 Coil B1 = Pin 35 Coil B2 = Pin 37 Driver board is attached vio GPIO pins

24 Senior Design II, Slide 24 Proposed Solution Hardware Design Clockwise Step # Winding A Winding B Winding C Winding D Counter- Clockwise Coil activated in series 513 steps/rev Activation of coils determines the direction

25 Senior Design II, Slide 25 Proposed Solution Hardware Design GPIO pin 18 is used for the purpose of generating the pulse width modulation necessary to control the positioning of the servo motor.

26 Senior Design II, Slide 26 Proposed Solution Hardware Design PWM signals with pulse widths of 0.53 ms and 2.13 ms at a frequency of 50Hz are used to drive the servo motor to the extreme left and right positions respectively. PWM signal with a pulse width of 1.33 ms at a frequency of 50Hz is used to drive the servo motor to the center position. A ms change in the pulse width of the PWM signal corresponds to 1 degree of servo movement.

27 Senior Design II, Slide 27 Proposed Solution Mechanical Targeting and Stabilization System 2 DOF system to aim camera Mitigate and minimize external rotational forces Cylindrical package design Drag damping moment arms Multiple support lines limit twist Decouple video payload from balloon Load-rated ball-bearing swivel Eliminate internal rotational effects Eliminate induced torque of main scanning motor using counterweight

28 Senior Design II, Slide 28 Proposed Solution Mechanical Stabilization System Coaxial contra-rotation Gearbox uses motor input to simultaneously rotate camera and counterweight in opposite directions Design counteracts induced torque and maintains payload balance due to its physical symmetry.

29 Senior Design II, Slide 29 Proposed Solution Video Payload Design Layered Payload.75 polystyrene insulation protects payload components Acrylic plates provide hardpoints for component installation and rigging Extensive use of nylon hardware keeps weight low Cast acrylic dome allows for clear view of sky Total video payload weight: 5.06 lb

30 Senior Design II, Slide 30 Balloon Fill Requirements Determine ballast weight required for 5 m/s ascent rate W payload + W balloon = W net (14.41 lb) W gross = 1.28 x W net (18.44 lb) W neck = W gross - W balloon (14.03 lb) W ballast = W gross - W fill valve = (13.5 lb) Set ballast weight using fish scale, then attach ballast to balloon until the balloon just lifts the ballast Cleared for liftoff!

31 Senior Design II, Slide 31 Parachute Sizing 1500 ft/min maximum allowable descent rate 1.5 NASA safety factor for unmanned descent Drag coefficient is 1.75 for dome-shaped chute At terminal velocity, drag force equals gravitational force

32 Flight String Schematic Senior Design II, Slide 32

33 Senior Design II, Slide 33 Testing Methods and Results

34 Testing Methods and Results - Autonomous Tracking System Senior Design II, Slide 34

35 Senior Design II, Slide 35

36 Senior Design II, Slide 36

37 Testing Methods and Results - Test Launch Senior Design II, Slide 37

38 Senior Design II, Slide 38 Testing Methods and Results - Test Launch Continued Flight Path Prediction Test Launch Flight Path

39 Testing Methods and Results - Test Launch Continued Senior Design II, Slide 39

40 Senior Design II, Slide 40 Testing Methods and Results - Improvements for the future Damage Report Top acrylic plate Three foam rings 3D-printed camera mount Assessment All damaged items resulted from payload recovery. Approximately 15 foot free fall from tree to ground. Solution Just have someone catch the thing.

41 Senior Design II, Slide 41 Testing Methods and Results - Improvements for the future Release of objects in flight string can be done smoother to dampen pendular motion during ascent. Had connection issues with the video payload. Were able to connect to the payload from the Ground Station laptop over SSH once the Ubiquiti modem on the Ground Station had four bars. Likely due to issues with the Ground Station using the Iridium system to automatically point the dish towards the location of the balloon.

42 Senior Design II, Slide 42 Testing Methods and Results - Improvements for the future The video of the flight onboard the Raspberry Pi got interrupted when the balloon popped. Once the successful test of the manual control of the Pi camera was completed the camera was left pointing up at the balloon. In the video it is possible to see the balloon expanding. Thus, once the balloon popped it must of hit the video payload thereby bringing the video capturing to an end.

43 Senior Design II, Slide 43 Testing Methods and Results - Improvements for the future Cutdown System failed to trigger cutdown event with remote packet. Timer was set and activated when desired, however the blade became stuck on the plastic casing due to a slight offset when the blade was screwed to the DC motor Balloon ascended until burst around ft

44 Senior Design II, Slide 44 Future Usage Eclipse in April 8, 2024 Documentation and implementation for future Temple ballooning teams Construction of ground station for senior design team starting in Fall 2017 Possible addition of higher quality camera

45 Senior Design II, Slide 45 Deliverables Reliable means of video capture Sensor and Tracking data from full launch 360 Video Capture Capability Extensive testing to guarantee project success Minimum video capture of 20 mins Ability to manually and autonomously track eclipse/sun Full GPS tracking data, reported at 30 second intervals. 360 Video Capture Capability Extensive testing to guarantee project success 30+ mins of test data collected

46 Senior Design II, Slide 46 Thanks for Listening!