RiBBIT CDR River Bathymetry Based Integrated Technology Abdullah Almugairin, Paul Andler, Andy Benham, Daniel Crook, Mikaela Dobbin, Courtney Gilliam, Megan Jones, Jessica Knoblock, Phil Miceli, Sam Razumovskiy 1 Table of Contents 1. Project Purpose and Objectives 2. Design Solution 3. Critical Project Elements 4. Design Requirements Satisfied 5. Project Risks 6. Verification and Validation 7. Project Planning 2 Project Critical Design Design Project Project Purpos Project Requirements V&V Solution Risks Planning e Elements Satisfied Project Purpose and Objectives 3 Mission Motivation Problem Existing Solutions Market Gaps Rivers are a critical resource to monitor due to contributions to Earth Orbiting Satellites Data Resolution agriculture, urban development, hazard monitoring, and Boat tagline system with Safety environmental monitoring. acoustic instrument and velocity tracker Low-Cost There is a lack of updated and accurate global data for river Helicopters towing radar Ease of use discharge, especially in hard to systems access rivers. Quick set-up and data collection ASTRALite EDGE A hard to access river is one which presents a physical risk for humans to access on foot. Mission Statement “The long term goal of this project is to design, manufacture, and test a drone-mounted sensor system to gather river depth profile and velocity data in hard-to-access areas for the purpose of monitoring river discharge.” 5 CONOPS 5. The drone is safely landed and the captured data is off-loaded for post processing. 2.3.4. TheA float dronefloat is thenis is dragged flown deployed above across from the the riverthe water drone to gathertosurface the water stereo to profile surface camera the to entiredata capture of river the the crossriver river to calculatedepthsection profile (this the happenswaterusing avelocity. sonar in 2 passes). instrument. 1. Vehicle and equipment arrive at the field site, and the equipment is prepared for river survey. Project Critical Design Design Project Project Purpos Project Requirements V&V Solution Risks Planning e Elements Satisfied Design Solution 7 UAV Tarot 680 Pro 8 Science Instruments Zed 2 Stereo Camera Ping Sonar Echosounder 9 Deployment Mechanism *Bottom view - no load attached *Front view - load is attached 10 Sonar Float Design Total est. weight: 961 grams 11 FBD 12 Project Critical Design Design Project Project Purpos Project Requirements V&V Solution Risks Planning e Elements Satisfied Critical Project Elements 13 Critical Project Elements ● UAV ● Science Instruments ○ Depth Sensing Instrument ○ Velocity Instrument ● Sonar Deployment Mechanism ● Deployed Sonar Float Angular Displacement Technique ● Payload Housing and Drone Mount ● Command and Data Handling ● Data Post-Processing 14 Project Critical Design Design Project Project Purpos Project Requirements V&V Solution Risks Planning e Elements Satisfied Design Requirements and Their Satisfaction 15 Design Analyses Conducted ● Error Uncertainty Quantification ● Stereo Camera Image Capturing and Velocity Post-Processing ● Float Stability and Contribution to Sonar Uncertainty ● Deployment Mechanism Analysis ● UAV Stability Analysis ● Software Data Flow Analysis ● Positional Tracking Analysis ● Power Analysis ● Weight Budget 16 Data Flow Overview Sensors Data Output Post Processing/Software River Images PIVlab Stereo Camera Final Product Image Depth River RIVeR Point Cloud Discharge Corrected Ping Sonar River Depth Depth Profile Accelerations, IMU Angular Rates GNSS RTK Positional SLAM Receivers Data 17 Velocimetry Error Uncertainty Quantification DESIGN REQUIREMENT 7.1: The stereo camera data shall be post-processed to calculate river surface velocity. The surface velocity of the river is calculated using a Particle Image Velocimetry (PIV) tool developed in MATLAB. Using this software we can achieve a bias error of less than 0.005 pixels and and random error of less than 0.02 pixels.[1,2] Stereo Camera River Images PIVlab 18 Velocimetry Error Uncertainty Quantification To get these results, we must prove that our images fall under the optimal conditions as defined by the PIVlab analysis[1,2]: ● Particle Image Diameter (1-4 pixels) ● Particle Density (1-8%) ● Sensor Noise ● Particle Pair Loss ● Motion Blur 19 Velocimetry Error from PIVlab Camera Resolution: 1920 x 1080p Bias Error < 0.005 pixels* 30 Frames per Second Random Error < 0.02 pixels* 20 * assuming optimal conditions, additional information in backup slides Depth Profile Error Uncertainty Quantification The Ping Sonar outputs depth (m) and percent confidence in measurement. The IMU data will be correlated to the Sonar data in time series to correct the measured depth with angular displacement. The percent confidence will be used calculate a weighted average for the depth at each measurement station along the river bed. The final depth data will be georeferenced/localized via a SLAM (simultaneous localization and mapping) algorithm using IMU and GNSS data. Corrected Depth Ping Sonar River Depth Profile Accelerations, IMU Angular Rates RTK Positional 21 GNSS Receivers Data SLAM Depth Error Due to Angular Displacement DESIGN REQUIREMENT 4.1.3-.4: - SONAR shall measure depths to an accuracy of <1% total depth. - The angle between the SONAR and the gravity shall be measured. Given error in depth and angle, what level of disturbance can the float experience and remain <1% accurate? ● Monte Carlo Analysis ● Created by using a uniform distribution of errors that are added to test data whose results are then compared to a baseline value ● Shows that we can have a displacement of up to 24.6˚ but do to the random nature we will be setting our threshold to 20˚ 22 Float Requirements DESIGN REQUIREMENT 4.2: Minimize the angular displacement of sonar to <20˚. Bottom 2.5 cm of sonar is beneath waterline. Two prototype float designs 23 Boat Stability Overview Governed by Archimedes Principle, our analysis assumes: - Roll and pitch dominated by interaction of Center of Gravity (CG) and Center of Buoyancy (CB) - Heading dominated by interaction of CG and Center of Pressure (weather vane) Righting moment caused by roll CB is a function of submerged Sway moment caused by pitch shape Longitudinal view Takeaway: - Always want a corrective moment - Need CB below CG for roll stability - Want CB behind CG longitudinally so there is a moment 24 keeping tension on drone rope Float Design Inspiration Looked at designs for passenger ships as they prioritize smooth, level travel ● Most of displacement of trimaran is found in main hull ● Stabilizers do not provide much buoyancy and are nearly entirely for roll stabilization ● Bow influences drag and how quickly boat reacts to 25 vertical motion Float Hull Comparison Weight 269 g Weight 668 g Weight 446 g Waterline height 3.2 cm Waterline height 2.2 cm Waterline height 2.4 cm CG location from 12.6 cm CG Location from 26.6 cm CG Location from 17.3 cm leading edge leading edge leading edge CB location from 12.4 cm CB location from 29.2 cm CB location from 17.4 cm leading edge leading edge leading edge 26 Float Stability Analysis Technical performance measurements for float prototyping Structure Weight 640 g Waterline height 3.2 cm CG location from -14.2 cm leading edge CB location from -14.5 cm leading edge CG distance from 4.4 cm bottom of hull CB distance from 1.81 cm Calculated waterline where bottom of hull weight of displaced water = weight of float 27 Deployment Requirements Satisfaction DESIGN REQUIREMENT 4.6: There shall be a mechanism which lowers the float to the water surface. Technical Performance Our design: Feasible? Measure (TPM) Weight 0.64 kg yes Time to Deploy 10 s yes Deployment Power 2.34 W yes Consumption 28 Deployment Mechanism Analysis ● Main components: ○ Motor - 300 RPM ○ Pulley - 1 cm radius ○ Fishing line - 4.5kg holding strength ○ Servo - 10kg throwing capability ○ Swivel - Prevent tangling ● Total weight = 290 g 29 Deployment Mechanism Analysis 30 Deployment Mechanism Analysis ● Deploy the float to 3 m ● Deployment duration 10 s 31 Project Critical Design Design Project Project Purpos Project Requirements V&V Solution Risks Planning e Elements Satisfied Project Risks 32 Pre-Mitigation Risk Matrix Risks: Severity 1. Stereo Camera Data inadequate for measuring Negligible Minor Moderate Major Severe velocity Ext. High High 5 1,2 2. Sonar Collection Errors Likelihood Medium 3,4 Low 3. Environmental Hazards Extra Low 4. Float Deployment Mechanism Failure 5. Test Schedule Slips 33 Stereo Camera Data Inadequate for Velocity Calculations Consequences: Severity - River discharge Negligible Minor Moderate Major Severe calculations won’t be Ext. High computed High 1 Mitigation: Likelihood Medium - Test post-processing Low 1 capabilities Extra Low - Seed the river for easier tracking - Single object tracking 34 Sonar Data Collection Errors Consequences: Severity - River depth profile will Negligible Minor Moderate Major Severe be erroneous, Ext. High contributing to discharge error High 2 Likelihood Medium Mitigation: Low 2 - Stable boat design Extra Low - Data post-processing angular corrections and outlier filtering capabilities 35 Environmental Hazards Consequences: - Equipment damaged Severity or lost Negligible Minor Moderate Major Severe - Inaccurate data Ext. High Mitigation: High - Safe testing site Likelihood Medium 3 chosen Low 3 - Release mechanism to drop caught payload Extra Low - Professional drone pilot - Drone flown in line of sight 36 Float Deployment Mechanism Failure Consequences: - No sonar depth data Severity collected Negligible