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Autonomous Unmanned Surface Vehicle System for Bathymetric Measurements

Electrical Engineering

Senior Design Project Proposal

Flor Luna, Brian Gomez Jimenez, Evan Garcia

Sonoma State University Department of Engineering

Advisor: Dr. Nansong Wu

Industry Advisor: Jeff Church; Senior Environmentalist Specialist of Sonoma Waters

Date: December 8, 2023

Flor Luna

Brian Gomez Jimenez

Evan Garcia

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Overview

  • Problem Statement & Value Proposition
  • Existing & Proposed Solutions
  • Marketing & Engineering Requirements
  • System & Hardware Block Diagram
  • Software Flowchart
  • Alternate Design Matrices
  • Risks/Challenges
  • Test Plans
  • Estimated Budget
  • Gantt Chart
  • Supporting Courses
  • Questions/Comments

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The problem we are exploring addresses local researchers who want to obtain salinity, temperature and bathymetric measurements within the Russian River estuary. They are trying to collect depth, salinity and temperature to analyze river ecosystems. This leads them to feel exhausted and frustrated due to current equipment being expensive and having to collect data manually.

Problem Statement

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Our Unmanned Surface Vehicle (USV) helps local Russian River researchers who want to measure salinity, temperature and depth in estuaries by avoiding expensive equipment and manual work. Thus, enabling an autonomous and inexpensive solution to accurately collect data and visualize in wide-coverage areas.

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Value Proposition

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Existing Solutions

YSI Pro Solo

Manual Data Collection

Jenner Estuary Photograph

Multibeam Echosounders System

Pros

Cons

Real-time feedback

Hand-held

Accessible

Limited Area covered

Pros

Cons

Accurate

Stationary

Real-time

Expensive

Pros

Cons

Accurate

Limited Area covered

Personal Interaction

Requires group of people/ work station

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Proposed Solution

PATH PLAN ALGORITHM

SENSOR INTEGRATION

We propose an unmanned vehicle that is: autonomous, wide-coverage, hands-free, open-source, & cost-efficient

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Marketing Requirements

  1. The device shall accurately measure depth of the Russian River.
  2. The device shall measure Salinity in the Russian River.
  3. The device shall autonomously follow the user's programmed path plan.
  4. The device shall simultaneously collect sensor data with location coordinates.
  5. The device shall measure temperature in the Russian River.
  6. The device shall be water resistant.
  7. The device shall be able to run for a full programmed path plan.
  8. The depth data collected will be 3D plotted

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Engineering Requirements

  1. The device must record depth with no more than 5% error. (MR1)
  2. The device must measure +/- 5 ppt (parts per thousand) of the salinity reading. (MR2)
  3. GPS must have a minimum accuracy of 20 meters. (MR3)
  4. The path deviation from any programmed waypoint must be less than 20 meters. (MR3)
  5. The device must log salinity, temperature, time data and gps coordinates at least every 30 seconds. (MR4)
  6. The device should measure within +/- 3 Degrees (Celsius) of the temperature reading. (MR5)
  7. The device shall meet IPX5 standard. (MR6)
  8. The device must operate at a minimum of 30 minutes. (MR7)

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System Block Diagram

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Hardware Block Diagram

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System Flowchart I

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System Flowchart II

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Alternate Design Matrices

Weight

Ping 2 Sonar

URM-12

IRU-3430

Community Support

0.67

0.38

0.36

0.26

Accuracy

0.19

0.28 (+- 0.5%)

0.15 (+- 1%)

0.57 (+- 0.25%)

Power Consumption

0.14

0.4 (100mA)

0.1 (400mA)

0.5 (20mA)

score

0.36

0.29

0.35

SONAR SENSOR

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Alternate Design Matrices II

Weight

Mega Board

ESP32

ESP8266

Community Support

0.60

0.5

0.25

0.25

GPIO Ports

0.20

0.55 (70)

0.30 (39)

0.15 (17)

Cost

0.20

0.18 (20.99$)

0.36 (9.99$)

0.46 (7.99$)

score

0.45

0.28

0.27

MICROCONTROLLER

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Challenges & Risks

CHALLENGES:

  • Collecting accurate depth readings from Sonar sensor.
  • Ensuring path planned algorithm functions accurately.
  • Implementing functional communication between flight controller and MCU.

Risks

Qualitative Risk Score

Mitigation Plan

Contingency Plan

Costly Sonar sensor gets damaged.

Likelihood = 3 (Possible)

Consequence = 5 (Major)

Total=15 (Extreme)

We will carefully test our sensor and secure it to our boat.

We will buy another one and place safer precautions with new one.

River debris obstructs function of boat thrusters.

Likelihood = 3 (Possible)

Consequence = 4 (Major)

Total=12 (High)

Test in debri free areas of estuary.

Manually retrieve boat.

The river current overpowering the cruising speed of the boat.

Likelihood = 2 (Unlikely)

Consequence = 4 (Major)

Total= 8 (High)

Check weather and current conditions prior to boat deployment.

Emergency manual override.

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Test Plans

Objective

Pass/Fail Criteria

Measure the inaccuracy of sonar sensor. (ER1) (FT-1)

Sonar sensor will have no more than a 5% error. PASS

Calibrate salinity sensor to ensure accuracy of -/+ 5 ppt in data collection. (ER2) (FT-2)

Pass if accuracy of data collection is within -/+ 5 ppt of known values. PASS

Establish communication between flight controller and microcontroller.(MR4) (ST-1)

This test is a pass when data on flight controller user interface(QGroundControl) matches on MCU serial monitor. PASS

MCU should log sensor data and gps coordinates to SD card at least every 30 seconds (ER4)

The test will pass if it successfully logs: Date, time, longitude, and latitude,salinity, temperature and depth. IN PROGRESS

The path deviation from any programmed waypoint must be less than 20 meters. (MR3)

The test will pass if the USV comes within 20 meters of the programmed waypoints. INCOMPLETE

The device shall meet IPX5 standard. (MR6)

The test will pass if no water gets inside enclosure. PASS

The device should measure accuracy of at least +/- 3 Degrees (Celsius) of the temperature reading. (MR5)

The test will pass if the accuracy of the data collection is within -/+ 3 Degrees (C) of the known temp. values. PASS

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(FT-1) SONAR Sensor

Objective:

Measure the %error of sonar sensor in

pool at different depths.

Procedure:

Measure the known depth with tape ruler.

Connect sonar sensor to MCU Rx/Tx.

Upload code and open serial monitor.

Submerge sonar sensor into pool.

Read serial monitor only at 100% confidence.

Setup: Circuit Schematic

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(FT-1) SONAR Sensor Results

Pass/Fail Criteria: Sonar sensor will have no more of a 5% error.

Conclusion:

Highest %error value is 4.1%. Test has passed.(4.1<5)

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(FT-2) Salinity Sensor

Objective:

Achieve a Salinity sensor accuracy within -/+ 5 ppt using Vernier Salinity Sensor in a controlled environment.

Procedure:

  • Carefully make various salinity solutions from 0 - 35 (ppt) with distilled water and NaCl
  • Two-point calibration with LabQuest 2 (manufacturer's calibration equipment)
  • Test accuracy by connecting salinity sensor to MCU and reading the known salinity solutions

Set-up Circuit Schematic:

Calibration Equation: 14.2532 * VOLTAGE - 1.65312

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(FT-2) Salinity Sensor Results

Pass/Fail Criteria:

The readings shall be within +/- 5 ppt of known salinity solution.

Conclusion: Our Vernier Salinity Sensor had the most discrepancies when measuring a known solution of 35 ppt. The error was -/+ 3.567 ppt and ultimately still less than -/+ 5 ppt.

Figure 1: Graph of Measured Salinity Mean vs Calculated Salinity Value

Figure 2: Graph of Salinity Reading of 35 ppt

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(ST-1) Mavlink Communication

Setup:

Objective:

Communication between flight controller

and microcontroller to receive: current date,time,latitude and longitude coordinates.

Procedure:

Set up hardware shown on right side. →

Download QGroundControl station.

Set up UART serial communication baud rate 57600.

Request and receive date, time, latitude and longitude.

Pass/Fail Criteria: Test passes when received data is on serial monitor.

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(ST-1) Mavlink Results

Serial Monitor:

Qground Station:

Conclusion: Successfully received date, time, latitude and longitude.

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(FT-3) GPS Accuracy

Objective:

Test the Accuracy of our GPS Module and see if it is within 20 meters.

Procedure:

Power up Pixhawk and peripherals and connect it to Mission Planner. View displayed GPS values and compare to values from Google GPS through 10 data points around campus.

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(FT-3) GPS Results

Results: After conducting 10 tests, the largest discrepancy was 8.35 meters.

Test #

1

2

3

4

5

6

7

8

9

10

(m)

5.75

5.80

8.35

4.39

0.85

6.60

2.76

2.92

4.07

6.47

Conclusion: Pass, all measurements were less than 20 meters

1

2

8

7

6

5

4

3

9

10

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(FT-4) Waypoint Accuracy

Objective:

Test the accuracy of each programmed waypoint of our USV in route.

Procedure:

Power up USV and check if all preflight requirements are met(Battery, GPS, Radio, Telemetry). Deploy boat in predetermined location, and start path to waypoint . Measure the distance from the desired location of waypoint to the closest point the USV reached that location.

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(FT-4) Waypoint Results

Pass or Fail: If all measurements

come within 20 meters.

Results:

Waypoint test 1: 9.14 meters

Waypoint test 2: 3.04 meters

Waypoint test 3: 7.97 Meters

Conclusion: Incomplete only 3 measurements were measured.

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(FT-5) IPX5 Rating

FT-6: Check IPX5 Rating

  • Objective: Check to see if the enclosure of our USV has IPX5 protection (water-resistant)

  • Setup: Remove all components from USV and replace them with paper. Then close enclosure and hose it down from all sides for 3 minutes.

  • Pass/fail Criteria: If any of the paper is wet then the test has failed. If the paper is dry, the test has passed.

Enclosure being hosed down for 3 minutes with water

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(FT-5) IPX5 Rating Results

Results: After hosing the enclosure with water for 3 minutes, the paper inside it was dry.

Conclusions: The enclosure is able to protect the paper showcasing it is water-resistant and therefore IPX5 rated.

BEFORE: Paper inside enclosure test

AFTER: Paper inside enclosure test

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Estimated Budget

Component

Quantity

Price

Description

ping2 SONAR

1

$ 390.00

SONAR Sensor

Arduino Mega

1

$ 20.99

Microcontroller

Lipo Battery 5000mAh

2

$ 30.99

Additional Battery

Pixhawk 2.4.8

1

$ 189.99

Flight Controller

Vernier Salinity Sensor

1

$139.00

Salinity sensor

Vernier Temperature Sensor

1

$119.00

Temperature sensor

TOTAL: $ 889.97

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Gantt Chart

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Supporting Courses

EE282 - Engineering Modeling Lab

Utilize MATLAB Programming Language

EE470 - Internet of Things

Power Consumption & Serial Communications

EE345 - Probability & Statistics

Learning how to calculate probabilities & Stats of data points

EE310 - Microprocessors & Systems

C Programming & Embedded Systems

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Questions

Questions / Comments?

Check out our Website for more information!

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Appendix

Edge Step Pool Picture:

Stirring Hotplate

Analytical Balance

LabQuest 2

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Appendix

Temp Sensor Results

Figure 1: Mean of Measured Values vs. Known Values

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Appendix

3D plot of pool: