hydrobotics industries - MATE Competition... · hydrobotics industries Specifications Safety...

Z3 hydrobotics industries

Specifications

Safety Features

Special Features

San Miguel Family

Daniel Gonzalez CEO

Harrison Mast CFO

Miguel Rosales Programming

Chris Delagarza R&D

Meagan Hernandez Creative Solutions

Primary Construction Materials: PVC, Lexan, Marine Sealant Approximate dimensions: 21.5x17x12 Total Weight: 16lbs. Total Cost: $713

25 amp fuse Waterproofed all components Protective Frame

1000 GPH Motors Adjustable buoyancy system Multiple Voltage Regulators

First Time Participants 2014

Houston, TX to Alpena, Michigan:

2,455 KM

Z3 Technical Report Hydrobotics Industries 2

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Z3 hydrobotics industries

Table of Contents

Cover Page .................................................................................................................................................... 1

Abstract ......................................................................................................................................................... 4

Design Rationale ........................................................................................................................................... 4

Focus ......................................................................................................................................................... 4

Mechanical Design Process ....................................................................................................................... 4

Software .................................................................................................................................................... 5

Vehicle Systems ........................................................................................................................................ 6

Frame ........................................................................................................................................................ 6

Pictures of the Z3 ROV .................................................................................................................................. 7

Thrusters ................................................................................................................................................... 8

Buoyancy ................................................................................................................................................... 8

Housing ..................................................................................................................................................... 8

Electronics ................................................................................................................................................. 9

Safety .......................................................................................................................................................... 12

Company Safety Philosophy.................................................................................................................... 12

Training ................................................................................................................................................... 12

ROV Safety Features ............................................................................................................................... 12

Safety Checklist ....................................................................................................................................... 13

Pre-Power ........................................................................................................................................... 13

During Power ...................................................................................................................................... 13

Post Power .......................................................................................................................................... 13

Budget ......................................................................................................................................................... 14

Challenges ................................................................................................................................................... 14

Troubleshooting Techniques ...................................................................................................................... 15

Lessons Learned and Skills Gained .............................................................................................................. 15


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Future Improvements ................................................................................................................................. 16

Reflections .................................................................................................................................................. 16

Teamwork ................................................................................................................................................... 16

References .................................................................................................................................................. 17

Acknowledgments ....................................................................................................................................... 17

Sponsors ...................................................................................................................................................... 18


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Abstract

SJC Aquanauts is a brilliant team of skilled engineering students from various backgrounds

with diverse skill sets. Our goal was to build an adroit and robust Remote Operated Vehicle

(ROV) for the economical consumer. During our first year alone, we have built many

prototypes to ensure we are providing a quality product for our clients. To create our latest

model, we brainstormed form and function, researched materials, sought parts, and,

through trial and error, created the Z3.

The ROV, Z3, was entirely designed and tested to perform exceptionally on underwater

tasks. Through long mornings that turned into late nights, our team worked cohesively,

devised creative solutions for any shortcomings in design, consistently sustained high

morale, supported and discussed any suggestions related to the ROV and exhausted all

available informational resources. Our frame is constructed from PVC with a waterproof

housing that has viewing panes on either side to gauge water-tightness, four bilge pump

motors, RC boat propellers, multiple voltage regulators and a control box consisting of an

Arduino, two axis joysticks, Sabertooth motor drivers, and a healthy length of deliberate

wiring. We have achieved neutral buoyancy through the utilization of closed cell

polyethylene foam and waterproof weights.

Design Rationale

Focus

The Z3 was designed to excel in Marine Archaeology tasks that humans are unable to

complete such as water conductivity testing at ground level, navigate through confined

spaces, and recover objects that have been displaced due to wreckage or cast off as

debris. We strove to exceed NOAA standards in safety, reliability, ease of use, and support

of coastal communities.

Mechanical Design Process

At the onset of our project, we initially designed a rectangular frame with a 3” Wye PVC

Fitting (shown in the housing section below) as the waterproof housing with see through

lenses for the Raspberry Pi Cameras. Initial sealing techniques included PVC Cement and


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a light coating of sealant on the lenses. Early testing of this model resulted in water-logging

through inefficient sealing techniques. We were able to salvage parts through unscrewing

the endcaps.

After our initial design failed we brainstormed using new ideas and researched proper

sealing techniques. We completely redesigned the housing and added Lexan viewing panes

to both ends as a quick way to gauge water-tightness. We then sealed the chamber so

water couldn’t permeate its crustaceanesque exterior. Proper sealing and materials were

key in order to not have to open the chamber and reseal again. As a precaution, the Z3 has

a way to open the chamber in case of any mechanical failures through the gasket system

utilized.

Software

Software is broken down into the following categories:

Streaming Software Setup

Water Sensor Programming

Control System Programming

The streaming software runs entirely on the Raspberry Pi that also captures images from

the attached Raspberry Pi camera. The Raspberry Pi runs the stock Raspian operating

system and is controlled remotely through the use of the SSH protocol. In addition to the

basic essentials provided by Raspian, Motion JPEG (MJPEG) is installed and used to take

image feedback from the camera and stream it over a network via web browser or any

stream viewing application. The MJPEG software runs through the java runtime

environment which allows the stream to be accessed through any platform. This use of the

raspberry pi allows for use of a dynamic number of monitors for viewing.

The programming for the water sensor is implemented via Arduino. The source code was

developed in the Arduino programming environment and written in the Processing

programming language. The Arduino is programmed to read the sensor data from the water

sensor as an analog value. This analog value is then used to calculate the conductivity of

the water. This piece of information is then relayed through serial communication back to a


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computer on the surface through a modified USB cable. The information is then displayed

on a monitor.

The control system is another Arduino based solution. The source code was developed in

the Arduino IDE and is written in the Processing programming language. The control

system is based around two 2-axis analog joysticks. The joysticks control the direction and

speed of the Z3 while it is powered in the water. By using the analog value from the

Sabertooth motor shields, the position of the joysticks causes the appropriate motors to run

at various speeds due to pulse-width modulation. In addition to motors, the onboard

manipulator is also being controlled the same system via input from a potentiometer. The

analog signal from the potentiometer is translated into a goal position for the motor that

releases and contracts the manipulator.

Vehicle Systems

The initial concept and the final design of the Z3 had a multitude of key differences such as

the housing materials, configuration of the motors and the sealing techniques implemented.

Through long days and frequent shopping trips, we were able to culminate and construct

our final design. Each team member worked diligently on their respective pieces of the ROV

as well as helped each other when initial designs fell through.

Frame

The Z3 is composed of plumbing grade polyvinyl chloride pipe. The PVC is arranged in a

rectangle-like structure. The main purpose behind the shape of the frame is to allow for

ease of access to components while leaving ample room for the attachment of weights and

closed cell polyethylene foam for buoyancy. The floor of the frame is composed of high

density polystyrene for the payload netting. This allows for a lightweight base to attach

components while leaving plenty of overhead for buoyancy adjustments.


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Pictures of the Z3 ROV

Right view of ROV

Top view of ROV

Left view of ROV

Back view of ROV


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Thrusters

The Z3 is equipped with four 1000 GPH thrusters. Two horizontally mounted on the rear

end of the ROV and two located vertically at the center for maximum propulsion. Each

thruster is securely fastened down to the frame within the perimeter for supreme safety.

With an operating voltage of 13.6 VDC and current draw of 3.6A, two thrusters can run at a

time within the power budget.

Buoyancy

When designing the frame, our water tests concluded the frame alone has neutral

buoyancy. When the latest waterproof housing was added, the neutral buoyancy was

disrupted. With no weights or flotation devices added in, the Z3 had a tendency for the front

to float up while the back tried to sink. To counteract this, we added closed cell polyethylene

foam on the rear of the vehicle with weights added to even the payload of the ROV. This

brought the Z3 back to neutral buoyancy.

Housing

The first idea used was nicknamed the aorta, due to its Y shaped PVC piece (a large 3”

Wye tee PVC pipe fitting) that resembled an artery. Inside the housing was a Raspberry Pi

and a camera which was mounted behind 2 layers of Lexan polycarbonate resin that acted

as our visibility panes. Various issues were raised in initial testing with this design such as

being too large for the components it housed, heavy, and lack of waterproofing. We

redesigned the housing completely and went with a shorter, lighter and wider piece of PVC

pipe with Lexan panels affixed on both sides after being sanded and primed. The new

housing is now 8.5 inches long, much shorter than its predecessor at 18 inches: securing

the same components more efficiently. The only difference in the two viewing panes is that

one circle is cut a centimeter from the bottom so that we may route all the cables through

the chamber while also being able to seal it in one central location. The new chamber is


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housed at the front center of the ROV with the camera facing forward so that there are no

obstructions in view.

Wye Tee PVC Fitting

Electronics

All electronic components are included within the PVC chamber. These components are:

One Raspberry Pi with camera, voltage regulator (12v down to 5v), as well as the beginning

of our tether. The camera receives power through the Raspberry Pi which in turn

is powered by USB that runs through the voltage regulator.

The Z3 is equipped with the following electronic features:

Live stream visual feed

Independent water conductivity sensor

Two axis joysticks for easier maneuverability

The streaming system onboard the Z3 is comprised of a B model Raspberry Pi and

Raspberry Pi Camera. To keep the design simple and to save space within the chamber, a

waterproof DC-DC 12 volts to 5 volts regulator was implemented. This system makes use of

the Raspberry Pi as a computer by using it as a streaming server in addition to its function


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as a camera. This allows for use of unlimited wireless displays without an increase in the

number wires on the ROV’s tether.

The water conductivity sensor is a simple Arduino sensor manufactured by KEYES. The

sensor functions by allowing water to complete a circuit by filling in grooves on the surface

of the sensor. The voltage from the circuit then gets measured by a potentiometer and is

returned as an analog signal voltage value ranging up to 5 volts. This voltage reading can

then be analyzed through an Arduino to compute the conductivity of the water across

various spectrums and in areas where conditions change in time. With this data, it is

possible to create a voltage gradient based on the conductivity of the water as the ROV

navigates through an ocean space. This process would be advantageous for diagnostic

testing.

The motor control system is entirely Arduino based. The Arduino platform allows for

modularity in the system such that parts can be integrated or removed entirely easily with

no impact on the function of the system as a whole. Two 2-axis analog joysticks are

implemented for user input and are connected directly to the Arduino making the Z3 user-

friendly and easy to maneuver. The motors are controlled through two Sabertooth 2x5

motor drivers. The Sabertooth motor drivers are capable delivering up to 5 amperes of

power to each of the 4 motors. The use of the entire control system as a whole allows for

the implementation of pulse-width modulation (PWM). PWM allows for variation on motor

speeds as opposed to a hard wired binary control system where the motors either run at full

speed or are off, and is very crucial for precise movement underwater.


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SID


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Safety

Company Safety Philosophy

The Z3 was designed and built with safety as a priority to protect the ROV and the team

members operating the vehicle. We followed strict protocols and guidelines during the

testing, design, and construction processes. Many safety features were implemented on the

Z3 such as built in handles, propeller guards, and the removal or covering of all sharp

objects on board. We made sure all wires were connected correctly before allowing power

through to the ROV and that all members were out of the water during all testing. With all

the safety features covered, consumers are free to focus on the diagnostic and

maneuvering capabilities of the Z3.

Training

Being that this is our first year as a company, we were faced with many new challenges and

obstacles. Each member of the company underwent rigorous amounts of time reading and

researching specifications on various parts in our initial design. This led to many hours of

constant communication and problem solving as we moved forward through our

development. We found working together through our journey was the most rewarding as it

made good ideas, great ideas! This not only prepares us for future upgrades on the ROV

but is a great experience for future team members who can easily apply these skills to

designing and troubleshooting any ROV.

ROV Safety Features

The Z3 utilizes many key safety features that not only protect the hardware on board but

protects the team handling the ROV as well. There are four handles all around for easy and

efficient transportation. This enables strength and durability for maximum safety for the

team and ROV. To ensure a fully waterproofed housing, we pressure tested the chamber

holding the electronics at a depth of thirteen feet.


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Safety Checklist

Pre-Power

Here at Hydrobotics, safety is vitally important. There are a few key steps to take before

operating the Z3.

1. All personnel who are controlling and positioning the ROV should be well familiarized with

the equipment at hand.

2. Fuse should be securely fastened and connections from the tether to the power supply

are secure.

3. In order to conduct the ROV, 48 volts must be sent down the tether for maximum

operating power. How you wish to fulfill this requirement is up to you. A power inverter that

produces 48v and 20-40 amps would be ideal in this case.

5. Before connecting power, the working space should be clear of any safety hazards

(scattered objects, tools and electronics turned off when not in use). ALL POWER to the

ROV and power source should be in the OFF position during this connection process.

6. Once power is provided, the tether to the ROV should be unwound for full maneuvering

capabilities.

During Power

1. In the midst of maneuvering the Z3, be sure to keep a safe distance (3-5ft) from the edge

of the pool or deck you're navigating from.

2. It is strongly recommended that a secondary person is on hand to assist you with the

leveraging of the tether for maximum direction.

Post Power

1. To shut down the ROV, safely unplug the power cord from the outlet providing the power.

2. Allow five to ten seconds before removing tether from the power source.

3. Wind up the tether with the included cable organizer and place within the frame for easy

transport.


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Budget

Hydrobotics Industries had a starting budget of $400.00 that was provided by the

Aerospace Academy. As the team developed the design of the Z3, a preliminary budget

was created for required materials. The cost of the Z3 was estimated to be more than what

was initially funded by the Aerospace Academy, so the team worked together to create a

donation solicitation package and video. The team members were able to fundraise an

additional $160.11 in donated components and $35 in services to help cover costs as well

as come out of pocket for any components the allotment did not cover. Our spending

worked out as follows:

Category Company Expenditure Donated Total

Frame and Buoyancy $42.87 $0.00 $42.87

Propulsion $185.39 $19.23 $204.62

Cameras & Sensors $48.55 $3.95 $52.50

Various Boards $102.65 $111.98 $214.63

Various Electronics and Wiring $138.29 $24.95 $163.24

Services Performed $0.00 $35.00 $35.00

Challenges

The initial design of the ROV utilized plane propellers on the thrusters due to the inability to

locate any boat propellers that would fit on the thruster props. We realized in early testing

stages that the airplane propellers spun too fast causing a negative effect on the propulsion

abilities (similar to spinning tires in the sand). This was remedied by replacing the airplane

propellers and adapters with RC boat propellers and master airscrew adapters we

located with extensive research and helpful insight from several experts. The team was

Donated Total: $195.11

Expenditure Total: $517.75

Grand Total: $712.86


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also financially set back since our budget was not large enough and our fundraising

attempts fell short of our goal. At that point, we decided to purchase necessary parts out of

pocket since we didn't have any other means of acquiring these parts.

Troubleshooting Techniques

There were several issues that the team ran into while trying to perfect the Z3. Our initial

design was not water tight, so our initial water test with our first ROV design ended up

failing due to water seeping in the chamber. Once we replaced our aorta chamber with the

new housing, we began secondary water testing of the completed assembly including

motors, frame and the new housing. Our second issue was that the ROV would not move

underwater due to the use of propellers designed for RC aviation instead of RC marine.

Buoyancy was also an issue at the time of the propeller replacement, so we added weights

and closed cell polyethylene foam before putting the ROV back in the water for final testing.

Lessons Learned and Skills Gained

This competition has opened our eyes to a new world of ideas as well as taught us a few

new skills. During the process of building the ROV we have had to:

Use PVC pipe, which taught us how to cut using a PVC cutter.

Make a controller, which taught us how to fabricate materials as well as solder wires

together, utilize heat shrink, use a drill, arrange wires on a breadboard, and calculate

resistance and current using Ohm’s law

Create the housing, which taught us how to properly water seal a container using

marine seal.

The mistakes we’ve made throughout this learning process has further strengthened our

skills and changed the way we will conduct testing in the future such as:

Using marine grease to waterproof the servo without testing the component first,

causing us to scrap the part not knowing if it came faulty or was the result of

improper sealing technique.

Initial housing (Aorta) was bulky and wasted a massive amount of space

Motors were initially placed on the frame on the four corners for balance when they

should have been placed at the center of buoyancy


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Future Improvements

In future models of the ROV, we would like to improve on the frame. Our frame used

currently was designed with cost effectiveness in mind, but we aim to improve by seeking a

similar material that is stronger and just as lightweight such as carbon fiber. By using

Carbon Fiber, we would be able to bolt the pieces into place and drill the same holes as the

PVC, but increase mobility and durability.

Reflections

We have an outstanding group of team members that have developed their engineering,

design and communications skills over the past few months. The team was excited to be

able to do so much hands-on work building the Z3 and sharpening their technical and

mechanical skills for future projects. In future projects, as we grow and mature together as a

team, we will be able to stay on task and delegate work so that we can complete projects

more efficiently. We were grateful for the experience.

Teamwork

The team has put countless hours these past few months working together to design, build,

test, and write up the specifications of the Z3. We accomplished this through frequent

meetings, both in person and online. Communication is key in group projects, so meetings

were made at least twice a week (or 5-6 times a week when a crucial test did not pass with

flying colors) for at least 6-12 hours per meeting. Taking into consideration that most

schedules were conflicting, it was a challenge for every single member to be present for all

meetings, but we did keep each other constantly updated. Each meeting consisted of

assigning sections of an assignment to each team member for them to review and complete

before the next meeting. For example, during the frame construction process, team

members were given the task of fabricating the frame, building the motor housing, painting

the frame, and wiring the electronics.


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References

“2014 MATE ROV Competition Manual Scout Class.” Marine Advanced Technology

Education Center. MATE, 2014. January 21, 2014.

Arduino. Arduino, 2014. Web. April 1, 2014.

SeaPerch. SeaPerch Online, 2013. Web. May 17, 2014.

Acknowledgments

We are grateful to the San Jacinto Community College for providing facilities for us to use

weekly, and the blackboard system for internal team communications during the week.

The following people provided generous donations so that the team could procure supplies

for the Z3 and provided their technical expertise to help the team during the design process:

Mike Samano

Ike Coffman

Jose San Miguel

Nathanial Wiggins

Sara Malloy

Miguel Rosales

Cory Tharling

Victor Mejia

James Donlin

Meagan Hernandez

Thank you to Marine Advanced Technology Education (MATE) for allowing us to submit this

design and to our regional coordinator Ike for working our demonstration into his busy

schedule.


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Sponsors

Hidden Lake for allowing us to use their facility for water testing

San Miguel Family for assistance with our viewing panes

SFEI for moral support during these last few months

Technologydude.com for guidance on buoyancy

Samanos hobbies for guidance on propulsion and donating their balancing

services for the propellers

San Jacinto College for moral support and allowing us to use their

facilities during the construction process

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