Multidisciplinary Engineering Senior Design Project 06606 Underwater ROV Preliminary Design Review 11/11/05 Project Sponsor: Daniel Scoville Team Members: Josh Figler, Chris Nassar, Matt Paluch, Antoine Joly, Jason Caulk, Scott Gerenser, Larry Shaver, Daniel Scoville Team Mentor: Prof. Walter Kate Gleason College of Engineering Rochester Institute of Technology
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Multidisciplinary Engineering Senior Design Project 06606 Underwater ROV Preliminary Design Review 11/11/05 Project Sponsor: Daniel Scoville Team Members:
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Team Members: Josh Figler, Chris Nassar, Matt Paluch, Antoine Joly, Jason Caulk, Scott Gerenser, Larry Shaver, Daniel
Scoville
Team Mentor: Prof. Walter
Kate Gleason College of EngineeringRochester Institute of Technology
ROV Project Overview
Goal• Construct an underwater vehicle capable of
diving 400 ft deep to video an underwater shipwreck from the mid 1800’s in Lake Ontario
Side Scan Sonar Images of the Wreck
Major Project Needs
• Vehicle movement joystick controlled• Vehicle speed must be variable • Minimum tether diameter to reduce drag• Temp and depth data returned to operator• 400ft operating depth• 4.5°C operating environment• Vehicle must be deployable by at most two
• Total cost less than $3000• Finish within 20 weeks• Doesn’t leak• Can send video to boat• Controlled from boat• Recoverable in emergency situation• Reliable communications• Able to illuminate at least 20 ft in clear water• Measures and relays current depth
Overall System Diagram/Block Diagram
ROV User Interface
• The ROV user interface is going to be implemented using Qt 4 which is a complete C++ Application framework for building GUI’s.
• The design of the GUI is such that there is one main window with several “Groups” of information that can be easily removed, added, changed, moved and resized within the code.
• The GUI displays information to the user that is required in order to control the ROV underwater. Some of the information displayed is:
– Depth– Temperature– Pressure
• The layout of the interface has already been determined and created and now needs to interact with the MCU which is on board the ROV. Most of this will be completed during the early parts of SD 2.
ROV User Interface
• There are several highly desirable features that would be useful and convenient to have on the GUI. Some of these features are:
– To have live video from the ROV fed directly to the GUI.– Speed Reporting.– Light selection to maximize power efficiency.– Some form of error reporting for the different components of the ROV.
• Due to constraints such as time, some of the desirable features will most likely have to be omitted. However, this is something that could easily be followed up on in the future.
• The GUI will have an “Admin” mode for the purposes of debugging and to follow the general theme for designing for testability.
• Designing for testability is one of the most important concepts that have and will continue to lead the design of the GUI for the ROV.
• Finally, a key feature of the GUI is that it will be portable between operating systems should the owner ever switch or update the machine he uses to run the ROV.
The RIT ROV Display
Communications
• One fiber optic line (approximately 3mm diameter) will be multiplexed to include one video line and up to five data lines.
• Prizm Inc’s Micromux will multiplex the video and data lines into the fiber optic line and de-multiplex the signals on the other end.
Microcontroller Requirements
• 16 GPIO• Low error baud rate generation• UART capable of RS232 interrupt driven communication• Real time clock with at least 10ms resolution for polling• PWM generation in the 1-10kHz band with a minimum of
8-bit resolution• Analog to digital conversion with a minimum of 8-bit
• 2 – 16 bit compare timers with 3 compare modules each. These timers can be used for PWM generation. 7.5kHz can be generated using the clock frequency/8 with 8 bit resolution.
• Built in A/D converter with 10-bit resolution. Only 8-bit resolution is required by the pressure and temperature inputs.
• Built in differential A/D input. This option may be useful for finding the times when the navigational sinusoids cross.
• 15.36 MHz Crystal allows even baud rate generation (0% error for 9600 baud).
• Real-time clock with 1ms resolution attainable (60 overflows of the 8 bit timer)
• Real-time clock with 10ms resolution attainable (capture at clock counter = 150, clock prescaler of 1024). Much more real-time efficient with only 1 capture event required.
Pressure sensor
MSP 800 Series – MSI SENSORS
Hydrostatic pressure Depth
1 bar 10 meters
2 bars 20 meters
3 bars 30 meters
4 bars 40 meters
and so on …
When the ROV is 122 meters (400 feet) undersea level, the hydrostatic pressure will be equal to:
output voltage ofthe pressure sensor
hydrostatic pressure
Phydro_max = 12.2 bars = 176.9 PSI
0.5V 4.5V
MSP 800 Series – MSI SENSORS
RTD : Resistance Temperature Detector
Temperature probe
resistance ofthe probe
temperature
Temperature sensorWheatstone bridge
)()(2
5RRTD
RTDRVVV BAAB
What we would like is to have VAB = 0 when T=0°C.
For that we need to choose R = RTD(T=0°C).
Compass
Dinsmore R16552 axis analog compass
H-Bridge Concept• When high side (left) and low side (right)
are closed motor operates forward.
• When high side (right) and low
side (left) are closed motor operates
in reverse.
• Closing both switches on one
side is forbidden (causes short).
Our H-bridge Schematic
HI
V124Vdc
R7
10k
Q22N3904
R8
10k
R110k
R310k
R5
10k
Q5STP12PF06
Q4STF20NF06
R410k
Q3STF20NF06
Q12N3904
R210k
MOTOR
R6
10k
0
Q6STP12PF06
0
0
0
LO
Speed Control using PWM
• Pulse width modulation (PWM) is a powerful technique for controlling analog circuits with a microprocessor's digital outputs.
• By controlling analog circuits digitally, system costs and power consumption can be drastically reduced.
Prototype H-Bridge
Power?
Evaluate each additional concept against the
baseline, score each attribute as: 1 = much
worse than baseline concept 2 = worse than
baseline 3 = same as baseline 4 = better than
baseline 5= much better than baseline
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Suffi cient Team Member Skills? 4.0 4.0 2.0 1.0 4.0
Suffi cient Available Equipment? 5.0 5.0 4.5 1.0 5.0
Cost of Materials? 3.0 4.0 3.0 1.0 4.5
Cost of Purchased Components? 3.0 4.0 4.0 1.0 4.0
Complete by end of Winter Quarter? 3.0 3.0 2.0 1.0 2.0
Make Repeated Sequential Dives? 3.0 3.0 4.0 5.0 1.0