As of this Spring semester, San Diego City College is offering a course in cooperation with our project. The course title is “Building Educational Bridges Through Robotics Competitions” and takes place during our usual meeting times, Saturdays 9am-11:30am.
The course has already proven to be very positive for our project. Although we try hard to reach out to students to join our project, we are not able to reach everyone. Having the course listed in the San Diego City College course catalog reaches many more students that we were not yet able to tell about our project. This semester we have added about half a dozen new members to our team as a direct result of having the class in the course catalog.
While being enrolled in the course is in no way a requirement for participation in the project, it is highly encouraged. Enrolling in the course makes our team members’ participation in our project appear on their official transcripts.
We would like to thank The San Diego City College Engineering Department, Dean Paulette Hopkins, Prof. Bob Priutt and Prof. Ron Worley for making this happen. Thank You!
February 23rd, 2008 | Category: Academics | Leave a comment
This is a video of our final run at the 2007 10th annual ONR & AUVSI Autonomous Underwater Vehicle Competition. In our last run we just barely missed surfacing in an octagon. Had we come up only a few inches in the direction of the octagon, we would have been in the finals.
The song that is playing during the video has the prominent line “What are the odds?”. Appropriately, this same song just happened to be playing over the competition’s PA system during the runs shown in the video. As we were only able to get so close by dead reckoning, we almost beat the odds by surfacing in the nearest octagon.
February 19th, 2008 | Category: Competition, Video | Leave a comment
I finally was able to complete the new site. My hope is that this site gives us a better platform to showcase our project and sponsors. If you have any problems please let us know.
I decided to use Wordpress due the large amount of extremely useful plugins and large selection of themes. In accordance with the theme license, here is the Wordpress Theme with my modifications.
January 20th, 2008 | Category: Miscellaneous | Leave a comment
This is the new design that we are leaning towards. It is based loosely on the idea of a blimp or airship with a single thruster in the front. In the coming months we will be building and testing it.
This is a short rough CAD-sketch and animation of the design.
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September 10th, 2007 | Category: Mechanical, Research, Video | Leave a comment
The linked document outlines some of the mathematics required for analysing incoming audio signals arriving at multiple sensors (hydrophones). The challenge is to compare accurately the arrival times of the incoming signal with respect to some internal reference signal and from those results determine the differences in arrival times. In preference to this pure math approach, many implementers use approximations to simply get “close”, but sometimes that’s just not good enough. Here’s how to do it right.
heavy-math.pdf
July 23rd, 2007 | Category: Programming, Research | Leave a comment
The linked file presents the mathematical model underlying the direction finding algorithms as implemented in the simulation program and the actual vehicle. Note that without an enormous budget, nobody in the competition can determine exactly where the pinger is. The best that can be done is to determine the approximate direction.
Hydrophone Model
June 23rd, 2007 | Category: Electrical, Programming, Research | Leave a comment
you may as well use good ones as shown in the linked file. These are 40dB/decade for both low pass and high pass. Figure out the math for yourself.
Analog Filters
June 8th, 2007 | Category: Electrical | Comments (1)
The linked document outlines the method for determining the pinger frequencies to the nearest fraction of a Hertz. We don’t actually need the frequency per se, but we do need to know the signal period accurate to the nearest multiple of the DSP clock. This number is critical to locking on to the pinger burst.
Pinger Frequency Search
May 15th, 2007 | Category: Electrical, Programming, Research | Leave a comment
The linked file illustrates a possible approach to locating the Buoys with the flashing lights. Admittedly this is just a science experiment for this year, but it could give us some pointers for what to do in the future.
Buoy Challenge
May 8th, 2007 | Category: Electrical, Mechanical, Programming, Research | Leave a comment
Today’s experiment demonstrated the depth control algorithm that allows the AUV to maintain a fixed depth autonomously.
The closed loop system consists of the depth control program running on the F2812 DSP board, a pressure sensor, the two vertical thrusters and the driving MOSFET. The software continually monitors the output voltage of the pressure sensor, which increases with pressure, through the onboard A/D converter. It then compares this value with that corresponding to the desired depth and sets the duty cylcle of the PWM signal driving the thrusters proportional to that difference.
As the video shows, the system proved to be very effective. It maintains depth precisely and produces minimal oscillation.
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May 5th, 2007 | Category: Testing, Video | Leave a comment
