The Deliverator – Wannabee

So open minded, my thoughts fell out…

Archive for the 'ROV Project' Category

2nd Annual PNW MATE ROV Competition

Posted by Deliverator on 15th May 2007

As Ryan noted in this entry, I did indeed spend part of my weekend watching underwater robots built by high school students. It was a lot of fun and next year I hope to be able to stay the whole day. I don’t have time for an extensive entry, but click the picture below to see my photo gallery for the event.

MATE ROV

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1st Evaah PNW MATE Competition!

Posted by Deliverator on 13th May 2006

Spent the day at the King County Aquatic Center in Federal Way attending the MATE underwater robotics competition. This is the first time a MATE regional has been held in the northwest, so almost all the teams there were rookies. I was very impressed with the quality and functionality of the robots, especially given that most teams had no experience with underwater robotics and some had no experience with robotics at all, prior to the competition. In all, about a dozen teams from Oregon, Washington and B.C. participated. I hope that next year, the TRC will be among them.

My father is still using the nice camera up at Lake Chelan, so unfortunately I only have pictures from my Nokia 6620’s rather poor phone-cam.

ROV

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Regulation(s)

Posted by Deliverator on 24th February 2006

I will be heading down to Portland next Wednesday for the Pacific Northwest FIRST Robotics Competition. The robot was shipped this last Tuesday, and other people are handling most of the administrative stuff, so I have been endulging myself in a welcome break from anything that resembles responsibility. I am still working on a few robotics related projects, but they are non-essential, so I can putz with them at my leisure.

One of the things we wanted to do last year was mount a CCD camera on the robot itself and hook it into a well-protected DV camera. We got the camera mounted, but nobody had a DV camera that could capture composite video to tape (a few would capture to memory cards, but at low-resolution), so the project fell through at the last minute. This year, we are trying to anticipate any potential pitfalls.

This year, we are going to be using two hacked CVS cameras to capture on-robot footage. We have already hit our first pitfall. There is a regulation that states that all devices on the robot have to be powered by the main system battery, which is ~12 volts. The cameras run off 2 AA batteries = ~2.8 volts. In short, I have to build a voltage regulator to convert the 12 volts down to something that won’t fry the cameras. I am thinking of using a simple design based on a LM317, a couple of resistors, a diode and two capacitors to dampen transients. Ryan and I are going to head down to Frys and see what we can find in the way of components.

The other project I am working on is a regulator for LED modules, kindly donated to the ROV project by Lumileds. In the case of LEDs, the concern is current regulation. Once an initial forward voltage is surpased, LEDs will try to draw as much current as they possibly can, causing them to get VERY hot and start smoking and exploding and other un-good things. As such, you have to limit the ammount of current the LED can draw upon to something less than the LED’s exploding point. Ryan and I played around with a variable voltage/variable current power supply a few weeks ago and experimentally determined how high we could drive the LEDs with out them totally frying. You can “overdrive” LEDs by a fair ammount if you can get rid of the heat fast enough, although you will reduce the LEDs useful life by a substantial ammount. We ended up testing one module to the edge of destruction in a large glass of ice water. Even with this degree of cooling, we managed to get the LED smoking underwater! A more sensible voltage/current combo with better long-term surviveablity seems to be ~3.4 volts at ~700ma. I wasn’t in the mood to build some of the more complex circuits (many of them requiring microcontrollers) that I have seen online for doing both voltage and current control, so I searched around for something I could buy.

I found exactly what I was looking for at Taskled. They make a wide range of LED driver circuits for the Luxeon Star LEDs. I emailed the company and expained what we were trying to do and George, the owner/operator/1 man band that runs the outfit wrote me back promptly and offered to sell me whatever I wanted at cost (he still assembles, solders and tests all the units by hand). I orded five regulators to test. Five 3 watt LEDs may actually be bright enough given that we have a very sensitive CCD camera, but if not, we can already order some more. I would love to use some of the 18 LED modules. Those would certainly provide enough illumination. Unfortunately, the optimal voltage on these seems to be about 21 volts, which would require a switching power supply to achieve off 12 volts. We could use two 12 volt batteries to get 24 volts and then use a regulator to get the voltage to 21 volts and a resistor to limit the current, but that solution is less than optimal in a lot of ways.

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FRC Build Meeting – 020306 (awesome videos!)

Posted by Deliverator on 3rd February 2006

Arrived late to today’s build meeting. Had to earn money for a change. Larry and da kids had the roller mechanism nearly completed by the time I arrived. We got the shooter’s motor remounted to a position on top of the shooter instead of in front, to give us more space for the ball feed mechanism/hopper. Larry coded a callibration routine that maps the output range of the FIRST microprocessor controller to the full output range of the Victor motor speed controllers. This will hopefully let us drive the motors across their full possible range of speeds. We reassembled the frame and loaded the robot, now quasi-officially named Hoenir (aptly named after the Norse god of indecision), into the back of Cheuk’s mini-van to haul to school.

When I arrived at school, Ryan was hard at work with the drive team (and hangers on). They have been practicing with last year’s robot, Tyr, which has a very similar drive train. In particular, Ryan was working with Erik to produce code for using a strearing wheel for drive train control, instead of a joystick. We saw several teams that used this type of system very successfully last year and decided to try it on this year’s robot. Ryan got Larry’s code dump with the new calibration routines and managed to add his code for stearing wheel control. We then ate Pizza, after Dominos finally decided to believe that the International School was extant.

After Pizza, we improvised a ball hopper out of cardboard and hauled in a ramp/slot from outside. We loaded the hopper with 20-30 balls and let her rip. The result left us jumping up and down and dancing, dancing, dancing. Checkout the roller video to see why.

We also tested the shooter, which was dead on for accuracy and could pretty much shoot as fast as we could feed. Here is a video of the shooter for your viewing pleasure. The limiting factor is definitely going to be the rate at which we can feed balls into our shooting and rolling mechanisms without jamming. I think we are going to have a tradeoff between having a jam-proof hopper design and capacity.

After the meeting, we hauled the robot to my place for temporary storage until this Sunday’s meeting. I hope we can get some serious work done on Sunday before settling in to watch the Seahawks trounce their opponents in the Superbowl :)

While at my house, Ryan and I played around with a whole bunch of wonderful LEDs, which were recently donated to the club by Lumileds for use on the ROV project. They included twenty 3 watt star emitters, two boards with eighteen emitters each and two rings with 12 emitters each. We drove them using a nice current limiting power supply. Unfortunately, the supply only goes up to about 17.5 volts at max and the ring and boards don’t reach their peak luminosity until about 21 volts. Still the ammount of light put out by these is dazzling. Larry said to me “you can blind em with science or you can blind em with bs.” These LEDs definitely blinded us with science. These are the real deal folks. They are still expensive enough that they haven’t achieved real market penetration yet, but when they do I think they are going to have tons of applications.

Pictures of the LED fun and build meeting can be found here.

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Too Much Weekend

Posted by Deliverator on 30th January 2006

My weekend was very full and unfortunately it has caught up with me. I have a sore throat and my body aches and shivers. I spent a good deal of the weekend in damp clothes, which I am sure didn’t help. Seattle is a very wet place, but usually the rain follows the pattern of constant light drizzle which is just enough to make your hair frizzy all day. Most people here don’t carry umbrellas and normally I scoff at those who do. This weekend it seems like every time I needed to go outside it was pouring down rain hard enough to get me soaked just going from car to building.

Saturday I caught the ferry and headed to Keyport. Keyport is home of the Naval Undersea Museum, which this weekend graciously provided facilities for MATE to hold their kickoff event for the 1st Annual Pacific Northwest ROV Competition. Roughly 30 people (mainly educators) showed up to hear Jill Zande (from MATE) and Fritz Stahr (representing MTS/UW/Ocean Inquiry) talk about this year’s event and show footage from prior year’s. There was also a representative from the local naval base who showed footage and talked about how they use ROVs currently and how they intend to use them in the grim meathook future. The kickoff was definitely a low key event compared to a FIRST competition kickoff and frankly a lot of the information presented during the day was repetitive and redundant. They could have presented all the necessary information in an hour  or two instead of six (plus ferry rides/waiting at ferry docks). I know it sounds like I am bitching. I really had a lot of fun, I am just majorly crunched for time atm. The highlight of the event was when we all broke into groups to create small ROVs, designed to pick up PVC T junctions off the bottom of a large water filled cow trough. It was a lot of fun and I got a lot of pictures

I didn’t get home until about 7:45, at which point I met up with Ryan at my house and hauled the ROV over to Larry’s. We were intending to spend most of the time at Larry’s working on a nagging encoder issue, but got sidetracked when we realise that the right side drivetrain was locked in place. Turns out that when the gearbox was assembled a locking key designed to hold the driving gear in place had not been inserted. The driving gear was being held in place by a single small set screw. As FIRST co-founder Woody Flowers has noted, “set screws inhale audibly.” Of course, the set screw backed out and the gear it was holding in place slid down its shaft and managed to lock the gearbox up. I am just glad it did so now, rather than during the competition. Thankfully, no damage was done to the gearbox. Ryan (and larry the next day) worked on fabricating a new key to properly fix the gear in place. I disassembled the other gear box to check for the same problem. Thankfully the other one was done properly.

Sunday afternoon I headed to Larry’s and mainly spent time taking pictures. We had more hands than needed for a change. Most of the afternoon was spent fabricating and welding an outer frame and working on the shooting mechanism. The shooter is hitting a pretty small target now and all nay-sayers (including myself) now think this mechanism is going to work out. There is still some mechanical work that needs to be done in working out a good joint feed mechanism for the roller & shooter. The roller mechanism itself still needs to be built (easy as pi according to Larry) and the hopper needs to be extended in the front to the full 5′ limit. Still, the robot is definitely taking shape. We hauled it over to school, where Ryan and Kevin worked on the encoder issues while Erik and Ian ran a competition to determine this year’s human player. It looks like Yevgeniy Mikhaylov is going to be this year’s player. With the addition of Yev, this year’s drive team is now complete. Ian (last year’s arm controller) is taking over as driver. Cheuk is going to be handling the shooter/roller controls and feeding balls to Yev during the defensive period. I am pretty sure Erik Thulin is going to take over as coach, given that he is heading up this year’s strategy sessions. Erik and Ryan have been building the scouting program up for the last few years,  and are hard at work creating STAMP, a web based joint scouting application.

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ROV Project Update – 012806

Posted by Deliverator on 26th January 2006

The ROV project has definitely been on the back burner for a while now, with the flurry of ongoing activity related to the FRC robot taking priority. I know people are going to be pretty wiped out after getting the robot finished, hosting the unofficial pre-ship event and finally shipping the robot off to Portland. Hopefully we will be able to start working on it again after spring break. While the project has been a bit idle of late, I have not.

This weekend I am hauling my butt out of bed to attend an all day ROV conference put on by MATE in Keyport at the Naval Museum. Among other things, the conference will be an organizing event for the 1st annual Pacific Northwest ROV competition, being held in Washington sometime in the Middle of May. I somehow doubt the TRC has enough stamina for another grueling build season this year, but you never know. At the very least, I hope to make some fundraising contacts. I might try and find a group of kids from one of the ther local schools that would be interested in giving it a shot.
Helena Wu from Lumileds emailed me this morning to inform me to expect a package in the mail shortly containing all sorts of wonderful high wattage LED emitters. It sounds like they were able to supply everything that i requested, except a few parts that had been discontinued, which they replaced with newer models that put out even more Lumens. It sounds like adequate lighting will not be an issue on our ROV. Many thanks Lumileds!

I need to find some Victor 884 or equivalent motor speed controllers for the ROV. We had two 884’s and an older 883 allocated to the ROV project, but we were running short. so I gave them to Larry to use on this year’s FRC robot. This year’s robot will be using SEVEN 40 amp motor speed controllers, if you can believe it. That battery is not going to last long! Anyways, if anyone has some 12v motor speed controllers to donate to the project, they would be much appreciated.

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Robo-cam

Posted by Deliverator on 6th December 2005

I was contacted yesterday by a reporter today asking if the TRC would like a Robosapien. He just finished reviewing it for his paper and decided to give it to us, afterwards. I am not sure if it is an original Robosapien, or its much more capable elder brother, Robosapien V2. I got a call from Brad Moore, the TRC’s faculty advisor, saying that it had been dropped off in his room. Brad is a big kid at heart and his phone call was just overflowing with glee. I will try and make sure he has a chance to play with it before we vivisect it for servos and sensors. Who knows, we may keep it relatively intact and add our own control modules. Between the Robosapien and the mouse trap cars, the next general meeting promises to be loads of fun. In other TRC news, I read on Ryan’s Blog that the TRC has paid its $6000 entrance fee to the 2006 PNW First Regional. Now I just hope there is enough money left over to well…build the robot. If worse comes to worse, we will wrap Ian Hovander up in tinfoil and push him out onto the floor :)

I spent the afternoon shopping for Christmas gifts on eBay. I noticed there are a number of brand new vex kits for sale right now at a fraction of the cost of retail. If you are looking for a great educational gift, I highly recommend it. After finishing my online shopping, I went to Computerstop and the hardware store. I picked up a couple gifts, as well as a some ram and a neat little wireless camera.

I had seen the cameras on the shelves months before, but passed them buy. I saw one in use on a hatcam at Mindcamp. I decided right then to buy one, but the next time I was at the store, they were gone. The store must have found some in the back or something, because this time I managed to find ONE on the shelves. I took it home and mounted it on my Vex Trike’s new gear reduced camera mount. I had fun driving it around the basement from several rooms away, watching it on a 5″ LCD that I had sitting around. I think I will mount the LCD and receiver unit in a project box and make myself a portable rig. I plan on making a still better camera mount that allows for both pan and tilt control. I found a great, simple pan and tilt design earlier this year while browsing the web for DIY ROV projects. I picked up some threaded rods while at the hardware store that should be suitable. I will see if Larry will let me machine the other needed parts sometime.

In still more robotics news, I just learned that MATE will be holding the 1st annual PNW Rov Competition in Washington in May. I hope to get the TRC motivated enough to enter. We have been working on our own ROV project for a while now. I just hope we have time and money enough to build an entry.

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Vex Kit – OTW

Posted by Deliverator on 24th November 2005

Purchased a Vex kit on eBay this week. I was a little worried about making the purchase, as the seller only had one purchase feedback (another vex kit), but I got him to send me a number of picture of himself, photo identity and picture of him holding the kit. The next best thing to information super-highway street cred is knowing where someone lives :) The box is coming from California, so hopefully it will be here by the end of the week.

After this week’s hacknight (which is deserving of its own entry) I headed across the street to Rob’s place. Rob bought a kit after I told him about the Vex system a few weeks back and he hasn’t been idle. I got to play around with his first creation, a highly modified squarebot. He changed the design to utilize two bigger, powered wheels, shifted the axle and added a tiny third wheel (which acts a bit like a caster). To this base, he added a laser pointer to the front and a plastic rod with string attach at the back; each attached to respective servos. In short, he created a robot to torment his cat! I got to play around with it for a few minutes in the parking lot in front of his place and took some pics. Rob was nice enough to loan me the programming interface. I am loading up all the VEX software and documentation on an old laptop, along with all the FRC dev environement stuff for the IFI mini robot controller. We are using the IFI mini robot controller in the ROV project. First/IFI has been using PIC18 chips for their controllers for quite a while. I am hoping that I will be able to figure out how to program the VEX controller without having to spend $100 on the official programming kit , which looks to be little more than a USB->serial dongle and the install files for the EasyC dev environment.

Here is a pic of Rob’s cat-bot:

vex cat robot

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Another checkmark for the ROV project

Posted by Deliverator on 18th November 2005

Met up with Erik today at school and headed over to Larry’s garage (by way of Jack in the Box) to work on the ROV. Larry took the plastic backing off the mini controller board to examine the power regulators for the board. Though the power plug on the housing says +9v, the regulators are of a type that will happily run off higher voltages just fine. We were concerned that we might have to have a bunch of power supplies for the control unit, lights, camera, etc. Larry hooked the controller up to a bench supply just to make sure and the controller ran happily on 12v. He scrounged around on one of his computers and found some code that he had written for it 3-4 years ago, while waiting for the full-size FIRST boards to arrive. Larry hooked up the controller to a neat circuit that simulates PWM input from a radio-interfaced operator interface (Joystick) and the controller with his code responded to it. It is questionable whether we can run PWM over such a long tether wire as will be used, but I think we will give it a try. If not, the control board has a TTL port and we can probably get some TTL->RS485 chips that do differential voltage signalling for longer distances.

After playing around with the controller for a while, we figured out where to mount everything on the “sled.” We will have 2 cameras, 3 motor speed controllers, the controller and a fuse panel. The only fuse panel I had been able to find was total overkill for the job and would not have fit. It had mounts for about a dozen fuses. Rather than scrounge for a smaller panel (Larry though IS might have a 4 fuse unit somewhere in the rat-sized Labyrinth that is the TRC room), Larry solved the problem by cutting the panel in half with the bandsaw! Larry is definitely a master of quasi destructive creation! Perhaps he is the American version of Shiva, ala American Gods. After figuring out where to mount everything, we used the drill press and created some threads and bolted everything in place. We test fit the sled (with all electronics mounted) in the cavity and everything fit, with a planned 1/4″ margin for error. Measure twice, cut once, indeed! There will definitely be quite the rats nest of wires inside once we get everything wired up. Next time, we will have to unmount all the electronics, get the sled welded, drill and tap the holes for the electronic connectors and start wiring everything up. I think this sled idea is really going to work out quite well, as we can remove all the electronics from the cavity by simply pulling off the end cap and disconnecting the tether. Should make things simple to replace if we burn out a fuse or something. Here are some pictures from tonight’s events.

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ROV Build Meeting 11/04/05 – Work Apace

Posted by Deliverator on 4th November 2005

Today I dropped off Tyr and a load of TRC related materials at the building at which Mind Camp is being held tomorrow. After dropping off my load and doing a short demo of my poor robot driving skills, I headed over to IS and filled up the van with more robot materials and some students. We headed over to Larry Barello’s to do some work on the ROV. We got all the waterproof connectors unmounted from the old busted endcap for eventual use with our nice, newly machined one. Larry has been restocking the garage and now has the correct size taps to create the threaded holes into which the connectors will be inserted. Before we could figure out the connector placement, we really had to figure out how to attach & where to mount a platform/sled for all the electronics. Larry made the platform out of random bits of aluminum and did a beautiful job of measuring, machining & welding them. A bandsaw blade broke while Larry was cutting one of the aluminum pieces, which frightened the rest of us far more than him. By the end of the meeting, Larry had finished the platform/sled, but was running out of shielding gas and energy. We will be picking up where we left off next Friday to weld the finished plaform to the endcap and get all the holes drilled and tapped (the tapping may take quite some time). I have uploaded some pictures of the day’s events at my ROV Project Gallery and included a few quick ones below.

Larry at Mill All Clamped Playing with Crescent Wrenches Finished Sled

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