Alfred the butler bot *Advanced*

Let's Make Robots Robots
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*New Update*

If you are interested in my other robots/projects please visit my personal webpage at www.secondrobotics.com

 

*Older Update*

I recently took Alfred to a class of kids, they were having robot week. So Alfred went to visit we had him use his text to speech to say all of the kids names as well as read a story to the kids as my wife flipped though a book,  I knew if I did not have the robot move around the kids might not have though of alfred as a true robot so I loaded up roborealm and had it chase a green ball around the room carried by the children here is a video of the kids playing with the robot.  At the end I had Alfred serve the children some juice by this time they were super excited to meet a real robot.  As you can see in the video the room had a few green colored objects on the wall that confused the vision software, I also reduced the speed at which the robot moved as not to fighten them.  All and all if was a fun experiance for me as well as the kids.

 

I found a program to read the LM335 sensor and calibrated it.  I then kicked on the TeC fridge to see what temps I could get I got down to a measured 51.40 F which im very happy with. Its a temperature that covers alot of wine serving temps.  I now need to work on a program that can keep the temperature at the desired temp I set.

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Small but oh so awesome update It occured to me that everytime I open the my own fridge is a nice white light that shines everyware so I decited to add a super bright LED to the LM335 precision temperature sensor board. I scuffed up the plastic of the LED to defuse the light a bit and volla a fully functioning fridge that can be temperature controlled.  I also can account for the heat given off by the LED so the temp will be accurate.  I used non-conductive thermal epoxy to mount the board. 

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*First Post*

So the project will be to make my very own butler bot, I will call him Alfred and it shale be that

To start here is a site I used to blog Alfred's progress

http://www.lynxmotion.net/viewtopic.php?f=20&t=7051

 

I wanted a robot butler so I set out to create something useful I ended up with a robot that can pump wine into a glass once it detected one, though I did not stop there I added a on board 50 Watt TEC mini fridge to keep the temperature of the wine down as It served it. Though that's when I started getting into trouble with the battery life with the fridge on the main battery pack will last about 40 mins.  I use a solid state dual realy control board to switch on the TEC and the pump.  For higher lvl processing there is a sony viao on the top level doing vision processing with RoboRealm.

It has on board a 5 port usb hub that is powered by a DC to DC converter off the main pack this allows the robot to play music though on board speakers when a laptop is not available or to simple be a charger for mobile devices.

50 Watt Mini Fridge
50 Watt Mini Fridge768×1024

 

Here is the mini fridge made of Styrofoam and a layer of carbon fiber.

Drip collector
Drip collector640×480

Here is a drip collector I made by gutting a 80mm computer case fan and inserting a sponge n case of drips

Me showing off the wine clearance
Me showing off the wine clearance1024×768

Some of the earlier pictures of the process

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Here is a link to the video of it serving tea at a lan party

http://s155.photobucket.com/albums/s291/ollopat/?action=view&current=MOV03556.mp4

Features:
Drink pouring system(on board TEC chiller)
Pandora radio
charging system for I-pod or phone(anything that uses usb to charge)
on board robo-realm navigation and higher lvl processing
5 volt DC-DC converter

Future upgrades:

bigger battery pack for longer run time
sensor's and lots of em so that the base can navigate with out the laptop if needed
remote docking to charge

Hope you like the video, please feel free to ask questions or leave comments

DoCDoC

 

 

Serves chilled wine among other things

  • Actuators / output devices: 1x windscreen wiper water pump, Two DC motors, 1 Servo for pan, TEC
  • Control method: autonomous (very)
  • CPU: Arduino Mega 2560
  • Operating system: Linux (Ubuntu), windows 7 64bits
  • Power source: li-ion laptop batteries rated at 2200ah so the battery pack is about 12v at 4400ah
  • Programming language: Arduino Processing
  • Sensors / input devices: Logitech Webcam, multiple Sharp IR
  • Target environment: The house
This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/alfred-the-butler-bot-advanced
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Nice project! Please keep us

Nice project! Please keep us updated.

From your pictures on the album you linked, it looks like you made some encoder wheels from CDs. How has that worked out?

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Encoders

The CD encoders worked out well.  I used DVD’d as its what I had around.  Though as im begining to understand Roborealm’s features I find that encoders are becoming more and more obsolete.  As a map with can be made with vision alone and the robot can be told where along the route to go.  Also the disks got in the way of the set screws on the wheels which was a problem as I need to tighten them every once and a while as I have yet to throw some tread locker on the screws. 

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Very cool

How big is the battery on your bot? I have a TEC unit I’m going to use for my Peltier Pal bot and was looking at a 12AH lead-acid battery for a few hours of operation. I think it’s 50W (~4A current draw IIRC).How much time do you get out of yours?

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Great Work!

Great Work! I love this robot. It would be real cool if alfred had a robotic arm or arms that would be able to serve the cup. If you want naviagation, I would suggest a compass and maybe a gps module. Keep up the great work!

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What type of motors are

What type of motors are those?

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TEC and Nav

Thanks for the comments

The battery is a li-ion battery pack from a laptop that push out about 4,400mAH at 12volts. It runs the TEC unit I have which  is 50Watts, I get about 40mins with the TEC at full blast before the battery drains below 9volts I consider it close to dead at this point as it will no longer kick over the pump im using.  Id say a lead-acid battery would get you about 108mins of run time until it fell to around the same voltage. Though I do not know the age of the battery you are using or how many charge cycles its been though. I chose a li-ion for the weight as well as charge cycles which are in the 1000’s.  I was however thinking of expanding the current battery or switching to cheaper create NiMH batterys so I can triple the run time with the TEC on.  To give you a idea of the cooling power of the onboard fridge.  I placed a 12oz soda in there and it was chilled to 47 degrees F in about 25 mins.  45-48 degrees F is as cold as it gets though calculation and ambient temperature.  In a few days installing a temp sensor so I can read values off the robot or it can tell me them with its voice.

The arm is a bit down the road I just dont have the cash to do one that I would like to see. I do however plan on having a tray I can install for partys that will carry appetizer’s as it navigates though the croud. As for navigation Im going to try and rely on video as much as I can a compass module would help.  Though a GPS module does not work that well inside which is where this robot is 99.9 percent of the time.

 

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Motors

The motors came with the base here is a link. They also have ready made units.

http://www.zagrosrobotics.com/shop/item.aspx?itemid=534

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I never considered Li+

I never considered Li+ batteries :checking google: Well, I can’t seem to find one with a price tag under three figures so I’ll stick with the SLA solution. That and the charger can be made for chump change.

Your estimation of 108 minutes is pretty precise. Is this off the top of your head or do you have a handy battery calc you can share? :slight_smile: I plan to have a solar panel to add juice to the system as it will most likely operate outdoors in sunlight. In reality it will probably only add minutes to the runtime. I’m also considering pulsing the TEC to conserve power once it gets to a stable temp inside the unit. If the cooling assembly gets turned off it immediately starts to sink the heat from environment back into the cold-side heatsink, which is a bummer.

If you know of a place with reasonably priced, large capacity Li-ion batteries, I’m keen to hear about it as well.

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Cheap Li-ions

You and me both on the cheap Li-ions, what I have found is that ebay has good deals on replacement li-ion laptop packs which sell for much cheaper at times then buying pre built open packs.  Though ebay also has replacement I-robot crate batteries that would offer lighter weight but for a slightly higher price then lead acid. The way I see it is the lighter the gas tank the better mileage you get for the amount of gas you have.  I.E. lighter packs/better chems = longer run times. Its really a balancing act. The joke being how much battery tech is behind other techs.  The 108 mins is a estimate off the top of my head and a bit of calcs based that you have the same power draw as my own TEC.  Though its going to be very close to that.  As for the solar panel Idea it would be an ok one as you could have the robot track light then power to a low usage state and trickle charge the battery.  It may not be impressive to watch, but the robot does not care how long it takes.  It can stay in this state for hours even days until its battery is back to full charge.

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I like the idea of this

I like the idea of this robot, it looks really neat!

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the decks

nice bot! what did you use for the decks?

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Base

The base is from a kit found at the site below, the rest is me piecing it together over time with various other parts.

I believe it is pvc sheet plastic though in case you are looking into the base material Ive found it easy to drill into and cut, and so far the strength has been impressive.

http://www.zagrosrobotics.com/shop/

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Increadble robot!

I have been working on a robot butler for years and I must say yours is very impressive! I just recently finalized the base design for mine after 4 years of scrapped designs and have been working on a lot on basic navigation. I am excited to see what you can do as far as navigating using the connect because my design has been reliant mostly on ultrasonic and ir sensors so far which has resulted in very poor navigation.

Please keep us posted on your endeavors into navigation because that is most certainly the hardest part. 

Also I noticed you where considering using a compass sensor to aid in navigation, a word of caution on that, compass sensors are very inaccurate “I have been trying to use one on my bot for a while and it varies ±10 degrees just driving down the hall”. However I recently purchased a rate gyroscope and using some cleaver math I can determine my heading to ±1 degree after executing a complex series of turns. One method I have yet to investigate for determining heading is a combination of both I saw in this seattle robotics society tutorial http://www.seattlerobotics.org/encoder/200311/brown/building_a_directional_gyro.html . You might want to check it out because my biggest problem with navigation so far has been poor turns due to error first with encoders then with my compass.

Good luck! Hope to see some impressive navigation!

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Nice work.

Nice work.  Kinda makes me thirsty.  I could really use one with sand-tires to follow me down the beach and carry a 6-pack of my cheap beer for me.

On the nav front, some people don’t like the results from using a compass, but I have been very happy with mine, can’t imagine doing without it.  It will turn or lock onto any heading and hold it very closely.  If you come up with a good substitute for GPS indoors, please pass it on.  I’ve been racking my brain to come up with video based methods as well, mostly OpenCV.  Even tried OCR for a time…it worked but I didn’t want to have to put words on the walls in every room.

Regards,

Martin

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Are you sure the windshield

Are you sure the windshield wiper pump is safe for human consumption?  I noticed Trossen has pumps that are food safe.

http://www.trossenrobotics.com/barbots-pumping-supplies

 

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Hello

I would agree that the windshield wiper pump is not the best option. I did take it under consideration and used silicon tubing on the build, however a peristaltic pump would be ideal as the liquid only touches the interior of the silicon tubing. Cost of a decent peristaltic pump at the time of the build was outside my budget.

Thanks for you comment.

DoCDoC