Introducing The Altair Ez:2 Robot

 
#21

@zackarybay, thanks for the comments, no video's yet as most of the EZ:2 tech is still being tested on the EZ:1 robot development platform (the AIMEC body version).

Thanks Pat for the kind words.

Tony

#22

Further to my other threads on the Kangaroo, I though some of you might be interested in the slave locomotion PIC processor (to the V4) and its teach pendant. These "overseer" processors are very useful as they take a lot of the robots mundane tasks away from the V4 so it can do more important things.

Thanks to the Kangaroo/Sabertooth setup the locomotion system moves incredibly accurately and in a straight line, this is pretty cool as it means that the robot can be taught to move from place to place (room to room etc) in predefined routines that the V4 can call. For example "charging pod to kitchen" or "charging pod to hall" etc, with this type of system you have to start at a known place and the Charging pod is good for this as it is the EZ:2 Robots little home base. For this to work you need some serious odometry and thats were the motor encoders and Kangaroo come in, with 63500 pulses per wheel Revolution you can see why its pretty accurate!

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In the above picture you can see the wireless teach pendant, due to the high accuracy required the PIC commands the Kangaroo to do the highly accurate turns (like 45 degrees right etc) from a single key press from the user/teacher, the joystick is there for just moving the robot around and not for teaching new journey routes. Journey routes/paths are all held in EEPROM (the 8pin IC next to the PIC), hundreds of routes can be stored here.

Tony

#23

I'm always surprised when I read how many pulses per rotation those encoders are. Correct me if I am wrong (and this isn't an area I have looked in to much yet) but aren't encoders usually between 100 and 1000 (give or take a bit, I remembered it easier by rounding up/down).

Basically, it's accurate to something like 0.006 of a degree?

#24

Great job tony , I'm interested about the encoders for sure. With my robots I'm playing with steppers to move in increments and a gearbox on the stepper to increase torque if needed. Can you tell me what kind of encoder you are using?

#25

As ALWAYS ... very impressed with your work!

I too am a believer that slave pics should be employed for certain task, as to free up the EZB and computer from getting bogged down with routines.

Do you ever have plans to post the pic circuit and Hex or is this something that you feel must stay private for the Atair EZ2?

#26

I so want one ! Id definitely pay the high cost for shipping to get one here. I look forward to seeing it in the market next year!

#27

Rich, its quite common to have encoders of this resolution, here is the spec for the motor/encoder that I use you will see the "Encoder Pulses per Revolution = 63500" at the bottom

www.zagrosrobotics.com/shop/item.aspx?itemid=639

@Josh, here is the encoder datasheet

www.zagrosrobotics.com/files/heds55xx.pdf

@Herr Ball, yes the slave pics are very useful all the V4 has to do is send a command to the locomotion PIC such as "go to the Dining room" and then the job gets done with the PIC reporting back to the V4 when it gets to the target location. The (very sensitive) lower ultrasonic sense array seen below is also connected to the locomotion PIC so if an obstacle is found in one of the route paths then the V4 gets flagged to make a decision of what to do next.

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Tony

#28

@Tony, This is amazing to me. I hope some day to be able to use your drive system in my full size B9. I can see him now moveing from Pinball machine to Pinball machine in my game room reaching out and wanting to play and makeing snide comments. I still say you should offer this as a kit that can be assembled at home and sold in parts. It would be simper and more afffordable to sell and ship world wide. A person could buy it in different sections over a peroid of time and others that just want to put your arms and drive sections on their robots could do so. Heck, I'd get a whole bot and a few extra parts.

@All, I'm useing these encoders in my B9 for the hips and waist. I also plan to get one installed in the radar section sometime soon. They are amazing and so simple to use and ind install. I bought the motor with the encoder attached Tony points to (Mine was the faster geared version) and a stand alone encoder. I mounted the stand alone one to a shaft of a DC motor and it works great. I was amazed how smooth and exact it makes my motor in combo with the Kangaroo X2. I had to get used to the large numbers returned by the Kangaroo from encoder for position poisition and speed. Position was from 0 to 32000 between my limit switches and 0 to 22000 for speed. They come in indexed type for super high accuracy and unindexed types if you just need to get within a fraction. You dont have to be too critical with centering on the motor with the unindexed type (that's the one I bought).

Hope I'm not taking away from @Tony's excelent topic but you guys seem interesetd. Here's a couple pics of the motor I have installed and the stand alone encoder:

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#29

Hey tony, I noticed some "button" type sensors around the bottom from. By any chance are those ultrasonic sensors like on a cadillac? If they are where are the from and did you have to make a custom ping generator / receiver circuit for them? If they are distance sensors that is a very cool yet subtle touch. Smile

Thanks for the specs link by the way.

#30

What an amazingly visually stunning robot, I am relatively new to robotics and like many of you am waiting for my v4 to awaken my robot "TRAKX". You guys are such an inspiration to me and each time I come on the forum I learn so much.

Thanks guys Smile