About the sneezing… I learned to do most things lefthanded. Including eating Wheat Thins with only vertical arm movements to avoid rotating the turret - when I wasn’t wearing the arm. And yes, I most often had it deactivated anyway.
After autonomous, it took me about fifteen seconds to get myself completely strapped into the hockey pads (donated by one of the team members as an attachment for the arm). I learned to do it on my own so the driver was free to move the bot for the first 10 seconds of the match - I had three or four seconds of lag time between the buzzer to end autonomous and the activation bell. Not that this came down to any sort of precise art.
Yeah…well…I am not sure that any company would really want to embrace PWMs as a connection standard…
That being said we clipped PWMs and soldered the female ends to the pots.
Ugly #1 We use cable bundles to get from the RC up the mast/arm with a DB15 disconnect between chassis and mast. PWM cables are soldered to the DB15 on the chassis. PWM cables are soldered into the cable bundle to connect to the PWM cables soldered to the pots and other sensors.
*** Ugly #2 *** For this human-arm application we used DB15 (game port) to Cat5 cables to modular connectors…to Cat5 cables to the vest…then to modular connectors…back to Cat5 cables…then soldered on PWM cables…to the pots. We wanted the ability to disconect the vest assembly in multiple places therefore the use of Cat5 modular connectors.
and…we are always looking for a better way to manage connections across the bot and also the OI. Suggestions?
We bought the pots from Allied Electronics (www.alliedelec.com)…the account exec was VERY helpful and even assisted in getting pots from another supplier when he was short of stock.
Here is a paper from IFI on the OI that will explain the use of each game port pin. From this you can see which are analog and which are digital…and which will light up LEDs. http://www.ifirobotics.com/docs/oi-ref-guide-1-30-07.pdf
Tables 4.3.1-4.3.4 cover the game ports.
In the paper I send it will have the pin-out assignments we used.
by the way, how did you guys decide to do this control system?
im sure some other teams with an arm thought of something like this but was there a person who researched and/or drew up designs to show the team that this was do-able?
Well…here’s the story:
We had two joy sticks and found it was not very intuitive to control the arm segments, wrist joint, wrist rotation and turret rotation. The team did not have a lot of time to practice…
At BMR Team 1138 (Eagle Engineering) was in the pit next to us. Their robot did not show up until 4:00 PM on Thursday (it was lost, not shipped, wrong truck, etc.). Their robot (when it did arrive) had a similar (without the turret) arm segments as our bot…and they used a joy stick. But…they showed us this OI with a small segmented wooden arm and pots on plexiglass that was manipulated by their fingers…that they had not yet been able to get to work successfully. On Saturday afternoon they got it to work…and it was cool.
On the 5.5 hours drive back to Grosse Pointe from BMR I worked out a physical prototype in my head…knowing that most of the arm code was already in place from the PID control and the functions that the programmer had already written (good ol’ modular code). During a fix it window we built a simple wooden prototype, attached pots and lots of loose wires back to the OI game port…and duct taped it to my son’s (the programmer) arm.
The prototyped proved to be feasible.
In the next fix it window the build team constructed the arm, the wiring was done (good ol’ LAN cables and modular connectors)…and it was tested…the pots tweaked…and tested…and tweaked…and tested…and finally passed the tests to be called ‘good’.
So…we gained inspiration from Team 1138’s concept and took it to the next level.
btw…a thank you email was sent to Team 1138 for their sharing and inspiration. And now… a public note of thanks: Thank You, Team 1138.
A note on this for individuals who would like to use this or a similar idea in the future: one team in 2005 (I don’t remember which) had an arm mounted controller much like this one. In order to get around “strap-in” time, they simply waited untill the beginning of teleoperated period to plug the arm controller into the OI - it’s fine if you are wearing it during autonomous, as long as it is not connected to the OI! Plugging a DB-15 into the OI should take way less time (2-3 seconds total) than putting the assembly on.
Hope this will help people trying to use a control system like this maximize efficiency in the future!
