Robot Arm C

[chalker]

Sure, but that is immensely difficult for most teams (including myself, as I do not have the programming abilities). And also, (this is mainly to Chalker, yes I realize "this isn't the place for official clarifications" =P) if we use servo motors like they do in the "master and slave" control systems, will they be counted towards the total number of motors?

It seems to me a motor is a motor, regardless of the specific type. (But of course I encourage you to submit an official clarification request).

[sachleen]

Sure, but that is immensely difficult for most teams (including myself, as I do not have the programming abilities). And also, (this is mainly to Chalker, yes I realize "this isn't the place for official clarifications" =P) if we use servo motors like they do in the "master and slave" control systems, will they be counted towards the total number of motors?

You would probably want to just use a potentiometer or something for the master arm. I also agree with chalker, a motor is a motor.

[iwonder]

Now you're at crossroads, while manual control would let you account for supervisor error in the setup, an autonomous robot will provide significantly more coordination and fluidity, and look at industry, most robots put on plant floors are autonomous, which would indicate that there is a definite benifit to an autonomous robot over a manually controlled one(the pay for a worker to run the robot vs the autonomous controls would be about the same).

If you're still concerned about item placement(which should be at most 2 mm off, in my mind) there are vision systems used in industry to locate objects, which could be put on said robot, albeit with some difficulty. However I do not believe that the parts would be placed far enough off for an autonomous arm to care either way.

Yeah, I thought about that, but another benefit in the industry is the robots are doing the same thing all day. You need this to do something once without error. In a production line, i'd imagine everything would be placed in the exact same spot every time so the robot would never miss, here it'll be slightly different every time and you'd have to come up with a more complicated solution to account for it. I would love to see an autonomous bot do this, but I don't think anybody will.

There's a video on YouTube of a bot with an arm, and a kid has a replica of the arm as the control, so as he moves the joints of the control arm, the robot's arm moves in the same way. That'd probably be the solution for this event, I think.

But if you think about it, that's exactly what you want this to do, exactly the same thing, every time... In reality it can't be more than 2 mm or so off(seeing as positions are specified to the mm) and if a robot is designed correctly, that shouldn't be a problem. Anyways, it's not like a human could line things up perfectly. Regardless, with a good robot design, that shouldn't matter if you're slightly off, it would still pick up the object.

[jander14indoor]

Sure, but that is immensely difficult for most teams (including myself, as I do not have the programming abilities). And also, (this is mainly to Chalker, yes I realize "this isn't the place for official clarifications" =P) if we use servo motors like they do in the "master and slave" control systems, will they be counted towards the total number of motors?

It seems to me a motor is a motor, regardless of the specific type. (But of course I encourage you to submit an official clarification request).

Uhh, last I checked, if you put mechanical energy into an electric motor it became a generator, not a motor. Physically the same thing, but not functionally.

But I'm not sure that's relevant to a master and slave system. The master needs to have position sensors, not motors. If you are using servos as sensor, just like a generator isn't a motor, it shouldn't matter. Of course every servo in the slave is a motor.

Course official clarification couldn't hurt.

Jeff Anderson
Livonia, MI

[iwonder]

All this talk of using servos for position sensors has me wondering... are you using standard r/c servos? or some active servo system?

[illusionist]

Heh, I don't even know what my design will be. Our team has very little experience with this kinda thing (programming servos), so I might end up using my Vex kit

[iwonder]

Vex might actually be a good option... all the electronics for a simple arm are there, and the mechanics shouldn't take to long to build... you could even(if you spent the time) do some active stuff with the pic box they have, and some potentiometers(like a button to move an object and drop it in the goal box).

[sachleen]

Vex might actually be a good option... all the electronics for a simple arm are there, and the mechanics shouldn't take to long to build... you could even(if you spent the time) do some active stuff with the pic box they have, and some potentiometers(like a button to move an object and drop it in the goal box).

My experience with making an arm out of VEX hasn't been the best. First off, using the metal parts is not a good idea as it's just too heavy. Even when I didn't use that, I didn't get very good results. With the way you attach shafts to the servos (simply inserting a square shaft into the servo), you have some wiggle before the servo actually spins. So, in an arm with a few joints, it'll be wiggling around way too much even though the shaft isn't actually turning. I haven't worked with VEX in a few years so I don't know if they've changed anything.

[illusionist]

Nope, not much has changed (last I used was about two years ago). And you're right about those factors.

[sachleen]

Nope, not much has changed (last I used was about two years ago). And you're right about those factors.

In that case, I would advise against using VEX for this event. Especially if you're considering buying a kit. I'd assume VEXplorer has the same issues.