Shop OBEX P1 Docs P2 Docs Learn Events
Gripper questions — Parallax Forums

Gripper questions

SciTech02SciTech02 Posts: 154
edited 2006-03-11 18:32 in Robotics
Hello,· I'm interested in getting the gripper kit for my robot.· First, I have the PING))) Ultrasonic senser and mounting bracket for it, and I wanted to see some ideas on how to have the gripper and the mounting bracket on at the same time?· The other is what can I do with the gripper, I saw that it could play fetch but it was very vague on it.· Any help will be great.···························· -SciTech02.

Post Edited (SciTech02) : 3/7/2006 8:56:12 PM GMT

Comments

  • JavalinJavalin Posts: 892
    edited 2006-03-08 13:25
    SciTech02,

    Try www.lynxmotion.com - they sell various grippers and servo kits & brackets.

    james
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-08 17:54
    Thank you for your reply.· But I see my question was to big and/or complex, let me narrow it down.· I wanted to know what can the gripper do?· You know, what projects could I do with it, Do I have to buy extra items for it like a third IR LED/receiver for it to detect an object and grab it?· You know, stuff like that so I·would know what I can/need to do so it would work.· Any help will be great.········ -SciTech02.
  • Steve JoblinSteve Joblin Posts: 784
    edited 2006-03-08 20:24
    It is difficult to answer your question directly... I think you might want to step back and start with an objective first. For example, you can create a remote controlled robot that can pick up a block of wood, you can create an autonomous robot that picks up only red objects, you can create a robot that will turn up the volume dial on your stereo... you first have to start with what you want to do, then you will know what types of sensors you need to incorporate to accomplish your task.
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-09 00:18
    Thank you for answering!· What I wanted it to do is play catch, or if possible fetch.· Detect the object, and grab·it.· I saw on a website that it would chase a ping pong ball, and grab it.··That's what I wanted it·to do,·and to·be autonomous.· Just so you'll·know, I have a PING))) ultrasonic senser.··It will be on top of my robot,·like Zax's super Boe-bot.············ -SciTech02.· ·
  • Steve JoblinSteve Joblin Posts: 784
    edited 2006-03-09 14:11
    Great... now we have a project!· I think that playing "catch" may be a bit much...· To catch a ball requires some pretty complex and fast processing (you basically need to study the path and speed of the ball, anticipate where it will be when you are in range to catch it, move to that exact spot and close the grippers at an exact moment.· Think about how difficult it is to teach a human to catch a ball...

    I think "fetch" is a bit more realistic project since the target is stationary.· I think you still need some rather sophisticated sensors to even do this... I would think that a CMUCam would be a good sensor for this application... the CMUCam can track a specific color, so for example, you could use a small, soft, bright red ball.· You could then use the CMUCam to locate the object and move to it... then I think you would need mechanical switches as bumpers (or feelers) to help position the robot so that it can pick up the ball.· Then it is just a matter of running a pre-defined routine to open the jaws, move in a pre-defined amount, close the grippers and raise up the gripper.

    I don't think that IR or Sonar types of sensors will have the accuracy you will require...
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-03-09 14:29
    SciTech2 -

    WARNING: The following recommendation may result in a very ADDICTIVE hobby, and cause HUGE sums of money to be spent, and EXTENSIVE amounts of time to be expended!

    Punch any of the following into Google and check the results:
    Soccer Bots or soccer robots or RoboCup

    Here is one place to start: http://www.robocup.org/

    Just don't blame me if it gets completely out of hand! smile.gif

    Regards,

    Bruce Bates

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    <!--StartFragment -->

    Post Edited (Bruce Bates) : 3/9/2006 2:32:50 PM GMT
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-09 16:41
    Thank you for helping me this far.· What I meant by "Catch" was to just roll up to a staitionary object and grab it·and not·return it.· My·project·is to grab a stationary ball and·end the program, then I can grab the ball and put it·somewere in the room and it would find it again.· Or, when it grabs the ball, it would start roaming.· Would I have to buy another senser to do that?· I have the PING))) senser, is that enough?



    P.S Bruce Bates, I know, this hobby is very addictive, and·very expensive.· Have you seen the new ROBONOVA?··It's over $1,000!freaked.gif···········

    ·········· -SciTech02.
  • Steve JoblinSteve Joblin Posts: 784
    edited 2006-03-09 16:49
    The problem is the resolution and accuracy of the PING (or other Sonar type sensors)... they don't work very well at very close ranges and may have difficulty detecting such a small object (especially one that is round and would deflect much of the sound, as compared to being able to reflect the sound back to the sensor).
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-09 18:06
    I see. ·It might be·a bit late to ask this but, can I do anything without buying extra stuff?· I mean, let's say someone just finished the Robotics with the Boe-Bot text, and got the gripper, what can he/she do with it?· If I have to buy extra stuff, what should I buy? confused.gif· I mean, the CMU camera is neat, but it costs alot.· Besides, I have seen other people use the gripper and they don't have it.· Your help has ben great so far, thanks.



    P.S·I'd kind of like to see what other people have done with there grippers.··So if Zax or anyone else has a gripper, please show us what you have done.


    Post Edited (SciTech02) : 3/9/2006 6:12:08 PM GMT
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-10 17:28
    Hello?··I'm sorry,·I hope I didn't scare anyone.······· -SciTech02.
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-03-10 21:02
    SciTech2 -

    This particular gripper is relatively new in the Parallax line, so I don't know how many there are in the field. I may be undersestimating their popularity however, as there was a significant reduction in price with the announcement of this new grippr.

    I wish I could offer more information on the following, but it has temporarily prevented me from ordering a gripper for my BOE-Bot. The Parallax Gripper, and I think it's the Parallax Tank Tread kit are mutually exclusive, if i remember correctly. You can use either one of them, but not both of them together. When I get the time, I may work on that compatability problem, but at present I have the tank treads, so I'm holding off on the gripper.

    Regards,

    Bruce Bates

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    <!--StartFragment -->
  • Jake11611Jake11611 Posts: 47
    edited 2006-03-10 21:32
    Maybe you could use a ball full of IR led's or something?
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-11 04:57
    Thank you for answering my question.· I don't think I'm quite·ready to buy the CMU camera just yet.· It's cool, no, very cool, but it costs alot of doh.· I'm sort of disapointed in that I thought I could buy it and it would be able to do·all·that·stuff, without geting extra stuff.· Oh well.· Thank you guys for helping me out.· smile.gif
  • SciTech02SciTech02 Posts: 154
    edited 2006-03-11 18:32
    Wait!· I got an idea!idea.gif· What if I got 3 IR sensers and put 2 on the edge of the gripper plates, and the other in the middle of the gripper.· That way, it would work·sort of·like the QTI line follower.· If the middle one detected somthing, it would grab it, and if the other one's detected somthing, it would turn to it.· It sounds posible.
Sign In or Register to comment.