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What sensor would you recommend for sensing hand closing pressure — Parallax Forums

What sensor would you recommend for sensing hand closing pressure

mikedivmikediv Posts: 825
edited 2009-07-02 00:11 in Robotics
Guys I am building a robot that will have hands well claws anyway and I want to be able to get feedback when the hand is clamping what would everyone recommend for a sensors to do this

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2009-06-19 23:31
    Some sort of pressure sensitive sensor should work. See the link below for an example. Take care.

    http://www.parallax.com/Store/Sensors/PressureFlexRPM/tabid/177/CategoryID/52/List/0/Level/a/ProductID/384/Default.aspx?SortField=ProductName%2cProductName

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    Chris Savage
    Parallax Engineering
  • kwinnkwinn Posts: 8,697
    edited 2009-06-20 05:09
    The sensor from this post (http://forums.parallax.com/forums/default.aspx?f=10&m=360969) might be worth looking at.
  • LeonLeon Posts: 7,620
    edited 2009-06-20 18:02
    Strain gauges have been used on high-end robotic hands.

    Leon

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    Amateur radio callsign: G1HSM
    Suzuki SV1000S motorcycle
  • mikedivmikediv Posts: 825
    edited 2009-06-21 01:26
    Thanks guys ,,,Hey Chris can I ask you ..? I was looking at that sensor from you guys but the gripper/hand that I am building is on 1.8 inches wide at maximum and less than an 1/8 of an inch closed the flexi sensor is 8 inches long right???
    Could you give me pointer on how I could use it in this circumstance does the entire Flex have to be used or can I cut it down?

    Oh Leon I have looked at strain gauges and transducers I should have been more clear in my question I was wondering what Parallax product might be used.
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2009-06-21 06:33
    mikediv,

    The FlexForce sensor that Chris mentions will work fine if the sensing element (circular area) has a flat rigid back support. on the opposite side you can build up the sensor with a rubber or plastic contour. (see attachment). For your application, this is mainly to protect the sensor over repetitive motion and sheer stress. If the sensor becomes creased or is deformed your readings will become inaccurate and you will lose repeatability.

    The use of strain gauges is also a very effective method, but generally requires more electronic hardware to decode them.

    Another effective method is to use a coil separated by a compressible medium and a metal foil on the opposite side of the medium. As the material between the coil and the foil compresses, the inductance of the coil changes a measurable amount and can be translated into a pressure reading. This method requires some electronic hardware as well.

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • mikedivmikediv Posts: 825
    edited 2009-07-02 00:11
    Hey Beau that's an excellent idea thanks
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