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Schunk_svh_driver : how stop the hand in case of contact with anything?

During the homing (or reset) if one of the motors touches an obstacle it stops. I wish also during the phase of achievement target position in case of contact with any object the motor concerned to stop. How can I do? Can I modify the topics?

Asked by Alba on 2015-04-30 09:55:20 UTC

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what do you really want? the motors seem to stop when they reach a current-limit or a reset_timeout, so if through your "phase of achievement target position" it will stop if there is something in the way of the fingers, or?

Asked by inflo on 2015-04-30 10:01:06 UTC

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I want that the motor stops if it touches an object, during the contact the motor reach a current limit (isn't it?) but the motors don't seem to stop. Why?

Asked by Alba on 2015-04-30 10:12:16 UTC

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what do you mean with "dont SEEM to stop" ? dont you have a svh hand and test it ?

Asked by inflo on 2015-04-30 11:47:50 UTC

If for example the finger is supposed to reach 400mA but is stuck and only manages to get up to 200mA the threshold will not be reached. In such cases the reset timeout should abort the timeout after the amount of seconds specified. However the timeout is only active once there is no measurable difference in current.

In case the current changes a little bit but does not reach the threshold it will be in an infinite loop. In this (rare) case stop the driver execution, maybe restart the hardware, and set a lower reset current factor.

Asked by inflo on 2015-05-01 06:17:53 UTC

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Hey Alba,

maybe you confuse the two operation modes?

  1. Reset/Homing:
    During homing, the fingers will stop when they hit a hard stop. This is the desired behaviour as the fingers try to find the maximum movement range. If you block them during this movement they will not be referenced properly

  2. Normal movement:
    During normal operation the controllers will try to reach the target position you have given them. Refer to this answer.

Best Regards Georg

Asked by heppner on 2015-06-06 09:11:56 UTC

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