Most of the robots I have worked with - like this 6 axis, rely on the absolute encoders retaining their position as rehoming after a power loss cannot be insured as many of them will crash if they do not know where they are at on powerup.
To "rehome" they they have to be manual jogged into a certain position, shot pins installed in the joints, and then some sequence followed to reset their position, usually via the pendant. I think this scenario is pretty common with 6 axis robots. Dave On 10/26/2013 4:09 PM, Jon Elson wrote: > Duesentrieb Yahoo wrote: >> Jon, I just opened an accout on picasa. You will find a lot of pictures >> there. If something is missing pls let me know: >> >> https://picasaweb.google.com/104662429729242075783/FanucS420f?authkey=Gv1sRgCJaFwtDZ7dve3AE >> >> > OK, I saw 4 pictures showing a Fanuc A860-0320-T111 encoder. > I definitely have a converter for these, but I'm not sure they support > all the functionality needed on a robot. The problem comes during > homing. At power-on, the encoder and encoder converter don't > know absolute position. The ABS encoders, if battery backup > is provided, apparently put out a burst of quadrature pulses to > revolve the apparent position to the offset from the index > position, thereby eliminating the need to home the axis. But, > I've never tried this with my PWM system. > > Anyway, if you can provide a homing routine for the robot when > LinuxCNC is restarted, then it should work fine. Our > Fanuc encoder converter will handle proper commutation > info at startup, and will provide the encoder index when it > reaches that position. If the work envelope is such that the > robot cannot be homed to angle sensors in the joints plus > the index position, then it gets more complicated. > > Jon > > ------------------------------------------------------------------------------ > October Webinars: Code for Performance > Free Intel webinars can help you accelerate application performance. > Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from > the latest Intel processors and coprocessors. See abstracts and register > > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
