Hi chris, i would like ask you something, based on you said , I need to figure out how my elbow angle is moved in function to my base angle, and after this i will need to add this function to my kinematics file, in that case i would be using the DH parameters so, i should modificate genserkins, shouldn't I? do you have maybe some file which can help me about this function?
El jue., 21 de mar. de 2019 a la(s) 14:15, Chris Albertson ( albertson.ch...@gmail.com) escribió: > I think what you have is a circular link. That means a > parallelogram type geometry. I have a robot arm like this too but mine > is MUCH smaller and lower cost. > > Mine is nearly identical to this arm on Amazon. > .amazon.com/Blesiya-Professional-Aluminum-Mechanical-Educational > < > https://www.amazon.com/Blesiya-Professional-Aluminum-Mechanical-Educational/dp/B07LCNBJJL/ref=sr_1_16?keywords=6dof+arm&qid=1553194112&s=gateway&sr=8-16 > > > > Notice that these are two motors on the shoulder and the "elbow" is pushed > by a link. I think we have the same geometries, except for scale. > The way to model it using DH is to re-draw the robot arm. Make a paper > drawing of an equivalent arm that has a motor on each axis and no > circular links and no passive links. You WILL need to transform the > shaft angle of the moved motor. > > I don't use MK for this. I like "move it" but still DH parameters really > only work for serial links so the trick is to model your arm as a serial > link arm, just pretend the elbow motor is on that elbow and it's shaft > angle is a function of the base motor shaft angle. This geometry is VERY > common and yes there are names for it but most people call them palletizing > robots. THese robots need to lift heavy loads, like bags of dog food off > belts and place them on wood pallets so the motors are plased in the base > and force transmitted to push rods. Most are only 4-DOF A Google search > for "palletizing robot kinematics" will ,give tons of information. But > "cheating" works. Remove the pushlinks and move the motor and make DH > parms for that. The later "fix" the elbow motor shaft angle. . > > The arm in the above link is like mine in that it uses model airplane > servos. These are very inaccurate and are open loop. So the plan is to > close the control loop with a video cameras. This is not something MK was > designed for hence using Moveit. moveit.ros.org Then I find I need to > sychronize the video shutters so that is on hold for now. > > > On Thu, Mar 21, 2019 at 6:45 AM yomin estiven jaramillo munera < > yejm...@gmail.com> wrote: > > > Hi guys is me again, our kinematics problem have progressed, this is > > because we are sure that our D-H parameters were correctly extracted, > but > > seems that our robot couldn't be defined with this parameters. > > I'm saying this 'cause our robot is a miller MR 2000 and is very old, it > > is moving how you can see in the follow link > > > > https://www.youtube.com/watch?v=Hp0gVXj5u-I&feature=youtu.be > > > > the D-H parameters could define the kinematics but when a joint depend of > > the before one, but in this case our joint 2 is not changing the > > orientation of our joint 3. The joint 2 is able to change the position on > > the space of the final tool, but is unable to change its orientation on > the > > space. this kinematics is obviously very different to PUMA kinematics and > > we are doubting about DH parameters can solve this. > > is there any name for this kind of kinematics? > > could i solve this using D-H parameters? > > could i solve this using genserkins? > > All my axes are set like angular joint, could that involved in a possible > > solution? > > > > <https://www.youtube.com/watch?v=Hp0gVXj5u-I&feature=youtu.be> > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
