On 05/14/2014 10:59 PM, Ralph Stirling wrote: > Ray, > > I think it would be best for you to spend some time reading > through LinuxCNC documentation. There are quite a few > excellent manuals on the entire set of software, from G-code > interpreter all the way to axis movement. > > Here are some suggested starting points: > > kinematics: http://linuxcnc.org/docs/html/motion/kinematics.html > > block diagram of the system: > page 14 of http://linuxcnc.org/docs/2.5/pdf/LinuxCNC_Developer_Manual.pdf > > -- Ralph
Just what I was looking for! I'm embarrassed I didn't find them looking through the site. I guess I didn't think of this as being a developer issue, given it's a pretty settled function, as I understand it. I'd still be interested in picking up a robotics text, if anyone has any recommendations. Thanks again to everyone for the education! Back to lurking. Raymond Julian Kettle River, MN ________________________________________ > From: rayj [raymo...@frontiernet.net] > Sent: Wednesday, May 14, 2014 8:38 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] axes definition > > Raymond Julian > Kettle River, MN > > The things we admire in men, kindness and generosity, openness, honesty, > understanding and feeling are the concomitants of failure in our system. > And those traits we detest, sharpness, greed, acquisitiveness, meanness, > egotism and self-interest are the traits of success. And while men > admire the quality of the first they love the produce of the second. > -John Steinbeck, novelist, Nobel laureate (1902-1968) > > On 05/14/2014 10:18 PM, Ralph Stirling wrote: >> G-code *is* how you specify your Cartesian motion. Kinematics converts that >> to motions of each joint or axis. >> >> -- Ralph >> > What language is used to program the kinematics module with the > information to allow it to interpret the G code? > > > > >> rayj <raymo...@frontiernet.net> wrote: >> >> >> On 05/14/2014 09:43 PM, Stuart Stevenson wrote: >>> On Wed, May 14, 2014 at 8:31 PM, rayj <raymo...@frontiernet.net> wrote: >>> >>>> I understand Cartesian and Polar coordinate systems. I'm looking for >>>> the actual method of deriving the commands that need to be sent to the >>>> motor (assuming the motor shaft is the axis of rotation for the arm >>>> segment under discussion). >>>> >>> The Cartesian and Polar coordinate system are on the same side of the >>> kinematics. >>> The Joint system is on the other side of the kinematics. >>> >>> >>>> Example: you want to move the tip of the mill in a vertical line >>>> parallel to the Z axis. How do you take the description of that line >>>> (motion from the Cartesian point <a,b,c1> to point <a,b,c2) and >>>> calculate (ow!) or use software to generate the commands to be sent to >>>> the (3, I'm guessing)motors? >>>> >>> You program the machine to move in the Cartesian coordinate system using >>> Cartesian and/or Polar coordinates. >>> LinuxCNC reads what you want, calculates where you want to move, sends the >>> move coordinates to the kinematics module, the kinematics module calculates >>> where the motor/slides should be to give you what you want then sends its >>> calculation to the control to move the motor/slide to position. >>> >>> >>>> And back to the original question, are those joints designated by one of >>>> the xyzabcuvw designations, or is there a completely different >>>> designation system. >>>> >>> Axes in LinuxCNC are labeled XYZABCUVW >>> Joints in LinuxCNC are labeled joint0, joint1 ... >>> >>> There are some confusing areas where the labels are mixed but the context >>> should make it clear for you. "crossed fingers" >>> >>> >>>> >>>> Is there a robotics textbook out there that anyone can recommend? I've >>>> found that out of date textbooks can be gotten for very little and are a >>>> wealth of information. >>>> >>> Robotics kinematics is a different animal than the trivial kinematics of >>> the 3 axis mill. >>> But the hard work has been done for most robot configurations. >>> >> The robot kinematics is one aspect that I'm interested in. That's one >> of the reasons I chose to work with LCNC for my machining setup. It has >> far wider applications. >> >> So when I designate a motion in Cartesian space, the kinematics module >> generates the G code to make the motors move. So the setup for a given >> system is the programing the kinematics module with the information >> about what G code, or perhaps a lower level language, that will result >> in the commanded Cartesian space motion. Is most of this information in >> the integrators manual, or some other LCNC manual? >> >> Thanks very much for taking the time to reply. I can't imagine how long >> it would have taken me to get the overall view you've explained to me. >> Assuming I have understood correctly. :>) >> >> >> Raymond Julian >> Kettle River, MN >> >>> >>>> >>>> Raymond Julian >>>> Kettle River, MN >>>> >>>> The things we admire in men, kindness and generosity, openness, honesty, >>>> understanding and feeling are the concomitants of failure in our system. >>>> And those traits we detest, sharpness, greed, acquisitiveness, meanness, >>>> egotism and self-interest are the traits of success. And while men >>>> admire the quality of the first they love the produce of the second. >>>> -John Steinbeck, novelist, Nobel laureate (1902-1968) >>>> >>>> On 05/14/2014 07:40 PM, Stuart Stevenson wrote: >>>>> Joint space is the physical movement of the machine components. >>>>> Cartesian space perfect theoretical XYZ space sitting on the machine >>>> table >>>>> It is the desired path of the tool (end effector). >>>>> With a robot you can move the joints but a single joint movement likely >>>>> would not give you the tool motion you were trying to achieve. >>>>> On a 3 axis mill you can have the same effect if the X and Y axes are not >>>>> square with one another. >>>>> Let's say you move the X axis only: >>>>> in joint space only the X axis moves and if the X and Y are not square >>>> you >>>>> would cut a corner that would not be 90 degrees. >>>>> On the same machine cartesian space X motion would also see the Y move to >>>>> compensate for the squareness problem. >>>>> In other words your Cartesian space would be square (as assumed) but your >>>>> joint space is not square. >>>>> This compensation would have required you to input correction amounts in >>>>> the kinematics to describe to the control the out of square condition. >>>>> Kinematics is the mathematical description of the joint space converted >>>> to >>>>> cartesian space. >>>>> as Sam said - clear as mud >>>>> >>>>> >>>>> >>>>> On Wed, May 14, 2014 at 6:57 PM, rayj <raymo...@frontiernet.net> wrote: >>>>> >>>>>> >>>>>> >>>>>> Raymond Julian >>>>>> Kettle River, MN >>>>>> >>>>>> The things we admire in men, kindness and generosity, openness, honesty, >>>>>> understanding and feeling are the concomitants of failure in our system. >>>>>> And those traits we detest, sharpness, greed, acquisitiveness, meanness, >>>>>> egotism and self-interest are the traits of success. And while men >>>>>> admire the quality of the first they love the produce of the second. >>>>>> -John Steinbeck, novelist, Nobel laureate (1902-1968) >>>>>> >>>>>> On 05/14/2014 06:43 PM, andy pugh wrote: >>>>>>> On 15 May 2014 00:17, rayj <raymo...@frontiernet.net> wrote: >>>>>>> >>>>>>>> Is there a similar standard in the control of robotic arms? >>>>>>> >>>>>>> It is the same there. (Or it can be). >>>>>>> >>>>>>> XYZ is end-effector point in space (room coordinates). >>>>>>> ABC are end-effector angles >>>>>>> UVW (could) be ways to define moves in end-effector space. >>>>>>> >>>>>>> But that rather depends on if you are moving the robot in cartesian >>>>>>> space or joint space. >>>>>>> >>>>>> >>>>>> There's what I'm trying to learn. I'd never heard of joint space! Does >>>>>> this stuff fall under the category of "robotics" or "kinematics", or >>>> what? >>>>>> >>>>>> >>>>>> >>>> ------------------------------------------------------------------------------ >>>>>> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >>>>>> Instantly run your Selenium tests across 300+ browser/OS combos. >>>>>> Get unparalleled scalability from the best Selenium testing platform >>>>>> available >>>>>> Simple to use. Nothing to install. Get started now for free." >>>>>> http://p.sf.net/sfu/SauceLabs >>>>>> _______________________________________________ >>>>>> Emc-users mailing list >>>>>> Emc-users@lists.sourceforge.net >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >>>> Instantly run your Selenium tests across 300+ browser/OS combos. >>>> Get unparalleled scalability from the best Selenium testing platform >>>> available >>>> Simple to use. Nothing to install. Get started now for free." >>>> http://p.sf.net/sfu/SauceLabs >>>> _______________________________________________ >>>> Emc-users mailing list >>>> Emc-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/emc-users >>>> >>> >>> >>> >> >> ------------------------------------------------------------------------------ >> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >> Instantly run your Selenium tests across 300+ browser/OS combos. >> Get unparalleled scalability from the best Selenium testing platform >> available >> Simple to use. Nothing to install. Get started now for free." >> http://p.sf.net/sfu/SauceLabs >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> ------------------------------------------------------------------------------ >> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE >> Instantly run your Selenium tests across 300+ browser/OS combos. >> Get unparalleled scalability from the best Selenium testing platform >> available >> Simple to use. Nothing to install. Get started now for free." >> http://p.sf.net/sfu/SauceLabs >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. > Get unparalleled scalability from the best Selenium testing platform available > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. > Get unparalleled scalability from the best Selenium testing platform available > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
