Re: [Emc-users] How to home a joint when position depends on other joint?
I tried simple configuration (without offset component) too. And it worked perfectly. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
On 14 December 2013 08:08, Marius Alksnys marius.alks...@gmail.com wrote: I tried simple configuration (without offset component) too. And it worked perfectly. If it goes wrong with the offset component but works without it, then I suspect that the problem is with the execution order of the motion controller and the offset component. If you change the sequence of the addf statements in the HAL then you can probably make it work. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
Thanks, I will try it. This is something what I was thinking about and even tried to swap pid and offset addf lines, but I never found importance of addf order in documentation, which would be worth noting there.. On 2013.12.14 13:12, andy pugh wrote: On 14 December 2013 08:08, Marius Alksnys marius.alks...@gmail.com wrote: I tried simple configuration (without offset component) too. And it worked perfectly. If it goes wrong with the offset component but works without it, then I suspect that the problem is with the execution order of the motion controller and the offset component. If you change the sequence of the addf statements in the HAL then you can probably make it work. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
On Saturday 14 December 2013 11:38:26 Marius Alksnys did opine: Thanks, I will try it. This is something what I was thinking about and even tried to swap pid and offset addf lines, but I never found importance of addf order in documentation, which would be worth noting there.. It is important. In both threads. General rule of thumb in base thread, addf anything that needs a sample from hdwe (encoder?) addf in order, the chain of non-fp stuff the sample flows through addf last (for steppers) the parport.N functions General rule of thumb for servo thread speed stuff: addf signal receiver FP stuff (such as an encoder) addf the module its net output goes to addf next module the net of the above goes to addf continue till this function is completed That way any changes in the signal are propagated thru the processing chain in a single servo cycle. And when the actual control outputs are updated, they are working with the most up to date data they can get. There are times I expect when you may have another function chain that needs to be interleaved with the above, but I haven't run across a case where I could test and get a demonstratable advantage. YMMV of course. Spindle control servos, based on an encoders velocity, will get very unstable if the path is backwards thru the addf's because this severely restricts the bandwidth of the control. Even with what I THINK is all the ducks in a row, I found that double the speed of the servo thread from 1 millisecond to .5 milliseconds was a huge improvement. Because of non- linearity in the pwmgen and controller, I have a linear module between the PID.out and the PWMGEN.in, additional time delay, but it sure tames the PID.error range. Decent load torque at creep speeds (50 rpms) without hunting at 75% speeds (1200 on up) where its very sensitive. In retrospect, and I'd have to make additional room for it now, I know I would have been schmardter to have used the PMDX-106 (or whatever is being sold for that now) in place of the cheaper, too darned cheap and slow needs modification to raise its control bandwidth if its anywhere in a feedback chain, CNC4PC C41 for that translation function. Dumb, but its done. I won't make that mistake again, it, out of the bag, is simply not suitable for use in a servo controlled environment. You have been warned... On 2013.12.14 13:12, andy pugh wrote: On 14 December 2013 08:08, Marius Alksnys marius.alks...@gmail.com wrote: I tried simple configuration (without offset component) too. And it worked perfectly. If it goes wrong with the offset component but works without it, then I suspect that the problem is with the execution order of the motion controller and the offset component. If you change the sequence of the addf statements in the HAL then you can probably make it work. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.cl ktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Genes Web page http://geneslinuxbox.net:6309/gene Isn't it nice that people who prefer Los Angeles to San Francisco live there? -- Herb Caen A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
What you want to do is perform a topological sort (man tsort) on the graph. It should be simple enough to write a tool to do that. Ken On 12/14/2013 12:18 PM, Gene Heskett wrote: On Saturday 14 December 2013 11:38:26 Marius Alksnys did opine: Thanks, I will try it. This is something what I was thinking about and even tried to swap pid and offset addf lines, but I never found importance of addf order in documentation, which would be worth noting there.. It is important. In both threads. General rule of thumb in base thread, addf anything that needs a sample from hdwe (encoder?) addf in order, the chain of non-fp stuff the sample flows through addf last (for steppers) the parport.N functions General rule of thumb for servo thread speed stuff: addf signal receiver FP stuff (such as an encoder) addf the module its net output goes to addf next module the net of the above goes to addf continue till this function is completed That way any changes in the signal are propagated thru the processing chain in a single servo cycle. And when the actual control outputs are updated, they are working with the most up to date data they can get. There are times I expect when you may have another function chain that needs to be interleaved with the above, but I haven't run across a case where I could test and get a demonstratable advantage. YMMV of course. Spindle control servos, based on an encoders velocity, will get very unstable if the path is backwards thru the addf's because this severely restricts the bandwidth of the control. Even with what I THINK is all the ducks in a row, I found that double the speed of the servo thread from 1 millisecond to .5 milliseconds was a huge improvement. Because of non- linearity in the pwmgen and controller, I have a linear module between the PID.out and the PWMGEN.in, additional time delay, but it sure tames the PID.error range. Decent load torque at creep speeds (50 rpms) without hunting at 75% speeds (1200 on up) where its very sensitive. In retrospect, and I'd have to make additional room for it now, I know I would have been schmardter to have used the PMDX-106 (or whatever is being sold for that now) in place of the cheaper, too darned cheap and slow needs modification to raise its control bandwidth if its anywhere in a feedback chain, CNC4PC C41 for that translation function. Dumb, but its done. I won't make that mistake again, it, out of the bag, is simply not suitable for use in a servo controlled environment. You have been warned... On 2013.12.14 13:12, andy pugh wrote: On 14 December 2013 08:08, Marius Alksnys marius.alks...@gmail.com wrote: I tried simple configuration (without offset component) too. And it worked perfectly. If it goes wrong with the offset component but works without it, then I suspect that the problem is with the execution order of the motion controller and the offset component. If you change the sequence of the addf statements in the HAL then you can probably make it work. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.cl ktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] How to home a joint when position depends on other joint?
6 axis articulated robot. Its 5th and 6th joint motion is transferred from servo motor to the end by belts. Controlling 1-5 joints is trivial, but 6th one has to be offset by 5th position. This means you have to rotate both 5th and 6th motors equally to move only 5th joint. ( BTW, this is the reason why I started to think that there could be three different objects / levels in linuxcnc: motor - joint - axis ) There are resolvers on the motors and I use 7i49 card to read them. I am using genserkins for world mode and an offset component for offsetting 6th motor position and feedback signals in relation from 5th motor position signal. And it works correctly, except for homing, but I can't figure out how it _normally_ works. My homing uses resolver index. The problem is that I get following errors even when MIN_FERROR is 60 degrees. And I see that resolver position feedback signal makes a step when homing. I do see that big steps happen in resolver feedback signals, when they approach index. But the same is with normal joints. Any ideas how to solve this? I know I could do this in kins, but I would like to be able to use standard genserkins. Some lines from my config (joint / motor components and signals are numbered from 0): .hal file: --- loadrt offset names=offset-j56 addf offset-j56.update-feedback servo-thread addf offset-j56.update-output servo-thread net mot.4.pos-cmd joint.4.motor-pos-cmd = pid.4.command offset-j56.offset net mot.4.index-enable pid.4.index-enable net mot.4.index-enable joint.4.index-enable = [HM2](BRD)resolver.04.index-enable net mot.5.pos-cmd offset-j56.out = pid.5.command net mot.5.pos-fb = offset-j56.fb-in pid.5.feedback [HM2](BRD)resolver.05.position net jnt.5.pos-cmd joint.5.motor-pos-cmd = offset-j56.in net jnt.5.pos-fb offset-j56.fb-out joint.5.motor-pos-fb net mot.5.index-enable pid.5.index-enable net mot.5.index-enable joint.5.index-enable = [HM2](BRD)resolver.05.index-enable -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
2013/12/13 Marius Alksnys marius.alks...@gmail.com 6 axis articulated robot. Its 5th and 6th joint motion is transferred from servo motor to the end by belts. Controlling 1-5 joints is trivial, but 6th one has to be offset by 5th position. This means you have to rotate both 5th and 6th motors equally to move only 5th joint. I understand that moving motor 6, when motor 5 is standing still, will move only joint 6. Is that correct? Have you looked at Home_sequence variable in INI file? Home joint 5 to a known position and then home joint 6. Viesturs -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
On 12/13/13 07:42 , Marius Alksnys wrote: 6 axis articulated robot. Its 5th and 6th joint motion is transferred from servo motor to the end by belts. Controlling 1-5 joints is trivial, but 6th one has to be offset by 5th position. This means you have to rotate both 5th and 6th motors equally to move only 5th joint. ( BTW, this is the reason why I started to think that there could be three different objects / levels in linuxcnc: motor - joint - axis ) Currently motor and joint are nearly the same. A joint is just a motor with a home offset applied to it. This is the robot i'm playing with: http://highlab.com/~seb/linuxcnc/scorbot-er-3/1024131507a.jpg It's got a differential drive on the wrist. The wrist has two motors and two degrees of freedom (pitch and roll). There's a good picture on page 2-1 of the manual here: http://highlab.com/~seb/linuxcnc/scorbot-er-3/ER3-Manual.pdf Each of the two wrist motors causes hand motion in both pitch and roll. By running the wrist motors in a coordinated way you can effect just pitch, or just roll, or any combination. This coordination between the two wrist motors will be handled by kinematics. Below kinematics, at the joint level, the two wrist joints home independently (though maybe simultaneously). I just got the control box hooked up to LinuxCNC (non-realtime via RS-232, boo), kinematics comes next... :-) -- Sebastian Kuzminsky -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
On Friday 13 December 2013 13:50:44 Marius Alksnys did opine: 6 axis articulated robot. Its 5th and 6th joint motion is transferred from servo motor to the end by belts. Controlling 1-5 joints is trivial, but 6th one has to be offset by 5th position. This means you have to rotate both 5th and 6th motors equally to move only 5th joint. ( BTW, this is the reason why I started to think that there could be three different objects / levels in linuxcnc: motor - joint - axis ) There are resolvers on the motors and I use 7i49 card to read them. I am using genserkins for world mode and an offset component for offsetting 6th motor position and feedback signals in relation from 5th motor position signal. And it works correctly, except for homing, but I can't figure out how it _normally_ works. My homing uses resolver index. The problem is that I get following errors even when MIN_FERROR is 60 degrees. And I see that resolver position feedback signal makes a step when homing. Yikes. I know little to zip about resolvers, only that if its lying to you, I would call it a resolver problem and would be all over the maker asking for a solution from them until it was proven that it was indeed my setup generating the error. I'd move one of them that is doing this to a stepper just laying on the table, and log what it says for at least a turn going both ways when the stepper is driven in full step mode, one step at a time, where it generally will rest at very close to 1.8 degrees per step. Probably closer than .05 degrees per step from ideal. If there is a repeat error cycle every 4 steps, thats the motor itself, so use the average of the last 4 steps which should remove that error, but anything else has to be a funkity resolver. IMO of course. Over 200 steps, a full revolution of the motor, it has to be 1.8 degrees per step for most steppers. I do see that big steps happen in resolver feedback signals, when they approach index. But the same is with normal joints. Any ideas how to solve this? See above as a I have got the tools way to isolate resolver error to the resolver. I know I could do this in kins, but I would like to be able to use standard genserkins. Some lines from my config (joint / motor components and signals are numbered from 0): .hal file: --- loadrt offset names=offset-j56 addf offset-j56.update-feedback servo-thread addf offset-j56.update-output servo-thread net mot.4.pos-cmd joint.4.motor-pos-cmd = pid.4.command offset-j56.offset net mot.4.index-enable pid.4.index-enable net mot.4.index-enable joint.4.index-enable = [HM2](BRD)resolver.04.index-enable net mot.5.pos-cmd offset-j56.out = pid.5.command net mot.5.pos-fb = offset-j56.fb-in pid.5.feedback [HM2](BRD)resolver.05.position net jnt.5.pos-cmd joint.5.motor-pos-cmd = offset-j56.in net jnt.5.pos-fb offset-j56.fb-out joint.5.motor-pos-fb net mot.5.index-enable pid.5.index-enable net mot.5.index-enable joint.5.index-enable = [HM2](BRD)resolver.05.index-enable Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Genes Web page http://geneslinuxbox.net:6309/gene * Knghtbrd notes he has mashed potatoes for brains tonight Valkyrie yum, can I have some? Knghtbrd um ... * Knghtbrd hides from Valkyrie A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
On 13 December 2013 19:14, Gene Heskett ghesk...@wdtv.com wrote: My homing uses resolver index. The problem is that I get following errors even when MIN_FERROR is 60 degrees. And I see that resolver position feedback signal makes a step when homing. Yikes. I know little to zip about resolvers, only that if its lying to you, I would call it a resolver problem and would be all over the maker asking for a solution from them until it was proven that it was indeed my setup generating the error. If there is a problem there then it is a problem of my creation, as I wrote the resolver driver for the 7i49. Resolvers don't have an index, but I have pretended that they do because LinuxCNC is used to seeing index behaviour with encoders. The thing is that LinuxCNC should be used to seeing an enormous step at encoder index during homing, and should know how to ignore it. I use resolvers, homing to index, on my own machine, and there are no issues with f-error during homing. Are you allowing LinuxCNC to control the resolver.N.index-enable pins, or are you doing something clever in HAL? -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] How to home a joint when position depends on other joint?
On Friday 13 December 2013 18:17:43 andy pugh did opine: On 13 December 2013 19:14, Gene Heskett ghesk...@wdtv.com wrote: My homing uses resolver index. The problem is that I get following errors even when MIN_FERROR is 60 degrees. And I see that resolver position feedback signal makes a step when homing. Yikes. I know little to zip about resolvers, only that if its lying to you, I would call it a resolver problem and would be all over the maker asking for a solution from them until it was proven that it was indeed my setup generating the error. If there is a problem there then it is a problem of my creation, as I wrote the resolver driver for the 7i49. I'll take that 30 lashes with a wet noodle then Andy. If you made a mistake, I'd have to paint it on the wall. Resolvers don't have an index, but I have pretended that they do because LinuxCNC is used to seeing index behaviour with encoders. The thing is that LinuxCNC should be used to seeing an enormous step at encoder index during homing, and should know how to ignore it. I use resolvers, homing to index, on my own machine, and there are no issues with f-error during homing. Are you allowing LinuxCNC to control the resolver.N.index-enable pins, or are you doing something clever in HAL? Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) Genes Web page http://geneslinuxbox.net:6309/gene The soul would have no rainbow had the eyes no tears. A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. -- Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831iu=/4140/ostg.clktrk ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
