On Tue, Jan 11, 2022 at 12:14 PM Todd Zuercher <to...@pgrahamdunn.com> wrote:
> Isn't this how most closed loop stepper drives claim to work? > It might be, but the commercial closed-loop stepper drivers retain the step/dir interface, so they can be commanded only to position but not velocity or torque. This library would allow the stepper to be commanded as if it were a serial interfaced servo motor. The other neat thing about this library is it is open source and designed to use a wide range of cheap and available hardware. If you drill down into their web site they have a procedure and advice for picking the parts and then based on the parts they show how to use the library to make a controller. The documentation is excellent and aims at a reader with only mid-level technical background. This last part is unique for FOC controllers. Usually, this subject is a very complex specialty engineering subject. They made it accessible. I'll try it on the Z-axis of my mini mill. Likely the hardest part will be learning how to interface this with LCNC. > > Todd Zuercher > P. Graham Dunn Inc. > 630 Henry Street > Dalton, Ohio 44618 > Phone: (330)828-2105ext. 2031 > > -----Original Message----- > From: Chris Albertson <albertson.ch...@gmail.com> > Sent: Tuesday, January 11, 2022 2:06 PM > To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> > Subject: [Emc-users] Field Oriented Control (FOC) algorithm for BLDC and > Stepper motors. > > [EXTERNAL EMAIL] Be sure links are safe. > > Here is a different way to control a stepper motor. This control method > treats the stepper as if it is just a plain old BLDC motor but with 50 > poles and 2 phases. Positional accuracy is determined by an encoder, not > the number of steps as the controller is not doing "steps" but using the > motor as a continuous motion servo. It seems like this could be a > retrofit to a machine that uses steppers to give an increased performance > while keeping the same motors. > > You can read the theory used here: > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FVector_control_&data=04%7C01%7Ctoddz%40pgrahamdunn.com%7Cc21d1504e33b42a15eaf08d9d535a470%7C5758544c573f47cebee96c3e0806fb43%7C0%7C0%7C637775249503911306%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=CnWkF%2BhmPNQmnNLXcRJePq%2FO1YdMMdCBvrBKVdACd%2Bk%3D&reserved=0(motor) > > What this project offers is not a controller, but Open Source software > that runs on any of a shortlist of microcontrollers and uses a long list of > sensors and motors. The website was a project design walk-through. This is > also, as you can see very low cost, he is using a $5 driver board from eBay. > > What they are saying is that small steppers have better performance and use > less power when driven using their closed-loop algorithm. But it does > require that you place a current sensor (Hall effect or in in-line > resister) on both phases and drive the stepper with a PWM capable pair of > full-H-bridges. What is going on is the control software is measuring > current and forcing it to have the desired waveform against the inductance > and mechanical loads. > > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2Fzcb86TRxTxc&data=04%7C01%7Ctoddz%40pgrahamdunn.com%7Cc21d1504e33b42a15eaf08d9d535a470%7C5758544c573f47cebee96c3e0806fb43%7C0%7C0%7C637775249503911306%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=GXOX24h9HBSe3wGa%2BTwmhzw7vMc3E0SGfFUrAfZL8gw%3D&reserved=0 > > Here is the project website > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsimplefoc.com%2F&data=04%7C01%7Ctoddz%40pgrahamdunn.com%7Cc21d1504e33b42a15eaf08d9d535a470%7C5758544c573f47cebee96c3e0806fb43%7C0%7C0%7C637775249503911306%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=0xzqDAizMu8CL9EgF0yVHA7pXwJJUf%2BQ72JUBh8Zpu0%3D&reserved=0 > > > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=04%7C01%7Ctoddz%40pgrahamdunn.com%7Cc21d1504e33b42a15eaf08d9d535a470%7C5758544c573f47cebee96c3e0806fb43%7C0%7C0%7C637775249503921326%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Rv%2BriLj8Cg5KjS8l6PQ2VWG6K%2FRg4%2BHcIqi0jH2Hvr8%3D&reserved=0 > > > _______________________________________________ > 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
