Peter Nachtwey
Member
Over a year ago Tom Jenkins mentioned that he used sliding mode control for temperature control. I have seen sliding mode control (SMC) mentioned in my control books but they just glossed over what it is. The last out of curiousity I searched the web and bought a book ( a waste ). What I learned is that sliding mode control is indeed a VERY SIMPLE and VERY ROBUST means of control. SMC is not for every closed loop application, but it does work extremely well for temperature control. In most temperature control applications a heater or banks of heaters are simpley turned on and off. These are the applications where SMC will excel.
I used Ron Beaufort's soldering iron system data as example data for the link below. What would be nice is if Ron Beaufort implemented the third and forth equations of the link on his test system and report on the results. Notice that the link below is much simpler than the lambda tuning calculations done in a earlier posts. I think Ron Beaufort should scrutinize the link below as it too could help his customers that want zero overshoot but at the same time providing quick response. See the link.
To be honest, I could not hold back what I know now. Too many people use PID for applications where SMC is a much simpler and robust control method. The recent questions about PID and problems with PID have prompted me to to make this post. My Mathcad has also been upgraded which makes it much easier for me to post these simulations.
Temperature Control using Slidling Mode Control.
I am hoping that my explantion is simple enough for a couple of people to understand. I am also hoping that others consider this alternative to PID control because it is easy. One of the main problems I see is that there is no SMC block in a PLC. PLCs only offer PID blocks which is a shame.
I bet Tom has been shaking his head with each temperature PID post.
Tom, I am a believer now. Actually I have been for about year now. At least for applications that only require on/off control.
I used Ron Beaufort's soldering iron system data as example data for the link below. What would be nice is if Ron Beaufort implemented the third and forth equations of the link on his test system and report on the results. Notice that the link below is much simpler than the lambda tuning calculations done in a earlier posts. I think Ron Beaufort should scrutinize the link below as it too could help his customers that want zero overshoot but at the same time providing quick response. See the link.
To be honest, I could not hold back what I know now. Too many people use PID for applications where SMC is a much simpler and robust control method. The recent questions about PID and problems with PID have prompted me to to make this post. My Mathcad has also been upgraded which makes it much easier for me to post these simulations.
Temperature Control using Slidling Mode Control.
I am hoping that my explantion is simple enough for a couple of people to understand. I am also hoping that others consider this alternative to PID control because it is easy. One of the main problems I see is that there is no SMC block in a PLC. PLCs only offer PID blocks which is a shame.
I bet Tom has been shaking his head with each temperature PID post.
Tom, I am a believer now. Actually I have been for about year now. At least for applications that only require on/off control.