PID Loop for stepper motors
- Ameone
- Offline
- Senior Member
- 
				  
		Less
		More
		
			
	
		- Posts: 42
- Thank you received: 8
			
	
						10 Feb 2020 16:27				#156968
		by Ameone
	
	
		
			
	
			
			 		
													
	
				Replied by Ameone on topic PID Loop for stepper motors			
			
				Ok thanks! Regarding the encoder scale, I have a rotary encoder with a resolution of 2000 steps/rev. Since it's directly connected to the motor axis, I've concluded an encoder scale of 2000/360 = 5.55. Is it correct?			
					Please Log in or Create an account to join the conversation.
- PCW
- 
				  
- Away
- Moderator
- 
				  
		Less
		More
		
			
	
		- Posts: 17370
- Thank you received: 5062
			
	
						10 Feb 2020 17:13				#156972
		by PCW
	
	
		
			
	
			
			 		
													
	
				Replied by PCW on topic PID Loop for stepper motors			
			
				Is this a rotary axis?
Is it a 2000 PPR encoder?
					Is it a 2000 PPR encoder?
Please Log in or Create an account to join the conversation.
- Ameone
- Offline
- Senior Member
- 
				  
		Less
		More
		
			
	
		- Posts: 42
- Thank you received: 8
			
	
						10 Feb 2020 17:17				#156973
		by Ameone
	
	
		
			
	
			
			 		
													
	
				Replied by Ameone on topic PID Loop for stepper motors			
			
				Yes, rotary acis with a 2000 ppr encoder!			
					Please Log in or Create an account to join the conversation.
- PCW
- 
				  
- Away
- Moderator
- 
				  
		Less
		More
		
			
	
		- Posts: 17370
- Thank you received: 5062
			
	
						10 Feb 2020 17:24				#156975
		by PCW
	
	
		
			
	
			
			 		
													
	
				Replied by PCW on topic PID Loop for stepper motors			
			
				Right so the scale would be 22.2222222
(8000/360)
This is because a 2000 line (PPR) encoder has 8000 counts per turn
when using quadrature.
					(8000/360)
This is because a 2000 line (PPR) encoder has 8000 counts per turn
when using quadrature.
Please Log in or Create an account to join the conversation.
- Ameone
- Offline
- Senior Member
- 
				  
		Less
		More
		
			
	
		- Posts: 42
- Thank you received: 8
			
	
						10 Feb 2020 17:26				#156976
		by Ameone
	
	
		
			
	
			
			 		
													
	
				Replied by Ameone on topic PID Loop for stepper motors			
			
				Ok thank you very much, tomorrow I’ll retest everything and let you know if it works.			
					Please Log in or Create an account to join the conversation.
- Ameone
- Offline
- Senior Member
- 
				  
		Less
		More
		
			
	
		- Posts: 42
- Thank you received: 8
			
	
						11 Feb 2020 13:31				#157050
		by Ameone
	
	
		
			
	
			
			 		
													
	
				Replied by Ameone on topic PID Loop for stepper motors			
			
				Ok so my mistake, the encoder has 1000 PPR. I've tried to move the axis at 90 degrees using both 1000/360 and 4000/360 encoder scales. The scale 1000/360 gives the correct effective angle, is there some problem?
Also, do you know why the axis moves so slowly, without changing speed?
					Also, do you know why the axis moves so slowly, without changing speed?
Please Log in or Create an account to join the conversation.
- PCW
- 
				  
- Away
- Moderator
- 
				  
		Less
		More
		
			
	
		- Posts: 17370
- Thank you received: 5062
			
	
						11 Feb 2020 13:38				#157051
		by PCW
	
	
		
			
	
			
			 		
													
	
				Replied by PCW on topic PID Loop for stepper motors			
			
				Maybe this is a terminology issue
A 1000 PPR encoder has 1000 slots and will generate 4000 counts per turn in quadrature 4X mode
A 250 PPR encoder has 250 slots and will generate 1000 counts per turn in quadrature 4X mode
Posting your hal/ini files would be the quickest way to diagnose your motion issues.
					A 1000 PPR encoder has 1000 slots and will generate 4000 counts per turn in quadrature 4X mode
A 250 PPR encoder has 250 slots and will generate 1000 counts per turn in quadrature 4X mode
Posting your hal/ini files would be the quickest way to diagnose your motion issues.
Please Log in or Create an account to join the conversation.
- Ameone
- Offline
- Senior Member
- 
				  
		Less
		More
		
			
	
		- Posts: 42
- Thank you received: 8
			
	
						11 Feb 2020 13:56				#157054
		by Ameone
	
	
		
			
	
	
		
			
			 		
													
	
				Replied by Ameone on topic PID Loop for stepper motors			
			
				Ok thanks, I'm attaching the files!
 
			
					Attachments:
Please Log in or Create an account to join the conversation.
- PCW
- 
				  
- Away
- Moderator
- 
				  
		Less
		More
		
			
	
		- Posts: 17370
- Thank you received: 5062
			
	
						11 Feb 2020 14:17				#157060
		by PCW
	
	
		
			
	
			
			 		
													
	
				Replied by PCW on topic PID Loop for stepper motors			
			
				At first glance:
you still have statements like
setp pid.a.maxerror .0005
These all need to be removed
Also you have the maxvel on the rotary axis set to 11 degrees per second which is pretty slow
					you still have statements like
setp pid.a.maxerror .0005
These all need to be removed
Also you have the maxvel on the rotary axis set to 11 degrees per second which is pretty slow
Please Log in or Create an account to join the conversation.
- Ameone
- Offline
- Senior Member
- 
				  
		Less
		More
		
			
	
		- Posts: 42
- Thank you received: 8
			
	
						11 Feb 2020 14:39				#157062
		by Ameone
	
	
		
			
	
			
			 		
													
	
				Replied by Ameone on topic PID Loop for stepper motors			
			
				Yeah I modified only the x axis (axis 0) to speed up the configuration. I'll modify the other ones later on.
Sorry but where did you see that 11 degrees per second speed?
					Sorry but where did you see that 11 degrees per second speed?
Please Log in or Create an account to join the conversation.
		Time to create page: 0.084 seconds	
