# Working of ac servo drive in position control mode and algos for position control

I have started working with a Panasonic AC servo drive of capacity 400W (manual). While trying to understand how a ac servo works in position control mode. After experimenting I have come to the following conclusions:

The AC servo maintains position by comparing.

For example if I want to reach a position of 1000(say), and I am giving 1002 pulses(forward) and once it is running, I am giving a reverse of 2 pulses when the motor has reached 999(using Quadrature Encoder Interface). The drive will reach a position of 1000 by (999-2=997 position) and the remaining 3 pulses to go forward or reverse is decided by the closeness of the position as going forward of 3 pulses will be close to my 1002 position it will go from 997 to 1000. So finally it will reach a position of 1000.

Now if I want to make a position control algorithm, the thing I have to do is play with forward and reverse pulses. Is it right?

Can anyone give me some guide on position control algorithms? The load will be like a 1 or 2kg.

• For starters, post a link to the datasheet for the exact servo drive you're using. Commented Mar 1, 2013 at 4:54
• This is the directlink to the manual minas-a5.panasonic.biz/manual/en/minas-a5_manu_e.pdf