Is this a position or velocity PI controller

[ccdubs]

Hi all,

I have a discrete representation of an analogue PI control algorithm. On the surface it looks very much like a velocity algorithm except for the integral part which is:

Ki*Ts*(E1+E2)

I was expecting to see:

Ki*Ts*E1

What affect will this have? And why has it been done like this?

On my basic level of thinking, this will act as to increase the integral action. What sort of system would this be required for?

The overall algorithm is:

u(i)=u(i-1)+Kp*(E1-E2)+Ki*Ts*(E1+E2)

Many thanks.

 

[ccdubs]

I have discovered (since posting) that the integral term in this instance is for trapezoidal integration and that the algorithm is correct.