Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001
· A useful method for this form is the ratio of the actual output to the desired output, (c/r)
· If we are planning on applying the PID controller to the water tank example from before we get the following block diagram, (Note: the block diagram is overkill in this application)
· We can find the closed loop transfer function for this process and controller,
· For the problem below, use the PID values, with the valve/tank parameters used previously to find the system response to a step input to 20 at time zero, and 10 at time 10. (hint: convert the closed loop equation back to a difference equation)
