26-09-2013, 03:16 PM
REPORT ON PID ALGORITHM VERIFICATION FOR DIFFERENT ERROR INPUT
PID ALGORITHM VERIFICATION.doc (Size: 376 KB / Downloads: 19)
DESCRIPTION:
Problem description
The proportional term works on the present error, the integral term works on past errors and the derivative term works on the present and past error to forecast a future response of the system.
The derivative term makes an adjustment based on the
rate at which the Plant output is changing from its Setpoint.
A notable characteristic in this type of control is when the error is constant, or at the maximum limit, the effect is minimal. There are some systems where proportional and/or integral do not provide enough
control. In these systems, adding in the derivative term completes the control requirements. The PID output is calculated after the proportional,integral and derivative terms have been determined.
CONCLUSION:
The Controller’s processing capabilities will dictate the system’s ability to respond to the error. In cases where the Plant response is sluggish, it may be possible to decrease the processor speed and save on power, but still be able to execute the PID routine in acceptable time. The Program measurements shown PID can vary, depending on the size of the error and how much of the math routines will be used. For different error inputs we get different output accordingly.
And from the above result we can conclude that when error is zero then output goes into saturation mode.