Howtosignalprocessing
The "integral time" refers to a hypothetical sequence of events where the error starts at zero, then abruptly jumps to a fixed value. Such an error would cause an instantaneous response from the controller's proportional term and a response from the integral term that starts at zero and increases steadily.
- What does the integral do in PID?
- What does integral time mean?
- What is derivative time in PID?
- What is the unit of integral time?
What does the integral do in PID?
The integral in a PID controller is the sum of the instantaneous error over time and gives the accumulated offset that should have been corrected previously. The accumulated error is then multiplied by the integral gain (Ki) and added to the controller output.
What does integral time mean?
The integral time (I) is defined as the time required to develop, when a stepwise change in deviation is imposed, an output change due to integral action that is exactly equal to the change due to proportional action.
What is derivative time in PID?
More properly, a derivative describes the slope or the rate of change of a signal trace at a particular point in time. Accordingly, the derivative term in the PID equation above considers how fast, or the rate at which, error (or PV as we discuss next) is changing at the current moment.
What is the unit of integral time?
Integral units can be either minutes or repeats per minute, either of which is the reciprocal of the other: 2 rpm = 0.5 min. So the 1/Ti is probably in units of repeats per minute, whereas Rate is usually in units of minutes.
