Integraalisäätö

Integraalisäätö, or integral control, is a method used in control systems to eliminate steady-state errors. It works by adding a component to the controller's output that is proportional to the integral of the error signal over time. The error signal is the difference between the desired setpoint and the actual measured output of the system. By integrating this error, the controller can determine the accumulated deviation from the setpoint.

When there is a persistent error, the integral term will continue to grow, pushing the controller's output to counteract the error. This ensures that eventually, the error will be driven to zero, and the system's output will match the setpoint. This is particularly useful in applications where even a small steady-state error is unacceptable, such as in temperature control or motor speed regulation.

However, integral control can also introduce undesirable dynamics into the system. A common issue is integral windup, which occurs when the integral term continues to accumulate even when the controller output is saturated (i.e., it has reached its maximum or minimum limit). This can lead to overshoot and oscillations when the system eventually recovers from saturation. To mitigate this, anti-windup strategies are often employed. Integraalisäätö is a fundamental concept in PID (Proportional-Integral-Derivative) controllers, where it works in conjunction with proportional and derivative control actions to achieve robust and accurate system performance.