Overshoots

An overshoot is the phenomenon in which a system's response temporarily exceeds its eventual steady-state value after a change in input or reference. It is a common feature of transient responses in dynamic systems and can occur in mechanical, electrical, economic, and ecological contexts.

In control engineering and signal processing, overshoot is often described in response to a step input; the peak value relative to the final value is called the overshoot percentage. It is influenced by damping, natural frequency, and nonlinearity. Systems with high gain or low damping tend to show larger overshoot; nonlinearities can create irregular overshoot patterns or multiple peaks.

Types include peak overshoot; undershoot is the opposite when the response undershoots the target before converging to the final value.

Contexts and examples: In engineering, a servo motor or temperature controller may overshoot a setpoint before settling. In ecology, population overshoot occurs when numbers temporarily exceed carrying capacity, followed by resource depletion. In economics, exchange-rate overshoot describes a currency moving beyond its long-run target after a shock, before stabilizing.

Mitigation and analysis: design choices such as appropriate damping, gain scheduling, feedforward control, and slower reference changes can reduce overshoot. Analysis uses step response plots and time-domain specifications like maximum percentage overshoot and settling time.