overshoot

Overshoot is the temporary excursion of a system's output beyond its final steady-state value after a disturbance or input change. It occurs when the response is underdamped or feedback is strong relative to damping. Overshoot can be seen in engineered systems, natural processes, and social contexts where a predicted target is briefly exceeded.

In control theory and signal processing, overshoot commonly refers to the step response of a system. After a sudden input change, the output may exceed the final value before settling. For standard second-order systems, overshoot is governed by the damping ratio; a typical expression gives percent overshoot as exp(-pi zeta / sqrt(1 - zeta^2)) times 100% for 0<zeta<1.

Overshoot is usually accompanied by ringing or oscillations as energy shifts between modes. High overshoot signals insufficient damping; little overshoot indicates heavier damping and a slower, more stable response.

In environmental science, ecological overshoot describes a situation where humanity's demand on natural resources exceeds Earth's annual regeneration. This concept is linked to ecological footprint metrics and to Earth Overshoot Day, the date when annual global demand outstrips capacity.

In economics and finance, overshoot can describe a temporary move of prices or exchange rates beyond their long-run equilibrium after a shock, often due to price stickiness in other markets. It features in models of currency adjustment and asset-price dynamics.

Mitigating overshoot typically involves increasing damping, adjusting feedback gains, or slowing the rate of input change so the system settles without large transient excursions.