activesemipassive

Activesemipassive refers to a hybrid control paradigm that integrates active and semi-passive elements to improve dynamic performance while limiting energy use. It is used to describe systems where semi-active components handle most of the adaptation and energy dissipation, while occasional bursts of energy are injected to achieve superior responses.

The idea sits between active control (which uses energy continuously to command actuators) and semi-active control (which modulates existing energy without energy generation). In activesemipassive schemes, a control algorithm monitors structure or process state and switches or tunes devices, occasionally drawing energy from an onboard reservoir to augment damping or stiffness during high-demand events.

Common implementations involve magnetorheological or fluid-based dampers whose impedance is adjusted in real time, combined with energy storage or smart switching to deliver short power injections. The approach emphasizes robustness to model uncertainty and energy efficiency, trading some constant energy draw for improved peak performance. It may also employ energy harvesting elements to extend operation.

Applications include vibration isolation for buildings and aerospace structures, automotive suspensions, precision manufacturing, and any system requiring adaptive damping with constrained power. Limitations include controller complexity, the need for reliable energy storage, and potential fatigue of actuators. The term activesemipassive is sometimes used variably across literature, and some sources prefer describing such systems as a blended active-semi-active approach.