lagdemping

Lagdämpning (lagdemping) refers to the set of methods and techniques used to reduce the negative effects of time delay in dynamic systems, particularly in feedback control. Time delays can originate from sensing, computation, communication, or actuation, and they often cause phase lag, reduced stability margins, and slower or less accurate responses.

In control engineering, lagdämpning aims to maintain stability and performance in the presence of lag. Common approaches include Smith predictors for known constant dead time, which use a model of the delay to compensate in the controller, and model predictive control, which optimizes future control actions while accounting for delays. Dead-time compensation and Pade approximations can be used to model delays in the controller design. Lead-lag compensation, where a lead element improves phase margin and a lag element shapes the low‑frequency response, is another strategy. In addition, filtering and careful sampling can reduce the impact of measurement noise, but these techniques can also introduce additional delay, requiring careful tuning.

Applications of lagdämpning span process automation, robotics, autonomous vehicles, and any system where communication or sensing delays are significant. Practical measures include improving hardware to reduce latency (faster sensors, shorter communication paths, parallel processing), as well as choosing robust or adaptive control strategies that tolerate variations in delay.

Key considerations in lagdämpning include the accuracy of delay models, the trade-off between responsiveness and robustness, and the potential for delay variation over operating conditions.