بهبود عملکرد کنترل مود لغزشی در جاذب ارتعاش فعال با استفاده از رویکرد تطبیقی

Unwanted vibrations in mechanical systems are among the main factors that reduce the service life of components, degrade performance accuracy, and generate noise and instability. To actively suppress the vibration of a structure subjected to base excitation, an active vibration absorber (AVA) can be effectively employed, in which the control force is generated based on the motion of the main mass or the base to mitigate the system’s vibrational response. Among various active control strategies, Sliding Mode Control (SMC) has gained wide attention due to its high robustness against parameter variations and external disturbances. However, frequent switching of the control signal during the reaching phase causes a phenomenon known as *chattering*, which leads to high-frequency oscillations in the control force, increased power consumption, and potential damage to the actuator. To address this limitation, an adaptive approach is proposed in this study to adjust the control gain of the SMC law dynamically based on the instantaneous distance of the system state from the sliding surface. When the state is near the sliding surface, the control gain decreases to minimize chattering and power usage, whereas under strong excitation or disturbance, it increases automatically to maintain system stability. To evaluate the proposed method, an active vibration absorber consisting of a spring–damper–mass system controlled by an electrodynamic linear actuator is considered. The results indicate that the proposed adaptive SMC preserves the robustness of the classical sliding mode while effectively reducing the main mass vibration, power consumption, and chattering amplitude compared to the conventional approach.