"主动减震系统" can be translated as "active damping system" or "active vibration control system" in English, depending on the specific context and the level of technical detail required.
"Active damping system" is a more straightforward and commonly used term in engineering contexts, referring to a system that actively reduces vibrations or oscillations.
"Active vibration control system" provides a more detailed description, emphasizing the system's ability to actively control and mitigate vibrations.
In most cases, "active damping system" would be sufficient and appropriate.