AI 中文总结
该研究针对自适应振动控制的参数漂移问题，提出基于RMS的自适应终止准则，集成RCAC后经悬臂梁实验验证，可有效防止参数漂移且计算开销小。
AI 中文摘要
参数漂移是自适应振动控制系统的实际局限，尤其在扰动衰减后激励持续性减弱，或测量扰动使自适应问题病态时更为突出。该问题在柔性结构中尤为相关，此时自适应控制器在实现满意的振动抑制后仍可能持续更新参数。本文提出一种计算高效的基于均方根（RMS）的停止准则，当在规定区间内维持满意的振动衰减时，通过冻结自适应来缓解参数漂移。该准则通过递归计算性能变量的指数加权移动均方根实现，所需额外计算量可忽略。所提机制与回溯成本自适应控制（RCAC）集成，并在具有非共置执行器配置的悬臂梁振动抑制平台上通过数值模拟和闭环实验验证。未采用所提停止准则时，扰动抑制后的持续自适应会导致参数逐渐漂移，使振动抑制性能下降；启用基于RMS的阈值后，控制器参数保持有界，且已实现的振动衰减得以保留。结果表明，简单的基于性能的监测机制可有效防止自适应振动控制中的参数漂移，保留自适应的瞬态优势，且计算开销极小。
英文摘要
Parameter drift remains a practical limitation of adaptive vibration control systems, particularly when persistence of excitation diminishes after disturbance attenuation or when measurement disturbances render the adaptation problem ill-conditioned. This issue is especially relevant in flexible structures, where adaptive controllers may continue updating parameters even after satisfactory vibration suppression has been achieved. This paper proposes a computationally efficient root-mean-square (RMS)-based stopping criterion that mitigates parameter drift by freezing adaptation once satisfactory vibration attenuation has been sustained over a prescribed interval. The criterion is implemented by recursively computing an exponentially weighted moving RMS of the performance variable and requires negligible additional computational effort. The proposed mechanism is integrated with retrospective cost adaptive control (RCAC) and validated through both numerical simulations and closed-loop experiments on a cantilever-beam vibration-suppression platform with a noncollocated actuator configuration. Without the proposed stopping criterion, continued adaptation after disturbance rejection leads to gradual parameter drift and degradation of vibration suppression performance. When the RMS-based threshold is enabled, controller parameters remain bounded, and the achieved vibration attenuation is preserved. The results demonstrate that a simple performance-based monitoring mechanism can effectively prevent parameter drift in adaptive vibration control, retain the transient benefits of adaptation, and incur minimal computational overhead.
CommentsSubmitted to the Journal of Sound and Vibration
