超精密气浮轴的混合预测建模与控制参数整定

Hybrid predictive modeling and controller parameter tuning for ultra-precision aerostatic guideway

  • 摘要: 超精密气浮轴是实现纳米级运动的关键部件,其控制参数的仿真整定依赖于气浮轴模型,模型偏差会导致整定结果难以应用于实际系统。对此,提出一种基于残差网络修正的混合预测建模方法及控制参数整定策略。通过开环扫频试验辨识线性模型,构建残差网络学习线性模型的未建模动态,再基于混合预测模型进行控制参数的贝叶斯优化,结果表明,基于残差网络的混合预测建模提高了开环模型精度,在扫频测试下的拟合度由线性模型的64.00%提升至75.05%,仿真与实际响应的阶跃性能指标偏差仅为5.59%。基于混合预测模型的整定参数使阶跃响应超调量由33.03%降至10.84%,显著提升了气浮轴的动态性能。

     

    Abstract: Ultra-precision aerostatic guideways are key components for achieving nanometer-level motion. The reliability of controller parameter tuning in simulation depends on the accuracy of the open-loop model, as model deviations can render the tuned parameters inapplicable to the actual system. To address this issue, a hybrid predictive modeling method with residual network-based correction along with a controller parameter tuning strategy is proposed. A linear model is identified through an open-loop frequency sweep test, and a residual network is constructed to capture its unmodeled dynamics. Bayesian optimization is then performed based on the hybrid predictive model for controller parameter tuning. The results show that the hybrid prediction modeling based on residual networks has improved the accuracy of the open-loop model. The fitting degree under swept-frequency testing has increased from 64.00% of the linear model to 75.05%, and the deviation of the step performance indicators between the simulation and the actual response is only 5.59%. The parameter tuning based on the hybrid prediction model reduced the overshoot of the step response from 33.03% to 10.84%, significantly improving the dynamic performance of the air-float shaft.

     

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