Imaging Quality Evolution of Precision Dual-Reflective Optical Systems Under Thermomechanical Coupling Conditions

Precision dual-reflective optical systems are extensively utilized in spaceborne remote sensing and guided detection applications. Imaging quality, a critical performance parameter, is influenced not only by the fabrication precision of optical components but also, crucially, by the accuracy of system assembly. During operational deployment, these systems are subjected to complex environmental conditions, including temperature fluctuations, vibrational stresses, and microgravity. These factors collectively affect mirror stress distribution, disrupt optical axis alignment, and introduce component positioning errors, all of which contribute to the degradation of imaging performance. This study presents a comprehensive simulation framework that integrates optical assembly modeling with imaging performance analysis, explicitly accounting for mirror surface figure errors and pose deviations. Imaging quality is assessed using energy concentration metrics. A convolutional neural network (CNN) is employed to extract spatial features from imaging distributions, while Latin hypercube sampling (LHS) is utilized to generate pose deviation scenarios. The coupled simulations yield a multiphysics dataset, which supports the development of a multilayer perceptron (MLP) surrogate model incorporating Sigmoid activation functions to map deformation states to imaging performance indicators. Leveraging the outputs of multiphysics simulations, the proposed model systematically evaluates imaging performance under the isolated and combined influences of thermal, vibrational, and microgravity environments. The results indicate that the developed MLP achieves the highest prediction accuracy among the models considered, with an average error of 3.26%. Microgravity has a minimal impact on imaging quality when combined with vibration or thermal loads. Under fully coupled conditions, nonlinear interactions emerge: thermal stress accumulation from prolonged temperature exposure reduces transient vibration impacts, thereby improving imaging consistency.