The existing methods for thermal barrier coating (TBC) life prediction rely mainly on experience and formula derivation and are inefficient and inaccurate. By introducing deep learning into TBC life analyses, a convolutional neural network (CNN) is used to extract the TBC interface morphology and analyze its life information, which can achieve a high-efficiency accurate judgment of the TBC life. In this thesis, an Adap–Alex algorithm is proposed to overcome the problems related to the large training time, over-fitting, and low accuracy in the existing CNN training of TBC images with complex tissue morphologies. The method adjusts the receptive field size, stride length, and other parameter settings and combines training epochs with a sigmoid function to realize adaptive pooling. TBC data are obtained by thermal vibration experiments, a TBC dataset is constructed, and then the Adap–Alex algorithm is used to analyze the generated TBC dataset. The average training time of the Adap–Alex method is significantly smaller than those of VGG-Net and Alex-Net by 125 and 685 s, respectively. For a fixed number of thermal vibrations, the test accuracy of the Adap–Alex algorithm is higher than those of Alex-Net and VGG-Net, which facilitates the TBC identification. When the number of thermal vibrations is 300, the accuracy reaches 93%, and the performance is highest.

Wheel rail rolling contact fatigue is a very common form of damage, which can lead to uneven rail treads, railhead nuclear damage, etc. Therefore, ANSYS software was used to establish a three-dimensional wheel–rail contact model and analyze the effects of several main characteristics, such as the rail crack length and crack propagation angle, on the fatigue crack intensity factor during crack propagation. The main findings were as follows: (1) With the rail crack length increasing, the position where the crack propagated by mode I moved from the inner edge of the wheel–rail contact spot to the outer edge. When the crack propagated to 0.3–0.5 mm, it propagated to the rail surface, causing the rail material to peel or fall off and other damage. (2) When the crack propagation angle was less than 30°, the cracks were mainly mode II cracks. When the angle was between 30 and 70°, the cracks were mode I–II cracks. When the angle was more than 70°, the cracks were mainly mode I cracks. When the crack propagation angle was 60°, the equivalent stress intensity factor reached the maximum, and the rail cracks propagated the fastest.

At present, visual imaging is widely applied for surface defects such as bumps and scratches in the manufacture of precise parts with a highly reflective surface. However, the high light reflection and halo disturbance as a result of the illumination in visual imaging exert a direct influence on the accuracy of defect detection. In this regard, the present paper develops an adaptive illumination method based on space–time modulation for a visual imaging system. Furthermore, a digital micro-mirror device (DMD) is employed to realize the pixel-level spatiotemporal modulation of illumination. Then, in combination with the illumination intensity feedback of charge coupled device (CCD), the time-space ratio is adjusted automatically to achieve adaptive uniform illumination and effectively suppress the high light reflection and halo disturbance of highly reflective surfaces. The experimental results show that, in terms of restraining high light disturbance, the visibility and accuracy of visual imaging are improved.

High precision and efficiency are main advantages of contact scanning probes. However, the measurement result distortion caused by the high-speed and high-frequency scanning has become increasingly prominent. Therefore, this paper proposes a two-stage dynamic compensation strategy based on damping ratio and frequency mapping, which utilizes the compensation effect of different damping ratios to enhance compensation in series after the primary compensation. The time-domain response function of the probe system is constructed, revealing its characteristics and error distribution in transient and steady state responses. Then, the mapping spectrum of the damping ratio and compensation error at multiple discrete frequencies is studied, and a dynamic compensator based on the zero-pole cancellation principle is designed. Furthermore, a dynamic solution framework based on Kalman filtering is proposed, achieving accurate compensation of the target frequency, especially for medium to high-frequency signals. Finally, compensation simulations and experiments for low-to-high frequency mixed signals are designed, verifying the significant effect of the proposed method through compensation precision comparison.

To address the dynamic measurement problem of a rigid bar under dynamic measurement conditions, this study uses a laser tracker, a coordinate measuring machine, a pyramid prism bar, and a pyramid prism to form a measurement system. Through the study and analysis of the laser tracker at different sampling frequencies, two important conclusions are obtained: firstly, there is a difference in measurement results between the geometric center measurement method and the optical center measurement method for the pyramid prism bar. Secondly, after reflection by a pyramid prism, double-speed measurement can be achieved on a low-speed sliding table. This provides a general idea for the research on measurement systems based on laser trackers and a pyramid prism bar.