The accuracy of traditional measuring machines is affected by the measuring range and sensitive geometric errors, and it is not possible to combine large caliber and high-precision measurements. This study proposes a differential geometric error-weighting method for designing a high-precision, large-diameter measuring machine. The machine utilized a zero-Abbe arm structure and applied the rigid body theory and small-angle hypothesis to model geometric errors. Weights were calculated for 23 geometric errors, identifying eight sensitive ones. A picometer-precision laser interferometer (quDIS) with a theoretical positioning accuracy of 0.2 nm/mm and standard flat rulers are used to ensure highly accurate positioning of the Y-axis/Z-axis of the measuring platform and reduce the straightness of both axes by approximately 75%, with radial and axial runout of the rotary table under 100 nm. The development and design method of the high-precision measuring machine proposed in this study is applicable to large-diameter high-precision flexible measurement, and the accurate control of measuring machine movement accuracy is realized by calculating the geometric error weights.

The influence mechanism and identification of mass defects in hemispherical resonators are currently highly challenging and significant research directions. This paper first establishes a shell–rod coupling vibration model under the influence of mass error, and, based on this model, constructs a characterization system for the vibration characteristics (quality factor and frequency split) of the resonator. The influence of the first four harmonic components of the mass defect on the quality factor and frequency split of the resonator was systematically studied, and the analytical expression of its quantitative representation was derived, which reveals the internal physical relationship between the mass defect and the vibration characteristics. Subsequently, the theoretical model was verified by using finite element simulation. Finally, an efficient and high-precision method for identifying the first four harmonics of hemispherical resonator mass defects was proposed, and an experimental device was set up to successfully achieve the synchronous identification of the first four harmonic components. An innovative beam-split optical system that streamlines displacement metrology reduced test complexity by >60%.

The characteristic parameters of fixed joint surfaces, such as stiffness and damping, play a dominant role in determining the overall performance of various mechanical structures, especially in high-performance machine tools. However, accurate characterization of these joint parameters remains challenging, due to a lack of direct validation methods. In this study, we consider the deformation of the base caused by the interaction of micro-convex bodies based on the 3D Kogut and Etsion (KE) model, and modify the characteristic parameter model of joint surfaces. Interfacial fractal parameters were determined using the structural function method, which enabled direct experimental validation of the characteristic parameter model. Finally, a comprehensive dynamic performance analysis of the GP300 grinding machine was conducted, and the results revealed that the joint surface changed the various modes of vibration and the corresponding natural frequencies of the machine tool. These findings deepen our understanding of the characteristic parameters of the binding surface and their effects, and have important guiding significance for the performance analysis and design of machine tools.

On-machine measurement is a highly effective approach for enhancing machining accuracy and efficiency. A critical factor influencing the accuracy of on-machine measurements is the straightness error of the linear guideway. However, this error is significantly affected by environmental factors such as temperature, vibration, and gravity deformation. To improve the measurement accuracy of machine tools, this study investigates the impacts of these factors on straightness errors and proposes an innovative separation and compensation model for linear guideway straightness. A thermo-mechanical coupling simulation is employed to establish a model that quantifies the influence of thermal errors on straightness. The results demonstrate that thermal gradients cause the straightness error to bend to varying degrees, depending on the temperature distribution. Furthermore, a vibration error model is developed, revealing that the vibration period is approximately twice the ball diameter. Notably, vibration errors can be effectively mitigated using a band-stop filter to eliminate the corresponding frequency components. The study also addresses the effect of gravity deformation, comparing the deformation under different support conditions, highlighting the significance of precise support positioning. Through experimental validation of the straightness error separation and compensation model, it is shown that the straightness error of a conventional linear guideway can be reduced by 95%, and the compensated straightness error is less than 0.2 μm. This novel approach not only improves the accuracy of on-machine measurement but also provides valuable insights for optimizing machine tool performance under dynamic operating conditions.