High-precision micro-thrust measurement instrument: Dynamic structural design and virtual diagnosis optimization

Space-based gravitational wave detection missions urgently require the development of high-resolution, low-noise micro-thrust measurement instruments and technologies at the micronewton (μ N) or even nanonewton (nN) scale. However, current technologies suggest significant challenges in the design, fabrication, commissioning, calibration, and operation of such instruments. This paper proposes an improved Roberval configuration based on an H-type linked parallelogram torsion balance structure to enhance measurement resolution and interference resistance. A simulation kernel is developed to model the structural dynamics of the instrument. Key measurement-influencing factors are identified and modeled to integrate a comprehensive virtual measurement instrument (VMI). The reliability of the VMI is validated against analytical solutions of the structural model alongside noisy experimental data from the physical measurement instrument (PMI). The VMI is then utilized to measure responses under noisy conditions, calibrate its characteristics, and perform comparative analyses with the PMI. In particular, this tool enables efficient verification and optimization of the dynamic structure, prediction of measurement performance, and optimization of passive environmental suppression strategies. Consequently, this work establishes a digital design framework based on iterative structural optimization and virtual diagnostics, significantly enhancing the development efficiency and reliability of micro-thrust measurement instruments.