A Model-Driven Scheme to Compensate the Strain-Based Non-Intrusive Dynamic Pressure Measurement for Hydraulic Pipe

TLDR

Strain‑based non‑intrusive pressure sensors are attractive for pipe monitoring, but they typically rely on static strain‑pressure sensitivity coefficients, which limits accuracy for dynamic measurements. This study proposes a dual‑stage, model‑driven scheme to compensate dynamic pressure measurements in hydraulic pipes. The method analytically derives dynamic strain‑pressure sensitivity coefficients from pipe axial equations for both thin‑ and thick‑wall pipes, calibrates their physical parameters against experimental data, and then uses the calibrated coefficients to adjust dynamic pressure readings via their relation to static coefficients. When applied to an industrial hydraulic pipe system, the compensation reduced relative error substantially, confirming the scheme’s effectiveness.

Abstract

Strain-based non-intrusive approaches for measuring the pressure of pipes have attracted widespread attention due to their great convenience and ability to avoid destroying the integrity of structures. However, the mentioned method usually measures the dynamic pressure based only on the static strain-pressure sensitivity coefficients (SSSCs) instead of the dynamic strain-pressure sensitivity coefficients (DSSCs) due to its complicated calibration, which will inevitably affect the accuracy significantly. To address this issue, a model-driven scheme with dual stages is proposed in the present study to compensate the dynamic pressure measurement. The DSSCs are analytically derived for the first time from the axial governing equations of the pipe, considering the general boundary conditions for the thin-wall pipe and thick-wall pipe simultaneously. In the first stage, the physical parameters involved in the DSSCs are calibrated by minimizing the residual of the experimental results and the theoretical counterparts. In the second stage, the DSSCs calculated from the calibrated analytical model are utilized to compensate the dynamic pressure based on the relationship between the DSSCs and the SSSCs. The proposed method is applied to an industrial hydraulic pipe system, and the experimental results show that the relative error is reduced greatly after the compensation is implemented, demonstrating the validity of the proposed compensation method.