Research On High Precision Measurement Method Of Target Position In Tubular Structure

Tubular structures(hydraulic cylinders,accumulators,gun barrels,etc.)have application needs in many fields such as industrial production,national defense technology,and so on.However,due to the complex internal conditions of tubular structures,they often work in special environments,and traditional measurement methods cannot well complete the detection task.Moreover,research on tubular structures,a special structure,is relatively scarce at home and abroad,Therefore,high-precision detection of target positions in tubular structures has very important academic research value and engineering application value.Based on the project background,combined with the tubular structure,and starting from the basic issue of target detection,this paper selects FMCW millimeter wave radar for research.Firstly,theoretical research on electromagnetic transmission characteristics within the tubular structure is conducted,and the electromagnetic loss formula within the tubular structure is derived.The transmission loss under different distances,pipe diameters,and pipe media is simulated,verifying the correctness of the theory,it provides a certain reference for subsequent radar design.Then,research was carried out on target information detection.Due to the complex environment in the pipe and the large amount of clutter,the first step was to conduct signal preprocessing and extract effective signals.By improving the EMD algorithm,the algorithm’s clutter removal effect was improved.Then,theoretical analysis was conducted on ranging algorithms,including the theoretical analysis and derivation of the improved frequency spectrum thinning algorithm based on CZT algorithm and the improved phase method algorithm based on phase difference,through simulation,the feasibility and accuracy of the two algorithms are verified.Finally,an actual test was conducted to verify the effectiveness and enforceability of the algorithm by processing the measured signal data in a metal pipeline.The conclusion was drawn that the improved algorithm based on CZT can achieve ranging accuracy of 0.25 mm,while the improved ranging algorithm based on phase method can achieve accurate ranging accuracy of 0.014 mm under ideal conditions.The ranging accuracy of the spectrum thinning algorithm was compared,the phase method can achieve higher theoretical accuracy.