Improved Self-Calibration of a Multilateration System Based on Absolute Distance Measurement

Area of Science:

• Metrology
• Industrial Instrumentation
• Coordinate Measuring Systems

Background:

• Multilateration tracking systems (MLTSs) are crucial for industrial 3D coordinate measurements.
• Accurate calibration of MLTS system parameters is essential for high-precision measurements.
• Conventional self-calibration methods for MLTSs with absolute distance measurement (ADM) are inefficient due to simultaneous estimation of all parameters.

Purpose of the Study:

• To develop a novel self-calibration method for ADM-based MLTSs that enhances estimation efficiency and accuracy.
• To optimize ADM by reducing system parameters through precise, separate estimations of dead paths.
• To simplify the residual function for estimating tracking station locations.

Main Methods:

• A novel self-calibration method optimizing ADM for MLTSs.
• Separate and precise estimation of dead paths to reduce system parameters.
• Mathematical procedures to solve the initial guess problem without external devices.
• Experimental validation of the proposed method against conventional techniques.

Main Results:

• The proposed method achieved a maximum deviation of 68.6 µm for system parameters, compared to 711.9 µm for the conventional method.
• 3D coordinate measurements showed good agreement with a commercial laser tracker, with a maximum difference (standard deviation) of 17.7 µm.
• The conventional method resulted in a maximum difference of 98.8 µm in validation measurements.

Conclusions:

• The proposed self-calibration method significantly improves the efficiency and accuracy of ADM-based MLTSs.
• The method demonstrates feasibility and superior performance compared to conventional self-calibration techniques.
• This advancement offers enhanced precision for industrial 3D coordinate measuring applications.