A Spectrum Correction Algorithm Based on Beat Signal of FMCW Laser Ranging System

Area of Science:

• Optoelectronics
• Signal Processing
• Metrology

Background:

• Frequency Modulated Continuous Wave (FMCW) laser ranging systems are crucial for accurate distance measurements.
• System accuracy is compromised by White Gaussian Noise (WGN), spectrum leakage, and the picket fence effect.
• Existing spectrum correction algorithms offer unsatisfactory performance in mitigating these errors.

Purpose of the Study:

• To introduce a novel algorithm, Decomposition Filtering-based Dual-Window Correction (DFBDWC), for enhancing FMCW laser ranging accuracy.
• To address the limitations of traditional methods in correcting spectrum-related errors.
• To demonstrate the superior performance of DFBDWC compared to existing algorithms.

Main Methods:

• Development of the DFBDWC algorithm, incorporating decomposition filtering.
• Utilizing a dual-window approach in the time domain.
• Leveraging two phase values of the spectral peak in the frequency domain for correction.

Main Results:

• DFBDWC significantly reduces the maximum absolute error in target distance calculations.
• Error reduced from 0.7937 m (Discrete Fourier Transform algorithm) to 0.0407 m.
• DFBDWC outperformed all compared traditional spectrum correction algorithms in simulations and experiments.

Conclusions:

• The proposed DFBDWC algorithm offers a substantial improvement in FMCW laser ranging accuracy.
• This algorithm effectively mitigates errors from WGN, spectrum leakage, and the picket fence effect.
• DFBDWC enables the realization of high-performance FMCW laser ranging systems with broad application potential.