Laser Ranging Calibration via Dual-Path Phase Comparison
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Solution Overview
Problem
Existing calibration methods for laser distance measurement devices face challenges such as mechanical complexity, high cost, and reduced accuracy due to environmental factors and mechanical wear, particularly in industrial precision instruments.
Innovation Solution
A calibration method and device based on single-wavelength double-laser-tube phase measurement, which uses a laser automatic power control circuit to switch between internal and external light paths, allowing for phase comparison and error compensation without mechanical switches, thereby reducing environmental noise and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical switches are used to switch between internal and external light paths, then the calibration can be performed, but the device complexity increases and mechanical wear reduces reliability
Solution Approach 1:
The patent replaces mechanical switches with an electrical control mechanism. The light path switching is achieved through electronic control of the laser tube's operating state (on/off or different wavelengths) rather than physical mechanical movement. This eliminates mechanical wear and improves reliability while reducing device complexity.
2Measurement precision
If traditional calibration methods are used with beam splitters and multiple receivers, then phase calibration can be performed, but the device complexity and cost increase
Solution Approach 1:
The patent merges the functions of multiple components into a single laser tube. The same laser tube serves as both the external light source and the internal reference light source, eliminating the need for separate receivers and complex beam splitting optics. This simplifies the optical path structure while maintaining phase calibration accuracy through wavelength-based differentiation.
Solution Approach 2:
The laser tube performs multiple functions: it acts as the external light source for distance measurement, the internal reference light source for calibration, and can switch between different operating wavelengths to differentiate between these functions. This multi-functionality reduces the number of components needed and simplifies the overall system structure.
3Measurement precision
If environmental factors are not compensated, then the device structure remains simple, but measurement accuracy decreases due to phase shifts
Solution Approach 1:
The patent uses wavelength as a controllable parameter to differentiate between calibration and measurement modes. By changing the laser tube's operating wavelength or switching it between on/off states, the system performs calibration without requiring additional hardware. This maintains measurement accuracy through environmental compensation while keeping the calibration system simple.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the measurement accuracy and stability of laser ranging systems, reduces the influence of environmental factors on measurement errors, and decreases the system's component performance requirements, leading to lower costs and broader industrial applications.
Implementation Method 1
a laser automatic power control circuit to switch between internal and external light paths
Implementation Method 2
sending the external light path to a measured target, reflecting the external light path back through the measured target and receiving the reflected external light path by a photoelectric receiving circuit
Data Source
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AI summary
A calibration method and a calibration device based on single-wavelength double-laser-tube phase measurement are disclosed. The calibration method includes: (S1) generating an external light path via a laser automatic power control circuit through a high frequency modulation signal, sending the external light path to a measured target, reflecting the external light path back through the measured target and receiving the reflected external light path by a photoelectric receiving circuit; (S2) generating an internal light path via the laser automatic power control circuit through the high frequency modulation signal, directly sending the internal light path to the photoelectric receiving circuit, and receiving the internal light path through the photoelectric receiving circuit; and (S3) performing phase comparison between two paths of light waves respectively corresponding to the external light path and the internal light path which are received firstly and secondly by the photoelectric receiving circuit, and a reference phase signal through the photoelectric receiving circuit, calculating a distance phase, and outputting a signal whose base is eliminated. By means of the method, the phase error is compensated and calibrated, so that the effect of environmental factors on the distance measurement error is reduced, thereby improving the distance measurement precision of the laser ranging, and improving the distance measurement stability of the system.