High-Fidelity Modeling of Laser Levels via Pulse-Window Software Lock-In PSD Sensing

Area of Science:

• Mechanical Engineering
• Vibration Analysis
• Precision Instrumentation

Background:

• Accurate dynamic parameters (natural frequency, damping ratio) are crucial for self-leveling mechanisms.
• Traditional Finite Element Analysis (FEA) struggles with micro-friction, and contact methods cause interference.
• Existing methods lack the precision needed for advanced applications.

Purpose of the Study:

• To develop an integrated framework for precise identification of dynamic parameters in laser level self-leveling mechanisms.
• To overcome limitations of traditional FEA and contact measurement techniques.
• To enable refined design of precision pendulum instruments through accurate modeling.

Main Methods:

• Integration of Pulse-Window Software Lock-in (PWSL) sensing with data-driven model updating.
• Development of a non-contact Position Sensitive Detector (PSD) system.
• Utilizing a custom PWSL algorithm with a 10 kHz laser carrier for high-fidelity signal extraction and noise suppression.

Main Results:

• Experimental natural frequency (2.861 Hz) showed a 4.22% error compared to simulation (2.987 Hz).
• Measured damping ratio (0.1435) exceeded simulation (0.1255) by 14.34%, indicating unmodeled friction.
• FEA model updating with an equivalent friction coefficient reduced damping prediction error to 0.97%.

Conclusions:

• The PWSL method accurately captures dynamic parameters, revealing unmodeled energy dissipation.
• Data-driven model updating effectively refines FEA models by incorporating friction.
• This integrated framework provides a reliable basis for designing high-performance precision instruments.