Online axial drift measurement of ball screw ends using dual-wavelength microwave photonics

To address the challenge of real-time monitoring of ball screw end drift under constrained and disturbed environments, a microwave photonic measurement method integrating environmental interference suppression and link optimization is proposed. A wavelength-division multiplexer (WDM)-based dual-wavelength common-path model is constructed to compensate for optical path drift caused by temperature changes and vibrations. Simultaneously, to enhance the signal-to-noise ratio under weak reflection conditions, a distortion suppression method is implemented through joint control of the Mach-Zehnder modulator (MZM) bias point combined with cascaded amplification strategies. Experimental results demonstrate a measurement resolution better than 3 µm and an accuracy of 2.3 µm. Under temperature variations, the drift fluctuation is limited to 0.85 µm, verifying superior environmental stability. This work provides reliable support for condition monitoring and error compensation in precision transmission systems.