Design of Atomic Force Microscope Photoelectric Sensing Circuit Based on Kalman Filter

The noise performance of photoelectric sensing circuits hinders the performance development and intelligent application of atomic force microscopy systems. This article successfully developed an atomic force microscope photoelectric sensing circuit based on Kalman filtering. This article embeds the Kalman filter algorithm into the photoelectric sensing circuit to filter and denoise the output signal. This article uses the STM32 microcontroller to achieve analog-to-digital conversion, thereby reducing the attenuation and distortion of signal transmission. Specifically, the photoelectric sensing circuit has a detection limit of ±5 V, a fast response speed of about 10 us, and a laser wavelength detection range of 100-1100 nm. This method reduces the transmission attenuation of the output signal of the photoelectric sensing circuit. It improves the signal-to-noise ratio of the output signal without interfering with the performance of the photoelectric sensor itself. In addition, for the dynamic atomic force microscope system, this paper combines the photoelectric sensing circuit with negative feedback control to improve the negative feedback detection method of the dynamic working mode.