2results about How to "Realize ranging" patented technology

The invention discloses an unmanned aerial vehicle track barrier detection and height estimation method and medium based on image segmentation. The unmanned platform is used to install a monocular visible light camera and a small computing device to detect and identify the track barrier target; the visible light camera realizes the shooting of the visible light image of the target area and outputs the visible light video stream; the small computing device realizes the reception of the visible light camera video and runs the target key point detection algorithm and the height estimation algorithm; the high-speed target key point detection algorithm realizes the real-time detection of the target key point in the video stream, outputs the pixel coordinates of the target key point, and simultaneously outputs the pixel length, pixel width and pixel position of the target rectangular boundary box; the height estimation algorithm calculates the distance between the monocular visible light camera and the top surface of the track barrier according to the pixel coordinates of the target key point. The invention realizes the rough distance measurement of the monocular camera and realizes the hovering aiming of the unmanned platform within the specified height range at a relatively low cost.

This invention discloses a dual-comb absolute distance measurement system based on Raman gain modulation of a single-frequency laser. The system includes an optical frequency comb, a single-frequency laser, a rare-earth-doped amplifier, an optical coupler, a wavelength division multiplexer, a Raman gain fiber, an optical circulator, an optical collimator, a target, an optical bandpass filter, and a photodetector. The single-frequency laser is split into two paths, each coupled to an amplified optical frequency comb and then into the Raman gain fiber, generating two highly coherent Raman gain modulated dual combs: a signal comb and a local oscillator comb. The signal comb is divided into two groups; one group is reflected from the target and carries distance information, coupled to the other group and then to the local oscillator comb. After aliasing is eliminated by an optical bandwidth filter, the signal is collected by the photodetector, and the phase is de-encapsulated to calculate the distance. Due to the Raman gain modulation process, simple optical longitudinal mode stabilization and carrier wavelength readout can be achieved, ultimately using interferometry to achieve nanometer-level ranging accuracy.