chanelink logo
CHANELINK
English

The visual LiDAR fusion calibration board improves the detection accuracy of the vehicle navigation system and does not need to be adjusted before sailing

1010
2023-08-23 14:12:19
See translation
At present, the navigation system has become an important equipment on ships, aircraft, missiles, automobiles and other navigational vehicles. Laser Doppler radar has become an important development direction in the field of velocity measurement technology because of its high accuracy, good spatial resolution and fast dynamic response.
 
The application of the three-beam Doppler Lidar in the vehicle navigation system can continuously measure the navigation parameters of the vehicle relative to the ground, such as three-dimensional axial speed and instantaneous position, and realize the autonomous navigation, and it does not need to be adjusted before sailing, and it is simple and convenient to use.

With the continuous improvement of the detection performance of multi-beam radar such as SNR and velocity sensitivity in engineering applications, more in-depth research on beam configuration is needed. The vehicle-mounted three-beam Doppler Lidar beam is illuminated by a combined transceiver antenna. Whether direct detection or coherent detection is used, it is desirable to obtain a large echo signal intensity.
 
However, in the actual measurement process, the intensity of the echo signal is greatly attenuated because of light scattering on the rough surface. The bidirectional reflection distribution function (BRDF) of a rough surface can describe not only the optical radiation properties of the surface, but also the directional scattering properties.

Three beam Doppler Lidar uses continuous wave laser for optical mixing (homodyne detection) measurement. After the signal light transmitted by liDAR in the atmosphere, the echo signal and the local oscillator signal of the system generate the difference frequency signal through the optical mixer. When the local oscillator frequency is equal to the emitted laser frequency, the difference frequency is the Doppler shift of the echo signal.

When the three-beam laser illuminates the ground at an oblique Angle, the different beam illumination Angle will cause the different working distance of the beam, which will affect the signal-to-noise ratio of the system. If the installation height of the three-beam antenna is H, the working distance of the beam is R=H/sinα. The SNR of the system monotonically increases with the increase of the remaining zenith Angle. When the signal-to-noise ratio of coherent laser radar is higher than 8dB, the estimated maximum likelihood reaches the Kramerlau lower bound (CRLB).

When the system hardware parameters and algorithms are selected, the sensitivity of velocity measurement is only related to the zenith Angle and decreases with the increase of the zenith Angle. Speed measurement sensitivity can not be too small, otherwise the instrument will fail to respond to the operating speed, usually need to give the practical application of speed measurement sensitivity or can be converted to the index requirements.

Hangxin photoelectric laser radar calibration plate has good stability and can obtain repeated accurate data. Suitable for automatic driving distance, identification testing and remote sensing targets and other fields, the reflectivity is 1-99% optional, does not drop powder and does not change yellow, with nearly perfect Lambert characteristics. Hangxin photoelectric diffuse reflector adopts exclusive spraying process, which can provide a variety of reflectivity splicing diffuse reflector for seamless splicing.

Source: Sohu
Related Recommendations

  • Breakthrough! Extending the lifespan of solar panels to 50 years using lasers

    Recently, the National Renewable Energy Laboratory (NREL) under the US Department of Energy has made a revolutionary breakthrough by developing a concept validation method aimed at completely removing polymers from solar panel manufacturing, thereby achieving more efficient and environmentally friendly recycling.Solar panels have always been praised for their recyclability. However, the thin plast...

    2024-04-30
    See translation

  • Shanghai Optical and Mechanical Institute has made progress in ultra-low threshold Rydberg state single mode polariton lasers based on symmetric engineering

    Recently, the research team of Dong Hongxing and Zhang Long from the Research Center of Infrared Optical Materials of the Chinese Academy of Sciences Shanghai Institute of Optics and Precision Mechanics, in cooperation with Huazhong University of Science and Technology, reported a new mechanism for generating dynamically tunable single-mode lasers from exciton polaritons with ultra-low thresholds,...

    2023-10-12
    See translation

  • San’an and Inari acquire Lumileds for $239 million

    San’an Optoelectronics, an LED chip manufacturer, based in China, and Inari Amertron Berhad, a Malaysian company that provides outsourced semiconductor assembly and test (“OSAT”) services to the semiconductor industry, are to acquire Lumileds Holding B.V. and its European and Asian subsidiaries (“Lumileds International”). Lumileds is based in Schiphol, The Netherlands.The all-cash deal is valued a...

    08-13
    See translation

  • Abnormal relativistic emission generated by strong interaction between laser and plasma reflector

    The interaction between strong laser pulses and plasma mirrors has been a focus of recent physical research, as they generate interesting effects. Experiments have shown that these interactions can generate a nonlinear physical process called high-order harmonics, characterized by emitting extreme ultraviolet radiation and brief flashes of laser light.Researchers from the Czech Extreme Light Infra...

    2023-12-04
    See translation

  • Redefining optical limits: Engineers discover enhanced nonlinear optical properties in 2D materials

    Recently, according to a paper published in Nature Communications titled "Phonoenhanced nonlinearities in hexagonal boron nitride," engineers from Columbia University collaborated with theoretical experts from the Max Planck Institute of Material Structure and Dynamics to discover that pairing lasers with lattice vibrations can improve the nonlinear optical properties of layered two-dimensional ma...

    2024-02-23
    See translation