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

1245
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

  • Medium-long wavelength infrared quantum cascade laser of MOCVD on silicon

    Us researchers report 8.1 μm wavelength quantum cascade laser (QCL) grown on silicon (Si) by MOCVD [S. Xu et al., Applications. Physics Letters, v123, p031110, 2023]. "There are no previous reports of QCL growth on silicon substrates by metal-organic chemical vapor deposition (MOCVD)," commented the team from the University of Wisconsin-Madison, the University of Illinois at Urbana-Champaign an...

    2023-08-04
    See translation

  • Yawei Group and Zhonggang Metal signed a complete set of sheet metal laser processing equipment to assist in the development of curtain wall materials industry

    Recently, Yawei Group signed a complete set of sheet metal laser processing equipment with Hubei Zhonggang Metal Xianning Second Production Base, adding bricks and tiles to the takeoff of Zhonggang Metal Business. After full production, the annual production of various aluminum metal plates will exceed 6 million square meters, and Zhonggang Metal will usher in another leap forward development!Zhon...

    2023-11-03
    See translation

  • IPG Photonics announces 2024 financial loss of $162 million

    On February 11th, global industrial fiber laser giant IPG Photonics announced its financial performance for the fourth quarter and full year of 2024. Annual sales have fallen below the $1 billion mark for the first time, with a year-on-year decline of 24% and a pre tax loss of up to $162 million. As an industry leader, IPG's financial report not only reflects the deep adjustment faced by the ind...

    02-13
    See translation

  • Progress in the Application of China University of Science and Technology's Femtosecond Laser Processing Technology in the Biomedical Field

    Recently, Associate Professor Li Jiawen's research group at the Micro and Nano Engineering Laboratory of the School of Engineering Science, University of Science and Technology of China proposed a femtosecond laser dynamic holographic processing method suitable for efficient construction of three-dimensional capillary scaffolds, which is used to generate a three-dimensional capillary network. This...

    2024-02-11
    See translation

  • Scientists simulate the conditions that allow photons to collide with photons by using lasers

    As far as quantum physics is concerned, one of the most striking predictions is that matter can be produced entirely from light (i.e., photons). Pulsars are an example of an object capable of achieving this feat.In a recent study reported in the journal Physical Review Letters, a research team led by scientists at Osaka University simulated the conditions that allow photons to collide with photons...

    2023-08-11
    See translation