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

1142
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
  • Goethe, University of Central Florida research team showcases light and thin achromatic diffractive liquid crystal optical systems

    Headdisplay devices such as Apple Vision Pro, Meta Quest, and PICO are expected to completely change the way we perceive and interact with various digital information. By providing more direct interaction with digital information, MR has become one of the key driving forces for the metaverse, spatial computing, and digital twins, and has begun to be widely applied in fields such as intelligent tou...

    2023-09-26
    See translation
  • BluGlass successfully raised $5.87 million to accelerate GaN laser production and delivery

    Recently, BluGlass, a leading global semiconductor development company, successfully completed its stock purchase plan (SPP) and raised $5.87 million in funds (excluding costs). This SPP provides eligible shareholders with the opportunity to subscribe to up to $100000 in new shares of BluGlass at a discounted price of $0.037 per share, along with free additional options. This initiative has gained...

    2024-04-12
    See translation
  • The United States has successfully developed a full 3D printed electric spray engine

    The fully 3D printed electric spray engine is suitable for small satellite in orbit maneuver, and its production cost is only a small part of that of traditional thrusters.Image source: Massachusetts Institute of Technology, USAThe Massachusetts Institute of Technology team recently demonstrated an electric spray engine made entirely of 3D printing technology, which can be propelled by emitting ...

    02-20
    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
  • Diamond Light Source and NPL reach a new five-year agreement

    Recently, two leading UK scientific institutions, Diamond Light Source and National Physical Laboratory (NPL), have reached a new five-year agreement to promote joint collaborative efforts.The agreement was approved by signing a Memorandum of Understanding (MoU), which will bring these two institutions together.Diamond Light Source is a national synchrotron facility in the UK known for generating ...

    2024-04-25
    See translation