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

228
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
  • WVU engineers develop laser systems to protect space assets from the impact of Earth orbit debris

    The research from the University of West Virginia has been rewarded, as debris scattered in planetary orbits that pose a threat to spacecraft and satellites may be pushed away from potential collision paths by a coordinated space laser network.Hang Woon Lee, director of the Space Systems Operations Research Laboratory at the University of West Virginia, said that artificial debris dumps, including...

    2023-10-10
    See translation
  • Tongkuai and KDPOF launch their first 980 nm multi gigabit automotive interconnection system

    Tongkuai Optoelectronic Devices, a global leader in vertical cavity laser emitters (VCSEL) and laser diodes (PD) solutions based in Germany, and a Spanish expert in high-speed optical network solutions, KDPOF, showcased the first 980 nm multi gigabit interconnect system for automotive systems at last week's ECOC.Both companies are committed to achieving the most advanced optical data communication...

    2023-10-17
    See translation
  • Hamamatsu Photonics completes construction of new factory area

    Recently, Hamamatsu Photonics in Japan completed the construction of a new building at Miyakoda Manufacturing Co., Ltd. in Hamami ku, Hamamatsu City. The completion ceremony was held on July 29th, and the factory will start full production in November 2024, increasing overall production capacity by 2.5 times.Source: Hamamatsu PhotonicsIt is reported that Hamamatsu Photonics focuses on the developm...

    2024-08-01
    See translation
  • Unlocking visible femtosecond fiber oscillators: progress in laser science

    The emergence of ultrafast laser pulses marks an important milestone in laser science, triggering astonishing progress in a wide range of disciplines such as industrial applications, energy technology, and life sciences. Among various laser platforms that have been developed, fiber optic femtosecond oscillators are highly praised for their compact design, excellent performance, and cost-effectiven...

    2024-03-28
    See translation
  • The world's first scalable optical quantum computer prototype has been launched

    Canada's Xanadu Quantum Technologies has developed the world's first scalable optical quantum computer prototype. The company published an article in the latest issue of Nature detailing its design and construction process, and demonstrating how the prototype can be flexibly scaled up to the required scale. This breakthrough lays an important foundation for the development of large-scale quantum c...

    02-12
    See translation