chanelink logo
CHANELINK
Русский

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

561
2023-08-23 14:12:19
Посмотреть перевод
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
Связанные рекомендации

  • Researchers have reinvented laser free magnetic control

    In a significant advancement in material physics, researchers from Germany and the United States have theoretically demonstrated that only extremely thin materials need to be α- RuCl3 can be placed in an optical cavity to control its magnetic state.This discovery may pave the way for new methods of controlling material properties without the use of strong lasers.The Role of Optical Vacuum W...

    2023-11-09
    Посмотреть перевод

  • TDK introduces a new gold-wire-bonded optional NTC thermistor for laser diode temperature measurement

    TDK Corporation (TSE: 6762) announced the introduction of the new NTCWS series of NTC thermistors with gold wire bonding. These bonding NTC thermistors can be installed in packages via gold wire bonding to enable high precision temperature detection of laser diodes (LD) for optical communication. The series will begin mass production in September 2023.The use of LD devices in optical communication...

    2023-09-08
    Посмотреть перевод

  • Northeastern University of Japan: Breakthrough Laser Technology for Nanoscale Laser Processing

    In the fields of optics and micro/nano processing, precise manipulation of lasers to meet the growing demand for miniaturization is an important challenge in driving the development of modern electronic and biomedical equipment. Recently, researchers from Tohoku University in Japan successfully demonstrated the use of interference technology to enhance the longitudinal electric field of radially p...

    2024-04-12
    Посмотреть перевод

  • Dr. Gu Bo, a renowned expert in the laser industry, has been elected as a member of the Canadian Academy of Engineering

    On May 7, 2024, the official website of the Canadian Academy of Engineering announced that Dr. Gu Bo, a renowned expert in the laser industry, has been elected as a member of the Canadian Academy of Engineering.Dr. Gu BoAcademician of the Canadian Academy of EngineeringFounder/President of Bose Photonics, USADr. Gu Bo is recognized as a pioneer and academic leader in the global field of fiber lase...

    2024-05-07
    Посмотреть перевод

  • Coherent and Faraday sign a partnership to expand the manufacturing scale of high-temperature superconducting (HTS) tapes

    Recently, American photonics giant Coherent and Japan's Faraday 1867 Holdings signed a Letter of Intent (LOI), with the goal of expanding the manufacturing scale of high-temperature superconducting (HTS) tapes to be widely used in large-scale deployment of nuclear fusion reactors, while also promoting the transformation of green energy. Coherent's excimer laser is expected to be more widely used i...

    2023-10-12
    Посмотреть перевод