chanelink logo
CHANELINK
Tiếng Việt

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

176
2023-08-23 14:12:19
Xem bản dịch
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
Đề xuất liên quan

  • Laser Photonics officially launches its SaberTech laser cutting system

    Recently, Laser Photonics (LPC) officially launched its SaberTech laser cutting system. This system not only enriches the product line of LPC's laser cleaning, welding, marking, and engraving systems, but also marks another important breakthrough for the company in the field of laser technology. This product release is another heavyweight measure after LPC's latest generation laser cleaning system...

    2024-06-19
    Xem bản dịch

  • NASA's laser reflector instrument helps to accurately locate Earth measurements

    The most famous use of GPS satellites is to help people understand their location, whether it is driving cars, ships or planes, or hiking in remote areas. Another important but little-known use is to distribute information to other Earth observation satellites to help them accurately locate measurements of our planet.NASA and several other federal agencies, including the US Space Force, the US Spa...

    2023-12-12
    Xem bản dịch

  • The scientific research team of Shenzhen University of Technology has discovered a new mechanism of attosecond pulse coherent radiation

    Recently, a team of Professor Ruan Shuangchen and Professor Zhou Cangtao from Shenzhen University of Technology proposed for the first time internationally a physical solution based on the generation of attosecond pulses and subperiodic coherent light shock radiation from a superluminal plasma wake field, and explained a new coherent radiation generation mechanism dominated by collective electron ...

    2023-10-14
    Xem bản dịch

  • Trumpf and SiMa. ai collaboration to develop AI laser

    Recently, Trumpf Group, a leading global provider of machine tools and laser technology solutions, announced that it has partnered with software company SiMa AI has signed a partnership agreement to develop lasers with artificial intelligence (AI).It is reported that SiMa. ai is a software centric embedded edge machine learning chip system company, and the goal of both parties is to equip Trumpf'...

    2024-07-19
    Xem bản dịch

  • Laser communication is expected to completely change optical links

    Laser technology is becoming a game changer in the field of satellite communication (SATCOM), capable of creating ultra secure networks that can transmit large amounts of data at unprecedented speeds through satellite networks and constellations.With continuous progress, the industry is ready for growth and collaboration, seizing the untapped potential of disconnected populations. The ability to h...

    2023-09-20
    Xem bản dịch