Português

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

560
2023-08-23 14:12:19
Ver tradução
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
Recomendações relacionadas
  • Switzerland's top 100 sales drop to 330.9 million Swiss francs in the first half of the year

    Recently, Swiss company Bystronic disclosed its financial performance for the first half of 2024.The financial report shows that the market situation for the Swiss Super 100 in the first half of 2024 remains very tense. Customers in various end markets are unable to fully utilize their production capacity, and operations in all regions are relatively cautious.Despite Swiss supercar actively reduci...

    2024-07-24
    Ver tradução
  • Chinese researchers have developed for the first time a room temperature HoYLF thin film laser

    In a study published in Optics Express, the research team led by Professor Fu Yuxi of the Xi'an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences developed the room temperature holmium doped lithium yttrium fluoride (Ho: YLF) composite thin slice laser for the first time, which can achieve high efficiency and high-quality CW laser output.Laser devices operating...

    02-21
    Ver tradução
  • New, low-cost, and high-efficiency photonic integrated circuits

    The rapid development of photonic integrated circuits (PICs) has combined multiple optical devices and functions on a single chip, completely changing optical communication and computing systems.For decades, silicon-based PICs have dominated the field due to their cost-effectiveness and integration with existing semiconductor manufacturing technologies, despite their limitations in electro-optic ...

    2024-05-10
    Ver tradução
  • Researchers have created the first organic semiconductor laser that can be operated without the need for a separate light source

    Researchers at the University of St. Andrews in Scotland have manufactured the first organic semiconductor laser to operate without the need for a separate light source - which has proven to be extremely challenging. The new all electric driven laser is more compact than previous devices and operates in the visible light region of the electromagnetic spectrum. Therefore, its developers stated that...

    2023-11-15
    Ver tradução
  • Laser blasting promises to solve global plastic problem

    Recently, researchers announced the development of a way to use laser blasting to break down plastic and other material molecules into their smallest parts for future reuse.This method involves placing these materials on a two-dimensional material called transition metal dichalcogenides and then irradiating them with light.This discovery has the potential to improve the way we handle plastics that...

    2024-07-16
    Ver tradução