chanelink logo
CHANELINK
한국어

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

773
2023-08-23 14:12:19
번역 보기
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
관련 추천

  • Innovative laser technology: a novel quantum cavity model for superradiance emission

    Quantum optics is a complex field where theoretical and experimental physicists collaborate to achieve breakthroughs in explaining subatomic level phenomena.Recently, Farokh Mivehvar from the University of Innsbruck used the most comprehensive model in quantum optics, the Dicke model, to study the interaction between two groups of atoms in a quantized field. This new study makes it possible to obs...

    2024-03-16
    번역 보기

  • Lockheed Martin announces expansion of 16000 square feet 3D printing center

    Recently, US military industry giant Lockheed Martin announced that it will significantly increase its additive manufacturing capabilities and expand its factory in Texas. The expansion project includes approximately 16000 square feet of dedicated space for 3D printing technology, and the addition of some of the largest large format multi laser printers in the space (it is worth noting that Lockhe...

    2024-12-02
    번역 보기

  • Coherent's revenue for 2024 is $5.301 billion

    International laser giant Coherent's Q4 2024 sales exceeded expectations, reaching a historic high!Recently, Coherent released its highest quarterly sales data in history, mainly due to the demand for optical transceivers in artificial intelligence data center applications. For the three months ending December 31, the company's revenue was $1.43 billion, a year-on-year increase of 27% and a 6% inc...

    02-10
    번역 보기

  • Upgrading 3000W fiber laser to high energy and miniaturization has become a new trend

    Recently, the discussion on "miniaturization" in the domestic laser industry has become increasingly heated. From various exhibition venues, miniaturization and lightweight have become important display directions for fiber laser manufacturers.High energy and miniaturization have become new trendsIn the past few years, high-power has undoubtedly been the main development direction in the field of ...

    2023-09-20
    번역 보기

  • Ultra capillary properties of composite liquid absorbing cores manufactured by laser powder bed melting additive manufacturing

    Researchers from Sichuan University, the Key Laboratory of Advanced Special Materials and Preparation Processing Technology of the Ministry of Education, and the Nuclear Additive Manufacturing Laboratory of China Nuclear Power Research and Design Institute reported on the study of the ultra capillary performance of laser powder bed melting additive manufacturing composite structure liquid absorbin...

    03-20
    번역 보기