chanelink logo
CHANELINK
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

769
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

  • Measuring invisible light through an electro-optic cavity

    Researchers have developed a new experimental platform that can measure the light wave electric field captured between two mirrors with sub periodic accuracy. This electro-optical Fabry Perot resonant cavity will achieve precise control and observation of the interaction between light and matter, especially in the terahertz (THz) spectral range. The research results were published in the journal "...

    02-19
    See translation

  • Holographic Laser Processing: Rapid Manufacturing and Image Reconstruction of Artificial Biomimetic Compound Eyes

    IntroductionIn recent years, inspired by insect compound eyes, artificial biomimetic compound eyes have shown great advantages in overcoming the limitations of existing imaging devices such as large, bulky, and heavy, and improving the performance of medical endoscopy, panoramic imaging, micro navigation, and robot vision due to their unique optical imaging solutions such as small size, distortion...

    2023-10-25
    See translation

  • Blue laser enterprise NUBURU obtains $5.5 million bridge financing

    Recently, NUBURU, a supplier of high-power and high brightness industrial blue laser technology in the United States, announced that it has reached bridge loan agreements ("bridge loans" or "bridge financing") with existing and new institutional investors.The principal of this bridge financing is $5.5 million, aimed at providing funding for the company until it obtains long-term credit financing,...

    2023-11-23
    See translation

  • Deep Photon Network Platform, Empowering Any Functional Photon Integrated Circuit

    The widespread application in the fields of optical communication, computing, and sensing continues to drive the growing demand for high-performance integrated photonic components. Recently, Ali Najjar Amiri of Kochi University in Türkiye and other scholars proposed a highly scalable and highly flexible deep photonic network platform, which is used to realize optical systems on chip with arbi...

    2024-03-11
    See translation

  • The green and blue laser diode series provides higher beam quality

    Rutronik has expanded its optoelectronic product portfolio by introducing green and blue laser diodes packaged in metal cans TO38 and TO56 using AM OSRAM. They leave a deep impression with improved beam quality and stricter electro-optic tolerances. The power level of the laser diode ranges from 10mW to 100mW. Diodes such as PLT3 520FB and PLT5 450GB are now available on the market.The flexibility...

    2024-01-31
    See translation