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

1187
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

  • MKS Instruments announces full year 2024 financial report

    Recently, MKS Instruments released its Q4 and full year financial results for 2024. According to the report, MKS's revenue for the fourth quarter of 2024 reached $935 million, a year-on-year increase of 4.7%, with a GAAP net income of $90 million; In 2024, the annual revenue was nearly 3.6 billion US dollars, a year-on-year decrease of 0.9%. GAAP net revenue was 190 million US dollars, turning los...

    02-20
    See translation

  • Artists transform paper into meticulous laser cutting designs

    In the past few years, paper artists have demonstrated the versatility of their common fiber materials. Some people manually cut or carve paper, while others combine traditional craftsmanship with digital design. Ibbini Studio is in this situation. Abu Dhabi artist Julia Ibni collaborated with computer scientist Stephen Noye to create sculptural paper works inspired by decorative patterns such as ...

    2024-01-23
    See translation

  • Germany's leading optoelectronics industry (Jenoptik) in the first half of the gold over 4.2 billion

    On August 9, local time, Germany's leading optoelectronics company Jenoptik released its 2024 second quarter interim financial results forecast. The financial data show that the company in the challenging market environment still shows strong growth momentum.In the first half of the year, Jenoptik achieved significant growth in revenue and earnings before interest, taxes, depreciation and amortiza...

    2024-08-15
    See translation

  • New research on achieving femtosecond laser machining of multi joint micromachines

    The team of Wu Dong, professor of the Micro/Nano Engineering Laboratory of University of Science and Technology of China, proposed a processing strategy of femtosecond laser two in one writing into multiple materials, manufactured a micromechanical joint composed of temperature sensitive hydrogel and metal nanoparticles, and then developed a multi joint humanoid micromachine with multiple deformat...

    2023-09-15
    See translation

  • Sivers Semiconductors, an optoelectronic semiconductor company, splits off its photonics business and goes public independently

    Recently, Sivers Semiconductors, a leading supplier of integrated chips and photonics modules for communication and sensing solutions, announced a significant strategic initiative:It will divest its subsidiary Sivers Photonics Ltd, which has signed a non binding letter of intent (LOI) with byNordic Acquisition Corporation and plans to achieve independent listing through a merger. This move aims ...

    2024-08-26
    See translation