- No Data
English
- English
- 简体中文
- 繁体中文
- Français
- Русский
- Italiano
- 日本語
- 한국어
- Português
- Deutsch
- Español
- Türkçe
- Ελληνικά
- Nederlands
- Tiếng Việt
- Polski
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
100
2023-08-23 14:12:19
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.
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
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
Laser gyroscopes measure small changes in daytime length on Earth
Recently, scientists used laser gyroscopes to measure that the change in Earth's rotational speed is less than one millionth. This technology can help scientists understand the complex flow of water and air, which can cause the smallest adjustments to the Earth's rotation.The Earth's rotation is not completely stable. Planets accelerate or slow down as they rotate, slightly shortening or prolongin...
2023-09-19Comparison of Blue and Infrared Wavelength in Pure Nickel Laser Deep Fusion Welding Process
It is reported that researchers from BIAS Bremer Institution f ü r angewandte Strahltechnik GmbH in Germany have reported a comparative study of laser deep penetration welding processes for pure nickel using blue and infrared light wavelengths. The related research was published in Welding in the World under the title "Process comparison of laser deep penetration welding in pure nickel using blue ...
2024-08-13Polarization polariton topology pointing towards a new type of laser
Semi light, partially matter quasi particles, known as excitons polaritons, can easily bypass obstacles and condense into a single coherent state - both of which are characteristics of topological insulators. Researchers from the United States and China have developed a new technology to manufacture microcavities from chloride based halide perovskites. They expect this work to lead to a new type o...
2024-05-30Laser technology reveals hidden gases in complex mixtures
Laser Network reported on January 11th that modern equipment has been fine tuned to detect highly specific gases, including trace gases found in the atmosphere, gases present in combustion exhaust emissions, and gases used in technology plasma applications.They achieve this by calculating the percentage of light at a certain wavelength that is absorbed or attenuated by the sample. This way, the co...
2024-01-11Laser engraving: Researchers have created a revolutionary technology
Recently, a group of researchers from the University of Cambridge developed an innovative method of using high-energy lasers to improve 3D printing of metals. This discovery has the potential to change the way we design and manufacture complex metal objects.3D printing has completely changed the landscape of the manufacturing industry. However, it faces obstacles, especially in terms of the charac...
2023-11-24