- 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
142
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
Scientists demonstrate powerful UV-visible infrared full-spectrum laser
Figure: a. Schematic diagram of the HCF-LN-CPPLN experimental setup. W. CaF? Window M, mirror.b. The bright white light circular spots emitted by the CPPLN sample.c. The first-order diffraction beam of B displays a colorful rainbow pattern from purple to red.d. The HCF-LN-CPPLN module generates normalized spectra of the output full spectrum laser signal through the second NL HHG and third NL SPM e...
2023-08-25In situ bubble point measurement using spectroscopy
Develop and research a new downhole bubble point pressure measurement technology suitable for black oil and volatile oil to enhance well analysis using spectroscopy.Representative fluid characteristics are required for a wide range of oilfield lifespans, such as the initial scale and production planning of reservoir hydrocarbon reserves. Fluid characteristics are usually obtained from laboratory s...
2024-01-31Researchers Obtaining Scientific Returns from Raman Spectroscopy for External Bioexploration Using Lasers
We investigated the potential of laser selection in a wide optical range from ultraviolet to visible light, and then to infrared (excitation wavelengths of 325, 532, 785, and 1064 nm), in order to combine and analyze extreme microorganisms related to Earth (such as Cryptomeria elegans, cold floating nematodes, and circular green algae), carbon water compound molecules, as well as simulated mineral...
2023-10-23The construction of Hefei Advanced Light Source Project held a launch ceremony, expected to be completed and released in 5 years
Recently, in the Future Science City of Hefei City, Anhui Province, the National Major Science and Technology Infrastructure Project and Supporting Projects of Hefei Advanced Light Source announced the start of construction, with a planned land area of approximately 656 acres. The first phase of the project is expected to be completed by September 2028.After completion, it will become an internati...
2023-09-23A German research team has developed a new type of perovskite stacked battery
According to relevant media reports, a research team from the Helmholtz Center in Berlin, Germany, and Humboldt University has jointly developed a new type of perovskite stacked battery. This battery has broken the world record for similar batteries with a photoelectric conversion efficiency of 24.6%. In the solar cell family, in addition to silicon-based solar cells, there are also thin-film so...
02-08