11results about How to "Improve detection distance" patented technology

This disclosure relates to a lidar, a scanner for the lidar, and an apparatus. The lidar includes a transmitter and a scanner. The transmitter is configured to emit a probe light. The scanner is configured to oscillate about a rotation axis within an oscillation range, deflecting the probe light into a field of view. The oscillation range includes a first fixed-speed region, a first variable-speed transition region, and a second fixed-speed region along a first direction. The first direction is perpendicular to the rotation axis. The scanner rotates at a greater speed in the first fixed-speed region than it rotates at the second fixed-speed region. In the first variable-speed transition region, the scanner's rotational speed varies with angle according to a half-period cosine function.

This invention relates to electromagnetic logging technology and discloses a forward-focusing electromagnetic logging method while drilling, comprising two stages: (1) Pre-testing stage: using a magnetic ring antenna array arranged in a straight line along the drill collar, the last antenna is used as a reference antenna to transmit signals, and the preceding antennas simultaneously receive them, so as to synchronously acquire the amplitude and phase delay of the received signals of each preceding antenna. (2) Forward focusing stage: configuring the transmission parameters for the preceding antennas, setting their initial phase to the negative value of the measured phase delay, and calculating an inversely proportional weighting coefficient based on the received amplitude, thereby configuring the driving amplitude of each preceding antenna; finally, driving the reference antenna and the configured preceding antennas to transmit synchronously, and coherently superimposing them in front of the drill bit to form a focused beam, while weakening the signal interference from the instrument's sides and back to the formation. This invention does not require pre-setting equipment in un-drilled formations, is fully compatible with existing instruments, and can significantly improve the signal strength and signal-to-noise ratio of forward detection.

The invention relates to the technical field of wireless communication, in particular to a risk early warning method, device and equipment, a medium and a product, the method is applied to a computing power server, and the method comprises the following steps: acquiring perception information reported by reconfigurable intelligent metasurface equipment and aircraft information reported by a low-altitude aircraft; matching the sensing information with the aircraft information to obtain a matching result; wherein the matching result is used for indicating whether a sensing target corresponding to the low-altitude aircraft is included in a plurality of sensing targets in a signal coverage range of the reconfigurable intelligent metasurface equipment; based on the matching result, determining collision risks between the low-altitude aircraft and other sensing targets except the sensing target corresponding to the low-altitude aircraft; and under the condition that the collision risk meets an early warning requirement, generating risk early warning information, and returning the risk early warning information to the low-altitude aircraft.

The invention relates to a laser radar system, which comprises at least two groups of receiving and transmitting modules and a single-axis galvanometer, the receiving and transmitting modules are arranged at intervals, laser emitted by each group of receiving and transmitting modules enters the single-axis galvanometer at different preset angles, the laser is reflected by the single-axis galvanometer to scan a target, and the laser subjected to diffuse reflection by the target is reflected back to the receiving and transmitting modules through the single-axis galvanometer; wherein scanning ranges covered by at least two groups of adjacent receiving and transmitting modules are partially overlapped, and the at least two groups of adjacent receiving and transmitting modules adopt time-sharing emission or code the laser, so that mutual interference of the laser emitted by the at least two groups of adjacent receiving and transmitting modules is avoided.

The application relates to the fields of optics and fire rescue, and discloses a fluorescent conversion sheet with wavelength conversion function and a handheld smoke penetration imaging device. The fluorescent conversion sheet comprises, in sequence, a heat dissipation substrate layer, a mirror layer, a photonic crystal layer and a core-shell structure fluorescent layer. After short-wave near-infrared laser is incident, the core-shell structure fluorescent layer performs wavelength conversion; the mirror layer and the photonic crystal layer form an optical micro resonant cavity, and the unconverted laser is reflected back to the fluorescent layer for secondary conversion; and the heat dissipation substrate layer effectively suppresses the thermal quenching effect. The imaging device utilizes the fluorescent conversion sheet to efficiently convert the easily obtained short-wave near-infrared laser into middle-wave near-infrared laser with strong smoke penetration capability and safety to human eyes and emits the middle-wave near-infrared laser, and a receiving device containing a polarizer is used to image the target echo. Through systematic and synergistic optimization design, the conversion efficiency and thermal stability are greatly improved, excellent smoke penetration imaging effect is realized, and the safety and efficiency of fire rescue are improved.

The present application belongs to the technical field of laser radar measurement, and provides a pseudo-random code phase modulation wind measurement laser radar signal-to-noise ratio improving method and system, the method comprising: generating a pseudo-random code sequence, BPSK phase modulating a continuous wave seed laser to convert into an encoded pulse signal; transmitting the encoded pulse signal to the atmosphere, receiving a back wave and mixing with a local oscillator light; multiplying the coherent beat frequency signal with the same pseudo-random code sequence and integrating, so that the back wave signal of the matching distance gate obtains coherent accumulation gain in the correlation output, and the non-matching signal energy is expanded to a noise base, realizing correlation demodulation; performing spectrum analysis on the demodulated signal, and inverting the wind speed. The present application significantly improves the average power and processing gain under the premise of not improving the peak power through high duty cycle encoding pulse and pseudo-random code correlation demodulation, thereby improving the signal-to-noise ratio and detection distance.

A method for generating low-frequency limited acoustic beams in a well, the method comprising: determining a transducer aperture according to a downhole borehole size, calculating a nonlinear action region of a radiated acoustic field based on the transducer aperture and a distance parameter; selecting a sound source design modulation theory model according to the nonlinear action region, determining sound source parameters of the transducer based on the sound source design modulation theory model and the transducer aperture; carrying out nonlinear radiated acoustic field simulation according to the sound source parameters, determining a critical propagation distance corresponding to a maximum value of a difference frequency sound source level, and extracting nonlinear acoustic wave signal characteristics at the distance, generating a loadable modulation signal based on the characteristics; measuring and comparing signal characteristics of the transducer under a loadable modulation signal loading state and under a natural radiated modulation signal loading state, and determining the loadable modulation signal with a larger difference frequency sound source level. The present application can generate nonlinear acoustic wave signals containing larger low-frequency components at a smaller radiated distance, and the difference frequency conversion efficiency of the generated nonlinear radiated signals is high.

This application provides a time-of-flight statistics device and a laser ranging device, relating to the field of laser ranging technology. The statistics device includes a statistics unit and a memory: the statistics unit is used to acquire S sets of first initial flight time data within S first integration periods, and to accumulate each first initial flight time data set by grouping every N adjacent first initial flight time data sets to obtain S sets of accumulated flight time data corresponding to the S sets of first initial flight time data, where S is a positive integer, S≥2, and N is a positive integer, N≥2; and to superimpose the S sets of accumulated flight time data to obtain a superimposed flight time data set, and to store at least one superimposed photon count value in the superimposed flight time data set in the memory as a single superimposed photon count value stored in a memory unit; this statistics device can increase the detection range of the laser ranging device.

The invention relates to a divergence angle regulation and control method and a vortex beam radar, and relates to the technical field of vortex beam radars. The method comprises the following steps: acquiring a target divergence angle and radar basic parameters; determining a divergence angle control phase based on the target divergence angle and the radar basic parameters; determining a feed source compensation phase based on the distance from the metasurface unit to the feed source; determining a vortex phase based on the position of the metasurface unit; determining a total phase based on the divergence angle control phase, the feed source compensation phase and the vortex phase; and adjusting the unit structure of the corresponding metasurface unit based on the total phase. By loading the divergence angle control phase in the total phase, the beam main lobe divergence angles of different modes can be unified as the target divergence angle, so that the problem that the divergence angles of beams of different modes are different is solved, cooperative receiving of signals, mode decoupling and information reconstruction are facilitated, and the detection precision and the operating distance of the vortex beam radar are improved.

The application provides a smart driving drivable area detection method and device, the method comprising: acquiring point cloud data of multiple laser radars under the same timestamp; performing fusion processing on multiple frames of point cloud data to obtain a fused point cloud set; determining non-ground point cloud data from the fused point cloud set according to the z-direction coordinate values of the fused point cloud data contained in the fused point cloud set, so as to obtain a non-ground point cloud set composed of the determined non-ground point cloud data; mapping the non-ground point cloud set to a pre-established target polar coordinate system, so as to determine the closest distances between obstacles around the vehicle under full angles and the vehicle respectively according to the non-ground point cloud set under the target polar coordinate system; and determining the drivable area of the vehicle according to the closest distances between the obstacles around the vehicle under full angles and the vehicle respectively. The application uses multiple laser radars to collect point cloud data, greatly improves the detection distance, and has better environmental adaptability. Since it does not need the assistance of high-precision maps, structured roads and other conditions, the autonomous detection performance is high.

The application is a laser Doppler rotational speed calibration device, belonging to the technical field of Doppler velocity measurement, comprising a shell, a regulating cavity is formed in the inner side of the shell, an installation cavity two is formed in one end of the regulating cavity, an installation cavity three is formed in the end of the installation cavity two away from the regulating cavity, and a helium-neon laser is arranged in the inner side of the installation cavity three. The application solves the problem that only the inner cavity of the rotating drum can be detected, which requires the laser to be obliquely shot into the inner cavity of the rotating drum, and since the diameter and depth of the rotating drum of each centrifuge are different, the laser directly irradiating the rotating drum is hindered. In the application, the laser focusing points of the first and zero levels can be adjusted through the use of the sliding block, so as to facilitate the automatic adjustment of the detection distance of the device, make the laser focusing points hit the detection column, so that the outer side of the detection column is hit, and the rotation of the detection column can be detected, and the laser can directly hit the detection column horizontally.