141results about How to "Improve distance accuracy" patented technology

The invention relates to a night preceding vehicle detection method based on a millimeter-wave radar and machine vision, which belongs to the field of vehicle control. The night preceding vehicle detection method comprises the following steps: (1) performing camera calibration, so as to obtain a projection matrix of world coordinates to image pixel coordinates, establishing a transition relation between a radar coordinate system and a world coordinate system, and converting radar coordinates into the image pixel coordinates; (2) resolving received millimeter-wave radar data, excluding false targets and determining effective targets through data processing, and synchronously collecting camera images; (3) projecting radar scanning points under the world coordinate system to an image pixel coordinate system, and establishing an region of interest (ROI) on the images according to projective points; (4) detecting whether a vehicle exists in the region of interest based on an image processing method. Compared with the prior art, the night preceding vehicle detection method has the characteristics of fusion of the millimeter-wave radar and the machine vision, high real-time performance and high accuracy.

The invention discloses an industrial robot calibration method based on distance error models. The method comprises: establishing a robot MDH (modified Denavit-Hartenberg) kinematic model; subjecting the errors of a matrix to homogeneous transformation; establishing a robot distance error calibration model; measuring the end actual pose of a robot; calibrating geometrical parameter errors of every connecting rod of the robot; and performing experimental verification. The industrial robot calibration method based on the distance error models has the advantages of being simple, practical, high-efficiency and rapid, is applicable to any series articulated robots, has a strong commonality, and can improve the positioning accuracy and the distance accuracy of an industrial robot simultaneously.

Systems and methods for distance and location tracking a wireless device are disclosed. More specifically, according to one aspect of the present disclosure, a Wireless Area Network-Location Based Services (WAN-LBS) algorithm that utilizes a hybrid Wireless Area Network (WAN) and Global Positioning System (GPS) circuit board and method for seamless indoor and outdoor tracking is disclosed. The WAN-LBS algorithm, in conjunction with the hybrid WAN/GPS circuit board, optimizes the degrees of precision and accuracy for distance measurements in locating a fixed or mobile IEEE 802® device. In one embodiment, the hybrid WAN/GPS circuit board according to the present disclosure integrates the data of a GPS receiver and several IEEE 802 standards based receivers. In another embodiment, the WAN-LBS algorithm according to the present disclosure utilizes received data, acquired by the hybrid circuit board, to calculate distances to the tracking devices, seamlessly in both indoor and outdoor environments.

A time-frequency standard signal fusion transmission system and transmission method are provided. The system compensates the phase noise of optical frequency signal, radio frequency signal and time signal when they are transmitted in the optical fiber link through the compensation module 1, the compensation module 2 and the communication signal transmitter of the local terminal, and sends the calculated link delay to the remote terminal together with the communication data. Through the optical frequency and RF reference signal output module at the remote end, The time signal output module andthe communication signal receiver, the spectrum purification of the optical frequency standard signal, the spectrum purification of the radio frequency standard signal and the time delay calibration of the time signal are realized, so that the user can simultaneously obtain the high-quality optical frequency standard signal, the radio frequency standard signal, the time signal and the communication data signal. The technical scheme of the invention solves the problems of mutual crosstalk and low detection signal-to-noise ratio when a plurality of signals are simultaneously transmitted, and greatly improves the transmission distance and transmission accuracy of the transmission of the plurality of standard signals.

Apparatus and method are provided for distance measurement to a remote surface using high frequency modulated transmitted and reflected laser beams and phase-shift calculations. To improve phase-shift resolution, the reflected bean is further modulated, before detection, at a high frequency similar yet different from that of the transmitted beam so as create a resulting detector signal having at least a lower frequency signal which is easily detected by a response limited detector. The lower frequency signal retains the phase-shift information and thus enables determination of the phase-shift information with stable, inexpensive low-frequency optical detectors. Three-dimensional mapping can performed wherein one or more apparatus employ a plurality of detectors or a scanner producing a plurality of sequential reflected beams, each of which results in a plurality of phase-shift information for an area on the surface.

The invention discloses a data sending method, a device, and an electronic device based on sound wave. The invention also provides a data transmission system based on sound wave. The data sending method based on sound wave comprises the steps of obtaining the sent data; obtaining the sound wave frequency sequence corresponding to the data to be sent based on the preset sound wave frequency mappingtable; generating a sound wave signal sequence after filtering processing based on the sound wave frequency sequence and the preset sending duration, wherein the sending duration is the time durationfor the sound wave signal corresponding to the single character; sending out the sound wave signal corresponding to the data to be sent based on the sound wave signal sequence after the filtering processing. The invention is advantageous in that the data sending method based on sound wave is adopted to send out the sound wave signal after filtering, which can effectively increase communication distance and enhance identification precision, and can prevent noise brought by frequency switching.

The present invention discloses an ultra-long-range distributed fiber Raman photon temperature sensor of an integrated Raman amplifier, and comprises a distributed fiber Raman photon temperature sensor, a distributed fiber Raman amplifier and a fiber grating narrowband reflecting filter. The distributed fiber Raman amplifier is adopted to be embedded into the distributed fiber Raman photon temperature sensor; the gain of the amplifier is used to overcome fiber loss, strengthen the intensity of spontaneous Raman scattering light in the fiber, improve signal-to-noise ratio of the distributed fiber Raman photon temperature sensor system, augment the transmission distance of the distributed fiber Raman photon temperature sensor and improve temperature-measuring precision. With the fiber stimulated Raman scattering effect, the fiber spontaneous Raman scattering effect and the optical time domain reflection principle, the invention skillfully merges the technologies of the distributed fiber Raman amplifier and the distributed fiber Raman photon temperature sensor and achieves the ultra-long-range distributed fiber Raman temperature sensor.

An image capturing apparatus illuminates and captures an image of an object using reflected light therefrom, with simplified distance measurement. A plurality of light-emitting devices are mounted around an image sensor, and a light guide member guides the light of the light-emitting devices to an image capturing region for illumination. The image capturing apparatus having the closely disposed image capturing system and illumination system, further has a distance-measuring light-emitting device and an aperture on the distance-measuring light-emitting device and for generating an optical path having narrowed downside and broadened upside. Thus, diffused reflected light rays of distance-measuring light-emitting device can be selected, converged and output to one direction. It becomes possible to obtain sufficient irradiation amount even when using a power-saving light-emitting device of a small emission amount, and to miniaturize a distance sensor irradiating spot light, contributing to miniaturization of the image capturing apparatus.

The invention relates to a novel submersible for capturing and recovering AUV through long-distance acousto-optic bidirectional guidance. The submersible is connected with a winch through a umbilical cable and comprises a supporting frame, and an acoustic receiving and transmitting transducer is installed on the supporting frame; an acoustic transponder in butt joint with the acoustic receiving and transmitting transducer is arranged at the end of the AUV; an optical generator is installed in the supporting frame, and an optical receiver in butt joint with the optical generator is installed at the end of the AUV. According to feedback signals of the optical generator and the acoustic receiving and transmitting transducer, the own forward direction of the submersible is corrected, and the own forward direction of the AUV is corrected so that the AUV can be in butt joint with the submersible. The submersible can get away from a mother ship to actively capture the AUV, acousto-optic bidirectional guidance of the submersible and the AUV is adopted for butt joint, the butt joint positioning distance and accuracy of butt joint recovery can be improved, the long-distance butt joint guidance capacity is improved, and the AUV can be recovered and released in the mode of being away from the mother ship.

The invention, which belongs to the field of laser radar detection, proposes a two-dimensional MEMS scanning galvanometer laser radar system, thereby extending a receiving field of view and increasinga signal-to-noise ratio. A two-dimensional MEMS scanning galvanometer is a scanning mechanism. A control system controls the laser to emit high-frequency pulsed laser; the returned laser signal lightpasses through a filter and a large relative aperture optical lens successively and then is imaged on the incident end face of an image transmission fiber light cone; the image transmission fiber light cone transmits to the surface of an APD array detector. The image transmission fiber light cone is formed by arranging a cone-shaped optical fiber bundle. The APD array detector selects a corresponding APD detector unit to collect signals according to scanning angle of the two-dimensional MEMS scanning galvanometer and the position of a light spot outputted by corresponding echo light at the image transmission fiber light cone. Therefore, , when the caliber, focal length, and detector area of the receiving optical system are certain, the field of view of the MEMS laser radar can be extended, the interference of the ambient background light on the system can be reduced, and the signal-to-noise ratio of the signal receiving can be improved.

The invention relates to a micro-pulse laser radar light source with high pulse energy. The light source is formed by an oscillator stage and an amplifier stage; and the light path of the amplifier stage and the light path of the oscillator stage are in a coaxial mode. At the oscillator stage, a dual-path Q switch is used for compensating thermal depolarization loss of a laser; dual-path outputs are amplified respectively by the independent amplifier stage and then are combined, thereby realizing functions of thermal depolarization compensation and energy amplification. At the oscillator stage, a holophote, a laser crystal rod, two dielectric film polarizers, two Pockels boxes, and two output coupling mirrors are successively arranged on the light path; the two dielectric film polarizers are arranged at a brewster angle, incident surfaces of other elements are parallel to each other; and two end surfaces of the laser crystal rod are parallel to each other. According to the invention, losses of output energy by thermal depolarization can be compensated and the output energy can be amplified further; compared with the prior art, the conversion efficiency, the pulse energy, and the light beam quality of the light source are substantially improved; and the detection distance and detection precision of the micro-pulse laser radar are enhanced.

The invention, which relates to the technical field of meteorological radar signal processing, provides a multi-scanning multi-pulse-repetition-frequency full-airspace meteorological target detection method for an airborne weather radar. With a multi-scanning airborne weather radar, low-beam, middle-beam, and high-beam scanning methods are used at a vertical direction, variable-density scanning is carried out at a horizontal direction, and intensive scanning is employed at a course area and areas at two sides, so that the detection precision is improved; and a proper sparse scanning way is employed for the course area, so that the scanning and post data processing speeds are increased. The obtained tree-beam scanning echo signals are synthesized and thus full-airspace meteorological target distribution situation ahead of the aerial carrier is obtained, thereby providing the powerful guarantee for flight safety. According to the invention, the detection precision of the airborne weather radar can be improved; the detection distance can be increased; the earth clutter interference can be suppressed; and the full-airspace meteorological target distribution situation can be obtained.

Information recording equipment of the present invention includes a multiplexer to generate n pieces of synchronous high-speed pulses. Instead of a normal m:1 multiplexer configuration for parallel-serial conversion, an m:n multiplexer configuration is used which generates m pieces of output signals from n pieces of input signals. The recording equipment including the m:n multiplexer enables high-resolution and high-speed pulse generation and carries out multipulse and multilevel signal generation.

A method is provided for detecting at least one structure-borne sound signal, in particular for detecting at least one damage event and/or at least one contact event. On a motor vehicle with a sensor, provision is made for a site of impact of the damage event and/or contact event to be determined by recording at least one measurement signal at a single sensor having a single structural unit, and for separately determining the distance between the sensor and the site of impact and the direction from which the structure-borne sound signal hits the single sensor. A device is also provided for detecting at least one structure-borne sound signal, in particular a structure-borne sound signal influenced by a damage event and/or contact event, with at least one sensor. The sensor has at least one storage device and at least one signal-transferring connection with at least one evaluation device.

A housing for protecting a wafer-level camera module and fixing the wafer-level camera module to a printed circuit board (PCB) includes: four side plates, defining a quadrilateral frame; four supporting plates each fixed to a lower portion of an inner face of a corresponding one of the four side plates, each supporting plate having a top face supporting a portion of the camera module; and four bottom plates each fixed to a lower portion of an outer face of a corresponding one of the four side plates, each bottom plate having a bottom face fixed to the PCB. The housing is capable of addressing the issues of poor housing-PCB soldering, paint falling off and surface scratching and improving the efficiency in UV lamp-utilized UV adhesive curing.

The present invention relates to a three-dimensional imaging photon counting system using N-fold pulse coding and a counting method. The system includes a total controller, a signal generator, a pulselaser, a transmission optical system, a receiving optical system, a Gm-APD array detector, and a TCSPC (time-correlated single photon counter) and a signal processing unit. According to the method ofthe present invention, the total controller controls the signal generator to generate N-fold pulse signals; the N-fold pulse signals are converted into pulse optical signals through the pulsed laser;thee pulse optical signals hit a target object through the transmission optical system; the energy of echo pulse signals reflected by the target object is collected by the receiving optical system; the echo pulse signals irradiate the Gm-APD array detector; signals generated by the detector pass through the TCSPC (time-correlated single photon counter); counted signals are transmitted to the signal processing unit for time correlation and solution; and a counting result is transmitted to the total control module, and the total control module outputs a result. With the counting method of the invention adopted, the problems of strength information loss and incapability of resisting environmental interference in the prior art can be solved.

The invention provides an optical fingerprint module, a screen assembly and an electronic device, which relate to the technical field of the fingerprint module. The optical fingerprint module comprises: a lens barrel, a lens, a light filter and a fingerprint identification chip. the fingerprint identification chip includes a first plane, The optical filter is arranged on the first plane, the lensbarrel comprises a connecting part and a mounting part remote from the connecting part, the lens is mounted on the mounting part, and the connecting part is arranged on the first plane of the fingerprint identification chip so that the distance between the lens and the fingerprint identification chip is a preset value. As that len is arranged in the len barrel and the lens barrel is directly connected with the fingerprint identification chip, the factors affect the distance between the fingerprint identification chip and the fingerprint identification chip are reduced, the precision of the optical fingerprint module can be effectively improved, and the defect rate of the product can be reduced.

The invention discloses a method for improving pulse ranging precision. The method is characterized by comprising the following steps of a, transmitting a laser pulse and simultaneously starting timing; b, respectively recording time t1 between laser signal transmission and an echo wave rising edge signal and time t2 between laser signal transmission and an echo falling edge signa; c, obtaining an initial measurement distance x=(t1*V)/2, echo signal pulse width y=(t2-t1)*v, wherein v represents light velocity and unit is m/s; and d, through a Levenberg-Marquardt method, by means of the initial measurement distance x and the echo pulse width y, obtaining a functional relation of a final measurement distance z through fitting based on a nonlinear curve of matrix data: z=p1+p2*x+p3*x^2+p4*x^3+p5*x^4+p6*x^5+p7*Ln(y)+p8*(Ln(y))^2+p9*(Ln(y))^3+p10*(Ln(y))+p11*(Ln(y))^5), wherein the unit of z is m, P1 to P11 are constants, and an average value is calculated from a plurality of detection results. The invention further discloses pulse ranging equipment applied to the method. The method and the pulse ranging equipment have advantages of high detection precision and large measurable distance range.