80results about How to "Improve ranging accuracy" patented technology

The invention belongs to the technical field of underwater positioning, and discloses an underwater single-beacon Gaussian Newton positioning method and system under a linear sound profile condition. According to the method, underwater acoustic signal propagation time observation noise is modeled into Gaussian distribution, a maximum likelihood estimation problem is constructed, and then the maximum likelihood estimation problem is converted into a nonlinear least square estimation problem; and solving the gradient of the observed quantity to the position coordinates of the AUV based on a chain rule, iteratively solving a nonlinear least square estimation problem based on a Gauss-Newton method, and obtaining the position coordinates of the AUV after iterative convergence. Compared with other single beacon positioning methods which do not consider sound propagation refraction, the method of the invention can obtain a more accurate position calculation result under a linear sound profile condition, and enhances single beacon positioning, especially the practical application capability of the method in deep sea areas.

The invention provides a near-electricity operation risk dynamic identification method fusing fine segmentation and binocular vision. The near-electricity operation risk dynamic identification method comprises the steps that a left view image, shot by a binocular camera, of substation near-electricity operation is acquired; initializing calibration parameters of the segmentation model, the binocular three-dimensional distance measurement model and the binocular camera; identifying and extracting key job elements in the left view image through a segmentation model, wherein a segmentation result comprises each detected instance and a two-dimensional position thereof; for each instance, the three-dimensional position of the instance in the space is predicted through a binocular three-dimensional ranging model, and the three-dimensional coordinates of the instance are obtained; according to the three-dimensional coordinates of each instance, the Euclidean distance between different key operation elements is calculated, and the minimum distance between the key operation elements is obtained; according to the invention, whether there is an operation risk is determined according to the minimum distance between different key operation elements, and the method has high distance measurement precision and real-time performance, and is helpful for improving the safety of near-electricity operation and the risk early warning capability.

The invention relates to an optical imaging system and method of a resonant cavity. The system comprises a light source; the emission modulator is in signal connection with the light source; the emission modulator comprises an entrance pupil lens, an exit pupil lens, an electro-optical crystal and a resonant cavity formed between the entrance pupil lens and the exit pupil lens, and the electro-optical crystal is arranged in the resonant cavity; the receiving demodulator is connected to the front end of the imaging module; the receiving demodulator and the transmitting modulator have the same configuration; the microwave generator is respectively in signal connection with the transmitting modulator and the receiving demodulator; the processing module is in signal connection with the microwave generator; and the processing module is also in signal connection with the imaging module and is used for controlling a frame synchronization signal of the imaging module and enabling the imaging module to receive a demodulation signal in an effective time window of microwave optical modulation. The method is applied to the system. According to the invention, the frequency of the emitted light can be modulated to the GHz level, so that the ToF ranging precision can be accurate to the millimeter level, and the ToF ranging precision can be improved.

The invention discloses a vehicle distance measurement and calibration method based on laser radar and binocular vision fusion, relates to the technical field of measurement and calibration, and is used for solving the problem that the precision of a vehicle distance calibration result is reduced when a laser radar used for calibrating a highway vehicle distance snapshot system is under the conditions of rain, snow, wet and slippery or waterlogging road surfaces. Joint modeling is carried out on spatial distribution and echo energy characteristics of laser radar low-height point cloud, a point cloud echo coefficient and a low-height number proportion are introduced, a specular reflection state code is constructed, a self-calibration mechanism is adaptively triggered accordingly, and a specular reflection state is obtained. The discrete characteristic of a laser radar vehicle distance time sequence and the degradation trend of binocular vision parallax connectivity are subjected to quantitative analysis, the dominant source of ranging abnormity is judged through symbolic analysis, and an offset calibration or fusion correction strategy is selected according to the dominant source. Reliability and engineering adaptability of vehicle distance measurement under the wet and slippery road surface condition can be improved under the condition of not depending on an additional sensor.

The invention relates to the technical field of frequency modulated continuous wave ranging, in particular to an intermediate frequency signal adaptive filtering method for a frequency modulated continuous wave ranging radar. The method comprises the following steps: acquiring an intermediate frequency signal, and processing the intermediate frequency signal to obtain an optimal filter molecular coefficient; obtaining an optimal filter parameter according to the optimal filter molecular coefficient; and inputting the intermediate frequency signal into the optimal parameter filter for filtering operation to obtain a filtered intermediate frequency signal. According to the adaptive filtering method for the intermediate-frequency signal of the frequency-modulated continuous wave range radar, spurious frequency in the intermediate-frequency signal can be filtered out, the signal-to-noise ratio of the intermediate-frequency signal is improved, the range finding precision of the frequency-modulated continuous wave range radar is improved, the intermediate-frequency signal can be directly subjected to extraction operation after adaptive filtering, and the frequency-modulated continuous wave range radar is more accurate. Operation resources occupied by a post-stage intermediate frequency signal spectrum refinement algorithm can be reduced exponentially, and the ranging speed is improved.

The invention provides a pulse laser calibration-based high-precision laser ranging system and method. The system comprises a ranging light path and a calibration light path, in the distance measurement light path, an arbitrary waveform generator performs frequency modulation on a laser signal of a semiconductor laser, the laser signal is divided into two beams through an optical fiber coupler, the two beams are respectively incident to a distance measurement unit and a calibration light path, and the distance measurement unit transmits the laser signal to a target for distance measurement; in the calibration light path, a pulse laser emits frequency calibration laser, the frequency calibration laser is transmitted to a second optical fiber coupler, and the frequency calibration laser is coupled with the laser signal to obtain a frequency mixing light signal; and the processor obtains a distance measurement result based on the distance measurement signal, determines a change curve of the laser signal frequency along with time based on the frequency calibration laser, obtains a non-linear quantity of frequency modulation, and calibrates the distance measurement result based on the non-linear quantity of frequency modulation. The pulse laser is used for calibrating the output frequency of the semiconductor laser, the distance measurement result is corrected, and the distance measurement precision is improved.

This invention discloses an optimization method for a dual-source FSI ranging system based on wavelet synchronous compression transform, mainly addressing the problems of high system complexity and poor performance in existing dual-source FSI ranging systems when separating mixed interference signals. The solution includes: constructing a dual-source FSI ranging optical path to generate mixed interference signals; building a signal processing module based on the wavelet synchronous compression transform algorithm; sending the mixed interference signals to the signal processing module through a data acquisition device in the ranging optical path; using wavelet synchronous compression transform to separate the interference signals generated by the two lasers in the frequency domain; then achieving separation of the individual interference signals by reconstructing the frequency bands of the two interference signals; and finally using the separated two interference signals to calculate the distance and obtain the final ranging result. This invention can guarantee ranging accuracy without increasing the complexity and design cost of the dual-source FSI ranging system.

This invention provides a wireless ranging and clock synchronization method for aviation search and rescue scenarios, relating to the fields of spread spectrum communication and wireless ranging technology. The method includes: determining the relative motion state; performing unilateral bidirectional ranging between two nodes; obtaining clock offset and clock frequency offset estimates using the least squares method; and processing these estimates according to different motion states. When the master node and slave node are in a high-speed radial motion state, the slave node sends a spread spectrum signal to the master node to obtain pseudorange and carrier phase observations. Based on the clock offset estimate, compensation calculations are performed on the pseudorange observations; and based on the clock frequency offset estimate, compensation calculations are performed on the carrier distance increment. Based on the compensated pseudorange observations and the compensated carrier distance increment, carrier smoothing pseudorange recursion is performed to obtain the ranging result. Through this method, the cumulative errors of clock offset and clock frequency offset are suppressed within a unified smoothing framework, effectively improving ranging accuracy under high-speed motion conditions.

The invention belongs to the technical field of intelligent operation inspection of power transmission lines, and more specifically relates to a rapid registration method for extrinsic parameters of an offset camera based on acquisition of a point cloud image. The method comprises the steps that an original image and an offset image shot by the same camera are acquired, tower detection is completed respectively, and a main line tower is marked; using a feature extraction matching method to complete image matching of the two images and calculating an offset; according to the method, registration information between an original image and point clouds collected at the same moment is utilized, and feature matching information between the original image and the deflection image is combined, so that automatic registration between the deflection image and the point clouds collected at the original moment is completed, and further point cloud distance measurement under the offset image is realized. The method can effectively solve the problem of distance measurement errors caused by camera offset in a power transmission scene, and provides solid data support for the safety of a power transmission line.

The invention provides an operation method and system of a wireless positioning anti-error safety helmet, and relates to the technical field of wireless positioning of anti-error safety helmes.Positioning signals are continuously and bidirectionally sent twice between a UWB tag installed in the helmet and a base station, and the distance between the helmet and the base station is calculated by calculating the transmission time of the positioning signals, so that the anti-error safety helmet is obtained. A helmet positioning mathematical model composed of base station coordinates and distances between the base stations and the helmets is constructed, the coordinate positions of the helmets are calculated, and when the number of the base stations connected with the to-be-positioned helmets is less than 3, the helmets with high communication scores at the determined positions are used as temporary base stations to position the to-be-positioned helmets, so that the positioning accuracy of the helmets is improved. When the number of the base stations and the helmets in the helmet communication range is not enough to establish a helmet positioning mathematical model, the helmets update the coordinate positions of the helmets according to the motion data of the helmets, and the coordinate positions are corrected through the distances between the base stations and the helmets.

The application discloses a ranging method and system, wherein the method comprises the following steps: acquiring a ranging image; acquiring a contour in the ranging image, determining a plurality of positioning points according to the contour, and obtaining a positioning point cluster; determining a two-dimensional code in the ranging image according to the positioning point cluster; determining a three-dimensional coordinate of the two-dimensional code in a camera coordinate system according to the two-dimensional code and an internal parameter matrix and a distortion matrix of the camera; converting the three-dimensional coordinate of the two-dimensional code to a world coordinate system, and determining a vertical distance from the two-dimensional code to a plane formed by an xy axis group of an origin of the world coordinate system. The method has the advantages of high ranging accuracy, simple method, fast calculation speed and wide application range. The system has the advantages of low ranging cost, low cost and low technical risk, and can provide accurate ranging with low error.

The invention relates to the technical field of radars, and discloses an FMCW laser radar ranging method, device and equipment and a storage medium, and the method comprises the steps: receiving an echo signal reflected by a target object; performing frequency mixing on the echo signal and the local oscillator signal to obtain a frequency mixing signal; generating a target reference signal based on the mixing signal and the initial control signal; performing phase-locked amplification on the frequency mixing signal based on the target reference signal to generate a detection amplitude, and determining the distance between the target object and the laser radar and the position of the target object based on the detection amplitude; and generating a PID control signal as a new initial control signal based on the position of the target object, and returning to the step of receiving the echo signal obtained by reflecting the laser signal emitted to the target object. By dynamically generating the target reference signal, the adaptive capacity to targets with different distances is improved, high-precision distance measurement in a complex detection environment is realized through phase-locked amplification, and meanwhile, the flexibility and dynamic adaptability of the laser radar are enhanced through dynamic distance measurement.

The invention relates to the technical field of binocular stereoscopic vision, and discloses a binocular ranging system calibration method and system based on an electronic map. Selecting a first target reference object, adjusting the observation angle of the binocular distance measurement system, and obtaining a plurality of groups of images of the first target reference object at preset positions in the image; calculating a correction parameter of the binocular distance measurement system based on the plurality of groups of images of the first target reference object; selecting a plurality of second target reference objects on the electronic map according to predetermined constraints, acquiring a plurality of groups of images of the second target reference objects, and calculating a parallax value of the binocular ranging system by combining the distance from the second target reference objects on the electronic map to the binocular ranging system and the correction parameters; the calibration value of the distance measurement parameter of the binocular distance measurement system is obtained according to the parallax value, calibration of the binocular distance measurement system is completed, the calibration of the binocular distance measurement system is achieved by selecting the second target reference object on the electronic map, and the applicability of the binocular distance measurement system is improved.

The present invention proposes a frequency modulated continuous wave laser radar chip, which relates to the field of laser radar technology. The frequency modulated continuous wave laser radar chip includes: a tunable laser, a transmitting optical phased array, a receiving optical phased array and a balanced photodetector; the tunable laser is used to output a detection laser signal and realize wavelength tuning, the transmitting optical phased array is used to transmit laser signals outward, the receiving optical phased array is used to collect light from the outer space into an optical waveguide as signal light, and the balanced photodetector is used to receive local light and signal light, and convert the optical signal into an electrical signal with distance information and speed information of the object to realize ranging. The present invention uses a tunable laser to achieve more precise control of the wavelength tuning of the laser radar chip, realize wavelength tunability, and improve the ranging accuracy of the laser radar; the tunable laser uses a multi-path semi-reflective array waveguide to improve the stability of the laser radar chip ranging.

A steel rope deformation monitoring device comprises a steel strand or a steel cable, a hollow cylindrical cover shell and a distance measuring device, the cover shell comprises an outer shell located on the left side and an inner shell located on the right side, the inner shell and the outer shell can be mutually staggered left and right, one part of the distance measuring device used for measuring the mutual dislocation degree of the inner shell and the outer shell is installed in the outer shell, and the other part of the distance measuring device is installed in the inner shell. The steel strand or the steel cable is sleeved with the outer shell and the inner shell, and the outer shell and the inner shell are fixedly connected with the steel strand or the steel cable. According to the structure, the distance measuring device is arranged in the inner shell and the outer shell which can be staggered mutually, so that the measuring accuracy is improved, and the distance measuring instrument is prevented from being damaged. The structure is convenient to install and is not limited by a steel cable / steel strand structure.

The present invention discloses a vehicle ranging method, device, vehicle-mounted terminal, vehicle and medium, wherein the vehicle includes at least one UWB communication module, and the method includes: controlling the UWB communication module to send a first ranging frame, and controlling the UWB communication module to receive a second ranging frame and a data frame sent by a mobile terminal, wherein the first time of sending the first ranging frame is earlier than the second time of sending the second ranging frame, and the third time of sending the data frame is later than the second time, and the clock compensation value of the UWB communication module is determined according to the first time, the second time, the third time, the fourth time of receiving the second ranging frame, and the fifth time of receiving the data frame, and the ranging information of the UWB communication module is determined according to the clock compensation value, the first time, the second time, the fourth time, and the sixth time of the mobile terminal receiving the first ranging frame. On the basis of not increasing the hardware cost, the synchronization of data is effectively guaranteed, the error caused by the clock non-synchronization between the UWB communication module and the mobile terminal is reduced, and the ranging accuracy is improved.

The application discloses a warehouse scene mobile robot and sensor network node cooperative positioning method, which comprises the following steps: S1, arranging sensor network nodes, starting the robot, collecting robot motion information, robot and node distance measurement information and node distance measurement information, and filtering the relevant distance measurement information; S2, establishing a distance measurement correction model, and using the least square method to fit to obtain distance measurement correction parameters and initial values of position coordinates of unknown nodes in the sensor network; S3, establishing a state equation and a measurement equation of the robot-sensor network system; and S4, based on the derived system state equation and measurement equation, the overall state of the system is estimated based on the improved extended Kalman filter algorithm, and the simultaneous positioning of the mobile robot and the sensor network node in the warehouse scene is realized. The method can improve the distance measurement accuracy in a complex environment and the positioning accuracy of the robot and the sensor network node.

The present invention belongs to the technical field of image sensors, and relates to a TOF image sensor pixel structure and a ranging system, wherein the TOF image sensor pixel structure includes a first reading control module, a second reading control module and at least two small light sensors of preset sizes. The first reading control module includes at least two first transmission transistors, and the first reading control module is connected to at least two small light sensors of preset sizes in a one-to-one correspondence through at least two first transmission transistors. The second reading control module includes at least two second transmission transistors, and the second reading control module is connected to at least two small light sensors of preset sizes in a one-to-one correspondence through at least two second transmission transistors. The first transmission transistor and the second transmission transistor connected to the same small light sensor are symmetrically arranged. Therefore, the present invention can improve the transmission efficiency of photogenerated charges, and thus can achieve the purpose of improving ranging capability and ranging accuracy.

This application relates to the field of lidar technology, disclosing a calibration method, a ranging method, a lidar, and a robot. The calibration method includes: obtaining the spot center values ​​corresponding to calibration targets of different materials; determining several segmented calibration parameters corresponding to each type of calibration target based on the theoretical distance between each calibration target and the lidar in each calibration sub-segment within the lidar's range, and the spot center values ​​corresponding to each type of calibration target in each calibration sub-segment. By determining several segmented calibration parameters corresponding to each type of calibration target using the distance in each calibration sub-segment within the lidar's range and the spot center values ​​corresponding to each type of calibration target, this application can solve the problems of low calibration accuracy across the entire area and / or deviations in ranging accuracy caused by using only white target material for calibration, thereby improving the calibration and ranging accuracy of the lidar.

In order to solve the problems that a circuit structure is simple, and distance measurement with good accuracy and precision can be achieved, the invention provides a method which does not need to adopt an array antenna, does not need to measure time difference, and only measures phases of two pilot frequency signals to achieve ambiguity-free and high-precision distance measurement. Different from the existing mode of solving the distance by measuring the phase difference, the new method directly uses a distance measurement equation for measuring the phase. In order to eliminate phase ambiguity, the frequency interval of two different-frequency signals is limited to ensure that the same wavelength integer cycle number exists during different-frequency phase detection on the detected distance length. On the basis, the wavelength whole cycle number can be solved through joint solution of a double-frequency phase ranging equation set. And then the detection distance can be obtained by using the phase distance measurement equation again. Simulation analysis shows that in a distance range without phase shift ambiguity, the double-frequency phase distance measurement method is not only good in accuracy, but also capable of obtaining distance measurement precision smaller than 0.2%.

The invention discloses a vehicle automatic driving visual ranging learning method and device, and the method comprises the steps: obtaining a driving image, generating a preset number of driving points in the driving image in the driving direction, and obtaining a road curve image according to all the driving points; recording the time, the distance and the vehicle speed of driving to each driving point; obtaining a road mapping function according to the road curve image and the time, the distance and the vehicle speed corresponding to all the current driving points; selecting a point location after the current target driving point location in the road curve image as a detection point location; obtaining the target time of the detection point according to the road mapping function; and calculating the actual distance between the current target driving point position and the detection point position according to the time of the current target driving point position, the vehicle speed and the target time. The target time of the detection point is obtained based on the road mapping function, and the actual distance is calculated by combining the time of the previous target driving point and the vehicle speed, so that the distance measurement precision is improved.

The present invention provides a high-precision ranging system and method based on beat sampling, comprising two completely identical terminals; wherein the two terminals both comprise: a ranging frame sending unit for generating a ranging frame and sending the ranging frame to another terminal; a ranging frame receiving unit for receiving a ranging frame feedback signal including a ranging frame sending time calculated by the other terminal, and obtaining the time when the ranging frame calculated by the current terminal arrives at the other terminal; an ADC sampling calculation module for obtaining a frequency difference and a phase difference between a sending clock and a receiving clock through frequency and phase discrimination; a ranging frame sending time calculation module for obtaining a ranging frame sending time calculation value; and a ranging calculation module for obtaining a ranging calculation value and a distance between the two terminals according to the ranging frame arrival time and the ranging frame sending time calculation value calculated by the other terminal in the ranging frame feedback signal.

The invention discloses a carrier communication line distance measurement method based on sequence correlation, and the technical scheme comprises the following steps: step 1: sending an m sequence to a low-voltage power line channel through a test host; step 2: through timing synchronization, a measurement device slave performs correlation operation on the collected sequence to obtain a correlation sequence; step 3: performing peak value judgment and peak-to-average ratio judgment on the correlation sequence to determine the synchronization moment of the first correlation peak; step 4: taking the synchronization moment of the first correlation peak as the standard, the test device slave adds a fixed delay time on the basis of the synchronization moment, and sends the same spread spectrum sequence to the low-voltage power line, and the test device host obtains the synchronization moment in the same manner as step 2 and step 3; step 5: calculating a single line transmission delay, and calculating the distance between the two ends of the test point according to the signal transmission rate in the power line.

This invention discloses a laser pulse phase-based ranging system with low walking error, comprising a TIA circuit, a pulse amplification unit, a timing discrimination circuit, an RS latch circuit, and an ADC circuit. The output of the TIA circuit is connected to the pulse amplification unit, the output of the pulse amplification unit is connected to the timing discrimination circuit, and the output of the timing discrimination circuit is connected to the RS latch circuit and the ADC circuit. The pulse amplification circuit includes a differential amplification circuit and a post-amplifier circuit connected to the output of the differential amplification circuit. This invention proposes that the phase-based ranging section directly performs undersampling of the acquired analog pulse signal to a sine wave using an ADC, eliminating the need for a subsequent mixing and filtering circuit unit, thus simplifying the system circuitry and reducing power consumption. Furthermore, it proposes using the comparator delay to compensate for the walking error of pulses with different amplitudes, thereby reducing the walking error of pulses with different amplitudes and overcoming the negative impact of comparator delay on walking error.

The present disclosure relates to a resonant frequency correction device, a reversing radar alarm system and a ranging system, and the device includes: a bandpass sampling module, a down-conversion filter module, and a frequency deviation detection module. Through the above device, the embodiment of the present disclosure can perform bandpass sampling and filtering on the received ultrasonic signal to obtain a complex baseband signal, perform frequency deviation detection on the complex baseband signal to obtain the first carrier frequency deviation of the complex baseband signal, and use the first carrier frequency deviation and the complex baseband signal to determine the second carrier frequency deviation, and use the preset transmission frequency of the ultrasonic transmitter and the second carrier frequency deviation to determine the resonant frequency of the ultrasonic transmitter, so as to perform frequency correction on the ultrasonic transmitter. By correcting the actual resonant frequency of the ultrasonic transmitter, the frequency drift problem can be solved to improve the transmission efficiency, reduce the influence of the carrier frequency deviation, and thus improve the ranging accuracy.

The invention provides a method and a system for online registration of an ONU (Optical Network Unit) of a P2MP (Point to Multipoint) system. The ONU randomly selects a sequence from the sequence code set, carries out analog intensity modulation on the sequence, then moves a registration signal to a frequency band protection interval, and sends the registration signal to the OLT together with a service signal. After the OLT receives the signals, the signals are subjected to frequency shift and filtering to extract registration signals. The method comprises the following steps of: performing resampling operation on a registration signal, performing simulation square detection, removing a direct current component in the registration signal, combining two polarized signals, performing multiple periodic averaging, performing cyclic cross-correlation operation on the processed signal and a local sequence code set, and detecting an obtained peak value; and if the peak value is detected to exceed a preset judgment threshold value, indicating that the sequence code is activated, and estimating the time delay of the sequence code. According to the invention, high frequency offset estimation and time delay estimation precision can be realized, and the designed registration signal has small influence on the performance of the service signal; registration signal power is allowed to be far smaller than service signals.

The application provides a pulse pile-up effect error correction method of a dTOF module, comprising: determining a second function based on actual depth data of a direct flight time module and a first function; determining a third function based on the first function and the second function, performing Fourier series fitting on error data based on the third function to obtain a periodic error model; and performing error correction on corresponding actual depth data according to the periodic error model; in this way, the overall trend of the actual depth data is separated from the nonlinear error introduced by the pulse pile-up effect by fitting the second function, and only the error component containing periodic fluctuations is reserved; the nonlinear change trend of the error is fitted by the third function, and the periodic fluctuation component is accurately modeled by the Fourier series, which can completely cover the nonlinear error characteristics of the pulse pile-up effect, so that the compensation value completely matched with the actual error can be calculated, thereby realizing accurate compensation of the error.

The application provides a surface topography measuring device and method, and an object surface height calculation method, and applies to the technical field of optical precision measurement, and comprises a fiber F-P interference measuring head and a three-dimensional displacement table; the fiber F-P interference measuring head is composed of a fiber head array and a microlens array, and an object to be measured is fixed on the three-dimensional displacement table; a light beam is transmitted to the fiber F-P interference measuring head, is emitted from an exit surface of the microlens array after passing through the fiber head array and the microlens array, and is collimated and irradiated to the surface of the object to be measured; and the three-dimensional displacement table drives the object to be measured to perform three-dimensional movement to measure the surface topography of the object to be measured. Through the scanning measurement scheme of the combination of the fiber head array and the microlens array and the three-dimensional displacement table, the problems of small measurement range and slow measurement speed of the fiber F-P interference measuring head are solved, the measurement range and the measurement speed of the fiber F-P interference surface topography detection product are improved, and the cost thereof is reduced.

The application discloses a ranging method, comprising: obtaining a mapping relationship between serial numbers of actual data boxes and serial numbers of preset data boxes, wherein each actual data box is mapped to at least one preset data box; obtaining ranging data, assigning storage space to the actual data boxes and storing the ranging data; determining a target data box and a serial number of the target data box according to data distribution of the ranging data in the actual data boxes; determining a target value of a preset data box corresponding to the target data box according to the mapping relationship between the serial numbers of the actual data boxes and the serial numbers of the preset data boxes and according to a preset algorithm; and determining a distance of a measured target according to the target value of the preset data box and a width of the preset data box. The application also provides a ranging system, which can reduce storage space.

The utility model discloses a low noise continuous wave modulation laser drive source for high speed laser range finder, the utility model discloses a clock chip of CDCEL925 series is used to generate clock signal, and generates fundamental wave main vibration signal with this, wherein, compared with remaining frequency synthesis technique, it can produce the clock signal of lower phase noise, so, can generate the fundamental wave main vibration signal of low phase noise, simultaneously, through low noise direct current voltage module, the bias current of laser is generated, and it is combined with the fundamental wave main vibration signal of low phase noise through ac coupling, then can constitute the laser drive source of low phase noise, based on this, then can effectively reduce the random error of phase difference measurement, in addition, the utility model discloses still through optical power feedback module to carry out the power feedback of laser, and through integral regulator to feedback and adjust the bias current of laser loop, so, then can realize the transient stability of optical power in the modulation process, to further improve the ranging precision.