37results about How to "Improve distance measurement accuracy" patented technology

The invention relates to a time measurement circuit and an optoelectronic range finder using such a time measurement circuit. The time measurement circuit and for an incoming signal, in such a condition, has a comparator stage for generating a comparator output signal depending on a fulfillment of a criterion by the incoming signal, wherein exceeding or falling below a threshold value is defined as the criterion. Furthermore, a digitization stage is provided, for sampling, which is performed at a defined sampling rate, of an input signal fed to the digitization stage and converting it into digital data containing sampled values for the input signal, and an evaluation unit for determining a chronological location for the incoming signal by evaluating the digital data. A signal generating stage is interconnected between the comparator stage and the digitization stage, which is designed to generate and output, in a chronologically fixed manner dependent on the content of the comparator output signal, a shape signal, which is designed for post-sampling interpolation ability, of known shape. The evaluation unit then determines the time for the incoming analog signal while using a chronological interpolation of the values contained in the digital data and the known shape of the shape signal.

The invention discloses a low-altitude target detecting system of a three-coordinate continuous wave one-dimensional phase sweeping unmanned aerial vehicle, and is aimed at providing a detecting device high in data detecting rate and anti-interference capacity. By means of the technical scheme, the system measures a target distance through a frequency modulation continuous wave ranging system, anantenna feedback subsystem converts radio frequency signals into electromagnetic wave signals to be radiated to the space, a receiving subsystem conducts amplifying, frequency varying and SFC controlprocessing on echo signals output by an emission and wave control subsystem, a signal processing subsystem generates the working time sequence of the whole system, measures the three-coordinate vectors of the distance, direction and pitching of a target position and calculates frequency modulation continuous wave ranging data of target signals, and a data processing and communication control subsystem parses the target angle, establishes the trajectory of target movement, controls the working mode of a radar and detects three-coordinate target information according to the target signals calculated by the signal processing subsystem and the antenna angle information output by the antenna control subsystem.

An imaging device includes: a controller which generates a light emission signal and an exposure signal; a light source unit which receives the light emission signal and emits light; a light receiver which obtains the exposure amount of reflected light at a timing in accordance with the exposure signal; and a calculator which outputs a distance signal (distance image) by calculation on the basis of the amount of signals included in imaging signals received from the light receiver. The controller generates two or more patterns of varying phase relationships between the light emission signal and the exposure signal, and outputs the light emission signal and the exposure signal in a cycle that is different between at least two of the patterns.

The present invention provides a laser transmitting circuit, a laser receiving circuit, a distance calculation circuit and devices thereof. The laser transmitting circuit comprises an energy storage capacitor, a laser transmitting tube, an MOS switch circuit and an MOS switch driving circuit. The laser receiving circuit comprises a laser receiving tube, a first low-noise triode, a second low-noise triode and a low-noise wideband amplifier. The distance calculation circuit comprises a singlechip, a programmable logic circuit, a clock source and an echo identification circuit. The present invention further provides a low-voltage power circuit that provides a reverse polarity protection to an external power supply without additional diode connected in reverse polarity. According to the technical solutions provided by the present invention, the measurement range and precision of a semiconductor laser rangefinder can be improved effectively.

A counting device includes a counting unit, period measuring unit, frequency distribution generating unit, representative value calculation unit, and correction value calculation unit. The counting unit counts the number of signals input during a counting interval. The number of signals has a linear relationship with a physical quantity. The signals have a substantially single frequency when the physical quantity is constant. The period measuring unit measures the period of a signal every time a signal is input during the counting interval. The frequency distribution generating unit generates the frequency distribution of signal periods from the measurement result. The representative value calculation unit calculates the representative value of the distribution of periods of signals from the frequency distribution. The correction value calculation unit obtains a total sum Ns of frequencies in a class not more than a first predetermined multiple of the representative value calculated and a total sum Nw of frequencies in a class not less than a second predetermined multiple of the representative value from the frequency distribution, and corrects the count result on the basis of the frequencies Ns and Nw.

The invention discloses a distance measuring system, which comprises an emitter, a collector and a processing circuit, wherein the emitter and the collector are arranged along a baseline, the emittercomprises a light source array composed of a plurality of light sources, the light source array comprises a plurality of sub light source arrays, the sub light source arrays are configured to be started one by one in the baseline direction to emit spot light beams, the collector comprises a pixel array composed of a plurality of pixels, the pixel array comprises a plurality of sub-pixel arrays, the plurality of sub-pixel arrays are configured to collect photons in a light beam reflected back by the spot light beam through a to-be-measured target object and form a photon signal, the processingcircuit comprises a plurality of sub-processing circuits, and the sub-processing circuits are connected with the sub-pixel arrays in a one-to-one correspondence mode so as to control pixels in the sub-pixel arrays to be started, collect photons in the reflected light beams and calculate flight time. According to the invention, the spatial resolution is improved, the problem of superpixel overlapping is solved, and the distance measurement precision is improved; and the process cost and the complexity are effectively reduced.

The invention discloses a method for measuring a CPII control network in a long and large tunnel with a receiving well, and relates to the field of control network measurement of rail transit. The measurement method mainly comprises the steps of (1) CPII remeasurement and encryption outside a hole: forming a triangular or geodetic quadrilateral connected strip-shaped net by adopting a GNSS staticmeasurement mode and an edge connection type net, and performing unified adjustment; (2) receiving well connection measurement: carrying out in-hole introduction edge measurement by adopting a one-well orientation principle, calculating the coordinates of a reflective sticker fixed by a steel wire on the ground through edge measurement and angle measurement of a ground total station, transmittingthe coordinates of the reflective sticker below the vertical shaft to the coordinates of the reflective sticker below the vertical shaft through the steel wire for orientation again, and then introducing the coordinates into the point position buried in the tunnel (3) CPII measurement in the tunnel: adopting a free observation station method; (4) data processing; and (5) final result checking. Themethod provided by the invention is good in point position stability, high in net type strength and flexible in observation station arrangement; the centering error is reduced, and the angle and distance measurement precision is improved.

The invention relates to a semiconductor laser distance measuring device based on switched capacitor array sampling. The distance measuring device comprises an emission end and a receiving end which are connected with a main control module. The emission end successively comprises an LD driving module, an LD module and an LD shape adjusting emission module. The receiving end successively comprises an echo receiving module, an APD amplifying module, an SCA sampling integration module and an ADC module. The SCA sampling integration module comprises N sampling units. Each of the sampling units comprises a sampling switch, an output switch and a sampling capacitor. Digital pulses are transmitted in order, so the sampling switches of the sampling units are successively closed. When the sampling switches are closed, input current signals will charge the sampling capacitors in the corresponding positions. Compared with the traditional AD sampling and storing method, requirements on power consumption of a system and operation speed of a processor are greatly reduced; and quite far acting distance and quite high distance measuring precision can be achieved via quite small size of the system and quite low power consumption.

The present invention relates to a capacitive distance measurement method. The method comprises the steps of using a control unit to determine the time when an excitation unit applies a first excitation signal; using the excitation unit to apply the first excitation signal to a probe; using a capacitance-voltage conversion unit to obtain a first voltage signal corresponding to the capacitance formed between the probe and a measured member; using the control unit to determine the time when a logarithm amplification processing unit carries out the logarithm amplification processing; using the logarithm amplification processing unit to carry out the logarithm amplification processing on the first voltage signal to obtain a second voltage signal; using a data acquisition conversion unit to convert the second voltage signal into a third voltage signal; using the control unit to convert the third voltage signal into a distance value. The present invention also discloses a capacitive distance measurement device and a calibration method thereof.

The invention relates to a time point discrimination method, a time point discrimination system and a laser ranging system. The time point discrimination method is characterized in that echo pulses detected during measurement are divided into two parts; the peak of one part of pulses is maintained, peak maintenance processing is used to convert the echo pulses into a DC level, the voltage value of the DC level is the peak voltage of the echo pulses, and the DC level is attenuated at a set proportion; the other part of pulses is delayed, delay processing is used to delay the echo pulses by nanoseconds, and the delay should be greater than the time delay caused by peak maintenance and attenuation; and the voltage value of the DC level after attenuation and the voltage value of the echo pulses after delay are compared, the moment when the voltage value comparison result changes is taken as the arrival time of echo pulses, and when the amplitude of echo pulses changes, the voltage value of the time point discrimination level changes, and thus, time point discrimination independent of echo intensity is realized. The time point discrimination method is widely used in ranging of pulsed laser ranging systems or of 2D or 3D laser radar systems based on different beam scanning modes.

The invention relates to an improved method of distance measurement accuracy of a linear frequency-modulated continuous wave detection system. The linear frequency-modulated continuous wave detectionsystem has outstanding advantages of low transmission power, high receiving sensitivity, high range resolution and simple structure and the like and has the stronger target identification, anti-background clutter and anti-interference abilities than the pulse system. In addition, for spectrums obtained by fast Fourier transform (FFT), discrete spectrums occur in a frequency range with the frequency component as the center under the non-simultaneous sampling; spectral lines beyond the signal frequency component are indicated to be leaked from the signal component, so that the spectrum leakage occurs. Moreover, offsets exit between the frequencies corresponding to all discrete spectral lines and the signal frequency component, so that the fence effect exists. In order to avoid the phenomena,the invention puts forward a method for improving the measurement accuracy of the signal frequency based on the invariable point number N of FFT to improve the distance measurement accuracy by usingthe signal amplitude distribution caused by spectral leakage.

The invention discloses an intelligent slipper low-temperature distance measurement device and method. The device comprises a distance detection module, a temperature module, a power management module, a battery, a main control module, and a wireless transmission module. The distance detection module, the wireless transmission module and the temperature module are respectively connected with the main control module, and the main control module is used for the operation coordination of a whole system. The method employs four types of methods to improve the low-temperature ultrasonic ranging precision according to temperature difference, and comprises the steps: correcting a sound speed through temperature; adjusting a driving voltage of an ultrasonic probe; dynamically adjusting the number of transmitted pulses according to the temperature, and adjusting the threshold voltage of a receiving end. Through the adjustment of software and hardware circuits, the device and method improve the distance measurement precision of an intelligent slipper under low temperature, especially in a northern cold region, and plays an important role in preventing a train from escaping and guaranteeing the safety.

The invention discloses a drilling footage measuring method for a roadheader, and relates to the technical field of drilling footage measuring. According to the measuring method, a distance measuringdevice and a reflecting target are arranged, a laser sensor is used for emitting a laser beam to the reflecting target, the laser beam reflected by the reflecting target is received, and according tothe duration from emitting to receiving of the laser beam measured by a timer, the distance L from the laser sensor to the reflecting target is measured and the drilling footage of the roadheader is automatically measured; and meanwhile, the light return amount C is monitored, whether the laser beam hits the target or not is measured according to the light return amount, and a target searching procedure is started at proper time. The invention discloses the drilling footage measuring method for the roadheader. The drilling footage of the roadheader is automatically measured through the arrangement of the distance measuring device and the reflecting target, automatic measuring replaces manual measuring, the measuring precision is high, and the labor intensity is reduced. Meanwhile, whetherthe leaser beam hits the target or not is judged according to the measured light return amount of the laser sensor, so that a steering engine pan-tilt is started according to requirements, the targetsearching work is carried out, and the accuracy and integrity of distance measuring are further improved.

The invention discloses an underwater target detecting device based on a single-photon counting method. Narrow-pulse laser which is output from a pulse laser is divided into two parts by an optical isolator assembly. One part is directly detected by a photoelectric detecting module. An electric signal which is output from the photoelectric detecting module is input into a time-related single-photon counting system and a time delay module, wherein the signal which is input into the time-related single-photon counting system is used as a timing starting signal. The signal which is input into thetime delay module is used as a distance gating control signal. The other part irradiates a target after light beam shaping. After a target echo signal is emitted to the single-photon detecting module, the target echo signal is used as a timing terminating signal for being input into the time-related single-photon counting system. Through performing data processing on the signal of the time-related single-photon counting system, thereby obtaining target information. The underwater target detecting device has advantages of high precision and high sensitivity and furthermore facilitates realization of low power consumption and miniaturization of an underwater target detecting system.

The invention provides a radio navigation distance measurement radio wave refraction error correction method. A mathematical model of the apparent elevation angle, the flight height and the apparent distance between an aircraft and a ground beacon is constructed, the geocentric field angle of the aircraft apparent elevation angle and the ground beacon at different heights is calculated, the real elevation angle between the aircraft and the ground beacon is calculated, the real distance between the aircraft and the ground beacon is calculated, and the atmospheric refraction distance measurementerror is calculated. The method is based on the atmospheric refraction theory and radio navigation equipment application, the mathematical model of the radio navigation atmospheric refraction distance measurement error, the flight height of the aircraft and the apparent distance of the ground beacon is constructed, a distance correction algorithm is provides, and the method has practicability anduniversality for radio navigation distance atmosphere refraction error correction, can obviously improve the radio navigation distance measurement precision, and fills up the blank in the field of radio navigation atmosphere refraction error correction. The method also has a certain reference value for distance measurement based on radio pulses.

The invention provides an absolute distance measurement system and method based on the phase method and the synthetic wavelength method. The output laser of a femtosecond laser is reflected by a polarization beam splitting prism I and then returned along an original path by a 0-DEG reflector after passing through an acousto-optic modulator; the reflected light is transmitted through the polarization beam splitting prism I into a polarization beam splitting prism II into two beams, one beam is a reference arm light path and is received by a photodetector I, the other beam is a measuring arm light path and is received by a photodetector II, and the photodetectors are electrically connected with a computer through a phase meter. The system and the method are advantaged in that a technical problem that the range and measurement accuracy cannot be simultaneously satisfied in the absolute distance measurement process in the prior art is solved; an erbium-doped femtosecond laser frequency comb is utilized as a light source, the pulse repetition frequency is high, and distance measurement accuracy is improved by utilizing higher harmonics; through interference between femtosecond optical comb pulses, combined with the phase method and the synthetic wavelength method, the large extended measurement range is realized; the system is simple in structure and easy to operate.

A distance measurement image pickup apparatus has two measurement periods. In a first distance measurement period, short pulsed light (1T) is irradiated, and exposure is performed in a plurality of exposure periods (A, B, and C) in which exposure timings are shifted. In each exposure period, an exposure gate is opened a plurality of times to perform repetitive exposure, and a first non-exposure period is provided from when a last exposure gate is closed until subsequent pulsed light is irradiated. In a second distance measurement period, long pulsed light (4T) is irradiated, and exposure is performed in a plurality of exposure periods (A, B, and C) in which exposure timings are shifted. In each exposure period, exposure is performed by opening the exposure gate only once, and a second non-exposure period is provided from when a last exposure gate is closed until subsequent pulsed light is irradiated.

The invention discloses a correction method and device for ultrasonic distance measurement and an ultrasonic receiving device. The correction method comprises the following steps: determining the positioning distance of an ultrasonic receiving device in a second period according to the moving speed and acceleration of the ultrasonic receiving device and the ultrasonic measurement distance betweenthe ultrasonic receiving device and an ultrasonic transmitting device in a first period; determining the ultrasonic measurement distance between the ultrasonic receiving device and the ultrasonic transmitting device in the second period; and correcting the ultrasonic measurement distance between the ultrasonic receiving device and the ultrasonic transmitting device in the second period according to the result of comparison between the ultrasonic measurement distance and the positioning distance of the ultrasonic receiving device in the second period, wherein the second period is a signal period next to the first period. Thus, the error of ultrasonic distance measurement is reduced, and the accuracy of measurement is improved.

A distance measurement device (1) is provided with an irradiation unit (2), a light receiving array unit (3), a signal intensity calculation unit (S50), a signal time calculation unit (S60), intensity correction units (S70, S82, S76, S86), and distance calculation units (S110, S120). The irradiation unit irradiates pulse-shaped signal light. The light-receiving array unit is provided with a plurality of photodetectors (31) that output a pulse signal by the incidence of photons. The signal intensity calculation unit calculates the signal intensity of the received signal light. The signal time calculation unit calculates a rise time and a fall time of the detected signal light. The intensity correction unit corrects at least one of the rise time and the fall time on the basis of the signal intensity. The distance calculation unit calculates the object distance on the basis of at least one of the corrected rise time and the corrected fall time.

The invention discloses a visual well logging video depth calibration method based on coupling data and inter-frame motion estimation, and relates to the technical field of storage type visual well logging in the petroleum and petrochemical industry, the visual well logging depth calibration method is higher in distance measurement precision compared with existing distance measurement, and the problems of well logging cable extension, time asynchronization and the like are solved; the casing coupling is automatically identified by utilizing an edge detection technology, feature parameter extraction, feature matching and intelligent judgment, and the position of the image with the coupling in the video is recorded; according to the method, coupling parameters are intelligently and automatically extracted, and the distance from a coupling to a camera is calculated according to the proportional relation between the imaging distance of the camera and the imaging size; the method comprises the following steps of: interpolating coupling data by using a method based on inter-frame motion estimation to obtain depth data between couplings; according to the method, the accurately calibrated data is automatically merged with the video, and intelligent matching is carried out, so that the data accuracy is ensured.

The invention discloses a method for measuring the footage of a roadheader, which relates to the technical field of footage measurement. In this measurement method, by setting the distance measuring device and the reflective target, the laser sensor is used to emit a laser beam to the reflective target, and the laser beam reflected by the reflective target is received, and the time from the emission to the reception of the laser beam is measured according to the timer, so as to calculate from The distance L from the laser sensor to the reflective target automatically measures the advance of the roadheader; at the same time, it monitors the amount of returned light C, and determines whether the laser beam hits the target according to the amount of returned light, and starts the target-seeking process in due course. A method for measuring the length of a roadheader disclosed by the invention, by setting a distance measuring device and a reflective target, automatically measures the length of the roadheader, and replaces manual measurement with automatic measurement, which has high measurement accuracy and reduces labor intensity; at the same time, it can be measured by laser The amount of light returned by the sensor is used to determine whether the laser beam hits the target, so as to start the steering gear pan / tilt according to the requirements, and carry out the target-finding work, further improving the accuracy and integrity of the distance measurement.

The invention discloses a correction method and device for ultrasonic distance measurement and an ultrasonic receiving device. The correction method comprises the following steps: determining the positioning distance of an ultrasonic receiving device in a second period according to the moving speed and acceleration of the ultrasonic receiving device and the ultrasonic measurement distance betweenthe ultrasonic receiving device and an ultrasonic transmitting device in a first period; determining the ultrasonic measurement distance between the ultrasonic receiving device and the ultrasonic transmitting device in the second period; and correcting the ultrasonic measurement distance between the ultrasonic receiving device and the ultrasonic transmitting device in the second period according to the result of comparison between the ultrasonic measurement distance and the positioning distance of the ultrasonic receiving device in the second period, wherein the second period is a signal period next to the first period. Thus, the error of ultrasonic distance measurement is reduced, and the accuracy of measurement is improved.

The invention discloses an underwater target detecting device based on a single-photon counting method. Narrow-pulse laser which is output from a pulse laser is divided into two parts by an optical isolator assembly. One part is directly detected by a photoelectric detecting module. An electric signal which is output from the photoelectric detecting module is input into a time-related single-photon counting system and a time delay module, wherein the signal which is input into the time-related single-photon counting system is used as a timing starting signal. The signal which is input into thetime delay module is used as a distance gating control signal. The other part irradiates a target after light beam shaping. After a target echo signal is emitted to the single-photon detecting module, the target echo signal is used as a timing terminating signal for being input into the time-related single-photon counting system. Through performing data processing on the signal of the time-related single-photon counting system, thereby obtaining target information. The underwater target detecting device has advantages of high precision and high sensitivity and furthermore facilitates realization of low power consumption and miniaturization of an underwater target detecting system.

The invention discloses an anti-NLOS interference visible light positioning method and system based on a linear regression model. The anti-NLOS interference visible light positioning system comprisesa transmitting module, a receiving module, a training module and a positioning module. The transmitting module comprises a plurality of LED lamps, a signal generator, a baseband modulation module anda driving circuit; each LED lamp is provided with an ID; the receiving module comprises an optical filter, a photoelectric detector, an amplifier, an analog-to-digital converter and a microprocessor,and is used for receiving signals of different LED lamps in different time slices in one period and extracting the intensity of the received signals. According to the method, non-line-of-sight transmission (NLOS) interference is removed by adopting a machine learning method, and then, positioning is realized by adopting a geometric positioning method, so that the influence of the NLOS interferenceon positioning can be eliminated, the positioning precision is improved, and the requirement of an existing fingerprint positioning method based on machine learning on positioning data is also reduced.

The present invention relates to a capacitive distance measurement method. The method comprises the steps of using a control unit to determine the time when an excitation unit applies a first excitation signal; using the excitation unit to apply the first excitation signal to a probe; using a capacitance-voltage conversion unit to obtain a first voltage signal corresponding to the capacitance formed between the probe and a measured member; using the control unit to determine the time when a logarithm amplification processing unit carries out the logarithm amplification processing; using the logarithm amplification processing unit to carry out the logarithm amplification processing on the first voltage signal to obtain a second voltage signal; using a data acquisition conversion unit to convert the second voltage signal into a third voltage signal; using the control unit to convert the third voltage signal into a distance value. The present invention also discloses a capacitive distance measurement device and a calibration method thereof.

The invention provides a device for measuring an object distance. The device comprises a pulse generator, an optical emission unit, an optical receiving unit and a measurement unit, wherein the pulse generator is used for sequentially transmitting electrical pulses to the optical emission unit at fixed frequency; the optical emission unit is used for transmitting optical pulse signals in real time every time when receiving the electrical pulses, a part of the optical pulse signals directly enter the optical receiving unit as reference signals, and the other part of the optical pulse signals enter the optical receiving unit after being reflected through an area to be detected as measurement signals; the optical receiving unit is used for transmitting the reference signals and the measurement signals to the measurement unit in real time; and the measurement unit is used for subtracting the measurement signal when a target obstacle does not exist at the last moment from the measurement signal when the target obstacle exists in the area to be detected to obtain a background interference-free measurement signal, and obtaining a distance with the target obstacle in real time according to the background interference-free measurement signal and the reference signal. Correspondingly, the invention provides a method for measuring the object distance. According to the device and the method, the influence of temperature and background interference signals on the distance measurement accuracy can be reduced or eliminated, and the distance measurement accuracy is higher.