101results about How to "Measuring distance" patented technology

An anti-interfering method of short-range FMCW radar includes designing a set of pseudo-random code according to occasion of radar, distributing different pseudo-random code to different radar operated at different area, applying different pseudo-random code to modulate frequency start-point of FM emission signal for the same radar on each cycle, making frequency-mixture on received echo signal by utilizing emission signal, using filter to filter off interference signal and applying FM signal processing means to treat reserved usable signal for obtaining object distance and speed information in high resolution.

A laser distance measuring apparatus, for measuring the distance between objects existing in two directions at least as seen from the apparatus by using laser light, comprises two projectors for projecting laser beams along a specified projection axis toward each one of the objects, a photo detector for receiving reflected light of projection from each object, a distance measurement processor for measuring the distance from a reference point of the apparatus to each object on the basis of the reception signal to the projection by the photo detector, and a distance calculation processor for calculating the distance between the objects on the basis of the distance data measured by the distance measurement processor and the angle formed by two projection axes, in which the projection axis by one projector is variable in angle with respect to the other projector. Therefore, the distance between objects can be measured easily and at high precision by one distance measuring operation only.

The invention discloses an FMCW anti-collision radar multi-target detecting and tracking system and method. The system comprises a radar array processing unit, a target detecting and estimating unit, a post-processing unit and a debugging unit. The radar array processing unit sends target information in front of a vehicle to the target detecting and estimating unit through a CAN bus for multi-target rapid detecting and tracking, and tracking results and obstacle avoidance early warning information are sent to the post-processing unit and the debugging unit through RS 422 serial ports respectively. The post-processing unit displays the received target tracking results and the obstacle avoidance early warning information and performs voice reminding. In the system debugging process, the debugging unit displays and evaluates intermediate data and the tracking results and controls the target detecting and estimating unit to be started or shut down. Radar data processing is converted into image processing, and the effective means is provided for meeting the application requirement for high-reliability anti-collision radar multi-target detecting of an automobile, a tramcar and other traffic systems.

The present invention relates to an encoding frequency-hopping high-resolution distance-measuring speed-measuring method and radar. In particular, it is applicable to automobile anti-collision radar and police speed-measuring radar, and can be substituted for infrared alarm to make all-weather real-time safety supervisory control for large-range sensitive area. Said invention also provides the concrete steps of said distance-measuring and speed-measuring method, and can make several radars have strong anti-interference power when they are simultaneously worked.

The invention relates to the technical field of traffic monitoring, in particular to a highway agglomerate fog early warning system based on intervisibility distance monitoring and an early warning method thereof. The highway agglomerate fog early warning system comprises a highway agglomerate fog early warning detection device and a server. The highway agglomerate fog early warning detection device comprises a laser emitting module, a laser receiving module, a control module and a data transmission module. The laser emitting module and the laser receiving module are oppositely arranged on the two sides of a highway. The highway agglomerate fog early warning detection device is in communication with the server through the data transmission module. The early warning method includes the step that the laser receiving module is used for receiving light intensity data to calculate an intervisibility distance, the step that the intervisibility distance is compared with a greasy weather traffic safety early warning threshold value, and the step that the server issues early warning information. By means of the highway agglomerate fog early warning system based on intervisibility distance monitoring and the early warning method thereof, agglomerate fog monitoring of highway narrow strip-shaped space can be achieved, the current intervisibility distance can be obtained automatically and accurately, corresponding early warnings are given out, and thus highway traffic safety is improved.

A camera distance measurement device displays an image in which a plurality of graduation lines which are arranged in the form of a grid with respect to a vehicle is superimposed on a camera image which is captured by a camera mounted to the vehicle on a display unit, and estimates a distance in a direction of the width of the vehicle, and a distance in a direction of the capturing by the camera from a unit distance defined for each grid side of the graduation lines.

A high-accuracy distance measurement device of laser consists of microcontroller, storage expansion module, communication interface module, power supply module, laser modulation-driving module, laser emitter, driving module of laser start-up signal, laser-receiving power supply module, laser receiving module, filtering amplifier, high-accuracy time interval measurer and output module.

The invention relates to a basic programming system (BPS) automatic deflection correction method and a BPS automatic deflection correction system for a crane cart. Left and right guide rails are provided with a bar code strip respectively; corresponding bar code readers are arranged on a cart frame; and a control unit acquires and compares the numerical values read by the readers on two sides in time, judges whether the travels of driving wheels on left and right sides of the cart are synchronous, automatically adjusts the driving wheels on two sides by reducing the rotation speed of the driving wheel on the front side or increasing the rotation speed of the driving wheel on the rear side if the driving wheels are not synchronous, and keeps the two driving wheels are in the same bar code section. Whether the travelling wheels on two sides are deflected and the deflection degree can be judged accurately and timely, and a control circuit can give an instruction for adjusting the rotation speed of a driving motor timely, so that the reliability is high. The deflection detection accuracy of the crane cart is high, so that the deflection can be corrected accurately under the condition of curves and slopes. Moreover, a BPS system has the advantages that: the BPS system has a Proibus function and low cost and can configure with a programmable logic controller (PLC) freely; and the measurement distance can reach 10,000 meters.

The invention belongs to the technical field of engineering measurement, and relates to a device for measuring ground settlement, in particular to a device for measuring the settlement of a tunnel or a subway pipeline by combining an optical fiber grating sensor. The device for measuring the ground settlement comprises the optical fiber grating sensor, and is characterized by also comprising a lever and three supports which are positioned under any three positions of the lever respectively; the bottoms of the three supports are fixed on the ground; the tops of the supports are connected with the lever positioned over the supports or the optical fiber grating sensor; and when the tops of the supports are connected with one end of the optical fiber grating sensor, the other end of the optical fiber grating sensor is connected with the lever positioned over the optical fiber grating sensor. The device has the advantages of simple structure and measuring accuracy.

The invention discloses a ground measurement method for accuracy of a distance measurement sensor for rendezvous and docking of airships. The coordinate system of a distance measurement sensor body is visibly derived by using an electronic theodolite measurement system, and a plurality of kinds of the coordinate systems are converted by combining a controlling field method. The coordinate system of the distance measurement sensor body and the coordinate system of the controlling field are unified by using a high-precision ground measurement control network. Distance measurement is performed on a reflection target of the distance measurement sensor by using a high-precision total station. The data of the plurality of kinds of the coordinate systems is integrated according to existing measurement data so as to deduce the relative distance between the distance sensor and a target marker; and the relative distance is compared with the actual measurement result of the distance measurement sensor so as to obtain the measurement accuracy of the distance measurement sensor finally.

The invention discloses a TOF based ranging system and its correction method. A main transmitting tube and a transmitting focusing lens group are arranged inside a transmitting lens barrel. A receiving lens barrel is in parallel arrangement with the transmitting lens barrel; the receiving lens barrel comprises an anti-stray light structure and a receiving focusing lens group. The anti-stray light structure is of a conical structure; the big end part of the conical structure's opening is connected with the receiving focusing lens group while the small end part of the opening is provided with an optical filter. A photosensitive receiving tube and an auxiliary transmitting tube are arranged under the optical filter and both are welded on a circuit board. During the rapid correction of the system, the main transmitting tube does not work, and the auxiliary transmitting tube transmits a beam of modulated infrared light, which is received by the photosensitive receiving tube and is converted into an electric signal. The internal circuit of the circuit board records the phase different between the modulated signal and the photosensitive receiving tube received signal at the time, calculates the ranging distance error at the time, and stores the distance error in a storage device. In this manner, the correction process is completed and compensation can be made to each measurement result.

An in-vehicle pulse wave radar device is required to detect an object in a wide range of several tens of centimeters to several tens of meters and therefore the receiving circuit requires an amplification circuit having a wide dynamic range covering the receiving pulse waves of both a large signal level and a small signal level. The pulse wave radar device according to the invention controls the amplification degree of the receiving circuit downward at the time of measuring an object at a short distance immediately after transmission of the transmitting pulse wave and upward with time for measuring an object at a long distance by increasing the amplification degree of the receiving circuit progressively with the elapse of time after transmission of the transmitting pulse wave.

The invention discloses a compact ultra short pulse laser remote ranging system and a ranging method thereof. The system comprises a laser source, a first beam expanding module, a second beam expanding module, a beam splitter, a transmitting and receiving module, a reflector, a filter module, a focusing lens, and a photodetector, wherein the laser source is an ultra short pulse laser transmitting laser beams, and the width of the outputted laser pulse is picosecond to subpicosecond. The system whose transmitting light path and receiving light path are coaxial is adopted, one reflector is adopted to complete sampling of main wave pulse signals; through changing coating reflectivity of the reflector, the size of an incident main wave signal is adjusted, and over strong main wave pulse signals can be prevented from damaging the photodetector; and the laser ranging system is long in ranging, high in ranging precision, simple and compact in structure, and low in cost.

The invention discloses a distributed temperature sensing optical cable, comprising a fiber; a tight tube wraps the fiber, a flexible metallic tube wraps the tight tube, an aramid fiber reinforcing layer wraps the flexible metallic tube, wire sheathing wraps the aramid fiber reinforcing layer and a low-smoke halogen free flame retardant sheath wraps the wire sheathing. The optical cable can be applied to a distributed temperature monitoring system, which can be used as a temperature sensor and a channel for data information transmission.

The invention discloses a distribution-type optical-fiber Raman temperature sensor adopting circulating pulse coding and decoding and Rayleigh demodulation, and the sensor comprises a pulse optical-fiber laser, an acoustic-optic demodulator, an integrated optical-fiber wavelength division multiplexer with four ports, two photoelectric receiving amplification modules, a coding-decoding demodulation digital signal processor, an optical-fiber temperature sampling ring, an intrinsic temperature measuring optical fiber, a digital temperature detector and a personal computer (PC). The sensor codes and decodes a signal on the basis of the circulating S matrix conversion, and the online location temperature measurement of the optical fiber is realized by utilizing an effect that the optical-fiber Raman optical strength is demodulated by the temperature and utilizing an optical time domain reflection principle. The circulating laser pulse coding and decoding is realized, and a Rayleigh channel is used as a temperature demodulation reference channel, so that the signal-to-noise ratio of the system is greatly improved, and the measuring precision and the measuring distance of the system are improved.

Disclosed herein are systems, media, and methods for identifying and assessing topographical features such as vegetation density and surface water using satellite data, comprising: a digital processing device; a database of digital maps, each indicative of grazing area(s); and a computer program to create an application comprising: a software module receiving a first set of satellite data indicative of a first topographical feature of the land; a software module calculating a normalized index array of the first topographic feature for the time period using the first set of satellite data; a software module generating a custom map indicative of density of the first topographical feature; a software module combining the custom map with one of the digital maps to generate a combined map indicative of the density of the first topographical feature within the grazing areas; and a software module allowing a user to visualize or print the combined map.

The invention discloses a measuring method of slope-assisted Brillouin fiber sensing vibration measuring device of a fixable frequency shifting structure, and has the characteristics of comprising thefollowing steps: 1) obtaining BGS in a sensing fiber with a spectrum analyzer; 2) selecting a single mode fiber; 3) producing a continuous probe light; 4) producing a pulse pump light which a difference between the pulse pump light and a upper road continuous optical frequency is half of the half height and full width of a gain spectrum; 5) generating a stimulated Brillouin effect; 6) generatinga backscattered signal light; 7) collecting and processing data; 8) demodulating the vibration frequency on a sensing fiber. According to the measuring method of slope-assisted Brillouin fiber sensingvibration measuring device of a fixable frequency shifting structure, the effective measuring distance is far , the use method is simple, is convenient in operation, and can quickly detect dynamic strain to achieve the purpose of measuring vibration. The invention also discloses a slope-assisted Brillouin fiber sensing vibration measuring device of fixable frequency shifting structure.

The invention relates to a non-contact displacement measurement method and device based on the spectral wavelength. The non-contact displacement measurement device comprises a point-shaped light source, an optical element, a first measuring appliance and a second measuring appliance, wherein the point-shaped light source emits multi-color light; the optical element enables the light to generate axial chromatic aberration and enables the light generating the axial chromatic aberration to be converged on a measurement object; the first measuring appliance is provided with an opening and enables the light focused on the measurement object in the light converged by the optical element to pass; the second measuring appliance solves the spectrum of the light passing through the opening and solves the distance between the optical element and the measurement object based on the peak wavelength of the spectrum; and the first measuring appliance solves the position offset between the center-of-gravity position of a light ring of a predetermined reference spectrum and an optical axis center point on the first measuring appliance and corrects the distance by using distance compensation value associated with the position offset. The non-contact displacement measurement device can also obtain a measurement result with high accuracy without changing the distance between the optical element and the measurement object.