25 results about "Laser velocimetry" patented technology

The invention relates to the technical field of fluid dynamic testing, in particular to a multiphase jet flow characterization system and method.The system comprises a control unit, a particle image velocity measurement unit, a phase Doppler particle analysis unit, a laser Doppler velocity measurement unit and a planar laser-induced fluorescence unit, and the particle image velocity measurement unit, the phase Doppler particle analysis unit, the laser Doppler velocity measurement unit and the planar laser-induced fluorescence unit are connected with the control unit; the particle image velocity measurement unit is used for measuring a macroscopic velocity field; the phase Doppler particle analysis unit is used for measuring microdynamics information; the laser Doppler velocity measurement unit is used for measuring a velocity profile; the planar laser-induced fluorescence unit is used for measuring a concentration field of a target component in the multiphase jet flow; the control unit is used for receiving measurement results of all the units, conducting fusion processing on the measurement results and outputting characterization results. The multi-phase jet flow can be comprehensively represented, multi-dimensional physical information can be synchronously obtained, and the solid-liquid-gas interphase coupling and phase change mechanism of the multi-phase jet flow can be accurately revealed.

The application relates to the technical field of laser speed measurement, and discloses a laser Doppler speed measurement system and a speed measurement method. The system comprises a dual-frequency laser device, a first detection beam splitter, a second detection beam splitter, a first detection device, a second detection device and a signal processing device. The dual-frequency laser device is optically connected with the first detection beam splitter and the second detection beam splitter. The first detection beam splitter and the second detection beam splitter are respectively optically connected with the first detection device and the second detection device. The first detection device and the second detection device are optically connected with the signal processing device. The application constructs a set of optical path "cross pairing" dual-channel differential heterodyne interference systems, so that the interference optical path of each detection device simultaneously contains frequency components from two lasers. The inherent output frequencies of the two detection devices are equal in size and opposite in sign, have common mode rejection characteristics, effectively reduce the dependence of the system on the long-term stability of the core frequency shift device, and improve the measurement accuracy and reliability.

The present application belongs to the technical field of metallurgical equipment intelligence, and provides a strip steel transverse flatness measurement method and system based on multiple laser vision sensors, comprising: sequentially installing a laser speed measuring instrument, a first set of laser vision devices, a second set of laser vision devices and a third set of laser vision devices on a support above a strip steel roller, and collecting laser stripe images on the surface of the running strip steel; performing ROI region processing on the laser stripe images to identify the laser stripes in the laser stripe images; using a gray center of gravity method to extract the center coordinates of the laser stripes, and using a least squares method to fit the center coordinates to obtain a fitting equation; performing vibration filtering on the fitting equation, setting a vibration compensation term, calculating the strip steel transverse flatness, and adjusting the equipment parameters of the rolling mill and the straightening machine and the placement position of the flattening machine pad based on the strip steel transverse flatness. The present application realizes high-precision dynamic detection of the flatness of the strip steel.

The utility model discloses a cutting and developing device for steel pipe processing, include: the base plate, the outer wall fixedly connected with the guiding device and the flattening device of base plate top, the inner wall sliding connection has cutting device of guiding device, the utility model relates to steel pipe cutting and developing technical field, this guiding device and flattening device, through fixed plate, threaded rod and the resistance board form "screw thread adjustment and clamping fixed " structure, and the operator can accurately control the resistance board spacing through rotating threaded rod, firmly fixed in the mounting hole with flame cutting nozzle, ensure that the flame nozzle always aligns the bus direction of steel pipe, simultaneously, the MSE-V-ONE laser doppler velocimetry sensor real -time monitoring steel pipe moving speed and position, not only can judge whether the steel pipe reaches the cutting area through the reflected laser intensity, but also can feed back the speed signal to the PLC controller, and dynamically match the gas supply amount of flame cutting nozzle and the conveying speed of steel pipe.

The invention provides a turbulent flow space statistical magnitude measuring method, which comprises the following steps of: acquiring a sampling signal for laser Doppler velocity measurement, processing, setting filtering and pre-signal amplification coefficient parameters, carrying out data enveloping and modulation, checking a calculation result, filtering again if the calculation result is unqualified after the calculation result is checked, and if the calculation result is not qualified after the calculation result is checked, judging whether the calculation result is qualified or not. If the inspection is qualified, outputting a result; determining a laser Doppler measurement volume diameter corresponding to the low-intensity steady turbulence by applying a Taylor freezing hypothesis, and performing Fourier transform by adopting a time slot auto-covariance method to draw a turbulence space kinetic energy spectrum density curve; second-order and third-order structure function curves of a turbulent space are drawn based on a convection recording method and a time slot auto-covariance method to be verified respectively, a turbulent average dissipation value is calculated according to the initial slope of a third-order structure function of the turbulent space, and then the dissipation scale is calculated according to the energy dissipation rate of fluid and the kinematic viscosity coefficient of the fluid. According to the measurement method, the measurement precision of the turbulence space is improved.

The invention relates to a railway line side airwave active noise reduction system which comprises a multi-mode sensing module, a control module and an execution module which are deployed on two transverse sides of a noise reduction area line. The multi-mode sensing module comprises a microphone array and a laser velocimeter and is used for collecting noise signals and train speed signals and sending the noise signals and the train speed signals to the control module. The control module receives the noise signal and the train speed signal, obtains a self-adaptive anti-phase sound wave signal through calculation processing, converts the self-adaptive anti-phase sound wave signal into driving information and sends the driving information to the execution module; the execution module comprises airwave generating devices which are arranged in an array mode, and after the driving information is received, airwaves are sent out according to the power indication of the driving information. According to the invention, air waves with the same frequency and opposite phase as train noise are actively emitted, opposite consumption of low-frequency noise energy is realized, the problem that a traditional sound barrier is poor in low-frequency noise reduction effect is solved, frequency tracking and adjustment are realized, and accurate matching of opposite-phase sound waves and noise frequencies is ensured.

This invention relates to the field of textile processing technology, and more particularly to a high-speed loom unwinding guide device for a yarn feeding frame, comprising a guide ring and a yarn feeding frame. A transverse beam and a vertical beam are fixedly installed inside the yarn feeding frame. A positioning mechanism for fixing the yarn feeding roller is installed on the surface of the vertical beam. The guide ring is disposed on the upper surface of the transverse beam. This invention achieves dynamic stability of the yarn air ring during high-speed unwinding through an intelligent closed-loop control system. The system integrates a high-speed industrial camera, a tension sensor, and a laser velocimeter to collect real-time data on air ring diameter, tension, and yarn speed. A programmable logic controller (PLC) precisely adjusts the guide ring spacing based on a PID algorithm, ensuring the air ring remains within the ideal diameter range. This significantly reduces yarn vibration and breakage rate, improves weaving efficiency and fabric quality, and also features overspeed braking and tension redundancy calibration functions, ensuring the reliability and safety of high-speed operation.

The application relates to a laser Doppler velocimetry system and method based on detector temperature control. The system comprises an optical path detection component for acquiring an electric signal, and a signal processing component for processing the electric signal. A temperature control assembly is arranged in the optical path detection component, the temperature control assembly is used for temperature control of the optical path detection component, so that the signal-to-noise ratio of the output signal of the optical path detection component is adjusted; the signal processing component is electrically connected with the optical path detection component, the signal quality of the electric signal is judged according to the signal-to-noise ratio at the corresponding temperature, then the temperature control assembly is controlled according to the electric signal not meeting the requirements, and the electric signal meeting the requirements is calculated, so that the velocity of a to-be-measured motion surface is obtained. The application can improve the signal-to-noise ratio of the Doppler signal, and improves the detection capability of the weak signal.

The application discloses a kind of inertial reference-based road reflectivity correlation laser speed measurement error determination method, it is related to laser speed measurement accuracy calibration field, the method includes according to signal-to-noise ratio extraction road reflectivity feature vector;According to original measurement speed, three-axis angular velocity and three-axis specific force, short-time speed is calculated based on inertial navigation mechanical arrangement and combined filtering, and consistency test is carried out by dynamics constraint, generates inertial reference speed;According to inertial reference speed and original measurement speed, determine instantaneous speed measurement error, and according to instantaneous speed measurement error and the road reflectivity feature vector of corresponding moment generates error training sample pair;According to error training sample pair, on-line learning and parameter dynamic adjustment are carried out to adaptive mapping model, and the error dynamic compensation model of laser speed measuring instrument based on road reflectivity function is obtained.The application can improve the precision and environmental adaptability of laser speed measurement.

The application discloses a kind of steel plate profile measuring device and method, the device includes: laser speedometer measured real-time speed of steel plate to be measured is provided to PLC, sends first and second pulse signals;PLC obtains steel plate real-time integral displacement according to real-time speed, and sends second level signal according to displacement;According to the first level signal that light curtain detects loss condition is sent;First logic control unit obtains first control signal according to the and of first pulse signal and level signal;Second logic control unit obtains second control signal according to the and of second pulse signal and level signal;Second camera obtains steel plate head image according to second control signal photographing;First camera obtains steel plate middle tail image according to first control signal photographing;Image processing workstation is spliced to steel plate head and middle tail image, and steel plate profile data based on actual size is obtained by using cutting auxiliary line method to the pixel coordinate conversion of spliced image.This application can improve the measurement accuracy of steel plate profile.

The invention belongs to the technical field of metallurgical equipment intelligence, and provides a strip steel transverse straightness measuring method and system based on multi-laser vision sensing, and the method comprises the steps: sequentially installing a laser velocimeter, a first set of laser vision device, a second set of laser vision device and a third set of laser vision device on a support above a strip steel roller bed, collecting a laser stripe image on the surface of the running strip steel; carrying out ROI area processing on the laser stripe image, and identifying laser stripes in the laser stripe image; extracting the center coordinates of the laser stripes by adopting a gray gravity center method, and fitting the center coordinates by adopting a least square method to obtain a fitting equation; and vibration filtering is conducted on the fitting equation, a vibration compensation item is set, the transverse straightness of the strip steel is solved, and equipment parameters of a rolling mill and a straightening machine and the placement position of a flattening machine base plate are adjusted based on the transverse straightness of the strip steel. According to the technical scheme, high-precision dynamic detection of the straightness of the strip steel is realized.

The invention relates to a method for improving the shearing precision of hot-rolled strip steel flying shear equipment, which comprises the following steps of: performing heat insulation protection on a measuring head of a laser velocimeter to avoid the problem of overheat alarm of the measuring head and prolong the service life of the measuring head; in order to ensure the accuracy and reliability of the speed measurement of the laser velocimeter, the aperture of the speed measurement hole of the laser velocimeter is doubled; the air blowing device is additionally arranged on the edge of the speed measuring hole, and the axial flow fan is additionally arranged near the measuring head, so that the detection precision of the speed measuring instrument is effectively ensured through the means. Technical analysis and measure implementation are performed from the aspects of accurate application of a laser velocimeter, detection precision improvement of a hot metal detector (HMD), interference prevention of field working conditions and the like, the shearing stability and the shearing precision of the flying shear are ensured, and maximum optimized shearing of the flying shear is realized.

A calibration device intended to be coupled to a laser velocimeter includes a disk; a mirror rigidly connected to the disk; a first illumination / reception device to: receive a first light signal at a first frequency; orient and focus the first light signal so as to form a first incident signal illuminating the surface of the mirror at a normal incidence for a position of the disk during a passage of the disk, and over a diameter on the determined surface; recover a first signal reflected by the mirror at a frequency shifted from the first frequency by a Doppler shift (Δf); with the calibration device also to output at least a fraction of the first reflected signal and a value of a first standard tangential velocity determined from the angular velocity (ω) and the measurement radius, intended for the laser velocimeter to be calibrated.

The invention relates to a rapid sizing and accurate shearing system of a hydraulic shear. The system is characterized in that a shearing station is arranged in a transportation assembly; the shearing assembly comprises a hydraulic shear driving device, a lower tool apron and an upper tool apron, the hydraulic shear driving assembly is located in the shearing station and located below the shearing station, a shear blade is formed when the upper tool apron makes contact with the lower tool apron, the lower tool apron is arranged on the hydraulic shear driving device, the upper tool apron is located above the lower tool apron, and the upper tool apron is located above the shearing station. A movable sensor is arranged on the side of the lower tool apron; the detection assembly comprises a neutral position sensor, a laser velocimeter and a laser metal detector, the neutral position sensor is arranged on the outer side of the hydraulic shear driving device, the laser metal detector is arranged above the shear blade position, and the laser velocimeter is arranged above the side, close to the before-shear roller bed unit, of the upper tool apron. According to the invention, the fixed-length shearing function of automatically removing the head cutting blank and automatically measuring the length of the steel billet is realized, and the fixed-length efficiency of the hydraulic shear is greatly improved.

The invention discloses a driving circuit of a laser sensor and a laser speed measuring device. The driving circuit comprises a constant current source module and a temperature compensation module. The constant current source module is used for outputting stable driving current; and the temperature compensation module is used for compensating the driving current according to the environment temperature. The driving circuit of the laser sensor provided by the invention can provide stable driving current, ensures that the laser sensor can output stable power, improves the stability and reliability of the laser sensor, further improves the measurement result of the laser sensor, and meets the requirement of high-precision measurement.

The application discloses a spring steel wire automatic conveying device and method, and belongs to the technical field of spring steel wire automatic conveying. The device comprises a conveying track, at least two intelligent driving nodes arranged in an array along the conveying track, each of the intelligent driving nodes comprising a driving wheel pair for clamping and driving the spring steel wire, and a local vibration sensor for measuring the lateral displacement of the spring steel wire at the outlet of the driving wheel pair, at least an optical attitude sensing station arranged on the conveying track, the optical attitude sensing station comprising a binocular vision module for measuring the torsion angle of the spring steel wire, and a laser speed meter for measuring the axial advancing speed of the spring steel wire, and a controller electrically connected with the intelligent driving nodes and the optical attitude sensing station, respectively. The application significantly improves the stability of the conveying process.

The invention provides a device for measuring the flow velocity in a natural circulation process, and the device comprises a circulating water system which is connected with a reactor to form a complete closed loop, and is used for simulating a natural circulation loop of a passive containment cooling system of a nuclear power station; the tachymeter system is used for measuring the flow velocity of the fluid in the circulating water system to obtain high-resolution three-dimensional velocity measurement; and the data acquisition system is connected with the tachymeter system and is used for converting the physical signals into fluid mechanics parameters. According to the invention, the measurement precision is high, the spatial resolution can reach micron to millimeter magnitude, the time resolution can reach microsecond magnitude, and the instantaneous characteristics of low flow velocity and high turbulence in natural circulation can be accurately captured. Laser Doppler velocity measurement is an absolute measurement method based on light wave frequency, the result does not need field calibration, and the reliability is high.

The utility model relates to the technical field of recreation facilities, in particular to a large recreation facility safety protection device which comprises a supporting column, the top end of the supporting column is fixedly connected with a slide allowing multiple persons to slide at the same time, baffles are arranged on the sides of the slide, and a sponge block used for relieving impact on the persons is arranged at the bottom of the slide. A groove is formed in the top end of the sponge block, an inclined plate is rotationally arranged on the transverse parallel outer side of the groove, a laser velocimeter is embedded in one inner side of each slide, the speeds of people with different weights can be monitored at any time when the people slide to the bottoms of the slides, and if the speeds exceed 5 m / s, the laser velocimeters can transmit signals to a controller, so that the people can slide to the bottoms of the slides. At the moment, the controller transmits an instruction to open the hydraulic rod in advance to drive the inclined plate to rotate clockwise upwards with the rotating column as the center shaft, a certain included angle is formed between the inclined plate and the sponge block, kinetic energy generated when the person slides down from the slide is converted into potential energy, and active protection on the person is achieved.

This invention discloses a method for determining the interfacial activity of chemical agents used in oil displacement. The method specifically includes: determining the average pore throat radius *r* of the target reservoir; determining the average displacement rate *v*; determining the average shear rate gradient based on the average pore throat radius *r* and the average displacement rate *v*; determining the aqueous phase shear force based on the average shear rate gradient; determining the variation of the oil and water phase velocities at the oil-water interface with distance from the interface through laser velocimetry experiments; and determining the capillary force required to initiate residual oil removal. This method avoids the drawbacks of traditional interfacial tension determination methods, such as the inability to quantitatively analyze the impact of interfacial activity of the oil displacement system on the residual oil stripping and initiation process. It more realistically reflects the oil-water interfacial tension required for residual oil stripping and initiation during the displacement process, taking into account factors such as displacement shear force and porous media characteristics. This method has guiding significance for the evaluation and screening of surfactants used in oilfield chemical flooding.

The application provides a DC motor feedback speed regulation system of analog quantity detection control and belongs to the technical field of motor control. The application comprises a base, a variable voltage power supply arranged on the base and used for providing power supply for the DC motor feedback speed regulation system, and an upper plate arranged above the base; a control execution module used for controlling the operation of a DC motor MA, a rotating disc, the DC motor MA used for driving the rotating disc to rotate, and a generator MF rotationally connected with the DC motor MA are arranged on the upper plate; three groups of load inertia adjusting devices with the same structure and a laser speed measuring instrument with a speed measuring reflective sticker are arranged on the rotating disc. The application can experiment the knowledge of classical control theory, and can also actively change the rotational inertia of the load, so as to facilitate the research on the tracking effect of the DC motor feedback speed regulation when the rotational inertia is changed.

The application provides a laser velocity measuring device for particle groups, comprising a fiber installation frame, a multi-laser emitting device, a multi-laser receiving device and a particle emitting device; a plurality of groups of parallel distributed light curtain installation frames are arranged on the fiber installation frame, and optical fibers are installed on the light curtain installation frames; the optical fibers comprise input optical fibers and output optical fibers; one end of the input optical fibers is connected with the multi-laser emitting device, and the other end is installed on one side of the light curtain installation frame; one end of the output optical fibers is connected with the multi-laser receiving device, and the other end is installed on the other side of the light curtain installation frame; the particle emitting device is arranged on one side of the fiber installation frame, and the particle group emitting direction is perpendicular to the light curtain; and the application further provides a laser velocity measuring method for particle groups. The application realizes the measurement of the particle cloud movement velocity vector and trajectory, can conveniently and flexibly adjust the distance between laser beams to measure the trajectories of the maximum number of particles, and has the advantages of simple operation, low cost and strong practicability.

The application discloses a kind of double-loop laser doppler velocimetry method and system, the method includes: first, the incident laser beam is split into signal light and reference light;Signal light is again split into first signal light and second signal light parallel in emission direction, so that first signal light and second signal light irradiate to the surface of the measured moving object, and the two-way scattered light of original road returns is combined into one way;While modulating reference light, reference light is split into two ways and irradiated on the photosensitive surface of first detector and second detector together with scattered light, generating two-way beat frequency signals;Finally, the positive and negative input terminals of differential amplifier are connected respectively by first detector and second detector, and high signal-to-noise ratio signal is obtained, and then the speed and direction of moving object are measured simultaneously by signal processing solution.The application is applied to the field of optical measurement technology, and can effectively improve the utilization of light energy, solve the problem that the existing laser velocimeter cannot distinguish direction and the utilization of light energy is low.

This invention discloses a high-speed blade pitch angle measurement system and method, belonging to the field of aerodynamic performance testing technology for aero-engine and wind turbine blades. The system includes a high-speed image acquisition module, a laser velocimetry and trigger prediction module, a synchronous trigger control module, and an image processing and calculation module. The laser velocimetry unit predicts the arrival time of the blade before it enters the camera's field of view, and an FPGA generates a nanosecond-level synchronous trigger signal to control the high-speed camera for precise exposure. Furthermore, an image processing algorithm calculates the blade tip position and pitch angle in real time, and feeds the position information back to the synchronous trigger control module to optimize the next trigger parameters, forming an adaptive closed-loop control. This method achieves non-contact, real-time, and high-precision dynamic measurement of the pitch angle of high-speed rotating blades, effectively solving the technical bottleneck of traditional methods' inability to capture angle changes under dynamic operating conditions, and providing reliable data support for the verification of blade aerodynamic design and control systems.

The application discloses a dynamic laser Doppler spectrum correction method, and the traditional laser Doppler spectrum correction method only suppresses fixed position noise of a spectrum, the position of Doppler spectrum noise corresponding to different laser velocimeter systems is not necessarily the same, therefore, the method is not universal, the suppression effect of the method is poor, and the spectrum noise is still unstable, thereby causing interference to spectrum resolution of the velocimeter system, and therefore, the application provides a laser Doppler spectrum correction method based on power spectrum analysis.The application performs signal suppression based on power spectrum analysis, has good universality, the spectrum noise suppression effect is obvious, the spectrum noise is stable, and the application lays a foundation for accurately extracting a Doppler signal in subsequent spectrum resolution.

The invention discloses a head and tail optimized shearing device for an intermediate billet of a hot-rolled stainless steel band and a control method, and relates to the technical field of hot-rolled stainless steel band production, an imaging mechanism is arranged between an outlet of a roughing mill and a hot coil box, and the imaging mechanism comprises a width gauge and a first laser velocimeter which are arranged on a moving mechanism; the tracking and shearing mechanism is arranged at an outlet of the hot coil box, the tracking and shearing mechanism comprises a second laser velocimeter and a scanning type hot metal detector which are arranged on the moving mechanism, and the second laser velocimeter and the scanning type hot metal detector provide power for synchronous movement through a motor; the moving mechanism comprises a bottom plate, and a wheel carrier and a vertical plate which can be used in a replaceable mode are rotationally assembled on the bottom plate. Compared with the prior art, the device has the advantages that measuring and shearing components are flexible to adjust, head and tail shape data are accurately obtained in real time, the mobility of the device is high, and the synchronism of the components is good.