148results about How to "Flexible measurement" patented technology

The invention provides a method and system for measuring parameters of a bent pipe. The method comprises the following steps of: acquiring an inner parameter and an outer parameter of a multi-view camera; acquiring an image of the bent pipe through the multi-view camera to acquire a planar gray scale image of the bent pipe; correcting the planar gray scale image according to the inner parameter and the outer parameter of the multi-view camera to acquire a corrected image; acquiring a bent pipe region from the corrected image; acquiring an edge line and a center line of the bent pipe region; acquiring the diameter of the bent pipe according to the edge line; dispersing the center line into a plurality of characteristic points and acquiring space coordinates of the plurality of characteristic points; re-fitting the space coordinates of the plurality of characteristic points to obtain a center line of the bent pipe; and determining space parameters of the bent pipe according to the diameter and the center line of the bent pipe. During measurement of the bent pipe, the method and the system are high in speed and more precise.

The invention discloses a CMOS (complementary metal-oxide-semiconductor)-machine-vision-based component size measuring system and a measurement test method. The CMOS-machine-vision-based component size measuring system comprises an image acquisition module, an image processing module and a size measuring module, wherein the image acquisition module acquires images of contour edges of a shot component; the image processing module performs binaryzation and filtering processing on the acquired images, and then performs edge detection to obtain edges of the images of the component; and the size measuring module calculates a pixel value of an edge contour of a measured object through feature extraction, and the pixel value can directly reflect the size of the component through calibration. According to the CMOS-machine-vision-based component size measuring system and the measurement test method disclosed by the invention, the measurement of the contour size can be realized, and the measurement of the aperture of a small through hole can be finished; and after a special assistant tool is provided, the measurement of the bottom width of a trumpet-shaped groove can be realized.

The invention relates to an optic fiber type voltage measuring method used in an electric-power grid system for measuring various transient voltages, and a device thereof. The measurement method comprises the steps: a metal induction polar plate is placed on the surface of a measured high-voltage conductor; capacitances formed by the induction polar plate respectively with the measured high-voltage conductor and the ground are utilized for forming a capacitive voltage divider; after the voltage dividing ratio of the capacitive voltage divider and the voltage value on the capacitance between the induction polar plate and the measured high-voltage conductor are measured, the voltage value to ground of the measured high-voltage conductor is acquired by conversion. The measuring device consists of a front end processor externally provided with the metal induction polar plate, an optic fiber, a photoelectric converting module and a computer part, wherein, the induction polar plate and a shielding case of the front end processor form a capacitance type voltage sensor. Compared with the prior art, the invention adopts the method that the capacitance type voltage sensor directly measures the field strength of an electrified body surface to measure the voltage, thus having the advantages of good measurement property, simple structure and convenient use.

The invention provides a mask device as well as a system and a method for manufacturing the mask device. The mask device comprises a mask tray and a plurality of mask plates on one side of the mask tray, wherein the mask tray comprises a plurality of support ribs; a plurality of grid openings which are arrayed in matrix are formed among the plurality of support ribs; each mask plate comprises a mask hole array and a plurality of fixed parts outward extending from the mask hole array; the fixed parts are used for connecting the support ribs of the mask tray; the mask hole array of one mask plate corresponds to one grid opening on the mask tray. By adopting the invention, the mask plates and the mask tray are simultaneously improved, and the traditional mask tray is designed into grid shape with support ribs in the middle instead of big openings; the plurality of mask plates respectively correspond to each grid and are respectively unfolded so that micro-distortion caused by large tension can be avoided and the mask plates can be more accurately unfolded to correct positions.

The invention discloses a three-dimensional shape measurement system and method for a large-size object. According to the invention, two sets of stereoscopic vision systems in a three-dimensional scanner are calibrated and local data of single measurement of the large size object is acquired by using the three-dimensional scanner. By using the two sets of the stereoscopic vision systems, the single measurement range can be expanded. The three-dimensional scanner is moved for measuring different parts of the large-size object and local data obtained through multiple measurements is subjected to three-dimensional data integration by a server according to distance change measured by a laser ranger. By adopting the method and system provided by the invention, accurate measurement of the large-size object can be realized flexibly.

The invention discloses a water quality sensing device with an automatic cleaning function. The water quality sensing device comprises a vertical supporting part, a cleaning structure and a sensing driving structure, wherein the sensing driving structure does reciprocating rotation around a rotating shaft; the sensing driving structure comprises a motor, a driving rod and a sensing probe; the driving rod does reciprocating movement under the driving of the motor; and when the sensing driving structure rotates to the cleaning structure, and the cleaning structure cleans the sensing probe. By the water quality sensing device, when a water body does not need to be detected, the driving rod takes the sensing probe out of water, so that the sensing probe cannot be influenced continuously by impurities in water and the speed the sensing probe is influenced by impurities can be slowed down greatly; when a water body needs to be detected, the driving rod puts the sensing probe into water; aims of flexible measurement and reduction of influence of impurities are fulfilled; and furthermore, when the probe needs to be cleaned, the sensing driving structure rotates around the rotating shaft, so that the probe is rotated to the cleaning structure to be scrubbed and cleaned.

The invention discloses a large-scale antenna field directional diagram measuring system and method for multi-rotor unmanned aerial vehicles. The system includes a multi-rotor unmanned aerial vehiclesubsystem, a signal source link subsystem, a receiving link subsystem and a data processing subsystem. A multi-rotor unmanned aerial vehicle is used to fly at near and far field areas of a to-be-measured antenna according to a set cruise mission; through remote real-time control on a signal source link module, an electromagnetic wave signal in the air can be swept and received in real time; and through the screening, error compensation and data fitting on a received level signal, final directional diagram information can be generated, and the maximum radiation direction, 3dB lobe width, sidelobe level, front-to-back ratios and corresponding position information can be given. On-the-spot directional diagram performance measuring of large-scale antennas under service status can be realized,so that accurate measured data can be provided for fault diagnosis; the system is convenient in operation, high in degree of automation and simple in dismounting; and single sortie flight can accomplish the testing of multifrequency directional diagrams.

The invention discloses a method for detecting the geometrical motion error of triaxial numerical control equipment in the technical field of mechanical detection. In accordance with the characteristic that a plane grating can measure the linear motion error and the circular motion error of the triaxial numerical control equipment, the method separates 12 error components including the linear error, the position error and the vertical error of a guide rail X, a guide rail Y and a guide rail Z, and then separates 9 rotation angle error components of the three guide rails.

The invention discloses a temperature measurement device for the surface of a hearth workpiece, consisting of an endoscope temperature measurement probe, a cycle cooling system, a thermal imaging system, a terminal thermal imagery processing system and a support adjustment system. One end of the thermal imaging system is connected to the endoscope temperature measurement probe and the other end of the endoscope temperature measurement probe is connected to the terminal thermal imagery processing system; the thermal imaging system is installed and fixed on the support adjustment system; the endoscope temperature measurement probe is provided with a cycle water inlet and a cycle water outlet; the cycle cooling system is communicated with the cycle water inlet and the cycle water outlet of the endoscope temperature measurement probe through pipelines. The temperature measurement device disclosed by the invention can perform detection on the inside walls of various modes of the direct fire hearth and the workpiece wall and can perform wide range and wide visual angle thermal imaging measurement on the temperature filed of the surface of the workpiece inside health. The invention also discloses a temperature measurement method.

The invention provides a method and a system for measuring parameters of round holes in a plate. The method comprises the following steps: obtaining inner and outer parameters of a multi-view camera; performing image acquisition on the plate by utilizing the multi-view camera to obtain a local plane grey image of the plate; obtaining pixel values of characteristic parameters of linear segment end points and the round holes in the plate according to the local plane grey image; determining local space parameters of the round holes in each pair of binocular camera coordinate systems according to the pixel values of the characteristic parameters of the round holes in the local plane grey image and the inner and outer parameters of the multi-view camera; switching and concatenating the local space parameters of the round holes in each pair of binocular camera coordinate systems through the inner and outer parameters of the multi-view camera, and determining overall space information of the round holes in the plate. According to the scheme, the measurement precision and the completeness of the holes in the plate are improved, the measurement speed of the holes in the plate is increased, and the measurement cost of the holes in the plate is reduced.

The invention provides a rod bundle channel flow pressure measuring test device, which comprises a water storage tank, a pressure measuring body, and a centrifugal pump, a regulating valve and a thermometer sequentially connected with the water storage tank through a pipeline, wherein the pressure measuring body comprises a rod bundle channel barrel, a rod bundle channel formed by rod bundles arranged in the rod bundle channel barrel; the upper ends of the rod bundles are connected with a high-accuracy rotating disk arranged on a rotating table support through a coupler; two body pressure ports formed up and down are formed in the rod bundle channel barrel; a pressure guiding port is formed in each rod bundle of the rod bundle channel; a sealing rubber plug is arranged at the lower end of each rod bundle; a fast adapter is arranged at the upper end of each rod bundle; pressure difference transmitters are respectively arranged between each pressure guiding port and each fast adapter as well as between the two body pressure ports. The rod bundle channel flow pressure measuring test device provided by the invention can simulate single-phase flow in a reactor rod bundle channel so as to research a resistance characteristic of the rod bundle channel, and is simple in structure, low in cost, accurate and convenient to acquire data, and wide in research working condition range.

The invention provides a measuring method and a measuring device of conduit connector space pose parameters. The method includes: obtaining inner parameters of a multi-view camera; reading three-dimensional models of conduit connectors to obtain contour wireframe models of the conduit connectors; respectively building a spherical coordinate system and a plurality of virtual cameras in different positions; obtaining two-dimensional images, projected on the plurality of virtual cameras in the different positions, of the contour wireframe models; through the multi-view camera, respectively carrying out image acquisition on the plurality of connectors on a conduit to obtain plane gray level images of the conduit connectors; processing the two-dimensional images and the plane gray level images to be matching templates and search images with an edge filter, and carrying out template matching based on shapes on the search images; obtaining the space pose parameters of the plurality of conduit connectors in respective camera coordinate systems; and unifying poses of the plurality of conduit connectors in the camera coordinate systems in a world coordinate system to confirm the conduit connector space pose parameters. In the process of measuring the conduit connector space pose parameters, the speed is high, and the accuracy is high.

The invention relates to a drive-by-wire differential steering system and method for a distributed driving electric vehicle. The drive-by-wire differential steering system for the distributed driving electric vehicle comprises a detection module, a drive-by-wire differential steering control module and a steering executing module, wherein the detection module is used for detecting running parameters; the drive-by-wire differential steering control module is used for obtaining target output torques of a front axle driving motor and a front axle right driving motor and transmitting a motor control signal; and the steering executing module is used for realizing differential steering of the electric vehicle. The drive-by-wire differential steering method for the distributed driving electric vehicle comprises the steps that a vehicle controller obtains the running speed of the electric vehicle; the drive-by-wire differential steering controller calculates according to a steering angle of a steering wheel and the running speed to obtain a front axle differential torque of the electric vehicle; the vehicle controller calculates to obtain a front wheel driving motor target torque; the drive-by-wire differential steering controller respectively obtains target output torques of a left front wheel and a right front wheel through calculation; and a motor controller controls a driving motor and a steering executing component to move and also controls a steering wheel aligning moment motor to output moment. Compared with the prior art, the drive-by-wire differential steering system for the distributed driving electric vehicle has the advantages of simple structure, accurate steering and so on.

The invention relates to a contact and non-contact type dual-purpose surface roughness measuring system which comprises a measuring sensor a computer and is characterized in that the computer is connected and provided with two groups of measuring sensors through measurement and data acquisition circuit, and the two groups of measuring sensors are respectively a non-contact type measuring head and a contact type measuring head. The contact and non-contact type dual-purpose surface roughness measuring system can realize the contact and non-contact type engineering surface roughness measuring method through a measuring instrument, centralize the advantages of contact type and non-contact type, enlarge the range of measuring objects, reduce the cost, provide the precise and reasonable measuring data, implement the real-time contrast and deviation correction for the two measuring results, and be applied to the two-dimensional or three-dimensional mark measurement of engineering roughness of various complex workpiece surfaces to be measured.

The invention provides an uplink / downlink antenna pulling away device, transmitter, receiver and channel measuring method, relating to the channel measuring technology. The downlink antenna pulling away device used for distributed multilink multiple antenna broadband channel measuring system comprises an electro-optic converter used for modulating a radio frequency signal emitted by the transmitting unit of the distributed multilink multiple antenna broadband channel measuring system into an optical signal, an optical fiber which is connected with the electro-optic converter and is used for transmitting the optical signal generated by modulation of the electro-optic converter as well as an antenna pulling away unit which is connected with the optical fiber, comprises an optic-electro converter connected with the optical fiber and is used for receiving the optical signal transmitted by the optical fiber and demodulating the optical signal into the radio frequency signal. By the embodiment of the invention, the measuring on distributed channel can be more flexible and convenient.

The invention relates to full-automatic contact type measuring equipment and method. The full-automatic contact type measuring equipment comprises a test bench, a longitudinal sliding table and a cross beam, wherein the longitudinal sliding table is longitudinally and slidably arranged on the test bench and can be used for fixedly placing a measured workpiece, the cross beam is suspended above thetest bench, and at least one measuring arm which can move back and forth along the cross beam is arranged on the cross beam. Compared with the prior art, the equipment in the invention is the equipment specially for rapid and high-precision measurement of the geometric dimension of the large-size workpieces with pores and burrs on the surface, the size of the workpiece is measured by means of a contact type displacement sensor, the defects of the existing measuring method are avoided, so that the influence of the pores and burrs on the surface of the workpiece on precision can be avoided by the measuring equipment, the measurement of the large-size workpiece is more efficient and accurate, relatively complicated workpiece shapes can be adapted to, various dimensions of the thickness, theperpendicularity, the parallelism, the flatness and the like can be measured; meanwhile, the cost of the measuring equipment is lower, and the maintenance and the calibration are simpler and more convenient.

The invention relates to a frequency spectrum automatic monitoring analyzer for a satellite ground station intermediate-frequency signal. The frequency spectrum automatic monitoring analyzer consists of a frequency spectrum information acquisition module, a cabinet and a power supply, wherein the frequency spectrum information acquisition module consists of a frequency spectrum information acquisition card, a state indication panel, a shielding shell and a sliding rail; and the frequency spectrum information acquisition card consists of hardware and singlechip software, is provided with an intermediate-frequency signal input interface, a communication interface and a power supply interface and has functions of repeated mixing, filtering change-over, logarithmic transformation, amplification, analog / digital (A / D) conversion and serial port communication. By the automatic monitoring analyzer, required frequency spectra can be measured by using one special intermediate-frequency frequency spectrum information acquisition module; the measurement range of the frequency spectra can be expanded by increasing the number of frequency spectrum acquisition modules; and the seamless automatic monitoring and real-time alarming of network-wide frequency resources of a satellite communication network is realized by utilizing a computer network technology, a database technology and a software technology so as to improve communication quality.

Provided is a needle-plate electrode medium space charge and partial-discharge ultrahigh-frequency signal synchronous measurement device in the field of electric variable measuring. An inner insulation piece is arranged in the middle of an outer insulation piece in a sleeved mode. The outer side of the inner insulation piece is provided with a tooth structure. The top end of a needle electrode is provided with a metal voltage-sharing ball. The bottom end of the needle electrode penetrates through middle through holes of the inner insulation piece and the outer insulation piece respectively. A height adjusting gear is matched with the tooth structure on the outer insulation piece. By rotating the height adjusting gear, the relative positions of the inner insulation piece and the outer insulation piece are adjusted, the proper distance between the needle electrode and a lower electrode is selected, a voltage pulse is applied at the top end of the needle electrode, vibration of a liquid oil sample to be detected is generated, mechanical wave signals are sent out, the mechanical wave signals are received by a piezoelectric film and are converted into voltage signals, and accordingly space charge distribution in the liquid oil sample to be detected is reflected. Space charge and partial-discharge ultrahigh-frequency signal synchronous measurement under needle-plate electrodes of liquid or solid media is achieved.

The invention discloses an adjustable deviation prevention device based on a cable detection robot. The adjustable deviation prevention device comprises a support shaft connected with a cable detection robot support leg, a fixing frame arranged on the support shaft, a deviation prevention support frame connected with the support shaft, a stepped shaft connected with the deviation prevention support frame, and a deviation prevention wheel arranged on the stepped shaft. The support shaft passes through the fixing frame; meanwhile, two horizontal extension plates are arranged on the bottom side of the fixing frame, one side is clamped on the cable detection robot support leg, and the other side is clamped on the deviation prevention support frame, so that one face of the fixing frame is attached to the support leg, and the other face of the fixing frame is attached to the deviation prevention support frame.

The invention discloses an integrated measuring device and method for the flow velocity and the depth of a flume test. The integrated measuring device for the flow velocity and the depth of the flumetest comprises a measuring device body, and the measuring device body comprises a measuring instrument and a monitoring probe; the integrated measuring device further comprises switching assemblies for mutual switching of velocity measuring and depth measuring and further comprises an adjusting device for adjusting the position of the measuring device body, and the adjusting device comprises a left-right position adjusting assembly, a front-rear position adjusting assembly and a height adjusting assembly; and the switching assemblies are connected with the height adjusting assembly. Accordingto the integrated measuring device, velocity measuring and depth measuring can be converted, and a depth measuring device and a velocity measuring device are integrated; the problems that traditionalequipment is limited in measuring space, inflexible in moving, complex in operation and long in consumed time can be effectively solved; and compared with a traditional flume scouring test, the integrated measuring device for the flow velocity and the depth of the flume test is simple in structure, small in occupied space, convenient to operate and high in efficiency.

The invention relates to a photo-etching projector's focus plat tuning sensor and its technology, especially a focus plat tuning sensor with projection network and detection network. It comprises two mutually perpendicular branches with each branch comprises two measuring optical path and two reference optical path, wherein measuring optical path measures the height of relative projection objective's optimum focal surface of base plate surface, reference optical path measures the height of projection objective's surface, four optical paths of each branch shares imaging system, the measuring optical path has water opening which can change measuring flare.

The invention discloses a butterfly spring three-dimensional size automatic measuring system based on machine vision. The system comprises a hardware part which comprises a detecting device, the detecting device comprises a base, one side of the upper part of the base is symmetrically and fixedly equipped with two vertical rods through corner connecting pieces, and a cross rod is installed betweenthe two vertical rods and is close to the upper ends of the vertical rods. In on-site measurement, a butterfly spring is placed in an area to be measured, the butterfly spring can be replaced at anytime when multiple butterfly springs are detected, the automatic judgment and detection is achieved, the operation is convenient and simple, and the detection efficiency is high. The invention also discloses the butterfly spring three-dimensional size automatic measuring system and measuring method based on machine vision, the method comprises three steps, the measuring method of machine vision isused, and the damage to the butterfly spring during manual measurement is reduced through a non-contact mode, especially a butterfly spring with a smaller specification.

The invention discloses a three-dimensional profile measuring system of a trinocular camera with a two-dimensional laser profile scanning sensor. The system comprises a camera array, a camera array base, a frame synchronous triggering device, a handheld laser profile scanner and a computer, wherein the camera array is placed on the camera array base; the camera array and the handheld laser profile scanner are connected with the computer by collecting cards; the frame synchronous triggering device receives a control instruction of the computer through a serial port so as to control the camera array and the handheld laser profile scanner to synchronously collect image data; and the collected data is transmitted to the computer by the collecting cards. Advantages of a photography measurement technology and the two-dimensional laser profile scanning sensor are combined in the system; high accuracy and flexibility in measurement are achieved; a plurality of object planes of a large-sized complex object can be flexibly measured through the two-dimensional laser profile scanning sensor in one camera view plane; moreover, objects with internal profiles, such as tires and the like, can be detected, so that a profile shielding problem is avoided.

The invention belongs to the technical field of electromagnetic induction, in particular relates to a device for real-time measurement of fluid conductivity by use of electromagnetic method, and aims at the conditions of low fluid conductivity, and little effect on the amplitude of electromagnetic mutual inductance signals; the device uses a method of excitation frequency adjusting and phase component extracting to replace the amplitude for extraction of useful information to the maximum in order to obtain the most accurate measurement results; aiming at the condition that the measurement of fluid conductivity by use of the electromagnetic method is susceptible to the interference of the surrounding electromagnetic environment, the device uses a method of real-time calibration and probe shielding to prevent measurement result drift caused by electromagnetic interference; and aiming at the problem that the high frequency signal transmission is susceptible to noise interference when the fluid conductivity is low and the excitation signal frequency is high, the device uses a method of coaxial cable shielding for signal transmission to ensure the signal stability and reliability.

The invention provides a dual-probe manual ultrasonic detection method, and belongs to the field of conventional A ultrasonic detection. The method is a new detection method which is added when a manual A ultrasonic detection reflection method is used for performing normal detection. Particularly, main characteristics that a reflection angle of acoustic beams of ultrasonic waves in the same medium is equal to an incidence angle, wave mode switching is performed, and the like are used; two discrete probes, namely, a transmitting probe and a receiving probe, are used; and the position of the receiving probe is changed, so that direction flaws which form certain angles with the incidence acoustic beams are detected.

The invention provides a method and system for measuring parameters of a bent pipe. The method comprises the following steps of: acquiring an inner parameter and an outer parameter of a multi-view camera; acquiring an image of the bent pipe through the multi-view camera to acquire a planar gray scale image of the bent pipe; correcting the planar gray scale image according to the inner parameter and the outer parameter of the multi-view camera to acquire a corrected image; acquiring a bent pipe region from the corrected image; acquiring an edge line and a center line of the bent pipe region; acquiring the diameter of the bent pipe according to the edge line; dispersing the center line into a plurality of characteristic points and acquiring space coordinates of the plurality of characteristic points; re-fitting the space coordinates of the plurality of characteristic points to obtain a center line of the bent pipe; and determining space parameters of the bent pipe according to the diameter and the center line of the bent pipe. During measurement of the bent pipe, the method and the system are high in speed and more precise.

The invention discloses a scribing and distance measuring device. The scribing and distance measuring device comprises a scribing and distance measuring device body, a straight ruler, an angle disc, arotating ruler, a measuring tape assembly, a sliding scribing assembly and a chalk clamping assembly, wherein the straight ruler is arranged on one side of the scribing and distance measuring devicebody, the angle disc is fixedly welded to the outer wall of one end of the straight ruler, the rotating ruler is arranged on one side of the angle disc, a first rotating shaft is fixedly welded to theouter wall of one end of the rotating ruler, a rotating shaft hole is formed in the portion, corresponding to the first rotating shaft, of the center of the outer wall of one side of the angle disc,and the first rotating shaft penetrates through the rotating shaft hole. Various combinations of lengths, angles and the like can be carried out, single-hand operation can be carried out more conveniently and quickly when the straight ruler and the angle disc are matched for measuring, and the rotating ruler is rotated to be overlapped with the straight ruler, so that folding of the device is achieved, and storage and carrying are convenient to achieve; and when some long objects are measured, measurement can be carried out through a measuring tape, and the problem that the measurement error is large due to multi-section measurement of the straight ruler is solved.

The invention provides a body height measurement method and a body height measurement system and a portable device. The body height measurement method comprises the following steps: calculating the double-step length of a tested person; determining the body height level of the tested person according to the double-step length, wherein the body height level comprises the tall height, the medium height and the short height; analyzing to determine the footprint length of the tested person, wherein the footprint length is the length of the footprint of the tested person; and calculating the body height of the tested person according to the body height level, the double-step length and the footprint length. With the adoption of the body height measurement method, the direct measurement for the height of the tested person is avoided, meanwhile, the height of the tested person can be flexibly measured anytime and anywhere, therefore, the body height of the tested person can be obtained flexibly and conveniently, and meanwhile, the accurate body height measurement result can be obtained.

The invention discloses a non-contact three-dimensional automatic scanning testing system, and the system comprises a positioner, a portal frame, a robot, a measurement workpiece, and a data processing control system. The positioner comprises two supports and a rotating clamping device. The portal frame comprises two X-axis moving guide rails for a walking mechanism, two Y-axis moving support columns, and one Z-axis moving cross beam. The tops of the Y-axis moving support columns are provided with the Z-axis moving cross beam, and the Z-axis moving cross beam is provided with a moving guide rail and a robot installation support. The robot installation support is provided with a flange seat, and a robot is fixedly installed on the flange seat. An end part of the robot is provided with a 3Dscanning measurer. The 3D scanning measurer comprises a camera and a projector, and the data processing control system comprises a robot control cabinet, an electrical control cabinet, and a PLC operating system. The robot control cabinet is electrically connected with the robot. According to the technical scheme of the invention, the travel control range can be enlarged, and the measurement precision and detection efficiency are improved. The system timely collects, processes and displays the measurement data, and can meet the requirements of various angles, precisions and speeds of differentworkpieces, and can be widely used for online application.

The invention provides handheld radar for measuring the surface velocity of a river-way. The radar comprises a radar module, a processing module and a display module, wherein the radar module is used for transmitting a first radar wave to a liquid surface of the river-way and receiving a second radar wave reflected by the liquid surface, so as to generate Doppler beat frequency signals; the processing module is used for acquiring the angle of an incidence liquid surface of the first radar, and outputting the surface velocity by combining the Doppler beat frequency signals; and the display module is used for displaying the surface velocity. Compared with the prior art, the handheld radar provided by the invention can calculate the surface velocity according to the radar wave reflected by the radar module and the radar wave reflected by waves; furthermore, the handheld radar can be used for measuring the surface velocity precisely in a non-contact way in case of high-speed water current, sewage and floaters, even debris flow and slurry.