267results about How to "Avoid systematic errors" patented technology

The invention relates to a projection objective lens wave aberration detection device and method. Light emitted by a light source is uniformly radiated on a projection objective lens object plane, a scatter plate and a needle hole are installed on a masking stage, the needle hole is arranged on an object plane of a projection objective lens, the field of view is selected through the movement of the masking stage, a shearing grating is arranged on an image plane of the projection objective lens, the shearing grating is installed on a wafer stage together with a detector, the phase shifting function is realized through the transverse precise movement of the grating by the wafer stage, and simultaneously each frame of a shearing interference figure in the phase shifting process is recorded by utilizing the detector. Two-dimensional shearing is realized by utilizing the two-dimensional grating, the phase shifting function is integrated into the shearing interference instrument, and the high-precise measurement of the projection objective lens wave aberration is realized by adopting the characteristics of the phase space vector.

The invention discloses a comprehensive servo motor and harmonic speed reducer testing platform. The comprehensive servo motor and harmonic speed reducer testing platform comprises a machine frame, a vibration isolation platform, a linear guide rail and a magnetic powder brake, wherein the vibration isolation platform is arranged on the machine frame, and the linear guide rail and the magnetic powder brake are installed on the vibration isolation platform in a matched mode. The linear guide rail is provided with a wide-range torque revolving speed sensor, a first angle encoder, a harmonic speed reducer, a second angle encoder, a narrow-range torque revolving speed sensor and a servo motor. The comprehensive servo motor and harmonic speed reducer testing platform is simple and reasonable in structure, the load torque is not prone to fluctuation, data detecting accuracy is high, the system error is small, and assembling and adjusting are convenient.

The invention discloses a non-contact three-dimensional optical measuring head and a non-contact three-dimensional optical measuring method for in-situ measurement of a numerical control machine, which are characterized in that: the non-contact three-dimensional optical measuring head consists of an image measuring system and a focus positioning system. The non-contact three-dimensional optical measuring method comprises the following steps of: firstly, making a focus judgment on the image measuring system by using an astigmatism method, determining a measuring plane, positioning the non-contact three-dimensional optical measuring head in a Z-axis direction at the same time and acquiring a Z-axis direction positioning value of a surface characteristic point of a workpiece; secondly, performing two-dimensional image measurement on basic geometric elements, of the workpiece, on the measuring plane by using a surface measuring method in image projection measurement to obtain two-dimensional plane coordinate values of the surface characteristic point of the workpiece; and finally, combining the two-dimensional plane coordinate values with the Z-axis direction positioning value to obtain the three-dimensional coordinate values of the surface characteristic point of the workpiece. The non-contact three-dimensional optical measuring head and the non-contact three-dimensional optical measuring method can effectively perform high-precision in-situ measurement of the geometric size of the workpiece processed by the numerical control machine, shorten the manufacturing period of products effectively and guarantee product quality.

The invention discloses an orthogonal polarization optical fiber biological refractive index sensor and a detecting method thereof. The refractive index sensor includes a broadband light source, a polarizer, a polarization controller, a sensor probe and an orthogonal polarization demodulation processing unit which are sequentially connected with one another by optical fibers; the sensor probe includes a microfluidic control chip for control of injection and discharge of a trace biological solution, and tilted optical fiber optical gratings arranged in microfluidic channels of the microfluidic control chip; the orthogonal polarization demodulation processing unit includes an optical fiber polarization beam splitter, a first spectral detector, a second spectral detector and a spectrum differential module; the sensor probe is connected with the input ends of the first spectral detector and the second spectral detector through the optical fiber polarization beam splitter, and the output ends of the first spectral detector and the second spectral detector are connected with the spectrum differential module. The refractive index sensor has the advantages of high measuring precision of the refractive index, and can realize simultaneous measurement of environmental temperatures.

The invention discloses a method for testing the grouting compactness degree of a prestressed pore of a bridge based on an elastic-wave energy dissipation rate, belonging to the technical field of quality detection on bridge / culvert engineering. In the grouting construction on a prestressed anchor (cable) of a bridge, the prestressed anchor (cable) can be corroded caused by undesirably-packaged cement mortars and anchor rods, thereby causing the failure of the prestressed anchor (cable) and then endangering the safety of structures. In the prior art, the anchoring quality of an anchor rod can not be evaluated completely. The method provided by the invention is implemented through analyzing the fluctuation characteristics (speed, frequency, elastic-wave energy dissipation, and the like) of pickup signals of sensors at the two ends of the prestressed anchor by adopting impact elastic waves generated by vibrations at the two ends of the prestressed anchor of the bridge so as to detect the grouting compactness degree of the prestressed anchor (cable) of the bridge. The method provided by the invention has the advantages of maximizing the elimination of system errors caused in the process of test, accurately testing the elastic-wave energy dissipation rate of the prestressed anchor (cable), and effectively completing the test on the grouting compactness quality of the prestressed anchor (cable) of the bridge. The method provided by the invention is also applicable for the test on the grouting compactness qualities of all prestressed structures the two ends of which are provided with exposed anchor heads.

The invention discloses a self-calibration measurement device for bridge deformation or displacement parameters, comprising an imaging system (12) and at least one measurement target (13) installed at a measurement point of a bridge (11). The self-calibration measurement device is characterized in that the device further comprises a benchmark target (14) installed in a deformation or displacement change-negligible region of the bridge (11), the benchmark target (14) and the measurement target (13) are imaged in different positions of a sensitive element of the imaging system (12), and the displacement or deformation parameters of the measurement point are calculated according to the measurement results of the measurement target (13) and the benchmark target (14) after the influence of bridge bending deformation caused by load loading is deducted. As the influence of bridge bending deformation caused by load loading is deducted, the measurement accuracy of the system is improved.

The invention discloses an organic light emitting diode (OLED) device and a manufacturing method and a display device thereof, relating to the technical field of display. The production process of the OLED device can be simplified, the production cost is reduced, and the product quality is improved. The OLED device comprises a first electrode, a second electrode and an organic film layer, wherein the organic film layer comprises a hole layer, an electronic layer and an organic luminous layer positioned between the hole layer and the electronic layer; the organic film layer also comprises a hole barrier layer; the organic luminous layer comprises a first luminous unit, a second luminous unit and a third luminous unit; the hole barrier layer and the third luminous unit are formed through a one-step composition process. The OLED device is suitable for manufacturing a display panel.

The invention discloses a structure and a control method of a direct-drive fiber-optic gyroscope stabilized platform. The structure is characterized in that a rectangular coordinate axes structure is adopted; an outer frame is a roll frame, and an inner frame platform is a pitch frame; an inertial measurement unit and a stabilized object are arranged on a platform of the inner frame platform; a platform framework is directly driven through a direct-drive moment motor. A control system is of the modular design and the double-central processing unit (CPU) combined design of a digital signal processor (DSP) and a singlechip computer, is stable, and is easy to operate. According to the structure and the control method, the problems of large machining and assembling difficulty of the existing stabilized platform system, difficulty in precision retention, large transmission gear clearance error, low control response speed and heavy load of a single-CPU multi-task control system are solved. The structure and the control method can be effectively applied to stabilization of airborne measurement equipment, ship-borne measurement equipment and vehicle-borne measurement equipment.

The invention relates to a quantitative analysis method of solution chromogenic reaction and a detector thereof. According to the invention, by utilizing the photopermeability characteristics of a solution generated by reaction between chromogenic substances and a chromogenic agent, and utilizing a calculation module designed according to color space concept, the three primary colors including red, green and blue which are shown by transmission light are converted into measurement points shown by performance numbers including lightness, green-red and blue-yellow, the hue and target color difference of the solution are calculated, a standard curve of hue, target color difference and concentration of chromogenic substances is fitted by a polynomial expression, and the concentration of a practical sample is calculated by an interpolation method. According to the principle, the designed detector consists of an upper computer and a lower computer which are connected by a communication data line (16), and comprises a lower computer circuit (5), a sample cell (2), an LED light source (14), an upper computer circuit (18), a color collecting system, a data acquisition and processing system, an operation system and working procedures. The detector is simple in structure, is convenient and rapid to operate, is accurate in result, and can be widely applied to the quantitative detection of the solution chromogenic reaction.

The invention discloses an in-place non-contact detection method for a shaft type workpiece. The in-place non-contact detection method for the shaft type workpiece comprises the following steps that adetection system is established, the detection system is demarcated, and the detection coordinate system is established; the pose of the workpiece in the detection system is analyzed, and the coordinate system of a workpiece clamping device is established; a clamping device of a shaft type workpiece machining machine tool is controlled to rotate, continuous data collection is conducted by a linelaser measurement instrument, computational analysis is conducted on collected data, and the ideal datum axis of the axle type workpiece is acquired; continuous data collection is conduct on a detected position by a laser displacement sensor, computational analysis is conducted on collected data, and the actual jumping machining accuracy of the shaft neck of a cam shaft is acquired; and the line laser measurement instrument is adopted to conduct continuous data collection on the detected position, computational analysis is conducted on collected data, and the coaxiality machining accuracy of the shaft type workpiece is acquired. By means of the in-place non-contact detection method for the shaft type workpiece, the shaft neck circle center and the ideal datum axis thereof of the shaft typeworkpiece can be detected in real time, and systematic errors and compensatory difficulties brought about by traditional use of ejector pin standards or a V-shape block are avoided.

The invention discloses a measurement method for the rotation angle of an automobile steering wheel. A main rotation body in the automobile steering wheel drives an auxiliary rotation body to rotate under the rotation driving of a transmission shaft; the transmission ratio of the main rotation body and the auxiliary rotation body is m:n; the main rotation body gains the relative rotation angle Theta1 of the main rotation body by a first rotation angle sensor; the auxiliary rotation body gains the relative rotation angle Thelta2 of the auxiliary rotation body by a second rotation angle sensor, thus gaining practical intercept K; theoretical intercept L is gained by the practical intercept K; the rotation ring number P of the main rotation body is then gained by the theoretical intercept L; the relative rotation angle Thelta1 of the main rotation body and the relative rotation angle Theta2 of the auxiliary rotation body are input into a micro-processor; after processing, the micro-processor outputs an absolute rotation angle Theta in m ring of the main rotation body, namely, the absolute rotation angle Theta in m ring of the main rotation body is gained by the rotation ring number P of the main rotation body and the relative rotation angle Theta1 of the main rotation body. The measurement method of the automobile steering wheel can eliminate the system error which is caused by idle course and realize precisely measuring the absolute rotation angle Theta in m ring in small volume and simple structure.

The invention discloses an ionospheric error correction method. On the basis of an international reference ionospheric model, a correction scale model of a theoretical value of an IRI model of the total electron content at any longitude and latitude in each time period relative to a measured value is established and used for determining an estimated value of the total electron content from a preset datum point in a service region to a navigational satellite path, and a user can obtain a corresponding ionospheric error correction value according to the estimated value. By means of the ionospheric error correction method for direct correction of ionospheric errors on a slanted path between the user and a navigational satellite, system errors caused in the conversion process from a vertical TEC to a slanted TEC can be avoided, and the accuracy of correction of ionospheric delay of satellite navigation signals is effectively improved.

The invention discloses a method and a device for large-range and high-resolution atomic force micro detection for a large sample. By adopting a method combining the scanning of a piezoelectric ceramic probe and the large-range motion of a step motor and designing an open sample stage, the micro-nano detection of large-sized super-precise workpieces is realized. The device is provided with a large-range and high-resolution scanning probe system, an X-Y-axis step electric translation stage, an optical platform and a scan imaging and feedback control system, wherein the large-range and high-resolution scanning probe system consists of a laser, a light path tracking lens, piezoelectric ceramics, a micro cantilever probe and a photoelectric detection element; and the X-Y-axis step electric translation stage is used for moving large-sized samples in large range. The method and the device have the advantages of overcoming the limitation that a conventional AFM is only suitable for small-range detection of small samples, designing a simple and practical lens system to solve the light path tracking problem when the probe scans in the large range, and adopting the open sample stage and the two-dimensional step motor to realize large-range scanning and detection in any area for the large-sized super-precise workpiece samples under the condition of keeping the ultra-high resolution of the AFM.

The invention discloses an automatic moxa cone winding device which comprises a rack, a paper delivery mechanism, a feeding mechanism and a winding mechanism, and the paper delivery mechanism, the feeding mechanism and the winding mechanism are in signal interconnection with a control mechanism arranged on the rack. The winding mechanism is arranged on the front portion of the feeding mechanism, the paper delivery mechanism is arranged on one side of the winding mechanism, and the feeding mechanism and the paper delivery mechanism are movably connected in a matched mode through a linkage device. Through matching of the mechanisms, the production efficiency and the production speed of moxa cones are greatly improved, and the automatic moxa cone winding device is worthy of application and popularization.

The invention relates to a high-precision RV speed reducer comprehensive testing device, which comprises a base, a first sliding platform, a second sliding platform, a first motor, a first torque sensor, a second motor, a second torque sensor, a first angle sensor, an input shaft bracket and an output shaft bracket. Compared with the prior art, the high-precision RV speed reducer comprehensive testing device designs the sliding platform assembly capable of being rapidly disassembled and assembled, so that the assembling and disassembling process of an to-be-tested RV speed reducer is more convenient and faster; the output shaft bracket and the input shaft bracket can be used for adapting to the requirements of sensors with different specifications; the limiting parts of the sliding platforms improve the test precision; the double-measuring-range torque sensors can adapt to measurement of speed reducers of different series models, and can also realize test of transmission precision under light load; an input shaft of the to-be-tested RV speed reducer is installed in two bearing inner rings sharing the same horizontal axis, thereby facilitating the adjustment of a bearing clearance;and the double-reading-head circular grating angle sensors meet the requirement that the transmission precision is tested in a high-speed state.

The invention discloses a gas component detection laser radar based on a laser source with the tunable wavelength. A laser source with the tunable wavelength is used for carrying out scanning to obtain absorbing lines of to-be-detected gas at different distances; a femtosecond optical comb is used for calibrating the frequency of emergent laser precisely; and non-linear fitting is carried out on the absorbing lines of the to-be-detected gas after frequency calibration and database comparison is carried out, so that concentration information of the to-be-detected gas is obtained. In order to measure the absorbing lines of the to-be-detected gas, the invention provides two kinds of solutions: one solution based on a direct detection mode and the other solution based on a coherent detection mode. According to an optimized wavelength scanning range, the gas component detection laser radar based on a laser source with the tunable wavelength is capable of realizing detection of various gas components and has characteristics of high detection precision, high distance resolution and high time resolution.

The invention relates to an atmospheric automatic monitoring apparatus capable of realizing sampling / calibrating alternative equivalent operation, and a method thereof. An air path center system is arranged, a standard gas introduction mode during apparatus calibration is improved, and a relay connects a dynamic calibrator, a solenoid valve and a sampling pump; when calibration is carried out, the dynamic calibrator is started, and the solenoid valve and the sampling pump are closed through powering off the relay; and when sampling is carried out, the dynamic calibrator is closed, and the solenoid valve and the sampling pump are started through powering on the relay in order to realize the alternative equivalent operation process of calibrating / sampling. An air acquisition system is a sampling head, a standard gas generation system comprises a standard gas tank, a zero gas generator and the dynamic calibrator, the air path center system comprises an air path center channel, an intelligent transition control system comprises the sampling pump, the solenoid valve and the relay, a temperature control device comprises a humiture probe and asensor, a humiture controller and a heat insulation cover, and a pollutant analysis system comprises a plurality of filtering devices and an analyzer.

The invention provides a method for reconstructing a CP-OFDM signal in a time-domain synchronous orthogonal frequency-division multiplexing (TDS-OFDM) system. A novel frame structure is designed on asending end of the TDS-OFDM system; and a receiving terminal of the TDS-OFDM system utilizes the newly designed frame structure to reconstruct the CP-OFDM signal of frame body OFDM data through simpleadd-subtract operation. The method combines the characteristics of the TDS-OFDM system and a CP-OFDM system skillfully, replaces the prior method that the interference of PN on a data part is eliminated through multiple iterations to reconstruct a ZP-OFDM signal to further obtain the CP-OFDM signal in the TDS-OFDM system, reduces the complexity of the hardware implementation of the receiving endgreatly, and is particularly suitable for the mobile receiving of high-speed broadband.

The invention relates to a method for machining a butterfly-shaped nanometer gap through coordinative shaping of femtosecond laser phase position amplitude and belongs to the technical field of laserapplication. A reflecting type phase position type liquid crystal spatial light modulator can carry out phase position modulation on incident light, thus reflected light has designated phase positiondistribution on space, meanwhile, a narrow gap is utilized for carrying out amplitude shaping on light beams obtained after phase position shaping, and thus coordinative shaping of the phase positionand the amplitude of the initial light beams is achieved. The light beams obtained after coordinative shaping pass through a focusing objective lens to be focused, and multi-light-point light beams with different structure parameters are formed. The generated multi-light-point light beams are utilized for machining a designated material, material removal can be achieved in the area with strong light intensity, the material is kept in the area with the weak light intensity, and thus the butterfly-shaped nanometer gap can be obtained. According to the method, a light path needing to be set up issimple, use is convenient, a mask and vacuum environment are not needed, the machining cost is low, the machining efficiency is high, and the method plays an important role in the machining field oflaser micro nanometer structures.

The invention provides a microfluidic-circulation analysis-based high-precision in-situ seawater pH analysis system and method. The analysis system comprises a microfluidic chip with a circulation mixing structure, a filter head, a seawater pipeline, an indicator bag, an indicator pipeline, a waste discharging pipeline, a highlight while light LED lamp, an optical fiber and a spectrograph. According to the analysis system, the quantified mixing and detection of samples can be finished on the chip by a microfluidic chip technology, so that the instrument size is decreased, the dosage of reagents is reduced, the system integration level is high and the analysis system is suitable for in-situ measurement; the chip has the circulation mixing structure, after seawater and an indicator are quantified through chip channels, the two quantification channels form a closed loop, a piezoelectric pump is used for driving the seawater and the indicator to flow and mix in the loop and then the perfect mixing of the seawater and the indicator in a constant ratio is realized. According to the analysis system and the analysis method, the precision of the measurement system is improved and an operation step of indicator interference correction in a laboratory is omitted, so that manpower and material resources are saved.

The present invention provides a method for monitoring three-dimensional deformation of main body structures at two sides of a deformation joint. The method for monitoring three-dimensional deformation of main body structures at two sides of the deformation joint can monitor the displacement change of the main body structures at the two sides of the deformation joint at the vertical direction, the first horizontal direction and the second horizontal direction perpendicular to the first horizontal direction, and comprises the following steps: S1, determining the position of monitoring points on the main body structures at the two sides of the deformation joint, cleaning a finishing layer and adjuncts at the surfaces of the main body structures, and exposing the member main bodies in the main body structures; S2, installing a monitoring device; and S3, collecting data and performing data processing. Through adoption of a double-shaft tilt sensor and a displacement monitoring member, the method for monitoring three-dimensional deformation of main body structures at the two sides of the deformation joint can monitor the deformation of X, Y and Z directions of the main body structures at two sides of the deformation joint, so that the operation is simple, the monitoring data is accurate.

The invention provides a water-soluble acid-base testing device and a water-soluble acid-base testing method. The bottom end of an extracting container in the testing device is communicated with a funnel via a first liquid charge pipe; the first liquid charge pipe is provided with a first flow meter and a first electromagnetic valve; an indicator bottle is communicated with the funnel via a second liquid charge pipe; the second liquid charge pipe is provided with a second flow meter and a second electromagnetic valve. According to the testing device, by the arrangement, an extracting phase at the lower layer and an indicator respectively fall into the funnel continuously under the respective gravity, so that the extracting phase and the indicator are uniformly mixed on the bottom of the funnel. Therefore, the testing device overcomes the defects that the existing water-soluble acid-base testing device adopts many components and is difficult to assemble, and has the characteristics of simple structure, and convenience in use and maintenance.

The invention discloses an anti-rollover control system and control method for a tank truck tank body. The system comprises a tank body side inclination angle measuring unit, an alarm control unit, abrake control unit and an anti-rollover control unit. The method comprises the following steps of (1),constructing the anti-rollover control system for the tank truck tank body; (2), calculating the side inclination angle of the tank body through a displacement sensor; (3), calculating the rollover index of a tank truck, wherein the rollover index is a quasi-static rollover threshold value K; and(4), and when the rollover index monitored in real time is higher than the set threshold value, letting the alarm control unit and the brake control unit work; and when the rollover index monitored inreal time is lower than the set threshold value, releasing the alarm control unit and the brake control unit. According to the system and the method, the vehicle is monitored in real time through thesensor, so that the vehicle can be timely prevented from rollover.

The invention discloses a current meter high-speed linear formula integration detection method and a detection device. The method comprises the following steps: cleaning a ball bearing; detecting average frictional resistance moment M of the ball bearing; detecting a propeller current meter rotating speed V0 and an instrument rotation bearing internal frictional resistance moment M, and confirming that a standard is reached; fixedly installing three detected current meters at the lower end of a measuring rod and placing them into water of a detection water tank; adjusting an axial directions of the current meters; tranquilizing a water body in the tank; starting a motor, a detection vehicle running from a lowest speed and gradually increasing its speed, and detecting instrument output signals and data; and according to a GB / T21699 detection method of rotor type current meter in linear open channel, by use of a least square method, calculating values of a and b of a detection formula and a middle and high-speed whole-line average mean square deviation sigma. According to the invention, the program and steps of a conventional detection method in the prior art are substantially simplified, the precision of detection results of the current meters can be ensured, at the same time, the production efficiency is improved, the working conditions are improved, the management rules are simplified, manpower and material resources are reduced, and the production operation cost is decreased.

The invention provides a differential pressure flowmeter verification system and aims at solving the problem that a differential pressure flowmeter verification system in the prior art is large in verification error, complicated in operation and the like. The differential pressure flowmeter verification system comprises an industrial computer, a differential pressure verification module, an electromagnetic flowmeter standard table and a highway addressable remote transducer (HART) converter. The differential pressure verification module comprises a data processing module and a control module and is built in the industrial computer. One end of the HART converter is connected with an HART interface built in a differential pressure flowmeter transducer to be verified, and the other end of the HART converter is connected with the data processing module of the differential pressure verification module through a computer interface. The electromagnetic flowmeter standard table is connected with the industrial computer through an RS232 data interface on the electromagnetic flowmeter standard table. The differential pressure flowmeter verification system has the technical advantages of avoiding system errors at a data acquisition stage of a verification table and some errors caused by misoperation and improving the accuracy of verification results and work efficiency.

The invention relates to a high-precision double-wheel shaft double-vernier earth's axis precession demonstration and quantitative measurement experiment instrument, which comprises a base, a motor, a cross beam, a rotating disk, a balance weight, wheel shafts, a cross beam support frame, a precession rotation head shaft, a right vernier scale vertical rod, a left vernier scale vertical rod, a main ruler and main ruler disc and a hollow support column. The motor is fixedly arranged at the right end of the cross beam; the rotating disk is fixedly arranged on a motor shaft; the balance weight is sleeved in a slide groove in the left end of the cross beam; outer edges of the two wheel shafts are clamped in a wheel shaft sleeve; the precession rotation head shaft is fixedly sleeved in inner edges of the two wheel shafts; the upper end of the precession rotation head shaft is fixedly provided with the cross beam support frame; the right vernier scale vertical rod and the left vernier scale vertical rod are connected at the right and left sides of the precession rotation head shaft respectively; the main ruler and the main ruler disc are sleeved in the middle portion of the hollow support column; the precession rotation head shaft is arranged at the upper end of the hollow support column; and a cross beam shaft of the cross beam is sleeved on a rotation shaft of the cross beam support frame. The beneficial effects of the experiment instrument are that the experiment instrument is reasonable in structure and good in experiment effect.

The invention provides a laser radar calibration device based on space-time transformation, which is used for calibration of an all-solid-state three-dimensional planar array laser radar. The laser radar calibration device comprises a to-be-calibrated three-dimensional planar array laser radar installation portion, a cooperative calibration target installation part, an ambient light shielding boxbody, a directional reception active light source conduit and a time delay module, wherein the to-be-calibrated three-dimensional planar array laser radar installation portion, the cooperative calibration target installation part, the ambient light shielding box body, the directional reception active light source conduit and the time delay module are fixed by means of fixing screws and positioningholes, so as to form an integrated three-dimensional planar array laser radar calibration device. The invention further discloses a corresponding calibration method. the simple, convenient and rapidcalibration device and calibration method can perform rapid and precise calibration on the three-dimensional planar array laser radar, is high in calibration precision and wide in calibration distancerange, and does not require a special calibration environment and a special cooperative calibration target.

The invention discloses a mine safety early warning system based on multi-fiber-core optical fibers. By means of the mine safety early warning system, the downhole temperature, strain and vibration are measured at the same time. Different fiber cores in one multi-fiber-core optical fiber are adopted to sense the temperature, the strain, the vibration and other physical quantities, and distributed real-time measurement of all the physical quantities is achieved through a multi-fiber-core beam splitter. According to the mine safety early warning system, the healthy condition of a coal mine downhole can be comprehensively evaluated in a multi-sensor fusion mode through one optical fiber, the optical cable installation cost is greatly saved, meanwhile only less bandwidth of a communication optical cable is occupied, and the mine safety early warning system is suitable for the monitoring requirement in a severe environment.

The invention discloses a mirror surface object three-dimensional shape measurement method and device based on double-screen transmission display. The device comprises a computer, a CCD camera, a liquid crystal display screen and a transparent display screen, wherein the CCD camera, the liquid crystal display screen and the transparent display screen are fixed on an optical platform, and the liquid crystal display screen and the transparent display screen are perpendicular to the optical platform; light paths of an image displayed on the liquid crystal display screen and an image displayed onthe transparent display screen are parallel; a horizontal guide rail is arranged on the optical platform and is perpendicular to the liquid crystal display screen; and the computer is connected with the liquid crystal display screen, the transparent display screen and the CCD camera. The method comprises the following steps: 1, establishing a measurement system; 2, removing a to-be-measured mirrorsurface object to obtain an absolute phase expansion diagram of a reference plane; 3, removing the reference plane, adding the to-be-measured mirror surface object, and obtaining the absolute phase expansion diagram of the to-be-measured mirror surface object according to the method in the step 2; and 4, solving three-dimensional morphology depth information of the to-be-measured mirror surface object.

The invention provides a fan rotating speed control system for an electric vehicle battery charger. The fan rotating speed control system comprises a control device and charging modules, wherein the control device and the charging modules are connected through a CAN bus. Relevant parts in each charging module of the fan rotating speed control system comprise a core processor, a CAN bus communication circuit, a fan control unit, fans and a temperature measuring unit, wherein the fan control unit is connected with the fans through fan power input circuits correspondingly and connected with the temperature measuring unit and the CAN bus communication circuit through the core processor. According to the technical scheme provided by the invention, the stability of the rotating speed of the fans is enhanced, fan operating noise is lowered, and the fan fault diagnosis accuracy is improved.