38results about How to "Avoid introducing errors" patented technology

The invention discloses a method and a system for verifying synchronous exposure of a camera and electronic equipment. The method for verifying synchronous exposure of the cameras comprises the following steps of obtaining at least two groups of identification images obtained by simultaneously shooting a marker through at least two cameras, the marker being changed at an interval of a predetermined time, and the identification images of different frames in each group of identification images comprising different images of the marker, identifying the image of the marker contained in the identification image of the corresponding frame in the at least two groups of identification images to obtain a time difference between the identification images of the corresponding frame; and judging whether the time difference between the identification images of the corresponding frames is less than a time threshold, if so, judging that the at least two cameras are synchronously exposed, and if not,judging that the at least two cameras are not synchronously exposed.

The invention discloses a track inspection vehicle positioning method and system based on visual identification, and the method comprises the steps: S1, taking a certain number of marking points on the side surface of a track, setting a label at each marking point, and recording the absolute positions of all labels; s2, a camera and an encoder are arranged on the track inspection vehicle, the camera can shoot the label, the encoder transmits a signal to the upper computer in real time to obtain an encoder record value, after transmission is completed, the encoder record value is reset, the encoder counts again, the track inspection vehicle stops at the label, and the distance between a camera coordinate system and the label is obtained; and S3, the relative mileage information of the encoder is calibrated by using the difference value between the absolute position of the label and the relative position of the encoder, errors are eliminated, the actual value of the track length is obtained, a large number of accumulated errors caused by snakelike motion of the track inspection vehicle are avoided, and the relative positioning precision is remarkably improved.

The invention relates to an in-situ microextraction and portable Raman spectrometer combined method for determining polycyclic aromatic hydrocarbon. The method comprises the following steps: performing mercaptan modification on silver nanoparticle surfaces and microextraction on polycyclic aromatic hydrocarbon in a food contact material, condensing the prepared silver nanoparticle solution modified with mercaptan on the surface to be 10-100 folds, then mixing the concentrated solution with the extract solution in situ according to a volume ratio of the concentrated solution to the extract solution being (1-2):(1-2), and adopting the Raman spectrometer to detect surface enhancement Raman spectroscopy signals of polycyclic aromatic hydrocarbon, so as to obtain the polycyclic aromatic hydrocarbon surface enhancement Raman spectroscopy signals. According to the invention, the extraction method and the surface enhancement Raman spectroscopy method are combined, the extracting solution is not required to be transferred into a detector, but the pollutant can be detected in situ, so that the sample pretreatment procedure can be avoided and the error introduced during the pretreatment process can be avoided; the determination method is simple, environment-friendly, rapid and capable of solving the problem that the food contact material is required to be screened rapidly on the site to prevent migration of polycyclic aromatic hydrocarbon into the food.

The invention discloses a brushless doubly-fed motor control system, a feed forward control method and a parameter identification method. The control system comprises a d-axis control structure for outputting a d-axis component of a voltage command value and a q-axis control structure for outputting a q-axis component of the voltage command value. The d-axis control structure comprises a first PIcontroller, a first proportional controller, a second proportional controller, a first differential controller, a first superimposer and a second superimposer. The first proportional controller, the second proportional controller and the first differential controller are used for generating a first d-axis intermediate component, a second d-axis intermediate component and a third d-axis intermediate component respectively. The first PI controller is used for outputting a d-axis component of a voltage initial reference value; and the second superimposer is used for carrying out superposition processing on the d-axis feed forward quantity of the voltage reference value and the d-axis component of the voltage initial reference value to output a voltage command value. The control system eliminates a coupling term between the current and voltage of a control winding, and realizes accurate closed-loop control.

The invention discloses an RF system group delay parameter measuring method which comprises the steps as follows: the moving contact of a single-pole double-throw switch is combined with a first fixed terminal; a first pulse signal is sent to a first analog-digital converter through a pulse signal generator, and a second pulse signal is sent to a modulator through the pulse signal generator; a first carrier signal is sent to the modulator through a first RF source; the second pulse signal is modulated into the first carrier signal through the modulator; a signal with a new time delay is demodulated through a square law detector; a first synchronous sampling clock signal is sent to a power divider through a second RF source, and the first synchronous sampling clock signal from the second RF source is divided into two paths through the power divider. The measuring method utilizes the square law detector to demodulate a modulated signal, so as to avoid the introducing errors and improve the measuring accuracy which is better than 1 ns. The applicable frequency range of the measuring method is 100 MHz-50 GHz.

The invention discloses an ethanol content detection device. A shell (9) of the ethanol content detection device is provided with an LCD (10), a circuit board (8) is arranged inside the ethanol content detection device, a calibration pad (4) and a test paper strip slot (1) are arranged below the ethanol content detection device, a test paper strip clamp (2) with a groove is arranged inside the test paper strip slot (1), a test paper strip (3) is arranged inside the groove, a light limiting tube (5) is arranged on the test strip (3), a photocell (7) is arranged on the light limiting tube (5), two sides of the photocell (7) are arranged with LEDs (6), the circuit board (8) is arranged on the photocell (7), and the LEDs (6) is welded with the circuit board (8). Light from the LEDs shoots on the test paper strip and is reflected to the photocell by the light limiting tube, passes through a signal adjustment circuit, and is acquired, computed, displayed and stored by an A / D converter in a single-chip microcomputer, which can quickly and exactly obtain alcohol content detection for a human body and effectively prevent a detection result from being affected by human factors.

The invention belongs to the technical field of motor control, and provides a brushless doubly-fed motor integrated parameter identification method based on steady-state electric quantity amplitude sampling, the method is realized based on a general reduced order dq mathematical model of a brushless doubly-fed motor, simple open-loop control under a no-load and pure resistive load working condition is only needed, and the identification accuracy of the brushless doubly-fed motor integrated parameter is greatly improved. The method is suitable for different occasions of independent operation, grid-connected operation and the like, is suitable for brushless doubly-fed motors with different structural design processes, and has good universality; all parameters rc, Lpe, Lce and Me in the reduced-order model are directly identified based on simple calculation, processing such as approximate conversion is avoided, errors introduced in the intermediate identification and complex calculation process can be avoided, and good accuracy is achieved; and meanwhile, only voltage and current amplitude and frequency data are needed, dq component data are not needed, so that the rotor position angle information is not required to be acquired, and the method can be universally used in application occasions with coded discs and without coded discs.

The invention discloses a magnetic ball calibration method and a magnetic ball calibration device. The magnetic ball calibration method comprises the steps that a magnetic ball rotates around a first shaft by a first angle, detection data in the rotating process are obtained, and the zero point position P0 of the magnetic ball with the magnetic field intensity component being zero in the direction of a second shaft is obtained according to the detection data; obtaining a calibration position of the magnetic ball according to the detection data and the zero point position P0; calibrating the magnetic ball according to the calibration position of the magnetic ball; when the magnetic ball is located at the calibration position, the magnetic polarization direction of the magnetic ball coincides with the second axis; the first shaft is perpendicular to the second shaft; the three-axis magnetic field component comprises an X-axis magnetic field component, a Y-axis magnetic field component and a Z-axis magnetic field component; the direction of the Z-axis magnetic field component coincides with the direction of the second axis; the Y-axis magnetic field component coincides with the direction of the first axis. According to the magnetic ball calibration method and the magnetic ball calibration device, the magnetic ball can be calibrated conveniently, quickly and accurately.

Pound-Drever-Hall laser frequency stabilization system without phase shifter, including laser source, MCU controller, DDS RF signal source, electro-optic modulator, reference cavity, photodetector, frequency selective amplifier network, mixer, low-pass filter device, A / D, D / A converter, DSP processor, switch module and PZT drive circuit. The system has two working modes, the working mode is selected by the DSP processor, and one of the RF reference signals output by the DDS RF signal source is switched by the switch module or the frequency drift signal output by the conditioned photodetector enters the mixer; DDS The radio frequency signal source generates two orthogonal radio frequency reference signals, which are mixed with the signal selected by the switch module respectively. After acquisition, phase sensitive detection and control strategy calculation are performed in the DSP processor to achieve the effect of frequency stabilization. The invention improves the frequency stabilization accuracy and realizes laser automatic tracking and locking.

The embodiment of the invention provides an image processing method and device, and the method comprises the steps: obtaining a to-be-processed image which comprises a face image; acquiring a color value and a conversion coefficient of the face image in the first coordinate system; converting the color value of the face image through the conversion coefficient to obtain a reference color value, wherein the reference color value is used for indicating the color value of ambient light corresponding to the face image in the first coordinate system. According to the image information of the to-be-processed image and the reference color value, a target color value is determined, white balance processing is carried out on the to-be-processed image through the target color value, and the target color value is used for indicating the color value of ambient light corresponding to the to-be-processed image in the first coordinate system. The reference color value is determined through the conversion coefficient of the linear relationship between the reference color value and the color value of the face image, and the linear relationship is a primary linear relationship, so the white balance processing effect of the portrait can be effectively improved.

The invention discloses a mean valve with multiple air circuits. The mean valve comprises a valve body, a valve seat and a mean piston. A valve cavity is formed in the valve body, the mean piston is arranged in the valve cavity, and the mean piston comprises a piston rod and a plurality of piston bodies, wherein the piston rod is sleeved with the piston bodies, the piston bodies are fixedly arranged on the piston rod, and the areas, under the air pressure action, of the piston bodies are equal. The sides, close to the valve seat, of the piston bodies and the inner wall of the valve body form pressure cavities only communicated with an air pressure inlet channel, and the pressure cavity formed by the side, close to the valve seat, of each piston body and the inner wall of the valve body is connected with a mean pressure outlet. The mean valve is suitable for the mean of two- or more-channel air spring pressure, and it is avoided that when two- or more-channel air spring pressure is processed, a plurality of mean valves need to be connected in parallel or in series, and consequently errors are caused; the concentricity is better, the situations that the friction between the piston and the wall surface of the valve body is enlarged due to overlarge deviations of the concentricity, and the resistance is increased, so that valve action is out of order are avoided.

According to the electric energy metering device verification equipment start-stop parameter early warning method and system provided by the invention, the real-time start-stop parameter of the verification equipment is obtained when the verification equipment is switched in the operation state, and whether the verification equipment is in the alarm state is determined according to the real-time start-stop parameter of the verification equipment, when the verification equipment is in an alarm state, an alarm signal can be sent out, the parameter condition of the verification equipment when the verification equipment is input or cut out is fed back to an operator or a control system in time, and the information that the starting and stopping parameters of the verification equipment are abnormal is provided for the operator or the control system of the verification equipment in time, an operator or a control system can conveniently make adjustment in time, it can be avoided that errors are possibly introduced to the verification result of the electric energy metering device when verification equipment is input or cut out in the state that the verification equipment does not meet the conditions, and the verification accuracy is improved.

The invention belongs to the technical field of induction current detection, and specifically relates to a non-contact induction current detection system and method based on phase-locked amplification, including a control circuit, a wave-to-wave converter, a double-ridge waveguide, a power module, and a first radio frequency signal source , a lock-in amplifier, a second radio frequency signal source, two ends of the double ridge waveguide are respectively connected with a wave-to-wave converter, and the double-ridge waveguide is respectively connected to a control circuit, a power module, a first radio frequency signal source, A lock-in amplifier, the lock-in amplifier is connected with a second radio frequency signal source, a sensitive unit bridge wire and a tunnel magneto-resistance probe are arranged in the double ridge waveguide, and the sensitive unit bridge wire is connected with the tunnel magneto-resistance probe. The invention can effectively avoid the error introduced by the test equipment, and can extract the effective output voltage value of the tunnel reluctance probe in the interference environment through the phase locking method, thereby indirectly obtaining the magnitude of the induced current on the bridge wire of the sensitive unit. The invention is used for the detection of induced current.

The invention relates to the technical fields of image processing and projection focusing, and specifically discloses a focusing method, a focusing device and a readable storage medium for an ultra-short-focus projector. The present application projects the projection image to the projection surface; drives the focus motor to rotate a stroke in a stepwise manner, and obtains the first projection screen image and the second projection screen image at each step position of the focus motor; obtains the corresponding image of the first image acquisition device The position of the first focus motor, and the position of the second focus motor corresponding to the second image acquisition device; determine the focus position according to the position of the first focus motor and the position of the second focus motor; drive the focus motor to reach The focus position, the method to complete the focus. By analyzing the sharpness of the images of the projected screen areas on both sides to determine the optimal focus position on both sides, and then comprehensively determine the final focus position, the computational complexity is greatly reduced, and at the same time, the introduction of sharpness data in the original image due to the error of the splicing method can be avoided. error problem.

The invention discloses a ratio method for correcting topographic influence in electromagnetic prospecting. The ratio method comprises the steps of acquiring a surface layer resistivity value without topographic influence to serve as a standard resistivity of topographic correction; drawing an in-line topographic profile, respectively comparing the topographic profile with a frequency point profile of a frequency domain electromagnetic method and a time channel profile of a time domain electromagnetic method, and judging the topographic influence suffered by the actually measured data according to the influence rule of the topography on the resistivity in the frequency domain and the time domain electromagnetic field; observing from the highest frequency point of the frequency domain electromagnetic method and the earliest time channel of the time domain electromagnetic method so as to obtain the topographic response which is closest to the surface layer until the absence of low-frequency frequency point of the topographic influence is observed in the frequency domain electromagnetic method and the absence of the late time channel of the topographic influence is observed in the time domain electromagnetic method, and acquiring the observation data without topographic influence; and performing topographic correction according to a ratio formula of pcorrected(i,j)=pmeasured(i,j) [pstandard(i) / pmeasured(i,l)]C(i,j). The ratio method is good in correction effect in the process of correcting the topographic influence, is high in feasibility and can be widely applied to topographic influence correction in electromagnetic prospecting.

The invention discloses a sample preparation instrument which comprises an outer shell; a nitrogen blow tank is formed in the top in the shell; the lower part of the nitrogen blow tank is provided with a nitrogen blow plate device; slide ways are respectively arranged at the two sides of the nitrogen blow plate device and in the middle of the nitrogen blow plate device; the nitrogen blow plate device is also provided with nitrogen blow plates capable of sliding along the slide ways; each slide way is provided with a blocking groove, and each nitrogen blow plate is fixed by the corresponding blocking groove; a first fixing groove used for placing a sample liquid receiving plate is formed in the bottom in the outer shell; the first fixing groove is sequentially provided with an intermediate sealing ring and a second fixing groove; the second fixing groove is provided with a sample preparation plate and a solid phase extraction (SPE) bracket; a lever, an oscillator and a negative pressure pump are arranged at the lower part of the first fixing groove; the side surface of the first fixing groove is provided with two small holes which are respectively connected with two fans, and a gas heating device located at the back of the first fixing groove; and the back of the outer shell is provided with a waste liquid outlet hole, an outer nitrogen interface, a negative pressure interface, a power interface and a nitrogen heating device.

The invention discloses a computational imaging-based optical lens numerical aperture measurement method. The method includes the following steps that: a microscopic optical path system for numericalaperture measurement is constructed; the relative positions of a photographed object and a camera in the microscopic optical path system are adjusted, so that a microscopic image with a high dynamic range is obtained; a system magnification factor is calculated on the basis of to the size of the pixels of the camera and according to the size of the photographed object in the image; digital image processing is performed on the obtained image, so that a frequency diagram with a circular contour is obtained, and image processing is performed, so that the diameter of the circle is calculated; andthe numerical aperture of the lens is calculated according to the diameter of the circle and on the basis of the size of the pixels of a light sensing component, the system magnification factor, and an illumination light center wavelength. With the method of the invention adopted, the numerical aperture of any lens in life can be measured. The method has the advantages of simple operation processand high measurement precision. According to the method, the numerical aperture is obtained through calculation, human observation is rarely required, and the introduction of additional error can be effectively avoided.

The invention relates to the technical field of image processing and projection focusing, and particularly discloses a focusing method and a focusing device of an ultra-short-focus projector and a readable storage medium. The method comprises steps of projecting projection image to the projection surface; driving the focusing motor to rotate for one stroke in a stepping mode, and obtaining a firstprojection picture image and a second projection picture image at each step position of the focusing motor; acquiring a first focusing motor position corresponding to the first image acquisition device and a second focusing motor position corresponding to the second image acquisition device; determining a focusing position according to the first focusing motor position and the second focusing motor position; and driving a focusing motor to reach a focusing position to finish the focusing method. The optimal focusing positions on the two sides are determined by conducting definition analysis on the projection picture area images on the two sides respectively, then the final focusing position is comprehensively determined, the calculation complexity is greatly reduced, and meanwhile the problem that errors are introduced into definition data in an original image due to errors of a splicing method can be avoided.

The present invention belongs to the radiotherapy field and discloses a method or apparatus for correcting the subsidence amount of a sickbed. The method comprises the following steps that: the image of a patient is obtained; the distribution function of the subsidence amount of the sickbed is searched according to the weight of the patient and the movement distance of the sickbed, a subsidence amount corresponding to the image is obtained, and the distribution function of the subsidence amount of the sickbed is the distribution of the relative subsidence amount of the sickbed with respect to the weight of the load and the movement distance of the sickbed; and the subsidence amount is utilized to correct the image or the arrangement error of the patient. With the method or apparatus for correcting the subsidence amount of the sickbed of the invention adopted, the relative subsidence amount of a radiotherapy device and an imaging device can be corrected, the relative subsidence amounts of the sickbed at the imaging device side which are obtained under a condition that the sickbed moves different distances can be corrected, and correction accuracy is higher.

The present invention is entitled "Self-Contained Biological Indicators". Disclosed herein is a biological sterilization indicator that, in some embodiments, includes a housing having a first housing and a second housing, an ampoule containing a liquid growth medium, and at least partially An insert disposed in the first housing. A portion of the ampoule may be disposed within the interior of the first housing. The insert may have a platform comprising a top surface, a docking surface and side surfaces, a first void disposed in the platform and a second void configured to allow a first volume of liquid growth medium to enter the second void. In the housing, a second void is disposed through at least a portion of the side surface and is configured to allow a second volume of liquid growth medium to enter the second housing. The second void of the insert may be an angled cut through the abutment surface and the side surface, the angled cut may be disposed completely below the top surface. In some embodiments, stress concentrators and other features are included to reduce the force required to activate the biological sterilization indicator.