30results about How to "Improve calibration reliability" patented technology

The invention relates to a camera calibration system and method thereof, which is capable of easily performing camera calibration using a concentric circle pattern. According to the invention, a method of calibrating a camera calibrates the intrinsic parameters of the camera required to measure geometric information of an object using projection invariable characteristics of concentric circles. The method includes the steps of: taking images of the calibration pattern consisting of two or more concentric circles located in the same plane and having different radius at different angles to obtain projected images; calculating the central point of the projected images using a given algorithm, and calculating the principal point and focal point of camera using a nonlinear minimization algorithm based on the central point thus obtained.

A calibration procedure for a real-time load-pull system whereby the signal passes through at least one of the tuners of said real-time load-pull system. A calibration standard is connected to the test ports and an electromagnetic wave signal passes through one of the tuners before passing through the wave sensing structure. After having passed the wave sensing structure the electromagnetic wave signal interacts with the calibration element. This results in a reflected and eventually a transmitted electromagnetic wave signal that pass through the wave sensing structures of the system. The sensed electromagnetic wave signals are measured by means of a receiver. The procedure is repeated with different calibration standards. Then a line element is connected to the test ports and, one after the other, a set of calibration standards, a power meter and a harmonic phase reference generator are connected to the output tuner, each time sending a signal and measuring the wave signals. The measured data is used to calculate the error coefficients of the real-time load-pull system.

The invention provides a method for calibrating a pre-tightening force of an external thread fastener with a sensor. The method comprises the following steps: carrying out temperature correction on each ultrasonic flight time delta tnact' by using a reference temperature; establishing a function fitting relation between an acoustic time difference delta tnkorr'-delta t0korr after temperature correction and different loads Fn and acquiring a fitting equation of a pre-tightening force F relative to the acoustic time difference after temperature correction. Therefore, a measurement result with high reliability can be obtained during measurement.

The invention belongs to the technical field of network switching, and particularly relates to a mimicry thought-based security switching chip, an implementation method of the security switching chipand network switching equipment, and the method comprises the following steps: carrying out scheduling processing on message data of each port according to input scheduling; aiming at each piece of message data, extracting a message header and caching the message data; parsing through a heterogeneous parsing algorithm, and carrying out mimicry judgment on a parsing result; generating a message descriptor according to the judgment result, wherein the message descriptor at least comprises message feature information related to the message forwarding strategy behavior; searching for a mimicry table item verification-based table item cache to obtain forwarding strategy behavior data and updating a message descriptor; and extracting corresponding message data from the cached message data, and sending the extracted message data to a corresponding port in the form of a data packet. The security and reliability of the switch chip are enhanced by introducing such technologies as de-collaborative caching, mimic forwarding engines and mimic table item checking, and the method has important guiding significance for the development of the network switching technology.

A method of locating a linear defect on a photographic element, the element having a useful imaging width and the defect aligned with length of the element, includes the steps of: exposing a region of the element to create a latent image which is substantially uniform across the useful imaging width of the element; developing the latent image to produce a density signal; sampling the density signal with a photometric device; and analyzing the sampled density data for the presence of significant deviations aligned with the length of the element to locate the defect.

A line of sight detection apparatus includes: a line of sight detection device which detects the line of sight of an occupant; an operation detection device which detects the operation of on-board equipment by the occupant; and a calibration device which calibrates a detection value of the line of sight detection device based on the operation of the on-board equipment by the occupant which is detected by the operation detection device and position data of the on-board equipment.

The invention provides a user data verification method and system. The timestamp of the client is used as a variable private key to encrypt the user data during encryption; the safety and the reliability of the first Sign data are improved; the problem that user data is tampered, the server side cannot be accurately verified; and economic loss of a user is caused can be solved. meanwhile, the server receives the first Sign data of the information, judges whether information corresponding to the first Sign data is processed or not according to the list; If processing has been performed, the information is directly abandoned, meanwhile, the time difference between the second timestamp and the first timestamp of the server is within a preset first time value range when the information is received; By means of the method, the problem that the server is attacked maliciously for multiple times within a period of time can be prevented, the data verification reliability is improved, the user data is safer, and unnecessary loss is avoided.

The invention relates to a system and device for verifying an electronic current transformer. The system is provided with a standard current transformer, a control processing part, a to-be-detected electronic current transformer, and a temperature adjustment device which is used for adjusting the temperature of a detection environment of the to-be-detected electronic current transformer. The control processing part enables the current signals, detected under different detection environment temperatures, of the electronic current transformer to be compared with a standard current signal, and carries out the corresponding processing of the comparison result, so as to achieve the verification of the electronic current transformer. The system can achieve the full-automatic verification of the detection precision during the batch production and verification of related electronic current transformers, and effectively improves the verification precision and efficiency. Moreover, the detection precision obtained through verification is closer to the actual detection precision, so the system is higher in verification reliability, and is higher in reliability of detection precision.

The invention relates to a transformer zero sequence differential protection self-checking system and a transformer zero sequence differential protection self-checking method. The transformer zero sequence differential protection self-checking system comprises a first current transformer module, a zero-sequence current transformer module, a second current transformer module, a signal conditioningmodule, a signal processing module, a power module and a display and input module, wherein secondary current signal output ends of the first current transformer module, the zero-sequence current transformer module and the second current transformer module are connected to an input end of the signal conditioning module separately, an output end of the signal conditioning module is connected to an analog quantity sampling input port of the signal processing module, a communication port of the signal processing module is connected with a communication end of the display and input module, and thepower module supplies power to the signal conditioning module, the signal processing module and the display and input module respectively. The transformer zero sequence differential protection self-checking system and the transformer zero sequence differential protection self-checking method improve the zero sequence differential polarity verification efficiency, improve the operation reliabilityof zero sequence differential protection, prevent maloperation accidents after transformer zero sequence differential operation, and reduce the operation cost; and the transformer zero sequence differential protection self-checking method is simple in operation and is convenient and practical.

A calibration device is provided. The calibration device includes a frame, a first optical sensing device, a second optical sensing device and a third optical sensing device. The frame includes a bottom plate and at least four sidewalls, wherein the sidewalls have a first grating hole, a second grating hole, a third grating hole and a fourth grating hole at a first height. The bottom plate has an image recognition pattern, a first measurement point, a second measurement point and a third measurement point.

The invention belongs to the technical field of laser processing, and particularly relates to an iterative calibration method and system for optical distortion and poses of a laser scanning system. The method comprises the following steps: S1, generating N ideal points; s2, performing two-dimensional coordinate transformation on the ideal point; s3, N actual points are printed on the target paper on the translation table; s4, calculating target coordinates of the N translation stages; s5, measuring the coordinate of the current target coordinate point in the camera coordinate system; s6, performing data processing by using the rotation matrix; s7, calculating the transformed rotation matrix and a vector from the original point of the camera to the original point of the laser scanning system; s8, calculating to obtain a distortion coefficient matrix obtained by current iteration; s9, fusing the data obtained by the current iteration with the value of the last iteration, and taking the fused value as the input value of the next iteration; and S10, repeating the steps S2 to S9 to obtain a final calibration result. The method has the advantages of being convenient to operate and high in calibration precision.

The embodiment of the invention discloses a substation undervoltage relay verification device, system and method. The transformer station undervoltage relay verification device comprises a rectifier used for accessing commercial power and converting the commercial power into direct current, a slide rheostat electrically connected with the rectifier and used for adjusting the voltage of the direct current, an inverter electrically connected with the slide rheostat and the substation undervoltage relay, and used for converting the voltage-regulated direct current into alternating current and outputting the alternating current to the substation under-voltage relay, a signal collector electrically connected with the substation undervoltage relay and used for collecting an action signal of the substation undervoltage relay, and a controller electrically connected with the rectifier, the slide rheostat, the inverter and the signal collector, and used for controlling the working states of the rectifier, the slide rheostat and the inverter and determining the state of the substation under-voltage relay according to the action signal. According to the technical scheme provided by the embodiment of the invention, the verification reliability of the undervoltage relay of the transformer substation can be improved.

The invention relates to the field of communication security, and in particular relates to a data security transmission system and method. The system comprises user nodes A1, A2,..., An, fidelity system nodes a1, a2,..., an in one-to-one correspondence with the user nodes, and a plurality of broadcast points. Any user node Ai comprises a user terminal and an application system, and the applicationsystem comprises a sending terminal and a receiving terminal. An object of directly transmitting data by any fidelity system node ai is only limited to a user node Ai corresponding to the fidelity system node ai and any other fidelity system node aj. Data are not directly transmitted between the non-corresponding fidelity system node ai and the user node Aj.