32results about How to "Compensation System Error" patented technology

The invention provides a distributed stimulated Brillouin temperature strain sensing system based on double-sideband modulation, which includes a narrow linewidth light source, a power divider, a microwave source, a pulse signal emitter, an optical receiver, an optical amplifier, an electrooptical modulator and a sensing optical fiber, wherein a pulse optical signal and a continuous signal that is modulated by double-sideband are input into the two ends of the sensing optical fiber respectively; the pulse optical signal serves as a pumping optical signal; the double-sideband continuous optical signal serves as a detecting optical signal; the pumping optical and detecting optical signals encounter to produce the stimulated Brillouin; and the continuous light carries the temperature or strain information of the points distributed along the sensing optical fiber. The double-sideband technology can effectively controls the Brillouin consumption of the pumping pulse during transmission, and greatly reduces the system error in measurement. The distributed stimulated Brillouin temperature strain sensing system is applicable to the fields as transmission cable and oil-gas pipeline monitoring and fire control, and is particularly applicable to sensing of long distance more than 50km.

The invention discloses a method for solving an attitude and heading reference system of a four-rotor unmanned aerial vehicle based on gradient descent. The method comprises the following steps of: acquiring attitude information of a micro four-rotor unmanned aerial vehicle through a gyroscope, an acceleration sensor and a geomagnetic sensor, wherein the gyroscope is used for measuring the angular rate of the micro four-rotor unmanned aerial vehicle, the acceleration sensor is used for measuring the linear acceleration of the micro four-rotor unmanned aerial vehicle, and the geomagnetic sensor is used for measuring magnetic field information of the position where the micro four-rotor unmanned aerial vehicle is positioned; fusing data of the acceleration sensor and the geomagnetic sensor with data acquired by the gyroscope by employing a quaternion update algorithm based on gradient descent, and correcting drift of the gyroscope; and solving the attitude angle information of the micro four-rotor unmanned aerial vehicle by employing a quaternion method. By employing a data fusion method based on the gradient descent method, the drift of the gyroscope data is corrected in real time by fully utilizing the data of the acceleration sensor and the geomagnetic sensor, and three-dimensional attitude angle information is output, so that the system error is reduced, and the attitude measurement accuracy and stability are effectively improved.

The invention discloses an inertia/vision integrated navigation method adopting a PSO (particle swarm optimization)-based CKF (cubature kalman filter). The method comprises the following main steps: Step 1, when a visual signal is effective, acquiring a dynamic video with a camera carried by a mobile robot and determining the speed of the camera by an image feature extraction and nearest neighbor matching method; Step 2, calculating the speed of the mobile robot according to a course angle measured by an inertia navigation system and in combination with the speed of the camera and estimating the speed and the accelerated speed of the mobile robot with the CKF; Step 3, updating time and measurement with the CKF according to measurement values and status values at all time of the system and selected filter parameter values, so as to obtain an estimation value of a status of the system; Step 4, optimizing filter parameters Q and R by using a particle swarm algorithm according to current objective function values and filter parameter values at all time and taking an obtained modification value as an input parameter of the CKF until an optimal status estimation value is obtained.

The invention relates to a method for establishing an equivalent geometric imaging model of a high-resolution satellite image by using RPC parameters. The method comprises: selecting a random scanningline of a high-resolution satellite image and listing a collinear condition equation of a projection center, an image point and a corresponding object square point; on the basis of operating characteristics and geometric characteristics of the high-resolution satellite, abstracting three rotation angles and six orbital numbers in an equivalent principal distance, a principal point coordinate, andan offset matrix and forming 11 independent parameters of an equivalent geometric imaging model; and with RPC parameters, calculating parameters of the equivalent geometric imaging model directly. Therefore, inherent problems of the over-parameterization of the RPC, strong correlation between parameters, and residual error existence of the fitting tight imaging model are solved; the parameters have the obvious geometric and physical meanings; and modeling analysis can be carried out on various imaging error sources conveniently. The mutual conversion of RPC parameters is realized; and the positioning accuracy of high-resolution satellite image is improved.

The invention discloses a current/voltage conversion traceability method for precision alternating current measurement. The method comprises (1) enabling an alternating current voltage-stabilizing source to be input to an alternating voltage proportion standard with known proportional error Eu to perform voltage/voltage proportion conversion, and obtaining standard voltage; (2) enabling the alternating current voltage-stabilizing source to be connected to a voltage type standard resistor with known resistance error Eru, and obtaining standard current; (3) inputting the obtained standard current to a current/voltage converter, performing corresponding current/voltage proportional conversion according to the standard current, and obtaining the converted voltage; (4) comparing the converted voltage with the standard voltage to obtain errors, and using the alternating voltage proportion standard and the voltage type standard resistor to correct the current/voltage converter, namely enabling the proportional conversion accuracy of current/voltage conversion to be traced to the alternating voltage proportion standard and the voltage type standard resistor. According to the current/voltage conversion traceability method, the current/voltage conversion traceability accuracy can be improved.

A Beidou accurate time-space bus networking communication monitoring terminal comprises a Beidou positioning unit, a miniature communication unit, an on-bus computing unit, a signal transceiver unit and a displaying module. The miniature communication unit, the Beidou positioning unit, the on-bus computing unit and the displaying module are successively connected. The on-bus computing unit is connected with the signal transceiver unit. The miniature communication unit is connected with the signal transceiver unit. The Beidou accurate time-space bus networking communication monitoring terminal realizes real-time accurate positioning of the bus in driving and communication between the bus and an upper control center, thereby more accurately estimating arrival time of the bus, so that the passenger can be liberated from waiting without information. Bus scheduling is optimized so that buses are reasonably and uniformly distributed in a line. Communication between the bus, a signal machine control center and a traffic administration bureau master control center is realized. A bus preferable communication strategy is reasonably arranged.

The invention relates to a coal spontaneous combustion danger degree multi-source information fusion early warning method, and solves the problems that an existing coal spontaneous combustion early warning method is low in early warning precision, and scientific decision is hard to make to obtain the spontaneous combustion position, ignition time and hidden danger degree of coal spontaneous combustion. The method comprises the following steps: step 1, arranging a sensor; : step 2, registering the sampling time of the sensor; : step 3, acquiring the acquisition value z (k) of each sensor at different moments; : step 4, performing noise reduction processing on the acquisition value z (k) of each sensor in the step 3; : step 5, taking historical actual detection data of the sensor at the early warning point as coal spontaneous combustion characteristics, and performing normalization processing; : step 6, determining the hidden danger degree and the ignition time of coal spontaneous combustion; and : step 7, through the coal spontaneous combustion target early warning point obtained in the step 5 and the coal spontaneous combustion hidden danger degree and ignition time obtained in thestep 6, early warning of the coal spontaneous combustion danger degree is completed.

The invention discloses a telescope pointing error correction method based on D-H matrix modeling under a motion platform. The pointing error of a telescope on a motion platform comprises the system error of the telescope, the measurement error of an attitude sensor and the installation error between the attitude sensor and the telescope. On the basis of error source analysis, a correction model of the pointing error on the motion platform is established through a D-H method, and the correction model comprises an error parameter calculation model and a guide value calculation model. According to the model, all error sources are considered at the same time, the influence of error parameter coupling is avoided, and the pointing correction precision is improved. According to the method, firstly, multiple fixed stars are tracked to obtain pointing data, then all error parameters are calculated in one step through the error parameter calculation model, and a guide value after error correction is calculated in two steps according to target information and the guide value calculation model. The method is easy to implement, high in correction precision, stable in performance and capable of achieving rapid and high-precision pointing of the telescope on the motion platform.

The invention relates to the hand-written signature identification input equipment based on the ultrasound and the infrared waves. It is composed of the signal transmitting pencil 2, the writing plate 1 and the signal receiving processor 3. The signal transmitting pencil is composed of the force sensor connected to the circuit board and the thin-film switch connected to the sensor. The slope angle sensor is included in the circuit. And the signal receiving processor 3 is composed of the left signal receiving amplifier, the right signal-receiving amplifier and the signal processor. The force sensor and the slope angel sensor are added to the transmitting apparatus of the ultrasound infrared location system as the input equipment, which may reflect the writing trace and the writing habit accurately. Moreover, it can compensate the system error generated by pencil tilting while writing to improve the identification accurateness of the system.

The invention discloses a fusion method capable of reasonably quantizing the conflict and the coupling degree between measured values of a plurality of satellite sensors. The fusion method is characterized in that the conflict and the consistence between the measured values of the same measured target are quantized by a coupling degree and conflict degree matrix between different measured values and the process of quantizing the conflict and the consistence comprises the following steps: (1) providing a system error correction coefficient for the difference in average values of measurement results of the same batch of target values by the satellite sensors; (2) calculating the coupling degree of data according to an intersection set of a system error interval of each satellite sensor and the measurement result for the same measured target, and calculating a weight of each measured value; (3) calculating the conflict degree of the data according to a complementary set of the intersection set of the system error interval of each satellite sensor and the measurement result for the same measured target, and calculating a weight of each measured value; and (4) calculating the coupling weight and the conflict weight between the measured values for the same target by a plurality of satellite sensors through the system error correction coefficient so as to obtain a fusion value and a fusion error of seawater sea surface temperatures measured by a plurality of satellite sensors.

The invention belongs to the technical field of liquid flow or volume measurement, and particularly relates to a main-standard volume calibration device and a main-standard volume calibration method based on positive and negative strokes of a commutator. A water pump is arranged in a water storage container and is connected with a filter. The filter is connected with a voltage-stabilized container, the voltage-stabilized container is connected with a hand valve, the hand valve is connected with a two-position four-way reversing electrically-operated valve, and the two-position four-way reversing electrically-operated valve is connected with a volume tube. A volume tube piston is positioned in the volume tube. A controller is connected with a photoelectric switch A, a photoelectric switch B and a photoelectric switch C. A light shielding plate is connected with a piston rod of the volume tube piston. The controller is connected with a positive-negative switch, and the positive-negative switch is connected with a two-position three-way reversing electromagnetic valve. The two-position four-way reversing electrically-operated valve is connected with the two-position three-way reversing electromagnetic valve. A weighing container is put on an electric scale and is arranged in a right access of the three-way reversing electromagnetic valve, and a recycling container is arranged in a left access of the three-way reversing electromagnetic valve. During reverse testing, positions of the weighing container and the recycling container are exchanged.

The invention is suitable for the technical field of microwaves, and provides a terahertz frequency band noise parameter measuring system and method, and the system comprises a signal source, a frequency mixing device, at least five noise sources, a switching device and a noise receiver. The at least five noise sources are respectively connected with the input end of the to-be-tested piece through the switch device; wherein only one noise source is communicated with the input end of the to-be-tested piece each time; the first input end of the frequency mixing device is connected with the output end of the to-be-tested piece, the second input end of the frequency mixing device is connected with the signal source, and the output end of the frequency mixing device is connected with the noise receiver; the at least five noise sources are used for providing at least five different source impedance states for the to-be-tested piece through the switching device. According to the terahertz frequency band noise measurement system provided by the invention, five different source impedance states are provided through the at least five noise sources, system errors introduced by source impedance mismatch of the to-be-measured piece are corrected, and the accuracy of terahertz frequency band noise parameter measurement is improved.