196results about How to "Avoid estimation error" patented technology

The invention relates to an airborne SAR radiation external calibration processing method based on weak arrangement of corner reflectors. The method comprises the following steps: obtaining original SAR image data of a calibration field; on the basis of a point target radar equation, reconstructing an radiation external calibration equation; performing stable estimation on calibrator image energy and geometric optical solution on a calibration RCS; carrying out fitting and correcting on a radar system transfer function to obtain preliminary radiation calibration SAR image data; carrying out the stable estimation on the calibrator image energy and the geometric optical solution on the calibration RCS; and estimating a system constant item so as to generate calibration data and obtain final radiation calibration SAR image data. According to the invention, on the basis of the point target radar equation, according to the characteristic of parameters of a radar system, the SAR radiation external calibration equation comprising a change system transfer function and a constant system constant item is reconstructed, the application process of radiation external calibration is simplified, and the problem is avoided that it is quite difficult for airborne SAR flight to obtain a large-scope homogeneous stable tropical rainforest area frequently used by similar spaceborne SAR radiation calibration.

The invention relates to a multi-condition fault prediction method for complex mechanical equipment. The method comprises the following steps: (1) establishing a multi-PCA (Principal Component Analysis) model specific to a multi-condition process, and calculating corresponding detection indexes, namely, a T2 statistic and an SPE (Square Prediction Error) for each PCA model; (2) optimizing the two detection indexes of T2 statistic and SPE in each of the PCA models, and performing fault detection on the mechanical equipment to obtain fault data of the mechanical equipment in a transition process; (3) performing fault reconstruction on the fault data of the mechanical equipment in the transition process detected by using the two optimized detection indexes of T2 statistic and SPE to obtain an amplitude estimation value fi for minimizing the reconstructed SPE; (4) performing consistent amplitude estimation on the amplitude estimation values fi obtained after reconstruction of the same fault under different conditions in the transition process; (5) performing trend prediction on the fault amplitude value by using a support vector machine prediction model according to an amplitude estimation value fi obtained after the consistent amplitude estimation. The method can be widely applied to fault prediction of electromechanical equipment.

The invention discloses a voltage control type virtual synchronizing method of a double-feed wind power generator set. Through simulating inertia and a frequency-modulating and voltage-modulating characteristic of a synchronizer, the set can be different from a characteristic of no electric grid frequency change response in a traditional current control type, thereby possessing capability of supporting voltage and frequency of a weak power grid based on the voltage control type through virtual inertia. The method provides and realizes a VCT-DFIC virtual synchronous control structure of which an inner ring is controlled by an improved double-feed generator stator voltage rotor current double-closed-loop structure based on adaptive stator virtual impedance and transmission line sag voltage feedforward compensation in a control manner which includes crossed control between stator voltage and rotor current and furthermore an outer ring is controlled by a virtual synchronous realizing algorithm. The method realizes output power control in VCT-DFIG grid integration operation in a weak grid condition with any actual impedance and effective decoupling, and furthermore a designed control structure realizes higher inertia and frequency supporting capability of the double-feed generator.

The invention discloses an interactive filtering method for satellite attitude determination, and aims to overcome the defect that constant gyro drifts cannot be estimated by utilizing the optimal-REQUEST algorithm and improve the algorithm applicability. The method comprises the following steps: step 1, acquiring sensor measurement data, including gyroscope data and star sensor data; step 2, building a state space model of a satellite attitude estimation system, as well as building an attitude K matrix; step 3, according to the state space model, the state estimate of the known moment k, and a gyro measurement value, estimating constant gyro drifts at the moment k+1 by utilizing the CKF algorithm and the optimal quaternion at the moment k, and then compensating the gyro measurement value; step 4, according to the compensated gyro measurement value, carrying out time update and measurement update by utilizing the optimal-REQUEST algorithm, so as to obtain the optimal K matrix at the moment k+1; the remaining steps of obtaining the optimal quaternion at the moment k+1. The interactive filtering method is beneficial to improvement of the estimation precision.

The invention discloses a synchronous positioning and map constructing method under a random finite set framework, and the method is applied to the field of mobile robot environment perception and composition. The method is mainly characterized in that: a random finite set theory is utilized to model an SLAM problem, both sensor observation information and an environment map are expressed in a random finite set form, and a plurality of kinds of uncertain information are completely described; after Rao-Blackwellised decomposition is carried out on SLAM total probability distribution, unscented transformation is introduced, and a proposal distribution function of particle filtering used for robot state estimation is generated by UKF, and when environment map PHD function filtering is realized by a Gaussian mixture model, the UKF is fused with the observation information to realize the updating of Gaussian members; and finally, in order to prevent the calculation amount of the algorithm to rapidly rise along with the iteration process, merging and pruning mechanisms of the Gaussian members are introduced, and the calculation amount of the algorithm is controlled in a reasonable range. According to the invention, the estimation precision and robustness of the system in a non-linear non-Gaussian problem processing process are effectively improved.

A double-input and double-output NDCS unknown time delay hybrid control method belongs to the technical field of a multiple-input and multiple-output NDCS having a limited bandwidth resource. A method using a real network data transmission process between all nodes in a TITO-NDCS to replace a network time delay compensation model between the nodes is brought forward aiming at the problems that, for the TITO-NDCS double input signals and double output signals of which are influenced and coupled with each other and which needs decoupling processing, stability of each closed-loop control circuit is influenced, stability of the whole system is influenced and that even loss of stability of the TITO-NDCS is resulted in due to network time delay of network data during transmission between the nodes. SPC and IMC are separately applied to a circuit of the TITO-NDCS. Measurement, estimation or identification of the network time delay between the nodes can be avoided, a clock signal synchronization requirement is reduced, an influence of a network uncertain time delay on TITO-NDCS stability is lowered, and the control performance quality of the system is improved.

The invention provides an estimation method of target motion parameters for a mine platform. A pseudo linear least square estimation method and the Kalman filtering algorithm are combined. The targetmotion parameters are initialized by adopting the pseudo linear least square estimation method to adaptively update target initial motion parameters. An optimal initial motion parameter is obtained asan iteration initial value of the Kalman filtering to solve the motion parameters of the target. The target motion parameter estimation method for the radar platform can increase the convergence speed and improve the estimation accuracy.

The invention relates to a method for generating a SOC source in BMS detection and a method for testing the SOC estimated accuracy and belongs to the technical field of power battery or power battery pack management and tests. The method for testing the SOC estimated accuracy aims at solving the problem that the SOC estimated algorithm accuracy, in a BMS to be tested, tested by a battery management system test platform is relatively low. The method for generating the SOC source in BMS detection comprises the steps that firstly, a sample battery is selected; secondly, the test environment temperature of the sample battery is set to be N; thirdly, preprocessing is conducted; fourthly, an available capacity test is conducted on the preprocessed target sample battery; fifthly, a common working condition test is conducted on the target sample battery after the available capacity test is conducted; sixthly, a calibration working condition test is conducted on the target sample battery after the common working condition test is conducted. The method for testing the SOC estimated accuracy comprises the steps of setting of the test environment temperature N, preprocessing, execution of the common working condition test and execution of the calibration working condition test.

The invention relates to a star sensor external field conversion reference measurement system and a star sensor external field conversion reference measurement method. The system comprises a star sensor 1, an astronomical north theodolite 2, a theodolite A3, a theodolite B4, a global positioning system (GPS) antenna 5, a GPS receiver 6, a gas pressure temperature sensor 7 and a control computer 8;the method uses the system provided by the invention; the method applies the fixed stars as a measurement reference to determine the conversion relationship between a measurement coordinate system ofthe star sensor and a reference prism coordinate system. The system and the method avoid the estimation error caused by the parameter coupling, of parameters such as a principal point in a calibration process of the star sensor in the traditional laboratory test method. The measurement accuracy of the conversion reference is effectively improved. The method is widely applicable to the determination of external lead-out references for various types of star sensors.

The invention is applicable to the technical field of lithium ion batteries, and provides a method and device for improving SOC estimation precision of a lithium ion battery, and the method comprisesthe steps: obtaining the working state of the lithium ion battery at the moment k, and obtaining the maximum discharge capacity of the battery through the calculation of obtained characteristic parameters when the lithium ion battery is in a charging state. And after the lithium ion battery is converted into a discharge state, obtaining current and voltage in the working process of the lithium ionbattery, carrying out online identification, obtaining identification parameters of the lithium ion battery at the moment, calculating terminal voltage, current and identification parameters of the lithium ion battery at the moment k and the obtained maximum discharge capacity, and obtaining the SOC of the lithium ion battery at the moment k. According to the invention, the residual electric quantity of the lithium ion battery can be accurately estimated after the ambient temperature changes and the battery is aged, the efficiency and accuracy of estimating the residual electric quantity of the lithium ion battery are improved, and the anti-interference capability is strong.

The invention relates to a method for synchronizing time and carrier frequency in a short-range wireless network, and belongs to the technical field of wireless communication. The method comprises the following steps of: obtaining the range of the tolerance of a receiving system to frequency deviation by tests; according to the maximum tolerance, performing phase deviation compensation of a local frequency-expanded modulation sequence, and obtaining a new local frequency deviation correlation value sequence; correlating the received correlation value sequence with the local correlation value sequences, and obtaining a group of correlation value sequences; and according to the position of the sequence corresponding to the maximum correlation value, realizing the decoding of the data. The time-frequency synchronizing method has the advantages of improving the time synchronization performance under the influence of the frequency deviation, making a receiver have lower energy consumption and higher receiving performance under the condition of bigger frequency deviation, improving an operational precision in the frequency deviation compensation and effectively improving the time synchronization performance of the receiver.

The invention provides a compensation method of random time-delay of the external forward and internal feedback paths of a network cascade control system, belonging to the technical field of the network control system. The method uses the actual external forward network path nodes of the network cascade control system and adopts the network data transmission process between the internal feedback network path nodes to replace the compensation model of network time-delay between the nodes, avoid the measurement, observation, estimation or identification of the network data transmission random time-delay between the nodes and remove the synchronization requirement on the node clock signal. By adopting the method, the influence of the random network time-delay on the system stability can be reduced and the performance quality of system control can be imprved. The method of the invention is suitable for the dynamic compensation and control of random network time-delay when the mathematicalmodels of the main controlled object and auxiliary controlled object are known and the network only exists in the external forward and internal feedback paths of the cascade control system.

The invention discloses a hybrid control method for an uncertain time delay of a two-input and two-output network control system (TITO-NCS), and belongs to the technical field of multi-input and multi-output network control systems with limited bandwidth resources. Aiming at the problems that the two input signals and two output signals of the TITO-NCS are mutually affected, the stability of one closed loop control circuit is affected and the stability of another closed loop control circuit is also affected due to a network time delay generated by transmission of network data among nodes, or even loss of the stability of the TITO-NCS is caused, a compensation model for replacing the uncertain time-delay with network data transmission process among all real nodes in the TITO-NCS is provided; and IMC and SPC hybrid control is carried out on two circuits separately, so that measurement, estimation or recognition of the network time delay among the nodes can be avoided, the requirements of clock signal synchronization of the nodes are avoided, the influence of the uncertain time delay on the stability of the TITO-NCS can be reduced and the control performance quality of the system is improved.

The invention discloses a sparse recovery STAP method based on knowledge assistance. The method comprises the following steps: constructing a sample data set; constructing a space-time steering vectormatrix of a distance unit sample; performing sparse recovery on the sample data; constructing a steering vector matrix containing prior information; judging whether the steering vector of sparse recovery corresponds to clutter or not based on the steering vector matrix containing prior information, and updating the sparse recovery vector and the dictionary based on a judgment result; performing secondary sparse recovery on the sample data based on the updated sparse recovery vector and dictionary; and performing clutter covariance matrix estimation by using the estimation sample of secondarysparse recovery. According to the method, the sparse recovery dictionary is corrected by means of sample sparse recovery and prior information of clutter distribution, clutter covariance matrix estimation errors caused by off-grid are solved. Meanwhile, the influence of dense interference in samples is removed, the moving target cancellation phenomenon is overcome, and the moving target detectionperformance is improved.

The invention discloses a tone quality auralization evaluation method and system of a non-linear audio system. A one-dimensional Volterra filter parameter is solved by a time domain, so that a problem of inaccurate auralization model estimation of the non-linear system due to a phase difference in frequency domain solution in the prior art can be solved. The method comprises: S1, constructing a non-linear model based on a one-dimensional Volterra filter to simulate a non-linear response of a non-linear audio system; S2, identifying a kernel function parameter of the one-dimensional Volterra filter; S3, feeding an audio testing signal to the established non-linear model and evaluating the one quality of an output result; and S4, according to the evaluation result of the S3, adjusting a parameter of the non-linear model, returning to the S3, evaluating the tone quality improvement situation after adjustment, and carrying out steps in circles until finding an optimal non-linear model parameter.

The invention belongs to the technical field of bandwidth resource limited MIMO-NCSs (multiple-input multiple-output networked control systems) and relates to a two-input two-output networked control system delay compensation SPC (smith predictor control) and IMC (internal model control) method. In order to solve the problems that two-input two-output signals in a TITO-NCS (two-input two-output networked control system) have mutual effect, network delay due to the transmission of network data between nodes affects the stability of one closed-loop control circuit of the system and may also affect the stability of another closed-loop control circuit while even stability loss is caused to the TITO-NCS, it is presented that an inter-node network delay compensation model is replaced by network data transmission process between all true node s in the TITO-NCS, with dynamic feedforward as well as SPC and IMC applied to the two circuits; by using the method of the invention, it is possible to omit the measurement, estimation or identification of inter-node network delay, omit the requirement on node clock signal synchronization, reduce the effect of network delay upon TITO-NCS stability, and improve the control performance quality of the system.

The invention provides a time-varying network time delay compensation method of a forward access of a networked cascade control system (NCCS), belonging to the technical field of networked control system. In the method, a network data transmission process among forward access nodes is used instead of a network time delay compensation model among the forward access nodes so as to avoid measurement, observation, estimation or recognition of time-varying time delay when network data among the real forward access nodes are transmitted and prevent the requirements of synchronization of node clock signals. By using the method, the influence of the time-varying network time delay on the stability of a system can be reduced and the control performance quality of the system can be improved. The method is suitable for dynamic compensation and control of the time-varying network time delay when a network only exists in the forward access of the networked cascade control system under the condition that a mathematical model of a main controlled object is known or uncertainly known, a mathematical model of a vice controlled object is known, and certain interference signals exist in the system.

The invention provides a method for compensating for an unknown network time delay in a forward path of a network cascade control system and belongs to the technical field of network control systems. A real network data transmission process between forward path nodes is adopted to substitute for a network time delay compensation model between the nodes; the measurement, the observation, the estimation or the identification of a network data transmission unknown time delay between the forward path nodes are eliminated; and the requirement on the synchronization of a node clock signal is eliminated. By the method, the influence of the unknown network time delay on the stability of the system can be reduced and the control performance quality of the system is improved. The method is applied to the dynamic compensation and control of the unknown network time delay only existing in the forward path of the network cascade control system, in which the main and secondary controlled target mathematical models are known or unknown, the network has a certain amount of packets, and the network time delay can be more than several even over ten sampling periods.

The invention provides a TITO-NDCS variable network delay compensation method, and belongs to the technical field of bandwidth resource limited MIMO-NDCS. Aiming at the problems of loss of stability of TITO-NDCS and influencing the stability of each closed control loop and influencing the stability of the whole system due to network delay generated by transmission of network data between nodes in the TITO-NDCS in which two-input and two-output signals are mutually influenced and coupled and require to be decoupled, the method that the network data transmission process between all the real nodes in the TITO-NDCS replaces a network delay compensation model is put forward, and two-degree-of-freedom IMC and SPC are performed on the two loops respectively so that measurement, estimation or identification of the network delay between the nodes can be omitted, the synchronization requirement of node clock signals can be omitted, the influence of the variable network delay on the stability of the TITO-NDCS can be reduced and the system control performance quality can be improved.

The invention provides an InSAR atmospheric delay correction method assisted by a GNSS chromatography technology. The InSAR atmospheric delay correction method comprises the following steps of S10, reconstructing a three-dimensional total refractive index field of atmospheric water vapor in a research area, S20, taking the radiosonde data of the research area as a reference value, carrying out the precision evaluation of the chromatography result, and carrying out the step S30 if the precision meets the requirements, S30, obtaining a refined three-dimensional total refractive index field by using a spatial interpolation algorithm, S40, estimating the oblique path total delay amount of the SAR signals in the main image and the auxiliary image by using a Ray-tracing algorithm, S50, generating an atmospheric delay phase diagram of the interferometric SAR image, S60, generating an SAR unwrapping interferometric phase diagram, and S70, obtaining an InSAR phase diagram of atmospheric correction. According to the InSAR atmospheric delay correction method assisted by a GNSS chromatography technology, the GNSS chromatography technology and the spatial interpolation algorithm are utilized to acquire the refined three-dimensional total refractive index field, and the Ray-tracing algorithm is combined to accurately estimate the oblique path atmospheric delay amount of the three-dimensional SAR signal, so that the inversion precision of the atmospheric delay phase of the SAR image is improved, and high-precision correction of InSAR atmospheric delay is realized.

The invention provides a delay compensation method for a network control system, belonging to the technical field of network control systems. True network data transmission processes from a transmitter node to a controller node and from the controller node to an actuator node are adopted in the method to replace network delay compensation models between the transmitter node and the controller node and between the controller node and the actuator node, thereby omitting measurement, estimation or identification on network data transmission delay between nodes and also avoiding the requirement on the node clock signal synchronicity. When an offset exists between an estimated model of a controlled object and a true model, a model offset correction controller can enhance the robustness and theantijamming capability of a system. By adopting the method, the influence of delay on the stability of the system can be lowered and the quality of the control performance of the system can be improved. The method is suitable for sectional, real-time, on-line and dynamic compensation and control on the delay of a network control system of which the network exists between the transmitter node and the controller node and between the controller node and the actuator node and of which the mathematical model of the controlled object is known or incompletely known.

The invention discloses a two dimensional direction of arrival angle estimation method of an electromagnetic signal, the two dimensional direction of arrival angle estimation method mainly solves the problems of slow reaction rate and large estimation error of the target reconnaissance and passive location caused by huge computation task of the two dimensional direction of arrival angle estimation in the prior art. The two dimensional direction of arrival angle estimation method comprises the following steps that even planar arrays are formed by the adoption of antenna receivers, echo signals of all antenna receivers are calculated, noise subspaces of the echo signals of the antenna receivers are calculated, a direction vector of the included angle of a y axis is obtained by plugging the included angle of an x-axis, which is made to be a fixed value, into an angle solving function, multiple sets of values are obtained through multiple times of computations, an amplitude spectra is generated by the adoption of multiple sets of values, the included angle of the x axis is obtained by seeking peak points of the amplitude spectra, and the included angle of the y axis is obtained through the least square method. By means of the two dimensional direction of arrival angle estimation method, the two dimensional direction of arrival angle estimation process is simplified into a one dimensional direction of arrival angle estimation process, the computation tasks are greatly reduced, the reaction rates of the target reconnaissance and passive location are improved, the parameter estimation error caused by delayed information can be avoided, and the method can be used for the quick target reconnaissance and passive location.

The invention provides a compensation method for unknown network delay of a network cascade control system, belonging to the technical field of network control systems. The method adopts a network data transmission process among all forward and feedback network path nodes of the actual network cascade control system to replace a network delay compensation model thereof, avoids measurement, observation, estimate or identification for unknown delay of network data transmission among the nodes, and also avoids the synchronization requirement on node clock signals. The method can reduce the influence of unknown network delay on stability of the system and improve the control performance quality of the system. The method is suitable for dynamically compensating and controlling unknown network delay in all forward and feedback network paths of network simultaneously existing in the network cascade control system, when mathematical models of main auxiliary controlled objects are known or unknown, the system has unknown interference, and the network exists a certain amount of data packet losses.

The invention discloses a sight angle estimation method based on a human eye difference image, and the method comprises the steps: inputting two different human eye images: a tested human eye image and a reference human eye image into a twin neural network, and obtaining a difference value of a corresponding sight angle through network regression; when the sight angle of the reference human eye image is known, the sight angle of the tested human eye image can be obtained. The method solves the problem that in an existing sight line angle estimation method, the sight line angle is directly estimated from an image, and large estimation errors are caused by personal apparent differences. Meanwhile, the problem that the workload of data calibration for a certain individual is quite large is solved. According to the method, the difference value of the sight angles in the two images is estimated by using the twin neural network technology, so that the sight angle of the tested human eye image is obtained, the angle estimation precision is high, and the robustness is good.

The invention provides a method for compensating unknown external feedback and inner loop network time delay of a network cascade control system, which belongs to the technical field of network control systems. A network data transmission process between an external feedback network path node and an inner loop network path node of a true network cascade control system is used instead of a networktime delay compensating model, so that the measurement, observation, estimation or identification of unknown network data transmission time delay between the nodes is eliminated and the requirement on the synchronization of a node clock signal is eliminated. The method can reduce the influence of unknown network time delay on the system stability and improves the system control performance and quality. The invention is suitable for dynamically compensating and controlling unknown network time delay when a network only exists in the external feedback and inner loop paths of the network cascadecontrol system, the mathematical models of main and auxiliary controlled objects are known or uncertain, unknown interference exists in the system and a certain quantity of packet losses exist in thenetwork.

The invention discloses a random time delay compensation method for a TITO-NDCS (two-input and two-output networked decoupling control system) and belongs to the technical field of multiple-input and multiple-output networked decoupling control systems with limited bandwidth resources. As for the TITO-NDCS with two-input and two-output signals mutually affected and coupled requiring decoupling, in consideration that network time delay generated in a transmission process of network data among nodes affects stability of respective closed-loop control loops and the whole system and even leads to that the TITO-NDCS loses stability, the method for substituting a network data transmission process among all real nodes in the TITO-NDCS for a network time delay compensation model is put forward, so that measurement, estimation or identification of the network time delay among the nodes can be avoided, requirements on clock signal synchronization are lowered, influences of random time delay on stability of the TITO-NDCS are lowered and system control performance quality is improved.

The invention concerns a method for estimating the angular deviation of a mobile element relative to a reference direction, the method comprising the following steps: acquiring a reference image (101) representative of a reference direction of the mobile element; acquiring a current image (102) representative of the current direction of the mobile element; identifying points of interest in the reference image and in the current image (103); determining at least two pairs of points of interest (104), one pair consisting of a point of interest of the current image and a point of interest corresponding to same in the reference image; determining the angular deviation (105) between the current direction and the reference direction of the mobile element by using the at least two pairs of points identified in the previous step.

The invention provides a long delay compensation method for two-input and two-output networked decoupling control systems, and belongs to the technical field of bandwidth resource limited MIMO-NDCS. Aiming at the problems of loss of stability of TITO-NDCS and influencing the stability of each closed control loop and influencing the stability of the whole system due to network delay generated by transmission of network data between nodes in the TITO-NDCS in which two-input and two-output signals are mutually influenced and coupled and require to be decoupled, the method that the network data transmission process between all the real nodes in the TITO-NDCS replaces a network delay compensation model is put forward, and SPC and IMC are performed on the two loops respectively so that measurement, estimation or identification of the network delay between the nodes can be omitted, the synchronization requirement of clock signals can be reduced, the influence of long delay on the stability of the TITO-NDCS can be reduced and the system control quality can be improved.

The invention provides a method for compensating uncertain network delay of a forward passage of a network cascade control system, belonging to the technical field of a network control system technology. A real network data transmission process among forward passage nodes is adopted instead of a network delay compensation model; the measurement, observation, estimation and identification of the uncertain delay of network data transmission among the forward passage nodes are omitted; and requirements on the clock signal synchronization of the nodes are eliminated. By adopting the method, the influence of uncertain network delay on the system stability can be reduced, and the control performance quality of the system is improved. The method provided by the invention is suitable for compensating and controlling the uncertain delay for which the mathematical models of the primary and secondary controlled objects are known, the network only exists in the forward passage of the network cascade control system, and the network delay is greater than several or even dozens of sampling periods.

The invention relates to a method for compensating the uncertain time delay of a double-input-output network decoupling control system, belongs to the technical field of multi-input-output network decoupling control systems with limited bandwidth resources, and aims to solve the problems that the double-input-output signals of TITO-NDCS affect each other and are coupled and need to be decoupled, the time delay generated during network data transmission among nodes affects the stability of each closed-loop control loop and the stability of the whole system, and even TITO-NDCS instability is caused. The method which uses the network data transmission process among all real nodes in the TITO-NDCS to replace network time delay compensation models among the nodes has the advantages that measuring, estimation or identification of the network time delay among the nodes can be avoided, clock signal synchronization requirements are lowered, influence of the uncertain network time delay on TITO-NDCS stability is lowered, and system control performance quality is improved.