165 results about "Condition number" patented technology

A multi-user MIMO downlink beamforming system with limited feed forward (200) is provided to enable preceding matrix information to be efficiently provided to a subset of user equipment devices (201.i), where zero-forcing transmit beamformers (w_i) are computed at the base station (210) and assembled into a precoding matrix (W). The precoding matrix is encoded using a compact reference signal codebook (225, 207.i) for forward link signaling, either by sending bits indicating the index of the transmission matrix used, or by transmitting one or more precoded pilots or reference signals wherein the pilot signals are precoded using vectors uniquely representative of the transmission matrix used which includes candidate reference signal matrices which meet a predetermined condition number requirement, such as a condition number threshold. The preceding matrix information (227) is extracted at the user equipment devices (201.i) using the compact reference signal codebook (207.i) and used by the MMSE receiver (209.i) to generate receive beamformers (v_i).

In accordance with the present invention, there is provided a method of determining whether a particular high fidelity vibratory seismic survey phase encoding is likely to be a good one based on an analysis of the eigenvalue structure (i.e., eigenvalues, eigenvalue separation, condition number, and model resolution matrix) of a matrix formed from the Fourier transforms of the sweep signals. Preferably, a singular value decomposition will be used to calculate the eigenvalues. Using this same approach, the condition number and eigenvalues of matrices that are associated with multiple proposed designs can be compared with each other to determine which is likely to be yield the best seismic data. This approach is preferably used either as a component of the advanced planning for a survey or in the field during pre-survey testing. The use of the instant approach to determine an optimal phase encoding scheme is also taught.

The embodiment of the invention provides an obstacle avoidance path planning method of obstacle avoidance task unrelated artificial potential field guide. The obstacle avoidance path planning method comprises the steps of using the energy consumption, end speed and frictional wear of a manipulator as optimization objectives according to the use cost of the space manipulator, and providing a minimum singular value index to which a speed limit is introduced on the basis; providing a gradient potential field offline construction method considering the operating cost of the manipulator according to the minimum singular value of a jacoby matrix to which the speed limit is introduced and the operability, condition number and joint limits of the manipulator; and expanding by using constructed random trees in a gradient potential field guided RRT algorithm, and planning to obtain an obstacle-free operating path of the space manipulator. According to the obstacle avoidance path planning method provided by the embodiment of the invention, when an obstacle avoidance path planning task of the redundant space manipulator is executed, the efficiency of an obstacle avoidance planning algorithm can be improved, and the use cost of the manipulator can be reduced.

This invention provides a relay precoder selection method for two-way amplify-and-forward multiple-input multiple-output (MIMO) relay systems and communication devices using the selection method or the selected relay precoder. According to the relationship between a relay precoder and the singular values of the effective MIMO channels, a set of candidate relay precoders are constructed based on the singular vector subspaces of cascaded MIMO channels, and one of them is selected for meeting a specific design criterion, such as the minimum sum of mean-squared errors, the maximum sum of channel capacities, and the minimum or maximum sum of condition numbers, where the condition number is defined as the ratio of the largest to the smallest singular value of a MIMO channel. As compared with the iterative design methods with the best performance, this invention achieves close performance while requiring much lower computational complexity.

The invention relates to a method for designing a Mars entry phase autonomous navigation scheme based on observability degree analysis, belongs to the technical field of deep space exploration, and particularly aims to optimize the geometric configuration of a navigation beacon so as to realize the design of the Mars entry phase autonomous navigation scheme and ensure the optimal navigation property by utilizing observability degree of a navigation system to represent the property of the navigation system and by combining the Mars entry phase autonomous navigation scheme based on radio measurement. According to the method provided by the invention, the observability matrix is calculated through a linearization method, the calculation amount is small, and the calculation speed is high; the observability degree of the navigation system is defined by inverse of the condition number of the observability matrix, and a quantitative gauge is provided for observability of the navigation system; and the observability degree of the navigation system can be maximized, so that the property of the navigation system can be further improved.

The invention provides a rotating strapdown system on-site proving method based on digital high-passing filtering, which comprises the steps: (1) determining an initial position parameter of a carrier by a GPS; (2) collecting data output by an optical fiber gyroscope and an acceleration meter, and processing the data; (3) rotating and stopping at four positions of a single axis of an inertia measurement unit; (4) analyzing biased observability degree of an inertia device by using a spectral condition number method; (5) filtering the Schuler period contained in velocity information of a navigation system by adopting an IIR high-passing digital filter; and (6) taking filtered velocity information as observed quantity, and estimating the deviation of the inertia device by adopting a Kalman filtering technique. When the carrier is in anchoring state, the adoption of the method can obtain higher on-site proving precision.

The present invention introduces a new concept of applying a parallel mechanism in automated fiber placement for aerospace part manufacturing. The proposed system requirements are 4DOF parallel mechanism consisting of two RPS and two UPS limbs with two rotational and two translational motions. Both inverse and forward kinematics models are obtained and solved analytically. Based on the overall Jacobian matrix in screw theory, singularity loci are presented and the singularity-free workspace is correspondingly illustrated. To maximize the singularity-free workspace, locations of the two UPS limbs with the platform and base sizes are used in the optimization which gives a new design of a 4DOF parallel mechanism. A dimensionless Jacobian matrix is also defined and its condition number is used for optimizing the kinematics performance in the optimization process. A numerical example is presented with physical constraint considerations of a test bed design for automated fiber placement.

The invention relates to a decision making technique for the events, in order to solve the problem of decision-making simply and rapidly under the condition of a large amount of knowledge. The invention, for each event, can group each condition and become one group for the condition with identical prior probability and identical ' and , or ' relation to form one condition group, the corresponding relation table can be established according to the mapping relation between events, conditions and condition group, then the knowledge base for decision making is established based on the information in the relation table. A decision making application system for the events, which includes a server providing with the knowledge base and a computer connected with the server, can be established based on the knowledge base; the computer may receive one or more conditions inputted by user, the server, for every condition received, can carry out special ergodic process in the knowledge base, and look up out all condition groups with the condition, and the relative decision probability for one or more events can be figured out based on the information such as maximum probability or value of condition group, the satisfied condition number.

Method and apparatus for improved processing for multi-channel signals. In an exemplary embodiment, an anomaly metric is computed for a multi-channel signal over a time window. The magnitude of the anomaly metric may be used to determine whether an anomaly is present in the multi-channel signal over the time window. In an exemplary embodiment, the anomaly metric may be a condition number associated with the singular values of the multi-channel signal over the time window, as further adjusted by the number of channels to produce a data condition number. Applications of the anomaly metric computation include the scrubbing of signal archives for epileptic seizure detection/prediction/counter-prediction algorithm training, pre-processing of multi-channel signals for real-time monitoring of bio-systems, and boot-up and/or adaptive self-checking of such systems during normal operation.

The invention relates to a processing method of a singular region by virtue of five-axis machining. The method comprises the following steps: establishing a kinematics conversion relationship of an AC (alternating current) dual-rotary-table five-axis machine tool, carrying out primary optimization treatment on a C-axle rotation angle while inverse kinematics changes so as to obtain cutter shaft data, and traversing the cutter shaft data; in the traversing process of the cutter shaft data, detecting the boundary range of the singular region by using a method based on a Jacobian matrix condition number; carrying out secondary optimization treatment on a singular point and a C angle nearby the singular point within the boundary range of the singular region to obtain new cutter shaft data; and carrying out recursion interpolation treatment on a subinterval with still larger C angle change between the two adjacent lines in the new cutter shaft data to obtain the final cutter shaft data. By adopting the method provided by the invention, velocity jump of a rotation shaft in the singular region can be effectively reduced, overlarge non-linear errors generated by the velocity jump can be reduced, the processing precision can be improved, and the machine tool as well as parts and components can be effectively protected.

The invention belongs to the fields of navigation, and measurement and control, and relates to a division-of-amplitude angle sensing design method and device for carrying out navigation by using sky scattering light polarization information. The method comprises the following steps: a) detecting an incident light polarization state by adopting a division-of-amplitude multi-channel synchronous detection method; b) achieving light-concentration and directional measurement functions by a small-field telescope; c) analyzing a vibration azimuth angle of a linear polarized electric field vector by a stokes vector and a matrix analysis method; d) carrying out system optimization design on indexes and debugging states of internal elements of a sensing device by taking an instrument matrix condition number as an evaluation factor; and e) accurately calibrating an instrument matrix of the sensing device by a benchmark polarization generator, and calibrating and accurately checking the sensing device. A new technological approach is provided for autonomous navigation by using an optical means; the method and the device can be widely applied to navigation targets of equipments such as vehicles, ships and warships, low-altitude aircrafts and autonomous robots, also can be applied to the fields such as polar research, outdoor adventure and geologic assay.

A method allows reconfigurable multi-element antennas to select the antenna configuration in MIMO, SIMO and MISO communication system. This selection scheme uses spatial correlation, channel reciprocal condition number, delay spread and average Signal to Noise Ratio (SNR) information to select the antenna radiation pattern at the receiver. Using this approach, it is possible to achieve capacity gains in a multi-element reconfigurable antenna system without modifying the data frame of a conventional wireless communication system. The capacity gain achievable with this configuration selection approach is calculated through numerical simulations using reconfigurable circular patch antennas at the receiver of a MIMO system that employs minimum mean square error receivers for channel estimation. Channel capacity and Bit Error Rate (BER) results show the improvement offered relative to a conventional antenna selection technique for reconfigurable MIMO systems.

The data retransmission method of multiple antennae system includes following steps: (1) receiving end checks the received data to determine whether data are received correctly or not; if not, then informing the sending end to retransmit; (2) sending end carries out linear transformation for data needed to retransmit, and carrying out weighting process for the linear transformed data, then sending the weighted data through multiple antennae. The linear transformation reduces condition number of channel so as to raise quality of data transmission. The invention realizes reliability of data transmission in multiple antennae system.

The invention discloses an arrangement method for a leaf apex timing sensor used for distinguishing blade multi-modal vibration. The method comprises the following steps that: measuring the revolvingspeed and the vibration frequency of a blade, on the basis of the revolving speed and the vibration frequency of the blade, determining the vibration order of the blade and the number of the leaf apextiming sensors; on the basis of the installation angle of the leaf apex timing sensor and the vibration order, constructing the design matrix of a blade vibration model; calculating the condition number of the design matrix; and taking the condition number of the design matrix as a target function, and utilizing an optimization algorithm to enable the condition number of the design matrix a to achieve a minimum value so as to determine the installation angle of the leaf apex timing sensor.

The invention discloses a frequency domain load identification method based on Tikhonov regularization. The method aims at solving the problems existing in frequency response function acquisition in practical engineering application of a matrix inversion method and the morbidity problems existing in calculation. A frequency response function is acquired through a finite element method, the morbidity of mechanical equipment is evaluated through the number of matrix conditions of the frequency response function, and loads are identified based on different regularization methods when the morbidity is different. A proper mobility condition number threshold value is determined. The method has the advantages that the problem that the frequency response function of the mechanical equipment is difficult to acquire in practical engineering application of the matrix inversion method and the morbidity problems existing in calculation can be solved, the load identification accuracy in a frequency domain is improved, and high engineering application value is achieved.

The invention discloses a method for choosing sending the antenna in a multi-antenna input and output wireless system, which comprises the following steps: the receiving part dose channel estimation by the sent training sequence to obtain all the possible channel array H_e, and feedbacks the H_e to the sending part; it chooses K sending antennas from M sending antennas and first chooses I antennas, wherein I, M, K are natural number and K<M; if the rate of the corresponding condition number of the channel array of the chosen sending antenna and the candidate channel array condition is less than the pre-set threshold quantity alpha, it chooses the new chosen channel array as the candidate channel array and ascertains the chosen sending antenna as the sending antenna.

The invention provides a three-dimensional frequency domain controllable source numerical simulation method. The method comprises the steps of S100: defining a calculation region in a resistivity anomaly body and an adjacent wrapping layer, and dividing the calculation region into multiple regular unit bodies; S200: calculating an initial electric field under an artificial source excitation condition, and by adopting a weighted residual method, establishing a finite element equation set of edge midpoints of the unit bodies in the calculation region; S300: defining an observation point as a boundary node by using a Green function, and enabling a secondary electric field of an internal node to express a secondary electric field of the boundary node; S400: substituting a Green function expression into a mixed equation set to obtain a first equation set only about the secondary electric field of the internal node; and S500: solving the first equation set to obtain secondary electric fieldvalues of nodes comprised in the unit bodies. According to the method, a vector finite element method and a volume integral equation method are applied; the calculation region is reduced; the calculation amount is reduced; the calculation precision is improved; formed equations are sparse in coefficient matrix and good in condition number; and a calculation result is accurate.

The invention relates to an observation condition number-based method for selecting an autonomously located road sign of a deep space probe, which is particularly applicable to an autonomously location determining system for a dual-road-sign detector, belonging to the field of autonomous navigation. By calculating and comparing the number of observation matrix conditions, the method can construct the position of the detector in a target celestial fixedly connected coordinate system by selecting two road signs, ensures the precision of determining the detector position can be greatly improved, and provides an accurate and practical located road sign autonomously selecting method for the deep space probe in low-earth orbit flight. The method not only considers the impact of the road sign position to navigation precision, but also has the characteristics of small calculation, practical analysis and the like.

The present invention discloses a composite wave plate phase delayer optimal design method which comprises the following steps of (1) forming a composite wave plate phase delayer by n quarter zero order wave plates, (2) determining the change range of the central wavelength and optical axis azimuth of each quarter zero order wave plate, (3) obtaining the transmission Jones matrix of a kth quarter zero order wave plate, (4) obtaining the equivalent Jones matrix of the composite wave plate phase delayer, (5) obtaining the equivalent characteristic parameter of a composite wave plate, (6) obtaining the system matrix of an ellipsometer measurement system, (7) obtaining the system matrix condition number of the ellipsometer measurement system, (8) obtaining the maximum value of the ellipsometer measurement system in a wave band range Gamma, and (9) adjusting the central wavelength and optical axis azimuth of each quarter zero order wave plate, obtaining the maximum value of each adjustment, and then obtaining the minimum value in all maximum values. The method can be well adapted to the use need of the ellipsometer measurement system.

The invention discloses a working space solving method of a flexible supporting industrial robot. The working space solving method comprises the steps that a reachable working space is subjected to primary refining at first by utilizing industrial robot kinematics Jacobi local condition number indexes proposed based on a fixing substrate, so that a flexible working space is obtained, that is, theindustrial robot can be away from singularities in the working space when working in the working space, and accordingly kinematics precision is ensured; then, force system (force and moment) ellipsoidindexes are proposed for the flexible supporting industrial robot so that the flexible working space of the industrial robot can be further refined, and the flexible working space is named as a combined vibration suppression working space; and when the industrial robot works in the working space, a counterforce system borne by a flexible supporting platform from the industrial robot can be effectively controlled, so that the terminal precision of the industrial robot is not damaged and is the same with the kinematics terminal precision of a fixing substrate industrial robot.

Signal to interference plus noise ratio information, delay spread information, or condition number information of a channel matrix in a multiple input multiple output communication are taken into account in addition to spatial fading correlation information for selecting a combination of at least two antennas from a plurality of antennas, then, the multiple input multiple output communication is conducted by using the selected antennas.