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127 results about "Coordinate vector" patented technology

In linear algebra, a coordinate vector is a representation of a vector as an ordered list of numbers that describes the vector in terms of a particular ordered basis. Coordinates are always specified relative to an ordered basis. Bases and their associated coordinate representations let one realize vector spaces and linear transformations concretely as column vectors, row vectors, and matrices, hence are useful in calculations.

Standard pose calibration method for six-degree-of-freedom parallel robot used for Stewart platform structure

The invention discloses a standard pose calibration method for a six-degree-of-freedom parallel robot used for a Stewart platform structure. The method comprises the following steps: establishing a base coordinate system {O} and a motion platform coordinate system {P}; under the condition of six-degree-of-freedom parallel robot open chain organization, calibrating position coordinate vectors of Hooke hinge centers and spherical hinge centers of the parallel robot in the{O} and the {P} respectively; selecting three mark points on a motion platform and measuring local coordinates of the mark points in the motion platform coordinate system; installing an optocoupler limit switch at the push rod extending end of an electric cylinder of each supporting leg, and assembling the parallel robot to form a closed chain organization; controlling each supporting leg of the six-degree-of-freedom parallel robot to shorten slowly at a constant speed until each optocoupler limit switch is triggered and stimulates the six legs to stop moving successively, and thus the standard pose of the motion platform is generated; measuring the three mark points on the motion platform, ad calculating the standard pose of the parallel robot; and calculating the initial length of the supporting leg corresponding to the standard pose according to the standard pose. With the method, repeated positioning accuracy is high and reliability is high.
Owner:XIDIAN UNIV

Method and apparatus for crowd behavior analysis in video monitoring

The invention is suitable for video monitoring technologies and relates to a method and an apparatus for crowd behavior analysis in video monitoring. The method comprises: obtaining a video stream and dividing each frame of image in the video stream into image sub-blocks with different perspective degrees by taking human height as a size reference by row; extracting deep neural network features in the image sub-blocks; classifying and optimizing the deep neural network features, obtaining a corresponding vector feature set, establishing SVR mathematical models of different kernel functions according to the vector feature set, and making statistics on the number of people in crowds with different density; and adopting a camera calibration method for obtaining coordinate vectors of the deep neural network features, comparing displacements of the deep neural network features of the two continuous frames of image sub-blocks, and calculating a moving direction and a moving speed of the crowd according to the displacement. According to the method and the apparatus, the crowd in the video monitoring is tracked and analyzed to obtain feature information, such as the moving speed, the moving direction, the number of people and the like, of the crowd, the feature information and historical data are analyzed and compared, a state of the crowd is judged, and an alarm is given for an abnormal event.
Owner:CHONGQING INST OF GREEN & INTELLIGENT TECH CHINESE ACADEMY OF SCI

Binocular camera-based living body identification method and apparatus

The invention provides a binocular camera-based living body identification method. The method comprises the steps of collecting human face images corresponding to an object under visible light and infrared light by utilizing a binocular camera; extracting human face key points corresponding to the human face images respectively in the human face images under the visible light and the infrared light; obtaining human face key point coordinate vectors, reflected in the binocular camera, of the target object; performing distance measurement according to the human face key point coordinate vectors, and calculating distances from the human face images to the camera; and under a light source with the same frequency and the same distance, calculating whether the light intensities of the human face key point coordinate vectors are in a preset range or not, judging whether the object providing a human face is a living body or not according to a calculation result. The invention furthermore provides a binocular camera-based living body identification apparatus. Under the condition of obtaining the frequency of the light source, whether the object is the living body or not is judged according to the reflected light intensities of different materials under the same distance, so that other devices do not need to be additionally purchased and the manufacturing cost is reduced.
Owner:四川云从天府人工智能科技有限公司

Target locating method of miniature drone full-strapdown down looking camera

ActiveCN107727079AAvoid mechanical movementImprove the ability to resist overload shockPicture interpretationObservational errorCoordinate vector
The invention discloses a target locating method of a miniature drone full-strapdown down looking camera. The target locating method comprises the step that the camera focal length is calculated through the camera field angle and the width of a camera square pixel array, then the distance length from the pixel position to the origin of coordinates is obtained through the camera focal length and the position of a target on the pixel array, the unit coordinate vector of the target in the camera coordinate system is obtained through the distance length from the pixel position to the origin of coordinates and the position of the target on the pixel array, the relative distance from the target to a drone is obtained through estimation in combination with a Kalman filter algorithm, the relationbetween geographic position information of the target and the relative distance from the target to the drone is obtained through coordinate conversion, and geographic position information of the target is calculated through the distance from the target to the drone, the drone position information amount obtained through measurement of a satellite navigation system and the unit coordinate vector ofthe target in the camera coordinate system. By means of the target locating method, the high locating precision can be obtained, and part of measurement errors can be removed.
Owner:湖北航天飞行器研究所

Self-adaptive finite time convergence sliding-mode control method of robot

The invention relates to a self-adaptive finite time convergence sliding-mode control method of a robot and belongs to the technical field of control. The method comprises steps as follows: establishing a robot kinetic equation considering uncertainty, determining a sliding mode surface, then introducing n-dimensional self-adaptive updating rate, calculating value of active power/moment required for driving the robot finally, and driving a robot system based on the value so as to enable generalized coordinate vectors of the robot to converge to a steady-state or trace command signals in finite time. The method has the characteristics and benefits as follows: firstly, the problem of chattering of the sliding-mode control is solved greatly while high-precision control is realized; secondly, possible influence of different dynamic characteristics in all directions of freedom degrees of the robot system can be eliminated; thirdly, the problem of moment saturation and chattering of the robot system at the starting stage can be solved; fourthly, kinetic compensation guaranteeing real-time performance of the control can be realized. The method is applicable to the robot systems with structure types of parallel connection, series connection, series-parallel connection and the like.
Owner:广东若贝特设备制造有限公司

Expression recognition method and device, electronic equipment and storage medium

The embodiment of the invention provides an expression recognition method and device, electronic equipment and a storage medium. The expression recognition model comprises a convolutional neural network model, a full connection network model and a bilinear network model. The method comprises steps of in the expression recognition process, preprocessing the to-be-identified image to obtain a face image and a key point coordinate vector; carrying out operation on the face image through a convolutional neural network model to output a first feature vector, performing operation on the key point coordinate vector through the full connection network model to output a second feature vector, performing operation on the first feature vector and the second feature vector through the bilinear networkmodel to obtain second-order information, and further obtaining an expression recognition result according to the second-order information. In the process, the prior expression information containedin the face key points is considered, the robustness to postures and illumination is good, and the expression recognition accuracy is improved. Furthermore, when the expression intensity is low, the expression can be correctly identified.
Owner:BAIDU ONLINE NETWORK TECH (BEIJIBG) CO LTD

Calibration method for strapdown inertial navigation installation attitude of photoelectric tracking system

ActiveCN110940354AAvoid the defect that the synchronization accuracy of time is very highAvoid the defect that the synchronization accuracy is very highNavigational calculation instrumentsNavigation by speed/acceleration measurementsTheodoliteCoordinate vector
The invention discloses a calibration method for a strapdown inertial navigation installation attitude of a photoelectric tracking system. The calibration method comprises the following steps: establishing a coordinate system n system, a coordinate system b system, a coordinate system t system and a coordinate system s system; conducting the strapdown inertial navigation initial alignment for multiple times, obtaining the average value, and obtaining a strapdown inertial navigation initial attitude Euler angle; sequentially placing the theodolite with the azimuth reference at each measurementposition, completing alignment, recording an azimuth angle and a pitch angle of the theodolite with the azimuth reference and an azimuth angle and a pitch angle of a photoelectric tracking system, performing north-seeking for multiple times, recording a north-seeking result average value, and calculating a vertical disc index difference; establishing an attitude matrix vector r which is parallel to the visual axis of the photoelectric tracking system, takes a unit vector of which the starting point is the origin of the coordinate system, the coordinate of the vector r being vector r<s> in the s system, calculating the attitude matrix C<s><t>, i of from the t system and the s system, according to the vector r<s> and the C<s><t>, i, calculating the coordinate vector r<t>of thevector r in the t system, calculating the coordinate vector r<n>of the vector r in the n system, calculating the attitude matrix C<n> from the n system to the b system according to the Euler angle, calculating the coordinate vector r of the vector r in the b system according to the vector r<n> and C<n>, establishing a linear equation (as shown in the description) according to the vector r<t> and the vector r, and solving C<t> by combining with the k linear equations. The the method can be used for indoor calibration.
Owner:THE GENERAL DESIGNING INST OF HUBEI SPACE TECH ACAD

Method for displaying movable target trajectory in three-dimensional scene

ActiveCN105427361AWill not cause a jump in proportionImprove efficiencyAnimationCoordinate vectorEuclidean vector
The invention provides a method for displaying a movable target trajectory in a three-dimensional scene. Latitude and longitude data of a trajectory point of a movable target are generated; a frame-interpolation-based discrete data smoothing and spatial coordinate vector transformation method is adopted, such that a curve trajectory, which is continuous and steady in position and flexible in gesture transformation, is formed; a real-time calculation expansion proportion calculation method is adopted, such that the same pixel width is displayed when the distances between the target trajectory and an observer are different; simultaneously, a front and reverse colour value comparison method is adopted; different colour values of front and reverse surfaces are obtained through freedom change, such as heading, pitching and rolling; and thus, the flexible effect of a ribbon-like trajectory is realistically realized. According to the invention, the blanking phenomenon of a three-dimensional curve of the movable target trajectory in different observation distances in the three-dimensional scene can be solved; and the continuous, steady and smooth ribbon-like trajectory display effect of the trajectory point generated by the movable target can be realized.
Owner:THE 28TH RES INST OF CHINA ELECTRONICS TECH GROUP CORP

Method for realizing radioactive particle implantation by using laser guidance

The invention belongs to the technical field of radioactive particle implantation, and discloses a method for realizing radioactive particle implantation by using laser guidance, comprising the following steps: S1, marking a target area on the body surface of a patient; S2, obtaining the image examination data of the patient target area and introducing the image examination data into the processing system to generate a disease body model; 3, introducing the disease body model into a computer three-dimensional treatment plan system for dimension development, determining and adding a source lineof a puncture needle path, arranging radioactive particles on the source line, and derive the radioactive particles in the form of a three-dimensional data packet; S4, introducing the three-dimensional data packet into the orbit equipment and emitting laser rays according to the three-dimensional coordinate vector of the distribution source line; and 5, inserting a particle needle along that laser ray and implant radioactive particles. The invention adopts laser technology to guide, combines the advantages of freehand puncture and template puncture, shortens the preparation period before operating, lowers the cost, and can change the implantation scheme in time according to the change of the tumor in the patient body, and has strong flexibility.
Owner:成都真实维度科技有限公司 +1

Method for predicting stability of vehicles

The invention provides a method for predicting the stability of vehicles, and belongs to the field of automotive technologies, and the method can be used for solving the problem that in the prior art, methods for predicting the stability of vehicles are not high in accuracy and low in reliability. The method comprises the following steps: S10, detecting an acting force Fi exerted on each wheel of a target vehicle by the ground; S20, analyzing and calculating a force-center coordinate vector as shown in the specification of the target vehicle; and S30, substituting the force-center coordinate vector as shown in the specification into a vehicle force-center/stability transfer function which is as shown in the specification and is pre-stored in a vehicle-mounted controller of the target vehicle so as to calculate a stability signal Scar of the target vehicle, and according to the value of the stability signal Scar, judging the current stability state of the target vehicle; a test vehicle and the target vehicle are same in type or similar in technical parameter, the test vehicle is defined as a vehicle for calibrating test data under experimental conditions, and the target vehicle is defined as a vehicle normally running on the road. The judging process in the method is simple and convenient, and the method is accurate in judgment and high in reliability.
Owner:韦志强

High speed positionless operation technology for three-phase electrical excitation double salient pole motor

The invention discloses a high speed positionless operation technology for a three-phase electrical excitation double salient pole motor. Characteristics of a counterelectromotive force change rule are reflected according to end voltages of non-conduction phases of the electrical excitation double salient pole motor. End voltage amplitude values of the motor in high speed operation are firstly identified under three control strategies of constant conduction of a switch tube of a three-phase inverter, PWM wave chopping of an upper tube of the switch tube and PWM wave chopping of a lower tube of the switch tube, the end voltages after sampling filtering are conditioned to 0-3V, coordinate vector transformation is carried out on a basis that a fixed rotation angle alpha does not change along with a rotation speed and the control strategies, and commutation logic is determined by capturing a zero crossing point of the end voltages after the coordinate vector transformation. The high speed positionless operation technology solves problems that a tradition positionless sensor counterelectromotive force method has relatively great phase time-delay, difficult commutation and commutation error caused by direct current bias under different control strategies. The control method provided by the invention is simple and reliable.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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