516 results about "Point tracking" patented technology

The present invention provides an efficiency booster circuit and accompanying switch mode power conversion technique to efficiently capture the power generated from a solar cell array that would normally have been lost, for example, under reduced incident solar radiation. In an embodiment of the invention, the efficiency booster circuit generates an output current from the solar cell power source using a switch mode power converter. A control loop is closed around the input voltage to the converter circuit and not around the output voltage. The output voltage is allowed to float, being clamped by the loading conditions. If the outputs from multiple units are tied together, the currents will sum. If the output(s) are connected to a battery, the battery's potential will clamp the voltage during charge. This technique allows all solar cells in an array that are producing power and connected in parallel to work at their peak efficiency.

Disclosed are a method and apparatus for feature-based stereo matching. A method for stereo matching of a reference image and at least one comparative image captured by at least two cameras from different points of view using a computer device includes collecting the reference image and the at least one comparative image, extracting feature points from the reference image, tracking points corresponding to the feature points in the at least one comparative image using an optical flow technique, and generating a depth map according to correspondence-point tracking results.

The invention relates to the technical field of four-rotor aircrafts, in particular to a small four-rotor aircraft control system and method based on an airborne sensor. The small four-rotor aircraft control system based on the airborne sensor comprises an inertia measurement unit module, a microprocessor, an electronic speed controller, an ultrasonic sensor, an optical flow sensor, a camera, a wireless module and a DC brushless motor. By merging the information of a light and low-cost airborne sensor system, the six-DOF flight attitude of the aircraft is estimated in real time, and a closed-loop control strategy comprising inner-loop attitude control and outer-ring position control is designed. Under the environment without a GPS or an indoor positioning system, flight path control and aircraft formation control based on the leader followed strategy over the rotorcraft are achieved through the airborne sensor system and the microprocessor, wherein the flight path control comprises autonomous vertical take-off and landing, indoor accurate positioning, autonomous hovering and autonomous flight path point tracking. According to the small four-rotor aircraft control system and method, a reliable, accurate and low-cost control strategy is provided for achieving autonomous flight of the rotorcraft.

A position measurement device is provided that can precisely measure the photographing position or posture of a photographing device or the coordinates of an object based on sequentially changing photographed images. A position measuring device 100 of the invention comprises: an image acquisition section 2 for acquiring a series of photographed images changing continuously or little by little along with position displacement relative to an object to be photographed; a positional relationship measurement section 9 for measuring position displacement and posture change of the image acquisition section 2; a feature extraction section 3 for extracting feature points from the photographed images obtained with the image acquisition section 2; a feature point tracking section 4 for tracking the feature points by searching corresponding points corresponding to the feature points on a plurality of the photographed images; an image selection section 61 for selecting an image to be processed from the series of photographed images based on a measurement result made with the positional relationship measurement section 9; and a position measurement section 7 for measuring the photographing position and the photographing posture of the image acquisition section 2 based on the image to be processed selected with the image selection section 61.

The invention discloses a monocular and IMU fused stable motion tracking method and device based on a mobile terminal, belonging to the technical field of AR/VR motion tracking. The method comprises the following steps of: judging whether the number of tracking feature points of a current frame of an image is greater than a pre-set threshold value or not, if so, performing feature point tracking by adopting an optical flow method so as to obtain the current pose of a camera, if not, obtaining feature points by adopting a FAST feature detection operator, and performing feature matching of the image by adopting a BRIEF algorithm calculation descriptor so as to obtain the current pose of the camera; performing Kalman filtering of the current pose of the camera so as to obtain a visual pose; obtaining acceleration and angular speed values generated by an IMU in a three-dimensional space, and performing integral operation of the acceleration and angular speed values so as to obtain the pose of the IMU; and performing Kalman fusion of the visual pose and the pose of the IMU, and performing motion tracking. Compared with the prior art, more stable and rapid motion tracking can be obtained on mobile terminal equipment.

Switched capacitor multilevel output DC-DC converters can be used as panel integrated modules in a solar maximum power point tracking system. The system can also include a central input current-controlled ripple port inverter. The system can implement per panel MPPT without inter-panel communication, electrolytic capacitors or per panel magnetics. A Marx converter implementation of the switched capacitor module is studied. Average total efficiencies (tracking×conversion) greater than 93% can be achieved for a simulated 510 W, 3 panel, DC-DC system.

The invention relates to an automatic generating method for a multi-lane vehicle track space-time diagram. The method comprises the steps that firstly, a camera is utilized for obtaining internal parameters and external parameters of the camera through off-line calibration, an area of interest is set according to the actual monitoring requirement, and three virtual detecting belts are set at the upstream initial position of the traffic flow; secondly, the vehicle feature points are extracted based on the three virtual detecting belts, the feature point tracking and grouping correction are carried out according to vehicle grouping, the vehicle tracks are extracted in a high-precision mode, a longitudinal space-time track diagram of passing vehicles is automatically generated for each lane, and a transverse space-time track diagram comprising all lanes is generated; finally, whether it is in the lane line correction stage or not is automatically judged, wherein if yes, the lane line position is automatically corrected based on the track clustering method. Compared with the prior art, the method improves the robustness of the target luminance change, improves the precision of vehicle detecting and track tracing, is capable of well automatically correcting the lane line on line and avoids misjudgment on the lane number to which the vehicle track point belongs.

The invention discloses a method for extracting an image region of interest based on eye movement data and bottom-layer features. On one hand, the image region of interest, namely, eye movement ROI (Region Of Interest), for reflecting human real semanteme is extracted by visual point tracking experimental data of an eye movement instrument, and on the other hand, the image region of interest, namely, feature ROI, in a general sense is extracted in a form of bottom-layer feature weighted combination, and weight combination with highest similarity, namely, optimal weight, is found out by similarity analysis of the feature ROI and the eye movement ROI. The region of interest of other image of the same type, extracted by using the weight, can more comply with the semantic demands of users.

A process and a system that determine a glint position and a pupil position are disclosed. The process includes illuminating one eye to produce a glint on that eye, and obtaining a glint image of that eye showing that glint on that eye. A glint position is determined at least in part from that glint image. The process further includes illuminating that eye using polarized light, and obtaining, through a polarizer that can attenuate reflected polarized light, a pupil image of that eye. A pupil position is determined at least in part from that pupil image.

The invention discloses a variable power point tracking control method of a two-stage type no-energy-storage photovoltaic virtual synchronization machine, and belongs to the technical field of new energy power systems and micro-grids. The variable power point tracking control method comprises the steps of changing an original single augmented variable mode into a mode of judging whether an SUdc(k) represented DC bus voltage value is steady based on a DC bus voltage through improving the conventional perturbation observation MPPT (Maximum Power Point Tracking) method for DC/DC circuit control in a two-stage type photovoltaic system; and giving full play of a regulation effect of a DC/DC converter on the output power of a photovoltaic battery. Inertia support for the virtual synchronization machine and energy supply needed by one regulation are realized under the precondition of not adding any energy storage device; and control of the photovoltaic virtual synchronization machine is realized by combining a VSG control strategy of an inverter. When a load changes suddenly or the external environment condition changes, the photovoltaic system can reflect the characteristics of the synchronization machine, can keep steady system voltage/frequency and power balance, and can realize variable power point tracking relevant to the DC bus voltage.

The method sets a plurality of key monitoring positions in place to be monitored, when no abnormal target occurs in the key monitoring monitor positions, the monitoring system controls the rotation of a horizontal stage to make the cam scanning in turn each position in the place to be monitored; when a testing apparatus in the monitoring system detects an abnormity occurs in one position of the plurality of key monitoring positions, the monitoring system controls the horizontal stage to make the cam performing camera shooting scanning to the key position where abnormity occurs. The monitoring system includes a horizontal stage, a video camera, a testing apparatus and a main control circuit, wherein the main control circuit includes a horizontal stage control circuit a camera control circuit and a single chip; the testing apparatus transmits the testing result to the single-chip in the main control circuit, and then the single-chip controls the horizontal stage and the video camera. The invention has advantages of simple structure, high degree of automation, strong practicability and high efficiency.

A client can store information about federation points. A federation point is a combination of an identifier of an account on a relying party and an identifier of an information card. The client can track which information cards are included n various federation points, and can use this information to assist the user in performing a transaction with relying parties.

A client can store information about federation points. A federation point is a combination of an identifier of an account on a relying party and an identifier of an information card. The client can track which information cards are included n various federation points, and can use this information to assist the user in performing a transaction with relying parties.

A head motion tracking method for three-dimensional facial model animation, the head motion tracking method includes acquiring initial facial motion to be fit to an image of a three-dimensional model from an image inputted by a video camera; creating a silhouette of the three-dimensional model and projecting the silhouette; matching the silhouette created from the three-dimensional model with a silhouette acquired by a statistical feature point tracking scheme; and obtaining a motion parameter for the image of the three-dimensional model through motion correction using a texture to perform three-dimensional head motion tracking. In accordance with the present invention, natural three-dimensional facial model animation based on a real image acquired with a video camera can be performed automatically, thereby reducing time and cost.

An image processing apparatus, a feature point tracking method and a feature point tracking program, which enable efficient feature point tracking by taking the easiness of convergence of a displacement amount according to the image pattern into account in a hierarchical gradient method, are provided. A displacement calculating unit reads a hierarchical tier image with the smallest image size from each of a reference pyramid py1 and a tracking pyramid py2 in an image memory, and performs repetitive detection of a tracking point using a gradient method. Then, the displacement calculating unit repeatedly calculates the displacement amount (dx_i, dy_i) between the feature points obtained as a result of the repetitive detection, and outputs the value of the repetition count inum_last of tracking point detection until convergence of the displacement amount (dx_i, dy_i) and the value of the displacement amount (dx_last, dy_last) for the point of time of convergence to a repetition criterion setting unit. The repetition criterion setting unit changes the criterion for determination of displacement amount convergence based on the repetition count inum_last and displacement amount (dx_last, dy_last) input from the displacement calculating unit. The displacement calculating unit reads upper hierarchical tier images and detects a tracking point according to the convergence determination criterion set by the repetition criterion setting unit. Then, the above-described repetitive tracking point detection and convergence determination criterion setting change are repeated. Consequently, the repetition count of repetitive tracking point detection is suppressed.

The invention discloses a multipurpose solar energy power generating system. Solar energy battery board assemblies are mutually connected in series or in parallel to form a photovoltaic array; the multipurpose solar energy power generating system is connected to a power grid by a grid-connected inverter module; the grid-connected inverter module comprises a grid-connected inverter unit, a maximumpower point tracking control unit and a power grid state detecting unit, wherein the power grid state detecting unit can detect power grid operation state in real time and cuts off the connection of the grid-connected inverter module and the power grid when the power grid operation state is abnormal so as to prevent islanding; the grid-connected inverter module is also connected with an intelligent charger in parallel on the connection end with the power grid and is connected to a storage battery by the intelligent charger so as to charge the storage battery; the intelligent charger is also connected with an off-grid inverter in parallel on the connection end with the storage battery; and the off-grid inverter is used for supplying electricity for AC load. The solar energy power generatingsystem can be suitable for grid-connected power generation of various normal and abnormal situations on the power grid and has strong system robustness and fault tolerance.

A vehicle periphery monitoring apparatus is comprised of a camera installed in the front or rear of a vehicle, for picking up images of side view of the vehicle; a feature point detecting section that detects feature points in the side images and calculates the motion vectors of the detected feature points; a moving object detecting section that detects a set of a plurality of feature points approaching the vehicle in the side images as an approaching object based on the calculated motion vectors of the feature points; a feature point tracking section that tracks the feature points of the detected approaching object; and a passage time calculating section that calculates the time at which the approaching object passes the front or rear of the vehicle from the feature points of the approaching object tracked by the feature point tracking section.

The invention provides a method for tracking a ground station through a low earth orbit space-borne antenna. The method comprises the following steps: 1) calculating UTC at the next pointing moment of the antenna; 2) calculating the number of transient satellite orbit at the next pointing moment of the antenna; 3) calculating the position of the satellite under a J2000 inertial coordinate system; 4) calculating the position of the ground station under the J2000 inertial coordinate system at the next pointing moment of the antenna; 5) calculating the opposite position vectors of the satellite and the ground station under the J2000 inertial coordinate system; 6) calculating the vector of the opposite position vectors of the satellite and the ground station under geo-center camber line; 7) calculating the vector of the opposite position vectors of the satellite and the ground station under the satellite orbit coordinate system; 8) calculating the vector of the opposite position vectors of the satellite and the ground station under a satellite body system; 9) calculating the vector of the opposite position vectors of the satellite and the ground station under an antenna coordinate system; 10) obtaining an antenna pointing angle, and driving the antenna to perform pointing tracking for the ground station.

The invention discloses a facial image acquiring method and device. The method comprises the steps of acquiring the feature point of a frame where a facial image in video data is located, carrying out weighted summation on the acquired feature point of the frame where the current facial image is located and the feature point of a frame where a former facial image is located according to the correlation coefficient of the frame where the current facial image in the video data is located and the frame where the former facial image is located to obtain a weighted feature point, and simulating facial expression and action according to the weighted feature point to obtain the facial image of the frame where the current facial image is located. According to the technical scheme, the technical problems existing in correlation techniques such as inaccurate feature point positioning are solved, therefore, a quite stable feature point tracking result can be obtained, and influence of feature point positioning deviation on the facial image is reduced.

The invention provides a face key point tracking system and method applied to a mobile device. The system is composed of an initial face frame detection module, a face key point regression model learning module, a face key point regression calculation module, a working mode determination module and a face key point post-processing module. The face key point regression calculation module includes a detection mode and a tracking mode; an initial face frame is used as an input to carry out regression calculation of a face key point model in the detection mode; and regression calculation of a current frame key point model is carried out by using a last-frame face key point model in the tracking mode. According to the system and method provided by the invention, on the basis of the face key point positioning technology having the detection mode and the tracking mode, initial face frame detection is only carried out at a first frame, the tracking mode is employed during a follow-up positioning process, and the key point positioning of the last frame is used as the input of the current frame. Therefore, the face detection module does not need to be invoked again during the tracking process, so that the calculation time is saved and the system efficiency is improved.

A maximum power point tracking method, applied to a tracking device, employs a DC/DC converter connecting with a solar cell array, and including a controller actuating the DC/DC converter to perform an active resistance characteristic; a maximum power point tracking circuit adjusting the active resistance of the DC/DC converter; monitoring a change of an output power of the solar cell array in determining a direction for adjusting the active resistance of the DC/DC converter; and the maximum power point tracking circuit repeatedly adjusting the active resistance of the DC/DC converter. If the change of the output power of the solar cell array is positive, the active resistance of the DC/DC converter is adjusted in the same direction; but, conversely, if the change of the output power of the solar cell array is negative, the active resistance of the DC/DC converter is adjusted in an opposite direction.

The invention relates to a precise path tracking control method for an autonomous underwater vehicle, and the method is used for linear path tracking control. The method is a path point tracking control method which is more precise. The method enables AUV to precisely move along a linear path between two path points through lateral tracking control, prevents an actual path from deviating from an expected line because of the initial position deviation of the AUV, and is more suitable for the fields with the higher requirements for the path tracking precision, such as the seabed exploration and butt joint recovery.

A system and method for supporting augmented reality in an ocean scene is provided. According to the system and method, camera rotation information is extracted from horizontal line information of a sea extracted from an original image including a focal length and at least two first natural feature point tracking data existing on a sea plane and a plane parallel to the sea plane, using long-distance background features; camera movement is sequentially calculated from the camera rotation information and at least two natural feature point tracking data existing on the sea plane of the original image; and a computer graphics object is placed on a ground plane by importing camera position data, and a rendering is performed as moving the camera. Accordingly, the camera rotation and the camera movement can be accurately calculated, assuming that the camera focal length information is known at the time of capturing a moving image with a sea image for a background, and thus the CG/real scene synthesis with the sea for a background can be accomplished more realistically and accurately during the production of videos such as movie and drama.