85 results about "Passive tracking" patented technology

A solar tracking system and methods based on passive tracking of solar illumination impinging on solar panels. The system includes a solar panel having cardinal points of the panel provided with piston assemblies. Actuating of pistons in the piston assemblies orients the solar panel to maximize solar illumination impinging on the solar panel. A conduit facilitates flow of a fluid between a solar illumination sensor and piston assembly based on changes in temperature of a canister and fluid contained within the canister. The heating of the fluid causes the fluid to flow toward and activate the piston assembly to rotate the solar panel about a longitudinal axis or lateral axis, which passively orients the solar panel in a position to maximize solar illumination impinging on a front face of the solar panel.

A passive tracking system is provided with a plurality of ultrawideband (UWB) receivers that is asynchronous with respect to a UWB transmitter. A geometry of the tracking system may utilize a plurality of clusters with each cluster comprising a plurality of antennas. Time Difference of Arrival (TDOA) may be determined for the antennas in each cluster and utilized to determine Angle of Arrival (AOA) based on a far field assumption regarding the geometry. Parallel software communication sockets may be established with each of the plurality of UWB receivers. Transfer of waveform data may be processed by alternately receiving packets of waveform data from each UWB receiver. Cross Correlation Peak Detection (CCPD) is utilized to estimate TDOA information to reduce errors in a noisy, multipath environment.

The invention relates to a multi-target passive tracking method based on a wireless sensor network. The technical characteristics are that the multi-target passive tracking method based on the wireless sensor network comprises the following steps that: (1) a measurement model is established according to the receiving signal intensity of the sensor network; (2) according to the established measurement model from the step (1), the variable multi-target positioning and tracking is realized under the indoor environment through the combination of a multi-target Bernoulli filter algorithm and a particle filter algorithm. The multi-target passive tracking method based on the wireless sensor network provided by the invention is reasonable in design; the established measurement model has high accuracy under the indoor environment, and the model forecast value is approximate to the actual observation value; the target detecting and tracking algorithm has high accuracy and stability, and can detect and track a plurality of targets; and the measurement model and the target algorithm are appropriate in calculation complexity, and thus guaranteeing the running real-time performance of the tracking system.

In one embodiment, the disclosure relates to a method for estimating and predicting a target emitter's kinematics, the method including the steps of: (a) passively sampling, at a first sampling rate, an emitter signal to obtain at least one passively measured signal attribute for estimating the target kinematics; (b) inputting the passively measured signal attribute to an estimator at a first sampling rate; (c) determining a radar duty cycle for active radar measurements as a multiple of the first sampling rate, the multiple defining a duration between radar transmissions; (d) directing a radar system to make active target measurements at the determined duty cycle; (e) inputting to the estimator the active target measurements at the determined duty cycle, while continuously inputting the passively measured signal attributes.

System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes an antenna array with three antenna elements, which preferably are patch antenna elements spaced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.

An interface apparatus (20) for tracking by a tracking system (40) of an object(s) in space for position and orientation and for interacting with the tracking system (40). The interface apparatus (20) comprises passive detectable devices (12,14,16,22) trackable for position by the tracking system (40). A mounting device (10,24) receives the passive detectable devices (12,14,16,22) in a known geometry, and is secured to the object(s) such that a position and orientation of the object(s) is calculable by the tracking system (40) as a function of a tracking of the known geometry of the passive detectable devices (12,14,16,22). One of the passive detectable devices (22) is displaceable with respect to the object(s). A displacement of the passive detectable device (22) with respect to the object(s) is detectable to initiate an interaction with the tracking system (40) while maintaining the tracking of the object(s).

The invention discloses a measurement storage-based track initiation method. The method is applied to target tracking of narrow-transmitting multi-receiving track-while-scan radar system and a passive tracking system in actual scenes. According to existing tracking algorithms, most algorithms assume that targets can be observed continuously and the measurement information of different targets are synchronous. According to the method of the invention, a condition that time intervals when a target is observed by a track-while-scan radar system is inconstant is considered; and historical measurement information is fully utilized, higher track initiation speed and successful tracking probability can be realized. With the measurement storage-based track initiation method of the invention adopted, track initiation problems of a centralized tracking system and a passive tracking system in multi-sensor asynchronous communication can be solved. The method has the advantages of full utilization historical information, simplicity in implementation and higher successful track probability, and can assist in effectively solving track initiation problems under a condition that the measurement information of different targets is asynchronous.

The invention provides an indoor target passive tracking method based on WiFi Doppler frequency shift. The method comprises steps of first, calculating a discrete coefficient by using channel state information (CSI) amplitude of a WiFi signal subcarrier, then using the discrete coefficient as a detection parameter, and realizing detection of a passive target by using hypothesis testing; then performing Fourier transformation on the CSI for a short time, so as to obtain a spatial spectrum of a signal, extracting a Doppler frequency shift value and a corresponding power value, and using a time sequence corresponding to the power value as a target moving direction marker discriminant feature; then designing a reference sequence according to a logarithmic decay model, performing sequence matching by using dynamic time warping (DTW), and identifying a moving trend of the passive target; and finally, estimating a moving speed of the passive target according to a geometric relationship between the Doppler frequency shift and target moving, so as to realize target tracking. Compared with the existing passive tracking technology, the method omits offline data collection and training, and has advantages of low cost and easy deployment.

The invention provides a technical scheme of simultaneously and precisely tracking a plurality of space objects only based on carrier observation data of ground monitoring equipment driven by an atomic frequency standard for fulfilling the purposes of high-precision orbit determination of regional navigation satellites and precise passive tracking of non-cooperative space objects. The invention designs a parameter evaluation estimation scheme of precise orbit determination only based on carrier phase data and provides a novel carrier phase cycle slip detection and repair method. The method makes full use of priori orbit and prior atomic clock speed information and is suitable for static users. The method is applied to orbit determination processing of an MEO (Medium Earth Orbit) satellite of a COMPASS system and is only based on carrier phase data of 6 regional ground stations, the mean residual of arc length orbit determination results of three days is 0.18m, and the mutual differences of one-day-arc overlap orbit are 0. 61m and 8. 09m in radial direction and three-dimensional position respectively; the mean residual of laser comparison is 0.28m; the mean residual of forecast for 24 hours and laser alignment is 1.34m. Compared with that of the prior art, the orbit determination precision is improved by 1 order.

Technologies are generally described for a broadband passive sensing and tracking system that may employ a number of passive receivers that each have the capability of sensing electromagnetic waves (e.g., Radio Frequency "RF" signals) from surrounding broadcast sources. Each passive receiver may be adapted to sense through one or more antennas. Multiple receivers at different positions may be utilized to form a broadband sensing network adapted to perform collaborative tracking of a scene of interest. According to some examples, a beam-forming algorithm may be applied over the broadband sensing network utilizing an antenna array formed by the passive receivers to localize and track objects.

The present invention involves a tracking antenna system with no moving parts that extends the range of wireless mobile links 16 to 256 times the range of regular omni-directional whip antennas. The antenna system comprises an array of antenna segments arranged in a sphere or circle, or other suitable geometry. Each antenna segment includes one or more antennas connected and combined in parallel. Each antenna segment feeds a tuner and subsequent diversity electronics that optimizes both the transmission and reception in order to achieve the best possible range. The antenna system can be used from unmanned air, ground, and surface vehicles to mobile ground stations in motion, as well as between flying planes, moving vehicles, sailing boats, or any combination thereof. The system may be expanded further to many more levels of architecture as required. For example, this system may be expanded to a Level 2 diversity engine combination of any number and type of Level 1 antenna array units depending upon the diversity expansion required and the criteria for Level 2.

The invention provides an indoor target passive tracking method based on WiFi multi-dimensional parameter characteristics. The method comprises the following steps: firstly, eliminating a phase errorand a static path signal component contained in original channel state information (CSI) by adopting a conjugate multiplication method so as to obtain a dynamic path signal component; then, using a serial interference elimination method for carrying out signal arrival angle, flight time and Doppler frequency shift multi-dimensional parameter initialization, and then using a frequency domain spacealternating generalized expectation maximization algorithm based on noise updating for completing time-frequency-space multi-dimensional parameter joint estimation; secondly, selecting a target path signal from the plurality of path signals by using a mixed data association method based on a minimum-cost multi-path network; and finally, constructing an ellipse-straight line joint model by utilizing the target path signal parameters to realize target positioning and tracking. Compared with an existing passive tracking technology, the method is based on existing commercial WiFi equipment, extracustomized hardware is not needed, high-precision parameter estimation is achieved, and then target tracking is achieved.

System for the tracking of devices, measurement and tracking of objects and people and of their behaviour related to their movements over time, taking measurement both in real time and in deferred, and including means to measure the strength and/or orientation of the signal received/emitted from nearby devices by means of receiver beacons (r-beacons) (1), means to connect sensors to the beacons (r-beacons) in order to measure external parameters (2), means to interconnect the different adjacent receiver beacons in order to create a mesh network (3), means to send data to the mesh network (4) means for receiving packages of information and sending them to Internet (5), electronic processing means for storing in a database and measurements obtained by the connected sensors (6) and electronic processing means in order to group diverse measurements obtained from the beacons (7).

The invention discloses an underwater multi-sensor cooperative passive tracking method based on a dynamic cluster. According to the method, a distribution type fusion estimation process with feedbackis introduced into a target tracking process, and a linear minimum variance fusion criterion weighted by a scalar quantity is used for minimizing a trace of fusion error covariance by utilizing components, and the optimal fusion state estimation is achieved. A dynamic clustering process selected based on adaptive nodes is used for dynamically selecting cluster head nodes and cluster member nodes which are involved in the passive target tracking process, wherein the selection of the cluster head nodes is mainly started from the view of energy; and the selection of the cluster member nodes is that an objective function is constructed by using utility functions and cost functions, the node selection problem is classified as a knapsack problem in mathematics, and finally a dynamic programmingmethod is used for selecting an optimal node combination to achieve the maximization of the objective function. By adopting the method, the convergence of the accuracy of the passive target tracking can be guaranteed and the energy consumption of the network in the passive tracking process can be effectively reduced.

The invention relates to the technical field of photovoltaic power generation, in particular to a sun tracking device for photovoltaic power generation. The sun tracking device is characterized in that a pile and a sleeve type structure combination is adopted, a winch drives a steel wire rope to pull a plurality of unpowered passive tracking supports to rotate to track change of solar azimuth; an dip angle adjusting mechanism can be arranged to enable a photovoltaic module board to rotate around a horizontal axis to track changes of solar elevation angle; a mirror reflecting board is arranged on the lower border of the photovoltaic module board to enhance light harvesting energy of the photovoltaic module board. The turn-off feature of the steel wire rope is utilized, and plane arrangement and elevation arrangement of the tracking supports are high in flexibility and quite adaptable to block foundations with irregular planes and land conditions with uneven sites; various deformation of the steel wire rope is consumed and compensated by the aid of a gravity tensioning balancer, and stable operation of a transmission system is sustained; the sun tracking device is high in cost performance, suitable for largescalization design of the supports and high in capability of fitting for complicated project conditions.

The application relates to a surgical robot system. The surgical robot system may include a robot having a robot base, a robot arm coupled to the robot base, and an end-effector coupled to the robot arm. The end-effector, surgical instruments, the patient, and/or other objects to be tracked include active and/or passive tracking markers. Cameras, such as stereophotogrammetric infrared cameras, areable to detect the tracking markers, and the robot determines a 3-dimensional position of the object from the tracking markers.

The invention provides a suspended zero-gravity simulated test bed comprising an active tracking subsystem, a plurality of passive tracking subsystems and a plurality of suspension systems, wherein the active tracking subsystem comprises a first guide rail and a plurality of active moving platforms moving along the first guide rail; the plurality of passive tracking subsystems are respectively fixedly arranged on the plurality of active moving platforms; each passive tracking subsystem comprises a second guide rail and a passive moving platform; and the plurality of suspension systems are respectively fixedly arranged on the plurality of passive moving platforms. The suspended zero-gravity simulated test bed has the beneficial effect that the zero-gravity simulated test bed provided by the invention adopts an active and passive mixed tracking mode, has a power-off protection function and can be used for a zero-gravity simulated test of a complex movement mechanism needing multi-point suspension. The invention also provides a using method of the suspended zero-gravity simulated test bed.

The invention provides a smart camera network system and dynamic task allocation method. The smart camera network system comprises a smart camera network which monitors intersection information, a management center which stores the operating state and analysis results of the smart camera network, and a remote configuration system which configures the node parameters and operating states of the smart camera network. When detecting a required target for the first time, a camera node establishes an active tracking task, and transmits a tracking task message in a multicast form; when receiving the tracking task message, a camera node establishes a passive tracking task; and when the tracked target enters the visual threshold range of a next camera node from the visual threshold range of a last camera node, the last camera node terminates the active tracking task, and the next camera node converts the passive tracking task of the tracked target into an active tracking task. With the smart camera network system and dynamic task allocation method of the invention adopted, multicast communication can be realized, and the problem of high cost of broadcast communication can be solved. The smart camera network system and dynamic task allocation method have the advantages of high tracking quality and excellent expansibility.

The invention relates to a surgical robot system that may include a robot having a robot base, a robot arm coupled to the robot base, and an end-effector coupled to the robot arm. The end-effector, surgical instruments, the patient, and/or other objects to be tracked include active and/or passive tracking markers. Cameras, such as stereophotogrammetric infrared cameras, are able to detect the tracking markers, and the robot determines a 3-dimensional position of the object from the tracking markers.

The invention relates to a satellite passive orbit measurement method and system, and relates to satellite technology. The satellite passive orbit measurement method of the present invention is to passively receive the radio signal broadcast by the satellite through the ground station, so as to realize the position measurement and orbit measurement of space objects such as satellites. The specific method is to set up 2 to 4 antennas in each measurement station, and use carrier signal waveform correlation to obtain the range difference D between the two antennas when receiving satellite signals. The rendezvous measurement model obtains the position and orbit of the satellite in space. While completing the above-mentioned rough orbit determination, 10-100 satellite position accuracy monitoring reference stations shall be established within the coverage area of ​​satellite signals. The vector correction number of the satellite position is obtained, so as to achieve the second high-precision orbit determination of the satellite.

The invention provides an intelligent sun tracking method. The latitude, the sun declination and the hour angle of the geographical position of a local place are obtained according to a GPS satellite data obtaining module, a sun elevation angle and a sun azimuth are calculated through an equation, and a motor is driven to enable a solar panel to track the sun so as to realize active tracking; and then illumination intensities in different directions are obtained according to illumination sensors, the illumination intensities are compared and analyzed, the motor is further driven for fine adjustment so as to realize passive tracking, the solar panel is enabled to track the sun more accurately and maintains vertical to sunshine in real time, and the problem of low sun tracking precision in the prior art is solved.