48 results about "Relative velocity" patented technology

The invention discloses a redundant biaxial rotation inertial navigation state monitoring method based on an error correction model, which is particularly suitable for a platform equipped with multiple sets of inertial navigation systems with indexing mechanisms. By correcting a speed error equation, the influence of a specific force item is eliminated, and the problem of inaccurate calculation of a speed error model in a dynamic environment is solved. Meanwhile, a combined state Kalman filter under a speed error correction model combining navigation information of the two inertial navigation systems is constructed, and the relative attitude, the relative speed and the relative position between the two systems are used as observation values. A residual error normalization strong tracking filtering technology is adopted, and gyroscopic drift and accelerometer zero offset of the two sets of systems are estimated and monitored on line. And designing a monitoring algorithm based on error parameters of online estimation, and evaluating the state of the inertial device. In the whole process, external reference information is not needed, and inertial device state monitoring can be realized only by depending on navigation data of the two inertial navigation systems.

The invention discloses an optical satellite drift angle accurate calculation and attitude correction method and system, and relates to the technical field of satellite attitude control, and the method comprises the steps: calculating a prime unitary circle curvature radius according to a WGS84 ellipsoid parameter, and converting the geodetic coordinate of a ground target point into an ECEF rectangular coordinate; calculating Julian days based on UTC time, determining an age difference angle and a nutation angle, and converting an ECEF coordinate into a J2000 coordinate; calculating the projection of the earth rotation angular velocity in a J2000 coordinate system, and determining a relative velocity vector; determining an orthogonalized body coordinate system in combination with a unit vector from the target satellite to the ground target point; and projecting the relative velocity vector to a body coordinate system, calculating a drift angle and a double-rotation-sequence Euler angle, and correcting a real-time execution attitude by rotating a matrix around a Z axis. According to the method, high-precision image motion compensation can be realized, the imaging quality of a high-resolution optical satellite in a complex task scene is improved, and a technical foundation is laid for wide application of sub-meter remote sensing images.

The invention provides a multi-agent collaborative surrounding tracking method and system for a dynamic target. The method comprises the steps that S1, the number of surrounding agents, the expected surrounding radius, the expected angular spacing, the expected relative surrounding speed and the communication topology between the agents are determined according to the surrounding requirement; s2, designing a distributed fixed time observer based on a communication topological relation to realize estimation of a target state; s3, acquiring an azimuth angle between the surrounding agent and the target, and constructing a radial unit vector, a tangent vector and an angular spacing coordination error pointing to the target; constructing an estimated azimuth angle change rate, an estimated relative speed, an estimated relative distance and an estimated relative speed tangential component; constructing a radial acceleration control item, a tangential acceleration control item and a dynamic target tracking item; and S4, according to the current linear velocity and course angle of the intelligent agent, calculating linear acceleration and angular velocity in a feedback linearization mode, and realizing multi-layer adjustable angular spacing circular surrounding tracking of the multi-intelligent-agent dynamic target.

This invention provides a method and system for high-fidelity physical modeling and detection performance evaluation of space targets, relating to the field of deep space exploration technology. The method first acquires the relative motion parameters of the spacecraft and the asteroid, as well as camera parameters, and determines the static apparent magnitude based on observation geometry and the asteroid's physical characteristics. Then, it calculates the angular velocity modulus through relative velocity, combines it with camera parameters to obtain tail parameters, and quantifies the equivalent magnitude loss and effective apparent magnitude based on a piecewise model. Subsequently, it constructs a two-dimensional parameter grid of focal length and exposure time, calculates the effective signal-to-noise ratio and detection margin for each combination, and selects the optimal parameters using a heatmap. Finally, it generates a high-fidelity simulation image and feeds back the observation values ​​to the guidance, navigation, and control system via a UDP asynchronous interface. This invention achieves quantitative assessment of tail loss and automated parameter optimization, balancing high fidelity and real-time performance, and improving detection accuracy and system reliability.

A system including an internal sensor configured to generate first sensor data, an external perception sensor configured to generate second sensor data, at least one memory configured to store computer executable instructions, and at least one processor is disclosed. The at least one processor is coupled to the internal sensor, the external perception sensor, and the at least one memory. The at least one processor is configured to execute the computer executable instructions to: (i) compute a first velocity output based upon the first sensor data; (ii) compute a second velocity output based upon the second sensor data; (iii) compute a relative velocity between the first velocity output and the second velocity output; (iv) determine the relative velocity is outside a predetermined threshold value; and (v) perform an intervening action in response to the determining.

According to the multi-aircraft high-precision relative navigation method based on multi-source information fusion, all aircrafts are equipped with inertial navigation and relative positioning equipment, and an inertial navigation system provides position, speed, acceleration, attitude and angular velocity information for the aircrafts carrying systems; according to the instruction, measuring a relative position coordinate between the aircraft A carrying the equipment and any aircraft B in other N aircrafts, and comprising the following steps: A1, determining a relative coordinate system and a relative speed provided by an inertial navigation system between the aircrafts; a2, determining a relative coordinate system provided by relative positioning equipment between aircrafts; measuring the three-axis relative coordinates of the aircraft B relative to the aircraft A under the local geographic coordinates as xrl12, yrl12 and zrl12 by the inter-missile relative positioning equipment of the aircraft A; a3, navigation data fusion based on adaptive filtering; and A4, calculating an adaptive filtering coefficient based on the error.

The invention relates to the technical field of vehicle-mounted radar signal processing, in particular to a millimeter-wave radar point cloud speed decoupling method suitable for a steering scene, and the method comprises the steps: firstly obtaining point cloud data with a radial distance, a radial relative speed and a horizontal / pitching angle in a vehicle steering scene, estimating the straight speed of a vehicle through employing a formula, estimating the vcar, and carrying out the calculation of the vcar after the vcar is estimated, the influence of the point cloud on the vehicle speed is filtered out, the abnormal speed at the position of the large horizontal observation angle caused by the filtered straight speed and residual steering speed of the vehicle is obtained, at the moment, the point cloud shows a linear relation on a sine value-relative speed relation graph, the linear speed value caused by steering of the vehicle is filtered out through a linear regression or RANSAC method, and the obtained slope k contains the angular speed; finally, the obtained road edge is a static point of which the speed is 0, the vehicle has the speed, and the point cloud becomes input data of a subsequent automatic driving perception algorithm module. Therefore, the problem of inaccurate point cloud absolute speed estimation during steering is solved.

The embodiment of the invention provides a space target maneuvering detection method and system based on an information energy momentum tensor, and relates to the technical field of spaceflight detection. Comprising the steps of obtaining orbital elements of an observation satellite and a space target; according to the number of the orbits, the number of the wide-area invariant opposite orbits is obtained; obtaining a space target relative position after dimension normalization under an observation satellite LVLH coordinate system according to the wide-area invariant relative orbital element; according to the relative position and the number of the relative orbits, the relative motion acting amount and the relative speed are obtained; carrying out filtering processing on the relative motion state of the observation satellite according to a mean filtering algorithm; acquiring a corresponding energy momentum tensor according to the filtered relative motion action quantity, relative position and relative speed; and obtaining a time-varying curve of the energy momentum tensor, and carrying out maneuvering detection on the space target. According to the method, the detection capability on low thrust and weak signal maneuver can be remarkably enhanced, and the limitation that a traditional method is high in dependence on model precision and insensitive to micro maneuver is overcome.

The present invention discloses a multimodal pose estimation method for tracking a moving target by an unmanned vehicle. The method comprises the following steps: processing point cloud data to obtain a potential motion region and the initial poses of the moving target at the previous and current moments in a camera coordinate system; projecting the potential motion region into image data to obtain a projection region; processing the projection region to obtain a first ORB keypoint pair; processing the projection region using a two-stage front-end odometer to obtain a first camera pose at the current moment; calculating the scene flow of the first ORB keypoint pair to determine the moving target; and then determining a global initial relative velocity based on the camera pose at the previous moment, the first camera pose at the current moment, the moving target pose at the previous moment, and the initial pose; and determining a global first relative velocity based on the global initial relative velocity, the current projection point coordinates, the current first camera pose, and the current first ORB keypoint coordinates. The present invention accurately estimates the six-dimensional pose and velocity of the moving target.

The present application relates to the field of space in-orbit close-range relative visual navigation technology, and particularly relates to a space target visual measurement method combined with acceleration drift estimation, a tracking spacecraft is provided with an acceleration sensor and a camera, S1: obtaining initial relative position information and relative velocity information through a measurement system, S2: obtaining acceleration values and space target images in real time; S3: establishing a relative motion equation, substituting the obtained acceleration values and the relative position and relative velocity information at the previous moment into the relative motion equation to calculate position information; S4: calculating an error amount, and estimating the errors of the relative position information, the relative velocity information and the acceleration values in the dynamic equation through a filtering algorithm according to the error amount to correct the calculation results obtained in the dynamic equation, so that accurate positioning of a target spacecraft can be realized.

The invention aims to provide a flow separation prediction method based on a mechanical energy gradient, and belongs to the field of flow separation prediction. Comprising the following steps: inputting a physical field and geometric conditions; selecting a monitoring interval; generating curve equidistant points in the interval based on the monitoring interval; generating corresponding tangent lines and angles based on the equidistant points; according to the obtained tangent line and the corresponding angle, speed conversion of the corresponding monitoring point is completed in combination with an existing physical field, and the speed conversion comprises the tangential speed and the normal speed. According to the method, curve equidistant points can be divided in the monitoring interval, the angle of the corresponding position is obtained to correct the relative speed, and a plurality of corresponding speed molded lines are generated according to the curve equidistant points, so that the relative speed molded lines are compared under the condition that uniform curve intervals are ensured, and the effectiveness and rationality of speed molded line comparison are ensured.

The present invention executes: first angular error estimation processing (S40) for determining an estimated first angular error value obtained by estimating an angular error in a radar device using azimuthal dependence of relative velocity with respect to a stationary object; second angular error estimation processing (S50) for calculating a stationary object movement direction in which the stationary object moves when viewed from a moving body if the moving body is assumed to be travelling straight, calculating the next distance to the stationary object at the next azimuth on the basis of the movement direction average value and the distance to the stationary object, calculating a true estimated angle value on the basis of the next distance and a reference movement direction in which the stationary object moves when there is no angular error, and determining an estimated second angular error value on the basis of the difference between the true estimated angle value and the next azimuth; and angular error integration processing (S60) for using the estimated first angular error value and / or the estimated second angular error value to estimate an angular error in an object detected by the radar device.

The present invention discloses a method for designing an orbit of a kinetic impact mission on a near-Earth asteroid with the optimal deflection effect, comprising the following steps: S1, selecting the initial parameters of the spacecraft, including the departure and arrival times of the spacecraft; S2, designing the spacecraft orbit as a splicing of three segments, namely a large elliptical Earth parking orbit, an Earth escape orbit starting from the large elliptical orbit, and an interplanetary transfer orbit, and calculating the orbit parameters; S3, evaluating the deflection effect of the target near-Earth asteroid; S4, traversing all possible departure and arrival times of the spacecraft, repeating steps S1 to S3, drawing a contour map of the deflection distance versus the departure and arrival times of the spacecraft, and determining the optimal spacecraft launch window from it after eliminating unreasonable times. By adopting a large elliptical Earth parking orbit and screening the spacecraft launch window, the present invention enables the mass and relative velocity of the spacecraft to be relatively large when impacting the asteroid, thereby achieving the optimal asteroid deflection effect.

The invention discloses a marine environment monitoring system based on inertial navigation, and the system comprises an inertial navigation system which is used for collecting three-dimensional attitude angle and three-dimensional linear acceleration data; the Doppler log is used for collecting moving speed data of the carrier relative to the seabed; the satellite navigation receiver is used for collecting a geographic position and a UTC time signal; and the temperature-salinity-depth instrument is used for collecting temperature, salinity and pressure data of seawater. And the acoustic Doppler flow velocity profiler is used for collecting relative velocity and direction data of water flows at different depths in a water column below the carrier. The inherent accumulated position drift error of the inertial navigation system is corrected in real time by comparing and fusing the real-time position, speed and attitude angle of the carrier provided by the inertial navigation system with the ground speed of the carrier provided by the Doppler log. And the existing residual position error is reset to zero by using the absolute geographic position, so that the problem of precision maintenance during long-endurance and long-distance operation of the carrier is thoroughly solved.

The estimation device (10) of the present application includes: a sensor section (11) that transmits and receives a sensor wave and detects positions and relative velocities of a plurality of reflection points on an object; a velocity vector calculation section (23) that calculates a velocity vector of an arbitrary reference point of the object; a reflection point distance calculation section (21) that calculates a distance from the reference point to a straight line having a reflection point direction as a slope; a rotational relative velocity calculation section (25) that calculates a rotational relative velocity of the reflection point by subtracting a relative velocity at the reflection point direction based on the velocity vector of the reference point from the relative velocity of the reflection point; and an angular velocity calculation section (27) that calculates an angular velocity of the object based on the reflection point distance and the rotational relative velocity calculated by the reflection point distance calculation section and the rotational relative velocity calculation section.

A measurement device includes: a calculation unit calculating, based on a signal inputted from a measurement instrument, a coordinate value of a position at which the shape of a measurement surface of an object under measurement changes; a recording unit recording measurement information concerning the time interval at which the shape of the measurement surface of the object under measurement changes; and a determining unit determining, if the time interval at which the shape of the measurement surface of the object under measurement changes as recorded by the recording unit is shorter than a prescribed first threshold defined in advance, that the relative speed between the measurement surface of the object under measurement and the measurement instrument is improper. Upon determining that the relative speed is improper, the measurement device communicates that the evaluation of the measurement surface of the object under measurement is not being correctly carried out.

A system and method for adaptive radar frame filtering are disclosed. The maximum signal strength at zero velocity is obtained from a range bin containing detections corresponding to an object within a range Doppler representation of a set of radar frames acquired during a time period preceding the radar frame. A motion vector representing the magnitude and direction of a determined motion of the radar device at the time the radar frame is acquired is obtained. A range Doppler representation of the radar frame is generated, and a direction vector representing the direction from the radar device to the object is determined. The radial relative velocity between the object and the radar device is determined based on the motion vector and the direction vector. For a range bin containing detections corresponding to the object in the range Doppler representation, an interval is set around the determined radial relative velocity based on the radial relative velocity and the maximum signal strength. If the detection is within the interval, the representation of the object is filtered out from the radar frame; if the detection is outside the interval, the detection corresponding to the object is not filtered out from the radar frame.

The invention aims to provide a speed profile generation method based on relative coordinates, and belongs to the field of fluid analysis. Comprising the following steps: inputting a physical field and geometric conditions; selecting a monitoring interval; generating curve equidistant points in the interval based on the monitoring interval; generating corresponding tangent lines and angles based on the equidistant points; according to the obtained tangent line and the corresponding angle, speed conversion of the corresponding monitoring point is completed in combination with an existing physical field, and the speed conversion comprises the tangential speed and the normal speed. According to the method, curve equidistant points can be divided in the monitoring interval, the angle of the corresponding position is obtained to correct the relative speed, and a plurality of corresponding speed molded lines are generated according to the curve equidistant points, so that the relative speed molded lines are compared under the condition that uniform curve intervals are ensured, and the effectiveness and rationality of speed molded line comparison are ensured.

Shooting method, apparatus and electronic device are disclosed. The electronic device includes a first camera and a second camera. The field of view of the first camera includes a first sub-field and a second sub-field. The first sub-field is within the field of view of the second camera, while the second sub-field is outside the field of view of the second camera. The shooting method includes: detecting the first relative speed of a target object to the electronic device based on the first camera in a case of detecting that the target object has moved into the second sub-field; adjusting a shooting parameter of the second camera based on the first relative speed in a case of detecting that the target object has moved from the second sub-field into the first sub-field; and shooting the target object using the second camera based on the adjusted shooting parameter.

The application provides a relative velocity analysis well-free constraint relative wave impedance inversion method, which comprises the following steps: step 1, velocity analysis is carried out by using seismic data to establish the time-depth relationship of a study area; step 2, seismic facies analysis is carried out on the seismic data to determine the geological model of the study area; step 3, velocity correlation analysis is carried out to determine the velocity migration amount; step 4, the velocity curve of a seismic trace is extracted; step 5, relative velocity normalization analysis of different lithologies at the same depth point is carried out; step 6, relative velocity wave impedance inversion processing is carried out; and step 7, lithology and reservoir identification, tracking and description are carried out. The relative velocity analysis well-free constraint relative wave impedance inversion method breaks through the limitation of conventional inversion which can only be used for single target layer and time domain wave impedance inversion, eliminates the influence of different velocities in time domain and depth domain of multiple target layers, and provides relative wave impedance inversion data for lithology or reservoir prediction under complex conditions in a well-free exploration area.

The invention relates to a system and a method for simultaneous range and velocity measurement in an FMCW LiDAR system. A first light source produces first light having a first frequency that varies according to a first chirp rate. A second light source produces second light having a second frequency that is constant or that varies according to a second chirp rate. A splitter separates the measuring light into reference light and output light, and a scanning unit directs the output light towards an object and receives input light that is obtained by reflection of the output light at the object. A detector detects a superposition of the reference light and the input light. A computing unit computes unambiguously the range and relative velocity by analyzing beat frequencies resulting from the superposition. Ambiguities due to Doppler frequency shifts are removed by performing a decision tree analysis.

A gesture sensing apparatus and a gesture sensing method are provided. The gesture sensing apparatus includes: a preprocessing unit that receives radar data from a sensor, and generates a first range-Doppler map including information on a distance and a relative velocity of an object based on the radar data, and generates a second range-Doppler map; a motion sensing unit receiving the first range-Doppler map and generating motion information including a motion start and a motion end based on a signal strength calculated on the basis of the first range-Doppler map; and a gesture sensing unit receiving the second range-Doppler map and the motion information, and generating a gesture probability by classifying a gesture feature of the object based on the second range-Doppler map. The second range-Doppler map may be generated in the pre-processing unit using the first range-Doppler map and the motion information.

An estimating device (10) comprises: a sensor unit (11) that transmits and receives sensor waves to detect the positions and relative velocities of a plurality of reflection points on an object; a velocity vector calculating unit (23) that calculates a velocity vector at an arbitrarily defined reference point in the object; a reflection point distance calculating unit (21) that calculates the distance from the reference point to a straight line inclined in the direction of the azimuth of each reflection point; a relative rotational velocity calculating unit (25) that calculates the relative rotational velocity of each reflection point by subtracting the relative velocity in the reflection point azimuth direction due to the velocity vector of the reference point from the relative velocity of the reflection point; and an angular velocity calculating unit (27) that calculates the angular velocity of the object on the basis of the reflection point distances and the relative rotational velocities calculated by the reflection point distance calculating unit and the relative rotational velocity calculating unit.

The invention mainly solves the problem of how to further reduce aerial image motion. An aerial photography image motion compensation method based on momentum conservation is characterized by comprising the following steps that a hyperspectral camera is installed under an aircraft through an image motion compensation device, and the image motion compensation device enables the hyperspectral camera to move in the direction opposite to the heading direction of the aircraft during shooting; the image motion compensation device controls the relative speed of the hyperspectral camera and the aircraft to be v + v = v + mv / M, and the relative speed is kept unchanged during shooting; and during shooting, the speed of the aircraft is kept to be v + mv / M. The method has the beneficial effects that the problem of momentum conservation at the shooting moment is usually ignored in the prior art, the relative speed v cannot enable the hyperspectral camera to keep relatively static with the ground, and image motion still exists in shooting imaging, and the method proposes and solves the problem of aircraft speed change at the shooting moment, so that the hyperspectral camera keeps relatively static with the ground; and image motion can be further reduced.

The present application relates to the technical field of measurement, and particularly to a method for measuring speed with a gravitational field as a reference system, which can measure the speed of a substance without an external physical reference system. A reference object having a direct force interaction with the substance is an absolute reference system, such as light or electromagnetic waves propagating in a gravitational field or a substance, which has a direct force interaction with the field or the substance. Relative to the light, the gravitational field and the substance are absolute reference systems of the light. Because of the existence of the absolute reference system, when the substance has a relative speed relative to the field, the speed of the substance itself can be measured by the optical path (the optical path refers to the propagation path length of light or electromagnetic waves) of the field, and this process is the speed measurement with the gravitational field as a reference system.

The application relates to a high-precision tracking and pointing control method and a control system under a non-planar intersection, and the control method comprises the following steps: establishing a three-dimensional line-of-sight coordinate system according to the line-of-sight directions of a task star and a target star and an orbit coordinate system, calculating a rotation quaternion of a body coordinate system of the task star relative to the three-dimensional line-of-sight coordinate system, calculating a feedforward target angular velocity in the body coordinate system according to the relative position and the relative velocity of the task star and the target star in the orbit coordinate system of the target star, obtaining a control attitude angle according to the rotation quaternion, obtaining an attitude angular velocity of the control system according to the feedforward target angular velocity, and finally calculating three-axis command jets according to the control attitude angle and the attitude angular velocity; when the two stars have relative motion, the line-of-sight angle of the target relative to the platform changes rapidly, and through the feedforward compensation angular velocity mode, the platform and the target can still be stably and accurately tracked when the platform and the target are in a grazing intersection.

This invention discloses a method for calculating the sub-satellite point based on the SGP4 orbital model, relating to the field of satellite navigation and orbit prediction technology. The polar spherical projector of this invention eliminates longitude jumps in latitude >75°, ensuring continuous trajectory output for scenarios such as polar scientific expeditions and glacier monitoring. By directly mapping three-dimensional radial information to generate latitude, it avoids the iterative convergence problem of the ellipsoidal model, ensuring natural symmetry of the North and South Poles coordinates and continuous longitude domain. Second-order differential compensation of the mean anomaly angle, combined with dynamic correction of the Earth's rotational angular velocity, strictly aligns the UTC timestamp with the orbital position. It suppresses the cumulative error generated by traditional linear interpolation at perigee. It enhances adaptability to complex perturbation environments; atmospheric drag vectorization compensation captures real-time aerodynamic direction through relative velocity cross terms, combined with continuous processing of the density index model, significantly improving the orbital attenuation prediction accuracy of low-Earth orbit satellites during geomagnetic storms.

A system including an internal sensor configured to generate first sensor data, an external perception sensor configured to generate second sensor data, at least one memory configured to store computer executable instructions, and at least one processor is disclosed. The at least one processor is coupled to the internal sensor, the external perception sensor, and the at least one memory. The at least one processor is configured to execute the computer executable instructions to: (i) compute a first velocity output based upon the first sensor data; (ii) compute a second velocity output based upon the second sensor data; (iii) compute a relative velocity between the first velocity output and the second velocity output; (iv) determine the relative velocity is outside a predetermined threshold value; and (v) perform an intervening action in response to the determining.

A gesture sensing device includes a preprocessor that generates a range-Doppler map including information about a distance, a relative velocity, and an angle to an object based on a reception data signal, and outputs sensing data, an analyzer that analyzes a gesture feature of the object based on the range-Doppler map, and a visualizer that visualizes a gesture of the object that was analyzed by the analyzer.

A method for evaluating the flux of near-earth objects colliding with the earth, comprising: dividing the solar system orbital space into a plurality of space units according to a preset heliocentric distance step and a preset yellow latitude step with the heliocenter as the center; calculating the spatial density of near-earth objects in the space unit; establishing a geocentric ecliptic inertial coordinate system, obtaining the relative speed of the near-earth object and the earth in the geocentric ecliptic inertial coordinate system; and calculating the impact flux of the near-earth object relative to the earth based on the spatial density and the relative speed.