28 results about "Relative velocity" patented technology

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.

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 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 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.

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.

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.

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 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.

This invention relates to the field of intelligent obstacle avoidance technology, and discloses an intelligent obstacle avoidance method and system for low-altitude aircraft. The method includes: acquiring a first binocular visual image and first inertial measurement data and processing them for correction to obtain a second binocular visual image and second inertial measurement data; identifying the current scene type of the aircraft based on the second inertial measurement data, adjusting the parameters of a first extended Kalman filter according to the current scene type to obtain a second extended Kalman filter, and inputting the second binocular visual image and the second inertial measurement data into the second extended Kalman filter for calculation to obtain the three-dimensional position and relative velocity of the obstacle; determining a target execution strategy based on the three-dimensional position, relative velocity, and semantic category of the obstacle, and controlling the flight control system according to the target execution strategy, thereby maximizing mission continuity while ensuring flight safety and meeting the need for rapid response to sudden obstacles in high-speed flight scenarios.

A measurement device according to the present disclosure comprises: a coordinates value calculation unit for calculating, on the basis of 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 measurement information recording unit for recording measurement information concerning the time interval at which the shape of the measurement surface of the object under measurement changes; and a speed improperness determining unit for determining, if the time interval at which the shape of the measurement surface of the object under measurement changes as recorded by the measurement information 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.

The present application belongs to the technical field of inertial navigation, and discloses a polar double-inertial navigation state monitoring method based on a Psi angle correction model, which is suitable for state monitoring of a carrier equipped with multiple sets of inertial navigation systems with a rotation mechanism in a polar environment. The present application is aimed at the problem of limited state monitoring of an inertial navigation system under the condition of no external reference information during long navigation in the polar region. Based on a Psi angle error model, the model is defined in a calculation coordinate system, and the position error is decoupled, which is suitable for the characteristics of long navigation in the polar region. A horizontal calculation coordinate system under an earth ellipsoid model is used as a navigation coordinate system, the relative attitude, relative velocity and relative position between two sets of inertial navigation systems are used as constraint observations, and through correction of a velocity error model, the present application avoids the influence of inaccurate solution caused by differential of specific force under dynamic conditions on the state monitoring precision of devices. Strong tracking filtering based on residual normalization is used to monitor the gyro drift and accelerometer zero offset of the two sets of systems online. Further, the state of inertial devices is evaluated according to the monitored error parameters. The method of the present application is completely autonomous and does not depend on external reference information, which has important engineering significance.

This invention discloses a simulation and evaluation method for inland waterway vessel navigation based on a hydrodynamic model. The method is characterized by the following stages: basic parameter configuration, test type and parameter selection, dynamic simulation and data calculation for vessel navigation in multiple scenarios, and result visualization and evaluation analysis. Specifically, the method uses the MMG hydrodynamic model to perform numerical calculations and verification of vessel navigation parameters for multiple scenarios, including: Z-shaped navigation, circular navigation, straight-line navigation, and obstacle avoidance navigation. The general dynamic calculation framework is as follows: all background simulation functions share a unified logic, and the specific process is: environmental disturbance calculation – relative velocity correction – hydrodynamic calculation of the vessel body – superposition of forces and moments – solving the differential equations of motion – state update.

The application provides a target object relative speed determination method, system, device and medium. The method comprises the following steps: obtaining the azimuth angle of a plurality of radar points of a target object, determining the azimuth angle sine value and the azimuth angle cosine value of each radar point; generating a first matrix and a second matrix based on the azimuth angle sine value and the azimuth angle cosine value of each radar point, determining a third matrix, determining the matrix determinant value and the eigenvalue of the third matrix according to the third matrix; if the matrix determinant value is greater than a first preset threshold value and the eigenvalue quotient is greater than a second preset threshold value, performing regularization processing on the third matrix; determining the target object relative speed of the target object relative to the vehicle based on the ground radial velocity of the radar point, the third matrix after regularization processing and the second matrix, wherein the ground radial velocity of the radar point is determined by the longitudinal speed, the lateral speed of the vehicle and the azimuth angle, and the azimuth angle is collected by the front millimeter wave radar of the vehicle.

A LiDAR system (14) for measuring a range and / or a relative velocity to an object (12) has a light source producing light having a varying frequency, a scanning unit (18) emitting the light into different directions that correspond to pixels in an image of the object. A detector (32) detects for each pixel an interference of a measuring portion of the light, which was reflected at the object, and a reference portion of the light, which was not reflected at the object, and produces, for each pixel, an electrical signal representing the interference. A computing unit (37) determines whether the electrical signal is strong enough so that it can be reliably distinguished from a noise floor. For first pixels for which the electrical signal is strong enough, the range and / or the relative velocity to the object (12) is computed based on the electrical signals that are associated with each of the first pixels. For a second pixel for which the electrical signal is not strong enough, this information is calculated in an interpolation step based on one or more electrical signals associated with one or more first pixels.

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.

The application discloses a UUV navigation method based on multi-source information fusion and a related device, and belongs to the technical field of underwater unmanned vehicle navigation; the method obtains multi-source marine environment sensing data, and performs adaptive inverse variance weighted fusion to obtain a flow field velocity gradient tensor estimation; based on the flow field velocity gradient tensor estimation, a non-uniform dissipation pheromone model is solved to generate a virtual pheromone field; according to the pheromone gradient of the virtual pheromone field and local ocean current velocity, a guide velocity of the UUV is generated; a robust fluid relative tracking controller is adopted to drive the actual fluid relative velocity of the UUV to track the guide velocity, so that the UUV navigation is realized. The application realizes the collaborative promotion of low energy consumption, high trajectory safety and strong sensor fault tolerance of the UUV navigation in a complex ocean current environment.