50 results about "Absolute scale" patented technology

An encoder configuration comprises an illumination portion, absolute scale pattern comprising absolute tracks, and a detector having a width dimension YDETABS. An absolute track pattern comprises geometrically congruent sub tracks, and the congruent sub tracks are arranged such that if one is translated by the width dimension YDETABS, then they will nominally coincide. The congruent sub tracks may be separated by a dimension YCENT that is less than YDETABS, and may each have a dimension YTOL, such that [YCENT+2(YTOL)] is greater than YDETABS. Thus, the detector may be narrower than the absolute track pattern, but because the detector edges are each nominally located over congruent sub tracks the detected signal is not sensitive to lateral misalignment of the detector within the pattern. These principles provide great freedom in configuring advantageous individual pattern features in the absolute track, even though the detector is narrower than the absolute track.

The present invention includes a method for determining interval values of seismic quality factor, Q, from seismic data. Seismic data is recorded and preprocessed as necessary. Estimates of amplitude spectra are determined from the seismic data. Logarithms are taken of the amplitude spectra and weights derived from the amplitude spectra. Interval values of seismic quality factor, Q, are determined by performing a weighted fit to the log-amplitude spectra with a function that is parameterized by an initial wavelet, an attenuation profile (1 / Q) and an absolute-scaling profile.

The invention relates to a robot positioning method with fusion of visual features and IMU information. The invention puts forward a method of fusion of monocular vision with IMU. Visual front-end pose tracking is performed and the post of a robot is estimated by using feature points; an IMU deviation model, an absolute scale and a gravity acceleration direction are estimated by using pure visualinformation; IMU solution is performed to obtain high-precision pose information and thus an initial reference is provided to optimize the search process, and the initial reference, a state quantity and visual navigation information are used for participating in optimization; and a rear end employs a sliding-window-based tightly coupled nonlinear optimization method to realize pose and map optimization. And the computational complexity is fixed while the speedometer is calculated based on a sliding window method, so that the robustness of the algorithm is enhanced.

An absolute position-sensing device is usable to measure the relative position of two elements. An absolute scale includes an integrated track extending along a measuring axis of the scale. The integrated track includes a plurality of periodic portions interleaved with a plurality of non-periodic portions. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along the measuring axis than the length of the periodic scale elements. The offset of the periodic-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

The invention discloses a real-time dense monocular simultaneous localization and mapping (SLAM) method based on an online learning depth prediction network. The method comprises: optimization of a luminosity error of a minimized high gradient point is carried out to obtain a camera attitude of a key frame and the depth of the high gradient point is predicted by using a trigonometric survey methodto obtain a semi-dense map of a current frame; an online training image pair is selected, on-line training and updating of a CNN network model are carried out by using a block-by-block stochastic gradient descent method, and depth prediction is carried out on the current frame of picture by using the trained CNN network model to obtain a dense map; depth scale regression is carried out based on the semi-dense map of the current frame and the predicted dense map to obtain an absolute scale factor of depth information of the current frame; and with an NCC score voting method, all pixel depth prediction values of the current frame are selected based on two kinds of projection results to obtain a predicted depth map, and Gaussian fusion is carried out on the predicted depth map to obtain a final depth map. In addition, the invention also provides a corresponding real-time dense monocular SLAM system based on an online learning depth prediction network.

An absolute 2D position-sensing device is usable to measure the position of a first element with respect to a second element. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a predetermined quasi-random pattern repeatedly interleaved with a plurality of code portions along each axis. Each code portion includes a plurality of code elements indicative of an absolute measurement value. The offset of the quasi-random pattern relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position to a very high resolution over a relatively large 2D range.

Method for generating scaled terrain information with an unmanned autonomous gardening vehicle (1), the gardening vehicle (1) comprising a driving unit comprising a set of at least one drive wheel (5) and a motor connected to the at least one drive wheel for providing movability of the gardening vehicle (1), a gardening-tool (7) and a camera (10a-b) for capturing images of a terrain, the camera (10a-b) being positioned and aligned in known manner relative to the gardening vehicle (1). In context of the method the gardening vehicle (1) is moved in the terrain whilst concurrently generating a set of image data by capturing an image series of terrain sections so that at least two (successive) images of the image series cover an amount of identical points in the terrain, wherein the terrain sections are defined by a viewing area of the camera (10a-b) at respective positions of the camera while moving. Furthermore, a simultaneous localisation and mapping (SLAM) algorithm is applied to the set of image data and thereby terrain data is derived, the terrain data comprising a point cloud representing the captured terrain and position data relating to a relative position of the gardening vehicle (1) in the terrain. Additionally, the point cloud is scaled by applying absolute scale information to the terrain data, particularly wherein the position data is scaled.

An absolute position-sensing device is usable to measure the relative position of two elements. An absolute scale includes an integrated track extending along a measuring axis of the scale. The integrated track includes a plurality of code portions interleaved with, or embedded in, a plurality of periodic portions. Each periodic portion includes a plurality of periodically-placed incremental scale elements. Each code portion includes a plurality of code elements indicative of an absolute measurement value. The code elements are arranged in code element zones along the direction perpendicular to the motion axis, and are detectable by associated variations along the direction perpendicular to the motion axis. The offset of the periodically placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

The invention relates to a reversing image three-dimensional (3D) scene reconstruction method and system. The invention discloses the following steps that (S100) continuous multi-frame images at the rear part of a vehicle are acquired, and the characteristic points of each frame of image are extracted; (S200) the characteristic points of adjacent two frames of images are tracked and matched; (S300) for the characteristic points which are matched successfully, the coordinates of the corresponding points of the two characteristic points in a space are computed through an outer-pole geometrical principle; two 3D reconstruction images without absolute scale of view are obtained; and (S400) steps S100 to S300 are repeated and the 3D reconstruction of the continuous multi-frame images without absolute scale is completed. According to the reversing image 3D scene reconstruction method and the system, the problem that a blind area is produced when a traditional ultrasonic reversing system meets a small obstacle and the problem of the sense of distance of a traditional video 2D reversing image system are solved, a moving object behind the vehicle can be extracted in real time so as to give key alarm, provide clearer and more accurate visual feedback to a user, and improve the safety in reversing. In addition, the whole system can be based on existing hardware equipment, a technology is mature, the cost is low, and large-scale popularization and use are facilitated.

The invention relates to an offshore oilfield reservoir prediction method based on a composite sand body construction plate. The offshore oilfield reservoir prediction method includes the following steps that firstly, according to the meandering stream composite sand body construction plate, composite sand body constructions at development positions of different sequences on an offshore target oil field are qualitatively forecasted; secondly, scale characteristic parameters of different types of composite sand bodies of the offshore target oil field are obtained, wherein the thicknesses of the different types of composite sand bodies are obtained through the well logging interpretation, sand / land ratios of the different types of composite sand bodies are calculated on the basis of the thicknesses of the sand bodies, the widths of the different types of composite sand bodies are calculated through ground penetrating radar interpretation and seismic profile measurement; thirdly, the predicted composite sand body constructions is combined with an obtained comparison result of the scale characteristic parameters and a standard value of the scale characteristic parameters, the exploration value of the offshore target oil field is judged and an exploration scheme is determined. The offshore oilfield reservoir prediction method can be widely applied to exploration and development of offshore oilfields with the sparse well density, the small dynamic information amount and the large absolute scale difference of construcion units.

An absolute 2D position-sensing device is usable to measure the position of a first element with respect to a second element. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a predetermined quasi-random pattern repeatedly interleaved with a plurality of code portions along each axis. Each code portion includes a plurality of code elements indicative of an absolute measurement value. The offset of the quasi-random pattern relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position to a very high resolution over a relatively large 2D range.

An absolute linear encoder includes a plurality of absolute scales aligned in the detection direction with absolute calibrations, a plurality of detectors for detecting the calibrations on the absolute scales, absolute position data generating portions of each scale for generating absolute position data of each detector, and a calculator for outputting an absolute position over the whole length of connected whole absolute scales adding the absolute position data of each detector and the distance between the detectors. The detectors are fixed at such intervals as to simultaneously detect the calibrations of the two absolute scales adjoining in a scale connecting section. Thus, the long absolute linear encoder which is easy to use is realized at low costs.

The invention relates to a scale track configuration for absolute optical encoder. An encoder configuration comprises an illumination portion, absolute scale pattern comprising absolute tracks, and a detector having a width dimension YDETABS. An absolute track pattern comprises geometrically congruent sub tracks, and the congruent sub tracks are arranged such that if one is translated by the width dimension YDETABS, then they will nominally coincide. The congruent sub tracks may be separated by a dimension YCENT that is less than YDETABS, and may each have a dimension YTOL, such that [YCENT+2(YTOL)] is greater than YDETABS. Thus, the detector may be narrower than the absolute track pattern, but because the detector edges are each nominally located over congruent sub tracks the detected signal is not sensitive to lateral misalignment of the detector within the pattern. These principles provide great freedom in configuring advantageous individual pattern features in the absolute track, even though the detector is narrower than the absolute track.

An absolute 2D position-sensing device is usable to measure the relative position of two elements. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a plurality of periodic portions interleaved with a plurality of non-periodic portions along each axis. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along each measuring axis is than the length of the periodic scale elements along each measuring axis. The offset of the periodically-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

The invention discloses an image depth estimation method and system based on a CNN (Convolutional Neural Network) and a depth filter. The image depth estimation method comprises the steps of obtainingimage depth estimation values based on the CNN, extracting local features points from the image, and establishing a minimum photometric error equation to solve the relative pose of a camera; optimizing the camera pose based on the feature points matched by polar line searching, selecting an image block by taking the feature points as a center, performing polar line searching on the image block toobtain the optimum matching, constructing a bundle adjustment equation according to the optimum matching to optimize the relative pose; and performing depth value filtering based on the camera pose,namely, filtering depth values by adopting Gaussian integration until the depth values converge. The image depth estimation method overcomes a problem of inaccurate image depth and a problem of absolute scale loss of monocular vision, and can be applied to many fields such as three-dimensional scene reconstruction, indoor positioning and augmented reality.

A measuring instrument comprises an spherical camera (8) for acquiring image data over total circumference, a laser scanner (6, 7) installed integrally with the spherical camera and for acquiring point cloud data of the surroundings, a synchronous control unit (9) for controlling acquisition of data of the spherical camera and the laser scanner, a storage unit (12) for recording the image data and the point cloud data, an absolute scale acquiring means for acquiring an absolute scale for obtaining an absolute position of when images are photographed by the spherical camera, and a control arithmetic unit (10), wherein the control arithmetic unit calculates a 3D model based on the image data, the point cloud data, and the absolute position.

The invention relates to a 3D reconstruction and measurement method for a spatial object via in-orbit hedgehopping imaging. The method comprises the steps of obtaining hedgehopping images via spatial hedgehopping shooting, carrying out multi-view 3D reconstruction aimed at the spatial object, and converting a 3D model of the spatial object into an absolute scale. Via the method, high-definition shooting and measurement can be carried out on a random spatial object rapidly in response to investigation requirement, and compared with ground investigation, strict observation weather condition and observation windows are not needed; and the object can be reconstructed and measured in a non-contact manner via groups of sequential images including the to-be-measured spatial object instead of providing camera parameters by a shooting platform, and the difficulty and cost of in-orbit measurement are reduced greatly.

Disclosed are a posture information determination method and determination device, a visual point cloud construction method and a visual point cloud construction device. The posture information determination method includes determining relative posture information of an image acquisition device when acquiring an image of a current frame relative to when acquiring an image of a previous frame; Determining, by a sensor with an absolute scale, a first set of translation parameters for movement of the image acquisition device during acquisition of images of the current and previous frames; Adjusting the relative posture information based on the relative posture information and a first set of translation parameters; And determining posture information of the image acquisition apparatus when acquiring an image of a current frame based on the adjusted relative posture information. In order to obtain more accurate posture information, the translation vector of the camera posture information isdirectly calibrated by the scale of the external sensor using the posture information determination method.

The invention provides a parking area recognition method and system and a medium. A structure of a feature point module, a pose calculating module, a distortion correcting module, an absolute scale restoring module, a space point rebuilding module and a parking area finding module is used. The feature point module completes the feature point extraction and detection of a camera-captured picture. The pose calculation module calculates a pose relationship of the camera at the times of capturing two frames of pictures. The distortion correction module performs distortion correction on an extracted fish-eye feature point. The absolute scale restoring module restores a real scale by using a true camera height. The space point rebuilding module restores the value of reconstructed point cloud byusing a camera pose and an absolute scale. The parking area finding module finds a structure and a method of a parking area according to reconstructed space point cloud. A disadvantage that an ultrasonic radar is failed and an actual scale can not be obtained based on a parking line detection method can be solved, and a parking area which satisfies a parking requirement is efficiently and accurately detected for a vehicle.

An absolute scale configuration is provided for use in a position encoder which includes a readhead and a scale. The absolute scale configuration includes a plurality of scale loops distributed along a measuring axis to provide a position dependent signal that varies depending on a relative position between the scale loops and the readhead. At least some of the scale loops are coupled to respective impedance modulating circuits connected to receive energy from current induced in the scale loop and to provide a unique coded modulation of the scale loop impedance during a code signal generating state. The unique coded modulations as sensed by the readhead are indicative of a coarse resolution absolute position, which may be utilized in combination with the position dependent signal to determine an absolute position with a high resolution.

A rotary absolute value scale includes a rotor in which two rotor side coil patterns provided with different pitches are laminated, and a stator in which two stator side coil patterns provided with different pitches are also laminated. A linear absolute value scale includes a slider in which two slider side coil patterns provided with different pitches are laminated, and a scale in which two scale side coil patterns provided with different pitches are also laminated.

A photoelectric encoder includes an absolute scale provided with an absolute pattern based on pseudo-random data, and a detection head including a light source that emits light to the absolute pattern of the absolute scale, and a light receiving unit that receives light from the absolute pattern, and it detects an absolute position of the detection head with respect to the absolute scale. In the photoelectric encoder, the absolute pattern is composed of a grating part and a dark part arranged in a repetitive manner. The photoelectric encoder further includes an interference pattern generation means that generates an interference pattern in combination with the grating part, and an interference pattern signal processing unit that detects the pseudo-random data of the absolute pattern based on the interference pattern received by the light receiving unit.

A method according to the invention for chassis measurement includes the steps of providing a chassis measurement system having four measuring heads (2, 4, 14, 16) arranged in known positions relative to one another, each having a monocular image recording device (22, 24, 26, 28), wherein the position of the measuring heads (2, 4, 14, 16) relative to one another is known; recording an image of a wheel (6, 8, 10, 12) or a measurement target applied thereto in an initial position (A) of the vehicle (1) with each of the four measuring heads (2, 4, 14, 16); shifting the vehicle (1) from the initial position (A) into at least one additional position (E); recording an image of a wheel (6, 8, 10, 12) or a measurement target applied thereto of the vehicle (1) in the additional position (E) using each of the four measuring heads (2, 4, 14, 16); recording an image of a reference target that has a known pattern (34, 36) and is attached to the vehicle (1) using one of the four measuring heads (2, 4, 14, 16) in at least one of the initial position (A) and the additional position (E) of the vehicle (1) and determining an absolute scale for the measuring heads (2, 4, 14, 16) therefrom; executing local 3D reconstructions for determining the translation vectors (t1, t2, t3, t4), the rotation vectors (R1, R2, R3, R4) and the angle of rotation of the wheels between the at least two positions (A, E) as well as the centers of rotation of the wheels and the axes of rotation of the wheels (6, 8, 10, 12); and determining the chassis measurement parameters of the vehicle (1), in particular inclination, single track and / or total track, wheelbase and track width.