301 results about "Angular distance" patented technology

A system and method for eye gaze tracking in human or animal subjects without calibration of cameras, specific measurements of eye geometries or the tracking of a cursor image on a screen by the subject through a known trajectory. The preferred embodiment includes one uncalibrated camera for acquiring video images of the subject's eye(s) and optionally having an on-axis illuminator, and a surface, object, or visual scene with embedded off-axis illuminator markers. The off-axis markers are reflected on the corneal surface of the subject's eyes as glints. The glints indicate the distance between the point of gaze in the surface, object, or visual scene and the corresponding marker on the surface, object, or visual scene. The marker that causes a glint to appear in the center of the subject's pupil is determined to be located on the line of regard of the subject's eye, and to intersect with the point of gaze. Point of gaze on the surface, object, or visual scene is calculated as follows. First, by determining which marker glints, as provided by the corneal reflections of the markers, are closest to the center of the pupil in either or both of the subject's eyes. This subset of glints forms a region of interest (ROI). Second, by determining the gaze vector (relative angular or Cartesian distance to the pupil center) for each of the glints in the ROI. Third, by relating each glint in the ROI to the location or identification (ID) of a corresponding marker on the surface, object, or visual scene observed by the eyes. Fourth, by interpolating the known locations of each these markers on the surface, object, or visual scene, according to the relative angular distance of their corresponding glints to the pupil center.

A multi-head actuator data storage device reads and writes data simultaneously to one of a plurality m of heads, the plurality of m heads mounted on each of n head actuators where the plurality of n head actuators are separated from each other by an angular separation distance of 360/n degrees. The data on the disk is organized into a plurality of logical sectors, each logical sector comprising n ordered physical sectors, where the plurality n of ordered physical sectors is separated by the same angular distance separating the head actuators. During a write operation, each head actuator independently seeks to a unique physical sector, and the order of the physical sectors is communicated to a data de-multiplexer which writes de-multiplexed data to the physical sectors in a predetermined order. During a read operation, each head actuator independently seeks to a unique physical sector selected for minimum access time, and the order of the physical sectors is communicated to the data multiplexer such that the predetermined order is preserved during the multiplexing of the data arriving from the n head actuators simultaneously.

A guiding grid of variable geometry comprises a plurality of guiding vanes in a housing in angular distances around a central axis in an axially extending vane space of a predetermined axial distance. Each vane is pivotal about an associated pivoting axis to assume different angles in relation to the central axis and, thus, to form a nozzle of variable cross-section between each pair of adjacent vanes. A nozzle ring supports the vanes around the central axis and forms a first axial limitation of the vane space. A unison ring is displaceable relative to the nozzle ring and is connected to the vanes to pivot them. An annular disk is fixed to the housing and faces the nozzle ring in an axial distance to form a second axial limitation of the vane space and a central opening. Into this opening, a sleeve may be inserted. A fixing arrangement determines the axial position of the annular disk with respect to the housing.

The invention provides a simulator of a star sensor. The simulator comprises a collimating objective lens, wherein a focal plane of the collimating objective lens is provided with a star point target; the star point target is imaged at infinity through the collimating objective lens; a light splitting component is arranged between the collimating objective lens and the star point target; the focal plane of a light splitting optical path on the side face of the light splitting component is also provided with a detection target; the star point target is fixed on a focal plane adjusting mechanism; and a target lighting device is used for lighting the star point target. In the simulator, a technology which is different from the scheme of the conventional star simulator is adopted, so that the problem of poor accuracy of simulation of angular distance between stars of the conventional star simulator is solved; and the simulator can be used for extremely-high-accuracy simulation of a star and asteroid array of an asteroid autonomous navigation extremely-high-accuracy star sensor, verification of measurement accuracy and autonomous navigation and positioning accuracy of the star sensor, and has broad application prospect in research of a deep space autonomous navigation sensor.

A control device is provided, in particular for use in endoscopes or the like. The control device has proximal and distal end sections each comprising an area of articulation and a central section arranged therebetween. The control device also comprises outer and inner hollow cylindrical shafts and a control element arranged between the shafts. Two or more longitudinal elements extend substantially from the proximal to the distal end section and transfer force. For an optimized control function, the longitudinal elements are arranged at essentially regular angular distances in a circumferential direction of the control device and are connected to one another in the circumferential direction in the region of their respective proximal and distal ends. The distal ends of the longitudinal elements are secured in the circumferential direction in angular positions which are different to the angular positions, in which the respectively associated proximal ends are secured.

The present invention relates to a medicament delivery device comprising an elongated housing arranged to contain a medicament container which medicament container contains a number of doses; a dose counter mechanism comprising a dose drum arranged with dose indicia on its outer surface and visible through a window on said housing; a rotatable driver connected to said dose drum; a plunger rod arranged to act on said medicament container for expelling a dose of medicament; an actuation mechanism connected to said rotatable driver and to said plunger rod when said medicament delivery device is actuated; wherein said dose drum is arranged with internal threads, in engagement with corresponding threads on said driver, wherein said threads have a certain pitch; wherein said dose drum is also arranged with external threads in engagement with corresponding threads arranged fixed in relation to said housing, wherein said threads have a certain pitch; and wherein the pitch of the threads between the dose drum and fixed in relation to the housing is lesser than the threads between the dose drum and the driver such that when said driver is rotated a certain angular distance, said dose drum is rotated a lesser angular distance.

A cutting tool has a shank with a cylindrical portion that is adapted to fit closely within a tool holder. The shank is adapted to be engaged by a setscrew of the tool holder at a first contact point. A clearance surface is provided opposite the first contact point. The clearance surface terminates adjacent two circumferentially spaced points that make contact with the tool holder upon tightening the setscrew. These contact points are circumferentially spaced from the first contact point angular distances greater than 90 degrees and less than 270 degrees.

A head-up display for a vehicle has a laser and a scanning system. An image, which is to be displayed in the field of vision of the driver of the vehicle and which is composed of individual pixels, is produced pixel-by-pixel by the laser and the scanning system. The head-up display has a projection system having a projection surface and a magnifying optical system. The projection system projects the image to be displayed onto a virtual image plane and magnifies the image in the process. The size of the pixels in the virtual image plane is smaller than the resolving ability of the human eye, which is the case for an angular distance less than 0.5′, for example.

The invention discloses a satellite autonomous navigation system and a satellite autonomous navigation method integrating a pulsar radiation vector and timing observation. The system obtains pulse arrival time and accurately obtains a pulsar radiation direction vector by using a time distinguishing detector and a collimator, and obtains a geocentric direction vector by using an infrared or ultraviolet horizon sensor; a navigation computer respectively completes a pulsar timing observation navigation algorithm under a geocentric coordinate system, a pulsar positioning algorithm based on angular distance measurement and a geometric orientation algorithm based on angular distance measurement by using the pulsar pulse arrival time, the radiation direction vector and the geocentric direction vector, and obtains the position, the speed, the attitude and the on-track movement direction of a spacecraft through integration of several algorithms, so as to complete the autonomous navigation of an orbiting satellite, and output high-precision position, attitude and speed information. The system is suitable for autonomous operation control of orbiting satellites or constellations of the earth or other planets.

The method includes steps: building up kinematical equation of earth satellite orbit based on rectangular coordinate system; building up measurement equation based on angular distance of starlight as measuring quantity; building up discrete type extended Kalman filtering equation to determine whether extended Kalman filtering is divergent; using prognostic filtering residual to determine whether extended Kalman filter is divergent; if yes, then the method carries out estimating statistic characteristics of noise; otherwise, carrying out calculation according to standard extended Kalman filtering program. The invention solves issue that divergence of noise filter caused by inaccurate determination of statistic characteristics of noise influences on navigation accuracy. Advantages are: independent, flexible and simple, and high precision. The invention is especially suitable to earth application satellite needed high navigation accuracy in resource, weather areas etc.

An apparatus and method for separating animal waste from litter are provided. In one form, the apparatus includes a drum that contains litter and a helical rake that is rotatable in the drum. The rake can rotate relative to the drum to reduce power requirements for the rotary rake drive. Preferably, the drum is also rotatable by turning of the rake in the drum, but only for a limited, fixed angular distance which also reduces peak power requirements for the rotary drive motor for the rake.

The invention discloses an identification method for a triangular star atlas based on the characteristics of inertia ratio. The method comprises the following steps: constructing and storing a navigational feature library containing centroid inertia ratio of navigational triangles and angular distance of one side of the navigational triangles; determining triangles to be observed according to theamount of stars to be observed in a field of view, and determining centroid inertia ratio of all the triangles to be observed and angular distance of sides of the triangles that have same attribute as the sides stored in the navigational feature library; matching the centroid inertia ratio and angular distance of the sides of all the triangles to be observed determined in the previous step with the centroid inertia ratio and angular distance of the sides in the navigational feature library, and determining navigational triangles matching with the triangles to be observed; establishing a referential star atlas based on the matched navigational triangles, and carrying out star and point matching on the referential star atlas and a star atlas to be observed so as to complete the process of identification. The method provided in the invention can reduce storage space as well as improve the speed of matching.

Control over velocity of a model train may be determined based upon the speed of rotation of a control knob. A processor receives electronic pulses indicating rotation of the knob beyond a predetermined increment of angular distance. The processor calculates the amount of power ultimately conveyed to the model train based not only upon the number of pulses received, but also upon the elapsed time between these pulses. The shorter the elapsed time between pulses, the greater the change in power communicated to the train. Initially, a user can rapidly rotate the knob to attain coarse control over a wide range of velocities, and then rotate the knob more slowly to achieve fine-grained control over the coarse velocity. Utilizing the control scheme in accordance with embodiments of the present invention, in a compact and uninterrupted physical motion, a user can rapidly exercise both coarse and fine control over velocity of a model train.

A self-calibration method and apparatus for on-axis rotary encoders comprising the steps of: receiving output signals from a detector during a spindle-free response period, the signals including a plurality of data sets wherein each data set comprises the periods between sampling events occurring in one revolution of the encoder at an angular speed, selecting a data set pair from the output signals, wherein the data set pair contains two linearly uncorrelated data sets; defining a model of the angular distances between each sampling event occurring in one revolution of the encoder as a function of one or more damping coefficients and the periods between each sampling event as contained in the data set pair; solving the model for the angular distances for the data set pair using circular closure and dynamic reversal techniques; and establishing an encoder error map using the selected solved angular distances from the model.

A fractal impeller design for stirred tank reactors comprising plurality of main branches, each of which further having plurality of sub-branches with each sub branch having plurality of blades to distribute/dissipate energy in uniform manner and to achieve uniform temperature throughout the reactor while operating it at lower impeller speed to avoid high shear zones; wherein, the angular distances covered by the blades vary and yield variation in the local blade passage velocity for a given impeller rotation speed.

A propulsion unit for an aircraft, comprising one turbine engine and a mounting device for a turbine engine designed to be added laterally on an aircraft structure and comprising a rigid mounting structure. The rigid mounting structure supports at least one arch which is concave towards the longitudinal axis of the propulsion unit and which has a distal end at an angular distance of between 45 and 120 degrees from a vertical plane passing through the axis, on the other side of the structure, and supporting a distal connecting element connecting the turbine engine to the arch.

The invention discloses a method and device for extracting image texture features, which can accurately and quickly extract the texture features of the original image and improve the robustness of the texture features. The method for extracting image texture features provided by the embodiments of the present invention includes: acquiring the grayscale image of the original image; dividing the grayscale image into a plurality of image blocks, and calculating the grayscale co-occurrence matrix of each image block; , contrast, entropy and related features are used as the selected texture features, and the texture features of each image block are calculated according to each gray level co-occurrence matrix; according to the texture features of each image block, the corresponding texture features of the original image are obtained.