2245results about "Instruments for comonautical navigation" patented technology

A holographic planar concentrator (HPC) for collecting and concentrating optical radiation is provided. The holographic planar concentrator comprises a planar highly transparent plate and at least one multiplexed holographic optical film mounted on a surface thereof. The multiplexed holographic optical film has recorded therein a plurality of diffractive structures having one or more regions which are angularly and spectrally multiplexed. Two or more of the regions may be configured to provide spatial multiplexing. The HPC is fabricated by: (a) recording the plurality of diffractive structures in the multiplexed holographic optical film employing angular, spectral, and, optionally, spatial multiplexing techniques; and (b) mounting the multiplexed holographic optical film on one surface of the highly transparent plate. The recording of the plurality of diffractive structures is tailored to the intended orientation of the holographic planar concentrator to solar energy. The HPC is mounted in the intended orientation for collecting solar energy and at least one solar energy-collecting device is mounted along at least one edge of the holographic planar concentrator. Examples of suitable solar energy-collecting devices include photovoltaic cells and fiber optic light guides for transmitting collected light into an interior of a building for illumination purposes and for transmitting collected solar radiation into a hot water tank for heating. The HPC permits efficient collection of solar energy without expensive requirements, while minimizing energy losses.

Apparatuses and methods include a solar array having one or more strings of series-connected local management units (LMUs). Each LMU is parallel-connected to one of a plurality of solar modules. The strings are connected in parallel via a parallel bus. Local string management units (LSMUs) can increase or decrease an output voltage of the solar array by upconverting or downconverting string output voltages from each string. LSMUs can also operate in a bypass mode to increase overall power output.

A light sensor system includes at least one light emitter, a light sensor unit and a processing unit. The light sensor unit is arranged to receive reflected light from an object in accordance with a time sequence in which the at least one light emitter is activated, and accordingly output a plurality of reflected signals. The processing unit is arranged to receive the reflected signals, identify a signal function of time by referring to occurrence sequence of local peak levels of the reflected signals, and determine motion of the object according to the signal function of time. Another light sensor system is proposed. The major difference between the two light sensor systems is that the processing unit of the another light sensor system is arranged to identify the signal function of time by comparing a predetermined threshold with signal levels of the reflected signals.

The present invention includes a sun sensor assembly having an aperture that defines an area that is less than the area of the photo-detecting surface of a corresponding first photo-detector. According to another aspect, the present invention also includes a solar concentrator includes at least two sun sensor assemblies mounted on the concentrator in a manner to help the solar concentrator track the sun. According to another aspect, the present invention also includes a method of processing electrical signals from two or more photo-detectors. According to yet another aspect, the present invention includes a sun tracking system that includes a solar panel that includes a solar concentrator and control system.

An autonomous unmanned space flight system and planetary lander executes a discrete landing sequence including performing an initial velocity braking maneuver to remove velocity at altitude, coasting during which the planet surface is imaged and correlated to reference maps to estimate cross-track and along-track navigation errors and one or more lateral braking maneuvers are performed to reduce cross-track navigation error, and performing a terminal velocity braking maneuver(s) to reduce the along-track braking maneuver and remove the remainder of the velocity just prior to landing. A bi-propellant propulsion system provides a very high T/M ratio, at least 15:1 per nozzle. Short, high T/M divert maneuvers provide the capability to remove cross-track navigation error efficiently up to the maximum resolution of the reference maps. Short, high T/M terminal velocity braking maneuver(s) provide the capability to remove along-track navigation error to a similar resolution and remove the remaining velocity in a very short time window, approximately 3-15 seconds prior to touchdown. The propulsive efficiency frees up mass which can be allocated to a fuel to remove the unknown navigation errors, perform hazard avoidance and/or relocate the lander by flying it to another site or be allocated to additional payload.

A system and method for imaging a three-dimensional scene having one or more objects. The system includes a light source, a detector array, a timing circuit, an inertial guidance system and a processor connected to the timing circuit and the inertial guidance system. The light source generates an optical pulse and projects the optical pulse on an object so that it is reflected as a reflected pulse. The detector array includes a plurality of detectors, wherein the detectors are oriented to receive the reflected pulse. The timing circuit determines when the reflected pulse reached detectors on the detector array. The inertial guidance system measures angular velocity and acceleration. The processor forms a composite image of the three-dimensional scene as a function of camera position and range to objects in the three-dimensional scene.

The invention relates to an unmanned aerial vehicle vision/inertia integrated navigation method in the unknown environment. The method relates to image processing, inertial navigation calculation and filtering estimation, so that the steps of defining coordinate system, aligning the coordinate system, setting up filter equation and the like are firstly carried out before the main navigation method is implemented. The navigation process of the method comprises five steps: acquiring and pretreating image; extracting feature points by a SIFT method; matching the feature points; updating the filter equation; and carrying out the filtering estimation on the updated filter equation. The method only needs the current ground image instead of specific external information for matching, so as to be used in any environment (including underwater, shelter, canyon, underground and the like) in theory; furthermore, the method has the advantages of good sheltered property and high accuracy.

A volumetric error compensation measurement system and method are disclosed wherein a laser tracker tracks an active target as the reference point. The active target has an optical retroreflector mounted at the center of two motorized gimbals to provide full 360 degree azimuth rotation of the retroreflector. A position sensitive detector is placed behind an aperture provided at the apex of the retroreflector to detect the relative orientation between the tracker laser beam and the retroreflector by measuring a small portion of the laser beam transmitted through the aperture. The detector's output is used as the feedback for the servo motors to drive the gimbals to maintain the retroreflector facing the tracker laser beam at all times. The gimbals are designed and the position of the retroreflector controlled such that the laser tracker always tracks to a pre-defined single point in the active target, which does not move in space when the gimbals and/or the retroreflector makes pure rotations. Special mechanism and alignment algorithm are used in the gimbal design and retroreflector centering alignment to achieve accurate rotational axis alignment and repeatability.

A suntracking system for a central receiver solar power plant includes a heliostat field for reflecting sunlight to a receiver, cameras directed toward at least a subset of the heliostats, and a controller. The cameras are configured to produce images of sunlight reflected from multiple heliostats. The heliostats include a mirrored surface having a settable orientation and have a geometry modeled by a set of parameters. A method of estimating heliostat parameters for open-loop suntracking includes acquiring pointing samples by setting the direction of reflection of the heliostats and detecting concurrent sunlight reflections into the cameras. The method uses the acquired pointing samples and surveyed locations of the cameras to estimate the heliostat parameters. The method accurately maintains the sun's reflection directed toward the receiver open-loop utilizing the estimated tracking parameters.

There is provided an optical projection system for projecting an image onto an object that is being manufactured and/or inspected. The system includes an image-projecting device, a target-locating device for determining the orientation of the image-projecting device relative to the object, and an image-rendering device for rendering the image that is projected onto the object. The target-locating device advantageously comprises a camera that locates at least one target in mechanical communication with the object to determine the orientation of the image-projecting device relative to the object. The image-rendering device advantageously stores a three-dimensional representation of the object that is converted into a two-dimensional image that is projected upon the object. The image projected upon the object is advantageously used during assembly and/or inspection of the object.

The invention relates to a remote high precision autonomous integrated navigation and positioning method, which is characterized in that a Strapdown Inertial Navigation System (SINS) is used as a main navigation system during the whole flight course of the aircraft, assisted by 3D high precision position and attitude angle information provided by celestial navigation system (CNS) based on the least square differential correction in boost phase (or middle segment). In reentry phase (terminal), using the characteristics of synthetic aperture radar (SAR), such as strong penetration capability, high resolving precision and all-weather, the SINS can be corrected through accurate location information and course information provided by SAR scene matching after motion compensation when the aircraft reentry into atmospheres, so the impact point (hit) accuracy of the aircraft can be increased and the invention has remarkable effects of eliminating or decreasing non-guidance error. The invention has advantages of autonomy and high precision, which can be used for improving remote ballistic missile, remote cruise missile, navigation and positioning accuracy of remote aircraft, such as long-endurance unmanned aerial vehicle, etc.

The present invention is a solar tracking system which utilizes three supports arranged in a generally tripod configuration. In one embodiment, two of the supports are linear actuators, and the third support is a stationary universally pivoting joint such as a ball and socket joint. The tracking system may include cross-supports for increased stability, a linear rail for additional range of motion, and a mounting base to facilitate installation. This solar tracking system offers a stable, cost-effective design which is also capable of moving the solar module into an optional stowed position.

The calculation device (36) according to the present invention receives a plurality of reflected light intensity information for indicating the intensity of each reflected light which reaches a single light receiver via a reflecting object, the reflected light having been emitted in sequence from a plurality of light emitters (31 through 33) provided in mutually different positions, computes a phase difference of an intensity variation which occurs among the reflected light, and determines a movement of the reflecting object on the basis of the calculation result.

The invention discloses a navigation method for an unmanned aerial vehicle, which is characterized in that an air route detection module with an air route data reckoning function is additionally arranged on the unmanned aerial vehicle and is capable of reckoning real-time navigation data independent on satellite navigation according to parameters including flight attitude, navigational speed and height of airborne equipment, an existing satellite navigation device and existing inertial navigation equipment, which are on the vehicle in flight, are combined to generate combined navigation data, the air route detection module is used for continuously comparing the real-time navigation data with the combined navigation data and judging confidence level of the satellite navigation according to comparison data. When satellite navigation is normal, the combined navigation data are preferentially used by the unmanned aerial vehicle for flight, and the real-time navigation data are temporarily suspended; and when satellite navigation is abnormal, the real-time navigation data are automatically started by the unmanned aerial vehicle for flight. By the navigation method, flight missions of the unmanned aerial vehicle can be guaranteed to be still completed according to preset air routes under the satellite navigation losing condition, and the unmanned aerial vehicle can be prevented from flying by no-fly zones or lands in no-landing zones, so that shortcomings of the prior art are overcome.

A sensor for determining the angular position of a radiating point source in two dimensions includes a mask encoded in two skewed directions with waveforms consisting of several frequencies in prescribed patterns. The frequency spectra of the received detector patterns are computed. In order to facilitate such computations, the constituent frequencies are separated so as to be distinguished in the Fast Fourier Transform (FFT). Each of the frequency patterns that are coded on the variable transmissivity mask consists of a series of low frequencies followed by a series of variable frequencies, and a series of high frequencies. The variable frequencies exhibit frequency changes responsive to various image positions. The low and high frequencies are responsive in phase to variations in image position. The frequency variations in the variable frequencies are used to indicate coarse position while the phases of the fixed low and high frequencies are used to indicate medium and fine position. In a second embodiment, the mask pattern is formed by a first pattern including low variable and high frequency components, a second pattern with fixed low and high frequency components, and a third pattern with variable frequency components. The method of determining position is also disclosed.

The invention provides a method and apparatus for guiding a weapon to a target using an optical seeker having dual semi-active laser (SAL) and laser radar (LADAR) modes of operation. The dual mode seeker incorporates a laser light source, an optical package including a quadrant detector for operating in SAL mode and a LADAR receiver for operating in LADAR mode. The seeker further includes a high speed scanning mirror for switching between modes to guide the weapon to the target. The method for guiding a weapon to a target includes receiving radiation from the target and tracking the radiation to guide the weapon; monitoring the detected radiation such that if the radiation falls below a predetermined level, a laser system on-board the weapon continues guiding the weapon by generating a laser beam; reflecting the laser beam off the target so that the reflected laser radiation is received from the target to track the radiation and guide the weapon to the target.

Embodiments of a device and a technique are disclosed for locating the angular position of a radiating point source with respect to a detector comprising a point source of radiation, a variable transmissivity mask with pseudo-random variations, a multi-element detector and computing means for interpreting the detected image. The mask pattern, when illuminated by a point source of radiation, casts an image on the detector array. Computing means determine the pattern shift to allow determination of point source angular location in two dimensions. The mask transmissivity pattern and corresponding image vary in two dimensions, in such a manner as to yield two correlation peaks that indicate the incident angle in two dimensions. The differential shift and common mode shift in correlation peaks indicate the respective angles of incidence, allowing determination of the angular position of the light source.

The invention discloses an ARM (advanced RISC (reduced instruction set computer) machines) and FPGA (field-programmable gate array) based navigation and autonomous flight control system for an unmanned helicopter. The system comprises a PC (personal computer), an integrated navigation subsystem, a power supply module and controllers, wherein the integrated navigation subsystem comprises a sensor group; the sensor group comprises a GPS (global positioning system), a gyroscope, an accelerometer, a magnetoresistive sensor, a barometric altimeter and a sonar altimeter; the controllers include a main controller and a steering engine controller; the main controller adopts an ARM microprocessor to operate the integrated navigation algorithm and flight control PID (proportion integration differentiation) algorithm and simultaneously completes data acquisition of the GPS, the barometric altimeter and the sonar altimeter; and the steering engine controller adopts an FPGA to realize data acquisition of the gyroscope, the accelerometer and the magnetoresistive sensor and transfers the data to the main controller via a concurrent bus to carry out attitude calculation and control operation on the unmanned helicopter. With the unmanned helicopter as a carrier, the hardware environment of a whole set of flight control system integrating study of the aircraft navigation and control theory problem, data acquisition, information transfer and embedded control is set up.

A method and system for at least three dimensional imaging comprising a processor for processing information; at least one photon light source generating a beam of light; a modulator for modulating the light of the at least one photon light source; a plurality of first receivers operative to detect the influence of a subject on the beam; the plurality of first receivers being operatively connected to the processor and operating to transmit nonspatial information to the processor; the plurality of first receivers being spaced at known, different distances from the subject, whereby comparison of each of the outputs of the plurality of first receivers provides three dimensional information concerning the subject; the processor operating to correlate the outputs of the plurality of first receivers with spatial information derived from the modulated light at correlating intervals of time to create a three dimensional image of the subject.