817results 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.

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.

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 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.

Motion sensing of a portable device using two cameras. A first camera is directed along a first viewing axis and a second camera is directed along a second viewing axis, different from the first viewing axis. The second viewing axis can be substantially opposite the first viewing axis. A motion processing module determines changes in images from the first camera and changes in images from the second camera. The motion processing module compares the direction of change determined from the first camera images relative to the direction of change determined from the second camera images. The motion processing module determines the motion of the portable device based in part on the comparison.

A tracking device for automatically following a moving light source that is detectable in the presence of ambient light. A carrier platform including one or more radiant energy conversion devices and a sensor array is mounted to an upright support column with a universal joint. Three independently-operated, linear actuators are equally angularly spaced about the support column with an upper end connected to the carrier platform with a universal hinge and a lower end connected to a floating base with a spherical hinge. A sensor array carried by the carrier platform includes a primary sensor associated with each actuator. During operation, when a primary sensor is not receiving direct radiant energy, the actuator retracts, and when it is receiving radiant energy directly, the actuator extends. The result is that the platform will directly track the sun across the horizon.

Apparatus and methods are disclosed that enable a device to locate and track a light source. In certain preferred embodiments, the device is a telescope and the light source is the sun. In some embodiments, the apparatus includes a plurality of photodetectors and a plurality of shade casting members. The shade casting members may be disposed substantially symmetrically about an optical axis of the apparatus. In certain embodiments, the apparatus can locate and track the light source by comparing one or more signals produced by the photodetectors in response to light received from the light source.

System, method, and apparatus for determining the composition of a sample of material. In one embodiment, the method pertains to the counting of photons that were inelastically scattered by the sample, and for minimizing the effects of fluorescent or phosphorescent photons. In yet another embodiment of the invention, a sample is illuminated by a repetitive pulse of monochromatic light, and the resultant scattered photons from the samples are collected and counted during a predetermined integration period. Yet other embodiments pertain to a low-cost, computer-controlled system for repetitively counting inelastically scattered photons so as to create a Raman histogram and a Raman spectrogram of the photons.

The invention discloses an integrated navigation system applied to a pilotless aircraft, which adopts a sensor comprising an inertial sensor, a radio altimeter, a communication module, a camera and the like, wherein the inertial sensor is used for acquiring motion acceleration and angular velocity of a carrier, and providing the motion acceleration and the angular velocity for an inertial navigation system and a vision navigation system in the unknown environment for setting up a system equation, thus further providing the current location information and matched trigger signals for scene matching navigation. The method integrates four combination ways which are inertial navigation, cellular wireless location navigation, vision navigation in the unknown environment and the scene matching navigation, and the four combination ways form each subsystem of the integrated navigation system and can be independently used for estimating the state of the aircraft; then, fault diagnosis and fusion estimation are carried out on the data output by the subsystems by a main filter, so that the accurate estimation of the state of the aircraft is obtained.

An occupancy sensor is provided with a separable override unit which can selectively override the operation of the occupancy sensor at designated times and for selected time intervals. The occupancy sensor includes a light sensor for actuating the occupancy sensor and a light assembly when the ambient light is below a predetermined level and to deactivate the occupancy sensor when the ambient light is above a threshold level to prevent the light assembly from being actuated when the light level is sufficient to avoid the need for actuating the light assembly. The override unit is removably attached to the occupancy sensor and is provided with a light source, such as an LED. The override unit is coupled to the occupancy sensor to emit light to actuate the light sensor of the occupancy sensor, thereby controlling the operation of the occupancy sensor, such as by preventing the occupancy sensor from being actuated regardless of the light level in the surrounding areas. The occupancy sensor includes a cavity on a top surface for receiving the override unit. The light sensor of the occupancy sensor is positioned in the cavity. The LED on the override unit is on an end that is inserted into the cavity to align with the light sensor. A control unit is operatively connected to one or more override units for selectively controlling the normal operation of the occupancy sensor.

An aircraft formation/refueling guidance system guides a follower aircraft relative to a leader aircraft. A datalink provides a position hold and a bias command from the leader aircraft to the follower aircraft. An optical tracker onboard the follower aircraft takes an image of the leader aircraft when receiving the hold command, tracks the leader aircraft using the image, and provides optical tracker movement outputs. A resolver resolves the optical tracker movement outputs to provide resolver control signals. A vernier control receives the bias command to change a position of the follower aircraft by biasing the resolver control signals with a bias signal. A sum circuit connected to the resolver and to the vernier control receives the resolver control signals and the bias signal to provide a sum circuit output signal. An autopilot and autothrottle receives the sum circuit output signal and the position hold command to control the follower aircraft.

Systems and methods of calibrating heliostat parameters for subsequent open-loop sun-tracking, the calibration based on driving artificial light source reflections from one or more heliostats into one or more image sensors.

The invention discloses a non-cooperative spacecraft attitude estimation method based on virtual sliding mode control, and belongs to the technical field of non-cooperative spacecraft navigation. The non-cooperative spacecraft attitude estimation method comprises the following steps: utilizing a virtual control sliding mode controller based on the Lyapunov principle; using target satellite absolute attitude obtained by a stereoscopic vision system as a control objective; according to motion characteristics of the target satellite, establishing a virtual satellite motion model of the target satellite; using a kinetic model of the virtual satellite as a controlled member to obtain attitude parameters of the virtual satellite; using attitude parameters estimated by the virtual satellite and the target satellite absolute attitude obtained by the stereoscopic vision system as controlled input, and calculating the virtual revolving moment on the motion model of the virtual satellite through the virtual sliding mode controller, so as to realize the estimation of the target satellite attitude parameters by the virtual control sliding mode controller. The non-cooperative spacecraft attitude estimation method disclosed by the invention is low in calculated amount, and can still achieve higher convergence rate and higher precision when the initial error of the state variables is high or the system error emerges, so as to meet the requirements of the high performance navigation system.

The invention discloses a high-precision vehicle positioning method for fusing multi-source information under a GPS (global positioning system) blind area and a device. By a strap-down matrix algorithm of the method, INS (inertial navigation system) vehicle position information and position information obtained by a pavement matching technology are calculated according to angular rate information output by a gyroscope and acceleration information output by an accelerometer and are fused by a kalman filtering algorithm to output final fused positioning information. As an INS positioning algorithm has an accumulated error, vehicle position information is recalibrated by arranging an anchor node beside a road. According to the method, stable and reliable high-precision vehicle position information can be obtained; the method is suitable for non-GPS-signal environments such as urban roads with dense buildings, mountain areas and tunnels.

A laser warning receiver is disclosed which has up to hundreds of individual optical channels each optically oriented to receive laser light from a different angle of arrival. Each optical channel has an optical wedge to define the angle of arrival, and a lens to focus the laser light onto a multi-wavelength photodetector for that channel. Each multi-wavelength photodetector has a number of semiconductor layers which are located in a multi-dielectric stack that concentrates the laser light into one of the semiconductor layers according to wavelength. An electrical signal from the multi-wavelength photodetector can be processed to determine both the angle of arrival and the wavelength of the laser light.

Concentrating solar collector systems that utilize a concentrating reflector to direct incident solar radiation to a solar receiver are described. In one aspect, the reflective surface is arranged to direct light to the receiver in a non-imaging manner in which the solar rays reflected from the opposing edges of the reflective surface are generally directed towards a central portion of the solar receiver. Rays reflected from selected central portions of the reflective surface are directed closer to the edges of the receiver than the solar rays reflected from the edges of the reflective surface. The described reflectors are generally intended for use in solar collector systems that track movements of the sun along at least one axis.

A trajectory is generated using non-uniform rational B-splines. A feasible corridor is approximated with at least one convex polytope. The at least one convex polytope is defined by a plurality of vertices. The feasible corridor comprises a region in a trajectory space that satisfies a plurality of trajectory constraints for a vehicle to pass through the trajectory space. The vehicle comprises a plurality of vehicle constraints. A non-uniform rational B-spline (NURBS) definition is constructed that comprises: a plurality of NURBS basis functions, a plurality of control points that comprise the plurality of vertices, and a plurality of weight points. The plurality of vehicle constraints are parameterized with the plurality of NURBS basis functions. At least one trajectory is generated for the vehicle through the trajectory space where the at least on trajectory lies within the feasible corridor to satisfy the plurality of trajectory constraints.

A light-sensing module and arrays of two or more light-sensing modules are described. Each light-sensing module comprises a mounting support structure that may include an air vehicle guidance section and an optical element adapted to direct incident light to a detector array that comprises an array of photodiodes and is attached to the mounting support structure. The detector array is adapted to receive the directed light and convert the received light to a set of electrical pulses via a plurality of photodetectors each of which is operatively coupled to an amplifier and a threshold circuit adapted to output a detection to a memory store adapted to associate a detection with a time-of-arrival. The light-sensing module may be adapted to output the associated detection and time-of-arrival. Air vehicles including the light-sensing modules are also disclosed.