42 results about "Inertial reference unit" patented technology

A method for estimating a precise position of a user device from signals from a low earth orbit (LEO) satellite includes receiving at least one carrier signal at a user device, each carrier signal being transmitted a distinct LEO satellite. The user device processes the carrier signals to obtain a first carrier phase information. The user device recalls an inertial position fix derived at an inertial reference unit. The user device derives a position of the user device based on the inertial position fix and the first carrier phase information.

Systems, methods, and machine-executable programming products adapted for the control of aircraft or other vehicles by receiving from at least one Inertial Reference System (IRS), including a plurality of Inertial Reference Units (IRUs), signals representing vehicle state data; receiving from at least one Augmented Direct Mode Sensor (ADMS) signals representing independently-acquired vehicle state data corresponding to at least a subset of the signals received from the IRS; performing signal selection and fault detection processes on the signals received from the at least one IRS and on the corresponding signals received from the ADMS; based at least partly on the signal and fault detection processes, determining whether at least one component of at least one of the IRS and ADMS is in a fault condition; and based on the fault condition, providing to at least one vehicle control system device one or more vehicle control command signals.

An on-board communication and navigation system for an aircraft is provided for allowing an aircraft to transmit and receive information via satellite link. Specifically, the system includes a radome assembly and a fuselage coupler. The radome assembly, for example, may include an antenna, an antenna control unit and an inertial reference unit. During installation, the fuselage coupler is securely and permanently mounted on the aircraft, typically on the fuselage at the top of the aircraft. Once the fuselage coupler is securely mounted, the radome assembly can be removably attached to the fuselage coupler, allowing the radome assembly to be quickly and easily removed and reattached to the aircraft, as needed.

A device providing an inertially stabilized laser beam as an optical reference. The device consists of a base and a small stabilized optical platform that emits the laser beam. The platform connects to the base through a mechanical flexure that allows relative motion in two axes. High-bandwidth angular rate sensors affixed to the platform measure platform motion in inertial space. Linear displacement sensors measure relative motion between base and platform. A closed-loop control system accepts these sensor measurements and command actuators that null the sensed platform motions, maintaining the optical platform fixed in inertial space. The digital controller implements a Sensor Blending Kalman Filter that blends high frequency signals from the platform with low frequency signals from a DC sensor (gyroscope) external to this device but affixed to the common base. The controller enables both stabilization of the laser beam and commanded pointing of the beam in inertial space.

A device for determining the bearing of a vehicle using Inertial Reference Unit (IRU) and Traffic Alert Collision Avoidance System (TCAS) data. The device includes a means to communicate with the vehicle such as a transmitter, receiver, and antenna. The device also includes a processor configured to receive the IRU and TCAS data from the vehicle via the communication means and then generate a bearing value using the received data.

The invention discloses a method for controlling a satellite from any attitude to a sun pointing attitude. The method for controlling the satellite from any attitude to the sun pointing attitude comprises the steps of measuring inertial angle increment by using an inertial reference unit; differentiating the inertial angle increment to obtain inertial angular velocity; measuring the specific direction of the satellite where the sun appears by using a 0-1 type sun sensor and carrying out sun acquisition to obtain a sun direction signal; controlling satellite attitude acquisition by using the change of the sun direction signal; and reducing an included angle between sun vector and one axis of the satellite so as to carry out sun pointing. By using the sun direction information of the 0-1 type sun sensor, the sun can be acquired; and through the change of the sun direction signal, the satellite can be controlled to point the sun to provide satellite guarantee for energy supply of the whole satellite; and beneficial effects of realizing the satellite from any attitude to the sun pointing attitude only by using the inertial reference unit and the 0-1 type sun sensor, improving the satellite attitude control accuracy and so on are achieved.

A system (30) for determining a missile kinematic property. The inventive system includes a radar system (36) for obtaining radar range measurements (34). An inertial reference unit (40) tracks changes in missile acceleration without the use of the radar range measurements and provides a signal (38, 42) in response thereto. An altitude Kalman filter (32) and a subtractor circuit (48) are used to combine the signal (38, 42) and the radar range measurements (34) to provide an accurate estimate (50) of the property. In a specific embodiment, the kinematic property includes missile vertical velocity and missile altitude. A radar system (36) supplies radar range information (34) to the Kalman filter (32). A loop (52) from the Kalman filter (32) to the radar system (36) facilitates estimating the radar range measurements (34) when invalid radar range measurements are provided by the radar system (36). The Kalman filter (34) is a two state filter, one state corresponding to missile altitude, and the other state corresponding to missile vertical velocity bias error in the inertial reference unit's (40) velocity measurements (42). In the illustrative embodiment, the Kalman filter (32) combines radar pseudo-measurement estimates of missile altitude with estimates (38) of missile altitude obtained from the inertial reference unit (40) and provides an output signal (46) representative of an accurate missile altitude estimate in response thereto. The Kalman filter (32) includes a velocity bias output (44) which provides an estimate of the error in a velocity measurement (42) obtained from inertial reference unit (40) to the subtractor circuit (48). The subtractor circuit (48) subtracts the estimate (44) of the bias error from the velocity measurement (42) and provides the missile velocity estimate (50) in response thereto.

Precision alignment of auxiliary equipment on an aircraft is accomplished by a locating tool for the aircraft inertial reference unit (IRU) attached to the auxiliary equipment mount. Aircraft attitude and heading are obtained using the IRU. The IRU is removed from its avionics tray in the aircraft and installed on the locating tool. The locating tool is connected for remote operation of the IRU and the IRU is operated to obtain attitude and heading. This attitude and heading is then compared to the IRU reading for the attitude and heading of the aircraft.

The invention relates to a factor graph-based cluster satellite collaborative navigation method. The method comprises the following steps that: the multi-sensor measurement information of each sub-satellite in cluster satellites is acquired; the factor graph framework of cluster satellite collaborative navigation is constructed by means of a factor graph theory; and finally a multi-source information collaborative navigation algorithm is designed so as to calculate navigation information. According to the factor graph-based cluster satellite collaborative navigation method of the invention, existing satellite sensors including an inertial reference unit (IRU), a GPS (global positioning system), an inter-satellite distance measuring sensor, a star sensor, an infrared horizon sensor and the like are adopted; the sensors can be randomly recombined; the factor graph theory and the multi-source information collaborative navigation algorithm are effectively combined; the processing of asynchronous multi-rate measurement information is realized; real-time navigation information can be provided for the cluster satellites quickly and accurately; and a certain technical support can be provided for the research field of aerospace and the like.

A system is provided to establish and maintain a data path between a Local Area Network (LAN) that is mounted on a moving vehicle and a satellite. In combination, an antenna assembly, an Antenna Control Unit (ACU), an Inertial reference Unit (IRU), and a modem are mounted together on the moving vehicle, under the overall control of a services platform. Operationally, the IRU generates parametric values indicative of the spatial attitude and location of the moving vehicle. The ACU then uses the parametric values to aim the antenna in a direction toward the satellite. In this combination, the modem is connected with the antenna to transmit and receive data between the system and the satellite. Individually or collectively, operationally compatible components of the system (IRU, ACU, antenna and modem) can be appropriately substituted to thereby customize the system.

The invention discloses camera visual axis disturbance measuring equipment and method based on an inertial reference unit. The measuring equipment is composed of a high-precision inertial reference unit and an associated measuring unit. The inertial reference unit generally adopts a fiber-optic gyroscope, an angular displacement sensor and the like, and can accurately measure absolute angular displacement information at a mounting position; the associated measuring unit can accurately measure the relative angular displacement information between the visual axis of the camera and the inertial reference unit; the absolute angular displacement information of the camera, namely the visual axis disturbance quantity of the camera, can be obtained by combining the two sets of angular displacementinformation, the information can be used for image motion blur compensation, and the imaging quality of the long-focus space camera is improved.

A method of accurately tracking and communicating with a satellite from a mobile platform that has an antenna that performs both transmit and receive functions from a single antenna aperture. The method involves initially acquiring signals from satellites using an inertial reference unit (IRU) of a mobile platform. The sequential lobe process is then used to more precisely align the antenna aperture with the receive beam from the satellite. The antenna is then used to send data and other information, and the antenna is kept pointing by an additional IRU local to the antenna with higher accuracy and lower latency than the mobile platform's IRU. The transmission from the antenna is suppressed periodically and the timing lobe process is repeated to remove any inertial reference drift errors. This approach allows for more precise antenna pointing when using a single antenna aperture for transmit and receive functions, without significantly interfering with the transmission of data or information from the antenna.

A heliostat including a mirror configured to reflect light directed towards a first surface of the mirror, the light being external to the heliostat, the first surface being opposite a second surface of the mirror. A control mechanism is connected to the mirror and configured to change at least two angles of the mirror. An inertial reference unit is in communication with the control mechanism and configured to produce a beam and use the beam to optically sample the second surface of the mirror, the beam at least reflecting from the second surface. The control mechanism is configured to use data from the beam and the inertial reference unit to control the least two angles such that a virtual beam from the inertial reference unit remains about co-aligned with a line of sight vector of the mirror when the heliostat is subjected to an exogenous disturbance.

A system may generate a modified flight plan for an aircraft based on an original flight plan. The system may provide an automatic strategic offset function that includes an autoflight system; a sensor system including at least one of a global positioning system, an inertial reference unit, or an air data computer; and a flight management computer. The flight management computer may be operably coupled with the autoflight system and/or the sensor system. The flight management computer may process a flight plan of the vehicle and generate a non-uniform offset value in the vertical and/or lateral orientation between the flight plan and a boundary. The offset value may be used to create an offset flight plan for navigating an aircraft.

An improved method and apparatus for determining the amount of turn coordination gain in an aircraft yaw damper during a turn maneuver is disclosed. The yaw damper includes inputs from the inertial reference units of the aircraft and also from the flight management computer of the aircraft. The flight management computer provides to the yaw damper a signal indicative of the position of the flaps of the aircraft. The yaw damper includes a turn coordination gain box that receives the flap position signal and outputs a turn coordination gain value, dependent upon the flap position. Generally, the turn coordination gain value increases as the flap position is more extended. The precise turn coordination gain value for each flap position is dependent upon the particular aerodynamic characteristics of the aircraft.

A method, apparatus, and system for adjusting inertial reference data. The inertial reference data is received from an inertial reference unit in an aircraft. Replacement magnetic navigation data is determined for the aircraft at a current position of the aircraft. Magnetic navigation data in the inertial reference data is replaced with the replacement magnetic navigation data for the aircraft to form adjusted inertial reference data. The adjusted inertial reference data is sent to a number of aircraft systems that use the adjusted inertial reference data during operation of the aircraft.

The invention belongs to the field of space laser communication and the field of servo control, and particularly relates to a broadband inertial reference unit finite time anti-interference control method, which comprises the following steps of: 1, considering an asymmetric load and rotor sideslip existing in a broadband inertial reference unit as disturbance, and establishing a second-order mathematical model of the broadband inertial reference unit; 2, designing a finite time extended state observer for estimating disturbance of the broadband inertial reference unit; 3, designing a finite time controller to reduce the influence of disturbance on the output of the broadband inertial reference unit by using a disturbance estimated value obtained by the finite time extended state observer, so as to realize high-precision position control; and 4, carrying out convergence test on the finite time extended state observer and the finite time controller by adopting a Lyapunov function. The problem that the high-precision position control process of the broadband inertial reference unit is easily influenced by asymmetric load and rotor sideslip is solved, and it is guaranteed that the broadband inertial reference unit can output a stable and high-precision deflection angle within finite time.