A system and method for determining a position of a remote object comprising inertial sensors and three axis magnetic sensor, together with a target sighting device aligned with the observation platform to determine a target line of sight and a target range finder to determine a distance to the target along the line of sight. A GPS receiver may be included for determining an observation platform position and orientation, The three axis magnetic sensor provides both magnetic north and vertical attitude information for improved rapid initialization and operation in motion. Magnetic anomaly information is detected by comparing IMU and magnetic navigation information and by other methods. Target identification may be determined by a human operator and/or by computer. The system may be integrated with a weapon system to use weapon system sights. The system may be networked to provide target location and/or location error information to another identical unit or a command information system.

Magnetically stabilized forward observation platform

Disclosed is a system and method for onboard optimal estimation of heading, pitch, and roll through real-time measurement of magnetic field, acceleration and angular motion in three dimensions. Magnetometer information is used to create an initial reference from which movement is measured. Thus, the process does not have to start when the body is in a known position. Further, the device does not have to continually rely on accelerometer data to get roll and pitch. To do this magnetic field data is used to complement gyro information. The magnetic data is used to estimate pitch, roll, and heading.

Inertial/magnetic measurement device

An exemplary inertial measurement apparatus incorporates self-calibrating bias correction signals. First and second inertial instruments generate respective input signals representative of an inertial attribute to be measured. A bias estimator generates first and second bias correction signals. First and second summation nodes receive the respective input signals and the respective first and second bias correction signals. The first and second summation nodes provide respective summed signals to the first and second inertial instruments. The first and second inertial instruments generate respective output signals representative of a value of the inertial attribute based on the respective summed signals. The bias estimator calculates the first and second bias correction signals based on first and second measurements made during respective first and second time intervals where a sign of one of the first and second bias error signals changes from one state during the first time interval to the other state during the second time interval.

Self-calibration for an inertial instrument based on real time bias estimator

For the fast and accurate self-localization of mobile robots, artificial landmarks can be used very efficiently in the complex workspace. In this paper, we designed a color artificial landmark with symmetric rectangles and seven-part numbers, which showed cross- ratio invariance under perspective transformation and proposed a fast landmark detection-recognition algorithm based on the proposed landmark model. Detection- recognition of the model was accomplished by color information and cross-ratio invariance. We also proposed a self-localization algorithm based on the landmark model. We demonstrated the feasibility of the proposed technique through practical experiments in cluttered indoor environments and simulation experiments. Experimental results show that proposed landmark is enough to be used in cluttered environment and landmark detection-recognition in cluttered scene is real-time robustly under various viewing angles, self-localization is accurate in the presence of additive random noise.

Color Landmark Design for Mobile Robot Localization

Systems and methods for attitude fault detection based on air data and aircraft control settings are provided. In one embodiment, a sensor monitor for an aircraft attitude measurement system comprises: an aircraft model configured to model a plurality of states, the plurality of states including at least an aircraft attitude state, an aircraft velocity state, a sink rate error state, and a wind velocity state; a propagator-estimator configured to utilize the plurality of states of the aircraft model to process air data measurements and attitude measurements from a first inertial measurement unit of the aircraft attitude measurement system; and a residual evaluator configured to input residual error values generated by the propagator-estimator, wherein the residual evaluator outputs an alert signal when the residual error values exceed a predetermined statistical threshold.

Systems and methods for attitude fault detection based on air data and aircraft control settings

A method and an arrangement for synthetically calculating redundant attitude and redundant heading by means of existing data in an aircraft. In one embodiment the heading of the aircraft is available and in another embodiment the heading is calculated from a magnetic heading sensor. When the heading is available (redundant heading) attitude is calculated by weighting together the signals from and angular rate gyros (2) in the aircraft's flight control system, information from air data (altitude, speed, angle of attack) as well as information about heading (redundant heading). When the heading is not available, attitude and heading are calculated in one embodiment with the aid of Kalman filters (11, 22) by weighting together the signals from the angular rate gyros in the aircraft's control system, information from air data (altitude, speed, angle of attack and sideslip angle) as well as information from a magnetic heading detector existing in the aircraft.

Redundant system for the indication of heading and attitude in an aircraft

Un procedimiento de control de un Vehiculo (100) Aereo No Tripulado desde una estacion (110) de control por medio de un enlace (115) de comando inalambrico, que implica: control de vuelo en un modo autonomo en el que el vehiculo (100) vuela de acuerdo con una ruta primaria (R1, R1') definida por un primer conjunto de puntos de referencia predefinidos (WP1-WP8, IP), control de vuelo en un modo manual en el que el vehiculo (100) vuela de acuerdo con una ruta primaria (R1') definida por comandos de control recibidos a traves del enlace (115) de comando inalambrico, y supervision funcional de un conjunto de parametros de control de vuelo (P1-Pn) tanto en el modo autonomo como el modo manual, en el que si, en alguno de los modos, al menos uno de los parametros de control de vuelo (P1-Pn) esta fuera de un intervalo aceptable se activa una condicion de alarma principal, el procedimiento implica volar el vehiculo (100) de acuerdo con una ruta de emergencia (R2') definida por un segundo conjunto de puntos de referencia predefinidos (HP4, HP3, IP, TP9), caracterizado por el conjunto de parametros de control de vuelo (P1-Pn) incluyendo al menos un parametro de motor, comprendiendo el procedimiento: activar una condicion de alarma principal con respecto a un fallo de motor en caso de que al menos uno del al menos un parametro de motor descienda por debajo de un valor umbral y, en tal caso, la ruta de emergencia (R2') implica volar el vehiculo (100) a un espacio aereo por encima de un punto de referencia de terminacion (TP1-TP9) en el suelo en el que se estima que el vuelo del vehiculo (100) puede terminarse sin herir a ningun personal o provocar danos de materiales no controlados.

Peter Adebjörk

Papers

Redundant system for the indication of heading and attitude in an aircraft

Navigation using landmarks