A method for guiding a terrestrial vehicle along a desired path can include receiving a position signal from a global navigation satellite system (GNSS) antenna and a gyro signal from a gyro sensor that is indicative of: (i) at least one of a pitch and a roll of the terrestrial vehicle, and (ii) a gyro-based heading direction. A position of a point of interest of the terrestrial vehicle at a location different than the GNSS antenna can be determined based on the position signal, the gyro signal, and a positional relationship between the first location and the second location. A position-based heading direction of the point of interest of the terrestrial vehicle can be determined based on the determined position of the point of interest and at least one previously determined position of the point of interest.

The present invention reduces an arithmetic operation amount for updating a state vector. The attitude estimating device includes (i) a gravitational direction estimating section for updating, by using an acceleration vector as an observation, a gravitational direction vector predicted from an angular velocity vector, (ii) a horizontal direction estimating section for updating, by using a magnetic vector as an observation, a horizontal direction vector predicted from the angular velocity vector, and an attitude estimating section for generating attitude information with use of the gravitational direction vector and the horizontal direction vector.

A disclosed method includes computing, for each of a plurality of values of at least one type of error parameter, a distance traveled for each of a plurality of directions of travel. The method includes selecting, from the plurality of values of the at least one type of error parameter, a value that provides a greatest distance traveled for any of the plurality of directions of travel relative to the unselected ones of the plurality of values. The method further includes applying the selected value of the at least one type of error parameter to gyroscopic sensor data, and then determining navigation information based on the gyroscopic sensor data with the selected value of the at least one type of error parameter applied.

A system and method for mounting a device to a piece of equipment is presented, and may include a handheld inertial measurement unit (IMU), a computer logic and a mounting interface. The piece of equipment may have a line replaceable unit (LRU) mount that allows a new LRU to be mounted thereon. The mounting interface may be mounted to a LRU mount. The handheld IMU may determine position data with respect to the LRU mount and the piece of equipment. The computer logic may be configured to calculate a positional error value based on the position data to indicate to a user whether corrections need to be made regarding how the new LRU is mounted to the LRU mount before the new LRU is mounted to the LRU mount or whether the new LRU can be mounted to the LRU mount without any corrections.

A method estimating orientation of a path followed by a carrier of a movement sensor includes: determining an orientation of the movement sensor with respect to the path; estimating an orientation of the movement sensor with respect to a fixed reference; estimating an orientation of the path with respect to the fixed reference by the determined orientation of the movement sensor and the estimated orientation of the movement sensor; detecting start and end of a phase of disorientation of the movement sensor with respect to the path; updating, after the detected end of the disorientation phase, determined orientation of the movement sensor with respect to the path by orientation of the path with respect to the fixed reference as estimated at the detected start of the disorientation phase and orientation of the movement sensor with respect to the fixed reference as estimated after the detected end of the disorientation phase.

A method for determining an orientation of a portable or mobile electronic device includes determining an orientation of the device using at least a first inertial motion sensor (e.g., a gyroscope) with which the portable electronic device is equipped. A correction factor is provided to the orientation of the electronic device using a feedback control signal based on motion data obtained from at least a second inertial motion sensor (e.g. an accelerometer) to reduce drift in motion data obtained from the first inertial sensor. Responsive to a loss of valid motion data from the first inertial motion sensor, a rate at which the correction factor is provided to the orientation of the portable electronic device is increased.

A disturbance estimation apparatus including a navigation data receiver, a thrust data receiver, and processing circuitry is provided. The navigation data receiver acquires navigation data including an actual position and time of the ship on a water surface. The thrust data receiver receives thrust data indicating a magnitude and a direction of a thrust force of the ship. The processing circuitry estimates a predicted position of the ship under an absence of a disturbance condition at a predetermined time in the future using a first state estimation model based on the navigation data and the thrust data and determines disturbance data including a drift direction of the ship drifted by an external force based on a difference between the predicted position estimated by the first state estimation model and an actual position of the ship at the predetermined time.

A disturbance estimation apparatus including a navigation data receiver, a thrust data receiver, and processing circuitry is provided. The navigation data receiver acquires navigation data including an actual position and time of the ship on a water surface. The thrust data receiver receives thrust data indicating a magnitude and a direction of a thrust force of the ship. The processing circuitry estimates a predicted position of the ship under an absence of a disturbance condition at a predetermined time in the future using a first state estimation model based on the navigation data and the thrust data and determines disturbance data including a drift direction of the ship drifted by an external force based on a difference between the predicted position estimated by the first state estimation model and an actual position of the ship at the predetermined time.

In one embodiment, a method includes, by an electronic device, accessing a first series of first magnetic values that represents a first magnetic recording that comprises a first set of first magnetic measurements that are each represented by one of the first magnetic values. The method includes, by the electronic device, accessing a second series of second magnetic values that represents a second magnetic recording that comprises a second set of second magnetic measurements that are each represented by one of the second magnetic values. The method includes, by the electronic device, approximately aligning the first and second series with each other; calculating a difference between the first and second series as aligned with each other; determining a similarity between the first and second series based on the difference; and performing navigation or localization based on the determined similarity.

In one embodiment, a method includes accessing a trajectory and comparing a first one of multiple portions of the trajectory with a second one of the portions. A greater level of confidence is associated with the first one of the portions than the second one of the portions. The method includes determining, based on the comparison, that the first and second ones of the portions approximately magnetically coincide with each other and are not approximately colocated with each other in the trajectory; comparing a first level of confidence associated with the first one of the portions with a second level of confidence associated with the second one of the portions; and, when the first level of confidence is greater than the second level of confidence, adjusting the second one of the portions to be approximately colocated with the first one of the portions in the trajectory.