A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. For smaller units, the bearing cooling system is effective to enable a flywheel with a moment of inertia less than 40,000 lb in.sup.2 to be accelerated at a rate of 5 rpm/s or greater. For larger units, the bearing cooling system is effective to enable a flywheel with a moment of inertia greater than 40,000 lb in.sup.2 to be accelerated at a rate of 2.5 rpm/s or greater.

An inertial sensor includes: a plurality of inertial force detection elements each configured to output an output signal corresponding to a detected inertial force; and a processor configured to execute processing relating to the output signal from each of the plurality of inertial force detection elements. The plurality of inertial force detection elements includes: a plurality of main inertial force detection elements configured to detect inertial forces of a plurality of first predetermined axes orthogonal to each other; and a sub-inertial force detection element configured to detect an inertial force of a second predetermined axis which intersects the plurality of first predetermined axes such that the second predetermined axis is orthogonal to none of the plurality of first predetermined axes.

An inertial sensor includes: a plurality of inertial force detection elements each configured to output an output signal corresponding to a detected inertial force; and a processor configured to execute processing relating to the output signal from each of the plurality of inertial force detection elements. The plurality of inertial force detection elements includes: a plurality of main inertial force detection elements configured to detect inertial forces of a plurality of first predetermined axes orthogonal to each other; and a sub-inertial force detection element configured to detect an inertial force of a second predetermined axis which intersects the plurality of first predetermined axes such that the second predetermined axis is orthogonal to none of the plurality of first predetermined axes.

The disclosed subject matter includes a method and system for navigating an unmanned ground vehicle (UGV), that include: generating, based on the scanning output data, a first map comprising a first group of cells and characterized by a first size; generating, based on the scanning output data, a second map representing an area smaller than that of the first map comprising a second group of cells, which are characterized by a second size being smaller than the first size; wherein each cell in the first group of cells and the second group of cells is classified to a class selected from at least two classes, comprising traversable and non-traversable, wherein the second part at least partly overlaps the first part; navigating the UGV based on data deduced from crossing between cells in the first map and second map.

A box regularized particle filtering method implements a binary representation of numbers. This implementation can be used to determine a box division coordinate and/or to modify state intervals according to a fixed probability kernel, for example according to an Epanechnikov kernel. The method can be executed autonomously within a navigation system using measurement correlation, in particular on board an aircraft such as an airplane, a flying drone or any self-propelled airborne vehicle.

A box regularized particle filtering method implements a binary representation of numbers. This implementation can be used to determine a box division coordinate and/or to modify state intervals according to a fixed probability kernel, for example according to an Epanechnikov kernel. The method can be executed autonomously within a navigation system using measurement correlation, in particular on board an aircraft such as an airplane, a flying drone or any self-propelled airborne vehicle.

An inertial navigation system includes a first inertial measurement unit with at least a first sensor and a second inertial measurement unit with at least a second sensor corresponding in type to the first sensor. The first inertial measurement unit is rotatably mounted relative to the second inertial measurement unit, The inertial navigation system further include a controller arranged to: acquire a first set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; rotate the first inertial measurement unit relative to the second inertial measurement unit; acquire a second set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; and calculate from the first set of measurements and the second set of measurements at least one error characteristic of the first sensor and/or the second sensor.

An inertial navigation system includes a first inertial measurement unit with at least a first sensor and a second inertial measurement unit with at least a second sensor corresponding in type to the first sensor. The first inertial measurement unit is rotatably mounted relative to the second inertial measurement unit, The inertial navigation system further include a controller arranged to: acquire a first set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; rotate the first inertial measurement unit relative to the second inertial measurement unit; acquire a second set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; and calculate from the first set of measurements and the second set of measurements at least one error characteristic of the first sensor and/or the second sensor.

An orientation assembly includes a platform and a locking assembly engageable with the platform and positionable in a first state in which the platform is permitted to rotate about a lateral axis and inhibited from rotating about a longitudinal axis perpendicular to the lateral axis, and a second state in which the platform is permitted to rotate about the longitudinal axis and inhibited from rotating about the lateral axis.

An orientation assembly includes a platform and a locking assembly engageable with the platform and positionable in a first state in which the platform is permitted to rotate about a lateral axis and inhibited from rotating about a longitudinal axis perpendicular to the lateral axis, and a second state in which the platform is permitted to rotate about the longitudinal axis and inhibited from rotating about the lateral axis.