Disclosed is a self-adaptive horizontal attitude measurement method based on motion state monitoring. Based on a newly established state space model, a horizontal attitude angle is taken as a state variable, an angular velocity increment Δω.sup.b for compensating a random constant zero offset is taken as a control input of a system equation, and a specific force f.sup.b for compensating the random constant zero offset is taken as a measurement quantity. Meanwhile, judgment conditions for a maneuvering state of a carrier are improved, and maneuvering information of the carrier is judged by comprehensively utilizing acceleration information and angular velocity information output by a micro electro mechanical system inertial measurement unit (MEMS-IMU), whereby a measurement noise matrix of a filter can be automatically adjusted, thereby effectively reducing the influence of carrier maneuvering on the calculation of a horizontal attitude. The method has no special requirement on the maneuvering state of the carrier, and can ensure that the system has high attitude measurement precision in different motion states without an external information assistance.

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 11.7 kg.m.sup.2 (40000 lbm 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 11.7 kg.m.sup.2 (40000 lbm in.sup.2) to be accelerated at a rate of 2.5 rpm/s or greater.

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 11.7 kg.m.sup.2 (40000 lbm 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 11.7 kg.m.sup.2 (40000 lbm in.sup.2) to be accelerated at a rate of 2.5 rpm/s or greater.

Systems and methods are disclosed herein for blind frequency synchronization. In one embodiment, a synthetic inertial measurement unit (IMU) is disclosed, comprising: a plurality of nodes wirelessly coupled to each other, each The method may further comprise: a wireless transceiver at a particular node for providing wireless communications with at least one other node of the plurality of nodes, configured to receive I and Q radio samples from the other node, and to determine a frequency offset of the other node based on the received I and Q radio samples, and to synchronize a clock at the particular node, a frequency offset synchronization module at the particular node coupled to the wireless transceiver, at the particular node, and an IMU sensor for determining rotation, acceleration, and speed of the particular node; and an IMU location estimation module for using time of arrival information assuming that the clock may be synchronized at the node, the determined distance, and the rotation, acceleration, and speed of the particular node received from the IMU sensor to determine the location of the nodes, thereby providing enhanced determination of location of the plurality of nodes.

Systems and methods are disclosed herein for blind frequency synchronization. In one embodiment, a synthetic inertial measurement unit (IMU) is disclosed, comprising: a plurality of nodes wirelessly coupled to each other, each The method may further comprise: a wireless transceiver at a particular node for providing wireless communications with at least one other node of the plurality of nodes, configured to receive I and Q radio samples from the other node, and to determine a frequency offset of the other node based on the received I and Q radio samples, and to synchronize a clock at the particular node, a frequency offset synchronization module at the particular node coupled to the wireless transceiver, at the particular node, and an IMU sensor for determining rotation, acceleration, and speed of the particular node; and an IMU location estimation module for using time of arrival information assuming that the clock may be synchronized at the node, the determined distance, and the rotation, acceleration, and speed of the particular node received from the IMU sensor to determine the location of the nodes, thereby providing enhanced determination of location of the plurality of nodes.

In an embodiment, a method comprises: estimating a first gravity direction in a source device reference frame for a source device; estimating a second gravity direction in a headset reference frame for a headset; estimating a rotation transform from the headset frame into a face reference frame using the first and second estimated gravity directions, a rotation transform from a camera reference frame to the source device reference frame, and a rotation transform from the face reference frame to the camera reference frame; estimating a relative position and attitude using source device motion data, headset motion data and the rotation transform from the headset frame to the face reference frame; using the relative position and attitude to estimate a head pose; and using the estimated head pose to render spatial audio for playback on the headset.

The invention relates to a daytime and nighttime stellar sensor (1), comprising: at least one video camera (2) suitable for taking images of stars (3) in the sky; and a control unit (4), characterized in that it furthermore comprises: a polarizer (5), the control unit (4) being configured: to obtain an estimation of a direction of polarization of the polarized light received from the sky by the video camera (2); and to control the orientation of the polarizer (5) so that said polarizer (5) filters polarized light from the sky directed toward the video camera (2) and having said polarization direction.

The invention relates to a daytime and nighttime stellar sensor (1), comprising: at least one video camera (2) suitable for taking images of stars (3) in the sky; and a control unit (4), characterized in that it furthermore comprises: a polarizer (5), the control unit (4) being configured: to obtain an estimation of a direction of polarization of the polarized light received from the sky by the video camera (2); and to control the orientation of the polarizer (5) so that said polarizer (5) filters polarized light from the sky directed toward the video camera (2) and having said polarization direction.

The present invention relates to a two-wheel electric vehicle, comprising: a frame (1); a housing (3) connected to the frame (1); one front wheel (2) and one rear wheel (6); and a gyroscope device (5), the gyroscope device (5) comprises a flywheel (13); and a control system (10), the control system (10) controlling a precession angular speed of the flywheel (13) within a period during which the two-wheel electric vehicle is started but does not run, a period during which the two-wheel electric vehicle runs normally or a period during which the two-wheel electric vehicle steers, to keep balance of a vehicle body. The two-wheel electric vehicles solves the technical problem existing in the prior art of poor stability of the two-wheel electric vehicle.

The present invention relates to a two-wheel electric vehicle, comprising: a frame (1); a housing (3) connected to the frame (1); one front wheel (2) and one rear wheel (6); and a gyroscope device (5), the gyroscope device (5) comprises a flywheel (13); and a control system (10), the control system (10) controlling a precession angular speed of the flywheel (13) within a period during which the two-wheel electric vehicle is started but does not run, a period during which the two-wheel electric vehicle runs normally or a period during which the two-wheel electric vehicle steers, to keep balance of a vehicle body. The two-wheel electric vehicles solves the technical problem existing in the prior art of poor stability of the two-wheel electric vehicle.