In some embodiments, an archery bow comprises a riser comprising a cavity and a grip attached to the riser and arranged to cover the cavity. A first limb is supported by the riser and a second limb is supported by the riser. A bowstring extends between the first limb and the second limb. A data device comprises an accelerometer. In some embodiments, the data device is oriented in the cavity and attached to the riser.

A method at a sensor apparatus, the method including calculating a value for a target function based on at least one sensor of the sensor apparatus; determining that the value of the target function is within a defined threshold range for a defined time period, thereby finding an in-flight state for the sensor apparatus; and turning off transmission from a radio of the sensor apparatus based on the in-flight state.

A method at a sensor apparatus, the method including calculating a value for a target function based on at least one sensor of the sensor apparatus; determining that the value of the target function is within a defined threshold range for a defined time period, thereby finding an in-flight state for the sensor apparatus; and turning off transmission from a radio of the sensor apparatus based on the in-flight state.

An object detection device includes an external sensor, an inertia sensor, and a control device. The external sensor is fixed to a ship. The external sensor detects an object. The inertia sensor detects information related to an inertial force applied to the ship. The control device acquires a state of relative displacement of a detection object on the basis of a signal output from the external sensor. The control device acquires a state of an attitude change of the ship on the basis of a signal output from the inertia sensor. The control device determines whether a detection object is present outside the ship according to a correlation between the state of the attitude change of the ship and the state of the relative displacement of the detection object.

An object detection device includes an external sensor, an inertia sensor, and a control device. The external sensor is fixed to a ship. The external sensor detects an object. The inertia sensor detects information related to an inertial force applied to the ship. The control device acquires a state of relative displacement of a detection object on the basis of a signal output from the external sensor. The control device acquires a state of an attitude change of the ship on the basis of a signal output from the inertia sensor. The control device determines whether a detection object is present outside the ship according to a correlation between the state of the attitude change of the ship and the state of the relative displacement of the detection object.

Obstacle detection and characterisation method, including the steps of: acquiring a first distance measurement obtained from at least one inertial measurement produced by at least one inertial sensor of a mobile terminal, and a second distance measurement obtained from at least one time of flight measurement; evaluating a distance error representative of a difference between the second distance measurement and the first distance measurement; from the distance error, detecting the presence of an obstacle between the mobile terminal and the reference equipment, and determining one or more characteristics of said obstacle.

Obstacle detection and characterisation method, including the steps of: acquiring a first distance measurement obtained from at least one inertial measurement produced by at least one inertial sensor of a mobile terminal, and a second distance measurement obtained from at least one time of flight measurement; evaluating a distance error representative of a difference between the second distance measurement and the first distance measurement; from the distance error, detecting the presence of an obstacle between the mobile terminal and the reference equipment, and determining one or more characteristics of said obstacle.

Embodiments of the present disclosure provide systems and methods to eliminate (or filter) drift for dynamics model based localization of multirotors. The dynamics equations require drag modelling, which is dependent on velocity, to generate vehicles' acceleration along the body axis. The present disclosure considers the drag contribution, at velocity level, as a low frequency component. Incorrect or nonmodelling of this low frequency component leads to drift at velocity level. This drift can then be removed through a high pass filter to obtain drift free velocity data for pose estimation and better localization thereof.

Embodiments of the present disclosure provide systems and methods to eliminate (or filter) drift for dynamics model based localization of multirotors. The dynamics equations require drag modelling, which is dependent on velocity, to generate vehicles' acceleration along the body axis. The present disclosure considers the drag contribution, at velocity level, as a low frequency component. Incorrect or nonmodelling of this low frequency component leads to drift at velocity level. This drift can then be removed through a high pass filter to obtain drift free velocity data for pose estimation and better localization thereof.

Systems and methods for determining orientations measurements are provided. In one aspect, the method includes receiving a magnetic field state of an object, receiving a magnetic field measurement associated with the object, receiving an inertial measurement unit (IMU) measurement associated with the object, receiving a previous gravitational state term associated with the object, determining a gravitational acceleration state term based on the IMU measurement and the previous gravitational state term, determining a magnetic field state term based on the IMU measurement, the magnetic field measurement, and the gravitational acceleration term, and determining an orientation of the object using the gravitational acceleration state term and the magnetic field state term. The magnetic field measurement may be received from a magnetometer, and the IMU measurement may be received from a gyroscope and an accelerometer.