Xsens Holding B.v.

Xsens Technologies, B.v.

Hendrik Johannes Luinge

Per Johan Slycke

Giovanni Bellusci

Freerk Dijkstra

Jeroen Diederik Hol

Daniel Roetenberg

Pieter Laurens Slot

A technique for calculating magnetic field information from a magnetic sensor employs a sensing unit containing the magnetic sensor and another sensor capable of providing a measure of change in orientation. The method includes sampling a magnetic field at points in time and sampling the other sensor at each point in time. The method then entails rotating to a common time instant the magnetic field samples using the orientation of the sensing unit estimated by means of the other sensing modality in order to eliminate variations between magnetic samples due to changes in orientation of the sensor unit within such time interval. The magnetic samples, corrected for the sensor rotation in such interval, are used to calculate magnetic field related information specific to the given time interval and the magnetic field related information is communicated to a receiver at a rate lower than the sample rate.

System and method for magnetic field data compression

A method, controller and system in accordance with various aspects of the present disclosure facilitate reduced energy consumption in a motion sensing device having an inertial measurement unit (IMU), with a strap down integration unit, and an application processing unit (AP). The system and method include rounding velocity increments and orientation increments at the inertial measurement unit, thereby producing a remainder values. The remainder values are added to subsequent velocity increments and orientation increments prior to rounding of those values, and so on. In this way, while motion granularity is slightly decreased, there is no drift of integration errors over time.

Compression of IMU data for transmission of AP

A method, controller and system in accordance with various aspects of the present disclosure facilitate reduced energy consumption in a motion sensing device having an inertial measurement unit (IMU), with a strap down integration unit, and an application processing unit (AP). The system and method include sensing acceleration values and rotational values at the IMU and converting the sensed acceleration and rotational values into velocity and orientation increments by strap down integration. The velocity and orientation increments are stored in a first buffer at the IMU between updates to the AP. When an update request is received at the IMU from the AP over an interrupt link, the buffer contents are transmitted over a serial link from the IMU to the AP.

Reduction of IMU/AP link requirements for SDI

The described principles provide a method and system for calibrating an UWB RF positioning system. Means for automated calibration of the UWB RF positioning system allow calibration based on simple user input that does not require accuracy. Thus, the disclosed calibration means enables nomadic deployment of UWB RF positioning systems by enabling fast and easy calibration and re-calibration of the system based on in-use data to correct for changes in the system during use. Furthermore, in an embodiment of the invention, means are provided for direct feedback of calibration accuracy to the user. In a further embodiment of the invention, the full use of a UWB positioning system is enabled by obtaining optimal accuracy even at the outskirts of the tracking space and by providing optimal accuracy for a given number of receivers.

Positioning system calibration

A six-degree-of-freedom (6DOF) tracking system adapts aspects of Ultra-Wideband (UWB) measurement and microelectromechanical systems (MEMS) inertial measurements within a unique tightly coupled fusion algorithm to accurately and efficiently measure an object's position as well as orientation. The principle of operation of the system protects against the negative effects of multipath phenomenon and non-line-of-sight (NLOS) conditions, allowing a more robust position and orientation tracking system.

Tightly coupled UWB/IMU pose estimation system and method

The invention relates to motion tracking system () for tracking a movement of an object (P) in a three-dimensional space, the said object being composed of object portions having individual dimensions and mutual proportions and being sequentially interconnected by joints the system comprising orientation measurement units (S, S, . . . SN) for measuring data related to at least orientation of the object portions, wherein the orientation measurement units are arranged in positional and orientational relationships with respective object portions and having at least orientational parameters; a processor () for receiving data from the orientation measurement units, the said processor comprising a module for deriving orientation and/or position information of the object portions using the received data and a calibration unit () arranged to calculate calibration values based on received data and pre-determined constraints for determining at least the mutual proportions of the object portions and orientational parameters of the orientation measurement units based on received data, pre-determined constrains and additional input data. The invention further relates to a method for tracking a movement of an object, a medical rehabilitation system and an animation system.

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Enschede, Netherlands

Hendrik Johannes Luinge