Xsens Holding B.v.

Xsens Technologies, B.v.

Per Johan Slycke

Jeroen Diederik Hol

Giovanni Bellusci

Hendrik Johannes Luinge

Freerk Dijkstra

Daniel Roetenberg

Raymond Zandbergen

Henk J Luinge

Petrus Hermanus Veltink

In an embodiment, a method and system are provided for determining a pedestrian position via dead reckoning on a portable device carried by the pedestrian (or 'user'). The device has at least a processor, a 3D accelerometer, and a 3D gyroscope. The 3D accelerometer, and a 3D gyroscope are sampled to calculate device orientation, and then 3D accelerometer samples are gathered during a sensor time frame and an average step frequency is calculated. The user's speed and direction of movement are estimated and a device velocity is calculated relative to a prior device velocity via dead-reckoning. The estimated device velocity is corrected for drift and the pedestrian position is calculated based on the corrected estimated current device velocity.

Pedestrian dead reckoning position tracker

An integrated inertial motion capture system includes external position aiding such as optical tracking. The integrated system addresses and corrects misalignment between the inertial (relative) and positioning reference (external) frames. This is especially beneficial when it is not feasible to rely on magnetometers to reference the heading of the inertial system. This alignment allows effective tracking of yaw in a common reference frame for all inertial sensing units, even those with no associated positional measurements. The disclosed systems and methods also enable an association to be formed between the inertial sensing units and positional measurements.

Integration of inertial tracking and position aiding for motion capture

A system and method of communicating efficiently and reliably between a sensor unit and a master unit, especially in a wireless system, is provided. The disclosed techniques require only minimal processing by the sensor unit for communications purposes and as such, the described system and method can be implemented in systems with tight constraints on the sensor unit side in terms of required memory, power consumption, and cost, such as in wearable sensor systems.

Reduced processor load for wireless communication between master unit and sensor unit

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

A method of enabling a wireless communication between a master unit and at least one sensor unit is executed within a frame, the sensor unit having an internal data sampling frequency and being adapted to store samples with corresponding sample sequence numbers. The sensor unit transmits an integrated value to the master unit. The master unit transmits, during a master unit portion of the frame, a data update request message comprising an initial sample sequence number from which integration by the at least one sensor unit has to be carried out. The sensor unit integrates the sample values from the initial sample sequence number to a current sample sequence number and then transmits the integrated sample value and the current sample sequence number. The master unit receives the integrated sample value and current sample sequence number and stores at least the current sample sequence number.

Method and a system for enabling a wireless communication between a master unit and a sensor unit

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

A system is provided for capturing motion of a moving object via a plurality of motion sensor modules placed on various body segments. The sensor modules capture both 3D position and 3D orientation data relating to their respective body segments, thereby gathering motion data having six degrees of freedom with respect to a coordinate system not fixed to the body. Each body sensor collects 3D inertial sensor data and, optionally, magnetic field data. In embodiments, either DSP circuitry within the sensor modules or an external computing device, processes the sensor data to arrive at orientation and position estimates by using an estimation algorithm, such as a Kalman filter or a particle filter. The processing includes biomechanical model constraints that allow flexibility in the joints and provide characteristics for various joint types. To improve estimation accuracy, the system may be integrated with various types of aiding sensors.

Motion tracking system

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.

Growing community of inventors

Schalkhaar, Netherlands

Per Johan Slycke