Abstract: A method comprising: digitally processing orientation measurements provided by each of first and second inertial measurement units, the first and second units being arranged on first and second body members of a person, respectively, according to a predetermined unit arrangement, and the first and second body members being connected by a joint; the measurements are digitally processed such that the computing device at least: computes a length vector of a segment of the first body member based on a first orientation measurement of the first unit; defines a joint axis plane of the joint based on a second orientation measurement of the second unit; and computes a heading rotation value for making the first orientation measurement to be contained within the joint axis plane defined; and the method further comprising digitally modifying the first orientation measurement or the second orientation measurement by applying a rotation at least based on the heading rotation value computed.

Abstract: A method comprising: digitally processing orientation measurements provided by each of first and second inertial measurement units, the first and second units being arranged on first and second body members of a person, respectively, according to a predetermined unit arrangement, and the first and second body members being connected by a joint; the measurements are digitally processed such that the computing device at least: computes a length vector of a segment of the first body member based on a first orientation measurement of the first unit; defines a joint axis plane of the joint based on a second orientation measurement of the second unit; and computes a heading rotation value for making the first orientation measurement to be contained within the joint axis plane defined; and the method further comprising digitally modifying the first orientation measurement or the second orientation measurement by applying a rotation at least based on the heading rotation value computed.

Abstract: A method for physical exercise using a motion tracking system having a computing device and inertial measurement units adapted to be arranged on body members of a person. The method includes: digitally processing first sets of measurements provided by the units to determine whether and adjust the operation of the motion tracking system when: any of the units is arranged on a body member with an orientation outside of a predetermined orientation range for a unit on that body member; and/or two or more units arranged on interchanged body members according to the predetermined unit arrangement; adjusting the operation of the motion tracking system when the computing device determines, based on at least the first sets of measurements, that: at least one unit has an orientation outside of the predetermined orientation range, and/or two or more units are arranged on interchanged body members; and digitally processing second sets of measurements.

Abstract: A method for adjusting operation of a motion tracking system includes a computing apparatus and sensors, each sensor having a gyroscope and an accelerometer. The method includes the steps of aligning the sensors; providing, each sensor to the computing apparatus, a first orientation when the sensors are aligned, the first orientation having a first heading; placing the sensors on a person; and providing, each sensor to the computing apparatus, a second orientation when the sensors are placed on the person, the second orientation having a second heading. The method further includes digitally determining, the computing apparatus, whether the sensors are placed on the person according to a predetermined sensor arrangement based on both the first and second headings of each sensor; and adjusting, the computing apparatus, the operation of the motion tracking system based on the determination. Also, a system for tracking motion of a person.

Abstract: A method for adjusting operation of a motion tracking system at least including first and second sensors and a computing device, each of the sensors at least having a gyroscope. The method includes the following steps: arranging the first sensor on an upper arm of a person, and the second sensor on their chest; measuring orientations each of the first and second sensors while the person performs a predetermined movement. The movement includes the person moving a torso with respect to their hip while keeping the upper arm parallel to the torso and not rotating the upper arm. The method further includes digitally processing, the computing device, the orientations measured so as to digitally compute an orientation difference between the orientations measured by the first sensor and by the second sensor; and adjusting, the computing device, the operation of the motion tracking system based on the orientation difference computed.

Abstract: Methods and systems for tracking movement of a person, including a method comprising: arranging a plurality of sensors of a motion tracking system on a body of the person; tracking movement of the person with the plurality of sensors at least while the person performs a movement; digitally estimating, with a computing device, a position of either the first joint or the sensor on the second body member, wherein the position of the first joint is estimated using measurements of the first sensor and the position of the sensor is estimated using measurements of both the first sensor and the sensor arranged on the second body member, and wherein the position is estimated while movement of the person is tracked; digitally computing, with the computing device, an acceleration of the estimated position while movement of the person is tracked; digitally computing, with the computing device, a first comparison between the computed acceleration of the estimated position and acceleration measurements of the sensor arrang

Abstract: A method for adjusting operation of a motion tracking system comprising a computing apparatus and a plurality of sensors, each sensor comprising a gyroscope and an accelerometer, the method comprising: aligning the plurality of sensors; providing, each sensor of the plurality of sensors to the computing apparatus, a first orientation when the sensors are aligned, the first orientation comprising a first heading; placing the plurality of sensors on a person; providing, each sensor of the plurality of sensors to the computing apparatus, a second orientation when the sensors are placed on the person, the second orientation comprising a second heading; digitally determining, the computing apparatus, whether the plurality of sensors is placed on the person according to a predetermined sensor arrangement based on both the first and second headings of each sensor of the plurality of sensors; and adjusting, the computing apparatus, the operation of the motion tracking system based on the determination.

Abstract: A method for adjusting operation of a motion tracking system having a computing device and sensors, wherein each sensor includes a magnetometer, a gyroscope and an accelerometer, includes the following steps: receiving, the computing device, a magnetic field measurement from each of the sensors; digitally processing, the computing device, each of the magnetic field measurements in order to determine if a difference of intensities and/or inclinations of at least one pair of magnetic field measurements exceeds a threshold value, and/or if an x,y point with the differences of intensities and inclinations as coordinates thereof falls outside of a threshold area; and adjusting the operation of the motion tracking system if at least one difference exceeds the threshold value and/or the x,y point falls outside of the threshold area.