System for analyzing a user's strides

摘要

A system for analyzing a user's strides has a first sensor assembly (EC1) furnished within a housing, with a triaxial magnetometer (3M) fixed to the housing (BT), which is associated with a moving frame (LF). First fixing means (MF1) fixes the first sensor assembly (EC1) to a leg segment of the user. Processing means (MT) calculates the angle of yaw (YawGF) and/or of pitch (PitchGF) and/or of roll (RollGF) of the first sensor assembly (EC1), and calculates the corresponding angular temporal variation or variations;(ⅆYawGFⅆt,ⅆPitchGFⅆt,ⅆRollGFⅆt),
in a fixed global frame (GF) relative to the terrestrial frame, on the basis of the measurements of the triaxial magnetometer (3M) delivered in the moving frame (LF).

主权项

1. A system for analyzing a user's strides, comprising:
a first sensor assembly having a housing, a triaxial magnetometer coupled to said housing, a triaxial accelerometer coupled to said housing, and having an associated moving frame; first fixing means adapted for coupling the first sensor assembly to a limb segment of a user; and a processor configured to calculate at least an angle of pitch of said first sensor assembly, and to calculate a corresponding angular temporal variation, in a fixed global frame associated with a terrestrial frame, utilizing measurements of said triaxial magnetometer delivered in said moving frame; wherein the processor is further configured to: determine an instant of start of a stride and an instant of end of said stride and phases of said stride, utilizing said temporal variation of the angle of pitch of the first sensor assembly; calculate values of parameters representative of a phase of said stride or of the complete stride, in three dimensions in the fixed global frame, by calculating a stride frame associated with the first sensor assembly, for the complete stride or for each phase of the stride, utilizing vectors obtained from said triaxial magnetometer at successive instants in the moving frame associated with the first sensor assembly, the stride frame being a principal plane of the complete stride or for each phase of the stride, the principal plane being determined by the processor as orthogonal to an axis calculated as a spatial axis onto which projections of the vectors obtained from said triaxial magnetometer at successive instants vary the least; and calculate orthogonal projections of measurement vectors obtained from the triaxial accelerometer and from the triaxial magnetometer on axes of the stride frame; wherein the fixed global frame associated with the terrestrial frame is the orthogonal projection on the stride frame of the measurement vectors obtained from the triaxial magnetometer.