Method for calculating personal dead-reckoning data using gait characteristics
AssigneeBionic Power Inc.
InventorsDaniel Loren Hepler, Clive Edward Mullins
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Abstract
Raw dead reckoning data is obtained from an inertial measurement unit (IMU) worn by a user. Drift in the raw data is compensated for by detecting a gait of the user and phase of that gait, and constraining the position of the IMU to lie within corresponding bounds as the IMU moves. The bounds depend on the bodily geometry of the user and the detected gait phase. The raw orientation data of the IMU may be also corrected for drift in a similar way. Gait and gait phase may be detected by sensors in an energy harvester worn around the knee, for example. Drift in the IMU measurements can be compensated for without depending on a GPS signal or on the earth's magnetic field.
Claims15
A method for outputting dead reckoned data for a user undergoing locomotion comprising:
- attaching an inertial measurement unit (IMU) to the user;
- defining a first point at which the IMU is located;
- detecting a phase of a gait of the user using one or more sensors;
- defining bounds for displacement of the IMU during said phase of the gait;
- obtaining raw positional data from the IMU for a second point, to which the IMU is displaced by the locomotion of the user;
- and
- either determining, by a processor, that the raw positional data lies within said bounds and then outputting, from the processor, the raw positional data as dead reckoned data for the second point, or, in the alternative, determining, by the processor, that the raw positional data lies outside of said bounds and then compensating the raw positional data to result in compensated positional data that is within said bounds and outputting, from the processor, the compensated positional data as the dead reckoned data for the second point.
Dependencies are inferred from the claim text.