DEVICE FOR ESTIMATING MOVING OBJECT TRAVEL DIRECTION AND METHOD FOR ESTIMATING TRAVEL DIRECTION

摘要

The present invention provides a device and method for estimating a travel direction of a moving body, the device and method allowing highly accurate estimation of the travel direction even in the case where the positional relationship between the moving body and the self-contained sensing device or the posture is changed freely.;The travel direction estimating device includes (i) a gravitational direction vector estimating section 2407 for estimating a gravitational direction vector on the basis of respective outputs of an acceleration sensor and an angular velocity sensor, (ii) a tentative travel direction vector generating section 2413 as a candidate of travel direction vector, (iii) a walk frequency estimating section 2424 for estimating a walk frequency from component data resulting from projecting acceleration component data for the gravitational direction vector, and (iv) a travel direction vector determining section 2425 for determining an objective function and a phase difference on the basis of a frequency component of a component Af resulting from projecting the acceleration component data for a travel direction vector, a frequency component of a component An resulting from projecting the acceleration component data for a side-to-side direction vector, a frequency component of a component Ws resulting from projecting angular velocity component data for the travel direction vector, a frequency component of a component Wn resulting from projecting the angular velocity component data for the side-to-side direction vector, a walk frequency, and the phase of the walk frequency, selecting as travel direction vectors, tentative travel direction vectors with which the phase difference is within a predetermined range and each of which maximizes the value of the objective function, and determining the side of the travel direction.

主权项

1. A travel direction estimating device for estimating a travel direction of a moving body,
the travel direction estimating device comprising: an acceleration measuring section for measuring an acceleration vector component of the moving body so as to generate acceleration vector component data; an angular velocity measuring section for measuring an angular velocity vector component of the moving body so as to generate angular velocity vector component data; a gravitational direction vector estimating section for estimating a gravitational direction vector of the moving body on a basis of the acceleration vector component data and the angular velocity vector component data; a tentative travel direction vector generating section for generating a tentative travel direction vector and a side-to-side direction vector on a basis of the gravitational direction vector outputted by the gravitational direction vector estimating section; a walk frequency calculation section for (i) calculating component data resulting from projecting, for the gravitational direction vector, the acceleration vector component data remaining after removing the gravitational direction vector from an acceleration component data and (ii) outputting a frequency domain component of the calculated component data so as to determine a walk frequency and a phase of a frequency component of the walk frequency; a computing section for, (i) on a basis of the tentative travel direction vector, the gravitational direction vector, and the acceleration vector component data, calculating component data resulting from projecting, for the tentative travel direction vector, the acceleration vector component data remaining after removing a gravitational acceleration vector from the acceleration vector component data and (ii) outputting a frequency domain component of the calculated component data; a computing section for, (i) on a basis of the gravitational direction vector, the side-to-side direction vector, and the acceleration vector component data, calculating component data resulting from projecting, for the side-to-side direction vector, the acceleration vector component data remaining after removing the gravitational acceleration vector from the acceleration vector component data and (ii) outputting a frequency domain component of the calculated component data; a computing section for, (i) on a basis of the tentative travel direction vector and the angular velocity vector component data, calculating a component resulting from projecting the angular velocity vector component data onto the tentative travel direction vector and (ii) outputting a frequency domain component of the calculated component; a computing section for, (i) on a basis of the side-to-side direction vector and the angular velocity vector component data, calculating a component resulting from projecting the angular velocity vector component data onto the side-to-side direction vector and (ii) outputting a frequency domain component of the calculated component; and a travel direction vector determining section for, (i) on a basis of the walk frequency, the frequency domain component resulting from projecting an acceleration component travel direction vector, the frequency domain component resulting from projecting an acceleration component side-to-side direction vector, the frequency domain component resulting from projecting an angular velocity travel direction vector, and the frequency domain component resulting from projecting an angular velocity side-to-side direction vector, calculating a power value from the frequency component of the walk frequency or a frequency component of a half of the walk frequency so as to calculate an objective function, (ii) from the frequency domain component resulting from projecting the acceleration component travel direction vector, calculating the phase of the frequency component of the walk frequency so as to calculate a phase difference between the phase of the frequency component of the walk frequency and a phase of the walk frequency calculated by the walk frequency calculation section, (iii) in a case where the phase difference falls within a predetermined range, selecting as a candidate at least one tentative travel direction vector having a value of the objective function, and (iv) outputting, as a travel direction vector out of the at least one tentative travel direction vector as the candidate, a tentative travel direction vector that maximizes the value of the objective function.