Information processing device, information processing method, and storage medium

1. An information processing device comprising:

a storage device having a program stored therein; and

a hardware processor,

wherein the hardware processor executes the program stored in the storage device to:

acquire first data having a dimension of position of an object represented in a generalized coordinate system, wherein the object is a human body and defined as including a plurality of segments and a joint that links two or more of the segments, the plurality of segments include a left foot and a right foot in the human body, and the joint is a knee in the human body, and the generalized coordinate system includes at least a rotation angle around one or more axes for each joint as a variable;

acquire at least second data having a dimension of acceleration from a plurality of inertial sensors attached to the plurality of segments and the joint of the object;

derive a transformation rule on the basis of the first data;

convert the second data into third data having a dimension of acceleration represented in the generalized coordinate system by applying the derived transformation rule to the second data; and

estimate a torque which is generated in the joint, a first ground reaction force which is applied to the left foot, and a second ground reaction force which is applied to the right foot on the basis of the first data, fourth data having a dimension of speed relating to the object obtained by differentiating the first data, and the third data.

2. The information processing device according to claim 1 , wherein the hardware processor further executes the program to estimate the torque which is generated in the joint, the first ground reaction force, and the second ground reaction, by performing one or both of a forward dynamics calculation and an inverse dynamics calculation.

3. An information processing method comprising causing a computer to:

acquire first data having a dimension of position of an object represented in a generalized coordinate system, wherein the object is a human body and defined as including a plurality of segments and a joint that links two or more of the segments, the plurality of segments include a left foot and a right foot in the human body, and the joint is a knee in the human body, and the generalized coordinate system includes at least a rotation angle around one or more axes for each joint as a variable;

acquire at least second data having a dimension of acceleration from a plurality of inertial sensors attached to the plurality of segments and the joint of the object;

derive a transformation rule on the basis of the first data;

convert the second data into third data having a dimension of acceleration represented in the generalized coordinate system by applying the derived transformation rule to the second data; and

estimate a torque which is generated in the joint, a first ground reaction force which is applied to the left foot, and a second ground reaction force which is applied to the right foot on the basis of the first data, fourth data having a dimension of speed relating to the object obtained by differentiating the first data, and the third data.

4. A computer readable non-transitory storage medium having a program stored therein, the program causing a computer to:

acquire first data having a dimension of position of an object represented in a generalized coordinate system, wherein the object is a human body and defined as including a plurality of segments and a joint that links two or more of the segments, the plurality of segments include a left foot and a right foot in the human body, and the joint is a knee in the human body, and the generalized coordinate system includes at least a rotation angle around one or more axes for each joint as a variable;

acquire at least second data having a dimension of acceleration from a plurality of inertial sensors attached to the plurality of segments and the joint of the object;

derive a transformation rule on the basis of the first data;

convert the second data into third data having a dimension of acceleration represented in the generalized coordinate system by applying the derived transformation rule to the second data; and

estimate a torque which is generated in the joint, a first ground reaction force which is applied to the left foot, and a second ground reaction force which is applied to the right foot on the basis of the first data, fourth data having a dimension of speed relating to the object obtained by differentiating the first data, and the third data.