System and method for motion capture
AssigneeGoogle Inc.
InventorDongeek Shin
Life of this patent
Estimating the term…
Abstract
Ultra-wideband (UWB) tags can be used as part of a high-resolution motion capture system that may not require a cost or a complexity that is typically associated with visually based motion capture systems. The UWB based motion capture uses a bundle of UWB tags, which in a possible implementation, can be affixed to body parts of a user to sense motion of the body parts. The absolute positions of each UWB tag can then be determined by reconstructing a skeletal topology from a Euclidean distance matrix based on inter-tag ranging measurements using handshake signals of a UWB protocol.
Claims20
A method for motion capture, the method comprising:
- coupling ultra-wideband (UWB) tags to a body;
- constructing a distance matrix, wherein the constructing includes:
- successively configuring each UWB tag as an anchor tag;
- determining distances between the anchor tag and other UWB tags;
- and
- updating the distance matrix with the determined distances until each UWB tag has been configured as the anchor tag;
- checking a validity of the distance matrix;
- reconstructing a skeletal topology of the body based on the distance matrix, the skeletal topology including nodes corresponding to three-dimensional (3D) positions of the UWB tags;
- and
- repeating the constructing, the checking, and the reconstructing to generate a set of skeletal topologies, the set of skeletal topologies arranged in time to capture a motion of the body.
A system for motion capture comprising:
- a first set of ultra-wideband (UWB) tags coupled to a first body, wherein UWB tags in the first set are configurable to take turns performing a handshake protocol with each other to determine elements of a distance matrix for the first set, the elements corresponding to pair-wise distances between the UWB tags;
- and
- a hub device communicatively coupled to one or more of the UWB tags, the hub device including a processor configured by software instructions to:
- check a validity of the distance matrix before reconstructing a skeletal topology of the first body based on the distance matrix;
- and
- reconstruct the skeletal topology of the first body based on the distance matrix.
A method for motion capture, the method comprising:
- acquiring round-trip times between pairs of ultra-wideband (UWB) tags affixed to points on a body, the round-trip times based on a handshake protocol;
- and
- estimating a pose of the body by:
- computing a distance matrix based on the round-trip times;
- checking a validity of the distance matrix;
- reconstructing a skeletal topology of the body, the skeletal topology including nodes corresponding to three-dimensional (3D) positions of the points the body;
- and
- repeating the acquiring and the estimating to capture a motion of the body.
Dependencies are inferred from the claim text.