Inertial orientation tracker having automatic drift compensation using an at rest sensor for tracking parts of a human body
First Claim
1. An apparatus for generating a signal that corresponds to at least two of the three orientational aspects of yaw, pitch and roll of a human-scale body, relative to an external reference frame, said apparatus comprising:
- a. a self contained sensor for generating first sensor signals that correspond to xth order integrals of the rotational accelerations of said body about certain axes relative to said body, where x is between and includes 1 and 2;
b. a mechanism for mounting said sensor to said body; and
c. coupled to said sensor, a signal processor for generating orientation signals relative to said external reference frame that correspond to said at least two orientational aspects from said xth order integral signals, wherein the first sensor signals are impervious to interference from electromagnetic, acoustic, optical and mechanical sources.
0 Assignments
0 Petitions
Accused Products
Abstract
A self contained sensor apparatus generates a signal that corresponds to at least two of the three orientational aspects of yaw, pitch and roll of a human-scale body, relative to an external reference frame. A sensor generates first sensor signals that correspond to rotational accelerations or rates of the body about certain body axes. The sensor may be mounted to the body. Coupled to the sensor is a signal processor for generating orientation signals relative to the external reference frame that correspond to the angular rate or acceleration signals. The first sensor signals are impervious to interference from electromagnetic, acoustic, optical and mechanical sources. The sensors may be rate sensors. An integrator may integrate the rate signal over time. A drift compensator is coupled to the rate sensors and the integrator. The drift compensator may include a gravitational tilt sensor or a magnetic field sensor or both. A verifier periodically measures the orientation of the body by a means different from the drift sensitive sate sensors. The verifier may take into account characteristic features of human motion, such as stillness periods. The drift compensator may be, in part, a Kalman filter, which may utilize statistical data about human head motion.
-
Citations
48 Claims
-
1. An apparatus for generating a signal that corresponds to at least two of the three orientational aspects of yaw, pitch and roll of a human-scale body, relative to an external reference frame, said apparatus comprising:
-
a. a self contained sensor for generating first sensor signals that correspond to xth order integrals of the rotational accelerations of said body about certain axes relative to said body, where x is between and includes 1 and 2;
b. a mechanism for mounting said sensor to said body; and
c. coupled to said sensor, a signal processor for generating orientation signals relative to said external reference frame that correspond to said at least two orientational aspects from said xth order integral signals, wherein the first sensor signals are impervious to interference from electromagnetic, acoustic, optical and mechanical sources. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. An apparatus for generating a signal that corresponds to the orientation of a human-scale body, relative to a reference frame, said apparatus comprising:
-
a. a self contained sensor for generating a rate signal that corresponds to the rotational rate of said body with respect to at least two degrees of freedom and is impervious to interference from electromagnetic, acoustic, optical and mechanical sources;
b. a mounting mechanism for mounting said sensing means to said body; and
c. coupled with said first sensor, an integrator for integrating said rotational rate signal over time to generate an orientation signal. - View Dependent Claims (32, 33, 34, 35)
-
-
36. An apparatus for generating a signal that corresponds to the orientation of a human-scale body, relative to a reference frame, said apparatus comprising:
-
a. a self contained first sensor for generating a drift sensitive orientation signal that corresponds to the rotational orientation with respect to at least two degrees of freedom of said body and is impervious to interference from electromagnetic, acoustic, optical and mechanical sources and is subject to drift over time;
b. a self contained second sensor for generating a drift compensating orientation signal that corresponds to the rotational orientation with respect to said at least two degrees of freedom of said body and is impervious to interference from electromagnetic, acoustic, optical and mechanical sources and which is relatively impervious to drift over time;
c. a mounting mechanism for mounting said first sensor and said second sensor to said body; and
d. coupled to said first sensor and said second sensor, a signal corrector means for generating a corrected rotational orientation signal based on said drift sensitive and drift compensating orientation signals. - View Dependent Claims (37, 38, 39)
-
-
40. A method for generating a signal that corresponds to the orientation of a human-scale body, relative to a reference frame, said method comprising the steps of:
-
a. using a first self contained sensor physically coupled to said body, generating a drift sensitive orientation signal that corresponds to the rotational orientation with respect to at least two degrees of freedom of said body and that is impervious to interference from electromagnetic, acoustic, optical and mechanical sources and is subject to drift over time;
b. using a second self contained sensor physically coupled to said body, generating a drift compensating orientation signal that corresponds to the rotational orientation with respect to said at least two degrees of freedom of said body and that is impervious to interference from electromagnetic, acoustic, optical and mechanical sources and which is relatively impervious to drift over time;
c. generating a corrected rotational orientation signal based on said drift sensitive and drift compensating orientation signals. - View Dependent Claims (41, 42, 43)
-
-
44. An apparatus for simulating a virtual environment that is displayed to a user, said apparatus comprising:
-
a. a self contained orientation sensor for generating an orientation signal that;
i. corresponds to at least two of the three orientational degrees of freedom of yaw, pitch and roll of a body member of said user, relative to a reference frame; and
ii. is impervious to interference from electromagnetic, acoustic, optical and mechanical sources;
b. a position sensor for generating a position signal that corresponds to the position of said body, relative to said reference frame;
c. a mechanism for mounting said position and orientation sensors to said body member;
d. a virtual environment means for generating signals that define, in part, said virtual environment;
e. a means for displaying said virtual environment signals to said user; and
f. means for coupling said position sensor and said orientation sensor to said virtual environment means. - View Dependent Claims (45, 46, 47, 48)
-
Specification