MOTION SENSING APPARATUS, SYSTEMS AND TECHNIQUES

• US 20070219744A1
• Filed: 05/15/2007
• Published: 09/20/2007
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: C-Lan Wireless Inc.
• Original Assignee: Magneto Inertial Sensing Technology, Inc.
• Inventors: Kolen, Paul
• Granted Patent: US 7,689,378 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: A63B 2024/0012 Comparing movements or motion sequences with a registered reference
• CPC Class Codes: A63B 2024/0015 Comparing movements or motion sequences with computerised simulations of movements or motion sequences, e.g. for generating an ideal template as reference to be achieved by the user
• CPC Class Codes: A63B 2069/0008 for batting
• CPC Class Codes: A63B 2071/0627 when used improperly, e.g. by giving a warning
• CPC Class Codes: A63B 2220/12 Absolute positions, e.g. by using GPS
• CPC Class Codes: A63B 2220/16 Angular positions
• CPC Class Codes: A63B 2220/40 Acceleration
• CPC Class Codes: A63B 2220/72 Temperature
• CPC Class Codes: A63B 2220/80 Special sensors, transducers or devices therefor
• CPC Class Codes: A63B 2220/803 Motion sensors
• CPC Class Codes: A63B 2220/833 Sensors arranged on the exercise apparatus or sports implement
• CPC Class Codes: A63B 2220/836 Sensors arranged on the body of the user
• CPC Class Codes: A63B 2225/50 Wireless data transmission, e.g. by radio transmitters or telemetry
• CPC Class Codes: A63B 60/42 Devices for measuring, verifying, correcting or customising the inherent characteristics of golf clubs, bats, rackets or the like, e.g. measuring the maximum torque a batting shaft can withstand
• CPC Class Codes: A63B 60/46 Measurement devices associated with golf clubs, bats, rackets or the like for measuring physical parameters relating to sporting activity, e.g. baseball bats with impact indicators or bracelets for measuring the golf swing
• CPC Class Codes: A63B 69/36 for golf
• CPC Class Codes: A63B 69/3632 Clubs or attachments on clubs, e.g. for measuring, aligning A63B69/3614 takes precedence; clubs for swinging exercises in general A63B15/00
• CPC Class Codes: A63B 71/0622 Visual, audio or audio-visual systems for entertaining, instructing or motivating the user
• CPC Class Codes: G01C 17/00 Compasses; Devices for ascertaining true or magnetic north for navigation or surveying purposes using gyroscopic effect G01C19/00
• CPC Class Codes: G01C 19/00 Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects

Abstract

A highly miniaturized electronic data acquisition system includes MEMS sensors that can be embedded onto moving device without affecting the static/dynamic motion characteristics of the device. The basic inertial magnetic motion capture (IMMCAP) module consists of a 3D printed circuit board having MEMS sensors configured to provide a tri-axial accelerometer; a tri-axial gyroscope, and a tri-axial magnetometer all in communication with analog to digital converters to convert the analog motion data to digital data for determining classic inertial measurement and change in spatial orientation (rho, theta, phi) and linear translation (x, y, z) relative to a fixed external coordinate system as well as the initial spatial orientation relative to the know relationship of the earth magnetic and gravitational fields. The data stream from the IMMCAP modules will allow the reconstruction of the time series of the 6 degrees of freedom for each rigid axis associated with each independent IMMCAP module.

Claims

1. A motion sensing system, comprising:

one or more motion sensors, each motion senor operable to measure data on motion and orientation of the motion sensor and comprising (1) a microprocessor to process and transform measured data into digital sensor data and (2) a sensor communication interface to output the digital sensor data; and

a controller comprising (1) a controller communication interface in communication with the one or more motion sensors via the sensor communication interface and (2) a controller memory to receive the digital sensor data from the one or more motion sensors,

wherein the controller processes, in real time as the digital sensor data is being received, the received digital sensor data to produce a measured motion profile of the one or more motion sensors and to compare the measured motion profile to a reference motion profile for the one or more motion sensors that is stored in the controller microprocessor, and

wherein the controller produces an indicator signal to indicate a deviation of the measured motion profile from the reference motion profile.

2. The system as in claim 1, wherein:

the sensor communication interface in each motion sensor is an RF interface that transmits a wireless RF signal carrying the digital sensor data, and

the controller communication interface is an RF interface that wirelessly transmits and receives data.

3. The system as in claim 2, wherein:

there are least two motion sensors, and

the at least two motion sensors and the controller form a wireless RF network.

4. The system as in claim 1, wherein:

each motion sensor comprises a tri-axial magnetometer to measure a local magnetic field vector at each motion sensor, and

wherein the system comprises a mechanism to process measured data on the local magnetic field to measure a differential rate of rotation of each motion sensor relative to a local earth magnetic field vector.

5. The system as in claim 4, wherein:

each motion sensor comprises a tri-axial gyroscope to measure a rate of rotation of each motion sensor in addition to the measured differential rate of rotation from the tri-axial magnetometer, and

wherein the system comprises a mechanism to use the measured differential rate of rotation from the tri-axial magnetometer to indicate a rotation rate of the motion sensor when the external earth magnetic field is not aligned with any one of three orthogonal axes of the tri-axial magnetometer and to select the measured rate of rotation from the tri-axial gyroscope when data when the external earth magnetic field is aligned with one of three orthogonal axes of the tri-axial magnetometer.

6. The system as in claim 4, wherein:

each motion sensor does not include a tri-axial gyroscope to measure a rate of rotation of each motion sensor, and

wherein the system comprises a mechanism to;

use data samples of the measured differential rate of rotation from the tri-axial magnetometer to estimate a rate of rotation of the motion sensor during a period when the external earth magnetic field is not aligned with any one of three orthogonal axes of the tri-axial magnetometer.

7. The system as in claim 1, comprises:

an alert mechanism that responds to the indicator signal to produce an alert signal to alert a person of the deviation of the measured motion profile from the reference motion profile when the deviation exceeds a tolerance range.

8. The system as in claim 7, wherein the alert signal is an audio signal.

9. The system as in claim 7, wherein the alert signal is an optical signal.

16. The system as in claim 1, wherein the controller comprises a communication link to send out the digital sensor data for further analysis and processing.

10. A motion sensing system, comprising:

at least one motion senor operable to measure data on motion and orientation of the motion sensor and comprising a tri-axial magnetometer to measure a local magnetic field vector at each motion sensor; and

a mechanism to process measured data on the local magnetic field vector from the tri-axial magnetometer to measure a differential rate of rotation of the motion sensor.

11. The system as in claim 10, wherein:

the motion sensor comprises a tri-axial gyroscope to measure a rate of rotation of each motion sensor in addition to the measured differential rate of rotation from the tri-axial magnetometer, and

wherein the system comprises a mechanism to use the measured differential rate of rotation from the tri-axial magnetometer to indicate a rotation rate of the motion sensor when the external earth magnetic field is not aligned with any one of three orthogonal axes of the tri-axial magnetometer and to select the measured rate of rotation from the tri-axial gyroscope when the external earth magnetic field is aligned with one of three orthogonal axes of the tri-axial magnetometer.

12. The system as in claim 10, wherein:

each motion sensor does not include a tri-axial gyroscope to measure a rate of rotation of each motion sensor, and

wherein the system comprises a mechanism to;

use data samples of the measured differential rate of rotation from the tri-axial magnetometer to estimate a rate of rotation of the motion sensor during a period when the external earth magnetic field is not aligned with any one of three orthogonal axes of the tri-axial magnetometer.

13. A motion sensing system, comprising:

one or more motion sensors, each motion senor comprising (1) a tri-axial accelerometer, (2) a tri-axial magnetometer, (3) a microprocessor to process and transform measured data from each motion sensor, including data from the tri-axial accelerometer and the tri-axial magnetometer, into digital sensor data, (4) a sensor RF communication interface to wirelessly output the digital sensor data; and

a controller comprising (1) a controller RF communication interface in wireless communication with the one or more motion sensors via the sensor RF communication interface and (2) a controller memory to receive the digital sensor data from the one or more motion sensors,

wherein the controller processes measured data on a local magnetic field from the tri-axial magnetometer to measure a differential rate of rotation of the motion sensor, and processes the received digital sensor data to produce a measured motion profile of the one or more motion sensors.

14. The system as in claim 13, wherein the controller operates to compare the measured motion profile to a reference motion profile for the one or more motion sensors that is stored in the controller microprocessor and to produce an indicator signal to indicate a deviation of the measured motion profile from the reference motion profile.

15. The system as in claim 13, wherein the controller comprises a communication link to send out the digital sensor data for further analysis and processing.