Swing quality measurement system
First Claim
1. A swing quality measurement system comprising:
- a memory;
a processor coupled with said memory;
a first communication interface;
a sensor configured to capture sensor data associated with a bat during a swing of said bat by a user;
a bat geometry stored in said memory, said bat geometry comprisinga hand position along a longitudinal axis of said bat; and
a sweet spot position along said longitudinal axis;
wherein said processor is coupled to said sensor via said first communication interface, and whereinsaid processor is configured toobtain said bat geometry;
receive said sensor data from said sensor;
obtain or calculate acceleration data from said sensor data;
obtain or calculate angular velocity data from said sensor data;
calculate a trajectory of said hand position from said acceleration data and said angular velocity data;
calculate a trajectory of said sweet spot position from said acceleration data and said angular velocity data;
calculate a trajectory of said longitudinal axis from said acceleration data and said angular velocity data;
determine a time of impact of said swing from said acceleration data and said angular velocity data;
calculate a body tilt axis of said user from said trajectory of said hand position, wherein said body tilt axis is perpendicular to a plane passing through three different points of said trajectory of said hand position;
calculate a swing plane, wherein said swing plane is spanned by a velocity vector of said sweet spot position at said time of impact and said longitudinal axis at said time of impact; and
,calculate one or more swing quality metrics based on one or more ofsaid sensor data;
said acceleration data;
said angular velocity data;
said time of impact;
said trajectory of said hand position;
said trajectory of said sweet spot position;
said trajectory of said longitudinal axis;
said body tilt axis; and
,said swing plane.
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Accused Products
Abstract
A system that measures a swing of a bat with one or more sensors and analyzes sensor data to create swing quality metrics. Metrics may include for example rotational acceleration, on-plane efficiency, and body-bat connection. Rotational acceleration measures the centripetal acceleration of the bat along the bat'"'"'s longitudinal axis at a point early in the rotational part of the swing; it is an indicator of the swing'"'"'s power. On-plane efficiency measures how much of the bat'"'"'s angular velocity occurs around the swing plane, the plane spanned by the bat and the bat'"'"'s sweet spot velocity at impact. Body-bat connection measures the angle between the bat and the body tilt axis, which is estimated from the trajectory of the hand position on the bat through the swing; an ideal bat-body connection is near 90 degrees. These three swing quality metrics provide a simple and useful characterization of the swing mechanics.
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Citations
17 Claims
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1. A swing quality measurement system comprising:
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a memory; a processor coupled with said memory; a first communication interface; a sensor configured to capture sensor data associated with a bat during a swing of said bat by a user; a bat geometry stored in said memory, said bat geometry comprising a hand position along a longitudinal axis of said bat; and a sweet spot position along said longitudinal axis; wherein said processor is coupled to said sensor via said first communication interface, and wherein said processor is configured to obtain said bat geometry; receive said sensor data from said sensor; obtain or calculate acceleration data from said sensor data; obtain or calculate angular velocity data from said sensor data; calculate a trajectory of said hand position from said acceleration data and said angular velocity data; calculate a trajectory of said sweet spot position from said acceleration data and said angular velocity data; calculate a trajectory of said longitudinal axis from said acceleration data and said angular velocity data; determine a time of impact of said swing from said acceleration data and said angular velocity data; calculate a body tilt axis of said user from said trajectory of said hand position, wherein said body tilt axis is perpendicular to a plane passing through three different points of said trajectory of said hand position; calculate a swing plane, wherein said swing plane is spanned by a velocity vector of said sweet spot position at said time of impact and said longitudinal axis at said time of impact; and
,calculate one or more swing quality metrics based on one or more of said sensor data; said acceleration data; said angular velocity data; said time of impact; said trajectory of said hand position; said trajectory of said sweet spot position; said trajectory of said longitudinal axis; said body tilt axis; and
,said swing plane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A swing quality measurement system comprising:
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a memory; a processor coupled with said memory; a first communication interface; a sensor configured to capture sensor data associated with a bat during a swing of said bat by a user; a bat geometry stored in said memory, said bat geometry comprising a hand position along a longitudinal axis of said bat; and a sweet spot position along said longitudinal axis comprising one or more of an optimum location on said bat for striking a ball; a position on said bat that maximizes energy transfer when striking said ball; a position on said bat that maximizes ball speed when striking said ball; and
,a position on said bat that minimizes vibration when striking said ball; said processor coupled to said sensor via said first communication interface, and configured to obtain said bat geometry; receive said sensor data from said sensor; obtain or calculate acceleration data from said sensor data; obtain or calculate angular velocity data from said sensor data; calculate a trajectory of said hand position from said acceleration data and said angular velocity data; calculate a trajectory of said sweet spot position from said acceleration data and said angular velocity data; calculate a trajectory of said longitudinal axis from said acceleration data and said angular velocity data; determine a time of impact of said swing from said acceleration data and said angular velocity data; calculate a body tilt axis of said user from said trajectory of said hand position, wherein said body tilt axis is perpendicular to a plane passing through three different points of said trajectory of said hand position; calculate a swing plane, wherein said swing plane is spanned by a velocity vector of said sweet spot position at said time of impact and said longitudinal axis at said time of impact; calculate a start time of centripetal acceleration comprising a time during said swing at or near a time when a longitudinal acceleration changes sign, wherein said longitudinal acceleration comprises said acceleration data projected onto said longitudinal axis; define a swing plane coordinate system comprising a z-axis along said longitudinal axis; a y-axis normal to said swing plane; and an x-axis orthogonal to said y-axis and to said z-axis; transform said angular velocity data to said swing plane coordinate system, to yield a time series of transformed angular velocities, wherein each transformed angular velocity of said time series of transformed angular velocities comprises a vector sum of a z-axis angular velocity; a y-axis angular velocity; and an x-axis angular velocity; calculate a time series of rotation-on-plane ratios, each rotation-on-plane ratio of said time series of rotation-on-plane ratios comprising a ratio of a magnitude of said y-axis angular velocity to a magnitude of a vector sum of said y-axis angular velocity and said x-axis angular velocity; calculate a time series of body-bat angles, wherein each body-bat angle of said time series of body-bat angles comprises an angle between said longitudinal axis and said body tilt axis; calculate one or more swing quality metrics comprising a rotational acceleration metric comprising a difference between
said longitudinal acceleration at an early rotation time, wherein said early rotation time comprises said start time of centripetal acceleration plus a fixed offset; and
said longitudinal acceleration at said start time of centripetal acceleration;an on-plane efficiency metric comprising an average of said time series of rotation-on-plane ratios from said start time of centripetal acceleration to said time of impact; a connection-at-impact metric comprising said body-bat angle at said time of impact; and
,a connection-early metric of said one or more swing quality metrics comprising said body-bat angle at said start time of centripetal acceleration.
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Specification