Interpretation of characteristics of a golf swing using motion analysis

Abstract

Methods, systems and apparatus for golf swing analysis are disclosed. One golf swing analysis system includes a motion sensing device attached to a golf club, the motion sensing device comprising a controller and one or more motion sensors. The golf swing analysis system further includes a remote processor, wherein a wireless link electronically connects the remote processor and the controller of the motion sensing device. Further, at least one of the controller and the remote processor are operative to access sensor data generated based on sensed signals of the one or more motion sensors, and perform pattern recognition analysis on the sensor data, comprising identifying and analyzing at least a portion of a golf swing based on the sensed data.

What is claimed: 
     
         1 . A golf swing analysis system, comprising:
 a motion sensing device attached to a golf club, the motion sensing device comprising a controller and one or more motion sensors;   a remote processor, wherein a wireless link electronically connects the remote processor and the controller of the motion sensing device;   wherein at least one of the controller and the remote processor are operative to:
 access sensor data generated based on sensed signals of the one or more motion sensors; 
 perform pattern recognition analysis on the sensor data, comprising identifying and analyzing at least a portion of a golf swing based on the sensed data. 
   
     
     
         2 . The system of  claim 1 , wherein at least one of the controller and the remote processor are further operative to:
 perform the identifying and analyzing of the at least a portion of a golf swing based sensed linear axis rotation and sensed angular axis of rotation of the golf club.   
     
     
         3 . The system of  claim 2 , wherein the sensed linear axis of rotation includes three degrees of freedom and the sensed angular axis of rotation includes three degrees of freedom. 
     
     
         4 . The system of  claim 1 , wherein the pattern recognition analysis comprises conditional processing, wherein conditions of the processing are dependent upon sensing motion thresholds. 
     
     
         5 . The system of  claim 4 , wherein the motion thresholds comprise at least one of linear axis of rotation motion thresholds and angular axis of rotation motion thresholds. 
     
     
         6 . The system of  claim 1 , wherein the at least one portion of the golf swing is identified based on a temporal component, a displacement component and an acceleration component. 
     
     
         7 . The system of  claim 1 , wherein the at least one portion of the golf swing includes at least one of an address portion, a takeaway portion, a first-half of back swing portion, a top of back swing portion, down swing portion, an impact portion, and a follow through portion. 
     
     
         8 . The system of  claim 7 , further comprising analyzing the address portion, comprising processing the sensor data to determine whether a lie angle is too shallow, optimal, or too high, comprising sensing an X-axis along a shaft of the golf club, sensing a gravity vector, and computing an angle between the x-axis and the gravity vector. 
     
     
         9 . The system of  claim 7 , further comprising analyzing the takeaway portion, comprising processing the sensor data to determine whether a takeaway direction of the takeaway portion is outward, straight back, or inward, wherein determining the takeaway direction comprises:
 sensing accelerometer data and gyroscope data of the sensor data during the takeaway portion, wherein the accelerometer data includes Z-axis motion, wherein the Z-axis motion is perpendicular to a shaft of the golf club and planar to grooves of the golf club, and wherein the gyroscope data includes rotational (β-axis) movement of the golf club that is perpendicular to a shaft of the golf club and planar to grooves of the golf club;   determining the takeaway direction by identifying negative or positive directions of the Z-axis motion and negative or positive rotational (β-axis) movement of the golf club.   
     
     
         10 . The system of  claim 7 , further comprising analyzing the first-half of back swing portion, comprising processing the sensor data to determine whether a backswing plane is vertical, optimal, or flat, wherein analyzing the first-half of the back swing comprises:
 continuously collecting the sensor data;   identifying a condition of no movement for greater than a threshold of time;   computing a backplane plane that is a closest match plane for a backswing arc;   computing an angle between the backswing plane and a gravity vector of the sensor data; and   comparing the angle with a predetermined set of thresholds, wherein the predetermined set of thresholds identify the backswing plane as vertical, optimal, or flat.   
     
     
         11 . The system of  claim 7 , further comprising analyzing top of back swing portion, comprising processing the sensor data to determine whether a backswing length is too short, optimal, or parallel at top of the back swing portion. 
     
     
         12 . The system of  claim 7 , further comprising analyzing the downswing portion, comprising processing the sensor data to determine whether a downswing plane is vertical, optimal, or flat, comprising:
 ascertaining that the golf swing is at a top of a back swing of the golf swing, comprising identifying a momentary pause and a transition of a Y-axis angular rotation from negative to positive, wherein the Y-axis is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club;   computing a three-dimensional arc of the downswing;   identifying a downswing plane by computing a closest match plane of the three-dimensional arc of the downswing;   computing an angle between the downswing plane and a gravity vector;   comparing the angle with a predetermined set of thresholds, wherein the predetermined set of thresholds identify the backswing plane as vertical, optimal, or flat.   
     
     
         13 . The system of  claim 7 , further comprising analyzing the impact portion, comprising processing the sensor data to determine whether a release time is too early, optimal, or too late, wherein determining whether the release time is too early, optimal, or too late comprises:
 continuously collecting the sensor data;   ascertaining the golf club to be at a top of a backswing by identifying a momentary pause of the golf club and identifying a transition of a Y-axis angular rotation from negative to positive, wherein the Y-axis is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club;   identifying a double pendulum motion based on a sensed γ-axis angular rotation, wherein the γ-axis angular rotation is perpendicular to shaft of the golf club and parallel to grooves of the golf club;   determining an angle between and X-axis of motion and a ground plane, wherein the X-axis is along a shaft of the golf club; and   based on the determined angle, identify whether the release time is too early, optimal, or too late.   
     
     
         14 . The system of  claim 7 , further comprising analyzing the impact portion, comprising processing the sensor data to determine whether a timing of top speed of the golf swing is reach before impact, at impact or after impact with a golf ball, wherein determining whether a timing of top speed of the golf swing is reach before impact, at impact or after impact with a golf ball comprises:
 continuously collecting the sensor data;   ascertaining the golf club to be at a top of a backswing by identifying a momentary pause of the golf club and identifying a transition of a Y-axis angular rotation from negative to positive, wherein the Y-axis is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club;   identifying a characteristic motion signature pattern to indicate impact between the golf club and a golf ball;   after identifying the characteristic motion signature pattern to indicate impact between the golf club and a golf ball, determining whether a sample of an γ-axis angular speed of the sensor data is faster, equal or slower than a prior sample of the γ-axis angular speed of the sensor data, wherein the γ-axis angular speed is perpendicular to shaft of the golf club and parallel to grooves of the golf club; and   determining whether the timing of top speed of the golf swing is reach before impact, at impact or after impact with the golf ball based on whether sample of the γ-axis angular speed of the sensor data is faster, equal or slower than the prior sample of the γ-axis angular speed of the sensor data.   
     
     
         15 . The system of  claim 7 , further comprising analyzing the down swing portion, comprising processing the sensor data to determine whether a downswing acceleration is constant, early or late, wherein determining whether a downswing acceleration is constant, early or late comprises:
 continuously collecting the sensor data;   ascertaining the golf club to be at a top of a backswing by identifying a momentary pause of the golf club and identifying a transition of a Y-axis angular rotation from negative to positive, wherein the Y-axis is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club;   collecting Y-axis angular acceleration and X-axis linear acceleration in the early stage of the downswing, wherein the Y-axis angular acceleration is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club and the X-axis linear acceleration is parallel to a shaft of the golf club;   collecting Y-axis angular acceleration and X-axis linear acceleration in the late stage of the downswing; and   determining the downswing acceleration to be constant, early or late based on whether the Y-axis angular acceleration and X-axis linear acceleration in the early stage of the downswing exceed, is equal to, or less than the Y-axis angular acceleration and X-axis linear acceleration in the late stage of the downswing.   
     
     
         16 . The system of  claim 7 , further comprising analyzing the down swing portion, comprising processing the sensor data to determine a downswing arc relative to a backswing arc, wherein determining the downswing arc relative to the backswing arc comprises:
 continuously collecting the sensor data;   ascertaining the golf club to be at a top of a backswing by identifying a momentary pause of the golf club and identifying a transition of a Y-axis angular rotation from negative to positive, wherein the Y-axis is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club;   using sensor data samples from the linear axes and the angular rotation axes to plot the backswing and downswing in 3-dimensional space;   recording relative positions of the downswing arc and backswing arc; and   identifying the downswing arc relative to the backswing arc as inside, same, or outside based on the relative positions of the downswing arc and backswing arc.   
     
     
         17 . The system of  claim 7 , further processing the sensor data to determine a sensed wrist rotation comprising determining an orientation of the golf club as the golf club traverses through a backswing and a downswing, comprising:
 continuously collecting the sensor data;   identifying a condition of no movement for greater than a threshold of time;   identifying a condition in which an Y-axis is moving in the negative direction combined with an γ-axis angular motion commencing, thereby indicating a start of the backswing, wherein the Y-axis is perpendicular to shaft of the golf club and perpendicular to grooves of the golf club and the γ-axis angular motion is perpendicular to shaft of the golf club and parallel to grooves of the golf club;   after start of the backswing, identifying a condition in which a γ-axis rotates 90 degrees;   after the condition in which a γ-axis rotates 90 degrees, computing an angle between a Z-axis and a ground plane, wherein the Z-axis is perpendicular to shaft of the golf club and planar to grooves of the golf club;   compute rotation in an α-axis, wherein the α-axis is planar to the shaft of the golf club;   determining the orientation of the golf club as the golf club traverses through a backswing and a downswing as under-rotation of the golf club, optimal rotation of the golf club, over-rotation of the golf club based on whether the angle is less than 90 degrees, approximately equal to 90 degrees, or greater than 90 degrees.   
     
     
         18 . A method of analyzing a golf swing, comprising:
 sensing motion, by a motion sensing device attached to a golf club, the motion sensing device comprising a controller and one or more motion sensors;   accessing, by a controller, sensor data generated based on sensed signals of the one or more motion sensors;   performing pattern recognition analysis on the sensor data, comprising identifying and analyzing at least a portion of a golf swing based on the sensed data, wherein the at least one portion of the golf swing includes at least one of an address portion, a takeaway portion, a first-half of back swing portion, a top of back swing portion, down swing portion, an impact portion, and a follow through portion.