The invention relates to an electronic system and method for the analysis of a golf swing, and in particular to quantifying the position, orientation, and velocity of the golf club as it moves through the golf ball impact zone.
The dynamics of a golf swing are the contributing factors, which when coupled with the club face construction and the surface characteristics of a golf ball, will ultimately determine the trajectory of the golf ball. The relative motion and orientation of the golf club head and, in particular, its face as it impacts the golf ball determines the effective transfer of energy from the club to the ball. Subtle changes to certain components of the golf swing can have dramatic effects on the flight of the golf ball, some desirable, a majority typically undesirable. It is known in the art to provide a quantifying of the relative motion of the golf club head as it impacts the golf ball through the use of multiple video cameras and extensive, costly digital image processing. By way of example, U.S. Pat. No. 5,501,463 to Gobush et al. discloses a video image processing system that uses cameras for viewing light patterns on the club. The light patterns are then processed by a computer for determining a movement of the golf club. Other methods using magnetic, optical, and mechanical techniques typically only provide a limited amount of information regarding various aspects of the club head such as speed, face angle or slice. U.S. Pat. No. 4,979,745 to Kobayashi discloses the use of a sensor in the club head which detects light from a ground station emitter. The detection then causes an emitter in the club head to emit light. A measurement of time between peak light outputs provides a timing measure from which an angle and club head speed is determined. Yet another approach includes the use of sensors placed on the ground under a ball for detecting the shadow of the club head as it passes over the sensor. The timing differences between sensor detection of a shadow are used to determine club head speed and acceleration. In a similar manner, sensors are positioned to measure the heel and toe portion of the head for determining an angular component of the swing. Many approaches require sensor loops, reflective optics and other such devices that are cumbersome and thus obstruct the club swing, limit access to the golf ball, or require such extensive setup that they become impractical for use by the average golfer. There is a need to measure the characteristics of the golf swing without devices or techniques that are complex, costly, and or limited effectiveness.
In view of the foregoing background, it is therefore an object of the invention to provide a system and method for analyzing a golf swing by quantifying a complete characterization of a golf club head movement as it passes through the impact zone of the golf ball. It is further an object of the invention to provide location coordinates, angular orientation, and velocities descriptive of the golf club head motion. It is yet another object of the invention to provide a system and method for measuring the club face loft angle, club face opening angle, club face toe-heel angle, slice magnitude, hook magnitude, chop direction and magnitude, club head height and lateral position relative to the ball both of which define the club head xe2x80x9csweet spot,xe2x80x9d and club head velocity.
These and other objects, advantages, and features of the present invention are provided by a golf swing analysis system comprising a radiation source for providing a plane of radiation through which radiation plane a golf club can pass, a radiation sensor carried by the golf club, which sensor is responsive to an orientation of a ball striking face of a golf club head, timing means operable with the radiation sensor for receiving a radiation sensing signal and for determining a time period between passage of the first and second portions of the head through the radiation plane, and processing means for processing the time period and calculating a characteristic value for club head movement through a ball impact zone. The radiation sensor provides the radiation sensing signals in response to first and second portions of the golf club head passing through the plane of radiation. The timing means receive the radiation sensing signals for determining a time period between signals and thus between the passage of the first and second portions. In one embodiment of the present invention, communication means are operable between the timing means and processing means for providing the processing means at a location removed from the golf club.
In a preferred embodiment of the present invention, the radiation source provides a fan shaped laser beam generally perpendicular to the surface upon which a player stands for swinging the golf club. Preferably, the laser beam extends from the player to a golf ball to be struck, and is perpendicular to a target line passing through the club face and the golf ball toward a target. Further, the radiation sensor comprises a radiation receiver having a plurality of radiation sensors orthogonally arranged at measurable preselected locations with at least three of the plurality of radiation sensors for defining a radiation sensor plane. The radiation sensor plane is representative of the striking face of the club head. Each radiation sensor comprises an optical sensor responsive to a laser beam.
A preferred embodiment of the timing means comprises a trigger input module and a counter. The trigger input module receives the detection signal from the radiation sensor and provides a pulsed output indicative of the time period between passage of the first and second locations passing the radiation plane. The counter operates with the trigger module for receiving the pulsed output and counting a number of pulses between the radiation sensor signals.
The characteristic value for club head movement comprises loft angle, face angle, and golf club head velocity. With the radiation plane comprising first and second fan shaped laser beams intersecting each other and each vertically orientated and arranged at a measurable fixed angle to each other, and with the first fan shaped laser beam perpendicular to a target line passing through the club face and ball, the characteristics value comprises loft angle, face angle, toe-heel angle, slice velocity, hook velocity, and golf club head velocity. With the radiation plane comprising first, second, and third planar shaped laser beams intersecting each other, the characteristic value for club head movement comprises loft angle, face angle, toe-heel angle, slice velocity, hook velocity, chop velocity, golf club head velocity, and sweet spot. Here, the first and second planar shaped laser beams are vertically orientated, intersecting, and arranged at a measurable fixed angle to each other. The first planar shaped laser beam is perpendicular to a target line passing through the club face and ball, and the third planar shaped laser beam intersects the first and second planar shaped laser beams at a non-vertical angle.
Included in a preferred embodiment of the present invention herein describes is a laser module base unit consisting of three laser sources. Each laser source is coupled to a cylindrical lens assembly for the projection of a plane of laser light. The laser sources are oriented in a specific geometrical alignment to provide three intersecting planes of laser light at predetermined angles. The base unit containing the laser sources is positioned on the ground between the golfer and golf ball with the lasers directed toward the golf ball. The sensor module is clipped to the shaft of the golf club just above the club head and contains four sensors in a three dimensional, orthogonal pattern with predetermined distances between each sensor. The sensors contained in the sensor module trigger the system counter upon intersection with the planes of laser light. The relative counts are stored in a data queue and then transmitted via radio frequency to the base unit containing the laser source module and a microprocessor which calculates the club head location coordinates, angles and velocities at the point of impact with the golf ball.