Tennis let calling system and method using ball flight characteristics

Abstract

This disclosure relates to a let calling system and method, which is configured to determine that a let has occurred based on ball flight characteristics, as opposed to, for example, monitoring for changes in the net. In an example method, following a serve of a tennis ball, the method indicates that contact between the tennis ball and a tennis net has occurred when a flight characteristic of the tennis ball changes by a predetermined threshold amount in an area adjacent the tennis net.

1 . A method, comprising:
 following a serve of a tennis ball, indicating that contact between the tennis ball and a tennis net has occurred when a flight characteristic of the tennis ball changes by a predetermined threshold amount in an area adjacent the tennis net.   
     
     
         2 . The method as recited in  claim 1 , wherein the flight characteristic is determined using a controller in communicate with at least one of a camera, radar, infrared light, and a launch monitor. 
     
     
         3 . The method as recited in  claim 1 , wherein the flight characteristic is a spin rate. 
     
     
         4 . The method as recited in  claim 1 , wherein the flight characteristic is one or more of spin rate, trajectory, velocity, and acceleration. 
     
     
         5 . The method as recited in  claim 4 , wherein, following the serve of the tennis ball, the method includes indicating that contact between the tennis ball and the tennis net has occurred when at least two different flight characteristics of the tennis ball change by respective predetermined threshold amounts in the area adjacent the tennis net. 
     
     
         6 . The method as recited in  claim 5 , wherein, following the serve of the tennis ball, the method includes indicating that contact between the tennis ball and the tennis net has occurred when at least three different flight characteristics of the tennis ball change by respective predetermined threshold amounts in the area adjacent the tennis net. 
     
     
         7 . The method as recited in  claim 1 , wherein the area adjacent the tennis net includes a point on a side opposite the side of the tennis net as a server of the tennis ball. 
     
     
         8 . The method as recited in  claim 1 , wherein the area adjacent the tennis net includes a point on a same side of the tennis net as a server of the tennis ball. 
     
     
         9 . The method as recited in  claim 1 , wherein the area adjacent the tennis net includes a point above the tennis net. 
     
     
         10 . The method as recited in  claim 1 , wherein the area adjacent the tennis net includes a point on a side opposite the side of the tennis net as a server of the tennis ball, a point on a same side of the tennis net as a server of the tennis ball, and a point above the tennis net. 
     
     
         11 . The method as recited in  claim 1 , wherein the predetermined threshold amount is a drop of a predefined percentage. 
     
     
         12 . The method as recited in  claim 11 , wherein the predetermined threshold amount is 5%. 
     
     
         13 . The method as recited in  claim 1 , wherein the predetermined threshold amount excludes gradual changes in the flight characteristic. 
     
     
         14 . The method as recited in  claim 1 , wherein the predetermined threshold amount is a fingerprint and is represented as a sudden drop in the flight characteristic. 
     
     
         15 . A system, comprising:
 a sensor configured to generate signals indicative of a flight characteristic of a tennis ball; and   a controller configured to interpret signals from the sensor and, based on the signals from the sensor, to indicate that contact between a tennis ball and a tennis net has occurred when the flight characteristic of the tennis ball changes by a predetermined threshold amount in an area adjacent the tennis net.   
     
     
         16 . The system as recited in  claim 15 , wherein the sensor is one of a plurality of sensors in communication with the controller. 
     
     
         17 . The system as recited in  claim 16 , wherein each of the plurality of sensors is a different type of sensor. 
     
     
         18 . The system as recited in  claim 15 , wherein the sensor is one of a camera, radar, infrared light, and a launch monitor. 
     
     
         19 . The system as recited in  claim 15 , wherein the flight characteristic is one or more of spin rate, trajectory, velocity, and acceleration. 
     
     
         20 . The system as recited in  claim 19 , wherein the controller is configured to indicate that contact between the tennis ball and the tennis net has occurred only if at least two different flight characteristics of the tennis ball change by respective predetermined threshold amounts in the area adjacent the tennis net.