Abstract:
This invention relates to the field of sports training devices and more specifically electronic training devices that show the user in a quantitative manner the quality of a particular performance criteria to be measured. The device is either part of or is attached to a flying disc, and is used for measuring and improving rotational velocity and time aloft, both of which help athletes-beginners to advanced-improve their overall throwing skill. There are many disc sports that are growing and can use such a device to provide instant feedback, which is a fundamental training technique that enables quick improvement of skills.

Description:
REFERENCES CITED 
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                 Patent # 
                 Issue Date 
                 Inventor 
               
               
                   
               
             
             
               
                 4,898,389 
                 February 1990 
                 Plutt 
               
               
                 4,963,096 
                 October 1990 
                 Khattak 
               
               
                 4,974,833 
                 December 1990 
                 Hartman 
               
               
                 5,509,809 
                 April 1996 
                 Clay 
               
               
                 5,605,336 
                 February 1997 
                 Gaoiran 
               
               
                 5,771,492 
                 June 1998 
                 Cozza 
               
               
                 6,110,052 
                 August 2000 
                 Sprager 
               
               
                 6,431,990 
                 August 2002 
                 Manwaring 
               
               
                   
               
             
          
         
       
     
       FEDERALLY SPONSORED DEVELOPMENT 
       [0002]    Not applicable 
       JOINT RESEARCH AGREEMENT 
       [0003]    Not applicable 
       MATERIAL ON COMPACT DISC 
       [0004]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    1. Field of Invention 
         [0006]    This invention relates generally to electronic training devices which measure a particular performance criteria in a sport, and displays the result to enable the user to see the resulting performance change directly. 
         [0007]    2. Description of the Related Art 
         [0008]    There are numerous sports which have high-tech training devices available that allow an athlete to see directly the quality of their performance, and then be able to measurably improve their performance through the use of these devices. Take the sport golf, for instance. Those familiar with the sport know that the golf swing is fundamental to achieving a good score. The golf swing has been analyzed by many professionals in the field and broken down into smaller components that may each be understood and improved. Manwaring explains in U.S. Pat. No. 6,431,990 that the components of interest in a golf swing include golf club head orientation, golf club head velocity, and golf club spin. He then breaks down each of these into sub-components of interest. For instance, golf club head velocity can be further broken down into path of the golf club head, attack of the golf club head and downrange information. In this patent, Manwaring explains a device and method for measuring some of these components of performance so that the golfer may baseline his performance and try various changes in style to see the resulting performance change. 
         [0009]    Another sport that has training devices available to help the athlete improve his or her game is bowling. David G. Sprager et al. explain in U.S. Pat. No. 6,110,052 that spin rate and angle of spin have an effect on the result of how well the bowling ball will knock down pins. Ball velocity, ball position, coefficient of friction, launch angle, and entry angle are also important performance components that will affect the end result of knocking fewer or more pins down. In this patent, a method and apparatus is presented that measures and displays some of these characteristics so that the user may get feedback on how well and how consistent they are with any particular component of performance. 
         [0010]    And in still another sport, boxing, it is very important to be quick and also exert a lot of power in the direction of the opponent. Gaoiran et al. explain in U.S. Pat. No. 5,605,336 a device and method of detecting such characteristics as reaction time and power of an impact to a punching bag for instance. The resulting performance is displayed to the athlete so that they can baseline their performance so that they may set goals to continuously improve. 
         [0011]    The above examples illustrate that sports in general have an “end result” that matters, i.e., getting the ball in the hole in as few strokes as possible in the case of golf, or in bowling, knocking down as many pins as possible. But if you want to improve, you can&#39;t just say “reduce your strokes” or “get more pins down”. It is required that you know specifically what can be done that results in the above improvement. For the case of golf, having a good swing is a fundamental characteristic that may be improved. But even this is too general. To improve your swing, you must break the swing down into components, then work on each component individually. The best way to train is to be able to quantitatively measure the performance criteria so that 1) you can see instant response so you can easily see cause and effect, and 2) you can see a baseline performance and watch steady progress. As each of these characteristics is improved and made more consistent, the end result will improve as well. 
         [0012]    While many sports have such devices available to them to improve their game, the game of flying disc has no such device. Since there are many sports that use a flying disc, and the sport of Ultimate Disc and Disc Golf are becoming more and more competitive, it is apparent to anyone skilled in the art of training, that a training device that helps disc players to improve their game would be a useful tool. There are 3 basic components that control the throw of a disc: The linear speed of the release, the spin (or rotational velocity) of the release, and the accuracy of the release. When new players try throwing a disc, it often flies very poorly. The reason most often is that the rotational velocity (rotations per minute) of the spin is very low. It is therefore not stable. As the rotational velocity or spin increases, the throw becomes more stable. Then accuracy may be developed, and finally speed. The present invention is a tool to allow the user to directly measure the spin of the throw with instant feedback so that they may see what technique changes helped and which ones did not help. It also gives the user a way to baseline their playing and see gradual improvement which adds to the experience of learning a sport, and will usually result in the athlete&#39;s continual improvement. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention is a small device that is either part of a flying disc or is attached to a flying disc, which is capable of measuring, calculating, and displaying the rotational speed of the disc in RPM (rotations per minute). This aids the user in developing and honing a key component of his or her throwing technique. And spin is the most fundamental property of a good stable throw. In addition, the device can sense, calculate, and display total time that the disc is in the air, which is useful if user is trying to develop a long distance throw or trying to improve in the game of “Maximum time aloft“competitions. 
         [0014]    What is fundamental to the invention is have a sensing device that detects motion, the ability to compute a performance characteristic based on what is sensed, the ability to display the performance in any appropriate manner that makes logical sense to the user; and having this functionality be portable and essentially part of the disc. It is important to note here that the device must be small enough and light enough so that it does not substantially affect the flight of the disc. For the present invention, two flying disc characteristics are important to be pointed out. The rotational velocity and the time aloft are two prime characteristics that a disc thrower will care about and want to improve. While the present invention displays the rotational velocity in rotations per minute at the beginning of the throw, for those skilled in the art, it can be seen that displaying the RPM for the middle or the end of the throw or even the average could all be calculated and displayed as well. 
         [0015]    With the addition of other sensors oriented in other axes with respect to the spin axis, it can be seen to those skilled in the art, that other performance characteristics could be measured such as angle of attack of the disc and linear speed of the throw. These are characteristics that, if monitored, can help the user improve their skills because they have instant feedback to show them either improvement or degradation of their throw. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  Drawing showing the top view of the module inside the disc 
           [0017]      FIG. 2  Electronic module top and bottom view with plastic housing removed 
           [0018]      FIG. 3  Forces acting on module 
           [0019]      FIG. 4  Drawing showing block diagram of electrical schematic 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    For terminology, an item in a figure will be referred to as “X-Y” where “X” is the figure and “Y” is the item # in the figure. Where the same item is referenced again in a subsequent figure, the original designator will be used again to avoid confusion. 
         [0021]    Referring to  FIG. 1 , the present invention is shown. Item ( 1 - 1 ) is a standard flying disc, and can be any brand or type including Ultimate disc or Golf disc or a custom disc. Item ( 1 - 2 ) is the electronic module housed in a plastic casing. The entire assembly as shown is item ( 1 - 3 ). In the preferred embodiment, the module ( 1 - 2 ) is attached to the disc ( 1 - 1 ) using plastic rivets. However, those familiar with the art will understand that any adequate method of attachment such as adhesive provides the same means, i.e. to make the module and the disc one rigid object ( 1 - 3 ). 
         [0022]      FIG. 2  shows the electronic module assembly with the plastic housing removed. The key items to point out in the circuit are the accelerometer sensor ( 2 - 1 ), the microcontroller ( 2 - 2 ), the liquid crystal display or LCD ( 2 - 3 ), batteries ( 2 - 4 ), switch ( 2 - 5 ), and raw circuit card ( 2 - 6 ). The module assembly ( 2 - 7 ) is mounted inside the plastic housing, and is attached to the flying disc ( 1 - 1 ) such that the centerline of the module (point labeled  2 - 8 ) is collinear with the pivot axis of the flying disc ( 1 - 1 ). So when the disc/module assembly ( 1 - 3 ) spins in the air, it spins about point  2 - 8 , which is the same as the axis of rotation of the flying disc. As can be seen from  FIG. 2 , this puts the position of the sensor ( 2 - 1 ) off axis. So as the disc/module ( 1 - 3 ) spins, the sensor ( 2 - 1 ) revolves around the pivot axis. This causes a centripetal force on the sensor. The module/disc assembly ( 1 - 3 ) is shown in  FIG. 3 . As the rotational velocity ( 3 - 1 ) increases, the G-force on the sensor ( 3 - 2 ) also increases. The force magnitude is independent of the direction of the spin. 
         [0023]    There is a direct relationship between the value of the rotational velocity ( 3 - 1 ) and the force on the sensor ( 3 - 2 ). Below are equations that relate the two: 
         [0000]        a=V   2   /R  where:  a =acceleration (in/sec 2 )       V=linear velocity (in/sec)   R=distance between sensor and axis of rotation (inch)         
         [0000]      V=2 pi R W where: W=angular or rotational velocity (rotations/sec) 
         [0000]        G=a/ 386 where  G  is gravitational constant (386 in/sec 2 ) 
         [0026]    Combining these equations, we have equation 1.0. 
         [0000]        W =(9.78 G/R ) 1/2    Equation 1.0 
         [0027]    If we preset the distance between the sensor and the spin axis ( 2 - 8 ), then it becomes a 2 variable equation. If we know the G-force ( 3 - 2 ), then the rotational velocity ( 3 - 1 ) may be calculated. There are many types of sensors that detect force. In the present invention, a MEMS (micro-electromechanical system) type of sensor is used. However, for those skilled in the art, it is apparent that there are many ways to measure force including capacitive type and electromechanical type sensors. 
         [0028]    For the preferred embodiment, the sensor used has an electronic (voltage) output that is proportional to the force ( 3 - 2 ) exerted on the sensor. Reference  FIG. 4  for electronic block diagram. Knowing that voltage output ( 4 - 1 ) of the sensor is proportional to the G-force and also knowing that the force is related to the rotational velocity ( 3 - 1 ) through the equation 1.0, then we can say that the rotational velocity ( 3 - 1 ) is related to the voltage output ( 4 - 1 ) of the sensor. Assuming that the distance between the sensor ( 2 - 1 ) and the spin axis ( 2 - 8 ) is 0.591 inch, one can substitute this into equation 1.0 to come up with a final equation. 
         [0000]        W =(16.56 G ) 1/2    Equation 2.0 
         [0029]    Referring to  FIG. 4 , the output of the sensor ( 4 - 1 ) feeds to the input of an analog to digital converter built into a micro-controller ( 2 - 2 ). The analog to digital converter or ADC works as follows: The voltage range that the ADC may accept is divided into 256 equal parts or ranges. The voltage that is output by the sensor and presented to the ADC will lie within one of these ranges or “buckets”. The micro-controller ( 2 - 2 ) responds according to which bucket the voltage lies in. For example, if the total range is 5 volts, then if this is divided by 256, then this makes the range of each bucket 19.5 mV. So the first bucket is 0-19.5 mV, the second bucket is 19.5-39.0 mV, etc. When a voltage ( 4 - 1 ) appears at the micro-controller&#39;s ADC, it will lie within one of the buckets. The bucket # is saved in one of the micro-controller&#39;s registers for reading at any time. By reading the value of this register, we in essence read what voltage ( 4 - 1 ) is coming from the sensor. 
         [0030]    The micro-controller is programmed to read and interpret the signal at this pin as activity from the sensor. By doing this, the microcontroller ( 2 - 2 ) can detect when a throw begins and ends along with the magnitude of the throw. For instance, when the disc is in the user&#39;s hands and not spinning, the G-force ( 3 - 2 ) is essentially zero. When the sensor ( 2 - 1 ) has no force exerted on it, the output voltage ( 4 - 1 ) is 0 volts. The micro-controller is programmed to recognize 0 volts as a stationary flying disc. If on the other hand, the disc is spinning, then the force exerted on the sensor is greater than zero, and so the voltage output ( 4 - 1 ) is greater than 0 volts by an amount depending on the sensor used and the amount of force exerted on the sensor. 
         [0031]    The equation 2.0 is programmed into the micro-controller so that at any time, it “knows” when the flying disc assembly ( 1 - 3 ) is spinning, and if it is spinning, it “knows” how fast it is spinning. 
         [0032]    Since the micro-controller ( 2 - 2 ) is a time based device with an oscillator as part of the system, and the micro-controller can detect when a throw starts and ends, then it is possible for the micro-controller to calculate the total time that the disc is spinning. Since whenever a disc is spinning, it can be assumed that the disc is flying in the air, then this gives us the “total time aloft” which is a figure of merit that a disc thrower might be interested in if they want to compete in this sport. 
         [0033]    Referring to  FIG. 4 , after the micro-controller ( 2 - 2 ) calculates the result of the throw, either “rotational velocity” or “time aloft” need to be displayed to the user so they know the result of the throw. In the preferred embodiment, the micro-controller is tied directly to a 3 digit liquid crystal display or LCD ( 2 - 3 ) to pass the results to the user. For those skilled in the art, it is apparent that light emitting diodes (LEDs) could be used or an LCD that has graphical capabilities to show more information on the flight of the flying disc. 
         [0034]    A switch ( 2 - 5 ) is used for the user to turn on the module ( 2 - 7 ) and to select which mode of operation to monitor, calculate, and display results for. Two modes of interest are “rotational velocity” and “time aloft”. Rotational velocity is displayed directly as rotations per minute (RPM) but could be displayed in other units such as rotations for second if desired. In the present invention, results from the two most recent throws are displayed sequentially. It is apparent that you could program other modes of operation such as RPM for various parts of the throw or displaying results for the most recent 10 throws instead of two. Since this is a training device, it could be useful if the device was programmed to be able to upload data results to a personal computer through the built-in serial port of the micro-controller ( 2 - 2 ). The data could then be graphically analyzed or studied statistically to assist in training.