Spin determination for a rotating object
First Claim
1. An apparatus for use in determining spin characteristics of a rotating object, said apparatus comprising:
- a transmitter positionable for transmitting electromagnetic radiation of at least a first frequency at an object configured for reflecting at least a portion of said transmitted radiation in a modulated manner wherein said reflected radiation includes modulation characteristics from which at least a spin axis of the object is determinable;
a receiver positionable for receiving at least a portion of said reflected radiation; and
a demodulator for detecting the modulation characteristics of said reflected radiation received by said receiver and outputting a demodulated signal including information about at least the spin axis of the object.
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Accused Products
Abstract
An apparatus for use in determining spin characteristics of an appropriately configured rotating object, such as a golf ball, includes a transmitter, a receiver, and a demodulator. The object is configured for reflecting radiation of at least a first frequency in a modulated fashion corresponding to at least one spin characteristic of the object. In this regard, an appropriately configured object may include at least one contrast area comprised of a material having different reflectivity than the rest of the object to electromagnetic radiation of at least the first frequency. The transmitter is positioned for transmitting electromagnetic radiation of at least the first frequency at the object. The receiver is positioned for receiving at least a portion of the modulated reflected radiation. The transmitter and receiver may comprise a single transceiver unit. The demodulator detects the modulated nature of the reflected radiation received by the receiver and outputs a demodulated signal including information about at least one spin characteristic of the object.
79 Citations
40 Claims
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1. An apparatus for use in determining spin characteristics of a rotating object, said apparatus comprising:
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a transmitter positionable for transmitting electromagnetic radiation of at least a first frequency at an object configured for reflecting at least a portion of said transmitted radiation in a modulated manner wherein said reflected radiation includes modulation characteristics from which at least a spin axis of the object is determinable;
a receiver positionable for receiving at least a portion of said reflected radiation; and
a demodulator for detecting the modulation characteristics of said reflected radiation received by said receiver and outputting a demodulated signal including information about at least the spin axis of the object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
a pre-amplifier/filter; and
a comparator;
and wherein;
said pre-amplifier/filter receives said difference signal from said transceiver and both amplifies and filters said difference signal;
said demodulator detects said modulation characteristics of said amplified and filtered difference signal and outputs a demodulated analog signal including information about at least one spin characteristic of the object; and
said comparator converts said demodulated analog signal to a digital signal including information about at least one spin characteristic of the object.
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8. The apparatus of claim 7 further comprising:
automatic gain control circuitry for further amplification of said difference signal prior to detection by said demodulator.
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9. The apparatus of claim 7 wherein:
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the object includes at least one contrast area having higher reflectivity to said transmitted radiation than the rest of the object;
said reflected radiation is amplitude modulated as a result of said at least one contrast area coming into view of said transceiver as the object rotates; and
said demodulator is an AM demodulator having envelope detection circuitry.
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10. The apparatus of claim 7 further comprising:
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signal processing means for processing said digital signal to determine at least one spin characteristic of the object from said information included in said digital signal; and
a display for displaying said determined spin characteristic.
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11. The apparatus of claim 7 wherein the apparatus is interfaceable with a computer programmed for processing said digital signal to determine at least one spin characteristic of the object from said information included in said digital signal and displaying said determined spin characteristic.
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12. The apparatus of claim 6 wherein said Doppler shifted reflected radiation exhibits Doppler broadening of a bandwidth of said frequency spectrum around said center Doppler frequency as a result of surface characteristics of the object, said Doppler broadening corresponding to a rate of spin of the object.
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13. The apparatus of claim 12 wherein the object is a golf ball and said Doppler broadening results from a dimple pattern on the surface of the golf ball.
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14. The apparatus of claim 6 wherein asymmetry of the object produces both frequency and amplitude modulation of the said Doppler shifted reflected radiation, said frequency and amplitude modulation of said Doppler shifted reflected radiation corresponding to a rate of spin of the object.
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15. The apparatus of claim 14 wherein the object is a golf ball and said asymmetry results from deformation of the golf ball due to impact from a golf club.
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16. An apparatus for use in determining spin characteristics of a golf ball moving over an expected flight path, said apparatus comprising:
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a transceiver positionable for transmitting electromagnetic radiation of at least a first frequency into an expected flight path of a ball configured for reflecting at least a portion of said transmitted radiation in a modulated manner wherein said reflected radiation includes modulation characteristics from which at least a spin axis of the ball is determinable;
a portion of said reflected radiation being receivable by said transceiver and mixed therein with a signal at the same frequency as said transmitted radiation to generate a difference signal including modulation characteristics corresponding with the modulation characteristics of said reflected radiation;
a pre-amplifier/filter for receiving said difference signal from said transceiver and both amplifying and filtering said difference signal;
a detector for detecting said modulation characteristics of said amplified and filtered difference signal and outputting a demodulated analog signal including information about at least the spin axis of the ball; and
a comparator for converting said demodulated analog signal to a digital signal including information about at least the spin axis of the ball. - View Dependent Claims (17, 18, 19)
automatic gain control circuitry for further amplification of said difference signal prior to detection by said detector.
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18. The apparatus of claim 16 wherein:
said reflected radiation is amplitude modulated in a manner such that a spin rate of the ball is determinable.
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19. The apparatus of claim 16 wherein:
said reflected radiation is amplitude modulated in a manner such that a spin rate and the spin axis of the ball is determinable.
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20. A ball adapted for determination of its spin characteristics, comprising:
at least one contrast area comprised of a material having different reflectivity than the rest of the ball to electromagnetic radiation of a predetermined frequency, said contrast area being configured for causing reflected radiation of the predetermined frequency reflected from the ball to be modulated in a manner from which at least a spin axis of the ball is determinable. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 32)
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29. A ball adapted for determination of its spin characteristics, comprising:
two contrast areas comprised of a material having different reflectivity than the rest of the ball to electromagnetic radiation of a predetermined frequency, wherein said two contrast areas are configured for causing radiation of said predetermined frequency reflected from the ball as it rotates to have periodic pairs of amplitude peaks, said pairs occurring at a frequency corresponding to a spin rate of the ball, and wherein said two contrast areas are arranged such that an interval between sequential pairs of amplitude peaks varies in a known manner as a spin axis of the ball changes. - View Dependent Claims (30, 31)
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33. A ball adapted for determination of its spin characteristics, comprising:
three contrast areas comprised of a material having different reflectivity than the rest of the ball to electromagnetic radiation of a predetermined frequency, wherein said three contrast areas are configured for causing radiation of said predetermined frequency reflected from the ball as it rotates to have groups of three amplitude peaks, said groups occurring at a frequency corresponding to a spin rate of the ball, and wherein said three contrast areas are arranged such that a ratio of an interval between a first and a second amplitude peak in a group to an interval between said second and a third amplitude peak in the same group varies in a known manner as a spin axis of the ball varies. - View Dependent Claims (34, 35)
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36. A method of determining spin characteristics of a rotating object, said method comprising the steps of:
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providing an object including at least one contrast area having different reflectivity than the rest of the object to electromagnetic radiation of a predetermined frequency and being configured for causing radiation of the predetermined frequency reflected from the object to be modulated in a manner from which a spin axis of the object is determinable;
transmitting electromagnetic radiation of the predetermined frequency in the direction of the object, a portion of the transmitted radiation being reflected from the object and amplitude modulated in a manner corresponding to at least one spin characteristic of the object as a result of the contrast area periodically facing a source of the transmitted radiation as the object rotates;
receiving a portion of the amplitude modulated reflected radiation; and
demodulating the reflected radiation to generate a demodulated signal including information corresponding to at least a spin axis of the object. - View Dependent Claims (37, 38)
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39. A method of determining spin characteristics of a rotating object, said method comprising the steps of:
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providing an object including at least one contrast area having different reflectivity than the rest of the object to electromagnetic radiation of a predetermined frequency;
transmitting electromagnetic radiation of the predetermined frequency in the direction of the object, a portion of the transmitted radiation being reflected from the object and amplitude modulated in a manner corresponding to at least one spin characteristic of the object as a result of the contrast area periodically facing a source of the transmitted radiation as the object rotates;
receiving a portion of the amplitude modulated reflected radiation; and
demodulating the reflected radiation to generate a demodulated signal including information corresponding to at least one spin characteristic of the object, wherein the demodulated signal includes periodic pairs of pulses, a spin rate of the object being determinable from a frequency of the pairs of pulses and a spin axis of the object being determinable from an interval between sequential pairs of pulses.
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40. A method of determining spin characteristics of a rotating object, said method comprising the steps of:
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providing an object including at least one contrast area having different reflectivity than the rest of the object to electromagnetic radiation of a predetermined frequency;
transmitting electromagnetic radiation of the predetermined frequency in the direction of the object, a portion of the transmitted radiation being reflected from the object and amplitude modulated in a manner corresponding to at least one spin characteristic of the object as a result of the contrast area periodically facing a source of the transmitted radiation as the object rotates;
receiving a portion of the amplitude modulated reflected radiation; and
demodulating the reflected radiation to generate a demodulated signal including information corresponding to at least one spin characteristic of the object, wherein the demodulated signal includes periodic groups of three pulses, a spin rate of the object being determinable from a frequency of the groups of three pulses and a spin axis of the object being determinable from a ratio of an interval between a first and a second pulse of a group to an interval between the second and a third pulse of the same group.
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Specification