Roll Quality of Putting Green

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 12/981,656 filed on Dec. 30, 2010, and entitled “System for Measuring the Roll Quality of a Putting Green,” which is a non-provisional application of and claims priority to U.S. Provisional Application No. 61/291,686, entitled “SYSTEM FOR MEASURING THE ROLL QUALITY OF A PUTTING GREEN”, filed Dec. 31, 2009, both of which are incorporated herein by reference.

FIELD

The present disclosure is generally related to systems, devices, and methods configured to measure a roll quality of a putting green.

BACKGROUND

In the area of golf course putting greens, green speeds (ball roll distance from a known starting energy level) are commonly measured using a variety of devices. These devices are exclusively focused on the length (distance) a golf ball travels over any surface. However, the ball roll distance, or green speed, is only one measure of the surface.

SUMMARY

In some embodiments, a system may include a golf ball having at least one accelerometer configured to generate signals proportional to acceleration along three axes and a microprocessor coupled to the accelerometer. The microprocessor may be configured to correlate the signals to produce a roll data file for each roll event of a plurality of roll events. The golf ball may also include a memory configured to store the roll data file for each roll event and a transceiver configured to communicate roll data associated with at least some of the plurality of roll events to a computing device. The system may further include the computing device configured to receive the roll data from the golf ball and, in a first mode, to process the roll data file to determine at least one of an overall roll quality associated with a surface and a firmness parameter associated with a surface.

In other embodiments, a method may include receiving roll data from a golf ball including accelerometer data measured along three axes at an interface of a computing device. The method may further include processing, using a processor of the computing device, the roll data to determine, in a first mode, at least one of a smoothness metric, a plane deviation metric, and a firmness metric associated with a surface. Further, the method may include providing data related to at least one of the smoothness metric, the plane deviation metric, and the firmness metric from the processor to a display of the computing device.

In still other embodiments, a computer readable storage device may embody software including instructions that, when executed, cause a processor to process roll data from a golf ball to determine a roll quality metric for a surface of a putting green, in a first mode. The instructions may also cause the processor to provide data corresponding to the roll quality metric to a display device. In a second mode, the instructions may cause the processor to process the roll data from the golf ball to determine a characteristic of a putting stroke and provide data related to the characteristic of the putting stroke to a display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a diagram of a system configured to determine roll quality of a putting green, in accordance with certain embodiments of the present disclosure.

FIG. 2 depicts a golf ball shown in partial cross-section and including circuitry configured to determine a roll quality of a putting green, in accordance with certain embodiments of the present disclosure.

FIG. 3 is a side view of a golf ball rolling from left to right or right to left, in accordance with certain embodiments of the present disclosure.

FIG. 4A is a rear view schematic of a golf ball rolling directly away from a viewer, that is, rolling into the sheet, in accordance with certain embodiments of the present disclosure.

FIG. 4B is a top view of a initial roll path and an actual roll path of the golf ball of FIG. 4A, in accordance with certain embodiments of the present disclosure.

FIG. 5 depicts a block diagram of a system including a golf ball configured to communicate with a computing device, in accordance with certain embodiments of the present disclosure.

FIG. 6A depicts a representative example of a graph of acceleration over time for a golf ball that is rolling along a surface, in accordance with certain embodiments of the present disclosure.

FIG. 6B illustrates a representative example of a graph of acceleration over time for a golf ball that is rolling along a surface, in accordance with certain embodiments of the present disclosure.

FIG. 7A depicts a graph of raw accelerometer data for a tri-axial accelerometer as the golf ball is rolled across a pool table, in accordance with certain embodiments of the present disclosure.

FIG. 7B depicts a graph of raw accelerometer data for a tri-axial accelerometer as a golf ball is rolled across a green, in accordance with certain embodiments of the present disclosure.

FIG. 7C illustrates a graph of raw accelerometer data for a tri-axial accelerometer as a golf ball is rolled across a fringe of a green, in accordance with certain embodiments of the present disclosure.

FIG. 7D depicts a graph of raw accelerometer data for a tri-axial accelerometer as a golf ball is rolled across the rough, in accordance with certain embodiments of the present disclosure.

FIG. 8 illustrates a graph of velocity over time for a golf ball rolled on a three-foot putt, in accordance with certain embodiments of the present disclosure.

FIG. 9 illustrates a flow diagram of a method of determining a roll quality of a green, in accordance with certain embodiments of the present disclosure.

FIG. 10 depicts a flow diagram of a method of determining putt characteristics, in accordance with certain embodiments of the present disclosure.

In the following discussion, the same reference numbers are used in the various embodiments to indicate the same or similar elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of embodiments, reference is made to the accompanying drawings which form a part hereof, and which are shown by way of illustrations. It is to be understood that features of various described embodiments may be combined, other embodiments may be utilized, and structural changes may be made without departing from the scope of the present disclosure. It is also to be understood that features of the various embodiments and examples herein can be combined, exchanged, or removed without departing from the scope of the present disclosure.

In accordance with various embodiments, the methods and functions described herein may be implemented as one or more software programs running on a computer processor or controller. In accordance with various embodiments, the methods and functions described herein may be implemented as one or more software programs running on a computing device, such as a tablet computer, smart phone, personal computer, server, or any other computing device. Dedicated hardware implementations including, but not limited to, application specific integrated circuits, programmable logic arrays, and other hardware devices can likewise be constructed to implement the methods and functions described herein. Further, the methods described herein may be implemented as a device, such as a computer readable storage device or memory device, including instructions that when executed cause a processor to perform the methods.

Additionally, in some embodiments, data processing functions performed by circuitry within a golf ball may be implemented using a general purpose processor, such as an 8-bit, 32-bit, or 64-bit processor (for example). Alternatively, such data processing functions may be performed using application specific integrated circuits, programmable logic arrays, and other hardware devices can likewise be constructed to implement the methods and functions described herein.

Embodiments of systems are described below that may include a golf ball having circuitry configured to measure acceleration along three axes as a golf ball is rolled across a surface of a putting green. In a first mode, the measurement data may be processed to determine characteristics of the surface of the putting green, including green speed, firmness, and overall roll quality of a putting green. High frequency signal elements within accelerometer signals may reflect imperfections in the surface that may cause the golf ball to jump or bounce. Lower frequency elements within the accelerometer signals may reveal slopes in the surface of the putting green both in the horizontal plane and in the vertical plane. If the ground in the direction of the roll is perfectly flat, perfectly uphill, or perfectly downhill, then hitting the ball into the hole may require putting the ball along a straight line that points directly to the hole. The acceleration measurements may reflect an initial acceleration due to the putt followed by one or more deceleration measurements reflected by changes in the frequency and amplitude of the accelerometer signal along at least one axis. In some examples, slopes and imperfections in the green surface can impact the trajectory of the roll, causing the ball to deviate from the straight line. The circuitry embedded within the golf ball can measure such deviations and associated accelerations, store the measurement data, and transmit the measurement data to a computing device for further processing.

In some embodiments, circuitry within a golf ball may include one or more accelerometers configured to measure acceleration along three axes (X, Y, and Z). The acceleration measurements in each dimension may reflect imperfections and slopes that may be correlated to determine a roll quality of a putting green. In one example, the circuitry may measure deviation of a center of a golf ball from an initial horizontal plane that extends parallel to the surface of the putting green while the golf ball is stationary (prior to the putt or roll). Since the slope of the putting green surface may vary from instant to instant as the ball rolls, the deviation of the golf ball from the initial horizontal plane may be measured by changes in the acceleration in all three dimensions. Further, the circuitry configured may be configured to measure horizontal deviation from a plane extending through the center of the golf ball and aligned with an initial trajectory of the rolled ball. As the slope varies, the accelerometer measurements reflect the changing slope in X, Y, and Z dimensions. Further, abrupt changes in acceleration may reflect imperfections in the surface of the green, such as foot prints, bumps, pock marks, or other imperfections that can impact the roll of the ball, such as by causing the ball to bounce or jump (sometimes deviating from the initial trajectory in the X-Y plane). Additionally, the golf ball may be configured to determine a firmness characteristic of the surface by measuring bounce from an initial impact dropped from a known height above the surface. In some instances, the bounce may also be determined by a distance of travel between the putter strike and a point when the ball may begin to roll, which distance may be determined by double integrating the accelerometer data along the axis of motion.

The golf ball may include a golf ball outer surface (formed, for example, from a thermoplastic or ionomer resin) and a solid rubber core, which may be partially removed to form an interior cavity. An electronic system can be positioned within the interior cavity. The electronic system may include one or more accelerometers, a microprocessor, a communications system, and a rechargeable battery. In response to movement of the ball, e.g., a roll or putt of the golf ball on any surface, the circuitry may be configured to measure the acceleration (or deceleration) of the ball using the one or more accelerometers. The circuitry may store the data in a memory and may process the data, to produce a roll data file. The roll data file may be further processed to determine a roll quality of the surface.

In certain embodiments, the golf ball circuitry may include a communications system (such as a transceiver) configured to communicate the roll data file to a computing device, such as a portable computer, a smart phone, a tablet computer, another data processing device, or any combination thereof. The communications system may transfer the roll data file from the golf ball to the computing device, which may be configured to analyze the roll data file. In a first mode, the computing device may be configured to determine a “speed” parameter (i.e., green speed), a firmness parameter, and an overall roll quality parameter for the surface. The computing device may be configured to display the speed, the firmness, and the roll quality or to provide the data to another device for display.

In a second mode, the computing device may process the roll quality data to evaluate a particular putting stroke. By analyzing accelerometer data for a given stroke, putting stroke flaws may be detected. In an example, a golfer who turns the club face at impact may impart a side spin to the putt, which may be reflected by acceleration measurements along two axis reflecting acceleration in two directions, one of which dominates the other when the ball begins to roll. In another example, a golfer who snaps his or her wrists during the putting stroke may cause the ball to skid, skip, or bounce more than a desired putting stroke would before the ball begins to roll. Such skids, skips, or bounces may be reflected in the accelerometer data by acceleration without rotation (i.e., straight line acceleration as compared to sinusoidal acceleration reflecting rotation) or by high frequency noise superimposed on the sinusoidal signal reflecting bouncing after the initial impact of the putter. Further analysis of the roll data file may reveal additional swing imperfections.

Embodiments of a system are described below that may be configured to determine surface parameters of a putting green in a first mode and to determine imperfections in a putting stroke in a second mode. It should be understood, however, that the disclosed embodiments are illustrative only, and other embodiments and combinations of embodiments can be determined in light of the present disclosure. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as a basis for teaching one skilled in the art how to make and use the systems, devices, or methods.

Referring now to FIGS. 1 and 2, a system 10 for measuring the roll quality of a putting green 12 is disclosed, in accordance with certain embodiments of the present disclosure. The system 10 may include a golf ball 14 including circuitry configured to measure acceleration of the golf ball in three dimensions (represented by the X, Y, and Z axis 17) and to communicate the measurement data to a computing device 16, such as a tablet computer, a smart phone, another computing device, or any combination thereof. In the illustrated example, the computing device 16 is depicted as a special purpose data processing device. The computing device 16 may be configured to execute a custom computer software interface. Further, the computing device 16 may be configured to determine both a green speed and a roll quality for the putting green 12 based on the measured acceleration data. The computing device 16 may communicate information corresponding to the green speed and the roll quality to a display, to an audio output, to another computing device, or any combination thereof.

In some embodiments, the computing device 16 may be configured to determine how smoothly a golf ball 14 travels over a surface, such as the putting green, toward a cup 15, for example. The acceleration data may indicate a plurality of changes in acceleration in three dimensions (X, Y, and Z) as the golf ball 14 rolls, indicating changes in the slope as well as imperfections in the surface of the putting green. The combination of the slopes and the imperfections can be processed by a processor within the golf ball 14 or by a processor within the computing device 16 to determine a “roll quality” measurement of the surface of the putting green 12.

Further, the system 10 can also determine a green speed measurement for the putting green 12. In some embodiments, the golf ball 14 can communicate the roll data file to the computing device 16 to determine the green speed measurement as well as the slope and imperfection measurement data. The computing device 16 may be configured to present the data to golf course officials, who regularly seek this information. In certain embodiments, the system 10 can also provide feedback to a golfer, such as how solidly (with regard to side spin and energy transfer) he or she has struck a putt. The golfer can use the feedback as a learning aid when practicing putting.

In a particular example, the impact of a putter with the surface of the golf ball 14 may be detected as an abrupt change in acceleration. In some embodiments, the accelerometers may generate an electrical signal resembling a spike or impulse in response to the golf ball 14 being struck by a putter. In some instances, the golf ball 14 may roll beginning at the initial impact of the putter, and the accelerometers may be configured to detect a “rolling” profile, which may be characterized by variations in the accelerometer measurements in the X, Y, and Z dimensions consistent with rolling across a variable surface. In some instances, when the golf ball 14 is struck by the putter, the golf ball 14 may skid for a short distance before rolling, which may indicate poor putting mechanics. The skid may be detected as acceleration in a particular direction without the variations common to rolling (e.g., the accelerometer signal variations caused by the changing rotational orientation of the accelerometer within the golf ball 14).

Further, in some instances, a golfer may misalign the club face or may turn his or her club face at impact such that the club face is turned slightly relative to the putting stroke, which may cause the golf ball 14 to spin briefly in a plane that is different from a direction of the putt. The brief spin may cause the golf ball 14 to roll off-line (i.e., away from intended direction of the putt), almost like a curve ball or slider in baseball. In either instance, the accelerometers within the golf ball 14 may measure the “skid” and the “spin” independent from the desired roll. In a particular example, the initially imparted spin may be quickly subsumed by the roll of the golf ball 14, but the abrupt change in the accelerometer signals may be detected and the swing error may be inferred from the detected spin. In certain embodiments, the computing device 16 may provide feedback in terms of analysis of the putting stroke based on detecting the skid or the spin.

In certain embodiments, the golf ball 14 can be a solid core two piece USGA (United States Golf Association) approved golf ball of standard size and weight specifications, with at least one cavity 20 milled to hold the components of the electronic system 22, including the one or more accelerometers 24, the microprocessor 26, the communications system 28, the memory 29, and the battery 30. The golf ball 14 may include a conventional golf ball outer surface 18 (formed, for example, from a thermoplastic or ionomer resin) and a solid rubber core, which may be partially removed to form an interior cavity 20. The electronic system 22 can be inserted and potted into the interior cavity 20, and the golf ball 14 can be reassembled, removing any seams caused through the formation of the cavity 20. In an example, a golf ball 14 may be cut in half, and a portion of the rubber core may be removed to create the cavity. After insertion and potting of the electronic system 22, the outer surfaces 18 of the two halves of the golf ball 14 may be reassembled and glued or welded (e.g., sonic weld) to reform the golf ball 14. The resulting golf ball system 14 may have the standard size and weight of a USGA approved golf ball. In some embodiments, special materials could be used within the golf ball 14 to duplicate the weight and balance characteristics of a standard golf ball, and the outer surface of the golf ball 14 could be covered with various sized and shaped dimples to duplicate the various geometries of existing or future dimple configurations, or could be dimple free.

As briefly discussed above, the electronic system 22 may be positioned within the interior cavity 20. The electronic system 22 may include one or more accelerometers 24, a microprocessor 26, a communications system 28, and battery 30. Further, the electronic system 22 may include a memory 29 configured to store instructions executable by the microprocessor 26 and to store data (such as roll file data). The one or more accelerometers 24 may be configured to measure acceleration in X, Y, and Z dimensions. The one or more accelerometers 24 may be coupled to the microprocessor 26, which may be coupled to the communications system 28 and the battery 30. The battery 30 may be rechargeable, such as via an inductive recharge unit. In a particular example, the battery 30 may include a rechargeable nickel metal hydride (NiHM) battery.

In some embodiments, the one or more accelerometers 24 may generate electrical signals that are proportional to the acceleration in X, Y, and Z dimensions and may communicate the electrical signals to the microprocessor 26. In some embodiments, the one or more accelerometers 24 may include an analog-to-digital converter (ADC) or may communicate with the microprocessor 26 through the ADC. The microprocessor 26 may be configured to process the signals received from the one or more accelerometers 24. In an example, the microprocessor 26 may correlate data from each of the accelerometers 24 and may store the correlated data into a roll data file. The microprocessor 26 may subsequently provide the roll data file to the communications system 28, which may send the roll data file to the computing system 16.

In certain embodiments, the accelerometers 24, the microprocessor 26, the communications system 28, and the computing device 16 may cooperate to gather and process information to determine not only the green speed, but also the roll quality of a putting green. The electronic system 22 may be configured to record data relating to the roll quality (thereby creating a “roll data file”) in response to a roll or a putt of the golf ball 14. In certain embodiments, the one or more accelerometers 24 may generate raw data and may provide the raw data to the microprocessor 26 for processing. In an example, the microprocessor 26 may process the data from the one or more accelerometers 24 to correlate the data in the three dimensions (X, Y, and Z).

The processed data may constitute a “roll data file”. The communications system 28 can transmit (via a radio frequency signal, such as a Bluetooth signal, a WiFi signal, or other wireless communications signal) the “roll data file” from the golf ball 14 to the custom computer software interface 16 or to a portable computing device, such as a smart phone, configured to analyzes the data and report on the surface green speed and overall “roll quality” of the putting green (or surface) 12. Further, the microprocessor 26 may store the roll data file in the memory 29.

In some embodiments, the portable computing device 16 may further process the roll data file to determine not only the green speed, but also firmness and roll quality of the putting green 12. By dropping the golf ball 14 from a known height above the surface, such as one foot (12 inches), the golf ball 14 may accelerate toward the surface, impact the surface, and bounce, and the interaction between the golf ball 14 and the putting green 12 may be captured in the accelerometer data, which data may be analyzed to determine a firmness of the putting green 12. Further, rolling the golf ball 14 across the putting green in different directions and at different speeds may allow the electronic system 22 to capture accelerometer data corresponding to the roll of the golf ball 14. Such accelerometer data may be analyzed by the computing device 16 to determine parameters of the putting surface, including the green speed and the roll quality. The roll quality may be determined based on bumps, slopes, and other perturbations in the surface of the putting green (or surface) 12, which may cause deflections from an initial horizontal plane as the golf ball 14 rolls and which may be reflected in high frequency accelerometer signal components and low frequency signal components that can impact the roll of the golf ball (either distance or direction).

In an example, the initial horizontal plane may extend through a center of the golf ball 14 and in parallel to the putting green (or surface) 12 when the ball is at rest before the ball is rolled. In some instances, the golf ball 14 may roll along the surface 12 and such bumps, slopes, and other perturbations may cause the golf ball 14 to deviate from the initial horizontal plane as it follows the variations of the surface 12. In some instances, the bumps or perturbations may cause the golf ball 14 to bounce or otherwise experience intermittent contact with the putting green (or surface) 12, which intermittent contact can influence the distance the ball rolls since the air will likely provide less resistance to movement than the putting green (or surface) 12.

Further, the roll quality may indicate bumps, slopes, and other perturbations in the putting green (or surface) 12 that may cause deflections from an initial roll path of the golf ball 14, which may be defined by a vertical plane extending through the center of the golf ball 14 and on an initial roll path of the golf ball 14. In particular, as the golf ball 14 rolls, the putting green (or surface) 12 may cause the golf ball 14 to deviate from the initial path (vertical plane) of the golf ball 14, turning or jumping off of the initial path. Abrupt changes may indicate imperfections in the surface (such as pock marks, divots, or other imperfections) that can influence the roll path of the golf ball 14, such as by abruptly redirecting the golf ball 14. In contrast, a substantially constant change may indicate a slope, which can cause the golf ball 14 to curve away from the initial path (vertical plane). The substantially constant change may be reflected in an increased amplitude of an accelerometer measurement along at least one axis that is different from an axis associated with the roll path (assuming that one of the measurement axes of the accelerometer 24 is aligned to the roll path). The abrupt changes may be reflected in the accelerometer signals as high frequency noise superimposed on the sinusoidal signal. In some instances, bounces may be reflected as discontinuities in the sinusoidal waveform. Other embodiments are also possible.

In an example, the accelerometer 24 may include acceleration measurements corresponding to three axes (X, Y, and Z). In some embodiments, the X-Y plane of the axes may extend through the center of the golf ball 14 at its initial position (prior to rolling) and parallel to the surface of the putting green (or surface) 12. Further, the Z-axis may reflect vertical displacement (as depicted in FIG. 6 and discussed below). Abrupt changes in the accelerometer data (e.g., acceleration signal variations in the plus and minus Z direction) may reflect slopes, bumps, divots, or other perturbations that may cause the ball to bounce rather than roll and, in some instances, to change direction.

In general, as the golf ball 14 rolls, the one or more accelerometers 24 may measure acceleration relative to the axes. Gravitational forces and centripetal forces may act on the accelerometers 24, which produce sinusoidal signals proportional to gravity and with an offset due to centripetal forces. The frequency and duration of the sine wave can be used to determine the speed and distance the golf ball 14 travels. The accelerometers 24 may measure acceleration relative to gravity to produce sine waves as the golf ball 14 rotates. When a selected axis is parallel to the ground, the accelerometer 24 may measure zero (0) g (gravity). When the axis is oriented down, the accelerometer 24 may measure one (1) g, and when the axis is oriented up, the accelerometer 24 may measure minus one (−1) g. When the axis is at an angle other than ninety degrees or zero degrees, the accelerometer 24 may measure a value that is related to the cosine of the angle (e.g., 1g*cos(θ), where θ represents the angle relative to gravity). The distance traveled may be determined by the number of rotations times the circumference of the golf ball 14. However, deviations from the initial roll path (such as curvature due to slope) may alter the roll distance calculation with respect to a single axis, and the distance may be calculated based on a circumferential distance determined along each of the three axes. Subsequently, the green speed may be determined based on the distance divided by the time (duration of the roll).

In some embodiments, the accelerometers 24 may measure bounces as having a higher frequency component (e.g., 30-100 Hz) as compared to rolling (e.g., less than 15-20 Hz for putts). Thus, the microprocessor 26 or a processor of the computing device 16 may detect bounces based on such high frequency components, and the bounces may be recorded within the roll data file, together with data representing a smooth rolling motion. The roll data file may be communicated by the communications system 28 to the computing device 16.

In some embodiments, the golf ball 14 may be rolled on a putting green (or surface) 12 multiple times. For example, the golf ball 14 may be rolled multiple times from a first position and along a first path at different speeds. Further, the golf ball 14 may be rolled multiple times from each of a plurality of positions, at different speeds, and along multiple paths. The resulting plurality of roll data files may be processed by the computing system to fully characterize the putting green (or surface) 12. In some embodiments, such data may be used by golfers to enhance their putting approach based the position of the particular golf ball on the putting green 12 relative to the cup. In some embodiments, such characterization data may be used by a greens keeper, a designer, landscape personnel, or other golf professionals to assess the quality of a particular green and sometimes to determine when maintenance (beyond routine maintenance) may be needed.

In accordance with some embodiments, the “roll quality” of a surface may be determined based on a smoothness metric and a plane deviation metric. The smoothness metric may represent the relatively high frequency measurements captured by the accelerometers 24, which may indicate bumps, divots, or other imperfections in the surface that may impact the roll of the golf ball 14. The plane deviation metric may determine slopes, which may cause the golf ball 14 to curve relative to an initial roll path.

In certain embodiments, the “roll data file” may be generated by the microprocessor 26 as it processes and correlates measurement data from the one or more accelerometers 24. The roll data file may be stored in memory 29 within the golf ball 14 for a time period while the golf ball 14 is rolling and until it stops rolling. The communications system 28 may then transmit the “roll data file” to the computing device 16. In certain embodiments, the memory 29 may store roll data files corresponding to a plurality of independent rolls of the golf ball 14. In an example, the memory 29 may be configured to store roll data files for over 100 independent rolls and may continue to maintain the roll data files until the golf ball 14 uploads the data to the computing device 16 for storage and analysis. In an alternative embodiment, the golf ball 14 may communicate the measurement data continuously (in real time or near real-time) during the roll.

In accordance with a preferred embodiment, the golf ball 14 can be a traditional size (e.g., the ball may have an outer diameter of 1.68 inches in accordance with USGA rules) and may include a uniform interior shell material 32 shaped and dimensioned to house the electronic system 22, which may be configured for the monitoring and collection of data relating to the surface under study. In certain embodiments, the accelerometer may be a tri-axial accelerometer 24. The communications system 28 can include a radio frequency (RF) transmitter 28 (such as, an 802.11x RF transmitter, a 2.4 GHz RF Transmitter, a Bluetooth® transceiver, a 900 MHz RF transmitter, another type of transmitter, or any combination thereof).

In some embodiments, the cavity 20 of the golf ball 14 may include charging contacts 34 extending between the interior cavity 20 and the exterior surface of the golf ball 14 to receive electrical current to recharge the battery 30. Alternatively, the circuitry 22 may include charging circuitry for receiving an inductive charging current from an external charging unit (in which case the charging contacts 34 may be omitted). In accordance certain embodiments, the various components of the electronic system 22 can be press fit within the cavity 20, and the electronic system 22 can be potted in place. The potting material may include a solid compound configured to insulate the electronic system 22 from shock, vibration, moisture, and corrosive agents.

During operation, in a first mode, the computing device 16 may receive roll data from the golf ball 14 and may process the roll data to determine parameters of the putting green 12. Such parameters may include the green speed, the firmness parameters, and an overall roll quality. The computing device 16 may provide data related to one or more of the parameters to a display device, such as a touchscreen. In a second mode, the computing device 16 may receive roll data from the golf ball 14 and may process the roll data to determine characteristics of a putting stroke. The computing device 16 may present feedback to the display device based on the determined characteristics. Other embodiments are also possible.

Referring to FIG. 3, the smoothness metric considers the deviation of the center 40 of the golf ball 14 from a plane 42, which is parallel to the putting green, or other surface 12, upon which the golf ball 14 is rolling. Typically, a putting green may have a surface that includes multiple different slopes, which may vary in X, Y, and Z dimensions. In the illustrated example, the ball 14 may roll in the X-direction as indicated by arrow 300. As the golf ball 14 rolls, the elevation of the center 40 of the golf ball 14 may change, as depicted by the golf ball 14′ and its center 40′ (shown in phantom). The changing elevation of the ball in the Z-direction may be reflected in a changing acceleration in the Z-direction (Δα_z) as measured by the accelerometers 24. The frequency of the variation may be processed to determine whether the variation is due to changing elevation of an otherwise smooth surface or an imperfection that caused the golf ball 14 to bounce. Further, the center 40′ may deviate from the initial plane 42, resulting in a relative deviation along the Z-axis (ΔZ). As the golf ball 14 moves across the surface of the putting green 12, the elevation of the golf ball 14 along the Z-axis and the acceleration of the golf ball 14 in the Z-direction may vary. Further, the slope may vary in the X and Y axes as well, causing both the roll pattern and the trajectory of the golf ball 14 to vary along the roll path.

Referring to FIG. 4A, the plane deviation metric considers the deviation of the center 40 of the golf ball 14 from an initial plane 44 extending through the center of the golf ball 14 at an angle that is perpendicular to the putting green 12 upon which the golf ball 14 is rolling and extending in a direction of an initial trajectory of the golf ball 14. Since the putting green 12 may include various slopes, the plane 44 may therefore change relative to gravity to maintain its perpendicular relationship with the surface of the putting green 12.

In the illustrated example of FIG. 4B, the golf ball 14 is rolling in a direction extending into the drawing (along the X-axis). The accelerometers 24 may be at a tilt angle (θ) relative to gravity. Further, the golf ball 14 may be advanced along a slope that may tilt to the right (for example), and which may cause the golf ball 14 to deviate from its initial path 402 and to travel along the path 404. The slope may be determined based on the measured acceleration in the X and Y dimensions. In general, slopes may be determined from the lower frequency (i.e., roll frequency) changes in the measured acceleration, while bumps and imperfections may be detected as high frequency anomalies.

In accordance with certain embodiments, the smoothness metric can be derived based, at least in part, upon the changes in acceleration (i.e., the distance and frequency with which the golf ball 14 moves in each of the axes) along each axis (X, Y, and Z). High frequency changes may indicate bumps and other irregularities. Further, the smoothness metric can also determined based upon the deceleration of the golf ball at different time intervals and for different interval lengths as the golf ball 14 rolls along the surface of the putting green 12. In some embodiments, the golf ball 14 may be rolled across the surface of the putting green 12 at various initial roll speeds (e.g., 6, 5, and 4 feet per second) and in different directions to develop a plurality of measurements characterizing the smoothness surface.

In certain embodiments, the plane deviation metric may be determined based upon a sum of rotation plane deviations, that is, the number of times the golf ball moves laterally right or left such that a center 42 of the golf ball 14 deviates laterally from the initial vertical plane 44. In an embodiment, the plane deviation metric can be derived based upon a plurality of samples, for example, 100 samples, captured at different initial speeds (e.g., 6, 5, and 4 feet per second) and in different directions to develop a plurality of measurements characterizing the plane deviations of the surface of the putting green 12.

In certain embodiments, the plurality of measurements of the smoothness of the surface and the plurality of measurements of the plane deviations of the surface may be processed to characterize the surface of the putting green 12. In an example, the smoothness and the plane deviations of the surface may be interpolated to produce a roll quality value, which may be a numeric value within a range from zero to 100, where zero represents a uniformly rough surface that may cause the golf ball 14 to bounce until its initial energy is dissipated, while a score of 100 may represent a uniformly smooth and flat surface on which the golf ball 14 rolls and maintains an initial trajectory until its initial energy is dissipated. In an example, the roll quality value may be an integer value. In another example, the roll quality value may be a floating point number. In another example, the roll quality value may be a letter grade, such as A+, A, A−, B+, B, B−, etc. Other embodiments are also possible. In a particular embodiment, the USGA may define a roll quality evaluation scale, which may standardize the roll quality valuation so that the roll quality of the putting green 12 may be compared to that of another putting green.

FIG. 5 depicts a block diagram of a system 500 including a golf ball 14 configured to communicate with a computing device 502, in accordance with certain embodiments of the present disclosure. The computing device 502 may be an embodiment of the computing device 16 of FIG. 1. In some examples, the computing device 502 may include a smart phone, a tablet computer, a laptop computer, another data processing device, or any combination thereof.

The golf ball 14 may include the circuitry 22, which may include a microprocessor 26 coupled to a memory 29, communications system 28, a timer 40, the battery 30, and the tri-axial accelerometer 24. In some embodiments, the microprocessor 26 may also be coupled to a microelectromechanical (MEMs) magnetometer 42, which may be configured to operate as a compass to determine a direction of magnetic north, which direction data may be correlated to roll data from the tri-axial accelerometer 24 to provide roll data corresponding to a roll vector. In certain embodiments, the memory 29 may store processing instructions 36 that, when executed may cause the microprocessor 26 to correlate data received from the accelerometer 24 with direction data from the MEMs magnetometer 42 and with time data from the timer 40 to produce a roll data file and to store the roll data file (roll data 38) in memory 29. Subsequently or concurrently, the microprocessor 26 may communicate the roll data file to the communications system 28 for transmission to the computing device 502 directly or through a network 506 or to another computing device 504 via the network 506.

The computing device 502 may include a transceiver 514 configured to communicate wirelessly with the communications system 28 of the golf ball 14. The transceiver 514 may be coupled to a processor 510, which may be coupled to a network transceiver 508, an input/output (I/O) interface 512, and a memory 516. The network transceiver 508 may be configured to send and receive data to other devices through the network 506. The I/O interface 512 may include a display interface to provide display data to a display device (such as a liquid crystal display (LCD) device, a light-emitting diode (LED) display device, another display device, or any combination thereof), an input interface to receive data from an input device (such as a pointer, mouse, keyboard, and the like), or a touchscreen interface.

The memory 516 may store data and instructions that, when executed, may cause the processor 510 to determine a green speed and a roll quality for a particular surface. The memory 516 may include a graphical user interface (GUI) generator 518 that, when executed, may cause the processor 510 to produce a GUI including data corresponding to a particular roll of the golf ball 14, a plurality of rolls, a green speed, a roll quality, or any combination thereof. The memory 516 may include a roll data extractor 520 that, when executed, may cause the processor 510 to extract data from the roll data file and to store the data in one or more temporary tables or storage files. The memory 516 may also include a perturbation analysis module 522 that, when executed, may cause the processor 510 to detect bounce events within the roll data, such as based on high frequency variations in the accelerometer data extracted by the roll data extractor 520.

The memory 516 can also include a slope threshold module 524 that, when executed, may cause the processor 510 to determine changes in slope based on the accelerometer data and to differentiate between acceleration measurements due to slope as compared to such measurements caused by imperfections in the surface. The memory 516 may also include an impact threshold 526 that may be compared to the accelerometer data to identify impact events, such as a club striking the golf ball 14, a golf ball 14 bouncing and impacting the surface, the golf ball 14 landing in the cup 15, and so on. The memory 516 may also include a firmness calculator 529 that, when executed, may cause the processor 510 to determine a firmness parameter for a surface based on the bounce of a golf ball 14, either when it is dropped from a known height or based on a skid distance from an initial strike to when the golf ball 14 begins rolling.

The memory 516 can also include a plane deviation module 530 that, when executed, may cause the processor 510 to determine initial horizontal and vertical planes (as discussed above with respect to FIGS. 3, 4A, and 4B. The memory 516 may further include a green speed calculator 532 that, when executed, may cause the processor 510 to determine a green speed based on a roll distance and time determined from the extracted roll data. The memory 516 may also include a roll quality module 534 that, when executed, may cause the processor 510 to evaluate the perturbations determined by the perturbation analysis module 522, slopes determined using the slope threshold 524, impacts determined using the impact threshold 526, smoothness calculations from the smoothness calculator 528 and slopes in the horizontal plane determined by the plane deviation module 530. The roll quality module 534 may cause the processor 510 to determine a value for the overall roll quality of the surface based on the determined impacts, smoothness, slopes, perturbations, and planar deviations. The roll quality module 534 may also take into account the firmness of the surface (as determined by the firmness calculator 529) in determining an overall roll quality of a surface. The firmness calculator 529 may be configured to evaluate a particular roll data file (e.g., a dropped ball file), which may be selected or designated by the operator to determine bounce characteristics of a dropped golf ball 14, which bounce characteristics may be reflected in the accelerometer signals as the kinetic energy from the drop event dissipates and which may be used to determine the firmness of the surface.

In some embodiments, the memory 516 may include putt analytics 536 that, when executed, may cause the processor 510 to analyze the extracted roll data to identify characteristics of a particular putt. In an example, an initial side spin included within the accelerometer data may indicate club head turn at impact. In another example, excessive skidding of the golf ball 14 before rolling may indicate a poor putt stroke. The putt analytics 536 may be configured to provide instruction to a golfer to suggest swing adjustments to correct for such potential putt swing characteristics. Other embodiments are also possible.

In an example, in a first mode, the computing device 502 may receive roll data from the golf ball 14 and may process the roll data to determine parameters or characteristics of a putting green 12. The parameters or characteristics may include at least one of a firmness parameter and a roll quality parameter. The roll quality parameter may be determined for each independent roll and an overall roll quality parameter may be determined based on a plurality of roll events. In some embodiments, the parameters or characteristics may also include a green speed parameter. The computing device 502 may present data corresponding to the determined parameters to the I/O interface 512.

In a second mode, the computing device 502 may receive roll data from the golf ball 14 and may process the roll data to determine characteristics of a putting stroke that initiated to roll event. Side spin, skid, bounce, and other characteristics of the movement of the golf ball 14 may reflect improper putting mechanics. The computing device 502 may present data corresponding to the characteristics of the putting stroke to the I/O interface 512 to provide feedback to the golfer. Other embodiments are also possible.

FIG. 6A depicts a representative example of a graph 600 of acceleration over time for a golf ball that is rolling along a surface, in accordance with certain embodiments of the present disclosure. In the illustrated example, the graph 600 may include a sinusoidal signal indicating a rolling motion as seen from the perspective of the accelerometer 24 relative to the Z-axis. At 604, the fourth oscillation has decreased in amplitude and frequency relative to the initial impulse (generally indicated at 602). The sinusoidal signal appears as a dampened sinusoid. However, the damping effect along the Z-axis may be influenced by slope, perturbations, friction, surface firmness, and so on. Such influences may vary as the ball rolls. Further, such accelerations may have a greater or lesser effect on the roll of the golf ball 14 depending on the speed of motion.

In the illustrated example of FIG. 6A, the golf ball 14 may be rolling across a relatively level surface having little, if any, slope relative to elevation along the roll path. However, imperfections that may cause bounces can be visible as high frequency noise associated with the sinusoidal waveform. One possible example showing such high frequency noise is described below with respect to FIG. 6B.

FIG. 6B illustrates a representative example of a graph 620 of acceleration over time for a golf ball that is rolling along a surface, in accordance with certain embodiments of the present disclosure. The graph 620 depicts a sinusoidal waveform beginning with an initial impulse generally indicated at 622. Between a first time (T₁) 624 and a second time (T₂) 626, the golf ball 14 experienced an imperfection causing a bounce, which is generally indicated in the accelerometer data at 628 as high frequency noise (high frequency relative to the frequency of the sinusoid). The amplitude and extent of the noise may indicate the extent of the imperfection.

The graph 620 further depicts noise generally indicated at 634, between a third time (T₃) 630 and a fourth time (T₄) 632. The noise 634 may indicate an imperfection that may impact the roll direction, cause the ball to bounce, or both.

It should be appreciated that the graphs 600 and 620 in FIGS. 6A and 6B are illustrative only. The actual signal response from the accelerometer 624 may be provided as digital data, as opposed to an analog waveform. Further, the noise may be more or less significant, and the processor 510 may be configured to process the data to extract and separately process the noise to detect imperfections. Other embodiments are also possible.

FIG. 7A depicts a graph 700 of raw accelerometer data for a tri-axial accelerometer as the golf ball is rolled across a pool table, in accordance with certain embodiments of the present disclosure. The raw accelerometer data includes accelerometer measurement data from first, second and third accelerometers (Accelerometer A, Accelerometer B, and Accelerometer C) as a golf ball 14 is rolled across a surface of a pool table.

FIG. 7B depicts a graph 710 of raw accelerometer data for a tri-axial accelerometer as a golf ball 14 is rolled across a green 12, in accordance with certain embodiments of the present disclosure.

FIG. 7C illustrates a graph 720 of raw accelerometer data for a tri-axial accelerometer as a golf ball 14 is rolled across a fringe of a green 12, in accordance with certain embodiments of the present disclosure.

FIG. 7D depicts a graph 740 of raw accelerometer data for a tri-axial accelerometer as a golf ball 14 is rolled across the rough, in accordance with certain embodiments of the present disclosure.

FIG. 8 illustrates a graph 800 of velocity over time for a golf ball rolled on a three-foot putt, in accordance with certain embodiments of the present disclosure. The graph 800 depicts a rapid increase corresponding to the initial acceleration from a putt or roll followed by deceleration due to slope, friction, or other roll characteristics.

In the graphs of FIGS. 7B-8, the accelerometers may register high frequency components of the accelerometer signal, which high frequency components may represents bounces, jumps, or other deviations, some of which may cause the ball to deviate from the normal roll path of the golf ball.

FIG. 9 illustrates a flow diagram of a method 900 of determining a roll quality of a green, in accordance with certain embodiments of the present disclosure. In some examples, the method 1000 may be implemented as a particular operating mode of the computing device 16 of FIG. 1 or 502 of FIG. 5. The method 900 may include receiving accelerometer data corresponding to a roll of a golf ball, at 902. The accelerometer data may be received from a memory, from a communications system 28 of a golf ball 14, from another source, or any combination thereof. At 904, the method 900 may include determining a change in the accelerometer data in one of a first plane and a second plane. In some embodiments, the change may be determined based on the three axes. The change may be determined based on the noise signal associated with the accelerometer data.

At 906, if the change is greater than a first threshold, the method 900 may include determining a bounce event. In an example, the change may include a high frequency signal component that deviates from the damped sinusoidal signal. At 910, the method 900 may include characterizing the data corresponding to the bounce event. In some embodiments, the processor 510 may apply a label or otherwise mark the data associated with a bounce event and may correlate the bounce data to a particular roll, directional data, and other data. The method 900 may further include storing the accelerometer data and associated label information in a memory 912.

At 906, if the change is less than the first threshold, the method 900 may include determining if the change is greater than a second threshold, at 914. If the change is greater than a second threshold at 914, the method 900 may include determining a slope 916. In this example, the slope may exert a lower frequency force on the roll of the golf ball 14. At 918, the method 900 may include characterizing the data corresponding to the slope. In some embodiments, the processor 510 may apply a label or otherwise mark the data associated with a slope and may correlate the slope data to a particular roll, directional data, and other data. In an example, the second threshold may include an accelerometer force that is sufficient to alter a roll path of the golf ball. The method 900 may further include storing the accelerometer data and associated label information in a memory 912.

Returning to 914, if the change is less than the second threshold, the method 900 may include determining the data corresponds to a flat and smooth surface, at 920. At 922, the method 900 may further include labeling the data corresponding to the flat and smooth surface. In some embodiments, the processor 510 may apply a label or otherwise mark the data associated with the flat and smooth surface and may correlate the flat and smooth data to a particular roll, directional data, and other data. The method 900 may further include storing the accelerometer data and associated label information in a memory 912.

In some embodiments, the method 900 may include determining imperfections or other external factors associated with the surface that may impact the roll of the golf ball 14. In certain examples, the imperfections may include any surface imperfection sufficient to produce a detectable noise signal with respect to the output of the accelerometer. In some embodiments, the imperfection may cause a high frequency noise signal that may be superimposed on the sinusoidal waveform attributable to the roll of the golf ball 14. The “high frequency” noise signal may be high frequency as compared to the frequency of the revolutions of the golf ball rolling. The method 900 may further include determining imperfections significant enough to alter the roll path of the golf ball 14 based on an amplitude of the noise. Further, low frequency noise consistent with the frequency of the rolling of the golf ball 14 and along an axis different form the initial roll path may indicate a slope that may influence the roll path at a frequency associated with the roll frequency. Other embodiments are also possible.

While the embodiment of FIG. 9 describes a method 900 of determining a roll quality, in some instances, the method 900 may also include determining a firmness parameter by dropping the golf ball 14 onto the surface and analyzing the bounce characteristics. Further, in some embodiments, the method 900 can also include determining a green speed based on the accelerometer data. Other embodiments are also possible.

FIG. 10 depicts a flow diagram of a method 1000 of determining putt characteristics, in accordance with certain embodiments of the present disclosure. In some examples, the method 1000 may be implemented as a particular operating mode of the computing device 16 of FIG. 1 or 502 of FIG. 5. At 1002, the method 1000 may include receiving accelerometer data corresponding to a roll of a golf ball. The accelerometer data may be received from a memory, from a communications system 28 of a golf ball 14, from another source, or any combination thereof.

At 1004, the method 1000 may include determining an initial putt from the accelerometer data. The initial putt may include an impulse accelerating the golf ball from a stationary state. Characteristics of the initial putt may include a skid, bounce or other characteristics that differ from the accelerometer data when the ball is rolling.

At 1006, the method 1000 may include determining a roll direction based on the sinusoidal waveforms. The roll direction may be determined based on the relative amplitudes of the accelerometer readings as the ball rotates. At 1008, the method 1000 may include determining an anomalous accelerometer signal subsumed in the roll direction waveforms. In particular, at the outset of the putt, the golf ball may spin in a direction different from the rotation of the roll. Such spin may be imparted by the face of the putter striking the ball at an angle, and the spin may quickly disappear into the rotation of the golf ball. However, such spin may change the roll path of the golf ball at the outset, impacting the efficacy of the putt.

At 1010, the method 1000 may include selectively determining putt analytics based on the anomalous accelerometer signal. In general, a good putt include striking the ball when the club face is perpendicular to the swing path in order to strike the ball along the swing path. The size of the angle of the putt face relative to the desired perpendicular angle may impact the amplitude of the anomalous accelerometer signal.

At 1012, the method 1000 may further include providing information related to the putt analytics to an interface. The information may include data corresponding to a putter face offset angle or other information to assist a golfer in correcting his or her putt mechanics.

While the example of FIG. 10 is related to turning of the club face, excessive skidding of the golf ball at ball strike may indicate a faulty putt stroke as well. In an example, a pendulum type of swing may impart a brief skid followed by a roll of the golf ball, while wrist snap or other improper mechanics may cause the ball to bounce or skid for a larger period of time before rolling. Such mechanics may be detected based on noise associated with the initial acceleration along the three axes. Other embodiments are also possible.

By accurately measuring the “roll quality” of balls on various putting greens and surfaces (as their rolls are misdirected, disturbed, bounced and/or deflected off-line by imperfections on the measured greens and surfaces, as compared to what their “perfect” roll trajectories would have been on a “perfectly smooth surface”), the system 10 of FIG. 1 and the system 500 of FIG. 5 may be used to determine a roll quality metric to describe and compare the roll quality of various putting greens and surfaces. In the area of golf course putting greens, green speeds (ball roll distance from a known starting energy level) are commonly measured using a variety of devices. These devices are exclusively focused on the length (distance) a golf ball travels over any surface. However, the ball roll distance, or green speed, is only one measure of the surface. In contrast, in addition to the green speed, the system 10 and the system 500 may be configured to measure the smoothness of roll across the putting green 14 as well as the firmness of the putting green 14, making it possible to fully characterize the roll quality of the putting green 14 as a function of the green speed, firmness, smoothness, and plane deviation of the surface.

When imported into the computing device 16 (or 502), the roll path of the golf ball can be viewed and analyzed. The overall smoothness and pureness of the golf ball's roll is determined by comparing the ball's actual roll direction and motion (obtained by evaluating the ball's actual three axis accelerometer data) at several different time intervals and rolling speeds to the theoretically pure motion it would have experienced if the surface upon which it rolled would have been perfectly smooth and flat. The green speed of any putting surface can be determined as a result of knowing the rate of deceleration of the golf ball across the surface. Further, the firmness can be determined based on the elastic bounce response of the golf ball 14 relative to the surface and the smoothness can be determined from noise in the accelerometer signals.

In conjunction with the systems, methods, and devices described above, a computing system may be configured to receive roll data from a golf ball and to determine one or more parameters associated with the surface or with a putting stroke in response to receiving the roll data. In a first mode, the computing system may process the roll data to determine an overall roll quality associated with a surface of a putting green, and optionally to determine a green speed, firmness, imperfections, and plane deviations (slopes) associated with the surface. In a second mode, the computing system may process the roll data to determine irregularities in a putting stroke, such as snapping wrists and turning the club face. In either case, the computing system may provide data to a display interface.

Although the present invention has been described with reference to particular embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the invention.