Ball Machine for Providing Player Ratings for Racquet Sports and Related Methods

This application filed is a non-provisional of U.S. Provisional Application No. 63/632,509 filed Apr. 10, 2024, the entire contents of which are hereby incorporated by reference. This application is a continuation-in-part of U.S. application Ser. No. 19/060,366, filed Feb. 21, 2025, the entire contents of which are hereby incorporated by reference. This application relates to U.S. patent application Ser. No. 18/083,203 filed Dec. 16, 2022, U.S. patent application Ser. No. 18/097,345, filed on Jan. 16, 2023, U.S. patent application Ser. No. 18/198,167, filed on May 16, 2023, and U.S. patent Ser. No. 18/512,451, filed Nov. 17, 2023, the entire content of each of these applications being incorporated by reference herein.

Rating systems in racquet sports are desirable not only for providing competition between expert players, but desirable for beginners and intermediate players as well. Racquet sports competition between players of imbalanced skill levels results in shorter rallies, which is not fun for any of the players. Without a proper rating system in place, organizing a game with groups of players at equivalent skill levels becomes much harder.

Most rating systems in racquet sports are based on player performance in matches over time. Some use the lastmatches, others use a rolling scoring system taking into account the strength compared to your opponent(s). With so many matches to be played, such rating systems take a significant amount of time to find an appropriate rating for a player.

In addition, an inherent problem with these rating systems is determining a start rating (an initial rating) for players. When people are mis-ranked—for example a college tennis player being marked as a beginner—they will dominate their opponents. The result of the match will be an adjustment in the player's rankings to more accurately reflect the performance on the court. However, in this scenario, a person who has lost to a very good tennis player (e.g., a college level player) may have had their ranking unfairly adjusted in a negative way.

Start ratings can be very important. Ratings are used to select similarly skilled players for practice and competition matches. Currently, start ratings are generally assigned by pros/coaches who evaluate performance of individuals to determine a start rating of a player. The problem with this approach is that the criteria to evaluate a player varies from pro to pro, which leads to inconsistent ratings.

With tennis being the dominant racquet sport today, criteria for determining a player's start rating tends to be based on skills important tennis. Thus, providing accurate player ratings becomes exacerbated for non-tennis racquet sports, as the evaluation criteria may be based on criteria that may be less important to alternative racquet sports than such criteria are to tennis.

Further, there may be shots uniquely important to such alternative racquet sports but not important or relevant to tennis. For example, topspin groundstrokes do not have the same importance to pickleball as in tennis, as the plastic pickleball does not achieve the same speed as a tennis ball. In addition, tennis rankings evaluation criteria would not include evaluation of the accuracy of a dink shot that is highly important in pickleball. Similarly, because platform tennis and padel are both able to be played off walls, there are numerous variety of shots (e.g., before or after a wall ricochet), and different types of ball spin becomes significantly more important to the shot (e.g., backspin to a backwall to provide a soft bounce off the wall to provide a more difficult return shot). Experienced tennis players may have great ground strokes, but may be unable to play off the walls effectively as such wall play is completely new to them. Thus, the start rating is even more complex to assign in less typical racquet sports.

A ball machine may be placed onto one side of a racquet court to provide shots to a player on the other side of the court and evaluate the player's ability in returning the shots. The ball machine may comprise an imaging system configured to obtain an image of court; a ball launching system configured to launch a ball to a user on the other side of the court; and a controller configured determine a location of the ball machine on the racquet court based upon the obtained image. The controller may execute a first instance of a first evaluation routine to provide the user a sequence of shots, where each shot corresponds to a predefined shot described by initial parameters that may be modified by difficulty modifiers. The returned shot of the player is monitored and evaluated by the ball machine to determine if the returned shot meets various success criteria (e.g., location, speed, height, etc.).

When the player returns one or a certain amount of shots meeting the success criteria, the difficulty of the shots provided to the player is increased. As the difficulty of the evaluation routine is increased, a player is expected to no longer be able to successfully complete a segment of an evaluation routine or the player's performance may plateau. At this time, the evaluation routine may be terminated, the player's skill level is assessed (based on aggregating the player's skill ratings) to obtain a start rating for that player.

Several different types of evaluation routines may be executed by the ball machine to determine skill ratings of the player with respect to different shot types, the aggregate of which may be used to determine an overall rating (e.g., start rating) of the player, such as a start rating of the player. For example, the workout routines may include a serve return workout routine, backcourt workout routine, and a frontcourt workout routine to assess skills of the player relating to different aspects of the walled racquet court game (e.g., padel or platform tennis). As part of these routines, the ball machine may provide shots that interact with the racquet court walls (e.g., the ball trajectory of the shot would ricochet off the wall while still in play or the wall could interfere with player with inappropriate positioning) and evaluate the player's skill in returning such shots.

Additional instances of execution of the evaluation routine may be repeated for other players and to obtain ratings for additional players. The additional instances of the execution of the evaluation routines may be performed by the same ball machine or may be performed by other ball machines similarly programmed to execute the same evaluation routines (e.g., such ball machines may be located on different racquet courts that have the same layout (e.g., same dimensions)).

The ball machine(s) may adjust delivery of the shots based on the determined location and orientation of the ball machine on the racquet court. Thus, each instance of execution of a particular evaluation routine may be faithfully replicated to provide the same experience to each player (e.g., substantially the same shots to in an attempt to provide the same difficulty in performing against the evaluation routine). In each instance of execution of a particular evaluation routine, shots are provided with set shot parameters (e.g., predetermined for a particular difficulty level)—the ball machine may provide qualitatively the same shots with shot parameters faithfully replicated (or made substantially the same) between the different instances. Thus, evaluation of the player's execution of the evaluation routines may accurately reflect a player's skill relative to others to provide an accurate rating of the player. A player's ratings may be used to find other players of similar skill levels to play against (e.g., to play a conventional game without the ball machine). Thus, a player may obtain a rating relatively quickly, without the need to obtain ratings by playing a multitude of matches or be based on subjective ratings of a pro (which may be based on less relevant criteria).

The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. These example embodiments are just that—examples—and many implementations and variations are possible that do not require the details provided herein. It should also be emphasized that the disclosure provides details of alternative examples, but such listing of alternatives is not exhaustive. Furthermore, any consistency of detail between various examples should not be interpreted as requiring such detail—it is impracticable to list every possible variation for every feature described herein. The language of the claims should be referenced in determining the requirements of the invention.

Ordinal numbers such as “first,” “second,” “third,” etc. may be used simply as labels of certain elements, steps, etc., to distinguish such elements, steps, etc. from one another. Terms that are not described using “first,” “second,” etc., in the specification, may still be referred to as “first” or “second” in a claim. In addition, a term that is referenced with a particular ordinal number (e.g., “first” in a particular claim) may be described elsewhere with a different ordinal number (e.g., “second” in the specification or another claim).

illustrate varying orientation views of an automatic ball machineaccording to example embodiments. Referring to, the automatic ball machinemay include a frameonto which various components are coupled, such as a controller, a first camera, and a second cameramounted inside the housing of the controller. Although the entirety of the second camerais not illustrated in the drawings, the optical input of the second camerais illustrated in the drawings above speaker. The automatic ball machinemay include a ball launching system (or ball launcher)to launch (i.e., project) balls, a hopperto store a quantity of the ballsprior to launch, a mobility system(e.g., wheels) to move the automatic ball machine, and handlesconfigured to maneuver and adjust the automatic ball machine. The automatic ball machinemay be moved (pulled, pushed, carried) onto a court by a person (e.g., haulable or portable). Components of the automatic ball machinemay be physically connected to each other through the frameof the automatic ball machine. For example, in this example, the first cameraand the second cameraare physically connected to the ball launching systemthrough the frame. The height position, in the vertical direction, of the ball launching systemis shown in a lowered position inand in a raised position in. The height position of the ball launching systemmay be adjusted using the height actuator, for example. The height position of ball launching systemmay be adjusted and set anywhere in-between the illustrated lowered position and the illustrated raised position depending, for example, upon the trajectory needed to launch the ballsby the ball launching system. The height position of the ball launching systemmay also range from the lowered position to the raised position during a localization operation for automatically determining the location and orientation of the automatic ball machineon the court. Example structure and method for automatically determining the location and orientation of the automatic ball machineon the court are detailed in U.S. patent application Ser. No. 18/097,345 (“the '345 application”) filed on Jan. 16, 2023, the entire content of which is herein incorporated by reference. The automatic ball machinemay further include a ball feederto feed ballsthe ball launching systemto a launching position (e.g., to spinner wheels), such as from the hopper. The ball feedermay be controlled by the controllerto deliver a ball to the launching position, such as controlling the timing that a ball is placed in the ball launching position to therefore control the timing that such ball is launched from the ball launching system.

In this example, an imaging systemcomprises the first cameraand the second camera. According to example embodiments, the imaging systemmay be disposed on the frameof the automatic ball machineto capture digital images (e.g., still images, video and/or video frames or frames). The cameras (e.g.,and) of the imaging system may be oriented (i.e., having their optical axis extending towards) in substantially the same direction as the central shot path provided by the ball launching system. For example, when the automatic ball machine is positioned on a baseline (a boundary of the playing area of the racquet court), from a top down perspective, the optical axes and the central shot path may each extend to intersect the opposite side of the court (e.g., such as when the automatic ball machineis positioned symmetrically on the baseline). For example, the optical axes of the cameras and the central shot path may deviate from each other no more than 20 degrees. The central shot path of the ball launching systemmay refer, with respect to a top down view, to the center of the full angular range of shots that may be provided by the ball launching system. The imaging systemmay thus obtain images of the side of the court opposite to that on which the ball machineis placed when the ball launching systemis generally oriented toward the other side of the court. Note however, as discussed further below, orientation of the automatic ball machineneed not be carefully aligned, nor does automatic ball machineneed to be carefully positioned at a particular location on the court as the orientation and location of the ball machineon the court can be determined by the automatic ball machineand such determinations used to adjust parameters of the ball launching systemto provide desired shots independent of orientation and/or location of the automatic ball machine. The first cameraand the second cameramay be positioned to capture digital images at two different vantage points. Information may be extracted from the digital images through computer vision/analysis. In an example embodiment, the first cameraand the second cameraof the imaging systemmay form a stereo camera. In other embodiments, a single camera may be used as the imaging system. Stereo vision need not be implemented using multiple cameras, but may be implemented with a single camera by providing a moveable holder to move the camera to different positions, and/or a stereo camera may be used. The imaging systemneed not be formed with two cameras and may be formed by a single camera or three or more cameras disposed on the automatic ball machine. In an example embodiment, first cameraand second cameraof the imaging systemmay be replaced with or supplemented with a Time-Of-Flight (TOF) camera to detect a depth of field.

In a further example, the imaging systemmay include cameras in addition to camerasandto improve the data that is being received by the controller. For example, the imaging systemmay include a plurality of cameras configured to detect objects to the left of the launch direction, to the right of the launch direction, and away from the launch direction, respectively. The plurality of cameras may increase an effective field-of-view of the imaging system. The imaging systemmay be used to perform person detection, person identification, person tracking, and pose estimation procedures as described in detail in U.S. patent application Ser. No. 18/198,167 (“the '167 application”) filed on May 16, 2023, the entire content of which is herein incorporated by reference. In an example embodiment, a camera of the imaging systemmay have its optical axis extend rearwardly, in a direction away from the side of the court to which balls are launched, such as in order to locate and identify court features behind the automatic ball machine(such as to locate/identify the baseline, back walls, or back corners of the court behind the ball machine on the side of the court on which the automatic ball machineis placed).

The ball launching systemmay include a plurality of spinner wheels, each coupled to corresponding one of a plurality of motors, to launch the balls. For example, the ball launching systemmay include first, second, and third spinner wheels,,, coupled to first, second, and third spinner motors, respectively. As illustrated, for example in, the spinner wheelis shown as being disposed at approximately (+/−5 degrees) of the 12 o'clock position, with the spinner wheelbeing disposed at approximately (+/−5 degrees) of the 4 o'clock position, and the spinner wheel, being disposed at approximately (+/−5 degrees) of the 8 o'clock position.

In addition to performing functions related to shot identification and shot tracking procedures described in further detail below, the first cameramay also act as an environment sensor to detect objects in a direction that ballsare being launched from the automatic ball machine. For example, the automatic ball machinemay use the first cameraas an environment sensor to monitor, via the controller, an area in a direction that the ballis being launched, and in at least one configuration around the automatic ball machineto ensure no person or unintended objects are struck by the ballsbeing launched by the automatic ball machine, or harmed by any automated mechanical movement of the automatic ball machine. The automatic ball machinemay establish a keep-out region, that if violated, will result in the automatic ball machinestopping launching of the ballsand/or mechanical movement, such as the ball launching system, and in at least one configuration issuing a warning to a player. The warning may comprise a visual cue via, for example, a displayor a lighting system (not illustrated). The warning may also comprise an audio cue via, for example, a speaker. The displaymay be a flat-panel display, such as an LCD display, an LED display (such as an OLED display or a QLED display), or the like. Several discrete keep-out regions may be established by the automatic ball machine automatically. For example, a keep-out region may be automatically determined by the automatic ball machine, such as by obtaining one or more images by the imaging system, based on the image(s), determining the location of the automatic ball machine on the court and the location of the net at the center of the court, and establishing a keep-out region comprising a triangle formed by the ball machineand outer edges of the net (such as ends of the net or at posts holding the net). Such a keep-out region may be expanded from sides of the triangle or may be a smaller version of the triangle, such as ending at sidelines comprising the playing area boundaries (i.e., corners of the triangle being truncated where the ends of the net and posts of the net are positioned outside the playing boundaries, such as doubles sidelines).

The automatic ball machinemay adjust a distance the keep-out region extends from the automatic ball machinebased on a court location of the automatic ball machine. To vary the coverage area around the automatic ball machine, additional environment sensors may be included. For example, the automatic ball machinemay include an additional environment sensor, such as a Light Detection and Ranging (LiDAR) sensor or similar, to detect objects outside a field-of-view of the imaging system, and/or to provide backup or additional data for the controller. A full 360-degree coverage around the automatic ball machinemay be implemented via additional environment sensors, for example, LiDAR sensors. In other configurations, additional environment sensors may further include, for example, barometric sensors, temperature sensors, humidity sensors, anemometer sensors, and the like.

As used herein, the term “court” refers to a playing area and a flat playing surface (e.g., a ground surface on which players stand and move around while playing the racquet sport). The playing surface may include both an inbounds portion and out-of-bounds portion, or the entire playing surface may be inbounds. The inbounds portion of the playing surface may be a flat rectangular ground surface defined by line markings on the playing surface and/or enclosures surrounding the playing surface. The inbounds portion of the playing surface is also considered part of the playing area. The playing area of the court refers to the inbounds portion(s) of the court. In addition to all or some of the playing surface, the playing area may include structures and enclosures surrounding the playing surface (e.g., walls that a ball may contact and still be considered “in play”). The line markings may delineate regions within the playing area (e.g., a service box) and boundaries of the playing area (e.g., a sideline and a baseline) on the playing surface. The playing surface may extend beyond the boundaries of the playing area (i.e., where a player may move to return a ball, but where the ball would be “out” if the ball were to contact the same). Structures that may be a part of the playing area may include a net, a cord or cable suspending the net, and net posts to which the net, suspended by the cord or cable, is attached. In racquet sports such as platform tennis and padel, wherein the official rules and regulation of the games provide for a ball to be played off (i.e., come into contact with and remain in play) an enclosure surrounding the playing surface during regulation game play, the enclosures may be a part of the playing area of the “court” as used herein. With respect to platform tennis, the enclosure may comprise a screen (e.g., a metal mesh wall forming a fence around a platform). With respect to padel, the enclosure may comprise walls formed of a transparent or opaque material and walls composed of metal fencing.

Directional descriptions may be used herein with respect to a racquet court including “sideways,” referring to direction(s) perpendicular to the court sidelines/sides and parallel to the flat playing surface of the court (e.g., parallel to court baselines and/or backwalls), “lengthwise” referring to direction(s) parallel to court sidelines/sides and parallel to the flat playing surface of the court, and “vertical” referring to directions perpendicular to the court playing surface. The sideways, lengthwise and vertical directions may be perpendicular to one another. Sideways and lengthwise directions may be considered horizontal directions.

provide exemplary details of determining a player's start rating (or other rating) including evaluation by the automatic ballmachine in the player's ability to properly return different shot types delivered by the automatic ball machine. The automatic ball machinemay provide a plurality of shots of each shot type. For each shot type, the automatic ball machinemay increase the difficulty level of the delivered shots until the player is no longer able to adequately return the shot of that shot type. A skill rating for each shot type is generated. Other skill ratings that may not be associated with a shot type may also be generated. The player's start rating is determined based on aggregating these skill ratings.

is a flow chart for providing a start rating for a player. The steps ofmay be executed by automatic ball machine. In step S, for each of m shot types, the automatic ball machineperforms a corresponding evaluation routine to provide a corresponding skill rating of the player's ability to deliver that shot type. Note that an evaluation routine may be used to evaluate a single shot type or may be used to evaluate several shot types. In addition, the delivery of a shot type by a player may be evaluated in combination with a shot type delivered by the automatic ball machine (e.g., how well does the player return lobs, dinks, wall shots, etc.) The evaluation routine may thus provide a skill rating requiring the player to return a first shot type with respect to a second shot type launched to the player.

Each shot type to be evaluated with the automatic ball machine positioned on the court in a certain area of the court. For example, evaluating the shot type serve return may have the automatic ball machine positioned near the baseline, where evaluating the shot type dink or volley may have the automatic ball machine moved closer to the net or near the kitchen. Thus, between various evaluation routines, the automatic ball machine may be moved to an appropriate area on the court. However, as discussed elsewhere herein, the automatic ball machine need not be placed with precision (either with a precise location or with a precise orientation) as the automatic ball machine may determine its location and orientation on the court and adjust the shots it delivers appropriately.

In step S, a skill rating of the player for each shot type is determined. In some examples, other skill ratings of the player that are not associated with a single shot type also may be determined (S). For example, a skill rating of agility or a skill rating of court coverage may be determined by evaluating the player's movement in one or more of the evaluation routines.

In step S, the player's start rating is determined based on aggregating the determined skill ratings (determined in S(and Sif applicable)). The player's start rating may be an average or a weighted average of the determined skill ratings.

In step S, a report may be provided to the player. The report may provide the individual skill rating of the m shot types determined in Sand thus provide insight to the player into areas that should be improved. In addition, the report may identify criteria the player struggled to achieve with respect to a certain skill rating and identify the difficulty factors that were more problematic to a player than others (e.g., the player experienced a relatively higher rate of failure when difficulty level was increased by adding spin vs speed, e.g.). In addition, the report may provide analysis outside of shot parameters of the returned shot. For example, relatively high failure rates (of success criteria described herein) and/or relatively low skill ratings may be correlated with separate analysis of stroke data, footwork, posture to provide possible reasons for such high failures and/or relatively low skill ratings.

illustrate a flowcharts setting forth exemplary steps of executing an evaluation routine of a player (which may also be referred to herein as a “user”). The steps ofmay be executed by automatic ball machine. As the evaluation routines ofare similar, and either/both may be used to determine one or more skill ratings for determining a start rating of a player in S), the evaluation routines ofwill be described together with certain differences noted as applicable.

The automatic ball machinemay be moved onto one side of a racquet court and a player may position themself on the other side of the racquet court (e.g., with a net interposed between these two sides). The automatic ball machineis preferably light enough to be pulled onto the racquet court (i.e., haulable), such as by being rolled onto the court by a person. Although the automatic ball machineofis depicted with four wheels, two of the wheels may be replaced with a fixed base (a frame or legs) that may be lifted off the ground when wheeling the automatic ball machine onto the racquet court. In some embodiments, the automatic ball machineis light enough to be lifted by one or two people. The automatic ball machinemay be positioned anywhere on one side of the racquet court, but is preferably placed in an area where a player would typically be positioned to return a ball during normal play of the racquet sport, such as near the baseline in tennis or back court in padel and platform tennis. The automatic ball machineneed not be positioned precisely either in its location or in its orientation. After moving the automatic ball machineonto one side of the racquet court, the automatic ball machineis typically fixed in its location and orientation during subsequent operation (e.g., during execution of an evaluation routine), although parts of the automatic ball machine may move. For example, the wheels and frame of the automatic ball machine(forming the base of the automatic ball machine) may be fixed in their location and orientation during execution of an evaluation routine, while the ball launching systemmay rotate and/or adjust its height relative to the wheels and frame of the automatic ball machine. In other embodiments, the automatic ball machinemay include one or more motors operatively connected to drive the wheels (e.g., connected via one or more axles) to move the automatic ball machinearound the court during subsequent operation (e.g., under the control of controllerto execute another evaluation routine).

At step Sand S′, a first instance of an evaluation routine is initiated by the automatic ball machine. A plurality of different evaluation routines may be stored by or accessible by the automatic ball machine. An evaluation routine may comprise a single shot type that is repetitively provided to the player by the automatic ball machineto the same location with different difficulty levels. Alternatively, an evaluation routine may comprise a sequence of different shots (shots of different shot types and/or launched to different locations), where the sequence of different shots are repeated with different difficulty levels.

In Sof, an evaluation routine of an ith shot-type is initiated. In the example of, an evaluation routine may repetitively provide a shot of the same shot type to the same location to the player (e.g., to repetitively provide this shot to a player, albeit with certain shot parameters adjusted to provide this otherwise “same” shot at different difficulty levels). The evaluation routine ofis suited to evaluate the player with respect to a single shot type.

In S′ of, an evaluation routine of one or more shot-types is initiated. In the example of, an evaluation routine may repeat a sequence of different shots (with different shot types and/or different shot locations), where the sequences are provided with different difficulty levels. The evaluation routine ofmay evaluate a single shot type or may be used to evaluate several different shot types and thus provide skill ratings for one or more shot types.

Each shot may be defined by targeted shot parameters that are derived from initial shot parameters. In some examples, the initial shot parameters may be predetermined, and may be either stored shot parameters (e.g., stored in a computer memory) and/or shot parameters derived from the stored shot parameters. For example, a list of shots may be stored as a table in computer memory, with each entry of the list corresponding to a shot to be provided by the automatic ball machine. For example, each entry of the list may identify a set of shot parameters (which may be referred to herein as “stored shot parameters”) corresponding to the shot to which the entry corresponds. Each entry may include the corresponding set of stored shot parameters or point to a secondary memory location where the stored shot parameters may be obtained (which may be helpful when the same shot is desired to be repeated in the same or different evaluation routines). An evaluation routine executed according to the steps ofmay comprise repetitively providing one shot of the list of shots provided with different difficulty levels. An evaluation routine executed according to the steps ofmay comprise a repetitively providing a sequence of all or a subset of the list of shots with different difficulty levels.

The evaluation routine to be executed may be selected by a person (such as a user (player) or coach) with a user interface, such as a user interface connected to the automatic ball machineor a remote user device (e.g., a mobile phone, smart watch, personal computer, tablet, or other mobile device) connected (e.g., wirelessly or wired) to the automatic ball machine. It should be appreciated that in implementations that allow a user to control aspects of the automatic ball machine via an application installed on a user device, the user interface of that device may be considered the user interface of the automatic ball machine, although such a user interface may also be shared with other applications not related to the automatic ball machine. The user interface may include conventional inputs and outputs of computing and mobile devices, such as one or more of a display, a touchscreen, a keyboard, a touchpad, a mouse, a microphone, a speaker, etc. The evaluation routine may be selected from a displayed list of predetermined evaluation routines stored locally with the controlleror stored remotely and accessible by the controllerof the automatic ball machinevia a wired or wireless connection. The user may also initiate the execution of the selected evaluation routine to start the launching of balls to the user with a further input, e.g., with the remote user device or with a gesture (such as waving of the hands or racquet in a predetermined pattern that is recognized by the automatic ball machinevia analysis of images taken by the imaging system).

The duration of each evaluation routine may be based on user associated performance metrics. For example, the evaluation routine may repetitively provide shots that become more and more difficult by altering some of the shot parameters of the shots (e.g., by increasing shot speed, shot spin, placing shot location closer to the walls and/or providing a flatter (more horizontal) shot trajectory, etc.) while maintaining others of the shot parameters. In the evaluation routine executed according to, the types of shots (i.e., shot types) (as well as the shot locations) of the shots provided by the automatic ball machine may be the same. In addition, the evaluation routine ofmay evaluate and provide a corresponding skill rating for a particular shot type (the shot type that should to be returned by the player). In the evaluation routine executed according to, one or both of the shot type and shot location may differ between the shots provided by the automatic ball machine. In addition, the evaluation routine ofmay evaluate one shot type, or may evaluate more than one shot type (to respectively provide a corresponding skill rating for one shot type or multiple shot types).

In step S, the automatic ball machinedetermines its location and orientation on the court. The imaging systemmay obtain images of the court. Controllerperforms feature extraction by analyzing the obtained images of the court to extract one or more features of the court, such as the orientation and location of line markings, intersections of the line markings, vanishing points corresponding to parallel line markings, structures that are a part of the playing area of the court (e.g., a net, net posts, etc.), and, when present, enclosures (e.g., walls) surrounding the playing surface. The extracted features may be identified in an image space, a two dimensional (2D) space, which may correspond to one of the images obtained by the imaging system, whose coordinates may correspond to pixel coordinates of the corresponding image. The controllermay perform a model fitting process to find a transformation from the three dimensional (3D) world coordinate system (i.e., “3D world space” or “world space”) of a court model into the 2D image space, selecting a court model with appropriate 3D transformation of magnification, location and orientation that most closely aligns with (i.e., “best fits”) the extracted features identified in the 2D image space. The controllermay have several such different court models stored (e.g., court models providing a 3D description of standard courts associated with padel, tennis, pickleball, platform, etc.) and a user may have identified (via a user interface) the appropriate court model (corresponding to the court on which the automatic ball machinehas been positioned) with which the model fitting process is then performed. The selected court model may be transformed in 3D space (magnified/shrunk, rotated, moved/shifted, such as by applying a transformation matrix to the 3D coordinates defining the selected court model) multiple times, each transformed court model being compared to the 2D image space having the extracted features to determine the best fitting transformed model. The determined best fitting transformed model may be used to determine 3D locations of the images taken by the imaging system. For example, pixel coordinates of the 2D image space of the images taken by the imaging system may each correspond to and identify a corresponding 3D world coordinate. When images are provided by multiple cameras of the imaging system, each camera may have a different mapping of its 2D image space to 3D world coordinates associated with the determined best fitting transformed model. The determined best fitting transformed model along with the intrinsic parameters of a camera of the imaging systemare used to calculate (via geometric transformation) the 3D position and orientation of the camera with respect to the court (e.g., using a fixed point on the court as the origin) and thus the location of the ball machineon the court(corresponding to the location of the camera) as well as any desired element of the ball machine (such as the ball launcher). Further details and alternatives of determining location and orientation of the automatic ball machineon the court may be found in the '345 application and may be implemented herein.

In steps Sand S′, the difficulty level of the next shot in the evaluation routine is determined. Note that the first time steps Sand S′ are performed in executing the evaluation routine, the next shot is simply the first shot of the evaluation routine. Also, the first time steps Sand S′ are performed, the difficulty level may be predetermined or it may be based on a user input of an estimated skill level of the player. When step S′ is performed subsequently, S′ selects this next shot as the next shot in the repetitive sequence of different shots being performed by the evaluation routine of. The set of initial shot parameters corresponding to this next shot in the evaluation routine may be obtained (e.g., loaded from memory) at this time if appropriate. The set of initial shot parameters for a shot may be predetermined and represented by stored data (which may be referenced as stored shot parameters), and may include shot parameters such as location, speed, spin, peak height, launch height, shot type, etc.

In some examples, the initial shot parameters are stored (e.g. in computer storage or memory) and controllerobtains the initial shot parameters of each shot directly from computer storage (i.e., the shot parameters that are stored are the same as the initial shot parameters). In other examples, data in storage may define initial shot parameters but may not be the initial shot parameters themselves. For example, initial shot parameters and stored shot parameters may be represented with different types of shot parameters, but still describe the same shot (e.g., as Euclidean coordinates and polar coordinates may represent the same location in space, but use different data sets to do so). In some examples, a shot may be represented (e.g., in storage) with a set of parameters along with certain modifiers associated with the shot from which the initial shot parameters are derived. For example, a standard shot type of drive may be defined, and include modifiers of difficulty level, speed, shot location, etc., that define a shot, from which the initial shot parameters are derived (e.g., as data representing an object, such as a trajectory, may be modified by transformation matrices, to rotate, scale, shear, reflect, etc. the representation of the object). Thus, the shot may be represented by the initial shot parameters that are stored (for each shot, the initial shot parameters are the same as the stored shot parameters) or the shot may be represented by initial shot parameters that are defined by the stored data (which may include other types of shot parameters or other representations from which the initial shot parameters are derived).

In step S, the ball launching systemlaunches a ball to the player on the other side of the court according to targeted shot parameters corresponding to the next shot (e.g., identified in S/S′). The targeted shot parameters may be obtained by modifying the initial shot parameters of this next shot. Modification of the initial shot parameters may be performed by applying tuning modifiers and difficulty modifiers to the initial shot parameters.

Tuning modifiers may be applied to the initial shot parameters such that, without applying additional modifiers, the resulting targeted shot parameters provide qualitatively the same shot as represented by the initial shot parameters. Tuning modifiers may take into consideration the position and orientation of the automatic ball machine, the current environment (temperature, humidity, rain, etc.), ball conditions (worn, new, hardness, etc.) and court conditions (e.g., court surface type, court surface wear, etc.). For example, the location and/or orientation of the automatic ball machine determined in Sare used by the controllerto generate targeted shot parameters. If targeted shot parameters are obtained by applying only tuning modifiers to initial shot parameters (e.g., without additional modification, e.g., without applying difficulty modifiers or other modifiers to the initial shot parameters), the launcher settings are derived in order to launch a ball having these targeted shot parameters (i.e., obtaining the targeted shot parameters is the goal). Furthermore, a ball launched with the launcher settings derived from these targeted shot parameters (obtained by applying only the tuning modifiers to the initial parameters) is intended to faithfully represent the shot defined by the initial shot parameters; the tuning modifiers are applied to modify the initial shot parameters to qualitatively provide the same shot as represented by the initial shot parameters in view of automatic ball machine location and orientation, the environment, ball conditions and/or court conditions. For facilitating understanding, such targeted shot parameters may be referred to as “baseline targeted parameters” when subject to possible further modification, such as by difficulty modifiers—(not to be confused with the baseline of a court) these baseline targeted parameters represent a baseline, or starting point, of a shot qualitatively the same as the shot represented by the initial shot parameters, taking into consideration the current situation of the automatic ball machine, such as one or more of location of the ball machine, orientation of the ball machine, environmental factors, court conditions, ball conditions and the ball machine conditions. For example, the controller may first generate baseline targeted shot parameters and then apply difficulty modifiers to obtain the target shot parameters which are then used to obtain launcher settings. Some or all of the baseline targeted shot parameters may be the same as the initial shot parameters, while others of the baseline targeted shot parameters may be adjusted according to the determined location and/or orientation of the ball machine(as well as other tuning parameters as described herein).

Difficulty modifiers may be applied to the initial shot parameters such that the resulting targeted shot parameters provide qualitatively a more difficult or less difficult shot than that represented by the initial shot parameters. More than one shot parameter may be modified by a corresponding difficulty modifier (which parameters are adjusted may depend on the shot type of the shot). The difficulty modifiers may be identified by the difficulty level. The magnitude of a difficulty modifier may correlate to the determined difficulty in S, such as being proportional to the determined difficulty level or inversely proportional to the determined difficulty. In some examples, a difficulty modifier (or a value proportional to the difficulty modifier) may be added or subtracted from the corresponding initial shot parameter. In some examples, a look up table may be used to store difficulty modifiers, and the determined difficulty level may be used to identify the set of difficulty modifiers in the look up table to be applied to the initial shot parameters. It should also be appreciated that different sets of difficulty modifiers may be identified by the difficulty level depending on the shot type of the shot. Thus, for a repetitive series of different shots (e.g. with different shot types), different sets of difficulty modifiers may be applied to the initial parameters of the different shots. For example, a difficulty level of 5 determined in Smay result in modifying the speed shot parameter to increase by 50% as compared to the speed represented by the initial shot parameters of the shot, a difficulty level of 6 may modify the speed shot parameter to increase by 60%, etc. For example, incrementing or decrementing the difficulty of a shot or segment (a set of sequential shots) of the evaluation routine, may cause one or more of the shot parameters of landing point, spin, speed, etc. to be adjusted (e.g., increased or decreased) by a corresponding predetermined amount (e.g., for each difficulty level), such as by 5%. In addition, ball trajectory may be similarly adjusted by a predetermined amount such that the ball is moved further from or closer to a strike zone (an optimum spot for hitting the ball) of the player for a particular shot type the player should return. For example, the strike zone may have a favorable player launch height (the height when the ball is launched from the player's racquet), such as for example, a player launch height of +/−6 inches from waist height of the player, +/−12 inches from waist height of the player, or at a ball height of 2.5 feet to 3.5 feet above the playing surface. The strike zone may be located to the side of the player, such as within a horizontal range from the player's foot (the same side foot as the hand holding the racquet) to 2 feet. To provide shots that are harder for the player to return, the shot location (and possibly in combination with other shot parameters) may be adjusted to provide the ball to the player outside the strike zone by an amount proportional to the difficulty level (unless the player properly moves on the playing surface into a better position). Further discussion of modification based on difficulty modifiers is discussed below.

It should be appreciated that the initial shot parameters may be modified by the tuning modifiers and the difficulty modifiers in any order (i.e., first modified by the tuning modifiers and then modified by the difficulty modifiers, or first modified by the difficulty modifiers and then by the tuning modifiers) or simultaneously. The description of modifiers being “applied to” the initial shot parameters (or similar description) will be understood to encompass modifications of the initial shot parameters in any order (i.e., to reference modification of unadjusted initial shot parameters, to reference further modification of previously modified initial shot parameters or to reference modifications of the initial shot parameters simultaneously with other adjustments made by other modifiers). Similarly, it should be understood that description regarding “baseline target parameters” is provided for better understanding and not to require any particular order of modification of the initial parameters.

The controlleruses the targeted shot parameters to generate appropriate launcher settings. The launcher settings are applied (e.g., input) to the ball launching systemby the controllerto control operation of the ball launching system, and may include (in the form of digital commands or applied voltages), spinner wheel speeds, ball launcher height, ball launcher angle, ball launcher orientation, etc. In general, the launcher settings may cause the ball launcherto launch a ball corresponding to targeted shot parameters related to the selected shot. Different ball launching systems may have different mechanisms (e.g., spinner wheels, air gun, spring actuator, electromagnetic actuator, etc.) to obtain the generated launcher settings. Thus, the controllermay be configured differently to appropriately control the mechanism of the ball launching system of the ball launching system of the automatic ball machine.

In S, the launcher settings are then generated according to the obtained targeted shot parameters (e.g., with at least some, but not necessarily all, of the initial shot parameters having been adjusted to account for the determined location and/or orientation of the automatic ball machineand adjusted according to the determined difficulty level in S(if appropriate)). The ball is then launched by the automatic ball machinewith these launcher settings to provide a shot according to the targeted shot parameters.

After launching the ball in step Sto the player on the other side of the court from the automatic ball machine, the player returns (or attempts to return) the launched ball (i.e., by hitting the ball with a racquet). The returned shot must meet certain criteria for being considered a successful return (which may be referred to herein as “success criteria”). The success criteria may be communicated to the player by the automatic ball machine(e.g., the user interface, such as the display, other visual indicators, or a speaker of the automatic ball machine). The success criteria may include one or more the shot parameters discussed herein, such as one or more of a target shot location/area, shot type, a minimum speed, a maximum speed, a maximum peak height, a minimum peak height, a maximum net clearance and a minimum spin, for example. The success criteria may differ depending on the evaluation routine, the skill of the player being evaluated, and/or the difficulty level most recently determined in S.

Prior to the first launched ball of an evaluation routine, or after a returned ball by the player, a target location or area on the ball machine side of the court is identified indicating where the player should return the ball. For example, an identified return target location may be identified on a display of the automatic ball machine, such as by highlighting a corresponding location on a graphical representation of a court (e.g., a court corresponding to the one being played on), such as with an “x”, a circle, colored shading or with flashing, or by displaying text or graphics (e.g., an arrow) indicating the target location. The identified return target location may be identified by an audio message from the automatic ball machine. The identified return target location may be identified by lighting up a portion of the court by the automatic ball machine(e.g., directing a light beam, such as a laser, of the automatic ball machine, that is controlled by controller). In some examples, the identified return target location may be an object placed on the court that is identified by the automatic ball machineby analysis of images taken by the imaging system. For example, a flat pad may be placed on the court or a bucket (e.g., trash can) to identify a target location for the player to return the ball. In some example, several objects with unique identifying indicia (e.g., different colors, shapes or markings) may be provided on the court and the ball machine may identify the location by communicating the unique identifying indicia (e.g., by broadcasting “red” or “one” (or displaying a red color or “red” or “1”) to respectively denote a red pad or a pad having the label of “1” on it). In some examples, different shots of the evaluation routine may have corresponding success criteria with a different return target location. The different target locations may be identified ahead of time (e.g., at the same time with instructions to the player as to which shot return should be provided to which target location), or may be identified by the automatic ball machineduring the launch of the corresponding shot by the automatic ball machinethat is associated with the target location. In some examples, an evaluation routine may be created by allowing user input (e.g., by a coach) to select return target location(s), such as by having the user identify via a user interface area(s) of the court as target(s). For example, a user may draw (via a touchscreen) or drag a shape on a displayed image of the court via a user interface of the automatic ball machine.

In step S, the automatic ball machinemonitors the player's return of the shot launched by the automatic ball machine in Sand determines if the return shot meets the success criteria. If the returned shot meets all of the success criteria, the returned shot is considered to have passed. If any of the success criterial of the returned shot is not met, the returned shot is considered to have failed. The passing or failing of the shot is recorded (stored in memory), along with the difficulty level and the associated with the shot provided by automatic ball machine (the shot number in the evaluation routine and the shot parameters of the shot). The success criteria that was not met may also be recorded when the returned shot was determined as a failed return. Thus, as step Sis repeated, a pass/fail record of the player is updated.

When evaluating whether the returned shot meets a success criteria of target location, the return shot need not land at the point corresponding to the identified target location, but may be considered to pass when the returned shot lands within a target area associated with the target location, such as within predetermined distance from the target location, or a predetermined area defined around the target location. The difficulty level associated with the shot may adjust the predetermined distance or predetermined area such that relatively higher difficulty levels result in smaller predetermined distances and smaller predetermined areas as compared to relatively lower difficulty levels.

When evaluating a player's skill with respect to walled racquet sports, the target location may be on a wall or on the playing surface near a wall. In such case, the predetermined area may be on both the playing surface and/or one or more walls. For example, a predetermined area may be defined around the target location as a projection onto the court of landing points of hypothetical shots surrounding an ideal returned shot (or standard return shot at the current difficulty level) that vary no more than a predetermined deviation (e.g., no more than a predetermined angle) from the ideal return shot (where these hypothetical shots have the same shot type and same or similar speed and same or similar shot height).