Drop-point-based quality evaluation method and device in tennis match

Abstract

The invention discloses a drop-point-based quality evaluation method and device in a tennis match, and relates to the technical field of tennis matches. According to the main technical scheme, the method comprises the steps that multi-modal track data in the tennis ball landing process is collected; the sideline distance and the bottom line distance between the actual drop point position and an effective area corresponding to tennis ball landing and the deviation distance between the actual drop point position and a preset expected drop point position in the effective area are calculated; processing the sideline distance, the bottom line distance, the deviation distance, the linear speed, the rotating speed, the angle of the rotating direction and the first bounce height by using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result; and generating a quality evaluation report corresponding to the tennis ball drop point based on the tennis ball quality evaluation result. The tennis quality evaluation method mainly aims at providing accurate and comprehensive tennis quality evaluation in a tennis match and providing fair and accurate judgment assistance and technical guidance for referees and players.

Description

Technical Field

[0001] The present application relates to the technical field of tennis matches, and in particular to a quality evaluation method and device based on placement in a tennis match. Background Art

[0002] Tennis is a popular sport with complex and varied skills and tactics. In a tennis match, the player's serve technique is particularly critical, which directly affects the progress and outcome of the match. Traditional tennis match evaluation mainly relies on the subjective judgment of the referee, which may lead to inaccurate and unfair evaluation.

[0003] In recent years, with the development of science and technology, especially the progress of computer vision, sensor technology and data analysis, the technical assistance in tennis games has been significantly enhanced. These technologies can not only help referees judge the game situation more accurately, but also provide players and coaches with detailed training feedback, thereby improving the level of competition and training efficiency.

[0004] At present, some tennis matches and training have begun to use technologies such as Hawk-Eye to assist in judging in-bounds and out-of-bounds. However, these technologies mainly focus on the ruling of controversial balls and do not provide a comprehensive evaluation of the quality of receiving and serving. In addition, existing technologies usually rely on image processing and visual systems, which may be affected by external factors such as light and weather. This results in the inability to provide fair and accurate ruling assistance and technical guidance to referees and players through accurate and comprehensive quality evaluation in current tennis matches. Summary of the invention

[0005] In view of the above problems, the present application provides a quality evaluation method and device based on landing points in a tennis match. The main purpose is to provide accurate and comprehensive tennis quality evaluation in a tennis match, and to provide fair and accurate decision assistance and technical guidance for referees and players.

[0006] In order to solve the above technical problems, this application proposes the following solutions: In a first aspect, the present application provides a quality evaluation method based on placement in a tennis match, the method comprising: Collecting multimodal trajectory data of a tennis ball landing process, wherein the multimodal trajectory data includes an actual landing point of the tennis ball when it lands, a linear speed of the tennis ball when it lands, a rotation speed of the tennis ball when it lands, a rotation direction of the tennis ball when it lands, and a first bounce height of the tennis ball after it lands; Calculating the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, as well as the deviation distance from the expected landing point preset in the effective area; Using a preset comprehensive scoring function to process the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height, to obtain a tennis ball quality evaluation result; A quality evaluation report corresponding to the tennis ball landing point is generated based on the tennis ball quality evaluation result.

[0007] Further, calculating the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, and calculating the straight-line distance to a preset target position in the effective area, includes: The horizontal distance between the actual landing point and the nearest edge in the effective area is taken as the edge distance, which is expressed as: ; in, is the edge distance, is the horizontal coordinate of the actual landing point, and are the horizontal coordinates of the left and right sidelines respectively; The vertical distance between the actual landing point and the bottom line in the effective area is taken as the bottom line distance, which is expressed as: ; in, is the baseline distance, The ordinate of the actual landing point, are the ordinates of the bottom line respectively; The Euclidean distance between the actual landing point position and the expected landing point position is taken as the deviation distance, which is expressed as: ; in, is the deviation distance, ( ) is the coordinate of the actual landing point, ( ) are the coordinates of the expected landing point.

[0008] Furthermore, the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height are processed using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result, including: The sideline distance and the bottom line distance are evaluated and processed respectively using a piecewise function to obtain a first score and a second score, which are respectively expressed as: ; in, It is the first rating. is the maximum edge distance, is the minimum edge distance; ; in, The second rating is is the maximum baseline distance, is the minimum baseline distance; The deviation distance is evaluated using a nonlinear function to obtain a third score, which is expressed as: ; in, The third rating. is the deviation distance, is the maximum deviation distance; The linear speed is evaluated using the peak function to obtain a fourth score, which is expressed as: ; in, The fourth rating. is the linear velocity of the tennis ball when it hits the ground. The ideal speed for a tennis ball to hit the ground. is the standard deviation, which is used to control the peak width; The rotation speed and the rotation direction are evaluated using trigonometric functions to obtain a fifth score, which is expressed as: ; in, The fifth rating. is the rotation speed, is the ideal rotation speed, is the angle of rotation, ; The first bounce height is evaluated using a threshold function to obtain a sixth score, which is expressed as: ; in, It is the seventh rating. It is the height of the first bounce of a tennis ball after it hits the ground. is the first bounce height threshold; The tennis ball quality evaluation result is calculated based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient.

[0009] Further, the tennis ball quality evaluation result is calculated based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient, including: The first score, the second score, the third score, the fourth score, the fifth score, the sixth score and the weight coefficient are respectively expressed as a score function value vector and a weight vector, and the vector inner product method is used to calculate the comprehensive score corresponding to the tennis ball quality evaluation result, which is expressed as: ; in, is the comprehensive score corresponding to the tennis quality assessment results, is the scoring function value vector, is the weight vector, , , , , and are weight coefficients of each score, satisfying .

[0010] Furthermore, before calculating the tennis ball quality evaluation result based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient, the method further includes: collecting statistics of tennis matches, the statistics including sideline distance, baseline distance, deviation distance, straight line speed, spin speed, spin direction, and first bounce height; A linear regression model is constructed based on the statistical data, and the weight coefficients corresponding to the first score, the second score, the third score, the fourth score, the fifth score and the sixth score are estimated using the least squares method.

[0011] Further, a linear regression model is constructed based on the statistical data, and the weight coefficients corresponding to the first score, the second score, the third score, the fourth score, the fifth score and the sixth score are estimated using the least squares method, including: The linear regression model is expressed as: ; in, is the independent variable, which includes the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height. is the dependent variable, which is any one of the following: scoring rate, quality of the return ball by the receiving side, serve accuracy, serve speed, serve success rate, and serve failure rate. is the intercept term, is the error term.

[0012] Furthermore, a quality evaluation report corresponding to the tennis ball landing point is generated based on the tennis ball quality evaluation result, including: Obtaining the use requirements of the report, including adjudication assistance requirements and technical guidance requirements; If it is the adjudication assistance requirement, generating a first report focusing on the accuracy of the tennis ball landing point and whether the tennis ball violates the rules based on the tennis ball quality evaluation result, and generating the quality evaluation report based on the first report focusing on the information; If it is the technical guidance requirement, a second report focusing on technical parameter analysis and technical improvement suggestions is generated based on the tennis ball quality assessment result, and the quality evaluation report is generated based on the second report focusing on the information.

[0013] In a second aspect, the present application provides a quality evaluation device based on placement in a tennis match, the device comprising: A collection unit, used to collect multimodal trajectory data of a tennis ball during its landing process, wherein the multimodal trajectory data includes an actual landing point of the tennis ball when it lands, a linear speed of the tennis ball when it lands, a rotation speed of the tennis ball when it lands, a rotation direction of the tennis ball when it lands, and a first bounce height of the tennis ball after it lands; A calculation unit, used to calculate the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, and the deviation distance from the expected landing point preset in the effective area; a processing unit, configured to process the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the bounce height by using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result; A generating unit is used to generate a quality evaluation report corresponding to the tennis ball landing point based on the tennis ball quality evaluation result.

[0014] In order to achieve the above-mentioned purpose, according to the third aspect of the present application, a storage medium is provided, wherein the storage medium includes a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute the quality evaluation method based on placement in a tennis match according to the first aspect.

[0015] In order to achieve the above-mentioned purpose, according to a fourth aspect of the present application, a processor is provided, wherein the processor is used to run a program, wherein when the program is running, the quality evaluation method based on placement in a tennis match according to the above-mentioned first aspect is executed.

[0016] By means of the above technical scheme, the present application provides a method and device for evaluating the quality of a tennis match based on the landing point. When quality evaluation based on the landing point is required in a tennis match, multimodal trajectory data of the tennis ball landing process is first collected, and the multimodal trajectory data includes the actual landing point position of the tennis ball when it lands, the linear speed of the tennis ball when it lands, the rotation speed of the tennis ball when it lands, the rotation direction of the tennis ball when it lands, and the first bounce height after the tennis ball lands. Then, the sideline distance and the bottom line distance of the effective area corresponding to the landing of the tennis ball are calculated, as well as the deviation distance from the expected landing point position preset in the effective area. Then, a preset comprehensive scoring function is used to process the sideline distance, bottom line distance, deviation distance, linear speed, rotation speed, rotation direction, and first bounce height to obtain a tennis ball quality evaluation result. Finally, a quality evaluation report corresponding to the tennis ball landing point is generated based on the tennis ball quality evaluation result. Through the technical solution provided by the present application, the sideline distance, the baseline distance and the deviation distance from the expected landing point of the actual landing point in the effective area can be determined, and the sideline distance, the baseline distance and the expected landing point are combined with multiple parameters such as the linear speed, the rotation speed, the rotation direction and the first bounce height as the basic data for subsequent evaluation, and the evaluation is processed through a comprehensive scoring function to obtain the tennis quality evaluation result, and then the final quality evaluation report is generated from the tennis quality evaluation result. Not only the direct evaluation factors such as the sideline distance, the baseline distance and the deviation distance from the expected landing point of the tennis ball landing point in the effective area are considered, but also the indirect evaluation factors such as the linear speed, the rotation speed, the rotation direction and the first bounce height are combined, which can provide a more comprehensive and objective evaluation than the traditional method, thereby providing a comprehensive and accurate shot quality score, which can not only provide auxiliary penalty basis for referees, but also provide personalized technical improvement suggestions for players and coaches, thereby improving the fairness of the game and the efficiency of training.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A flow chart of a quality evaluation method based on placement in a tennis match provided by an embodiment of the present application is shown; Figure 2A block diagram showing a quality evaluation device based on drop points in a tennis match provided by an embodiment of the present application is shown; Figure 3 A block diagram showing the composition of another device for quality evaluation based on drop points in a tennis match provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the drawings in the specification.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0021] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present application. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0022] Example 1, reference Figure 1 , which is the first embodiment of the present application, and which provides a quality evaluation method based on placement in a tennis match, the method comprising: 101. Collect multimodal trajectory data of a tennis ball during its landing process, wherein the multimodal trajectory data includes the actual landing point of the tennis ball when it lands, the linear speed of the tennis ball when it lands, the rotation speed of the tennis ball when it lands, the rotation direction of the tennis ball when it lands, and the first bounce height of the tennis ball after it lands.

[0023] It should be noted that by arranging multiple high-speed cameras around the tennis court that can cover the entire venue to capture the image sequence of the tennis ball during flight, the movement of the tennis ball can be recorded at a very high frame rate for subsequent analysis. By synchronizing these high-speed cameras, video data of the entire process of the tennis ball from hitting to landing and even bouncing can be obtained. A three-dimensional motion capture system (such as Vicon, OptiTrack, etc.) is constructed using infrared cameras and markers, that is, reflective markers are attached to the tennis ball, or a specially made tennis ball with markers is used, and the position changes of the markers are captured by multiple infrared cameras to calculate the three-dimensional trajectory of the tennis ball. Pressure sensing pads are laid in key areas of the tennis court. When the tennis ball lands, the sensing pads can record the position and force of the contact point to help determine the landing point and bounce of the tennis ball. Specialized software tools are used to fuse and analyze the data collected by the above-mentioned various devices to obtain multi-modal trajectory data, so as to accurately extract key parameters such as the actual landing point of the tennis ball when it lands, the linear speed of the tennis ball when it lands, the rotation speed of the tennis ball when it lands, the rotation direction of the tennis ball when it lands, and the first bounce height of the tennis ball after it lands, so as to perform subsequent steps.

[0024] 102. Calculate the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, as well as the deviation distance from the preset expected landing point in the effective area.

[0025] The further execution process is as follows: The horizontal distance between the actual landing point and the nearest edge in the effective area is taken as the edge distance, which is expressed as: ; in, is the edge distance, is the horizontal coordinate of the actual landing point, and are the horizontal coordinates of the left and right sidelines respectively; The vertical distance between the actual landing point and the bottom line in the effective area is taken as the bottom line distance, which is expressed as: ; in, is the baseline distance, The ordinate of the actual landing point, are the ordinates of the bottom line respectively; The Euclidean distance between the actual landing point and the expected landing point is taken as the deviation distance, which is expressed as: ; in, is the deviation distance, ( ) is the coordinate of the actual landing point, ( ) are the coordinates of the expected landing point.

[0026] It should be noted that in this step, the actual landing point position refers to the actual landing point coordinates ( ), while the effective area refers to the scoring area corresponding to the player's receiving serve ( ), and the expected landing point refers to the center coordinates of the best position where the tennis ball falls in the effective area when the player receives the serve ( ). Therefore, the relevant distance values ​​can be determined by calculating the coordinates of the actual landing point and the sideline, bottom line and expected landing point coordinates of the effective area, where the sideline distance d is used to measure how far the tennis ball lands from the nearest sideline. If d is very small, it means that the tennis ball is very close to the sideline and may go out of bounds. The bottom line distance s is used to measure how far the tennis ball lands from the bottom line. If s is very small, it means that the tennis ball is very close to the bottom line and may also go out of bounds. The deviation distance e is used to measure the deviation between the actual landing point of the tennis ball and the expected landing point. If e is large, it means that the shot is not accurate enough. These distance values ​​are very important for evaluating the quality of the landing point of the tennis ball, which can effectively help the referee make more accurate decisions, and can also provide training feedback to players to help them improve their hitting skills.

[0027] 103. The tennis ball quality evaluation result is obtained by processing the sideline distance, bottom line distance, deviation distance, straight line speed, rotation speed, rotation direction and first bounce height using the preset comprehensive scoring function.

[0028] The further execution process is as follows: The sideline distance and the bottom line distance are evaluated by piecewise function to obtain the first score and the second score, which are expressed as: ; in, It is the first rating. is the maximum edge distance, is the minimum edge distance; ; in, The second rating is is the maximum baseline distance, is the minimum baseline distance.

[0029] It should be noted that the first and second scores use piecewise functions. It is a mathematical function that is used to divide the domain into several parts, each of which corresponds to a specific function expression. From the above formula, we can see that the function and According to the different values ​​of the distance between the tennis ball's landing point and the sideline and baseline, the definition domain is divided into three parts, and the function expression corresponding to each part is given. Different output values ​​(i.e., scores) are generated according to different input values ​​(i.e., different landing point distances). Therefore, the first score and the second score can help the referee determine whether the tennis ball is close to the sideline, and thus determine whether it is likely to go out of bounds. A higher score means that the tennis ball is farther from the sideline or baseline and is not likely to go out of bounds. In addition, players can use the first score and the second score to understand whether their shots are too close to the sideline, so as to adjust their shot strategies, reduce the probability of going out of bounds, and improve the safety of receiving serves.

[0030] The deviation distance is evaluated using a nonlinear function to obtain a third score, which is expressed as: ; in, The third rating. is the deviation distance, is the maximum deviation distance.

[0031] It should be noted that the third score uses a nonlinear function, specifically a square function. The square function is used to process the deviation distance. , the score can be made to drop rapidly as the deviation distance increases. The logic is that if the deviation distance between the actual landing point and the expected landing point exceeds the maximum deviation distance, the score is 0 points. If the actual landing point is at the expected landing point, that is, the actual landing point coincides with the expected landing point, the score is 10 points. If the deviation distance is between 0 and the maximum deviation distance, the score will be reduced according to the square of the deviation, that is, the greater the deviation, the faster the score drops. This design can effectively reflect the accuracy of the tennis landing point, especially when there is a large deviation from the expected landing point. Therefore, the third score can help the referee judge whether the player's shot has reached the expected landing point, thereby evaluating the player's shot accuracy. And the player can use the third score to understand whether his serve is accurate enough and whether it has reached the landing point in the tactical intention. A lower score means that the accuracy of the serve needs to be improved.

[0032] The peak function is used to evaluate the linear speed and obtain the fourth score, which is expressed as: ; in, The fourth rating. is the linear velocity of the tennis ball when it hits the ground. The ideal speed for a tennis ball to hit the ground. is the standard deviation, which controls the peak width.

[0033] It should be noted that the fourth scoring method uses a peak function, specifically a Gaussian function. This Gaussian function is used to simulate the relationship between the speed of the tennis ball when it lands and the score. The Gaussian function part of the function It means that as the speed v deviates from the ideal value, the score will decrease linearly. This design can effectively reflect the speed quality of the tennis ball landing point, especially when it is close to the ideal speed. The logic is that if the speed of the tennis ball when it lands is equal to the ideal speed, the score is 10 points. If the speed of the tennis ball when it lands is not equal to the ideal speed, the score is between 0-10 points, that is, the more deviation, the smaller the score, and vice versa. Therefore, the fourth score can help the referee judge the speed of the player's batting, so as to evaluate the threat and control of the batting. A faster speed may increase the difficulty of the opponent's receiving the ball. And the player can understand whether his batting speed is appropriate through the fourth score. A faster speed can increase the offensiveness, but too fast a speed may affect the controllability. The player can adjust the batting speed according to the game situation.

[0034] The rotation speed and the rotation direction are evaluated using trigonometric functions to obtain a fifth score, which is expressed as: ;in, The fifth rating. is the rotation speed, is the ideal rotation speed, is the angle of the spin direction (0 degrees for topspin, 90 degrees for sidespin, and 180 degrees for backspin), .

[0035] It should be noted that the fifth scoring method uses trigonometric functions, which considers the deviation between the rotation speed and the rotation direction and the ideal value to calculate the rotation quality. The logic is that if the actual rotation speed of the tennis ball when it lands is equal to the ideal rotation speed and the actual rotation direction is equal to the ideal rotation direction, the score is 10 points. If the actual rotation speed deviates from the ideal rotation speed or the actual rotation direction deviates from the ideal rotation direction, the score will gradually decrease between 0 and 10 points as the deviation increases, because and It is a proportional item. The fifth score can help the referee judge whether the rotation intensity and rotation direction of the player's shot are in line with expectations, thereby evaluating the variability and controllability of the shot. A higher rotation speed can make the ball more variable, increasing the difficulty of the opponent's receiving the ball, while a smaller deviation angle means that the rotation direction is closer to expectations, increasing the variability of the ball. And players can use the fifth score to understand whether their serve rotation is sufficient and the direction is in line with expectations, so as to determine whether they have achieved the rotation effect in their tactical intentions. Appropriate rotation can increase the controllability and variability of the ball, and the accurate rotation direction can increase the variability and controllability of the ball, making it more difficult for opponents to deal with.

[0036] The first bounce height is evaluated using a threshold function to obtain a sixth score, which is expressed as: ; in, The sixth rating. It is the height of the first bounce of a tennis ball after it hits the ground. is the first bounce height threshold.

[0037] It should be noted that the sixth scoring method uses a threshold function, specifically a step function. A step function is a function that suddenly jumps from 0 to 1 (or from 1 to 0) at a specific threshold. As can be seen from the above formula, the step function is used to evaluate the first bounce height of a tennis ball after it lands. The logic is that if the first bounce height of a tennis ball after it lands is greater than or equal to , score 10 points, if the bounce height is less than , the score is 0. Therefore, the sixth score can help the referee judge the bounce height of the ball after the player hits it, so as to evaluate the effect of the shot and the difficulty of the opponent to catch the ball. A higher bounce height may make it more difficult for the opponent to catch the ball. And the player can use the sixth score to understand whether his shot has generated enough bounce height. The appropriate bounce height can increase the control and offensiveness of the ball, making it more difficult for the opponent to deal with it.

[0038] The tennis ball quality evaluation result is calculated based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and the preset weight coefficient.

[0039] It should be noted that, in this step, the first score, the second score, the third score, the fourth score, the fifth score and the sixth score have their own corresponding weight coefficients. The weight coefficients are used to reflect the relative importance of each score in the overall evaluation. Specifically, they can be set by expert experience or statistical analysis.

[0040] For the above calculation of tennis ball quality evaluation results combining various scores and preset weight coefficients, the further execution process is as follows: The first score, the second score, the third score, the fourth score, the fifth score, the sixth score and the weight coefficient are respectively expressed as the score function value vector and the weight vector, and the vector inner product method is used to calculate the comprehensive score corresponding to the tennis ball quality evaluation result, which is expressed as: ; in, is the comprehensive score corresponding to the tennis quality assessment results, is the scoring function value vector, is the weight vector, , , , , and are weight coefficients of each score, satisfying .

[0041] It should be noted that the expanded form of this formula is: By means of vector inner product, each scoring function value can be multiplied by the corresponding weight and summed to obtain a comprehensive score .

[0042] In addition, the specific determination process of the weight coefficient corresponding to each score is as follows: Collect statistics of tennis matches, including sideline distance, baseline distance, deviation distance, straight-line speed, spin speed, spin direction, and first bounce height; A linear regression model is constructed based on statistical data, and the least squares method is used to estimate the weight coefficients corresponding to the first score, the second score, the third score, the fourth score, the fifth score and the sixth score.

[0043] The linear regression model is expressed as: ; in, is the independent variable, which includes the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height. is the dependent variable, which is any one of the following: scoring rate, quality of the return ball by the receiving side, serve accuracy, serve speed, serve success rate, and serve failure rate. is the intercept term, is the error term.

[0044] Since this model is a multivariate linear regression model, the least squares method can be used to solve it. That is, the residual sum of squares is calculated by the least squares method, and the weight coefficient with the smallest residual sum of squares is , calculate the partial derivative and set it equal to zero to get the final weight coefficient. The least squares method can provide a reasonable parameter estimate, making the difference between the model's predicted value and the actual value as small as possible, thereby making the obtained weight coefficient more reasonable and accurate.

[0045] It should be noted that in this step, the tennis match corresponding to the statistical data can be a match of the same venue type and the same level as the current match, or a match of the same player in the current match, without limitation. In addition to the sideline distance, bottom line distance, deviation distance, straight-line speed, rotation speed, rotation direction and first bounce height corresponding to the actual landing point position of the tennis ball when it lands, the straight-line speed when the tennis ball lands, the rotation speed when the tennis ball lands, the rotation direction when the tennis ball lands, and the first bounce height after the tennis ball lands extracted from the multimodal trajectory data in the aforementioned step, the statistical data also includes the scoring rate, the quality of the return ball of the receiving side, the accuracy of the serve, the serve speed, the serve success rate and the serve failure rate. For the statistical data, the data can be cleaned to remove outliers and missing values, and standardized for use in the model, and the most relevant features, i.e., the sideline distance, bottom line distance, deviation distance, straight-line speed, rotation speed, rotation direction and first bounce height, are selected as independent variables according to correlation analysis or other feature selection methods. The dependent variables can be selected from scoring rate, return quality of the receiving side, serve accuracy, serve speed, serve success rate and serve failure rate according to demand or actual situation of the game, so as to accurately obtain the weight coefficient of each score to ensure the accuracy of subsequent quality evaluation.

[0046] The specific implementation process for collecting statistical data of tennis matches is as follows: obtaining historical match data of the same venue type and level as the current match; selecting match data of the same match period and weather conditions as the current match from the historical match data as statistical data. Among them, weather conditions include temperature, humidity, wind speed and weather conditions, and match periods include daytime or nighttime. By limiting the statistical data to make it similar to the environment of the current match, the data of tennis matches can be collected and analyzed more comprehensively and scientifically, making the weight coefficients of each score more reasonable and accurate, thereby improving the accuracy and reliability of subsequent scores.

[0047] The specific selection process for multiple dependent variables such as scoring rate, return quality of the receiving side, serve accuracy, serve speed, serve success rate and serve failure rate is as follows: use the Pearson correlation coefficient and Spearman rank correlation coefficient to calculate the correlation between each independent variable and each dependent variable respectively; count the number of dependent variables that exceed the preset correlation threshold in the correlation between each independent variable and each dependent variable, and select the dependent variable with the largest number of dependent variables as the dependent variable of the linear regression model.

[0048] Among them, the Pearson correlation coefficient is used to characterize the strength of the linear relationship between each independent variable and each dependent variable, and the Spearman rank correlation coefficient is used to characterize the strength of the monotonic relationship between each independent variable and each dependent variable. The correlation threshold can be customized, such as 0.3 or 0.5, to filter variables with high correlation. The dependent variable with the largest number of independent variables with correlation exceeding the threshold is selected as the final dependent variable.

[0049] In addition, application scenarios and applicable objects can be set for each dependent variable, and a custom user interface can be generated based on the application scenarios and applicable objects to receive the target dependent variable selected by the user in the custom user interface according to the application scenarios and applicable objects. The target dependent variable can be one or more. When the target dependent variable is one, the target dependent variable is used as the dependent variable of the linear regression model. When the target dependent variable is multiple, each dependent variable in the target dependent variable is used as the dependent variable of the linear regression model, and the weight coefficients obtained from each linear regression model are added and averaged, and the added and averaged weight coefficients are used as the final weight coefficients of each score.

[0050] 104. Generate a quality evaluation report corresponding to the tennis ball landing point based on the tennis ball quality evaluation result.

[0051] The further execution process is as follows: The usage requirements of the report are obtained, and the usage requirements include the requirements for adjudication assistance and technical guidance. If it is a requirement for adjudication assistance, a first report focusing on the accuracy of the tennis ball landing point and whether it violates the rules is generated based on the tennis ball quality assessment results, and a quality evaluation report is generated based on the first report focusing on the information. If it is a requirement for technical guidance, a second report focusing on the technical parameter analysis and technical improvement suggestions is generated based on the tennis ball quality assessment results, and a quality evaluation report is generated based on the second report focusing on the information.

[0052] It should be noted that before generating a quality evaluation report, it is necessary to determine the usage requirements of the report. Different usage requirements have different focuses on the contents contained in the report. The usage requirements are divided into two categories: ruling assistance requirements and technical guidance requirements. Among them, the ruling assistance requirements are used to assist referees in making more accurate and fair judgments, while the technical guidance requirements are used by players and coaches to make technical and tactical adjustments. Specifically, relevant information is collected from the previous multimodal trajectory data and tennis quality evaluation results. According to user needs, a report template is written, including basic information, technical parameter analysis, scoring results and conclusions, and the corresponding relationship between different templates and different requirements is set. After determining the template, the collected data is filled into the template, and the filled template is used to generate the final report document, that is, the quality evaluation report. In order to ensure the accuracy and completeness of the information, the generated report can also be reviewed and then distributed to the referee's display screen or the player's visible shared large screen.

[0053] Take the adjudication assistance requirement as an example: The goal is to generate reports on the accuracy of tennis ball placement and whether the rules are violated, helping referees make more accurate decisions.

[0054] The report includes: basic information: match date, time, venue, contestants, etc.; landing point accuracy: provide the actual landing point of the tennis ball and compare it with the valid area (such as the sideline and baseline); whether it is a violation of the rules: determine whether it is out of bounds or violates other rules based on the landing point; scoring results: provide scoring results such as sideline distance, baseline distance, deviation distance, etc.; conclusion: summarize the legality of the tennis ball landing point and make recommendations for the referee.

[0055] Take the technical guidance requirement as an example: The goal is to generate reports on technical parameter analysis and technical improvement suggestions to help players and coaches with training and tactical adjustments.

[0056] The report includes: basic information: match date, time, venue, contestants, etc.; technical parameter analysis: providing scoring results for technical parameters such as the tennis ball's linear speed, rotation speed, rotation direction, first bounce height, etc.; technical improvement suggestions: based on the scoring results, making specific technical improvement suggestions; summary: summarizing the player's performance and making overall improvement suggestions.

[0057] Based on the above Figure 1It can be seen from the implementation method that the present application provides a quality evaluation method based on landing points in a tennis match. When quality evaluation based on landing points is needed in a tennis match, multimodal trajectory data of the tennis ball landing process is first collected, and the multimodal trajectory data includes the actual landing point position of the tennis ball when it lands, the linear speed of the tennis ball when it lands, the rotation speed of the tennis ball when it lands, the rotation direction of the tennis ball when it lands, and the first bounce height of the tennis ball after it lands. Then, the sideline distance and the bottom line distance of the effective area corresponding to the landing of the tennis ball are calculated, as well as the deviation distance from the expected landing point position preset in the effective area. Then, the preset comprehensive scoring function is used to process the sideline distance, bottom line distance, deviation distance, linear speed, rotation speed, rotation direction and first bounce height to obtain a tennis ball quality evaluation result. Finally, a quality evaluation report corresponding to the tennis ball landing point is generated based on the tennis ball quality evaluation result. Through the technical solution provided by the present application, the sideline distance, the bottom line distance and the deviation distance from the expected landing point in the effective area can be determined according to the actual landing point position, and the sideline distance, the bottom line distance and the expected landing point are combined with multiple parameters such as linear speed, rotation speed, rotation direction and first bounce height as the basic data for subsequent evaluation, and the evaluation and processing are performed through a comprehensive scoring function to obtain the tennis quality evaluation result, and then the final quality evaluation report is generated from the tennis quality evaluation result. Not only the direct evaluation factors such as the sideline distance, the bottom line distance and the deviation distance from the expected landing point of the tennis ball landing point and the effective area are considered, but also the indirect evaluation factors such as linear speed, rotation speed, rotation direction and first bounce height are combined, which can provide a more comprehensive and objective evaluation than the traditional method, thereby providing a comprehensive and accurate shot quality score, which can not only provide auxiliary penalty basis for referees, but also provide personalized technical improvement suggestions for players and coaches, thereby improving the fairness of the game and the efficiency of training.

[0058] Example 2, reference Figure 2 and Figure 3 , which is the second embodiment of the present application, as an alternative to the above Figure 1 The implementation of the method embodiment shown in the figure provides a quality evaluation device based on drop points in a tennis match. The embodiment of the device corresponds to the aforementioned method embodiment. For ease of reading, this embodiment will not repeat the details of the aforementioned method embodiment one by one, but it should be clear that the device in this embodiment can correspond to all the contents of the aforementioned method embodiment. The device includes: The acquisition unit 21 is used to acquire multimodal trajectory data of the tennis ball landing process, wherein the multimodal trajectory data includes the actual landing point of the tennis ball when it lands, the linear speed of the tennis ball when it lands, the rotation speed of the tennis ball when it lands, the rotation direction of the tennis ball when it lands, and the first bounce height of the tennis ball after it lands; A calculation unit 22, used to calculate the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, and the deviation distance from the expected landing point preset in the effective area; The processing unit 23 is used to process the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height by using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result; The generating unit 24 is used to generate a quality evaluation report corresponding to the tennis ball landing point based on the tennis ball quality evaluation result.

[0059] Further, such as Figure 3 As shown, the calculation unit 22 includes: The first calculation module 221 is used to take the horizontal distance between the actual landing point position and the nearest edge line in the effective area as the edge line distance, expressed as: ; in, is the edge distance, is the horizontal coordinate of the actual landing point, and are the horizontal coordinates of the left and right sidelines respectively; The second calculation module 222 is used to take the vertical distance between the actual landing point position and the bottom line in the effective area as the bottom line distance, expressed as: ; in, is the baseline distance, The ordinate of the actual landing point, are the ordinates of the bottom line respectively; The third calculation module 223 is used to use the Euclidean distance between the actual landing point position and the expected landing point position as the deviation distance, which is expressed as: ; in, is the deviation distance, ( ) is the coordinate of the actual landing point, ( ) are the coordinates of the expected landing point.

[0060] Further, such as Figure 3 As shown, the processing unit 23 includes: The first processing module 231 is used to evaluate the sideline distance and the bottom line distance respectively using a piecewise function to obtain a first score and a second score, which are respectively expressed as: ; in, It is the first rating. is the maximum edge distance, is the minimum edge distance; ; in, The second rating is is the maximum baseline distance, is the minimum baseline distance; The second processing module 332 is used to evaluate the deviation distance using a nonlinear function to obtain a third score, which is expressed as: ; in, The third rating. is the deviation distance, is the maximum deviation distance; The third processing module 233 is used to evaluate the straight-line speed using the peak function to obtain a fourth score, which is expressed as: ; in, The fourth rating. is the linear velocity of the tennis ball when it hits the ground. The ideal speed for a tennis ball to hit the ground. is the standard deviation, which is used to control the peak width; The fourth processing module 234 is used to evaluate the rotation speed and the rotation direction using a trigonometric function to obtain a fifth score, which is expressed as: ; in, The fifth rating. is the rotation speed, is the ideal rotation speed, is the angle of rotation, ; The fifth processing module 235 is used to evaluate the first bounce height using a threshold function to obtain a sixth score, which is expressed as: ; in, It is the seventh rating. It is the height of the first bounce of a tennis ball after it hits the ground. is the first bounce height threshold; The comprehensive determination module 236 is used to calculate the tennis ball quality evaluation result based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient.

[0061] Further, such as Figure 3 As shown, the comprehensive determination module 236 includes: The first score, the second score, the third score, the fourth score, the fifth score, the sixth score and the weight coefficient are respectively expressed as a score function value vector and a weight vector, and the vector inner product method is used to calculate the comprehensive score corresponding to the tennis ball quality evaluation result, which is expressed as: ; in, is the comprehensive score corresponding to the tennis quality assessment results, is the scoring function value vector, is the weight vector, , , , , and are weight coefficients of each score, satisfying .

[0062] Further, such as Figure 3 As shown, the device also includes: A collecting module 237, configured to collect statistical data of a tennis match before calculating the tennis ball quality evaluation result based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient, wherein the statistical data includes sideline distance, baseline distance, deviation distance, straight line speed, rotation speed, rotation direction and first bounce height; The model estimation module 238 is used to construct a linear regression model based on the statistical data, and use the least squares method to estimate the weight coefficients corresponding to the first score, the second score, the third score, the fourth score, the fifth score and the sixth score respectively.

[0063] Further, such as Figure 3 As shown, the model estimation module 238 includes: The linear regression model is expressed as: ; in, is the independent variable, which includes the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height. is the dependent variable, which is any one of the following: scoring rate, quality of the return ball by the receiving side, serve accuracy, serve speed, serve success rate, and serve failure rate. is the intercept term, is the error term.

[0064] Further, such as Figure 3 As shown, the generating unit 24 includes: An acquisition module 241 is used to acquire usage requirements of the report, wherein the usage requirements include adjudication assistance requirements and technical guidance requirements; A first generating module 242 is configured to generate, if the adjudication assistance requirement is met, first report focus information on the accuracy of the tennis ball landing point and whether the tennis ball violates the rules based on the tennis ball quality evaluation result, and generate the quality evaluation report according to the first report focus information; The second generating module 243 is used for generating the second report focus information of the technical parameter analysis and technical improvement suggestions based on the tennis ball quality evaluation result if it is the technical guidance demand, and generating the quality evaluation report according to the second report focus information.

[0065] Furthermore, an embodiment of the present application further provides a storage medium, wherein the storage medium is used to store a computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the above Figure 1 The quality evaluation method based on placement in a tennis match described in .

[0066] Furthermore, the embodiment of the present application also provides a processor, the processor is used to run a program, wherein the program executes the above Figure 1 The quality evaluation method based on placement in a tennis match described in .

[0067] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0068] It is understandable that the related features in the above methods and devices can be referenced to each other. In addition, the "first", "second" and the like in the above embodiments are used to distinguish the embodiments, but do not represent the advantages and disadvantages of the embodiments.

[0069] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0070] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the application is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the description of the specific language above is for the purpose of disclosing the best mode of implementation of the application.

[0071] In addition, the memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0072] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0073] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0074] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0075] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0076] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0077] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0078] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0079] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0080] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0081] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A quality evaluation method based on placement in a tennis match, characterized in that: The method comprises: Collecting multimodal trajectory data of a tennis ball landing process, wherein the multimodal trajectory data includes an actual landing point of the tennis ball when it lands, a linear speed of the tennis ball when it lands, a rotation speed of the tennis ball when it lands, an angle of rotation direction of the tennis ball when it lands, and a first bounce height of the tennis ball after it lands; Calculating the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, as well as the deviation distance from the expected landing point preset in the effective area; The sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction angle and the first bounce height are processed by using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result; A quality evaluation report corresponding to the tennis ball landing point is generated based on the tennis ball quality evaluation result.

2. The method according to claim 1, characterized in that: Calculating the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, and calculating the straight-line distance to a preset target position in the effective area, including: The horizontal distance between the actual landing point and the nearest edge in the effective area is taken as the edge distance, which is expressed as: ； in, is the edge distance, is the horizontal coordinate of the actual landing point, and are the horizontal coordinates of the left and right sidelines respectively; The vertical distance between the actual landing point and the bottom line in the effective area is taken as the bottom line distance, which is expressed as: ； in, is the baseline distance, The ordinate of the actual landing point, are the ordinates of the bottom line respectively; The Euclidean distance between the actual landing point position and the expected landing point position is taken as the deviation distance, which is expressed as: ； in, is the deviation distance, ( ) is the coordinate of the actual landing point, ( ) are the coordinates of the expected landing point.

3. The method according to claim 1, characterized in that: The sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height are processed using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result, including: The sideline distance and the bottom line distance are evaluated and processed respectively using a piecewise function to obtain a first score and a second score, which are respectively expressed as: ; in, It is the first rating. is the maximum edge distance, is the minimum edge distance; ; in, The second rating is is the maximum baseline distance, is the minimum baseline distance; The deviation distance is evaluated using a nonlinear function to obtain a third score, which is expressed as: ； in, The third rating. is the deviation distance, is the maximum deviation distance; The linear speed is evaluated using the peak function to obtain a fourth score, which is expressed as: ; in, The fourth rating. is the linear velocity of the tennis ball when it hits the ground. The ideal speed for a tennis ball to hit the ground. is the standard deviation, which is used to control the peak width; The rotation speed and the rotation direction are evaluated using trigonometric functions to obtain a fifth score, which is expressed as: ; in, The fifth rating. is the rotation speed, is the ideal rotation speed, is the angle of rotation direction, ; The first bounce height is evaluated using a threshold function to obtain a sixth score, which is expressed as: ; in, The sixth rating. It is the height of the first bounce of a tennis ball after it hits the ground. is the first bounce height threshold; The tennis ball quality evaluation result is calculated based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient.

4. The method according to claim 3, characterized in that Calculating the tennis ball quality evaluation result based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient includes: The first score, the second score, the third score, the fourth score, the fifth score, the sixth score and the weight coefficient are respectively expressed as a score function value vector and a weight vector, and the vector inner product method is used to calculate the comprehensive score corresponding to the tennis ball quality evaluation result, which is expressed as: ； in, is the comprehensive score corresponding to the tennis quality assessment results, is the scoring function value vector, is the weight vector, , , , , and are weight coefficients of each score, satisfying .

5. The method according to claim 3, characterized in that: Before calculating the tennis ball quality evaluation result based on the first score, the second score, the third score, the fourth score, the fifth score, the sixth score and a preset weight coefficient, the method further includes: collecting statistics of tennis matches, the statistics including sideline distance, baseline distance, deviation distance, straight line speed, spin speed, spin direction, and first bounce height; A linear regression model is constructed based on the statistical data, and the weight coefficients corresponding to the first score, the second score, the third score, the fourth score, the fifth score and the sixth score are estimated using the least squares method.

6. The method according to claim 5, characterized in that A linear regression model is constructed based on the statistical data, and a weight coefficient corresponding to each of the first score, the second score, the third score, the fourth score, the fifth score, and the sixth score is estimated using the least squares method, including: The linear regression model is expressed as: ; in, is the independent variable, which includes the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction and the first bounce height. is the dependent variable, which is any one of the following: scoring rate, quality of the return ball by the receiving side, serve accuracy, serve speed, serve success rate, and serve failure rate. is the intercept term, is the error term.

7. The method according to claim 1, characterized in that Generating a quality evaluation report corresponding to the tennis ball landing point based on the tennis ball quality evaluation result, including: Obtaining the use requirements of the report, including adjudication assistance requirements and technical guidance requirements; If it is the adjudication assistance requirement, generating a first report focusing on the accuracy of the tennis ball landing point and whether the tennis ball violates the rules based on the tennis ball quality assessment result, and generating the quality evaluation report based on the first report focusing on the information; If it is the technical guidance requirement, a second report focusing on technical parameter analysis and technical improvement suggestions is generated based on the tennis ball quality assessment result, and the quality evaluation report is generated based on the second report focusing on the information.

8. A quality evaluation device based on placement in a tennis match, characterized in that: The device comprises: A collection unit, used to collect multimodal trajectory data of a tennis ball during its landing process, wherein the multimodal trajectory data includes an actual landing point of the tennis ball when it lands, a linear speed of the tennis ball when it lands, a rotation speed of the tennis ball when it lands, a rotation direction of the tennis ball when it lands, and a first bounce height of the tennis ball after it lands; A calculation unit, used to calculate the distance between the actual landing point and the sideline and bottom line of the effective area corresponding to the landing of the tennis ball, and the deviation distance from the expected landing point preset in the effective area; a processing unit, configured to process the sideline distance, the bottom line distance, the deviation distance, the straight line speed, the rotation speed, the rotation direction, and the first bounce height using a preset comprehensive scoring function to obtain a tennis ball quality evaluation result; A generating unit is used to generate a quality evaluation report corresponding to the tennis ball landing point based on the tennis ball quality evaluation result.

9. A storage medium, characterized in that: The storage medium includes a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute the quality evaluation method based on placement in a tennis match as described in any one of claims 1 to 7.

10. A processor, characterized in that: The processor is used to run a program, wherein the program, when running, executes the quality evaluation method based on placement in a tennis match as described in any one of claims 1 to 7.

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