CN112969142A

CN112969142A - Method and system for obtaining fastening and killing ball of badminton player

Info

Publication number: CN112969142A
Application number: CN202110159890.0A
Authority: CN
Inventors: 谷周亮; 李升�; 刘强
Original assignee: Beijing Shenlan Changsheng Technology Co ltd
Current assignee: Beijing Shenlan Changsheng Technology Co ltd
Priority date: 2021-02-05
Filing date: 2021-02-05
Publication date: 2021-06-15
Anticipated expiration: 2041-02-05
Also published as: CN112969142B

Abstract

The invention relates to a method and a system for obtaining a killed ball of a badminton player, wherein the method is realized based on a Bluetooth AoA real-time positioning system, and comprises the following steps: s0, recording the height of the athlete; s1, the Bluetooth base station receives the broadcast signal of the Bluetooth positioning label at a first frequency; s2, analyzing the position of the Bluetooth positioning label; s3, calculating the position difference between the badminton body and the player according to the positions, and executing S4 if the position difference is smaller than a first threshold value; s4, calculating the motion direction of the badminton body corresponding to the X axis according to the position of the badminton body, and executing the step S5 if the height difference between the position of the badminton body and the height of the athlete at the first moment is a second threshold value, and the motion direction of the badminton body corresponding to the X axis is changed and faces the opposite field at the second moment; and S5, if the increment of the position of the player in the Z axis between the first time and the second time is larger than a third threshold value, judging that the player kills the ball.

Description

Method and system for obtaining fastening and killing ball of badminton player

Technical Field

The invention relates to the field of badminton, in particular to a method and a system for obtaining a killing ball of a badminton player.

Background

Shuttlecocks are small-sized indoor sports items made of soft wood and feathers hit with a long-handled tennis racket, with a net interposed therebetween. Badminton is played on a rectangular field, the middle of the field is separated by a net, and the two parties use various technical skills of serving, batting, moving and the like to carry out the counterbatting of the ball on the net, so that the ball is not fallen into the effective area of the badminton or the batting of the other party is made to be wrong.

In the training process of badminton players, each movement moment or posture of each badminton player contains a large amount of training information, particularly a killing ball, and the badminton players can adjust each action according to the training information, so that the badminton players can better accord with the training targets, and the winning rate of the badminton players can be greatly improved. Most of the traditional training information for obtaining badminton players is that all image information of the badminton players is recorded at all times simply through a high-speed camera, and then each posture information is analyzed by personnel, so that a large amount of manpower and material resources are consumed in the process, and manual errors exist in judgment.

The invention aims to design a method and a system for obtaining a killed ball of a badminton player aiming at the problems in the prior art.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method and a system for obtaining a killed ball of a badminton player, which can effectively solve the problems in the prior art.

The technical scheme of the invention is as follows:

a method for obtaining a killed ball of a badminton player is characterized by comprising the following steps: the method is realized based on a Bluetooth AoA real-time positioning system, the Bluetooth AoA real-time positioning system comprises a plurality of Bluetooth positioning tags, a plurality of Bluetooth base stations and a positioning server, the Bluetooth positioning tags are respectively arranged on a badminton body and a sportsman body, the Bluetooth base stations are arranged on the periphery of a badminton court, each Bluetooth base station comprises a Bluetooth antenna array, and the method comprises the following steps:

s0, establishing an X axis by the long side of the badminton court, establishing a Z axis by the long side perpendicular to the ground, and recording the height of the athlete;

s1, the Bluetooth base station receives the broadcast signal of the Bluetooth positioning label at a first frequency;

s2, the positioning server analyzes the positions of the Bluetooth positioning tags through the broadcast signals, wherein the positions comprise badminton body positions and player positions;

s3, calculating the position difference between the badminton body and the player according to the positions, and executing S4 if the position difference is smaller than a first threshold value;

s4, calculating the motion direction of the badminton body corresponding to the X axis according to the position of the badminton body, and executing the step S5 if the height difference between the position of the badminton body and the height of the athlete at the first moment is a second threshold value, and the motion direction of the badminton body corresponding to the X axis is changed and faces the opposite field at the second moment;

and S5, if the increment of the position of the player in the Z axis between the first time and the second time is larger than a third threshold value, judging that the player kills the ball.

Further, the difference between the first time and the second time is 0.003-0.007 s.

Further, the change of the motion direction of the badminton body corresponding to the X axis is specifically as follows:

and defining the motion direction of the first moment as a first direction and the motion direction of the second moment as a second direction, wherein if the first direction is opposite to the second direction, the motion direction of the ball body of the badminton corresponding to the X axis occurs.

Further, the second threshold value is 80-100 cm.

Further, the first threshold value is 80-120 cm.

Further, the third threshold value is 15-25 cm.

Further, the first frequency is 150Hz-250 Hz.

Further, in step S2, the step of analyzing, by the bluetooth base station through the broadcast signal, the location information of the bluetooth positioning tag includes: and the Bluetooth base station calculates the position of the Bluetooth positioning label through an AoA angle position algorithm by acquiring the broadcast signal of the Bluetooth positioning label and extracting to obtain the broadcast signal intensity of the Bluetooth positioning label.

Further provided is a system for acquiring a killed ball of a badminton player, which is used for realizing the method, and comprises the following steps:

the Bluetooth AoA real-time positioning system comprises a plurality of Bluetooth positioning tags and a plurality of Bluetooth base stations, wherein the Bluetooth positioning tags are respectively arranged on a badminton body and a body of a player, and the Bluetooth base stations are arranged on the periphery of a badminton court;

the position calculation module is used for acquiring the broadcast signal through the Bluetooth base station and analyzing the position of the Bluetooth positioning tag;

the position difference calculating module is used for calculating the position difference between the badminton body and the athlete according to the position;

the direction judging module is used for calculating the motion direction of the badminton body according to the position of the badminton body;

the height difference calculating module is used for calculating the height difference between the badminton body position and the height of the athlete;

and the athlete jumping calculation module is used for calculating the variation of the position of the athlete on the Z axis.

Accordingly, the present invention provides the following effects and/or advantages:

the invention relates to a real-time positioning technology based on Bluetooth AoA arrival angle, which is characterized in that a Bluetooth base station is arranged around a badminton court, a Bluetooth label is placed in a badminton ball, a Bluetooth positioning label is placed on a player body and used for positioning the position of the player and the position of the badminton ball, and the movement direction and the movement speed of the badminton ball are calculated according to the change of the position of the badminton ball along with time. According to the method, the condition that the position difference between the badminton body and the athlete is smaller than the first threshold, the height difference between the badminton body and the athlete is larger than the second threshold, the movement direction of the badminton is changed, and the take-off of the athlete is larger than the third threshold is simultaneously generated between the first moment and the second moment, so that the athlete is judged to take the action of killing the badminton, the moment of killing the badminton and the position information of the killing ball can be accurately obtained, and an accurate time point is provided for the follow-up output of the position information or the image information of the athlete before and after the killing of the badminton.

According to the invention, the real-time positions of the players and the badminton are obtained through reasonable acquisition of the data of the Bluetooth positioning tags, and the distance between the badminton and the players is calculated. Since the speed of the shuttlecock is fast, the distance can be more specifically analyzed to determine whether the shuttlecock is close to the player, so that S4 is performed immediately after the shuttlecock and the player are close to each other, and a starting point of calculation is provided for the speed and direction change of the shuttlecock when the shuttlecock is received.

According to the invention, the physical significance corresponding to each moment is judged by acquiring the information of a plurality of moments, calculating the difference value between the moments and judging whether the difference value between the moments is smaller than the corresponding threshold value, wherein the physical significance comprises the ball catching moment of the athlete, so that a time basis is provided for acquiring the position of the athlete, and the position and the moment of the ball catching and killing of the athlete can be accurately acquired.

According to the invention, the position of the Bluetooth positioning tag is calculated through the AoA angular position algorithm, the precision can be accurate to within 10cm, compared with the traditional method of shooting through a high-speed camera and manually analyzing, the precision is higher, and manual analysis is not needed.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Drawings

Fig. 1 is a schematic diagram of the positions of bluetooth positioning tags.

Fig. 2 is a schematic location diagram of a bluetooth base station.

Fig. 3 is a schematic flow chart of calculating the tag position using AoA.

Fig. 4 is a schematic diagram of AoA arrival angle.

Fig. 5 is a schematic diagram of the AoA angle of arrival algorithm.

FIG. 6 is a model diagram of AOA to calculate the angle of arrival.

FIG. 7 is a model diagram of AOA calculation of azimuth.

Fig. 8 is a position difference diagram between the badminton body and the player.

FIG. 9 is a schematic view of the shuttlecock playing at a first moment.

FIG. 10 is a schematic view of the shuttlecock playing at a second moment in time.

Fig. 11 is a schematic structural diagram of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

To facilitate understanding of those skilled in the art, the structure of the present invention will now be described in further detail by way of examples in conjunction with the accompanying drawings:

the utility model provides a method for obtaining badminton player's knot and kill ball, the method is realized based on bluetooth AoA real-time positioning system, bluetooth AoA real-time positioning system contains a plurality of bluetooth location label and a plurality of bluetooth basic station and positioning server, bluetooth location label 1 sets up respectively on the badminton body and on the sportsman's health, specifically, refer to figure 1, bluetooth location label 1 sets up respectively in the center of sphere department of badminton body and the collar department of sportsman's jacket in this embodiment, refer to figure 2, bluetooth basic station sets up in the periphery in badminton court, every bluetooth basic station includes bluetooth antenna array, and positioning server is used for providing the computing power.

The process of calculating the tag location by bluetooth AoA is described in detail below with reference to fig. 3.

Referring to fig. 4-5, in the present embodiment, the bluetooth positioning tag refers to a bluetooth peripheral device having a broadcast protocol, and is installed at two positions, namely, the center of the tennis ball and the collar of the player's coat, while the bluetooth tag will continuously and periodically broadcast to its surroundings, and it will not be connected by other devices. The broadcast signal sent by the Bluetooth positioning tag comprises a direction finding data packet, wherein the direction finding data packet comprises information such as the ID of the current tag, the ID of a logic clock synchronization unit where the current tag is located and the like. The Bluetooth base station comprises a Bluetooth antenna array, and after the system is started, logic clocks are synchronized between all the Bluetooth base stations and the Bluetooth positioning tags. The Bluetooth base station can calculate the positioning data of the Bluetooth label in real time by acquiring parameters such as signal intensity, arrival angle and the like of the Bluetooth label in real time and the positioning server. Specifically, in this embodiment, the position of the bluetooth positioning tag is obtained at a frequency of 50-200Hz, and the higher the frequency is, the more abundant the position data of the bluetooth positioning tag is obtained, so as to provide smoother data for the subsequent steps, which is not limited herein.

In the embodiment, a bluetooth 5.1 standard specification version is applied to include a direction finding function, and the function is used for positioning by receiving a broadcast signal of a bluetooth tag through a base station. The Direction Finding function (page 281 of the Bluetooth core specification document) includes two Direction measurement techniques, namely Angle of Arrival (AoA) and Angle of Departure (AoD). The system uses the AoA arrival angle technology to realize the positioning of each sub-model in the motion field model. The calculation formula for calculating the arrival angle is as follows: θ ═ arccos ((ψ λ)/(2 π d)), where d is the distance between the antennas, λ electromagnetic wave wavelength, and ψ is the phase difference when the electromagnetic wave passes through the two antennas. The more evenly calculated positions distributed around the field by the bluetooth base station are more accurate. In this embodiment, when the bluetooth base station receives the broadcast signal of the bluetooth positioning tag, the signal strength can be calculated through the RSSI value, and the signal strength reflects the distance between the tag and the base station, and the smaller the RSSI value, the farther the distance. The bluetooth base station sends the specified tag ID, the specified logical clock synchronization unit ID, and other ancillary information (e.g., signal strength value) to the location server. The specific algorithm is described in the bluetooth 5.1 standard specification version and is not specifically set forth herein.

Specifically, the broadcast signal is uniformly spread to the x, y and z three-dimensional space by taking the label as the sphere center. For noise generated by reflection of a broadcast signal indoors, a bluetooth base station receives a plurality of signals having the same tag ID and sync unit ID but different RSSI (received signal strength) values. The denoising scheme of the base station is as follows: and keeping the signal with the maximum RSSI value and discarding other signals.

Referring to fig. 6, the bluetooth base station disposed in the planar array calculates the arrival angle of the broadcast signal by using a multiple signal classification algorithm (MUSIC) according to the received broadcast signal, and referring to fig. 7, the base station based on the two-bit planar antenna array can calculate the azimuth angle and the pitch angle of the signal. The two angles, azimuth and elevation, define a line starting at the base station, on which the tape location tag is located.

When the base station receives the broadcast signal, the base station close to the tag is preferably selected according to the RSSI (received signal strength) value of the signal to calculate the azimuth angle and the elevation angle. Specifically, this embodiment further adopts any one of the following two schemes:

the first scheme is as follows: and the Bluetooth base station automatically discards the signals smaller than the RSSI threshold according to the preset RSSI threshold. According to the scheme, the calculation resources can be saved, but a proper threshold value needs to be set according to the scene on the spot, and at least three Bluetooth base stations are guaranteed to participate in calculating the azimuth angle and the pitch angle of each positioning signal.

Scheme II: the Bluetooth base station calculates all received broadcast signals, calculates an azimuth angle and a pitch angle, and transmits the content, two angle values and the RSSI value of the signals in the payload field of the broadcast signals to the positioning server. And the server selects the first 30% of elements to participate in the calculation of the subsequent xyz coordinate according to the sequence of the RSSI values from large to small, and discards the rest elements.

And finally, the positioning server receives the screened data transmitted by the base stations, and calculates the xyz coordinate values of the tags in the competition field model according to the coordinate values of each base station in the competition field model coordinate system and the azimuth angle and the pitch angle of the tags. The positioning server comprehensively considers the results output by two or more base stations, and more accurate coordinate values can be obtained by using algorithms such as weighted average and the like.

Referring to fig. 11, the method comprises the steps of:

s0, referring to the figure 2, establishing an X axis by the long edge of the badminton court, establishing a Z axis by the long edge of the badminton court perpendicular to the ground, and recording the height of the athlete;

s1, the Bluetooth base station receives the broadcast signal of the Bluetooth positioning label at a first frequency; further, the first frequency is 150Hz-250 Hz; in this embodiment, the first frequency is 200Hz, and in other embodiments, the first frequency may be any one of frequencies from 150Hz to 250Hz, and the higher the frequency is, the more accurate the obtained real-time positioning information is, and the specific value of the first frequency is not limited herein.

s3, referring to fig. 8, calculating a position difference D between the badminton body and the player from the position, and if the position difference D is smaller than a first threshold, performing S4; further, the first threshold is 80-120cm, specifically 100cm in this embodiment, and may also be 80cm or 120cm in other embodiments, which is not limited herein. Because the flight speed of the badminton is high, the distance can be analyzed more specifically to determine whether the badminton is close to the athlete, so that S4 is executed immediately after the badminton and the athlete are close to each other, and a calculated starting point is provided for the change of the ball speed and the direction of the badminton; in addition, in the embodiment, only the X axis and the Z axis are established, and the position difference between the badminton body and the athlete is also corresponding to the difference of the numerical values of the X axis;

further, the difference between the first time and the second time is 0.003-0.007 s. In this embodiment, the difference between the first time and the second time is 0.005s, and may be 0.003s or 0.007s in other embodiments.

Further, in step S4, the change of the movement direction of the sphere of the badminton corresponding to the X axis is specifically:

and defining the motion direction of the first moment as a first direction and the motion direction of the second moment as a second direction, wherein if the first direction is opposite to the second direction, the motion direction of the ball body of the badminton corresponding to the X axis occurs. The following are exemplified: according to the ball speed, the motion direction of the badminton body is towards the positive direction of the X axis or the negative direction of the X axis, and the motion direction of the badminton body corresponding to the X axis is changed, for example: referring to fig. 9-10, defining the first time as 9s, the first direction as the positive direction toward the X axis, and the second time as 9.005s, where the second direction is the negative direction toward the X axis, and the first direction is opposite to the second direction and the time difference between the first time and the second time is within 0.005s, it is determined that the motion direction of the badminton corresponding to the X axis changes.

The difference between the badminton body position and the height of the player's height at the first moment is illustrated as a second threshold. Because the height and the distance between the position of the badminton and the position of the athlete are different, the athlete can make different postures corresponding to the position of the badminton. Only when there is certain difference in the difference in height between badminton height and the sportsman's height, refer to fig. 9, the sportsman just can make the gesture of withholding the ball, and this condition is grabbed accurately to this embodiment, prevents to hang the ball, the condition mistake such as cut the ball is judged as withholding the ball. Further, the second threshold is 80-100cm, that is, the height difference between the height of the shuttlecock and the height of the player must be greater than or equal to 80cm, and the method will execute step S5 to prevent misjudgment.

And S5, if the increment of the position of the player in the Z axis between the first time and the second time is larger than a third threshold value, judging that the player kills the ball. Further, the third threshold value is 15-25 cm. In this embodiment, the third threshold is 20cm, but may be 15cm or 25cm in other embodiments.

Next, for example, between the first time and the second time, the increment of the position of the player in the Z axis is greater than the third threshold, and in the process of killing the ball, the player needs to increase the hitting point, so that the player jumps upward by a certain distance, and a corresponding increment also occurs in the Z axis information corresponding to the position information of the bluetooth positioning tag on the player, in this embodiment, if the increment of the Z axis corresponding to the position of the player is greater than 20cm, it may be determined that the player jumps upward and prepares to perform a ball killing action. Meanwhile, in the embodiment, the badminton body and the athlete can be judged to take the action of killing the badminton only under the four conditions that the position difference H between the badminton body and the athlete is less than 100cm, the height difference D between the badminton body and the athlete is greater than 80cm, the movement direction of the badminton is changed, and the take-off of the athlete is greater than 20cm, so that the accuracy is greatly improved.

Further, in step S2, the step of the positioning server analyzing the position information of the bluetooth positioning tag through the broadcast signal specifically includes: and the Bluetooth base station calculates the position of the Bluetooth positioning label through an AoA angle position algorithm by acquiring the broadcast signal of the Bluetooth positioning label and extracting to obtain the broadcast signal intensity of the Bluetooth positioning label.

Example two

A system for obtaining a kill ball of a badminton player, for implementing the method, comprising:

The working principle of the present embodiment is substantially the same as that of the first embodiment, and will not be described here.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

Claims

1. A method for obtaining a killed ball of a badminton player is characterized by comprising the following steps: the method is realized based on a Bluetooth AoA real-time positioning system, the Bluetooth AoA real-time positioning system comprises a plurality of Bluetooth positioning tags, a plurality of Bluetooth base stations and a positioning server, the Bluetooth positioning tags are respectively arranged on a badminton body and a sportsman body, the Bluetooth base stations are arranged on the periphery of a badminton court, each Bluetooth base station comprises a Bluetooth antenna array, and the method comprises the following steps:

2. The method of claim 1 for obtaining a kill ball for a badminton player, wherein: the difference between the first time and the second time is 0.003-0.007 s.

3. The method of claim 2, wherein the method comprises the steps of: in step S4, the change of the movement direction of the badminton body of the badminton corresponding to the X axis is specifically:

4. The method of claim 1, wherein the method comprises the steps of: the second threshold value is 80-100 cm.

5. The method of claim 1 for obtaining a kill ball for a badminton player, wherein: the first threshold value is 80-120 cm.

6. The method of claim 1 for obtaining a kill ball for a badminton player, wherein: the third threshold value is 15-25 cm.

7. The method of claim 1 for obtaining a kill ball for a badminton player, wherein: the first frequency is 150Hz-250 Hz.

8. The method of claim 1 for obtaining a kill ball for a badminton player, wherein: in step S2, the step of analyzing, by the bluetooth base station, the position information of the bluetooth positioning tag through the broadcast signal includes: and the Bluetooth base station calculates the position of the Bluetooth positioning label through an AoA angle position algorithm by acquiring the broadcast signal of the Bluetooth positioning label and extracting to obtain the broadcast signal intensity of the Bluetooth positioning label.

9. A system for obtaining a pinkill of a shuttlecock player for carrying out the method of any of claims 1 to 8, wherein: comprises the following steps: