TW202314285A - Method for calculating ball trajectory using radar sensing data of ball and radar sensing device using the same - Google Patents

Abstract

The present invention relates to a radar sensing device for sensing a ball that has been hit and is moving, and the purpose of the present invention is to provide a ball trajectory calculation method using sensed radar data relating to a hit ball, and a radar sensing device using same, the method enabling a robust ball movement trajectory calculation despite radar signal distortion or phase jitter caused by interference between a person and a club or curvature on the surface of the ball. To this end, a ball trajectory calculation method of a radar sensing device for a hit ball, according to an embodiment of the present invention, comprises the steps of: collecting sensed radar data; and determining the validity of a trajectory by using the sensed radar data collected during a period preset as an initial movement period of the ball, and calculating a ball movement trajectory using a physics engine, on the basis of the result of the determination.

Description

Ball trajectory calculation method using radar sensing data of hit ball and radar sensing device using same

The present invention belongs to a radar sensing device which utilizes the Doppler effect (Doppler Effect) of the radar signal to analyze the signal reflected from the moving ball, and calculates the motion parameters of the ball from it, and uses the device to use the radar which is hit by the ball Invention of the method of calculating ball trajectory from sensing data.

In the case of ball sporting events, especially golf, attempts have been made to accurately sense the physical properties of the ball being struck by the golfer and use the sensed values for play analysis or to Realized as images for application in the field of analog golf such as so-called screen golf.

In particular, since the spin of a ball that is hit and flies away rotates at a very high speed around an axis in three-dimensional space, it is difficult to measure it with conventional camera sensors. We are actively conducting research and development on radar sensors that utilize the Doppler effect of signals as equipment that can more accurately calculate the rotation of a moving ball.

Conventional radar sensors, for example, the rotation calculation technology disclosed in Korean Patent Laid-Open No. 10-0947898 etc. propose a method of receiving a signal reflected from a rotating ball in flight and analyzing the frequency and the frequency from the received signal. A method of calculating spin etc. corresponding to the motion of the ball.

Although the specific frequency analysis methods themselves are different from the technologies disclosed in multiple prior art documents such as Japanese Authorized Patent Publication No. 6048120, Korean Laid-Open Patent Publication No. 2016-0054013, and Korean Laid-Open Patent Publication No. 2015-0139494, But also basically rely on the analysis of the signal itself and directly calculate the motion characteristic information of the ball therefrom.

Thus, in the conventional radar sensing system of the golf ball monitor type, the Doppler effect of the radar signal is used to analyze the signal reflected from the ball to provide information on the speed, trajectory, direction, and rotation of the ball or information on the club ( angle of attack, dynamic loft, club passing, etc.) and ball flight trajectory, etc.

However, radar signals can be subject to noise caused by frequency interference from environmental noise, interference from people and clubs, and buckling of the ball surface. In this way, noise caused by the interference of people and the club or the buckling of the ball surface will cause distortion and phase jitter of the radar signal, and such signal distortion will have a bad influence on the calculation of the trajectory of the ball, etc., and there will be a reduction in radar sensing. device performance issues.

In order to solve such a problem, the present applicant has proposed a method of calculating an accurate ball moving trajectory in a radar sensing device through Korean Granted Patent No. 10-1931592.

That is, Korean Patent No. 10-1931592 discloses a method of calculating ball position data using radar signals, and using it to calculate the initial trajectory of the ball, and using the initial trajectory to calculate the trend data of the overall ball trajectory, to use the trend data A method for calculating the overall ball trajectory with ball position data.

However, since the radar signal reflected from the moving ball is most disturbed by people and golf clubs in the predetermined distance interval at the beginning of the ball's movement, problems such as signal distortion and phase jitter occur the most, so there is a problem with the initial movement of the ball. An issue where the accuracy of the overall ball trajectory is significantly reduced when the trajectory is calculated incorrectly.

Existing patent documents: Korean Patent No. 10-1931592; Japanese Patent No. 5824857; Korean Patent Publication No. 2018-0047142; Korean Laid-Open Patent Publication No. 2019-0085152.

technical problem The present invention aims to provide a radar sensing device capable of calculating distortion and phase jitter of a radar signal caused by disturbance to a person and a club or buckling of a ball surface, etc. A ball trajectory calculation method using radar sensing data of a batted ball moving trajectory and a radar sensing device using the same.

Technical solutions A ball trajectory calculation method of a radar sensing device for a hit ball according to an embodiment of the present invention includes: transmitting a radar signal and receiving reflected waves from a hit ball to collect radar sensing about the movement of the ball The step of data; the step of calculating initial motion characteristic information using the radar sensing data in the interval preset as the initial motion interval of the ball; the step of judging the validity of the trajectory corresponding to the initial motion characteristic information; and after judging the Ballistic validity, when valid, calculate the trajectory of the ball through the physics engine based on the initial motion characteristic information; when invalid, use the radar sensing data of the predetermined interval after the initial motion interval of the ball to calculate the trajectory of the ball through the physics engine A step of.

In addition, preferably, the step of calculating the initial motion characteristic information includes: calculating from the radar sensing data within the initial motion interval of the ball, which is a preset distance interval from the initial position of the ball when the ball is hit. Steps for ball speed, trajectory and direction information.

In addition, preferably, the step of judging the validity of the ballistic trajectory includes: analyzing the radar sensing data within the initial movement interval of the ball, which is a preset distance interval from the initial position of the ball when the ball is hit. A step of judging the reliability of the initial motion characteristic information based on the level of the phase jitter.

In addition, preferably, the step of judging the validity of the ballistic trajectory includes: by analyzing the radar sensing data in the initial movement interval of the ball as the preset distance interval from the initial position of the ball when the ball is hit calculating a linear regression model by linear fitting, and judging the level of phase jitter from the linear regression model; and judging whether the trajectory of the ball calculated from the radar sensing data in the initial motion range of the ball is preset The step of low trajectory below the angle, the step of calculating the trajectory of the ball includes: when it is determined that the level of the phase jitter is below a preset reference and the trajectory of the ball is the low trajectory, based on the initial motion characteristic information through the Steps for the physics engine to calculate the trajectory of the ball.

In addition, preferably, the step of calculating the trajectory of the ball includes: removing noise and flattening the radar sensing data in the initial motion range of the ball; , the lower the level of the phase jitter, the higher the weight value is assigned to the step of calculating the weight value of the validity of the radar sensing data in the initial motion interval of the ball; and applying the calculated weight value to the initial motion characteristic information The weight value of the validity and the step of calculating the trajectory of the ball through the physics engine.

In addition, preferably, the step of calculating the trajectory of the ball when the judgment result of the ballistic validity is invalid includes: using a radar based on an interval set between the last position of the initial movement interval of the ball and the position of the highest point of the ball. The ball position coordinate information of the sensing data is used to calculate the ball moving track through the physics engine.

In addition, preferably, the step of calculating the trajectory of the ball when the judgment result of the ballistic validity is invalid includes: a step of calculating ball position coordinate information at predetermined time intervals based on the collected radar sensing data; from the calculated The ball position coordinate information determines the highest point position of the ball, and specifies the interval step corresponding to the height of the preset ratio relative to the highest point position of the ball; calculates the interval of the interval by using the ball position coordinate information in the specified interval the step of trajectory; and the step of calculating the trajectory of the ball through the physics engine based on the interval trajectory.

On the other hand, a radar sensing device for sensing a hit ball according to an embodiment of the present invention includes: a signal transmitting unit that transmits a radar signal; a signal receiving unit that receives a signal directed to the signal transmitting unit from a moving A reflected wave signal reflected by the ball; a signal analysis unit that analyzes the received reflected wave signal to calculate radar sensing data about the movement of the ball; and an information calculation unit that uses Calculate the initial motion characteristic information from the radar sensing data in the interval, and judge the validity of the trajectory corresponding to the initial motion characteristic information. When valid, calculate the trajectory of the ball through the physics engine based on the initial motion characteristic information. When invalid, The trajectory of the ball is calculated by using the radar sensing data of a predetermined interval after the initial motion interval of the ball through the physics engine.

The effect of the invention The ball trajectory calculation method using the radar sensing data of the hit ball and the radar sensing device using the same of the present invention have the following effects: even if the radar signal is distorted by interference between a person and the club or buckling of the ball surface, etc. And phase jitter, etc., can also be used to calculate the accurate trajectory of the ball being hit and moved by judging the ballistic validity of the radar sensing data of the initial motion of the ball, and using an effective trajectory calculation method based on the validity result.

The specific content of the ball trajectory calculation method using the radar sensing data of the hit ball and the radar sensing device using the same will be described below with reference to the accompanying drawings.

First, the structure of a radar sensing device according to an embodiment of the present invention and the functions of each constituent element will be described with reference to FIG. 1 . Fig. 1(a) is a block diagram showing the structure of a radar sensing device according to an embodiment of the present invention, and Fig. 1(b) is a block diagram showing a radar sensing device according to an embodiment of the present invention A diagram of the structure of the signal receiving unit of the device.

A radar sensing device according to an embodiment of the present invention is a device that basically uses the Doppler Effect of radar (Radar) to calculate various information about the movement characteristics of a ball hit by a golf club, such as As shown in (a) of FIG. 1 , it may include a signal sending unit 110 , a signal receiving unit 120 , a signal analyzing unit 130 and an information calculating unit 140 .

The radar sensing device according to an embodiment of the present invention may be set on or near the ground at a predetermined distance behind the position of the ball to be hit by the user, and may be configured to move toward the ball to be hit at the set position. The direction of the ball's movement sends a radar signal of a specific frequency, and tracks the ball being hit while moving while receiving and analyzing the reflected waves reflected from the ball.

The signal transmitting unit 110 is configured to transmit a specific radar (Radar) signal in a targeted direction, and, although not shown in the drawing, may include a transmitting antenna for transmitting the radar signal.

The signal receiving part 120 is configured to receive the reflected wave signal returned by the radar signal sent by the signal sending part 110 after being reflected from the ball. Due to the Doppler effect, the frequency of the signal transmitted by the signal transmission unit 110 is changed for the reflected wave signal transmitted by the signal transmission unit 110 and reflected from the ball, thereby causing a Doppler shift. That is, the signal receiving unit 120 receives a Doppler shifted signal.

The signal receiving unit 120 is configured to have a plurality of receiving antennas for receiving the reflected wave signal, so that information such as the position, velocity, trajectory, and direction angle of the moving ball can be calculated by using the phase difference of the respective receiving signals of the plurality of receiving antennas. .

(b) of FIG. 1 schematically shows an example of the structure of the above-mentioned signal receiving unit 120. As shown in the figure, when the signal receiving unit 120 of FIG. Each receiving antenna RA1, RA2, and RA3 can receive the reflected wave signal received from the ball B, and can calculate the trajectory (altitude angle) and direction angle of the moving ball B using the phase difference of the signal between each receiving antenna, respectively.

For example, according to the configuration of the receiving antennas in the signal receiving unit 120 shown in (a) of FIG. 3 , the phase difference of the signals received by RA1 and RA2 can be used to calculate the trajectory of the moving ball B, and the trajectory of the moving ball B can be calculated using RA1 and RA2. The phase difference of the signals received by RA3 is used to calculate the direction angle of the moving ball B.

Then, the phase value information can be calculated by digitizing the phase information of the ball at predetermined time intervals of receiving the reflected wave signal using the phase difference of the signal between the receiving antennas as described above.

In addition, as the signal receiving unit 120 receives the reflected wave signal, the distance between the ball B and the signal receiving unit 120 can be easily calculated. Therefore, when the signal receiving unit 120 receives the reflected wave signal reflected from the ball B, The distance to the ball B, the trajectory angle of the ball B, and the direction angle information of the ball B can be known, and the position coordinate information of the ball B can be calculated by using the above information. When the position coordinate information of the ball B is calculated, it can also be used to calculate the speed of the ball.

As such, the signal analyzing part 130 may be configured to calculate phase value information by analyzing the radar signal reflected by the ball at every predetermined time interval when the ball moves, and calculate position coordinate information of the moving ball at predetermined time intervals.

That is, the signal analysis unit 130 may calculate radar sensing data about the movement of the ball by analyzing the reflected wave signal of the radar received as described above, the radar sensing data may be phase value information of the ball calculated at predetermined time intervals, It may also be position coordinate information of the ball calculated based on the phase value information.

In the state where the signal transmitting unit 110 is transmitting the radar transmission signal St, the user hits a ball with a golf club, the radar signal is reflected from the hit ball, and the reflected wave signal Sr is received by the signal receiving unit 120. In the received reflected wave signal, distortion and phase jitter of the radar signal due to interference of the user and the club, buckling of the ball surface, etc., occur seriously.

In particular, the distortion and phase jitter of the radar signal as described above appear more in the initial interval when the ball is hit and moves, as the phase value (vertical axis) of the ball calculated by receiving the radar signal is plotted by the distance (horizontal axis ) shown in (a) of Figure 2, it can be seen that the phase jitter occurs more seriously in the initial interval of several meters when the ball is hit and moved.

The information calculation unit 140 of the radar sensing device according to an embodiment of the present invention may be configured to calculate the initial movement by using the radar sensing data in the interval of the initial movement interval of the ball that is preset to be hit and moved. Characteristic information, judging the validity of the trajectory corresponding to the initial motion characteristic information. After judging the validity of the trajectory, if valid, calculate the trajectory of the ball through the physics engine based on the above initial motion characteristic information; when invalid, use the initial motion range of the ball After that, the radar sensing data of the predetermined interval is used to calculate the trajectory of the ball through the physics engine.

Here, the physics engine refers to a program configured to calculate motion trajectory and kinematics feature information based on the kinematics of the object for the motion of the object according to given conditions by analogy or the like.

The information calculation unit 140 of the radar sensing device according to an embodiment of the present invention can be equipped with the above-mentioned physical engine, and use the radar sensing data to calculate the kinematics through the physical engine based on the motion characteristic information in the initial motion interval of the ball. The movement trajectory of the whole ball, or the movement characteristic information of the ball in the interval after the initial movement interval of the ball is calculated in kinematics by the physics engine.

At this point, judge whether the radar sensing data in the initial motion interval of the ball is reliable data through phase jitter, etc. If the data is reliable, you can use the data in the initial motion interval of the ball to calculate the overall ball through the physics engine. Trajectory, when the data is not reliable, instead of the data in the initial motion interval of the ball, the data in the other interval can be used to calculate the overall ball trajectory through the physics engine, so that the phase that occurs at the initial stage of the ball's movement can be calculated Robust ball trajectory for images caused by shakes, etc.

Therefore, in the calculation of the ball trajectory through the radar sensing device in an embodiment of the present invention, based on the interval from when the ball starts to be hit to the preset distance, that is, the radar sensing data in the initial movement interval of the ball Whether the ballistic is effective or not is important.

(b) of FIG. 2 shows an example of ball position coordinate information shown by regressing ball position coordinates at predetermined time intervals calculated using radar signals received by a radar sensing device to a y-z plane according to an embodiment of the present invention, As shown in (b) of FIG. 2 , the information calculation unit of the radar sensing device can use the data corresponding to the initial motion interval Ti of the ball to calculate the initial motion characteristic information, and can use the initial motion characteristic information to calculate the initial motion interval of the ball. Ballistics in Ti.

When the ballistic trajectory in the initial motion interval Ti of the ball is reliable level data, it can be used to calculate the overall trajectory; when it is not reliable level, the overall trajectory can be calculated using other interval data.

Referring to FIG. 3 to FIG. 7 , a ball trajectory calculation method using radar sensing data of a hit ball according to an embodiment of the present invention will be described in detail below.

First, with reference to the flow chart shown in FIG. 3 , the overall process of the ball trajectory calculation method using the radar sensing data of the hit ball according to an embodiment of the present invention will be described.

Put the radar sensing device at a predetermined distance based on the user's hitting position, and make the ball to be hit in place, then the radar sensing device senses the position where the ball is placed, thus becoming the ball ready (meaning radar sensing The device is ready to sense the ball) (S110).

The signal transmitting unit of the radar sensing device may transmit the radar signal toward the ball, and the signal receiving unit may prepare for sensing when receiving a reflected wave signal of the transmitted radar signal ( S120 ).

When the ball is hit ( S130 ), the signal analyzing unit of the radar sensing device analyzes the signal received by the signal receiving unit to collect radar sensing data on the movement of the ball, such as phase value information of the ball ( S140 ).

The information calculation unit of the radar sensing device may calculate information about the movement characteristics of the ball in the interval, that is, initial movement characteristic information, using radar sensing data in a preset distance interval as the initial movement interval of the ball (S150) .

Then, the information calculation part can judge the "trajectory validity", and the "trajectory validity" judges whether the trajectory of the initial motion characteristic information is valid, that is, whether the radar sensing data in the initial motion interval of the ball is reliable data and how reliable the information is (S200).

After judging the validity of the ballistic ( S250 ), if valid, the information calculation unit may calculate the trajectory of the ball through the physics engine based on the initial motion characteristic information ( S270 ).

After judging the validity of the trajectory, when it is invalid, the information calculation part can use the ball's position coordinate information based on the radar sensing data of the interval set between the final position of the initial motion interval of the ball and the highest point of the ball through the physics engine to calculate Ball moving track (S300).

On the other hand, an example of a specific procedure for judging the ballistic validity in the above-mentioned step S200 will be described with reference to the flowchart shown in FIG. 4 .

The above ballistic validity confirms whether the radar sensing data in the initial motion interval of the ball shown in (a) of Figure 2 is valid, that is, whether the overall ball trajectory can be calculated accurately based on the data in the corresponding interval. sexual reliability.

Firstly, the reflected wave signal of the radar signal in the initial movement interval of the ball may be analyzed, and the phase value information of the ball in the interval is calculated as shown in (a) of FIG. 2 ( S210 ).

The information calculation part of the radar sensing device may analyze the level of the phase jitter from the phase value information in the initial interval as shown in (a) of FIG. 2 ( S220 ).

When the ball actually draws a trajectory and moves, according to the actual trajectory, the ball position connecting each time interval will appear in the form of a smooth curve, but in the case of a radar signal, due to the influence of the surrounding environment, the signal may include Quite a lot of noise, especially, in the initial motion interval of the ball, due to the interference of the user and the golf club, for the radar signal, the phase will shake severely, thus, as shown in (a) or (b) of Figure 2 , the phase values of the ball may appear very irregular.

Therefore, in the above-mentioned step S220, the information calculation part judges how seriously the distortion of the radar signal occurs due to the external disturbance by analyzing the shaking level indicating the degree of the ball shaking in the initial movement interval of the ball.

The level of phase jitter can be distinguished by stage, for example, after analyzing the distribution of the phase value of the sphere, the case of no jitter, the general case, the severe case, etc. The level of phase jitter can be divided into 3 or 4 stages, or can be divided into more stages. The flow chart shown in FIG. 4 shows the situation that the level of phase jitter is divided into 3 stages.

In the flow chart shown in FIG. 4 , dividing phase jitter into three stages is just an example. Of course, phase jitter levels may be divided into more than three stages.

When the level of phase jitter is divided into three stages, for example, it can be divided into A level (no phase jitter), B level (slight phase jitter), and C level (severe phase jitter), and the degree of phase jitter can be quantified Set the numerical ranges corresponding to the phase jitters of A level, B level, and C level respectively, and determine which range the value related to the level of the phase jitter analyzed in the above step S220 corresponds to, that is, corresponding to the above-mentioned A level, B level, and Which stage in the C level.

As an example of digitizing the level of the phase jitter, as shown in (a) of FIG. 5 , a linear regression model by linear regression analysis of phase value information can be used.

Linear regression analysis is a regression analysis that models the linear correlation between the dependent variable and more than one argument (explanatory variable) when there are multiple data distributed. statistical analysis techniques. This linear regression model can usually be modeled using the Least Square Method.

As shown in (a) of Figure 5, the linear regression model Lf can be obtained for the phase data Dp in the initial motion interval of the ball through the linear regression analysis as described above, and the jitter level of the phase data Dp can be calculated from the linear regression model Lf digitize.

As an example of a criterion for judging phase jitter, the coefficient of determination R^2 in the linear regression model can be used.

When the coefficient of determination is 1, in the current data, 100% of the dependent variables can be explained with quotations, which means that all data exist on the regression line. When the coefficient of determination is 0, it means that in the current data, there is no Predict the dependent variable with the arguments.

The closer the coefficient of determination R^2 is to 1, it can be regarded as the slighter the phase jitter, and the closer the coefficient of determination is to 0, it can be regarded as the more serious the phase jitter.

As mentioned above, the phase data in the initial motion interval of the ball can be used to establish a linear regression model, and the determination coefficient derived from this can be used to quantify the level of phase jitter, and it can be judged that it corresponds to the pre-set jitter stage. which stage of.

From the flow chart shown in FIG. 4, after analyzing the level of phase jitter in step S220, when the numerical value corresponds to the numerical range set for the A level with almost no phase jitter (S221), the information calculation part can pass The set program removes noise from the radar sensing data in the initial motion range of the ball ( S231 ), and uses the data to calculate the trajectory to determine whether it is a low trajectory ( S241 ).

Here, whether it is a low ballistic is determined by whether the result of calculating the ballistic by analyzing data corresponds to the angle preset as low ballistic, that is, equal to or smaller than the reference angle of low ballistic. When corresponding to low ballistics, validity may be recognized; otherwise, validity is not recognized.

In order to judge whether the above-mentioned trajectory is low, in the trajectory calculation of the radar sensing data in the initial movement range of the ball, as shown in (b) of Figure 5, the position coordinate information of the ball calculated using the phase value of the radar signal can be used .

As mentioned above, the position coordinate information of the ball can be calculated from the radar signal at predetermined time intervals, and (b) of FIG. 5 shows an example of the result of calculating the position coordinate information of the ball in the initial movement interval of the ball in this way.

In the graph shown in (b) of Fig. 5 that displays the position coordinates of the balls at predetermined time intervals, the fitted curve can be calculated by fitting using the position coordinates of each ball as data, and the ballistic angle can be obtained using it , can also calculate the trend and calculate the ballistic angle based on the trend line.

When the trajectory of the radar sensing data in the initial motion range of the ball is low to some extent, it is less affected by signal distortion and phase jitter, so it can be set as a condition that the validity of the trajectory can be approved.

Here, how many degrees should be set as the reference angle for low trajectory, the upper limit of the trajectory angle that can be judged to be acceptable for the effectiveness of the trajectory can be determined through multiple experiments, and this angle is set as the reference angle for low trajectory.

Therefore, for the radar sensing data in the initial motion interval of the ball, the level of phase jitter is analyzed in step S220, and it corresponds to a good level, and, after judging whether it is a low trajectory in step S241, when it corresponds to a low trajectory ballistic effectiveness (S251) is only recognized when

For example, by adding the value for the level of phase jitter and the value for the low degree of ballistic, when the ballistic validity can be approved, corresponding to the preset value range, the ballistic validity can be approved.

On the other hand, after analyzing and digitizing the level of phase jitter in step S220, when the numerical value corresponds to the numerical range set for level B in which phase jitter slightly exists (S222), the information calculation unit can pass the preset The program removes noise from the radar sensing data in the initial motion range of the ball, and corrects slight phase jitter through a flattening process ( S232 ).

Then, the trajectory can be calculated using the corresponding data to determine whether it is a low trajectory (S242).

As mentioned above, even if there is a certain degree of phase jitter, when it can be recognized as reliable data by a certain degree of correction, if the trajectory of the data corresponds to a low trajectory, the ballistic validity can be recognized (S252 ).

Therefore, for the radar sensing data in the initial motion interval of the ball, after analyzing the level of the phase jitter in step S220, when the phase jitter corresponds to a slightly existing level, a certain degree of correction is carried out; after step S242 It is judged whether it is a low ballistic, and if it corresponds to a low ballistic, the validity of the ballistic can be recognized ( S252 ).

For example, by adding the value for the level of phase jitter and the value for the low degree of ballistic, when the ballistic validity can be approved, corresponding to the preset value range, the ballistic validity can be approved.

However, the reliability of the radar sensing data whose ballistic validity is recognized is not all the same. Even within the range of ballistic validity recognized, there may be more severe phase jitter, and there may be less severe phase jitter. Condition.

That is, even in the range where ballistic effectiveness is recognized, the lower the degree of phase jitter, the higher the reliability of the data may be evaluated; the higher the degree of phase jitter, the lower the reliability of the data may be evaluated. This evaluation can be performed by assigning weight values.

When the ballistic validity is recognized in step S251 and step S252, respectively, the information calculation unit may calculate the weight value of validity by assigning a higher weight value to the lower degree of phase jitter of the corresponding data (S261), and may The calculated weight value is applied to the data in the initial motion interval of the ball to calculate the ball moving trajectory through the physics engine ( S271 ).

For example, when some material is given a weight value of 90% and some material is given a weight value of 80%, in the former case, 90% of the material is believed and the trajectory can be calculated by the physics engine accordingly; in the latter case In the case of , 80% of the data is believed and the trajectory can be calculated by the physics engine accordingly.

In this way radar sensing data in the initial range of motion of the ball is used to determine ballistic validity and, when judged to be valid, an accurate trajectory can be calculated by calculating the overall ball movement trajectory taking into account the corresponding weight values.

On the other hand, after analyzing and digitizing the level of phase jitter in step S220, when the value corresponds to the numerical range set for level C with serious phase jitter (S223), the information calculation unit may not judge the data Whether ballistic validity is immediately disapproved for low ballistics (S253).

As described above, when the phase jitter corresponds to the severe C level, the information calculation section ignores the radar sensing data in the initial motion interval of the ball, and sets a predetermined interval in an interval after the initial motion interval to utilize the set interval A process of calculating a ball trajectory based on the radar sensing data ( S301 ).

A specific example of the ball trajectory calculation process using the radar sensing data in the set interval after the initial motion interval as described above will be described with reference to FIGS. 6 to 8 .

6 shows an example of ball position coordinate information shown by regressing ball position coordinates at predetermined time intervals calculated using radar signals received by a radar sensing device to a y-z plane according to an embodiment of the present invention.

As shown in Figure 6, the ballistic validity is judged by the data in the initial motion interval Ti of the ball. When the validity cannot be recognized, the data in the initial motion interval Ti of the ball is unreliable, so it cannot be used to calculate The trajectory of the whole ball, so it is necessary to find other reliable data intervals.

In the case of radar signals, the farther away from the radar sensing device, the more serious the noise in the reflected signal due to the interference of the surrounding environment, and the more serious the distortion of the signal, resulting in a significant reduction in the reliability of the data.

Therefore, preferably, when the ballistic validity of the data in the initial motion interval Ti of the ball is not approved, find out a predetermined interval Ts not far from the radar sensing device after the initial motion interval Ti of the ball, and use this interval The data in Ts calculates the trajectory of the ball. According to an embodiment of the present invention, the reference point for finding the interval Ts after the initial movement interval Ti of the ball is the highest point position Ph of the ball.

Referring to the flow chart in Figure 7, the validity of the trajectory is judged by the radar sensing data in the initial movement interval of the ball. When the validity of the ballistic is not recognized (S253), the information calculation department uses the collected radar sensing data as shown in the figure As shown in 6, the ball position coordinate information is calculated at predetermined time intervals (S310).

Then, the highest point position Ph of the ball is determined from the ball position coordinate information (S320), and a distance section corresponding to a height corresponding to a predetermined ratio with respect to the height of the highest point of the ball is specified and set as the reference section Ts( S330).

Referring to Fig. 6, in the ball position coordinate information based on the radar sensing data, the data with the largest z value on the coordinate can be determined as the highest point position Ph, and, in order to set the reference interval, for the height of the highest point, for example, the A section corresponding to a height of 10% to 60% is set as a reference section Ts.

Here, the ratio to the height of the highest point can be arbitrarily set in advance, and the ratio of the data interval that can be recognized as the most reliable can be determined through multiple experiments, and the ratio can be set in advance.

Assuming that the above ratio is 10%~60%, when the position corresponding to the height of 10% of the height of the highest point position Ph in Figure 6 is Pa, corresponding to the height of 60% of the height of the highest point position Ph When the position is Pb, the interval between the Pa position and the Pb position may be set as a reference interval Ts for calculating the trajectory.

Returning to FIG. 7 again, the reference interval Ts for calculating the trajectory can be determined as described above (S330), and the interval trajectory in the corresponding interval Ts can be calculated by using the ball position coordinate information Rs within the determined interval Ts (S340).

Then, the trajectory of the whole ball can be calculated by the physics engine based on the interval trajectory ( S350 ).

The above step S340 and step S350 will be described in more detail below with reference to FIG. 8 . (a) of Fig. 8 shows an example of calculating the section trajectory Cs using the coordinate information of the ball position in the reference section Ts as described above, and Fig. 8 (b) shows the calculation of the overall ball movement by the physics engine based on the section trajectory Cs Example of trajectory CH.

After the reference interval Ts is determined from the overall ball position coordinate information, the interval trajectory Cs can be calculated using the ball position coordinate information Rs in the reference interval Ts as shown in Figure 8 (a). At this time, the least square method or random The RANdom SAmple Consensus (RANSAC) algorithm calculates the interval trajectory Cs from the ball position coordinate information Rs.

After the section trajectory Cs is calculated in this way, based on the section trajectory Cs, as shown in (b) of FIG. 8 , the overall ball movement trajectory CH can be calculated by the physics engine.

As described above, in the radar sensing device of an embodiment of the present invention and the method for calculating the trajectory of the ball using it, the radar sensing data in the initial motion interval of the ball is used to determine the validity of the ballistic trajectory. After judging, when When it is valid, use the ball motion characteristics information in the initial motion range of the ball to calculate the overall ball movement trajectory. When the ballistic validity is not recognized, set a reference range after the initial motion range of the ball, and use the data in the reference range to calculate After the section trajectory is calculated, the overall ball trajectory is calculated based on this, so that even if distortion of the radar signal and phase jitter occur, calculation of the ball trajectory that is robust to this can be performed.

110:Signal sending department 120: Signal receiving department 130: Signal Analysis Department 140: Department of Information Computing B: ball Cs: interval track CH: Whole ball moving track Pa, Pb, Ph: position RA1~RA3: receiving antenna RH: Rs: coordinate information Sr: reflected wave signal St: Radar transmit signal Ti: initial motion interval Ts: benchmark interval

Fig. 1(a) is a block diagram showing the structure of a radar sensing device according to an embodiment of the present invention, and Fig. 1(b) is a block diagram showing a radar sensing device according to an embodiment of the present invention A diagram of the structure of the signal receiving part of the device; (a) of FIG. 2 shows the phase value information in the initial motion interval of the ball calculated from the radar signal received by the radar sensing device according to an embodiment of the present invention, and (b) of FIG. 2 shows the position coordinate information of the ball. ; 3 is a flow chart illustrating a method for calculating a ball trajectory using radar sensing data of a hit ball according to an embodiment of the present invention; FIG. 4 is a flow chart showing an example of a process for judging ballistic validity in the process shown in FIG. 3; FIG. 5 is a diagram for explaining an example of a specific means for judging the effectiveness of ballistics in the process shown in FIG. 4; FIG. 6 is a diagram for explaining a process of calculating a ball movement trajectory when ballistic validity is not recognized in the process shown in FIG. 3; FIG. 7 is a flowchart illustrating a process of calculating a ball movement trajectory when ballistic validity is not approved in the process shown in FIG. 3; FIG. 8 is a diagram for explaining calculation of a ball movement trajectory according to the procedure shown in FIG. 7 .

110:Signal sending department

120: Signal receiving department

130: Signal Analysis Department

140: Department of Information Computing

B: ball

Sr: reflected wave signal

St: Radar transmit signal

Claims (8)

A ball trajectory calculation method of a radar sensing device for a hit ball, characterized in that it includes: the step of transmitting a radar signal and receiving reflected waves from the struck ball to gather radar sensing data about the movement of the ball; a step of calculating initial motion characteristic information using radar sensing data in a preset interval as the initial motion interval of the ball; the step of determining the validity of ballistics corresponding to the initial motion characteristic information; and After judging the validity of the ballistic, if it is valid, calculate the trajectory of the ball through the physics engine based on the initial motion characteristic information; The steps of the ball moving trajectory. The ball trajectory calculation method of a radar sensing device for a hit ball as described in claim 1, wherein, The steps of calculating the initial motion characteristic information include: The step of calculating the speed, trajectory and direction information of the ball from the radar sensing data in the initial movement interval of the ball which is the preset distance interval from the initial position of the ball when the ball is hit. The ball trajectory calculation method of a radar sensing device for a hit ball as described in claim 1, wherein, The steps for judging the validity of this ballistic include: To judge the reliability of the initial motion characteristic information by analyzing the level of phase jitter of the radar sensing data in the initial motion interval of the ball which is a preset distance interval from the initial position of the ball when the ball is hit A step of. The ball trajectory calculation method of a radar sensing device for a hit ball as described in claim 1, wherein, The steps for judging the validity of this ballistic include: A linear regression model is calculated by linear fitting to the radar sensing data in the initial motion interval of the ball as a preset distance interval from the initial position of the ball when the ball is struck, and from the linear regression the step of the model judging the level of phase jitter; and a step of judging whether the trajectory of the ball calculated from the radar sensing data in the initial motion range of the ball is a low trajectory below a preset angle, The steps for calculating the trajectory of the ball include: When it is determined that the level of the phase jitter is below a preset standard and the trajectory of the ball is the low trajectory, the step of calculating the trajectory of the ball through the physics engine based on the initial motion characteristic information. The ball trajectory calculation method of the radar sensing device for the hit ball as described in claim 4, wherein, The steps for calculating the trajectory of the ball include: A step of removing noise and flattening the radar sensing data in the initial motion range of the ball; A step of calculating the weight value of the validity of the radar sensing data in the initial motion range of the ball in such a way that the lower the level of the phase jitter is, the higher the weight value is assigned to the phase jitter below the preset reference ;as well as A step of applying the calculated effective weight value to the initial motion characteristic information and calculating the trajectory of the ball through the physics engine. The ball trajectory calculation method of a radar sensing device for a hit ball as described in claim 1, wherein, The steps of calculating the trajectory of the ball when the judgment result of the ballistic validity is invalid include: The step of calculating the moving trajectory of the ball by the physics engine using the ball position coordinate information based on the radar sensing data of the interval set between the last position of the initial movement interval of the ball and the highest point position of the ball. The ball trajectory calculation method of a radar sensing device for a hit ball as described in claim 1, wherein, The steps of calculating the trajectory of the ball when the judgment result of the ballistic validity is invalid include: a step of calculating ball position coordinate information at predetermined time intervals based on the collected radar sensing data; Determining the highest point position of the ball from the calculated coordinate information of the ball position, and specifying the interval step corresponding to the height corresponding to the preset ratio relative to the highest point position of the ball; A step of calculating the interval trajectory of the interval by using the ball position coordinate information specified in the interval; and A step of calculating the trajectory of the ball through the physics engine based on the interval trajectory. A radar sensing device for sensing a hit ball, comprising: a signal transmitting unit, which transmits radar signals; a signal receiving part, which receives a reflected wave signal reflected from a moving ball for the signal of the signal sending part; a signal analysis section, which analyzes the received reflected wave signal to calculate radar sensing data about the movement of the ball; and an information calculation section that calculates initial motion characteristic information using radar sensing data in a preset interval as the initial motion interval of the ball, and judges the validity of the ballistic trajectory corresponding to the initial motion characteristic information, and when valid, based on the The initial motion characteristic information is used to calculate the trajectory of the ball through the physics engine. When it is invalid, the radar sensing data of the predetermined interval after the initial motion interval of the ball is used to calculate the trajectory of the ball through the physics engine.

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