JP-2026076385-A - A reference point switching type dynamic synchronous playback system and method for time-series media data of repetitive motion.

Abstract

【assignment】 When comparing and analyzing multiple recordings of repetitive movements, there is no means to dynamically switch the reference point for synchronized playback. Therefore, it was difficult to recognize the discrepancies between movements that appeared different depending on the selection of the reference point, and to identify their causes. [Solution] The system accepts multiple time-series media data, each recording multiple repetitive actions, with multiple reference point candidates assigned to each recording. It displays these data in parallel or superimposed, and presents the reference point candidates on a timeline. For each type of reference point candidate, the system calculates the median time position across multiple recordings as the representative position, and sets intervals on the timeline using the midpoint between adjacent representative positions as boundaries. The system designates the reference point candidate corresponding to the interval to which the user's input location belongs as the reference point, and realigns all recordings to the time position of that reference point to update synchronized playback. [Selection Diagram] Figure 3

Inventors

• 友岡湖太

Assignees

• 友岡 湖太

Dates

Publication Date

20260511

Application Date

20260224

Claims (20)

1. A repetitive motion comparison and analysis system, A display unit that receives multiple time-series media data, each recording multiple repetitive operations, and each recording is assigned multiple reference point candidates corresponding to characteristic events that occur during the operation; displays the multiple time-series media data in parallel or superimposed on each other, and presents the multiple reference point candidates on a timeline; An input receiving unit that, in response to user input on the timeline, designates one of the candidate reference points as the reference point, A repetitive operation comparison and analysis system comprising: a synchronization processing unit that, in accordance with the above specification, realigns all of the multiple time-series media data so that they coincide with each other at the time position of the specified reference point, and synchronizes the playback of the multiple time-series media data in the realigned state.
2. A computer-based method for comparing and analyzing repeated actions, The process involves receiving multiple time-series media data, each recording multiple repetitive actions, and assigning multiple reference point candidates to each recording, corresponding to characteristic events that occur during the action; displaying the multiple time-series media data in parallel or superimposed; and presenting the multiple reference point candidates on a timeline. The steps include: designating one of the candidate reference points as the reference point in response to user input on the timeline; A method for iterative operation comparison and analysis, comprising the steps of: realigning all of the multiple time-series media data so that they coincide with each other at the time position of the specified reference point, and synchronously playing back the multiple time-series media data in the realigned state, according to the above specification.
3. Computers, A display means that receives multiple time-series media data, each recording multiple repetitive actions, and each recording is assigned multiple reference point candidates corresponding to characteristic events that occur during the action; displays the multiple time-series media data in parallel or superimposed on each other; and presents the multiple reference point candidates on a timeline. An input receiving means that, in response to user input on the timeline, designates one of the candidate reference points as the reference point, and, in response to the designation, realigns all of the multiple time-series media data so that they coincide with each other at the time position of the designated reference point. A program for functioning as a synchronization processing means for synchronously playing back the multiple time-series media data in a realigned state.
4. A repetitive motion comparison analysis system according to claim 1, The repetitive motion comparison analysis system is characterized in that the input receiving unit sets intervals for each type of reference point candidate on the timeline and designates the reference point candidate of the type corresponding to the interval to which the position on the timeline to which the operation input belongs as the reference point.
5. A repetitive motion comparison analysis system according to claim 4, The input receiving unit calculates a representative position for each type of reference point candidate based on the time position in the plurality of time-series media data, and sets the midpoint between adjacent representative positions as the boundary of the interval, in this iterative motion comparison analysis system.
6. A repetitive motion comparison analysis system according to claim 5, The aforementioned representative position is calculated as a robust statistic of the time position of each type of reference point candidate in the plurality of time-series media data, characterized in that iterative motion comparison analysis system.
7. A repetitive motion comparison analysis system according to claim 6, A repeating motion comparison analysis system characterized in that the robust statistic is the median.
8. A repetitive motion comparison analysis system according to any one of claims 5 to 7, A repetitive motion comparison analysis system characterized in that the intervals prior to the earliest representative position and the intervals after the latest representative position on the timeline are each assigned to the reference point candidate of the type corresponding to the closest representative position.
9. A repetitive motion comparison analysis system according to claim 1, The synchronization processing unit is characterized by being able to change the playback speed while maintaining the synchronization state between the multiple realigned time-series media data.
10. A repetitive motion comparison analysis system according to claim 1, The synchronization processing unit is characterized by sending or returning the multiple time-series media data in a synchronized manner on a frame-by-frame basis while maintaining the synchronization state between the multiple time-series media data that have been realigned.
11. A method for comparing and analyzing repeated motions according to claim 2, A method for comparing and analyzing repeated motions, characterized in that, in the step of specifying the reference point, intervals for each type of reference point candidate are set on the timeline, and the type of reference point candidate corresponding to the interval to which the position on the timeline where the operation input was made belongs is specified as the reference point.
12. A method for comparing and analyzing repeated motions according to claim 11, A method for comparing and analyzing repeated motions, characterized in that, in setting the interval, a representative position is calculated for each type of candidate reference point based on the time position in the plurality of time-series media data, and the midpoint between adjacent representative positions is set as the boundary of the interval.
13. A method for comparing and analyzing repeated motions according to claim 12, The method for iterative motion comparison analysis is characterized in that the representative position is calculated as a robust statistic of the time position of each type of reference point candidate in the plurality of time-series media data.
14. A method for comparing and analyzing repeated motions according to claim 13, A method for comparing repeated actions, characterized in that the robust statistic is the median.
15. A method for comparing and analyzing repeated motions according to any one of claims 12 to 14, A method for comparing and analyzing repeated motions, characterized in that the intervals prior to the earliest representative position and the intervals after the latest representative position on the timeline are each assigned to the reference point candidate of the type corresponding to the closest representative position.
16. A method for comparing and analyzing repeated motions according to claim 2, A method for comparing and analyzing repeated actions, characterized in that, in the step of synchronized playback, the playback speed can be changed while maintaining the synchronization state between the multiple realigned time-series media data.
17. A method for comparing and analyzing repeated motions according to claim 2, A method for comparing and analyzing repeated motions, characterized in that, in the step of synchronized playback, the plurality of time-series media data are sent forward or backward in a synchronized manner on a frame-by-frame basis while maintaining the synchronization state between the plurality of realigned time-series media data.
18. The program according to claim 3, The input receiving means is a program characterized by setting intervals for each type of reference point candidate on the timeline and designating the reference point candidate of the type corresponding to the interval to which the position on the timeline to which the operation input was made belongs as the reference point.
19. The program according to claim 18, The input receiving means is a program characterized by calculating a representative position for each type of reference point candidate based on the time position in the plurality of time-series media data, and setting the midpoint between adjacent representative positions as the boundary of the interval.
20. The program according to claim 19, The program is characterized in that the representative position is calculated as a robust statistic of the time position of each type of reference point candidate in the plurality of time-series media data.

Description

This invention relates to a system and method for comparing and analyzing multiple time-series media data of repetitive actions through synchronous playback. More specifically, it relates to a technique for dynamically realigning and synchronously playing back all recordings at the time position of a specified reference point, provided that multiple reference point candidates corresponding to characteristic events occurring during the action are assigned to each recording of time-series media data of multiple recorded repetitive actions. In the fields of sports science and biomechanics, it is common practice to perform comparative analysis by filming repetitive motions such as pitching, batting, and swinging multiple times, and then playing these videos side-by-side in sync. In this comparative analysis, when aligning and synchronizing multiple videos, a reference point is established, and each video is aligned to match the time position of that reference point. Typically, a single repetitive motion has several characteristic points that could serve as reference points. For example, in a baseball pitching motion, the starting point of the form (set position), the point of contact of the front foot (footplant), and the ball release point could all be alignment reference points. Similarly, in a golf swing, the address (stance), the peak of the backswing (top), the moment of impact from the downswing, and the end of the follow-through could all be candidate reference points. The motion characteristics that emerge from the comparison will fundamentally differ depending on which reference point is used to align the time positions and synchronize the videos. For example, in baseball pitching, synchronized playback aligned at the release point visualizes differences in take-back timing, while synchronized playback aligned at the foot plant visualizes differences in trunk rotation and arm swing from that point onward. Similarly, in golf swings, aligning at impact reveals differences in downswing trajectory, while aligning at the top reveals differences in backswing tempo. Non-patent document 1 (Honert & Pataky, 2021) compares 40 different gait events as alignment reference points in gait analysis and demonstrates that the selection of reference points significantly impacts the statistical analysis results. Applying the findings from Non-Patent Document 1, the following situation may occur. Consider a scenario comparing and analyzing two types of pitches, fastball A and fastball B. When the footage is aligned and synchronized using the footplant (the point of contact of the lead foot) as the reference point, it appears that at the same time, the arm is already fully extended in fastball A, while in fastball B, the arm is not yet fully extended. This synchronized playback leads to the conclusion that "fastball B has a slow arm swing and a problem with its form." However, when the footage is realigned using the release point (the moment the ball leaves the hand) as the reference point, it can be seen that the arm position and core usage immediately before release are almost identical for both fastball A and fastball B. In other words, there is no difference in the form itself; only the time (tempo) from footplant to release differs. Thus, simply changing the reference point for the same data can fundamentally change the conclusion drawn from the analysis from a "form problem" to a "tempo problem." While some conventional repetitive motion analysis systems partially offer multiple synchronization methods and display configurations, they do not disclose a function that allows the user to dynamically switch reference points and synchronize playback of multiple recordings of a repetitive motion. Patent Document 1 (Blast Motion, US9349049B2) discloses a motion analysis system centered on motion capture using an IMU sensor and a mobile device, featuring multi-format display functions such as 3D overlay, stroboscopic effects, and Bullet Time display, as well as multiple reference frames (world coordinate system, equipment parts, virtual spine, bone landmarks, etc.). However, it does not disclose a function to dynamically realign and synchronize playback multiple recordings of a repetitive motion using different reference points. Patent Document 2 (K-Motion Interactive, US7264554B2 and its continuation family) discloses a motion analysis system using inertial sensors, with synchronized display of live video, 3D animation, and time-series data graphs as its core functions. This patent describes functions such as display configuration and performance parameter selection (multiple, selectable configurations), Kinetic Index scoring, a motion prescription engine, and real-time biofeedback (color changes and sound). However, while display configurations and parameters can be selected, the function of dynamically resynchronizing and playing back multiple recordings of repetitive movements at different alignment reference points is n