Table Tennis Ball Marking Pattern for Spin Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring spin in table tennis balls are too slow and unreliable, especially in fast-paced games where the ball's position and orientation are unknown, making real-time spin determination challenging.
Innovation Solution
A table tennis ball with a spherical surface featuring a marking pattern of 18 pseudo-randomly distributed marking points, where each point is at least 63% of the mean distance from its nearest neighbors, ensuring global homogeneity and local irregularity, facilitating quick and accurate spin detection using infrared imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement methods are used to locate and measure the spin of a table tennis ball in flight, then spin measurement is possible under favorable conditions, but the measurement process is too slow and consumes significant time to be practically applicable in fast-paced table tennis
Solution Approach 1:
The ball surface is divided into multiple distinct marking points (at least three, preferably four or more) that are spatially separated and individually detectable. This segmentation allows the measurement system to identify and track multiple reference points simultaneously, enabling faster processing and more reliable spin calculation compared to using a single complex marking pattern.
Solution Approach 2:
The marking points are positioned at specific distances from each other (at least 63% of the mean distance to nearest neighbors), creating a standardized geometric configuration. This parameter optimization ensures that the markings remain clearly distinguishable and measurable across various ball orientations and distances, improving both measurement reliability and processing speed.
2Adaptability or versatility
If the ball's position and orientation are unknown at the start of measurement (as in table tennis), then the measuring device must first locate the ball before measuring spin, but this consumes significant measurement time
Solution Approach 1:
The marking points are pre-positioned in a specific geometric pattern on the ball surface before the ball enters flight. This preliminary configuration of reference points allows the measurement system to immediately recognize and establish the ball's position and orientation as soon as the ball enters the detection field, eliminating the need for time-consuming location and orientation procedures.
Solution Approach 2:
The marking points are distributed homogeneously on the ball surface with consistent spacing requirements (at least 63% of mean distance to nearest neighbors). This homogeneous distribution ensures that the ball can be reliably recognized and measured regardless of its orientation, allowing the system to process any ball position efficiently without requiring special handling for different orientations.
3Reliability
If markings are applied to make ball rotation visible, then spin detection is enabled, but the markings must be clearly identifiable in any orientation to ensure reliable measurement
Solution Approach 1:
While the overall distribution of marking points follows a homogeneous pattern, each individual ball has a specific asymmetric arrangement of points in space. This asymmetric configuration of reference points creates a unique geometric signature that allows the measurement system to reliably determine ball orientation and spin by tracking the relative positions of the points, ensuring accurate measurement across all orientations without requiring overly complex marking patterns.
Data Source
Figure 1~3
Figure 4~6
Figure 7
AI summary
The invention relates to a table tennis ball (2) which has, on the spherical surface (6) thereof, a marking (8) to make a ball rotation measurable. The marking (8) comprises a number of marking points (Pi) which are distributed on the ball surface (6) in such a way that the standard deviation of the lengths (Zi,j) of the orthodromes (20) between each of the marking points (Pi) and the three nearest neighbouring points (14, 16, 18) thereof is at least 12% of the average value (μ) of these lengths (Zi,j), and the minimum length of the orthodromes (20) between each of the marking points (Pi) and the three nearest neighbouring points (14, 16, 18) thereof is at least 40% of the average value (μ) of these lengths (Zi,j).