Method and device for measuring rotating speed of table tennis ball

Abstract

The invention discloses a method and a device for measuring the rotating speed of a table tennis ball. The method comprises the following steps of: constructing a coordinate system, setting an image acquisition range and acquiring an image; identifying a mark of a table tennis ball and acquiring a main direction of the mark; calculating an included angle alpha between the main direction and the xaxis of the coordinate system; obtaining an included angle beta between the main direction of the mark of the table tennis ball in the image and the x axis of the coordinate system after a time interval T; obtaining the rotating direction of the table tennis ball according to the angle difference between the included angle alpha and the included angle beta; and calculating the rotating speed omegaof the table tennis ball according to the angle difference and the time interval T. According to the invention, the characteristics of the table tennis ball in the small-range image are analyzed by setting the image acquisition range, so that the defects of large transmission data volume and low speed in the traditional high-speed vision field are overcome, and the rotating speed of the table tennis ball can be calculated in an extremely short time.

Description

technical field [0001] The invention relates to the technical field of computer vision, in particular to a method and device for measuring the rotational speed of a table tennis ball. Background technique [0002] In recent years, computer vision technology has been increasingly used to assist the teaching and training of sports, and it is also widely used in sports events. In the application of computer vision in table tennis, the observation of the rotating ball is a major difficulty. A system that can calculate the rotation direction and speed of the table tennis ball in real time can facilitate athletes and coaches to review the training or competition process, and enhance the teaching effect of rotating balls . [0003] In the prior art, high-speed cameras are generally used to observe the rotation of table tennis balls in the state of motion, but it needs to cover the entire table tennis field to obtain a complete table tennis motion track, and the equipment needs to ...

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Problems solved by technology

[0004] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a method and device for measuring the rotational speed of table tennis balls. By setting the image acquisition range to analyze the characteristics of table tennis balls in small-scale images, the traditional high-speed rotation speed is solved. The shortcomings of the large amount of data transmitted in the visual field and the slow speed ensure that the rotation speed of the table tennis ball can be calculated in a very short time

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