Patent ID: 7346194

Claim:
A method of measuring rotational and flight characteristics of a sphere, comprising the steps of: photographing said sphere, at predetermined intervals, having a plurality of marks given to a surface thereof while said sphere is rotating to obtain a plurality of two-dimensional images of said sphere; generating an imaginary sphere, having a plurality of marks given to a surface thereof, formed at coordinates of a three-dimensional space of a computer screen; and setting an arbitrary posture of said imaginary sphere and an arbitrary position thereof as a reference posture and a reference position respectively; deriving a relationship between three-dimensional coordinates and two-dimensional coordinates by using at least one photographing means; converting positions of said marks given to said surface of said imaginary sphere formed at said coordinates in said three-dimensional space into positions on a two-dimensional image by using said relationship to find coordinate values of two-dimensional imaginary marks and find coordinate values of said marks present on said two-dimensional images of said sphere; performing an operation of displacing a posture of said imaginary sphere relative to said reference posture and said reference position in such a way that said coordinate values of said two-dimensional imaginary marks and said coordinate values of said marks present on said two-dimensional images of said sphere are coincident with each other to specify a three-dimensional posture of said sphere and a three-dimensional position thereof for each of said two-dimensional images of said sphere, according to an amount of said posture displacement operation; and computing said rotational and flight characteristics of said sphere, according to said three-dimensional posture and position of said sphere specified for each of said two-dimensional images of said sphere at one time and said three-dimensional posture and position thereof at another time, wherein said posture displacement operation comprises an operation of moving and rotating said imaginary sphere; and an amount of said posture displacement operation relative to said reference posture and said reference position is found by computations based on an optimization method called a genetic algorithm.