Abstract

The sports ball market is extremely competitive and in the US alone valued in excess of $1200 million [SG1]. In order to research and develop sport balls it is vital to quantitatively measure the launch and flight characteristics of the ball. Original equipment manufacturers (OEM’s) are currently using a wide range of systems to measure these parameters, allowing direct comparison between products. The purpose of this investigation is to compare some of the most methods currently available to measure soccer ball launch characteristics. The three measurement systems used were an optical system, a radar system and a high speed video (HSV). A detailed operational description of each method is provided which highlights system strengths and weaknesses. All systems were tested by assessing the launch characteristics of 30 kicks representing a maximal velocity strike, along with 30 impacts representing a curve kick. The kicks were carried out using a purpose built mechanical kicking simulator developed at Loughborough University (LU) in order to obviate inconsistencies achieved with player testing. The main findings from the work showed statistically that the optical system gave a higher soccer ball velocity, whereas the radar system gave a lower launch angle to the other systems. The measured spin rates for kicks highlighted the limitations of current measurement systems, due to discrepancies between all measured spin rate values. In summary this is the first comprehensive study to compare current soccer ball launch measurement systems using a highly repeatable kicking simulator. The study highlighted the uncertainties involved and particular attention was given to the fidelity of the spin measurement. Verf.-Referat