Optoelectronic vertical jump height measuring method and device

Abstract

Various vertical jump height measurement systems are being used today. Mostly used types are mechanical wheel jump-meter, video systems and electrical contact operated systems. In this paper, these systems have been studied and possible errors are defined. It has been determined that the wheel operated systems are setting a limit to the athlete's movement. There is an error because of moment of inertia. Also, there occurs an error because of the loose wire. Video systems (tabulated list method) have the satisfactory sensitivity, so they can be used to calibrate the device type systems. However, these types of systems have subjective errors since initial position of the athlete affects the measurement results. The cord limits the movement of the athlete in the mechanical wheel operated systems. Moreover, an error occurs in the measurement because of the momentum. Also, another error occurs in stretching of the cord before jumping and the cord is worn out with time. Jump height is to be calculated from rise and fall times in contact operated systems. Fall time is to be extended from the athlete folding his legs. Also this situation causes an error. Mechanical contacts loose their flexibility and electrical properties as the time passes. Even distance between strips causes an error. In addition, movements of athlete's on the floor between his foot fingers and heel can trigger the contacts and this will be the cause of jump height calculation without jumping. To eliminate these disadvantages a new measuring method for vertical jump height has been developed and a laser operated optoelectronic device designed. In the suggesting method have been measured "the time of flying" same as contact operated method, but fall down on the floor is not to take into account in the new method and athlete cannot affect on the result in this way.