THE MICROCOMPUTER SYSTEM OF MEASUREMENT OF THE LENGTH OF JUMP AND OTHER PARAMETERS IN SKI-JUMPING

Abstract

The electronic measurement systems are used more and more frequently in different kinds of sports. Previous attempts to utilize the automatic systems for the jumping length measurement were not successful in practice (HEINICKE, 1969, HOLZ, 1969, BENEDIK and BOLEO, 1973, KREISELMAYER, 1977, HOCHMUTH and WOITAS, 1979, GEODYNAMIK AB, 1983). The main problems were in very high material, technical and personal demands for the operation of such systems. At present time only one system developed by HOCHMUTH is operated and it is used as an official measurement system at the World Cups and World Championships events. This system must be operated only by a special staff. In our Laboratory a new version of the measurement system has been developed and verified. This system is designed for the jumping hills covered by a mat and it is built in the jumping hill Frenštát p.R., K 92m. The system operates on the electromagnetic principle. The magnet located on the ski generates the electrical signal in the net which covered the in-run and the landing area of the jumping hill. The microcomputer PC-AT is connected with the measured system through the port COM 1 and using a special software the system gives the information about the length of jump, the time of the flight, the in-run velocity and the landing speed. The big advantage of this system is a very simple operation by one skilled person (e.g. coach). The number of the other measured parameters can be extended according to the user's requirement. Since this time about 250 jumps in 1993 have been measured and also taped and the measured lengths of jumps have been used as the official values for the event GP Frenštát p.R. '93. The statistical analysis of the measured length of jumps using this system and with the official judges in comparison with kinematographically analyzed jumps have shown a very high accuracy of the electronic measurement (0.5 m) . The utilization of this method both in the training and in the competition has been checked in practice.