Abstract
Accurate measurement of the ground speed of agricultural tractors is fundamental to automatic control of field equipments or a tractor performance monitor, by which a high field working accuracy or a maximized energy efficiency can be obtained.
As a fundamental research for the development of a new speed sensor, the measuring characteristics of micro-wave Doppler radars were investigated under various working conditions. Based on these results, an ultra-sonic Doppler speed sensor was developed. This speed sensor has a high measuring accuracy in a low speed range. The basic measuring accuracy, the dynamic response and the error resulting from field conditions, air temperature and wind velocity were analyzed experimentally. These analyses show that the developed speed sensor works with a sufficient performance in practical applications.
