Microcomputer Control of Electronic-Hydraulic Three-Point Hitch for Agricultural Tractors ( I ) -Computer Simulation-

농용(農用) 트랙터 3점(點)히치시스템의 마이크로컴퓨터 제어(制御)( I ) -컴퓨터 시뮬레이션-

A mechanical-hydraulic hitch control system has been adapted to most agricultural tractors. But it has various defects due to friction, inertia and hysteresis. Recently a number of electronic-hydraulic hitch control systems have been developed in several countries to improve control performance of the agricultural tractors equipped with a mechanical-hydraulic hitch control system. This study was conducted to develop a new electronic-hydraulic hitch control system using an electro-hydraulic servo valve instead of an on-off valve and to carry out computer simulation of the system. According to the result of computer simulation, the control system showed the best performance when the proportional constants were 9 and 4 for position and draft control respectively. The step and frequency responses were improved as flow rate increased.