Draft load control systems

摘要

A control system and method for adjusting the depth of a tractor-drawn draft implement in response to a detection of draft load. The control system compares actual engine rpm to a stored or mapped value of engine rpm at zero engine load conditions for the throttle setting in use. An indication of engine lug-down is thereby obtained. Through the use of another memory related to the engine torque versus rpm curve, for the actual throttle setting in use, a draft load signal is obtained. As determined by an operator sensitivity setting, a preselected portion of the draft load signal is then combined with a preselected portion of an actual draft depth position signal to form a feedback signal. A signal represntative of the draft depth desired by the operator is then combined with the feedback signal to form a command signal for raising or lowering the draft implement via a hydraulic powerlift valve.