Draft control system for a vehicle.

摘要

A filtered draft load signal FDRFT is derived from the signals A1 - A3 from three draft load sensors (16) and is subtracted from a filtered command load signal DCOM, which is derived from a signal A6 from a load setting lever (36), to provide a load error signal LERR. A model error signal DMOD is derived from LERR by a first order filter function:
DMOD = 0.96 DMOD + 0.06 LERR
DMOD is filtered to provide a filtered model error signal FMOD = 0.17 FMOD + 0.83 DMOD. FDRFT is subtracted from FMOD to provide a model error signal ELIT. A gain increment DELGN is proportionally to the product of GAA and ELIT and LERR where GAA is a inversely related to DCOM. A gain factor GAIN3 is obtained by integrating DELGN and the ultimate draft error signal DERR is derived as 17.5 (GAIN3. LERR + ZPOS - A(4)), where ZPOS is derived to represent the position of the rockshaft (22) at which the implement (14) enters the ground and A(4) is the actual rockshaft position given by a transducer (28). Control by the draft error signal DERR is overridden by a position error signal
PERR = 17.5 (A(5) - A(4))
when PERR is greater than DERR. A(5) is provided by a rockshaft positioning lever (32) used by the operator to lift the implement from the ground and lower it into the ground again.