Driving force control apparatus and method for 4-wheel driving vehicle

摘要

In a driving force control apparatus for a 4-wheel driving vehicle, a target driving torque is obtained based on a value determined by subtracting a feedback correction torque corresponding to a slip amount from a reference torque corresponding to a vehicle body speed. Slip is suppressed by a throttle control so that the engine output is reduced to the target driving torque. A retard command is output when the slip amount DVS and a slip rate GDVS are greater than predetermined values to control retarding of an ignition timing of the engine, thereby suppressing an abrupt slip. Further, the two greatest values of slip amounts of each of four wheels DVS1, DVS2, DVS3, and DVS4 are differentiated to determine slip rates GDVS1 and GDVS2, and the smaller of the slip rates GDVS1 and GDVS2 is used for control of ignition timing retarding. The apparatus causes a 4-wheel driving vehicle equipped with a limited slip differential (LSD) to provide a sufficient effect of the LSD and further suppresses the occurrence of an excessive slip.