Driving force distribution control apparatus for four-wheel drive vehicle and driving force distribution control method for four-wheel drive vehicle

• Main Authors: OHYAGI SHOICHI, NIHANDA NORIHISA, SEKI TAKAYUKI
• Format: Patent
• Language: English
• Published: 02.02.2016
• Subjects: ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS INVEHICLES; ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OFTRANSMISSIONS IN VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GASEXHAUST OR FUEL SUPPLY OF PROPULSION UNITS, IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLETECHNOLOGY; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; PERFORMING OPERATIONS; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; TRANSPORTING; VEHICLES IN GENERAL

A driving force distribution control apparatus for a four-wheel drive vehicle includes a basic distribution determination device and a servo controller. The basic distribution determination device is configured to determine basic distribution of a driving force to secondary drive wheels in accordance with the driving force and driving conditions of the vehicle. The basic distribution determination device includes a tire force limit determination device and an arithmetic device. The tire force limit determination device is configured to calculate a tire required acceleration in accordance with the driving conditions of the vehicle and configured to output a basic distribution adjustment signal having a characteristic that gradually decreases a ratio of the basic distribution for the secondary drive wheels to zero in a transient region in which the calculated tire required acceleration is lower than a predetermined threshold value.