Anti-lock braking system for motor vehicle that can be driven in two or four-wheel drive mode

• Main Authors: HATANO, KUNIMICHI, WAKO, SAITAMA, JP, YAHAGI, TOSHIO, WAKO, SAITAMA, JP, FUKAMI, KAZUAKI, WAKO, SAITAMA, JP, SUZUKI, SHOUJI, WAKO, SAITAMA, JP, KOJIMA, TAKESHI, WAKO, SAITAMA, JP
• Format: Patent
• Language: English; German
• Published: 27.07.1995
• Edition: 6
• Subjects: ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; 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; BLASTING; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; LIGHTING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OFVEHICLES; THERMAL INSULATION IN GENERAL; TRANSPORTING; VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES; VEHICLES IN GENERAL; WEAPONS

The ABS system is for a vehicle that can be switched between two-wheel and four-wheel drive. The wheel speeds are all measured, as is the vehicle acceleration or deceleration. Then from the latter and just the highest wheel speed is estimated the vehicle speed. The vehicle speed is also estimated from all four wheel speeds. The higher of these two vehicle speed estimates is compared with a speed that is a certain amount below the first value estimated, denoted as a "qualification speed". If higher speed estimate is equal to, or less than, this qualification speed for a certain length of time and the vehicle is already in 4WD mode, it is switched to 2WD mode.