Differential limiting control apparatus for a vehicle and the method thereof

A differential limiting control apparatus for a vehicle having a clutch unit interposed between one rotational shaft and another rotational shaft for variably changing a driving force transmission between the one rotational shaft and the other rotational shaft, comprising:

• a target differential speed setting unit for setting a target differential speed between the one rotational shaft and the other rotational shaft,
• an actual differential speed detecting unit for detecting an actual differential speed between the one rotational shaft and the other rotational shaft,
• a first control unit for computing a first clutch torque of the clutch unit based on a deviation between the target differential speed and the actual differential speed,
• a throttle opening amount detecting unit for detecting a throttle opening amount,
• a second control unit for computing a second clutch torque of the clutch unit based on the throttle opening amount,
• a tire diameter difference computing unit for computing a diameter difference of a tire and outputting a tire diameter difference value, and
• a final clutch torque computing unit for computing a final clutch torque wherein the final clutch torque computing unit receives, as an input, said tire diameter difference value and computes the final clutch torque by a computation involving the first clutch torque and the second clutch torque, and which computation includes a ratio coefficient value which ratio coefficient value changes according to the diameter difference of the tire so as to vary the final clutch torque to promote wheel slippage suppression.

A differential limiting control apparatus for a vehicle having a clutch unit interposed between one rotational shaft and another rotational shaft for variably changing a driving force transmission between the one rotational shaft and the other rotational shaft, comprising:

• a target differential speed setting unit for setting a target differential speed between the one rotational shaft and the other rotational shaft,
• an actual differential speed detecting unit for detecting an actual differential speed between the one rotational shaft and the other rotational shaft,
• a first control unit for computing a first clutch torque of the clutch unit based on vehicle behavior through a feedback control,
• a second control unit for computing a second clutch torque of the clutch unit based on behavior of the vehicle through a feed forward control,
• a tire diameter difference computing unit for computing a diameter difference of a tire and outputting a tire diameter difference value, and
• a final clutch torque computing unit for computing a final clutch torque wherein the final clutch torque computing unit receives, as an input, said tire diameter difference value and computes the final clutch torque by a computation involving (i) the first clutch torque and a first weighting value associated with said tire diameter difference value and (ii) and the second clutch torque and a second weighting value associated with said tire diameter difference value, and wherein said first and second weighting values vary in opposite fashion upon a change in the tire diameter value.