US 6,487,486 B1 · Automatic differential control logic

Abstract

A process for continuously controlling the transfer of torque within a differential where a target delta (ΔT) value is determined as a function of a first differential output shaft speed (ωa) and a second differential output shaft speed (ωb) and then normalized according to the vehicle speed when the vehicle is being driven under a no wheel slip condition. A normalized actual delta (ΔA) is also determined as a function of the first output shaft speed (ωa) and the second output shaft speed (ωb), a comparison is made between ΔT and ΔA and torque is transferred between the first and second output shafts of the differential according to a logic control methodology such as proportional, integral, and/or derivative (PID) control methodologies if the comparison result of ΔA to ΔT is outside of a tolerance range established around ΔT.

Claims20

Dependent claims

A method of controlling torque within a vehicle differential comprising the steps of:

providing a differential having first and second output shafts;
determining a first speed (ωa) of said first output shaft;
determining a second speed (ωb) of said second output shaft;
determining a target delta (ΔT) as a function of said first speed (ωa) of said first output shaft and said second speed (ωb) of said second output shaft under preselected vehicle operating conditions;
determining an actual delta (ΔA) as a function of said first speed (ωa) of said first output shaft and said second speed (ωb) of said second output shaft under actual vehicle operating conditions;
determining a control value (CV) as a function of said actual delta (ΔA) and said target delta (ΔT);
and
comparing said control value (CV) to said target delta (ΔT).

5 more elements

Dependencies are inferred from the claim text.

Automatic differential control logic

Life of this patent

Automatic differential control logic

Life of this patent

Abstract

Claims20