Method for controlling output torque in powertrains

A method of controlling output torque in a vehicle transmission including at least one electric machine and in electrical communication with a battery, comprising:

• calculating a first long-term output torque constraint with a processor;
• calculating a first short-term output torque constraint with the processor;
• calculating a rate limit with the processor;
• determining a first effective output torque constraint with the processor from the first long-term output torque constraint and the first short-term output torque constraint,
• wherein the first effective output torque constraint is bounded by both of the first long-term output torque constraint and the first short-term output torque constraint,
• wherein determining the first effective output torque constraint includes restricting the magnitude of changes in the first long-term output torque constraint to the rate limit, and
• wherein restricting the magnitude of changes in the first long-term output torque constraint to the rate limit occurs only when the first long-term output torque constraint is tightening;
• and
• operating the transmission at the first effective output torque constraint determined by the processor.