An excavator includes a rotatable house and a bucket operably coupled to the rotatable house. The excavator also includes one or more swing sensors configured to provide at least one rotation sensor signal indicative of rotation of the rotatable house and one or more controllers coupled to the sensor. The one or more controllers being configured to implement inertia determination logic that determines the inertia of a portion of the excavator and control signal generator logic that generates a control signal to control the excavator, based on the inertia of the portion of the excavator.