1. An engine control system for a vehicle propulsion system comprising: a processor; a plurality of engine model modules executing independently and programmed to receive engine operating condition values from a plurality of sensors positioned on an engine, each of said plurality of engine model modules programmed to determine an estimate of a process parameter of a location in the engine where at least one of a sensor for the process parameter is not available, a sensor for the process parameter is not present at the location, a sensor at the location has failed, and a sensor at the location is determined to be inaccurate; an estimate source selector configured to determine model blending factors; and a model blending module configured to determine an estimated virtual sensor value using the determined estimates from at least two of the plurality of engine model modules and the model blending factors.