1. A method comprising: obtaining, by a processor, a preliminary model associated with a system to be controlled; constructing, by the processor, a weighted model using one or more weighting factors; identifying, by the processor, a final model of the system using the preliminary and weighted models, the final model having a stability margin that is greater than an uncertainty associated with the final model, wherein identifying the final model comprises: determining a coprime factorization of the preliminary model and a normalized coprime factorization of the weighted model; determining an error using input data to the system, output data from the system, and the coprime factorizations; and determining frequency content of the input data, the output data, and the error; and controlling the system using a controller designed based on the final model.