1. A process control system, comprising: a non-linear model comprising an empirical representation of a plant or process, wherein the non-linear model is configured to receive an input value and generate a first output value using the empirical representation of the plant or process; and a linearized first principles model comprising an analytic representation of the plant or process, wherein the linearized first principles model is configured to receive the input value and generate a second output value using the analytic representation of the plant or process; wherein the first output value and/or the second output value is usable to control the plant or process.