1. A multiple-input, multiple-output controller for controlling a system, comprising: a discretized system model describing one or more distinct states, where each input has a distinct output and disturbance; an extended state estimator implemented in a computer component that receives a signal from a sensor that is operably connected to the system; and at least one correction term in the extended state estimator, where the at least one correction term is determined as a function of a single tuning parameter and the at least one correction term and the signal estimates system states and extended states of one or more orders.