Systems and Methods for Sensorless State Estimation, Disturbance Estimation, and Model Adaption for Rotary Steerable Drilling Systems

A method of estimating a state of a rotary steerable drilling system comprising applying a control input to a rotary steerable drilling system, sensing an actual output of the rotary steerable drilling system, inputting the control input into a mathematical model of the rotary steerable drilling system, receiving an estimated output of the rotary steerable drilling system from the mathematical model, generating an error compensation signal based on a difference between the actual output and the estimated output, and applying the error compensation signal to the mathematical model.