Position and Altitude Control of a Quadcopter Using State-Dependent Riccati Equation (SDRE) Control

This paper presents a solution to the problem of trajectory tracking for a quadcopter using a State-Dependent Riccati Equation (SDRE) controller. SDRE requires a pseudo-linear model of the system to be controlled so a pseudo-linear model of the quadcopter is derived first. At each time step, a control law is obtained using the SDRE approach but the state used to form the control law at each of those steps is fed from an estimator (Kalman filter). The results of a simulation done in Python are presented in the simulations section.