A New HOFA Approach and Evaluation for Quadrotor Control over Feedback Linearization Methods

Considering the technical similarities and wide impacts in control design, this paper presents comparative studies and evaluations of a new high-order fully actuated system (HOFA) approach with respect to the well-known (partial) feedback linearization (PFL/FL) methods for quadrotor systems. For quadrotors and other highly coupled underactuated systems, FL typically transforms an entire nonlinear system into a linear model with extended states. In contrast, PFL selectively linearizes a subset of dynamics and creates an inner-outer loop control structure. On the other hand, HOFA constructs a dual-layer architecture, decoupling a nonlinear system into a linear high-order subsystem and a linear low-order one. The study discusses the practical challenges of FL in measuring high-order states, the simplified design of PFL, and the modular advantages of HOFA. Simulation results show that the HOFA approach can provide effective control, which is easier tuning than PFL and has a lower-order model with fewer observation requirements than FL. Hence, the new HOFA control design reveals a promising and better approach for quadrotor control and other nonlinear control systems to which PFL/FL are commonly applied.