High-order fully actuated (HOFA) system approaches
High-order fully actuated (HOFA) systems represent a nuanced frontier in control theory, bridging intricate dynamics with profound control capabilities. Rooted in the realm of systems with advanced differential degrees, these systems, which are often derived from complex physical laws such as Lagrangian mechanics, boast a balanced ratio of control inputs to system outputs. This characteristic, synonymous with being “fully actuated”, ensures a more direct control strategy, rendering them particularly favorable in fields like mechanical engineering, aerospace, and electrical systems. While their high-order nature encapsulates multifaceted behaviors, the full actuation empowers engineers and scientists with a robust platform to achieve precise and desired system responses. Included in this collection is a set of ten seminal papers published in the International Journal of Systems Science, which forms the foundation of the HOFA systems theory. In fact, due to their theoretical significance and practical importance, HOFA systems have already attracted widespread attention with applications to various control problems such as robust control, adaptive control, disturbance rejection, optimal control, and tracking control. It is envisaged that this collection of the pioneering results would help disseminate the HOFA systems theory, which would have a lasting impact on control theory and control engineering.