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The modern trend of developing highly automated aircraft is characterized by a transition from traditional methods and technical solutions to innovative approaches in order to control the system, inceptor and display design. This paper deals with the development and comparison of flight control system algorithms based on inverse dynamics, H-infinity and traditional feedback methods. The integration of a controller based on inverse dynamics with a novel type of sidestick, shaping the pilot output signal such that it is proportional to the control force (force sensing control—FSC), is studied. The inverse dynamics-based controller is chosen, as it provides a variance of error that is up to 2.3 times less than that of the feedback gains and up to 1.5 times less than that of the H-infinity controller in a pitch tracking task. The synergetic effect arising from the proposed integration is also evaluated. The evaluation of the effectiveness of the methods is carried out through mathematical modeling of the pilot–aircraft system and ground-based simulations on a helicopter mathematical model in a pitch tracking task.

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This paper introduces and investigates several methods of filtering and delay synchronization in incremental control law structures. It is shown that proper filter and delay synchronization is of great importance for both the performance and stability of the control laws. It is derived how to synthesize complementary filters in case of sensor dynamics, sensor delays and internal control law filtering such as roll-off filters and notch filters. The complementary filters are compared to common synchronization approaches previously applied in incremental control laws. It is shown that the proposed methods are beneficial for Multiple Input Multiple Output (MIMO) systems in case that different delays and filtering is present in the different measurement signals. In case of strongly coupled input effectiveness, the synchronization on the actuator feedback may become even unstable, where the complementary filter approach recovers the design closed-loop behavior. In addition, it is derived how to initialize the complementary filters for a transient-free engagement in non-steady-state conditions. The results are compared in simulation with a roll rate control law for a fixed wing aircraft.

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