INDI Application in Flight Control Law Design of Civil Aircraft

The stringent safety requirements for civil aircraft flight control have consistently favoured the application of Proportional Integral Derivative (PID) in conventional flight control design. However, PID gain adjustment becomes burdensome when designing multimode flight control laws within the full envelope. For advanced civil aircraft, the complexity of mode management and gain adjustment is likely to escalate further. The Incremental Nonlinear Dynamic Inverse (INDI) holds promise as an effective solution. The scientific validity of INDI has been demonstrated through cases such as F35-B. However, there remains significant challenges in applying INDI to the flight control laws design of civil aircraft. One key challenge is the design of a unified INDI control scheme that can accommodate Level 1 flight quality commands. Another challenge is to demonstrate that INDI can effectively simplify gain tuning and mode management while achieving the desired control effect. This paper addresses these issues by proposing a model-based INDI control scheme and corresponding evaluation scheme, demonstrating satisfactory adaptability to the stringent safety requirements and the simplification advantages. The proposed solution herein is a meaningful endeavour to apply INDI to civil aircraft flight control law design, which contributes to leverage the advantages of advanced civil aircraft in various scenarios.