Experimental chattering reduction in sliding mode control using integral resonant signal shaping on a twin rotor aerodynamic system

Due to its high resilience to uncertainties and disturbances, Sliding Mode Control (SMC) is frequently employed in nonlinear systems; however, it suffers from an inherent drawback of chattering, resulting in high-frequency control oscillations, increased actuator wear, and energy inefficiency, which often limit its practical application. This paper presents a practical solution to reduce chattering without altering the fundamental structure of SMC, by introducing an Integral Resonant Control (IRC) loop as a signal-shaping stage that preserves robustness while smoothing switching-induced oscillations. The proposed SMC–IRC approach is experimentally validated on a twin rotor aerodynamic system, a strongly coupled nonlinear MIMO platform that emulates helicopter-like dynamics, and its performance is evaluated under both step and sinusoidal tracking tasks in comparison with conventional SMC and Super-Twisting SMC. The results demonstrate that the proposed method maintains comparable tracking accuracy while significantly reducing chattering and control energy; in sinusoidal tracking, it improves actuator command smoothness and reduces control signal variation, while step-response results confirm reduced mechanical stress with only a slight trade-off in transient speed. Overall, the findings indicate that resonance-based signal shaping provides an effective and actuator-friendly enhancement to SMC, offering a simple, computationally efficient solution suitable for robotic and real-time aerospace applications where hardware protection and smooth control action are critical.