Robust direct acoustic impedance control using two microphones for mixed feedforward-feedback controller

This paper presents an acoustic impedance control architecture for electroacoustic absorber combining both feedforward and feedback microphone-based strategies on a current-driven loudspeaker. Feedforward systems enable good performance direct control. However, inaccuracies in the required actuator model can lead to loss of passivity, which cause unstable behaviour. The contribution allows better handle errors still achieve accurate impedance, preserving passivity. Numerical experimental studies were conducted compare this new against state-of-the-art method.