Active vibration control over the flexible structure of a kitchen hood

This paper presents the full analysis and the complete development of a system for mechanical vibration reduction in a kitchen hood by using piezoelectric actuators. The control system is based on a feedback controller whose action depends on a single acceleration sensor collocated with the actuator. A model of the collocated actuator-sensor pair mounted on the hood and a model of the disturbance are provided. A Minimum Variance (MV) controller is able to provide the theoretically best performance in terms of noise reduction. A single-tones Minimum Variance controller (resonant controller) provides quasi-optimal performance while maintaining the stability of the system. Two different resonant control laws have been designed: the first one operates without the information of the hood motor velocity; the second one is a more sophisticated controller, which also exploits the velocity information. Both controllers are effective in reducing the mechanical vibration with performances that well approximate those achievable with an MV controller. Overall, through the motor velocity’s information, the best performances are guaranteed with an 85% vibration reduction. The resonant control system without the motor velocity information provides the best compromise in terms of performances (75% of reduction) and complexity of the implemented system. Tests held in an anechoic chamber have shown the vibration reduction’s influence upon the acoustic noise.