Active control of noise and vibration for time-varying transfer paths

Development of a flexible large-area array based on printed polymer transducers for mid-air haptic feedback

Ultrasound based mid-air haptic feedback devices can produce tactile sensations at any time and position without restricting human motion. This is useful for augmented and virtual reality, feedback buttons and virtual user interfaces. The haptic feedback mechanism is caused by acoustic radiation force and streaming. Typical solutions to induce...

An acoustic radiator with integrated cavity and active control of surface vibration

This paper presents a method to realize an acoustic source for low frequencies with relatively small thickness. A honeycomb plate structure which is open on one side combines the radiating surface and the major part of the air cavity. The vibration of the plate is controlled with a decentralized feedback controller. The fundamental resonance...

Real-time steerable directional sound sources

Warning signal generators in cars are being developed that have the objective to warn vulnerable road users. Several sensor systems exist which are able to reveal the position of the vulnerable road users, which information can be used by the warning signal generator. Based on this information, the signal generator can be designed to generate...

Tracking and convergence of multi-channel kalman filters for active noise control

The feed-forward broadband active noise control problem can be formulated as a state estimation problem to achieve a faster rate of convergence than the filtered reference least mean squares algorithm and possibly also a better tracking performance. A multiple input/multiple output Kalman algorithm is used to perform this state estimation. To...

Active vibration control for underwater signature reduction of a navy ship

Dutch navy ships are designed and built to have a low underwater signature. For low frequencies however, tonal vibrations of a gearbox can occur, which might lead to increased acoustic signatures. These vibrations are hard to reduce by passive means. To investigate the possibilities of active vibration control to reduce the underwater signature,...

Optimal and robust feedback controller estimation for a vibrating plate

This paper presents a method to estimate the H2 optimal and a robust feedback controller by means of Subspace Model Identification using the internal model control (IMC) approach. Using IMC an equivalent feed forward control problem is obtained, which is solved by the Causal Wiener filter for the H2 optimal controller. The robust variant, called...