Active noise control systems with optimized secondary path

In many real-world active noise control (ANC) applications such as electronic mufflers, the sensors may not be placed at the optimum locations in order to protect them from the high temperature, fast airflow, and corrosive environment. This work presents an optimized algorithm for compensating sensor placement effects when the error sensor is placed at a secured physical location. This algorithm uses a compensation filter for pre-filtering the anti-noise such that the ANC system with the error sensor located at the physical location has the optimized secondary path as the sensor placed at the virtual location. An electronic muffler has been built and used for testing this optimized ANC system using engine noise. Computer simulations show significant improvement of the performance for the new ANC system with the optimized virtual secondary path.