ANC Simulation vs Measured
In ANC product development modelling and simulation tools tools are an essential part of the process. The use of simulation tools allows the designer to predict the ANC performance as well as understand key characteristics such as phase and gain margin.
The question is however, how well does the simulation data match the actual results we get when a physical implementation is built. Lets take a look at one example.
In this case we use a feedback ANC earphone and measure the so called acoustic plant.
Using the development software we develop a suitable feedback filter, also known as the controller. The process of developing the filter is semi-automated given some constraints on the stability and required ANC level. The resulting filter is shown in the plot below.
Next we build the physical implementation based on this simulation data. The filter is constructed according the model and is connected as the feedback controller for the earphone we started with. Then the ANC performance measured and compared to the performance predicted by the model.
The graph above shows simulated ANC overlaid with the measured ANC. Indeed we find the simulation produces excellent results and matches very closely to the measured data. With this kind of outcome we can use the simulation with a high degree of confidence and build designs very efficiently.