RFQVibration analysis
Recognizing the commands from the host's voice is important for a smart-home device, especially a smart speaker that plays music simultaneously. When talking to people on the Internet, the capability of echo cancellation allows smooth communications. Both functions rely on the high quality of the receiving path through the microphone. The quality will be significantly impacted if the vibrations of the device's walls and/or components are conducted from working speakers to microphones. We can build the simulation model to predict the situation and then give solutions to prevent it in the early design stage. Figure 1 shows a smart speaker that is designed with four array microphones.
The simulation results indicate which significant vibrations at 71Hz will impact the receiving quality of the microphones. Figure 2 shows the initial result of the simulation (the area of red color has the highest displacements (vibrations) and blue is the opposite.
KS suggests two suggestions to deal with the situation. The first one is to directly modify the plastic walls to stiffer materials. The example here is to use ABSPC to replace the original ABS for all devices' plastic walls. Figure 3 shows the simulation results, the vibrations are efficiently suppressed.
Another solution is to add ribs to strengthen the stiffness of the walls. Figure 4 shows where the ribs are added.
Simulating the model after adding the ribs, the result shown in Figure 5 indicates the vibrations are suppressed and not able to conduct to the microphones. Using proper tools to predict the designing issues and solve them as early as possible during the development can save time and costs, so strengthen the abilities of competition.
