Vibration analysis

Recognizing the commands from the host's voice is essential 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 device's walls and components vibrate 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.

Figure 1  shows a smart speaker design 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.

Figure 2  shows the initial result of the simulation; the red color indicates high displacement, and the blue indicates low.

KS suggestwaysstions to deal with the situation. The first one is to modify the plastic directly 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 r; as a result, the vibrations are efficiently suppressed.

Figure 3 shows the simulation results showing that the vibrations are efficiently supported.dressed.

Another solution is to add ribs to strengthen the stiffness of the walls—figure 4 shows where the ribs are added.

Figure 4 shows where the ribs are added

Simulating the model after adding the ribs, the result shown in Figure 5 indicates that the vibrations are suppressed and not able to conduct to the microphones. Using proper tools to identify issues and solve them as early as possible during development can save time and effort and strengthen the abilities of the competition.

Figure 5  The simulation results after adding the ribs