Noise Cancellation of the Fan Noise of Anthropomorphic Robot's Head

Xu, Shaoyuan

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https://hdl.handle.net/2142/79006 Copy

Description

Title

Noise Cancellation of the Fan Noise of Anthropomorphic Robot's Head

Author(s)

Xu, Shaoyuan

Contributor(s)

Levinson, Stephen

Issue Date

2015-05

Keyword(s)

• Noise type
• Signal recording
• Signal analysis
• Filter design
• Actual filtering

Abstract

There is an anthropomorphic robot in out lab whose name is Bert. One of the basic methods to control the robot is by voice. The voice signal goes into Bert's ears. But there is a problem in that to cool down the chips in Bert's head, there are two fans in its head which make a lot of noise. Because the microphones are mounted to the frame of Bert's head and they are very close to the fans, the sound is mixed with a lot of noise, thus making the signal inaccurate and the sound noisy. So the noise must be filtered. First, the type of noises must be determined. After our analysis, there are two kinds of noises, air-borne noise and structure-borne noise. After further experiments and analysis, we found that the structure-borne noise is the more significant one. Another external microphone was bought to record the sound in the robot's head. In order to get the noise we want, we put the external microphone 1 mm-2 mm away from the fans to get the noise signals containing more structure-borne noise and less air-borne noise. Then, we analyzed the noise signals using Matlab. After doing FFT on the signals to get the diagrams of the noise signal in frequency domain, we found the frequencies of the noise signals. The next step is designing the filter using Matlab. In order to notch out the noise, the windows of the filter must match the frequency of the signals. The result was very positive. Most of the noise signals were filtered out. In the final step we recorded sound signals with people's voice and did the analysis on the signals. We then redesigned the filter according to the new signals and did the noise cancellation.

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/79006

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