Nxp B.v.

Guanqing Wang

Jie Zhang

Vasanth Reddy Gaddam

Yifeng Zhang

Yuanwei Wu

A method and apparatus for activity tracking based on time domain and frequency domain processing are disclosed. Embodiments according to the present invention are used to improve the accuracy of activity detection and step counting. The activity tracking starts from sample collection to generate 3-D accelerometer data. By pre-processing, the 3-D accelerometer data is calibrated and filtered. Then, the dominant component is calculated and statistical attributes or features used for activity detection are extracted. The statistical attributes are derived from time domain sensor data, frequency domain transformed data, or both. A classifier is developed using representative training data set. The activity detector determines the current activity status based on the statistical attributes and the classifier. To further refine the activity, post-processing is performed on the activity status.

Time and frequency domain based activity tracking system

A system for counting steps comprising a 3-D accelerometer is disclosed. The system also includes a pre-processor module coupled to the 3-D accelerometer and a dominant component computation unit coupled to the pre-processor module. The dominant component computation unit is configured to identify a dominant component in an output of the 3-D accelerometer. The system further includes a step counter for counting a number of steps using the output of the dominant component computation unit. The step counter includes a Fast Fourier Transform (FFT) module and a direct current (DC) remover module to remove a static component from the output of the FFT module. The step counter also includes a derivative filter and a zero crossing detector.

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Beijing, China

Guanqing Wang