Walking detection method based on FFT

Abstract

The invention discloses a walking detection method based on FFT. A sensitive axis detection is carried out for x, y and z triaxial angular velocity under a smart phone device coordinate system, spectrum analysis processing is carried out for an angular velocity data corresponding to the sensitive axis, and amplitude mean value is calculated in order to determine relations of the two; an amplitudecurve is fitted, walking frequency of human is calculated, total step numbers of continuous walking at present of a pedestrian is calculated by using a walking time, time window is slid forward, and execution is repeated. Unstabilization factors of a coordinate system are considered, and walking motion of the pedestrian can be more sensitively, accurately and rapidly detected.

Description

technical field [0001] The invention belongs to the technical field of walking detection, in particular to an FFT-based walking detection method. Background technique [0002] The most representative of the existing walking detection methods are the following four: [0003] 1. Threshold-based walk detection. [0004] The threshold method is the simplest, but the difficulty lies in how to choose the optimal threshold, especially for unconstrained smartphones. Threshold selection is primarily determined through multiple trials, and once a threshold is determined, it is used across all test subjects. If there are many categories, multiple thresholds need to be set, and the posture and position of the sensor have a great influence on the selection of thresholds. In addition, it is not easy to choose an appropriate threshold because different testers have great differences in performing the same action. In the threshold-based walking detection method, the measured value adopt...

AI Technical Summary

Problems solved by technology

[0016] First, in order to improve the accuracy of step counting, some existing walking detection methods adopt the method of fixing the sensor device on a certain part of the human body (wrist, ankle, etc.), which limits the flexibility of the system

[0017] Second, most of the existing walking detection methods process the acceleration values ​​of the x, y, and z axes acquired by the acceleration sensor, and the accuracy of step counting based on the acceleration sensor is greatly affected by the stability of the coordinate system of the system

[0018] 3. The threshold-based walking detection method and the standard autocorrelation coefficient method judge the movement of pedestrians by means of a threshold greater than a fixed value. This method can easily misjudge other daily activities of people as displacement movements, which affects step counting. the accuracy of

[0019] Fourth, the wavelet transform method makes the mother wavelet and the signal repeatedly correlated, and short-term and reasonable scaling can capture the sudden change of the acceleration signal, but the cost of completing such calculations is expensive

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