| Along with the high efficiency and fast pace of life, people always ignore taking proper exercises to improve the physical function themselves, according to the advice which is given by the health experts of WHO, one should maintain an appropriate amount of exercise each day to prevent disease. With continuous development of science and technology, wearable smart devices are changing the existing users’ form of exercise, by wearing a smart pedometer, the user may remind himself to take proper exercises, to further keep a healthy body. In order to change the shortcomings of conventional pedometers, whose wearing positions are not in accordance with user habits, the power consumption is very high,as well as the accuracy of step counting is relative low, in this paper, a portable step counting system based on low-power Bluetooth is designed, which can implement the real-time detection of the user’s walking data and has a better interactive experience of the mobile handheld terminal for the user.Therefore, this paper mainly presents a system which has a good user experience and is based on low-power Bluetooth technology. The proposed system is implemented by taking advantages of TI CC2540 development kits, which performs the function of collecting the user’s walking data through an acceleration sensor, then transmit the data into an Android system based portable device through an RF module after filtering process, the user may access the relevant sports data directly in the mobile terminal, which brings a good user experience. Due to the complexity of the arm swing trajectory of the human body is far greater than that of the waist and feet in the process of walking, in this project, how to improve the user experience and the measuring accuracy of the proposed pedometer worn on the wrist are the issues to be designed.In order to ensure the high accuracy of the pedometer, the characteristics of human walking process are first modeled in this paper, for the sake of analyzing the periodic feature of the acceleration during human walking, and take it as a design basis for the step counting algorithm; in order to achieve high accuracy of the step counting algorithm, the number of walking steps is calculated by making use of the improved waveform peak-detection based approach, as well as the improvement of the step counting method is accomplished which is on the basis of the original algorithm:adding a "disturbance state" into the state rules of the parameters of the original step counting algorithm, while the system detects the current state as the "disturbance state", the counting process will be stopped, as well as the threshold value in the time span will be prolonged to a certain extent, to further improve the step counting accuracy. Moreover, according to the user’s habit of using portable devices, a program for the mobile terminal is designed in this paper, which has a good user experience.Through the analysis and verification of the proposed system, it can be concluded that the proposed system has a relatively low power consumption, which can serve for a long period and is able to meet the user’s needs. Test results show that the receiving sensitivity of the proposed system is -92.5dBm, The step counting accuracy can reach around 90% eventually by the testing courses of various users, whose performance and functional indices can meet the design standards. |
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