Research On Human Motion Detection Based On Human Body Communication And Multi-inertial Sensors

In recent years,the provision of effective digital guidance in the fields of medical health and sports training,by human motion monitoring based on wearable sensors in body area networks(BANs),has advanced rapidly.Primarily,radio frequency technology(RF)is used to transfer data in BANs.However,RF is prone to multi-path effects,can produce interference among multiple individual networks,and has low security,poor network throughput,and power consumption issues,resolving the problems usually by using algorithm to improve network quality.This paper researches human body communication(HBC),which uses the body as a communication channel.Its lower frequency,hence very local propagation,ensures greater security,its power consumption is low,and it has improved network performance.This paper proposes,and investigates the feasibility of using HBC in BANs based on inertial sensors,and studies the performance of the overall system as the following aspects:Firstly,the AHRS inertial sensor platform was introduced,as well as the data processing algorithm,so the processing time and data output format could be obtained,which could be help to calculating the data rate in HBC and the sampling rate of system.Secondly,the transceiver was designed by analyzing the cycle time of motion detection and researching the channel attenuation characteristics of the human body.Then the bit error rate(BER)of the channel was discussed in this paper which would provide prerequisite for discussing BAN performance.Thirdly,requirement of body monitoring system,topology and MAC protocol of BAN were discussed,meanwhile,the mathematical model of maximum network throughput was built based on the parameters of previous study about data rate and the BER of the channel,so that the viability of HBC technology in human motion monitoring system could be verified.Finally,the three-nodes' posture monitoring system based on HBC was established,and its throughput with different data rate and sampling rate was tested.Meanwhile,the throughput performance of the system would be observed and parsed via the monitoring software,developed on PC,which would display the kinetic data as well as 3D reconstruction.Above study results show that the designed HBC transceiver hardware based on OOK modulation has low BER with less than 10-5.Besides,body motion has little effect on the performance of BER.In the three-node network monitoring system based on PCF MAC protocol can provide about maximum 66Hz refresh rate on human channel.The results indicate that HBC of inertial sensor action provides reliable monitoring in a BAN.