Body Movement Sensing Based On Inertial Sensors

In recent years,due to the portability of wearable device,wearable device has become increasingly popular in people's daily life.Modern wearable devices are basically equipped with inertial sensors including accelerometer and gyroscope,etc.Body movement sensing mechanism based on inertial sensors has also become a hotspot in recent years.In this paper,we focus on two aspects of body movement sensing based on inertial sensors:authentication for multi-sensor devices and space synchronization for multi-sensor devices.First,the wireless ad hoc network allows devices to spontaneously find and interact with each other.However,due to the nature of Wireless ad hoc network,authentication between devices has become a serious problem.In this paper,we propose a gyroscope based attitude tracking model called GYAT and implement an authentication system based on inertial sensors.By using our system,two users with wearable devices can build authentication through realworld handshake.During the authentication process,we explore the correlation of the inertial sensor data,and extract secret keys independently on the devices.We implement our system on MOTO 360 smart watch.The experiments show that our GYAT algorithm can achieve an average data similarity of 85%,and an average key generation rate of 14b/s.Second,based on the research of GYAT model in handshake authentication system,we have made further research and define the concept of space synchronization for mobile devices.Space synchronization can be the enabling technology for many applications such as motion sensing in virtual reality and Human Computer Interaction(HCI).In this paper,we propose a scheme called Mobile Space Synchronization(MOSS)for devices with two sensors:an accelerometer and a gyroscope,which are available on most mobile devices.Accelerometer readings from multiple mobile devices on a human subject are used to achieve space synchronization when the human subject is moving forward,such as walking and running.Gyroscope readings from multiple mobile devices on a human subject are used to maintain space synchronization when the human subject stops moving forward,which means that we can no longer obtain the consistent acceleration caused by body moving forward.We implemented our MOSS system on six mobile devices including one Google Glass and five Sam-sung S5 smart phones.Experiment results show that our MOSS scheme can achieve an average angle deviation of 6.80 and an average measurement similarity of 93%.The main contribution we made in this paper are as follows:1.We propose a gyroscope-based attitude tracking model called GYAT,which can track the attitude of the wearable device and calibrate the sensor data,so that the sensor data between the devices can achieve maximum similarity.2.We implement an authentication system based on inertial sensors and carried out the experimental analysis in the real environment.The experimental results show that our authentication system can achieve an average data similarity of 85%,and an average key generation rate of 14b/s.3.We define the concept of space synchronization for mobile devices and propose the MOSS scheme to achieve space synchronization among multiple mobile devices.4.We implemented MOSS on COTS mobile devices,and the experiment results show that our MOSS scheme can achieve an average angle deviation of 6.80 and an average measurement similarity of 93%.