Using multiple sensor triads for enhanced misalignment estimation for portable and wearable devices

Some existing applications on smartphones and tablets use the accelerometers, gyroscopes, and magnetometers to provide basic indoor positioning solution starting from a known position for short time periods. However, this can be achieved only if the portable device is kept in a fixed orientation, which is unrealistic and inconvenient for the user. In unconstrained portable navigation, the mobile device orientation can be freely changed with respect to the human body without any constraints. In this paper, a novel method is proposed to estimate or enhance the heading misalignment angle between one or more smart device(s) and/or wearable appcessories and the moving platform (person or vehicle). An accurate estimation for heading misalignment angle enables users to change their devices' orientation freely with respect to their bodies without any constraint. Different test scenarios are conducted to assess the performance of the proposed technique including different use cases. The results clearly demonstrated the efficacy of the proposed technique in enabling real-time, continuous and reliable consumer localization indoors and outdoors with mobile device.