A novel inertial positioning update method, using passive RFID tags, for indoor asset localisation

The benefits of the fourth industrial revolution are realised through accurate capture and processing of data relating to product, process, asset and supply chain activities. Although services such as Global Positioning Services (GPS) can be relied on outdoors, indoor positioning remains a challenge due to the characteristics of indoor environments (including metal structures, changing environments and personnel). An accurate Indoor Positioning System (IPS) is required to provide end-to-end asset tracking within a manufacturing supply chain to improve security and process monitoring. Inertial measurement units (IMU) are commonly used for indoor positioning and routing services due to their low cost and ease of implementation. However, IMU accuracy (including heading and orientation detection) is reduced by the effects of indoor environmental conditions (such as motors and metallic structures) and require low-cost reliable solutions to improve accuracy. The current state of the art utilises algorithms to adjust the IMU data and improve accuracy, resulting in error propagation. The research outlined in this paper explores the use of passive RFID tags as a low cost, non-invasive method to reorient an IMU step and heading algorithm. This is achieved by confirming reference location to correct drift in scenarios where magnetometer and zero velocity updates are not available. The RFID tag correction method is demonstrated to map the route taken by an asset carried by personnel in an indoor environment. The test scenario task is representative of warehousing and delivery tasks where asset and personnel tracking are required.