Intelligent Mixed-Signal Embedded Systems for Electromagnetic Tracking Applications

Real-time analytics is the main advantage of Edge Computing (EC) in the concept of Artificial Intelligence (AI). AI EC brings high-performance computing capabilities to the edge, where sensors of Internet of Things (IoT) devices are located and data is processed locally, which significantly improves processing speed as compared to cloud computing. The core of AI EC is based on real-time embedded systems. This work presents intelligent embedded systems for electromagnetic tracking (EMT) applications. EMT is a novel development trend in sensor electronics and object navigation for IoT, Virtual, and Augmented Reality. The EMT technology relies on calculating the position of an object being tracked based on dynamic measurement of reference electromagnetic field vectors. In contrast to optical tracking systems, EMT does not require any clear line of sight (LOS) and therefore is not susceptible to occlusions. Inertial sensor tracking (IST) systems, which are based on inertial measurement units (IMUs), suffer from measurement errors intrinsic for accelerometers and gyroscopes, primarily from bias drift and random walk. EMT systems are free of these errors and overcome inertial tracking systems in their accuracy. The former provides the opportunity to obtain high-precision measurements of the sensor coordinates in 3D EM field space formed by the actuator array. Nevertheless, EMT systems have a limited application area. Such limitations are caused by significant signal changes and strict requirements set to the environment where reference EM fields are supposed to be formed. We have shown that one faces two main issues when designing an EMT system. Firstly, one should ensure a wide measurement range (up to 120 dB). Secondly, highly noise-immune measurements are required under specific operating conditions. The novelty of the presented solution is the intelligent algorithm of noise-immune conversion in conditions when the signal chain parameters are switched dynamically. This solution creates the necessary prerequisites for measurement accuracy enhancement and expansion of the volume in which tracking takes place. The signal chain was implemented using the PSoC 5LP and thus conforms to the concept of EC Programmable Systems-on-Chip.