State Estimation with Correlated Packet Drops: An Experimental Evaluation with a Mobile Robot

Networked control system (NCS) is a composite technology of control system and communication network where each element of the system interconnected by a common network back-end. However, as these systems often depend on unreliable communication channels, it may lead to packet drops during the transmission of measurement or control data. If we identify fading as the cause of packet drops, it implies that these drops may be correlated in time. This phenomenon poses a major challenge for accurate estimation of state variables, which is essential for ensuring the stability and performance of the system. This necessitates the estimation algorithms to be modified to incorporate this additional information to ensure accurate assessment. In this work, a modified state estimation algorithm is developed which can be utilized for the analysis of estimation error covariance in the presence of correlated packet drops. Also, bounds on error covariance in terms of channel condition is derived. The algorithm is validated through simulations and an experimental evaluation has been done using a mobile robot platform.