A Compensation Model for Packet Loss Using Kalman Filter in Wireless Network Control Systems

In Wireless Network Control System (WNCS), a study approach is relevant for the development and analysis of control strategies that provide the operation of dynamic systems. Among the real characteristics of the communication channels, a packet loss is one of the main deficiencies present in the transmission of data in a wireless network. For a dynamic system in the presence of losses, a filtering technique makes it possible to estimate system states using process output measurements and to mitigate a performance drop. It is important to study packet losses in Wireless Network Control Systems because packet loss can severely degrade the network performance. Wireless networks are particularly vulnerable to packet loss due to factors such as interference, fading and signal attenuation. The present work analyzed the behavior of a real WNCS plant at different levels of packet loss using the IEEE 802.15.4 protocol. Also, we propose a compensation model for packet loss using the Kalman filter. The packet loss process is based on a Gilbert-Elliot model and is compared with a Proportional-Integral-Derivative (PID) controller. The results show that by applying Kalman filters it is possible to improve the operation of the process in case of losses during data transmission. It was observed through the simulation that it is possible to reduce the error of the system output in relation to the reference in the presence of packet loss. For a loss ratio of 30%, the observed improvement in the system behavior with the use of the Kalman filter was 26.1%.