Linear Quadratic Gaussian Control for Wireless Communication Reliability for a Mobile Monitoring Robot in a UHV Power Substation

In ultrahigh-voltage (UHV) power substations, mobile robots equipped with sensors and cameras have been adopted for patrolling and inspecting the operational status of devices. The robots connect with a management system via wireless communication. However, environmental factors, such as distance to the wireless access point, surrounding structures, or electromagnetic interference, affect the reliability of wireless communication and, therefore, impact robot operation. To meet the reliability requirement specified by the smart grid communication standard, we propose a linear quadratic Gaussian (LQG) control on the wireless link to ensure its reliability. First, a state-space model of wireless links is constructed based on a path loss model, in which the signal-to-interference-plus-noise ratio (SNIR) is chosen as the state of the system. Then, an improved Kalman filter and a linear quadratic regulator control are adopted to estimate the state and obtain the optimal transmitting power, respectively. In addition, the confidence interval of the SNIR is estimated to compensate for the filtered random factors on the SNIR. Finally, to evaluate the proposed LQG controller, we compare it with state-of-the-art methods through simulation and verify its effectiveness in a real-world UHV substation.