Relaying in Cislunar Telemetry and Telecommand Communication: An Information Value Loss Guided Scheduling Mechanism for Multiple Time-Delay Control Systems

In the lunar missions, relay satellites on the various orbits play critical roles in the cislunar communications, i.e. telemetry and telecommand to the probers on the far side of moon, which could help achieving the constant visibility between the actuator and the controller. However, huge time span in the end-to-end communication incurs obvious delay during the control loop which current controller design could not deal with effectively. In this work, therefore, we propose a greedy algorithm-based scheduling mechanism (GASM) for multiple time-delay control loops through the cislunar relay communication. In particular, we develop a novel metric of information value loss (IVL) to measure the utility of the proposed GASM by considering the timeliness of telemetry and telecommand data on the control loop. The simulations show that the proposed GASM could achieve excellent control stability and timeliness of data compared with typical scheduling algorithms based on age of information (AoI).