Bumpless Transfer Control Strategy for Event-Based Cloud Control System

This paper proposes the integration of Bumpless Transfer Control (BTC) strategy into an Event-based Cloud Control System (EBCCS). The proposed EBCCS is a cloud-based Nonlinear Model Predictive Control (NMPC) framework equipped with a time-delay compensator, which utilizes the most recent input sequence during communication and computation delays until a new input sequence is received from the cloud controller. To minimize abrupt jumps (bumps) in the control input during the transition from the previous input sequence to the newly computed one, a novel simulation-based BTC strategy is introduced. The proposed BTC consists of two components. The first component of the proposed BTC approach initiates NMPC computation using simulated future system states, leveraging the knowledge of previously computed input sequences that will be applied during the delay. The second component, applied after NMPC computation, matches the current system states with the predicted system states and their corresponding input, optimizing the starting point of the new sequence for smoother transitions. This BTC strategy suppresses bumps during transitions between control sequences without modifying the core structure of the NMPC optimization algorithm, ensuring straightforward integration into existing control frameworks. The effectiveness of the proposed EBCCS equipped with the BTC strategy is demonstrated through simulations on a crane pendulum system and an inverted pendulum system, highlighting its effectiveness in improving control performance under time delays. The results indicate that the BTC strategy can significantly enhance stability and performance in event-based cloud control settings, paving the way for more robust implementation in real-world, delay-prone cloud control systems.