Passivity-Based Pinning Synchronization Control of Switched Directed Networks With Improved Switching Strategy

This research delves into the passivity-based pinning synchronization problem for switched directed networks (SDNs) within the context of a sampled-data-based event-triggered (SDET) communication environment. An improved state-dependent switching strategy (SDSS) using sampled measurements alongside a novel time-dependent Lyapunov-Krasovskii functional (LKF) approach is constructed. Subsequently, a relaxed passivity analysis framework is then presented, ensuring that the resultant synchronization error system (SES) remains passive, and that the examined SDNs achieve asymptotic synchronization in the absence of external inputs. Unlike conventional strategies, the proposed switching protocol depends exclusively on system states at discrete sampling instants and effectively utilizes historical state data, yielding a less conservative theoretical framework for passivity synthesis in SDNs. Furthermore, the resulting synchronization criterion is independent of the number of network nodes, rendering it suitable for SDNs with large size. Ultimately, two examples involving relevant application in image encryption and decryption are provided to verify the effectiveness and applicability of the proposed scheme, and highlight the distinct advantage of switching behaviors in enhancing encryption confidentiality.