An investigation into the stability of helicopter control system under the influence of time delay using an improved LKF

This paper presents an improved Lyapunov–Krasovskii functional (LKF)-based stability analysis of time-delay systems (TDS) and its application to helicopter control systems. A novel LKF is proposed for the stability analysis of linear TDS after thoroughly examining the effects of each integral associated with a general class of LKF. The suggested stability results in the form of linear matrix inequalities (LMIs) are obtained using the Wirtinger-based integral inequality (WII), reciprocally convex combination lemma (RCCL), and extended reciprocally convex matrix inequality (ERCMI). Numerical examples are utilized to evaluate the impact of the presented theorems on stability. The proposed theorems are then used to examine the stability of helicopter control systems, and the results of these stability analyses are verified using a laboratory model of a helicopter control system. •A novel LKF is proposed for the stability analysis of time-delay systems.•Extended reciprocally convex matrix inequality is exploited to get the stability results.•Stability results are used to investigate the stability of the laboratory model of the helicopter control system.