Robust Control of Single-Link Flexible-Joint Manipulators with Perturbed Inertia Based on Fully Actuated System Approach

This paper proposes a fully actuated system (FAS) approach for the robust control problem of single-link flexible-joint manipulators (SLFJMs) with perturbed inertia. Unlike previous studies, the method proposed in this paper only requires the design of a simple robust state feedback controller to achieve high-precision control without the use of neural networks, observers, etc. Meanwhile, the control problem of FASs with perturbed input matrices is still rarely studied, and this paper proposes an effective control method for this case, which broadens the application scope of the FAS approach. Firstly, the SLFJM with perturbed inertia is transformed into a FAS with perturbed input matrix using an appropriate state transformation. Meanwhile, a converted control problem is formulated for the transformed FAS. Then, a robust controller is designed based on the full-actuation property, which ensures that the states are globally bounded and eventually converge into an arbitrarily small region centered at the origin. Finally, the effectiveness of the method is demonstrated by simulation.