Robotic architecture as unknown discrete-time system based on variable-frequency drive and adaptive controller

•The novel robotic architecture is established by task multiplexer and modelfree adaptive control.•The flexible robotic system is operated by using input-output data.•Improved the outdated robotic arms by the proposed architecture. The new architecture for outdated robotic arm (ABB: IRB-1400) is developed by the direct variable-frequency drive (VFD) and considered as a class of unknown nonlinear discrete-time systems. The identification model is established by Multi-input fuzzy rules emulated network (MiFREN) with the online learning algorithm and the database of IF-THEN rules. The controller is designed by using the identification model and feedback signals from the multiplexer when kinematic and dynamic models of the robotic system are neglected. The convergence of tracking errors and internal signals is guaranteed by both theoretical and practical aspects. The performance validation of the proposed robotic system is accomplished by the experimental setup with comparative results.