This article proposes a fractional order nonsingular terminal super-twisting sliding mode control (FONT-STSMC) method for a micro gyroscope with unknown uncertainty based on the double-loop fuzzy neural network (DLFNN). First, the advantages of nonsingular terminal sliding control are adopted, a nonlinear function is used to design the sliding hyper plane, then the tracking error in the system could converge to zero in a specified finite time. Second, fractional order control can increase the order of differential and integral, which greatly improves the flexibility of control method. The fractional-order controller has some advantages that integer-order systems cannot achieve, thus obtaining better control effects than that without adding fractional order control. Furthermore, the chattering problem of control input can be effectively solved by using the super-twisting algorithm, which makes the control input smoother. Finally, the unknown model of the micro gyroscope is estimated by using the DLFNN. Because the DLFNN can adjust the base width, the center vector and the feedback gain of the inner and outer layers adaptively, the accurate approximation of the unknown model can be achieved, and the robustness and accuracy can be enhanced. The simulation results and the comparisons with conventional neural sliding mode control prove the presented scheme can realized better tracking property and estimate the unknown model more accurately.

Fractional-Order Finite-Time Super-Twisting Sliding Mode Control of Micro Gyroscope Based on Double-Loop Fuzzy Neural Network

In recent development in the control area, advanced control schemes are well established for the systems under the influence of parametric uncertainties due to modelling error, nonlinearities, and the external disturbances. Among the different robust control schemes sliding mode control (SMC) has made attention for the control engineer due to its merits. SMC has grown rapidly as a control in comparison with other robust control strategies due to its distinguish features like insensitive to matched uncertainties, reduced order sliding mode equations, zero error convergence of closed loop system and it offers a nonlinear control. The objective of this paper is to present the literature review of SMC development in an era of control technology. The development of SMC based technique with integration of intelligent control in the field of control engineering has been surveyed by considering numerous applications.

Review of sliding mode based control techniques for control system applications

This work proposes a model-free robust control for cable-driven manipulators with disturbance. To achieve accurate, singularity-free and fast dynamical control performance, we design a new NFTSM surface utilizing a new continuous TSM-type switch element. By replacing the integral power with fractional one for the error dynamics, the designed TSM-type switch element can effectively enhance the dynamical performance of the NFTSM surface. Time-delay estimation (TDE) technique is applied to cancel out complicated nonlinear dynamics guaranteeing an excellent model-free scheme. Thanks to the designed NFTSM surface, adopted reaching law and TDE, our control can provide good comprehensive control performance effectively. Stability and comparisons of control precision and convergence speed have been theoretically analyzed. Finally, comparative experiments were conducted to prove the superiorities of our control.

Model-free continuous nonsingular fast terminal sliding mode control for cable-driven manipulators.

This paper presents the results for model-independent control of uncertain ${n}$ -degree of freedom robotic manipulators in the presence of external disturbances and backlash hysteresis. In order to improve the response characteristics of the system and attenuate the uncertainties, the developed robust model-free controller incorporates time delay control (TDC) as well as adaptive terminal sliding mode control (ATSMC) methods. Particularly, the time delay estimation is designed to estimate the unknown dynamics of the robotic manipulators by adopting the theory of TDC. Further, the ATSMC is utilized to obtain the robustness, finite-time convergence, and an adaptive tuning is exploited to deal with bounded derivative of unknown dynamics. The overall system stability is investigated by the Lyapunov theorem application and computed the finite convergence rate thereafter. Finally, a simulation comparison with an existing adaptive fractional-order terminal sliding mode control under backlash hysteresis is provided to illustrate the effectiveness and the superiority of the proposed method.

Adaptive High-Order Terminal Sliding Mode Control Based on Time Delay Estimation for the Robotic Manipulators With Backlash Hysteresis

In this article, we propose a novel adaptive time-delay control (ATDC) for accurate trajectory tracking of cable-driven robots. The designed ATDC utilizes time-delay estimation (TDE) to estimate the lumped dynamics of the system and provides an attractive model-free structure. Then, a robust control is designed for ATDC with fractional-order nonsingular terminal sliding mode (FONTSM) dynamics. Afterward, a novel nonlinear adaptive law is proposed for the control gains to improve the control performance. Thanks to TDE and FONTSM dynamics, the proposed ATDC is model free and highly accurate. Benefiting from the proposed nonlinear adaptive law, suppression of chattering issue and enhanced control performance have been obtained simultaneously. Stability is analyzed based on the Lyapunov approach. Then, practical experiments have been performed to illustrate the advantages of the proposed ATDC.

Time-Delay Control Using a Novel Nonlinear Adaptive Law for Accurate Trajectory Tracking of Cable-Driven Robots

This paper proposes a novel adaptive super-twisting fractional-order nonsingular terminal sliding mode (AST-FONTSM) control scheme using time delay estimation (TDE) for the cable-driven manipulators. The designed control scheme utilizes TDE to obtain the estimation of system dynamics, and therefore no system dynamic model information will be required. Afterwards, AST and FONTSM schemes are applied to ensure good control performance in both reaching and sliding mode phases. Due to the adoption of AST scheme, good robustness and high control precision are obtained in the reaching phase, while the boundary information of the lumped uncertainties will be no longer required. Thanks to the utilization of FONTSM error dynamics, fast convergence and accurate tracking and strong robustness can be simultaneously ensured in the sliding mode phase. Corresponding comparative simulation and experimental results demonstrate the effectiveness and superiorities of our proposed method over the existing control methods.

Adaptive super-twisting fractional-order nonsingular terminal sliding mode control of cable-driven manipulators.

Adaptive super-twisting nonsingular fast terminal sliding mode control for cable-driven manipulators using time-delay estimation

A new practical robust control of cable-driven manipulators using time-delay estimation

This paper presents an adaptive proportional-integral-derivative fractional-order nonsingular terminal sliding mode (PID-FONTSM) control for the cable-driven manipulators using time-delay estimatio...

Kangwu Zhu

Papers

Adaptive super-twisting fractional-order nonsingular terminal sliding mode control of cable-driven manipulators.

Model-free continuous nonsingular fast terminal sliding mode control for cable-driven manipulators.

Adaptive super-twisting nonsingular fast terminal sliding mode control for cable-driven manipulators using time-delay estimation

A new practical robust control of cable-driven manipulators using time-delay estimation

Adaptive PID-fractional-order nonsingular terminal sliding mode control for cable-driven manipulators using time-delay estimation