Sliding Mode Control Techniques for Robot Manipulators

Sliding mode control (SMC) has established itself as a robust methodology for the precise and reliable operation of robot manipulators in the presence of model uncertainties, external disturbances and payload variations. By enforcing system trajectories onto a predefined sliding surface, SMC ensures high-accuracy tracking while maintaining stability through discontinuous control actions. Traditional implementations suffer from chattering and energy inefficiency, prompting the evolution of advanced frameworks such as high-order super-twisting algorithms, adaptive gain schemes and integration with time-delay estimation. These refinements mitigate oscillatory behaviour, reduce control effort and guarantee finite-time or fixed-time convergence. Furthermore, hybrid approaches incorporating neural network approximators and fractional-order dynamics have extended SMC’s applicability to complex, nonlinear robotic tasks ranging from industrial manipulators to rehabilitation devices. As a result, contemporary sliding mode techniques offer a versatile toolkit for modern robotics, balancing resilience, precision and energy economy.

Research from Nature Portfolio

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Research from all publishers

A study on energy optimisation in a two-degree-of-freedom SCARA robot demonstrated an SMC scheme whose gains were tuned via a meta-heuristic Bat algorithm. By minimising the control forces required for position tracking, the optimised controller significantly reduced energy consumption without compromising tracking accuracy, illustrating how evolutionary algorithms can refine sliding mode parameters for sustainable robotic operation.

A robust composite high-order super-twisting SMC was developed for six-degree-of-freedom industrial manipulators. This controller couples a super-twisting sliding mode observer with a high-order sliding mode law to estimate uncertainties and enforce the sliding dynamics. Experimental results on a PUMA arm showed marked improvements in root-mean-square tracking error and reduced chattering compared with conventional sliding mode variants.

A novel widely and stably adaptive sliding-mode control (WS-ASMC) introduced dual adaptive switching gains and a nonsingular terminal sliding variable. The fast-adaptation gain accelerates reaching phase convergence, while the stability-oriented gain enhances sliding phase robustness. Simulations on multi-link manipulators confirmed uniformly ultimately bounded tracking errors and superior disturbance rejection relative to standard adaptive SMC.

Sliding Mode Control Techniques for Robot Manipulators publication trend

The graph below shows the total number of articles in sliding mode control techniques for robot manipulators across all publications each year (not limited to Nature Index journals).

Technical terms

Sliding mode control: A control strategy that drives system states onto a predetermined manifold (sliding surface) and maintains motion along it to achieve robustness against uncertainties.

Chattering: High-frequency oscillations in control signals or system trajectories arising from the discontinuous nature of sliding mode control.

Sliding surface: A manifold defined in the state-error space where the desired dynamics are enforced once reached by the control system.

Super-twisting algorithm: A second-order sliding mode technique that provides continuous control action to reduce chattering while guaranteeing finite-time convergence.

Time-delay estimation: A method for approximate cancelling of unknown dynamics by using delayed measurements of control inputs and system responses.

References

1. Optimization of Sliding Mode Control to Save Energy in a SCARA Robot. Mathematics (2021).
2. Robust Composite High-Order Super-Twisting Sliding Mode Control of Robot Manipulators. Robotics (2018).
3. A New Widely and Stably Adaptive Sliding-Mode Control With Nonsingular Terminal Sliding Variable for Robot Manipulators. IEEE Access (2020).
4. Design of RBFNN-Based Adaptive Sliding Mode Control Strategy for Active Rehabilitation Robot. IEEE Access (2020).
5. Novel Dynamic-Sliding-Mode-Manifold-Based Continuous Fractional-Order Nonsingular Terminal Sliding Mode Control for a Class of Second-Order Nonlinear Systems. IEEE Access (2020).
6. High-Accuracy Tracking Control of Robot Manipulators Using Time Delay Estimation and Terminal Sliding Mode. International Journal of Advanced Robotic Systems (2011).