Complete model-free sliding mode control (CMFSMC)

Abstract

This study presents a complete model-free sliding mode control (CMFSMC) framework for the control of continuous-time non-affine nonlinear dynamic systems with unknown models. The novelty lies in the introduction of two equalities to assign the derivative of the sliding functions, which generally bridges the designs of those model-based SMC and model-free SMC. The study includes a double SMC (DSMC) design, state observer design, and desired reference state vector design (whole system performance), which all do not require plant nominal models. The preconditions required in the CMFSMC are the plant dynamic order and the boundedness of plant and disturbances. U-model based control (U-control) is incorporated to configure the whole control system, that is (1) taking model-free double SMC as a robust dynamic inverter to cancel simultaneously both nonlinearity and dynamics of the underlying plants, (2) taking a model-free state observer to estimate the state vector, (3) taking invariant controller to specify the whole control system performance in a linear output feedback control and to provide desired reference state vector. The related properties are studied to support the concept/configuration development and the analytical formulations. Simulated case studies demonstrate the developed framework and show off the transparent design procedure for applications and expansions.

An improved sliding mode approach for trajectory following control of nonholonomic mobile AGV

“…AGVs are widely used in scientific studies, transportation, and research because of their high degrees of automation, flexibility, and anti-interference capability. As one of the core technologies of AGVs, trajectory tracking control has attracted much research attention, and various control methods have been proposed for this purpose, including robust control, backstepping control, PID control, fuzzy control, adaptive control, and sliding mode control 1 – 6 . Sliding mode control, as an effective method for nonlinear systems, has the advantages of fast response and insensitivity to parameter changes and external disturbances.…”

U-Model-Based Adaptive Sliding Mode Control Using a Deep Deterministic Policy Gradient

“…Di erent from other modelbased and model-free control methods, it is a model-independent method in that it uses the dynamic model of the plant to design the controller, while the nal performance is independent of the target plant. In doing this, the U-model provides a general routine to separate the system design and control design processes [2]. e gist of the U-model lies in designing a robust dynamic inverter that transforms the original plant into an identity matrix [2,3].…”

“…In doing this, the U-model provides a general routine to separate the system design and control design processes [2]. e gist of the U-model lies in designing a robust dynamic inverter that transforms the original plant into an identity matrix [2,3]. is brings about two advantages.…”

Current sensorless position-tracking control with angular acceleration error observers for hybrid-type stepping motors

“…The energy-shaping approach combining the two techniques of flatness and passivity alleviates the dependence on inverse dynamics and parameters, using the function of open-loop energy 34 . Sliding mode control (SMC) that forces closed-loop dynamics into the desired surface with the suppression of disturbances from model-plant mismatches is available; here, a discontinuous function with a conservative gain is used in the feedback loop 35 – 37 . Closed-loop performance improvement can be achieved by incorporating a learning part for the feedback-loop in the back-stepping controller that minimizes the cost-function using a learning algorithm 38 .…”