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As the anti-skid control and speed tracking control of high-speed trains (HSTs) are interrelated and mutually constrained, it is very challenging to achieve simultaneous tracking of speed and slip ratio. In this paper, it is proposed for the first time that when the traction braking force has been limited to a reasonable range by the adhesion anti-skid condition, the high-precision tracking of the position and velocity curves of HSTs can be achieved, and the tracking error of the slip ratio is acceptable. Firstly, a novel modelling of the adhesion dynamics of HSTs under realistic gusts of wind disturbance is developed, and a model based on strict feedback is obtained by linearising the feedback for high-order non-linear systems. Then, this paper first presents the design scheme of fast terminal sliding mode controller based on disturbance observer for HSTs, which can ensure the anti-disturbance performance and accurate tracking of HSTs. Finally, an example is used to verify the validity of the results. Note to Practitioners—The actual traction/braking force of HSTs is provided by adhesion, and the existing literature on slip ratio tracking essentially sacrifices the tracking performance of the traction/braking system to meet the anti-skid requirements, while considering velocity and position tracking alone may leave the train in an undesired condition such as “idling” or “skidding”. This paper seeks to achieve high accuracy tracking of velocity and position profiles of HSTs under restricting the slip ratio to a reasonable range, which is expected to be an effective method for train tracking controller design. To avoid discomfort to passengers, nonlinearities dynamics are considered and an anti-disturbance controller is designed to compensate the impact of natural wind disturbances. To enhance the practicality, feedback linearization is introduced to reduce the complexity of the controller implementation. The designed fast terminal sliding mode controller also avoids jitter and singularity problems and obtains finite time stability. The stability analysis and numerical simulation have confirmed the effectiveness of the proposed scheme, which still needs to be verified by experiments in the future.

This paper investigates the position and velocity tracking control of the high-speed train (HST) formation with communication delay and proposes a distributed anti-disturbance control criterion based on the graph theory and the Lyapunov-Razumikhin theory. Firstly, the tracking error systems of the $n$ -HSTs convoy is established with the consideration of the non-linearity of aerodynamic drag, the gust force disturbance and the time-varying heterogeneous delay caused by the transport process. Secondly, a distributed control strategy for the HST formation under communication delays based on disturbance observers is proposed, which can ensure the asymptotic stability of the tracking error system for the HST formation under disturbances and effectively improves the system robustness. Finally, a simulation example is given to verify the validity of the results.

A novel hierarchical control framework combining computed-torque-like control (CTLC) with disturbance-observer-based event-triggered robust model predictive control (DO-ET-RMPC) is proposed for the trajectory tracking control of robotic manipulators with bounded disturbances and state and control input constraints. The CTLC approach is first used to cancel the exact nonlinear dynamics of the original tracking error system to obtain a set of decoupling linear tracking error subsystems, thus reducing the optimization complexity of model predictive control (MPC). The composite DO-ET-RMPC scheme is then developed based on the so-called dual-mode MPC approach to robustly stabilize the tracking error subsystems, which could improve the robustness of MPC and save its computational resources simultaneously. The continuous-time theoretical properties of the DO-ET-RMPC scheme, considering disturbances and state and control input constraints simultaneously, are provided for the first time, including the avoidance of Zeno behavior, robust constraint satisfaction, recursive feasibility, and stability. In the end, the superiorities of the proposed control scheme are verified by the comparative simulations.

This article addresses the composite hierarchical antidisturbance control issue for the front steering vehicle system with uncertain parameters. First, the front steering vehicle system is modeled as an interval type-2 Takagi–Sugeno (T–S) system, which contains the unknown disturbance matching the input channel and the norm bounded disturbance. Considering that the embedded membership functions of the interval type-2 fuzzy system are unknown, the definite part and the uncertain part of the interval type-2 T–S fuzzy system are separated to facilitate the subsequent analysis. Next, a novel disturbance observer design structure under the fuzzy framework is introduced. Through the novel design method, the expression of the unknown disturbance can be transformed into a new form containing only the uncertain parameter, and the estimation is realized by estimating the uncertain parameter. Then, a fuzzy integral sliding mode controller is adopted in combination with the disturbance estimation to ensure the stability of the composite system and the reachability of the specified fuzzy integral switching surface. Finally, simulation results of the front steering vehicle model that demonstrate the effectiveness of the proposed control scheme are provided.

The high-precision and fast-response safety proximity control for servicing spacecrafts is affected by dynamic obstacle constraints and multiple disturbances, such as actuator deviations and flexible vibration. To address this challenge, an adaptive fixed-time disturbance observer (AFTDO)-based composite proximity control scheme is proposed for the servicing spacecrafts to achieve effective obstacle avoidance and high-precision position tracking. Because the multiple disturbances are coupled with the system physical variables (e.g., control input and relative position) and exhibit complicated dynamics, an AFTDO is proposed to estimate the disturbances in fixed time by adaptively learning the bound information of disturbance derivative. For the dynamic obstacle constraints, an artificial potential function-based terminal sliding mode manifold is designed to convert the obstacle constraints to a path planning problem, which effectively provides the repulsion effect of the servicing spacecraft on obstacles and the attractive effect on the target position. Through the designed finite-time composite proximity controller, the antidisturbance ability of the servicing spacecraft can be effectively improved, and the coordinated performance optimization under the obstacle constraints can be also ensured. Simulation results verify the effectiveness of the proposed scheme.