The present paper addresses linear parameter-varying systems with high-order time-varying parameter dependency known as polynomial LPV systems and their controller design. Throughout this work, a procedure ensuring a state-feedback controller from a parameterized linear matrix inequality (PLMI) solution is presented. As the main contribution of this paper, the controller is designed by considering the time-varying parameter rate as a tuning parameter with a continuous control gain in such a way that the closed-loop eigenvalues lie in a complex plane subset, with high-order time-varying parameters defining the system dynamics. Simulation results are presented, aiming to show the effectiveness of the proposed controller design.

Dip coating is a widely used laboratory method for depositing thin films and functional coatings. However, commercial dip-coaters remain costly and often exceed the needs of teaching labs and early-stage research. This paper presents a simple, low-cost automated dip-coater capable of delivering repeatable rise–dwell–fall motion for benchtop applications. The system integrates a 3D-printed PLA structure, a stepper-lead-screw actuator, and a PC-hosted graphical user interface that learns and executes user-specified trajectories without additional hardware controls. A compact mathematical model generates triangular and trapezoidal profiles and maps them to step pulses via the steps-per-millimeter factor. The mechatronic design and sequential control are described, and the prototype is validated through simulations and experiments. Non-contact measurements demonstrate high repeatability, accurate dwell timing, and bounded accelerations with minor deviations at switching instants. The bill of materials is 50 USD (≈1–2% of entry-level commercial systems), underscoring stability, robustness, and accessibility for instructional and resource-constrained settings. These results indicate strong potential for routine laboratory use and a clear path to future enhancements.

An ankle sprain can be caused by daily activities such as running, walking, or playing sports. In many cases, the patient’s ankle suffers severe or permanent damage that requires rehabilitation to return to its initial state. Thanks to technological advances, robotics has allowed for the development of machines that generate precise, efficient, and safe movements. In addition, these machines are manipulated by a specific control depending on the rehabilitation objective. Impedance control is used in ankle rehabilitation machines for active–resistive-type rehabilitation, where the patient participates by exerting a force on the machine repeatedly. Serious games are an example of an activity where the patient can interact with a video game while rehabilitating. Currently, most machines involving impedance control and targeted at serious gaming applications are mechanically composed of one degree of freedom, so the addition of another degree is a novelty. This paper presents simulation results comparing different impedance controls reported in the literature to determine the best option for applying a 2-DOF ankle rehabilitation machine using serious games. The results obtained are presented by comparing them according to the force applied to the rehabilitation machine (emulating the behavior of a patient). From the impedance controllers analyzed for horizontal (abduction/adduction) and vertical (dorsiflexion/plantarflexion) movements in the rehabilitation machine, it was determined that the PD control, which considers some mechanical parameters, presents a better performance. With this controller, fast and smooth angular movements are generated, while the consumption of kinetic energy is kept in a low range, proportional to the applied forces, compared to the other impedance controls analyzed.

Bilateral robotic rehabilitation has emerged as a technological approach for promoting coordinated upper-limb training after stroke. This state-of-the-art review critically analyzes bilateral upper-limb rehabilitation robots with emphasis on mechanical architecture, actuation and transmission, bilateral interaction modalities, control strategies, assistance modes, and validation evidence. A structured literature search covering 2010 to 8 July 2026 identified 141 records; 23 technology-related publications were retained for the state-of-the-art analysis, comprising 18 primary bilateral robotic studies and 5 supporting technical/contextual publications. The reviewed systems were organized according to a hierarchical framework distinguishing end-effector, exoskeleton, and hybrid architectures from simultaneous bilateral, master–slave/mirror-based, and cooperative bimanual interaction modalities. The evidence indicates that end-effector systems favor mechanical simplicity and adaptable workspaces, whereas exoskeletons provide more direct joint-level control at the cost of greater alignment and mechanical complexity. Control approaches increasingly incorporate impedance, admittance, assist-as-needed, and bio-signal-based strategies to improve compliant interaction and adapt assistance to user contribution. However, many advanced systems remain supported primarily by engineering validation or experiments involving healthy participants, while direct post-stroke clinical validation is comparatively limited. Future development should therefore prioritize clinically validated adaptive assistance, control strategies capable of accommodating asymmetric bilateral contribution, and safe, usable, and affordable systems suitable for clinical and home-based rehabilitation.