AUTHOR=Zhang Feilong , Wang Tian , Zhang Liang , Shi Enming , Wang Chengchao , Li Ning , Lu Yu , Zhang Bi TITLE=Sliding-mode control based on prescribed performance function and its application to a SEA-Based lower limb exoskeleton JOURNAL=Frontiers in Robotics and AI VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/robotics-and-ai/articles/10.3389/frobt.2025.1534040 DOI=10.3389/frobt.2025.1534040 ISSN=2296-9144 ABSTRACT=A sliding-mode control based on a prescribed performance function is proposed for discrete-time single-input single-output systems. The controller design aims to maintain the tracking error in a predefined convergence zone described by a performance function. However, due to the fixed structure of the controller, the applicability and universality of this method are limited. To address this issue, we separate the controller into two parts and analyze the principle of the prescribed performance control (PPC) method. Then we can replace the linear part of the controller with model-based control methods to adapt to the specific characteristics of the controlled system. Compared with current works, when the established system model is inaccurate, we can enhance the smoothness or response speed of the system by introducing a penalty constant to alter the system’s transient characteristics while the tracking error is within the prescribed domain. Finally, numerical comparison simulations and a lower limb exoskeleton experiment illustrate the established results and the effectiveness of the proposed method.