The existence of unmatched uncertainties is known as a serious challenge for designing a robust sliding mode control (SMC) law for nonlinear systems. To pass over this obstacle, a novel robust passivity-based sliding mode approach is proposed here for a large class of MIMO nonlinear systems. The design procedure is accomplished in two steps in presence of both matched and unmatched uncertainties. First, an efficient adaptive sliding surface is designed based on the passivity concept. The passivity provides a flexible robust structure for the sliding surface and guarantees the global asymptotic stability of the reduced-order equations of the system as well. Furthermore, simple adaptation laws are obtained to eliminate the effects of uncertainties. Then, the robust controller is formulated using the SMC method. As another important advantage, the proposed approach is relaxed from the upper bound’s constraints of the uncertainties. It is also applied to n-link rigid electrically driven robot manipulator as a widely-used practical nonlinear system. The simulation results show the appropriate tracking performance for the industrial selective compliance assembly robot arm (SCARA) in the presence of noisy external disturbances. Also, an extending case is studied with related research to emphasize the potential of the proposed approach.

无与伦比的不确定性的存在被认为是设计非线性系统鲁棒滑模控制（SMC）定律的严峻挑战。为了克服这一障碍，本文针对一大类 MIMO 非线性系统提出了一种新颖的基于无源性的鲁棒滑模方法。在存在匹配和不匹配不确定性的情况下，设计过程分两步完成。首先，基于被动性概念设计了高效的自适应滑动面。无源性为滑动面提供了灵活的鲁棒结构，并保证了系统降阶方程的全局渐近稳定性。此外，获得简单的适应律以消除不确定性的影响。然后，使用SMC方法制定鲁棒控制器。作为另一个重要优势，所提出的方法放松了不确定性上限的限制。它也适用于n-连杆刚性电驱动机器人机械手作为一种广泛应用的实用非线性系统。仿真结果表明，工业选择性顺应性装配机器人手臂 (SCARA) 在存在噪声外部干扰的情况下具有适当的跟踪性能。此外，还研究了一个扩展案例和相关研究，以强调所提出方法的潜力。