Research on Human Upper Limb Tremor Suppression Method Based on Port-Controlled Hamiltonian System and Sliding Mode Control

In upper-limb rehabilitation training aided by robotic systems, patients often develop tremors due to insufficient muscle strength or neurological control disorders, adversely impacting the rehabilitation process. Based on the Port-Hamiltonian Systems (PHS) theoretical framework, this paper proposes a Sliding Mode Control (SMC) strategy to suppress tremors during upper-limb rehabilitation. The approach employs two Lyapunov functions: on one hand, the Hamiltonian (the system's energy function) ensures overall Lyapunov stability; on the other, an additional Lyapunov function enforces finite-time convergence of the sliding variable, thereby rapidly mitigating tremors and maintaining tracking accuracy. Simulation results indicate that this method not only achieves outstanding stability but also guarantees finite-time convergence of the sliding variable, significantly reducing arm tremors. Consequently, it provides an efficient and viable advanced control solution for upper-limb rehabilitation robots.