Comments on “Global Terminal Sliding‐Mode Control for the Synchronization Problem of Uncertain Bilateral Teleoperation System With Time‐Varying Delays”

ABSTRACT Assumption 4 and the claims that finite‐time convergence of tracking errors in Theorems 1 and 2 of [A. Ounissi, et., Global terminal sliding‐mode control for the synchronization problem of uncertain bilateral teleoperation system with time‐varying delays, Asian J. Control 26 (2024), 2180–2205] are invalid, making the proposed controls therein untenable. The circular argument problem of the proposed controls and other significant flaws are also pointed out. The correction of Assumption 4 on the upper bound of the lumped uncertainties is presented.