Comment on S. Ahmed, H. Wang, and Y. Tian, "Robust adaptive fractional‐order terminal sliding mode control for lower‐limb exoskeleton," Asian J. Control, vol. 21, no. 1, pp. 1–10 (2019).

In this comment, it is shown that there are some non‐negligible big mistakes in the analyses and stability proof of the proposed controller in the quoted paper, which makes the main results of this paper to be incorrect. The main unavoidable mistakes in the stability analysis of the main theorem (Theorem 1) are stated and some remarks are also mentioned to fix some of them. [ABSTRACT FROM AUTHOR]