following error的用法和樣例：
例句
- By theoretical analysis, it is shown that tracking error converges to a small neighborhood of zero.
通過(guò)李亞普諾夫方法，證明了跟蹤誤差收斂到零的一個(gè)小鄰域內。 - It was proved that the tracking error converges to the prescribed boundary layer and all the signals in the closed-loop system were bounded.
算法保證閉環(huán)系統所有信號的有界性且使得跟蹤誤差收斂于任意設定的飽和層內。
