The damping ratio is an important characteristic parameter in a second-ordersystem, which has great effect on the dynamic characteristic of the secondordersystem.
阻尼比是二阶系统的一个重要的特征参数，它对二阶系统动态特性有较大的影响。
2
The vehicle steering system is a slowly varying non-linear system, in a short time interval, its dynamic characteristics can be described by a parameter-varying second-order linear system.
Valid dynamic sliding mode output that guarantees the system stable zero dynamics was constructed, and a global secondorder sliding mode control was adopted to circumvent chattering phenomena.