在参数扰动和外部干扰情况下，对非完整机械控制系统设计了变结构模型参考跟踪控制器．基于适当的矩阵分解、非线性控制理论中的输入输出解耦概念及变结构控制理论，为解决干扰非完整机械控制系统的跟踪问题提出了三级控制设计过程．最后通过一非完整机械控制系统的例子（在给定平面上运动的垂直轮）的计算机仿真说明了提出方法的优越性 In the condition of parameter disturbance and external disturbance, a variable structure model reference tracking controller is designed for the nonholonomic mechanical control system. Based on the appropriate matrix decomposition, the concept of input-output decoupling and the theory of variable structure control in nonlinear control theory, a three-level control design process is proposed to solve the problem of tracking the nonholonomic mechanical control system. Finally, the computer simulation of an example of a non-complete mechanical control system (vertical wheel moving in a given plane) shows the superiority of the proposed method