中文摘要：

通过对欠驱动系统构造相对阶等于原非线性系统状态空间维数的光滑函数，得到惯性轮摆的平滑输出函数，将非线性惯性轮摆系统变换为线性系统，并针对此模型设计了相应的变结构控制律来实现惯性轮摆的稳定性控制．通过MATLAB仿真验证了设计控制器的正确性．

英文摘要：

The paper indicates that the flat output of the inertia wheel pendulum can be obtained by setting up a smooth output function whose relative degree equals to the dimension of the state space. According to the flat output acquired, the nonlinear system based on the inertia wheel pendulum can be transformed to the linear system. The authors set up a variable structure control rule upon the linear system to realize the stability control for the inertia wheel pendulum. The result of the simulation verifies the correctness of the controller.