对桁架结构系统的模型降阶和主动控制进行了研究。系统模型采用有限元方法进行建模;模型降阶分别采用模态价值分析方法和内平衡降阶方法;控制设计采用最优控制方法。同时详细给出了模态价值分析方法和内平衡降阶方法的降阶过程,并将两者的结果进行了数值对比。仿真结果显示,两种降阶方法均能够有效地对桁架系统进行模型降阶,本文采用的最优控制律能够有效地抑制结构的振动。 The model reduction and active control of truss structure system are studied. The system model is modeled by the finite element method. The model reduction is modeled by the value analysis method and the internal balance reduction method respectively. The control design adopts the optimal control method. At the same time, the process of the reduction of modal value analysis and the internal balance reduction method are given in detail, and the numerical results of the two methods are compared. The simulation results show that the two reduction methods can effectively reduce the model of the truss system. The optimal control law used in this paper can effectively suppress the vibration of the structure.