为了判定状态空间方程的阶次 ,提出了相关分析方法。其步骤是 :把状态空间模型化为能观测性规范性 ,导出系统输出相关函数所满足的线性回归方程 ,通过观查数据乘积矩矩阵行列式随其维数的变化情况 ,从而确定系统的阶次。该方法的特点是 :无论系统是否存在噪声 ,都是通过检验某一准则函数值是否为零而获得系统阶次。在系统无噪声和有噪声两种情况下进行了数字仿真研究 ,利用相关方法确定的阶次与系统的真实阶次相吻合。结果表明 :该文的方法在判定状态空间方程的阶次方面是有效的 In order to determine the order of the state space equation, a correlation analysis method is proposed. The method includes the following steps: the state space is modeled as observability normalization, and the linear regression equation satisfied by the output function of the system is derived. By observing the change of the matrix of the product moment matrix with its dimension, the order of the system Times. The characteristic of this method is that no matter whether there is noise in the system, the system order is obtained by checking whether a criterion function value is zero or not. In the system of no noise and noisy two cases of digital simulation study, the use of related methods to determine the order and the system is consistent with the true order. The results show that the method in this paper is effective in judging the order of the state space equation