Its basic principle is to select a set of secondary variables that are easy to detect and have close relationship with the primary variable according to certain " optimal " criteria . the selected secondary variables are then used to obtain the on - line estimation of the primary variable by constructing some mathematic relationship between these variables 软测量技术的基本原理是根据某种最优准则，选择一组在工业上容易检测而且与主导变量有密切关系的辅助变量，通过构造某种数学关系，用计算机软件实现对主导变量的在线估计。
Specially for the particularity of the path - length control system in the laser gyros consist of total reflecting prisms and the necessity of identifying the parameters in the system , the mathematical model of the temperature control system in the trp laser gyros is presented , and three new identifying algorithms are deduced in theory based on the method of the least squares : algorithm of immediately identifying , algorithm of instrumental variables and recursion algorithm 摘要针对全反射棱镜式激光陀螺腔长控制系统的特殊性及其模型参数辨识的必要性，给出trp激光陀螺温度控制系统的数学模型，并基于最小二乘法从理论上分析推导出3种新型参数辨识法：直接辨识算法、辅助变量法和递推算法。
