Poor information evaluation of friction torque test on bearing for space application (I Theory)

Considering poor information characteristics of friction torque for rolling bearing, a dynamic evaluation method called ldquofrom individual identification to population inference modelrdquo is proposed in the paper to evaluate the friction torque of bearing for space application. It mainly includes dynamic DGM(1, 1) model, new initial value DGM(1, 1) model and GBM(1, 1) model. The former two models are used for individual identification, the latter population inference. This dynamic evaluation method can not only exactly forecast the friction torque values but also its fluctuation interval and reliability. The forecasting model solves the lagging and leading forecasting in DGM model, at the same time, it permits trend of non-stationary random process unknown and the number of data small without any requirements for probability distribution.