The problem of satisfactory PID control for a class of stochastic systems with constraints on dynamic error coefficient, steady-state output variance and relative stability margin is considered.

In comparison with BP method and RBF method, the SVM method is proved to be the best in terms of absolute error, relative error, correlation coefficient and variance.

The relative and absolute error equations of closures are deduced, which can be the reference of tracing ray quantities for solving the radiation transfer coefficient.