This control theory employed two basic concepts of primary and secondary controls.

In this paper, the severe challenge facing with voltage stabilization, heat dissipation, import noise, cost and so on in the designing of low voltage and heavy current communication power supply is introduced briefly, the new technology, such as multiphase technology, on board supply, synchronous rectification, and secondary control are discussed in detail.

The article introduces the life-span theory of control and the model of optimization in primary and secondary control.

In this paper the complex system is divided into reduced order subsystems with different time scales according to the singular perturbation theory and the method of the variable structure control, and the controller in each subsystem using sub-optimal control algorithm of second order sliding mode which can eliminate the chattering is designed.

On the basis of one-fourth automobile suspension, a nonlinear model is built for electromagnetic active suspension and a sub-optimal controller is designed by applying modern control theory.

In order to simplify the calculation and implementation of controllers, a sub-optimal control design method based on model reduction techniques is proposed in this paper.

Successive approximation approach of suboptimal control for nonlinear time-delay systems;

Singular LQ suboptimal control problem with disturbance rejection for nonregular descriptor systems;

Suboptimal control study for a class of nonlinear systems