(1) Feedback control method
As mentioned earlier, the feedback control method is controlled according to the deviation. It is characterized by the deviation of the extension of the expected value of the accusations from the expected amount of control. The amount of control is consistent with the expectations. It can be said that the feedback control system composed of feedback control methods has the ability to inhibit any internal and external disturbances on the control of the control, and has high control accuracy. However, there are many components and complicated structures used in this system. It is more troublesome to hold the performance analysis and design of other systems. Nevertheless, it is still an important and widely used control method. The main research object of automatic control theory is a system composed of this control method.
(2) Open ring control method
Open -loop control method refers to the control process between the control device and the controlled object without reverse connection. The system composed of this method is called the opening control system. It is characterized by the output volume of the system. It affects the control of the system. The opening control system can be composed of a presented control method, or it can also be composed of disturbance control.
According to a premium -controlled opening control system, its control effect is directly generated by the system input. Given a given input that there is an output corresponding to it. The control accuracy depends entirely on the components and calibration accuracy used. In the plane speed control system, if you only consider the parts in the dotted frame, you can be regarded as an open -loop control system that is controlled by a presented quantitative control.
CF’s control voltage is determined. In this way, in the process of work, even if the speed of plane deviates from the expected value, it will not affect the control voltage. Therefore, this type of opening control does not have the ability to automatically modify the deviation and has poor antipity. However, due to its simple structure, convenient adjustment, and low cost, this control method still has a certain practical value when the accuracy requirements are not high or the irritation effect is less impact. At present, some automated devices used in various departments of the national economy, such as automatic vending machines, automatic washing machines, product production automatic lines, CNC lathes, and traffic lights in directing traffic, are generally a ring control system.
The opening control system based on disturbance control is a compensation effect using the measurement that can be measured to reduce or offset the impact of disturbance on the output volume. This control method is also called smooth feed control. For example, in the general DC speed control system, the speed often decreases with the increase of load, and the decrease of its speed is caused by the decrease of the voltage of the agent circuit. If we try to cause the load
The change is measured and produced an additional control effect according to its size to compensate for the speed decrease caused by it, so that it can constitute an open -loop control system that is controlled by disturbance. The opening control method is to obtain information directly from disturbances, and to change the amount of control. Therefore, its antipity is good and the control is slightly higher, but it only applies to the occasion that can be measured.
(3) Compound control method
It is simple to control the technical method in accordance with the deviation control method, but it only applies to the measurement that can be measured, and — the compensation device can only compensate for one disturbance factor, and it does not play a compensation effect on the remaining disturbances. Therefore, a more reasonable way to control is to combine bias control with the disturbance control control. For the main disturbances, an appropriate compensation device is used to implement the disturbance control. The deviation. In this way, the main disturbance of the system has been compensated, and the feeding control system is easier to design, and the control effect will be better. The control method of combining this bias control and boring control is called a composite control method.