Two-speed adaptive proportional-derivative control method

Abstract

For the control problem of a non-affine nonlinear uncertain system, the invention relates to a two-speed adaptive proportional-derivative (2SAPD) control method independent of a controlled object model. According to the control method in the invention, system dynamics and internal and external uncertainty are defined as total disturbance; therefore, the non-affine nonlinear uncertain system is converted into a linear uncertain system, so that an error dynamics system under total disturbance excitation is constructed; thereby, a two-speed adaptive proportional-derivative control model by takingthe central speed factor as the core is designed; the facts that a closed-loop control system composed of a 2SAPD controller has the global asymptotic stability robustness and the 2SAPD controller also has good anti-disturbance robustness are theoretically analyzed; and the two-speed adaptive proportional-derivative control method in the invention has wide application value in the fields of power, mechanisms, chemical engineering, traffic, aviation, spaceflight and the like.

Description

technical field [0001] Nonlinear uncertain system control, control theory and control engineering. Background technique [0002] For more than half a century, classical control (cybernetics) based on frequency-domain design methods and modern control (model theory) based on time-domain design methods have developed independently, forming their own methodological systems. In the practice of control engineering, the error between the control target and the actual behavior of the controlled object is easy to obtain and can be dealt with appropriately. Therefore, the prototype of the control strategy of "eliminating errors based on errors", that is, PID (Proportional-Integral -Derivative, PID) controllers have been widely used in the field of actual industrial control. For practical control engineering problems, since it is usually difficult to give a "description of internal mechanism", the control strategy given by modern control theory based on mathematical models is difficu...

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Problems solved by technology

Since the principle of PD control is to weight the present (P) and future (change trend D) of the error to form a control signal, although the effective control can be exerted as long as the two gain parameters of the PD controller are reasonably selected, however, the error and The differential of the error is two physical quantities with different attributes. The inventor believes that it is unreasonable to carry out independent weighted summation of the two physical quantities with different attributes to form a PD control law model:

[0003] (1) Not only violates the basic rules of arithmetic operations (physical quantities of different dimensions cannot be independently weighted and summed), but also cannot accurately understand the mathematical model of the PD control law in a physical sense;

[0004] (2) The mathematical model of the PD control law separates the two links of proportional and differential attributes and treats them independently, which leads to the fact that the two links of proportional and differential are independent of each other in the control process, and thus lack of coordination the scientific idea of ​​control;

[0005] (3) Because of the irrationality of the PD control law model, the tuning of PD parameters has been a major problem in the field of control science and control engineering for more than 80 years.

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