Saturated PD type sliding mode control method and system of four-degree-of-freedom tower crane system

Abstract

The invention provides a saturated PD type sliding mode control method and system of a four-degree-of-freedom tower crane system. The method comprises the following steps that parameter data of the four-degree-of-freedom tower crane system are acquired; a positioning error vector is obtained according to the obtained parameter data; by means of the obtained positioning error vector and a load swing angle, according to a PD type sliding mode control model constructed by the sum of a PD linear control part, a sliding mode control part and an anti-swing control part, cantilever control torque and trolley translation force are obtained; the four-degree-of-freedom tower crane system is controlled according to the obtained cantilever control torque and trolley translation force; only the positioning error, the time derivative of the positioning error and the load swing angle are needed, model parameters are irrelevant, so that the robustness of the tower crane system is greatly improved.

Description

technical field [0001] The present disclosure relates to the technical field of tower crane control, in particular to a saturated PD type sliding mode control method and system for a four-degree-of-freedom tower crane system. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. [0003] The PD / PID control method has the advantages of simple structure and easy engineering implementation, so it has been widely used in underactuated electromechanical systems such as crane systems, surface ships, inverted pendulum systems, and mobile manipulator systems. As a class of model-free linear control methods, the control gains of PD / PID control methods are easy to adjust individually, and appropriate transient control performance can be achieved in many cases. However, the uncertainty of the model and the presence of external disturbances may seriously affect t...

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Problems solved by technology

[0006] The inventor found that one problem related to the above SMC method is that its equivalent control part is difficult to calculate and requires accurate knowledge of the tower crane system model; The state and the non-drivable state are merged into the same sliding mode surface, and the convergence of the sliding mode surface to zero cannot guarantee the convergence of all states on the sliding mode surface; another problem is to simplify the design of the controller and analyze the stability of existing control methods Some nonlinear terms in the tower crane model need to be ignored; moreover, the above SMC method focuses on the improvement of control performance rather than the actual constraint problem: the study of control input constraints is not deep enough, so it is difficult to obtain in practice application

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