Frequency domain control method of automotive semi-active suspension system

Abstract

The invention discloses a frequency domain control method of an automotive semi-active suspension system. The frequency domain control method includes measuring a vertical acceleration of an automobile body, solving vertical acceleration change rate of the automobile body and vertical speed of the automobile body according to the vertical acceleration of the automobile body, and calculating frequency values of f1, f3 and f5 corresponding to a first fixed point, a third fixed point and a fifth fixed point respectively; and assigning fc to take the f1, f3 and f5 respectively, calculating and determining the belonging frequency band range of a vibration frequency f, and setting a damping coefficient value of the damper. The frequency domain control method is based on frequency-domain transmitting characteristics of the vertical acceleration of the automobile body, wheel dynamic load and suspension dynamic deflection, the belonging frequency band range of suspension system vibrations can be determined adaptively, so that corresponding damp is applied, good control performance in entire frequency domain can be achieved, and suspension performance of an automobile is obviously improved.

Description

technical field [0001] The invention relates to a frequency domain control method of an automobile semi-active suspension system, belonging to the field of structural vibration control. Background technique [0002] Automotive suspension systems include automotive active suspension systems, automotive semi-active suspension systems and automotive passive suspension systems. In recent years, the automotive suspension system has made great progress in structural vibration control, especially the semi-active control has the advantages of both passive and active control, with less energy consumption, but can achieve performance close to active control, which has very good Application prospect. [0003] Semi-active control includes two control methods of variable stiffness and variable damping. Because changing the damping characteristics of the shock absorber is easier than changing the spring stiffness, the semi-active suspension system of the car is mainly composed of a sprin...

AI Technical Summary

Problems solved by technology

[0004] First, the control effect is not ideal

Existing semi-active control methods directly determine the vibration suppression effect of automotive semi-active suspension systems. Some existing semi-active control methods increase certain indicators at the expense of other indicators, or are only effective in certain frequency bands.

[0005] Second, the existing semi-active control methods are complex

Although the existing semi-active control method can achieve a relatively good control effect, its design or calculation process is complicated. On the one hand, the online calculation is large, resulting in a large control time lag, and it is difficult to achieve rapid control response. , the level of complexity makes semi-active control methods even difficult to implement

[0006] Third, the existing semi-active control methods require more sensors, which can easily lead to increased errors

by figure 1 The two-degree-of-freedom model of a typical automobile semi-active suspension system shown in , as an example, most of the existing semi-active control methods need to arrange acceleration sensors 60 on each wheel 20 and the vehicle body 10 corresponding to each wheel 20, and some The semi-active control method also needs to arrange displacement sensors (not shown in the figure) between each wheel 20 and the corresponding vehicle body 10, and each sensor needs a lead wire to transmit a signal. When the suspension system is deformed, the lead wire is easily damaged. The problem of unreliable signal transmission due to pulling

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