Control parameter optimization method of automobile automatic steering system containing feedback time lag

Abstract

The invention discloses a control parameter optimization method for an automobile automatic steering system containing feedback time lag. The method comprises the steps that (1) an automobile automatic steering system dynamic model of a PD controller containing the feedback time lag is established; 2) obtaining a system characteristic equation through Laplace transformation, and substituting the system characteristic equation into the lowest stability margin translation equation to a critical node so as to obtain a real and imaginary part equation; 3) deducing a system instability boundary curve and an oscillation instability boundary curve under the condition that the main frequency of the system is zero and not zero; 4) substituting the target attenuation rate of the controller, drawing two boundary curves on a control parameter plane, and obtaining a closed parameter domain meeting target requirements; and 5) when the two boundaries coincide critically, obtaining the optimal system attenuation rate which can be realized by the system under time lag, and calculating the optimal control parameter combination. According to the method, the control meeting the expected performance under the time lag can be efficiently realized at low cost, so that the time lag effect can be obviously inhibited, and the driving safety of the automatic steering system of the automobile is effectively improved.

Description

technical field [0001] The invention belongs to the field of dynamics and control of an automobile automatic steering system, in particular to a control parameter optimization method of an automobile automatic steering system including feedback time lag. Background technique [0002] The time lag that widely exists in electromechanical systems is a difficult problem that cannot be ignored in engineering applications. Similarly, in the automatic steering control system of automobiles, it comes from the sampling of vehicle physical sensor signals, ECU processing operations, electromechanical actuation, and tire deformation hysteresis. Various time lags not only greatly damage the expected design performance of the automatic steering controller, but also destroy the dynamic stability of the vehicle steering system itself, especially when the vehicle is running at a medium or high speed, a series of Problems, such as repeated steering oscillations that cause the body to sway lef...

AI Technical Summary

Problems solved by technology

The control effect and performance of this type of PD controller depend entirely on the selection of controller parameters or coefficients. In previous projects, the selection of this coefficient was often based on experience and a large number of test results. The cost was high, and it was not universal and could not adapt to Changes in system parameters or system time delays

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