Four-wheel steering rolling time domain control method based on Koopman operator

Abstract

The invention belongs to the technical field of four-wheel steering control, and discloses a four-wheel steering rolling time domain control method based on a Koopman operator, which comprises the following steps of: S1, establishing an ideal reference model in combination with adhesion conditions of a road surface and stability factors of a vehicle, and determining an expected yaw velocity gamma * and a side slip angle beta * through the ideal reference model; s2, collecting target data based on Carsim and Simulink joint simulation, wherein the target data is used for reflecting the relationship between the yaw velocity and the side slip angle and the front wheel rotation angle and the rear wheel rotation angle of the vehicle; raising the dimension of the vehicle four-wheel steering model to a high-dimensional space based on a Koopman operator theory and extended dynamic mode decomposition to obtain a vehicle four-wheel steering global linearization model; and s3, designing a linear rolling time domain controller according to the vehicle four-wheel steering global linearization model, wherein the controller takes an expected yaw velocity gamma * and a side slip angle beta * as reference inputs, takes a front wheel rotation angle and a rear wheel rotation angle of the vehicle as reference outputs, and acts the reference outputs on the vehicle system.

Description

technical field [0001] The invention belongs to the technical field of four-wheel steering control, and in particular relates to a four-wheel steering rolling time-domain control method based on a Koopman operator. Background technique [0002] The steering system of the vehicle is the medium through which the driver communicates with the vehicle and is an important part of the vehicle chassis. Compared with traditional car steering, four-wheel steering has the following advantages: [0003] 1) In low-speed steering conditions, the front wheels and rear wheels turn in the opposite direction, that is, the turning radius is reduced to make the steering of the vehicle more flexible. [0004] 2) Under high-speed steering conditions, the front wheels and rear wheels turn in the same direction, which can compensate part of the centrifugal force to prevent the vehicle from flicking, rollover, etc., and improve the maneuverability and stability of the curve. [0005] 3) Under high...

AI Technical Summary

Problems solved by technology

However, rolling time domain control needs to deal with non-convex optimization problems at each sampling time for nonlinear models, so certain computing resources are required, which increases the burden on the vehicle ECU

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