Observation Method of Center of Mass Side Slip Angle Based on Fusion Technology for Four-Wheel Drive Electric Vehicle

Abstract

The invention belongs to the technical field of electric vehicles, and in particular relates to a method for observing the side slip angle of the center of mass of a four-wheel drive electric vehicle based on fusion technology. The present invention deduces the steady-state expression of the side slip angle of the center of mass based on the two-degree-of-freedom dynamic model; uses the recursive least squares method to estimate the tire cornering stiffness; introduces the UniTire tire model to form a closed-loop estimation loop, and dynamically adjusts the steady-state model parameters at the same time , and construct a center-of-mass sideslip angle observation structure with simple structure and good suppression of sensor noise. The kinematic observation method is introduced, and the fusion rules are formulated through dynamic feature extraction to improve the estimation bandwidth of the steady-state observation structure. The revised estimation method has better high-frequency transient estimation ability. Finally, the trapezoidal test, angle step test and sine test are simulated under high adhesion and low adhesion road surfaces, and statistical principles are used to analyze the estimated results, which proves the effectiveness of the design method.

Description

technical field [0001] The invention belongs to the technical field of electric vehicles, in particular to a method for observing the sideslip angle of the center of mass of a four-wheel drive electric vehicle based on fusion technology. Background technique [0002] Four-wheel distributed drive electric vehicle has been an important research direction in academia and industry because of its fast response speed of motor torque, high control precision, independent controllable torque of each wheel, and convenient power adjustment in a timely manner. [0003] As an important control quantity, the sideslip angle of the center of mass of the vehicle is closely related to the stability of the vehicle. When the steady-state model is used to estimate the side slip angle of the center of mass, the calculation amount of the algorithm is small, but the estimation method is affected by the linear tire model, and the accuracy is insufficient. The state estimation ability needs to be di...

AI Technical Summary

Problems solved by technology

When the steady-state model is used to estimate the side slip angle of the center of mass, the calculation amount of the algorithm is small, but the estimation method is affected by the linear tire model, and the accuracy is insufficient. The state estimation ability needs to be discussed

Based on the kinematics observation method, its dynamic estimation effect is still acceptable, but the kinematics method is sensitive to noise factors, and is easily affected by noise factors to produce integral drift

For the center-of-mass sideslip angle observation method using nonlinear tire model correction, its complexity is an important factor to be considered. At the same time, some high-precision tire models are affected by the complexity of the model. When designing a nonlinear state observer, its mathematical The transformation is very complex, and the estimation results are also affected by parameter uncertainties and tire model errors

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