Method for estimating road adhesion coefficient of four-wheel-drive electric automobile

Abstract

The invention provides a method for estimating a road adhesion coefficient of a four-wheel-drive electric automobile and belongs to the technical field of control. The invention aims at providing themethod for estimating the road adhesion coefficient of the four-wheel-drive electric automobile, which comprises the steps of providing two estimation strategies first, designing a final estimator tointegrate the two estimation strategies, obtaining a method I to utilize points with adhesion coefficients above a mean value and substituting into a method II to obtain accurate and effective road adhesion coefficient estimation information. The method for estimating the road adhesion coefficient of the four-wheel-drive electric automobile comprises the steps of pavement adhesion coefficient estimation based on a formula method, pavement adhesion coefficient estimation based on formula deformation and algorithm fusion. According to the method for estimating the road adhesion coefficient of the four-wheel-drive electric automobile, the estimation method can be more suitable for complicated and changeable working conditions, the adaptability is higher, and the adhesion coefficient estimation value is more effective and accurate.

Description

technical field [0001] The invention belongs to the technical field of control. Background technique [0002] With the rapid development of electric vehicle on-board batteries, power electronic devices and other technologies, electric vehicles are gradually catching up with traditional internal combustion engine vehicles in terms of power and economy, and will inevitably become mainstream products in the future automotive market. The development of internal combustion engine vehicles has been slow due to energy consumption and environmental pollution. Electric vehicles will be an effective way to achieve the best of both worlds. The research and development of electric vehicles has been put on the agenda by many countries. China has implemented the "Energy Saving and New Energy Vehicle Industry Development Plan (2012-2020)" to promote the deeper application of electric vehicles in many fields such as public transportation, logistics, and leasing. [0003] While enjoying the...

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Problems solved by technology

[0005] 1. An electric vehicle is a nonlinear system with many variables and coupling, complex motion mechanism and many constraints. The relationship between variables is intricate. The estimation of the road surface adhesion coefficient is a relatively complicated problem in the state of the vehicle.

If the road surface adhesion coefficient information is not obtained properly during the vehicle form process, there may be safety hazards and even cause traffic accidents

[0006] 2. Whether it is a Cause-based or Effect-based strategy, the method of further obtaining the road surface adhesion coefficient by installing sensors has corresponding disadvantages

For example, the optical sensor has very strict requirements on the working environment and cannot adapt to complex and changeable working conditions. The recognition accuracy depends on experience and the cost is high.

The method of installing acoustic sensors requires energy self-sufficiency and wireless transmission of data, which makes the cost too high to realize commercial value

[0007] The method of directly obtaining the road surface adhesion coefficient according to the slip rate-adhesion coefficient curve cannot obtain the adhesion coefficient under complex and mixed road conditions, and the accuracy is flawed. The trend and value of the curve are easily affected by the hardware status of the car while driving

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