A Determination Method of Road Surface Adhesion Level for Braking Distance Compensation

Abstract

The invention discloses a method for determining road surface adhesion level for braking distance compensation. The method is as follows: in the case of satisfying the braking distance compensation condition, if the brake pedal is depressed and the anti-lock braking function is triggered, control The controller determines the first road surface adhesion level according to the master cylinder pressure, and then takes the first road surface adhesion level as the current road surface adhesion level, and starts to calculate the mileage; Determine the second road surface adhesion level, and then use the second road surface adhesion level as the current road surface adhesion level, and start to calculate the mileage; If the start anti-skid function is not triggered, when the mileage is greater than the set mileage threshold, the controller will use "normal" as the current road adhesion level. The present invention can simply and quickly determine the current road surface adhesion level.

Description

technical field [0001] The invention belongs to the field of low-speed auxiliary driving systems, and in particular relates to a method for determining a road adhesion level for braking distance compensation. Background technique [0002] In the low-speed driving assistance system, the automatic emergency braking function can perform emergency braking on the relative relationship between the vehicle and obstacles below 10km / h to avoid collisions. This function needs to consider the impact of different road conditions on the system, especially for ice and snow roads in the north, where the adhesion coefficient of the road surface is small, and it is very easy to lock the wheels or the vehicle starts to skid. On roads with poor adhesion, the braking distance of the vehicle becomes longer, and the deviation from the braking distance on good roads is large. If the control parameters of good roads are still used, collisions are likely to occur. At present, this problem is genera...

AI Technical Summary

Problems solved by technology

On roads with poor adhesion, the braking distance of the vehicle becomes longer, and the deviation from the braking distance on good roads is large. If the control parameters of good roads are still used, collisions are likely to occur

At present, this problem is generally solved by the brake controller calculating the specific road surface adhesion coefficient according to the parameters of the engine, transmission, and braking system; it needs to collect the parameters of the engine, transmission, braking system, vehicle, steering and other systems, and the calculation is complicated. It is mainly aimed at the body stability control system at high speeds; but limited to the problem of division of responsibilities, brake system manufacturers are reluctant to open this parameter to OEMs for automatic driving. At the same time, many parameters and complex calculation strategies of each system require long-term accumulation and a large number match test

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