ESP Enhanced Control Method for Rear-drive Vehicle Based on Rear-wheel Steering

Abstract

The invention discloses an ESP enhanced control method for a rear-wheel drive vehicle based on rear wheel steering, including a control method for how to avoid obstacles by left deflection and a control method for obstacle avoidance by right deflection when the vehicle is running straight; In the process of obstacles, align the Z axis with the left rear wheel center Q 1 The distance as the moment arm L f Or align the Z axis with the right rear wheel center Q 2 The distance as the moment arm L r , so that the moment arm L f or L r Always maintain the maximum value during the torque control process using the resultant force of the rear wheels; when the same control torque is required, it is beneficial to reduce the resultant braking force applied to the rear wheels, especially on wet or icy roads It works on road conditions with a low ground adhesion coefficient; when the same force is applied to the rear wheels, it can generate a greater control torque on the Z axis, which is conducive to the car's front speed when avoiding obstacles in front of it. Steer to avoid hitting obstacles.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to an ESP enhanced control method for rear-wheel steering based on rear-wheel steering. Background technique [0002] Electronic Stabilization System (ESP for short) includes anti-lock braking system, traction control system and vehicle driving dynamics control system. driving safety. [0003] Taking the front and rear direction of the car as the Y axis, the left and right direction of the car as the X axis, taking the direction perpendicular to the X axis and the Y axis plane as the Z axis, and taking the center of mass C of the car as the coordinate origin, a three-dimensional coordinate system is formed as follows: Figure 3-5 Shown; For rear-wheel drive cars, the existing ESP working process is as follows Figure 1-2 as shown, figure 1 It is a schematic diagram of a car driving to the left to avoid obstacles. The state of the car running in a straight line at a constant s...

AI Technical Summary

Problems solved by technology

Therefore, applying the braking force on the outer front wheel to generate the corresponding torque will bring a lot of uncertainty, in order to generate enough torque T 2 or T 4 , ESP needs to continuously and substantially correct F 2 or F 4 value, which brings great difficulty to the ESP control process. At the same time, when driving on the slippery or icy road as mentioned above, the F 2 or F 4 The value of will also decrease accordingly, and then consider that when F 2 or F 4 In the special case where the line of action intersects the Z axis, there are many variables in the process of torque control of the ESP on the outer front wheel, the control process is not precise, and even the situation that the control cannot be realized under special circumstances

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