Rear-wheel-steering-based ESP enhanced control method for rear-drive vehicle

Abstract

The invention discloses a rear-wheel-steering-based ESP enhanced control method for a rear-drive vehicle. The control method comprises a control process for performing left deflection obstacle avoidance and a control process for performing right deflection obstacle avoidance on a vehicle in linear driving. In the process of obstacle avoidance through the control method, the distance between the Zaxis and the center Q1 of a left rear wheel serves as a force arm Lf or the distance between the Z axis and the center Q2 of a right rear wheel serves as a force arm Lr, so that the force arm Lf or Lrkeeps the maximum value all the time in the process of torque control through the resultant force of the acting force of the rear wheels. When the same control torque is needed, the braking force resultant force applied to the rear wheels can be reduced, and particularly, the effect can be achieved under the road surface conditions with low ground adhesion coefficients, such as wet and slippery or iced road surfaces; and under the condition that the same acting force resultant force is applied to the rear wheels, larger control torque can be generated on the Z axis, and a vehicle head can quickly steer to avoid colliding with obstacles when the vehicle avoids the front 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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