Follow-up control method and control system of vehicle rear axle electronically controlled steering wheel

Abstract

The invention provides a follow-up control method of a vehicle rear axle electronically controlled steering wheel which is used for controlling electro-hydraulic proportional valves for driving the rotation of each rear axle steering wheel. The method comprises the following steps: detecting the actual intersection angle value of a following object and calculating the variable quantity of the following object intersection angle; and judging whether the intersection angle variable quantity is out of the range of the preset dead zone or not, if so, adding a preset modulation parameter to the control parameter which is used for driving and controlling corresponding controlled objects to modify the driving and controlling signals. The core of the invention lies in that the variable quantity ofthe following object intersection angle is utilized to judge whether the follow-up control of each rear axle is started or not, and the driving and controlling signals are modified by adding the preset modulation parameter on the basis of the original control parameter, thus effectively solving the problems of less follow-up control parameter and follow-up startup hysterisis of rear axle steeringwheel in traditional control method. On the basis, the invention also provides a follow-up control system of the vehicle rear axle electronically controlled steering wheel.

Description

technical field [0001] The invention relates to the field of automatic control of engineering machinery, in particular to a follow-up control method and a control system for an electronically controlled steering wheel of a rear axle of a vehicle. Background technique [0002] At present, engineering vehicles show a trend of large-scale development with the continuous improvement of load-carrying requirements. [0003] The steering system of the existing large-scale engineering vehicle chassis has multiple sets of front axles and multiple sets of rear axles, wherein each set of front axles is rigidly connected by mechanical structure, and the steering operation of the front axles is directly controlled by the driver's steering wheel; each set of rear axles There is no mechanical connection with the front axle, and the electro-hydraulic proportional closed-loop control method is used to control the steering action of the steering wheels of the rear axle. [0004] See figure ...

AI Technical Summary

Problems solved by technology

If due to the action speed and performance of hydraulic valves and other actuators, the control dead zone of the 4th, 5th, 6th and 7th axle angles is 0.3°; then according to the existing control method, the wheels of the 1st axle need to rotate about 3 degrees respectively. °, 3°, 0.6° and 0.42°, the corresponding steering wheels of the rear axle start to follow the steering action, that is to say, the existing control method has the problem of lag in the start of the rear axle follow-up

In particular, when the wheels of the 4th and 5th axles start follow-up steering, the 1st bridge has turned about 3°; with the traditional fixed parameter PID as the follow-up control strategy, the difference between the target value and the actual value when the follow-up action is started That is to say, the deviation is very small (that is, slightly larger than the dead zone of 0.3°), and the corresponding output control amount obtained after the PID calculation is also small, resulting in a slow action speed during follow-up start, and the steering wheel angle of the rear axle is relatively the same as the first The start-up lag of the axle wheel angle is very noticeable

[0010] The above analysis shows that the traditional vehicle chassis wheel steering follow-up control method has the problem that the start of the follow-up steering of the steering wheel of the rear axle lags behind, and the follow-up speed after starting is relatively slow, which cannot ensure a good fast start of the follow-up steering control action. Sex, resulting in poor synchronization of the steering action of the front and rear axle steering wheels

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