THE CONCEPT OF THE CLUTCH CONTROL LAW OF A CAR

Mykola Mykhalevych,Alina Fandieieva

doi:10.30977/at.2219-8342.2021.48.0.17

Abstract

Problem. The combination of comfortable automatic control of the car's transmission and at the same time preservation of high indicators of energy efficiency and cost of a design is possible by use of automatic mechanical transmission. The automatic clutch control system plays a significant role in providing comfort in such transmissions. The laws of controlling it are not perfect today. Goal. The aim of the work is to create a clear concept of the law of clutch control, which is easy to implement in a microcontroller and is well adapted to adapt to different driving conditions. Methodology. Graphically, the concept of the perspective law of clutch control is formed by two Bezier curves. One of the curves acts as a guide, and the other forms the surface of the law. Results. On the basis of the Bézier curves of the third degree the concept of the law is formed and the connection of the reference points of the Bézier curves with the physical parameters of the working process of vehicle movement is substantiated. Originality. The formation of the Bézier curve, which is decisive for the concept of the law, is formed on the basis of a typical working process of synchronization of the angular velocity of the clutch discs during the movement of the vehicle. In contrast to the laws of clutch control considered in the scientific literature, the proposed concept provides for clutch control outside the site of the synchronization process and ensures the avoidance of jerks during further acceleration. Practical value. The proposed algorithm provides full engagement of the clutch only after full synchronization of the clutch discs. The formation of a special form of the law in the form of a curve tangent to the abscissa axis reduces the jerks when closing the clutch discs.

Highlights

With the development of automatic control systems for transmission units, the clutch control laws have been evolving in the same way as their hardware
There is the law of control of the bite point as a function of the angle of rotation of the accelerator pedal and as a function of the speed of the engine crankshaft among them
The latter is more adjusted to adapt to the pace of movement of the accelerator pedal because it responds directly to the operation of the engine, and not to the position of the accelerator pedal

Summary

Introduction

With the development of automatic control systems for transmission units, the clutch control laws have been evolving in the same way as their hardware. Only three numbers ( x1 , x2 , y1 ) determine the quality of the curve approximation that characterizes the desired process of synchronization of the angular velocitys of the leading and driven parts of the clutch This approach is very convenient to use for the adaptive changes in the electronic control unit because it is much more convenient to control such coordinates than the coefficients of the polynomial which often acquire very inconvenient values for processing in ECU (Fig. 3). Each point of such a line reproduces the desired control effect in accordance with the real values r and c.

Conclusions

Clutch Engagement for Vehicle Launches via a