Method and system for controlling speed ratio of CVT

Abstract

The invention discloses a method and system for controlling speed ratio of a CVT, and belongs to the technical field of continuously variable transmissions. According to the method and system controlling speed ratio of the CVT, the problem that the speed ratio adjustment cannot respond to the driving mode intention of a driver in time and accurately is solved. The method for controlling the speedratio of the CVT includes the following steps of collecting opening data of an accelerator pedal; judging whether the opening of the accelerator pedal is less than or equal to the first preset threshold according to the opening data of an accelerator, and if yes, outputting economic speed ratio ieco by the CVT; and otherwise judging whether the opening of the accelerator pedal is greater than or equal to the second preset threshold, if yes, outputting dynamic speed ratio ispt by the CVT, and if not, outputting comprehensive speed ratio by the CVT, wherein the comprehensive speed ratio is the accelerator pedal opening. According to the method and system controlling speed ratio of the CVT, the self-adaptive adjustment among the economic speed ratio, comprehensive speed ratio and dynamic speed ratio is achieved, so that the problem that the speed ratio adjustment is not timely and accurate due to the need of manual operation in the prior art is avoided.

Description

technical field [0001] The invention relates to the technical field of continuously variable transmissions, in particular to a method and system for controlling the speed ratio of a continuously variable transmission. Background technique [0002] With the rapid development of automatic control technology, various industries are undergoing technological reforms of automation and intelligence. Many important parts of the car have an integrated control unit. As an important part of the car, the continuously variable transmission can automatically and continuously change the speed ratio according to the driving conditions of the vehicle so that the engine always works in the ideal area. Through the continuously variable transmission control unit , to control the speed ratio of the transmission, and then adjust the speed ratio of the vehicle. [0003] At present, the speed ratio control of most continuously variable transmissions in China adopts two modes, namely economic mode ...

AI Technical Summary

Problems solved by technology

[0003] At present, the speed ratio control of most continuously variable transmissions in China adopts two modes, namely economic mode and power mode, which are usually set as two button switches for the driver to choose, but in fact most of the time the driver keeps the economic mode switch normally. On, because this is enough to cope with most situations in daily life. When encountering extreme conditions such as climbing a steep slope, the driver may turn on the power mode, but after passing this condition, the driver will switch back to In economical mode, the manual switching of modes brings inconvenience to the driver, and makes the speed ratio adjustment untimely and inaccurate due to manual operation

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