A method and system for controlling automatic transmission parking and downshifting

Abstract

The present invention relates to the technical field of gearbox control, and provides a method and system for controlling automatic transmission downshifts during parking. The method includes: calling a pre-generated shift map query curve to obtain the target gear position of the current vehicle; The deceleration of the shaft or the deceleration of the whole vehicle is monitored and judged; when there is a sudden deceleration, the gear correction matrix is ​​called to correct the obtained target gear, and the corrected target gear is obtained; according to the current gear of the vehicle And the corrected target gear, control the vehicle to perform the gear shift operation when the shift delay time arrives; when there is no sudden deceleration condition, continue to execute the deceleration of the current vehicle transmission output shaft or the deceleration of the whole vehicle The steps of monitoring and judging, so as to realize the shift control during the downshifting process of the automatic transmission, effectively avoid frequent shifting, and switch from two-step shifting to single-step shifting, which can greatly shorten the shifting time and improve Shift quality.

Description

technical field [0001] The invention belongs to the technical field of transmission control, and in particular relates to a control method and system for downshifting when an automatic transmission is parked. Background technique [0002] Clutch shift control and shift strategy are the core control technologies of hydraulic automatic transmissions, which affect the driving performance and shift quality of the vehicle. And the shift control under low gear position and low vehicle speed is the technical difficulty of automatic transmission control. This driving condition often occurs in crowded urban traffic conditions, which is prone to frequent shifting and shifting shock. Because in crowded urban conditions, the driver's driving intention is very unclear during the process of starting and stopping, and the accelerator and brake will often change irregularly. Therefore, it is difficult to realize the exchange through signal processing such as accelerator acceleration and bra...

AI Technical Summary

Problems solved by technology

The shift control at low gears and low vehicle speeds is also a technical difficulty in automatic transmission control. This driving condition often occurs in congested urban traffic conditions, which is prone to frequent shifts and shift shocks.

Because in crowded urban conditions, the driver's driving intention is very unclear during the process of starting and stopping, and the accelerator and brake will often change irregularly. Therefore, it is difficult to realize the exchange through signal processing such as accelerator acceleration and braking Gear delay control, thus affecting the normal shift strategy

[0003] In addition, the change of accelerator and brake will also cause the torque and speed of the engine to be unstable, which will also increase the difficulty of clutch control, which will easily cause shift shock and drag feeling, thus affecting the shift quality.

Images