Vehicle and shifting control method and power transmission system thereof

Patent metadata

Field	Value
Publication number	US-10166973-B2
Application number	US-201615230992-A
Country	US
Kind code	B2
Filing date	Aug 8, 2016
Priority date	Oct 20, 2014
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

The present disclosure discloses a shifting control method for a hybrid vehicle. The shifting control method includes: detecting operating parameters of the hybrid vehicle, where the operating parameters of the hybrid vehicle includes vehicle speed, vehicle acceleration as reflected from an accelerator-pedal signal and a current gear of the hybrid vehicle; determining a work mode of the hybrid vehicle; performing speed adjustment and shifting control to the first motor-generator according to a work mode and the operating parameters of the hybrid vehicle to implement shifting control of the hybrid vehicle, where the work mode includes an electric-vehicle mode and a hybrid-electric-vehicle mode. The method considers performing speed adjustment and shifting control under various working conditions. This improves smoothness and comfort of the vehicle and enlarges the use scope. The present disclosure further discloses a power transmission system of a hybrid vehicle and a hybrid vehicle.

First claim

What is claimed is:

1. A shifting control method for a vehicle comprising:
detecting operating parameters of the vehicle, wherein the operating parameters of the vehicle comprises vehicle speed, vehicle acceleration as reflected from an accelerator-pedal signal, and a current gear of the vehicle;
determining a work mode of the vehicle; and
performing speed adjustment and shifting control to a first motor-generator of the vehicle configured to rotate together with a motor shaft of the vehicle according to the operating parameters of the vehicle and work modes to implement shifting control of the vehicle, wherein the motor shaft of the vehicle is configured to rotate together with one of input shafts, wherein the work modes comprises an electric-vehicle mode and a hybrid-electric-vehicle mode, and wherein when the work mode of the vehicle is the electric-vehicle mode, performing speed adjustment and shifting control to the first motor-generator comprises:
controlling, by an electromotor controller, to perform a first unloading of torque to the first motor-generator, after determining that a request gear sent by the electromotor controller is the same as a target gear sent by a transmission control unit;
after the first unloading of torque of the first motor-generator is finished, controlling, by the transmission control unit, a motor shaft synchronizer of the power transmission system to disconnect according to a motor speed adjustment request sent by the electromotor controller, and when the first motor-generator is at neutral, calculating, by the electromotor controller, a target shifting rotational speed of the first motor-generator and controlling, by the electromotor controller, to perform loading of torque to the first motor-generator to perform speed adjustment until a rotational speed of the first motor-generator reaches a preset rotational speed range;
controlling, by the electromotor controller, to perform a second unloading of torque to the first motor-generator until the second unloading of torque of the first motor-generator is finished, controlling, by the transmission control unit, the motor shaft synchronizer to start connecting according to the request gear sent by the electromotor controller and feeding back, by the transmission control unit, whether the request gear of the electromotor controller is shifted successfully; and
determining, by the electromotor controller, that the current gear of the first motor-generator sent by the transmission control unit is the request gear, and determining, by the electromotor controller, that the first motor-generator is shifted successfully.

2. The method of claim 1 , wherein the preset rotational speed range is in a preset motor shifting target rotational speed range, and the preset motor shifting target rotational speed range is obtained according to the target shifting rotational speed of the first motor-generator.

3. The method of claim 1 , wherein when the electromotor controller determines that the first motor-generator needs to be performed upshifting control, the preset rotational speed range is greater than an upper limit of a target shifting rotational speed range of the first motor-generator; and
when the electromotor controller determines that the first motor-generator needs to be performed downshifting control, the preset rotational speed range is smaller than a lower limit of the target shifting rotational speed range of the first motor-generator.

4. The method of claim 1 , when performing speed adjustment and shifting control to the first motor-generator, further comprising:
performing, by the electromotor controller, PID adjustment to the first motor-generator to reduce speed-adjustment time of the first motor-generator.

5. The method of claim 4 , wherein performing, by the electromotor controller, PID adjustment to the first motor-generator comprises:
obtaining a proportional coefficient, an integral time constant and a differential time constant of the first motor-generator when the first motor-generator outputs without load;
controlling the first motor generator to increase an output load, adjusting the proportional coefficient, the integral time constant and the differential time constant when outputting without load until oscillation which the first motor-generator outputs disappears and recording a current proportional coefficient, a current integral time constant and a current differential time constant; and
calculating an integral coefficient and a differential coefficient according the current proportional coefficient, the current integral time constant and the current differential time constant.

6. The method of claim 1 , wherein, when the work mode of the vehicle is the hybrid-electric-vehicle mode, if the transmission control unit determines that an engine needs an upshifting control according to the vehicle speed and the vehicle acceleration of the vehicle, performing speed adjustment and shifting control to the first motor-generator comprises:
if the current gear of the first motor-generator is a first gear, controlling a gear of the first motor-generator to adjust from the first gear to a second gear;
controlling, by the electromotor controller, to perform the first unloading of torque to the first motor-generator, after determining that the request gear sent by the electromotor controller is the same as the target gear sent by the transmission control unit;
after the first unloading of torque of the first motor-generator is finished, controlling, by the transmission control unit, the motor shaft synchronizer of the power transmission system to disconnect according to the motor speed adjustment request sent by the electromotor controller, and when the first motor-generator is at neutral, calculating, by the electromotor controller, the target shifting rotational speed of the first motor-generator and controlling, by the electromotor controller, to perform loading of torque to the first motor-generator to perform speed adjustment until the rotational speed of the first motor-generator reaches the preset rotational speed range;
controlling, by the electromotor controller, to perform the second unloading of torque to the first motor-generator until the second unloading of torque of the first motor-generator is finished, controlling, by the transmission control unit, the motor shaft synchronizer to start connecting according to the request gear sent by the electromotor controller and feeding back, by the transmission control unit, whether the request gear of the electromotor controller is shifted successfully; and
determining, by the electromotor controller, that the current gear of the first motor-generator sent by the transmission control unit is the request gear, and determining, by the electromotor controller, that the first motor-generator is shifted successfully.

7. The method of claim 1 , wherein, when the hybrid vehicle is switched from the electric-vehicle mode to the hybrid-electric-vehicle mode, the electromotor controller determines whether an engine needs to be started;
if no, the electromotor controller further determines whether the first motor-generator needs to be performed speed adjustment and shifting control;
if the electromotor controller determines that the first motor-generator needs to be performed speed adjustment and shifting control, controlling, by the electromotor controller, to perform the first unloading of torque to the first motor-generator, after determining that the request gear sent by the electromotor controller is the same as the target gear sent by the transmission control unit;
after the first unloading of torque of the first motor-generator is finished, controlling, by the transmission control unit, the motor shaft synchronizer of the power tran

Assignees

• Byd Co Ltd

Inventors

• Yang Dongsheng
• Lian Yubo
• Zhang Jintao
• Luo Hongbin

Classifications

• B60W2510/081

  Speed · CPC title

• B60W10/11

  Stepped gearings · CPC title

• B60W2710/021

  Clutch engagement state · CPC title

• B60W2510/1005

  Transmission ratio engaged · CPC title

• Y02T10/6286

  Cross-Sectional Technologies · mapped topic