CN-121993303-A - Shutdown control strategy for power split type hybrid diesel engine of commercial vehicle

CN121993303ACN 121993303 ACN121993303 ACN 121993303ACN-121993303-A

Abstract

The invention discloses a shutdown control strategy of a power split type hybrid diesel engine of a commercial vehicle, which comprises the steps that a whole vehicle controller sends a shutdown request command to an engine controller after recognizing that the shutdown requirement of the engine is met, the engine controller receives the shutdown request command, controls an engine to reduce torque to stop oil injection according to a first preset slope so as to start reducing the rotation speed of the engine, controls the rotation speed of the engine to be reduced to a target preset rotation speed according to a second preset slope after stopping oil injection of the engine, and controls a driving motor to output preset compensation torque after the rotation speed of the engine is reduced to the target preset rotation speed, and the rotation speed of the engine is continuously reduced to zero. The scheme is simple in principle, the aim of optimization can be achieved through calibration, shaking and abnormal sound caused to a transmission system in the shutdown process of the power split type hybrid diesel engine of the commercial vehicle can be reduced, and the problem that the control is unstable due to poor consistency of the commercial vehicle is solved.

Inventors

LIN LI
ZHANG LIN
YANG JING

Assignees

安徽江淮汽车集团股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260313

Claims (7)

1. A shutdown control strategy for a power split hybrid diesel engine for a commercial vehicle, comprising: After the whole vehicle controller recognizes that the engine stopping requirement is met, a stopping request instruction is sent to the engine controller; the engine controller receives a stop request instruction, and controls the engine to reduce torque to stop oil injection according to a first preset slope so that the rotation speed of the engine starts to be reduced; after the engine stops injecting fuel, the whole vehicle controller controls the engine speed to be reduced to a target preset speed according to a second preset slope; When the engine speed is reduced to the target preset speed, the driving motor controller controls the driving motor to output a preset compensation torque, and the engine speed is continuously reduced to zero.
2. The shutdown control strategy of a commercial vehicle power split hybrid diesel engine of claim 1, wherein the engine controller receives a shutdown request command to control the engine to reduce torque to stop fueling according to a first preset slope, further comprising: The engine controller adjusts one or more parameters of intake air amount, oil pump pressure and oil injection advance angle so that the output torque of the engine is reduced to a certain value and kept unchanged.
3. The shutdown control strategy of a commercial vehicle power split hybrid diesel engine of claim 2, wherein the engine controller controls the engine to stop injecting fuel when the output torque of the engine decreases below a calibrated value.
4. The shutdown control strategy of a commercial vehicle power split hybrid diesel engine according to claim 1, wherein after stopping the injection of the engine, the vehicle controller controls the engine speed to decrease to a target preset speed according to a second preset slope, comprising: the whole vehicle controller sends a control instruction to the motor controller; The motor controller controls the output torque of the generator so that the rotation speed of the generator is reduced to the target preset rotation speed according to the second preset slope.
5. The shutdown control strategy of a commercial vehicle power split hybrid diesel engine of claim 4, wherein the motor controller controls the output torque of the generator comprising: According to the friction torque, the target angular acceleration and the system inertia of the engine, calculating to obtain the request torque of the generator; And the whole vehicle controller controls the motor controller to adjust the actual output torque of the generator according to the request torque.
6. The shutdown control strategy for a commercial vehicle power split hybrid diesel engine of claim 5, wherein the friction torque of the engine is obtained by a preset MAP table look-up.
7. The shutdown control strategy for a commercial vehicle power split hybrid diesel engine of claim 1, wherein the compensation torque is determined by the following equation: ; ; Wherein, the For the torque of the ring gear, As the friction torque of the engine, Torque is required for the wheel end and, To request torque.

Description

Shutdown control strategy for power split type hybrid diesel engine of commercial vehicle Technical Field The invention relates to the technical field of automatic control, in particular to a shutdown control strategy of a power split type hybrid diesel engine of a commercial vehicle. Background At present, the main flow mixed running mode comprises P13, P2, power split and the like, a clutch is arranged between an engine and a gear system of a mixed running vehicle such as P13, P2 and the like, the power split mixed running vehicle can realize the functions of pure electric running, parallel running, series power generation and the like without the clutch, the engine torque and the wheel end torque of the power split mixed running vehicle without the clutch are coupled, and the vibration of the engine can be transmitted to the wheel end in real time. Whereas the characteristics of commercial vehicle diesel engines are significantly affected by environmental factors and are multi-dimensional (e.g., low temperature, plateau, high temperature, etc.), the compression ignition characteristics of diesel engines are very sensitive to environmental changes. The engine state is different and has a great influence on the stopping performance. Meanwhile, the engine of the commercial vehicle has a lot of starting requirements, including an idle engine start, a warm air engine start, an inflation pump engine start and an intelligent charging engine start (hereinafter referred to as EC mode), and the running states of the engine are different after the engine is started according to the different requirements. When the engine is required to stop working, the rotation speed and the torque of the engine are also different, and the stopping consistency is difficult to ensure. In order to improve drivability, the prior art calculates by acquiring signals of a crank sensor in real time by means of signals of the crank sensor, and simultaneously, a motor adjusts torque output in real time according to a calculated result, so that torque of the motor is controlled, the stop position of the crank is controlled, the rotating speed of the engine is reduced to 0, and stop is completed. The stopping mode in the prior art has high precision requirement on the sensor, is not beneficial to reducing the cost of the commercial vehicle, and simultaneously, when the engine is stopped, the motor needs to be controlled continuously by torque, and the engine is dragged to rotate reversely due to improper control, so that the engine is damaged. Disclosure of Invention In view of the foregoing, the present invention is directed to providing a shutdown control strategy for a power split hybrid diesel engine of a commercial vehicle, so as to solve the aforementioned technical problems. The technical scheme adopted by the invention is as follows: the invention provides a shutdown control strategy of a power split type hybrid diesel engine of a commercial vehicle, which comprises the following steps: After the whole vehicle controller recognizes that the engine stopping requirement is met, a stopping request instruction is sent to the engine controller; the engine controller receives a stop request instruction, and controls the engine to reduce torque to stop oil injection according to a first preset slope so that the rotation speed of the engine starts to be reduced; after the engine stops injecting fuel, the whole vehicle controller controls the engine speed to be reduced to a target preset speed according to a second preset slope; When the engine speed is reduced to the target preset speed, the driving motor controller controls the driving motor to output a preset compensation torque, and the engine speed is continuously reduced to zero. Optionally, the engine controller receives a stop request command, and controls the engine to reduce torque to stop oil injection according to a first preset slope, and the method further comprises: The engine controller adjusts one or more parameters of intake air amount, oil pump pressure and oil injection advance angle so that the output torque of the engine is reduced to a certain value and kept unchanged. Optionally, the engine controller controls the engine to stop injecting fuel when the output torque of the engine decreases to less than a calibrated value. Optionally, after the engine stops injecting fuel, the whole vehicle controller controls the engine speed to decrease to a target preset speed according to a second preset slope, including: the whole vehicle controller sends a control instruction to the motor controller; The motor controller controls the output torque of the generator so that the rotation speed of the generator is reduced to the target preset rotation speed according to the second preset slope. Optionally, the motor controller controls the output torque of the generator, including: According to the friction torque, the target angular acceleration and the system inertia of the engine,