阅读说明：本技术 一种混合动力车辆发动机启停动态控制方法 (Dynamic control method for starting and stopping engine of hybrid vehicle ) 是由 涂鹏飞 孙天乐 颜盟 方增辉 于 2021-08-26 设计创作，主要内容包括：本发明涉及一种混合动力车辆发动机启停动态控制方法。属于发动机控制方法技术领域。发动机启动过程动态控制包括以下步骤：步骤11整车控制器向发动机发送发动机的启动请求；步骤12整车控制器向电机控制器发送扭矩控制命令及请求扭矩初始值；步骤13 ISG电机跟随扭矩请求值拖起发动机；步骤14整车控制器优化ISG电机的扭矩请求值;步骤15判断发动机实际转速是否大于发动机目标怠速,如果结果为是,则进入步骤16,如果结果为否,则返回步骤13；步骤16整车控制器向发动机发送允许喷油指令；步骤17发动机喷油,发动机反馈状态为运行。本发明可以在纯电模式时停止发动机工作,在串联或者并联模式时快速启动发动机,有效提升动力性。(The invention relates to a dynamic control method for starting and stopping an engine of a hybrid vehicle. Belonging to the technical field of engine control methods. The dynamic control of the engine starting process comprises the following steps: step 11, the vehicle control unit sends a starting request of the engine to the engine; step 12, the vehicle control unit sends a torque control command and a request torque initial value to the motor controller; step 13, the ISG motor drags the engine along with the torque request value; step 15, judging whether the actual rotating speed of the engine is greater than the target idle speed of the engine, if so, entering step 16, and if not, returning to step 13; step 16, the vehicle control unit sends an allowed fuel injection instruction to the engine; and step 17, injecting oil into the engine, wherein the feedback state of the engine is running. The invention can stop the engine in the pure electric mode and quickly start the engine in the series or parallel mode, thereby effectively improving the dynamic property.)

1. A dynamic control method for starting and stopping an engine of a hybrid vehicle comprises dynamic control of the starting process of the engine and dynamic control of the stopping process of the engine, and is characterized in that: the engine starting process dynamic control comprises the following steps:

step 11, the vehicle control unit sends a starting request of the engine to the engine;

step 12, the vehicle control unit sends a torque control command and a request torque initial value to the motor controller;

step 13, the ISG motor drags the engine along with the torque request value;

step 14, the vehicle control unit optimizes the torque request value of the ISG motor;

step 15, judging whether the actual rotating speed of the engine is greater than the target idling speed of the engine, if so, entering step 16, and if not, returning to step 13;

step 16, the vehicle control unit sends an allowed fuel injection instruction to the engine;

and step 17, injecting oil into the engine, wherein the feedback state of the engine is running.

2. The hybrid vehicle engine start-stop dynamic control method according to claim 1, characterized in that: step 11 of the method should satisfy the condition that the SOC value of the electric quantity of the battery pack is higher than a set threshold value and the whole vehicle has no engine starting related fault.

3. The hybrid vehicle engine start-stop dynamic control method according to claim 1, characterized in that: in step 13 of the method, the ISG motor monitors the engine speed in real time while pulling up the engine following the requested torque value, and controls the current requested torque value not to exceed the ISG torque capacity.

4. The hybrid vehicle engine start-stop dynamic control method according to claim 1, characterized in that: the step 14 in the method specifically comprises the following steps: in the dragging process, the software interior carries out table lookup according to the cooling water temperature of the engine, the actual rotating speed value of the engine and the rotating speed value difference value with optimal starting performance and energy consumption, carries out real-time optimization on the torque request value of the ISG, ensures that the rotating speed and time images of the engine started each time are kept consistent, and simultaneously optimizes the noise, vibration and sound vibration roughness performance in the starting process of the engine.

5. The hybrid vehicle engine start-stop dynamic control method according to any one of claims 1 to 4, characterized in that: the method for dynamically controlling the engine stop process comprises the following steps:

step 21, the vehicle control unit sends a stop request of the engine to the engine;

step 22, the vehicle control unit sends a torque control command and a request torque initial value to the motor controller;

step 23, the ISG motor reduces the rotating speed of the engine along with the torque request value;

24, optimizing a torque request value of the ISG motor by the vehicle control unit;

step 25, judging whether the actual rotating speed of the engine is less than the target idling speed of the engine, if so, entering step 26, and if not, returning to step 23;

step 26, the vehicle control unit sends an oil injection prohibition instruction to the engine;

and 27, stopping fuel injection of the engine, wherein the feedback state of the engine is stop.

6. The hybrid vehicle engine start-stop dynamic control method according to claim 5, characterized in that: in step 23, the ISG motor monitors the engine speed in real time while reducing the engine speed following the requested torque value, and controls the current requested torque value not to exceed the ISG torque capability.

7. The hybrid vehicle engine start-stop dynamic control method according to claim 5, characterized in that: the method comprises the following steps of 24: in the stopping process, the internal part of the software looks up a table according to the cooling water temperature of the engine, the actual rotating speed value of the engine and the rotating speed value difference value with the optimal starting performance and energy consumption, and optimizes the torque request value of the ISG in real time, thereby ensuring that the rotating speed and time images of the engine stopped each time are kept consistent, and simultaneously optimizing the noise, vibration and sound vibration roughness performance of the engine in the stopping process.

Technical Field

The invention relates to a dynamic control method for starting and stopping an engine of a hybrid vehicle, in particular to a self-adaptive ISG starting and flameout engine control method. Belonging to the technical field of engine control methods.

Background

In a hybrid electric vehicle, a power system mainly comprises an engine, a motor, a battery and other parts, and when the power required by the whole vehicle needs to be supplied by the engine and the motor simultaneously, the start-stop control function of the engine is needed to ensure that the engine normally outputs torque to drive the whole vehicle. In order to ensure normal engine start and stop, two schemes can be provided to achieve the purpose at present: firstly, starting and stopping an engine through the output torque of the ISG (the ISG and an engine flywheel are in a direct connection state); and secondly, the engine starting and stopping function is realized through the output torque of the driving motor.

For example: the Chinese patent invention publication No. CN110341685A, whose publication date is 2019, 10, 18 and entitled "Dual-motor Range-extended Driving hybrid vehicle Engine Start-stop control method and System" discloses a hybrid vehicle Engine Start-stop control method, which drags the engine to start by controlling ISG output torque and unloads the ISG torque in time after the start is completed. The shutdown process stops the engine by controlling the ISG tow-back torque (ISG out of negative torque).

Disclosure of Invention

The invention aims to provide a dynamic control method for starting and stopping an engine of a hybrid vehicle, which can stop the engine in a pure electric mode and quickly start the engine in a series or parallel mode, thereby effectively improving the dynamic property.

The invention discloses a dynamic control method for starting and stopping an engine of a hybrid vehicle, which comprises the dynamic control of the starting process of the engine and the dynamic control of the stopping process of the engine, wherein the dynamic control of the starting process of the engine comprises the following steps:

step 11, the vehicle control unit sends a starting request of the engine to the engine;

step 12, the vehicle control unit sends a torque control command and a request torque initial value to the motor controller;

step 13, the ISG motor drags the engine along with the torque request value;

step 14, the vehicle control unit optimizes the torque request value of the ISG motor;

step 15, judging whether the actual rotating speed of the engine is greater than the target idling speed of the engine, if so, entering step 16, and if not, returning to step 13;

step 16, the vehicle control unit sends an allowed fuel injection instruction to the engine;

and step 17, injecting oil into the engine, wherein the feedback state of the engine is running.

Further, step 11 in the method should satisfy the condition that the SOC value of the battery pack is higher than a set threshold value and the whole vehicle has no engine start related fault.

Further, in step 13 of the method, the ISG motor monitors the engine speed in real time while pulling up the engine following the torque request value, and controls the current torque request value not to exceed the ISG torque capacity.

Further, step 14 in the method specifically includes: in the dragging process, the software interior carries out table lookup according to the cooling water temperature of the engine, the actual rotating speed value of the engine and the rotating speed value difference value with optimal starting performance and energy consumption, carries out real-time optimization on the torque request value of the ISG, ensures that the rotating speed and time images of the engine started each time are kept consistent, and simultaneously optimizes the noise, vibration and sound vibration roughness performance in the starting process of the engine.

Further, the method comprises the following steps of dynamically controlling the engine stop process:

step 21, the vehicle control unit sends a stop request of the engine to the engine;

step 22, the vehicle control unit sends a torque control command and a request torque initial value to the motor controller;

step 23, the ISG motor reduces the rotating speed of the engine along with the torque request value;

24, optimizing a torque request value of the ISG motor by the vehicle control unit;

step 25, judging whether the actual rotating speed of the engine is less than the target idling speed of the engine, if so, entering step 26, and if not, returning to step 23;

step 26, the vehicle control unit sends an oil injection prohibition instruction to the engine;

and 27, stopping fuel injection of the engine, wherein the feedback state of the engine is stop.

Further, in step 23 of the method, the ISG motor monitors the engine speed in real time while reducing the engine speed following the requested torque value, and controls the current requested torque value not to exceed the ISG torque capacity.

Further, step 24 in the method specifically includes: in the stopping process, the internal part of the software looks up a table according to the cooling water temperature of the engine, the actual rotating speed value of the engine and the rotating speed value difference value with the optimal starting performance and energy consumption, and optimizes the torque request value of the ISG in real time, thereby ensuring that the rotating speed and time images of the engine stopped each time are kept consistent, and simultaneously optimizing the noise, vibration and sound vibration roughness performance of the engine in the stopping process.

Compared with the scheme in the prior art, the dynamic control method for starting and stopping the engine of the hybrid vehicle has the following advantages that:

the invention provides a novel dynamic control method for starting and stopping an engine of a hybrid vehicle, which can stop the engine in a pure electric mode and quickly start the engine in a series or parallel mode, thereby effectively improving the dynamic property. In addition, the dynamic control method for starting and stopping the engine of the hybrid vehicle replaces a traditional starter by the ISG motor, ensures that the rotating speed time images of the engine are kept consistent when the engine is started and stopped each time by controlling the output torque of the ISG motor, can improve the NVH performance when the engine is started and stopped, can also improve the smoothness of the whole vehicle when the engine is started and stopped, considers various high-voltage fault conditions, can effectively improve the safety, and has good application value.

Drawings

FIG. 1 is a dynamic control flow chart of an engine starting process of the dynamic control method for starting and stopping the engine of the hybrid electric vehicle.

FIG. 2 is a dynamic control flow chart of the engine stop process of the dynamic control method for starting and stopping the engine of the hybrid electric vehicle.

Detailed Description

When the whole vehicle is in a high-voltage state, the vehicle controller sends an engine starting request and meets the starting conditions of the engine: the SOC value of the electric quantity of the battery pack is higher than a certain threshold value, and the whole vehicle has no engine starting related fault;

as shown in fig. 1, the vehicle control unit sends a start request of the engine to the engine;

the vehicle control unit sends a torque control command and a torque to a Motor Controller (MCU) so as to enable a motor to drag an engine which is rigidly connected with the motor to rotate, enable the torque of an ISG motor (permanent magnet synchronous motor) to quickly follow the magnitude of a requested torque value, monitor the rotating speed of the engine in real time and control the current requested torque value not to exceed the torque capacity of the ISG.

In the dragging process, the internal part of the software looks up a table according to the cooling water temperature of the engine, the actual rotating speed value of the engine and the rotating speed value difference value with optimal starting performance and energy consumption, and optimizes the torque request value of the ISG in real time, so that the rotating speed time images of the engine during each starting are ensured to be consistent as much as possible, the starting consistency is kept, and the NVH (noise, vibration and harshness) performance of the engine during the starting process is optimized.

When the rotating speed of the engine is higher than a set oil spraying rotating speed threshold value, an oil spraying allowing instruction is sent to an engine controller, the engine executes the oil spraying instruction, and the starting rotating speed threshold value is not smaller than the idling rotating speed value of the engine;

and when the feedback state received from the engine controller is the running state, the vehicle controller considers that the engine is started completely and enters a normal idling state or a vehicle running state.

As shown in FIG. 2, the dynamic control method for the engine stop process comprises the following steps:

the vehicle control unit sends a stop request of the engine to the engine;

the vehicle control unit sends a torque control command and a torque magnitude to a Motor Controller (MCU) so as to enable a motor to drag the rotating speed of an engine rigidly connected with the motor to be reduced, enable the torque of an ISG motor to quickly follow the magnitude of a requested torque value of the ISG motor, simultaneously monitor the rotating speed of the engine in real time and control the current torque requested value not to exceed the torque capacity of the ISG.

In the shutdown process, the interior of the software looks up a table according to the cooling water temperature of the engine, the actual rotating speed value of the engine and the rotating speed value difference value with the optimal starting performance and energy consumption, as shown in table 1:

TABLE 1

Water temperature/rotational speed difference	-1200	-1000	-800	-600	-400	-200	0	100
									-20	90	80	70	50	40	30	10	0
-10	90	80	70	45	40	30	10	0
									0	80	70	55	45	40	30	5	0
10	80	70	55	40	35	25	0	0
									30	70	60	45	35	30	10	0	0
50	70	60	40	30	20	10	0	0
									70	70	60	40	30	15	10	0	0

The torque request value of the ISG is optimized in real time, so that the rotation speed and time images of the engine in each stop are ensured to be consistent as much as possible, the consistency in the stop process is kept, and the NVH performance of the engine in the stop process is optimized.

When the rotating speed of the engine is lower than a set oil injection rotating speed threshold value, an oil injection prohibition instruction is sent to an engine controller, and the engine executes the instruction;

when the HCU receives the feedback state of the engine controller and is in a stop state, the vehicle control unit considers that the engine stops completely and enters a normal pure electric driving state and a stop state.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.