CN115285102A

CN115285102A - Method for controlling engine speed of hybrid vehicle and hybrid vehicle

Info

Publication number: CN115285102A
Application number: CN202210892086.8A
Authority: CN
Inventors: 祝浩; 郭丁伊; 于长虹; 徐家良; 刘加明; 尹建坤; 巴特
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2022-07-27
Filing date: 2022-07-27
Publication date: 2022-11-04

Abstract

The invention provides a control method of the rotating speed of an engine of a hybrid vehicle and the hybrid vehicle, wherein the control method comprises the following steps: determining a current driving mode of the hybrid vehicle, the driving mode comprising: a series drive mode and a parallel drive mode; acquiring the actual rotating speed of the engine, and calculating a deviation value between the actual rotating speed and the target rotating speed; determining whether the rotating speed of the engine is overspeed under different driving modes based on the actual rotating speed and/or the deviation value; calling corresponding control strategies based on different driving modes; and controlling the rotating speed of the engine to be within the target rotating speed range based on the control strategy. Therefore, the duration time of the condition that the rotating speed of the engine exceeds the speed can be shortened, the problem that the clutch plate is ablated due to overlong rotating speed exceeding time of the engine is avoided, the problem that the engine is damaged due to the fact that the rotating speed of the engine exceeds the speed in the prior art is solved, the technical effect of guaranteeing the safety of vehicle parts is achieved, and the driving safety of the vehicle is improved.

Description

Method for controlling rotational speed of engine of hybrid vehicle, and hybrid vehicle

Technical Field

The invention relates to the technical field of vehicle control, in particular to a method for controlling the rotating speed of an engine of a hybrid vehicle and the hybrid vehicle.

Background

At present, the petroleum resources are gradually in shortage, and in the face of increasingly strict fuel consumption regulations, the cost of reducing the fuel consumption of a vehicle driven by a traditional pure internal combustion engine is higher and higher, and the difficulty is higher and higher; the hybrid vehicle has great potential in reducing oil consumption due to the assistance of the motor, and the P2 configuration represented by European manufacturers, the double-motor planetary gear power splitting configuration represented by Toyota and the like realize mass production, obtain good oil consumption performance and gain favor of mass consumers; however, both the P2 configuration and the power splitting configuration face more technical difficulties and technical barriers in domestic application, and the application of autonomous vehicle models is slow all the time.

The double-motor hybrid configuration is proved to be a hybrid configuration scheme which is more suitable for the situation of China in recent years, the switching between the HEV and the PHEV can be conveniently realized, and particularly, the fuel saving advantage of the double-motor hybrid configuration is obvious for the congested road working condition in the urban area of China. The double-motor hybrid configuration can operate in three driving modes, namely pure electric driving mode, series driving mode and parallel driving mode, under the series driving mode, the rotating speed of the engine and the speed structure of the vehicle are determined according to the power requirement calculated by the whole vehicle energy management module, and the torque of the engine is balanced by outputting a certain torque through the generator, so that the rotating speed of the engine is stabilized at a specific rotating speed. In the parallel driving mode, a clutch between the engine and the driving system is combined, the output torque of the engine is directly transmitted to wheels so as to drive the vehicle to move forward, and the rotating speed of the engine is stabilized at a fixed speed ratio rotating speed point with the vehicle speed through the torque of the clutch.

In the series drive mode, the rotational speed of the engine is secured by the generator, and the rotational speed is controlled by the torque correlation therebetween, so that there is a possibility that the rotational speed of the engine is out of control, which may cause the engine to overspeed to damage the engine and cause user complaints. In the parallel driving mode, when a clutch control system or a clutch mechanical system fails, the torque capacity of the clutch is reduced, the engine speed is increased, and the clutch plates are easy to ablate for a long time, so that the vehicle is damaged.

Therefore, aiming at a novel configuration of double-motor hybrid, it is urgently needed to develop an engine speed overspeed control method, so as to prevent the engine speed from exceeding a set interval and ensure the safety of vehicle components.

Disclosure of Invention

The invention mainly aims to provide a method for controlling the rotating speed of an engine of a hybrid vehicle and the hybrid vehicle, so as to solve the problem that the rotating speed of the engine is over-speed to damage the engine in the prior art.

In order to achieve the above object, according to one aspect of the present invention, there is provided a control method of a rotational speed of an engine of a hybrid vehicle, comprising: determining a current driving mode of the hybrid vehicle, wherein the driving mode comprises the following steps: a series drive mode and a parallel drive mode; acquiring the actual rotating speed of the engine, and calculating a deviation value between the actual rotating speed and the target rotating speed; determining whether the rotating speed of the engine is overspeed under different driving modes based on the actual rotating speed and/or the deviation value; calling corresponding control strategies based on different driving modes; and controlling the rotating speed of the engine to be within the target rotating speed range based on the control strategy.

Alternatively, in the case where the driving mode is the series driving mode, wherein the determining whether the rotation speed of the engine is overspeed in the different driving modes based on the actual rotation speed and/or the deviation value includes: and if the deviation value between the actual rotating speed and the target rotating speed exceeds a first threshold value and/or the actual rotating speed exceeds a preset highest rotating speed, setting a series overspeed flag bit, wherein the series overspeed flag bit is used for representing the overspeed of the rotating speed of the engine in a series driving mode.

Alternatively, in the case where the driving mode is the parallel driving mode, wherein the determining whether the rotation speed of the engine is overspeed in the different driving modes based on the actual rotation speed and/or the deviation value includes: and if the deviation value between the actual rotating speed and the target rotating speed exceeds a first preset value and/or the duration time of the deviation value exceeding a second preset value meets a preset condition, setting a parallel connection overspeed flag bit, wherein the parallel connection overspeed flag bit is used for representing the rotating speed overspeed of the engine in a parallel connection driving mode.

Optionally, invoking a corresponding control strategy based on the different driving modes comprises: and calling a corresponding series overspeed control strategy under the condition that the driving mode is a series driving mode and the series overspeed flag bit is set, wherein the series overspeed control strategy comprises the following steps: a first overspeed control strategy and a second overspeed control strategy; wherein the first overspeed control strategy is for controlling the generator to output a series-drive negative torque, and the second overspeed control strategy comprises: controlling the generator to output the series driving negative torque, controlling the engine to output the target torque, controlling the absolute value of the series driving negative torque to reduce by a magnitude smaller than that of the target torque, and controlling the speed of a torque correction coefficient of the engine.

Optionally, the method further comprises: when the driving mode is a series driving mode and the series overspeed flag bit is set, the deviation value is differed with a first threshold value to obtain a first difference value, and/or the actual rotating speed is differed with a preset highest rotating speed to obtain a second difference value; judging whether the first difference value is larger than a third preset value and/or judging whether the second difference value is larger than a fourth preset value; under the condition that the first difference is smaller than a third preset value and/or the second difference is smaller than a fourth preset value, determining series driving negative torque based on the actual rotating speed and the deviation value, and calling a first overspeed control strategy; and under the condition that the first difference is larger than a third preset value and/or the second difference is larger than a fourth preset value, determining a torque correction coefficient based on the deviation value and the second difference, determining a target torque based on the torque correction coefficient, and calling a second overspeed control strategy.

Optionally, invoking a corresponding control strategy based on different driving modes further comprises: and under the condition that the driving mode is a parallel driving mode and the parallel overspeed flag bit is set, calling a corresponding parallel overspeed control strategy, wherein the parallel overspeed control strategy is used for controlling the generator to output a parallel driving negative torque and/or controlling the engine to output a parallel target torque, and the parallel driving negative torque is calculated by a deviation value based on an integral controller algorithm.

Optionally, the method further comprises: after the rotating speed of the engine is controlled to be within a target rotating speed range, controlling the driving mode to be switched from a parallel driving mode to a series driving mode, and resetting a parallel overspeed zone bit which is used for representing that the rotating speed of the engine in the parallel driving mode is within the target rotating speed range; counting the overspeed times of the engine in a parallel driving mode in a driving cycle from power-on of the hybrid vehicle to power-off of the hybrid vehicle, wherein the overspeed times are increased by one each time the parallel overspeed flag bit is reset to set; judging whether the number of overspeed times is greater than a preset number of times; and if so, generating a reminding strategy based on the overspeed times, wherein the reminding strategy is used for controlling the hybrid vehicle to exit the parallel driving mode and generating reminding information, and the reminding information is used for reminding a driver to maintain the hybrid vehicle.

According to another aspect of an embodiment of the present invention, there is provided a hybrid vehicle including: an engine; the driving motor is selectively connected with the engine through the clutch, when the clutch is separated from the engine, the driving mode is a series driving mode, and when the clutch is combined with the engine, the driving mode is a parallel driving mode; a control system for executing the above-described control method of the rotational speed of the engine of the hybrid vehicle, comprising: determining a current driving mode, the driving mode comprising: a series drive mode and a parallel drive mode; acquiring the actual rotating speed of the engine, and calculating a deviation value between the actual rotating speed and the target rotating speed; determining whether the rotating speed of the engine is overspeed under different driving modes based on the actual rotating speed and/or the deviation value; calling corresponding control strategies based on different driving modes; the rotational speed of the engine is controlled to be within a target rotational speed range based on a control strategy.

Optionally, the hybrid vehicle further comprises: the engine controller is used for acquiring the rotating speed of the engine and the actual torque of the engine; the CAN bus is connected with the engine controller and used for sending the information acquired by the engine controller to the vehicle control unit; and the vehicle control unit is used for calculating the target torque and the target rotating speed of the engine based on the torque demand of the vehicle and sending the target torque of the engine to the engine controller for execution.

Further, the hybrid vehicle further includes: the generator is rigidly connected with the engine through a reduction gear mechanism; the generator controller is connected with the CAN bus and used for acquiring the rotating speed of the generator and the actual torque of the generator; the CAN bus is connected with the generator controller and used for sending information collected by the generator controller to the vehicle control unit, the vehicle control unit calculates the target torque of the generator in the series driving mode based on a closed-loop control algorithm, and sends the target torque of the generator to the generator controller for execution.

By applying the technical scheme of the invention, the current driving mode of the hybrid vehicle is firstly determined, and the driving mode comprises the following steps: the method comprises the steps of serially driving a mode and a parallel driving mode, then collecting the actual rotating speed of an engine, calculating a deviation value between the actual rotating speed and a target rotating speed, determining whether the rotating speed of the engine is overspeed or not in different driving modes based on the actual rotating speed and/or the deviation value, calling corresponding control strategies based on different driving modes under the condition that the rotating speed of the engine is overspeed, and controlling the rotating speed of the engine to be within a target rotating speed range based on the control strategies, so that the duration of overspeed of the rotating speed of the engine can be reduced, the problem that a clutch plate is ablated due to overlong overspeed time of the rotating speed of the engine is avoided, the problem that the rotating speed of the engine is overspeed to damage the engine in the prior art is solved, the technical effect of guaranteeing the safety of vehicle components is achieved, and the driving safety of a vehicle is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiment(s) of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic configuration of a power system of an embodiment of a hybrid vehicle according to the invention;

FIG. 2 shows a schematic flow chart of an embodiment of a method of controlling the rotational speed of an engine of a hybrid vehicle according to the present invention;

FIG. 3 shows a flow chart of another embodiment of a control method of a rotational speed of an engine of a hybrid vehicle according to the present invention;

fig. 4 shows a flowchart of a control method of the rotation speed of the engine of the hybrid vehicle according to still another embodiment of the invention.

Wherein the figures include the following reference numerals:

1. an engine; 2. a generator; 3. a torsional damper; 4. a reduction gear mechanism; 5. a clutch; 6. a drive motor; 7. a differential gear.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Exemplary embodiments according to the present application will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art, and in the drawings, it is possible to enlarge the thicknesses of layers and regions for clarity, and the same reference numerals are used to designate the same devices, and thus the description thereof will be omitted.

In accordance with an embodiment of the present invention, there is provided a method embodiment of a method of controlling rotational speed of an engine of a hybrid vehicle, wherein the steps illustrated in the flowchart of the drawings may be performed in a computer system, such as a set of computer-executable instructions, and wherein, although a logical order is illustrated in the flowchart, in some cases, the steps illustrated or described may be performed in an order different than presented herein.

As shown in fig. 2, which is a flowchart of a first embodiment of a control method of the rotational speed of the engine of the hybrid vehicle according to the present application, as shown in fig. 2, the control method of the rotational speed of the engine of the hybrid vehicle includes the steps of:

step S101, determining the current driving mode of the hybrid vehicle, wherein the driving mode comprises the following steps: a series drive mode and a parallel drive mode;

step S102, collecting the actual rotating speed of the engine, and calculating a deviation value between the actual rotating speed and a target rotating speed;

step S103, determining whether the rotating speed of the engine in different driving modes is overspeed or not based on the actual rotating speed and/or the deviation value;

step S104, calling corresponding control strategies based on different driving modes;

and step S105, controlling the rotating speed of the engine to be within a target rotating speed range based on the control strategy.

Through the steps, the duration time of the condition that the rotating speed of the engine is over-speed can be shortened, the problem that the clutch plate is ablated due to overlong rotating speed over-speed time of the engine is avoided, the problem that the engine is damaged due to over-speed of the engine in the prior art is solved, the technical effect of ensuring the safety of vehicle components is achieved, and the driving safety of the vehicle is improved.

Alternatively, in a case where the driving mode is the series driving mode, wherein determining whether the rotation speed of the engine is overspeed in the different driving modes based on the actual rotation speed and the deviation value includes: and if the deviation value between the actual rotating speed and the target rotating speed exceeds a first threshold value or the actual rotating speed exceeds the preset highest rotating speed, setting a series overspeed flag bit, wherein the series overspeed flag bit is used for representing the overspeed of the rotating speed of the engine in the series driving mode. In this embodiment, a deviation value between an actual rotation speed of the engine and a target rotation speed of the engine is calculated in real time by the vehicle controller, the first threshold value is represented by spddlltthd _ Se, and preferably, the value of the first threshold value spddlltthd _ Se may be 100 revolutions. Therefore, whether the rotating speed of the engine is overspeed or not in the series driving mode can be accurately judged.

Alternatively, in a case where the driving mode is a parallel driving mode, wherein determining whether the rotation speed of the engine is overspeed in the different driving modes based on the actual rotation speed and the deviation value includes: and if the deviation value between the actual rotating speed and the target rotating speed exceeds a first preset value or the duration time of the deviation value exceeding a second preset value meets a preset condition, setting the overspeed flag bit connected in parallel. Preferably, the first preset value is set to 100 revolutions, the second preset value is set to 100 revolutions, and the preset condition is set such that the duration of the deviation value exceeding the second preset value is 1.5 seconds or more. The parallel overspeed flag bit is used for representing the overspeed of the engine in the parallel driving mode. Therefore, whether the rotating speed of the engine is overspeed or not in the parallel driving mode can be accurately judged. In this embodiment, in the parallel driving mode, the vehicle control unit calculates a deviation value between an actual engine speed and a target engine speed in real time, and the target engine speed in the parallel driving mode is obtained by performing speed ratio conversion according to a driving motor speed, specifically, in the parallel driving mode, the target engine speed and the driving motor speed have the following relationship:

target engine speed/engine speed ratio = drive motor speed/drive motor speed ratio

Therefore, the torques at the driving motor end and the engine end in the parallel driving mode can be basically equal, and the excessive heat productivity of the clutch can be avoided under the target rotating speed of the engine, so that the problem of clutch plate ablation is prevented.

Optionally, invoking a corresponding control strategy based on the different driving modes comprises: and calling a corresponding series overspeed control strategy under the condition that the driving mode is a series driving mode and the series overspeed flag bit is set, wherein the series overspeed control strategy comprises the following steps: a first overspeed control strategy and a second overspeed control strategy. Wherein the first overspeed control strategy is used to control the generator to output the series-drive negative torque, and the second overspeed control strategy comprises: controlling the generator to output the series driving negative torque, controlling the engine to output the target torque, controlling the absolute value of the series driving negative torque to reduce by a magnitude smaller than that of the target torque, and controlling the speed of a torque correction coefficient of the engine. In this embodiment, when the series overspeed flag is set, the corresponding series overspeed control strategy is invoked, so that the rotation speed of the engine can be controlled within the target rotation speed range, and the normal operation of the engine in the series driving mode is ensured.

Optionally, as shown in fig. 3, the method further comprises the steps of:

step S31, under the condition that the driving mode is a serial driving mode and the serial overspeed flag bit is set, the deviation value is differed from a first threshold value to obtain a first difference value, and the actual rotating speed is differed from a preset highest rotating speed to obtain a second difference value;

step S32, judging whether the first difference value is greater than a third preset value and whether the second difference value is greater than a fourth preset value;

step S33, determining series driving negative torque based on the actual rotating speed and the deviation value and calling a first overspeed control strategy under the condition that the first difference value is smaller than a third preset value and the second difference value is smaller than a fourth preset value;

step S34, determining a torque correction coefficient based on the deviation value and the second difference value under the condition that the first difference value is larger than a third preset value or the second difference value is larger than a fourth preset value;

and step S35, determining the target torque based on the torque correction coefficient, and calling a second overspeed control strategy.

Specifically, the preset maximum rotation speed is represented by EngSpdMax, the third preset value is set to 200 revolutions, the fourth preset value is set to 100 revolutions, when a first difference between the deviation value and the first threshold value spddlttthse is smaller than 200 revolutions and a second difference between the actual rotation speed and the preset maximum rotation speed EngSpdMax is smaller than 100 revolutions, at this time, the generator is controlled to output a certain negative torque to perform balance control, so that the rotation speed of the engine can be restored to the target rotation speed range, namely, the first overspeed control strategy is called at this time. The negative torque of the generator comprises two parts, wherein one part is a negative value of the actual torque reported by the engine and is multiplied by a feedforward torque value obtained by multiplying the speed ratio of the engine and the generator, and the other part is a negative value of the PI torque obtained by calculating through a closed-loop control algorithm based on a deviation value. When the first difference between the deviation value and the first threshold value spddlttthd _ Se is greater than 200 revolutions or the second difference between the actual rotation speed and the preset maximum rotation speed EngSpdMax is greater than 100 revolutions, it means that the rotation speed of the engine cannot be restored to the target rotation speed range by controlling the generator to output a certain negative torque, so that the rotation speed of the engine needs to be reduced by adjusting the torque of the engine at the same time, that is, the second overspeed control strategy needs to be called at this time. Wherein, the engine torque correction coefficient is represented by EngTrqFac, the correction coefficient EngTrqFac is obtained by looking up a table according to the degree that the actual rotating speed of the engine exceeds the target rotating speed in the series driving mode and the degree that the actual rotating speed of the engine exceeds the preset maximum rotating speed (the maximum allowable rotating speed of the engine), and the example values of the table are as follows:

the smaller value of both EngTrqFac1 and EngTrqFac2 is used as the final engine torque correction coefficient EngTrqFac.

And when the serial overspeed flag position is set, and a first difference value between the deviation value and a first threshold value SpdDltThd _ Se is greater than 200 revolutions, or a second difference value between the actual rotation speed and a preset highest rotation speed EngSpdMax is greater than 100 revolutions, multiplying a serial engine target torque value calculated by the whole vehicle control serial energy management module by a final engine torque correction coefficient EngTrqFac to serve as a final engine request torque value, and gradually reducing the engine request torque after overspeed. Since the actual engine torque is used as the feedforward part of the negative generator torque, when the engine request torque is reduced, if the negative generator torque value is also reduced synchronously (the absolute value of the negative torque is reduced, which means the resistance provided by the generator is reduced), the engine speed is not necessarily reduced, so that the feedforward torque of the generator should be reduced by a smaller magnitude than the reduction of the engine torque while the engine is reduced, 1/EngTrqFac is used as the correction coefficient GmTrqFac, and GmTrqFac is multiplied by the feedforward torque value of the generator as the updated feedforward torque value of the generator. When the serial overspeed flag is set, and a first difference between the deviation value and a first threshold value spddlttthse is greater than 200 revolutions, or a second difference between the actual rotation speed and a preset highest rotation speed EngSpdMax is greater than 100 revolutions, in order to prevent the rotation speed of the engine from being reduced synchronously and stabilizing at a certain overspeed value after the requested torque of the engine is reduced, the correction coefficient EngTrqFac needs to be subjected to rate limiting processing, when the correction coefficient EngTrqFac is reduced, the change rate of the correction coefficient EngTrqFac is not limited, and when the correction coefficient EngTrqFac is increased, the slope of the change rate of the final output value of the correction coefficient EngTrqFac is limited, so that the increase rate of the final output value of the correction coefficient EngTrqFac is ensured to be slower than the value of the correction coefficient EngTrqFac.

Optionally, invoking a corresponding control strategy based on different driving modes, further comprising: and under the condition that the driving mode is a parallel driving mode and the position of the parallel overspeed flag is set, calling a corresponding parallel overspeed control strategy, wherein the parallel overspeed control strategy is used for controlling the generator to output a parallel driving negative torque or controlling the engine to output a parallel target torque, the parallel driving negative torque is obtained by calculating a deviation value based on an integral controller algorithm, and an integral coefficient of the integral controller algorithm is obtained by looking up a table through the deviation value of the actual rotating speed and the target rotating speed of the engine. The deviation value of the actual rotating speed of the engine and the target rotating speed value of the engine is smaller than 30 revolutions through the control, and the rotating speed of the engine can be controlled to be within the target rotating speed range rapidly.

Optionally, as shown in fig. 4, the method further comprises the steps of:

step S41, after the rotating speed of the engine is controlled to be within a target rotating speed range, controlling the driving mode to be switched from a parallel driving mode to a series driving mode, resetting a parallel overspeed flag bit, wherein the resetting of the parallel overspeed flag bit is used for representing that the rotating speed of the engine is within the target rotating speed range in the parallel driving mode;

step S42, in a driving cycle from the power-on of the hybrid electric vehicle to the power-off of the hybrid electric vehicle, counting the overspeed times of the engine in a parallel driving mode, wherein when the parallel overspeed flag bit is reset to set each time, the overspeed times are increased by one;

step S43, judging whether the number of times of overspeed is greater than the preset number of times;

and S44, if so, generating a reminding strategy based on the overspeed times, wherein the reminding strategy is used for controlling the hybrid vehicle to exit the parallel driving mode and generating reminding information, and the reminding information is used for reminding a driver to maintain the hybrid vehicle.

In the present embodiment, the preset number of times is set to 3, and the number of times of overspeed is counted by a parallel overspeed counter. Through the control, a driver can be timely reminded that the vehicle has a fault and the vehicle can be timely maintained. Wherein, relevant trouble is saved and the driver is reminded to maintain the vehicle through vehicle control unit.

According to another embodiment of the present application, there is also provided a hybrid vehicle, as shown in fig. 1, including an engine 1, a drive motor 6, and a control system. The drive motor 6 is selectively connected to the engine 1 through a clutch 5. When the clutch 5 is separated from the engine 1, the driving mode is the series driving mode, and when the clutch 5 is combined with the engine 1, the driving mode is the parallel driving mode. The control system is configured to execute the steps of the control method of the rotational speed of the engine of the hybrid vehicle in the above-described embodiment, the steps of the control method including: determining a current driving mode, the driving mode comprising: the method comprises the steps of collecting the actual rotating speed of the engine 1 in a series driving mode and a parallel driving mode, calculating a deviation value between the actual rotating speed and a target rotating speed, determining whether the rotating speed of the engine 1 is overspeed in different driving modes based on the actual rotating speed and/or the deviation value, calling corresponding control strategies based on the different driving modes, and controlling the rotating speed of the engine 1 to be within a target rotating speed range based on the control strategies. In the embodiment, when the clutch 5 is combined with the engine 1, the driving mode is a parallel driving mode, and in the parallel driving mode, when the rotating speed of the engine is overspeed, the characteristic of fast torque response of the motor is fully utilized by calling a corresponding parallel overspeed control strategy, namely, by controlling the engine to output a certain negative torque, so that the component torque on the driving side of the clutch 5 can be fast reduced to reduce the rotating speed on the driving side of the clutch 5, and the purpose of controlling the rotating speed of the engine to be within a target rotating speed range is further achieved.

Further, the hybrid vehicle further comprises an engine controller, a CAN bus and a whole vehicle controller. The engine controller is configured to acquire a rotation speed of the engine 1 and an actual torque of the engine 1. The CAN bus is connected with the engine controller and used for sending the information collected by the engine controller to the vehicle control unit. The vehicle control unit is used for calculating a target torque and a target rotating speed of the engine 1 through an energy management algorithm in the vehicle control unit based on the torque requirement of the whole vehicle, and sending the target torque of the engine 1 to the engine control unit for execution.

Further, the hybrid vehicle further includes a generator 2 and a generator controller, the generator 2 is rigidly connected with the engine 1 through a reduction gear mechanism 4, so that the rotation speed of the engine and the rotation speed of the generator are in a fixed speed ratio relationship. The generator controller is connected with the CAN bus and used for acquiring the rotating speed of the generator 2 and the actual torque of the generator 2. The CAN bus is connected with the generator controller and used for sending information collected by the generator controller to the vehicle control unit, the vehicle control unit calculates the target torque of the generator 2 in the series driving mode based on a closed-loop control algorithm, and sends the target torque of the generator 2 to the generator controller for execution. The driving of the whole vehicle in the series driving mode is completed only by the driving motor 6, and the driving of the whole vehicle in the parallel driving mode is completed by the engine 1 and the driving motor 6 together.

As shown in fig. 1, the hybrid vehicle further includes a torsional damper 3 and a differential 7. The torsional damper 3 is provided between the reduction gear mechanism 4 and the engine 1, and the differential 7 is connected to the drive motor 6.

By adopting the technical scheme, under the serial driving mode and the parallel driving mode, when the rotating speed of the engine is overspeed, the corresponding serial overspeed control strategy is called based on the serial driving mode, and the corresponding parallel overspeed control strategy is called based on the parallel driving mode, so that the rotating speed of the engine is controlled within a target rotating speed range, and the component safety of the vehicle is ensured.

For ease of description, spatially relative terms such as "over 8230 \ 8230;,"' over 8230;, \8230; upper surface "," above ", etc. may be used herein to describe the spatial relationship of one device or feature to another device or feature as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary terms "at 8230; \8230; 'above" may include both orientations "at 8230; \8230;' above 8230; 'at 8230;' below 8230;" above ". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition to the foregoing, it should be noted that reference throughout this specification to "one embodiment," "another embodiment," "an embodiment," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described generally throughout this application. The appearances of the same phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the scope of the invention to effect such feature, structure, or characteristic in connection with other embodiments.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method of a rotational speed of an engine of a hybrid vehicle, characterized by comprising:

determining a current driving mode of the hybrid vehicle, the driving mode comprising: a series drive mode and a parallel drive mode;

acquiring the actual rotating speed of the engine, and calculating a deviation value between the actual rotating speed and a target rotating speed;

determining whether the rotation speed of the engine is overspeed in the different driving modes based on the actual rotation speed and/or the deviation value;

calling corresponding control strategies based on different driving modes;

controlling the rotational speed of the engine to be within a target rotational speed range based on the control strategy.

2. The control method of rotation speed of engine of hybrid vehicle according to claim 1, characterized in that, in the case where the drive mode is the series drive mode,

wherein determining whether the rotational speed of the engine in the different driving modes is overspeed based on the actual rotational speed and/or the deviation value comprises:

and if the deviation value between the actual rotating speed and the target rotating speed exceeds a first threshold value, and/or the actual rotating speed exceeds a preset highest rotating speed, setting a series overspeed flag position, wherein the series overspeed flag position is used for representing that the rotating speed of the engine is overspeed in the series driving mode.

3. The control method of rotation speed of engine of hybrid vehicle according to claim 1, characterized in that, in the case where the drive mode is the parallel drive mode,

and if the deviation value between the actual rotating speed and the target rotating speed exceeds a first preset value and/or the duration time of the deviation value exceeding a second preset value meets a preset condition, setting a parallel overspeed flag bit, wherein the parallel overspeed flag bit is used for representing that the rotating speed of the engine is overspeed in the parallel driving mode.

4. The control method of the rotational speed of the engine of the hybrid vehicle according to claim 2, characterized in that invoking the corresponding control strategy based on different driving modes comprises:

when the driving mode is the series driving mode and the series overspeed flag bit is set, calling a corresponding series overspeed control strategy, wherein the series overspeed control strategy comprises the following steps: a first overspeed control strategy and a second overspeed control strategy;

wherein the first overspeed control strategy is used to control the generator to output a series-drive negative torque, the second overspeed control strategy comprising: controlling the generator to output the series-drive negative torque, controlling the engine to output a target torque, controlling a magnitude of decrease in an absolute value of the series-drive negative torque to be smaller than a magnitude of decrease in the target torque, and controlling a rate of a torque correction coefficient of the engine.

5. The control method of the rotational speed of the engine of the hybrid vehicle according to claim 4, characterized by further comprising:

in the case where the driving mode is the series driving mode and the series overspeed flag bit is set,

obtaining a first difference value by subtracting the deviation value from the first threshold value, and/or obtaining a second difference value by subtracting the actual rotating speed from the preset highest rotating speed;

judging whether the first difference value is greater than a third preset value and/or judging whether the second difference value is greater than a fourth preset value;

determining the series driving negative torque based on the actual rotating speed and the deviation value and calling the first overspeed control strategy when the first difference value is smaller than a third preset value and/or the second difference value is smaller than a fourth preset value;

and determining the torque correction coefficient based on the deviation value and the second difference value, determining the target torque based on the torque correction coefficient and calling the second overspeed control strategy when the first difference value is larger than a third preset value and/or the second difference value is larger than a fourth preset value.

6. The control method of the rotation speed of the engine of the hybrid vehicle according to claim 3, characterized in that the corresponding control strategy is invoked based on different driving modes, further comprising:

and under the condition that the driving mode is the parallel driving mode and the parallel overspeed flag bit is set, calling a corresponding parallel overspeed control strategy, wherein the parallel overspeed control strategy is used for controlling a generator to output a parallel driving negative torque and/or controlling the engine to output a parallel target torque, and the parallel driving negative torque is calculated by the deviation value based on an integral controller algorithm.

7. The control method of the rotational speed of the engine of the hybrid vehicle according to claim 6, characterized by further comprising:

after the rotating speed of the engine is controlled within a target rotating speed range, controlling the driving mode to be switched from the parallel driving mode to the series driving mode, and resetting the parallel overspeed flag bit, wherein the resetting of the parallel overspeed flag bit is used for representing that the rotating speed of the engine in the parallel driving mode is within the target rotating speed range;

counting the number of overspeed times of said engine in said parallel drive mode during a drive cycle from power-up of said hybrid vehicle to power-down of said hybrid vehicle, wherein said number of overspeed times is incremented by one each time said parallel overspeed flag is reset to set;

judging whether the number of times of overspeed is greater than a preset number of times;

and if so, generating a reminding strategy based on the overspeed times, wherein the reminding strategy is used for controlling the hybrid vehicle to exit the parallel driving mode and generating reminding information, and the reminding information is used for reminding a driver to maintain the hybrid vehicle.

8. A hybrid vehicle, characterized by comprising:

an engine (1);

a drive motor (6), the drive motor (6) being selectively connected to the engine (1) by a clutch (5), wherein when the clutch (5) is disengaged from the engine (1), a driving mode is a series drive mode, and when the clutch (5) is engaged with the engine (1), the driving mode is a parallel drive mode;

a control system for executing a control method of a rotational speed of an engine of a hybrid vehicle according to claims 1 to 7, comprising:

determining a current driving mode, the driving mode comprising: the series drive mode and the parallel drive mode;

acquiring the actual rotating speed of the engine (1), and calculating a deviation value between the actual rotating speed and a target rotating speed;

determining whether the rotational speed of the engine (1) is overspeed in the different driving modes based on the actual rotational speed and/or the deviation value;

calling corresponding control strategies based on different driving modes;

controlling the rotational speed of the engine (1) to be within a target rotational speed range based on the control strategy.

9. The hybrid vehicle according to claim 8, characterized by further comprising:

an engine controller for acquiring the rotating speed of the engine (1) and the actual torque of the engine (1);

the CAN bus is connected with the engine controller and used for sending the information acquired by the engine controller to the vehicle control unit;

and the vehicle control unit is used for calculating the target torque and the target rotating speed of the engine (1) based on the torque demand of the vehicle and sending the target torque of the engine (1) to the engine controller for execution.

10. The hybrid vehicle according to claim 9, characterized by further comprising:

the generator (2), the said generator (2) is rigidly connected with said engine (1) through the reduction gear mechanism (4);

the generator controller is connected with the CAN bus and used for acquiring the rotating speed of the generator (2) and the actual torque of the generator (2);

the CAN bus is connected with the generator controller and used for sending information collected by the generator controller to the vehicle control unit, and the vehicle control unit calculates the target torque of the generator (2) in the series driving mode based on a closed-loop control algorithm and sends the target torque of the generator (2) to the generator controller for execution.