Method for controlling the rotation speed of engine of hybrid vehicle and hybrid vehicle

Abstract

The present invention provides a method for controlling the speed of the engine of a hybrid vehicle and a hybrid vehicle, the control method comprising: determining the current driving mode of the hybrid vehicle, the driving modes comprising: a series drive mode and a parallel drive mode; collecting the actual speed of the engine, and calculating the deviation value between the actual speed and the target speed; determining whether the speed of the engine is overspeeding in different driving modes based on the actual speed and / or the deviation value; calling corresponding control strategies based on different driving modes; and controlling the speed of the engine within the target speed range based on the control strategy. This can reduce the duration of the engine speed overspeeding situation, avoid the problem of clutch plate ablation caused by the engine speed overspeeding for too long, and solve the problem of engine damage caused by engine speed overspeeding in the prior art, achieve the technical effect of ensuring the safety of vehicle components, and improve the driving safety of the vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to a method for controlling the rotation speed of an engine of a hybrid vehicle and the hybrid vehicle. Background Art

[0002] As oil resources become increasingly scarce and facing increasingly stringent fuel consumption regulations, it is becoming increasingly costly and difficult for traditional pure internal combustion engine-driven vehicles to reduce fuel consumption. Hybrid vehicles, with the assistance of electric motors, have great potential to reduce fuel consumption. The P2 configuration represented by European manufacturers and the dual-motor planetary gear power split configuration represented by Toyota have all been mass-produced and have achieved good fuel consumption performance, winning the favor of the general public. However, both the P2 configuration and the power split configuration face many technical difficulties and technical barriers when applied in China, and the application of independent models has been relatively slow.

[0003] In recent years, the dual-motor hybrid configuration has been proven to be a hybrid configuration solution that is more suitable for China's national conditions, and it can easily switch between HEV and PHEV. In particular, for the more congested road conditions in China's urban areas, the dual-motor hybrid configuration has obvious fuel-saving advantages. The dual-motor hybrid configuration can operate in three driving modes: pure electric, series and parallel. In the series driving mode, the engine speed and vehicle speed structure are determined according to the power demand calculated by the vehicle energy management module to determine the engine speed. The generator outputs a certain torque to balance the engine torque and stabilize the engine speed at a specific speed. In the parallel driving mode, the clutch between the engine and the drive system is engaged, and the engine output torque is directly transmitted to the wheels to drive the vehicle forward. The engine speed is stabilized at a fixed speed ratio speed point with the vehicle speed through the clutch torque.

[0004] In the series drive mode, the engine speed is guaranteed by the generator, and the speed is controlled by the torque relationship between the two. Therefore, there is a possibility of engine speed loss, which will cause the engine to overspeed and damage the engine, and cause user complaints. In the parallel drive mode, when the clutch control system or clutch mechanical system fails, the clutch torque capacity will be reduced, which will cause the engine speed to increase, and the clutch plate will be easily burned over time, causing vehicle damage.

[0005] Therefore, for the emerging dual-motor hybrid configuration, it is urgent to develop an engine speed overspeed control method to prevent the engine speed from exceeding the set range and ensure the safety of vehicle components. Summary of the invention

[0006] The main purpose of the present invention is to provide a method for controlling the rotation speed of an engine of a hybrid vehicle and a hybrid vehicle, so as to solve the problem in the prior art that the engine is damaged due to overspeeding of the engine.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present invention, a method for controlling the speed of an engine of a hybrid vehicle is provided, comprising: determining a current driving mode of the hybrid vehicle, the driving modes comprising: a series drive mode and a parallel drive mode; collecting an actual speed of the engine, and calculating a deviation value between the actual speed and a target speed; determining whether the speed of the engine is overspeeding in different driving modes based on the actual speed and / or the deviation value; calling corresponding control strategies based on different driving modes; and controlling the speed of the engine within a target speed range based on the control strategies.

[0008] Optionally, in the case where the driving mode is a series drive mode, determining whether the engine speed is overspeeding in different driving modes based on the actual speed and / or the deviation value includes: if the deviation value between the actual speed and the target speed exceeds a first threshold value, and / or the actual speed exceeds a preset maximum speed, setting a series overspeed flag position, wherein the series overspeed flag position is used to indicate that the engine speed is overspeeding in the series drive mode.

[0009] Optionally, in the case where the driving mode is a parallel drive mode, determining whether the engine speed is overspeeding in different driving modes based on the actual speed and / or the deviation value includes: if the deviation value between the actual speed and the target speed exceeds a first preset value, and / or the duration for which the deviation value exceeds a second preset value satisfies a preset condition, setting a parallel overspeeding flag position, wherein the parallel overspeeding flag position is used to indicate that the engine speed is overspeeding in the parallel drive mode.

[0010] Optionally, corresponding control strategies are called based on different driving modes, including: when the driving mode is a series drive mode and the series overspeed flag is in position, a corresponding series overspeed control strategy is called, and the series overspeed control strategy includes: 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, and the second overspeed control strategy includes: controlling the generator to output a series drive negative torque, controlling the engine to output a target torque, controlling the absolute value of the series drive negative torque to decrease to be less than the target torque decrease, and controlling the rate of the engine's torque correction coefficient.

[0011] Optionally, the method also includes: when the driving mode is a series drive mode and the series overspeed flag is in position, subtracting the deviation value from the first threshold value to obtain a first difference, and / or subtracting the actual speed from the preset maximum speed to obtain a second difference; judging whether the first difference is greater than a third preset value, and / or judging whether the second difference is greater than a fourth preset value; when the first difference is less than the third preset value, and / or the second difference is less than the fourth preset value, determining the series drive negative torque based on the actual speed and the deviation value, and calling the first overspeed control strategy; when the first difference is greater than the third preset value, and / or the second difference is greater than the fourth preset value, determining the torque correction coefficient based on the deviation value and the second difference, determining the target torque based on the torque correction coefficient, and calling the second overspeed control strategy.

[0012] Optionally, calling corresponding control strategies based on different driving modes also includes: when the driving mode is a parallel drive mode and the parallel overspeed flag is set, calling a corresponding parallel overspeed control strategy, the parallel overspeed control strategy is used to control the generator to output a parallel drive negative torque, and / or control the engine to output a parallel target torque, wherein the parallel drive negative torque is calculated by a deviation value based on an integral controller algorithm.

[0013] Optionally, the method also includes: after the engine speed is controlled to be within the target speed range, controlling the driving mode to switch from the parallel drive mode to the series drive mode, resetting the parallel overspeed flag, and resetting the parallel overspeed flag to indicate that the engine speed in the parallel drive mode is within the target speed range; in a driving cycle from hybrid vehicle power-on to hybrid vehicle power-off, counting the number of overspeeds of the engine in the parallel drive mode, wherein each time the parallel overspeed flag is reset to set, the number of overspeeds increases by one; determining whether the number of overspeeds is greater than a preset number; if so, generating a reminder strategy based on the number of overspeeds, the reminder strategy is used to control the hybrid vehicle to exit the parallel drive mode, and generate a reminder message, the reminder message is used to remind the driver to repair the hybrid vehicle.

[0014] According to another aspect of an embodiment of the present invention, a hybrid vehicle is provided, comprising: an engine; a drive motor, the drive motor being selectively connected to the engine via a clutch, wherein when the clutch is separated from the engine, the driving mode is a series drive mode, and when the clutch is coupled to the engine, the driving mode is a parallel drive mode; a control system, for executing the above-mentioned method for controlling the engine speed of the hybrid vehicle, comprising: determining a current driving mode, the driving modes comprising: a series drive mode and a parallel drive mode; collecting an actual engine speed, and calculating a deviation value between the actual speed and a target speed; determining whether the engine speed is overspeeding in different driving modes based on the actual speed and / or the deviation value; calling corresponding control strategies based on different driving modes; and controlling the engine speed within a target speed range based on the control strategies.

[0015] Optionally, the hybrid vehicle also includes: an engine controller, which is used to collect the engine speed and the actual torque of the engine; a CAN bus, which is connected to the engine controller and is used to send the information collected by the engine controller to the vehicle controller; the vehicle controller is used to calculate the target torque and target speed of the engine based on the torque demand of the vehicle, and send the target torque of the engine to the engine controller for execution.

[0016] Furthermore, the hybrid vehicle also includes: a generator, which is rigidly connected to the engine through a reduction gear mechanism; a generator controller, which is connected to the CAN bus and is used to collect the rotational speed of the generator and the actual torque of the generator; wherein the CAN bus is connected to the generator controller and is used to send the information collected by the generator controller to the vehicle controller, and the vehicle controller calculates the target torque of the generator in the series drive mode based on a closed-loop control algorithm, and sends the target torque of the generator to the generator controller for execution.

[0017] By applying the technical solution of the present invention, the current driving mode of the hybrid vehicle is first determined, and the driving modes include: a series drive mode and a parallel drive mode. Then, the actual speed of the engine is collected, and the deviation value between the actual speed and the target speed is calculated. Based on the actual speed and / or the deviation value, it is determined whether the engine speed is overspeeding in different driving modes. In the case of overspeeding of the engine speed, the corresponding control strategy is called based on different driving modes. Based on the control strategy, the engine speed is controlled within the target speed range. In this way, the duration of the engine speed overspeeding situation can be reduced, and the problem of clutch plate ablation caused by excessively long engine speed overspeeding time can be avoided. The problem of engine damage caused by engine speed overspeeding in the prior art is solved, and the technical effect of ensuring the safety of vehicle components is achieved, and the driving safety of the vehicle is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic structural diagram of a power system of an embodiment of a hybrid vehicle according to the present invention is shown;

[0020] Figure 2 A schematic flow chart showing an embodiment of a method for controlling the rotation speed of an engine of a hybrid vehicle according to the present invention;

[0021] Figure 3 A schematic flow chart showing another embodiment of a method for controlling the rotation speed of an engine of a hybrid vehicle according to the present invention;

[0022] Figure 4 A flow chart showing another embodiment of a method for controlling the rotation speed of an engine of a hybrid vehicle according to the present invention is shown.

[0023] The above drawings include the following reference numerals:

[0024] 1. Engine; 2. Generator; 3. Torsional vibration damper; 4. Reduction gear mechanism; 5. Clutch; 6. Drive motor; 7. Differential. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0029] According to an embodiment of the present invention, a method embodiment of a method for controlling the speed of an engine of a hybrid vehicle is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0030] like Figure 2 FIG. 1 is a flow chart of a first embodiment of a method for controlling the rotation speed of an engine of a hybrid vehicle according to the present application, as shown in FIG. Figure 2 As shown, the method for controlling the speed of the engine of a hybrid vehicle includes the following steps:

[0031] Step S101, determining the current driving mode of the hybrid vehicle, the driving modes including: a series driving mode and a parallel driving mode;

[0032] Step S102, collecting the actual speed of the engine and calculating the deviation between the actual speed and the target speed;

[0033] Step S103, determining whether the engine speed is overspeeding in different driving modes based on the actual speed and / or the deviation value;

[0034] Step S104, calling corresponding control strategies based on different driving modes;

[0035] Step S105, based on the control strategy, the engine speed is controlled to be within the target speed range.

[0036] Through the above steps, the duration of the engine speed overspeed situation can be reduced, the problem of clutch plate burning caused by the engine speed overspeeding for too long can be avoided, and the problem of engine damage caused by engine speed overspeeding in the prior art is solved, achieving the technical effect of ensuring the safety of vehicle components and improving the driving safety of the vehicle.

[0037] Optionally, when the driving mode is a series drive mode, based on the actual speed and the deviation value, determining whether the engine speed is overspeeding in different driving modes includes: if the deviation value between the actual speed and the target speed exceeds the first threshold value, or the actual speed exceeds the preset maximum speed, the series overspeed flag is set, wherein the series overspeed flag is set to indicate that the engine speed is overspeeding in the series drive mode. In this embodiment, the deviation value between the actual engine speed and the target engine speed is calculated in real time by the vehicle controller, and the first threshold value is represented by SpdDltThd_Se. Preferably, the first threshold value SpdDltThd_Se can be 100 revolutions. In this way, it is possible to accurately determine whether the engine speed is overspeeding in the series drive mode.

[0038] Optionally, in the case where the driving mode is a parallel drive mode, based on the actual speed and the deviation value, determining whether the engine speed is overspeeding in different driving modes includes: if the deviation value between the actual speed and the target speed exceeds the first preset value, or the duration of the deviation value exceeding the second preset value meets the preset condition, the parallel overspeed flag is set. Preferably, the first preset value is set to 100 rpm, the second preset value is set to 100 rpm, and the preset condition is set to the duration of the deviation value exceeding the second preset value for more than 1.5 seconds. Among them, the parallel overspeed flag is set to indicate that the engine speed is overspeeding in the parallel drive mode. In this way, it is possible to accurately determine whether the engine speed is overspeeding in the parallel drive mode. In this embodiment, in the parallel drive mode, the vehicle controller calculates the deviation value between the actual engine speed and the target engine speed in real time. The target engine speed in the parallel drive mode is obtained by converting the speed ratio according to the drive motor speed. Specifically, in the parallel drive mode, the target engine speed and the drive motor speed have the following relationship:

[0039] Engine target speed / engine speed ratio = drive motor speed / drive motor speed ratio

[0040] This ensures that the torque at the drive motor end and the engine end are basically equal in the parallel drive mode, and ensures that the clutch will not generate excessive heat at the target engine speed, thereby preventing the problem of clutch plate burning.

[0041] Optionally, the corresponding control strategy is called based on different driving modes, including: when the driving mode is a series drive mode and the series overspeed flag is in position, the corresponding series overspeed control strategy is called, and the series overspeed control strategy includes: a first overspeed control strategy and a second overspeed control strategy. Among them, the first overspeed control strategy is used to control the generator to output the series drive negative torque, and the second overspeed control strategy includes: controlling the generator to output the series drive negative torque, controlling the engine to output the target torque, controlling the absolute value of the series drive negative torque to decrease less than the target torque, and controlling the rate of the torque correction coefficient of the engine. In this embodiment, when the series overspeed flag is in position, the corresponding series overspeed control strategy is called, so that the engine speed can be controlled within the target speed range to ensure the normal operation of the engine in the series drive mode.

[0042] Alternatively, if Figure 3 As shown, the method also includes the following steps:

[0043] Step S31, when the driving mode is the series driving mode and the series overspeed flag is in position, the deviation value is subtracted from the first threshold value to obtain a first difference value, and the actual speed is subtracted from the preset maximum speed to obtain a second difference value;

[0044] Step S32, determining whether the first difference is greater than a third preset value, and determining whether the second difference is greater than a fourth preset value;

[0045] Step S33, when the first difference is less than the third preset value and the second difference is less than the fourth preset value, based on the actual speed and the deviation value, determine the series drive negative torque and call the first overspeed control strategy;

[0046] Step S34, when the first difference is greater than the third preset value, or the second difference is greater than the fourth preset value, determining a torque correction coefficient based on the deviation value and the second difference;

[0047] Step S35, determining the target torque based on the torque correction coefficient, and calling the second overspeed control strategy.

[0048] Specifically, the preset maximum speed is represented by EngSpdMax, the third preset value is set to 200 rpm, and the fourth preset value is set to 100 rpm. When the first difference between the deviation value and the first threshold value SpdDltThd_Se is less than 200 rpm, and the second difference between the actual speed and the preset maximum speed EngSpdMax is less than 100 rpm, at this time, the engine speed can be restored to the target speed range by controlling the generator to output a certain negative torque for balanced control, that is, the first overspeed control strategy is called at this time. Among them, the negative torque of the generator includes two parts, one part is the negative value of the actual torque reported by the engine and multiplied by the speed ratio of the engine and the generator to obtain the feedforward torque value, and the other part is the negative value of the PI torque calculated based on the deviation value and through the closed-loop control algorithm. When the first difference between the deviation value and the first threshold value SpdDltThd_Se is greater than 200 revolutions, or the second difference between the actual speed and the preset maximum speed EngSpdMax is greater than 100 revolutions, it means that the engine speed cannot be restored to the target speed range by controlling the generator to output a certain negative torque, so it is necessary to adjust the engine torque at the same time to reduce the engine speed, that is, it is necessary to call the second overspeed control strategy. Among them, the engine torque correction coefficient is represented by EngTrqFac, and the correction coefficient EngTrqFac is obtained by looking up the table using the degree to which the actual engine speed exceeds the target speed in the series drive mode and the degree to which the actual engine speed exceeds the preset maximum speed (the maximum allowable engine speed). The table example values ​​are as follows:

[0049]

[0050] The smaller value of EngTrqFac1 and EngTrqFac2 is used as the final engine torque correction coefficient EngTrqFac.

[0051] When the series overspeed flag is set, and the first difference between the deviation value and the first threshold value SpdDltThd_Se is greater than 200 revolutions, or the second difference between the actual speed and the preset maximum speed EngSpdMax is greater than 100 revolutions, the series engine target torque value calculated by the vehicle control series energy management module is multiplied by the final engine torque correction coefficient EngTrqFac as the final engine request torque value. After overspeeding, the engine request torque is gradually reduced. Since the actual engine torque is used as the feedforward part of the generator negative torque, when the engine request torque is reduced, if the generator negative torque value is also reduced synchronously (the absolute value of the negative torque is reduced, indicating that the resistance provided by the generator is reduced), the engine speed may not be reduced. Therefore, when the engine torque is reduced, the reduction amplitude of the generator feedforward torque should be less than the reduction amplitude of the engine torque. The value of 1 / EngTrqFac is used as the correction coefficient GmTrqFac, and GmTrqFac is multiplied by the generator feedforward torque value as the updated generator feedforward torque value. When the series overspeed flag is set, and the first difference between the deviation value and the first threshold value SpdDltThd_Se is greater than 200 rpm, or the second difference between the actual speed and the preset maximum speed EngSpdMax is greater than 100 rpm, in order to prevent the engine speed from not being able to decrease synchronously after the requested torque of the engine is reduced but eventually stabilizing at a certain overspeed value, the correction coefficient EngTrqFac needs to be rate-limited. When the correction coefficient EngTrqFac decreases, the rate of change of the correction coefficient EngTrqFac is not limited. When the correction coefficient EngTrqFac increases, the slope of the rate of change of the final output value of the correction coefficient EngTrqFac is limited to ensure that the increase rate of the final output value of the correction coefficient EngTrqFac is slower than the value of the correction coefficient EngTrqFac.

[0052] Optionally, calling corresponding control strategies based on different driving modes also includes: when the driving mode is a parallel drive mode and the parallel overspeed flag is in position, calling the corresponding parallel overspeed control strategy, the parallel overspeed control strategy is used to control the generator to output a parallel drive negative torque, or control the engine to output a parallel target torque, wherein the parallel drive negative torque is calculated by the deviation value based on the integral controller algorithm, and the integral coefficient of the integral controller algorithm is obtained by looking up the deviation value of the actual engine speed and the target speed. Such control can make the deviation value between the actual engine speed and the target engine speed value less than 30 revolutions, and thus can quickly control the engine speed to within the target speed range.

[0053] Alternatively, if Figure 4 As shown, the method also includes the following steps:

[0054] Step S41, after the engine speed is controlled to be within the target speed range, the driving mode is controlled to switch from the parallel driving mode to the series driving mode, and the parallel overspeed flag is reset. The parallel overspeed flag reset is used to indicate that the engine speed in the parallel driving mode is within the target speed range;

[0055] Step S42, counting the number of engine overspeeds in the parallel driving mode in a driving cycle from the hybrid vehicle being powered on to the hybrid vehicle being powered off, wherein the number of overspeeds is increased by one each time the parallel overspeed flag is reset to set;

[0056] Step S43, determining whether the number of overspeeding times is greater than a preset number;

[0057] Step S44: if yes, a reminder strategy is generated based on the number of overspeeding times, the reminder strategy is used to control the hybrid vehicle to exit the parallel drive mode, and a reminder message is generated, the reminder message is used to remind the driver to repair the hybrid vehicle.

[0058] In this embodiment, the preset number is set to 3, and the number of overspeeding is counted by a parallel overspeed counter. This control can promptly remind the driver that the vehicle has a fault and repair the vehicle in time. The vehicle controller stores the relevant faults and reminds the driver to repair the vehicle.

[0059] According to another specific embodiment of the present application, a hybrid vehicle is also provided. Figure 1 As shown, the hybrid vehicle includes 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 a series drive mode, and when the clutch 5 is combined with the engine 1, the driving mode is a parallel drive mode. The control system is used to execute the steps of the control method of the engine speed of the hybrid vehicle in the above embodiment, and the steps of the control method include: determining the current driving mode, the driving mode includes: a series drive mode and a parallel drive mode, collecting the actual speed of the engine 1, and calculating the deviation value between the actual speed and the target speed, determining whether the speed of the engine 1 is overspeeding in different driving modes based on the actual speed and / or the deviation value, calling the corresponding control strategy based on different driving modes, and controlling the speed of the engine 1 within the target speed range based on the control strategy. In this embodiment, when the clutch 5 is combined with the engine 1, the driving mode is a parallel drive mode. In the parallel drive mode, when the engine speed exceeds the speed limit, the corresponding parallel overspeed control strategy is called, that is, by controlling the engine to output a certain negative torque, the fast torque response of the motor is fully utilized, so that the component torque on the active side of the clutch 5 can be quickly reduced to reduce the speed of the active side of the clutch 5, thereby achieving the purpose of controlling the engine speed to within the target speed range.

[0060] Furthermore, the hybrid vehicle also includes an engine controller, a CAN bus, and a vehicle controller. The engine controller is used to collect the speed of the engine 1 and the actual torque of the engine 1. The CAN bus is connected to the engine controller and is used to send the information collected by the engine controller to the vehicle controller. The vehicle controller is used to calculate the target torque and target speed of the engine 1 based on the torque demand of the vehicle through the energy management algorithm in the vehicle controller, and send the target torque of the engine 1 to the engine controller for execution.

[0061] Furthermore, the hybrid vehicle also includes a generator 2 and a generator controller. The generator 2 is rigidly connected to the engine 1 through a reduction gear mechanism 4, so the speed of the engine and the speed of the generator are in a fixed speed ratio relationship. The generator controller is connected to the CAN bus, and the generator controller is used to collect the speed of the generator 2 and the actual torque of the generator 2. Among them, the CAN bus is connected to the generator controller, which is used to send the information collected by the generator controller to the vehicle controller. The vehicle controller calculates the target torque of the generator 2 in the series drive mode based on the closed-loop control algorithm, and sends the target torque of the generator 2 to the generator controller for execution. Among them, the drive of the whole vehicle in the series drive mode is completed only by the drive motor 6, and the drive of the whole vehicle in the parallel drive mode is completed by the engine 1 and the drive motor 6.

[0062] like Figure 1 As shown, the hybrid vehicle further includes a torsion damper 3 and a differential 7. The torsion damper 3 is arranged between the reduction gear mechanism 4 and the engine 1, and the differential 7 is connected to the drive motor 6.

[0063] By adopting the technical solution of the present application, when the engine speed exceeds the speed in the series drive mode and the parallel drive mode, the corresponding series overspeed control strategy is called based on the series drive mode, and the corresponding parallel overspeed control strategy is called based on the parallel drive mode, so as to control the engine speed within the target speed range, thereby ensuring the safety of vehicle components.

[0064] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0065] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0066] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling the rotation speed of an engine of a hybrid vehicle, characterized in that: include: Determining a current driving mode of the hybrid vehicle, the driving mode comprising: a series driving mode and a parallel driving mode; Collecting the actual speed of the engine and calculating the deviation between the actual speed and the target speed; Based on the actual speed and / or the deviation value, determining whether the speed of the engine in different driving modes is overspeeding; Call corresponding control strategies based on different driving modes; Based on the control strategy, controlling the speed of the engine to within a target speed range; In the case where the driving mode is the series driving mode, determining whether the engine speed in different driving modes is overspeeding based on the actual speed and / or the deviation value includes: If the deviation between the actual speed and the target speed exceeds a first threshold value, and / or the actual speed exceeds a preset maximum speed, a series overspeed flag is set, wherein the series overspeed flag is set to indicate that the speed of the engine is overspeeding in the series drive mode; Call corresponding control strategies based on different driving modes, including: When the driving mode is the series driving mode and the series overspeed flag is in position, calling a corresponding series overspeed control strategy, the series overspeed control strategy includes: a first overspeed control strategy and a second overspeed control strategy; Among them, the first overspeed control strategy is used to control the generator to output the series drive negative torque, and the second overspeed control strategy includes: controlling the generator to output the series drive negative torque, controlling the engine to output the target torque, controlling the absolute value of the series drive negative torque to decrease to be less than the target torque decrease, and controlling the rate of the torque correction coefficient of the engine.

2. The method for controlling the speed of the engine of a hybrid vehicle according to claim 1, characterized in that: When the driving mode is the parallel driving mode, Wherein, based on the actual speed and / or the deviation value, determining whether the speed of the engine in different driving modes is overspeeding includes: If the deviation between the actual speed and the target speed exceeds a first preset value, and / or the duration for which the deviation exceeds a second preset value satisfies a preset condition, the parallel overspeed flag is set, wherein the parallel overspeed flag is set to indicate that the engine speed is overspeeding in the parallel drive mode.

3. The method for controlling the speed of the engine of a hybrid vehicle according to claim 1, characterized in that: The method further comprises: When the driving mode is the tandem driving mode and the tandem speeding flag is in position, Subtracting the deviation value from the first threshold value to obtain a first difference value, and / or subtracting the actual speed from the preset maximum speed to obtain a second difference value; Determine whether the first difference is greater than a third preset value, and / or determine whether the second difference is greater than a fourth preset value; When the first difference is less than a third preset value, and / or the second difference is less than a fourth preset value, determining the series drive negative torque based on the actual speed and the deviation value, and calling the first overspeed control strategy; When the first difference is greater than the third preset value, and / or the second difference is greater than the fourth preset value, the torque correction coefficient is determined based on the deviation value and the second difference, the target torque is determined based on the torque correction coefficient, and the second overspeed control strategy is called.

4. The method for controlling the rotation speed of the engine of a hybrid vehicle according to claim 2, characterized in that: Calling corresponding control strategies based on different driving modes also includes: When the driving mode is the parallel drive mode and the parallel overspeed flag is in position, the corresponding parallel overspeed control strategy is called, and the parallel overspeed control strategy is used to control the generator to output a parallel drive negative torque, and / or control the engine to output a parallel target torque, wherein the parallel drive negative torque is calculated by the deviation value based on an integral controller algorithm.

5. The method for controlling the rotation speed of the engine of a hybrid vehicle according to claim 4, characterized in that: The method further comprises: After the speed of the engine is controlled to be within the target speed range, the driving mode is controlled to switch from the parallel drive mode to the series drive mode, and the parallel overspeed flag is reset, wherein the parallel overspeed flag reset is used to indicate that the speed of the engine in the parallel drive mode is within the target speed range; In a driving cycle from powering on the hybrid vehicle to powering off the hybrid vehicle, the number of overspeeds of the engine in the parallel driving mode is counted, wherein each time the parallel overspeed flag is reset to set, the number of overspeeds is increased by one; Determining whether the number of speeding times is greater than a preset number; If yes, a reminder strategy is generated based on the number of speeding times, the reminder strategy is used to control the hybrid vehicle to exit the parallel drive mode, and a reminder message is generated, the reminder message is used to remind the driver to repair the hybrid vehicle.

6. A hybrid vehicle, characterized in that: include: Engine (1); a drive motor (6), the drive motor (6) being selectively connected to the engine (1) via a clutch (5), wherein when the clutch (5) is separated from the engine (1), the driving mode is a series drive mode, and when the clutch (5) is connected to the engine (1), the driving mode is a parallel drive mode; A control system for executing the method for controlling the speed of an engine of a hybrid vehicle according to claims 1 to 5, comprising: determining a current driving mode, the driving mode comprising: the series driving mode and the parallel driving mode; Collecting the actual speed of the engine (1), and calculating the deviation between the actual speed and the target speed; Based on the actual speed and / or the deviation value, determining whether the speed of the engine (1) is overspeeding in different driving modes; Call corresponding control strategies based on different driving modes; Based on the control strategy, the rotation speed of the engine (1) is controlled to be within a target rotation speed range.

7. The hybrid vehicle according to claim 6, characterized in that: The hybrid vehicle further comprises: An engine controller, used for collecting the rotation speed of the engine (1) and the actual torque of the engine (1); A CAN bus, connected to the engine controller, for sending information collected by the engine controller to a vehicle controller; The vehicle controller is used to calculate the target torque and the target speed of the engine (1) based on the torque demand of the vehicle, and send the target torque of the engine (1) to the engine controller for execution.

8. The hybrid vehicle according to claim 7, characterized in that: The hybrid vehicle further comprises: A generator (2), the generator (2) being rigidly connected to the engine (1) via a reduction gear mechanism (4); A generator controller, the generator controller being connected to the CAN bus, and the generator controller being used to collect the rotation speed of the generator (2) and the actual torque of the generator (2); The CAN bus is connected to the generator controller and is used to send information collected by the generator controller to the vehicle controller. The vehicle controller calculates the target torque of the generator (2) in the series drive mode based on a closed-loop control algorithm, and sends the target torque of the generator (2) to the generator controller for execution.

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