Hybrid vehicle driving mode control method and system, and hybrid vehicle

Abstract

The application provides a hybrid vehicle driving mode control method and system and a hybrid vehicle. The method comprises the following steps: acquiring the driving condition of the hybrid vehicle at the current time, including speed information, road condition information, battery power and driving mode; if the acceleration intention of the driver is monitored and the battery power is lower than a preset threshold, the vehicle demand power at the next time is determined according to the speed information and the road condition information; if the driving mode is the series mode and the first output power when the next time enters the series-parallel switching transient stage is smaller than the second output power when the series mode is maintained, the entry prohibition instruction of the parallel mode is generated; if the driving mode is the parallel mode and the vehicle demand power and the third output power when the next time switches to the series mode are both greater than the fourth output power when the parallel mode is maintained, the exit instruction of the parallel mode is generated. The power shortage and the unstable driving problem when the driver accelerates with low battery power are avoided, and the driving comfort and safety are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, and in particular to a hybrid vehicle driving mode control method and system and a hybrid vehicle. BACKGROUND

[0002] With the continuous development of hybrid vehicle technology, improving fuel economy and optimizing driving experience have become core goals. In high-speed driving conditions, the hybrid vehicle switches the vehicle driving mode from the series mode of engine-generator-drive motor to the parallel mode of engine and drive motor driving the wheels together, while adjusting the engine torque to operate in the high-efficiency region to reduce fuel consumption, and the drive motor provides acceleration assistance or generates electricity based on the driver's real-time acceleration and deceleration demand torque, thereby balancing power and economy. However, in complex and variable driving scenarios, especially in low temperature conditions, the battery pack power continues to decline, triggering the BMS (Battery Management System) protection mechanism, which significantly reduces the battery charge and discharge power capability, causing the vehicle controller to receive a signal that the battery available power is insufficient in a short time, resulting in insufficient power for parallel steady-state or transient switching.

[0003] In related technologies, the vehicle controller monitors the actual battery pack power, actual charge and discharge power capability, and driver demand power in real time during vehicle driving, comprehensively judges the current power state and reserves a certain amount of backup power to identify potential power shortage risks and make driving mode switching decisions accordingly. However, due to the instantaneous nature of triggering the BMS protection mechanism, the actual output torque of the powertrain system may not meet the driver's acceleration demand during the vehicle controller's power shortage risk comprehensive judgment and processing, and even unexpected torque interruption or fluctuations may occur, still causing driving power shortage and driving smoothness to decline, affecting driving experience and driving safety. SUMMARY

[0004] The present application discloses a hybrid vehicle driving mode control method and system and a hybrid vehicle to solve the technical problems of power shortage and unstable driving of the hybrid vehicle when the driver accelerates under low power conditions.

[0005] The application provides a hybrid vehicle driving mode control method, the method comprising: obtaining a driving condition of a hybrid vehicle at a current time, the driving condition comprising speed information, road condition information, battery power and a driving mode, the driving mode comprising a series mode and a parallel mode; if an acceleration intention of a driver is monitored and the battery power is lower than a preset power threshold, determining a vehicle power parameter at a next time according to the speed information and the road condition information, wherein the vehicle power parameter comprises a vehicle demand power; if the driving mode is the series mode and a first output power when the next time enters a series-parallel switching transient stage is less than a second output power when the series mode is maintained, generating an entry prohibition instruction of the parallel mode; and if the driving mode is the parallel mode and both the vehicle demand power and a third output power when the next time switches to the series mode are greater than a fourth output power when the parallel mode is maintained, generating an exit instruction of the parallel mode.

[0006] In an embodiment of the application, the determination manner that the first output power is less than the second output power comprises: predicting a fifth output power of a generator when the next time enters the series-parallel switching transient stage and predicting a sixth output power of the generator when the next time maintains the series mode according to a target vehicle speed and a vehicle demand torque, wherein the vehicle power parameter further comprises the target vehicle speed and the vehicle demand torque; and if a first difference between the sixth output power and the fifth output power is greater than a preset first threshold, it is determined that the first output power is less than the second output power.

[0007] In an embodiment of the application, the determination manner that the third output power is greater than the fourth output power comprises: obtaining working parameters of a power assembly, the working parameters comprising a transmission efficiency of an engine, a fixed-point power generation power of the engine and a conversion efficiency of a driving motor; predicting a seventh output power of the engine when the next time maintains the parallel mode according to a target vehicle speed and a vehicle demand torque, wherein the vehicle power parameter further comprises the target vehicle speed and the vehicle demand torque; calculating the seventh output power and the transmission efficiency to obtain a first calculation result and calculating the fixed-point power generation power and the conversion efficiency to obtain a second calculation result; and if a second difference between the second calculation result and the first calculation result is greater than a preset second threshold, it is determined that the third output power is greater than the fourth output power.

[0008] In an embodiment of the application, the generation of the entry prohibition instruction of the parallel mode further comprises: obtaining working parameters of a power assembly, the working parameters comprising a charging power and a charging efficiency of a battery; if the driving mode is the series mode, calculating the fifth output power and the charging efficiency to obtain a third calculation result; and if a third difference between the third calculation result and the charging power is greater than a preset third threshold, the entry prohibition instruction is generated.

[0009] In an embodiment of the present application, the method further comprises: under the condition that the exit instruction is not generated, if the first decay rate of the battery charging and discharging power is greater than the preset rate threshold, and the first actual output power is greater than the charging power, then according to a fifth difference between the first output power and the charging power, the third threshold is modified.

[0010] In an embodiment of the present application, the method further comprises: under the condition that the exit instruction is not generated, if the second decay rate of the battery charging and discharging power is greater than the preset rate threshold, and the vehicle demand power and the third output power are both greater than the second actual output power when the parallel mode is maintained at the next moment, then according to a sixth difference between the third output power and the fourth output power, the second threshold is modified.

[0011] In an embodiment of the present application, the monitoring method of the acceleration intention comprises: obtaining environment information, the environment information comprising first obstacle information within a preset first distance in front of a driving path and second obstacle information within a preset second distance on left and right sides of the hybrid vehicle; if the first obstacle information and the second obstacle information both show no obstacle, and the driving speed is less than a preset speed threshold and the throttle opening is less than a preset opening threshold, then it is determined that the driver has the acceleration intention, wherein the speed information comprises the driving speed and the throttle opening, and the speed threshold is in a positive correlation with the first distance and the second distance.

[0012] In an embodiment of the present application, the method of determining the target working condition at the next moment according to the speed information and the road condition information comprises: determining a target acceleration according to the speed information, the road condition information and a preset acceleration mapping table, wherein the acceleration mapping table is constructed based on a multi-dimensional corresponding relationship between speed information, road condition information and acceleration, the speed information comprising driving speed, throttle opening and throttle opening change rate, and the road condition information comprising road speed limit value and road slope; calculating the driving speed, the target acceleration and a preset time step to obtain a target vehicle speed at the next moment; and determining the vehicle demand power according to the target vehicle speed.

[0013] In an embodiment of the present application, the determining the whole vehicle demand power according to the target vehicle speed comprises: determining a whole vehicle demand torque at a next time according to the target vehicle speed and a pre-constructed driving resistance model, and determining a wheel angular velocity at the next time according to the target vehicle speed, wherein the driving resistance model is constructed by rolling resistance, slope resistance and air resistance; and determining the whole vehicle demand power according to the whole vehicle demand torque and the wheel angular velocity.

[0014] The present application further provides a hybrid vehicle driving mode control system, comprising: an acquisition module configured to acquire a driving condition of the hybrid vehicle at a current time, wherein the driving condition comprises speed information, road condition information, battery power and a driving mode, and the driving mode comprises a series mode and a parallel mode; a calculation module configured to, if an accelerating intention of a driver is detected and the battery power is lower than a preset power threshold, determine a whole vehicle power parameter at a next time according to the speed information and the road condition information, wherein the whole vehicle power parameter comprises a whole vehicle demand power; and a control module configured to, if the driving mode is the series mode and a first output power at the next time when a series-parallel switching transient stage is entered is less than a second output power when the series mode is maintained, generate an entry prohibition instruction of the parallel mode; and the control module is further configured to, if the driving mode is the parallel mode and both the whole vehicle demand power and a third output power at the next time when the series mode is switched to are greater than a fourth output power when the parallel mode is maintained, generate an exit instruction of the parallel mode.

[0015] The present application further provides a hybrid vehicle, comprising: a controller configured to implement the hybrid vehicle driving mode control method as described above, and configured to generate a control instruction of the hybrid vehicle according to a driving condition at a current time and an accelerating intention of a driver, wherein the control instruction comprises an entry prohibition instruction or an exit instruction of a parallel mode in a driving mode; and a power system in communication connection with the controller, configured to receive and respond to the entry prohibition instruction to prohibit the hybrid vehicle from entering the parallel mode, or receive and respond to the exit instruction to make the hybrid vehicle exit the parallel mode, thereby realizing control of the driving mode.

[0016] The beneficial effects of the present application: the hybrid vehicle driving mode control method, system and hybrid vehicle provided by the present application first acquire the driving conditions of the hybrid vehicle at the current time, including speed information, road condition information, battery power and driving mode, the driving mode includes series mode and parallel mode, then in the case that the driver has an acceleration intention and the battery power is lower than the preset power threshold, according to the speed information and the road condition information, the vehicle power parameters at the next time are determined, including the vehicle demand power, if the driving mode is series mode, and the first output power when the next time enters the series-parallel switching transient stage is less than the second output power when the series mode is maintained, the entry prohibition instruction of the parallel mode is generated, if the driving mode is parallel mode, and the vehicle demand power and the third output power when the next time switches to series mode are both greater than the fourth output power when the parallel mode is maintained, the exit instruction of the parallel mode is generated, in the case of low power and the driver has an acceleration intention, by predicting the power demand at the next time in real time, the risk of insufficient power output of the powertrain at the next time in different driving modes and switching is identified in advance, so as to intelligently decide the driving mode at the next time for emergency response control, not only solving the problem of power switching response lag when the battery power is insufficient, but also avoiding the problem of insufficient power and unstable driving when the battery power is low and the driver accelerates, ensuring the driving comfort and safety performance. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings incorporated into the specification and forming a part thereof, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application. It is to be expressly understood that the drawings are only exemplary and are, therefore, not to be considered as limiting upon the scope for the application as it can be other than as illustrated and described.

[0018] In the drawings:

[0019] Figure 1 is a structural schematic diagram of a hybrid vehicle according to an exemplary embodiment of the present application;

[0020] Figure 2 is an implementation environment schematic diagram of a hybrid vehicle driving mode control system according to an exemplary embodiment of the present application;

[0021] Figure 3 is a flowchart of a hybrid vehicle driving mode control method according to an exemplary embodiment of the present application;

[0022] Figure 4 is a block diagram of a hybrid vehicle driving mode control system according to an exemplary embodiment of the present application;

[0023] Figure 5Fig. 1 is a structural schematic diagram of a vehicle terminal according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] The above objects and advantages of the present application will become more apparent by describing in detail the preferred embodiments thereof with reference to the attached drawings in which:

[0025] It is to be understood that the above-mentioned arrangements are merely meant to illustrate the basic principles of the application, and that the drawings do not show the components in the actual number, shape and size, and that the actual implementation of the components can be changed arbitrarily, and that the layout of the components can be more complicated.

[0026] In the following description, numerous specific details are discussed in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to one of ordinary skill in the art that the embodiments of the present application can be practiced without these specific details. In other instances, well-known structures and devices are not described in detail in order to avoid obscuring the embodiments of the present application.

[0027] Referring to Figure 1 , Figure 1 Fig. 1 is a structural schematic diagram of a hybrid vehicle according to an exemplary embodiment of the present application. As shown in Fig. 1, the power system of the hybrid vehicle includes engine, generator, drive motor, battery pack, hydraulic clutch and differential. When the parallel mode switching condition is met, the hydraulic clutch responds to the engagement request to push the clutch master and slave disc friction completely, complete clutch engagement, and the vehicle power transmission path includes two paths of engine and drive motor; when the series mode switching condition is met, the hydraulic clutch responds to the separation request to separate the clutch master and slave disc friction, complete clutch separation, and the vehicle power transmission path has only one path of drive motor, at this time, the engine drives the generator to generate electricity. Figure 1

[0028] ​In the high-speed driving condition, the hybrid vehicle switches the vehicle driving mode from the series mode of the engine-generator-driving motor to the parallel mode of the engine and the driving motor driving the wheels. However, the present inventors have found that in the complex and changeable driving scene, especially under low temperature conditions, the battery pack power is continuously reduced to trigger the BMS protection mechanism, so that the battery charging and discharging power capability is significantly reduced, resulting in insufficient power in parallel steady-state or transient switching. Although the actual battery pack power, actual charging and discharging power capability, and driver demand power during vehicle driving can be monitored in real time by the vehicle controller, the current power state can be comprehensively judged and a certain backup power can be reserved to identify the potential power shortage risk and make a driving mode switching decision accordingly. However, due to the instantaneous nature of triggering the BMS protection mechanism, the actual output torque of the powertrain system may not meet the driver's acceleration demand during the comprehensive judgment and processing of the vehicle controller power shortage risk, and even unexpected torque interruption or fluctuation may occur, which still has the problems of insufficient driving power and decreased driving smoothness, affecting the driving experience and driving safety.

[0029] Therefore, please refer to Figure 2 , Figure 2 is an exemplary embodiment of the present application, which shows an implementation environment diagram of a hybrid vehicle driving mode control system. As Figure 2 shown, the implementation environment includes a hybrid vehicle 210 and a hybrid vehicle driving mode control system 220, wherein the hybrid vehicle driving mode control system 220 is embedded in the hybrid vehicle 110, and is used to control the driving mode in the hybrid vehicle 110. The hybrid vehicle driving mode control system 220 includes but is not limited to a car machine system, a vehicle-mounted computer, etc. In the case of low power and driver's acceleration intention, the power demand at the next moment is predicted in real time, the risk of powertrain output power shortage in different driving modes and switching at the next moment is identified in advance, so as to make an intelligent decision on the driving mode at the next moment for emergency response control. Not only the problem of power switching response lag when the battery power is insufficient is solved, but also the problems of power shortage and unstable driving when the battery power is low and the driver accelerates are avoided, so as to ensure the driving comfort and safety performance.

[0030] Please refer to Figure 3 , Figure 3 is a flowchart of a hybrid vehicle driving mode control method according to an exemplary embodiment of the present application. The method can be applied to Figure 2 the implementation environment shown in the figure, and is specifically executed by the hybrid vehicle driving mode control system 220 in the implementation environment. It should be understood that the method can also be applied to other exemplary implementation environments and specifically executed by devices in other implementation environments, and the present embodiment does not limit the implementation environment to which the method is applied.

[0031] AsFigure 3 As shown, in an exemplary embodiment, the hybrid vehicle driving mode control method comprises at least steps S310 to S330, wherein step S330 comprises steps S331 and S332, which are described in detail as follows:

[0032] Step S310, obtaining the driving condition of the hybrid vehicle at the current time, the driving condition comprising speed information, road condition information, battery power and driving mode, the driving mode comprising series mode and parallel mode.

[0033] Step S320, if the driver has an acceleration intention and the battery power is lower than the preset power threshold, determining the vehicle power parameter at the next time according to the speed information and the road condition information, wherein the vehicle power parameter comprises vehicle demand power.

[0034] Step S331, if the driving mode is series mode and the first output power at the next time when the series-parallel switching transient stage is entered is less than the second output power when the series mode is maintained, generating an entry prohibition instruction of the parallel mode.

[0035] Step S332, if the driving mode is parallel mode and both the vehicle demand power and the third output power at the next time when the series mode is switched are greater than the fourth output power when the parallel mode is maintained, generating an exit instruction of the parallel mode.

[0036] The speed information can be obtained by a speed sensor, an accelerator pedal position sensor, etc.; the road condition information can be obtained by a vehicle-mounted camera, radar or navigation system; the battery power can be monitored in real time by a battery management system; the driving mode can be determined according to the current power distribution state and the mode identifier stored by the controller, the series mode refers to a mode in which the engine drives the generator to generate power and the electric energy is supplied to the drive motor to drive the wheels alone, and the parallel mode refers to a mode in which the engine and the drive motor jointly drive the wheels; the power threshold can be set based on specific conditions and requirements.

[0037] In addition, the vehicle demand power refers to the power required by the powertrain of the hybrid vehicle at the next time to meet the driver's acceleration driving and the road condition of the vehicle; the first output power refers to the actual output power of the powertrain predicted at the next time when the transient stage is switched from the series mode to the parallel mode at the current time when the series mode is maintained; the second output power refers to the actual output power of the powertrain predicted when the series mode is maintained at the next time at the current time when the series mode is maintained; the third output power refers to the actual output power of the powertrain predicted when the transient stage is switched from the parallel mode to the series mode at the next time at the current time when the parallel mode is maintained; and the fourth output power refers to the actual output power of the powertrain predicted when the parallel mode is maintained at the next time at the current time when the parallel mode is maintained.

[0038] In step S310, the driving condition of the hybrid vehicle is acquired in real time, which provides a basis for subsequent condition judgment and driving mode decision.

[0039] In step S320, when it is monitored that the driver has an acceleration demand and the battery power is lower than the set threshold, the whole vehicle power demand of the vehicle driving at the next moment is predicted in combination with the current vehicle speed and road condition information, so as to further make a driving mode decision.

[0040] In step S331, if the current driving mode of the vehicle is in the series mode and it is predicted that the power output by the engine in the transient process of switching to the parallel mode at the next moment is lower than the output power when the series mode is maintained, it is indicated that the power reduction in the transient stage of switching to the parallel mode will cause the power performance to decrease, and the vehicle needs to accelerate, and if the vehicle is in the transient stage of switching to the parallel mode at the next moment, the driving will be unstable, therefore, a control instruction of prohibiting the entry into the parallel mode is generated, so as to coordinate the working of the powertrain components and ensure that the driving demand is met with the maximum capacity, so as to avoid the problem of unstable driving under the acceleration condition.

[0041] In step S332, if the current driving mode of the vehicle is in the parallel mode and it is predicted that both the whole vehicle demand power and the power output after switching to the series mode at the next moment are higher than the output power when the parallel mode is maintained, it is indicated that the power maintained in the parallel mode is not optimal, and the vehicle needs to accelerate, and if the vehicle is still in the parallel mode at the next moment, the problem of serious power shortage will occur, therefore, a control instruction of exiting the parallel mode is generated, so as to coordinate the working of the powertrain components and ensure that the driving demand is met with the maximum capacity, so as to avoid the problem of power shortage under the acceleration condition.

[0042] In this embodiment, in the case of low power and the driver's intention to accelerate, by predicting the power demand at the next moment in real time, the risk of powertrain output power shortage in the next moment in different driving modes and switching is identified in advance, so that the driving mode at the next moment is intelligently decided for emergency response control, not only solving the problem of power switching response lag when the battery power is insufficient, but also avoiding the problems of power shortage and unstable driving when the battery power is low and the driver accelerates, especially in the case of triggering the battery management system protection mechanism during the driving process in the low-temperature and low-power scene, the problem of the actual output being non-expected power due to the identification of the parallel low-power acceleration power shortage risk by the whole vehicle controller during the power limitation period of the powertrain components, resulting in the driving power shortage, can be effectively avoided, and the driving comfort and safety performance are ensured.

[0043] In addition, the hybrid vehicle entering the parallel mode is provided with a critical vehicle speed, and whether the current driving mode is the series mode or the parallel mode, the subsequent comparison and judgment need to be made again under the condition that the predicted target speed reaches the critical vehicle speed.

[0044] In an embodiment, the monitoring manner of the accelerating intention comprises: acquiring environment information, the environment information comprising first obstacle information within a preset first distance in front of the driving path and second obstacle information within a preset second distance on the left and right sides of the hybrid vehicle; if the first obstacle information and the second obstacle information both show no obstacle, and the driving speed is less than a preset speed threshold and the throttle opening is less than a preset opening threshold, it is determined that the driver has an accelerating intention, wherein the speed information comprises the driving speed and the throttle opening, and the speed threshold is positively correlated with the first distance and the second distance, respectively.

[0045] In the embodiment, the first distance, the second distance, the speed threshold and the opening threshold can be set based on specific conditions or requirements; the first obstacle information can be collected by a vehicle-mounted forward millimeter wave radar or a camera, and the second obstacle information can be collected by a vehicle-mounted lateral millimeter wave radar or a camera; the speed threshold is positively correlated with the first distance and the second distance, respectively, which means that the greater the first distance and the second distance, the greater the speed threshold, and the speed threshold comprises the speed threshold and the opening threshold.

[0046] In the embodiment, the accelerating intention of the driver is predicted by combining multi-dimensional environment perception and driving behavior characteristics, which ensures the reliability of the prediction result, thereby effectively avoiding the problem of inaccurate driving mode control caused by misjudgment of the accelerating intention.

[0047] For example, the first distance is set to multiple levels, and each level of the first distance is configured with a corresponding speed threshold, or the first distance and the second distance are both set to multiple levels, and the same level of the first distance and the second distance is configured with a corresponding speed threshold, or the first distance and the second distance are both set to multiple levels, and the same level of the first distance and the second distance is configured with a corresponding speed threshold and opening threshold. In this way, the accelerating intention of the driver in different driving scenarios is accurately identified.

[0048] In the example embodiment, the first distance is set to multiple levels, and each level of the first distance is configured with a corresponding speed threshold. For example, when the hybrid vehicle is within 200 m in front of the driving path and within 5 m on the left and right sides of the hybrid vehicle, and there are no obstacles, and the driving speed is less than the preset first speed threshold of 90 km / h, and the throttle opening is less than 30%, it is determined that the driver has an acceleration intention; when the hybrid vehicle is within 100 m in front of the driving path and within 5 m on the left and right sides of the hybrid vehicle, and there are no obstacles, and the driving speed is less than the preset second speed threshold of 50 km / h, and the throttle opening is less than 30%, it is determined that the driver has an acceleration intention; when the hybrid vehicle is within 50 m in front of the driving path and within 5 m on the left and right sides of the hybrid vehicle, and there are no obstacles, and the driving speed is less than the preset third speed threshold of 25 km / h, and the throttle opening is less than 30%, it is determined that the driver has an acceleration intention; otherwise, it is determined that the driver has no acceleration intention.

[0049] For example, when the first obstacle information and the second obstacle information both show no obstacles, the driving speed is less than the preset speed threshold, and the throttle opening is less than the preset opening threshold, the driver's historical acceleration information is also used to comprehensively determine whether the driver has an acceleration intention, that is, the historical acceleration information shows that the driver has performed an acceleration operation under the same or similar conditions (i.e., environmental information, driving speed range, and throttle opening), and finally it is determined that the driver has an acceleration intention, otherwise, it is determined that the driver has no acceleration intention. In this way, the accuracy of the acceleration intention monitoring is further improved.

[0050] In an embodiment, the target working condition at the next time is determined according to the speed information and the road condition information, including: determining the target acceleration according to the speed information, the road condition information, and a preset acceleration mapping table, wherein the acceleration mapping table is constructed based on the multi-dimensional correspondence relationship between the speed information, the road condition information, and the acceleration, the speed information includes the driving speed, the throttle opening, and the throttle opening change rate, and the road condition information includes the road speed limit value and the road slope; calculating the driving speed, the target acceleration, and a preset time step to obtain the target vehicle speed at the next time; and determining the vehicle demand power according to the target vehicle speed.

[0051] The time step can be set based on specific circumstances or requirements, for example, 90 milliseconds, 100 milliseconds, 110 milliseconds, etc.; the acceleration mapping table can be constructed based on historical data of user's daily acceleration, that is, the acceleration data of different driving speeds, throttle openings, and throttle opening change rates under various road speed limit values and various slopes is calculated, and the acceleration mapping table is updated regularly based on the stored data.

[0052] In this embodiment, by establishing a multi-dimensional acceleration mapping relationship, considering multi-dimensional parameters such as driving speed, throttle operation characteristics and road environment, the motion state and the demand power of the vehicle at the next moment are more accurately predicted, thereby providing reliable input basis for the driving mode decision.

[0053] Exemplarily, the calculation formula of the target vehicle speed is:

[0054] Formula (1)

[0055] wherein, denotes the target vehicle speed at the next moment; denotes the driving speed at the current moment; denotes the target acceleration; denotes the time step.

[0056] In a possible embodiment, if there is no road speed limit value in front of the driving path of the hybrid vehicle, a lookup table is performed according to a preset speed limit threshold. For example, the speed limit threshold is set to 100 km / h (kilometers per hour), and of course, the speed limit threshold can be set based on specific circumstances or requirements.

[0057] In an embodiment, the demand power of the vehicle is determined according to the target vehicle speed, comprising: determining the demand torque of the vehicle at the next moment according to the target vehicle speed and a pre-constructed driving resistance model, and determining the wheel angular velocity at the next moment according to the target vehicle speed, wherein the driving resistance model is constructed by rolling resistance, slope resistance and air resistance; determining the demand power of the vehicle according to the demand torque of the vehicle and the wheel angular velocity.

[0058] wherein, the wheel angular velocity at the next moment can be obtained by calculating the ratio of the target vehicle speed and the wheel radius; the demand power of the vehicle can be obtained by calculating the product of the demand torque of the vehicle and the wheel angular velocity.

[0059] In this embodiment, the demand torque of the vehicle at the next moment is accurately estimated by the target vehicle speed and the driving resistance model containing rolling resistance, slope resistance and air resistance, and the corresponding wheel angular velocity is calculated combined with the target vehicle speed, and then the demand power of the vehicle is obtained, so that various driving resistance factors are considered, and the power prediction deviation caused by single parameter estimation is avoided.

[0060] Exemplarily, the driving resistance model is represented as:

[0061] Formula (2)

[0062] wherein, denotes the demand torque of the vehicle; denotes the kerb mass of the hybrid vehicle; represents the mass of each occupant, usually set to 75 kg (kilogram); represents the number of occupants; represents the acceleration of gravity; represents the rolling resistance coefficient; represents the slope percentage; represents the target vehicle speed at the next moment; represents the wheel radius; represents the transmission efficiency; 、 are the linear term and the quadratic term coefficients of the air resistance curve.

[0063] In an embodiment, the determination that the first output power is less than the second output power comprises: predicting a fifth output power of the generator at the next moment when entering the series-parallel switching transient stage and predicting a sixth output power of the generator at the next moment when maintaining the series mode according to the target vehicle speed and the vehicle demand torque, wherein the vehicle power parameters further include the target vehicle speed and the vehicle demand torque; and determining that the first output power is less than the second output power if a first difference between the sixth output power and the fifth output power is greater than a preset first threshold value.

[0064] wherein the fifth output power is the predicted maximum output power of the generator at the next moment when entering the series-parallel switching transient stage; the sixth output power is the predicted maximum output power of the generator at the next moment when maintaining the series mode; and the first threshold value is used to compensate for power fluctuations in the dynamic response process of the powertrain, is a preset first power offset, and can be determined according to historical data statistical analysis and dynamically adjusted by an adaptive algorithm in the decision-making process.

[0065] In this embodiment, it needs to be determined that the first output power at the next moment when entering the series-parallel switching transient stage is less than the second output power when maintaining the series mode, and the first output power includes the discharge power of the battery and the fifth output power of the generator at the next moment when entering the series-parallel switching transient stage, and the second output power includes the discharge power of the battery and the sixth output power of the generator at the next moment when maintaining the series mode, the discharge power of the battery is the current peak charging power, and the discharge powers in the first output power and the second output power are the same, so it is only necessary to compare the fifth output power and the sixth output power, and considering the prediction error and the influence of working condition fluctuations on the judgment result, a power offset, i.e. the first threshold value, is introduced to compensate for the prediction error and the working condition fluctuations.

[0066] In this way, by dynamically comparing the output power of the transient stage of maintaining the series mode and switching to the parallel mode at the next moment, the risk of power deficiency caused in the process of switching to the parallel mode is identified in advance in the low battery state, and the power deficiency problem caused by the power of the power assembly components being limited when switching to the parallel mode transient stage during acceleration can be avoided more accurately in combination with the offset compensation.

[0067] Exemplarily, the sixth output power - the fifth output power > the first threshold value can be represented as the sixth output power - the first threshold value > the fifth output power, or the sixth output power > the fifth output power + the first threshold value, and the first threshold value can be a positive value or a negative value.

[0068] Exemplarily, the first output power being less than the second output power can be represented as: |the current peak charging power of the battery| + |the maximum output power of the generator predicted when entering the series-parallel switching transient stage| < |the current peak charging power of the battery| + |the maximum output power of the generator predicted when maintaining the series mode| + the first power offset.

[0069] Exemplarily, the sixth output power is predicted according to the target vehicle speed and the vehicle demand torque, i.e., the target torque of the drive motor is determined according to the vehicle demand torque, the angular velocity of the drive motor is determined according to the target vehicle speed and the reduction ratio, the power required by the drive motor is determined in combination with the target torque and the angular velocity, and then the sixth output power is determined according to the power required by the drive motor and the power demand of the battery charging. In addition, the logic of predicting the fifth output power according to the target vehicle speed and the vehicle demand torque is the same as that of predicting the sixth output power, but although the determination logic is the same, the final value will be different due to different dynamic responses in different stages. Of course, the specific way of predicting the fifth output power and the sixth output power according to the target vehicle speed and the vehicle demand torque is not limited in the application, and the fifth output power and the sixth output power can also be predicted based on other feasible ways.

[0070] In an embodiment, the determination of the third output power being greater than the fourth output power includes: obtaining working parameters of the power assembly, the working parameters including the transmission efficiency of the engine, the fixed-point power generation power of the engine, and the conversion efficiency of the drive motor; predicting the seventh output power of the engine when maintaining the parallel mode at the next moment according to the target vehicle speed and the vehicle demand torque, wherein the vehicle power parameters further include the target vehicle speed and the vehicle demand torque; calculating the seventh output power and the transmission efficiency to obtain a first calculation result, and calculating the fixed-point power generation power and the conversion efficiency to obtain a second calculation result; and if a second difference between the second calculation result and the first calculation result is greater than a preset second threshold value, it is determined that the third output power is greater than the fourth output power.

[0071] The seventh output power is the predicted output power of the engine when maintaining the parallel mode at the next time; the fixed-point power generation power of the engine is the maximum power generation power of the engine; and the second threshold is used to compensate for power fluctuation in the dynamic response process of the powertrain and is an initial second power offset which can be determined according to historical data statistics and dynamically adjusted through an adaptive algorithm in the decision-making process.

[0072] In this embodiment, it is necessary to determine that the third output power when switching to the series mode at the next time is greater than the fourth output power when maintaining the parallel mode, and the calculation method of the third output power is (|discharge power of the battery|*discharge efficiency of the battery+fixed-point power generation power of the engine)*conversion efficiency of the drive motor, and the calculation formula of the fourth power is |discharge power of the battery|*discharge efficiency of the battery*conversion efficiency of the drive motor+seventh output power*transmission efficiency of the engine, wherein the discharge power of the battery is the current peak charging power, and therefore the comparison between the third output power and the fourth output power can be simplified as the comparison between the result of the fixed-point power generation power of the engine*conversion efficiency of the drive motor and the result of the seventh output power*transmission efficiency of the engine, and the power offset, i.e., the second threshold, is introduced to compensate for the prediction error and the working condition fluctuation.

[0073] In this embodiment, by dynamically comparing the output powers when maintaining the parallel mode and switching to the series mode at the next time, the risk of power shortage caused by maintaining the parallel mode in the process of low battery power state can be identified in advance, and the power offset is combined for compensation, so that the problem of power shortage when maintaining the parallel mode during acceleration caused by the power limitation of the powertrain components can be more accurately avoided.

[0074] Exemplarily, the second calculation result-first calculation result>second threshold can be represented as second calculation result-second threshold>first calculation result, or second calculation result>first calculation result+second threshold, and the second threshold can be a positive value or a negative value.

[0075] Exemplarily, the third output power being greater than the fourth output power is represented as: (|current peak discharge power of the battery|*discharge efficiency of the battery+maximum fixed-point power generation power of the engine)*conversion efficiency of the drive motor+third power offset>|current peak discharge power of the battery|*discharge efficiency of the battery*conversion efficiency of the drive motor+predicted output power of the engine when maintaining the parallel mode*transmission efficiency of the engine.

[0076] Exemplarily, the seventh output power is predicted according to the target vehicle speed and the vehicle demand torque, that is, the target speed of the engine at the next moment is determined according to the target vehicle speed, the current or predicted gear ratio of the transmission, the main reducer speed ratio and the wheel radius, then the target torque of the engine is obtained by looking up a table in combination with the target speed, the vehicle demand torque and the battery power change state (increasing, decreasing or unchanged), and finally the seventh output power is calculated based on the target torque and the target speed. Of course, the application does not limit the specific way of predicting the seventh output power according to the target vehicle speed and the vehicle demand torque, and the seventh output power can also be predicted based on other feasible ways.

[0077] In a possible embodiment, the fifth output power, the sixth output power and the seventh output power can be predicted according to a neural network model, that is, the target vehicle speed and the vehicle demand torque are input into a pre-trained neural network model, and the fifth output power, the sixth output power and the seventh output power are output.

[0078] In an embodiment, the generation of the no-entry instruction of the parallel mode further includes: obtaining working parameters of the powertrain, the working parameters including the charging power and the charging efficiency of the battery; if the driving mode is the series mode, calculating the fifth output power and the charging efficiency to obtain a third calculation result; and if a third difference between the third calculation result and the charging power is greater than a preset third threshold, generating the no-entry instruction.

[0079] The calculation of the fifth output power and the charging efficiency is the calculation of the product of the fifth output power and the charging efficiency; the third difference is used to compensate for power fluctuation in the dynamic response process of the powertrain, is a preset initial third power offset, and can be determined according to historical data statistical analysis and dynamically adjusted through an adaptive algorithm in the decision-making process.

[0080] In this embodiment, the driving mode decision is made based on the matching of the battery charging capacity and the output power at the mode switching transient state, which can effectively avoid the problem of power interruption or instability caused by limited charging power.

[0081] Exemplarily, the third calculation result - the charging power > the third threshold can be represented as the third calculation result - the third threshold > the charging power, or the third calculation result > the charging power + the third threshold, and the third threshold can be a positive value or a negative value.

[0082] Exemplarily, the value of the charging power of the battery being less than the third calculation result is represented as: |the current peak charging power of the battery| < |the maximum output power of the generator at the predicted entering of the series-parallel switching transient state| * the charging efficiency of the battery + the third power offset.

[0083] In addition, for other scenarios, if the generation of the parallel mode entry prohibition instruction is not triggered when the current driving mode is the series mode, or the generation of the parallel mode exit instruction is not triggered when the current driving mode is the parallel mode, the mode switching restriction is not triggered, and the current driving mode is maintained to continue driving.

[0084] In an embodiment, the method further comprises: under the condition that the generation of the prohibition instruction is not triggered, if the first attenuation rate of the battery charging and discharging power is greater than the preset rate threshold, and the second output power is greater than the first actual output power at the next time when the series-parallel switching transient stage is entered, the first threshold is corrected according to a fourth difference between the second output power and the first output power; under the condition that the generation of the prohibition instruction is not triggered, if the first attenuation rate of the battery charging and discharging power is greater than the preset rate threshold, and the first actual output power is greater than the charging power, the third threshold is corrected according to a fifth difference between the first output power and the charging power.

[0085] In the formula, the first attenuation rate of the battery charging and discharging power refers to the falling speed of the battery charging and discharging capability; the rate threshold can be set according to specific conditions or requirements; and the first actual output power is the actual output power of the powertrain at the next time when the series-parallel switching transient stage is entered.

[0086] In this embodiment, when the battery power is low, the driver currently has an acceleration intention, but the driving mode is the series mode, and the generation of the parallel mode entry prohibition instruction is not triggered, indicating that the parallel mode will be switched to, and the next time will enter the series-parallel switching transient stage. If the battery charging and discharging power sharply decreases, and the output power of the powertrain predicted at the last time to maintain the series mode at the next time is greater than the actual output power at the next time when the series-parallel switching transient stage is entered, it indicates that the power output by the powertrain during the switching process is actually reduced, that is, the parallel mode should not be switched to, but the generation of the parallel mode entry prohibition instruction is not triggered, so the comparison and judgment at the last time are not accurate, and therefore the first threshold is corrected to improve the reliability of the subsequent comparison and judgment. Similarly, if the battery charging and discharging power sharply decreases, and the actual output power at the next time when the series-parallel switching transient stage is entered is greater than the charging power of the battery, it indicates that the battery cannot withstand the energy input during the switching process, that is, the parallel mode should not be switched to, but the generation of the parallel mode entry prohibition instruction is not triggered, so the comparison and judgment at the last time are not accurate, and therefore the third threshold is corrected to improve the reliability of the subsequent comparison and judgment.

[0087] In this way, under the condition that the generation of the parallel mode entry prohibition instruction is not triggered, the initial bias threshold is adaptively corrected by real-time monitoring of the subsequent battery power attenuation rate and in combination with the actual output power, the power prediction deviation is more accurately compensated, the driving mode decision accuracy is improved, and the risk of insufficient acceleration power is further reduced.

[0088] Exemplarily, a formula for correcting the first threshold value is: corrected first threshold value = current stored first threshold value + fourth difference value * correction coefficient; and a formula for correcting the third threshold value is: corrected third threshold value = current stored third threshold value + fifth difference value * correction coefficient. The correction coefficient can be set according to specific conditions or requirements.

[0089] In addition, if the inaccurate comparison judgment occurs again in the same vehicle demand power and battery charging and discharging power region, the first threshold value and the third threshold value are continuously corrected, and if the inaccurate comparison judgment does not occur again, the last stored corrected first threshold value and the last stored corrected third threshold value are maintained.

[0090] In an embodiment, the method further comprises: under the condition that the exit instruction is not generated, if the second attenuation rate of the battery charging and discharging power is greater than a preset rate threshold value, and both the vehicle demand power and the third output power are greater than the second actual output power when the parallel mode is maintained at the next moment, the second threshold value is corrected according to a sixth difference value between the third output power and the fourth output power.

[0091] The second attenuation rate of the battery charging and discharging power refers to the descending speed of the battery charging and discharging capability; the rate threshold value can be set according to specific conditions or requirements; and the second actual output power is the actual output power of the powertrain when the parallel-serial switching transient stage is entered at the next moment.

[0092] In this embodiment, when the battery power is low, the driver currently has an acceleration intention, but the driving mode is the parallel mode, and no exit instruction of the parallel mode is generated, indicating that the parallel mode is maintained at the next moment. If the battery charging and discharging power rapidly decreases, and the predicted vehicle demand power and the predicted output power for switching to the serial mode at the last moment are greater than the actual output power when the parallel mode is maintained at the next moment, it indicates that the power output by the powertrain maintained in the parallel mode is lower, that is, the parallel mode should be exited, but no exit instruction of the parallel mode is generated, so the comparison judgment at the last moment is inaccurate, and therefore the second threshold value is corrected to improve the reliability of the subsequent comparison judgment.

[0093] In this way, under the condition that the exit instruction of the parallel mode is not generated, the initial bias threshold value is adaptively corrected by real-time monitoring of the subsequent battery power attenuation rate and in combination with the actual output power, the power prediction bias is more accurately compensated, the driving mode decision accuracy is improved, and the risk of insufficient acceleration power is further reduced.

[0094] Exemplarily, a formula for correcting the second threshold value is: corrected second threshold value = current stored second threshold value + sixth difference value * correction coefficient. The correction coefficient can be set according to specific conditions or requirements.

[0095] In addition, if the inaccurate comparison judgment occurs again in the same vehicle demand power and battery charging and discharging power region, the second threshold is continuously corrected, and if the inaccurate comparison judgment does not occur again, the last stored corrected second threshold is maintained.

[0096] The hybrid vehicle driving mode control method described above first acquires the driving condition of the hybrid vehicle at the current time, including speed information, road condition information, battery power and driving mode, and the driving mode includes series mode and parallel mode. Then, in the case that the driver has an acceleration intention and the battery power is lower than the preset power threshold, the vehicle power parameters at the next time are determined according to the speed information and the road condition information, including the vehicle demand power. If the driving mode is series mode, and the first output power when the next time enters the series-parallel switching transient stage is less than the second output power when the series mode is maintained, the entry prohibition instruction of the parallel mode is generated. If the driving mode is parallel mode, and both the vehicle demand power and the third output power when the next time switches to series mode are greater than the fourth output power when the parallel mode is maintained, the exit instruction of the parallel mode is generated. In the case that the battery power is low and the driver has an acceleration intention, the power demand at the next time is predicted in real time, the risk of insufficient power output of the powertrain at the next time in different driving modes and switching is identified in advance, so that the driving mode at the next time is intelligently decided for emergency response control. Not only the problem of power switching response lag when the battery power is insufficient is solved, but also the problems of insufficient power and unstable driving when the battery power is low and the driver accelerates are avoided, so that the driving comfort and safety performance are guaranteed.

[0097] Please refer to Figure 4 , Figure 4 is a block diagram of a hybrid vehicle driving mode control system according to an example embodiment of the present application. The system can be applied to Figure 2 The implementation environment shown in the figure should be understood as that the system can also be applied to other example implementation environments, and the implementation environment to which the system is applied is not limited by the embodiment.

[0098] As Figure 4 shown, in an example embodiment, the hybrid vehicle driving mode control system 400 at least includes a request acquisition module 410, a calculation module 420 and a control module 430, which are described in detail as follows.

[0099] The acquisition module 410 is configured to acquire the driving condition of the hybrid vehicle at the current time, including speed information, road condition information, battery power and driving mode, and the driving mode includes series mode and parallel mode.

[0100] The computing module 420 is configured to, if the driver has an acceleration intention and the battery power is lower than the preset power threshold, determine a vehicle power parameter at the next moment according to the speed information and the road condition information, wherein the vehicle power parameter includes a vehicle demand power.

[0101] The control module 430 is configured to, if the driving mode is the series mode and the first output power when entering the series-parallel switching transient stage at the next moment is less than the second output power when maintaining the series mode, generate an entry prohibition instruction of the parallel mode.

[0102] The control module 430 is further configured to, if the driving mode is the parallel mode and both the vehicle demand power and the third output power when switching to the series mode at the next moment are greater than the fourth output power when maintaining the parallel mode, generate an exit instruction of the parallel mode.

[0103] It should be noted that the hybrid vehicle driving mode control system provided in the above embodiments and the hybrid vehicle driving mode control method provided in the above embodiments belong to the same concept, and the content of the operation of each module has been described in detail in the method embodiments, which will not be described here.

[0104] The application further provides a hybrid vehicle, which comprises a controller configured to generate a control instruction of the hybrid vehicle according to the driving condition at the current moment and the acceleration intention of the driver, wherein the control instruction includes an entry prohibition instruction or an exit instruction of the parallel mode in the driving mode; and a power system in communication connection with the controller, configured to receive and respond to the entry prohibition instruction to prohibit the hybrid vehicle from entering the parallel mode, or receive and respond to the exit instruction to make the hybrid vehicle exit the parallel mode, so as to realize the control of the driving mode.

[0105] The power assembly components in the power system include an engine, a generator, a drive motor, a battery pack, a clutch and a differential, and the prohibition entry and exit of the parallel mode are realized based on the cooperative work of the power assembly components.

[0106] Please refer to Figure 5 , Figure 5 is a structural schematic diagram of a vehicle terminal provided by an embodiment of the application. Figure 5 The structural schematic diagram of the computer system of the vehicle terminal suitable for realizing the embodiments of the application is shown. It should be noted that Figure 5 The computer system 500 of the vehicle terminal shown is only an example and should not limit the functions and use range of the embodiments of the application.

[0107] As Figure 5As shown, the computer system 500 includes a central processing unit (CPU) 501 which can perform various appropriate actions and processes in accordance with programs stored in a read-only memory (ROM) 502 or loaded from a storage section 508 into a random access memory (RAM) 503, such as performing the methods in the above-described embodiments. In the RAM 503, various programs and data required for system operation are also stored. The CPU 501, the ROM 502, and the RAM 503 are connected to each other through a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0108] Connected to the I / O interface 505 are an input section 506 including a keyboard, a mouse, etc.; an output section 507 including a display such as a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as necessary. A removable recording medium 511 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc. is attached to the drive 510 as necessary, so that a computer program read therefrom is installed into the storage section 508 as necessary.

[0109] In particular, according to the embodiments of the present application, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, the embodiments of the present application include a computer program product including a computer program carried on a computer-readable medium, the computer program containing a computer program for executing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network by the communication section 509, and / or installed from the removable recording medium 511. When the computer program is executed by the central processing unit (CPU) 501, various functions defined in the system of the present application are performed.

[0110] The present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor of a computer, causes the computer to perform the hybrid vehicle drive mode control method as described above. The computer-readable storage medium can be included in the vehicle terminal described in the above embodiments, or can exist separately without being deployed in the vehicle terminal.

[0111] Note that the computer readable medium shown in the embodiments of the present application can be a computer readable signal medium or a computer readable storage medium or any combination of the two. The computer readable storage medium may, for example, be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any combination of the above. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this application, the computer readable signal medium can include a data signal propagated in baseband or propagated as a carrier wave in a propagated data signal, in which the computer readable computer program is embodied. Such a propagated data signal can take a variety of forms, including but not limited to, electro-magnetic, optical, or any suitable combination thereof. The computer readable signal medium can also be any computer readable medium other than the computer readable storage medium that can be used to carry or store computer readable computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer program contained in the computer readable medium can be transmitted or propagated using any suitable medium, including but not limited to wireless, wired, or any suitable combination of the above.

[0112] The above embodiments are merely illustrative of the principles of the present application and the effects thereof, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas of the present application shall be covered by the claims of the present application.

Claims

1. A hybrid vehicle drive mode control method characterized by comprising: The method comprises: acquiring a driving condition of the hybrid vehicle at a current time, the driving condition comprising speed information, road condition information, battery power and driving mode, the driving mode comprising series mode and parallel mode; if an accelerating intention of a driver is detected and the battery power is lower than a preset power threshold, determining a vehicle power parameter at a next time according to the speed information and the road condition information, wherein the vehicle power parameter comprises target speed, vehicle demand torque and vehicle demand power; if the driving mode is series mode and a first output power when entering a series-parallel switching transient stage at the next time is less than a second output power when maintaining the series mode, generating an entry prohibition instruction of the parallel mode; if the driving mode is parallel mode and both the vehicle demand power and a third output power when switching to the series mode at the next time are greater than a fourth output power when maintaining the parallel mode, generating an exit instruction of the parallel mode; the generating of the entry prohibition instruction of the parallel mode further comprises: acquiring working parameters of a power assembly, the working parameters comprising charging power and charging efficiency of the battery; if the driving mode is series mode, predicting a fifth output power of a generator when entering the series-parallel switching transient stage at the next time according to the target speed and the vehicle demand torque; calculating the fifth output power and the charging efficiency to obtain a third calculation result; if a third difference between the third calculation result and the charging power is greater than a preset third threshold, generating the entry prohibition instruction.

2. The hybrid vehicle drive mode control method according to claim 1, characterized by, the determination of the first output power being less than the second output power comprises: predicting a sixth output power of the generator when maintaining the series mode at the next time according to the target speed and the vehicle demand torque; if a first difference between the sixth output power and the fifth output power is greater than a preset first threshold, determining that the first output power is less than the second output power.

3. The hybrid vehicle drive mode control method according to claim 1, characterized by, the determination of the third output power being greater than the fourth output power comprises: acquiring working parameters of the power assembly, the working parameters comprising transmission efficiency of an engine, fixed-point power generation power of the engine and conversion efficiency of a driving motor; predicting a seventh output power of the engine when maintaining the parallel mode at the next time according to the target speed and the vehicle demand torque, wherein the vehicle power parameter further comprises the target speed and the vehicle demand torque; calculating the seventh output power and the transmission efficiency to obtain a first calculation result, and calculating the fixed-point power generation power and the conversion efficiency to obtain a second calculation result; if a second difference between the second calculation result and the first calculation result is greater than a preset second threshold, determining that the third output power is greater than the fourth output power.

4. The hybrid vehicle drive mode control method according to claim 2, characterized by, the method further comprises: if a first attenuation rate of battery charging and discharging power is greater than a preset rate threshold and the second output power is greater than a first actual output power when entering the series-parallel switching transient stage at the next time under the condition that the entry prohibition instruction is not generated, correcting the first threshold according to a fourth difference between the second output power and the first output power. In the condition that the exit instruction is not generated, if the second attenuation rate of the battery charging and discharging power is greater than the preset rate threshold, and the vehicle demand power and the third output power are both greater than the second actual output power in the next time maintaining the parallel mode, the second threshold is corrected according to a sixth difference value between the third output power and the fourth output power.

5. The hybrid vehicle drive mode control method according to claim 3, characterized by, The method further comprises: In the condition that the exit instruction is not generated, if the second attenuation rate of the battery charging and discharging power is greater than the preset rate threshold, and the vehicle demand power and the third output power are both greater than the second actual output power in the next time maintaining the parallel mode, the second threshold is corrected according to a sixth difference value between the third output power and the fourth output power.

6. The hybrid vehicle drive mode control method according to claim 1, characterized by, The monitoring manner of the acceleration intention comprises: Obtaining environment information, the environment information comprising first obstacle information within a preset first distance in front of a driving path and second obstacle information within a preset second distance on left and right sides of the hybrid vehicle; If neither the first obstacle information nor the second obstacle information shows an obstacle, and the driving speed is less than a preset speed threshold and the throttle opening is less than a preset opening threshold, it is determined that the driver has the acceleration intention, wherein the speed information comprises the driving speed and the throttle opening, and the speed threshold is in a positive correlation with the first distance and the second distance, respectively.

7. The hybrid vehicle drive mode control method according to claim 1, characterized by, The method further comprises: Determining a target acceleration according to the speed information, the road condition information and a preset acceleration mapping table, wherein the acceleration mapping table is constructed based on a multi-dimensional corresponding relationship among speed information, road condition information and acceleration, the speed information comprising driving speed, throttle opening and throttle opening change rate, and the road condition information comprising road speed limit value and road slope; Calculating the driving speed, the target acceleration and a preset time step to obtain a target vehicle speed in the next time; Determining the vehicle demand power according to the target vehicle speed.

8. The hybrid vehicle drive mode control method according to claim 7, characterized by, The method further comprises: Determining a vehicle demand torque in the next time according to the target vehicle speed and a pre-constructed driving resistance model, and determining a wheel angular velocity in the next time according to the target vehicle speed, wherein the driving resistance model is constructed by rolling resistance, slope resistance and air resistance; Determining the vehicle demand power according to the vehicle demand torque and the wheel angular velocity.

9. A hybrid vehicle drive mode control system characterized by comprising: The system comprises: An acquisition module, configured to acquire a driving condition of the hybrid vehicle in a current time, the driving condition comprising speed information, road condition information, battery power and driving mode, the driving mode comprising series mode and parallel mode; A calculation module, configured to, if it is monitored that the driver has an acceleration intention and the battery power is lower than a preset power threshold, determine a vehicle power parameter in the next time according to the speed information and the road condition information, wherein the vehicle power parameter comprises target vehicle speed, vehicle demand torque and vehicle demand power. The control module is configured to generate an entry prohibition instruction of the parallel mode if the driving mode is the series mode and a first output power at a next moment when entering a series-parallel switching transient stage is less than a second output power when maintaining the series mode. The control module is further configured to generate an exit instruction of the parallel mode if the driving mode is the parallel mode and both the vehicle demand power and a third output power when switching to the series mode at the next moment are greater than a fourth output power when maintaining the parallel mode. The control module is further configured to acquire working parameters of the powertrain, the working parameters including a charging power and a charging efficiency of the battery; if the driving mode is the series mode, to predict a fifth output power of the generator when entering the series-parallel switching transient stage at the next moment according to the target vehicle speed and the vehicle demand torque; to calculate the fifth output power and the charging efficiency to obtain a third calculation result; and to generate the entry prohibition instruction if a third difference between the third calculation result and the charging power is greater than a preset third threshold.

10. A hybrid vehicle characterized by comprising: The controller is configured to generate a control instruction of the hybrid vehicle according to a driving condition at a current moment and an acceleration intention of a driver, wherein the control instruction includes an entry prohibition instruction or an exit instruction of the parallel mode in the driving mode. The power system is in communication connection with the controller and is configured to receive and respond to the entry prohibition instruction to prohibit the hybrid vehicle from entering the parallel mode, or to receive and respond to the exit instruction to make the hybrid vehicle exit the parallel mode to realize the control of the driving mode. ​

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