Dual-motor hybrid system mode switching control method and system

Abstract

The application discloses a dual-motor hybrid system mode switching control method and system, and belongs to the technical field of dual-motor hybrid technology. The method comprises the following steps: acquiring a vehicle basic target mode request and road state information; and determining whether to execute switching to the basic target mode based on the road state information. Since the road state is considered in the mode switching decision process, the execution of the switching action is no longer dependent only on the vehicle's own power parameters, but can be adaptively judged according to the actual conditions of the current road. When the road state is not suitable for executing mode switching, the method can correspondingly delay or prohibit switching, thereby avoiding clutch engagement or power path change on uneven or disturbed road surfaces, effectively reducing the superposition of road excitation and disturbance generated by the switching action, and further reducing the jerk and body vibration in the mode switching process, and improving the switching smoothness of the dual-motor hybrid system and the overall vehicle ride comfort under different road conditions.

Description

Technical Field

[0001] This application relates to the field of dual-motor hybrid technology, specifically to a mode switching control method and system for dual-motor hybrid systems. Background Technology

[0002] With the development of hybrid vehicle technology, dual-motor hybrid, series-parallel hybrid, and multi-speed hybrid systems have been widely used. These systems typically offer multiple operating modes, including pure electric mode, series mode, parallel mode, engine direct drive mode, parking generator mode, and energy recovery mode. The mode switching strategy usually determines the target mode based on parameters such as vehicle speed, battery state of charge, power demand, throttle opening, and battery charging / discharging capacity, aiming to balance power, economy, and comfort. However, in actual operation, mode switching can easily cause jerking and vibration, affecting driving comfort. Summary of the Invention

[0003] This application provides a method and system for controlling mode switching in a dual-motor hybrid system, which aims to reduce jerking and vibration during mode switching and improve driving comfort by controlling the mode switching of the dual-motor hybrid system in advance.

[0004] According to a first aspect of this application, a mode switching control method for a dual-motor hybrid system is provided, comprising the following steps: Obtain the vehicle's basic target pattern request; Obtain road condition information, which includes current road condition information; the current road condition information includes at least one of continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics. Based on the road status information, determine whether to switch to the basic target mode.

[0005] In some embodiments, determining whether to switch to the basic target mode based on the road state information includes: Based on the current road status information, the current road risk level is determined; Based on the current road risk level, determine whether to switch to the basic target mode.

[0006] In some embodiments, determining the current road risk level based on the current road state information includes: Based on the aforementioned continuous vibration characteristics, determine the continuous vibration risk level; and / or, Based on the instantaneous impact characteristics, determine the instantaneous impact risk level; and / or, Based on the aforementioned left-right response difference characteristics, the risk level of the left-right response difference is determined; The current road risk level includes one of the following: no risk, low risk, medium risk, and high risk.

[0007] In some embodiments, the continuous vibration risk level is included in a preset first risk level set, which includes at least one of: no continuous vibration risk, low continuous vibration risk, medium continuous vibration risk, and high continuous vibration risk. The instantaneous impact risk level is included in a preset second risk level set, which includes at least one of the following: no instantaneous impact risk, low instantaneous impact risk, medium instantaneous impact risk, and high instantaneous impact risk. The left-right response difference risk level is included in a preset third risk level set, which includes at least one of: no left-right response difference risk, low left-right response difference risk, medium left-right response difference risk, and high left-right response difference risk. In some embodiments, the absence of risk includes: the absence of continuous vibration risk, the absence of instantaneous impact risk, and the absence of left-right response difference risk; The low risk includes at least one of the low continuous vibration risk, the low instantaneous impact risk, and the low left-right response difference risk, and does not include the medium risk or the high risk. The medium risk includes at least one of the medium continuous vibration risk, the medium instantaneous impact risk, and the medium left-right response difference risk, and there is no high risk; The high risk includes at least one of the following: high continuous vibration risk, high instantaneous impact risk, and high left-right response difference risk.

[0008] In some embodiments, determining the continuous vibration risk level based on the continuous vibration characteristics includes: Within a sliding time window, the vertical acceleration, pitch rate, and yaw rate of the vehicle are acquired, and the root mean square values ​​of the vertical acceleration, pitch rate, and yaw rate are determined. Based on the root mean square values ​​of the vertical acceleration, the pitch angular velocity, and the yaw angular velocity, the continuous vibration excitation index is obtained. The continuous vibration risk level is determined based on the magnitude of the continuous vibration excitation index.

[0009] In some embodiments, determining the instantaneous impact risk level based on the instantaneous impact characteristics includes: Within the sliding time window, the current vertical acceleration and pitch rate of the vehicle are obtained, and the rate of change of vertical acceleration is obtained based on the vertical acceleration. Whether a single impact event has occurred is determined based on at least one of the vertical acceleration, the pitch angular velocity, and the rate of change of vertical acceleration. The instantaneous impact risk level is determined by statistically analyzing the number of individual impact events and the cumulative impact intensity.

[0010] In some embodiments, determining the risk level of the left-right response difference based on the left-right response difference characteristics includes: Obtain the left wheel speed, right wheel speed, vehicle longitudinal speed, steering wheel angle or front wheel angle, and yaw rate; determine the wheel speed difference between the left wheel speed and the right wheel speed, and the theoretical wheel speed difference between the left and right wheels. Based on at least one of the following: the deviation of the wheel speed difference between the left and right wheels from the theoretical wheel speed difference, and the deviation of the yaw rate from the theoretical yaw rate, a risk index for left and right response difference is obtained. The risk level of the left and right response difference is determined based on the magnitude of the left and right response difference risk index.

[0011] In some embodiments, determining whether to switch to the basic target mode based on the current road risk level includes: Based on the current road risk level, a gating status is determined, which includes one of the following: allowing switching, delaying switching, and prohibiting switching. Based on the gating state, determine whether to switch to the basic target mode.

[0012] In some embodiments, the current road risk level includes one of no risk, low risk, medium risk, and high risk; determining the gate status based on the current road risk level includes: If the current road risk level is either no risk or low risk, it is determined that switching is permitted; If the current road risk level is medium risk, a delayed handover is determined; If the current road risk level is classified as high risk, switching is prohibited.

[0013] In some embodiments, the road status information further includes road ahead attribute information; The process of determining the gate control status based on the current road risk level also includes: Obtain the attribute information of the road ahead; If the attribute information of the road ahead is obtained and the current road risk level is no risk or low risk, an advance mode switching request is generated based on the attribute information of the road ahead. Upon receiving the advance mode switching request, and if the current road risk level is either no risk or low risk, an advance switch is determined.

[0014] In some embodiments, generating an advance mode switching request based on the preceding road attribute information includes: Obtain the predicted vehicle speed on the road ahead; Based on the road ahead attribute information and the predicted vehicle speed, the first working mode of the target road is determined; If the basic target mode request is inconsistent with the first working mode, an advance mode switching request is generated.

[0015] In some embodiments, the early switching includes: If the distance or time between the vehicle and the target road segment meets preset conditions, the vehicle switches to the preferred working mode before entering the target road segment.

[0016] In some embodiments, the delay switching includes: If the current road risk level drops to no risk or low risk during the delay period, the allowed switch will proceed. If the current road risk level rises to the high risk level during the delay period, the switching will be prohibited. If the driver's power demand exceeds the current operating mode's capacity during the delay period, the system will switch to a permissible mode and limit the rate of torque change.

[0017] In some embodiments, the inability to switch includes: In the gated state where switching is prohibited, it is prohibited to perform operating mode switching involving changes in the clutch state of the dual-motor hybrid system; When the current road risk level drops to medium risk, low risk, or no risk, or when the current working mode cannot meet basic power requirements, the prohibition on switching will be lifted.

[0018] According to a second aspect of this application, a dual-motor hybrid system mode switching control system is also provided. The system includes a first acquisition module, a second acquisition module, and a determination module. The first acquisition module is used to acquire a vehicle basic target mode request. The second acquisition module is used to acquire road state information, which includes current road state information. The current road state information includes at least one of continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics. The determination module is used to determine whether to perform a switch to the basic target mode based on the road state information.

[0019] This application provides a mode switching control method and system for a dual-motor hybrid system. The control method includes the following steps: obtaining a vehicle basic target mode request; obtaining road state information, including current road state information; the current road state information includes at least one of continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics; and determining whether to switch to the basic target mode based on the road state information. The method of this application, by incorporating consideration of road conditions into the mode switching decision process, ensures that the execution of the switching action no longer depends solely on the vehicle's own power parameters, but can adaptively judge based on the actual road conditions. Therefore, when the road conditions are unsuitable for mode switching, the method can delay or prohibit the switching accordingly, thereby avoiding clutch engagement or power path changes on uneven or disturbed road surfaces. This effectively reduces the superposition of disturbances caused by road excitation and switching actions, thereby reducing the jerking sensation and vehicle vibration during mode switching, and improving the smoothness of switching and overall vehicle ride comfort of the dual-motor hybrid system under different road conditions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a mode switching control method for a dual-motor hybrid system provided in an exemplary embodiment of this application; Figure 2 This is a system block diagram of a dual-motor hybrid system provided by an exemplary embodiment of this application; Figure 3 This is a flowchart illustrating the logic of obtaining the basic target mode of a vehicle in a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application. Figure 4 This is a schematic diagram illustrating the process of determining whether to switch to the basic target mode based on the current road state information in a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application. Figure 5 This is a flowchart illustrating the determination of continuous vibration risk level based on continuous vibration characteristics in a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application. Figure 6 This is a flowchart illustrating a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application, which determines the instantaneous impact risk level based on instantaneous impact characteristics. Figure 7 This is a flowchart illustrating the process of determining the risk level of the left and right response difference based on the characteristics of the left and right response difference in a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application. Figure 8 This is a schematic diagram illustrating the process of determining whether to switch to the basic target mode based on the current road risk level in a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application; Figure 9 This is a schematic diagram of the process of generating a gating state based on the current road risk level and the attribute information of the road ahead, according to an exemplary embodiment of the present application, for a mode switching control method for a dual-motor hybrid system. Figure 10 This is an overall logic flowchart of a mode switching control method for a dual-motor hybrid system provided by an exemplary embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0025] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0026] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0027] In related technologies, with the development of hybrid vehicle technology, dual-motor hybrid, series-parallel hybrid, and multi-speed hybrid systems have been widely used. These systems typically have multiple operating modes, including pure electric mode, series mode, parallel mode, engine direct drive mode, parking generator mode, and energy recovery mode. The mode switching strategy primarily determines the target mode based on parameters such as vehicle speed, SOC (state of charge), power demand, throttle opening, and battery charging / discharging capacity, to balance power, economy, and comfort.

[0028] For example, mode switching mainly includes three categories: 1) Rule-based mode switching based on vehicle speed, SOC, and power requirements; 2) Predictive energy management based on navigation, future vehicle speed, gradient, or traffic information; 3) Switching shock suppression based on coordinated control of engine, motor and clutch.

[0029] However, the above solutions mainly focus on when the conditions for switching power or economy are met and how to reduce the impact during the switching process. They do not determine whether the request is suitable for immediate execution based on the current road incentives or the abnormal road risks ahead after the target mode request is generated and before execution.

[0030] In view of this, embodiments of this application provide a mode switching control method and system for a dual-motor hybrid system, which aims to solve at least one of the above problems.

[0031] This application provides a mode switching control method for a dual-motor hybrid system, which can be executed by a vehicle controller, a hybrid controller, or a motor controller. Wherein, for example... Figure 2 As shown, the dual-motor hybrid system includes an engine, a P2 motor, a P3 motor, a C1 clutch, a C2 clutch, and a power battery. The P3 motor is connected to the wheels via a reduction gear; the P2 motor is connected to the front axle reducer via the C2 clutch; the engine is connected to the front axle reducer via both the C1 and C2 clutches; the engine can also connect to the P2 motor via only the C1 clutch to achieve range-extending power generation. By controlling the engagement and disengagement of the C1 and C2 clutches, this dual-motor hybrid system can achieve various operating modes, such as single-motor pure electric mode, dual-motor pure electric mode, series range-extending mode, and parallel direct drive mode.

[0032] Please refer to the following: Figure 1 and Figure 10 The mode switching control method for a dual-motor hybrid system includes the following steps S100 to S300.

[0033] S100: Request for vehicle basic target mode.

[0034] In this embodiment, the basic target mode request refers to a target operating mode generated based on the vehicle's conventional power parameters. These power parameters include, but are not limited to, vehicle speed, battery state of charge (SBC), driver torque request, accelerator pedal opening, brake pedal opening, and maximum battery charging / discharging power. The basic target mode request is generated by a basic energy management strategy, reflecting current power and economy requirements. For example, when the battery SBC is high and the vehicle speed is low, the basic target mode request may be a pure electric mode; when the battery SBC is low and the vehicle speed is high, the basic target mode request may be an engine direct drive mode or a parallel mode. This embodiment does not limit the specific method of generating the basic target mode request; any suitable method in the prior art can be used.

[0035] For details, please refer to Figure 3 The request to obtain the vehicle basic target mode in this embodiment may include the following steps S110 to S130.

[0036] S110: The controller first obtains the vehicle's current speed, the battery's state of charge, the driver's required torque (calculated from the accelerator pedal opening), and the battery's maximum charging and discharging power. Then, it determines the basic target mode request according to the following rules.

[0037] S120: Determine whether the battery state of charge and battery charging / discharging capacity meet the requirements of pure electric drive. If the battery state of charge is high, for example, above a preset threshold (which could be 30%), and the battery's allowable discharge power can cover the driver's required torque, then enter the pure electric mode candidate range; otherwise, the engine needs to be started to enter hybrid mode.

[0038] S121: Within the pure electric mode candidate range, further determine whether the driver's required torque is low. If the required torque is low, for example, below the motor's high-efficiency range or below a certain torque threshold, then select the single-motor pure electric mode, with only the P3 motor driving the wheels to reduce energy consumption. If the required torque is high, then select the dual-motor pure electric mode, with both the P2 and P3 motors driving the wheels together to meet the power requirements.

[0039] S122: When the battery's state of charge or charging / discharging capacity is insufficient to support pure electric drive, the controller enters the hybrid mode candidate range. At this point, it further determines whether to select series range extender mode or parallel direct drive mode based on vehicle speed and required torque. Generally, when the vehicle speed is low, such as below a certain speed threshold, and the required torque is high, series range extender mode is preferentially selected. The engine drives the P2 motor to generate electricity, and the P3 motor drives the wheels, ensuring the engine operates in its high-efficiency range. When the vehicle speed is high, such as exceeding the speed threshold, and the required torque is stable, parallel direct drive mode is preferentially selected. The engine directly participates in driving, while the P2 and P3 motors assist in driving or generate electricity as needed to improve transmission efficiency.

[0040] In addition, special cases such as parking power generation mode and energy recovery mode can be considered, but will not be discussed here.

[0041] Based on the above rules, the controller generates a basic target pattern request according to the real-time vehicle status. This request serves as one of the inputs for subsequent road risk gating decisions.

[0042] S200: Obtain road status information.

[0043] Road condition information reflects the excitation conditions of the road surface the vehicle is currently traveling on or the attribute characteristics of the road ahead. Road condition information can originate from various onboard sensors or external data sources. For example, a six-axis inertial measurement unit can acquire signals such as vertical acceleration, longitudinal acceleration, lateral acceleration, pitch rate, yaw rate, and roll rate to identify the smoothness, bumpiness, and adhesion uniformity of the current road. Furthermore, navigation maps, vehicle-to-everything (V2X) systems, cameras, or LiDAR can be used to obtain attribute information about the road ahead, such as road type, road length, speed limit, and traffic flow speed. The road type can include various types such as highways, long uphill slopes, long downhill slopes, sharp curves, and ramps.

[0044] In this embodiment, the road condition information includes at least current road condition information. Current road condition information may include at least one of continuous vibration characteristics, instantaneous impact characteristics, or left-right response difference characteristics. The specific extraction methods for these features will be described in subsequent embodiments.

[0045] S300: Based on road condition information, determine whether to switch to the basic target mode.

[0046] This application's embodiments do not simply execute the switch directly based on the basic target mode request, but instead use road conditions as a gating condition. The controller determines whether the current road conditions are suitable for mode switching based on the acquired road condition information, and accordingly decides to allow the switch, delay the switch, prohibit the switch, or switch ahead of schedule.

[0047] Specifically, when road condition information indicates a smooth road surface (e.g., no significant bumps, no impacts, and consistent left and right adhesion), the controller allows switching to the basic target mode. When road condition information indicates moderate continuous vibration, transient impacts, or differences in left and right response, the controller delays switching, waiting for road conditions to improve before making a judgment. When road condition information indicates dangerous conditions such as high-intensity bumps, strong impacts, or low adhesion, the controller prohibits switching and maintains the current operating mode. When road condition information includes the attributes of the road ahead and the current road conditions are smooth, the controller can generate a switching request in advance, completing mode adaptation before entering special road sections.

[0048] Through the above steps, this embodiment incorporates road conditions into the mode switching decision-making process, so that the execution of the switching action no longer depends solely on the vehicle's own power parameters, but can make adaptive judgments based on actual road conditions. This helps avoid clutch engagement or power path changes on uneven or disturbed road surfaces, reduces the superposition of disturbances caused by road excitation and switching actions, thereby reducing the jerking sensation and vehicle vibration during mode switching and improving driving comfort.

[0049] In some embodiments, the road state information includes at least current road state information. Current road state information includes at least one of continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics. These characteristics correspond to different types of road excitation conditions and can characterize the impact of the current road surface on vehicle attitude and stability from different dimensions.

[0050] Specifically, continuous vibration characteristics are used to characterize the medium-to-high frequency excitation continuously applied to vehicles by the road surface. Typical scenarios include continuous rough roads, wavy roads, washboard roads, and continuous moderately bumpy roads. Under these road conditions, the vehicle's vertical acceleration, pitch velocity, and yaw velocity will exhibit continuous fluctuations. By extracting the statistical characteristics of these signals within a sliding time window, such as the root mean square value, the intensity of continuous vibration can be quantified, thereby determining whether the current road surface belongs to a continuous vibration type road condition.

[0051] Instantaneous impact characteristics are used to characterize short-duration peak excitations on the road surface. Typical scenarios include speed bumps, potholes, bridge joints, and protruding manhole covers. Under these road conditions, the vehicle's vertical acceleration and pitch velocity will exhibit instantaneous spikes, and the rate of change of vertical acceleration will also increase significantly. By detecting the peak values ​​and durations of these signals, individual impact events can be identified, and their frequency and cumulative intensity within a time window can be statistically analyzed to determine whether there is an instantaneous impact risk on the current road surface.

[0052] The left-right response difference feature is used to characterize the inconsistency in road surface adhesion or excitation experienced by the left and right wheels of a vehicle. Typical scenarios include low-adhesion surfaces (such as icy or snowy surfaces) and surfaces with inconsistent left-right adhesion (such as unilateral icing or unilateral potholes). Under these road conditions, abnormal differences will occur in the wheel speeds of the left and right wheels, resulting in a deviation between the actual yaw rate and the theoretical yaw rate calculated based on steering geometry. The lateral acceleration may also deviate from the theoretical value. By calculating these deviations, the risk of left-right response difference can be quantified, and it can be determined whether the current road surface may lead to vehicle instability or traction control problems.

[0053] In this embodiment, the controller can select one or more of the three features mentioned above for identification based on vehicle configuration and actual needs. For example, for vehicles that mainly travel on paved roads, continuous vibration and instantaneous impact features can be prioritized; for vehicles that frequently travel on complex road surfaces, such as mountainous or icy areas, left-right response difference features can be configured simultaneously. When multiple features are selected, the controller can calculate the risk level of each feature separately and obtain a comprehensive current road risk level through a preset fusion rule, such as taking the highest risk level, for subsequent gating judgment.

[0054] This application embodiment concretizes the current road state information into the three features mentioned above, enabling the system to identify road excitation conditions from different dimensions and providing a more accurate and comprehensive basis for mode switching gating decisions. The specific signal processing and risk level calculation methods corresponding to different features will be described in detail in subsequent embodiments.

[0055] Please refer to the following: Figure 4 and Figure 10In some embodiments, step S300: Based on road state information, determining whether to switch to the basic target mode, includes the following steps S310 and S320.

[0056] In this embodiment, after obtaining the current road state information, the controller needs to determine whether to switch to the basic target mode based on this information. Specifically, this includes: S310: Determine the current road risk level based on current road condition information.

[0057] The controller calculates the current road risk level based on at least one of the previously acquired continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics. The current road risk level includes four levels: no risk, low risk, medium risk, and high risk.

[0058] No risk indicates that the current road conditions are good, there is no obvious continuous vibration, instantaneous impact or difference in left and right response, the vehicle is driving smoothly, and any mode switching action will not be significantly affected by road disturbances.

[0059] Low risk indicates that there are minor, continuous vibrations, transient shocks, or differences in left-right response on the road, but the disturbance is small enough not to have a substantial negative impact on the mode switching process. At this level, performing a mode switch is still acceptable.

[0060] Medium risk indicates that there is moderate continuous vibration, instantaneous impact, or left-right response difference on the road, and road disturbances have begun to affect vehicle attitude and driving stability. If a mode switch is performed at this level, the road disturbances and the disturbances generated by the switching action may be superimposed, posing a risk of jerking or vibration, so caution is required.

[0061] High risk indicates that the current road surface experiences high-intensity continuous vibration, strong impact, or significant inconsistency in left and right adhesion, which may cause noticeable fluctuations or instability in the vehicle's posture. Performing actions involving changes in clutch status or power path switching at this level is highly likely to cause severe vehicle jerking, body swaying, or even loss of traction control; any unnecessary mode switching should be avoided.

[0062] The specific method for determining the current road risk level will be described in detail in subsequent embodiments. In summary, the controller can calculate the continuous vibration risk level, the instantaneous impact risk level, and the left-right response difference risk level separately, and then obtain a comprehensive current road risk level according to a preset fusion rule, such as taking the highest level or weighting according to priority. For example, when the continuous vibration risk is low, the instantaneous impact risk is no risk, and the left-right response difference risk is no risk, the current road risk level is low; when any single risk reaches medium risk and there is no high risk, the current road risk level is medium; when any single risk reaches high risk, the current road risk level is high.

[0063] S320: Based on the current road risk level, determine whether to switch to the basic target mode.

[0064] After obtaining the current road risk level, the controller determines whether to switch to the basic target mode based on that level. The basic decision-making rules are as follows: When the current road risk level is no risk or low risk, the controller allows the switching to proceed. At this time, the road conditions are suitable for mode switching, and the controller executes actions such as clutch engagement or disengagement, engine start / stop, and motor torque coordination according to the basic mode switching procedure to achieve the transition to the basic target mode.

[0065] When the current road risk level is medium, the controller does not immediately perform a switchover, but instead enters a delayed waiting state. During the delay, the controller continuously monitors the current road risk level. If the risk level drops to low risk or no risk, a switchover is performed; if the risk level rises to high risk, a switchover is prohibited; if the driver's power demand exceeds the current operating mode's capacity, a switchover is allowed in a restricted manner with a limited torque change rate.

[0066] When the current road risk level is high, the controller prohibits switching. The controller maintains the current operating mode and does not perform any actions involving changes in clutch status or rapid engine engagement until the risk level drops to medium, low, or no risk, or the current operating mode can no longer meet basic power requirements, at which point the prohibition is lifted.

[0067] Through the aforementioned steps S310 and S320, this embodiment uses the current road risk level as the core basis for switching decisions, achieving differentiated processing for different road conditions. Compared to schemes that rely solely on power parameters such as vehicle speed and battery state of charge for switching decisions, this embodiment can proactively avoid the jerking and vibration problems caused by switching under unsuitable road conditions, thereby improving the smoothness of mode switching and the overall driving comfort of the vehicle.

[0068] In some embodiments, the controller first calculates the continuous vibration risk level, the instantaneous impact risk level, and the left-right response difference risk level based on various characteristics in the current road condition information. Details are as follows.

[0069] Based on continuous vibration characteristics, a continuous vibration risk level is determined, which is included in a preset first risk level set, including at least one of: no continuous vibration risk, low continuous vibration risk, medium continuous vibration risk, and high continuous vibration risk; and / or, based on instantaneous impact characteristics, an instantaneous impact risk level is determined, which is included in a preset second risk level set, including at least one of: no instantaneous impact risk, low instantaneous impact risk, medium instantaneous impact risk, and high instantaneous impact risk; and / or, based on left-right response difference characteristics, a left-right response difference risk level is determined, which is included in a preset third risk level set, including at least one of: no left-right response difference risk, low left-right response difference risk, medium left-right response difference risk, and high left-right response difference risk.

[0070] Furthermore, the continuous vibration risk level, instantaneous impact risk level, and left-right response difference risk level each include four possible values: no risk, low risk, medium risk, and high risk.

[0071] Specifically, for continuous vibration characteristics, the controller classifies the corresponding continuous vibration risk levels as: no continuous vibration risk, low continuous vibration risk, medium continuous vibration risk, and high continuous vibration risk. No continuous vibration risk means that there is almost no continuous vertical or pitch excitation from the road surface; low continuous vibration risk means that there are slight fluctuations in the road surface, but they do not affect the basic stability of the vehicle; medium continuous vibration risk means that there are obvious continuous bumps in the road surface, which may cause vehicle body vibration; high continuous vibration risk means that there is severe continuous excitation from the road surface, and the vehicle attitude fluctuates greatly.

[0072] For transient impact characteristics, the controller classifies their corresponding risk levels as: no transient impact risk, low transient impact risk, medium transient impact risk, and high transient impact risk. No transient impact risk means that no valid impact event was detected within the sliding time window; low transient impact risk means that a few low-intensity impact events were detected; medium transient impact risk means that multiple or medium-intensity impact events were detected; and high transient impact risk means that frequent or high-intensity impact events were detected.

[0073] For the left-right response difference characteristic, the controller classifies its corresponding risk level into: no left-right response difference risk, low left-right response difference risk, medium left-right response difference risk, and high left-right response difference risk. No left-right response difference risk means that indicators such as the wheel speed difference between the left and right wheels and the yaw rate deviation are within the normal range; low left-right response difference risk means that there is a slight deviation, but the vehicle still remains stable; medium left-right response difference risk means that there is a significant deviation, which may affect steering or traction; high left-right response difference risk means that there is a serious deviation, and the vehicle may be on a road surface with low adhesion or inconsistent adhesion, with a risk of instability.

[0074] The specific calculation methods for each of the above-mentioned risk levels will be described separately later. After obtaining the risk levels for each sub-item, the controller synthesizes the current road risk level according to the following rules.

[0075] The current road risk level is divided into four levels: no risk, low risk, medium risk, and high risk. Their definitions are as follows: The current road risk level is considered risk-free if and only if the continuous vibration risk level is zero, the instantaneous impact risk level is zero, and the left-right response difference risk level is zero. In other words, the current road is considered risk-free only when no risk is detected in any of the three sub-items.

[0076] The current road risk level is low. This means that at least one of the following risk components—continuous vibration risk, instantaneous impact risk, and left-right response difference risk—is at least low, i.e., at least one of these three risks is present, and there are no medium or high risks. In other words, the current road risk level is low only if all risk components are no higher than low and at least one is low. For example, if the continuous vibration risk level is low, the instantaneous impact risk level is no instantaneous impact risk, and the left-right response difference risk level is no left-right response difference risk, then the overall risk level is low. Similarly, if the continuous vibration risk level is low, the instantaneous impact risk level is low, and the left-right response difference risk level is no left-right response difference risk, this also constitutes a low risk level.

[0077] The current road risk level is medium risk. This is defined as the presence of at least one medium-level component risk among the continuous vibration risk level, instantaneous impact risk level, and left-right response difference risk level, meaning at least one of these three risk categories (medium continuous vibration risk, medium instantaneous impact risk, or medium left-right response difference risk) exists, and there is no high-risk component. In other words, as long as at least one component reaches the medium risk level and no component reaches the high risk level, the current road risk level is medium risk. For example, if the continuous vibration risk level is medium continuous vibration risk, the instantaneous impact risk level is no instantaneous impact risk, and the left-right response difference risk level is no left-right response difference risk, then the overall risk level is medium. Similarly, if the continuous vibration risk level is medium continuous vibration risk, the instantaneous impact risk level is low instantaneous impact risk, and the left-right response difference risk level is no left-right response difference risk, this also results in a medium risk level.

[0078] The current road risk level is high. If at least one of the following risk components—continuous vibration risk, instantaneous impact risk, and left-right response difference risk—is high (i.e., high continuous vibration risk, high instantaneous impact risk, or high left-right response difference risk), then regardless of the other risk components, the current road risk level is considered high. For example, if the continuous vibration risk level is high continuous vibration risk, the instantaneous impact risk level is no instantaneous impact risk, and the left-right response difference risk level is no left-right response difference risk, then the overall risk level is high. Similarly, if the continuous vibration risk level is high continuous vibration risk, the instantaneous impact risk level is medium instantaneous impact risk, and the left-right response difference risk level is no left-right response difference risk, this is also considered high risk.

[0079] The above rules can be expressed logically as follows: the overall risk level is the highest among the risk levels of each sub-item, but a distinction needs to be made between no risk and low risk. When the highest sub-item risk is none, the overall risk level is no risk; when the highest sub-item risk is low, the overall risk level is low; when the highest sub-item risk is medium, the overall risk level is medium; when the highest sub-item risk is high, the overall risk level is high.

[0080] Through the component risk identification and comprehensive rules in this application embodiment, the controller can comprehensively and accurately assess the overall risk status of the current road, providing a reliable quantitative basis for subsequent gating decisions (permission, delay, prohibition). This multi-dimensional evaluation and comprehensive decision-making approach retains sensitivity to different types of road disturbances while avoiding erroneous decisions caused by misjudgment of a single feature.

[0081] Please refer to the following: Figure 5 and Figure 10 In some embodiments, the continuous vibration risk level is determined based on the continuous vibration characteristics, which mainly includes the following steps S311 to S313.

[0082] S311: Within the sliding time window, acquire the vehicle's vertical acceleration, pitch rate, and yaw rate, and determine the root mean square values ​​of the vertical acceleration, pitch rate, and yaw rate.

[0083] S312: Obtain continuous vibration excitation indexes based on the root mean square values ​​of vertical acceleration, pitch angular velocity, and yaw angular velocity.

[0084] S313: Determine the continuous vibration risk level based on the magnitude of the continuous vibration excitation index.

[0085] In this embodiment, the continuous vibration risk level is specifically calculated using vehicle inertial measurement signals. Specifically, continuous vibration characteristics are mainly used to identify road conditions such as continuous rough surfaces, wavy surfaces, washboard surfaces, and continuously moderately bumpy surfaces. Under these conditions, the vehicle is subjected to continuous vertical, pitch, and yaw excitations, and the acceleration and angular velocity in each direction exhibit continuous fluctuation characteristics.

[0086] The controller first acquires the vehicle's vertical acceleration, pitch rate, and yaw rate within a sliding time window. Vertical acceleration reflects the intensity of vibration in the vertical direction, pitch rate reflects the severity of pitch forward and backward, and yaw rate reflects the amplitude of lateral sway. These three signals can be obtained from the vehicle's six-axis inertial measurement unit. The sampling frequency should be high enough to ensure accurate vibration capture; for example, the sampling frequency could be 100Hz or higher. The length of the sliding time window can be calibrated according to actual needs, for example, set between 0.5 seconds and 2 seconds. The window sliding step is typically one control cycle or one sampling cycle, allowing calculations to be performed based on the latest data in each cycle. An excessively long window may reduce the timeliness of the response, while an excessively short window may result in insufficient stability in judging continuous vibrations.

[0087] After acquiring the above signals, the controller filters each of the three signals. A low-pass filter can be used to remove high-frequency noise, and a sliding mean averaging process can be applied to eliminate the influence of constant value offset. The filtered signals better reflect the true characteristics of road condition excitation.

[0088] In each control cycle, the controller calculates the root mean square (RMS) values ​​of vertical acceleration, pitch rate, and yaw rate within the current slide time window. The formula for calculating the RMS values ​​is as follows: Az=sqrt((1 / M)*Σ(a z _i^2)); Qp=sqrt((1 / M)*Σ(q_i^2)); Ry=sqrt((1 / M)*Σ(r_i^2)).

[0089] Where M is the number of sampling points within the sliding time window, az _i represents the vertical acceleration value at the i-th sampling point, q_i represents the pitch angular velocity value at the i-th sampling point, and r_i represents the yaw angular velocity value at the i-th sampling point. Az represents the root mean square value of the vertical acceleration, Qp represents the root mean square value of the pitch angular velocity, and Ry represents the root mean square value of the yaw angular velocity.

[0090] The root mean square (RMS) value can effectively reflect the average energy level of a vibration signal over a period of time, and is more representative of the intensity of continuous vibration than simply using the peak or average value.

[0091] The controller further calculates the continuous vibration excitation index G1 based on these three root mean square values. G1 can be expressed as a weighted sum of the three root mean square values: G1 = α1·Az + α2·Qp + α3·Ry.

[0092] Among them, α1, α2, and α3 are calibration weighting coefficients. The values ​​of the weighting coefficients can be determined based on the degree of influence of vibrations in each direction on ride comfort at different vehicle models and speeds. For example, vertical acceleration usually has the most direct impact on ride comfort and can be assigned a higher weight; pitch and yaw rates have relatively minor effects and can be assigned lower weights. In practical applications, calibration can be performed through real vehicle testing.

[0093] Considering the significant impact of vehicle speed on vibration intensity—the same road surface produces different excitation magnitudes at different vehicle speeds—the controller can correct G1 based on vehicle speed. Specifically, vehicle speed can be pre-divided into multiple ranges, such as a low-speed range of 0-30 km / h, a medium-speed range of 30-60 km / h, and a high-speed range of over 60 km / h. Different thresholds can be set for each speed range, or G1 can be normalized for vehicle speed. For example, a vehicle speed correction coefficient k(v) can be set so that the corrected excitation index G1' = G1 / k(v). The higher the vehicle speed, the greater the vibration produced by the same road surface roughness; therefore, the correction coefficient can increase with increasing vehicle speed.

[0094] After obtaining the continuous vibration excitation index, the controller determines the continuous vibration risk level based on the magnitude of this index. Two thresholds are pre-calibrated: a first threshold G11 and a second threshold G12, where G11... <G12。

[0095] When the continuous vibration excitation index is less than G11, it is judged as low continuous vibration risk. At this time, although there are slight fluctuations in the road surface, they are not enough to have a significant impact on the smoothness of mode switching.

[0096] When the continuous vibration excitation index is greater than or equal to G11 and less than G12, it is judged as a medium continuous vibration risk. At this time, there is obvious continuous bumping on the road surface, and the mode switching action may be superimposed on the road disturbance, producing perceptible jerking or vibration.

[0097] When the continuous vibration excitation index is greater than or equal to G12, it is considered a high risk of continuous vibration. At this time, there is strong continuous excitation on the road surface, and the vehicle attitude fluctuates significantly. Any actions involving power path switching should be avoided.

[0098] Furthermore, when the continuous vibration excitation index is below a very low threshold, it can be determined that there is no risk of continuous vibration. This very low threshold can be calibrated based on the sensor noise level and actual road conditions.

[0099] Using the method described above, the controller can convert the raw inertial measurement signal into a quantified continuous vibration risk level, providing a reliable input for judging the overall current road risk level. This method does not rely on complex road surface type identification models, has low computational requirements, and is suitable for real-time operation in on-board controllers.

[0100] Please refer to the following: Figure 6 and Figure 10 In some embodiments, the instantaneous impact risk level is determined based on the instantaneous impact characteristics, mainly including the following steps S314 to S316.

[0101] S314: Within the sliding time window, obtain the current vehicle's vertical acceleration and pitch rate, and obtain the rate of change of vertical acceleration based on the vertical acceleration.

[0102] S315: Determine whether a single impact event has occurred based on at least one of vertical acceleration, pitch rate, and rate of change of vertical acceleration.

[0103] S316: Count the number of single impact events and the cumulative impact intensity to determine the instantaneous impact risk level.

[0104] In this embodiment, vehicle inertial measurement signals are specifically used to identify single impact events and quantify the instantaneous impact risk level. Specifically, instantaneous impact characteristics are primarily used to identify road conditions such as speed bumps, potholes, bridge joints, and manhole cover protrusions. Under these conditions, vehicles experience short-duration, high-intensity peak excitation, manifested as instantaneous abrupt changes in signals such as vertical acceleration and pitch angular velocity. Unlike continuous vibration, instantaneous impacts are characterized by short duration and high amplitude.

[0105] The controller acquires the vehicle's vertical acceleration and pitch rate within a sliding time window. These two signals can be obtained from a six-axis inertial measurement unit (IMU), with a sufficiently high sampling frequency, such as 100Hz or higher, to ensure accurate capture of impact peaks. Simultaneously, the controller calculates the rate of change of vertical acceleration based on the vertical acceleration. The formula for calculating the rate of change of vertical acceleration is: jz=d(a z ) / dt≈(a z (i)-a z(i-1)) / Δt.

[0106] Among them, a z (i) represents the vertical acceleration value of the current sampling period, a z (i-1) represents the vertical acceleration value in the previous sampling period, and Δt represents the sampling period. The rate of change of vertical acceleration reflects the degree of change in vertical acceleration and is very sensitive for identifying instantaneous impacts.

[0107] In each control cycle, the controller determines whether a single impact event has occurred based on at least one of vertical acceleration, pitch rate, and rate of change of vertical acceleration. The determination criteria are as follows: An impact event is determined to have occurred when the absolute value of the vertical acceleration is greater than the first threshold A2; or, an impact event is determined to have occurred when the absolute value of the rate of change of vertical acceleration is greater than the second threshold J2; or, an impact event is determined to have occurred when the absolute value of the pitch angular velocity is greater than the third threshold Q2.

[0108] The above three conditions are OR conditions, meaning that satisfying any one of them will trigger the impact event determination. Thresholds A2, J2, and Q2 can be obtained by calibrating actual vehicles on different types of impact surfaces. For example, by collecting the peak vertical acceleration on a speed bump surface, a value slightly lower than the measured peak value can be taken as A2.

[0109] To avoid misidentifying continuous fluctuations on undulating road surfaces (such as wavy roads) as multiple impact events, the controller can further impose an effective duration constraint on impact events. Specifically, an impact event is only identified as valid if the duration of the above condition is less than a preset upper limit for impact time. If the duration exceeds this upper limit, it is considered continuous vibration rather than a momentary impact and is not counted as an impact event. This constraint helps distinguish between momentary impacts and continuous vibrations, two different types of road conditions.

[0110] After identifying a single impact event, the controller calculates the intensity index H of that impact event. The impact intensity H can be expressed as a weighted sum of the peak vertical acceleration, the peak rate of change of vertical acceleration, and the peak pitch angular velocity: H = β1·|a z | p +β2·|j z | p +β3·|q| p .

[0111] Among them, |a z | p Let |j| represent the maximum absolute value of the vertical acceleration during this impact event. z | p |q| represents the maximum absolute value of the rate of change of vertical acceleration. pis the maximum absolute value of the pitch angular velocity; β1, β2, β3 are calibrated weight coefficients. The weight coefficients can be set according to the contribution degree of each signal to the impact intensity, and generally the vertical acceleration and the rate of change of vertical acceleration provide the most direct characterization of the impact intensity.

[0112] The controller counts the number of impact events and the cumulative impact intensity within a sliding time window. Let the length of the sliding time window be T, for example, 5 seconds to 10 seconds, and the window slides forward at a fixed step size, which is usually one control cycle. Within each window, the controller counts the number of valid impact events Ns, and calculates the cumulative impact intensity Ss = ΣHi, where Hi is the intensity of the i-th impact event within the window.

[0113] Based on Ns and Ss, the controller divides the instantaneous impact risk level into low risk, medium risk and high risk. The following thresholds are calibrated in advance: When the number of impact events Ns is less than the first number threshold N21, and the cumulative impact intensity Ss is less than the first cumulative intensity threshold S21, it is determined as low instantaneous impact risk. Alternatively, it can be further subdivided into no risk and low risk, which are specifically distinguished according to whether an impact event is detected: if Ns=0 and Ss=0, it is no instantaneous impact risk; if 0<Ns<N21 and Ss<S21, it is low instantaneous impact risk.

[0114] When the number of impact events Ns reaches the first number threshold N21 but does not reach the second number threshold N22, or the cumulative impact intensity Ss reaches the first cumulative intensity threshold S21 but does not reach the second cumulative intensity threshold S22, that is, when N21≤Ns<N22 or S21≤Ss<S22, it is determined as medium instantaneous impact risk.

[0115] When the number of impact events Ns reaches the second number threshold N22, or the cumulative impact intensity Ss reaches the second cumulative intensity threshold S22, that is, N22≤Ns or S22≤Ss, it is determined as high instantaneous impact risk.

[0116] The thresholds N21, N22, S21, S22 can be calibrated through real vehicle tests on different impact roads, such as roads with a single speed bump, multiple continuous speed bumps, and potholed roads. For example, N21 can be set to 2 or 3, N22 can be set to 5 or 6; S21 and S22 are determined according to the actual distribution of the cumulative intensity.

[0117] Through the above method, the controller can convert the original inertial measurement signal into a quantified instantaneous impact risk level. Compared with the method that only uses peak detection, the embodiment of the present application can evaluate the instantaneous impact risk of the road section more comprehensively by counting the occurrence frequency and cumulative intensity of multiple impact events; through the effective duration constraint, the confusion with continuous vibration is avoided, and the recognition accuracy is improved.

[0118] Please refer to the following: Figure 7 and Figure 10 In some embodiments, the risk level of the left and right response difference is determined based on the characteristics of the left and right response difference, which mainly includes the following steps S317 to S319.

[0119] S317: Obtain the left wheel speed, right wheel speed, vehicle longitudinal speed, steering wheel angle or front wheel angle, yaw rate, and determine the wheel speed difference between the left and right wheels, and the theoretical wheel speed difference between the left and right wheels.

[0120] S318: Obtain a risk index for left and right response difference based on at least one of the following: the deviation of the wheel speed difference between the left and right wheels from the theoretical wheel speed difference, and the deviation of the yaw rate from the theoretical yaw rate.

[0121] S319: Determine the risk level of left and right response difference based on the magnitude of the risk index of left and right response difference.

[0122] In this embodiment of the application, signals such as wheel speed, steering, yaw rate and lateral acceleration are used to identify the difference in response between the left and right wheels and to quantify the risk level of the difference in response between the left and right wheels.

[0123] Specifically, the left-right response difference feature is mainly used to identify low-adhesion road surfaces (such as icy, snowy, or waterlogged roads), road surfaces with inconsistent left-right adhesion (such as unilateral icing, unilateral potholes, or unilateral shoulders), and scenarios with significant differences in excitation between the left and right road surfaces. Under these conditions, the forces or adhesion coefficients on the left and right wheels of the vehicle are inconsistent, leading to abnormal differences in wheel speeds. This results in a deviation between the actual yaw rate and the expected yaw rate calculated based on steering geometry, and the lateral acceleration may also deviate from the theoretical value. If a mode switch involving clutch engagement or changes in the power transmission path is performed under such conditions, it may exacerbate vehicle yaw, sideslip, or even instability. Therefore, it is necessary to accurately identify and assess such risks.

[0124] The controller first acquires the following signals: left wheel speed ωL, right wheel speed ωR, vehicle longitudinal speed v, steering wheel angle or front wheel angle δ, yaw rate r, and lateral acceleration ay. The left and right wheel speeds can be obtained from wheel speed sensors; the longitudinal speed can be calculated from the average wheel speed or the speed of the non-driving wheels; the steering wheel angle is obtained from an angle sensor, and if the steering system transmission ratio is known, it can be converted to the front wheel angle δ; the yaw rate and lateral acceleration can be obtained from a six-axis inertial measurement unit.

[0125] The controller performs the following calculations based on the above signals.

[0126] 1) Calculate the deviation between the actual left and right wheel speed difference and the theoretical wheel speed difference.

[0127] The controller calculates the actual speed difference between the left and right wheels: Δω = |ωL - ωR|. This value reflects the degree of inconsistency between the actual rotational speeds of the left and right wheels.

[0128] Based on the vehicle's steering geometry, the controller calculates the theoretical left and right wheel speed difference Δω0=f(v,δ). Here, f(v,δ) can be determined based on the vehicle's track width, wheelbase, steering geometry, and wheel rolling radius.

[0129] The controller further calculates the left and right wheel speed deviation Ew: Ew = |Δω - Δω0|. Ew characterizes the degree of difference between the actual wheel speed difference and the theoretical wheel speed difference. When Ew is large, it indicates that there are additional sources of wheel speed difference, such as wheel slippage or braking on one side, differences in road surface adhesion, etc., and not just the normal wheel speed difference caused by steering.

[0130] 2) Calculate the deviation between the actual yaw rate and the theoretical yaw rate.

[0131] The controller calculates the theoretical yaw rate r0 based on the vehicle's kinematics: r0 = v·tan(δ) / L.

[0132] Where v is the longitudinal vehicle speed, δ is the front wheel steering angle, and L is the wheelbase. This formula is based on the assumption that the vehicle undergoes steady-state circular motion. For higher accuracy requirements, a stability coefficient can be introduced for correction.

[0133] The controller calculates the actual yaw rate deviation Er: Er = |r - r0|. r is the actual yaw rate of the vehicle, and Er characterizes the deviation between the actual yaw response and the expected yaw response. When Er is large, it indicates that the vehicle has experienced abnormal yaw motion, which may be caused by inconsistent left and right attachments or lateral force disturbances.

[0134] 3) Optionally, calculate the lateral acceleration deviation.

[0135] The controller can also calculate the theoretical lateral acceleration a. y0 :a y0 =v·r0. This value is the lateral acceleration predicted based on the steady-state steering model. Then, the lateral acceleration deviation Ey is calculated: Ey = |a y -a y0 |. Where, a y Ey represents the actual lateral acceleration and can help verify whether anomalies in lateral force have occurred.

[0136] The controller calculates the risk index G3 for the difference between the left and right responses based on at least one of the aforementioned deviations. G3 can be expressed as a weighted sum of the deviations: G3 = γ1·Ew + γ2·Er + γ3·Ey.

[0137] Wherein, γ1, γ2, and γ3 are calibration weighting coefficients. The values ​​of each coefficient can be determined based on the importance of different deviations to vehicle stability. Typically, the left and right wheel speed deviations Ew and yaw rate deviations Er are the most direct representations of response difference and can be assigned higher weights; the lateral acceleration deviation Ey serves as an auxiliary reference and can have a relatively lower weight. If the controller only uses a portion of the deviations, such as only Ew and Er, the weighting coefficients corresponding to the unused deviations can be set to zero.

[0138] The controller classifies the risk level of the left-right response difference into low, medium, and high risk based on the magnitude of the risk index G3. Two thresholds are pre-calibrated: a first threshold G31 and a second threshold G32, where G31... <G32。

[0139] When G3 is less than G31, it is considered a low risk of left-right response difference. At this time, the left and right wheel responses are basically the same, the road surface adhesion is uniform, and the vehicle is driving stably.

[0140] When G3 is greater than or equal to G31 and less than G32, it is judged as a medium risk of left-right response difference. At this time, there is a certain degree of difference in left-right response, which may be due to a slightly slippery or locally bumpy road surface on one side. The vehicle's stability is affected to some extent, but it has not yet reached a dangerous level.

[0141] When G3 is greater than or equal to G32, it is considered a high risk of left-right response difference. At this time, the difference in left and right response is significant, and the vehicle may be on one side of ice and snow, one side of severe water accumulation, or a broken road surface, which poses a risk of instability.

[0142] Furthermore, the risk-free level can be further subdivided: when G3 is below a minimum threshold, it can be considered that there is no risk of left-right response difference, and this minimum threshold is less than G31.

[0143] It should be noted that the risk level of the left-right response difference can also be determined without relying on continuous numerical indicators, but rather by a combination of conditions. For example, when the left-right wheel speed deviation Ew exceeds a certain threshold and persists for a certain period of time, and the yaw rate deviation Er also exceeds the threshold, it is directly judged as high risk. However, the advantage of using the weighted indicator G3 is that it can integrate information from multiple dimensions and output a smooth risk level.

[0144] In this embodiment of the application, the controller can accurately identify road conditions with inconsistent left and right responses based on wheel speed, steering, yaw rate and lateral acceleration signals, and quantify the identification results into risk levels of left and right response differences.

[0145] Please refer to the following: Figure 8 and Figure 10 In some embodiments, step S320, which determines whether to switch to the basic target mode based on the current road risk level, also includes steps S321 to S322.

[0146] S321: Determine the gating status based on the current road risk level. The gating status includes one of the following: allow handover, delay handover, and prohibit handover.

[0147] S322: Based on the gating state, determine whether to perform a switch to the basic target mode.

[0148] In this embodiment, the controller first determines the current road risk level based on the current road status information. The current road risk level includes four levels: no risk, low risk, medium risk, and high risk. Based on this, the controller does not directly execute or refuse handover unconditionally according to the level, but generates a gating state as an intermediate decision quantity. The gating state includes at least one of allowing handover, delaying handover, and prohibiting handover.

[0149] Specifically, the controller determines the gating state according to the following rules.

[0150] When the current road risk level is no risk or low risk, the controller generates a gating state that allows switching. This means that the road conditions are suitable for mode switching, and the controller can execute the switching action to the basic target mode according to the basic mode switching procedure, including clutch engagement or disengagement, engine start / stop, and motor torque coordination. In the allowed switching state, the smoothness of mode switching can be guaranteed, and there will be no significant superposition between road disturbances and disturbances generated by the switching action.

[0151] Risk-free means that the risk levels for continuous vibration, instantaneous impact, and left-right response difference are all zero. At this point, the road surface is completely flat, with no perceptible vertical excitation, pitch motion, impact events, or left-right adhesion differences. The vehicle is in an ideal, stable driving state, and any mode switching action will not be affected by road disturbances; the switching process can be smoothly completed according to the basic strategy.

[0152] Low risk means that at least one low-risk component exists (e.g., low risk of continuous vibration, low risk of instantaneous impact, or low risk of left-right response difference), and there are no medium or high risks. In this case, there may be slight road surface fluctuations or very few low-intensity impacts, but the disturbance amplitude is small and the duration is short, insufficient to substantially affect the vehicle's attitude. Under these conditions, the combined effect of road disturbances and the disturbance caused by the switching action can be ignored, and the smoothness of the switch can still be guaranteed. Therefore, allowing the switch is a reasonable and safe choice.

[0153] In practical applications, when a gating state that allows switching is generated, the controller directly confirms that the basic target mode request is valid, and performs actions such as clutch engagement or disengagement, engine start / stop, and motor torque coordination according to the basic mode switching process to complete the transition to the target working mode.

[0154] When the current road risk level is medium risk, the controller generates a delayed switching gating state. This means that the current road has moderate continuous vibration, instantaneous impact, or left-right response differences, and immediate switching might cause noticeable jerking or vibration. In the delayed switching state, the controller does not immediately execute the basic target mode request, but maintains the current operating mode and enters a preset delay waiting period. During the delay, the controller continues to monitor changes in the current road risk level. If the risk level drops to no risk or low risk, it switches to allowing switching and executes the switch; if the risk level rises to high risk, it switches to prohibiting switching; if the driver's power demand exceeds the capacity of the current operating mode, such as rapid acceleration causing insufficient torque in the current pure electric mode, the controller may allow a limited switching, but must limit the rate of torque change to reduce impact.

[0155] Medium risk means there is at least one medium-level risk component (e.g., medium-level continuous vibration risk, medium-level instantaneous impact risk, or medium-level left-right response difference risk), but no high risk. At this point, there are obvious continuous bumps on the road surface, multiple moderate-intensity impact events, or significant left-right response differences; road disturbances can already have a perceptible impact on vehicle stability. If a mode switch is performed immediately under these conditions, the road disturbances and the impacts generated by clutch engagement or changes in the power path may superimpose, causing a jerking sensation or vehicle vibration.

[0156] When the current road risk level is high, the controller generates a gating state prohibiting switching. High risk means the existence of at least one high-risk component, such as high continuous vibration risk, high instantaneous impact risk, or high left-right response difference risk. This means that the road experiences high-intensity continuous vibration, strong impact, or significant left-right adhesion inconsistency, and performing a switch involving changes in clutch status or rapid engine intervention may cause vehicle instability or severe jerking. In the prohibited switching state, the controller maintains the current operating mode and does not perform any operating mode switch involving changes in clutch status until the risk level drops to medium risk, low risk, or no risk, or until the current operating mode can no longer meet basic power requirements, at which point the prohibited state is lifted.

[0157] After generating the gating state, the controller determines whether to switch to the basic target mode based on the gating state. Specifically, when the gating state is "allow switching," the controller performs the switch; when the gating state is "delayed switching," the controller postpones the switch and enters the delay processing flow; when the gating state is "disallowed switching," the controller refuses to perform the switch and maintains the current mode.

[0158] Using the above method, the controller can perform the switching normally when the current road risk is low, cautiously delay it when the risk is medium, and decisively prohibit it when the risk is high. This effectively avoids the jerking, vibration, or even instability caused by performing mode switching under unsuitable road conditions. Compared with solutions that rely solely on torque coordination during the switching process to improve smoothness, this embodiment starts with the timing of switching confirmation, avoiding the superposition of road disturbances and switching disturbances from the source, thus achieving a more fundamental improvement effect.

[0159] In some embodiments, road condition information includes not only current road condition information but also forward road attribute information. Forward road attribute information reflects the characteristics of the road segment the vehicle is about to enter, such as road attribute labels, the length of the road segment, speed limits, and real-time traffic flow speeds. Road attribute labels include ordinary roads, highways, long uphill slopes, long downhill slopes, continuous rough road surfaces, speed bumps, potholes, construction zones, sharp curves, and ramps. This information can be obtained through navigation maps, vehicle-to-everything (V2X) systems, onboard cameras, or LiDAR. The controller continuously acquires road attribute information within a certain distance range ahead during vehicle operation and determines whether to use this information for advance planning based on the current road risk level.

[0160] It should be noted that the use of road attribute information ahead is conditional, namely, the current road risk level must be in a state that allows for proactive planning. Specifically, the controller will only consider generating an early mode switching request based on the road attribute information ahead when the current road risk level is no risk or low risk. If the current road risk level is medium risk or high risk, the controller will prioritize processing the current road conditions and will not generate an early switching request.

[0161] For details, please refer to the following: Figure 9 and Figure 10 Based on the current road risk level, the generation of the gating status also includes the following steps: First, obtain the attribute information of the road ahead.

[0162] S3211: The controller obtains road attribute information ahead from the navigation map or vehicle networking system.

[0163] The acquired information includes at least road attribute labels, such as long uphill slopes, long downhill slopes, continuous rough road surfaces, speed bumps, and sharp curves. Additionally, it can acquire the distance from the starting point of the road segment to the current vehicle's position, the length of the road segment, the speed limit for that segment, and the real-time traffic flow speed. This information is used to subsequently determine the optimal operating mode. The controller can acquire road information within a certain distance ahead in advance and process it sequentially from nearest to farthest.

[0164] Then, generate an advance mode switching request.

[0165] S3212: When the attribute information of the road ahead is obtained and the current road risk level is no risk or low risk, generate an advance mode switching request based on the attribute information of the road ahead.

[0166] An advance mode switch request is an intermediate instruction that indicates that the vehicle should adjust its operating mode before entering the target road segment in order to pass through the segment in the optimal mode.

[0167] Then, the pre-switched gating state is generated.

[0168] S3213: Upon receiving an advance mode switching request and if the current road risk level is no risk or low risk, determine to switch in advance; at this time, the gating status includes at least one of the following: allow switching, delay switching, prohibit switching, and advance switching.

[0169] Specifically, after generating an early mode switch request, the controller also needs to check whether the current conditions are suitable for immediate early switchover. The generation of an early switchover gating state requires two conditions to be met simultaneously: first, an early mode switch request has been received; second, the current road risk level is still no risk or low risk. When both conditions are met, the controller generates an early switchover gating state. Early switchover is a special state within the gating states, distinct from the previously mentioned permitted switchover, delayed switchover, and prohibited switchover. Permitted switchover corresponds to executing the basic target mode request, while early switchover corresponds to executing the preferred operating mode switch determined based on the preceding road attribute information, and this switchover must be completed before entering the target road segment.

[0170] It should be noted that after the road attribute information ahead is included in the judgment process, a gating state that may be switched in advance may be generated. Therefore, the gating state at this time includes allowed switching, delayed switching, prohibited switching, and early switching.

[0171] It should be noted that in this embodiment, generating the early mode switching request and generating the early switching gating state are two sequential steps, but both are completed within the gating state generation process. The controller first generates a request based on the road attribute information ahead and the current low-risk status, and then generates the early switching gating state based on the request and the still existing low-risk status. From an implementation perspective, these two sub-steps can be executed consecutively or combined into a single judgment logic: when the road attribute information ahead is obtained and the current road risk level is no risk or low risk, it determines whether early switching is necessary based on the road information ahead; if so, it directly generates the early switching gating state.

[0172] Through this embodiment, the controller can proactively generate an advance switching command when there is a special road section ahead and the current road surface is stable, enabling the vehicle to complete the adaptation of the working mode before entering the special road section. For example, when there is a long uphill ahead and the current road condition is low-risk, the controller can request in advance to switch from pure electric mode to series range extender mode to ensure climbing power; when there is a continuous bumpy road section ahead, it can request in advance to switch from engine direct drive mode to pure electric mode to avoid clutch operation on bumpy roads.

[0173] In some embodiments, generating an advance mode switching request based on the ahead road attribute information further includes the following steps: First, obtain the predicted vehicle speed on the road ahead.

[0174] The controller first acquires or predicts the vehicle's speed when it enters the target road segment. The predicted vehicle speed can be acquired through a combination of several sources.

[0175] One approach is to obtain the historical speed of traffic on that road segment or the map's fixed speed from a navigation map. Navigation maps typically store the average speed of traffic on different road segments at different times, or provide a reference speed based on road classification, speed limits, and other information. Let's denote this map speed as vm.

[0176] Another approach is to obtain the real-time traffic flow speed of this road segment through a vehicle-to-everything (V2X) system. The V2X system can collect the average speed of vehicles currently traveling on this road segment, reflecting the real-time traffic conditions. Let the real-time traffic flow speed be denoted as vt.

[0177] Another approach is to estimate the driving trend speed based on the current vehicle speed and longitudinal acceleration. The controller uses the current vehicle speed v0, the driver's accelerator pedal change trend, and driving resistance to extrapolate the estimated vehicle speed vd when entering the target road segment. For example, assuming the vehicle is accelerating uniformly at the current acceleration, the speed at the starting point of the target road is calculated based on the distance and the current speed.

[0178] The controller performs weighted fusion of one or more vehicle speed sources to obtain the predicted vehicle speed vp: vp = w1·vm + w2·vt + w3·vd.

[0179] Here, w1, w2, and w3 are weighting coefficients, and w1 + w2 + w3 = 1. The weight allocation can be determined based on the reliability and timeliness of the information source. For example, when real-time traffic flow speed is available and updated frequently, a higher weight can be assigned to vt; when real-time information is lacking, only vm and vd can be used.

[0180] Optionally, the controller can also adaptively adjust the predicted vehicle speed using historical data. For example, by recording the actual speed of the vehicle when passing through road segments with similar properties in the past, the controller can appropriately reduce the predicted speed when the recent actual passing speed is generally lower than the predicted speed, and vice versa. This adjustment allows the prediction results to better adapt to the current driver's driving style and the actual traffic conditions of the route.

[0181] Then determine the first working mode for the target road.

[0182] Based on the road attributes ahead and the predicted vehicle speed (vp), the controller determines the first operating mode for the target road. This first operating mode is the preferred operating mode for the target road, representing the ideal operating mode that balances smoothness, power, and economy when driving on that road segment. Different road attributes and vehicle speed ranges correspond to different preferred modes.

[0183] The following are some pattern matching rules.

[0184] When the target road is a speed bump, pothole, or construction section, such road surfaces present significant instantaneous impacts or continuous bumps, and clutch engagement or engine intervention should be avoided during passage. Therefore, when the predicted vehicle speed vp is below the low-speed threshold (e.g., 30 km / h), pure electric mode or series range extender mode is preferred, i.e., driven solely by the electric motor, with the engine decoupled from the wheels.

[0185] When the target road is a sharp bend or ramp, the vehicle needs to maintain a stable yaw response to avoid torque disturbances caused by sudden changes in the power path. When the predicted vehicle speed vp is in the low to medium speed range (e.g., 20km / h to 60km / h), pure electric mode or dual-motor pure electric mode is preferred to ensure smooth passage.

[0186] When the target road is a long uphill section, the vehicle needs continuous power output to overcome the gradient resistance. When the predicted vehicle speed vp is higher than the medium speed threshold (e.g., 50 km / h) and there is a continuous power demand, the series range extender mode or the parallel direct drive mode is preferred to ensure power performance and battery charge maintenance.

[0187] When the target road is a high-speed, stable cruising section, direct drive in the engine's high-efficiency zone generally provides better fuel economy. When the predicted vehicle speed (vp) is higher than the high-speed threshold (e.g., 70 km / h), parallel direct drive mode is preferred.

[0188] When the target road is a long downhill slope, the vehicle can use kinetic energy recovery to charge the battery. When the predicted vehicle speed vp is lower than the current vehicle speed or the vehicle has a significant deceleration trend, pure electric mode or series mode (which allows the motor to recover energy) is preferred.

[0189] When the target road is a regular road and does not belong to the above special types, the basic mode management strategy will not be changed proactively, that is, no early switching request will be generated, and the basic energy management strategy will still make the decision.

[0190] The pattern matching rules described above can be pre-stored in the controller using a mapping table. For roads that meet multiple rules simultaneously, such as long uphill sections with sharp bends, the final preferred pattern can be determined by priority (e.g., safety over economy) or by a weighted approach.

[0191] Finally, generate an advance mode switching request.

[0192] The controller compares the preferred operating mode with the basic target mode request. The basic target mode request is a target mode generated based on conventional parameters such as current vehicle speed, battery state of charge, and driver torque request, reflecting the current power economy requirements. If the preferred operating mode matches the basic target mode request, it means that the current basic strategy has anticipated the needs of the road ahead, and no additional intervention is required. In this case, the controller does not generate an advance mode switching request. If the preferred operating mode does not match the basic target mode request, it means that the basic strategy has not yet considered the special characteristics of the road ahead, and active mode adjustment is required. In this case, the controller generates an advance mode switching request. The advance mode switching request should at least include the target operating mode and the triggering condition, where the target operating mode is the preferred operating mode, and the triggering condition is that the vehicle is about to enter the target road. The advance mode switching request is sent to the gating state generation module, which generates an advance switching gating state when the current road risk level conditions are met.

[0193] In this embodiment, the controller can proactively determine whether to adjust the operating mode in advance based on the road attributes ahead and the predicted vehicle speed, and generate an advance mode switching request when necessary. Compared with passively waiting for the basic strategy to trigger the switch, this method can avoid the risk of performing the switch on special road sections in advance, improving the road adaptability and driving comfort of mode switching.

[0194] In some embodiments, after generating the early switching gating state, the controller prepares to switch to the first operating mode, but needs to select an appropriate execution window to ensure that the switch can be completed smoothly before entering the target road segment, while not executing too early and causing loss of energy consumption or comfort.

[0195] In this embodiment of the application, if the distance or time between the vehicle and the target road segment meets the preset conditions, the switch to the first working mode is completed before entering the target road segment.

[0196] Specifically, when performing an early switch, it is necessary to first determine the distance or time condition between the vehicle and the target road segment. The controller obtains the distance d from the current vehicle position to the starting point of the target road segment, and the current vehicle speed v, and calculates the estimated arrival time t = d / v (assuming constant speed, acceleration correction can also be considered). The controller compares d or t with a preset threshold.

[0197] When the distance between a vehicle and the target road segment is less than a preset distance threshold Dmax, it is considered to have entered the preparation range for early switching. Dmax is the maximum distance allowed for early identification. The distance threshold should not be too small, otherwise the switching may not be completed in time; nor should it be too large, otherwise the switching may be too early, causing the mode to be unsuitable for the current road conditions.

[0198] Another approach is to use a time threshold. When the expected arrival time t is less than a preset time threshold Tmax, it is considered to enter an early switching window. Tmax can be calibrated based on the time required for switching execution, such as considering the total time for clutch engagement, engine starting, and motor torque coordination, plus a certain safety margin. The calibration of Tmax should take into account the time differences of different switching types. For example, switching from pure electric to series range extender is usually faster than switching from series to parallel, so a more conservative value can be used to cover all switching types.

[0199] The controller can use a combination of distance and time conditions for judgment: when d ≤ Dmax and t ≤ Tmax, the preset conditions are considered met. Alternatively, an OR relationship can be used, meaning triggering occurs when either condition is met. However, the AND relationship is more stringent and can avoid insufficient time due to relying solely on distance judgment at high speeds. This embodiment does not limit the specific logic, as long as sufficient time and distance are guaranteed to complete the switching.

[0200] When distance or time conditions are met, the controller switches to the preferred operating mode before entering the target road segment. The controller performs actions such as clutch engagement or disengagement, engine start or stop, and motor torque adjustment according to the switching procedure corresponding to this preferred operating mode. During the advance switching process, the controller should continuously monitor the current road risk level. If the risk level unexpectedly rises to medium or high risk during the switching process, the switching can be paused or interrupted, and the original operating mode restored to ensure safety.

[0201] After the vehicle enters the target road segment, the controller can enter a mode hold state. Mode hold refers to fixing the current operating mode for a period of time to avoid unnecessary mode switching or re-switching triggered by short-term vehicle speed fluctuations, instantaneous changes in battery state of charge, or throttle vibrations. Specifically, mode hold can be implemented by setting a timer or distance counter in the controller to record the time or distance traveled within the target road segment. The mode hold state is released when the vehicle leaves the target road, the road returns to normal, the current mode cannot meet torque requirements, or the safety system requests a higher priority.

[0202] It should be noted that in some embodiments, after the controller generates a delayed gating state based on the current road risk level being medium risk, it does not simply wait a fixed time before reassessing. Instead, it dynamically determines subsequent actions based on changes in the current road risk level and changes in the driver's power demand during the delay period. Specifically, this includes the following processing methods.

[0203] During the delay period, if the controller detects that the current road risk level has decreased from the initial medium risk to no risk or low risk, it means that the vehicle has left the section of road that caused the medium risk, and the current road surface has returned to a stable state or has only slight disturbances. In this case, the controller exits the delayed switching state and enters the allowed switching state. After entering the allowed switching state, the controller confirms that the basic target mode request that was previously suspended due to medium risk is still valid, and executes the switch to the basic target mode according to the basic mode switching procedure. Since the road has returned to a stable state, the switch at this time will not significantly overlap with road disturbances, and the smoothness of the switch can be guaranteed.

[0204] It should be noted that if the risk level fluctuates multiple times during the delay period, such as repeatedly switching between medium and low risk, the controller can be set to a certain hysteresis or confirmation time. The controller can then switch to allow switching only after the risk level has stabilized at no risk or low risk for a period of time. This is to avoid frequent changes in the gate status due to rapid fluctuations in the risk level.

[0205] During the delay period, if the controller detects that the current road risk level has increased from medium to high risk, it means that the vehicle has entered a more severe road condition, such as changing from continuous moderate bumps to severe bumps, or moving from a moderate impact area to a severe impact area, or experiencing a high risk of inconsistent left and right attachment. In this case, the controller immediately switches from the delayed switching state to the prohibited switching state. After switching is prohibited, the controller executes the prohibited switching behavior: it prohibits the execution of operating mode switching involving changes in clutch state, maintains the current operating mode, and no longer considers executing the original basic target mode request. The prohibited switching state can only be lifted when the risk level drops to medium, low, or no risk, or when the current operating mode cannot meet the basic power requirements.

[0206] During the delay, although the current road risk level remains medium, if the driver exhibits a strong power demand, such as rapidly pressing the accelerator pedal to a large opening, or the throttle change rate exceeding a preset threshold, and the maximum output torque of the current operating mode is insufficient to meet the driver's needs (e.g., in pure electric mode, the motor torque has reached its peak but still cannot meet the demand), or the battery's state of charge is too low, resulting in power limitation, then safety (i.e., power response) may take precedence over smoothness. In this case, the controller can allow a switchover, i.e., perform a switch to the basic target mode to provide the required power as quickly as possible. However, to avoid excessive shocks in medium-risk road conditions, the controller must limit the rate of torque change during the switchover process. Specific limiting methods include: reducing the ramp rate of engine torque request, reducing the compensation rate of motor torque, and extending the clutch engagement time. By limiting the rate of torque change, although the switchover process may be slightly slower than normal, it can reduce the jerking and vibration caused by the superposition of sudden power changes and road disturbances.

[0207] In addition to the three scenarios mentioned above, if the delay time expires, the current road risk level remains at medium risk, and the driver's power demand does not exceed the current operating mode's capacity, the controller can continue to maintain the delay state, i.e., restart a new delay cycle, or switch to a no-switching state according to the calibration strategy. Typically, a maximum number of delays or a maximum total delay time can be set to avoid indefinite delays.

[0208] Through the refined processing in this embodiment, the delayed switching state can adaptively respond to road condition improvements, deterioration, and emergency power demands, thus ensuring both smoothness and timely power response. This dynamic decision-making mechanism prevents the vehicle from blindly switching and causing jerking in medium-risk road conditions, while also avoiding being overly conservative and affecting the driving experience.

[0209] It should be noted that in some embodiments, when the controller generates a prohibited switching gating state based on the current road risk level being high risk, it is necessary to specify which operations are prohibited in the prohibited switching state and under what conditions the prohibited switching state is lifted.

[0210] In the disabled gating state, the controller prohibits operating mode switching involving changes in clutch status in the dual-motor hybrid system. Clutch status changes include transitions in engagement, disengagement, or holding state of clutch C1 or clutch C2. Specific switching that must be prohibited includes: Switching from pure electric mode to series range extender mode involves disengaging clutches C1 and C2, and then engaging clutch C1 and disengaging clutch C2. This switching requires engaging clutch C1 to start the engine or establish a power generation path.

[0211] Switching from pure electric mode to parallel direct drive mode involves disengaging both clutches (C1 and C2) and engaging both clutches (C1 and C2). This switching requires engaging both clutches simultaneously and may start the engine.

[0212] Switching from the series range extender mode to the parallel direct drive mode involves engaging clutch C1 and disengaging clutch C2, and then engaging clutch C1 and disengaging clutch C2. This switching requires engaging clutch C2.

[0213] Switching from parallel direct drive mode to pure electric mode, i.e. from clutch C1 and clutch C2 engaged to clutch C1 and clutch C2 disengaged, requires disengaging the clutches.

[0214] Any switching that involves rapid engine intervention, such as starting the engine and engaging gears directly from pure electric mode.

[0215] It should be noted that disabling switching does not prohibit all control operations. In the disabling switching state, the following operations are still permitted and do not affect vehicle safety: In pure electric drive mode, the torque adjustment of the P3 motor is possible as long as it does not involve changes in the clutch state.

[0216] In series range extender mode, the generating torque of the P2 motor can be adjusted as long as the clutch state is not changed.

[0217] The negative torque control of the P3 motor during the regenerative braking process does not involve clutch disengagement or engagement.

[0218] The torque transmission capability of a clutch that is already engaged can be adjusted, but it is not allowed to change from disengaged to engaged or from engaged to disengaged.

[0219] In addition, if the current operating mode itself involves the clutch being engaged, such as parallel direct drive mode, the controller can maintain that state, but must not initiate a new switching action to change the mode to another mode.

[0220] It should be noted that the switch-disabled state is not permanent. When one of the following conditions is met, the controller should remove the switch-disabled state and reassess whether to perform a switch.

[0221] Condition 1: The current road risk level has dropped to medium risk, low risk, or no risk.

[0222] High risk is the threshold that triggers the prohibition of switching. When the risk level of the sub-items that cause high risk decreases, the overall risk level may decrease to medium risk or lower. Specifically, the controller continuously monitors changes in the current road risk level. When all high-risk sub-items have disappeared, that is, when there is no high continuous vibration risk, high instantaneous impact risk, or high left-right response difference risk, the current road risk level is reduced to medium risk or lower.

[0223] It should be noted that a decrease in risk from high to medium does not necessarily mean that a switchover can be performed immediately, as medium risk corresponds to a delayed switchover. However, it at least allows the lifting of the switchover prohibition status, enabling the controller to enter the decision-making process for delayed or permitted switchover. Therefore, the condition for lifting the switchover prohibition can be set as follows: the current road risk level no longer includes high risk, that is, the current road risk level is any one of medium risk, low risk, or no risk.

[0224] Condition 2: The current working mode cannot meet the basic power requirements.

[0225] In certain extreme situations, even if the road risk level remains high, continuing to prohibit switching may lead to power interruption or safety risks if the current operating mode can no longer meet the vehicle's basic power needs. For example, if the current mode is pure electric and the battery's state of charge is too low, the motor's output power may be insufficient to maintain the current vehicle speed, or the driver's requested torque may far exceed the motor's capacity, causing the vehicle speed to continue to decrease or even posing a risk of rear-end collision. In such cases, it is permissible to break the prohibition on switching and perform a necessary mode switch, such as switching from pure electric mode to series range extender mode to start the engine and generate electricity.

[0226] It is important to note that triggering condition two should be carefully considered. The controller should comprehensively assess the following factors: the difference between the current vehicle speed and the target vehicle speed, the trend of accelerator pedal opening, the remaining energy of the battery's state of charge, and the maximum sustainable output power of the current operating mode. Condition two should only be triggered when the assessment indicates that maintaining the current operating mode would result in severe power shortage or safety hazards. The switching operation performed after condition two is triggered should prioritize maintaining the continuity of wheel-end torque and limit the rate of torque change as much as possible to reduce impact.

[0227] When any of the above conditions are met, the controller lifts the prohibition on switching and generates a corresponding gating state based on the current road risk level. If the risk level has dropped to medium risk, it will enter a delayed switching state; if it has dropped to low risk or no risk, it will enter a permitted switching state; if it is still high risk, the prohibition on switching should continue, but necessary restricted switching is allowed.

[0228] Through the refined processing in this embodiment, the prohibition of switching states can effectively prevent unnecessary clutch operation in high-risk road conditions, ensuring vehicle stability and safety; at the same time, the explicit release conditions prevent permanent locking in the prohibited state from affecting normal driving. The introduction of condition two provides safety redundancy for extreme situations.

[0229] This application also provides a dual-motor hybrid system mode switching control system, which includes a first acquisition module, a second acquisition module, and a determination module; the first acquisition module is used to acquire a vehicle basic target mode request; the second acquisition module is used to acquire road state information, which includes current road state information, including at least one of continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics; the determination module is used to determine whether to perform a switch to the basic target mode based on the road state information.

[0230] The control system also includes a controller, which includes a first acquisition module, a second acquisition module, and a determination module. The controller is configured to execute the aforementioned dual-motor hybrid system mode switching control method.

[0231] There may be one or more controllers, and each controller may be at least one of a vehicle controller, a hybrid controller, or a motor controller. A controller typically includes a processor and a memory. The memory stores computer program instructions, which the processor executes to perform the steps in the above method embodiments. The processor may be a central processing unit, a microcontroller, a digital signal processor, a field-programmable gate array, or other programmable logic devices. The memory may be a non-volatile storage medium such as read-only memory, random access memory, flash memory, or magnetic disk.

[0232] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0233] The above provides a detailed description of a dual-motor hybrid system mode switching control method and system provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A mode switching control method for a dual-motor hybrid system, characterized in that, Includes the following steps: Obtain the vehicle's basic target pattern request; The system acquires road condition information, including current road condition information, which includes at least one of continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics. Specifically, the continuous vibration characteristics are determined based on fluctuations in the vehicle's vertical acceleration, pitch velocity, and yaw rate; the instantaneous impact characteristics are determined based on the instantaneous peak values ​​of the vehicle's vertical acceleration and pitch velocity; and the left-right response difference characteristics are determined based on the vehicle's left wheel speed, right wheel speed, longitudinal vehicle speed, steering wheel angle or front wheel angle, and yaw rate. Based on the road status information, it is determined whether to switch to the basic target mode, and accordingly decides to allow the switch, delay the switch, or prohibit the switch.

2. The mode switching control method for a dual-motor hybrid system according to claim 1, characterized in that, The step of determining whether to switch to the basic target mode based on the road state information includes: Based on the current road status information, the current road risk level is determined; Based on the current road risk level, determine whether to switch to the basic target mode.

3. The mode switching control method for a dual-motor hybrid system according to claim 2, characterized in that, The step of determining the current road risk level based on the current road status information includes: Based on the aforementioned continuous vibration characteristics, determine the continuous vibration risk level; and / or, Based on the instantaneous impact characteristics, determine the instantaneous impact risk level; and / or, Based on the aforementioned left-right response difference characteristics, the risk level of the left-right response difference is determined; The current road risk level includes one of the following: no risk, low risk, medium risk, and high risk.

4. The mode switching control method for a dual-motor hybrid system according to claim 3, characterized in that, The continuous vibration risk level is included in a preset first risk level set, which includes at least one of: no continuous vibration risk, low continuous vibration risk, medium continuous vibration risk and high continuous vibration risk. The instantaneous impact risk level is included in a preset second risk level set, which includes at least one of: no instantaneous impact risk, low instantaneous impact risk, medium instantaneous impact risk, and high instantaneous impact risk; The left-right response difference risk level is included in a preset third risk level set, which includes at least one of the following: no left-right response difference risk, low left-right response difference risk, medium left-right response difference risk, and high left-right response difference risk.

5. The mode switching control method for a dual-motor hybrid system according to claim 4, characterized in that, The absence of risk includes: the absence of continuous vibration risk, the absence of instantaneous impact risk, and the absence of left-right response difference risk; The low risk includes at least one of the following: low continuous vibration risk, low instantaneous impact risk, and low left-right response difference risk. The medium risk includes at least one of the medium continuous vibration risk, the medium instantaneous impact risk, and the medium left-right response difference risk; The high risk includes at least one of the following: high continuous vibration risk, high instantaneous impact risk, and high left-right response difference risk.

6. The mode switching control method for a dual-motor hybrid system according to claim 4, characterized in that, The determination of the continuous vibration risk level based on the continuous vibration characteristics includes: Within a sliding time window, the vertical acceleration, pitch rate, and yaw rate of the vehicle are acquired, and the root mean square values ​​of the vertical acceleration, pitch rate, and yaw rate are determined. Based on the root mean square values ​​of the vertical acceleration, the pitch angular velocity, and the yaw angular velocity, the continuous vibration excitation index is obtained. The continuous vibration risk level is determined based on the magnitude of the continuous vibration excitation index.

7. The mode switching control method for a dual-motor hybrid system according to claim 4, characterized in that, Based on the instantaneous impact characteristics, the instantaneous impact risk level is determined, including: Within the sliding time window, the current vertical acceleration and pitch rate of the vehicle are obtained, and the rate of change of vertical acceleration is obtained based on the vertical acceleration. Whether a single impact event has occurred is determined based on at least one of the vertical acceleration, the pitch angular velocity, and the rate of change of vertical acceleration. The instantaneous impact risk level is determined by statistically analyzing the number of individual impact events and the cumulative impact intensity.

8. The mode switching control method for a dual-motor hybrid system according to claim 4, characterized in that, Based on the aforementioned left-right response difference characteristics, the risk level of the left-right response difference is determined, including: The system acquires the left wheel speed, right wheel speed, vehicle longitudinal speed, steering wheel angle or front wheel angle, and yaw rate, and determines the wheel speed difference between the left wheel speed and the right wheel speed, and the theoretical wheel speed difference between the left and right wheels. Based on at least one of the following: the deviation of the wheel speed difference between the left and right wheels from the theoretical wheel speed difference, and the deviation of the yaw rate from the theoretical yaw rate, a risk index for left and right response difference is obtained. The risk level of the left and right response difference is determined based on the magnitude of the left and right response difference risk index.

9. The mode switching control method for a dual-motor hybrid system according to claim 2, characterized in that, Based on the current road risk level, determine whether to switch to the basic target mode, including: Based on the current road risk level, a gating status is determined, which includes one of the following: allowing switching, delaying switching, and prohibiting switching. Based on the gating state, determine whether to switch to the basic target mode.

10. The mode switching control method for a dual-motor hybrid system according to claim 9, characterized in that, The current road risk level includes one of the following: no risk, low risk, medium risk, and high risk. Determining the gate status based on the current road risk level includes: If the current road risk level is either no risk or low risk, it is determined that switching is permitted; If the current road risk level is medium risk, a delayed handover is determined; If the current road risk level is classified as high risk, switching is prohibited.

11. The mode switching control method for a dual-motor hybrid system according to claim 10, characterized in that, The road status information also includes the attribute information of the road ahead; The process of determining the gate control status based on the current road risk level also includes: Obtain the attribute information of the road ahead; If the attribute information of the road ahead is obtained and the current road risk level is no risk or low risk, an advance mode switching request is generated based on the attribute information of the road ahead. Upon receiving the advance mode switching request, and if the current road risk level is either no risk or low risk, an advance switch is determined.

12. The mode switching control method for a dual-motor hybrid system according to claim 11, characterized in that, The step of generating an advance mode switching request based on the preceding road attribute information includes: Obtain the predicted vehicle speed on the road ahead; Based on the road ahead attribute information and the predicted vehicle speed, the first working mode of the target road is determined; If the basic target mode request is inconsistent with the first working mode, an advance mode switching request is generated.

13. The mode switching control method for a dual-motor hybrid system according to claim 12, characterized in that, The early switching includes: If the distance or time between the vehicle and the target road segment meets preset conditions, the vehicle switches to the first working mode before entering the target road segment.

14. The mode switching control method for a dual-motor hybrid system according to claim 10, characterized in that, The delay switching includes: If the current road risk level drops to no risk or low risk during the delay period, the allowed switch will proceed. If the current road risk level rises to the high risk level during the delay period, the switching will be prohibited. If the driver's power demand exceeds the current operating mode's capacity during the delay period, the system will switch to a permissible mode and limit the rate of torque change.

15. The mode switching control method for a dual-motor hybrid system according to claim 10, characterized in that, The prohibition of switching includes: In the gated state where switching is prohibited, it is prohibited to perform operating mode switching involving changes in the clutch state of the dual-motor hybrid system; When the current road risk level drops to medium risk, low risk, or no risk, or when the current working mode cannot meet basic power requirements, the prohibition on switching will be lifted.

16. A mode switching control system for a dual-motor hybrid system, characterized in that, include: The first acquisition module is used to acquire the vehicle's basic target mode request; The second acquisition module is used to acquire road status information, including current road status information. The current road condition information includes at least one of the following: continuous vibration characteristics, instantaneous impact characteristics, and left-right response difference characteristics; wherein, the continuous vibration characteristics are determined based on the fluctuations of the vehicle's vertical acceleration, pitch angular velocity, and yaw angular velocity; the instantaneous impact characteristics are determined based on the instantaneous peak values ​​of the vehicle's vertical acceleration and pitch angular velocity; and the left-right response difference characteristics are determined based on the vehicle's left wheel speed, right wheel speed, vehicle longitudinal speed, steering wheel angle or front wheel angle, and yaw rate. The determination module is used to determine, based on the road state information, whether to perform a switch to the basic target mode, and accordingly decide whether to allow the switch, delay the switch, or prohibit the switch.

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