Motor assist control method and system for a p2 architecture hybrid vehicle

Abstract

The application provides a motor assistance control method and system of a P2 architecture hybrid vehicle, relates to the field of hybrid control strategies, and aims to solve the problem of large power consumption caused by unnecessary motor assistance access due to insufficient consideration of the running state of the hybrid vehicle. The running state of the hybrid vehicle is obtained, and the SOC state, the slope state, and the state of the maximum torque provided by the engine are judged in sequence. Through identification of the running state of the hybrid vehicle, the SOC state, the slope state, and the vehicle demand torque are comprehensively considered to intervene in the control of the motor assistance, reduce unnecessary motor assistance, reduce the frequent intervention and exit of the motor assistance, reduce unnecessary power consumption, and improve the economy of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hybrid control strategy, in particular to a motor assist control method and system for P2 architecture hybrid vehicle. BACKGROUND

[0002] The motor of P2 architecture hybrid vehicle is located between the engine and the gearbox, and can realize the separate driving of the vehicle by the disconnection and connection of the clutch, can realize the series connection of the engine and the motor to output power, and realize the motor assist of the engine, and the whole power system can output power together.

[0003] The prior art is based on the torque demand to distinguish the motor assist, when the vehicle demand torque is greater than the maximum torque that the engine can currently provide, the motor immediately assists, and if the vehicle demand torque is not greater than the maximum torque that the engine can currently provide, the engine alone provides the vehicle demand torque. The prior art does not consider the current SOC of the battery and the working condition, especially does not consider the running state of the hybrid vehicle in the uphill working condition, even if the uphill working condition is considered, the motor assist is easily misjudged to be connected due to the road bumping, the motor assist is frequently started and stopped, the unnecessary motor assist is increased, the unnecessary electric energy consumption is increased, and the economy is poor. SUMMARY

[0004] The purpose of the present application is to solve the defects in the prior art, provide a motor assist control method and system for P2 architecture hybrid vehicle, obtain the running state of the hybrid vehicle by identification, comprehensively consider the SOC state, the slope state and the vehicle demand torque, intervene the control of the motor assist, reduce the unnecessary motor assist, reduce the frequent intervention and exit of the motor assist, reduce the unnecessary electric energy consumption, and improve the economy of the vehicle.

[0005] The first purpose of the present application is to provide a motor assist control method for P2 architecture hybrid vehicle, which adopts the following scheme:

[0006] Comprising:

[0007] Obtaining the running state of the hybrid vehicle, and judging the SOC state, the slope state and the vehicle demand torque and the maximum torque that the engine can currently provide in sequence;

[0008] If the SOC state, the slope state and the vehicle demand torque and the maximum torque that the engine can currently provide all meet the corresponding calibration state, it is judged that the first duration of the vehicle demand torque greater than the maximum torque that the engine can currently provide, and if the corresponding set state is not met, the motor does not participate in the assist;

[0009] When the first duration is greater than a third calibration value, the motor participates in power assistance, and the vehicle demand torque is provided by the engine and the motor; if the first duration is not greater than the third calibration value, the motor does not participate in power assistance.

[0010] Further, the judgment on the SOC state comprises: if the current battery SOC is not greater than a first calibration value, the vehicle demand torque is provided by the engine, and the motor does not participate in power assistance; if the current battery SOC is greater than the first calibration value, the slope state is judged.

[0011] Further, the judgment on the slope state comprises: if the slope value of the current road is not greater than a second calibration value, the vehicle demand torque is provided by the engine, and the motor does not participate in power assistance; if the slope value of the current road is greater than the second calibration value, the state of the vehicle demand torque and the maximum torque that the engine can currently provide is judged.

[0012] Further, the judgment on the state of the vehicle demand torque and the maximum torque that the engine can currently provide comprises: if the vehicle demand torque is not greater than the maximum torque that the engine can currently provide, the vehicle demand torque is provided by the engine, and the motor does not participate in power assistance; if the vehicle demand torque is greater than the maximum torque that the engine can currently provide, the first duration of the state that the vehicle demand torque is greater than the maximum torque that the engine can currently provide is judged.

[0013] Further, the driving state of the hybrid vehicle comprises: the slope of the road, the vehicle demand torque, the maximum torque that the engine can currently provide, and the battery SOC.

[0014] Further, after the motor participates in power assistance, the SOC state and the state of the vehicle demand torque and the maximum torque that the engine can currently provide are judged in sequence.

[0015] If the SOC state and the state of the vehicle demand torque and the maximum torque that the engine can currently provide both satisfy the corresponding calibration state, a second duration of the state that the vehicle demand torque is not greater than the maximum torque that the engine can currently provide is judged.

[0016] If the second duration is not greater than a fourth calibration value, the motor keeps power assistance; if the second duration is greater than the fourth calibration value, the motor stops power assistance.

[0017] Further, the judgment on the SOC state comprises: if the current battery SOC is not greater than a first calibration value, the vehicle demand torque is provided by the engine, and the motor terminates power assistance; if the current battery SOC is greater than the first calibration value, the state of the vehicle demand torque and the maximum torque that the engine can currently provide is judged.

[0018] Further, the judgment of the whole vehicle demand torque and the maximum torque state that the engine can currently provide comprises: if the whole vehicle demand torque is greater than the maximum torque state that the engine can currently provide, the motor remains to assist; and if the whole vehicle demand torque is not greater than the maximum torque state that the engine can currently provide, the second duration of the whole vehicle demand torque not greater than the maximum torque state that the engine can currently provide is judged.

[0019] Further, during the driving of the hybrid vehicle, the whole vehicle demand torque is provided by the engine after the motor stops assisting.

[0020] The second object of the application is to provide a motor assisting control system of a P2 architecture hybrid vehicle, comprising:

[0021] The state acquisition module is configured to acquire the driving state of the hybrid vehicle, and sequentially judge the SOC state, the slope state and the whole vehicle demand torque and the maximum torque state that the engine can currently provide;

[0022] The duration calibration module is configured to: if the SOC state, the slope state and the whole vehicle demand torque and the maximum torque state that the engine can currently provide all satisfy the corresponding calibration state, judge the first duration of the whole vehicle demand torque greater than the maximum torque state that the engine can currently provide; and if the corresponding calibration state is not satisfied, the motor does not participate in assisting.

[0023] The assisting judgment module is configured to: when the first duration is greater than a third calibration value, the motor participates in assisting, and the whole vehicle demand torque is provided by the engine and the motor together; and if the first duration is not greater than the third calibration value, the motor does not participate in assisting.

[0024] Compared with the prior art, the application has the advantages and positive effects that:

[0025] (1) In view of the problem that the unnecessary motor assisting causes large power consumption due to the insufficient consideration of the running state of the hybrid vehicle, the driving state of the hybrid vehicle is identified and acquired, the SOC state, the slope state and the whole vehicle demand torque are comprehensively considered, the motor assisting is intervened and controlled, unnecessary motor assisting is reduced, the frequent intervention and exit of the motor assisting is reduced, unnecessary power consumption is reduced, and the vehicle economy is improved.

[0026] (2) The battery SOC, the slope, the whole vehicle demand torque and the maximum torque that the engine can currently provide, and the duration are comprehensively judged, the judgment conditions are calibrated, when the power is sufficient, the slope, the whole vehicle demand torque and the continuous running condition are judged, for the condition that the torque supplement is really needed, the motor is connected to assist the engine, the misjudgment during the running of the hybrid vehicle is reduced, and the power consumption is reduced.

[0027] (3) By comparing the whole vehicle demand torque with the maximum torque that the engine can currently provide, the engine is given priority to provide torque, when the whole vehicle demand torque is greater than the maximum torque that the engine can currently provide, and this state lasts for a certain time, it is determined that it is in the state of climbing and needs to be assisted, and the motor is connected to assist, for short and small slopes that can be passed, the motor does not need to be connected to assist, reducing unnecessary power consumption.

[0028] (4) After the motor participates in the assistance, the running state of the hybrid vehicle after participating in the assistance is obtained, the battery SOC is kept within the calibration range, the transition consumption of the battery is reduced, and at the same time, when the whole vehicle demand torque is not greater than the maximum torque that the engine can currently provide, and lasts for a certain time, it is determined that the hybrid vehicle no longer needs motor assistance, and the assistance is stopped, and the duration can reduce the frequent start and stop of the motor and protect the battery. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings constituting a part of the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application and do not constitute an improper limitation on the present application.

[0030] Figure 1 The logic flow chart for judging whether the motor participates in assistance in embodiments 1 and 2 of the present application.

[0031] Figure 2 The logic flow chart for judging whether the motor stops assisting in embodiments 1 and 2 of the present application. DETAILED DESCRIPTION

[0032] Embodiment 1

[0033] In a typical embodiment of the present application, as shown in Figures 1-2 , a motor assistance control method for a P2 architecture hybrid vehicle is given.

[0034] In the prior art, the motor assistance is based on the torque demand, when the whole vehicle demand torque is greater than the maximum torque that the engine can currently provide, the motor immediately assists, otherwise, the motor does not assist. However, it does not consider the current SOC of the battery and the running condition of the hybrid vehicle, if only the maximum assistance of the motor is considered, the battery SOC will be insufficient, the capacity of the matched power battery needs to be increased, resulting in an increase in cost; it does not intervene in the motor assistance according to the whole vehicle demand torque monitoring, causing unnecessary power consumption, and there is also the problem of frequent start and stop of the motor, which is poor in economy.

[0035] Based on this, the motor assist control method of the P2 architecture hybrid vehicle is provided in the embodiment, the motor assist control logic is optimized, the battery SOC, the slope, the vehicle demand torque, the maximum torque currently provided by the engine are comprehensively considered, the unnecessary motor assist working conditions are screened out, the unnecessary electric energy consumption is reduced, and the economy of electric energy consumption is improved.

[0036] Next, the motor assist control method of the P2 architecture hybrid vehicle is described in detail in combination with the drawings.

[0037] Referring to Figure 1 and Figure 2 , the motor assist control logic of the P2 architecture hybrid vehicle is optimized in the embodiment, and the state before the motor participates in assist and the state after the motor participates in assist are analyzed to determine whether the motor participates in assist and whether the motor stops assist.

[0038] Specifically, the control process of whether the motor participates in assist includes:

[0039] The driving state of the hybrid vehicle is obtained, and the SOC state, the slope state, and the vehicle demand torque and the maximum torque currently provided by the engine are judged in sequence;

[0040] If the SOC state, the slope state, and the vehicle demand torque and the maximum torque currently provided by the engine all meet the corresponding calibration state, the first duration that the vehicle demand torque is greater than the maximum torque currently provided by the engine is determined; if the corresponding set state is not met, the motor does not participate in assist;

[0041] When the first duration is greater than the third calibration value, the motor participates in assist, and the vehicle demand torque is provided by the engine and the motor; if the first duration is not greater than the third calibration value, the motor does not participate in assist.

[0042] In the driving process of the hybrid vehicle, the driving state of the hybrid vehicle is obtained, including the road state and the running state of the hybrid vehicle, the road state is the slope of the road, and the running state of the hybrid vehicle includes the vehicle demand torque, the maximum torque currently provided by the engine, the battery SOC, etc.

[0043] In the embodiment, the current road slope can be calculated by the running posture of the vehicle, and obtained through devices such as gyroscopes and accelerometer sensors; the running state of the hybrid vehicle can be obtained through sensing devices such as vehicle speed, accelerator pedal opening, engine speed, and engine torque, or through the CAN bus of the hybrid vehicle, and the parameter data in the driving state of the hybrid vehicle can be obtained and processed by using the existing scheme.

[0044] As Figure 1As shown, before the motor participates in assisting, the SOC state, the slope state, and the vehicle demand torque and the maximum torque that the engine can currently provide are judged, wherein the SOC state is the judgment of the battery SOC, the slope state is the judgment of the current road slope, and the vehicle demand torque and the maximum torque that the motor can currently provide are compared and the duration in this state is compared.

[0045] The motor assisting control method of the P2 architecture hybrid vehicle comprises:

[0046] If the current battery SOC is not greater than the first calibration value a, the vehicle demand is provided by the engine, and the motor does not participate in assisting; a is a positive value;

[0047] If the current battery SOC is greater than the first calibration value a, it is judged whether the current slope is greater than the second calibration value b; b is a positive value;

[0048] If the current slope is not greater than the second calibration value b, the vehicle demand torque is provided by the engine, and the motor does not participate in assisting;

[0049] If the current slope is greater than the second calibration value b, it is judged whether the vehicle demand torque is greater than the maximum torque that the engine can currently provide;

[0050] If the vehicle demand torque is not greater than the maximum torque that the engine can currently provide, the vehicle demand torque is provided by the engine, and the motor does not participate in assisting;

[0051] If the vehicle demand torque is greater than the maximum torque that the engine can currently provide, the first duration T is judged;

[0052] If the first duration T is not greater than the third calibration value c, the vehicle demand torque is provided by the engine, and the motor does not participate in assisting; c is a positive value;

[0053] If the first duration T is greater than the third calibration value c, the motor participates in assisting, and the vehicle demand torque is provided by the engine and the driving motor. Thus the cycle ends.

[0054] Through slope identification, battery SOC monitoring, comparison of the vehicle demand torque and the maximum torque that the engine can currently provide, and duration, the motor assisting is intervened, the engine is preferentially controlled to provide the torque of the vehicle demand, and unnecessary motor assisting is reduced in the climbing process.

[0055] And, considering the first duration T that the vehicle demand torque is greater than the maximum torque that the engine can currently provide, a third calibration value c is set for the first duration T. After a certain duration, it is determined that the vehicle is in a climbing state and needs assistance. The motor is connected to provide assistance. For short and small slopes that can be passed, the motor does not need to be connected to provide assistance, and short and small slopes and other working conditions that do not need to be connected to provide assistance are screened out, thereby reducing unnecessary power consumption.

[0056] It should be noted that in the embodiment, the selection of the calibration values a, b and c can be configured according to requirements.

[0057] In addition, during the driving process of the vehicle, if the motor participates in assistance, in order to avoid the motor frequently entering and exiting the assistance working condition, for example, Figure 2 The motor assistance control method of the P2 architecture hybrid vehicle also includes:

[0058] When the motor participates in assistance, the SOC state and the vehicle demand torque and the maximum torque that the engine can currently provide are sequentially determined;

[0059] If the SOC state and the vehicle demand torque and the maximum torque that the engine can currently provide satisfy the corresponding calibration state, it is determined that the second duration that the vehicle demand torque is not greater than the maximum torque that the engine can currently provide.

[0060] If the second duration is not greater than the fourth calibration value, the motor remains to assist; if the second duration is greater than the fourth calibration value, the motor stops assisting.

[0061] Specifically, after the motor participates in assistance, the driving state of the hybrid vehicle is obtained, and it is determined whether the motor stops assisting.

[0062] If the current battery SOC is not greater than the first calibration value a, the vehicle demand torque is provided by the engine, and the motor assistance is terminated;

[0063] If the current battery SOC is greater than the first calibration value a, it is determined whether the vehicle demand torque is greater than the maximum torque that the engine can currently provide;

[0064] If the vehicle demand torque is greater than the maximum torque that the engine can currently provide, the motor remains to assist;

[0065] If the vehicle demand torque is not greater than the maximum torque that the engine can currently provide, the second duration t is determined. If the second duration t is not greater than the fourth calibration value d, the motor remains to assist; wherein d is a positive value.

[0066] If the second duration t is greater than the fourth calibration value d, the motor stops assisting, and the vehicle demand torque is provided by the engine.

[0067] After the motor participates in assisting, the running state of the hybrid vehicle after participating in assisting is acquired, the battery SOC is kept in a calibration range, the transition consumption of the battery is reduced, when the SOC is less than a first calibration value, it is determined that the battery state is not suitable for continuing motor assisting, and the motor assisting is stopped, so that the excessive consumption of the battery is avoided.

[0068] Meanwhile, when the whole vehicle demand torque is greater than the maximum torque that the engine can currently provide, it is determined that the vehicle is still in a torque insufficient state, and the motor assisting is kept to meet the whole vehicle demand torque; when the whole vehicle demand torque is not greater than the maximum torque that the engine can currently provide, and after a certain time, it is determined that the hybrid vehicle no longer needs motor assisting, the assisting is stopped, the second duration is set to be greater than the fourth calibration value, the vehicle is determined to be in a stable driving state, the frequent start and stop of the motor is reduced, and the battery is protected.

[0069] Embodiment 2

[0070] In another typical embodiment of the present application, as shown in Figures 1-2 a motor assisting control system of a P2 architecture hybrid vehicle is given.

[0071] comprises:

[0072] The state acquisition module is configured to acquire the driving state of the hybrid vehicle, and sequentially judge the SOC state, the slope state and the whole vehicle demand torque and the maximum torque that the engine can currently provide state;

[0073] The duration calibration module is configured to: if the SOC state, the slope state and the whole vehicle demand torque and the maximum torque that the engine can currently provide state all meet the corresponding calibration state, judge the first duration when the whole vehicle demand torque is greater than the maximum torque that the engine can currently provide state; if the corresponding set state is not met, the motor does not participate in assisting;

[0074] The assisting judgment module is configured to: when the first duration is greater than a third calibration value, the motor participates in assisting, and the whole vehicle demand torque is provided by the engine and the motor; if the first duration is not greater than the third calibration value, the motor does not participate in assisting.

[0075] It can be understood that the working method of the motor assisting control system of the P2 architecture hybrid vehicle is the same as the motor assisting control method of the P2 architecture hybrid vehicle provided in embodiment 1, and can refer to the detailed description in embodiment 1, which will not be repeated here.

[0076] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A method for controlling the electric motor assist of a P2 architecture hybrid vehicle, characterized in that, include: The driving status of the hybrid vehicle is obtained, and the SOC status, slope status, and the torque required by the vehicle and the maximum torque that the engine can currently provide are judged in sequence. If the SOC state, slope state, and the vehicle's required torque and the engine's current maximum torque all meet the corresponding calibration states, then it is determined that the first duration of the vehicle's required torque being greater than the engine's current maximum torque is determined. If the corresponding set state is not met, the motor will not participate in assisting; The determination of the slope status includes: if the slope value of the current road is not greater than the second calibration value, the torque required by the vehicle is provided by the engine and the electric motor does not participate in the assist; If the current road gradient is greater than the second calibration value, then the required torque of the vehicle and the maximum torque that the engine can currently provide are judged. When the first duration is greater than the third calibration value, the motor participates in assist, and the torque required by the vehicle is jointly provided by the engine and the motor; if the first duration is not greater than the third calibration value, the motor does not participate in assist; after the motor participates in assist, the SOC state and the torque required by the vehicle and the maximum torque that the engine can currently provide are judged in sequence. If the SOC state and the vehicle's required torque and the engine's current maximum torque state both meet the corresponding calibration states, then it is determined that the vehicle's required torque is not greater than the second duration of the engine's current maximum torque state. If the second duration is not greater than the fourth calibration value, the motor continues to provide assistance; if the second duration is greater than the fourth calibration value, the motor stops providing assistance.

2. The electric motor assist control method for a P2 architecture hybrid vehicle as described in claim 1, characterized in that, The determination of the SOC state includes: if the current battery SOC is not greater than the first calibration value, the required torque of the vehicle is provided by the engine and the motor does not participate in the assist; if the current battery SOC is greater than the first calibration value, the slope state is determined.

3. The electric motor assist control method for a P2 architecture hybrid vehicle as described in claim 1, characterized in that, The determination of the vehicle's required torque and the engine's current maximum torque includes: if the vehicle's required torque is not greater than the engine's current maximum torque, the vehicle's required torque is provided by the engine, and the electric motor does not assist; if the vehicle's required torque is greater than the engine's current maximum torque, the determination is made on the first duration of the state in which the vehicle's required torque is greater than the engine's current maximum torque.

4. The electric motor assist control method for a P2 architecture hybrid vehicle as described in claim 1, characterized in that, The driving status of the hybrid vehicle is obtained by: road gradient, vehicle torque demand, maximum torque currently provided by the engine, and battery SOC.

5. The electric motor assist control method for a P2 architecture hybrid vehicle as described in claim 1, characterized in that, The determination of the SOC state includes: if the current battery SOC is not greater than the first calibration value, the required torque of the vehicle is provided by the engine and the motor stops assisting; if the current battery SOC is greater than the first calibration value, the required torque of the vehicle and the maximum torque that the engine can currently provide are compared.

6. The electric motor assist control method for a P2 architecture hybrid vehicle as described in claim 1, characterized in that, The determination of the required torque of the vehicle and the maximum torque that the engine can currently provide includes: if the required torque of the vehicle is greater than the maximum torque that the engine can currently provide, the motor continues to provide assistance; if the required torque of the vehicle is not greater than the maximum torque that the engine can currently provide, the second duration of the state in which the required torque of the vehicle is not greater than the maximum torque that the engine can currently provide is determined.

7. The electric motor assist control method for a P2 architecture hybrid vehicle as described in claim 1, characterized in that, During the operation of a hybrid vehicle, after the electric motor stops assisting, the torque required by the vehicle is provided by the engine.

8. A motor assist control system for a P2 architecture hybrid vehicle, characterized in that, include: The status acquisition module is configured to: acquire the driving status of the hybrid vehicle, and sequentially determine the SOC status, slope status, and the vehicle's required torque and the maximum torque that the engine can currently provide; The duration calibration module is configured to: if the SOC state, slope state, and the vehicle's required torque and the engine's current maximum torque state all meet the corresponding calibration states, then determine the first duration of the vehicle's required torque being greater than the engine's current maximum torque state. If the corresponding set state is not met, the motor will not participate in assisting; The determination of the slope status includes: if the slope value of the current road is not greater than the second calibration value, the required torque of the vehicle is provided by the engine and the electric motor does not participate in the assist; if the slope value of the current road is greater than the second calibration value, the required torque of the vehicle and the maximum torque that the engine can currently provide are determined. The assist judgment module is configured to: when the first duration is greater than the third calibration value, the motor participates in assist, and the torque required by the vehicle is jointly provided by the engine and the motor; if the first duration is not greater than the third calibration value, the motor does not participate in assist; when the motor participates in assist, the SOC state and the torque required by the vehicle and the maximum torque that the engine can currently provide are judged in sequence. If the SOC state and the vehicle's required torque and the engine's current maximum torque state both meet the corresponding calibration states, then it is determined that the vehicle's required torque is not greater than the second duration of the engine's current maximum torque state. If the second duration is not greater than the fourth calibration value, the motor continues to provide assistance; if the second duration is greater than the fourth calibration value, the motor stops providing assistance.

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