阅读说明：本技术 一种混合动力车及其控制方法、存储介质 (Hybrid vehicle, control method thereof and storage medium ) 是由 张书朋 于 2019-10-24 设计创作，主要内容包括：本发明提供一种混合动力车及其控制方法、存储介质,所述控制方法方法包括步骤：当混合动力车处于经济模式时,根据用户输入的里程总数构建电池的目标SOC轨迹：<Image he="146" wi="685" file="DDA0002246302690000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中,<Image he="63" wi="105" file="DDA0002246302690000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>为目标SOC轨迹,SOC<Sub>0</Sub>为初始SOC,SOC<Sub>f</Sub>为终值目标SOC,L<Sub>f</Sub>为里程总数,L为任意时刻的累积里程数；根据电池的实时SOC以及所述目标SOC轨迹控制发动机的启停状态和工作点,使所述混合动力车在经济模式下行驶。本发明通过目标SOC轨迹以及实时SOC来判断发动机的启停状态和工作点,使得发动机能尽可能多的在最经济区间行驶,以实现混合动力车燃油经济性的全局优化。(The invention provides a hybrid vehicle, a control method thereof and a storage medium, wherein the control method comprises the following steps: when the hybrid vehicle is in the economy mode, constructing a target SOC track of the battery according to the total mileage input by a user: wherein the content of the first and second substances, is a target SOC trajectory, SOC 0 Is an initial SOC, SOC f Is the final value target SOC, L f The total mileage is L, and the accumulated mileage at any moment is L; and controlling the starting and stopping state and the working point of the engine according to the real-time SOC of the battery and the target SOC track, so that the hybrid vehicle runs in an economic mode. The invention judges the engine according to the target SOC track and the real-time SOCThe starting and stopping states and the working points enable the engine to run in the most economical region as much as possible, so that the overall optimization of the fuel economy of the hybrid vehicle is realized.)

1. A control method of a hybrid vehicle, characterized by comprising the steps of:

when the hybrid vehicle is in the economy mode, constructing a target SOC track of the battery according to the total mileage input by a user:wherein the content of the first and second substances,

and controlling the starting and stopping state and the working point of the engine according to the real-time SOC of the battery and the target SOC track, so that the hybrid vehicle runs in an economic mode.

2. The control method of a hybrid vehicle according to claim 1, wherein the step of controlling the start-stop state and the operating point of the engine based on the real-time SOC of the battery and the target SOC map comprises:

if it is in real time

3. The control method of a hybrid vehicle according to claim 2, wherein the step of controlling the start-stop state and the operating point of the engine based on the real-time SOC of the battery and the target SOC map comprises:

if it is in real time

4. The control method of a hybrid vehicle according to claim 3, characterized by further comprising the step of:

if b is₃Percentage below real-time SOC < b₂And percent, performing open-loop control on the start-stop state and the working point of the engine, wherein b₃Taking a value between 15 and 20;

if the real-time SOC is less than or equal to b₃% for engineAnd the start-stop state and the working point execute closed-loop control.

5. The control method of a hybrid vehicle according to claim 4, wherein the step of performing open-loop control of the start-stop state of the engine includes:

drawing an optimal fuel economy curve with the output power of the engine as an abscissa and the specific power fuel consumption rate b as an ordinate according to the optimal BSFC curve of the engine-generator, and taking an inflection point value from high fuel consumption rate, steep curve to low fuel consumption rate and gentle curve on the curve as an engine start-stop threshold value

If it isControlling the engine to start;

if it is

6. The control method of a hybrid vehicle according to claim 4, wherein the step of performing open-loop control of the operating point of the engine includes:

if P_demand＜P₁Then controlling the open-loop operating point of the engine

If P₁≤P_demand≤P₂Then controlling the open-loop operating point of the engine

If P_demand＞P₂Then controlling the open-loop operating point of the engineWherein, the P₁And P₂Are all set constants, and said P₂Greater than P₁Said P is_optIs the optimal working point of the engine.

7. The control method of a hybrid vehicle according to claim 4, wherein the step of performing closed-loop control of the start-stop state of the engine includes:

drawing an optimal fuel economy curve with the output power of the engine as an abscissa and the specific power fuel consumption rate b as an ordinate according to the optimal BSFC curve of the engine-generator, and taking an inflection point value from high fuel consumption rate, steep curve to low fuel consumption rate and gentle curve on the curve as an engine start-stop threshold value

If P_demand＞P₀Then the engine is controlled to start, wherein,alpha is a closed-loop regulating coefficient;

if P_demand﹤P₀- Δ P, and the engine run time is greater than a preset engine minimum travel time, controlling the engine to an off state, wherein,

8. The control method of a hybrid vehicle according to claim 4, wherein the step of performing closed-loop control of the operating point of the engine includes:

if the operating point of the engine is performing closed-loop control, saidThe closed-loop control operating point of the engine isWherein beta is a closed-loop regulating coefficient.

9. A storage medium characterized by comprising a plurality of instructions stored, said instructions being adapted to be loaded by a processor and to perform the steps of the control method for a hybrid vehicle according to any one of claims 1 to 8.

10. A hybrid vehicle comprising a processor adapted to implement instructions; and a storage medium adapted to store a plurality of instructions adapted to be loaded by the processor and to perform the steps of the control method of the hybrid vehicle according to any one of claims 1 to 8.

Technical Field

The invention relates to the field of new energy automobile control, in particular to a hybrid electric vehicle, a control method thereof and a storage medium.

Background

With the increasing exhaustion of petroleum resources and the increasing severity of environmental problems, energy conservation and environmental protection become the core direction of the development of the automobile industry. New energy vehicles are taking an increasing share of the market with their energy saving and environmental protection advantages over traditional internal combustion engine vehicles. The plug-in series (extended range) hybrid electric vehicle combines an engine and a power battery with larger capacity, has the advantages of fuel economy and endurance mileage, and the fuel economy is determined by a control strategy of an entire vehicle energy management system to a great extent.

At present, most plug-in hybrid vehicles for mass production have multiple modes, such as a pure electric mode, an electric quantity keeping mode and the like, switching between the modes is completed by a driver, and setting of the modes and switching between the modes are simple and easy. However, most control strategies cannot fully exert the advantages of combining the engine and the battery motor, for example, if a driver selects the pure electric mode for long-distance driving, a small part of the previous journey is completed in the pure electric mode, the heat loss of the battery is large, when the electric quantity is reduced to the lowest limit, the engine is started and enters the power following mode to keep the electric quantity, and the engine cannot always run in an economic area; if the driver selects the electric quantity maintaining mode to drive for a short distance, the advantages of relatively economical and clean electric energy cannot be exerted, and the aim of using more electricity and less oil cannot be achieved.

Aiming at the conditions that the driving road conditions of a driver are variable, the distance between the long distance and the short distance of the travel is uncertain, and the driving habits are different from person to person, the prior art cannot achieve the global optimization of the fuel economy, and therefore the prior art still needs to be improved and developed.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a hybrid vehicle, a control method thereof, and a storage medium thereof, and aims to solve the problem that the prior art cannot achieve global optimization of fuel economy for the hybrid vehicle.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a control method of a hybrid vehicle, comprising the steps of:

when the hybrid vehicle is in the economy mode, constructing a target SOC track of the battery according to the total mileage input by a user:wherein the content of the first and second substances,

is a target SOC trajectory, SOC₀Is an initial SOC, SOC_fIs the final value target SOC, L_fThe total mileage is L, and the accumulated mileage at any moment is L;

and controlling the starting and stopping state and the working point of the engine according to the real-time SOC of the battery and the target SOC track, so that the hybrid vehicle runs in an economic mode.

The control method of the hybrid vehicle comprises the following steps of controlling the starting, stopping and working points of an engine according to the real-time SOC of a battery and the target SOC track:

if it is in real time

And P is_demand<P_batMaxControlling the engine to be in a closed state, and the hybrid vehicle to run in a pure electric mode, wherein P_demandFor driving the required power, P_batMaxIs the maximum discharge power of the battery, a₁Take a value between 3 and 5, b₁Taking a value between 96 and 98.

The control method of the hybrid vehicle comprises the following steps of controlling the starting, stopping and working points of an engine according to the real-time SOC of a battery and the target SOC track:

if it is in real time

Or P_demand>P_batMaxWhen the engine is started, the engine is controlled to start, wherein, a₂Take a value between 0 and 2, b₂Take a value between 93 and 95.

The control method of the hybrid vehicle, wherein, still include the step:

if b is₃Percentage below real-time SOC < b₂And percent, performing open-loop control on the start-stop state and the working point of the engine, wherein b₃Taking a value between 15 and 20;

if the real-time SOC is less than or equal to b₃And percent, executing closed-loop control on the start-stop state and the working point of the engine.

The control method of the hybrid vehicle, wherein the step of performing open-loop control on the start-stop state of the engine includes:

drawing an optimal fuel economy curve with the output power of the engine as an abscissa and the specific power fuel consumption rate b as an ordinate according to the optimal BSFC curve of the engine-generator, and taking an inflection point value from high fuel consumption rate, steep curve to low fuel consumption rate and gentle curve on the curve as an engine start-stop threshold value

If it is

Controlling the engine to start;

if it is

And controlling the engine to be in a closed state if the running time of the engine is longer than the preset shortest running time of the engine, wherein the delta P is a preset constant.

The control method of a hybrid vehicle, wherein the step of performing open-loop control of an operating point of an engine includes:

if P_demand＜P₁Then controlling the open-loop operating point of the engine

If P₁≤P_demand≤P₂Then controlling the open-loop operating point of the engine

If P_demand＞P₂Then controlling the open-loop operating point of the engineWherein, the P₁And P₂Are all set constants, and said P₂Greater than P₁Said P is_optIs the optimal working point of the engine.

The control method of the hybrid vehicle, wherein the step of performing closed-loop control on the start-stop state of the engine comprises:

drawing an optimal fuel economy curve with the output power of the engine as an abscissa and the specific power fuel consumption rate b as an ordinate according to the optimal BSFC curve of the engine-generator, and taking an inflection point value from high fuel consumption rate, steep curve to low fuel consumption rate and gentle curve on the curve as an engine start-stop threshold value

If P_demand＞P₀Then the engine is controlled to start, wherein,

alpha is a closed-loop regulating coefficient;

if P_demand﹤P₀- Δ P, and the engine run time is greater than a preset engine minimum travel time, controlling the engine to an off state, wherein,

alpha is a closed-loop regulating coefficient, and delta P is a preset constant.

The control method of a hybrid vehicle, wherein the step of performing closed-loop control of an operating point of an engine includes:

if the working point of the engine executes closed-loop control, the closed-loop control working point of the engine is

Wherein beta is a closed-loop regulating coefficient.

A storage medium comprising a plurality of instructions stored therein, the instructions being adapted to be loaded by a processor and to perform the steps of a control method of a hybrid vehicle according to the present invention.

A hybrid vehicle comprising a processor adapted to implement instructions; and a storage medium adapted to store a plurality of instructions adapted to be loaded by the processor and to perform the steps of the control method of the hybrid vehicle according to the present invention.

Has the advantages that: according to the invention, a reasonable and simple target SOC track is constructed by acquiring the total mileage input by a user for next charging, and the starting and stopping states and working points of the engine are judged according to the target SOC track and the real-time SOC, so that the engine can run in the most economic region as much as possible, and the overall optimization of the fuel economy of the hybrid vehicle is realized; meanwhile, the real-time SOC of the battery can approximately track the target SOC track to change, namely, the electric quantity of the battery can gradually decrease according to a reasonable trend until the electric quantity is just decreased to the lowest electric quantity when the battery can be charged next time.

Drawings

FIG. 1 is a diagram of the present invention calculating a target SOC trajectory varying with mileage according to a total number of mileage input by a user

Figure (a).

FIG. 2 is a graph of the optimum BSFC curves andand P_optSchematic diagram of the selection of (1).

Fig. 3 is a graph of a selected function of the closed loop adjustment coefficients alpha and beta.

FIG. 4 is a graphical representation of an engine open loop operating point curve.

FIG. 5 is a target SOC trace under mode switching

Fig. 6 is a system block diagram of the hybrid vehicle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In some embodiments, there is provided a control method of a hybrid vehicle, including the steps of:

s10, when the hybrid vehicle is in the economy mode, constructing a target SOC track of the battery according to the mileage sum input by the user:

wherein the content of the first and second substances,

is a target SOC trajectory, SOC₀Is an initial SOC, SOC_fIs the final value target SOC, L_fThe total mileage is L, and the accumulated mileage at any moment is L;

and S20, controlling the starting and stopping state and the working point of the engine according to the real-time SOC of the battery and the target SOC track, and enabling the hybrid vehicle to run in an economic mode.

In this embodiment, the SOC is a state of charge of a battery of the hybrid vehicle, 100% is a full state, 0% is a full state, and when the user switches the hybrid vehicle to an economy mode, the user may input "mileage predicted to be traveled for the next charging", that is, the total mileage L_fAnd recording the initial SOC in the mode as the SOC₀The initial mileage is 0, and the final value target SOC is recorded as SOC_fIf the accumulated mileage is L, the constructed target SOC trajectory is

As shown in fig. 1. In the present embodiment, to reduce the computational complexity and to be easily implemented in a product-level vehicle control unit, the target SOC trajectory is set as a straight line along the driving range from the initial SOC to the end SOC; but to achieve an approximate optimization goal, theIs not unique, e.g. will

Is defined as a curve, or

The rate of decrease is fast first and slow second or slow first and fast second, or

The deformation schemes such as the change of the descending speed along with the change of the vehicle speed and the like all belong to the technical scheme protected by the invention.

In the embodiment, after the target SOC track is successfully constructed, the starting and stopping states and the working points of the engine of the hybrid vehicle can be controlled according to the real-time SOC of the battery and the target SOC track, so that the engine can run in the most economic region as much as possible, and the overall optimization of the fuel economy of the hybrid vehicle is realized; meanwhile, the real-time SOC of the battery can approximately track the target SOC track to change, namely, the electric quantity of the battery can gradually decrease according to a reasonable trend until the electric quantity is just decreased to the lowest electric quantity when the battery can be charged next time.

In some embodiments, if real-time

And P is_demand<P_batMaxControlling the engine to be in a closed state, and the hybrid vehicle to run in a pure electric mode, wherein P_demandFor driving the required power, P_batMaxIs the maximum discharge power of the battery, a₁Take a value between 3 and 5, b₁Taking a value between 96 and 98. In this embodiment, the a₁A certain numerical value between 3 and 5 is taken, so that the situation that the real-time SOC exceeds the target SOC track is avoided; b is₁Taking a value between 96 and 98, overcharging of the battery pack can be avoided.

In some embodiments, if real-time

Or P_demand>P_batMaxWhen the engine is started, the engine is controlled to start, wherein, a₂Take a value between 0 and 2, b₂Take a value between 93 and 95.

In one embodiment, if real time

And P is_demand<P_batMaxWherein P is_demandFor driving the required power, P_batMaxAnd controlling the engine to be in a closed state if the maximum discharge power of the battery is reached, and driving the hybrid electric vehicle in the pure electric mode at the moment. If it is in real time

Or P_demand>P_batMaxAnd if so, controlling the engine to start. In this embodiment, to avoid frequent start and stop of the engine, the SOC threshold value at the time of starting the engine is set to

SOC threshold value during pure electric mode driving

The difference is 2%, and the difference of 2% is used as the hysteresis space.

In some embodiments, when the engine is started, if b₃Percentage below real-time SOC < b₂And percent, performing open-loop control on the start-stop state and the working point of the engine, wherein b₃Taking a value between 15 and 20; if the real-time SOC is less than or equal to b₃And percent, executing closed-loop control on the start-stop state and the working point of the engine. In this embodiment, b₃Is greater than SOC_fSaid SOC_fThe value of (a) is determined by the battery characteristics and technical requirements; as an example, when the SOC_fAt 15%, b is₃Any value between 15 and 20 may be used.

In some embodiments, the opening of the start-stop state of the engine is performedThe loop control step includes: drawing an optimal fuel economy curve with the output power of the engine as an abscissa and the specific power fuel consumption rate b as an ordinate according to the optimal BSFC curve of the engine-generator, and taking an inflection point value from high fuel consumption rate, steep curve to low fuel consumption rate and gentle curve on the curve as an engine start-stop threshold value

If it is

Controlling the engine to start; if it isAnd controlling the engine to be in a closed state if the running time of the engine is longer than the preset shortest running time of the engine, wherein the delta P is a preset constant.

In the present embodiment, as shown in fig. 2, an optimal fuel economy curve is plotted with the engine output power as the abscissa and the Specific power fuel consumption b (in g/kWh) as the ordinate on the basis of an engine-generator optimal BSFC (Brake Specific fuel consumption) curve, and the lowest point in the curve is set as the engine-generator optimal operating point P_optThe inflection point value of the curve from high fuel consumption rate, steep curve to low fuel consumption rate and gentle curve is used as the threshold value of starting and stopping the engine

In the embodiment, the optimal BSFC curve is obtained by an engine BSFC map calibrated by a rack, and because the series hybrid engine is decoupled from a transmission system and the rotating speed of the engine has no direct relation with the vehicle speed, a unique engine rotating speed can be found at each different power point to ensure that the fuel consumption rate is lowest, namely the output power corresponds to the optimal engine rotating speed one by one, and the points are connected from the minimum power to the maximum power to form the optimal BSFC curve. In the embodiment, Δ P is a preset constant, for example, 5kW, and the preset engine shortest travel time may be 5 to 15s, which are setThe constant value can avoid frequent starting and stopping of the engine.

In some embodiments, when real-time SOC ≦ b₃% of, wherein b₃And taking a value between 15 and 20, and executing closed-loop work on the starting and stopping states of the engine to avoid the influence of the too low SOC on the service life of the battery and the normal running performance of the hybrid vehicle. If P_demand＞P₀Then controlling the engine to start if P_demand﹤P₀- Δ P, and the engine run time is greater than a preset engine minimum travel time, controlling the engine to an off state, wherein,

alpha is a closed-loop regulating coefficient, and delta P is a preset constant. In this embodiment, α may be a constant, or may be an SOC function as shown in fig. 3, and when the engine start-stop state is controlled by a closed loop, the lower the real-time SOC is, the lower the engine start-stop point P is₀The smaller will be the following, making it easier for the engine to start to charge the battery pack while providing power, ensuring that the SOC is not too low, or stable near the target SOC during the superstain mode.

In some embodiments, the SOC should not always track the actual driving condition of the vehicle due to the influence of different driving styles

Can adopt a learning correction method to gradually pair

And adjusting to ensure that the trend of the SOC reduction is more reasonable so as to obtain better comprehensive fuel economy. If it is in real time

And P is_demand<P_batMaxThe condition of (1) is frequently satisfied, i.e., the SOC is easily higher than

May be increased stepwise

Value of (e.g. every 5 times the above condition is satisfied, can be

The numerical value is increased by 0.5, and the new numerical value is stored), and the aims of using less engines and using more batteries are achieved by improving the starting and stopping threshold of the engines; if the SOC is dropping faster than the normal

More, can be gradually reduced

When the SOC is lower than

When reaching 20%, the drugs can be decocted

The value is reduced by 0.5, a trip is only calculated once, and this new value is stored.

In some embodiments, since the series hybrid engine is decoupled from the drive train, the engine-generator set can always operate at P for an ideal system_optPower point and achieve optimal fuel economy (this strategy is called a thermostat strategy). However, in practical applications, the thermostat strategy is not feasible and the best fuel consumption is not necessarily obtained due to the influence of battery internal resistance, battery charge/discharge limit, NVH (Noise, Vibration, Harshness, Noise, Vibration, Harshness), and the like. Accordingly, when 20% falls below real-time SOC < 95%, open-loop control based on an improved thermostat strategy is performed on the operating point of the engine, as shown in FIG. 4, if P_demand＜P₁Then controlling the open-loop operating point of the engine

If P₁≤P_demand≤P₂Then controlOpen loop operating point of engine

If P_demand＞P₂Then controlling the open-loop operating point of the engine

Wherein, the P₁And P₂Are all set constants, and said P₂Greater than P₁Said P is_optIs the optimal working point of the engine. According to the embodiment, when the hybrid vehicle is in medium power demand, the thermostat strategy is executed, and the engine always works at the most economic point P_optThe above step (1); and when the power demand is small, the output power of the engine is higher than the power demand and increases along with the increase of the power demand, and when the power demand is large, the output power of the engine is lower than the power demand and increases along with the increase of the power demand, so that the driving feeling is more natural, and the engine can work in an economic area as much as possible.

In this embodiment, theoretically only P needs to be calculated_demand≥P₀Curve of operating point of engine when driving demand power is less than P₀The engine is not started. However, in actual conditions, P₀The value of (A) is also likely to vary with time, and under certain transient conditions, P is very fast after engine start_demandIs less than P₀E.g., the driver releases the accelerator pedal immediately after the driver re-steps the accelerator pedal; it is not advisable to stop the engine immediately after its start up to the minimum operating time, during which the injection is stopped or the engine is idling, and therefore the optimum operating point curve should also cover this region, which is indicated by a dashed line in fig. 4.

If the life of the battery, the potential energy consumption possibly caused by the heat dissipation of the battery, the auditory sensation of the driver and other factors are considered while the optimal fuel economy is considered, the P value can be set₁To P₂P of the interval_gensetIs constant P_optTo P_gensetWith P_demandIs increased by increasing, and at P₁And P₂Outside interval P_gensetIs closer to P_demand，P_gensetIndicated by a dashed line in fig. 4.

In some embodiments, when real-time SOC ≦ b₃% of, wherein b₃And taking a value between 15 and 20, and executing closed-loop operation on the working point of the engine to avoid the influence of the low SOC on the service life of the battery and the normal running performance of the hybrid vehicle. The closed loop control working point of the engine is

Wherein beta is a closed-loop regulating coefficient. In this embodiment, β may be a constant, or may be a function of SOC as shown in fig. 3, and when closed-loop control is adopted, the lower SOC is, the lower the engine-generator set output power P is_gensetThe larger the engine is, the more power the engine outputs to charge the battery pack while providing power, so that the SOC is not too low; in the charge-sustaining mode, if the SOC is higher than

When the engine works, the engine outputs less power to charge the battery pack, and if the SOC is lower than the lower value

When the engine works, more power is output to charge the battery pack so that the SOC is stabilized near the target SOC.

In some embodiments, if a user switches the hybrid vehicle from an economy mode to a battery conservation (sustain) mode, then

Recording the real value of the current SOC during switching and keeping the current value; recalculation after switching back to Economy (ECO) mode

As shown in fig. 5.

In some embodiments, there is also provided a storage medium in which a plurality of instructions adapted to be loaded by a processor and to perform the steps of a method of controlling a hybrid vehicle according to the present invention are stored.

In some embodiments, there is also provided a hybrid vehicle, wherein, as shown in fig. 6, a processor 10 is included, adapted to implement instructions; and a storage medium 20 adapted to store a plurality of instructions adapted to be loaded by the processor 10 and to perform the steps of the control method of the hybrid vehicle according to one aspect of the present invention.

In conclusion, the invention constructs a reasonable and simple target SOC track by acquiring the total mileage input by the user for next charging, and judges the starting and stopping states and the working points of the engine according to the target SOC track and the real-time SOC, so that the engine can run in the most economic region as much as possible, and the overall optimization of the fuel economy of the hybrid vehicle is realized; meanwhile, the real-time SOC of the battery can approximately track the target SOC track to change, namely, the electric quantity of the battery can gradually decrease according to a reasonable trend until the electric quantity is just decreased to the lowest electric quantity when the battery can be charged next time.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.