Extended-range automobile energy control method and device, controller and readable storage medium

Abstract

The invention relates to an extended-range automobile energy control method and device, a controller and a readable storage medium. The method comprises the steps that based on a preset dynamic programming algorithm, a Pareto solution set is obtained according to the Pareto leading edge between the fuel cost consumed by engine fuel and the power consumption cost consumed by battery power under the condition that the range extending automobile meets the required power; according to the NVH characteristics of a range extender in the range-extended automobile, determining a target working point sequence of the range-extended automobile from the Pareto solution set; the target working point sequence comprises working points sequenced according to a time sequence in the driving process of the extended-range automobile; determining a starting charge state threshold value in a preset energy control scheme of the extended-range automobile; and according to the target working point sequence, updating the starting charge state threshold value to obtain a target energy control scheme, and based on the target energy control scheme, carrying out energy control on the extended-range automobile. By adopting the method, the noise, vibration and sound vibration roughness of the whole vehicle can be reduced on the basis of improving the energy efficiency of the extended-range vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to an energy control method, device, controller and computer readable storage medium for a range extended vehicle. BACKGROUND

[0002] A range extended vehicle, also known as a range extended electric vehicle, is an electric vehicle equipped with an on-board auxiliary power generation system (also known as a range extender). The range extended vehicle is composed of an engine, a generator and a controller, etc. When the on-board rechargeable energy storage system cannot meet the vehicle's driving requirements, the range extender provides power for the vehicle's power system. In the actual operation process of the range extended electric vehicle, when the battery power drops to a threshold value, the range extender (usually a small fuel engine) will automatically start to provide continuous power supplement for the power battery pack. Although this process improves the energy efficiency of the range extended vehicle and alleviates the range anxiety, it increases the overall vehicle noise, vibration and harshness (NVH). SUMMARY

[0003] Therefore, it is necessary to provide an energy control method, device, controller and computer readable storage medium for a range extended vehicle to reduce the overall vehicle noise, vibration and harshness on the basis of improving the energy efficiency of the range extended vehicle.

[0004] In a first aspect, the present application provides an energy control method for a range extended vehicle, comprising:

[0005] determining the demand power of the range extended vehicle in the driving process;

[0006] obtaining a Pareto solution set according to the Pareto frontier between the fuel cost of the engine fuel consumption and the electricity cost of the battery power consumption of the range extended vehicle under the condition of meeting the demand power based on a preset dynamic programming algorithm;

[0007] determining a target working point sequence of the range extended vehicle from the Pareto solution set according to the NVH characteristics of the range extender in the range extended vehicle; wherein the NVH characteristics include the noise characteristics, vibration characteristics and harshness characteristics of the range extender, and the target working point sequence includes the working points of the range extended vehicle in the driving process sorted in time sequence;

[0008] determining a start state of charge threshold in a preset energy control scheme of the range extended vehicle; the start state of charge threshold is used to determine whether to trigger the range extended vehicle to switch to a range extended driving mode by the range extender;

[0009] updating the start state of charge threshold according to the target working point sequence to obtain a target energy control scheme, and performing energy control on the range extended vehicle based on the target energy control scheme.

[0010] In one embodiment, based on a preset dynamic programming algorithm, a Pareto solution set is obtained according to the Pareto front between the fuel cost of engine fuel consumption and the electricity consumption cost of battery power consumption when the extended-range vehicle meets the required power, including: determining each operating point of the extended-range vehicle, each operating point including initial state variables and initial control variables based on grid division, the initial state variables including the battery state of charge, engine speed and driving mode of the extended-range vehicle, the driving mode including at least a pure electric driving mode and an extended-range driving mode, and the initial control variables including the engine torque, generator torque and driving mode of the extended-range vehicle; determining a target state transition model based on the preset dynamic programming algorithm, determining the Pareto front between the fuel cost of engine fuel consumption and the electricity consumption cost of battery power consumption at each operating point of the extended-range vehicle when the required power is met; and determining a Pareto solution set from each operating point based on the Pareto front.

[0011] In one embodiment, the target state transition model is based on the state variables of each operating point. and control variables Perform state transfer processing, the state variables of each working point Based on the corresponding initial state variables, the control variables of each operating point are obtained. Based on the corresponding initial control variables; state variables The expression is: ;in, For the The state variables at the next state transition step, is the battery charge state of the range-extended vehicle, is the engine speed of the range-extended vehicle; control variable The expression is: , For the The control variable at the next state transition step, is the engine torque; the expression corresponding to the target state transfer model is: ;in, For the The state variables at the next state transition step, It is The state variable index at the next state transition step, For the The state variables at the next state transition step, It is The state variable index at the next state transition step; Indexed by control variables Determined The control variable at the next state transition step.

[0012] In one of the embodiments, the target working point sequence of the extended-range vehicle is determined from the Pareto solution set according to the NVH characteristics of the range extender in the extended-range vehicle, including: constructing a target function , the target function is expressed as:

[0013]

[0014] wherein: represents the start time of the driving process of the extended-range vehicle; represents the end time of the driving process of the extended-range vehicle; represents the fuel cost of the extended-range vehicle, determined based on the fuel consumption of the driving process of the extended-range vehicle; represents the electricity consumption cost of the extended-range vehicle, determined based on the electricity consumption change of the driving process of the extended-range vehicle; represents the NVH cost of the extended-range vehicle, determined based on the noise vibration quantification value of the driving process of the extended-range vehicle, the noise vibration quantification value being mapped based on the noise characteristics, vibration characteristics and sound vibration roughness characteristics of the range extender; is a mode switching penalty term, used to suppress the vibration caused by the start and stop of the range extender in the driving process of the extended-range vehicle; is a penalty factor, used to adjust the penalty of mode switching; is a preset mode switching penalty function; based on the NVH characteristics of the range extender in the extended-range vehicle and each working point included in the Pareto solution set, the optimal solution of the target function is determined, and the working points corresponding to the optimal solution are sorted in time sequence to obtain the target working point sequence of the extended-range vehicle.

[0015] In one of the embodiments, according to the target working point sequence, the start state of charge threshold is updated to obtain a target energy control scheme, including: based on each working point in the target working point sequence, a reference start state of charge threshold for the range extender is determined; the start state of charge threshold in the preset energy control scheme is updated through the reference start state of charge threshold to obtain the target energy control scheme.

[0016] In one of the embodiments, the preset energy control scheme includes: in the case that the state of charge of the battery of the extended-range vehicle drops to the start state of charge threshold, the extended-range vehicle is controlled to switch the driving mode based on the state of charge of the battery and the required power, the driving mode including the extended-range driving mode, the pure electric driving mode, the hybrid driving mode and the braking mode.

[0017] In one of the embodiments, the preset energy control scheme further comprises: in a case where the required power is greater than the preset power threshold and the battery state of charge continues to decrease, determining a power level of the range extender based on the battery state of charge and the preset state of charge interval, and controlling the range extender to drive the range extension according to the power corresponding to the power level.

[0018] In a second aspect, the present application further provides an energy control device for a range-extended vehicle, comprising:

[0019] a required power determination module configured to determine a required power of the range-extended vehicle during driving;

[0020] a dynamic programming processing module configured to obtain a Pareto solution set based on a preset dynamic programming algorithm and according to a Pareto frontier between fuel consumption cost of engine fuel and power consumption cost of battery power consumption of the range-extended vehicle under the condition of meeting the required power;

[0021] working state determination information configured to determine a target working point sequence of the range-extended vehicle from the Pareto solution set according to NVH characteristics of the range extender in the range-extended vehicle, wherein the NVH characteristics include noise characteristics, vibration characteristics and sound roughness characteristics of the range extender, and the target working point sequence includes working points of the range-extended vehicle in driving process in time sequence;

[0022] a state of charge threshold determination module configured to determine a start state of charge threshold in a preset energy control scheme of the range-extended vehicle, wherein the start state of charge threshold is used to determine triggering of switching the range-extended vehicle to a range extension driving mode through the range extender;

[0023] an energy control module configured to update the start state of charge threshold according to the target working point sequence, obtain a target energy control scheme, and perform energy control on the range-extended vehicle based on the target energy control scheme.

[0024] In a third aspect, the present application further provides a controller comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method in the first aspect when executing the computer program.

[0025] In a fourth aspect, the present application further provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the method in the first aspect.

[0026] In a fifth aspect, the present application further provides a computer program product comprising a computer program, wherein the computer program is executed by a processor to implement the steps of the method in the first aspect.

[0027] The energy control method, device, controller, computer readable storage medium and computer program product of the range-extended vehicle can determine a Pareto solution set by determining a Pareto frontier between fuel cost and electricity consumption cost of the range-extended vehicle under the condition of meeting demand power, and determine a target working point sequence of the range-extended vehicle from the Pareto solution set in combination with NVH characteristics of a range extender in the range-extended vehicle, that is, determine a working point corresponding to the range-extended vehicle for achieving comprehensive optimization of fuel cost, electricity consumption cost, and noise, vibration and harshness. The starting state of charge threshold in the preset energy control scheme is updated by the target working point sequence to obtain a target energy control scheme, which makes the target energy control scheme more accurate in triggering determination of switching of the range-extended vehicle to the range-extended driving mode, so that the energy control of the range-extended vehicle by the target energy control scheme can reduce fuel cost, electricity consumption cost, and noise, vibration and harshness of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 A schematic diagram of a possible transmission structure of a range-extended vehicle in an embodiment;

[0030] Figure 2 A schematic diagram of a flow of an energy control method of a range-extended vehicle in an embodiment;

[0031] Figure 3 Another schematic diagram of a flow of an energy control method of a range-extended vehicle in an embodiment;

[0032] Figure 4 A schematic diagram of a principle of state update of a dynamic programming algorithm in an embodiment;

[0033] Figure 5 A schematic diagram of a parameter optimization result of a multi-objective problem considering NVH in a range-extended mode in an embodiment;

[0034] Figure 6 A schematic diagram of engine and generator control modes and state switching in an embodiment;

[0035] Figure 7 A schematic diagram of an overall flow of a control strategy based on a determination rule in an embodiment;

[0036] Figure 8A schematic diagram of a three-stage power generation strategy process of the extended-range system in an embodiment;

[0037] Figure 9 A structural block diagram of the energy control device of the extended-range vehicle in an embodiment;

[0038] Figure 10 An internal structural diagram of the controller in an embodiment. DETAILED DESCRIPTION

[0039] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. The terms "comprise" and "have" and any variations thereof used in the present application are intended to cover non-exclusive inclusion. The term "multiple" used in the present application refers to two or more. The term "and / or" used in the present application refers to one of the options or any combination of multiple options.

[0040] An extended-range electric vehicle is an electric vehicle equipped with an on-board auxiliary power generation system (also known as a range extender), which is composed of an engine, a generator and a controller, etc. When the on-board rechargeable energy storage system cannot meet the vehicle's range requirements, the range extender provides power for the vehicle power system. The extended-range electric vehicle combines the advantages of pure electric vehicles and hybrid vehicles. In the actual operation process of the extended-range electric vehicle, when the battery power drops to a threshold value, the range extender (usually a small fuel engine) will automatically start to provide continuous power supply for the power battery pack. Although this process effectively alleviates the range anxiety of users, it increases the noise, vibration and harshness (NVH) of the vehicle. Based on the above analysis, the present application provides an energy control method for an extended-range vehicle to reduce the noise, vibration and harshness of the vehicle on the basis of improving the energy efficiency of the extended-range vehicle.

[0041] The technical solutions provided by the present application will be described below by way of embodiments: in an embodiment, an energy control method for an extended-range vehicle is provided, and the present embodiment takes the application of the method to an extended-range electric vehicle as an example for description, as shown in Figure 1 A possible structural schematic diagram of an extended-range electric vehicle is provided, in which 1 represents a battery, 2 represents an inverter, 3 represents a drive motor, 4 represents a transmission gear connected to the drive motor, 5 represents a differential input gear, 6 represents a wheel, 7 represents a differential, 8 represents an engine, 9 represents an engine end output gear, and 10 represents a first motor. The extended-range electric vehicle can have two modes of pure electric drive and extended-range drive. As shown in Figure 2As shown, the range-extending vehicle energy control method can include steps S201 to S205:

[0042] Step S201, determining the demand power of the range-extending vehicle in the driving process.

[0043] The demand power can refer to the power requirement of the range-extending vehicle to meet the driving demand in the driving process. In some embodiments, the demand power can be determined based on the battery power information and the driving demand information of the range-extending vehicle. The battery power information can be information representing the battery power related situation, such as the consumption rate of the power, the remaining power, etc. The driving demand information can be determined based on the driving instructions received by the range-extending vehicle, which can include acceleration, deceleration, turning on the air conditioner, reducing the temperature in the vehicle, playing music, etc. In some embodiments, the demand power can be dynamically changed. For example, on an uphill road, the demand power can be increased, and on a downhill road, the demand power can be reduced. In some embodiments, the range-extending vehicle can have at least two driving modes, such as pure electric driving mode, range-extending driving mode, etc.

[0044] In some embodiments, the driving process can be understood in a broad sense, which can include various working conditions of the range-extending vehicle, such as normal driving, temporary parking, parking standby, etc. In some embodiments, whether the range-extending vehicle is in the driving process can be determined according to whether the electronic control unit in the vehicle is powered on.

[0045] Step S202, based on a preset dynamic programming algorithm, obtaining a Pareto solution set according to the Pareto frontier between the fuel cost of engine fuel consumption and the power consumption cost of battery power consumption of the range-extending vehicle in the case of meeting the demand power.

[0046] The dynamic programming (DP) algorithm can be an algorithm for solving complex problems by decomposing the original problem into relatively simple sub-problems. In some embodiments, the range-extending vehicle is equipped with an engine to charge the battery. When the battery power is sufficient, the range-extending vehicle relies on electric power driving, at which time no fuel is consumed; when the battery power drops below a certain level, the engine starts to charge the battery, thereby consuming fuel.

[0047] In some embodiments, the fuel cost of engine fuel consumption can represent the fuel consumption of the range-extending vehicle to meet the demand power, and the power consumption cost of battery power consumption can represent the power consumption of the range-extending vehicle to meet the demand power. In some embodiments, the range-extending vehicle only needs to consume power to meet the demand power, i.e. only the power consumption cost exists. For example, in the case of sufficient battery power, the range-extender does not need to be started. In some embodiments, the range-extending vehicle needs to consume power and fuel to meet the demand power, i.e. there are power consumption cost and fuel cost.

[0048] The Pareto front, also known as the Pareto boundary or the Pareto optimal front, is a concept in multi-objective optimization. In a multi-objective optimization problem, there is usually no solution that can achieve optimality in all objectives, because there is a conflict between different objectives. Based on this, the Pareto front can be understood as a set of all Pareto optimal solutions in a multi-objective optimization problem. The Pareto solution set is a set composed of working points corresponding to each optimal solution in the Pareto front. In the Pareto solution set, each solution corresponding to the working point of the extended-range automobile is superior to other solutions in at least one objective, and is not inferior to other objectives. In some embodiments, the multi-objective optimization problem corresponding to the Pareto front can be: the fuel cost of the engine fuel consumption of the extended-range automobile under the condition of meeting the demand power, and the electricity cost of the corresponding battery power consumption. That is, in the Pareto solution set, each solution corresponding to the working point of the extended-range automobile is superior to the cost consumption of the working point corresponding to other solutions in at least fuel cost or electricity cost.

[0049] In step S203, a target working point sequence of the extended-range automobile is determined from the Pareto solution set according to the NVH characteristics of the range extender in the extended-range automobile; wherein the NVH characteristics include noise characteristics, vibration characteristics and harshness characteristics of the range extender, and the target working point sequence includes working points of the extended-range automobile in the driving process in time sequence.

[0050] The NVH characteristics can include noise characteristics, vibration characteristics and harshness characteristics of the range extender, and can be quantitatively characterized by NVH values, which can be determined based on the speed and torque of the range extender. Noise, vibration and harshness, abbreviated as NVH, is a comfort index used to measure the noise and vibration generated by vehicles or mechanical equipment during operation. In some embodiments, NVH can correspond to a corresponding target optimization problem, that is, to reduce the NVH of the extended-range automobile. In some embodiments, the point with the lowest NVH on the Pareto front can be found as a target point, and the working point of the extended-range automobile in the driving process is determined according to the target point, and the target working point sequence is arranged in time sequence according to the working point at each time in the driving process. In some embodiments, the target working point sequence can represent the working condition of the extended-range automobile corresponding to the lowest NVH on the Pareto front, and can specifically include working points of the extended-range automobile in the driving process in time sequence. The extended-range automobile can achieve a balance and optimization among fuel cost, electricity cost and NVH in this working condition.

[0051] Step S204, determining a start state of charge threshold in the preset energy control scheme of the range extended vehicle; the start state of charge threshold is used to determine triggering the range extended vehicle to switch to the range extended driving mode through the range extender.

[0052] The preset energy control scheme can be a scheme pre-set for energy control of the range extended vehicle. The start state of charge threshold can be a threshold for the state of charge of the battery of the range extended vehicle. The state of charge (SOC) of the battery refers to the percentage of the remaining power of the battery at a specific time relative to the rated capacity of the battery. In simple terms, it indicates how much power the battery currently stores, and is an important indicator for evaluating the charging level of the battery. The value of SOC is usually between 0% and 100%, where 0% indicates that the battery is completely discharged, and 100% indicates that the battery is fully charged.

[0053] In some embodiments, the preset energy control scheme can include controlling the start and stop of the range extender in the range extended vehicle according to the battery information of the range extended vehicle, such as the state of charge of the battery. For example, in the case where the state of charge of the battery of the range extended vehicle is less than the start state of charge threshold, it is determined to trigger the range extended vehicle to switch to the range extended driving mode through the range extender.

[0054] Step S205, updating the start state of charge threshold according to the target working point sequence to obtain a target energy control scheme, and controlling the energy of the range extended vehicle based on the target energy control scheme.

[0055] In some embodiments, the target state of charge corresponding to the switching of the range extended vehicle to the range extended driving mode during driving can be determined according to the target working point sequence, and the start state of charge threshold in the preset energy control scheme is updated based on the target state of charge to obtain the target energy control scheme.

[0056] In the above range extended vehicle energy control method, by determining the Pareto frontier between the fuel cost and the electricity consumption cost of the range extended vehicle under the condition of meeting the demand power, obtaining the Pareto solution set, and combining the NVH characteristics of the range extender in the range extended vehicle, the target working point sequence of the range extended vehicle is determined from the Pareto solution set, i.e., the working point corresponding to the range extended vehicle for achieving the comprehensive optimization of the fuel cost, the electricity consumption cost, and the noise, vibration, and roughness is determined; the start state of charge threshold in the preset energy control scheme is updated by the target working point sequence to obtain the target energy control scheme, which makes the triggering determination of the target energy control scheme for the range extended vehicle to switch to the range extended driving mode more accurate, so that the energy control of the range extended vehicle through the target energy control scheme can reduce the fuel cost and the electricity consumption cost while reducing the noise, vibration, and roughness of the vehicle.

[0057] In one embodiment, the obtaining the Pareto solution set based on the preset dynamic programming algorithm according to a Pareto frontier between fuel consumption cost of engine fuel consumption and power consumption cost of battery power consumption of the extended-range vehicle under the condition of meeting demand power can include: determining each working point of the extended-range vehicle, each working point including initial state variables and initial control variables based on grid division, the initial state variables including battery state of charge, engine speed and driving mode of the extended-range vehicle, the driving mode including at least electric-only mode and range-extended mode, and the initial control variables including engine torque, generator torque and driving mode of the extended-range vehicle; determining a target state transition model based on the preset dynamic programming algorithm, and determining the Pareto frontier between the fuel consumption cost of engine fuel consumption and the power consumption cost of battery power consumption of each working point of the extended-range vehicle under the condition of meeting demand power; and determining the Pareto solution set from each working point based on the Pareto frontier.

[0058] The working point can be used to represent the working condition of the extended-range vehicle, and each working point can correspond to a time point, so that the working point can represent the working condition of the extended-range vehicle at the corresponding time point. Each working point can include initial state variables and initial control variables based on grid division, the initial state variables including battery state of charge, engine speed and driving mode of the extended-range vehicle, the driving mode including at least electric-only mode and range-extended mode, and the initial control variables including engine torque, generator torque and driving mode of the extended-range vehicle. The electric-only mode is a mode in which the vehicle relies entirely on the power provided by the battery pack to drive the electric motor, thereby driving the wheels. This mode is usually used for daily short trips and can provide a zero-emission driving experience. When the battery power is sufficient, the vehicle will prefer to use this mode to fully utilize the high efficiency and quiet characteristics of the electric drive system. The range-extended mode is a mode in which the range extender system starts to work when the battery power falls below a preset threshold (such as a start-of-charge state threshold). The range extender can be used to generate electricity to charge the battery or directly supply the electric motor for use, thereby extending the driving range of the vehicle.

[0059] The target state transition model can be a state transition model in a dynamic programming algorithm. The state transition model can describe how to transition from one or more previous states to a current state, and such transition usually follows some optimization principle. A state in a state transition equation refers to a certain situation or position in a problem, which can be represented by one or a set of parameters. For example, in solving a knapsack problem, a state can refer to the maximum value considering the ith item and the capacity j of the knapsack. The target state transition model can be expressed by a specific state transition equation or expression, which can define how to calculate the solution of the current problem according to the known solution of the sub-problem. Among them, the state transition equation can refer to the transition rule used to describe the transition from one or more "source" states to the current state. It is established based on the principle of optimal substructure, that is, if the optimal solution of a problem contains the optimal solution of its sub-problem, the state transition equation can be used to construct the solution of this problem.

[0060] In some embodiments, an initial default original state transition model can be determined based on a preset dynamic programming algorithm, and the target state transition model can be obtained by simplifying the original state transition model. The target state transition model includes the fuel cost of engine fuel consumption and the electricity cost of battery power consumption of the extended-range vehicle under the condition of meeting the demand power. The fuel cost and the electricity cost can be used as the optimization target of the target state transition model, and the Pareto frontier between the fuel cost and the electricity cost can be constructed based on the target state transition model, so as to obtain a Pareto solution set.

[0061] Exemplarily, the controller can construct each working point of the extended-range vehicle and determine the target state transition model based on the preset dynamic programming algorithm. Each working point of the extended-range vehicle can include an initial state variable and an initial control variable of grid division, so that the target state transition model can be used to perform state transition based on the initial state variable and the initial control variable of each working point, to determine the Pareto frontier between the fuel cost and the electricity cost, and to obtain a Pareto solution set.

[0062] The above technical solution determines the target state transition model based on the preset dynamic programming algorithm, and the target state transition model can perform state transition based on the initial state variable and the initial control variable of each working point of the extended-range vehicle, so as to more quickly and accurately determine the Pareto frontier between the fuel cost of engine fuel consumption and the electricity cost of battery power consumption of the extended-range vehicle under the condition of meeting the demand power.

[0063] In one embodiment, the target state transition model performs state transition processing based on the state variable and the control variable of each working point, and the state variable Based on the corresponding initial state variables, the control variables of each operating point are obtained. Based on the corresponding initial control variables; state variables The expression is: ;in, For the The state variables at the next state transition step, is the battery charge state of the range-extended vehicle, is the engine speed of the range-extended vehicle; control variable The expression is: , For the The control variable at the next state transition step, is the engine torque; the expression corresponding to the target state transfer model is: ;in, For the The state variables at the next state transition step, It is The state variable index at the next state transition step, For the The state variables at the next state transition step, It is The state variable index at the next state transition step; Indexed by control variables Determined The control variable at the next state transition step.

[0064] For example, based on the expression corresponding to the target state transition model , the state variables of the operating point can be used and control variables Transfer to obtain the state variables for the next state transfer, and then perform the next state transfer process. is the state variable at the next moment, is the index of the next state variable (calculated by the transfer function and mapped to the discrete grid); is the state variable index, is indexed by the state variable Determine the current state variables, such as =0.5, =2000rpm; is the control variable index, Indexed by control variables Determine the current control variable (engine output torque), such as =100Nm.

[0065] Based on this, it can be determined that the expression corresponding to the current state transition step can be:

[0066]

[0067]

[0068]

[0069] wherein, is the total cost from the state transition step to the end point, the cumulative cost component of the future stage to the end point, represents the future optimal cost; is the optimal cumulative cost from the state transition step to the end point (which has been obtained by reverse solving); is the discrete state point at the state transition step . The end point (or terminal) refers to the end point of the time range of the dynamic programming optimization problem, i.e., the end state transition step of the complete driving period covered by the energy management strategy. For example, the entire journey (e.g., a 30-minute journey) of a vehicle from the starting point A to the end point B; the complete charging and discharging period of a battery from the initial SOC to the target SOC. In reverse solving, the end point state is the calculation starting point, and the end point cost is set to 0 or a fixed value. is the NVH cost item (noise vibration quantification value, unit dB), which is used to quantify the engine operating point vibration noise → mapping - to the noise decibel value; is the mode switching penalty, = 1, when the range extender is started and stopped → high-frequency switching vibration is suppressed, is the penalty coefficient; represents the current single-step cost; is the fuel consumption from state to state . And represents the total cost of the current state transition step, which is composed of the current single-step cost + the future optimal cost, which means minimizing the total cost of the current state transition step. Since the range-extended electric vehicle has pure electric and range-extending modes during driving, in order to reduce the switching frequency between modes, a preset mode switching penalty function is added to the objective function .

[0070] In some embodiments, based on the expression of the target state transition model, the target function at different time can be obtained in combination with the basic principle of dynamic programming (DP) algorithm. Exemplarily, the target function about energy consumption at the current time and the next time can be determined. In some embodiments, the target state transition model can calculate the fuel consumption and the electricity consumption at the current time, so that the fuel consumption and the electricity consumption can be sorted to form a Pareto boundary line, and a Pareto frontier between the fuel cost of the engine fuel consumption and the electricity cost of the battery electricity consumption of the extended-range vehicle under the condition of meeting the demand power can be obtained.

[0071] In one of the embodiments, determining the target working point sequence of the extended-range vehicle from the Pareto solution set according to the NVH characteristics of the range extender in the extended-range vehicle can include: constructing a target function , the expression of the target function is:

[0072]

[0073] wherein: represents the start time of the driving process of the extended-range vehicle; represents the end time of the driving process of the extended-range vehicle; represents the fuel cost of the extended-range vehicle, determined based on the fuel consumption of the driving process of the extended-range vehicle; represents the electricity cost of the extended-range vehicle, determined based on the electricity consumption change of the driving process of the extended-range vehicle; represents the NVH cost of the extended-range vehicle, determined based on the noise vibration quantification value of the driving process of the extended-range vehicle, the noise vibration quantification value being mapped based on the noise characteristics, the vibration characteristics and the roughness characteristics of the range extender; is a mode switching penalty term, used to suppress the vibration caused by the start and stop of the range extender in the driving process of the extended-range vehicle; is a preset penalty factor, used to adjust the penalty of mode switching; is a preset mode switching penalty function; based on the NVH characteristics of the range extender in the extended-range vehicle and each working point included in the Pareto solution set, the optimal solution of the target function is determined, and the working points corresponding to the optimal solution are sorted in time sequence to obtain the target working point sequence of the extended-range vehicle. Exemplarily, represents the fuel consumption rate at time t, which can be obtained by interpolating the current engine speed and torque through the pre-marked fuel consumption MAP (Performance Map, characteristic curve diagram); represents the electricity consumption of the extended-range vehicle at time t; The noise, vibration and harshness generated by the extended-range vehicle at time t can be determined based on a noise and vibration quantification value, which is mapped based on noise characteristics, vibration characteristics and harshness characteristics of the range extender.

[0074] In one embodiment, the start-of-charge state threshold is updated according to the target operating point sequence to obtain a target energy control scheme, including: determining a reference start-of-charge state threshold for the range extender based on each operating point in the target operating point sequence; and updating the start-of-charge state threshold in the preset energy control scheme by the reference start-of-charge state threshold to obtain the target energy control scheme.

[0075] The reference start-of-charge state threshold can be a start-of-charge state threshold determined based on each operating point in the target operating point sequence. For example, the SOC corresponding to each operating point can be determined based on each operating point in the target operating point sequence, and thus the SOC trajectory of the extended-range vehicle during driving can be obtained. Based on the SOC trajectory and the driving mode of the extended-range vehicle during driving, the reference start-of-charge state threshold for the range extender can be determined. The controller can update the start-of-charge state threshold in the preset energy control scheme by the reference start-of-charge state threshold to obtain the target energy control scheme. For example, the controller can perform energy control on the extended-range vehicle during driving according to the preset energy control scheme, and determine a deviation parameter in the energy control process. Based on the deviation parameter and the reference start-of-charge state threshold, an update amount can be determined, and the start-of-charge state threshold in the preset energy control scheme can be updated by the update amount to obtain the target energy control scheme. The deviation parameter can include a quantified parameter of NVH exceeding a standard (e.g., a measured noise at 1800 rpm = 68 dB), a fuel consumption deviation (e.g., an increase of 12% in fuel consumption under low-temperature conditions), a mode frequent switching parameter (e.g., an average switching of 5 times per 100 kilometers under urban conditions), etc. In some embodiments, in addition to updating the start-of-charge state threshold (SOC start-stop point) in the preset energy control scheme, the reference power generation switching point for the range extender can also be determined based on each operating point in the target operating point sequence, and the three-level power generation switching point in the preset energy control scheme can be updated by the reference power generation switching point to obtain the target energy control scheme.

[0076] In this embodiment, the start-of-charge state threshold in the preset energy control scheme is updated based on the reference start-of-charge state threshold determined based on each operating point in the target operating point sequence. Thus, the preset energy control scheme can be updated using the target operating point sequence, so that the start-of-charge state threshold in the preset energy control scheme is closer to the reference start-of-charge state threshold. This can reduce fuel cost and electricity consumption cost while reducing vehicle noise, vibration and harshness.

[0077] In one of the embodiments, the preset energy control scheme can include: in the case that the state of charge of the battery of the extended-range vehicle falls to the starting state of charge threshold, controlling the extended-range vehicle to switch the driving mode based on the state of charge of the battery and the demand power, the driving mode including the extended-range driving mode, the pure electric driving mode, the hybrid driving mode and the braking mode.

[0078] The pure electric driving mode is that the vehicle is driven completely by the electric motor powered by the power battery. The pure electric driving mode has the following characteristics: zero emission, low noise, high energy efficiency; the engine is not started, and only the battery provides power. The extended-range driving mode is that the engine is started to drive the generator to generate electricity to power the electric motor or charge the battery, thereby extending the cruising range. This mode has the following characteristics: the engine does not directly participate in driving the wheels, but only exists as a "generator"; the vehicle is always driven by the electric motor, which is closer to the electric vehicle experience than the traditional hybrid. Advantages: solving the pure electric cruising anxiety; the engine can operate in the high efficiency interval, improving fuel economy. The hybrid driving mode is that the power output of the electric motor and the engine is used to drive the wheels at the same time to achieve higher power output or better fuel efficiency. This mode has the following characteristics: the engine may directly participate in driving the wheels (parallel structure), or may work cooperatively with the electric motor. The power source can be intelligently switched according to the driving demand. Suitable scenarios: high power demand such as rapid acceleration and climbing. It is hoped to balance fuel consumption and power performance. The braking mode can include the braking energy recovery mode, that is, during the deceleration or braking of the vehicle, the electric motor is reversed to a generator to convert part of the kinetic energy into electrical energy and store it in the battery. This mode can have the following characteristics: improving energy utilization and extending cruising range; reducing wear of the traditional brake system; users can perceive different degrees of energy recovery intensity through gear or pedal.

[0079] In some embodiments, in the case that the state of charge of the battery of the extended-range vehicle falls to the starting state of charge threshold, such as 20%, and the demand power is large, such as the vehicle climbing a long steep slope, the extended-range device of the extended-range vehicle is controlled to start, for example, the extended-range vehicle is controlled to switch from the pure electric driving mode to the extended-range driving mode or the hybrid driving mode.

[0080] The above scheme determines the driving mode required to be switched by the extended-range vehicle according to the starting state of charge threshold, so that the extended-range vehicle can flexibly select between various driving modes, ensure that the state of charge of the battery is in a reasonable interval, avoid power loss, and meet the demand power at the same time.

[0081] In one of the embodiments, the preset energy control scheme can further include: in the case that the demand power is greater than the preset power threshold and the state of charge of the battery continues to fall, determining the power level of the extended-range device based on the state of charge of the battery and the preset state of charge interval, and controlling the extended-range device to perform extended-range driving according to the power corresponding to the power level.

[0082] The state of charge interval can be a preset numerical interval of the state of charge of the battery. For example, when the state of charge of the battery is in the state of charge interval, the battery power can meet the normal driving demand of the extended-range vehicle. In some embodiments, the preset power threshold can be fixed, dynamically adjustable, or customizable. In some embodiments, the power levels of the extended-range vehicle can be divided, such as levels 1 to 3, and different power levels can correspond to different demand powers and states of charge of the battery. In some embodiments, when the demand power of the extended-range vehicle is greater than the preset power threshold and the state of charge of the battery continues to decrease, i.e., the demand power is large and the SOC continues to decrease, the power level of the range extender can be determined based on the state of charge of the battery and the state of charge interval, for example, if the state of charge of the battery is lower than the state of charge interval, it can be considered that the power is too low, and thus the determined power level of the extended-range vehicle is high, so as to quickly increase the power of the vehicle battery.

[0083] The above scheme determines the driving mode to be switched by the extended-range vehicle according to the start state of charge threshold, so that the extended-range vehicle can flexibly select between various driving modes. By dividing the power levels of the range extender, the relationship between the state of charge of the battery and the state of charge interval is controlled, and the range extender is driven according to different power levels to ensure that the state of charge of the battery is in a reasonable interval, avoid power loss, and meet the demand power.

[0084] In one embodiment, the preset energy control scheme further includes: determining a braking demand of the extended-range vehicle when the demand power of the extended-range vehicle is less than or equal to 0; determining a demand braking force when the braking demand meets a preset regenerative braking condition; and controlling the motor of the extended-range vehicle to brake according to the demand braking force.

[0085] In some embodiments, the braking demand can represent that the extended-range vehicle receives an instruction from the driver to reduce the vehicle speed or even stop. In some embodiments, the preset regenerative braking condition can include at least one of the following: driving conditions: different driving conditions can affect the braking frequency and recoverable braking energy of the vehicle. Generally, in city cycle driving, there can be more opportunities for energy recovery due to frequent start-stop. Battery state: the state of charge (SOC), temperature, and charging current of the battery can affect the energy recovery capability. If the battery is close to full charge or the temperature is too high, it can not be able to accept more regenerative energy. Similarly, excessive charging current can cause the battery temperature to rise rapidly, thereby limiting energy recovery.

[0086] In one exemplary embodiment, as shown in FIG. 1, an energy control method for an extended-range vehicle is provided, which includes steps S301 to S303: Figure 3 ​

[0087] Step S301: determining the demand power of the extended-range vehicle in the driving process, based on the energy management control strategy of dynamic programming, in the case of meeting the demand power, according to the consumption of the battery power and the fuel consumption of the engine, the working points to be selected in different working modes are determined by reverse optimization, and the working points to be selected and the corresponding working modes are introduced into the dynamic programming algorithm, and the optimal control sequence is solved in the whole time sequence segment to obtain a first energy management scheme.

[0088] Among them, different working modes can include pure electric driving mode and extended-range driving mode, and the working point set composed of each working point to be selected can be used as a Pareto solution set, and the first energy management scheme can include a target working point sequence. In some embodiments, as shown in Figure 4 , a possible dynamic programming algorithm state update schematic diagram is given, Figure 4 In the figure, the vertical axis X represents the discrete values of the state variable, for example, the battery SOC (such as 0.2, 0.3, …, 0.8), the engine speed (such as 1000, 1500, …, 4600 rpm), and the working mode (pure electric driving / extended-range driving); the horizontal axis represents time, represents the initial state (such as the initial value of SOC), represents the current decision time (the kth state transition), represents the future time, is the prediction step; the white hollow node is the discretized grid point, which represents the feasible state, that is, each working point of the extended-range vehicle; the black line represents the state transition path (by controlling the action , such as adjusting the engine torque); the label D represents the decision driving factor, such as fuel cost, battery loss, NVH cost, and mode switching penalty.

[0089] In some embodiments, energy management optimization can be performed based on an improved dynamic programming algorithm to find a multi-objective optimal working point considering NVH in the extended-range mode, wherein the improvement of the dynamic programming algorithm includes: state transition model simplification, state grid length matching, and calculation logic improvement, such as Figure 5 As shown in the figure, it is a three-dimensional Pareto frontier analysis diagram, and the specific improvement is that the selection strategy is different, and the NVH is considered when selecting the point, so that the point selection can realize the joint optimization of NVH-fuel consumption-acceleration performance. Among them, the X axis is the NVH noise (dB(A)), which represents the vibration noise level of the extended-range device and reflects the comfort (the lower the value, the better), and the optimization target is to reduce the noise, that is, to improve the NVH performance; the Y axis is the acceleration time per hundred kilometers (s), which represents the vehicle dynamic performance (the lower the value, the better), and the optimization target is to reduce the acceleration time (that is, to improve the dynamic performance); the Z axis is the fuel consumption per hundred kilometers (L), which represents the fuel economy (the lower the value, the better), and the optimization target is to reduce the fuel consumption (that is, to improve the economy).

[0090] In some embodiments, a global energy management control strategy considering NVH characteristics based on dynamic programming is adopted, and the known cycle working condition is discretized into N stages in time domain, the discretization interval of the present application can be 1s (i.e. the interval length of each state transition is 1 second), the state variables of the system are represented by and the control variables are represented by , and the grid is established.

[0091] The state variables of the system are The engine speed and the battery state of charge SOC are selected as the control variables The engine torque is selected as the control variable, which can specifically include:

[0092] ,

[0093] ,

[0094] The state transition equation is:

[0095] ,

[0096] wherein, is the state variable at the k-th state transition step (or k time point), is the state of charge of the battery of the extended-range vehicle, which is the core optimization object; is the engine speed of the extended-range vehicle, which affects the NVH; is the control variable at the k-th state transition step, is the engine torque, which can realize the optimization of NVH by adjusting the engine torque; wherein, is the state variable at the k+1-th state transition step, is the state variable index at the k-th state transition step; is the state variable at the k-th state transition step, is the state variable index at the k-th state transition step; is the control variable at the k-th state transition step determined by the control variable index . is the state variable at the k-th state transition step, is the state variable index at the k-th state transition step; is the control variable at the k-th state transition step determined by the control variable index . The state transition equation represents that the control variable is applied under the current state variable , and the next time state variable is calculated through the vehicle dynamics model, so as to realize the present state transition. In the state transition equation,

[0097] the state transition equation represents that the control variable is applied under the current state variable , and the next time state variable is calculated through the vehicle dynamics model, so as to realize the present state transition. In the state transition equation, denotes the specific state number of the current kth state transition, the state space that the state variable belongs to can be discretized into a finite number of points (e.g. SOC is discretized with a step of 0.005), denotes the specific state number of the current kth state transition, the state space that the state variable belongs to can be discretized into a finite number of points (e.g. SOC is discretized with a step of 0.005), corresponds to SOC = 0.4, corresponds to SOC = 0.405, denotes the specific value of the current system state variable ; in the state transition equation, the next state variable is calculated by indexing the current state variable through the state transition equation . denotes the specific control number of the current kth state transition, the value range of the control variable can be discretized into a finite number of optional values, denotes the specific control number of the current kth state transition, the value range of the control variable can be discretized into a finite number of optional values, denotes the specific value of the current control variable.

[0098] The expression corresponding to the cumulative cost component of the future stage to the end point can be:

[0099] ,

[0100] The expression corresponding to the current single-step cost can be:

[0101] ,

[0102] The total cost of the current state transition step is further obtained as follows:

[0103] ;

[0104] wherein, is the cumulative cost component of the future stage to the end point in the total cost from the state transition step to the end point, denoting the future optimal cost; is the optimal cumulative cost from the state transition step to the end point (which can be obtained by reverse solving); is the discrete state point at the state transition step . Wherein, the end point (or terminal) refers to the time range end point of the dynamic programming optimization problem, i.e. the end state transition step of the complete driving cycle covered by the energy management strategy. For example, the whole journey (e.g. a 30-minute journey) of the vehicle from the starting point A to the end point B; the complete charging and discharging cycle of the battery from the initial SOC to the target SOC. In reverse solving, the end point state is the calculation starting point, and the end point cost is set to 0 or a fixed value. NVH cost term (quantified value of noise and vibration, unit: dB) for quantifying engine operating point vibration noise → mapping to noise decibel value; mode switching penalty, = 1, when the range extender is started and stopped → suppress high-frequency switching vibration, penalty coefficient; indicates the current single-step cost; is the fuel consumption from state to state . And the total cost of the current state transition step is composed of the current single-step cost + future optimal cost. Among them, since the range-extended electric vehicle has pure electric and range-extended modes during driving, in order to reduce the switching frequency between modes, a preset mode switching penalty function is added to the objective function .

[0105] In some embodiments, the values of the elements in the above expressions can be determined by repeated value taking, experience acquisition, etc.

[0106] In some embodiments, the energy management strategy of the range-extended electric vehicle is derived from the efficiency of the whole vehicle system, and generally selects fuel consumption as the objective function. Considering the NVH characteristics of the range extender and the normal operation of the battery next time, the battery SOC is generally maintained within a suitable range; in addition, considering the stability during system operation, frequent switching of modes and gears is avoided, so constraints can also be added, which can specifically include battery health interval constraints, power balance requirement constraints, engine operating range constraints, engine torque limit constraints, drive motor constraints, and battery charge and discharge protection constraints, as follows:

[0107]

[0108] Among them, engine torque constraint, engine speed operating range; drive motor (directly receiving battery power or generator power, output torque to drive wheels to travel) speed constraint, drive motor torque constraint; battery instantaneous power (unit: kW) at time (kth state transition). indicates the initial battery SOC and the final battery SOC. indicates the minimum engine speed, indicates the maximum engine speed; ​​MinEngineTorque, MaxEngineTorque, MinGeneratorSpeed, MaxGeneratorSpeed, MinMotorTorque, MaxMotorTorque, MinBatteryPower, MaxBatteryPower.

[0109] In some embodiments, the selection principles of the state variables and the control variables in the foregoing algorithm are as follows: the SOC change of the power battery represents the change of the energy storage of the power battery, and needs to be a state variable; the engine torque can change the size of the engine power output, and is a control variable; the generator torque can control the input power of the generator in the series mode, and can control the size of the output power in the dual-motor pure electric mode, and is a control variable; different working modes can change the state variables, and thus the working mode is a control variable; the frequent switching between modes has a greater impact on the ride comfort, and thus the mode is a state variable for easy control. The state variables and the control variables and the grid division thereof are shown in the following table.

[0110]

[0111] The first motor can be a motor generator (MG1) directly connected with the engine, and the second motor can be a drive motor (MG2) driving the wheels.

[0112] The selection strategy of the working point mainly changes the control variables and the state variables by adding a local optimization. The main idea is as follows: first, all feasible candidate working points of the engine in the extended range mode are obtained based on the DP algorithm inverse optimization, then the optimal working point is searched based on the fuel consumption and the electricity consumption, that is, the Pareto frontier is obtained, finally, the working point with the optimal NVH on the Pareto frontier is selected according to the NVH characteristics of the range extender, and the Pareto solution set is obtained. As shown in FIG. 1, the red pentagram in the figure is the optimal working point, which can correspond to the target working point sequence. Figure 5

[0113] In some embodiments, according to the NVH characteristics of the range extender, the working point with the optimal NVH on the Pareto frontier is selected, and the multi-objective function and the constraint condition of the offline optimization of the working point with the minimum fuel consumption and the NVH are optimized, and the formula of the objective function is as follows:

[0114]

[0115] wherein, ​a start time of a driving process of the extended-range vehicle; an end time of the driving process of the extended-range vehicle; a fuel cost of the extended-range vehicle, determined based on a fuel consumption of the driving process of the extended-range vehicle; an electricity cost of the extended-range vehicle, determined based on a change of electricity consumption of the driving process of the extended-range vehicle; an NVH cost of the extended-range vehicle, determined based on a noise vibration quantification value of the driving process of the extended-range vehicle, the noise vibration quantification value being mapped based on noise characteristics, vibration characteristics and sound roughness characteristics of the range extender; a mode switching penalty term, used to suppress vibration caused by starting and stopping of the range extender in the driving process of the extended-range vehicle; a penalty factor, used to adjust the penalty of mode switching; a preset mode switching penalty function; based on NVH characteristics of the range extender in the extended-range vehicle and each working point included in the Pareto solution set, an optimal solution of the target function is determined, and the working point corresponding to the optimal solution is sorted in time sequence to obtain a target working point sequence of the extended-range vehicle.

[0116] In some embodiments, the state variables are SOC, engine speed and mode, and the control variables are engine torque and mode; the grid division of the state variables and the control variables is as follows: engine speed: 1000:100:4600, wherein 1000 to 46000 is the value range of the engine speed, and 100 is the step size; SOC: 0.2:0.005:0.8, wherein 0.2 to 0.8 is the value range of the SOC, and 0.005 is the step size; engine torque: -20, 40:2:200, wherein -20, 40 to 200 is the value range of the engine torque, and 2 is the step size.

[0117] In this embodiment, when the required power is known, reverse optimization is performed (i.e., working backwards from the final state variables), and the power consumption and fuel consumption of each operating point in the pure electric / extended-range mode are compared. Among the candidate points that meet the fuel consumption and power consumption requirements, the operating point with the best NVH is selected based on the NVH characteristic curve of the range extender to obtain the Pareto solution set. Specifically, a large number of candidate operating points (different speed / torque combinations) can be generated by dynamic planning, and the fuel consumption cost and power consumption cost of each point are calculated. The Pareto frontier is screened to obtain the Pareto solution set. The operating points in the Pareto solution set meet the requirements of having lower fuel consumption than non-frontier points or lower power consumption cost than non-frontier points. In the Pareto solution set, the operating point with the lowest NVH is selected based on the NVH characteristics of the range extender in the extended-range vehicle, thereby obtaining the target operating point sequence.

[0118] In the process of determining the DP optimal sequence (i.e., the target working point sequence) based on the DP algorithm, it can be achieved through a multi-objective reverse recursive algorithm. Specifically, the end point cost can be set =0, reverse iteration starts from k=N-1, specifically decreasing from N-1 to 0: traverse all state variables ; Traverse all control variables ; Calculate single step cost ; Calculate future costs ; Update total cost ;Record the optimal control variables ; Save to DP table; Set k=k-1 for the next iteration. Among them, the single step cost It can be determined based on the fuel consumption from k to k+1, the change in battery energy, and the increase in vibration and noise at the engine operating point. Record the control variables that minimize the total cost. and its cost .

[0119] When generating the optimal sequence in the forward direction, the initial state variable of k=0 (i.e., the start time) can be determined. Taking the initial state variable as the starting point, from the starting point to the end point, the optimal control variable at time k is obtained by looking up the table in sequence. The state transfer is performed based on the vehicle dynamics model, and the corresponding control variables are determined, thereby obtaining the operating point at each moment, that is, the target operating point sequence.

[0120] Step S302: Based on the determination rule control strategy, a mode switching threshold in the feeding state of the extended-range electric vehicle is set, and combined with the optimal working range of the range extender, a second energy management solution is obtained.

[0121] The mode switching threshold value can be used as a starting charge state threshold value, and the second energy management scheme can be used as a preset energy control scheme. In some embodiments, the mode switching threshold value (i.e., the starting charge state threshold value) in the extended-range electric vehicle feeding state can be set based on a determination rule, and the second energy management scheme can be obtained in combination with the optimal working interval of the range extender and in consideration of NVH. In some embodiments, a rule-based multi-working point control strategy + power following combined energy management strategy is provided as the second energy management scheme. Specifically, when the battery SOC decreases to the range extender starting point, the multi-working point control strategy is used first to ensure excellent fuel economy and NVH, and when the vehicle demand power is large and the SOC continues to decrease, the power following strategy is used to ensure that the SOC is in a controllable interval.

[0122] In some embodiments, the range extension system needs to meet the demand of different power generation, and the engine and the generator need to be controlled in different modes to achieve the demand. The specific process of the range extension system designed in the present application from starting to power generation and then to shutdown can be divided into the following four stages, as shown in Figure 6

[0123] In the first stage, when starting the range extender, the generator is used as a starting motor to drag the engine to idle speed, so as to quickly start the range extender and avoid the engine working below idle speed, which leads to poor fuel economy and emission performance. At this time, the generator is in torque control mode.

[0124] In the second stage, when the engine is dragged to idle speed without power generation, the output torque of the generator needs to be controlled to be 0. At this time, the generator is still in torque control to avoid the engine speed overshooting, which leads to abnormal sound and other problems. At this time, the range extender does not output power to prepare for power generation at the next moment.

[0125] In the third stage, when the range extender receives a power generation request, the engine starts to inject oil and ignite, the engine is controlled in torque control mode, and the generator is switched from torque control mode to speed control mode to avoid unstable engine speed control, which leads to shaking of the range extender and other problems. Alternatively, in the third stage, PI (Proportional-Integral) closed-loop control is used for the actual power generation power and the target power generation power to obtain a feedback amount of engine torque, which is added to the requested target torque and then sent to the engine controller for execution. The power generation power coordination control strategy of the range extension system uses a multi-working point control strategy + power following combined energy management strategy.

[0126] ​The fourth stage, when the range extender receives a stop request, the engine clears the output torque, starts to stop fuel and extinguish, the generator is switched from the speed control mode to the torque control mode, outputs the reverse drag torque, and the range extender speed gradually decreases to 0. At this time, the engine speed drop process should be avoided due to inertia, and the size of the reverse drag torque and the time to stop the reverse drag need to be calibrated on the real vehicle.

[0127] In the embodiment, for the starting stage: the generator acts as a starting motor, and drags the engine to idle (torque control, to avoid degradation at low speed). For the idle and no power generation stage: the generator torque is 0 (torque control), the range extender does not generate power, and the speed is stable. For the power generation stage: the engine torque control, the generator switches to speed control, ensures stable speed to prevent shaking, and performs power generation power coordination control. For the stop stage: the engine torque is zero and the fuel is cut off, the generator switches to torque control to apply the reverse drag torque, and the speed is smoothly reduced to 0 to prevent reverse rotation.

[0128] In some embodiments, when the battery SOC decreases to the range extender starting point, a multi-working point control strategy is first adopted to ensure optimal fuel economy, and when the vehicle demand power is large and the SOC continues to decrease, a power following strategy is adopted to ensure that the SOC is in a controllable range.

[0129] Figure 7 A possible multi-working point control strategy is given, that is, a whole flowchart of a control strategy based on a determination rule. Specifically, the VCU (Vehicle Control Unit) determines the working mode (pure electric drive, regenerative braking, range extension mode) according to the SOC, vehicle speed and demand torque, and strictly follows the principle that the range extender is not started at low speed and high SOC.

[0130] Figure 8A possible power following combined energy management strategy, namely, a schematic diagram of a three-stage power generation strategy of the extended range system, is given. The WLTC (Worldwide Harmonized Light Vehicles Test Cycle) demand power is the demand power determined according to an international standard test cycle for evaluating vehicle energy consumption and emission. Specifically, the core is multi-working point control + power following, wherein SOC≤20% (first-stage power generation): start the extended range device, adopt multi-working point control, and the power generation power ≈ current demand power. In this mode, the working point with good fuel economy and NVH is preferentially selected. SOC≤15% (second-stage power generation): the power generation power is slightly higher than the current demand power, and small-scale power compensation (still possible with multi-working point) is attempted. SOC≤12% (third-stage power generation / power protection): adopt a power following strategy, the power generation power = real-time demand power + additional compensation power (such as +3kW), to ensure that the SOC does not decrease rapidly and is maintained controllable. Exemplarily, when the battery SOC decreases to the extended range device starting point, the multi-working point control strategy is first adopted to ensure excellent fuel economy and NVH, and when the vehicle demand power is large and the SOC continues to decrease, the power following strategy is adopted to ensure that the SOC is in a controllable interval. According to the height of the battery SOC.

[0131] In the embodiment, threshold rules based on working conditions (such as SOC, vehicle speed, demand torque / power) are set to determine the start-stop and working mode of the extended range device. The global optimal SOC sequence (SOC fluctuation curve over time), extended range device power distribution sequence can be determined by using each working point in the target working point sequence, so as to update the starting state of charge threshold.

[0132] Step S303: taking the first energy management scheme as a reference standard, recalibrating the switching threshold in the second energy management scheme to obtain a third energy management scheme, and performing extended range vehicle energy control based on the third energy management scheme.

[0133] The third energy management scheme can be used as a target energy control scheme. In some embodiments, the SOC trajectories of the battery in different periods, the extended range device power and the battery power based on the determination rule control strategy and the improved dynamic programming algorithm can be compared as a reference standard to recalibrate the switching threshold. In some embodiments, by constructing a perfect fuzzy rule base (calling the matlab software toolbox of the fuzzy logic algorithm), the system can dynamically adjust the power demand change rate in acceleration, deceleration and cruising conditions in real time. The control strategy realizes the collaborative optimization of fuel economy and NVH performance, effectively improves the extended range device NVH performance while ensuring energy efficiency.

[0134] In some embodiments, the energy recovery system can integrate ramping operation condition management, and maximize energy utilization through inertial kinetic energy recovery when descending. Based on the intelligent adjustment algorithm of the fuzzy controller, the optimal energy recovery efficiency can be maintained during long-time descending operation, and the recovery power is monitored and limited in the safe charging threshold of the power battery in real time.

[0135] In some embodiments, the vehicle VCU can adopt a SOC-vehicle speed-demand torque three-dimensional logical threshold decision model, and the rules are set to follow: low-speed operation priority pure electric drive; high SOC state prohibits the range extender to start. This strategy avoids the frequent start-stop of the engine in low-speed / high SOC operation from the source to solve the NVH problem of the traditional range extension system in typical urban operation.

[0136] In some embodiments, an equal power line partitioning control strategy can be adopted. For example, according to the engine power curve, the power can be divided every 5 kilowatts. Through accurate subdivision of the required power based on the vehicle speed-demand torque mapping, the system can avoid the high-speed resonance area of the engine, and stabilize the main working point in the NVH excellent interval, improving the driving experience of the vehicle. Based on the traditional range extension single working point, according to different demand power sections (mapped from vehicle speed and torque), multiple working areas are divided, and the working point of “low speed-high torque” is preferentially selected (instead of the traditional high-speed area), to avoid the high-speed resonance area of the engine and stabilize in the NVH excellent interval. Through the equal power line partitioning method, according to the vehicle speed and demand torque (i.e. demand power) conditions, the single working point of the traditional range extension scheme is converted to multiple working point logical threshold control according to the subdivision of the equal power line. When high power demand, the engine is controlled to be in high torque low speed working mode, to limit the high speed working point of the engine, so that the system works at the working point with better NVH as much as possible.

[0137] In this embodiment, the first energy management scheme (global result of DP optimization) is used as a reference standard to compare and analyze the SOC trajectory, range extender power and battery power performance of the second energy management scheme (rule control) at different time periods. According to the comparison results, the key threshold values (such as SOC start-stop point, three-stage power generation switching point, etc.) in the rule control strategy are adjusted to generate a third energy management scheme, so that the performance of the rule strategy is closer to the level of DP optimization, while solving the problems of NVH and real-time performance.

[0138] The range extending vehicle energy control method provided in the application has the core target of improving fuel economy while significantly optimizing the NVH performance (noise, vibration and harshness) of the vehicle to improve the driving comfort. Specifically, when the range extender (usually a small fuel engine) is started or operated when the battery power is low (power feeding), the noise and vibration increase significantly (the NVH performance is poor), which seriously affects the comfort. The range extending vehicle energy control method provided in the application aims to seek the best balance point of fuel consumption, power cost and NVH performance, and realize multi-objective optimization.

[0139] It should be understood that, although each step in the flowchart involved in each embodiment as described above is displayed in sequence according to the arrow, these steps are not necessarily executed in sequence according to the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other sequences. Moreover, at least part of the steps in the flowchart involved in each embodiment as described above can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of these steps or stages is not necessarily sequential, but can be alternately or alternately executed with at least part of other steps or steps or stages in other steps. It can be understood that the steps in different embodiments can be freely combined as needed, and various non-contradictory schemes formed by the combination are within the scope of protection of the application.

[0140] Based on the same inventive concept, the embodiments of the application also provide a range extending vehicle energy control device for implementing the range extending vehicle energy control method described above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more range extending vehicle energy control device embodiments provided below can refer to the limitations of the range extending vehicle energy control method described above, and will not be repeated here.

[0141] In one exemplary embodiment, as shown in Figure 9 a range extending vehicle energy control device 900 is provided, comprising:

[0142] The first determination module 901 is configured to determine the required power of the extended-range vehicle during driving; based on a preset dynamic programming algorithm, a Pareto solution set is obtained based on the Pareto front between the fuel cost of the engine fuel consumption and the electricity cost of the battery power consumption when the extended-range vehicle meets the required power; based on the NVH characteristics of the range extender in the extended-range vehicle, a target operating point sequence of the extended-range vehicle is determined from the Pareto solution set; wherein the NVH characteristics include the noise characteristics, vibration characteristics, and acoustic harshness characteristics of the range extender, and the target operating point sequence includes the operating points of the extended-range vehicle sorted in chronological order during driving;

[0143] The second determining module 902 is configured to determine a starting state of charge threshold in a preset energy control scheme for the extended-range vehicle; the starting state of charge threshold is used to determine a trigger for switching the extended-range vehicle to an extended-range driving mode for extended-range driving via the range extender; the starting state of charge threshold is updated based on the target operating point sequence to obtain a target energy control scheme;

[0144] The control module 903 is used to perform energy control on the range-extended vehicle based on the target energy control solution.

[0145] In one embodiment, the first determination module 901 is further used to determine each operating point of the extended-range vehicle, each operating point including initial state variables and initial control variables based on grid division, the initial state variables including the battery state of charge, engine speed, and driving mode of the extended-range vehicle, the driving mode including at least a pure electric driving mode and an extended-range driving mode, and the initial control variables including the engine torque, generator torque, and driving mode of the extended-range vehicle; determine a target state transition model based on a preset dynamic programming algorithm, and determine the Pareto front between the fuel cost of engine fuel consumption and the electricity cost of battery power consumption at each operating point of the extended-range vehicle while meeting the required power; and determine a Pareto solution set from each operating point based on the Pareto front.

[0146] In one embodiment, the target state transition model is based on the state variables of each operating point. and control variables Perform state transfer processing, the state variables of each working point Based on the corresponding initial state variables, the control variables of each operating point are obtained. Based on the corresponding initial control variables; state variables The expression is: ;in, For the The state variables at the next state transition step, is the battery charge state of the range-extended vehicle, is the engine speed of the range-extended vehicle; control variable The expression is: , For the The control variable at the next state transition step, is the engine torque; the expression corresponding to the target state transfer model is: ;in, For the The state variables at the next state transition step, It is The state variable index at the next state transition step, For the The state variables at the next state transition step, It is The state variable index at the next state transition step; Indexed by control variables Determined The control variable at the next state transition step.

[0147] In one embodiment, the first determining module 901 is further configured to construct an objective function , the objective function The expression is:

[0148]

[0149] in: Indicates the start time of the driving process of the extended-range vehicle; Indicates the end time of the driving process of the extended-range vehicle; represents the fuel cost of the extended-range vehicle, Determination of fuel consumption based on the driving process of the range-extended vehicle; represents the electricity consumption cost of the extended-range vehicle, Determination of the change in power consumption based on the driving process of the range-extended vehicle; represents the NVH cost of the extended range vehicle, The noise and vibration quantization value is determined based on the driving process of the range extender. The noise and vibration quantization value is obtained by mapping the noise characteristics, vibration characteristics and acoustic harshness characteristics of the range extender. The mode switching penalty term is used to suppress the vibration caused by starting and stopping the range extender during the driving process of the extended-range vehicle; is the penalty factor, used to adjust the penalty for mode switching; is the preset mode switching penalty function; based on the NVH characteristics of the range extender in the range-extended vehicle and the various working points included in the Pareto solution set, the objective function is determined The optimal solution of the optimal solution is obtained, and the working points corresponding to the optimal solution are sorted in chronological order to obtain the target working point sequence of the extended-range vehicle.

[0150] In one of the embodiments, the second determining module 902 is further configured to determine a reference start state of charge threshold for the range extender based on each working point in the target working point sequence; and update the start state of charge threshold in the preset energy control scheme by the reference start state of charge threshold to obtain a target energy control scheme.

[0151] In one of the embodiments, the preset energy control scheme comprises: in the case that the state of charge of the battery of the range extended vehicle decreases to the start state of charge threshold, controlling the range extended vehicle to switch the driving mode based on the state of charge of the battery and the demand power, the driving mode comprising a range extension driving mode, a pure electric driving mode, a hybrid driving mode and a braking mode.

[0152] In one of the embodiments, the preset energy control scheme further comprises: in the case that the demand power is greater than the preset power threshold and the state of charge of the battery continuously decreases, determining the power level of the range extender based on the state of charge of the battery and the preset state of charge interval, and controlling the range extender to drive in the range extension mode according to the power corresponding to the power level.

[0153] The modules in the range extended vehicle energy control device 900 described above can be realized by software, hardware and combinations thereof in whole or in part. The modules described above can be embedded in or independent of the processor in the controller in hardware form, or can be stored in the memory in the controller in software form so as to be called and executed by the processor to perform the operations corresponding to the modules.

[0154] In one exemplary embodiment, a controller is provided, and its internal structure diagram can be as shown in Figure 10 The controller comprises a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the controller is configured to provide computing and control capabilities. The memory of the controller comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the controller is configured to store data required for executing the range extended vehicle energy control method, such as the state of charge of the battery, the start state of charge threshold, etc. The input / output interface of the controller is configured to exchange information between the processor and external devices. The communication interface of the controller is configured to communicate with external terminals through network connection. The computer program is executed by the processor to implement a range extended vehicle energy control method.

[0155] Those skilled in the art can understand that Figure 10The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the controller to which the scheme of the present application is applied. The specific controller can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0156] In one embodiment, a controller is also provided, comprising a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method embodiments when executing the computer program.

[0157] In one embodiment, a computer readable storage medium is provided, storing a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0158] In one embodiment, a computer program product is provided, and the computer program product is executed by a processor to implement the steps in the above method embodiments.

[0159] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. In the embodiments provided in the present application, any reference to memory, database or other medium can include at least one of non-volatile memory and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. The volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0160] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described, however, any combination of the technical features is considered to be within the scope of the present application. The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A range-extended vehicle energy control method, characterized in that: The method comprises: Determine the power demand of the extended-range vehicle during driving; Obtaining a Pareto solution set based on a preset dynamic programming algorithm and a Pareto frontier between the fuel cost of the engine fuel consumption and the electricity cost of the battery power consumption of the extended-range vehicle when the required power is met; determining a target operating point sequence of the range-extended vehicle from the Pareto solution set based on NVH characteristics of the range extender in the range-extended vehicle; wherein the NVH characteristics include noise characteristics, vibration characteristics, and harshness characteristics of the range extender, and the target operating point sequence includes operating points of the range-extended vehicle sorted in chronological order during driving; Determining a starting state of charge threshold in a preset energy control scheme of the extended-range vehicle; the starting state of charge threshold is used to determine a trigger for switching the extended-range vehicle to an extended-range driving mode for performing extended-range driving via the range extender; According to the target operating point sequence, the starting charge state threshold is updated to obtain a target energy control scheme, and energy control is performed on the extended-range vehicle based on the target energy control scheme.

2. The method according to claim 1, characterized in that The preset dynamic programming algorithm is based on the Pareto frontier between the fuel cost of the engine fuel consumption and the electricity cost of the battery power consumption of the extended-range vehicle when the required power is met, and a Pareto solution set is obtained, including: Determining operating points of the range-extended vehicle, each operating point including initial state variables and initial control variables based on grid division, the initial state variables including a battery state of charge, an engine speed, and a drive mode of the range-extended vehicle, the drive mode including at least a pure electric drive mode and an extended-range drive mode, and the initial control variables including an engine torque, a generator torque, and the drive mode of the range-extended vehicle; Determining a target state transition model based on a preset dynamic programming algorithm, and determining a Pareto frontier between the fuel cost of engine fuel consumption and the electricity cost of battery power consumption at each operating point of the extended-range vehicle while meeting the required power; Based on the Pareto front, a Pareto solution set is determined from each of the operating points.

3. The method according to claim 2, characterized in that The target state transition model is used to determine the state variables of each working point based on the state variables of each working point. and control variables Perform state transfer processing, the state variables of each working point Based on the corresponding initial state variables, the control variables of each operating point are obtained. Based on the corresponding initial control variables, the state variables The expression is: ;in, For the The state variables at the next state transition step, is the battery state of charge of the range-extended vehicle, is the engine speed of the range-extended vehicle; the control variable The expression is: , For the The control variable at the next state transition step, is the engine torque; The expression corresponding to the target state transition model is: ; in, For the The state variables at the next state transition step, It is The state variable index at the next state transition step, For the The state variables at the next state transition step, It is The state variable index at the next state transition step; Indexed by control variables Determined The control variable at the next state transition step.

4. The method according to claim 1, wherein The determining, based on the NVH characteristics of the range extender in the range-extended vehicle, a target operating point sequence of the range-extended vehicle from the Pareto solution set includes: Constructing the objective function , the objective function The expression is: in: Indicates the start time of the driving process of the extended-range vehicle; Indicates the end time of the driving process of the extended-range vehicle; represents the fuel cost of the extended-range vehicle, Determining the fuel consumption during the driving process of the extended-range vehicle; represents the electricity consumption cost of the extended-range vehicle, Determining based on a change in power consumption during a driving process of the range-extended vehicle; represents the NVH cost of the EREV, Determining based on a noise and vibration quantization value during a driving process of the range-extended vehicle, the noise and vibration quantization value being obtained by mapping noise characteristics, vibration characteristics, and harshness characteristics of the range-extender; is a mode switching penalty term, used to suppress vibration caused by starting and stopping the range extender during the driving process of the range-extended vehicle; is the penalty factor, used to adjust the penalty for mode switching; Switch the penalty function for the preset mode; The objective function is determined based on the NVH characteristics of the range extender in the range-extended vehicle and the operating points included in the Pareto solution set. The optimal solution of the extended-range vehicle is obtained by sorting the operating points corresponding to the optimal solution in chronological order to obtain the target operating point sequence of the extended-range vehicle.

5. The method according to claim 1, wherein The updating of the startup state of charge threshold according to the target operating point sequence to obtain a target energy control scheme includes: determining a baseline starting state-of-charge threshold for the range extender based on each operating point in the target operating point sequence; The starting state of charge threshold in the preset energy control scheme is updated by using the reference starting state of charge threshold to obtain a target energy control scheme.

6. The method according to any one of claims 1 to 5, characterized in that The preset energy control scheme includes: When the battery state of charge of the extended-range vehicle drops to a starting state of charge threshold, the extended-range vehicle is controlled to switch a driving mode based on the battery state of charge and the required power. The driving modes include an extended-range driving mode, a pure electric driving mode, a hybrid driving mode, and a braking mode.

7. The method according to claim 6, characterized in that The preset energy control scheme also includes: When the required power is greater than a preset power threshold and the battery state of charge continues to decrease, the power level of the range extender is determined based on the battery state of charge and a preset state of charge interval, and the range extender is controlled to perform extended range driving according to the power corresponding to the power level.

8. An energy control device for a range-extended vehicle, characterized in that: The device comprises: A power demand determination module is used to determine the power demand of the range-extended vehicle during driving; a dynamic programming processing module, configured to obtain a Pareto solution set based on a Pareto frontier between the fuel cost of the engine fuel consumption and the electricity cost of the battery power consumption of the extended-range vehicle when the required power is met, based on a preset dynamic programming algorithm; Operating state determination information, used to determine a target operating point sequence of the range-extended vehicle from the Pareto solution set based on NVH characteristics of the range extender in the range-extended vehicle; wherein the NVH characteristics include noise characteristics, vibration characteristics, and harshness characteristics of the range extender, and the target operating point sequence includes operating points of the range-extended vehicle sorted in chronological order during driving; a state of charge threshold determination module, configured to determine a starting state of charge threshold in a preset energy control scheme for the range-extended vehicle; the starting state of charge threshold is used to determine a trigger for switching the range-extended vehicle to an extended-range driving mode for performing extended-range driving via the range extender; An energy control module is configured to update the startup state of charge threshold according to the target operating point sequence, obtain a target energy control scheme, and perform energy control on the range-extended vehicle based on the target energy control scheme.

9. A controller comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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