An online calculation method and system for acceleration time of hybrid electric vehicles

Abstract

This invention discloses an online calculation method and system for the acceleration time of a hybrid electric vehicle. The method includes: acquiring an acceleration condition trigger signal; collecting characteristic quantities of the vehicle's power system based on the acceleration condition trigger signal; establishing a piecewise energy supply characteristic curve function based on the power system characteristic quantities; establishing a load characteristic curve function that varies with vehicle speed based on vehicle parameters, and performing an integral averaging of the load characteristic curve function within the target acceleration speed range to obtain the equivalent average resistance power; establishing an energy conservation equation based on the piecewise energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, and solving the energy conservation equation to obtain the actual acceleration time. This invention enables accurate and real-time calculation of acceleration time during vehicle operation.

Description

Technical Field

[0001] This invention belongs to the field of hybrid vehicle power control technology, and particularly relates to an online calculation method and system for the acceleration time of a hybrid electric vehicle. Background Technology

[0002] Acceleration time (usually defined as the time required for a vehicle to accelerate from a starting position or initial speed to a target speed) is a core indicator for measuring vehicle dynamic performance. In the development and operation control of hybrid electric vehicles, accurate calculation of acceleration time is crucial for power distribution strategies, driving performance evaluation, and vehicle calibration. Existing closest technical solutions mainly fall into the following categories:

[0003] 1. Offline Integral Calculation for Pure Gasoline Vehicles: During vehicle development or calibration, engineers use Newton's second law and the engine's rated external characteristic curve to perform offline integration of the vehicle's acceleration process and calculate the theoretical acceleration time. This method is entirely based on the engine's steady-state external characteristics, does not consider the dynamic response process of the power source, and is only applicable to traditional gasoline vehicle scenarios with a single power source. It cannot be applied to hybrid electric drive architectures where the battery and engine are connected in parallel.

[0004] 2. Acceleration Time Estimation for Pure Electric Vehicles: Due to the extremely fast response of the motor in pure electric vehicles, which is approximately considered a step response, the acceleration time is usually estimated by directly integrating the peak power or rated power of the motor. This method is relatively simple. However, this method is not suitable for hybrid electric vehicles because it ignores the dynamic climbing process of the engine (range extender) building up output from zero power.

[0005] 3. Online table lookup estimation based on pedal MAP: During actual vehicle operation, the vehicle control unit (VCU) obtains the target driving power by looking up a table based on pedal depth, and estimates the acceleration time online by combining it with a preset ideal vehicle physical model. This method idealizes the engine power output as a step response, assuming that the engine reaches its maximum output power immediately upon the acceleration demand, ignoring the dynamic process of engine power buildup. This leads to overly optimistic calculation results and significant errors compared to actual vehicle acceleration performance.

[0006] The common flaw in the aforementioned existing technologies lies in their simplification of the engine (range extender) power output as an ideal step response, neglecting the actual dynamic characteristics of the engine, which is limited by mechanical inertia and thermodynamic processes, and whose power needs to gradually climb from the initial state to its maximum value at a certain slope. This step assumption means that existing methods, whether for gasoline vehicles, pure electric vehicles, or hybrid vehicles, cannot accurately reflect the acceleration time extension caused by engine dynamic response lag in real-world acceleration conditions for hybrid electric vehicles, resulting in a systematic deviation between the calculated results and actual vehicle performance. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes an online calculation method and system for the acceleration time of hybrid electric vehicles. This invention extracts three directly measurable or calibrable power system characteristic quantities to establish an energy supply characteristic curve that can truly reflect the dynamic energy supply process of the hybrid electric drive system. At the same time, it constructs a load characteristic curve that varies with vehicle speed. Based on the principle of energy conservation, the actual acceleration time is directly solved by integration, thereby achieving accurate and real-time calculation of the acceleration time during vehicle operation.

[0008] To achieve the above objectives, the present invention provides an online calculation method for the acceleration time of a hybrid electric vehicle, comprising:

[0009] Acquire acceleration condition trigger signal, and collect vehicle power system characteristic quantities based on acceleration condition trigger signal;

[0010] Based on the characteristic quantities of the power system, a piecewise energy supply characteristic curve function is established;

[0011] Based on the vehicle parameters, a load characteristic curve function that varies with vehicle speed is established, and the load characteristic curve function is integrated and averaged within the target acceleration speed range to obtain the equivalent average resistance power.

[0012] Based on the segmented energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, an energy conservation equation is established, and the actual acceleration time is obtained by solving the energy conservation equation.

[0013] Optionally, the power system characteristic quantities include: instantaneous battery discharge power, maximum target engine power, and engine power load rate;

[0014] Based on the acceleration condition trigger signal, the instantaneous discharge power of the battery is obtained in real time through the battery management system, wherein the instantaneous discharge power of the battery has a step response characteristic without delay.

[0015] Based on the acceleration condition trigger signal, the engine's maximum target power is obtained in real time through the engine management system;

[0016] Based on the acceleration condition trigger signal, the engine power loading rate is obtained by querying pre-stored calibration data or receiving dynamic estimates from the engine management system.

[0017] Optionally, based on the characteristic quantities of the power system, establishing a piecewise energy supply characteristic curve function includes:

[0018] The engine saturation time is obtained based on the engine's maximum target power and the engine's power loading rate.

[0019] Based on the engine saturation time, a segmented energy supply characteristic curve function is established.

[0020] Optionally, the segmented energy supply characteristic curve function is:

[0021] when hour:

[0022] ;

[0023] when hour:

[0024] ;

[0025] Where t is the current calculation time, T rise For engine saturation time, The energy supply characteristic curve function, This refers to the instantaneous discharge power of the battery. For the engine's maximum target power, This refers to the engine power loading rate.

[0026] Optionally, based on the vehicle parameters, the load characteristic curve function that varies with vehicle speed includes:

[0027] ;

[0028] in, This is the load characteristic curve function. The rolling resistance coefficient, For the overall vehicle quality, It is the acceleration due to gravity. air density, This is the drag coefficient. For windward area, The speed is the vehicle speed.

[0029] Optionally, the load characteristic curve function can be integrated and averaged over the target acceleration speed range to obtain the equivalent average drag power. include:

[0030] ;

[0031] in, The initial velocity is... The target speed.

[0032] Optionally, based on the segmented energy supply characteristic curve function, the equivalent average drag power, and the net kinetic energy increment, an energy conservation equation is established, and the actual acceleration time is obtained by solving the energy conservation equation, including:

[0033] The net kinetic energy increment is calculated based on the vehicle mass and the target acceleration speed range.

[0034] Based on the segmented energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, an energy conservation equation is established.

[0035] Based on the relationship between the acceleration time and the engine saturation time, the current operating condition type is determined, wherein the operating condition type includes unsaturated loading operating condition and saturated loading operating condition;

[0036] Based on the determined operating condition type, the corresponding algebraic solution strategy is selected to solve the energy conservation equation, thereby obtaining the actual acceleration time.

[0037] Optionally, based on the determined operating condition type, selecting the corresponding algebraic solution strategy to solve the energy conservation equation includes:

[0038] When the unsaturated loading condition is determined, the energy conservation equation is rearranged into a quadratic equation and the actual acceleration time is obtained by solving it.

[0039] When the saturated loading condition is determined, the energy conservation equation is rearranged into a linear equation form and the actual acceleration time is obtained by solving it.

[0040] When the actual acceleration time obtained by the solution is inconsistent with the currently determined working condition type, switch to another working condition type and solve again.

[0041] The present invention also provides an online calculation system for the acceleration time of a hybrid electric vehicle, comprising: a feature quantity acquisition module, a power supply curve establishment module, a load processing module, and an integral solution module;

[0042] The feature acquisition module is used to acquire the acceleration condition trigger signal and, based on the acceleration condition trigger signal, acquire the power system feature quantities of the vehicle.

[0043] The energy supply curve establishment module is used to establish a piecewise energy supply characteristic curve function based on the characteristic quantities of the power system.

[0044] The load processing module is used to establish a load characteristic curve function that varies with vehicle speed based on the vehicle parameters, and to perform integral averaging of the load characteristic curve function within the target acceleration speed range to obtain the equivalent average resistance power.

[0045] The integral solving module is used to establish an energy conservation equation based on the piecewise energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, and to solve the actual acceleration time based on the energy conservation equation.

[0046] Compared with the prior art, the present invention has the following advantages and technical effects:

[0047] (1) For the first time, a real dynamic power supply model was established for hybrid electric vehicles: This invention breaks through the limitations of the step assumptions of existing technologies for fuel vehicles and pure electric vehicles. By introducing the power loading rate λ, a three-segment power supply characteristic curve that can accurately describe the coexistence of battery step response and engine ramp loading was established, which truly restores the dynamic power output process of hybrid electric vehicles.

[0048] (2) Three characteristic quantities construct precise physical boundaries: This invention clearly defines the instantaneous discharge power P of the battery. bat Engine maximum target power P eng_max The three core characteristic quantities are the acceleration time, power loading rate, and λ. All three quantities can be obtained by actual measurement by on-board sensors or bench calibration. Their physical meaning is clear, which enables the calculation of acceleration time to have truly accurate physical boundary conditions.

[0049] (3) Equivalent average resistance power achieves load decoupling, balancing physical accuracy and computational real-time performance: Load characteristic curve P res The analytical expression for (v) fully preserves the physical law of road resistance changing with vehicle speed, and is used for the attached diagram description and technical disclosure. In the calculation phase, through the analysis of P... res (v) By performing integral averaging over the speed range, an analytical expression for the equivalent average resistance power containing only the initial and final vehicle speeds is derived, thus decoupling the time integral and giving the energy balance equation an algebraic solution.

[0050] (4) Applicable to online real-time calculation scenarios: The three feature quantities of the present invention can all be provided in real time by BMS and EMS. The calculation process is simple and can be embedded in VCU to realize online real-time calculation, providing real-time and accurate acceleration time input for driving performance evaluation and power distribution strategy optimization. Attached Figure Description

[0051] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0052] Figure 1 This is a flowchart of an online calculation method for the acceleration time of a hybrid electric vehicle according to an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of the power supply characteristic curve and load characteristic curve under the unsaturated loading condition according to an embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the power supply characteristic curve and load characteristic curve under saturated loading conditions according to an embodiment of the present invention. Detailed Implementation

[0055] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0056] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0057] The terms used in this embodiment are explained as follows:

[0058] 1. Power Supply Characteristic Curve: The curve showing the actual output power of the hybrid electric drive system under acceleration conditions as a function of time. It is composed of the superposition of the instantaneous discharge power of the battery (step segment) and the engine power (slope loading segment and steady-state segment), denoted as P. source (t).

[0059] 2. Load characteristic curve: The curve showing the change of road resistance power with vehicle speed during vehicle operation, including rolling resistance and air resistance, denoted as P. res It is used for physical modeling of the attached diagrams and the drag power.

[0060] 3. Instantaneous discharge power P of the battery bat (SOP, State of Power): The instantaneous discharge power that the power battery can output under the current operating conditions, provided in real time by the BMS, with a power output characteristic of a step response without delay.

[0061] 4. Engine maximum target power P eng_max The maximum power that the engine can continuously output under the current operating conditions is provided in real time by the EMS.

[0062] 5. Power loading rate λ (kW / s): The first derivative of engine output power with respect to time, characterizing the rate at which engine power is built up, i.e., the slope of the ramp segment in the Pt curve.

[0063] 6. Engine saturation time T rise T represents the time required for the engine to climb from zero to Peng_max at a power load rate λ. rise =P eng_max / λ.

[0064] 7. Equivalent average resistance power : The load characteristic curve P res (v) in the velocity range [v0, v target The equivalent constant resistance power obtained by integrating and averaging on the load is used to replace the changing load power in the energy conservation integral, thus achieving an analytical solution.

[0065] 8. Net kinetic energy increment ΔE k The vehicle accelerates from an initial speed v0 to the target speed v target The required change in kinetic energy is a fixed value.

[0066] 9. Unsaturated loading condition: Acceleration time T≤T rise This means that when acceleration ends, the engine power is still in the climbing phase and has not yet reached P. eng_max .

[0067] 10. Saturated loading condition: Acceleration time T > T rise This means that the engine has completed the climb and entered the steady-state output stage during acceleration.

[0068] This embodiment proposes an online calculation method for the acceleration time of hybrid electric vehicles, such as... Figure 1 As shown, the specific steps include:

[0069] Acquire acceleration condition trigger signal, and collect vehicle power system characteristic quantities based on acceleration condition trigger signal;

[0070] Based on the characteristic quantities of the power system, a piecewise energy supply characteristic curve function is established;

[0071] Based on the vehicle parameters, a load characteristic curve function that varies with vehicle speed is established, and the load characteristic curve function is integrated and averaged within the target acceleration speed range to obtain the equivalent average resistance power.

[0072] Based on the segmented energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, an energy conservation equation is established, and the actual acceleration time is obtained by solving the energy conservation equation.

[0073] Furthermore, the power system characteristic quantities include: instantaneous battery discharge power, maximum target engine power, and engine power loading rate;

[0074] Based on the acceleration condition trigger signal, the instantaneous discharge power of the battery is obtained in real time through the battery management system, wherein the instantaneous discharge power of the battery has a step response characteristic without delay.

[0075] Based on the acceleration condition trigger signal, the engine's maximum target power is obtained in real time through the engine management system;

[0076] Based on the acceleration condition trigger signal, the engine power loading rate is obtained by querying pre-stored calibration data or receiving dynamic estimates from the engine management system.

[0077] Specifically, this embodiment extracts and defines the following three core power system characteristic quantities as the basic inputs for constructing the energy supply characteristic curve function:

[0078] Characteristic quantity I: Instantaneous discharge power of the battery (State of Power, SOP) definition: The instantaneous discharge power that a power battery can output under its current state of charge (SOC) and state of health (SOH), measured in kW.

[0079] Features: The battery has extremely fast electrochemical response characteristics, reaching its maximum speed the instant the vehicle controller issues the drive command (t=0). It is considered as a step response with no delay.

[0080] Characteristic Quantity II: Maximum Target Power of the Engine Definition: The maximum steady-state output power that an engine (or range extender) can physically provide under current operating conditions, measured in kW.

[0081] Characteristic: This value represents the upper limit of power that the engine can maintain after it has completed its power ramp-up.

[0082] Characteristic Quantity III: Engine Power Load Rate (Unit: kW / s) Definition: The rate at which an engine (or range extender) builds torque and increases output power from its current power state, i.e., the first derivative of output power with respect to time. This reflects the engine's dynamic response capability.

[0083] Characteristics: It is represented by the slope of the engine power loading stage on the power-time curve.

[0084] Furthermore, based on the characteristic quantities of the power system, the segmented energy supply characteristic curve function is established, including:

[0085] The engine saturation time is obtained based on the engine's maximum target power and the engine's power loading rate.

[0086] Based on the engine saturation time, a segmented energy supply characteristic curve function is established.

[0087] Optionally, the segmented energy supply characteristic curve function is:

[0088] when hour:

[0089] ;

[0090] when hour:

[0091] ;

[0092] Where t is the current calculation time, T rise For engine saturation time, The energy supply characteristic curve function, This refers to the instantaneous discharge power of the battery. For the engine's maximum target power, This refers to the engine power loading rate.

[0093] Among them, engine saturation time For the engine to start from zero power at load rate Time required to climb to maximum power:

[0094] ;

[0095] This curve describes the three-stage real-world power supply process of the hybrid electric drive system: "instantaneous battery step load + engine ramp loading + engine steady-state saturation".

[0096] Furthermore, based on the vehicle parameters, the load characteristic curve function that varies with vehicle speed is established, including:

[0097] ;

[0098] in, This is the load characteristic curve function. The rolling resistance coefficient, For the overall vehicle quality, It is the acceleration due to gravity. air density, This is the drag coefficient. For windward area, The speed is the vehicle speed.

[0099] Due to vehicle speed During acceleration, the load curve changes unpredictably over time. To achieve real-time low-computing-power solution for the onboard controller and decouple time integration, this invention utilizes the variable load curve. In the target acceleration range By performing equivalent integration within the inner quadrant, the average drag power can be obtained. .

[0100] The mathematical integral average of the drag power over the speed range is calculated as follows:

[0101] ;

[0102] After integration and simplification, we obtain the analytical expression for the equivalent average load:

[0103] ;

[0104] in, The initial velocity is... The target speed.

[0105] Furthermore, based on the segmented energy supply characteristic curve function, the equivalent average drag power, and the net kinetic energy increment, an energy conservation equation is established, and the actual acceleration time is obtained by solving the energy conservation equation, including:

[0106] The net kinetic energy increment is calculated based on the vehicle mass and the target acceleration speed range.

[0107] Based on the segmented energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, an energy conservation equation is established.

[0108] Based on the relationship between the acceleration time and the engine saturation time, the current operating condition type is determined, wherein the operating condition type includes unsaturated loading operating condition and saturated loading operating condition;

[0109] Based on the determined operating condition type, the corresponding algebraic solution strategy is selected to solve the energy conservation equation, thereby obtaining the actual acceleration time.

[0110] Furthermore, based on the determined operating condition type, selecting the corresponding algebraic solution strategy to solve the energy conservation equation includes:

[0111] When the unsaturated loading condition is determined, the energy conservation equation is rearranged into a quadratic equation and the actual acceleration time is obtained by solving it.

[0112] When the saturated loading condition is determined, the energy conservation equation is rearranged into a linear equation form and the actual acceleration time is obtained by solving it.

[0113] When the actual acceleration time obtained by the solution is inconsistent with the currently determined working condition type, switch to another working condition type and solve again.

[0114] Specifically, according to the kinetic energy theorem, the vehicle starts from an initial velocity of... Accelerate to target speed Required net kinetic energy increment A constant value:

[0115] ;

[0116] Acceleration time Internally, the total energy output by the actual power source minus the energy consumed to overcome the equivalent average resistance equals the net increase in kinetic energy. Based on this, a macroscopic energy balance equation can be established:

[0117] ;

[0118] Based on actual acceleration time With engine saturation time The magnitude relationship is solved under two working conditions:

[0119] Operating Condition 1: Unsaturated Loading Condition Under this condition, the engine power is still in the climbing phase at the end of acceleration. Substituting the energy supply function into the energy balance equation:

[0120] ;

[0121] Performing the integration operation, we get:

[0122] ;

[0123] Organized into a list of things to do The quadratic equation of :

[0124] ;

[0125] By using the quadratic formula and taking the physically meaningful positive root, the algebraic solution for the actual acceleration time can be directly obtained:

[0126] ;

[0127] Working condition 2: Saturated loading condition );

[0128] Under this condition, the engine has completed its power ramp-up during acceleration and maintains maximum power operation. The power supply curve is integrated piecewise (ramp section + steady-state section):

[0129] ;

[0130] Substitution Combining the two integrals and simplifying the total energy supplied on the left side, the equation becomes:

[0131] ;

[0132] Organize and extract The linear algebraic solution for the actual acceleration time is obtained:

[0133] .

[0134] The following is a detailed description of this embodiment with reference to the accompanying drawings:

[0135] like Figure 1 As shown, the specific steps are as follows:

[0136] Step 1: Collect three core power system characteristic quantities:

[0137] When acceleration is triggered, the vehicle control unit (VCU) collects the following three characteristic quantities in real time via the CAN bus:

[0138] Battery instantaneous discharge power P bat : Calculated and output in real time by BMS;

[0139] Engine maximum target power P eng_max The EMS calculates and outputs the results in real time based on the current operating conditions.

[0140] Power loading rate λ: obtained by the VCU from the calibration MAP table, or dynamically estimated by the EMS and then transmitted to the VCU.

[0141] Step 2: Establish the energy supply characteristic curve:

[0142] Based on the three collected feature quantities, the engine saturation time T is calculated. rise =P eng_max / λ, establish segmented energy supply characteristic curve P source (t): 0 to T rise Phase P source (t)=P bat +λt (Battery step + Engine ramp loading); T rise Then P source (t)=P bat +P eng_max (Battery step output + engine steady-state output).

[0143] Step 3: Establish the load characteristic curve and derive the equivalent average resistance power:

[0144] Based on the vehicle parameters, establish the load characteristic curve of road resistance power as a function of vehicle speed: The accompanying diagram is used to illustrate the physical laws governing road loads.

[0145] To achieve analytical solution, for P res (v) in the acceleration range [v0, v target By integrating and averaging over the [aspect], we obtain the analytical expression for the equivalent average drag power:

[0146] ;

[0147] This value is calculated once when the acceleration condition is triggered, and does not need to be iteratively updated during the integration process.

[0148] Step 4: Calculate the net kinetic energy increment, determine the operating condition, and solve for the acceleration time.

[0149] Calculate the net kinetic energy increment .

[0150] Based on the parameters of the energy supply characteristic curve, the operating condition type is initially determined, and the corresponding equation is selected for solution:

[0151] Unsaturated loading condition (T≤T) riseThe energy conservation integral equation, after expansion and rearrangement, becomes a quadratic equation in one variable. Taking the positive root:

[0152] ;

[0153] Saturated loading condition (T>T) rise After piecewise integration and simplification to a linear equation, we obtain:

[0154] ;

[0155] If the solution result is inconsistent with the operating condition judgment (e.g., T>T under unsaturated operating condition), rise If the equation fails, then switch to another working condition equation and solve it again.

[0156] Figure 2 For unsaturated loading conditions (T≤T) rise A schematic diagram of the power supply characteristic curve and load characteristic curve (Pt coordinate system) is shown below. The shaded area between the two curves is the net kinetic energy increment ΔE. k ;

[0157] Figure 3 For saturated loading condition (T>T) rise A schematic diagram of the power supply characteristic curve and load characteristic curve under (Pt coordinate system); the shaded area between the two curves is equal to ΔE. k .

[0158] Step 5: Output the actual acceleration time:

[0159] The T obtained from the above solution is used as the acceleration of the vehicle from the initial velocity v0 to the target vehicle speed v. target The actual acceleration time output is used by the vehicle controller for power performance evaluation, driving performance feedback, and power distribution strategy optimization.

[0160] This embodiment also provides an online calculation system for the acceleration time of a hybrid electric vehicle, including: a feature quantity acquisition module, a power supply curve establishment module, a load processing module, and an integral solution module;

[0161] The feature acquisition module is used to acquire the acceleration condition trigger signal and, based on the acceleration condition trigger signal, acquire the power system feature quantities of the vehicle.

[0162] The energy supply curve establishment module is used to establish a piecewise energy supply characteristic curve function based on the characteristic quantities of the power system.

[0163] The load processing module is used to establish a load characteristic curve function that varies with vehicle speed based on the vehicle parameters, and to perform integral averaging of the load characteristic curve function within the target acceleration speed range to obtain the equivalent average resistance power.

[0164] The integral solving module is used to establish an energy conservation equation based on the piecewise energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, and to solve the actual acceleration time based on the energy conservation equation.

[0165] Specifically, the feature acquisition module communicates with the BMS and EMS to acquire the instantaneous discharge power P of the battery in real time. bat Engine maximum target power P eng_max The three dynamic system characteristic quantities are λ and λ'.

[0166] Energy supply curve generation module: based on P bat P eng_max Calculate the engine saturation time T using λ. rise Establish segmented energy supply characteristic curve P source (t) describes the real dynamic power output process where battery step loading and engine ramp loading coexist.

[0167] Load curve generation module: Generates load characteristic curves of road resistance power as a function of vehicle speed based on vehicle parameters. It is used for drawing diagrams and physical modeling.

[0168] Equivalent resistance calculation module: calculates the load characteristic curve function in the speed range [v0, v target The equivalent average drag power is calculated by integrating and averaging the values. The analytical value is obtained to decouple the time variable in the energy conservation integral equation.

[0169] Operating condition judgment module: Based on the current parameters, make a preliminary judgment on the acceleration time T and saturation time T rise Based on the magnitude relationship, select the corresponding equation model.

[0170] Integral solution module: Substitutes the energy supply characteristic curve function and the equivalent average resistance power into the energy conservation equation, solves the algebraic solution according to the operating conditions, and outputs the actual acceleration time T; if the operating condition judgment does not match the solution result, it will automatically switch and solve again.

[0171] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An online calculation method for the acceleration time of a hybrid electric vehicle, characterized in that, include: Acquire acceleration condition trigger signal, and collect vehicle power system characteristic quantities based on acceleration condition trigger signal; Based on the characteristic quantities of the power system, a piecewise energy supply characteristic curve function is established; Based on the vehicle's weight, frontal area, frontal coefficient, tire friction coefficient, and ground friction coefficient, a load characteristic curve function that varies with vehicle speed is established. The load characteristic curve function is then integrated and averaged within the target acceleration speed range to obtain the equivalent average resistance power. Based on the segmented energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, an energy conservation equation is established, and the actual acceleration time is obtained by solving the energy conservation equation.

2. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 1, characterized in that, The characteristic parameters of the power system include: instantaneous battery discharge power, maximum target engine power, and engine power loading rate; Based on the acceleration condition trigger signal, the instantaneous discharge power of the battery is obtained in real time through the battery management system, wherein the instantaneous discharge power of the battery has a step response characteristic without delay. Based on the acceleration condition trigger signal, the engine's maximum target power is obtained in real time through the engine management system; Based on the acceleration condition trigger signal, the engine power loading rate is obtained by querying pre-stored calibration data or receiving dynamic estimates from the engine management system.

3. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 2, characterized in that, Based on the aforementioned power system characteristic quantities, the piecewise energy supply characteristic curve function is established as follows: The engine saturation time is obtained based on the engine's maximum target power and the engine's power loading rate. Based on the engine saturation time, a segmented energy supply characteristic curve function is established.

4. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 3, characterized in that, The segmented energy supply characteristic curve function is: when hour: ； when hour: ； Where t is the current calculation time, T rise For engine saturation time, The energy supply characteristic curve function, This refers to the instantaneous discharge power of the battery. For the engine's maximum target power, This refers to the engine power loading rate.

5. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 4, characterized in that, Based on the vehicle parameters, the load characteristic curve function that varies with vehicle speed is established as follows: ； in, This is the load characteristic curve function. The rolling resistance coefficient, For the overall vehicle quality, It is the acceleration due to gravity. air density, This is the drag coefficient. For windward area, The speed is the vehicle speed.

6. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 5, characterized in that, The equivalent average drag power is obtained by integrating and averaging the load characteristic curve function over the target acceleration speed range. include: ； in, Let the initial velocity be , The target speed.

7. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 6, characterized in that, Based on the segmented energy supply characteristic curve function, equivalent average drag power, and net kinetic energy increment, an energy conservation equation is established, and the actual acceleration time is obtained by solving the energy conservation equation, including: The net kinetic energy increment is calculated based on the vehicle mass and the target acceleration speed range. Based on the segmented energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, an energy conservation equation is established. Based on the relationship between the acceleration time and the engine saturation time, the current operating condition type is determined, wherein the operating condition type includes unsaturated loading operating condition and saturated loading operating condition; Based on the determined operating condition type, the corresponding algebraic solution strategy is selected to solve the energy conservation equation, thereby obtaining the actual acceleration time.

8. The online calculation method for acceleration time of a hybrid electric vehicle according to claim 7, characterized in that, Based on the determined operating condition type, the corresponding algebraic solution strategy is selected to solve the energy conservation equation, including: When the unsaturated loading condition is determined, the energy conservation equation is rearranged into a quadratic equation and the actual acceleration time is obtained by solving it. When the saturated loading condition is determined, the energy conservation equation is rearranged into a linear equation form and the actual acceleration time is obtained by solving it. When the actual acceleration time obtained by the solution is inconsistent with the currently determined working condition type, switch to another working condition type and solve again.

9. An online calculation system for the acceleration time of a hybrid electric vehicle, used to implement the method as described in any one of claims 1-8, characterized in that, include: Feature quantity acquisition module, power supply curve establishment module, load processing module, and integral solution module; The feature acquisition module is used to acquire the acceleration condition trigger signal and, based on the acceleration condition trigger signal, acquire the power system feature quantities of the vehicle. The energy supply curve establishment module is used to establish a piecewise energy supply characteristic curve function based on the characteristic quantities of the power system. The load processing module is used to establish a load characteristic curve function that varies with vehicle speed based on the vehicle parameters, and to perform integral averaging of the load characteristic curve function within the target acceleration speed range to obtain the equivalent average resistance power. The integral solving module is used to establish an energy conservation equation based on the piecewise energy supply characteristic curve function, the equivalent average resistance power, and the net kinetic energy increment, and to solve the actual acceleration time based on the energy conservation equation.

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