Range extender control strategy analysis method and system

Abstract

The invention relates to the technical field of hybrid vehicles, in particular to an analysis method and system for a range extender control strategy. According to the method for analyzing the control strategy of the range extender, the control strategy of the range extender is obtained through fitting of theoretical derivation and a two-dimensional interpolation method on the basis of an analyzed CAN signal and a wheel end torque sensor test data set, and the test result is consistent with simulation through simulation and real vehicle verification. According to the invention, the blank that the extended-range hybrid control strategy of the reference vehicle cannot be obtained during the development of the extended-range hybrid vehicle model of the main engine plant is filled; the analyzed control strategy is based on the reference vehicle, and the drivability, the NVH and the power economy are considered; the new test method has already been applied to the development of existing extended-range hybrid vehicle type products of companies.

Description

Technical Field

[0001] The present invention relates to the technical field of hybrid vehicles, and in particular to an analysis method and system for a range extender control strategy. Background Art

[0002] The fuel consumption of extended-range hybrid vehicles is lower than that of gasoline vehicles, and the user cost is low. Extended-range hybrid models are favored by the majority of users. One of the key factors for the fuel saving of extended-range hybrid models is the control strategy of the range extender. The control strategy of the range extender mainly includes the series connection of the vehicle speed engine speed calibration table and the engine speed torque calibration table. In the existing vehicle power economy benchmarking test, the extended-range hybrid model is shipped to the vehicle test site and the vehicle is shipped to the emission room for direct testing. The test obtains vehicle-level indicators such as vehicle acceleration time, climbing performance and maximum speed, as well as fuel consumption, pure electric mileage, etc., or the vehicle is evaluated by adding some sensors. It is extremely difficult to deeply benchmark the control strategy of its range extender, and there is a problem that it is impossible to provide development suggestions for the company's key performance development of related extended-range hybrid models such as power economy, NVH and drivability;

[0003] The existing vehicle power economy, NVH and drivability tests are costly. If the control strategy of the range extender hybrid model cannot be obtained, in-depth benchmarking cannot be carried out. In-depth analysis requires access to relevant sensor equipment, which increases the testing cost exponentially. The entire control strategy cannot be analyzed as a whole, and only one-sided performance can be taken into account, resulting in problems of repeated testing. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the present invention provides an analytical method for the range extender control strategy, which can solve the problems of the traditional method that the control calibration strategy of the range extender hybrid vehicle cannot be obtained, the actual vehicle calibration is repeated, the test efficiency is low, and the test cost is high.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for analyzing the control strategy of a range extender, comprising: reversely analyzing the CAN signal of the whole vehicle to obtain the key signal of the control strategy of the range extender of the benchmark vehicle;

[0007] Formulate a range extender vehicle test condition matrix;

[0008] Place the vehicle on the test bench in the laboratory, connect the wheel-end sensor to measure the wheel-end torque, and test the relevant data according to the matrix test table;

[0009] Refresh the vehicle data in extended-range hybrid mode;

[0010] Calculate the drive motor power based on the wheel end torque and vehicle speed data in the test data;

[0011] Calculate the generator power requirement based on the drive motor power and drive motor efficiency, drive motor electronic control efficiency, generator efficiency and generator electronic control efficiency;

[0012] According to the generator power demand, vehicle speed and engine speed data column, two-dimensional interpolation is used to obtain the range extender engine operating speed matrix calibration table;

[0013] According to the generator power demand, engine speed and engine torque data columns, two-dimensional interpolation is used to obtain the range extender engine operating torque matrix calibration table;

[0014] Based on the company's existing engine characteristic data with similar displacement, the best economic line data is obtained in Excel according to the principle of minimum fuel consumption rate;

[0015] According to the obtained engine operation point matrix calibration table, the range extender generator speed torque working matrix calibration table is calculated according to the formula based on the speed ratio and transmission efficiency;

[0016] The obtained engine speed and engine torque calibration matrix table of the range extender control strategy is compared with the data of the engine's optimal economic line, and the operating points beyond the engine's operating range are deleted and replaced with the optimal economic operating points;

[0017] The obtained range extender control strategy calibration table is placed in the power economy model of the extended-range hybrid vehicle of the relevant product for simulation verification to evaluate whether it meets the vehicle fuel consumption target. The vehicle fuel consumption is tested according to the national standard to evaluate the consistency between the analyzed control strategy and the actual vehicle test results.

[0018] As a preferred solution of the analytical method of the range extender control strategy described in the present invention, the key signals include vehicle speed, throttle opening, engine speed, engine torque, generator speed, generator torque, drive motor speed, drive motor torque, and SOC.

[0019] As a preferred solution of the analytical method of the range extender control strategy described in the present invention, wherein: the calculated drive motor power is expressed as,

[0020]

[0021] Among them, T wheel is the wheel end torque, Nm; V veh is the vehicle speed, kph; i final Main reduction ratio; η gear is the main reducer efficiency; r tire is the tire rolling radius, mm.

[0022] As a preferred solution of the analytical method of the range extender control strategy described in the present invention, wherein: the calculated generator power demand is expressed as,

[0023]

[0024] Among them, η mot is the drive motor efficiency; η mot_controller is the electronic control efficiency of the drive motor; η gen is the generator efficiency -; η gen_controller is the generator electronic control efficiency.

[0025] As a preferred solution of the analytical method of the range extender control strategy described in the present invention, the calculation matrix calibration table of the range extender generator speed torque is expressed as:

[0026]

[0027] n gen =n eng i gen

[0028] Among them, T eng is the engine torque, Nm; i gen is the generator speed ratio.

[0029] As a preferred solution of the analytical method of the range extender control strategy described in the present invention, the brushing of vehicle data in the extended-range hybrid mode includes, according to the engine speed>0, brushing the vehicle speed data column, engine speed data column, engine torque data column and wheel end torque data column in the extended-range hybrid mode in Excel.

[0030] As a preferred solution of the analytical method of the range extender control strategy described in the present invention, the simulation verification includes evaluating whether the vehicle fuel consumption target is met, testing the vehicle fuel consumption according to the national standard, and evaluating the consistency between the analyzed control strategy and the actual vehicle test results.

[0031] As a preferred solution of the analytical system of the range extender control strategy described in the present invention, it includes: a CAN signal analytical analysis module, a range extender test data processing module, a generator power calculation and analysis module, an engine speed torque calibration module, and a control strategy calibration simulation module;

[0032] The CAN signal parsing and analysis module extracts key signals from the vehicle CAN bus, parses and records them;

[0033] The range extender test data processing module organizes, cleans and pre-processes the collected test data to ensure data quality;

[0034] The motor power calculation and analysis module calculates the power of the drive motor according to the wheel end torque and the vehicle speed data, and calculates the generator power requirement according to the drive motor power and the drive motor efficiency, the drive motor electronic control efficiency, the generator efficiency and the generator electronic control efficiency;

[0035] The engine speed calibration module establishes an engine operating speed matrix and an engine operating torque matrix calibration table by a two-dimensional interpolation method;

[0036] The control strategy calibration simulation module applies the calibrated range extender control strategy to the power economy model to evaluate whether it meets the vehicle fuel consumption target, and tests the vehicle fuel consumption according to the national standard to evaluate the consistency between the analyzed control strategy and the actual vehicle test results.

[0037] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the processor implements the steps of any one of the methods for analyzing a range extender control strategy.

[0038] 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 any one of the methods for analyzing a range extender control strategy are implemented.

[0039] The beneficial effects of the present invention are as follows: it fills the gap that the main engine factory cannot conduct in-depth benchmarking analysis and cannot obtain the extended-range hybrid control strategy of the reference vehicle in the development of extended-range hybrid models; the analyzed control strategy takes into account the drivability, NVH and power economy of the reference vehicle, and provides suggestions for the overall development of vehicle performance; without increasing the cost of vehicle testing and development, the vehicle control strategy is obtained, and at the same time, the vehicle energy data flow analysis is provided for the energy flow test of the whole vehicle and the solution of vehicle performance problems, which greatly improves the product development efficiency. The new test method has been applied to the company's current hybrid vehicle product development, and the main effects are as follows: the product development cycle is reduced by about 1 month, and the bench test cost is reduced by more than 1 million; the vehicle energy flow data and range extender control strategy of the mainstream extended-range hybrid vehicle are obtained, and the energy flow test database and control strategy library of the competing vehicle are formed; it helps the brand to move up and the vehicle performance of the listed products is recognized by the company and users. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0041] Figure 1 A schematic flow chart of a method for analyzing a range extender control strategy provided by an embodiment of the present invention.

[0042] Figure 2 A range extender analysis strategy simulation and actual vehicle test results comparison of a range extender analysis method of a range extender control strategy provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0044] Example 1

[0045] Reference Figure 1 , which is the first embodiment of the present invention, and provides a method for analyzing a range extender control strategy, comprising:

[0046] 1. Reverse analysis of the vehicle CAN signal to identify the key signals of the benchmark vehicle's range extender control strategy, including vehicle speed, throttle opening, engine speed, engine torque, generator speed, generator torque, drive motor speed, drive motor torque, and SOC;

[0047] 2. Develop a range extender vehicle test condition matrix, as shown in Table 1;

[0048] Table 1 Range extender control strategy analysis test condition matrix

[0049]

[0050] 3. Place the vehicle on the test bench in the laboratory, connect the wheel-end sensor to measure the wheel-end torque, and test the relevant data according to the matrix test table 1;

[0051] 4. According to the engine speed>0, select the vehicle speed data column, engine speed data column, engine torque data column and wheel end torque data column in the extended-range hybrid mode under different SOC in Excel;

[0052] 5. Calculate the drive motor power requirement according to the following formula based on the wheel end torque data column and vehicle speed data column in the test data;

[0053]

[0054] 6. According to the drive motor power demand data column in step 5 and the drive motor efficiency, drive motor electronic control efficiency, generator efficiency and generator electronic control efficiency, the generator power demand is calculated according to the following formula;

[0055]

[0056] 7. According to the generator power demand data column, the vehicle speed data column and the engine speed data column, two-dimensional interpolation is performed to obtain the range extender engine operating speed matrix calibration table, taking low SOC as an example, as shown in Table 2;

[0057] Table 2 Range extender engine operating speed matrix calibration table

[0058]

[0059] 8. According to the vehicle speed data column, the engine speed data column and the engine torque data column, two-dimensional interpolation is performed to obtain the range extender engine running torque matrix calibration table, taking low SOC as an example, as shown in Table 3;

[0060] Table 3 Range extender engine operating torque matrix calibration table

[0061]

[0062]

[0063] 9. Based on the company's existing engine characteristic data with similar displacement, obtain the best economic line data in Excel according to the principle of minimum fuel consumption rate;

[0064] 10. Compare the obtained engine speed and engine torque calibration matrix table of the range extender control strategy with the data of the engine's optimal economic line, delete the points that exceed the rated operating point of the engine and replace them with the optimal economic operating point;

[0065] 11. According to the obtained engine operation point matrix calibration table, the range extender generator speed torque working matrix calibration table is calculated according to the speed ratio and transmission efficiency according to the following formula, taking low SOC as an example, as shown in Table 4 and Table 5;

[0066]

[0067] n gen =n eng i gen

[0068] Table 4 Range extender generator operating speed matrix calibration table

[0069]

[0070]

[0071] Table 5 Range extender generator operating torque matrix calibration table

[0072]

[0073] 12. Put the range extender control strategy calibration table obtained in step 3-11 into the power economy model of the extended-range hybrid vehicle of the company's related products for simulation verification to evaluate whether it meets the vehicle fuel consumption target, and test the vehicle fuel consumption according to the national standard to evaluate the consistency of the analyzed control strategy and the actual vehicle test results. Figure 2 shown.

[0074] Example 2

[0075] The second embodiment of the present invention provides a range extender control strategy analysis system, which is characterized by comprising: a CAN signal analysis module, a range extender test data processing module, a generator power calculation analysis module, an engine speed torque calibration module, and a control strategy calibration simulation module;

[0076] The CAN signal parsing and analysis module extracts key signals from the vehicle CAN bus, parses and records them;

[0077] The range extender test data processing module organizes, cleans and pre-processes the collected test data to ensure data quality;

[0078] The motor power calculation and analysis module calculates the power of the drive motor according to the wheel end torque and the vehicle speed data, and calculates the generator power requirement according to the drive motor power and the drive motor efficiency, the drive motor electronic control efficiency, the generator efficiency and the generator electronic control efficiency;

[0079] The engine speed calibration module establishes an engine operating speed matrix and an engine operating torque matrix calibration table by a two-dimensional interpolation method;

[0080] The control strategy calibration simulation module applies the calibrated range extender control strategy to the power economy model to evaluate whether it meets the vehicle fuel consumption target, and tests the vehicle fuel consumption according to the national standard to evaluate the consistency between the analyzed control strategy and the actual vehicle test results.

[0081] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0082] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0083] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0084] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0085] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0086] Example 3

[0087] like Figure 2 As shown, it is the third embodiment of the present invention, which provides an analytical method for the range extender control strategy. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0088] In Amesim software, a simulation model of the power economy of the extended-range hybrid vehicle is established. The simulation model is as follows: Figure 2 As shown in the figure, the obtained control strategy of the range extender is replaced into the whole vehicle control strategy model for simulation, and the fuel consumption test of the whole vehicle under WLTC working condition is carried out. The test data is imported into the whole vehicle simulation model, and the simulation results are compared with the actual vehicle results. The effectiveness of the control strategy is judged by judging whether the fuel consumption test results and the simulation results are within 0.1L / 100km.

[0089] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for analyzing the control strategy of a range extender, characterized by: include, Reverse analysis of vehicle CAN signals to compare key signals of the range extender control strategy of the benchmark vehicle; Formulate a range extender vehicle test condition matrix; Place the vehicle on the test bench in the laboratory, connect the wheel-end sensor to measure the wheel-end torque, and test the relevant data according to the matrix test table; Refresh the vehicle data in extended-range hybrid mode; Calculate the drive motor power based on the wheel end torque and vehicle speed data in the test data; Calculate the generator power requirement based on the drive motor power and drive motor efficiency, drive motor electronic control efficiency, generator efficiency and generator electronic control efficiency; According to the generator power demand, vehicle speed and engine speed data column, two-dimensional interpolation is used to obtain the range extender engine operating speed matrix calibration table; According to the generator power demand, engine speed and engine torque data columns, two-dimensional interpolation is used to obtain the range extender engine operating torque matrix calibration table; Based on the existing characteristic data of engines with similar displacement, the best economic line data is obtained in Excel according to the principle of minimum fuel consumption rate; According to the obtained engine operation point matrix calibration table, the range extender generator speed torque working matrix calibration table is calculated according to the formula based on the speed ratio and transmission efficiency; The obtained engine speed and engine torque calibration matrix table of the range extender control strategy is compared with the data of the engine's optimal economic line, and the operating points beyond the engine's operating range are deleted and replaced with the optimal economic operating points; The obtained range extender control strategy calibration table is placed in the power economy model of the extended-range hybrid vehicle of the relevant product for simulation verification.

2. The method for analyzing the range extender control strategy according to claim 1, characterized in that: The key signals include vehicle speed, throttle opening, engine speed, engine torque, generator speed, generator torque, drive motor speed, drive motor torque, and SOC.

3. The analytical method for the range extender control strategy according to claim 2, characterized in that: The calculated driving motor power is expressed as, Among them, T wheel is the wheel end torque, Nm; V veh is the vehicle speed, kph; i final Main reduction ratio; η gear is the main reducer efficiency; r tire is the tire rolling radius, mm.

4. The method for analyzing the range extender control strategy according to claim 3, characterized in that: The calculated generator power demand is expressed as, Among them, η mot is the drive motor efficiency; η mot_controller is the electronic control efficiency of the drive motor; η gen is the generator efficiency; η gen_controller is the generator electronic control efficiency.

5. The method for analyzing the range extender control strategy according to claim 4, characterized in that: The calculation table of the range extender generator speed torque working matrix calibration is expressed as: n gen =n eng i gen Among them, T eng is the engine torque, Nm; i gen is the generator speed ratio.

6. The method for analyzing the range extender control strategy according to claim 5, characterized in that: The step of refreshing the vehicle data in the extended-range hybrid mode includes refreshing the vehicle speed data column, the engine speed data column, the engine torque data column and the wheel end torque data column in the extended-range hybrid mode in Excel according to the engine speed>0.

7. The method for analyzing the range extender control strategy according to claim 6, characterized in that: The simulation verification includes evaluating whether the vehicle meets the fuel consumption target, testing the vehicle fuel consumption according to the national standard, and evaluating the consistency between the analyzed control strategy and the actual vehicle test results.

8. A system based on the analytical method of a range extender control strategy according to any one of claims 1 to 7, characterized in that: Including CAN signal parsing and analysis module, range extender test data processing module, generator power calculation and analysis module, engine speed torque calibration module, control strategy calibration simulation module; The CAN signal parsing and analysis module extracts key signals from the vehicle CAN bus, parses and records them; The range extender test data processing module organizes, cleans and pre-processes the collected test data to ensure data quality; The motor power calculation and analysis module calculates the power of the drive motor according to the wheel end torque and the vehicle speed data, and calculates the generator power requirement according to the drive motor power and the drive motor efficiency, the drive motor electronic control efficiency, the generator efficiency and the generator electronic control efficiency; The engine speed calibration module establishes an engine operating speed matrix and an engine operating torque matrix calibration table by a two-dimensional interpolation method; The control strategy calibration simulation module applies the calibrated range extender control strategy to the power economy model to evaluate whether it meets the vehicle fuel consumption target, and tests the vehicle fuel consumption according to the national standard to evaluate the consistency between the analyzed control strategy and the actual vehicle test results.

9. A computer device 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.

Images