Method and system for engine fixed-point power control in automobile series connection mode

Abstract

The embodiment of the invention provides a method and system for fixed-point power control of an engine in an automobile series connection mode, and the method comprises the steps: obtaining the state data of a target automobile, and carrying out the calculation according to the state data, and obtaining the required power of the whole automobile; querying two identical preset power tables to circularly obtain two power points according to a query result, and continuously judging whether the required power of the whole vehicle is in a power interval range formed by the two power points or not; if the required power of the whole vehicle is within the power interval range, activating a rounding-off mode, and outputting a first target power point according to a first preset rule; actively entering an over-limit mode when the power interval range is circularly searched each time, and acquiring a second target power point in the over-limit mode according to a second preset rule; and a final target power point is selected from the first target power point and the second target power point, and the engine torque is calculated according to the target power points. According to the invention, the fuel economy and drivability of the whole vehicle can be ensured.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of output power control, and in particular to a method and system for fixed-point power control of an engine in a series mode of an automobile. Background Art

[0002] As the country's regulations on fuel consumption and emissions become more and more stringent, especially after the implementation of the National VI Emission Standard, major OEMs are vigorously developing new energy vehicles, and hybrid vehicles are also favored by manufacturers and consumers because of their low fuel consumption and long range. Hybrid vehicles have multiple working modes in use, and the series mode is one of them. The engine + P1 motor combination provides the required power of the vehicle, supplies the wheel-end drive or charges the battery pack and consumes accessories. This mode is generally used more in urban conditions. The power generation algorithm in the series mode is generally divided into two types: power following and fixed-point control. Power following is to calculate the required power of the vehicle, and then determine the engine speed according to the comprehensive optimal power line of the engine + P1 motor. After the power and speed are determined, the corresponding torque value is obtained. Although the best fuel economy of the vehicle is guaranteed here, the fluctuation of the driver's accelerator pedal or the change of the power of the vehicle's accessories will cause a small range of changes in the required power of the vehicle, and the power generation power will change accordingly, and finally cause the engine speed to change, thereby affecting the NVH and driving performance of the vehicle. Summary of the invention

[0003] Based on this, the purpose of the embodiment of the present application is to propose a method and system for fixed-point engine power control in automobile series mode, aiming to solve the problem that the engine speed and torque fluctuate when the power demand of the whole vehicle fluctuates in a small range, while ensuring the fuel economy and drivability of the whole vehicle.

[0004] In a first aspect, an embodiment of the present application provides a method for controlling engine power at a fixed point in a series mode of an automobile, the method comprising: Acquire the state data of the target vehicle, and calculate the required power of the whole vehicle according to the state data; Querying two identical preset power tables to cyclically obtain two power points according to the query results, and continuously determining whether the required power of the entire vehicle is within the power range formed by the two power points; If the vehicle's required power is within the power range, the rounding mode is activated, and the first target power point is output according to the first preset rule; When searching the power range in each cycle, actively enter the over-limit mode, and obtain the second target power point in the over-limit mode according to the second preset rule; The final target power point is selected from the first target power point and the second target power point, and the optimal engine speed under equal power is determined according to the comprehensive optimal power curve of the engine and the P1 motor, and the engine torque is calculated according to the optimal engine speed and the target power point.

[0005] In summary, according to the above-mentioned method for controlling the power of the engine at a fixed point in the automobile series mode, the present invention first calculates the required power of the whole vehicle, and then determines twenty power generation working points according to the engine power range to construct a preset power table (the specific number of working points can be determined according to the actual vehicle calibration), and then determines the power generation power according to which working point the required power is closer, and protects the over-limit power, and then determines the engine speed according to the comprehensive optimal power line of the engine + P1 motor, and finally obtains the engine torque value. Under this method, the fluctuation of the driver's accelerator pedal or the change of the vehicle's accessory power will cause a small range change in the vehicle's required power, which will not affect the change in the generated power, so that the engine torque and speed will not change, thereby ensuring the fuel economy and drivability of the whole vehicle.

[0006] In some embodiments, the step of obtaining the state data of the target vehicle and calculating the required power of the whole vehicle according to the state data includes: Obtain the torque request of the vehicle for the wheel end and the current speed of the target vehicle, and obtain the wheel end required power according to the torque request and the current speed. The low-voltage accessory power and the high-voltage accessory power are obtained, and the vehicle required power is obtained according to the sum of the wheel-end required power, the low-voltage accessory power and the high-voltage accessory power.

[0007] In some embodiments, the step of querying two identical preset power tables to cyclically obtain two power points according to the query results, and continuously determining whether the vehicle required power is within the power range formed by the two power points includes: By searching the initial serial number input in the mode and adding 1 to the initial serial number, two identical preset power tables are queried to obtain power A and power B, and to determine whether the vehicle power is between power A and power B.

[0008] In some embodiments, after the initial serial number input through the search mode and the initial serial number is increased by 1, two identical preset power tables are queried to obtain power A and power B, and the step of determining whether the vehicle power is between power A and power B also includes: If the vehicle power is not between power A and power B, the system returns to the search mode, and the sequence number is incremented by 1 to obtain two new power points in a loop until the vehicle power is within the power interval, which includes an upper power point and a lower power point. Obtaining a first difference between the required power and the lower limit working point, and a second difference between the upper limit power point and the lower limit power point, and determining whether a ratio of the first difference to the second difference is less than or equal to a first preset threshold; If the ratio of the first difference to the second difference is less than or equal to the first preset threshold, the first preset threshold is the lower power point; If the ratio of the first difference to the second difference is greater than the first preset threshold, the first preset threshold is the upper limit power point.

[0009] In some embodiments, the method comprises: If the power interval range is still not found, the first target power point is 0.

[0010] In some embodiments, the step of actively entering the over-limit mode and acquiring the second target power point in the over-limit mode according to the second preset rule each time the power interval range is cyclically searched further includes: When searching the power range in each cycle, the system will actively enter the over-limit mode to compare the maximum power value of the preset power table with the required power. If the maximum power is less than the required power, the maximum power in the table is output; If the maximum power is greater than or equal to the required power, the output power is 0.

[0011] In some embodiments, the steps of selecting a final target power point from the first target power point and the second target power point, determining an optimal engine speed under equal power according to a comprehensive optimal power curve of the engine and the P1 motor, and calculating the engine torque according to the optimal engine speed and the target power point include: Compare whether the final sequence number value is less than or equal to the preset sequence number threshold; If the final sequence number value is less than or equal to the preset sequence number threshold, the first target power point is selected as the final target power point; If the final sequence number value is greater than the preset sequence number threshold, the second target power point is selected as the final target power point.

[0012] In a second aspect, the embodiment of the present application also proposes a system for controlling the power of an engine at a fixed point in a series mode of an automobile, the system comprising: A calculation module is used to obtain the state data of the target vehicle and calculate the required power of the whole vehicle according to the state data; A search module, used to query two identical preset power tables, to cyclically obtain two power points according to the query results, and to continuously determine whether the required power of the whole vehicle is within the power range formed by the two power points; A rounding module, configured to activate a rounding mode if the vehicle required power is within the power range, and output a first target power point according to a first preset rule; An over-limit protection module, used to actively enter an over-limit mode each time the power range is searched in a cycle, and obtain a second target power point in the over-limit mode according to a second preset rule; The torque output module is used to select the final target power point from the first target power point and the second target power point, and determine the optimal engine speed under equal power according to the comprehensive optimal power curve of the engine and the P1 motor, and calculate the engine torque according to the optimal engine speed and the target power point.

[0013] In a third aspect, an embodiment of the present application also provides a storage medium, including one or more programs stored in the storage medium, which, when executed, implements the method for controlling the engine power at a fixed point in a series mode of a vehicle as described above.

[0014] In a fourth aspect, an embodiment of the present application further provides an electronic device, the electronic device comprising a memory and a processor, wherein: The memory is used to store computer programs; When the processor is used to execute the computer program stored in the memory, the method for controlling the power of an engine at a fixed point in a series mode of an automobile as described above is implemented.

[0015] Compared with the prior art, the embodiments of the present application also have the following advantages: 1. Find the appropriate interval working range of the vehicle's required power by combining the search cycle algorithm with the table lookup. This method is simple and clear, and is convenient for calibration engineers to calibrate. If you want to change the size of the interval range, just change the value in the table lookup. 2. By adding an over-limit protection mode, this mode ensures the rationality of the output power and protects the safety of the vehicle's power components.

[0016] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through examples of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a method for controlling engine power at a fixed point in a series mode of an automobile, which is proposed in the first embodiment of the present application; Figure 2 This is a schematic diagram of the structure of a system for fixed-point engine power control in automobile series mode proposed in the second embodiment of the present application.

[0018] The following specific implementation manner will further illustrate the embodiments of the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0019] In order to facilitate understanding of the embodiments of the present application, the embodiments of the present application will be described more fully below with reference to the relevant drawings. Several embodiments of the embodiments of the present application are provided in the drawings. However, the embodiments of the present application can be implemented in many different forms and are not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the embodiments of the present application more thorough and comprehensive.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the technical field of the embodiments of the present application. The terms used herein in the description of the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0021] See also Figure 1 , which is a flow chart of a method for controlling engine power at a fixed point in a series mode of an automobile in the first embodiment of the present application, the method comprises steps S101 to S105, wherein: Step S101: acquiring the state data of the target vehicle, and calculating the required power of the whole vehicle according to the state data; It should be noted that in this step, the wheel-end required power is obtained based on the vehicle's torque request for the wheel end (the wheel-end required torque is obtained based on the driver's accelerator pedal opening) and the current vehicle speed, and the low-voltage accessory power (obtained by DCDC input current and input voltage) and the high-voltage accessory power (such as AC actual power, PTC actual power, etc., obtained through CAN signals) are added to obtain the vehicle's required power.

[0022] It should be pointed out that, in this embodiment, the relationship between vehicle speed and wheel end speed, the relationship between power, speed and torque, and the relationship between current, voltage and power are common knowledge to professionals in this field and will not be described in detail here.

[0023] Step S102: querying two identical preset power tables to cyclically obtain two power points according to the query results, and continuously determining whether the vehicle required power is within a power interval formed by the two power points; Step S103: If the vehicle power requirement is within the power range, the rounding mode is activated, and the first target power point is output according to the first preset rule; It should be noted that in order to find the upper and lower power points of the range where the vehicle's required power is located, the initial sequence number input by the search mode and the initial sequence number plus 1 are queried to obtain power A and power B, and to determine whether the vehicle's power is between power A and power B.

[0024] In addition, the initial serial number in the search module is 0, and the serial number value must be input into the calculation module for calculation in each cycle. The calculation mode outputs two working efficiency points by looking up two identical tables, and determines whether the required power of the vehicle is within this power range. If not, it returns to the search module and adds 1 to the serial number in sequence and then inputs it into the calculation module for calculation until a suitable range is found. If it is within the power range, the calculation module outputs the flag position as 1 and gives it to the search module, terminating the superposition cycle.

[0025] If the vehicle power is not between power A and power B, the system returns to the search mode, and the sequence number is incremented by 1 to obtain two new power points in a loop until the vehicle power is within the power interval, which includes an upper power point and a lower power point. Obtaining a first difference between the required power and the lower limit working point, and a second difference between the upper limit power point and the lower limit power point, and determining whether a ratio of the first difference to the second difference is less than or equal to a first preset threshold; If the ratio of the first difference to the second difference is less than or equal to the first preset threshold, the first preset threshold is the lower power point; If the ratio of the first difference to the second difference is greater than the first preset threshold, the first preset threshold is the upper limit power point.

[0026] It should be noted that, in this embodiment, the first preset threshold is 0.5, and the exemplary preset power table is as shown in Table 1 below: Table 1 Step S104: actively entering the over-limit mode each time the power range is searched in a loop, and obtaining a second target power point in the over-limit mode according to a second preset rule; For example, but not limitation, after finding a suitable interval range, the rounding module will be activated, and the difference between the required power and the lower limit working point is divided by the difference between the interval working power points and 0.5. If it is less than or equal to 0.5, the output power is the lower limit power point, and if it is greater than 0.5, the upper limit power point is output. When the rounding module is not activated, its output power is 0. At the same time, the over-limit module compares the maximum power value of the table with the required power in each cycle. If it is less than, the maximum power value of the table is output, and if it is greater than or equal to, the output power is 0. When the vehicle's required power is greater than the maximum value in the table or less than the minimum value, the calculation module flag is always set to 0, then the serial number will be superimposed to the maximum value of 100, and finally by comparing the serial number value with 99, if it is less than or equal to, the search module outputs the rounding module power value, and if it is greater than, the search module outputs the over-limit protection module power value, so that the calculated power will not exceed the upper limit or be lower than the lower limit, thereby protecting components such as the battery pack and the engine.

[0027] Step S105: Select the final target power point from the first target power point and the second target power point, determine the optimal engine speed under equal power according to the comprehensive optimal power curve of the engine and the P1 motor, and calculate the engine torque according to the optimal engine speed and the target power point.

[0028] It should be noted that, in order to screen out a suitable target power point, the final sequence number value is compared to see whether it is less than or equal to a preset sequence number threshold; if the final sequence number value is less than or equal to the preset sequence number threshold, the first target power point is selected as the final target power point; if the final sequence number value is greater than the preset sequence number threshold, the second target power point is selected as the final target power point. In this embodiment, the preset sequence number threshold is 99.

[0029] Finally, the optimal engine speed under equal power is determined based on the comprehensive optimal power curve of the engine and the P1 motor, and the engine torque is calculated using the relationship between power, speed and torque.

[0030] In summary, according to the above-mentioned method for controlling the power of the engine at a fixed point in the automobile series mode, the present invention first calculates the required power of the whole vehicle, and then determines twenty power generation working points according to the engine power range to construct a preset power table (the specific number of working points can be determined according to the actual vehicle calibration), and then determines the power generation power according to which working point the required power is closer, and protects the over-limit power, and then determines the engine speed according to the comprehensive optimal power line of the engine + P1 motor, and finally obtains the engine torque value. Under this method, the fluctuation of the driver's accelerator pedal or the change of the vehicle's accessory power will cause a small range change in the vehicle's required power, which will not affect the change in the generated power, so that the engine torque and speed will not change, thereby ensuring the fuel economy and drivability of the whole vehicle.

[0031] See also Figure 2 , shown is a system for controlling engine power at a fixed point in a series mode of an automobile in a second embodiment, the system comprising: The calculation module 10 is used to obtain the state data of the target vehicle and calculate the required power of the whole vehicle according to the state data; A search module 20 is used to query two identical preset power tables to cyclically obtain two power points according to the query results, and continuously determine whether the required power of the whole vehicle is within the power range formed by the two power points; A rounding module 30, configured to activate a rounding mode if the vehicle required power is within the power interval, and output a first target power point according to a first preset rule; The over-limit protection module 40 is used to actively enter the over-limit mode each time the power interval range is searched in a cycle, and obtain the second target power point in the over-limit mode according to the second preset rule; The torque output module 50 is used to select the final target power point from the first target power point and the second target power point, and determine the optimal engine speed under equal power according to the comprehensive optimal power curve of the engine and the P1 motor, and calculate the engine torque according to the optimal engine speed and the target power point.

[0032] On the other hand, the embodiment of the present application further proposes a computer storage medium on which one or more programs are stored, and when the program is executed by a processor, the above-mentioned method for fixed-point control of engine power in a series mode of an automobile is implemented.

[0033] On the other hand, an embodiment of the present application further proposes an electronic device, including a memory and a processor, wherein the memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the above-mentioned method for fixed-point control of engine power in a series mode of a vehicle.

[0034] Those skilled in the art will appreciate that the logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be specifically implemented 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 purposes of this specification, "computer-readable medium" may be any device that can contain storage, communication, propagation or transmission of a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0035] 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.

[0036] It should be understood that the various parts of the embodiments of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple 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 a combination thereof: 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.

[0037] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0038] The above-described embodiments only express several implementation methods of the embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the embodiments of the present application. It should be noted that, for those of ordinary skill in the art, without departing from the concept of the embodiments of the present application, several variations and improvements can also be made, which all belong to the protection scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the attached claims.

Claims

1. A method for controlling engine power at a fixed point in a series mode of an automobile, characterized in that: The method comprises: Acquire the state data of the target vehicle, and calculate the required power of the whole vehicle according to the state data; querying two identical preset power tables to cyclically obtain two power points according to the query results, and continuously determining whether the required power of the entire vehicle is within the efficiency range formed by the two power points; If the vehicle's required power is within the power range, the rounding mode is activated, and the first target power point is output according to the first preset rule; When searching the power range in each cycle, actively enter the over-limit mode, and obtain the second target power point in the over-limit mode according to the second preset rule; The final target power point is selected from the first target power point and the second target power point, and the optimal engine speed under equal power is determined according to the comprehensive optimal power curve of the engine and the P1 motor, and the engine torque is calculated according to the optimal engine speed and the target power point.

2. The method for controlling engine power at a fixed point in a series mode of a vehicle according to claim 1, characterized in that: The step of obtaining the state data of the target vehicle and calculating the required power of the whole vehicle according to the state data comprises: Obtain the torque request of the vehicle for the wheel end and the current speed of the target vehicle, and obtain the wheel end required power according to the torque request and the current speed. The low-voltage accessory power and the high-voltage accessory power are obtained, and the vehicle required power is obtained according to the sum of the wheel-end required power, the low-voltage accessory power and the high-voltage accessory power.

3. The method for controlling engine power at a fixed point in a series mode of a vehicle according to claim 2, characterized in that: The steps of querying two identical preset power tables to cyclically obtain two power points according to the query results, and continuously determining whether the vehicle required power is within the efficiency range formed by the two power points include: By searching the initial serial number input in the mode and adding 1 to the initial serial number, two identical preset power tables are queried to obtain power A and power B, and to determine whether the vehicle power is between power A and power B.

4. The method for controlling engine power at a fixed point in a series mode of a vehicle according to claim 3, characterized in that: After the steps of searching the initial serial number input in the search mode and adding 1 to the initial serial number, searching two identical preset power tables to obtain power A and power B, and determining whether the vehicle power is between power A and power B, the method further includes: If the vehicle power is not between power A and power B, the system returns to the search mode, and the sequence number is incremented by 1 to obtain two new power points in a loop until the vehicle power is within the power interval, which includes an upper power point and a lower power point. Obtaining a first difference between the required power and the lower limit working point, and a second difference between the upper limit power point and the lower limit power point, and determining whether a ratio of the first difference to the second difference is less than or equal to a first preset threshold; If the ratio of the first difference to the second difference is less than or equal to the first preset threshold, the first preset threshold is the lower power point; If the ratio of the first difference to the second difference is greater than the first preset threshold, the first preset threshold is the upper limit power point.

5. The method for controlling engine power at a fixed point in automobile series mode according to claim 4, characterized in that: The method comprises: If the power interval range is still not found, the first target power point is 0.

6. The method for controlling engine power at a fixed point in automobile series mode according to claim 5, characterized in that: The step of actively entering the over-limit mode and acquiring the second target power point in the over-limit mode according to the second preset rule each time the power interval range is cyclically searched also includes: When searching the power range in each cycle, the system will actively enter the over-limit mode to compare the maximum power value of the preset power table with the required power. If the maximum power is less than the required power, the maximum power in the table is output; If the maximum power is greater than or equal to the required power, the output power is 0.

7. The method for controlling engine power at a fixed point in automobile series mode according to claim 6, characterized in that: The steps of selecting a final target power point from the first target power point and the second target power point, determining an optimal engine speed under equal power according to a comprehensive optimal power curve of the engine and the P1 motor, and calculating the engine torque according to the optimal engine speed and the target power point include: Compare whether the final sequence number value is less than or equal to the preset sequence number threshold; If the final sequence number value is less than or equal to the preset sequence number threshold, the first target power point is selected as the final target power point; If the final sequence number value is greater than the preset sequence number threshold, the second target power point is selected as the final target power point.

8. A system for controlling engine power at a fixed point in a series mode of an automobile, characterized in that: The system comprises: A calculation module is used to obtain the state data of the target vehicle and calculate the required power of the whole vehicle according to the state data; A search module, used to query two identical preset power tables, to cyclically obtain two power points according to the query results, and to continuously determine whether the required power of the whole vehicle is within the efficiency range formed by the two power points; A rounding module, configured to activate a rounding mode if the vehicle required power is within the power range, and output a first target power point according to a first preset rule; An over-limit protection module, used to actively enter an over-limit mode each time the power range is searched in a cycle, and obtain a second target power point in the over-limit mode according to a second preset rule; The torque output module is used to select the final target power point from the first target power point and the second target power point, and determine the optimal engine speed under equal power according to the comprehensive optimal power curve of the engine and the P1 motor, and calculate the engine torque according to the optimal engine speed and the target power point.

9. A storage medium, characterized in that: include: The storage medium stores one or more programs, which, when executed by the processor, implement the method for controlling the power of an engine at a fixed point in a series mode of an automobile as described in any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device comprises a memory and a processor, wherein: The memory is used to store computer programs; When the processor is used to execute the computer program stored in the memory, the method for fixed-point control of engine power in a series mode of an automobile as described in any one of claims 1 to 7 is implemented.

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