A predictive EGR control method, terminal device and storage medium

Abstract

The present application relates to a kind of predictive EGR control method, terminal device and storage medium, the method includes: according to the electronic horizon data in front of vehicle judges whether there is deceleration section in front of vehicle, if there is, calculate the engine output torque that needs to be reduced from the current position of vehicle travels to the starting position of deceleration section and / or the engine output torque that needs to be increased from the starting position of deceleration section travels to the end position of deceleration section, further according to the engine output torque that needs to be reduced adjusts the EGR ratio of vehicle at the current position of vehicle and / or according to the engine output torque that needs to be increased adjusts the EGR ratio of vehicle at the starting position of deceleration section.The present application makes full use of the terrain information in front provided by electronic horizon, opens EGR valve and increases EGR ratio in advance before entering decelerable environment, to reduce harmful gas emission.

Description

Technical Field

[0001] The present invention relates to the field of vehicle intelligent control, and in particular to a predictive EGR control method, terminal equipment and storage medium. Background Art

[0002] EGR, or exhaust gas recirculation, recirculates diesel engine exhaust gas back into the engine for combustion, reducing the oxygen concentration of the combustion mixture and lowering combustion temperatures, thereby reducing the amount of harmful NOx gases produced. Because diesel engines use oxygen-rich combustion, the exhaust gas mixture ratio, below a certain value, does not affect engine power (i.e., torque output for a given fuel consumption). However, exceeding a certain ratio will result in a loss of torque, but NOx emissions will continue to decrease. Therefore, the general principle of EGR control is: when the diesel engine is operating under low-load conditions, where power requirements are low, a higher EGR ratio can be used. When the diesel engine is operating under high load, the EGR valve is closed to address power requirements, but this increases NOx emissions. However, commercial vehicles typically operate under heavy loads for operational efficiency, and diesel engines rarely operate under low-load conditions. This poses challenges for fully utilizing EGR and achieving energy conservation and emission reduction. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a predictive EGR control method, a terminal device and a storage medium.

[0004] The specific plan is as follows:

[0005] A predictive EGR control method includes: determining whether there is a deceleration section in front of the vehicle based on electronic horizon data in front of the vehicle; if so, calculating the engine output torque that needs to be reduced when traveling from the vehicle's current position to the starting position of the deceleration section and / or the engine output torque that needs to be increased when traveling from the starting position of the deceleration section to the ending position of the deceleration section, and then adjusting the vehicle's EGR ratio at the vehicle's current position according to the engine output torque that needs to be reduced and / or adjusting the vehicle's EGR ratio at the starting position of the deceleration section according to the engine output torque that needs to be increased.

[0006] Furthermore, the method for calculating the engine output torque that needs to be reduced is: determine the safe vehicle speed for entering the deceleration section according to the type of the deceleration section, and calculate the engine output torque that needs to be reduced from the vehicle's current position to the starting position of the deceleration section according to the vehicle's current speed, the safe vehicle speed for entering the deceleration section, and the distance between the vehicle's current position and the starting position of the deceleration section.

[0007] Further, the method for calculating the required engine output torque to be reduced is: calculating the acceleration of the vehicle from the current speed to the safe speed when entering the deceleration section according to the current speed of the vehicle, the safe speed when entering the deceleration section and the distance between the current position of the vehicle and the start position of the deceleration section; calculating the required driving force to be reduced according to the calculated acceleration and the total mass of the vehicle; converting the required driving force to be reduced into the required engine output torque to be reduced according to the parameters of the transmission system of the vehicle.

[0008] Further, when the deceleration section is a section with multiple road conditions, the safe speed when entering the deceleration section is the minimum value among the safe speeds corresponding to all the road conditions.

[0009] Further, the safe speed is the speed when the current speed is reduced by m%, and m≤5.

[0010] Further, the method for adjusting the EGR ratio of the vehicle according to the required engine output torque to be reduced is: when the required engine output torque to be reduced is greater than the required engine output torque to be reduced when the EGR ratio of the vehicle is increased from the current value to the maximum value, adjusting the EGR ratio of the vehicle to the maximum value; otherwise, increasing the EGR ratio of the vehicle to reduce the engine output torque by the required engine output torque to be reduced.

[0011] Further, the method for calculating the required engine output torque to be increased is: calculating the required engine output torque to be increased when the vehicle exits the deceleration section according to the current speed of the vehicle and the speed when the vehicle is expected to exit the deceleration section.

[0012] Further, the method for calculating the required engine output torque to be increased is: calculating the acceleration increment when the vehicle is driving on the deceleration section according to the type of the deceleration section; calculating the acceleration of the vehicle from the current speed to the speed when the vehicle is expected to exit the deceleration section according to the current speed of the vehicle, the speed when the vehicle is expected to exit the deceleration section and the length of the deceleration section; calculating the required driving force to be increased according to the total mass of the vehicle, the acceleration increment when the vehicle is driving on the deceleration section and the acceleration when the vehicle exits the deceleration section; converting the required driving force to be increased into the required engine output torque to be increased according to the parameters of the transmission system of the vehicle.

[0013] Further, when the deceleration section is a downhill, the acceleration increment when the vehicle is driving on the deceleration section is the product of the slope value and the acceleration due to gravity.

[0014] Further, when the deceleration section is a section with multiple road conditions, the acceleration increment when the vehicle is driving on the deceleration section is the sum of the acceleration increments caused by each road condition.

[0015] Furthermore, a method for adjusting the vehicle's EGR ratio according to the required increase in engine output torque is to reduce the vehicle's EGR ratio according to an EGR ratio-torque relationship table to increase the engine's output torque by the required increase in engine output torque.

[0016] Furthermore, when the vehicle exits the deceleration section, the EGR ratio is adjusted to return to the value before adjustment.

[0017] A predictive EGR control terminal device includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method described above are implemented.

[0018] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method described above in an embodiment of the present invention.

[0019] The present invention utilizes the above technical solution, leveraging the predictive power of the electronic horizon to control EGR. When the vehicle is operating under heavy load, the electronic horizon provides information about the terrain ahead. Prior to entering a deceleration zone, the EGR valve is opened in advance and the EGR ratio is increased to reduce harmful emissions. This reduces the torque lost by emissions, allowing the vehicle to decelerate smoothly by a certain ratio within an acceptable range. After passing the deceleration zone, the EGR ratio is further reduced or EGR is disabled on subsequent sections to restore the torque increase to the original speed. This allows the vehicle to utilize the terrain to maximize the time EGR is open under heavy load conditions, further achieving energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure shows a flow chart of the calculation process of the engine output torque that needs to be reduced before entering the deceleration section in the first embodiment of the present invention.

[0021] Figure 2 The figure shows a flow chart of the calculation process of the engine output torque that needs to be increased after entering the deceleration section in this embodiment. DETAILED DESCRIPTION

[0022] To further illustrate various embodiments, the present invention provides accompanying drawings. These drawings form part of the present disclosure and are primarily used to illustrate the embodiments and, in conjunction with the relevant description in the specification, to explain the operating principles of the embodiments. By referring to these drawings, those skilled in the art will be able to understand other possible implementations and the advantages of the present invention.

[0023] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0024] Example 1:

[0025] An embodiment of the present invention provides a predictive EGR control method, including: determining whether there is a deceleration section in front of the vehicle based on electronic horizon data in front of the vehicle; if so, calculating the engine output torque that needs to be reduced when traveling from the current position of the vehicle to the starting position of the deceleration section and / or the engine output torque that needs to be increased when traveling from the starting position to the end position of the deceleration section, and then adjusting the vehicle's EGR ratio at the current position according to the engine output torque that needs to be reduced and / or adjusting the vehicle's EGR ratio at the starting position of the deceleration section according to the engine output torque that needs to be increased.

[0026] The deceleration section refers to the section where vehicles are required to decelerate according to traffic regulations, including but not limited to the following sections:

[0027] a) Downhill terrain ahead. The vehicle needs to slow down before going downhill to reduce energy consumption. During the downhill process, the vehicle can use the potential energy of gravity to restore the original speed, which is more economical.

[0028] b) Curving terrain ahead. Slow down before entering a curve to reduce energy consumption and ensure cornering safety. Avoid excessive use of the brake system and energy consumption when cornering.

[0029] c) The terrain of the intersection ahead. Slow down before passing the intersection to reduce energy consumption and ensure safety at the intersection, and avoid using the brake system to consume energy when crossing the intersection.

[0030] d) There are traffic signs ahead that require you to slow down, such as signs indicating a school, sidewalk, construction, narrowing of the road, or reduced speed limit.

[0031] e) There is a tunnel or bridge ahead.

[0032] f) There is a crossroad merging ahead.

[0033] g) Changes in the situation of the vehicle ahead, such as lane narrowing or lane reduction, etc.

[0034] The following describes in detail a predictive EGR control method provided by an embodiment of the present invention, using a downhill deceleration section as an example. It should be noted that the following implementation simultaneously adjusts the vehicle's position for both driving from the vehicle's current position to the start of the deceleration section and from the start to the end of the deceleration section. In other embodiments, adjustments can also be made for either situation alone.

[0035] (1) Calculate the engine output torque that needs to be reduced from the current position to the starting position of the deceleration section, and then adjust the vehicle's EGR ratio.

[0036] From the electronic horizon data, we can obtain the slope θ, slope length L of the downhill section ahead and the distance D between the starting position of the downhill section and the current position of the vehicle.i , the current vehicle speed V can be obtained from the onboard computer i .

[0037] In this embodiment, it is preferred to set the safe vehicle speed V for the downhill deceleration section k is relative to the current vehicle speed V i To minimize the impact on the driving experience, the vehicle speed is preferably set to m ≤ 5. In other embodiments, those skilled in the art may also configure other safe speed calculation methods or directly set a maximum speed. In this embodiment, the vehicle speed is set to be reduced by m%, which ensures safety without compromising the driving experience.

[0038] like Figure 1 As shown, the engine output torque ΔT1 that needs to be reduced can be calculated based on the above data. The specific calculation process is:

[0039] Step 1: According to the current speed V of the vehicle i , safe speed V when entering the deceleration section k The distance D between the vehicle's current position and the starting position of the deceleration section i Calculate the vehicle's current speed V i Reduce the speed to a safe speed V k Deceleration a1:

[0040]

[0041] Step 2: Calculate the required reduction in driving force ΔF1 based on the calculated deceleration a1 and the total mass M of the vehicle:

[0042] ΔF1=Ma1

[0043] When the vehicle is running at a near-constant speed, the engine output torque and the environmental resistance are stable. Assuming the vehicle maintains a constant speed, the required reduction in vehicle driving force to achieve deceleration a while maintaining the current throttle opening is approximately ΔF1 = Ma1. The vehicle's gross mass, M, can be estimated based on the vehicle load and speed, or provided by other load sensors.

[0044] Step 3: According to the vehicle's transmission system parameters, the driving force ΔF1 that needs to be reduced is converted into the engine output torque ΔT1 that needs to be reduced.

[0045] After the engine output torque ΔT1 that needs to be reduced is calculated, step 4 can be performed: adjusting the EGR ratio of the vehicle.

[0046] In this embodiment, it is considered that the adjustment cannot exceed the maximum value R maxTherefore, the adjustment method is set as follows: when the engine output torque to be reduced is greater than the engine output torque to be increased when the EGR ratio of the vehicle is increased from the current value to the maximum value R max , the EGR ratio of the vehicle is adjusted to the maximum value R max ; otherwise, the EGR ratio of the vehicle is increased to reduce the engine output torque by the engine output torque to be reduced ΔT1.

[0047] It should be noted that the deceleration section can not only be a single section, but also a section composed of multiple sections, such as a curve and a downhill, and there is also a sign of a school in front, and so on. When this is the case, the safe vehicle speed for entering the deceleration section is the minimum value of the safe vehicle speeds corresponding to all types of road conditions.

[0048] (2) Calculate the engine output torque to be increased from the start position to the end position of the deceleration section, and then adjust the EGR ratio of the vehicle.

[0049] Specifically, when the vehicle travels to the start position of the deceleration section, the engine output torque to be increased when the vehicle exits the deceleration section is calculated according to the current speed of the vehicle and the expected speed of the vehicle exiting the deceleration section, and the EGR ratio of the vehicle is adjusted according to the engine output torque to be increased.

[0050] The following is a detailed description of the downhill type deceleration section.

[0051] According to the data obtained from the electronic horizon data, the engine output torque to be increased ΔT2 can be calculated, as shown in Figure 2 , the specific calculation process is as follows:

[0052] Step 1: Calculate the acceleration increment Δa of the vehicle when traveling on the deceleration section according to the type of the deceleration section:

[0053] Δa = θg

[0054] Where g is the acceleration of gravity.

[0055] Step 2: Calculate the acceleration a2 of the vehicle exiting the deceleration section from the current speed to the expected speed of exiting the deceleration section according to the current speed of the vehicle, the expected speed of the vehicle exiting the deceleration section, and the length of the deceleration section.

[0056] Since the speed on the same road should be approximately equal, the speed of the vehicle exiting the deceleration section in this embodiment is set to be equal to the speed before deceleration when traveling to the deceleration section, which is the V i mentioned above, and the current speed of the vehicle should be the safe vehicle speed V k when entering the deceleration section, so the calculation formula of the acceleration a2 is:

[0057]

[0058] Step 3: Calculate the required additional driving force ΔF2 based on the total mass of the vehicle, the acceleration increment when the vehicle is traveling on the deceleration section, and the acceleration when the vehicle exits the deceleration section:

[0059] ΔF2=M(a2-Δa)

[0060] Step 4: According to the vehicle's transmission system parameters, the required increase in driving force is converted into the required increase in engine output torque ΔT2.

[0061] It should be noted that when the deceleration section is a composite section of multiple sections, the acceleration increment of the vehicle when traveling on the deceleration section is the sum of the acceleration increments caused by each road condition, that is:

[0062] Δa=Δa1+Δa2+…+Δan.

[0063] Δa1, Δa2, Δan, etc. correspond to different road segment types in the composite road segment.

[0064] The acceleration increments corresponding to different deceleration sections can be positive or negative. For example, the downhill section mentioned above is a positive value. If the deceleration section is a curved section, the vehicle speed will be reduced due to the resistance of the curve curvature, so the corresponding acceleration increment is a negative value.

[0065] After the required increase in engine output torque ΔT2 is calculated, step 5 can be performed: adjusting the vehicle's EGR ratio.

[0066] (3) Furthermore, this embodiment also includes: when the vehicle exits the deceleration section, the EGR ratio is adjusted to return to the value before the adjustment, that is, the value before the adjustment stage (1) is performed.

[0067] Embodiment 1 of the present invention utilizes the predictive power of the electronic horizon to control EGR. When the vehicle is operating under heavy load, the electronic horizon provides information about the terrain ahead. Prior to entering a deceleration section, the EGR valve is opened in advance and the EGR ratio is increased to reduce harmful gas emissions. This reduces the torque lost by emissions, allowing the vehicle to decelerate smoothly by a certain ratio within an acceptable range. After passing through the deceleration zone, the EGR ratio is further reduced or EGR is turned off in subsequent sections to restore the torque increase rate to the original vehicle speed. This allows the terrain to be utilized to maximize the time EGR is open under heavy load conditions, further achieving energy conservation and emission reduction.

[0068] Example 2:

[0069] The present invention also provides a predictive EGR control terminal device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiment of embodiment 1 of the present invention are implemented.

[0070] Furthermore, as an executable solution, the predictive EGR control terminal device can be a computing device such as an on-board computer or a cloud server. The predictive EGR control terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the above-described component structure of the predictive EGR control terminal device is merely an example of a predictive EGR control terminal device and does not constitute a limitation on the predictive EGR control terminal device. The predictive EGR control terminal device may include more or fewer components than those described above, or a combination of certain components, or different components. For example, the predictive EGR control terminal device may also include input and output devices, network access devices, buses, etc., which are not limited in this embodiment of the present invention.

[0071] Furthermore, as an executable solution, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the predictive EGR control terminal device, and utilizes various interfaces and lines to connect various parts of the entire predictive EGR control terminal device.

[0072] The memory can be used to store the computer programs and / or modules. The processor implements the various functions of the predictive EGR control terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required for a function; the data storage area can store data created based on the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as a hard disk, internal memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0073] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method in the embodiment of the present invention are implemented.

[0074] If the module / unit integrated in the predictive EGR control terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, ROM, Read-Only Memory), random access memory (RAM, Random Access Memory) and software distribution medium, etc.

[0075] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A predictive EGR control method for a diesel engine when the vehicle is running under heavy load and high load, characterized in that: The method includes: determining whether there is a deceleration section in front of the vehicle based on the electronic horizon data in front of the vehicle; if so, calculating the engine output torque that needs to be reduced when traveling from the current position of the vehicle to the starting position of the deceleration section and the engine output torque that needs to be increased when traveling from the starting position of the deceleration section to the end position of the deceleration section, and then adjusting the vehicle's EGR ratio at the current position of the vehicle according to the engine output torque that needs to be reduced and adjusting the vehicle's EGR ratio at the starting position of the deceleration section according to the engine output torque that needs to be increased.

2. The predictive EGR control method according to claim 1, wherein: The method for calculating the engine output torque that needs to be reduced is: determine the safe vehicle speed for entering the deceleration section based on the type of deceleration section, and calculate the engine output torque that needs to be reduced from the vehicle's current position to the starting position of the deceleration section based on the vehicle's current speed, the safe vehicle speed for entering the deceleration section, and the distance between the vehicle's current position and the starting position of the deceleration section.

3. The predictive EGR control method according to claim 2, wherein: The method for calculating the engine output torque that needs to be reduced is as follows: based on the vehicle's current speed, the safe speed for entering the deceleration section, and the distance between the vehicle's current position and the starting position of the deceleration section, calculate the vehicle's acceleration required to uniformly reduce from the current speed to the safe speed; based on the calculated acceleration and the vehicle's total mass, calculate the driving force that needs to be reduced; and based on the vehicle's transmission system parameters, convert the driving force that needs to be reduced into the engine output torque that needs to be reduced.

4. The predictive EGR control method according to claim 3, wherein: When the deceleration section is a composite section with multiple road conditions, the safe speed for entering the deceleration section is the minimum of the safe speeds corresponding to all road conditions.

5. The predictive EGR control method according to claim 3, wherein: The safe speed is the speed when the current speed is reduced by m%, m≤5.

6. The predictive EGR control method according to claim 1, wherein: The method for adjusting the EGR ratio of a vehicle according to the engine output torque that needs to be reduced is: when the engine output torque that needs to be reduced is greater than the engine output torque that needs to be reduced when the vehicle's EGR ratio is increased from the current value to the maximum value, the vehicle's EGR ratio is adjusted to the maximum value; otherwise, the vehicle's EGR ratio is increased to reduce the engine's output torque by the engine output torque that needs to be reduced.

7. The predictive EGR control method according to claim 1, wherein: The method for calculating the engine output torque that needs to be increased is as follows: based on the current vehicle speed and the expected vehicle speed when exiting the deceleration section, the engine output torque that needs to be increased when the vehicle exits the deceleration section is calculated.

8. The predictive EGR control method according to claim 1, wherein: The method for calculating the required increase in engine output torque is as follows: calculating the acceleration increment of the vehicle when traveling on the deceleration section based on the type of the deceleration section; calculating the acceleration of the vehicle when exiting the deceleration section from the current speed to the expected speed when exiting the deceleration section based on the vehicle's current speed, the expected speed when exiting the deceleration section, and the length of the deceleration section; calculating the required increase in driving force based on the total mass of the vehicle, the acceleration increment of the vehicle when traveling on the deceleration section, and the acceleration when exiting the deceleration section; and converting the required increase in driving force into the required increase in engine output torque based on the vehicle's transmission system parameters.

9. The predictive EGR control method according to claim 8, characterized in that: When the deceleration section is downhill, the acceleration increment of the vehicle when traveling on the deceleration section is the product of the slope value and the acceleration due to gravity.

10. The predictive EGR control method according to claim 8, wherein: When the deceleration section is a composite section of multiple road conditions, the acceleration increment of the vehicle when traveling on the deceleration section is the sum of the acceleration increments caused by each road condition.

11. The predictive EGR control method according to claim 1, wherein: The method of adjusting the vehicle's EGR ratio according to the required increase in engine output torque is to reduce the vehicle's EGR ratio according to an EGR ratio-torque relationship table to increase the engine's output torque by the required increase in engine output torque.

12. The predictive EGR control method according to claim 1, wherein: Also includes: When the vehicle exits the deceleration section, the EGR ratio is adjusted back to the value before adjustment.

13. A predictive EGR control terminal device, characterized by: The method comprises a processor, a memory, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of the method according to any one of claims 1 to 12 when executing the computer program.

14. A computer-readable storage medium storing a computer program, wherein: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 12 are implemented.

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