Engine smoke limit control strategy

Abstract

The present invention relates to an engine smoke limit control strategy, comprising the following steps: obtaining an engine speed and a circulating oil volume; obtaining a basic smoke limit under current working conditions; obtaining a corrected basic value of the smoke limit; obtaining a carbon accumulation rate; obtaining a correction coefficient of the carbon accumulation rate to the smoke limit; calculating a correction result of the carbon accumulation rate to the smoke limit; obtaining a vehicle load and a road slope; obtaining a correction coefficient of the vehicle load and the road slope to the smoke limit; calculating a correction result of the vehicle load and the road slope to the smoke limit; obtaining a final smoke limit correction result; and calculating a final smoke limit. The present invention improves the adaptability of the engine, reduces the occurrence of DPF blockage, improves the responsiveness of the engine, increases the vehicle speed, and reduces fuel consumption; and has very good adaptability. During application, the smoke limit control problem of the prior art is completely solved.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to an engine smoke limit control strategy. Background Art

[0002] On November 7, 2018, the Ministry of Ecology and Environment and the State Administration for Market Regulation first issued the national standard "Exhaust Smoke Limits and Measurement Methods for Non-road Diesel Mobile Machinery (GB 36886-2018)", which clearly stipulates the smoke density limits.

[0003] The standard specifies the exhaust smoke density limits for two detection methods, namely: light absorption coefficient (m-1) and Ringelmann blackness level.

[0004] The smoke density limit is divided into three categories: Ⅰ, Ⅱ and Ⅲ, and different limits are specified, corresponding to three types of products. That is: products of National II (GB20891-2007) and previous stages must meet the Class I limit, and products of National III (GB20891-2014) must meet the Class II limit. The formulation of the Class III limit is a standard that the municipal people's government must implement in specially designated areas. It should be pointed out that the smoke density limit also stipulates an additional coefficient, namely: for various types of non-road diesel mobile machinery used in areas with an altitude of 1,700m, the exhaust opaque smoke density (light absorption coefficient) limit should be increased by 0.25m-1 on the basis of the provisions of the three categories Ⅰ, Ⅱ and Ⅲ, indicating that the country has raised the standards for environmentally fragile areas and will strengthen law enforcement in the future. The following is a table of smoke density limits:

[0005] Smoke density limit table for "Exhaust smoke density limits and measurement methods for non-road diesel mobile machinery (GB 36886-2018)"

[0006]

[0007] The country's determination of smoke density limits follows the following rules:

[0008] First, if the Ringelmann smoke density of a non-road diesel mobile machine exceeds the standard, the smoke emission test will be deemed unqualified. Second, if the Ringelmann smoke density test is qualified, the ecological and environmental authorities will continue to conduct on-site exhaust smoke density testing using the opaque smoke density method. If the specified smoke density value is met, the machine will be deemed qualified; otherwise, it will be deemed unqualified. What is the difference between the two? The Ringelmann smoke density method is a normative test. The standard stipulates the technical conditions for the test, including: observation location, observation method, instrumentation, calculation method, and technical requirements of the Ringelmann smoke meter. An inspection report must be submitted after the test; while the opaque smoke density method can be understood as a random test.

[0009] In short, no matter which test is used, it can only be judged as qualified if the test results do not exceed the limit.

[0010] In order to solve the problem of controlling smoke density limit, the conventional method for controlling the smoke density limit of an engine generally uses a map with the speed as the horizontal axis and the fuel volume as the vertical axis to control the smoke density of the engine, such as Figure 1 As shown;

[0011] On the other hand, the smoke limit map reference table of the prior art is shown below, where the horizontal axis is the speed and the vertical axis is the single-cylinder circulating oil volume.

[0012] Reference table of existing technology smoke limit map

[0013] 600 1000 1200 1400 1600 1800 10 20.27 22.71 23.94 25.69 27.44 28.23 30 18.23 20.42 21.52 23.09 24.66 25.39 60 17.22 18.13 19.11 20.49 21.87 22.54 90 16.55 17.55 18.11 18.88 19.40 19.92 120 16.23 17.23 17.45 18.1 18.2 18.41 150 16.12 17.04 17.2 17.5 17.8 18.1

[0014] Typical prior art includes the Chinese invention patent application entitled “Control method and control system for smoke density limitation under engine idling conditions” and application number CN202010724300.X, which discloses the following technical solutions:

[0015] Set the activation conditions for smoke limiter at engine idle speed;

[0016] Constructing a new control strategy model, wherein parameters of the new control strategy model include an excess air correction coefficient and an intake air volume;

[0017] Obtain the actual engine speed and actual intake air volume, and query the corresponding excess air correction coefficient based on the preset smoke limit correction map under the engine idle condition;

[0018] Substituting the actual intake air volume and the queried excess air correction coefficient into a new control strategy model, and outputting a second output volume;

[0019] determining whether a current idle operating condition of the engine satisfies the activation condition, and selecting to use the first output or the second output to control the engine to perform fuel injection;

[0020] The specific steps of constructing a new control strategy model, wherein the parameters of the new control strategy model include an excess air correction coefficient and an intake air volume, include:

[0021] The excess air correction coefficient and intake air volume are used as parameters of the new control strategy model;

[0022] Calibrate the smoke limit correction map under engine idle conditions based on engine speed and intake air volume;

[0023] According to the actual engine speed and actual intake air volume, querying the corresponding excess air correction coefficient in the smoke limit correction map;

[0024] Divide the preset equivalent air-fuel ratio by the actual intake air volume and the queried excess air correction coefficient to obtain the smoke limit fuel volume under the engine idle condition;

[0025] The smoke limit oil quantity is converted into a smoke limit torque, and the smoke limit torque is the second output.

[0026] The defects of existing smoke limit control technology are as follows:

[0027] 1. Due to the poor adaptability of the existing smoke density limit control technology, there are problems with smoke density limit control during the application process;

[0028] The most obvious example is that after the implementation of the National VI emission regulations, diesel engines will be equipped with DPF to prevent particulate emissions. The installation of DPF can effectively reduce the emission of engine particulate matter. However, DPF clogging is a common phenomenon in the market, partly due to the problem of smoke limit control.

[0029] 2. To prevent DPF clogging, the engine smoke limit is often calibrated more strictly, resulting in poor dynamic response of the engine;

[0030] 3. Vehicles have different requirements for engine responsiveness under different loads and road conditions, but the current smoke limit strategy does not make corrections for loads and road conditions, resulting in poor dynamic responsiveness of the engine under different loads and road conditions. Summary of the Invention

[0031] In response to the above-mentioned problems, the present invention provides an engine smoke limit control strategy, the purpose of which is to improve the adaptability of the engine and reduce the occurrence of DPF blockage; improve the responsiveness of the engine, increase the vehicle speed, and reduce fuel consumption; make the adaptability very good, and in the application process, completely solve the smoke limit control problem of the prior art.

[0032] In order to solve the above problems, the technical solution provided by the present invention is:

[0033] An engine smoke limit control strategy includes the following steps:

[0034] S100 obtains engine speed and circulating oil volume;

[0035] S200. Obtaining a basic smoke limit value under the current operating conditions based on the engine speed and the circulating oil volume obtained in S100;

[0036] S300. Obtain a smoke limit correction base value based on the engine speed and the circulating oil volume obtained in S100;

[0037] S400 obtains the carbon accumulation rate;

[0038] S500. Obtain a correction coefficient of the carbon accumulation rate to the smoke density limit value based on the carbon accumulation rate obtained in S400;

[0039] S600. Calculate the correction result of the cumulative carbon rate on the smoke density limit based on the smoke density limit correction base value obtained in S300 and the correction coefficient of the cumulative carbon rate on the smoke density limit obtained in S500; S700. Obtain vehicle load and road slope;

[0040] S800. Based on the vehicle load and the road slope obtained in S400, obtain a correction coefficient for the vehicle load and the road slope to the smoke limit;

[0041] S900. Calculate the correction result of the vehicle load and road slope on the smoke density limit based on the smoke density limit correction base value obtained in S300 and the correction coefficient of the vehicle load and road slope on the smoke density limit obtained in S800;

[0042] S1000. Obtain a final smoke limit correction result based on the correction result of the carbon accumulation rate on the smoke limit calculated in S600 and the correction result of the vehicle load and road slope on the smoke limit calculated in S900;

[0043] S1100. Calculate a final smoke density limit based on the basic smoke density limit obtained in S200 and the final smoke density limit correction result obtained in S1000;

[0044] S1200. Output the final smoke density limit calculated in S1100, which is the final result of the present invention.

[0045] Preferably, in S200, the basic smoke limit value under the current working condition is obtained by searching a basic smoke limit value calibration map; wherein:

[0046] The basic smoke limit calibration map is a two-dimensional table; the abscissa of the basic smoke limit calibration map is the engine speed in r / min, and the ordinate is the circulating oil volume in mg / cycle; the intersection of the abscissa and ordinate of the basic smoke limit calibration map is the value of the basic smoke limit.

[0047] Preferably, in S300, the smoke limit correction base value is obtained by searching a smoke limit correction map; wherein:

[0048] The smoke limit correction map is a two-dimensional table; the abscissa of the smoke limit correction map is the engine speed in r / min, and the ordinate is the circulating oil volume in mg / cycle; the intersection of the abscissa and ordinate of the smoke limit correction map is the value of the smoke limit correction basis.

[0049] Preferably, in S500, the correction coefficient of the carbon accumulation rate to the smoke density limit is obtained by searching the carbon accumulation rate smoke density limit correction coefficient map; wherein:

[0050] The cumulative carbon rate smoke density limit correction coefficient map is a one-dimensional table; the cumulative carbon rate smoke density limit correction coefficient map has two rows, the first row is the cumulative carbon rate, and the second row is the correction coefficient of the cumulative carbon rate to the smoke density limit; in the cumulative carbon rate smoke density limit correction coefficient map, the value of the cumulative carbon rate in the first row and the value of the correction coefficient of the cumulative carbon rate to the smoke density limit in the second row are mapped.

[0051] Preferably, the correction result of the carbon accumulation rate to the smoke limit value calculated in S600 is expressed as follows:

[0052] c=a*b

[0053] Wherein: c is the correction result of the carbon accumulation rate on the smoke density limit; a is the correction base value of the smoke density limit; b is the correction coefficient of the carbon accumulation rate on the smoke density limit.

[0054] Preferably, in S800, the correction coefficient of the vehicle load and road slope to the smoke density limit is obtained by searching the vehicle load and road slope to smoke density limit correction coefficient map; wherein:

[0055] The vehicle load and road slope correction coefficient map for smoke density limit is a two-dimensional table; the horizontal coordinate of the vehicle load and road slope correction coefficient map for smoke density limit is the vehicle load, and the vertical coordinate is the road slope; the intersection of the horizontal coordinate and the vertical coordinate of the vehicle load and road slope correction coefficient map for smoke density limit is the value of the vehicle load and road slope correction coefficient for smoke density limit.

[0056] Preferably, the correction result of the vehicle load and road slope on the smoke limit value calculated in S900 is expressed as follows:

[0057] e=a*d

[0058] Wherein: e is the correction result of the vehicle load and road slope on the smoke limit value; d is the correction coefficient of the vehicle load and road slope on the smoke limit value.

[0059] Preferably, obtaining the final smoke limit correction result in S1000 specifically includes the following steps:

[0060] S1010. Calculate a temporary smoke density limit value based on the correction result of the carbon accumulation rate calculated in S600 for the smoke density limit value, and the correction result of the vehicle load and road slope calculated in S900 for the smoke density limit value;

[0061] S1020. Compare the temporary smoke limit result with the manually preset smoke limit correction upper threshold and the manually preset smoke limit correction lower threshold, and then perform the following operations based on the comparison results:

[0062] If the temporary smoke limit value result is higher than the smoke limit value correction upper threshold value, setting the smoke limit value correction upper threshold value as the final smoke limit value correction result;

[0063] If the temporary smoke density limit result is lower than the smoke density limit correction lower threshold, setting the smoke density limit correction lower threshold as the final smoke density limit correction result;

[0064] If the temporary smoke limit value result is not higher than the smoke limit value correction upper threshold value and not lower than the smoke limit value correction lower threshold value, the temporary smoke limit value result is set as the final smoke limit value correction result.

[0065] Preferably, the temporary smoke limit value calculated in S1010 is expressed as follows:

[0066] z=c+e

[0067] Where: is the temporary smoke limit result described by Z.

[0068] Preferably, the final smoke density limit value calculated in S1100 is expressed as follows:

[0069] smoke_lim=smoke_lim_base+z

[0070] Wherein: smoke_lim is the final smoke limit; moke_lim_bace is the basic smoke limit.

[0071] Compared with the prior art, the present invention has the following advantages:

[0072] 1. Because the smoke control technology of the present invention modifies the smoke limit value based on the carbon accumulation rate, it can improve the adaptability of the engine and reduce the occurrence of DPF clogging;

[0073] 2. Because the smoke control technology of the present invention modifies the smoke limit based on vehicle load and road slope, it can improve engine responsiveness, increase vehicle speed, and reduce fuel consumption;

[0074] 3. Since the smoke density control technology of the present invention amends the smoke density limit value based on various actual working conditions, it has excellent adaptability and completely solves the smoke density limit control problem of the prior art during application. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 A schematic diagram of a prior art smoke control technology involved in the background art of the present invention;

[0076] Figure 2 This is a schematic diagram of obtaining the basic smoke limit value under current working conditions according to a specific embodiment of the present invention;

[0077] Figure 3 A schematic diagram of a correction result of the carbon accumulation rate to the smoke limit value obtained by calculation according to a specific embodiment of the present invention;

[0078] Figure 4 A schematic diagram of a correction result of a vehicle load and a road slope on a smoke density limit value obtained by calculation according to a specific embodiment of the present invention;

[0079] Figure 5 This is a schematic diagram of obtaining the final smoke limit correction result according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0080] The present invention is further illustrated below with reference to specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0081] An engine smoke limit control strategy includes the following steps:

[0082] S100. Obtain engine speed and circulating oil volume.

[0083] In this specific embodiment, the engine speed and circulating oil volume are obtained by reading ECU data.

[0084] S200. Figure 2 As shown, the basic smoke limit value under the current working condition is obtained according to the engine speed and circulating oil volume obtained in S100.

[0085] In this specific embodiment, in S200, the basic smoke limit value under the current working condition is obtained by searching the basic smoke limit value calibration map; wherein:

[0086] The basic smoke limit calibration map is a two-dimensional table; the abscissa of the basic smoke limit calibration map is the engine speed in r / min, and the ordinate is the circulating oil volume in mg / cycle; the intersection of the abscissa and ordinate of the basic smoke limit calibration map is the value of the basic smoke limit.

[0087] In this specific embodiment, as shown in Table 1, a basic smoke limit calibration map is provided as a reference. The basic smoke limit calibration map for specific engines under different vehicle models and operating conditions is different.

[0088] Table 1. Basic smoke limit calibration map sample table

[0089] 600 1000 1200 1400 1600 1800 10 20.27 22.71 23.94 25.69 27.44 28.23 30 18.23 20.42 21.52 23.09 24.66 25.39 60 17.22 18.13 19.11 20.49 21.87 22.54 90 16.55 17.55 18.11 18.88 19.40 19.92 120 16.23 17.23 17.45 18.1 18.2 18.41 150 16.12 17.04 17.2 17.5 17.8 18.1

[0090] S300. Obtain a smoke limit correction base value based on the engine speed and circulating oil volume obtained in S100.

[0091] In this specific embodiment, in S300, the smoke limit correction base value is obtained by searching the smoke limit correction map; wherein:

[0092] The smoke limit correction map is a two-dimensional table; the horizontal axis of the smoke limit correction map is the engine speed, in r / min, and the vertical axis is the circulating oil volume, in mg / cycle; the intersection of the horizontal and vertical axes of the smoke limit correction map is the value of the smoke limit correction basis.

[0093] In this specific embodiment, as shown in Table 2, a smoke limit correction map is provided as a reference. The smoke limit correction map for a specific engine under different vehicle models and operating conditions is different.

[0094] Table 2. Smoke limit correction map sample table

[0095]

[0096]

[0097] S400. Obtain carbon accumulation rate.

[0098] In this specific embodiment, the carbon accumulation rate is obtained by reading ECU data.

[0099] S500. Obtain a correction coefficient of the carbon accumulation rate to the smoke density limit based on the carbon accumulation rate obtained in S400.

[0100] In this specific embodiment, in S500, the correction coefficient of the carbon accumulation rate to the smoke density limit is obtained by searching the carbon accumulation rate smoke density limit correction coefficient map; wherein:

[0101] The cumulative carbon rate smoke density limit correction coefficient map is a one-dimensional table. The cumulative carbon rate smoke density limit correction coefficient map has two rows, the first row is the cumulative carbon rate, and the second row is the correction coefficient of the cumulative carbon rate to the smoke density limit. In the cumulative carbon rate smoke density limit correction coefficient map, the value of the cumulative carbon rate in the first row is mapped to the value of the correction coefficient of the cumulative carbon rate to the smoke density limit in the second row.

[0102] In this specific embodiment, as shown in Table 3, a carbon accumulation rate smoke limit correction coefficient map is provided for reference. The carbon accumulation rate smoke limit correction coefficient map for specific engines under different vehicle models and operating conditions is different.

[0103] Table 3. Sample map of the correction coefficient of the carbon accumulation rate smoke limit

[0104] x -8 -6 -4 -2 0 2 4 6 8 y -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

[0105] S600. Figure 3 As shown, based on the smoke density limit correction base value obtained in S300 and the correction coefficient of the accumulated carbon rate to the smoke density limit obtained in S500, the correction result of the accumulated carbon rate to the smoke density limit is calculated.

[0106] In this specific embodiment, the correction result of the carbon accumulation rate to the smoke limit value calculated in S600 is expressed as follows:

[0107] c=a*b (1)

[0108] Where: c is the correction result of the cumulative carbon rate on the smoke density limit; a is the corrected basic value of the smoke density limit; b is the correction coefficient of the cumulative carbon rate on the smoke density limit.

[0109] It should be noted that the principle of S400~S600 is to correct the smoke limit according to the carbon accumulation rate of the DPF. When the carbon accumulation rate of the DPF is very small, the smoke limit can be relaxed to improve the responsiveness of the engine. When the carbon accumulation rate of the DPF is very large, the smoke limit will be tightened to prevent excessive carbon accumulation.

[0110] S700. Obtain vehicle load and road slope.

[0111] In this specific embodiment, the vehicle load and road slope are obtained by reading ECU data.

[0112] S800. Obtain correction coefficients of the vehicle load and road slope for the smoke density limit based on the vehicle load and road slope obtained in S400.

[0113] In this specific embodiment, in S800, the correction coefficients of vehicle load and road slope for smoke density limit are obtained by searching the map of vehicle load and road slope correction coefficients for smoke density limit; wherein:

[0114] The vehicle load and road slope correction coefficient map for smoke density limit is a two-dimensional table; the horizontal coordinate of the vehicle load and road slope correction coefficient map for smoke density limit is the vehicle load, and the vertical coordinate is the road slope; the intersection of the horizontal coordinate and the vertical coordinate of the vehicle load and road slope correction coefficient map for smoke density limit is the value of the vehicle load and road slope correction coefficient for smoke density limit.

[0115] In this specific embodiment, as shown in Table 4, a map of vehicle load and road slope correction coefficients for smoke limit is provided as a reference. The map of vehicle load and road slope correction coefficients for smoke limit is different for different models and working conditions of specific engines.

[0116] Table 4. Sample map of vehicle load and road slope correction coefficients for smoke density limits

[0117] 30 40 50 60 70 80 1％ 0 0 0 0 0 0 2％ -0.1 -0.1 -0.1 -0.1 -0.1 -0.1 3％ -0.3 -0.3 -0.3 -0.3 -0.3 -0.3 4％ -0.5 -0.5 -0.5 -0.5 -0.5 -0.5 6％ -0.7 -0.7 -0.7 -0.7 -0.7 -0.7 8％ -1 -1 -1 -1 -1 -1

[0118] S900. Figure 4 As shown, based on the smoke limit correction base value obtained in S300 and the correction coefficient of the vehicle load and road slope to the smoke limit obtained in S800, the correction result of the vehicle load and road slope to the smoke limit is calculated.

[0119] In this specific embodiment, the correction result of the vehicle load and road slope on the smoke limit value calculated in S900 is expressed as follows:

[0120] e=a*d (2)

[0121] Where: e is the correction result of vehicle load and road slope on the smoke limit; d is the correction coefficient of vehicle load and road slope on the smoke limit.

[0122] It should be noted that the principle of S700~S900 is that when the vehicle is heavily loaded and climbing a slope, the smoke limit can be relaxed to improve the engine's responsiveness.

[0123] It should be further explained that the reason for S700 to S900 is that on engineering vehicles, when the vehicle is heavily loaded and climbing a slope, the engine exhaust temperature is very high and the DPF regeneration rate is very fast. The vehicle has high requirements for the responsiveness of the engine. Therefore, when climbing a slope with a heavy load, the smoke limit can be released to improve the responsiveness of the engine, increase the vehicle speed and reduce fuel consumption.

[0124] S1000. Figure 5 As shown, the final smoke limit correction result is obtained based on the correction result of the carbon accumulation rate calculated in S600 on the smoke limit, and the correction result of the vehicle load and road slope calculated in S900 on the smoke limit.

[0125] In this specific embodiment, obtaining the final smoke limit correction result in S1000 specifically includes the following steps:

[0126] S1010. Calculate a temporary smoke density limit value based on the correction result of the carbon accumulation rate calculated in S600 on the smoke density limit value and the correction result of the vehicle load and road slope calculated in S900 on the smoke density limit value.

[0127] In this specific embodiment, the temporary smoke density limit value calculated in S1010 is expressed as follows:

[0128] z=c+e (3)

[0129] Where: z is the temporary smoke limit result.

[0130] S1020. Compare the temporary smoke limit result with the manually preset smoke limit correction upper threshold and the manually preset smoke limit correction lower threshold, and then perform the following operations based on the comparison results:

[0131] If the temporary smoke limit result is higher than the smoke limit correction upper threshold, the smoke limit correction upper threshold is set as the final smoke limit correction result.

[0132] If the temporary smoke density limit result is lower than the smoke density limit correction lower threshold, the smoke density limit correction lower threshold is set as the final smoke density limit correction result.

[0133] If the temporary smoke limit result is not higher than the smoke limit correction upper threshold and not lower than the smoke limit correction lower threshold, the temporary smoke limit result is set as the final smoke limit correction result.

[0134] It should be noted that the principle of S1000 is to compare the temporary smoke limit result with the manually preset upper limit threshold of the smoke limit correction, and take the smaller one; on the other hand, compare the temporary smoke limit result with the manually preset lower limit threshold of the smoke limit correction, and take the larger one; and finally obtain the final smoke limit correction result.

[0135] It should be noted that the final smoke density limit result has upper and lower limits and cannot exceed the upper and lower limits of the smoke density limit correction. Therefore, the final smoke density limit correction result requires the processing process of S1000.

[0136] S1100. Calculate the final smoke density limit based on the basic smoke density limit obtained in S200 and the final smoke density limit correction result obtained in S1000.

[0137] In this specific embodiment, the final smoke density limit value is calculated in S1100 and expressed as follows:

[0138] smoke_lim=smoke_lim_bace+z (4)

[0139] Among them: smoke_lim is the final smoke limit; moke_lim_bace is the basic smoke limit.

[0140] S1200. Output the final smoke density limit calculated in S1100, which is the final result of the present invention.

[0141] In the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of any individual disclosed embodiment. The appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0142] The above description of the disclosed embodiments is intended to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments presented herein but is intended to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0143] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above embodiments, but one of ordinary skill in the art will recognize that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to encompass all such changes, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent the term "comprising" is used in the specification or claims, the term is intended to be encompassed in a manner similar to the term "including," as explained in terms of "including," used as a transitional word in the claims. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or."

[0144] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An engine smoke limit control strategy, characterized by: The following steps are involved: S100 obtains engine speed and circulating oil volume; S200. Obtain the basic smoke limit under the current operating conditions according to the engine speed and the circulating oil volume obtained in S100; S300. Obtaining a smoke limit correction base value based on the engine speed and the circulating oil volume obtained in S100; S400 obtains the carbon accumulation rate; S500. Obtaining a correction coefficient of the carbon accumulation rate to the smoke limit based on the carbon accumulation rate obtained in S400; S600. Calculate a correction result of the accumulated carbonization rate to the smoke limit based on the smoke limit correction base value obtained in S300 and the correction coefficient of the accumulated carbonization rate to the smoke limit obtained in S500; S700. Get vehicle load and road slope; S800. Obtain a correction coefficient for the vehicle load and the road slope on the smoke limit based on the vehicle load and the road slope obtained in S400; S900. Calculate the correction result of the vehicle load and road slope on the smoke limit based on the smoke limit correction base value obtained in S300 and the vehicle load and road slope correction coefficient on the smoke limit obtained in S800; S1000. Obtain a final smoke limit correction result based on the correction result of the carbon accumulation rate on the smoke limit calculated in S600 and the correction result of the vehicle load and road slope on the smoke limit calculated in S900; Obtaining the final smoke limit correction result in S1000 specifically includes the following steps: S1010. Calculate a temporary smoke limit result based on the correction result of the carbon accumulation rate on the smoke limit calculated in S600 and the correction result of the vehicle load and road slope on the smoke limit calculated in S900; S1020. Compare the temporary smoke limit result with the manually preset smoke limit correction upper threshold and the manually preset smoke limit correction lower threshold, and then perform the following operations based on the comparison results: If the temporary smoke limit result is higher than the smoke limit correction upper threshold, setting the smoke limit correction upper threshold as the final smoke limit correction result; If the temporary smoke limit result is lower than the smoke limit correction lower threshold, the smoke limit correction lower threshold is set as the final smoke limit correction result; If the temporary smoke limit result is not higher than the smoke limit correction upper threshold and not lower than the smoke limit correction lower threshold, the temporary smoke limit result is set as the final smoke limit correction result; S1100. Calculate a final smoke limit value based on the basic smoke limit obtained in S200 and the final smoke limit correction result obtained in S1000; S1200. Output the final smoke limit value calculated in S1100, which is the final result.

2. The engine smoke limit control strategy according to claim 1, characterized in that: In S200, the basic smoke limit calibration map is searched to obtain the basic smoke limit under the current working condition; wherein: The basic smoke limit calibration map is a two-dimensional table; the horizontal axis of the basic smoke limit calibration map is the engine speed, in r / min, and the vertical axis is the circulating oil volume, in mg / cycle; the intersection of the horizontal axis and the vertical axis of the basic smoke limit calibration map is the value of the basic smoke limit.

3. The engine smoke limit control strategy according to claim 2, characterized in that: In S300, the smoke limit correction base value is obtained by searching the smoke limit correction map; wherein: The smoke limit correction map is a two-dimensional table; the horizontal axis of the smoke limit correction map is the engine speed, in r / min, and the vertical axis is the circulating oil volume, in mg / cycle; the intersection of the horizontal axis and the vertical axis of the smoke limit correction map is the value of the smoke limit correction basis.

4. The engine smoke limit control strategy according to claim 3, characterized in that: In S500, the correction coefficient of the accumulated carbon rate to the smoke limit is obtained by searching the map of the accumulated carbon rate smoke limit correction coefficient; wherein: The cumulative carbonization rate smoke limit correction coefficient map is a one-dimensional table. The cumulative carbonization rate smoke limit correction coefficient map has two rows, the first row is the cumulative carbonization rate, and the second row is the correction coefficient of the cumulative carbonization rate to the smoke limit. In the cumulative carbonization rate smoke limit correction coefficient map, the value of the cumulative carbonization rate in the first row is mapped to the value of the correction coefficient of the cumulative carbonization rate to the smoke limit in the second row.

5. The engine smoke limit control strategy according to claim 4, characterized in that: The correction result of the carbon accumulation rate to the smoke limit is calculated in S600 and is expressed as follows: c=a*b Wherein: c is the correction result of the cumulative carbon rate on the smoke limit; a is the smoke limit correction base value; b is the correction coefficient of the cumulative carbon rate on the smoke limit.

6. The engine smoke limit control strategy according to claim 5, characterized in that: In S800, the vehicle load and road slope correction coefficient map for the smoke limit is searched to obtain the vehicle load and road slope correction coefficient for the smoke limit; wherein: The vehicle load and road slope to smoke limit correction coefficient map is a two-dimensional table; the horizontal coordinate of the vehicle load and road slope to smoke limit correction coefficient map is the vehicle load, and the vertical coordinate is the road slope; the intersection of the horizontal coordinate and the vertical coordinate of the vehicle load and road slope to smoke limit correction coefficient map is the value of the vehicle load and road slope to smoke limit correction coefficient.

7. The engine smoke limit control strategy according to claim 6, characterized in that: The correction result of the vehicle load and road slope on the smoke limit is calculated in S900 and is expressed as follows: e=a*d Wherein: e is the correction result of the vehicle load and road slope on the smoke limit; d is the correction coefficient of the vehicle load and road slope on the smoke limit.

8. The engine smoke limit control strategy according to claim 7, characterized in that: The temporary smoke limit result is calculated in S1010 and is expressed as follows: z=c+e Where: is the temporary smoking limit result described in z.

9. The engine smoke limit control strategy according to claim 8, characterized in that: The final smoke limit value is calculated in S1100 and is expressed as follows: smoke_lim=smoke_lim_base+z Wherein: smoke_lim is the final smoke limit value; moke_lim_bace is the basic smoke limit.

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