Vehicle idle speed self-adaptive controller
By designing a vehicle idle adaptive controller, the idle target value is dynamically adjusted according to factors such as altitude, water temperature and vehicle speed, the problem of insufficient power in the low speed of the diesel engine and excessive pollutants is solved, and the effect of improving low speed power and reducing pollutants is achieved.
Patent Information
- Application Number
- CN202510175925.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2025-05-09
AI Technical Summary
Modern automotive diesel engines have weak power at low speeds, resulting in conflicts between low speed power and emissions of pollutants such as carbon soot, especially in plateau environments.
Design a vehicle idle adaptive controller, through the in-situ idle control module and the driving idle control module, dynamically adjust the idle target value according to factors such as altitude, water temperature and vehicle speed, improve the engine's low-speed power and reduce pollutants emissions.
By increasing the idle target value, increasing the idle intake volume, improving the engine's low-speed power, improving the starting and acceleration power, and reducing the smoke and THC emission pollutants during the acceleration process.
Smart Images
Figure CN119957372A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of diesel engine control, and in particular to a vehicle idle speed adaptive controller. Background Art
[0002] In order to achieve greater power and torque per liter, modern automotive diesel engines often meet the requirements of high-speed performance for ordinary mechanical exhaust valve superchargers, but cannot take into account low-speed performance. The phenomenon of a small horse pulling a big cart is common. The engine displacement is small, and although the power and torque at medium and high speeds are large, the supercharger's boosting ability is weak at low speeds. Compared with engines with larger displacements, weak low-speed power is a common flaw, especially in plateaus due to the low air density. In order to prevent acceleration smoke, the low-speed power is further limited under the effect of smoke restriction. Therefore, the power and carbon smoke and other emission pollutants under low-speed conditions are contradictory. How to improve the low-speed power of the engine and reduce emission pollutants needs to be improved. Summary of the invention
[0003] The present invention aims to solve at least one of the above-mentioned technical problems and provide a vehicle idle adaptive controller that can effectively improve the low-speed power of the engine and reduce emission pollutants.
[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a vehicle idle speed adaptive controller, comprising:
[0005] The stationary idle speed control module is used to control the stationary idle speed target value of the vehicle. The stationary idle speed target value is the basic idle speed value plus the compensation value of altitude / water temperature;
[0006] The driving idle speed control module obtains the gear information of the vehicle through the gear switch sensor and transmits the gear information to the idle mode selector to determine the driving idle speed target value, where:
[0007] When the gear is in forward gear D, the target idle speed is the basic idle speed plus the compensation value of altitude / vehicle speed;
[0008] When the gear position is neutral (N), the target idle speed is the basic idle speed plus the compensation value of altitude / water temperature;
[0009] When the gear position is reverse gear R, the driving idle speed target value is the basic idle speed value.
[0010] Preferably, the altitude / water temperature compensation value is obtained by looking up an altitude / water temperature compensation table, which uses atmospheric pressure as horizontal data and water temperature as vertical data, and the higher the altitude and the lower the water temperature, the greater the corresponding compensation value.
[0011] Preferably, the altitude / vehicle speed compensation value is obtained by looking up an altitude / vehicle speed compensation table. The altitude / vehicle speed compensation table uses atmospheric pressure as horizontal data and vehicle speed as vertical data. The higher the altitude and the lower the vehicle speed, the greater the corresponding compensation value.
[0012] The beneficial effect is that compared with the prior art, the vehicle idle speed adaptive controller of the present invention can increase the idle speed intake volume, improve the low-speed power of the engine, and improve the starting and acceleration power by increasing the idle speed target value in situ. At the same time, due to the increase in air volume at the time of starting, the emission pollutants such as smoke and THC in the acceleration process are also reduced accordingly, and the basic idle speed value can be compensated according to different vehicle speeds and atmospheric pressures, so that the engine speed will not fall to the basic idle speed when the vehicle coasts, but a higher speed than the basic idle speed. The neutral idle speed can also be compensated according to different water temperatures and atmospheric pressures, so that the engine will not fall to a lower idle speed when the vehicle shifts gears, so that the vehicle is beneficial to improve the acceleration power and reduce PM and other emission pollutants when it accelerates next time. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:
[0014] Figure 1 It is the working flow chart of the idle speed control module;
[0015] Figure 2 This is the working flow chart of the vehicle idle speed control module. DETAILED DESCRIPTION
[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0017] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is referred to as being "set in the middle", it does not only mean being set in the middle, as long as it is not set at both ends within the range defined by the middle. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.
[0018] 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 present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0019] like Figure 1 and Figure 2 As shown, the present application discloses a vehicle idle adaptive controller, including an in-situ idle control module and a driving idle control module, specifically:
[0020] The idle speed control module is used to control the idle speed target value of the vehicle. The idle speed target value is the basic idle speed value plus the compensation value of altitude / water temperature. The idle speed announcement declaration of different engines is different. For example, the basic idle speed value of a certain light engine is 750rpm.
[0021] The driving idle speed control module obtains the gear information of the vehicle through the gear switch sensor and transmits the gear information to the idle mode selector to determine the driving idle speed target value, where:
[0022] When the gear is forward gear D, the target driving idle speed is the basic idle speed value plus the altitude / vehicle speed compensation value. During vehicle driving, if the driver does not step on the accelerator, the engine speed of the traditional scheme will gradually return to the basic idle speed value as the vehicle coasts. When accelerating next time, due to the low initial speed, the supercharger cannot quickly establish the boost capacity. Not only does the vehicle accelerate slowly, but it is also easy to produce a lot of carbon smoke during acceleration, especially in plateau environments. This application can compensate for the idle speed according to different vehicle speeds and atmospheric pressures, so that the engine speed will not fall to the basic idle speed at the end of the vehicle coasting, but a higher speed than the basic idle speed. When accelerating next time, it is beneficial to improve the acceleration power and reduce PM and other emission pollutants;
[0023] When the gear position is neutral N, the driving idle speed target value is the basic idle speed value plus the compensation value of altitude / water temperature. During the driving process of the vehicle, the driver steps on the clutch to change gears, and the whole vehicle is in the neutral position. The engine speed will gradually return to the basic idle speed value with inertia. When the gear shift is completed, the traditional solution has a very low initial speed, and the supercharger cannot quickly establish the supercharging capacity. Not only does the vehicle accelerate slowly, but it is also easy to generate a large amount of carbon smoke during the acceleration process, especially in plateau environments. The technical solution of the present application can compensate for the neutral idle speed according to different water temperatures and atmospheric pressures, so that when the vehicle shifts gears, the engine will not fall to a lower idle speed, but a higher speed than the basic idle speed. When accelerating next time, it is beneficial to improve the acceleration power and reduce PM and other emission pollutants;
[0024] When the gear is reverse gear R, the driving idle speed target value is the basic idle speed value. Since the vehicle is in reverse gear, the basic idle speed is not corrected for safety and driver convenience.
[0025] Through research, the present application has found that when atmospheric pressure decreases, the engine torque output decreases due to the decrease in intake volume, the power of the traditional solution becomes weaker and the carbon smoke increases. However, the present application increases the target idle speed value by setting the above compensation value, which can increase the idle intake volume, improve the engine low-speed power, and improve the starting and acceleration power. At the same time, due to the increase in air volume at the start, the smoke density and THC and other emission pollutants during the acceleration process also decrease. Similarly, when the water temperature decreases, due to the decrease in combustion efficiency, the target idle speed can be increased by the above Maipu output compensation value, which can quickly increase the water temperature, and at the same time is conducive to improving combustion, improving power, and reducing the generation of exhaust pollutants.
[0026] For the above-mentioned compensation values of altitude / water temperature and altitude / vehicle speed, this application sets an altitude / water temperature compensation table and an altitude / vehicle speed compensation table, and obtains the compensation values of altitude / water temperature and altitude / vehicle speed by looking up the table. The setting method of the altitude / water temperature compensation table and the altitude / vehicle speed compensation table is as follows:
[0027] The horizontal data of the altitude / water temperature compensation table is the atmospheric pressure, and the standard value range is 0kPa~100kPa. However, the atmospheric pressure range at altitudes in most parts of my country is between 50kPa and 100kPa, and the representative test verification city altitudes are 85kpa (Kunming, Dunhuang), 76kpa (Xining), 72kpa (Golmud), 65kpa, and 53kpa (Kunlun Mountain). Therefore, the horizontal data can refer to the above breakpoint settings. The vertical data is the water temperature, which is usually below 60 degrees for a cold engine state. Considering that the temperature in the north usually drops below -35 degrees in winter, the range of the vertical data is set to between -40℃-80℃. The specific idle compensation value is the data corresponding to the horizontal and vertical data. If there is no value in the horizontal and vertical data, it is obtained by looking up the adjacent horizontal and vertical data tables for interpolation. As shown in Table 1:
[0028] Table 1 Compensation values for altitude / water temperature
[0029] 50kPa 65kPa 72kPa 76kPa 85kPa 100kPa -40 300 .... .... .... 50 -30 .... .... -20 .... .... 10 .... 50 .... 20 100 .... .... .... 0 40 60
[0030] The altitude / water temperature compensation value in the above table is determined. The lower the water temperature, the slower the idle speed stability and the engine water temperature increase speed. Appropriate idle speed compensation can increase the idle speed value, which can make the engine warm up quickly, improve the engine idle speed stability and reduce pollutant emissions. Under the longitudinal data water temperature shown in Table 1, the idle speed compensation value is gradually increased. The time for the engine water temperature to rise from the initial temperature at startup to 60°C meets the internal control requirements of the enterprise (the maximum time is recommended not to exceed 20 minutes). At the same time, the idle speed stability (idle speed fluctuation value does not exceed ±10 rpm) and pollutant emissions (CO and THC emissions at idle speed under cold engine do not exceed 200ppm) after compensation under different water temperatures meet the control requirements of the enterprise.
[0031] The higher the altitude, the weaker the engine idle loading capacity. Appropriate idle compensation can be used to increase the idle value, which can improve the engine's starting and acceleration capabilities. The idle speed is gradually increased under the atmospheric pressure on the horizontal axis shown in Table 1, so that the vehicle can start smoothly on a 15° slope in the second gear when fully loaded (different companies may have different acceptance standards). At the same time, the idle stability (idle fluctuation value does not exceed ±10 rpm) and pollutant emissions (CO and THC emissions at idle under cold engine conditions do not exceed 200ppm) after compensation under different atmospheric pressures meet the company's control requirements.
[0032] The horizontal data of the altitude / vehicle speed compensation table is the atmospheric pressure, and the standard value range is 0kPa~100kPa. However, the atmospheric pressure range at altitudes in most parts of my country is between 50kPa and 100kPa, and the representative test verification city altitudes are 85kpa (Kunming, Dunhuang), 76kpa (Xining), 72kpa (Golmud), 65kpa, and 53kpa (Kunlun Mountain). Therefore, the horizontal data can refer to the above breakpoint settings. The longitudinal data is the vehicle speed. Usually when the vehicle speed is lower than 40km / h, the vehicle is in the starting or acceleration stage, and the engine speed is low and idle compensation is required, so the range of the vertical coordinate is set between 0km / h-60℃. The specific idle compensation value is the data corresponding to the horizontal and vertical data. If there is no value in the horizontal and vertical data, it is obtained by looking up the adjacent horizontal and vertical data and interpolating the values, as shown in Table 2:
[0033] Table 2 Altitude / vehicle speed compensation table
[0034] 50kPa 65kPa 72kPa 76kPa 85kPa 100kPa 0 300 .... .... .... 50 5 .... .... 10 .... .... 20 .... 50 .... 40 100 .... .... .... 0 60 80
[0035] Generally speaking, the higher the altitude, the lower the speed, the greater the idle compensation value, and vice versa. During the test, for different atmospheric pressures in Table 2 (experimental sites at corresponding altitudes), idle compensation is not used first, and the original data vehicle's 0-80km acceleration time and urban road (average speed does not exceed 35km / h) smoke test are tested. If the power and acceleration smoke results can meet the development requirements, idle compensation is not required. If the power and acceleration smoke results cannot meet the requirements, 0-10km / h, 0-20km / h, 0-40km / h, and 0-40km / h start acceleration tests are carried out one by one for the atmospheric pressures shown in the horizontal data in Table 2 (different altitude test sites). During the test, the idle compensation value is gradually increased until satisfactory acceleration power and acceptable acceleration smoke are found. Finally, in order to prevent the vehicle speed from being too high during idling, it is necessary to finally determine the idle compensation value at different altitudes and vehicle speeds through drivability evaluation.
[0036] In this regard, this application also uses two comparative cases for illustration. One of the comparative cases is as follows:
[0037]
[0038] As shown in the above case, based on a vehicle with a standard load of 15 tons, the performance difference between the solution adopted in this application and the traditional solution at different water temperatures of -20 degrees is compared:
[0039] When the idle speed correction is not used: the basic idle speed is 750rpm, the idle speed stability is poor after starting at -20 degrees, the idle speed fluctuation is ±80rpm, the time from -20 degrees to 60 degrees water temperature is 25min, and the 2nd gear ramp start fails under standard load; after the idle speed correction is used, the idle speed compensation is 350rpm, the idle speed fluctuation is controlled at ±15rpm, the stability is significantly improved, and the time from -20 degrees to 60 degrees water temperature is shortened to 16min, the warm-up time is significantly shortened, and the 2nd gear ramp start is successfully started after 150rpm compensation. It can be seen that this patent has a significant effect on improving vehicle performance.
[0040] Another comparative example is as follows:
[0041]
[0042] As shown in the above case, based on a vehicle with a standard load of 15 tons, the performance difference between the solution adopted in this application and the traditional solution at an altitude of 2,800 meters is compared:
[0043] When the driving idle speed correction is not adopted: the basic idle speed is 750rpm, under the same driving road conditions and conditions, the actual DPF carbon deposit full-load mileage is 700km, which does not meet the expected value of 800km. At the same time, the vehicle's 0-80km / h acceleration time is 38 seconds, and the power is poor, which does not meet the expected 30 seconds; after the driving idle speed correction is adopted, the actual DPF carbon deposit full-load mileage is increased to 890km, and the acceleration smoke is significantly reduced, meeting the expected value of 800km; the vehicle's 0-80km / h acceleration time is 30 seconds, and the power is enhanced. It can be seen that this patent has a significant effect on improving vehicle performance.
[0044] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Any modification or equivalent substitution that does not depart from the spirit and scope of the present invention shall be included in the scope of the technical solution of the present invention.
Claims
1. A vehicle idle speed adaptive controller, characterized in that: include: The stationary idle speed control module is used to control the stationary idle speed target value of the vehicle. The stationary idle speed target value is the basic idle speed value plus the compensation value of altitude / water temperature; The driving idle speed control module obtains the gear information of the vehicle through the gear switch sensor and transmits the gear information to the idle mode selector to determine the driving idle speed target value, where: When the gear is in the forward gear D, the target idle speed is the basic idle speed plus the compensation value for altitude / vehicle speed; when the gear is in the neutral gear N, the target idle speed is the basic idle speed plus the compensation value for altitude / water temperature; when the gear is in the reverse gear R, the target idle speed is the basic idle speed.
2. A vehicle idle speed adaptive controller according to claim 1, characterized in that: The altitude / water temperature compensation value is obtained by looking up an altitude / water temperature compensation table. The altitude / water temperature compensation table uses atmospheric pressure as horizontal data and water temperature as vertical data. The higher the altitude and the lower the water temperature, the greater the corresponding compensation value.
3. A vehicle idle speed adaptive controller according to claim 1, characterized in that: The altitude / vehicle speed compensation value is obtained by looking up an altitude / vehicle speed compensation table. The altitude / vehicle speed compensation table uses atmospheric pressure as horizontal data and vehicle speed as vertical data. The higher the altitude and the lower the vehicle speed, the greater the corresponding compensation value.