A dual-fuel intelligent injection control system and method for a diesel engine

Abstract

The present invention discloses a dual-fuel intelligent injection control system and method for a diesel engine, which performs level-I signal determination, level-II signal determination, and level-III signal determination based on the road type, as well as the internal information and external information of the vehicle itself; according to the determination results, a torque pre-adjustment signal is obtained, and the torque pre-adjustment signal includes: a torque rapid increase signal, a torque slight increase signal, a torque slight decrease signal, a torque rapid decrease signal, and a constant-speed stable signal; according to the obtained torque pre-adjustment signal, an acceleration range corresponding to each torque pre-adjustment signal is set; in combination with the current basic operating conditions of the diesel engine, the fuel injection mode is judged; the fuel injection amount is selected, that is, a torque adjustment signal is obtained; and the dual-fuel injection of the diesel engine is controlled in real time according to the torque adjustment signal. The present invention can realize intelligent control of the power output of the internal combustion engine, which is beneficial to saving fuel consumption, reducing pollutant emissions, improving the driving comfort of users, and realizing the comprehensive development of intelligent driving.

Description

Technical Field

[0001] The present invention belongs to the technical field of internal combustion engines, and relates to a dual-fuel intelligent injection control system and a fuel injection strategy for a diesel engine for automotive intelligent driving. Background Art

[0002] In order to reduce the pollutant emissions of diesel engines, many scholars at home and abroad have conducted a large number of studies on alternative fuels for internal combustion engines, and the dual-fuel mode has been a research hotspot in recent years.

[0003] The dual-fuel mode has the advantages of flexible reaction ratio, which can reduce the emissions of pollutants from a single fossil energy source, has the characteristics of flexible adjustment under different driving conditions, can change the activity of reactants according to different needs, provide the required power output and maintain low pollutant emissions, and has smooth supply and switching between power regulation and fuel.

[0004] The control of the dual-fuel mode is achieved by changing the supply amounts of the two fuels. The supply methods of dual fuels are diverse. Among them, the reactivity controlled compression ignition technology (RCCI) is a combustion technology that uses a dual injection system to achieve in-cylinder mixed fuel combustion. It means that a fuel with a high cetane number is supplied into the cylinder by direct injection, and a fuel with a high octane number (such as methanol, ethanol, etc.) is supplied into the intake port. By changing the blending ratio, the fuel activity in the diesel engine cylinder can be adjusted. Through the RCCI combustion mode, the application of low-carbon fuels in diesel engines can be realized, which is beneficial to improving the combustion efficiency and reducing pollutant emissions. This method can not only achieve the uniformity of in-cylinder mixing but also has the condition of flexible ratio adjustment. Based on this dual-fuel regulation system, the imbalance problem between the implementation and regulation of dual fuels and environmental protection can be solved.

[0005] However, the current dual-fuel injection mode is not intelligent, cannot achieve intelligent control of the power output of the internal combustion engine, and cannot meet the needs of internal combustion engine vehicle users. However, realizing the intelligent injection control of diesel engine dual fuels can be beneficial to saving fuel consumption, reducing pollutant emissions, better accessing the future vehicle networking, realizing intelligent transportation, improving the driving comfort of users, and achieving the comprehensive development of intelligent driving. Therefore, there is an urgent need for an intelligent injection control system and method applicable to diesel engine dual fuels. Summary of the Invention

[0006] In order to solve the deficiencies existing in the prior art, the present invention proposes a dual-fuel injection control system and method for a diesel engine, aiming to achieve high-precision and intelligent control of the power of a vehicle with a dual-fuel diesel engine as the power system.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A dual-fuel injection control method, comprising the following steps:

[0009] Step 1, obtain the internal information and external information of the own vehicle, where the internal information includes the current vehicle speed V0 of the own vehicle; the external information includes the distance s between the vehicle ahead and the own vehicle, the distance s' between the vehicle behind and the own vehicle, the distance L between the side object and the own vehicle, the vehicle speed V1 of the vehicle ahead, and the vehicle speed V2 of the vehicle behind;

[0010] Step 2, perform a first-level signal determination, a second-level signal determination, and a third-level signal determination based on the road type, as well as the internal information and external information of the own vehicle;

[0011] Step 3, input the results of the first-level signal determination, the second-level signal determination, and the third-level signal determination in sequence, and obtain a torque pre-adjustment signal according to the determination results. The torque pre-adjustment signal includes: a torque rapid increase signal, a torque slight increase signal, a torque slight decrease signal, a torque rapid decrease signal, and a uniform stable signal;

[0012] Step 4, according to the torque pre-adjustment signal obtained in Step 3, set the acceleration corresponding to each torque pre-adjustment signal; combine the current basic operating conditions of the diesel engine to determine the fuel injection mode; select the fuel injection amount, that is, obtain a torque adjustment signal; and perform real-time control on the dual-fuel injection of the diesel engine according to the torque adjustment signal.

[0013] Furthermore, the first-level signal determination is made according to the distance and speed between the own vehicle and the vehicle ahead; among them, two distance thresholds s1 and s2 are set for the distance s between the own vehicle and the vehicle ahead, s1 < s2. If s > s2, a green feasible signal is output; if s2 > s > s1, a yellow signal is output; if s1 > s, a red warning signal is output; for the speed V0 of the own vehicle and the speed V1 of the vehicle ahead, if V1 > V0, a green feasible signal is output; if V1 ≤ V0, a red warning signal is output;

[0014] The second-level signal determination is made according to the distance and speed between the own vehicle and the vehicle behind; among them, a distance threshold s1' is set for the distance s' between the own vehicle and the vehicle behind. If s' > s1', a green feasible signal is output; if s' ≤ s1', a red warning signal is output; for the speed V0 of the own vehicle and the speed V2 of the vehicle behind, if V2 < V0, a green feasible signal is output; if V2 ≥ V0, a red warning signal is output;

[0015] The third-level signal determination is made according to the distance L between the own vehicle and the side object; a lateral distance threshold is set as L0. If L > L0, a green feasible signal is output; if L ≤ L0, a red warning signal is output.

[0016] Further, the process of obtaining the torque pre-adjustment signal based on the determination result in step 3 is as follows:

[0017] Input the determination result of the first-level signal determination. If the determination results of the distance and speed between the host vehicle and the vehicle in front of it in the first-level signal determination are both green feasible signals, then accept the determination result of the second-level signal determination; if the determination results of the distance and speed between the host vehicle and the vehicle behind it in the second-level signal determination are both green feasible signals, then accept the determination result of the third-level signal determination. If the determination result of the distance between the host vehicle and the object on its side in the third-level signal determination is a green feasible signal, at this time, the torque pre-adjustment signal is a torque rapid increase signal;

[0018] Input the determination result of the first-level signal determination. If the determination result of the first-level signal determination is a green feasible signal and the determination result of the second-level signal determination is not a double green feasible signal, at this time, the torque pre-adjustment signal is a constant-speed steady-state signal;

[0019] Input the determination result of the first-level signal determination. If in the determination result of the first-level signal determination, the determination result of the distance between the host vehicle and the vehicle in front of it is a yellow signal and the determination result of the speed between the host vehicle and the vehicle in front of it is a green feasible signal, then accept the determination result of the second-level signal determination; the determination result of the second-level signal determination is a double green feasible signal, at this time, the torque pre-adjustment signal is a torque slight increase signal;

[0020] Input the determination result of the first-level signal determination. If in the determination result of the first-level signal determination, the determination result of the distance between the host vehicle and the vehicle in front of it is a yellow signal and the determination result of the speed between the host vehicle and the vehicle in front of it is a red warning signal, at this time, the torque pre-adjustment signal is a torque slight decrease signal;

[0021] Input the determination result of the first-level signal determination. If the determination result of the first-level signal determination is a double red warning signal, at this time, the torque pre-adjustment signal is a torque rapid decrease signal.

[0022] Further, the accelerations corresponding to the torque pre-adjustment signals are respectively:

[0023] The magnitude of the acceleration corresponding to the torque rapid increase signal is a > 3m / s 2 ;

[0024] The magnitude of the acceleration corresponding to the torque slight increase signal is 0 < a ≤ 3m / s 2 ;

[0025] The magnitude of the acceleration corresponding to the torque slight decrease signal is -3 < a < 0m / s 2 ;

[0026] The magnitude of the acceleration corresponding to the torque rapid decrease signal is a ≤ -3m / s 2;

[0027] The acceleration corresponding to the uniform and stable signal is a = 0 m / s 2 .

[0028] Furthermore, the acceleration is expressed as: s is the distance between the vehicle ahead and the own vehicle.

[0029] Furthermore, according to the current basic operating conditions of the diesel engine, the method for judging the fuel injection mode is:

[0030] The basic operating conditions of the diesel engine include water temperature and rotational speed. If the water temperature ≥ 70 °C and the rotational speed ≤ 3700 r / min, a dual-fuel injection mode is adopted; if the water temperature < 70 °C or the rotational speed > 3700 r / min, only the diesel injection mode is adopted.

[0031] Furthermore, the method for determining the corresponding fuel injection quantity based on the fuel injection mode is:

[0032] Input the data graph of the relationship between vehicle acceleration, diesel engine rotational speed and fuel injection quantity obtained through experiments for the two required fuels in the data storage area of the dual-fuel ECU. The fuel injection quantity is saved in the form of two-dimensional data, and the two dimensions of the data represent acceleration and diesel engine rotational speed respectively. The data of the array is the fuel injection quantity; use the improved particle swarm algorithm to iteratively optimize the injection quantity.

[0033] Furthermore, if only the diesel injection mode is adopted, the dual-fuel ECU calls and reads the data graph of the fuel injection quantity, vehicle acceleration and diesel engine rotational speed in the pure diesel mode, and selects the fuel injection quantity according to the acceleration corresponding to the torque pre-adjustment signal from the iterated data;

[0034] If the dual-fuel injection mode is adopted, the dual-fuel ECU calls the data of the fuel injection quantity, vehicle acceleration and diesel engine rotational speed of the other fuel, and selects the fuel injection quantity according to the acceleration corresponding to the torque pre-adjustment signal from the iterated data.

[0035] A dual-fuel injection control system includes: an information acquisition module, an information analysis and processing module, and a fuel injection control module;

[0036] The information acquisition module includes a vehicle external information acquisition unit and a vehicle internal information acquisition unit, which are respectively used to acquire vehicle external information and vehicle internal information;

[0037] The information analysis and processing module includes an information analysis unit, an information processing unit, and an information storage unit. The information analysis unit is signal-connected to the information acquisition module to receive the acquired external vehicle information and internal vehicle information. The information storage unit pre-stores laws and regulations related to roads, high-precision map data, preset road conditions, distance thresholds, speed thresholds, and acceleration thresholds corresponding to different road conditions. The information processing unit is signal-connected to the information analysis unit and the information storage unit. In the information processing unit, based on the environmental information of the front, rear, and sides of the vehicle analyzed by the information analysis unit and the thresholds of the data pre-stored in the information storage unit, level-I signal determination, level-II signal determination, and level-III signal determination are sequentially performed; and a torque pre-adjustment signal is obtained by combining the results of the level-I signal determination, level-II signal determination, and level-III signal determination.

[0038] The fuel injection control module receives the torque pre-adjustment signal and performs real-time control on the dual-fuel injection of the diesel engine according to the torque pre-adjustment signal and the current basic operating conditions of the diesel engine.

[0039] Further, the fuel injection control module includes a dual-fuel ECU, a diesel injection controller, a diesel alternative fuel injection controller, a diesel alternative fuel pressure regulator, an accelerator control handle position sensor, a brake pedal controller, a speed sensor, a water temperature sensor, and a fuel rail pressure sensor. The fuel injection control module adjusts and controls the vehicle's power system.

[0040] Advantages of the present invention:

[0041] (1) Based on the existing research on dual-fuel internal combustion engines, the present invention provides an intelligent adjustment scheme for the dual-fuel supply system under various vehicle conditions that may exist on the road, which can increase the adaptability of the power system in actual vehicle conditions.

[0042] (2) The supply strategy of the dual fuel in the present invention is dynamically changed, and the substitution rate of the green fuel for diesel can be maximized while meeting the power requirements according to different needs. This not only optimizes the internal combustion engine system but also achieves the purpose of saving fuel consumption and reducing pollutant emissions.

[0043] (3) The present invention clearly sets the fuel substitution rate, which can ensure that the diesel engine will not have problems such as knocking and surging during operation, ensuring that the diesel engine runs more smoothly, extending the life of the diesel engine, and improving the driving comfort of users.

[0044] (4) The internal combustion engine dual-fuel control system and method proposed in the present invention based on vehicle networking and autonomous driving can achieve the purpose of intelligent driving of vehicles powered by internal combustion engines, contributing to the popularization and promotion of autonomous driving.

[0045] (5) The intelligent control system and method of the present invention are universal and can be applied not only to diesel engines, but also to some gasoline engines and some marine internal combustion engines, with broad application prospects. Description of the Drawings

[0046] Figure 1 is a schematic diagram for determining level-I signals. Figure 1 In it, (a) is a schematic diagram for judging the front vehicle distance signal, and (b) is a schematic diagram for judging the front vehicle speed signal.

[0047] Figure 2 is a schematic diagram for pre-adjusting the working conditions of a diesel engine based on external sensor information.

[0048] Figure 3 is a schematic diagram for fuel injection control based on the state parameters of a diesel engine.

[0049] Figure 4 is a schematic diagram for dual-fuel injection adjustment.

[0050] Figure 5 is a schematic diagram of the basic structure of a dual-fuel diesel engine.

[0051] In the figure, 1. air cleaner; 2. methanol nozzle; 3. intake pipe; 4. diesel engine; 5. dual-fuel ECU electronic control unit; 6. throttle position sensor; 7. diesel engine speed sensor; 8. cooling water temperature sensor; 9. intake manifold; 10. alcohol fuel distribution pipe; 11. alcohol fuel pressure regulator; 12. electric methanol pump; 13. alcohol fuel tank; 14. alcohol outlet; 13. alcohol return port. Detailed Embodiment

[0052] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] To achieve the above objectives, in combination with the attached Figures 1-5 The present invention provides a dual-fuel injection control system. The dual-fuel intelligent injection control system includes: an information acquisition module, an information analysis and processing module, and a fuel injection control module.

[0054] The information acquisition module includes a vehicle external information acquisition unit and a vehicle internal information acquisition unit, which are respectively used to acquire vehicle external information and vehicle internal information. The vehicle external information acquisition unit includes an infrared ranging sensor, a GPS positioning sensor, an image acquisition sensor, and a radar system arranged outside the vehicle; the vehicle internal information acquisition unit is signal-connected to the vehicle electronic control system and the diesel dual-fuel ECU. More specifically, the distance of vehicles around the vehicle is obtained through the radar system and the infrared ranging sensor, the GPS positioning sensor obtains the vehicle's own position information, and the image acquisition sensor is used to acquire the surrounding environment image of the vehicle. The vehicle external information that the vehicle external information acquisition unit can obtain includes: the vehicle speed of vehicles or objects around the own vehicle, the distance of surrounding vehicles or objects; the diesel engine information in the vehicle internal information includes the vehicle's own speed, diesel engine speed, diesel engine coolant temperature, and diesel engine torque. (The infrared ranging sensor has the advantages of fast ranging and sensitive response, and is suitable for a moving vehicle to obtain obstacle information around the vehicle)

[0055] The information analysis, judgment and processing module includes an information analysis unit, an information processing unit and an information storage unit. Among them, the information analysis unit is signal-connected to the information acquisition module and is used to receive the vehicle external information and vehicle internal information acquired by the information acquisition module; and based on the acquired vehicle external information, the environmental information in the front, rear and sides of the vehicle is obtained. The environmental information includes the speeds of the vehicle and the vehicles or objects around it, and the distances between the vehicle and the vehicles or objects around it.

[0056] The information storage unit pre-stores laws and regulations related to roads, high-precision map data, preset road conditions, distance thresholds, speed thresholds, acceleration thresholds, etc. corresponding to different road conditions.

[0057] The information processing unit is signal-connected to the information analysis unit and the information storage unit. In the information processing unit, based on the environmental information in the front, rear and sides of the vehicle analyzed by the information analysis unit and the thresholds of the data pre-stored in the information storage unit, the level-I signal determination, level-II signal determination, and level-III signal determination are sequentially performed (level-I is the highest priority, and level-II is the second), and the torque pre-adjustment signal is obtained by combining the results of the level-I signal determination, level-II signal determination, and level-III signal determination;

[0058] The fuel injection control module receives the torque pre-adjustment signal and performs real-time control on the diesel dual-fuel injection according to the torque pre-adjustment signal and the current basic working condition of the diesel engine.

[0059] More specifically, the fuel injection control module includes a dual-fuel ECU, a diesel injection controller, a diesel alternative fuel injection controller, a diesel alternative fuel pressure regulator, an accelerator control handle position sensor, a brake pedal controller, a rotational speed sensor, a water temperature sensor, and a fuel rail pressure sensor. The fuel injection control module adjusts and controls the power system of the vehicle.

[0060] A dual-fuel injection control method includes the following steps:

[0061] Step 1: Obtain the internal information and external information of the own vehicle. The internal information includes the current vehicle speed V0 of the own vehicle. The external information includes the distance s between the own vehicle and the vehicle in front, the distance s' between the own vehicle and the vehicle behind, the distance L between the own vehicle and the object on the side, the vehicle speed V1 of the vehicle in front, and the vehicle speed V2 of the vehicle behind.

[0062] Step 2: Based on the road type, as well as the internal information and external information of the own vehicle, perform a first-level signal determination, a second-level signal determination, and a third-level signal determination.

[0063] The first-level signal determination is made according to the distance and speed between the own vehicle and the vehicle in front. Among them, two distance thresholds s1 and s2 are set for the distance s between the own vehicle and the vehicle in front, and s1 < s2. If s > s2, a green feasible signal is output; if s2 > s > s1, a yellow signal is output; if s1 > s, a red warning signal is output. For the speed V0 of the own vehicle and the speed V1 of the vehicle in front, if V1 > V0, a green feasible signal is output; if V1 ≤ V0, a red warning signal is output. In this embodiment, in non-highway conditions, the two distance thresholds for the distance s between the own vehicle and the vehicle in front are set to s1 = 60 and s2 = 120 respectively; in highway conditions, the two distance thresholds for the distance s between the own vehicle and the vehicle in front are set to s1 = 120 and s2 = 240 respectively.

[0064] The second-level signal determination is made according to the distance and speed between the own vehicle and the vehicle behind. Among them, a distance threshold s1' is set for the distance s' between the own vehicle and the vehicle behind. If s' > s1', a green feasible signal is output; if s' ≤ s1', a red warning signal is output. For the speed V0 of the own vehicle and the speed V2 of the vehicle behind, if V2 < V0, a green feasible signal is output; if V2 ≥ V0, a red warning signal is output.

[0065] The third-level signal determination is made according to the distance L between the own vehicle and the object on the side. A lateral distance threshold is set to L0. If L > L0, a green feasible signal is output; if L ≤ L0, a red warning signal is output.

[0066] Step 3: Input the determination results of the first-level signal, the second-level signal, and the third-level signal in sequence. According to the determination results, obtain a torque pre-adjustment signal, where the torque pre-adjustment signal includes: a torque rapid increase signal, a torque slight increase signal, a torque slight decrease signal, a torque rapid decrease signal, and a constant-speed steady-state signal.

[0067] More specifically, the process of obtaining the torque pre-adjustment signal based on the determination results in Step 3 is as follows:

[0068] Input the determination result of the first-level signal. If the determination results of the distance and speed between the own vehicle and the vehicle in front of it in the first-level signal determination are both green feasible signals, then accept the determination result of the second-level signal; if the determination results of the distance and speed between the own vehicle and the vehicle behind it in the second-level signal determination are both green feasible signals, then accept the determination result of the third-level signal. If the determination result of the distance between the own vehicle and the object on its side in the third-level signal determination is a green feasible signal, at this time, the torque pre-adjustment signal is a torque rapid increase signal;

[0069] Input the determination result of the first-level signal. If the determination result of the first-level signal is a green feasible signal and the determination result of the second-level signal is not a double green feasible signal, at this time, the torque pre-adjustment signal is a constant-speed steady-state signal;

[0070] Input the determination result of the first-level signal. If in the determination result of the first-level signal, the determination result of the distance between the own vehicle and the vehicle in front of it is a yellow signal and the determination result of the speed between the own vehicle and the vehicle in front of it is a green feasible signal, then accept the determination result of the second-level signal; the determination result of the second-level signal is a double green feasible signal, at this time, the torque pre-adjustment signal is a torque slight increase signal;

[0071] Input the determination result of the first-level signal. If in the determination result of the first-level signal, the determination result of the distance between the own vehicle and the vehicle in front of it is a yellow signal and the determination result of the speed between the own vehicle and the vehicle in front of it is a red warning signal, at this time, the torque pre-adjustment signal is a torque slight decrease signal;

[0072] Input the determination result of the first-level signal. If in the determination result of the first-level signal, if the determination result of the first-level signal is a double red warning signal, at this time, the torque pre-adjustment signal is a torque rapid decrease signal.

[0073] Step 4: According to the torque pre-adjustment signal obtained in Step 3, set the acceleration corresponding to each torque pre-adjustment signal; combine the current basic operating conditions of the diesel engine to judge the fuel injection mode; take the fuel injection amount, that is, obtain the torque adjustment signal; and perform real-time control on the dual-fuel injection of the diesel engine according to the torque adjustment signal.

[0074] More specifically, the accelerations corresponding to the torque pre-adjustment signals are as follows:

[0075] The magnitude of the acceleration corresponding to the torque rapid increase signal is a > 3 m / s 2 ;

[0076] The magnitude of the acceleration corresponding to the torque slight increase signal is 0 < a ≤ 3 m / s 2 ;

[0077] The magnitude of the acceleration corresponding to the torque slight decrease signal is -3 < a < 0 m / s 2 ;

[0078] The magnitude of the acceleration corresponding to the torque rapid decrease signal is a < -3 m / s 2 ;

[0079] The magnitude of the acceleration corresponding to the uniform speed stable signal is a = 0 m / s 2 ;

[0080] where the acceleration s is the distance between the vehicle in front and the own vehicle.

[0081] More specifically, the method for determining the fuel injection mode according to the current basic operating conditions of the diesel engine is as follows:

[0082] The basic operating conditions of the diesel engine include the water temperature and the rotational speed. If the water temperature ≥ 70 °C and the rotational speed ≤ 3700 r / min, the dual fuel injection mode is adopted; if the water temperature < 70 °C or the rotational speed > 3700 r / min, only the diesel fuel injection mode is adopted.

[0083] More specifically, the method for determining the corresponding fuel injection quantity based on the fuel injection mode is as follows:

[0084] Input the acceleration, rotational speed, and fuel injection quantity data graphs obtained from the bench test of the two required fuels into the data storage area in the dual fuel ECU. Among them, the fuel injection quantity is saved in the form of two-dimensional data. The two dimensions of the data respectively represent the acceleration and the rotational speed of the diesel engine, and the data in the array is the fuel injection quantity;

[0085] Use the improved particle swarm optimization algorithm to perform iterative optimization on the injection quantity. At the same time, in order to make the decision variables more conform to the program algorithm, optimize the data (acceleration, diesel engine rotational speed) in the array. The specific operation is as follows: Divide the two coordinates of the array independent variable equally within its domain, and set each decision variable as X = (n1, n2, n3, n4,... ni, a1, a2, a3, a4,... ai), where: ni is the number of selected coordinate points of the rotational speed in the i-th equal division of the domain, and ai is the number of selected coordinate points of the acceleration in the i-th equal division of its domain. The specific number of equal divisions can be calculated with differences according to the characteristics of the fuel, and then the corresponding objective function is obtained.

[0086] If only the diesel injection mode is adopted, the dual-fuel ECU calls and reads the data graph of the fuel injection quantity, acceleration, and diesel engine speed in the pure diesel mode, and selects the fuel injection quantity from the iterated data according to the acceleration corresponding to the torque pre-adjustment signal;

[0087] If the dual-fuel injection mode is adopted, the dual-fuel ECU calls and reads the data graph of the fuel injection quantity, acceleration, and diesel engine speed of the other fuel, and selects the fuel injection quantity from the iterated data according to the acceleration corresponding to the torque pre-adjustment signal;

[0088] More specifically, by setting the extreme value of the vehicle speed after torque adjustment, it is ensured that the diesel engine operates under the limited rotational speed and load conditions. The method for setting the extreme value of the vehicle speed is as follows:

[0089] 1) Obtain the maximum vehicle speed V allowed by the surrounding environment under the current road type 环 and the maximum vehicle speed V allowed under the relevant road regulations conditions 道 , and set the currently allowed maximum vehicle speed V 环 according to the magnitudes of V 道 . If V m ≤V 环 , then set V 道 =V m ; if V 环 ≥V 环 , then set V 道 =V m , and obtain the maximum vehicle speed V 道 ;

[0090] 2) Based on the maximum vehicle speed V m , determine the desired vehicle speed V m , and V q ≤V q ; V m is the extreme value of the vehicle speed after torque adjustment; for example, if the current vehicle speed V0≤V q , the vehicle speed after torque increase should be less than the desired vehicle speed V q ; if the current vehicle speed V0>V q , the vehicle speed after torque decrease should be less than the desired vehicle speed V q . q

[0091] More specifically, set the maximum injection quantity P of the alternative fuel max :

[0092] P max =G d ×H Ld ×R t / H Lc

[0093] Among them, G d is the fuel injection quantity in the pure diesel MAP diagram, H Ld is the lower calorific value of diesel, H Lc is the lower calorific value of methanol, R t is the maximum percentage of alternative fuel set under the current load, R t Set the maximum substitution rate to 40% in the small load state, 60% in the medium load state, 60% in the high load state, and 60% in the full load state.

[0094] In this embodiment, the dual fuel used is diesel and methanol. In addition, alternative fuels such as ammonia, hydrogen, F-T diesel, methanol, methane, biodiesel, etc., which are currently mainstream fuels and potential fuels, can all be applied in the present invention.

[0095] The fuel injection control module is as Figure 5 shown. Its specific working mode is as follows: The information analysis and processing module inputs the obtained torque adjustment information into the diesel engine 3 - dual fuel ECU electronic control unit. The ECU converts the torque adjustment information into fuel injection quantity information. At the same time, set the opening condition of the 2 - methanol nozzle in the dual fuel ECU as the temperature of the 8 - water temperature sensor is higher than 70° and the speed of the 7 - diesel engine speed sensor is less than 3700 rpm. When the torque rapid increase information is input into the 3 - dual fuel ECU electronic control unit, the ECU issues an instruction to directly close the 2 - alcohol nozzle, stop spraying alcohol, and issue an instruction to the 4 - diesel engine to increase the diesel injection quantity (the internal structure of the diesel engine is not shown); when the torque slight increase information is input into the 3 - dual fuel - ECU electronic control unit, the ECU detects the opening state of the 2 - methanol nozzle. If the 2 - methanol nozzle is in the open state at this time, then issue an instruction to adjust the injection pulse width of the methanol nozzle and increase the alcohol spraying quantity. If it is detected that the 2 - methanol nozzle is in the closed state, then the ECU issues an instruction to directly adjust the diesel injection quantity and increase the fuel injection quantity; when the torque rapid decrease information is input into the 3 - dual fuel ECU electronic control unit, the ECU directly controls the alcohol injection nozzle to close, stops spraying alcohol, and reduces the diesel injection quantity; when the torque slight decrease information is input into the 3 - dual fuel ECU electronic control unit, the ECU issues an instruction to directly adjust the diesel injection quantity and reduce the diesel injection quantity.

[0096] All kinds of states obtained by the information processing system, including the torque rapid decrease state, torque rapid increase state, torque slight increase state, torque slight decrease state, can be used in combination with the throttle and braking system to ensure that the energy-saving control effect can also be achieved in the state of human participation.

[0097] In the present invention, the maximum values of some data can be set by manual input. For example, set a maximum vehicle speed value so that no matter what the vehicle condition is, it is not allowed to exceed this maximum vehicle speed value, thereby restricting the maximum value of the fuel injection quantity. It is also possible to manually input a maximum methanol injection quantity, manually input the maximum vehicle speed values under different road conditions, etc.

[0098] In the present invention, emphasis is placed on adjusting the continuity of the output torque based on the continuity of acceleration, thereby ensuring the stability of vehicle speed regulation. However, this does not mean that the present invention does not correct the continuity of fuel injection. The present invention can continue to add the setting of transitional working conditions to further ensure the continuity of fuel injection volume.

[0099] In the present invention, acceleration is used as a pivot to link fuel injection volume and torque. However, it is not limited to acceleration, and the fuel injection volume can also be determined by the difference between the current vehicle speed and the desired vehicle speed.

[0100] In the present invention, diesel / methanol is taken as an example. However, it is not limited to diesel and methanol. As long as one fuel is injected into the intake port and another fuel is injected into the cylinder, it can be applied in the present invention.

[0101] To ensure the normal operation of the dual-fuel system and the normal operation of the entire intelligent control scheme, an intelligent detection system can be added to judge, feedback, and process various situations in the actual operation state.

[0102] The system in the present invention can adapt to future development. On the basis of meeting mechanical control, it provides an electronic development idea. The external information acquisition can be connected to the future vehicle networking system, and the information analysis and processing continue to perform AI deep learning and upgrade to meet the requirements of future technology and intelligence.

[0103] On the basis of the present invention, it can be further optimized and upgraded. For example, the fuel injection control module can be refined into various data units, which can be divided into a fuel ratio calculation unit, a diesel engine information acquisition unit, a diesel engine detection unit, an information processing unit, etc. In the above systems and methods, it is not clearly specified. It is considered that the dual-fuel ECU in the fuel injection control module analyzes and processes the information to determine the fuel injection strategy. The external information and internal information acquired by the information acquisition unit can also be increased. For example, traffic light signal information, turning detection, vehicle load information, etc. are added, and the information analysis and processing module processes the information again to obtain torque adjustment information.

[0104] The above embodiments are only used to illustrate the design concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made according to the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A dual-fuel injection control method, characterized in that, It includes the following steps: Step 1: Obtain the internal information and external information of the host vehicle. The internal information includes the current vehicle speed V0 of the host vehicle; the external information includes the distance s between the leading vehicle and the host vehicle, the distance s' between the trailing vehicle and the host vehicle, the distance L between the side object and the host vehicle, the speed V1 of the leading vehicle, and the speed V2 of the trailing vehicle; Step 2: Based on the road type, as well as the internal information and external information of the host vehicle, perform level-I signal determination, level-II signal determination, and level-III signal determination; Step 3: Input the results of level-I signal determination, level-II signal determination, and level-III signal determination in sequence. According to the determination results, obtain a torque pre-adjustment signal, and the torque pre-adjustment signal includes: a torque rapid increase signal, a torque slight increase signal, a torque slight decrease signal, a torque rapid decrease signal, and a uniform speed stable signal; Step 4: According to the torque pre-adjustment signal obtained in Step 3, set the acceleration corresponding to each torque pre-adjustment signal; combine the current basic operating conditions of the diesel engine to judge the fuel injection mode; select the fuel injection amount, that is, obtain a torque adjustment signal; and perform real-time control on the dual-fuel injection of the diesel engine according to the torque adjustment signal; The method for judging the fuel injection mode according to the current operating conditions of the diesel engine based on the fuel used by the current diesel engine is as follows: The basic operating conditions of the diesel engine include water temperature and engine speed, etc. According to the fuel characteristics, limit the basic operating conditions of the fuel when applied to the diesel engine. When the water temperature and engine speed are both in the stable range, that is, the water temperature ≥ 70°C and the engine speed ≤ 3700 r / min, adopt the dual-fuel injection mode. If any one of the water temperature and engine speed is not in the stable range, that is, the water temperature < 70°C or the engine speed > 3700 r / min, then adopt the diesel injection mode.

2. The dual-fuel injection control method according to claim 1, characterized in that, The level-I signal determination is performed according to the distance and speed between the host vehicle and its leading vehicle; among them, two distance thresholds s1 and s2 are set for the distance s between the host vehicle and its leading vehicle, s1 < s2. If s > s2, output a green feasible signal; if s2 > s > s1, output a yellow signal; if s1 > s, output a red warning signal; for the speed V0 of the host vehicle and the speed V1 of its leading vehicle, if V1 > V0, output a green feasible signal; if V1 ≤ V0, output a red warning signal; The level-II signal determination is performed according to the distance and speed between the host vehicle and its trailing vehicle; among them, a distance threshold s1' is set for the distance s' between the host vehicle and its trailing vehicle. If s' > s1', output a green feasible signal; if s' ≤ s1', output a red warning signal; for the speed V0 of the host vehicle and the speed V2 of its trailing vehicle, if V2 < V0, output a green feasible signal; if V2 ≥ V0, then output a red warning signal; The level-III signal determination is performed according to the distance L between the host vehicle and its side object; a lateral distance threshold is set as L0. If L > L0, output a green feasible signal; if L ≤ L0, output a red warning signal.

3. A dual-fuel injection control method according to claim 1 or 2, characterized in that, The process of obtaining the torque pre-adjustment signal according to the determination results in Step 3 is as follows: Input the determination result of the first-level signal determination. If the determination results of the distance and speed between the vehicle itself and the vehicle in front of it in the first-level signal determination are both green feasible signals, then accept the determination result of the second-level signal determination; If the determination results of the distance and speed between the vehicle itself and the vehicle behind it in the second-level signal determination are both green feasible signals, then accept the determination result of the third-level signal determination. If the determination result of the distance between the vehicle itself and the object on its side in the third-level signal determination is a green feasible signal, the torque pre-adjustment signal is a torque rapid increase signal at this time; Input the determination result of the first-level signal determination. If the determination result of the first-level signal determination is a green feasible signal and the determination result of the second-level signal determination is not a double green feasible signal, the torque pre-adjustment signal is a uniform steady-state signal at this time; Input the determination result of the first-level signal determination. If in the determination result of the first-level signal determination, the determination result of the distance between the vehicle itself and the vehicle in front of it is a yellow signal and the determination result of the speed between the vehicle itself and the vehicle in front of it is a green feasible signal, then accept the determination result of the second-level signal determination; The determination result of the second-level signal determination is a double green feasible signal, and the torque pre-adjustment signal is a torque slight increase signal at this time; Input the determination result of the first-level signal determination. If in the determination result of the first-level signal determination, the determination result of the distance between the vehicle itself and the vehicle in front of it is a yellow signal and the determination result of the speed between the vehicle itself and the vehicle in front of it is a red warning signal, the torque pre-adjustment signal is a torque slight decrease signal at this time; Input the determination result of the first-level signal determination. If in the determination result of the first-level signal determination, if the determination result of the first-level signal determination is a double red warning signal, the torque pre-adjustment signal is a torque rapid decrease signal at this time.

4. A dual-fuel injection control method according to claim 3, characterized in that The accelerations corresponding to the torque pre-adjustment signal are respectively: The acceleration magnitude corresponding to the torque sudden increase signal is a > 3 m / s 2 ; The magnitude of the acceleration corresponding to the torque slightly increasing signal is 0 < a ≤ 3 m / s 2 ; The magnitude of the acceleration corresponding to the torque micro-reduction signal is -3 < a < 0 m / s 2 ; The magnitude of the acceleration corresponding to the torque sudden decrease signal is a ≤ -3 m / s 2 ; The acceleration magnitude corresponding to the uniform and stable signal is a = 0 m / s 2 .

5. A dual-fuel injection control method according to claim 1, characterized in that, The method for determining the corresponding fuel injection amount based on the fuel injection mode is: Input the data of vehicle acceleration, rotational speed, and fuel injection amount obtained through experiments for the two required fuels in the data storage area of the dual-fuel ECU. Among them, the fuel injection amount is saved in the form of two-dimensional data. The two dimensions of the data represent acceleration and the rotational speed of the diesel engine respectively, and the data in the array is the fuel injection amount; use the improved particle swarm algorithm to perform iterative optimization on the injection amount.

6. A dual-fuel injection control method according to claim 5, characterized in that If only the diesel injection mode is adopted, the dual-fuel ECU calls and reads the data map of the fuel injection amount, acceleration, and diesel engine rotational speed in the pure diesel mode, and selects the fuel injection amount from the iterated data according to the acceleration corresponding to the torque pre-adjustment signal; If the dual-fuel injection mode is adopted, the dual-fuel ECU calls the data map of the fuel injection amount, acceleration, and diesel engine rotational speed of the other fuel, and selects the fuel injection amount from the iterated data according to the acceleration corresponding to the torque pre-adjustment signal.

7. A dual-fuel injection control system, characterized in that, It includes: An information acquisition module, an information analysis and processing module, and a fuel injection control module; among them, The information acquisition module includes a vehicle external information acquisition unit and a vehicle internal information acquisition unit, which are respectively used to acquire vehicle external information and vehicle internal information; The information analysis and processing module includes an information analysis unit, an information processing unit, and an information storage unit. The information analysis unit is signal-connected to the information acquisition module to receive the acquired external vehicle information and internal vehicle information. The information storage unit pre-stores laws and regulations related to roads, high-precision map data, preset road conditions, distance thresholds, speed thresholds, and acceleration thresholds corresponding to different road conditions. The information processing unit is signal-connected to the information analysis unit and the information storage unit. In the information processing unit, based on the environmental information of the front, rear, and sides of the vehicle analyzed by the information analysis unit and the threshold values of the data pre-stored in the information storage unit, level-I signal determination, level-II signal determination, and level-III signal determination are sequentially performed; and a torque pre-adjustment signal is obtained by combining the results of the level-I signal determination, level-II signal determination, and level-III signal determination. The fuel injection control module receives the torque pre-adjustment signal and performs real-time control of the dual-fuel injection of the diesel engine according to the torque pre-adjustment signal and the current basic operating conditions of the diesel engine.

8. A dual-fuel injection control system according to claim 7, characterized in that, The fuel injection control module includes a dual-fuel ECU, a diesel injection controller, a diesel alternative fuel injection controller, a diesel alternative fuel pressure regulator, an accelerator control handle position sensor, a brake pedal controller, a speed sensor, a water temperature sensor, and a rail pressure sensor. The fuel injection control module adjusts and controls the vehicle's power system.

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