Engine cold start control method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention discloses an engine cold start control method and device, electronic equipment and a storage medium. The method comprises the steps of controlling a motor to drag an engine to a target rotating speed; controlling the engine to execute a first cold starting strategy until the engine is started; wherein the first cold starting strategy comprises at least one of the following starting conditions executed in a single cycle: the number of fuel injection times is greater than or equal to the target number of times; the interval between the last injection moment and the ignition moment is a crank angle within a target degree range; the ratio of the last fuel injection quantity to the total fuel injection quantity is in a target interval; the ratio of the total fuel injection amount to the amount of air entering the cylinder meets the target condition. The problem that cold start of the methanol engine is difficult can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicle control, and in particular, to an engine cold start control method and device, an electronic device, and a computer-readable storage medium. Background Art

[0002] Alcohol fuel engines have advantages such as good emissions and high economy, and can significantly reduce the carbon emissions in the life cycle of internal combustion power machinery. However, compared with traditional fuels such as gasoline, alcohol fuels have the characteristics of large latent heat of vaporization and poor low-temperature evaporability. At low temperatures, it is difficult for the concentration of the combustible mixture in the cylinder of an alcohol engine to reach the ignition limit, resulting in difficulties in cold starting an alcohol engine at low temperatures. Summary of the Invention

[0003] To solve the technical problem of the difficulty in cold starting an alcohol engine at low temperatures, embodiments of the present application respectively provide an engine cold start control method, an engine cold start control device, an electronic device, and a computer-readable storage medium.

[0004] In one aspect of the embodiments of the present application, an engine cold start control method is provided. The method includes: controlling a motor to drive an engine to a target speed; controlling the engine to execute a first cold start strategy until the engine starts; wherein the first cold start strategy includes performing at least one of the following starting conditions within a single cycle:

[0005] The number of fuel injections is greater than or equal to a target number;

[0006] The crankshaft angle between the last injection time and the ignition time is within a target degree range;

[0007] The ratio of the fuel injection amount of the last injection to the total fuel injection amount is within a target interval;

[0008] The ratio of the total fuel injection amount to the air amount entering the cylinder meets a target condition.

[0009] In another exemplary embodiment, the first cold start strategy includes performing all of the above starting conditions within a single cycle.

[0010] In another exemplary embodiment, among the starting conditions included in the first cold start strategy, the target number is 3 times, the target degree range is 10 degrees - 30 degrees, the target interval is 0.15 - 0.35, and the target condition is that the ratio of the air amount entering the cylinder to the total fuel injection amount is less than or equal to the fuel equivalent combustion air-fuel ratio.

[0011] In another exemplary embodiment, the method further includes: when the engine water temperature is lower than the first temperature threshold and higher than the second temperature threshold, controlling the engine to execute the first cold start strategy until the engine starts; when the engine water temperature is lower than the second temperature threshold, controlling the engine to execute the second cold start strategy until the engine starts; wherein, the second cold start strategy includes: after controlling and adjusting the exhaust valve lift state of the engine to increase the temperature of the engine, controlling the engine to execute the first cold start strategy.

[0012] In another exemplary embodiment, the method further includes: if the engine cannot be started by executing the first cold start strategy, controlling the engine to execute the second cold start strategy until the engine starts.

[0013] In another exemplary embodiment, the controlling and adjusting the exhaust valve lift state of the engine to increase the in-cylinder gas temperature includes: adjusting the exhaust valve lift to a low lift state, so that the in-cylinder gas is compressed as the piston moves upward during the exhaust stroke, thereby increasing the temperature of the engine; when the engine temperature rises to the target temperature condition, controlling the exhaust valve to switch to a high lift state.

[0014] In another exemplary embodiment, the method further includes: obtaining a first temperature value measured in real time by an intake manifold temperature sensor, or obtaining a second temperature value measured in real time by a water temperature sensor; when the first temperature value exceeds a first preset temperature value, or when the second temperature value exceeds a second preset temperature value, it is determined that the engine temperature has risen to the target temperature condition.

[0015] In another exemplary embodiment, the method further includes: if the exhaust valve fails to switch to the high lift state, controlling the fuel injector not to inject fuel and / or controlling the spark plug not to ignite.

[0016] Another aspect of the embodiments of the present application provides another engine cold start control method, the method including: controlling a motor to drive the engine to a target speed; adjusting the exhaust valve lift to a low lift state, so that the in-cylinder gas is compressed as the piston moves upward during the exhaust stroke, thereby increasing the temperature of the engine; when the engine temperature rises to the target temperature condition, controlling the exhaust valve to switch to a high lift state; controlling fuel injection and ignition to start the engine.

[0017] Another aspect of the embodiments of the present application provides an engine cold start control device, the device including: a motor control module configured to control a motor to drive the engine to a target speed; a start control module configured to control the engine to execute a first cold start strategy until the engine continuously outputs positive torque; wherein, the first cold start strategy includes executing at least one of the following start conditions within a single cycle:

[0018] The number of fuel injections is greater than or equal to the target number of times;

[0019] The crankshaft angle of the interval between the last injection timing and the ignition timing is within the target degree range;

[0020] The ratio of the fuel quantity of the last injection to the total fuel injection quantity is within the target range;

[0021] The ratio of the total fuel injection quantity to the air quantity entering the cylinder meets the target conditions.

[0022] Another aspect of the embodiments of the present application provides an electronic device, including: one or more processors; a memory for storing one or more programs, when the one or more programs are executed by the one or more processors, enabling the electronic device to implement the steps in the engine cold start control method as described above.

[0023] Another aspect of the embodiments of the present application provides a computer-readable storage medium, on which computer-readable instructions are stored, when the computer-readable instructions are executed by a processor of a computer, enabling the computer to execute the steps in the engine cold start control method as described above.

[0024] In one of the technical solutions provided by the embodiments of the present application, after controlling the motor to drive the engine to the target speed, the engine is further controlled to execute the first cold start strategy. Since the first cold start strategy is an optimization of the fuel injection strategy, the optimized fuel injection strategy can reduce the fuel wetting amount on the pistons and cylinder walls in the engine cylinder, and / or increase the concentration of the mixed gas in the engine cylinder, and / or increase the turbulent kinetic energy near the spark plug at the engine ignition timing, enabling the engine to start normally under low temperature conditions, thus solving the problem of difficult cold start of the engine.

[0025] In another technical solution provided by the embodiments of the present application, the engine is heated by controlling the exhaust valve lift state. Without using an additional heater, the engine can start normally under low temperature conditions only by improving the control strategy, thus solving the problem of difficult cold start of the engine.

[0026] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of an exemplary methanol engine control system;

[0028] Figure 2 is a flowchart of an exemplary engine cold start control method;

[0029] Figure 3 It is a schematic diagram showing the relationship between the number of methanol injections in a single cycle of a methanol engine and the engine starting effect at an ambient temperature of 0°C.

[0030] Figure 4 It is a comparison diagram of the engine starting effects when the methanol engine injects methanol 3 times in a single cycle at ambient temperatures of -10°C and 0°C respectively.

[0031] Figure 5 It is a schematic diagram of the structure of an exemplary exhaust valve lift variable mechanism.

[0032] Figure 6 It is a flowchart of another exemplary engine cold start control method.

[0033] Figure 7 It is a schematic diagram showing the change in exhaust valve lift and the change in in-cylinder temperature with the crankshaft angle.

[0034] Figure 8 It is a schematic diagram of an exemplary exhaust valve control strategy.

[0035] Figure 9 It is a flowchart of another exemplary engine cold start control method.

[0036] Figure 10 It is a block diagram of an exemplary engine cold start control device.

[0037] Figure 11 It is a block diagram of another exemplary engine cold start control device. Detailed Description of the Embodiments

[0038] Here, the exemplary embodiments will be described in detail, and the examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0039] The block diagrams shown in the accompanying drawings are only functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0040] In the embodiments of the present application, the term "module" or "unit" refers to a computer program with a predetermined function or a part of a computer program, which works together with other related parts to achieve a predetermined goal, and can be fully or partially implemented by using software, hardware (such as a processing circuit or a memory), or a combination thereof. Similarly, one processor (or multiple processors or memories) can be used to implement one or more modules or units. In addition, each module or unit can be a part of an overall module or unit that includes the function of that module or unit.

[0041] The flowcharts shown in the accompanying drawings are only illustrative and do not necessarily include all the contents and operations / steps, nor do they necessarily have to be executed in the described order. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined. Therefore, the actual execution order may change according to the actual situation.

[0042] As used in this application, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0043] The terms "first", "second", "third", "fourth", etc. in the description, claims, and drawings of this application are used to distinguish different objects, rather than to describe a specific order. The terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0044] First, refer to Figure 1 , Figure 1It is a schematic structural diagram of an exemplary methanol engine control system. The exemplary methanol engine control system includes an engine body 1, an electric motor 2, and a controller 3. Among them, the engine body 1 includes an intake manifold temperature sensor 101, a water temperature sensor 102, a spark plug 103, an injector 104, an intake camshaft 105, an exhaust camshaft 106, and a throttle valve 107. The intake manifold temperature sensor 101 is used to detect the temperature of the gas in the intake pipe and also transmits the detected temperature value to the controller 3. The water temperature sensor 102 is used to detect the engine water temperature and transmits the detected temperature value to the controller 3. The spark plug 103 is used to ignite the in-cylinder mixture gas, and the ignition timing is controlled by the controller 3. The injector 104 is used to directly inject fuel into the cylinder, and the injection timing and the number of injection times are controlled by the controller 3. The intake camshaft 105 is used to drive the intake valve, and the exhaust camshaft 106 is used to drive the exhaust valve. The throttle valve 107 is controlled by the controller 3 to adjust the opening degree, thereby controlling the amount of air entering the cylinder.

[0045] For alcohol fuel engines, especially methanol engines, due to the large latent heat of vaporization of the fuel, it is difficult to evaporate at low temperatures and it is difficult to form a combustible mixture, resulting in significant obstacles to the current popularization and application. The key to improving the low-temperature cold start performance of methanol engines lies in forming a combustible mixture. Therefore, this application proposes that the formation of the mixture can be improved by optimizing the fuel injection strategy or increasing the mixture temperature.

[0046] However, it should be noted that the technical concept of improving the formation of the in-cylinder mixture in the engine by optimizing the fuel injection strategy or increasing the mixture temperature proposed in this application can be applied not only to methanol engines or ethanol engines, but also to engines using other types of fuels. This embodiment does not limit the application conditions of the technical concept.

[0047] The main technical concept of the fuel injection strategy optimization proposed in this application is to expand the cold start limit temperature of methanol engines by reducing the fuel wetting amount on the in-cylinder piston and cylinder wall, increasing the concentration of the in-cylinder mixture gas, and increasing the turbulent kinetic energy near the spark plug at the ignition moment.

[0048] Based on this, as Figure 2 shown, an exemplary embodiment of this application illustrates an engine cold start control method, which can be executed by the controller 3 in the methanol engine control system shown in Figure 1 The method includes S210 - S220, which are introduced in detail as follows:

[0049] S210, control the electric motor to drive the engine to the target speed.

[0050] The target speed refers to the speed at which the engine is suitable for ignition. It can be understood that when the engine starts fuel injection and ignition while operating at the target speed, a better starting effect can be obtained. Exemplarily, the target speed can be 500 - 1250 rpm, but there is no limitation.

[0051] S220, control the engine to execute the first cold start strategy until the engine starts; wherein, the first cold start strategy includes executing at least one of the following starting conditions within a single cycle:

[0052] The number of fuel injection times is greater than or equal to the target number;

[0053] The crankshaft angle of the interval between the last injection moment and the ignition moment is within the target degree range;

[0054] The ratio of the last injection fuel quantity to the total injection fuel quantity is within the target interval;

[0055] The ratio of the total injection fuel quantity to the air quantity entering the cylinder meets the target condition.

[0056] The motor drags the engine to the target speed before the first cold start strategy can be executed to start the engine. Whether the engine starts successfully can be determined by judging whether the engine actually outputs positive torque.

[0057] It should be noted that the first cold start strategy is the optimized fuel injection strategy, aiming to expand the cold start limit temperature of the methanol engine by reducing the fuel wetting amount on the cylinder piston and cylinder wall, and / or increasing the concentration of the in-cylinder mixture gas, and / or increasing the turbulent kinetic energy near the spark plug at the ignition moment.

[0058] Exemplarily, the target number can be 3 times, or a higher number. Please refer to Figure 3 and Figure 4 , Figure 3 shows the relationship between the number of methanol injections within a single cycle of the methanol engine and the engine starting effect at 0°C ambient temperature, Figure 4 shows the comparison diagram of the engine starting effect of the methanol engine injecting methanol 3 times within a single cycle at -10°C ambient temperature and 0°C ambient temperature respectively. The IMEP indicated on the vertical axis refers to the mean indicated pressure. When IMEP is greater than 0, it means the engine starts successfully. The horizontal axis indicates the cycle number. From Figure 3 it can be seen that at 0°C ambient temperature, the more times methanol is injected within a single cycle, the better the engine starting effect. From Figure 4 it can be seen that even at -10°C ambient temperature, the engine can still start successfully within 3 cycles. This proves that controlling the number of methanol injections within a single cycle of the methanol engine to 3 times or more, such as 4 times, 5 times, 6 times, etc., can enable the methanol engine to start successfully at a lower temperature.

[0059] The target degree range of the crankshaft angle interval between the last injection timing and the ignition timing can be 10 - 30 degrees, such as 10 degrees, 15 degrees, 20 degrees, 30 degrees, etc.; the target interval where the proportion of the last injection fuel quantity to the total injection fuel quantity is located can be 0.15 - 0.35, for example, the proportion is 0.15, 0.2, 0.25, 0.3, 0.35, etc.; the target condition satisfied by the ratio of the total injection fuel quantity to the air quantity entering the cylinder can be that the ratio of the air quantity entering the cylinder to the total fuel injection quantity is less than or equal to the fuel equivalent combustion air-fuel ratio, that is, expressed as M air / M fuel / AFR is less than 1, where M air represents the total injection fuel quantity, M fuel represents the air quantity entering the cylinder, and AFR represents the fuel equivalent combustion air-fuel ratio.

[0060] It should be noted that one or more starting conditions within a single cycle included in the first cold start strategy can be selected according to actual application requirements, and this embodiment does not limit this. For example, in one embodiment, the first cold start strategy specifically includes executing all the starting conditions as shown above within a single cycle.

[0061] Thus, by controlling the engine to execute the optimized fuel injection strategy, this application can significantly expand the cold start limit temperature of the methanol engine, enabling the methanol engine and ethanol engine to start normally under low temperature conditions, thereby solving the problem of difficult cold start of the engine.

[0062] The main technical concept of this application for improving the formation of the in-cylinder mixture by increasing the mixture temperature is to rapidly increase the temperature of the in-cylinder mixture gas only through the improvement of the control strategy without using an additional heater, thereby expanding the cold start limit temperature of the methanol engine.

[0063] Figure 5 is a structural schematic diagram of an exemplary exhaust valve lift variable mechanism, which closes the exhaust valve by switching high and low lift cams. As Figure 5As shown, the exemplary exhaust valve lift variable mechanism includes a solenoid valve 4, a left pin 401 of the solenoid valve, a right pin 402 of the solenoid valve, a cam sleeve 5, a valve switching drive device 501, a low-lift cam 502, a high-lift cam 503, a cam core shaft 6, and a valve rocker 7. Among them, the left pin 401 and the right pin 402 of the solenoid valve are used to cooperate with the valve switching drive device 501. Specifically, the left pin 401 of the solenoid valve is used to drive the cam sleeve 5 to axially displace to the right, so that the low-lift cam 502 connected to the cam sleeve 5 is docked with the engine rocker 7, thereby enabling the engine exhaust valve to enter the low-lift stage; while the right pin 402 is used to drive the cam sleeve 5 to axially displace to the left, so that the high-lift cam 503 connected to the cam sleeve 5 is docked with the engine rocker 7, thereby enabling the engine exhaust valve to enter the low-lift stage.

[0064] In this application, by controlling the lift state of the engine exhaust valve, the temperature of the in-cylinder gas is increased, so that the engine can start normally even in a low-temperature environment. It should be understood that, in addition to Figure 5 the exhaust valve lift variable mechanism shown, other exhaust valve lift variable mechanisms that can control and adjust the lift state of the exhaust valve can also be used to implement the in-cylinder air temperature increase scheme mentioned in this application. The specific structure of the exhaust valve lift variable mechanism is not limited in this embodiment.

[0065] Based on this, as Figure 6 shown, another engine cold start control method proposed in another exemplary embodiment of this application includes S610 - S640, which is introduced in detail as follows:

[0066] S610, control the motor to drive the engine to the target speed.

[0067] S620, adjust the exhaust valve lift to the low-lift state, so that the in-cylinder gas is compressed as the piston moves upward during the exhaust stroke, thereby heating the engine.

[0068] After the motor drives the engine to the target speed, control the exhaust valve lift to the low-lift state. In the low-lift state, the engine cannot exhaust normally, which affects fuel combustion.

[0069] When the exhaust valve lift is in the low-lift state, the piston moves upward during the exhaust stroke, and at the same time, the intake valve opens during the intake stroke. The compressed high-temperature gas enters the intake port and the manifold, thereby quickly heating the engine intake air. For example Figure 7 shown, Figure 7 shows the change of the exhaust valve lift and the in-cylinder temperature with the crankshaft angle. It can be seen that after the exhaust valve lift is reduced, the in-cylinder temperature will rise rapidly. The high-temperature in-cylinder gas flows into the air passage and the intake manifold through the valve, and usually the temperature in the manifold can be heated from -20°C to 130°C within 10 seconds.

[0070] S630. When the engine warms up to the target temperature condition, control the exhaust valve to switch to the high lift state.

[0071] After the engine warms up to the target temperature condition, the exhaust valve can be controlled to switch to the high lift state. Under the high lift state, normal exhaust can be achieved, and then the fuel injector and the spark plug can be controlled to execute the fuel injection and ignition strategies, thereby starting the engine.

[0072] If the exhaust valve fails to switch to the high lift state, and ignition combustion occurs at this time, it will cause the combustion exhaust gas to not be discharged normally, thus affecting the combustion in the next cycle. Therefore, in the case where the exhaust valve fails to switch to the high lift state, it is necessary to control the fuel injector not to inject fuel and / or control the spark plug not to ignite.

[0073] Exemplarily, the first temperature value measured in real time by the intake manifold temperature sensor can be obtained, or the second temperature value measured in real time by the water temperature sensor can be obtained. When the first temperature value exceeds the first preset temperature value, or when the second temperature value exceeds the second preset temperature value, it can be determined that the engine has warmed up to the target temperature condition. It should be understood that the first temperature value and the second temperature value can be temperature values obtained through calibration tests, and are not limited herein.

[0074] S640. Control the execution of fuel injection and ignition to start the engine.

[0075] Please refer to Figure 8 , Figure 8 is a schematic diagram of an exemplary exhaust valve control strategy. It can be seen that taking a four-stroke engine as an example, during the process of the motor dragging the engine to the target speed, the exhaust cam is in the high lift state, and fuel injection and / or ignition will not be executed; after the motor drags the engine to the target speed, control the exhaust cam to switch to the low lift state, and at the same time control the piston in the exhaust stroke to move upward to compress the gas in the cylinder to warm up the engine; when the engine warms up to the target temperature condition, control the exhaust valve to switch to the high lift state, and at the same time control the start of fuel injection and ignition, thereby starting the engine.

[0076] Therefore, compared with the traditional heating strategy that requires deploying a heater in the intake pipeline and wasting the heated gas exhausted through the exhaust valve before reaching the target intake temperature, the strategy for increasing the mixture temperature proposed in this embodiment has the advantages of fast heating speed, no waste of heating energy, high utilization efficiency, etc., and does not require an additional heater. Coupled with the mature variable valve mechanism technology, it will not increase additional costs.

[0077] In addition, the technical concept of improving the formation of the in-cylinder mixture of the engine by optimizing the fuel injection strategy proposed in this application can also be combined with the technical concept of improving the formation of the in-cylinder mixture of the engine by increasing the mixture temperature.

[0078] Exemplarily, as Figure 9 shown, another exemplary engine cold start control method includes S910 - S920. This method can be executed by the controller 3 in the methanol engine control system shown in Figure 1 . The detailed content of this method is introduced as follows:

[0079] S910, when the engine water temperature is lower than the first temperature threshold and higher than the second temperature threshold, control the engine to execute the first cold start strategy until the engine starts.

[0080] When the engine water temperature is lower than the first temperature threshold and higher than the second temperature threshold, it can be understood that the ambient temperature is not very low. If the ambient temperature that makes the engine water temperature in the state of being lower than the first temperature threshold and higher than the second temperature threshold is called the first low - temperature level, and the ambient temperature that makes the engine water temperature in the state of being lower than the second temperature threshold is called the second low - temperature level, obviously, the second low - temperature level has a lower ambient temperature than the first low - temperature level. Therefore, in the ambient temperature of the first low - temperature level, the engine can be started by executing the optimized fuel injection strategy.

[0081] It should be noted that for the content related to the first cold start strategy, please refer to the records in the foregoing embodiments, and this embodiment will not elaborate here.

[0082] S920, when the engine water temperature is lower than the second temperature threshold, control the engine to execute the second cold start strategy until the engine starts; wherein, the second cold start strategy includes: after controlling and adjusting the exhaust valve lift state of the engine to increase the engine temperature, control the engine to execute the first cold start strategy.

[0083] When the engine is in the ambient temperature of the second low - temperature level, due to the lower temperature, it may be difficult to start the engine successfully by executing the optimized fuel injection strategy. Therefore, after first executing the strategy to increase the mixture temperature to increase the in - cylinder gas temperature, then control and execute the first cold start strategy to start the engine, which can greatly ensure the successful start of the engine.

[0084] It should be noted that the first temperature threshold and the second temperature threshold can also be obtained through calibration tests. For example, the first temperature threshold can be - 10°C, and the second temperature threshold can be - 20°C. Of course, in actual application scenarios, the first temperature threshold and the second temperature threshold can also be other calibrated values, and this embodiment does not limit this.

[0085] In addition, as another exemplary implementation manner, it is also possible to control the engine to execute the second cold start strategy until the engine starts when the first cold start strategy fails to start the engine, which can avoid controlling the execution of the first cold start strategy and the second cold start strategy according to the temperature.

[0086] It should also be noted that for the process of controlling and adjusting the exhaust valve lift state of the engine to increase the in-cylinder gas temperature, please refer to the description in the foregoing embodiments, and this embodiment will not elaborate on it.

[0087] Figure 10 is a block diagram of an engine cold start control device shown in an exemplary embodiment of the present application. This device can be configured on Figure 1 the controller 3 in the methanol engine control system shown. As Figure 10 shown, this exemplary engine cold start control device includes:

[0088] The motor control module 1010 is configured to control the motor to drive the engine to a target speed;

[0089] The start control module 1020 is configured to control the engine to execute a first cold start strategy until the engine continuously outputs positive torque; wherein, the first cold start strategy includes performing at least one of the following start conditions within a single cycle:

[0090] The number of fuel injection times is greater than or equal to the target number;

[0091] The crankshaft angle of the interval between the last injection moment and the ignition moment is within a target degree range;

[0092] The ratio of the last injection fuel quantity to the total injection fuel quantity is within a target interval;

[0093] The ratio of the total injection fuel quantity to the air quantity entering the cylinder meets the target condition.

[0094] In another exemplary embodiment, this engine cold start control device further includes a temperature judgment module. The temperature judgment module is configured to compare the engine water temperature with a preset first temperature threshold and a second temperature threshold; the start control module 1020 is further configured to:

[0095] When the engine water temperature is lower than the first temperature threshold and higher than the second temperature threshold, control the engine to execute the first cold start strategy until the engine starts;

[0096] When the engine water temperature is lower than the second temperature threshold, control the engine to execute a second cold start strategy until the engine starts; wherein, the second cold start strategy includes: after controlling and adjusting the exhaust valve lift state of the engine to increase the engine temperature, control the engine to execute the first cold start strategy.

[0097] In another exemplary embodiment, the start control module 1020 is further configured to: if the engine cannot be started by executing the first cold start strategy, control the engine to execute the second cold start strategy until the engine starts.

[0098] In another exemplary embodiment, the starting control module 1020 is further configured to:

[0099] Adjust the exhaust valve lift to a low lift state, so that the in-cylinder gas is compressed as the piston moves upward during the exhaust stroke, thereby warming up the engine;

[0100] When the engine warms up to the target temperature condition, control the exhaust valve to switch to the high lift state.

[0101] In another exemplary embodiment, the starting control module 1020 is further configured to:

[0102] Obtain the first temperature value measured in real time by the intake manifold temperature sensor, or obtain the second temperature value measured in real time by the water temperature sensor;

[0103] When the first temperature value exceeds the first preset temperature value, or when the second temperature value exceeds the second preset temperature value, it is determined that the engine has warmed up to the target temperature condition.

[0104] In another exemplary embodiment, the starting control module 1020 is further configured to: If the exhaust valve fails to switch to the high lift state, control the fuel injector not to inject fuel and / or control the spark plug not to ignite.

[0105] Figure 11 It is a block diagram of an engine cold start control device shown in another exemplary embodiment of the present application. This device can still be configured on Figure 1 the controller 3 in the methanol engine control system shown. As Figure 11 shown, this exemplary engine cold start control device includes:

[0106] The motor control module 1110 is configured to control the motor to drive the engine to the target speed;

[0107] The exhaust valve adjustment module 1120 is configured to adjust the exhaust valve lift to a low lift state, so that the in-cylinder gas is compressed as the piston moves upward during the exhaust stroke, thereby warming up the engine. When the engine warms up to the target temperature condition, control the exhaust valve to switch to the high lift state;

[0108] The injection and ignition module 1130 is configured to control the execution of fuel injection and ignition to start the engine.

[0109] It should be noted that the engine cold start control device provided in the above embodiments and the engine cold start control method provided in the above embodiments belong to the same concept. The specific ways in which each module and unit perform operations have been described in detail in the method embodiments, and will not be repeated here. In practical applications, the engine cold start control device provided in the above embodiments can, according to needs, allocate the above functions to different functional modules, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above. This is not limited here either.

[0110] An embodiment of the present application also provides an electronic device, including: one or more processors; a memory for storing one or more programs, which when executed by the one or more processors, cause the electronic device to implement the engine cold start control method provided in each of the above embodiments.

[0111] On the other hand, the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the engine cold start control method as described above. The computer-readable storage medium may be included in the electronic device described in the above embodiments, or may exist separately without being assembled into the electronic device.

[0112] It should be noted that the computer-readable storage medium shown in the embodiments of the present application may include, but is not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. The computer program included on the computer-readable medium can be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0113] The above content is only a preferred exemplary embodiment of the present application and is not used to limit the implementation of the present application. Those of ordinary skill in the art can easily make corresponding adaptations or modifications according to the main concept and spirit of the present application. Therefore, the protection scope of the present application should be subject to the protection scope required by the claims.

Claims

1. An engine cold start control method, characterized in that, the method includes: Controlling the motor to drive the engine to a target speed; Controlling the engine to execute a first cold start strategy until the engine starts; wherein, the first cold start strategy includes executing at least one of the following starting conditions within a single cycle: The number of fuel injections is greater than or equal to the target number; The crankshaft angle between the last injection moment and the ignition moment is within a target degree range; The ratio of the fuel quantity of the last injection to the total fuel injection quantity is within a target interval; The ratio of the total fuel injection quantity to the air quantity entering the cylinder satisfies a target condition.

2. The method according to claim 1, characterized in that, the method further includes: the first cold start strategy includes executing all of the following starting conditions within a single cycle: The number of fuel injections is greater than or equal to the target number; The crankshaft angle between the last injection moment and the ignition moment is within a target degree range; The ratio of the fuel quantity of the last injection to the total fuel injection quantity is within a target interval; The ratio of the total fuel injection quantity to the air quantity entering the cylinder satisfies a target condition.

3. The method according to claim 1, characterized in that, Among the starting conditions included in the first cold start strategy, the target number is 3 times, the target degree range is 10 - 30 degrees, the target interval is 0.15 - 0.35, and the target condition is that the ratio of the air quantity entering the cylinder to the total fuel injection quantity is less than or equal to the fuel equivalent combustion air-fuel ratio.

4. The method according to claim 1, characterized in that, the method further includes: When the engine water temperature is lower than the first temperature threshold and higher than the second temperature threshold, controlling the engine to execute the first cold start strategy until the engine starts; When the engine water temperature is lower than the second temperature threshold, then controlling the engine to execute a second cold start strategy until the engine starts; wherein, the second cold start strategy includes: after controlling and adjusting the exhaust valve lift state of the engine to increase the temperature of the engine, controlling the engine to execute the first cold start strategy.

5. The method according to claim 1, characterized in that, the method further includes: If the engine cannot be started by executing the first cold start strategy, then controlling the engine to execute the second cold start strategy until the engine starts.

6. The method according to claim 4 or 5, characterized in that, The controlling and adjusting the exhaust valve lift state of the engine to increase the temperature of the engine includes: Adjusting the exhaust valve lift to a low lift state, so that the gas in the cylinder is compressed as the piston moves upward during the exhaust stroke, thereby increasing the temperature of the engine; When the engine temperature rises to the target temperature condition, controlling the exhaust valve to switch to a high lift state.

7. The method according to claim 6, characterized in that, the method further includes: Obtaining a first temperature value measured in real time by an intake manifold temperature sensor, or obtaining a second temperature value measured in real time by a water temperature sensor; When the first temperature value exceeds a first preset temperature value, or when the second temperature value exceeds a second preset temperature value, it is determined that the engine temperature has risen to the target temperature condition.

8. The method according to claim 6, wherein, the method further includes: if the switching of the exhaust valve to the high lift state fails, controlling the fuel injector not to inject fuel and / or controlling the spark plug not to ignite.

9. An engine cold start control method, wherein, the method includes: controlling a motor to drive the engine to a target speed; adjusting the exhaust valve lift to a low lift state so that the in-cylinder gas is compressed as the piston moves upward during the exhaust stroke, thereby heating the engine; when the engine is heated to a target temperature condition, controlling the exhaust valve to switch to a high lift state; controlling fuel injection and ignition to start the engine.

10. An engine cold start control device, wherein, the device includes: a motor control module configured to control a motor to drive the engine to a target speed; a start control module configured to control the engine to execute a first cold start strategy until the engine continuously outputs positive torque; wherein, the first cold start strategy includes performing at least one of the following start conditions within a single cycle: the number of fuel injection times is greater than or equal to a target number; the crankshaft angle interval between the last injection time and the ignition time is within a target degree range; the ratio of the last injection fuel quantity to the total injection fuel quantity is within a target interval; the ratio of the total injection fuel quantity to the air quantity entering the cylinder satisfies a target condition.

11. An electronic device, wherein, it includes: one or more processors; a memory for storing one or more programs, which when executed by the one or more processors, cause the electronic device to implement the engine cold start control method according to any one of claims 1 to 9.

12. A computer-readable storage medium, wherein, computer-readable instructions are stored thereon, which when executed by a processor of a computer, cause the computer to execute the engine cold start control method according to any one of claims 1 to 9.

Images