Urea injection control methods, devices, computer equipment, readable storage media, and program products

Abstract

This application relates to a urea injection control method, apparatus, computer device, computer-readable storage medium, and computer program product. The method includes: when the current operating condition of the target vehicle is determined to be a long downhill slope, acquiring the temperature value of the target vehicle's after-processor; determining a urea injection strategy based on the temperature value; and adjusting the urea injection strategy during its execution, if the next operating condition of the target vehicle is predicted to be an uphill slope, to control the urea injection quantity. This enables precise urea control.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, and in particular to a urea injection control method, apparatus, computer equipment, computer-readable storage medium, and computer program product. Background Technology

[0002] With the development of vehicle technology, the requirements for NOx emissions (nitrogen oxides) in exhaust emissions are becoming increasingly stringent. In addition to the engine meeting the emission cycle requirements on the test bench, the vehicle's PEMS (Power and Environmental Monitoring System) operating conditions are also a major challenge.

[0003] In existing technologies, SCR (Selective Catalytic Reduction) systems are typically used to control urea injection and treat emissions in a timely manner. However, existing technologies cannot cope with changing operating conditions; that is, using existing technologies to control urea cannot effectively treat emissions under such circumstances. In other words, existing technologies cannot precisely control urea under changing operating conditions, resulting in inaccurate urea injection control. Summary of the Invention

[0004] Therefore, it is necessary to provide a urea injection control method, device, computer equipment, computer-readable storage medium, and computer program product that can improve the accuracy of urea injection control in response to the above-mentioned technical problems.

[0005] In a first aspect, this application provides a urea injection control method, comprising:

[0006] If the target vehicle is found to be in a long downhill condition, the temperature value of the after-processor of the target vehicle is obtained, and the urea injection strategy is determined based on the temperature value.

[0007] During the execution of the urea injection strategy, if it is predicted that the next working condition of the target vehicle is an uphill working condition, the urea injection strategy is adjusted to control the amount of urea injected.

[0008] Secondly, this application also provides a urea injection control device, comprising:

[0009] The strategy determination module is used to obtain the temperature value of the after-processor of the target vehicle when it is verified that the current working condition of the target vehicle is a long downhill working condition, and determine the urea injection strategy based on the temperature value.

[0010] The urea control module is used to adjust the urea injection strategy during the execution of the urea injection strategy, when it is estimated that the next working condition of the target vehicle is an uphill working condition, so as to control the amount of urea injected.

[0011] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0012] If the target vehicle is found to be in a long downhill condition, the temperature value of the after-processor of the target vehicle is obtained, and the urea injection strategy is determined based on the temperature value.

[0013] During the execution of the urea injection strategy, if it is predicted that the next working condition of the target vehicle is an uphill working condition, the urea injection strategy is adjusted to control the amount of urea injected.

[0014] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0015] If the target vehicle is found to be in a long downhill condition, the temperature value of the after-processor of the target vehicle is obtained, and the urea injection strategy is determined based on the temperature value.

[0016] During the execution of the urea injection strategy, if it is predicted that the next working condition of the target vehicle is an uphill working condition, the urea injection strategy is adjusted to control the amount of urea injected.

[0017] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0018] If the target vehicle is found to be in a long downhill condition, the temperature value of the after-processor of the target vehicle is obtained, and the urea injection strategy is determined based on the temperature value.

[0019] During the execution of the urea injection strategy, if it is predicted that the next working condition of the target vehicle is an uphill working condition, the urea injection strategy is adjusted to control the amount of urea injected.

[0020] The aforementioned urea injection control method, device, computer equipment, computer-readable storage medium, and computer program product determine a matching urea injection strategy based on the temperature value of the target vehicle's after-processor when the target vehicle's current operating condition is verified to be a long downhill condition, thereby providing timely and effective treatment of exhaust gases under long downhill conditions. During the execution of the urea injection strategy, if the next operating condition of the target vehicle is predicted to be an uphill condition—that is, in a scenario of a long downhill followed by an uphill—the urea injection strategy is adjusted in real time to precisely control the urea injection quantity under changing operating conditions, achieving precise control of urea injection in this scenario. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a diagram illustrating the application environment of the urea injection control method in one embodiment;

[0023] Figure 2 This is a flowchart illustrating a urea injection control method in one embodiment;

[0024] Figure 3 This is a schematic diagram of urea injection control in one embodiment;

[0025] Figure 4 This is a structural block diagram of a urea injection control device in one embodiment;

[0026] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] The urea injection control method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with sensors in the target vehicle, such as after-treatment temperature sensors, nitrogen oxide sensors, etc.

[0029] In some embodiments, when the terminal 102 detects that the target vehicle's current operating condition is a long downhill slope, the terminal 102 acquires the temperature value of the target vehicle's afterprocessor sent by the afterprocessor temperature sensor. Based on the temperature value, the terminal 102 determines a urea injection strategy. During the execution of the urea injection strategy, if the terminal 102 anticipates that the target vehicle's next operating condition is an uphill slope, the urea injection strategy is adjusted to control the urea injection quantity.

[0030] The terminal 102 can be an electronic control unit (ECU) integrated into the target vehicle, or it can be a terminal device independent of the vehicle 104. The terminal device can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, projection devices, etc. Portable wearable devices can include smartwatches, smart bracelets, head-mounted displays, etc. Head-mounted displays can include virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc.

[0031] In one exemplary embodiment, such as Figure 2 As shown, a urea injection control method is provided, which is applied to... Figure 1 Taking terminal 102 as an example, the explanation includes the following steps S202 to S204. Wherein:

[0032] Step S202: If the target vehicle is found to be in a long downhill condition, obtain the temperature value of the target vehicle's after-processor and determine the urea injection strategy based on the temperature value.

[0033] The target vehicle refers to the diesel vehicle to be urea injection controlled, i.e., a vehicle using a diesel engine, including but not limited to automobiles and commercial vehicles. The operating condition reflects the current road conditions of the target vehicle, such as uphill and downhill conditions. A long downhill condition is a type of downhill condition, referring to a downhill condition whose duration exceeds a time threshold, or a special downhill condition after urea injection has ceased.

[0034] The aftertreatment system of the target vehicle is the exhaust gas treatment device used to treat vehicle exhaust gases. The urea injection strategy is used to determine whether urea injection should be performed, and to determine the ammonia-to-nitrogen ratio (ANR) when urea injection is performed. The ANR can refer to the molar ratio of NH3 (ammonia) to NOx participating in the SCR reaction, or it can be understood as the ratio of the actual supplied ammonia to the ammonia required to completely reduce the current NOx. Urea refers to diesel engine exhaust fluid, used in the SCR system to convert NOx in the exhaust gas into ammonia. The urea injection quantity refers to the amount of urea injected into the exhaust aftertreatment system. Therefore, based on the desired ANR, the required urea injection quantity can be determined. The ANR characterizes the amount of urea injected into the exhaust pipe (urea injection quantity).

[0035] Optionally, the terminal obtains the vehicle information of the target vehicle at the current moment and identifies the current operating condition of the target vehicle based on the vehicle information. If the current operating condition is found to be a long downhill condition, the terminal obtains the sensor data of the target vehicle at the current moment, selects the temperature value of the post-processor from the sensor data, and determines the urea injection strategy corresponding to the temperature value.

[0036] For example, before identifying the current operating condition, the terminal performs an entry condition judgment based on vehicle information. For instance, the terminal obtains the ECU power-on signal, vehicle speed signal, engine speed signal, gear signal, throttle signal, atmospheric pressure signal, and the sensing signals of various sensors, urea defrosting signal, and urea injector status based on vehicle information;

[0037] Based on the ECU power-on signal, vehicle speed signal, engine speed signal, gear signal, throttle signal, atmospheric pressure signal, and the sensing signals of various sensors, urea defrosting signal, and urea nozzle status, determine whether the ECU power-on initialization is complete, whether the vehicle speed and engine speed are normal, whether the gear signal is normal, whether the throttle signal is normal, whether the atmospheric pressure is normal, whether the various sensors are normal, whether urea defrosting is complete, and whether the urea nozzle is in the injection state.

[0038] The signals from various sensors include, but are not limited to, signals from the temperature sensor, signals from the post-processing temperature sensor, and signals from the pre- and post-processing nitrogen and oxygen sensor.

[0039] Based on this, after confirming that the ECU power-on initialization is complete, the vehicle speed and engine speed are normal, the gear signal is normal, the throttle signal is normal, the atmospheric pressure is normal, the urea is defrosted, and the urea nozzle is in the injection state, the process returns to the step of identifying the target vehicle's current operating condition (current operating condition) based on vehicle information to continue execution.

[0040] For example, before determining the access conditions for operating condition identification based on vehicle information, the method further includes: the terminal verifying whether the urea injection correction control function is activated. If activated, the terminal performs the access condition determination for operating condition identification based on vehicle information. For example, the terminal obtains the switch signal of the urea injection correction control function for vehicle operating condition identification. If the switch signal indicates an on state, activation is confirmed; if the switch signal indicates a off state, inactivation is confirmed. For example, the switch signal is represented by "0" to indicate activation and "1" to indicate deactivation.

[0041] Step S204: During the execution of the urea injection strategy, if it is predicted that the next working condition of the target vehicle is an uphill working condition, the urea injection strategy is adjusted to control the amount of urea injected.

[0042] The urea injection rate is related to the ammonia-nitrogen ratio; for example, the urea injection rate is determined based on the ammonia-nitrogen ratio.

[0043] Optionally, during urea injection according to this urea injection strategy, the throttle change rate and engine fuel injection change rate are acquired, and the next operating condition is predicted based on these rates. If the predicted next operating condition is an uphill condition, the terminal acquires the adjustment method corresponding to the urea injection strategy, adjusts the urea injection strategy according to this method, and determines the urea injection quantity based on the ammonia-nitrogen ratio determined in the new urea injection strategy.

[0044] It should be noted that this application can be applied in mountainous driving environments. When the vehicle is currently driving on a long downhill slope and is injecting urea according to the urea injection strategy, if the next driving condition is predicted to be an uphill slope, it means that the road the target vehicle is traveling on will change from a long downhill slope to an uphill slope, i.e., a scenario of a long downhill slope followed by an uphill slope. In this case, it is necessary to adjust the urea injection strategy to meet the urea injection requirements of the scenario.

[0045] In the aforementioned urea injection control method, when the target vehicle's current operating condition is determined to be a long downhill slope, a matching urea injection strategy is determined based on the temperature value of the target vehicle's after-processor to effectively treat exhaust gases under long downhill conditions. During the execution of the urea injection strategy, if the next operating condition of the target vehicle is predicted to be an uphill slope—that is, in a scenario of a long downhill followed by an uphill slope—the urea injection strategy is adjusted in real time to precisely control the urea injection quantity under changing operating conditions, thus achieving precise control of urea injection in this scenario.

[0046] In some embodiments, the method further includes: acquiring the current atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value of the target vehicle; if it is determined that the target vehicle is in a downhill condition based on the atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value, acquiring the duration of the downhill condition and the temperature value of the after-processor; and determining whether the target vehicle is in a long downhill condition based on at least one of the duration and the temperature value.

[0047] Among them, the current atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value are the atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value corresponding to the current moment. That is, the current moment is the end moment of the data collection, the moment that is a preset time away from the current moment is the start moment of the data collection, and the preset time is the data collection period. Based on the atmospheric pressure signal data, engine instantaneous fuel quantity data, and exhaust temperature change data corresponding to the start moment and end moment of the data collection within the data collection period, the current atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value are obtained.

[0048] Optionally, the terminal acquires the atmospheric pressure signal change value, the engine instantaneous fuel quantity change value, and the exhaust temperature change value corresponding to the current moment. If the atmospheric pressure signal change value exceeds the first pressure threshold, the engine instantaneous fuel quantity change value exceeds the first fuel quantity threshold, and the exhaust temperature change value exceeds the first exhaust temperature threshold, then the target vehicle is determined to be in an uphill condition, and the corresponding marker positions s1 (representing uphill condition) = 1, s2 (representing downhill condition) = 0, and s3 (representing long downhill condition) = 0.

[0049] If the change in atmospheric pressure signal exceeds the second pressure threshold, the change in instantaneous engine fuel quantity exceeds the second fuel quantity threshold, and the change in exhaust temperature exceeds the second exhaust temperature threshold, then the target vehicle is determined to be in a downhill condition, and the corresponding marker positions are s2=1, s1=0, and s3=0.

[0050] When the target vehicle is determined to be in a downhill condition, the terminal obtains the duration of the downhill condition and the current temperature value of the after-processor. If the duration is greater than or equal to the duration threshold, or the temperature value drops to the temperature threshold, the target vehicle is determined to be in a long downhill condition, and the corresponding flag positions s3=1, s1=0, and s2=0. The duration threshold is the time required to reach the condition for exiting urea injection.

[0051] For example, the exit judgment for long downhill road conditions is as follows: when s1 or s2 = 1, the long downhill road conditions are exited.

[0052] In this embodiment, after determining that the target vehicle is in a downhill condition, it is further identified whether it is a long downhill condition to accurately identify the current downhill situation. This facilitates timely urea injection control when transitioning from a long downhill to an uphill situation, ensuring the accuracy of urea injection control.

[0053] In some embodiments, determining a urea injection strategy based on a temperature value includes: when the target vehicle is in a long downhill condition, the terminal determines a urea injection strategy corresponding to the temperature value based on a comparison result between the temperature value and a temperature threshold.

[0054] In this embodiment, based on the comparison between the current temperature value and the temperature threshold, a urea injection strategy that matches the result is selected from multiple candidate urea injection strategies to accurately control the urea injection process under long downhill conditions.

[0055] In some embodiments, determining a urea injection strategy based on a temperature value includes: acquiring a temperature threshold and comparing the temperature value with the temperature threshold; if the temperature value is less than or equal to the temperature threshold, determining that the target vehicle does not meet the urea injection conditions and determining the corresponding urea injection strategy as stopping urea injection; if the temperature threshold is greater than the temperature threshold, determining that the target vehicle meets the urea injection conditions, and then the corresponding urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio.

[0056] Optionally, if the temperature value is greater than the temperature threshold, the terminal determines that the current urea injection stage is the first urea injection stage, and determines that the urea injection conditions are still met. The corresponding urea injection strategy is the normal urea injection strategy, that is, urea injection is performed according to the preset ammonia-nitrogen ratio.

[0057] For example, if the temperature of the aftertreatment system is not below the temperature threshold, such as 180°C, during downhill operation, a normal urea injection strategy is adopted, that is, urea injection is performed according to the ammonia-nitrogen ratio required for engine emissions.

[0058] Optionally, if the temperature value is less than or equal to the temperature threshold, the terminal determines that the current urea injection stage is the second urea injection stage, determines that the urea injection conditions are not met, that is, does not inject, and the corresponding urea injection strategy is to stop urea injection.

[0059] For example, when the temperature value of the afterprocessor reaches a temperature threshold, such as 180°, under downhill conditions, the corresponding urea injection strategy is determined to be urea injection stop.

[0060] In this embodiment, the decision to continue urea injection is made by comparing the temperature value with the temperature threshold corresponding to the post-processor, thus enabling timely prediction of the timing of urea injection.

[0061] In some embodiments, the method further includes: obtaining the throttle change rate and the engine fuel injection change rate; obtaining the throttle threshold corresponding to the throttle change rate and obtaining the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then the next operating condition of the target vehicle is determined to be an uphill operating condition.

[0062] For example, the throttle threshold includes a first throttle threshold corresponding to the first urea injection stage and a second throttle threshold corresponding to the second urea injection stage. The fuel injection threshold includes a first fuel injection threshold corresponding to the first urea injection stage and a second fuel injection threshold corresponding to the second urea injection stage. The first throttle threshold and the second throttle threshold may be the same or different. For example, the throttle threshold corresponding to each urea injection stage can be determined separately based on the throttle characteristics and injection characteristics corresponding to each urea injection stage. Similarly, the first fuel injection threshold and the second fuel injection threshold may be the same or different. For example, the fuel injection threshold corresponding to each urea injection stage can be determined separately based on the fuel injection characteristics and injection characteristics corresponding to each urea injection stage.

[0063] For example, when currently in the first urea injection stage, the terminal obtains the current throttle change rate Alpha_1 and the engine fuel injection change rate Qfin_1. If the current throttle change rate Alpha_1 is greater than or equal to the first throttle threshold t1 and the current engine fuel injection change rate Qfin_1 is greater than or equal to the first fuel injection threshold q1, then the next operating condition is determined to be an uphill operating condition. Otherwise, it is not.

[0064] When currently in the second urea injection phase, the terminal acquires the current throttle change rate Alpha_1 and the engine fuel injection change rate Qfin_1. If the current throttle change rate Alpha_1 is greater than or equal to the second throttle threshold t2, and the current engine fuel injection change rate Qfin_1 is greater than or equal to the second fuel injection threshold q2, then the next operating condition is determined to be an uphill operating condition. Otherwise, it is not.

[0065] It should be noted that if the throttle change rate is greater than or equal to the throttle threshold of the corresponding urea injection stage, and the engine fuel injection change rate is greater than or equal to the fuel injection threshold of the corresponding urea injection stage, it indicates a drastic change in operating conditions, that is, the operating conditions change from a long downhill operating condition to an uphill operating condition, and the next operating condition is an uphill operating condition.

[0066] In this embodiment, based on the comparison results of the throttle change rate and the corresponding throttle threshold, and the comparison results of the engine fuel injection change rate and the corresponding fuel injection threshold, it is possible to predict in a timely and accurate manner whether the operating conditions have changed drastically. Thus, it is possible to perform corresponding urea injection control on the changed operating conditions in a timely manner, thereby improving control accuracy.

[0067] In some embodiments, adjusting the urea injection strategy to control the urea injection quantity includes: if the urea injection strategy is to stop urea injection, determining the ammonia-nitrogen ratio corresponding to the current exhaust flow rate based on the current exhaust flow rate of the target vehicle and a mapping table between exhaust flow rate and ammonia-nitrogen ratio, and determining the urea injection quantity based on the determined ammonia-nitrogen ratio; if the urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio, acquiring the current downstream nitrogen-oxygen sensor value and upstream nitrogen-oxygen sensor value of the target vehicle; determining the actual instantaneous nitrogen-oxygen conversion efficiency based on the downstream nitrogen-oxygen sensor value and the upstream nitrogen-oxygen sensor value; determining a new ammonia-nitrogen ratio based on the actual instantaneous nitrogen-oxygen conversion efficiency, and determining the urea injection quantity based on the new ammonia-nitrogen ratio.

[0068] The actual instantaneous nitrogen-oxygen conversion efficiency can be understood as the instantaneous nitrogen-oxygen conversion efficiency η. Downstream nitrogen-oxygen sensor values ​​reflect the NOx emission status in the exhaust gas located downstream of the SCR catalytic converter (such as the very end of the exhaust pipe). Upstream nitrogen-oxygen sensor values ​​reflect the NOx content in the original engine exhaust gas located before the engine exhaust system, i.e., the NOx concentration in the exhaust gas before any treatment.

[0069] For example, if the terminal determines that the urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio, it acquires the downstream nitrogen-oxygen sensor values ​​and the upstream nitrogen-oxygen sensor values ​​sent by the downstream and upstream ammonia-nitrogen sensors, respectively, and calculates the ratio between the downstream and upstream nitrogen-oxygen sensor values ​​to obtain the actual instantaneous nitrogen-oxygen conversion efficiency. After verifying the reasonableness of the actual instantaneous nitrogen-oxygen conversion efficiency, the terminal acquires the theoretical instantaneous nitrogen-oxygen conversion efficiency. Based on the difference between the actual and theoretical instantaneous nitrogen-oxygen conversion efficiency, it adjusts the preset ammonia-nitrogen ratio to obtain a new ammonia-nitrogen ratio, and determines the urea injection amount based on the new ammonia-nitrogen ratio.

[0070] For example, if the terminal determines that the urea injection strategy is to stop urea injection, it obtains a mapping table between exhaust flow rate and ammonia nitrogen ratio from the local machine, determines the ammonia nitrogen ratio corresponding to the current exhaust flow rate based on the mapping table, and performs advance injection according to the urea injection amount determined by the ammonia nitrogen ratio.

[0071] For example, after determining that the urea injection strategy is to stop urea injection, and after performing the pre-injection step based on the urea injection amount determined by the ammonia-nitrogen ratio, the method further includes: during the extraction and injection process of the urea injection amount determined by the ammonia-nitrogen ratio, acquiring the temperature value of the post-processor in real time during this process; if the temperature value rises to a preset temperature value, the urea injection conditions are met; at this time, the actual instantaneous nitrogen-oxygen conversion efficiency is calculated using the above calculation method, and a new ammonia-nitrogen ratio is determined based on the actual instantaneous nitrogen-oxygen conversion efficiency. For example, the larger the difference between the actual instantaneous nitrogen-oxygen conversion efficiency and the theoretical instantaneous nitrogen-oxygen conversion efficiency, the greater the correction to the preset ammonia-nitrogen ratio.

[0072] In this embodiment, when the urea injection strategy is determined to be to stop urea injection, a fixed ammonia-nitrogen ratio is determined based on the current exhaust flow rate to initiate injection in advance. This ensures timely treatment of the exhaust gas during the transition from a long downhill to an uphill condition, i.e., precise control of urea injection. When the urea injection strategy is determined to be to inject urea at a preset ammonia-nitrogen ratio, the preset ammonia-nitrogen ratio is adjusted based on the currently measured instantaneous nitrogen-oxygen conversion efficiency. This ensures that the new ammonia-nitrogen ratio is suitable for the transition from a long downhill to an uphill condition, ensuring precise control of urea injection.

[0073] In some embodiments, the method further includes: when the target vehicle is found to be currently operating as an uphill condition, or when the target vehicle is found to be currently operating as a short downhill condition, injecting urea at a preset ammonia-nitrogen ratio.

[0074] Among them, urea injection according to the preset ammonia-nitrogen ratio refers to control using the normal urea injection strategy. When it is verified that the downhill condition of the target vehicle is not a long downhill condition, the short downhill condition is determined.

[0075] The specific process for determining whether a vehicle is in an uphill condition is described above. If the duration of a downhill condition is less than a duration threshold and the temperature value is higher than a temperature threshold, then the vehicle is determined to be in a short downhill condition.

[0076] In this embodiment, when the current working condition is an uphill condition or a short downhill condition, normal urea injection is performed according to the preset ammonia-nitrogen ratio, without the need to judge and identify the next working condition.

[0077] In a specific embodiment, Figure 3 The diagram shown is a schematic representation of urea injection control in one embodiment. (Refer to...) Figure 3 Every preset time interval, the terminal checks whether the urea injection correction control function is activated. If activated, it performs condition identification and access condition judgment based on vehicle information, that is, it performs the injection control process for the current cycle, i.e., it starts urea injection control. The specific steps are as follows:

[0078] Step 1: Perform condition identification and admission criteria judgment at the current moment.

[0079] Specifically: Once it is confirmed that the ECU power-on initialization is complete, vehicle speed and engine speed are normal, gear position signal is normal, throttle signal is normal, atmospheric pressure is normal, urea defrosting is complete, and urea injector is in injection mode, the conditions for condition identification are met, and step 2 below is executed. If any of the above is not completed or is abnormal, the conditions for condition identification are not met, and the process continues to wait for a preset period of time before repeating step 1 in the next cycle.

[0080] Step 2: Perform operating condition identification.

[0081] Specifically, the terminal acquires the atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value corresponding to the current moment. Operating condition identification is then performed based on these data.

[0082] Step 3: Determine if it is a downhill working condition.

[0083] If not, proceed to step 4; if yes, determine whether it is a long downhill condition, i.e., proceed to step 5.

[0084] Specifically, if the change in atmospheric pressure signal exceeds the first pressure threshold, the change in instantaneous engine fuel quantity exceeds the first fuel quantity threshold, and the change in exhaust temperature exceeds the first exhaust temperature threshold, then the target vehicle is determined to be in an uphill condition.

[0085] If the change in atmospheric pressure signal exceeds the second pressure threshold, the change in instantaneous engine fuel quantity exceeds the second fuel quantity threshold, and the change in exhaust temperature exceeds the second exhaust temperature threshold, then the target vehicle is determined to be in a downhill condition.

[0086] Step 4: Implement the normal urea injection strategy.

[0087] Specifically, the terminal injects urea according to a preset ammonia-nitrogen ratio until the current cycle ends.

[0088] Step 5: Determine the working conditions of a long downhill slope.

[0089] Specifically, when it is determined that the target vehicle is in a downhill condition, the terminal obtains the duration of the downhill condition and the current temperature value of the after-processor. If the duration is greater than or equal to a duration threshold, or the temperature value drops to a temperature threshold, it is determined that the target vehicle is in a long downhill condition. Step 6 is then executed. If the duration is less than the duration threshold and the temperature value is higher than the temperature threshold, it is determined that the target vehicle is in a short downhill condition, and urea injection is performed according to the preset ammonia-nitrogen ratio until the current cycle ends.

[0090] Step 6: Determining the normal urea injection strategy.

[0091] Specifically, the temperature threshold is obtained, and the temperature value is compared with the temperature threshold.

[0092] If the temperature value is less than or equal to the temperature threshold, it is determined that the target vehicle does not meet the urea injection conditions, and the corresponding urea injection strategy is determined to be not the normal urea injection strategy. Instead, urea injection is stopped, and step 7 is continued.

[0093] If the temperature threshold is greater than the temperature threshold, and the target vehicle is determined to meet the urea injection conditions, then the corresponding urea injection strategy is the normal urea injection strategy, that is, urea injection is performed according to the preset ammonia-nitrogen ratio, and step 8 is continued.

[0094] Step 7: Determine if the operating conditions have changed drastically.

[0095] Specifically, the terminal acquires the throttle change rate and the engine fuel injection change rate; it acquires the throttle threshold corresponding to the throttle change rate and the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then a drastic change in operating condition is determined, i.e., the next operating condition for the target vehicle is an uphill condition, and step 9 is executed. If the throttle change rate is less than the throttle threshold or the engine fuel injection change rate is less than the fuel injection threshold, then a drastic change in operating condition is not observed, and the system returns to determine whether the urea strategy is normal at the next moment.

[0096] Step 8: The terminal acquires the throttle change rate and the engine fuel injection change rate; it acquires the throttle threshold corresponding to the throttle change rate and the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then a drastic change in operating condition is determined, i.e., the next operating condition for the target vehicle is an uphill condition, and step 10 is executed. If the throttle change rate is less than the throttle threshold or the engine fuel injection change rate is less than the fuel injection threshold, then a drastic change in operating condition is not determined, and the system returns to determine whether the urea strategy is normal at the next moment.

[0097] Step 9: Inject at a fixed ammonia-nitrogen ratio.

[0098] Specifically, the terminal determines the ammonia-nitrogen ratio corresponding to the current exhaust flow rate of the target vehicle and the mapping table between exhaust flow rate and ammonia-nitrogen ratio, and determines the urea injection quantity based on the determined ammonia-nitrogen ratio.

[0099] Step 10: Urea injection correction.

[0100] Specifically, the terminal acquires the current downstream and upstream nitrogen-oxygen sensor values ​​of the target vehicle; based on the downstream and upstream nitrogen-oxygen sensor values, it determines the actual instantaneous nitrogen-oxygen conversion efficiency; based on the actual instantaneous nitrogen-oxygen conversion efficiency, it determines the new ammonia-nitrogen ratio, and based on the new ammonia-nitrogen ratio, it determines the urea injection quantity.

[0101] The above process can also be reversed to reduce urea spraying in highly efficient operating conditions, thereby saving urea consumption.

[0102] In this embodiment, when the target vehicle's current operating condition is determined to be a long downhill slope, a matching urea injection strategy is determined based on the temperature value of the target vehicle's after-processor to effectively treat exhaust gases under long downhill conditions. During the execution of the urea injection strategy, if the next operating condition of the target vehicle is predicted to be an uphill slope—that is, in a scenario of a long downhill followed by an uphill climb—the urea injection strategy is adjusted in real time to precisely control the urea injection amount under changing operating conditions, achieving precise control of urea injection in this scenario. Therefore, in mountain driving scenarios involving continuous uphill and downhill sections or long downhill followed by an uphill climb, precise control of urea injection can be achieved. Furthermore, during a long downhill slope, if the next operating condition is an uphill climb, urea can be pre-injected to reduce or eliminate the nitrogen oxide peak during the uphill condition, thus reducing nitrogen oxide generation in this scenario and ensuring compliance with nitrogen oxide emissions requirements in vehicle exhaust. This has a strong effect on improving nitrogen oxide emissions during the initial acceleration uphill in special operating conditions such as mountainous areas.

[0103] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0104] Based on the same inventive concept, this application also provides a urea injection control device for implementing the urea injection control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of one or more urea injection control device embodiments provided below can be found in the limitations of the urea injection control method described above, and will not be repeated here.

[0105] In one exemplary embodiment, such as Figure 4 As shown, a urea injection control device 400 is provided, including: a strategy determination module 402 and a urea control module 404, wherein:

[0106] The strategy determination module 402 is used to obtain the temperature value of the after-processor of the target vehicle when it is verified that the current working condition of the target vehicle is a long downhill working condition, and determine the urea injection strategy based on the temperature value.

[0107] The urea control module 404 is used to adjust the urea injection strategy during the execution of the urea injection strategy, when it is estimated that the next working condition of the target vehicle is an uphill working condition, so as to control the amount of urea injected.

[0108] In some embodiments, the device further includes a working condition determination module, which is used to acquire the current atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value of the target vehicle; when it is determined that the target vehicle is in a downhill working condition based on the atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value, the module acquires the duration of the downhill working condition and the temperature value of the after-processor; and determines whether the target vehicle is in a long downhill working condition based on at least one of the duration and temperature value.

[0109] In some embodiments, the strategy determination module 402 is used to obtain a temperature threshold, compare the temperature value with the temperature threshold; if the temperature value is less than or equal to the temperature threshold, determine that the target vehicle does not meet the urea injection conditions, and determine the corresponding urea injection strategy as stopping urea injection; if the temperature threshold is greater than the temperature threshold, determine that the target vehicle meets the urea injection conditions, and then the corresponding urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio.

[0110] In some embodiments, the working condition determination module is further configured to obtain the throttle change rate and the engine fuel injection change rate; obtain the throttle threshold corresponding to the throttle change rate and obtain the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then the next working condition of the target vehicle is determined to be an uphill working condition.

[0111] In some embodiments, the urea control module 404 is configured to: if the urea injection strategy is to stop urea injection, determine the ammonia-nitrogen ratio corresponding to the current exhaust flow rate of the target vehicle based on the current exhaust flow rate and the mapping table between exhaust flow rate and ammonia-nitrogen ratio, and determine the urea injection quantity based on the determined ammonia-nitrogen ratio; if the urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio, obtain the current downstream nitrogen-oxygen sensor value and upstream nitrogen-oxygen sensor value of the target vehicle; determine the actual instantaneous nitrogen-oxygen conversion efficiency based on the downstream nitrogen-oxygen sensor value and the upstream nitrogen-oxygen sensor value; determine a new ammonia-nitrogen ratio based on the actual instantaneous nitrogen-oxygen conversion efficiency, and determine the urea injection quantity based on the new ammonia-nitrogen ratio.

[0112] In some embodiments, the urea control module 404 is used to inject urea according to a preset ammonia-nitrogen ratio when the target vehicle is found to be in an uphill condition or in a short downhill condition.

[0113] Each module in the aforementioned urea injection control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0114] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 5 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media to run. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements a urea injection control method.

[0115] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0116] In one exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: when it is verified that the current operating condition of the target vehicle is a long downhill condition, the temperature value of the after-processor of the target vehicle is obtained, and a urea injection strategy is determined based on the temperature value; during the execution of the urea injection strategy, when it is estimated that the next operating condition of the target vehicle is an uphill condition, the urea injection strategy is adjusted to control the urea injection amount.

[0117] In one embodiment, when the processor executes the computer program, it further performs the following steps: acquiring the current atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value of the target vehicle; if it is determined that the target vehicle is in a downhill condition based on the atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value, acquiring the duration of the downhill condition and the temperature value of the post-processor; and determining whether the target vehicle is in a long downhill condition based on at least one of the duration and the temperature value.

[0118] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining a temperature threshold and comparing the temperature value with the temperature threshold; if the temperature value is less than or equal to the temperature threshold, determining that the target vehicle does not meet the urea injection conditions and determining the corresponding urea injection strategy as stopping urea injection; if the temperature threshold is greater than the temperature threshold, determining that the target vehicle meets the urea injection conditions, and then the corresponding urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio.

[0119] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining the throttle change rate and the engine fuel injection change rate; obtaining the throttle threshold corresponding to the throttle change rate and obtaining the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then the next operating condition of the target vehicle is determined to be an uphill operating condition.

[0120] In one embodiment, when the processor executes the computer program, it further performs the following steps: if the urea injection strategy is to stop urea injection, then based on the current exhaust flow rate of the target vehicle and the mapping table between exhaust flow rate and ammonia-nitrogen ratio, the ammonia-nitrogen ratio corresponding to the current exhaust flow rate is determined, and the urea injection quantity is determined based on the determined ammonia-nitrogen ratio; if the urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio, then the current downstream nitrogen-oxygen sensor value and upstream nitrogen-oxygen sensor value of the target vehicle are obtained; based on the downstream nitrogen-oxygen sensor value and the upstream nitrogen-oxygen sensor value, the actual instantaneous nitrogen-oxygen conversion efficiency is determined; based on the actual instantaneous nitrogen-oxygen conversion efficiency, a new ammonia-nitrogen ratio is determined, and the urea injection quantity is determined based on the new ammonia-nitrogen ratio.

[0121] In one embodiment, when the processor executes the computer program, it further performs the following steps: if the target vehicle is found to be currently operating in an uphill condition, or if the target vehicle is found to be currently operating in a short downhill condition, urea is injected according to a preset ammonia-nitrogen ratio.

[0122] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, performs the following steps: when the current operating condition of the target vehicle is verified to be a long downhill condition, the temperature value of the target vehicle's after-processor is obtained, and a urea injection strategy is determined based on the temperature value; during the execution of the urea injection strategy, when the next operating condition of the target vehicle is predicted to be an uphill condition, the urea injection strategy is adjusted to control the urea injection quantity.

[0123] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: acquiring the current atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value of the target vehicle; if it is determined that the target vehicle is in a downhill condition based on the atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value, acquiring the duration of the downhill condition and the temperature value of the post-processor; and determining whether the target vehicle is in a long downhill condition based on at least one of the duration and the temperature value.

[0124] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining a temperature threshold and comparing the temperature value with the temperature threshold; if the temperature value is less than or equal to the temperature threshold, determining that the target vehicle does not meet the urea injection conditions and determining the corresponding urea injection strategy as stopping urea injection; if the temperature threshold is greater than the temperature threshold, determining that the target vehicle meets the urea injection conditions, and then the corresponding urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio.

[0125] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the throttle change rate and the engine fuel injection change rate; obtaining the throttle threshold corresponding to the throttle change rate and obtaining the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then the next operating condition of the target vehicle is determined to be an uphill operating condition.

[0126] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: if the urea injection strategy is to stop urea injection, then based on the current exhaust flow rate of the target vehicle and the mapping table between exhaust flow rate and ammonia nitrogen ratio, the ammonia nitrogen ratio corresponding to the current exhaust flow rate is determined, and the urea injection quantity is determined based on the determined ammonia nitrogen ratio; if the urea injection strategy is to inject urea according to a preset ammonia nitrogen ratio, then the current downstream nitrogen-oxygen sensor value and upstream nitrogen-oxygen sensor value of the target vehicle are obtained; based on the downstream nitrogen-oxygen sensor value and the upstream nitrogen-oxygen sensor value, the actual instantaneous nitrogen-oxygen conversion efficiency is determined; based on the actual instantaneous nitrogen-oxygen conversion efficiency, a new ammonia nitrogen ratio is determined, and the urea injection quantity is determined based on the new ammonia nitrogen ratio.

[0127] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: if the target vehicle is found to be currently operating in an uphill condition, or if the target vehicle is found to be currently operating in a short downhill condition, urea is injected according to a preset ammonia-nitrogen ratio.

[0128] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps: when the current operating condition of the target vehicle is verified to be a long downhill condition, the temperature value of the target vehicle's after-processor is obtained, and a urea injection strategy is determined based on the temperature value; during the execution of the urea injection strategy, when the next operating condition of the target vehicle is predicted to be an uphill condition, the urea injection strategy is adjusted to control the urea injection quantity.

[0129] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: acquiring the current atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value of the target vehicle; if it is determined that the target vehicle is in a downhill condition based on the atmospheric pressure signal change value, the instantaneous engine fuel quantity change value, and the exhaust temperature change value, acquiring the duration of the downhill condition and the temperature value of the post-processor; and determining whether the target vehicle is in a long downhill condition based on at least one of the duration and the temperature value.

[0130] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining a temperature threshold and comparing the temperature value with the temperature threshold; if the temperature value is less than or equal to the temperature threshold, determining that the target vehicle does not meet the urea injection conditions and determining the corresponding urea injection strategy as stopping urea injection; if the temperature threshold is greater than the temperature threshold, determining that the target vehicle meets the urea injection conditions, and then the corresponding urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio.

[0131] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the throttle change rate and the engine fuel injection change rate; obtaining the throttle threshold corresponding to the throttle change rate and obtaining the fuel injection threshold corresponding to the engine fuel injection change rate; if the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then the next operating condition of the target vehicle is determined to be an uphill operating condition.

[0132] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: if the urea injection strategy is to stop urea injection, then based on the current exhaust flow rate of the target vehicle and the mapping table between exhaust flow rate and ammonia nitrogen ratio, the ammonia nitrogen ratio corresponding to the current exhaust flow rate is determined, and the urea injection quantity is determined based on the determined ammonia nitrogen ratio; if the urea injection strategy is to inject urea according to a preset ammonia nitrogen ratio, then the current downstream nitrogen-oxygen sensor value and upstream nitrogen-oxygen sensor value of the target vehicle are obtained; based on the downstream nitrogen-oxygen sensor value and the upstream nitrogen-oxygen sensor value, the actual instantaneous nitrogen-oxygen conversion efficiency is determined; based on the actual instantaneous nitrogen-oxygen conversion efficiency, a new ammonia nitrogen ratio is determined, and the urea injection quantity is determined based on the new ammonia nitrogen ratio.

[0133] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: if the target vehicle is found to be currently operating in an uphill condition, or if the target vehicle is found to be currently operating in a short downhill condition, urea is injected according to a preset ammonia-nitrogen ratio.

[0134] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0135] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0136] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0137] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for controlling urea injection, characterized in that, The method includes: If the target vehicle is found to be in a long downhill condition, the temperature value of the target vehicle's after-processor is obtained, a temperature threshold is obtained, and the temperature value is compared with the temperature threshold. If the temperature value is less than or equal to the temperature threshold, it is determined that the target vehicle does not meet the urea injection conditions, and the corresponding urea injection strategy is to stop urea injection. If the temperature threshold is greater than the temperature threshold, and the target vehicle is determined to meet the urea injection conditions, then the corresponding urea injection strategy is to inject urea according to the preset ammonia-nitrogen ratio. During the execution of the urea injection strategy, if the next operating condition of the target vehicle is predicted to be an uphill condition, and the urea injection strategy is to stop urea injection, then based on the current exhaust flow rate of the target vehicle and the mapping table between exhaust flow rate and ammonia-nitrogen ratio, the ammonia-nitrogen ratio corresponding to the current exhaust flow rate is determined, and urea injection is performed in advance according to the urea injection amount determined by the ammonia-nitrogen ratio. During the process of extracting the urea injection amount determined by the ammonia-nitrogen ratio, the temperature value of the afterprocessor is acquired in real time. If the urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio, then the current downstream nitrogen-oxygen sensor value and upstream nitrogen-oxygen sensor value of the target vehicle are acquired. Based on the downstream nitrogen-oxygen sensor value and the upstream nitrogen-oxygen sensor value, the actual instantaneous nitrogen-oxygen conversion efficiency is determined. Based on the actual instantaneous nitrogen-oxygen conversion efficiency, a new ammonia-nitrogen ratio is determined, and the urea injection amount is determined based on the new ammonia-nitrogen ratio.

2. The method according to claim 1, characterized in that, The method further includes: Acquire the current atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value of the target vehicle; If the target vehicle is determined to be in a downhill condition based on the changes in atmospheric pressure signal, instantaneous engine fuel quantity, and exhaust temperature, the duration of the downhill condition and the temperature value of the after-processor are obtained. Based on at least one of the duration and the temperature value, it is determined whether the target vehicle is in a long downhill condition.

3. The method according to claim 1, characterized in that, The method further includes: Obtain the throttle change rate and the engine fuel injection change rate; Obtain the throttle threshold corresponding to the throttle change rate, and obtain the injection threshold corresponding to the engine injection change rate; If the throttle change rate is greater than or equal to the throttle threshold and the engine fuel injection change rate is greater than or equal to the fuel injection threshold, then the next operating condition for the target vehicle is determined to be an uphill operating condition.

4. The method according to claim 1, characterized in that, The method further includes: If the target vehicle is found to be operating on an uphill slope, or if the target vehicle is found to be operating on a short downhill slope, urea injection will be performed according to the preset ammonia-nitrogen ratio.

5. A urea injection control device, characterized in that, The device includes: The strategy determination module is used to, when the current operating condition of the target vehicle is a long downhill condition, obtain the temperature value of the target vehicle's after-processor, obtain a temperature threshold, and compare the temperature value with the temperature threshold; if the temperature value is less than or equal to the temperature threshold, determine that the target vehicle does not meet the urea injection conditions, and determine the corresponding urea injection strategy as stopping urea injection; if the temperature threshold is greater than the temperature threshold, determine that the target vehicle meets the urea injection conditions, and then the corresponding urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio. The urea control module is used to, during the execution of the urea injection strategy, determine the ammonia-nitrogen ratio corresponding to the current exhaust flow rate based on the target vehicle's current exhaust flow rate and a mapping table between exhaust flow rate and ammonia-nitrogen ratio, and inject urea in advance according to the urea injection amount determined by the ammonia-nitrogen ratio. During the process of extracting the urea injection amount according to the ammonia-nitrogen ratio, the temperature value of the afterprocessor is acquired in real time. If the urea injection strategy is to inject urea according to a preset ammonia-nitrogen ratio, the module acquires the current downstream and upstream nitrogen-oxygen sensor values ​​of the target vehicle; determines the actual instantaneous nitrogen-oxygen conversion efficiency based on the downstream and upstream nitrogen-oxygen sensor values; determines a new ammonia-nitrogen ratio based on the actual instantaneous nitrogen-oxygen conversion efficiency; and determines the urea injection amount based on the new ammonia-nitrogen ratio.

6. The apparatus according to claim 5, characterized in that, The device also includes a working condition judgment module, used to acquire the current atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value of the target vehicle; and, if it is determined that the target vehicle is in a downhill working condition based on the atmospheric pressure signal change value, engine instantaneous fuel quantity change value, and exhaust temperature change value, to acquire the duration of the downhill working condition and the temperature value of the after-processor. Based on at least one of the duration and the temperature value, it is determined whether the target vehicle is in a long downhill condition.

7. The apparatus according to claim 5, characterized in that, The urea control module is used to inject urea according to a preset ammonia-nitrogen ratio when the target vehicle is detected to be in an uphill condition or in a short downhill condition.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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