Control method, device and equipment for vehicle-mounted urea injection system

Abstract

The invention discloses a control method, device and equipment for a vehicle-mounted urea injection system, and relates to the field of engine tail gas denitration treatment. The method comprises the following steps: receiving real-time working condition data of an engine and a pre-stored urea injection MAP; a urea injection MAP is inquired according to the exhaust temperature and the nitrogen oxide concentration, the basic urea injection amount is determined, the basic urea injection amount is dynamically corrected according to the engine load rate and the exhaust flow, and the target urea injection amount is obtained; the operation of a peristaltic pump of the target vehicle is controlled according to the real-time pressure value; and a PWM control signal is determined based on the target urea spraying amount and the real-time pressure value, and a metering electromagnetic valve and an atomization electromagnetic valve of the target vehicle are driven to conduct urea water solution atomization spraying according to the PWM control signal. According to the method, accurate and customized adjustment on key parameters such as urea injection time sequence, precision, pre-injection logic and flushing logic can be guaranteed, and the inherent defects of insufficient control right and flexibility and the like in the prior art are effectively overcome.

Description

Technical Field

[0001] This application relates to the field of engine exhaust denitrification treatment, and in particular to a control method, device and equipment for a vehicle-mounted urea injection system. Background Technology

[0002] Currently, in the field of diesel engine exhaust nitrogen oxide (NOx) purification, selective catalytic reduction (SCR) technology is the mainstream solution, the core of which lies in the precise injection of urea solution into the exhaust pipe. Existing technologies generally employ highly integrated on-board urea injection systems, which typically consist of a urea pump, nozzles, a DCU (diesel engine control unit or dedicated injection control unit), and various sensors. Based on publicly available industry practices and common knowledge in the field, the closest existing technical solution is as follows: the engine's main ECU sends simple commands, such as the target urea injection quantity, to the dedicated DCU via a specific communication network. The DCU then drives the urea pump and nozzles to complete the injection action according to its internally fixed control logic and dedicated communication message protocol.

[0003] However, although the existing vehicle-mounted urea injection systems are mature in standard vehicle models, the existing systems encapsulate the core control logic inside a dedicated DCU and interact through preset, non-public dedicated communication messages. At this time, it is impossible to make precise and customized adjustments to key parameters such as the timing, accuracy, pre-injection logic, and flushing logic of urea injection. This results in inherent defects such as insufficient control and flexibility, which restricts its promotion and application in engineering projects that require high customization and diversity. Summary of the Invention

[0004] The purpose of this application is to at least address one of the aforementioned technical deficiencies.

[0005] On one hand, embodiments of this application provide a control method for an on-board urea injection system, the method comprising: Receive real-time engine operating data and pre-stored urea injection MAP of the target vehicle. The real-time engine operating data includes exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow. The base urea injection quantity is determined by consulting the urea injection MAP based on exhaust temperature and nitrogen oxide concentration. The base urea injection quantity is then dynamically corrected based on engine load rate and exhaust flow rate to obtain the target urea injection quantity. Obtain the real-time pressure value of the urea pipeline and control the peristaltic pump operation of the target vehicle based on the real-time pressure value; The PWM control signal is determined based on the target urea injection quantity and real-time pressure value, and the metering solenoid valve and atomizing solenoid valve of the target vehicle are driven to perform urea aqueous solution atomization injection according to the PWM control signal.

[0006] Optionally, receive real-time engine operating data of the target vehicle, including: The system receives real-time engine operating data from the previous controller, which is either a host computer controller or an engine controller, via an industrial communication protocol. The validity of the engine's real-time operating data is verified. If the validity verification result of the engine's real-time operating data is invalid, the engine's historical operating data is used as the engine's real-time operating data for this control.

[0007] Optionally, the base urea injection quantity can be dynamically corrected based on engine load rate and exhaust flow rate to obtain the target urea injection quantity, including: The load correction factor is determined based on the engine load rate, and the flow correction factor is determined based on the deviation between the exhaust flow rate and the reference flow rate. The target urea injection rate is obtained by multiplying the base urea injection rate by the load correction factor and the flow correction factor.

[0008] Optionally, controlling the operation of the peristaltic pump in the target vehicle based on real-time pressure values ​​includes: The real-time pressure value is compared with the preset pressure range. If the real-time pressure value is lower than the minimum value of the preset pressure range, the speed of the peristaltic pump is increased. If the real-time pressure value is higher than the maximum value of the preset pressure range, the speed of the peristaltic pump will be reduced. If the real-time pressure value is not within the preset pressure value range for a preset duration, the system will switch to the standby peristaltic pump.

[0009] Optionally, the PWM control signal is determined based on the target urea injection quantity and the real-time pressure value, including: Obtain the target pressure value and preset mapping table for the urea pipeline. The preset mapping table includes the mapping relationship between each equivalent flow rate and each basic duty cycle. Based on the target urea injection volume and real-time pressure value, the equivalent flow rate under standard pressure difference is calculated, and the basic duty cycle is determined based on the equivalent flow rate through a preset mapping relationship table. The base duty cycle is adjusted based on the target pressure value and the real-time pressure value to obtain the target duty cycle, and a PWM control signal is generated based on the target duty cycle.

[0010] Optionally, based on the target urea injection rate and real-time pressure value, the equivalent flow rate under standard pressure differential is calculated, including: Obtain the exhaust pipe pressure value and determine the actual pressure difference between the exhaust pipe pressure value and the real-time pressure value; Determine the standard pressure difference between the target pressure value and the real-time pressure value, and calculate the equivalent flow rate under the standard pressure difference based on the target urea injection volume, the actual pressure difference value, and the standard pressure difference value.

[0011] Optionally, the base duty cycle can be adjusted based on the target pressure value and the real-time pressure value to obtain the target duty cycle, including: Determine the deviation between the target pressure value and the real-time pressure value, and obtain the preset pressure compensation coefficient; The duty cycle fine-tuning amount is determined based on the deviation value and the pressure compensation coefficient, and then the duty cycle fine-tuning amount is added to the base duty cycle to obtain the target duty cycle.

[0012] Optionally, the method further includes: Close the metering solenoid valve and the atomizing solenoid valve, and open the purging solenoid valve; Control the peristaltic pump to run in reverse for a set time, and pump the residual urea in the urea pipeline back to the urea tank; Compressed air is continuously supplied to purge the urea pipeline, and after purging is completed, the target valves are closed and the system enters standby mode. The target valves include the metering solenoid valve, the atomizing solenoid valve, and the purging solenoid valve.

[0013] On the other hand, embodiments of this application provide a control device for an on-board urea injection system, characterized in that it includes: The data acquisition module is used to receive real-time engine operating data and pre-stored urea injection MAP of the target vehicle. The real-time engine operating data includes exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow. The injection quantity determination module is used to query the urea injection MAP based on exhaust temperature and nitrogen oxide concentration to determine the basic urea injection quantity, and dynamically correct the basic urea injection quantity based on engine load rate and exhaust flow rate to obtain the target urea injection quantity. The command control module is used to acquire the real-time pressure value of the urea pipeline and control the peristaltic pump of the target vehicle according to the real-time pressure value. The urea injection module is used to determine the PWM control signal based on the target urea injection quantity and real-time pressure value, and drive the metering solenoid valve and atomizing solenoid valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal.

[0014] In another aspect, embodiments of this application provide an electronic device, including a processor and a memory: The memory is configured to store machine-readable instructions that, when executed by the processor, cause the processor to perform any of the methods in a control method for an onboard urea injection system.

[0015] The beneficial effects of the technical solutions provided in this application include at least the following: In this application, real-time engine operating data can be acquired. Based on this data and the urea injection MAP, the basic urea injection quantity can be determined more quickly and conveniently, improving processing efficiency. Furthermore, the basic urea injection quantity is dynamically corrected based on engine load rate and exhaust flow to obtain the final target urea injection quantity. This allows for real-time compensation for flow deviations caused by pressure fluctuations, temperature changes, valve characteristic drift, and other factors, achieving high-precision, adaptive flow closed-loop control with excellent dynamic response and robustness. This ensures precise and customized adjustment of key parameters such as urea injection timing, accuracy, pre-injection logic, and flushing logic, effectively solving the inherent defects of insufficient control and flexibility in existing technologies, thus making it applicable to more application scenarios.

[0016] In this application, the injection rate can be dynamically adjusted according to the actual working conditions when determining the target urea injection rate, which avoids the decrease in denitrification rate due to sudden changes in working conditions and improves the denitrification efficiency. In addition, the injection rate can be reduced at low load or low flow rate to avoid excessive urea decomposition and ammonia escape. Furthermore, the correction strategy can be independently calibrated for different application scenarios to improve the versatility of the system.

[0017] This application employs a proportional-feedforward composite fine-tuning control method to fine-tune the duty cycle, achieving high-precision and robust control of urea injection flow rate. It also possesses adaptive learning capabilities, enabling it to adapt to various factors such as system aging and environmental changes. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating a control method for a vehicle-mounted urea injection system provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the vehicle-mounted urea injection system provided in the embodiments of this application; Figure 3 A schematic diagram of the structure of a control device for a vehicle-mounted urea injection system provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting the invention.

[0021] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0023] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0024] Specifically, such as Figure 1 As shown, the method may include: Step S101: Receive the real-time engine operating data and the pre-stored urea injection MAP (Calibration Map) of the target vehicle. The real-time engine operating data includes exhaust temperature, nitrogen oxide concentration, engine load rate, and exhaust flow rate.

[0025] Optionally, when controlling the vehicle-mounted urea injection system, after the system is powered on, the controller can automatically perform a system self-test, such as checking whether each sensor is normal, inspecting the status of the solenoid valve, peristaltic pump, and drive circuit, and confirming whether the communication link is unobstructed. If the self-test passes, the vehicle-mounted urea injection system enters standby mode; otherwise, an alarm is triggered and the system is locked.

[0026] Furthermore, the controller of the vehicle-mounted urea injection system receives real-time engine operating condition data, including exhaust temperature, nitrogen oxide concentration (NOx), engine load rate, and exhaust flow rate, and acquires a urea injection MAP. This urea injection MAP can be configured as a two-dimensional or three-dimensional data table, typically a mapping diagram with temperature-NOx concentration-injection quantity as the relationship axis.

[0027] In an optional embodiment of this application, receiving real-time engine operating data of the target vehicle includes: The system receives real-time engine operating data from the previous controller, which is either a host computer controller or an engine controller, via an industrial communication protocol. The validity of the engine's real-time operating data is verified. If the validity verification result of the engine's real-time operating data is invalid, the engine's historical operating data is used as the engine's real-time operating data for this control.

[0028] Optionally, the controller of the vehicle-mounted urea injection system can receive real-time engine operating condition data from the host computer controller or engine controller via an industrial communication protocol. It then verifies the validity of this data, specifically through format and integrity checks, as well as reasonableness assessments, such as determining whether the exhaust temperature is within the valid range of 0-700℃ and whether the NOx value is non-negative. Conversely, if the validity verification result of the real-time engine operating condition data is invalid, historical engine operating condition data is used as the current real-time engine operating condition data, and a data error message is sent to the host computer controller.

[0029] Step S102: Query the urea injection MAP based on exhaust temperature and nitrogen oxide concentration to determine the basic urea injection quantity, and dynamically correct the basic urea injection quantity based on engine load rate and exhaust flow rate to obtain the target urea injection quantity.

[0030] Optionally, the obtained exhaust temperature and nitrogen oxide concentration can be used as an index to query a pre-stored urea injection MAP to obtain the basic injection quantity. Then, the quantity is dynamically corrected based on the engine load and exhaust flow to obtain the target urea injection quantity. If the exhaust temperature reaches the minimum starting temperature for urea injection, the corrected injection quantity is used as the target urea injection quantity; otherwise, the target urea injection quantity is 0.

[0031] In an optional embodiment of this application, the base urea injection quantity is dynamically corrected based on the engine load rate and exhaust flow rate to obtain the target urea injection quantity, including: The load correction factor is determined based on the engine load rate, and the flow correction factor is determined based on the deviation between the exhaust flow rate and the reference flow rate. The target urea injection rate is obtained by multiplying the base urea injection rate by the load correction factor and the flow correction factor.

[0032] Since the basic urea injection calculation is mainly based on the static MAP diagram, while the changes in engine load rate and exhaust flow rate in actual engine operating conditions will significantly affect the residence time, mixing uniformity and reaction efficiency of exhaust gas, it is necessary to dynamically correct the basic urea injection amount so that the urea injection amount is more in line with the actual reaction requirements and avoid "under-injection" or "over-injection".

[0033] Optionally, the engine load rate sent from the engine controller or host computer controller can be obtained. This engine load rate represents the percentage of current output power to rated power. Then, a load correction factor is determined based on the engine load rate. This load correction factor includes low load, medium load, and high load segments. Specifically, the low load segment corresponds to an engine load rate <30%, with a load correction factor of 0.9-1.0. This is because exhaust temperature may be low and reaction may be insufficient at low loads, requiring a reduction in injection to avoid urea crystallization and ammonia escape. The medium load segment corresponds to an engine load rate of 30% ≤ engine load rate <90%, with a load correction factor of 1.0. In this range, engine operation is stable, and exhaust conditions are closest to the specified operating conditions on the MAP chart, therefore no correction is needed. The high load segment corresponds to an engine load rate ≥90%, with a load correction factor of 1.1-1.3. This is because exhaust flow is large and residence time is short at high loads, requiring increased urea injection to ensure sufficient reaction volume.

[0034] Alternatively, the exhaust flow rate can be directly measured using a flow meter, or indirectly calculated based on parameters such as engine speed, intake air volume, and exhaust temperature. The flow correction factor is then determined using the following formula based on the deviation between the exhaust flow rate and the reference flow rate: in, This is the flow correction factor. This is the sensitivity coefficient. For exhaust flow rate, This is the baseline flow rate.

[0035] Furthermore, the base urea injection quantity is multiplied by the load correction factor and the flow correction factor to obtain the target urea injection quantity. Then, it is determined whether the target urea injection quantity is within the minimum or maximum injection quantity range allowed by the system. If it exceeds the limit, the target urea injection quantity is restricted to the boundary value of the injection quantity range.

[0036] In this application, the injection rate can be dynamically adjusted according to the actual working conditions when determining the target urea injection rate, which avoids the decrease in denitrification rate due to sudden changes in working conditions and improves the denitrification efficiency. In addition, the injection rate can be reduced at low load or low flow rate to avoid excessive urea decomposition and ammonia escape. Furthermore, the correction strategy can be independently calibrated for different application scenarios to improve the versatility of the system.

[0037] Step S103: Obtain the real-time pressure value of the urea pipeline, and control the peristaltic pump of the target vehicle to operate based on the real-time pressure value.

[0038] Optionally, the real-time pressure value of the urea pipeline can be obtained based on the configured pressure sensor, and then the peristaltic pump of the target vehicle can be controlled according to the real-time pressure value.

[0039] In an optional embodiment of this application, controlling the operation of the peristaltic pump of the target vehicle based on the real-time pressure value includes: The real-time pressure value is compared with the preset pressure range. If the real-time pressure value is lower than the minimum value of the preset pressure range, the speed of the peristaltic pump is increased. If the real-time pressure value is higher than the maximum value of the preset pressure range, the speed of the peristaltic pump will be reduced. If the real-time pressure value is not within the preset pressure value range for a preset duration, the system will switch to the standby peristaltic pump.

[0040] Optionally, a pressure range for the urea pipeline can be set, such as 3.0 ± 0.2 bar. The acquired real-time pressure value is then compared with this range. If the real-time pressure value is lower than the minimum value of the preset pressure range (i.e., at the lower limit), the speed of the peristaltic pump needs to be increased. If the real-time pressure value is higher than the maximum value of the preset pressure range (i.e., at the upper limit), the speed of the peristaltic pump is decreased. Furthermore, this vehicle-mounted urea injection system is equipped with both a main peristaltic pump and a backup peristaltic pump. When the currently operating peristaltic pump is the main pump, the duration for which the real-time pressure value is not within the preset pressure range is recorded. If this duration reaches the preset duration, it indicates that the pressure in the urea pipeline is in a prolonged pressure fault state. In this case, the system switches to the backup peristaltic pump and triggers a pressure fault alarm.

[0041] Step S104: Determine the PWM (Pulse Width Modulation) control signal based on the target urea injection quantity and real-time pressure value, and drive the metering solenoid valve and atomizing solenoid valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal.

[0042] Optionally, after determining the target urea injection volume, the target urea injection volume can be converted into a corresponding PWM signal duty cycle and frequency. Then, the PWM signal duty cycle is fine-tuned based on the real-time pressure value to obtain a PWM control signal. This PWM control signal drives the metering solenoid valve and simultaneously opens the atomizing solenoid valve to atomize and inject the urea solution. After opening the atomizing solenoid valve, the pressure in the atomizing air pipeline is monitored to ensure it is not lower than the set value; otherwise, an insufficient atomization pressure alarm is triggered.

[0043] In an optional embodiment of this application, determining the PWM control signal based on the target urea injection quantity and the real-time pressure value includes: Obtain the target pressure value and preset mapping table for the urea pipeline. The preset mapping table includes the mapping relationship between each equivalent flow rate and each basic duty cycle. Based on the target urea injection volume and real-time pressure value, the equivalent flow rate under standard pressure difference is calculated, and the basic duty cycle is determined based on the equivalent flow rate through a preset mapping relationship table. The base duty cycle is adjusted based on the target pressure value and the real-time pressure value to obtain the target duty cycle, and a PWM control signal is generated based on the target duty cycle.

[0044] Optionally, a preset mapping table can be set, which represents the equivalent flow rate corresponding to different duty cycles under standard pressure difference. At this time, the equivalent flow rate under standard pressure difference can be calculated based on the target urea injection volume and real-time pressure value. Then, the base duty cycle can be determined by querying the preset mapping table using the calculated equivalent flow rate as an index.

[0045] Furthermore, the basic duty cycle is adjusted based on the set target pressure value and the obtained real-time pressure value to obtain the target duty cycle, and a PWM control signal is generated based on the target duty cycle.

[0046] In an optional embodiment of this application, the equivalent flow rate under standard pressure differential is calculated based on the target urea injection rate and the real-time pressure value, including: Obtain the exhaust pipe pressure value and determine the actual pressure difference between the exhaust pipe pressure value and the real-time pressure value; Determine the standard pressure difference between the target pressure value and the real-time pressure value, and calculate the equivalent flow rate under the standard pressure difference based on the target urea injection volume, the actual pressure difference value, and the standard pressure difference value.

[0047] Optionally, the pressure value of the exhaust pipe can be obtained based on a pressure sensor, and the difference between the calculated exhaust pipe pressure value and the real-time pressure value can be used to obtain the actual pressure difference value. Simultaneously, the standard pressure difference value between the target pressure value and the real-time pressure value can be calculated. Finally, based on the target urea injection quantity, the actual pressure difference value, and the standard pressure difference value, the equivalent flow rate under the standard pressure difference can be calculated using the following formula: in, The equivalent flow rate under standard pressure differential is The target urea injection volume, This is the actual pressure difference value. Standard differential pressure value.

[0048] In an optional embodiment of this application, adjusting the base duty cycle based on the target pressure value and the real-time pressure value to obtain the target duty cycle includes: Determine the deviation between the target pressure value and the real-time pressure value, and obtain the preset pressure compensation coefficient; The duty cycle fine-tuning amount is determined based on the deviation value and the pressure compensation coefficient, and then the duty cycle fine-tuning amount is added to the base duty cycle to obtain the target duty cycle.

[0049] Optionally, the target pressure value and the real-time pressure value can be subtracted to obtain the deviation value between them, and a preset pressure compensation coefficient can be obtained simultaneously. Specifically, the pressure compensation coefficient can include a proportional coefficient and a feedforward coefficient. Further, based on the pressure compensation coefficient and the calculated deviation value, a proportional-feedforward composite fine-tuning is performed to obtain the duty cycle fine-tuning amount.

[0050] in, This is the duty cycle fine-tuning amount. This is the proportionality coefficient. This is the deviation value. Forward coefficients, The pressure change rate is the ratio of the pressure value in the previous control cycle to the pressure value in the current control cycle.

[0051] Correspondingly, the duty cycle fine-tuning amount and the base duty cycle are added together, and the sum is the target duty cycle.

[0052] This application employs a proportional-feedforward composite fine-tuning control method to fine-tune the duty cycle, achieving high-precision and robust control of urea injection flow rate. It also possesses adaptive learning capabilities, enabling it to adapt to various factors such as system aging and environmental changes.

[0053] In this application, a proportional-feedforward composite fine-tuning control method is adopted to fine-tune the duty cycle, thereby achieving high-precision and robust control of urea injection flow rate. At the same time, it has adaptive learning capability and can adapt to various factors such as system aging and environmental changes.

[0054] In an optional embodiment, the method further includes: Close the metering solenoid valve and the atomizing solenoid valve, and open the purging solenoid valve; Control the peristaltic pump to run in reverse for a set time; Compressed air is continuously supplied to purge the urea pipeline, and after purging is completed, the target valves are closed and the system enters standby mode. The target valves include the metering solenoid valve, the atomizing solenoid valve, and the purging solenoid valve.

[0055] Optionally, after the urea solution atomization and injection are complete, the metering solenoid valve and the atomizing solenoid valve can be closed first, and the purging solenoid valve opened. Simultaneously, the currently operating peristaltic pump can be reversed; the reversal speed and time can be set, such as reversing at the rated speed for 30 seconds. After reversal, the remaining urea solution in the urea pipeline is pumped back to the urea tank while the purging solenoid valve remains open, continuously supplying compressed air to purge the urea pipeline to ensure no residual urea solution remains. After purging, the solenoid valves, atomizing solenoid valve, and purging solenoid valve are closed, putting the system into a low-power standby state.

[0056] In this application, real-time engine operating data can be acquired. Based on this data and the urea injection MAP, the basic urea injection quantity can be determined more quickly and conveniently, improving processing efficiency. Furthermore, the basic urea injection quantity is dynamically corrected based on engine load rate and exhaust flow to obtain the final target urea injection quantity. This allows for real-time compensation for flow deviations caused by pressure fluctuations, temperature changes, valve characteristic drift, and other factors, achieving high-precision, adaptive flow closed-loop control with excellent dynamic response and robustness. This ensures precise and customized adjustment of key parameters such as urea injection timing, accuracy, pre-injection logic, and flushing logic, effectively solving the inherent defects of insufficient control and flexibility in existing technologies, thus making it applicable to more application scenarios.

[0057] Optionally, to better understand the method provided in the embodiments of this application, the process of controlling the injection of urea solution by the vehicle-mounted urea injection system is described below with reference to the structural schematic diagram of the vehicle-mounted urea injection system. The vehicle-mounted urea injection system control includes a urea filter (1), a urea level sensor (2), a urea tank (3), a peristaltic pump (4), a peristaltic pump (5), a manual valve (6), a manual valve (7), an electric regulating valve (8), a metering solenoid valve (9), an atomizing solenoid valve (10), a purging solenoid valve (11), and a pressure sensor (12). The process specifically includes:

[0058] Step 1, Urea Supply and Monitoring: The external urea solution first enters the urea tank (3) through the urea filter (1), which is equipped with a urea level sensor (2) for real-time monitoring of the liquid level in the tank.

[0059] Step 2, Urea extraction and pumping: The system uses peristaltic pump (4) and peristaltic pump (5) as power sources, one for use and one for standby, which are redundant to each other, to draw urea solution from urea tank (3); electric regulating valve (8) is installed on the system loop to control the selection and switching operation of the two peristaltic pumps.

[0060] Step 3: Pipeline pressure monitoring and assurance: A pressure sensor (12) is installed on the pumping pipeline to monitor the pipeline pressure in real time. At this time, it is possible to check whether the peristaltic pump (4) or peristaltic pump (5) is operating normally, and to ensure that the system pressure always meets the injection requirements.

[0061] Step 4: Urea metering, injection, and atomization: The core metering injection unit consists of a metering solenoid valve (9) and a compressed air auxiliary system. The system's main control PLC (Programmable Logic Controller) calculates the required amount of urea solution in real time based on the engine's operating conditions, and then precisely controls the opening of the metering solenoid valve (9) through a PWM signal to achieve precise adjustment of the final injection flow rate. At the same time as the metering solenoid valve (9) is opened, the atomizing solenoid valve (10) is opened simultaneously to introduce compressed air, so that the urea solution is fully atomized at the nozzle.

[0062] Step 5, System purging and maintenance: After the operation is completed, the system executes an automatic purging procedure: first, the metering solenoid valve (9) and the atomizing solenoid valve (10) are closed; then, the purging solenoid valve (11) is opened, and the currently operating peristaltic pump (4) or peristaltic pump (5) is started in reverse to pump the residual urea solution in the pipeline back to the urea tank (3); at the same time, compressed air is used to purge the injection pipeline to ensure that the inside of the pipeline is clean and to prevent crystallization blockage. In addition, manual valves (7) and electric regulating valves (8) are also installed on the key pipelines of the system to facilitate daily inspection and maintenance.

[0063] This application provides a control device for a vehicle-mounted urea injection system, such as... Figure 3 As shown, the device may include: a data acquisition module 301, an injection quantity determination module 302, a command control module 303, and a urea injection module 304, wherein, The data acquisition module is used to receive real-time engine operating data and pre-stored urea injection MAP of the target vehicle. The real-time engine operating data includes exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow. The injection quantity determination module is used to query the urea injection MAP based on exhaust temperature and nitrogen oxide concentration to determine the basic urea injection quantity, and dynamically correct the basic urea injection quantity based on engine load rate and exhaust flow rate to obtain the target urea injection quantity. The command control module is used to acquire the real-time pressure value of the urea pipeline and control the peristaltic pump of the target vehicle according to the real-time pressure value. The urea injection module is used to determine the PWM control signal based on the target urea injection quantity and real-time pressure value, and drive the metering solenoid valve and atomizing solenoid valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal.

[0064] Optionally, when receiving real-time engine operating data from the target vehicle, the data acquisition module is specifically used for: The system receives real-time engine operating data from the previous controller, which is either a host computer controller or an engine controller, via an industrial communication protocol. The validity of the engine's real-time operating data is verified. If the validity verification result of the engine's real-time operating data is invalid, the engine's historical operating data is used as the engine's real-time operating data for this control.

[0065] Optionally, when the injection quantity determination module dynamically corrects the base urea injection quantity based on engine load rate and exhaust flow to obtain the target urea injection quantity, it is specifically used for: The load correction factor is determined based on the engine load rate, and the flow correction factor is determined based on the deviation between the exhaust flow rate and the reference flow rate. The target urea injection rate is obtained by multiplying the base urea injection rate by the load correction factor and the flow correction factor.

[0066] Optionally, when the command control module controls the peristaltic pump of the target vehicle based on the real-time pressure value, it is specifically used for: The real-time pressure value is compared with the preset pressure range. If the real-time pressure value is lower than the minimum value of the preset pressure range, the speed of the peristaltic pump is increased. If the real-time pressure value is higher than the maximum value of the preset pressure range, the speed of the peristaltic pump will be reduced. If the real-time pressure value is not within the preset pressure value range for a preset duration, the system will switch to the standby peristaltic pump.

[0067] Optionally, when determining the PWM control signal based on the target urea injection quantity and the real-time pressure value, the urea injection module is specifically used for: Obtain the target pressure value and preset mapping table for the urea pipeline. The preset mapping table includes the mapping relationship between each equivalent flow rate and each basic duty cycle. Based on the target urea injection volume and real-time pressure value, the equivalent flow rate under standard pressure difference is calculated, and the basic duty cycle is determined based on the equivalent flow rate through a preset mapping relationship table. The base duty cycle is adjusted based on the target pressure value and the real-time pressure value to obtain the target duty cycle, and a PWM control signal is generated based on the target duty cycle.

[0068] Optionally, when the urea injection module calculates the equivalent flow rate under standard pressure differential based on the target urea injection volume and real-time pressure value, it is specifically used for: Obtain the exhaust pipe pressure value and determine the actual pressure difference between the exhaust pipe pressure value and the real-time pressure value; Determine the standard pressure difference between the target pressure value and the real-time pressure value, and calculate the equivalent flow rate under the standard pressure difference based on the target urea injection volume, the actual pressure difference value, and the standard pressure difference value.

[0069] Optionally, when the urea injection module adjusts the base duty cycle based on the target pressure value and the real-time pressure value to obtain the target duty cycle, it is specifically used for: Determine the deviation between the target pressure value and the real-time pressure value, and obtain the preset pressure compensation coefficient; The duty cycle fine-tuning amount is determined based on the deviation value and the pressure compensation coefficient, and then the duty cycle fine-tuning amount is added to the base duty cycle to obtain the target duty cycle.

[0070] Optionally, the instruction control module is also used for: Close the metering solenoid valve and the atomizing solenoid valve, and open the purging solenoid valve; Control the peristaltic pump to run in reverse for a set time, and pump the residual urea in the urea pipeline back to the urea tank; Compressed air is continuously supplied to purge the urea pipeline, and after purging is completed, the target valves are closed and the system enters standby mode. The target valves include the metering solenoid valve, the atomizing solenoid valve, and the purging solenoid valve.

[0071] The control device of the vehicle-mounted urea injection system in this embodiment can execute the control method of the vehicle-mounted urea injection system shown in the embodiment of this application. The implementation principle is similar and will not be described again here.

[0072] This application provides an electronic device, which includes a processor and a memory configured to store machine-readable instructions that, when executed by the processor, cause the processor to perform a control method for an on-board urea injection system.

[0073] This application provides an electronic device, such as... Figure 4 As shown, Figure 4The illustrated electronic device includes a processor 2001 and a memory 2003. The processor 2001 and the memory 2003 are connected, for example, via a bus 2002. Optionally, the electronic device 2000 may further include a transceiver 2004. It should be noted that in practical applications, the transceiver 2004 is not limited to one type, and the structure of this electronic device 2000 does not constitute a limitation on the embodiments of this application.

[0074] Processor 2001 may be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 2001 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0075] Bus 2002 may include a pathway for transmitting information between the aforementioned components. Bus 2002 may be a PCI bus or an EISA bus, etc. Bus 2002 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0076] The memory 2003 may be ROM or other type of static storage device capable of storing static information and instructions, RAM or other type of dynamic storage device capable of storing information and instructions, or EEPROM, CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto.

[0077] The memory 2003 stores the application code that executes the scheme of this application, and its execution is controlled by the processor 2001. The processor 2001 executes the application code stored in the memory 2003 to implement... Figure 3 The illustrated embodiment provides the operation of a control device for a vehicle-mounted urea injection system.

[0078] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0079] The above description is only a partial embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a vehicle-mounted urea injection system, characterized in that, include: Receive real-time engine operating data and pre-stored urea injection MAP of the target vehicle. The real-time engine operating data includes exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow rate. The base urea injection quantity is determined by querying the urea injection MAP based on the exhaust temperature and the nitrogen oxide concentration, and then dynamically corrected based on the engine load rate and the exhaust flow rate to obtain the target urea injection quantity. The real-time pressure value of the urea pipeline is obtained, and the peristaltic pump of the target vehicle is controlled according to the real-time pressure value. The PWM control signal is determined based on the target urea injection volume and the real-time pressure value, and the metering solenoid valve and atomizing solenoid valve of the target vehicle are driven to perform urea aqueous solution atomization injection according to the PWM control signal.

2. The method according to claim 1, characterized in that, The receipt of real-time engine operating data of the target vehicle includes: The system receives real-time engine operating condition data from a previous controller, which may be a host computer controller or an engine controller, via an industrial communication protocol. The validity of the engine real-time operating data is verified. If the validity verification result of the engine real-time operating data is invalid, the historical operating data of the engine is used as the engine real-time operating data for this control.

3. The method according to claim 1, characterized in that, The step of dynamically correcting the base urea injection quantity based on the engine load rate and the exhaust flow rate to obtain the target urea injection quantity includes: The load correction factor is determined based on the engine load rate, and the flow correction factor is determined based on the deviation between the exhaust flow rate and the reference flow rate. The target urea injection quantity is obtained by multiplying the base urea injection quantity by the load correction factor and the flow correction factor.

4. The method according to claim 1, characterized in that, The step of controlling the peristaltic pump operation of the target vehicle based on the real-time pressure value includes: The real-time pressure value is compared with a preset pressure value range. If the real-time pressure value is lower than the minimum value of the preset pressure value range, the rotational speed of the peristaltic pump is increased. If the real-time pressure value is higher than the maximum value of the preset pressure value range, then reduce the speed of the peristaltic pump; If the real-time pressure value is not within the preset pressure value range for a preset duration, then switch to the standby peristaltic pump.

5. The method according to claim 1, characterized in that, The step of determining the PWM control signal based on the target urea injection quantity and the real-time pressure value includes: Obtain the target pressure value and preset mapping table of the urea pipeline. The preset mapping table includes the mapping relationship between each equivalent flow rate and each basic duty cycle. Based on the target urea injection volume and the real-time pressure value, the equivalent flow rate under standard pressure difference is calculated, and the basic duty cycle is determined based on the equivalent flow rate through a preset mapping relationship table. The base duty cycle is adjusted based on the target pressure value and the real-time pressure value to obtain the target duty cycle, and the PWM control signal is generated based on the target duty cycle.

6. The method according to claim 5, characterized in that, The step of calculating the equivalent flow rate under standard pressure differential based on the target urea injection volume and the real-time pressure value includes: Obtain the exhaust pipe pressure value and determine the actual pressure difference between the exhaust pipe pressure value and the real-time pressure value; Determine the standard pressure difference between the target pressure value and the real-time pressure value, and calculate the equivalent flow rate under the standard pressure difference based on the target urea injection volume, the actual pressure difference value, and the standard pressure difference value.

7. The method according to claim 5, characterized in that, The step of adjusting the base duty cycle based on the target pressure value and the real-time pressure value to obtain the target duty cycle includes: Determine the deviation between the target pressure value and the real-time pressure value, and obtain a preset pressure compensation coefficient; The duty cycle fine-tuning amount is determined based on the deviation value and the pressure compensation coefficient, and the duty cycle fine-tuning amount and the base duty cycle are added together to obtain the target duty cycle.

8. The method according to claim 1, characterized in that, The method further includes: Close the metering solenoid valve and the atomizing solenoid valve, and open the purging solenoid valve; Control the peristaltic pump to run in reverse for a set time, and pump the residual urea in the urea pipeline back to the urea tank; Compressed air is continuously supplied to purge the urea pipeline, and after purging is completed, the target valve is closed and the system enters a standby state. The target valve includes a metering solenoid valve, an atomizing solenoid valve, and a purging solenoid valve.

9. A control device for a vehicle-mounted urea injection system, characterized in that, include: The data acquisition module is used to receive real-time engine operating data and pre-stored urea injection MAP of the target vehicle. The real-time engine operating data includes exhaust temperature, nitrogen oxide concentration, engine load rate and exhaust flow rate. The injection quantity determination module is used to query the urea injection MAP based on the exhaust temperature and the nitrogen oxide concentration, determine the basic urea injection quantity, and dynamically correct the basic urea injection quantity based on the engine load rate and the exhaust flow rate to obtain the target urea injection quantity. The command control module is used to acquire the real-time pressure value of the urea pipeline and control the peristaltic pump of the target vehicle to operate according to the real-time pressure value. The urea injection module is used to determine a PWM control signal based on the target urea injection quantity and the real-time pressure value, and drive the metering solenoid valve and atomizing solenoid valve of the target vehicle to perform urea aqueous solution atomization injection according to the PWM control signal.

10. An electronic device, characterized in that, Including the processor and memory: The memory is configured to store a computer program that, when executed by the processor, causes the processor to perform the method according to any one of claims 1-8.

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