A urea tank thawing control method and device, vehicle and medium

Abstract

This invention discloses a method, device, vehicle, and medium for controlling the defrosting of a urea tank, belonging to the field of engine technology. The method includes the following steps: acquiring initial information from sensors and the ECU storage unit, wherein the initial information includes engine status, urea concentration status, urea tank temperature, ambient temperature, vehicle speed, and urea tank level information; based on the initial information, successively judging the urea tank status according to a first judgment condition, a second judgment condition, and a third judgment condition; if the urea tank status is determined to be "unfrozen," the urea tank does not enter or exits the defrosting process, and the heating coil is controlled to stop working; if the urea tank status is determined to be "suspected frozen" or "frozen," the urea tank enters the defrosting state, and the heating coil is controlled to heat. This invention can accurately identify the urea tank status and control it to enter and exit the defrosting process in a timely manner.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a method, device, vehicle, and medium for controlling the defrosting of a urea tank. Background Technology

[0002] Using SCR (Selective Catalytic Reduction) systems to treat nitrogen oxides (NOx) in diesel engine exhaust is a common emission control method. The China VI emission standards require that the SCR system can still complete reductant injection within a specified time at ambient temperatures of -15℃ (GB18352-2016) / -18℃ (GB17691-2018). However, the mainstream reductant used in domestically produced diesel engines is still automotive urea, which begins to crystallize at an ambient temperature of -11℃.

[0003] In existing technology, taking a vehicle equipped with an ultrasonic level and concentration sensor, operating in a low-temperature environment of -15°C and undergoing a cold start as an example, after the vehicle is powered on, the ECU (Electronic Control Unit) obtains initial ECU information such as the urea tank temperature, ambient temperature, and relevant sensor fault status. Based on the China VI emission standard for light-duty vehicles, it assigns a first-round defrosting time, calibrating to complete the first round of defrosting and begin pressure injection within 1130 seconds (GB18352-2016 regulations require injection to be completed within 20 minutes). At 1130 seconds, it continues to acquire ambient temperature and urea tank temperature information, calculating the next round of defrosting time according to the calibration logic, and repeating this cycle until defrosting is exited. When the lower value of either the urea tank temperature or the ambient temperature is higher than 5°C, the urea tank defrosting is exited; when it falls below a certain lower limit (e.g., -3°C), defrosting is restarted.

[0004] Existing technologies rely primarily on ECU information such as urea tank temperature and ambient temperature to determine whether to initiate or exit urea tank defrosting. This leads to a rapid rise in urea temperature near the heating coil in vehicles operating in extremely cold regions like Xinjiang, where prolonged idling and rapid increases in ambient temperature cause this rapid rise. The temperature around the urea tank temperature measuring point rises simultaneously but is insufficient to reflect the overall urea tank temperature and melting state. Furthermore, the ambient temperature is significantly affected by engine heat radiation or heated / cold storage conditions, further reducing its reliability. This results in the urea tank prematurely exiting defrosting, and coupled with urea injection consumption, greatly increases the risk of cavity-related errors. Therefore, without affecting relevant emissions testing, a control method is needed to accurately identify the urea tank status and control its timely initiation and exit from defrosting. Summary of the Invention

[0005] In view of the above, the present invention aims to provide a urea tank defrosting control method, device, vehicle and medium to solve the problem that the aforementioned defrosting strategy relies too much on the urea tank temperature and ambient temperature as the conditions for entering and exiting the urea tank defrosting. This leads to the problem that, under conditions such as rapid changes in ambient temperature and long vehicle idling, the urea tank may defrost near the heating coil while the top of the urea tank remains frozen, resulting in frequent premature exits from the defrosting program and urea consumption, which can easily lead to false urea tank empty diagnosis.

[0006] The technical solution adopted in this invention is as follows:

[0007] This invention provides a method for controlling the thawing of a urea tank, comprising the following steps:

[0008] Acquire initial information from the sensors and ECU storage unit, wherein the initial information includes engine status, urea concentration status, urea tank temperature, ambient temperature, vehicle speed, and urea tank level information;

[0009] Based on the initial information, the urea tank status is determined sequentially according to the first, second, and third determination conditions. If the urea tank status is determined to be "not frozen", the urea tank will not enter or exit the thawing process, and the heating coil will be controlled to stop working. If the urea tank status is determined to be "suspected frozen" or "frozen", the urea tank will enter the thawing process, and the heating coil will be controlled to heat.

[0010] Preferably, the step of judging the urea tank status sequentially based on initial information and according to the first judgment condition, the second judgment condition, and the third judgment condition includes:

[0011] The first determination condition includes sub-condition A and sub-condition B. If sub-condition A or sub-condition B is satisfied, the urea tank status is determined to be "unfrozen"; otherwise, the second determination condition is determined.

[0012] The second determination condition includes sub-condition C and sub-condition D. If sub-condition C or sub-condition D is satisfied, the urea tank status is determined to be "frozen"; otherwise, the third determination condition is determined.

[0013] The third determination condition includes sub-condition E. If sub-condition E is met, the urea tank status is determined to be "suspected frozen"; otherwise, the urea tank status is determined to be "unfrozen".

[0014] Preferably, sub-conditions A, B, C, D, and E are respectively:

[0015] Sub-condition A: The urea concentration status is readable, the urea tank level is higher than the calibration threshold, and the cold start flag is in cold start mode.

[0016] Subcondition B: The cold start flag is in cold start mode, and the urea tank temperature exceeds the first temperature threshold, and the ambient temperature exceeds the second temperature threshold.

[0017] Sub-condition C: The temperature of the urea tank is less than the third temperature threshold;

[0018] Sub-condition D: When the real-time urea tank level is less than or equal to the negative correction value of the remaining urea tank level, the urea tank temperature is less than or equal to the fourth temperature threshold or the current cold start flag is in a non-cold start state.

[0019] Sub-condition E: The urea concentration is frozen and cannot be read, or the tank is empty and there is no signal, and the remaining urea tank level is higher than the dead level threshold, and the urea tank temperature is lower than the first temperature threshold.

[0020] Preferably, the method further includes the following steps before acquiring the initial information from the sensor and ECU storage unit:

[0021] During the vehicle cold start process, after the urea tank cold start flag is set to 1, the ECU diagnoses the faults in the sensor signals required by the urea injection system.

[0022] Preferably, when the vehicle is in operation, based on continuously updated ECU information, a fourth, fifth, and sixth determination condition are set, and the fourth, fifth, and sixth determination conditions are judged sequentially to confirm the status of the urea tank.

[0023] Preferably, the fourth determination condition includes sub-condition F. If sub-condition F is satisfied, the urea tank status is determined to be "frozen"; otherwise, the fifth determination condition is determined.

[0024] The fifth determination condition includes sub-condition G and sub-condition H. If the current urea tank is not in a "frozen" state and sub-condition G or sub-condition H is met, then the urea tank is determined to be in a "suspected frozen" state; otherwise, the sixth determination condition is applied.

[0025] The sixth determination condition includes sub-condition I, sub-condition J, and sub-condition K. If sub-condition I, sub-condition J, or sub-condition K is satisfied, the urea tank is determined to be in an "unfrozen" state.

[0026] Preferably, the sub-conditions F, G, H, I, J, and K are respectively:

[0027] Subcondition F: The temperature of the urea tank is less than the fourth temperature threshold and remains so for the first time duration;

[0028] Sub-condition G: The temperature of the urea tank is less than the first temperature threshold, and the urea concentration is frozen and cannot be read, or the tank is empty and there is no signal, and the remaining urea tank liquid level is higher than the urea tank dead liquid level threshold, and this condition persists for the second time period.

[0029] Subcondition H: If a single unfreeze command fails to build up compression, the unfreeze process continues.

[0030] Sub-condition I: The current urea tank status is "frozen" or "suspected frozen", and the urea tank temperature is greater than the first temperature threshold, and the vehicle speed is higher than the first vehicle speed threshold for at least the third time length, and the real-time urea tank liquid level is greater than the negative correction value of the remaining urea tank liquid level. If all of the conditions in sub-condition I are met, continue to maintain the condition for at least the fourth time length.

[0031] Subcondition J: The current urea tank status is "unfrozen", and the urea tank temperature is less than the fourth temperature threshold, and the ambient temperature is less than 0°C. If all conditions of subcondition J are met, continue to maintain the status for at least the fifth time period.

[0032] Sub-condition K: The current urea tank status is "frozen" or "suspected frozen", and the real-time urea tank level reaches the calibrated threshold. All states of sub-condition K shall continue to remain for no less than the sixth time period.

[0033] Another aspect of the present invention provides a urea tank defrosting control device, comprising:

[0034] The acquisition unit is used to acquire initial information from the sensors and the ECU storage unit, wherein the initial information includes engine status, urea concentration status, urea tank temperature, ambient temperature, vehicle speed, and urea tank level information.

[0035] The judgment control unit, based on the initial information, successively judges the urea tank status according to the first judgment condition, the second judgment condition, and the third judgment condition. If the urea tank status is judged to be "not frozen", the urea tank will not enter or exit the thawing state, and the heating coil will stop working. If the urea tank status is judged to be "suspected frozen" or "frozen", the urea tank will enter the thawing state, and the heating coil will be controlled to heat.

[0036] In another aspect, the present invention provides a vehicle comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described urea tank defrosting control method.

[0037] In another aspect, the present invention provides a computer-readable storage medium storing a computer program that, when executed, implements the above-described urea tank thawing control method.

[0038] In summary, the urea tank defrosting control method and apparatus provided by this invention integrates initial information such as urea tank level, urea tank concentration, ambient temperature, urea tank temperature, and vehicle speed to form an accurate urea tank defrosting strategy. Based on the initial information, the urea tank status is determined sequentially according to the first, second, and third determination conditions. Furthermore, based on continuously updated ECU information, a fourth, fifth, and sixth determination condition are set, and these conditions are determined sequentially to confirm the urea tank status. For urea tanks using ultrasonic features, this significantly improves the rationality of defrosting entry and exit control, solving the problem of premature urea tank exiting defrosting under specific operating conditions, thus improving vehicle quality and customer satisfaction. When the ambient or urea tank temperature has not reached the crystallization temperature, the auxiliary judgment based on the urea tank level can be performed when the urea is in a completely liquid state, without needing to enter the defrosting state, achieving more rational defrosting control. The technical solution of this invention can accurately identify the urea tank status and control its timely entry and exit from the defrosting procedure. Attached Figure Description

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0040] Figure 1 This is a schematic diagram of the first process of the urea tank thawing control method provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the second process of the urea tank thawing control method provided in an embodiment of the present invention. Detailed Implementation

[0042] Embodiments of the present invention 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 the present invention, and should not be construed as limiting the present invention.

[0043] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in sequences other than those illustrated or described herein.

[0044] In existing technologies, the ECU information relied upon for determining whether to enter or exit the urea tank defrosting procedure mainly consists of urea tank temperature and ambient temperature. This leads to a rapid rise in urea temperature near the heating coil in vehicles in Xinjiang or extremely cold regions, especially under conditions of prolonged idling and rapid increases in ambient temperature. At this time, the temperature around the urea tank temperature measuring point rises rapidly but is insufficient to reflect the overall urea tank temperature and melting state. Furthermore, the ambient temperature is significantly affected by engine heat radiation or heated / cold storage environments, further reducing its reliability. This results in the urea tank prematurely exiting the defrosting procedure, and coupled with urea injection consumption, greatly increases the risk of cavity errors. This invention integrates key signals such as urea tank level, urea concentration, ambient temperature, urea tank temperature, and vehicle speed to form a new urea tank defrosting strategy. For urea tanks using ultrasonic features, this significantly improves the control rationality of defrosting entry and exit, solving the problem of premature urea tank de-freezing under specific operating conditions, thereby improving vehicle quality and customer satisfaction.

[0045] This invention proposes an embodiment of a urea tank thawing control method, specifically, as follows: Figure 1 As shown, it includes the following steps:

[0046] The system acquires initial information from sensors and the ECU storage unit. This initial information includes engine status (St_eng), urea concentration status (St_conc_tank), urea tank temperature (T_tank), ambient temperature (T_envt), vehicle speed (V_veh), and urea tank level. Engine status is determined based on engine speed and timing signal sensors, and includes "Ready," "Cranking," and "Running" states. Urea concentration status is categorized based on the number of ultrasonic feedback signals received per unit time, specifically: 0 - icing and unreadable, 1 - empty tank with no signal, and 2 - readable signal. Urea tank temperature is the value measured by the urea tank temperature sensor. Ambient temperature is the value measured by the ambient temperature sensor. Urea tank level information includes ELvl_len and Lvl_tank values. ELvl_len is the remaining urea tank level, which is continuously calculated, updated, and stored in the ECU storage unit, and read upon power-on. Lvl_tank is the real-time value read from the urea tank level sensor.

[0047] Additionally, the initial information includes: Flg_defReq, Flg_coldStrt_Dnox, T_SCR_B, and T_eng; where Flg_defReq represents the flag bit for continuing to defrost after a single defrost command fails to build pressure; Flg_coldStrt_Dnox represents the flag bit for cold start of the DNOx system, generally defined as being set to 1 if the vehicle has been off for more than 8 hours. The DNOx system, as part of the vehicle's exhaust aftertreatment system, is used to control the amount of nitrogen oxides (NOx) emitted in the vehicle's exhaust; T_SCR_B represents the temperature sensor value before the aftertreatment SCR system, used as a key input for determining the establishment of pressure injection control by the DNOX system; and T_eng represents the engine coolant temperature sensor value, used as a key input for determining engine cold start, configured so that when the deviation between the engine coolant temperature, the temperature value before the SCR, and the ambient temperature sensor value is less than 5°C, the engine is determined to be in a cold start state.

[0048] Based on the initial information, the urea tank status is determined sequentially according to the first, second, and third determination conditions. If the urea tank status is determined to be "not frozen", the urea tank will not enter or exit the thawing process, and the heating coil will be controlled to stop working. If the urea tank status St_tank is determined to be "suspected frozen" or "frozen", the urea tank will enter the thawing process, and the heating coil will be controlled to heat.

[0049] In this embodiment of the invention, the steps of determining the urea tank status St_tank sequentially based on initial information and according to the first determination condition, the second determination condition, and the third determination condition include:

[0050] The first judgment condition includes sub-condition A and sub-condition B. If sub-condition A or sub-condition B is satisfied, the urea tank status St_tank is determined to be "unfrozen"; otherwise, the second judgment condition is judged.

[0051] The second judgment condition includes sub-condition C and sub-condition D. If sub-condition C or sub-condition D is satisfied, the urea tank state St_tank is determined to enter "freeze"; otherwise, the third judgment condition is judged.

[0052] The third judgment condition includes sub-condition E. If sub-condition E is satisfied, the urea tank status St_tank is judged to enter "suspected frozen"; otherwise, the urea tank status St_tank is judged to enter "unfrozen".

[0053] In this embodiment of the invention, sub-conditions A, B, C, D, and E are respectively:

[0054] Sub-condition A: The urea concentration status St_conc_tank is in readable state 2, the urea tank level is higher than the calibration threshold, and the cold start flag Flg_coldStrt_Dnox is in cold start state 1. The calibration threshold for the urea tank level can be configured as follows: for example, if the full tank level of the urea tank is 210mm, the calibration threshold can be defined as a level of 200mm to ensure that the urea tank is in a fully melted state.

[0055] Subcondition B: The cold start flag Flg_coldStrt_Dnox is in cold start state, and the urea tank temperature exceeds the first temperature threshold, and the ambient temperature exceeds the second temperature threshold. Specifically, the first temperature threshold is configured to 2℃, and the second temperature threshold is configured to 2℃.

[0056] Sub-condition C: The urea tank temperature T_tank is less than the third temperature threshold, specifically, the third temperature threshold is configured to -9.5℃;

[0057] Sub-condition D: When the real-time urea tank level Lvl_tank is less than or equal to the negative correction value of the remaining urea tank level ELvl_len, the urea tank temperature T_tank is less than or equal to the fourth temperature threshold or the current cold start flag is in a non-cold start state. Specifically, to improve the robustness of operation, the negative correction is generally small, for example, 5-10 mm, the fourth temperature threshold is configured to -7℃, and the current cold start flag Flg_coldStrt_Dnox is in a non-cold start state, that is, the current cycle is not set to 1.

[0058] Sub-condition E: The urea concentration status St_conc_tank is in a state of being frozen and cannot be read (0) or empty and has no signal (1), and the remaining urea tank level ELvl_len is higher than the dead level threshold, and the urea tank temperature T_tank is lower than the first temperature threshold. Specifically, in order to prevent dry heating, the dead level threshold can be configured to 30mm; the first temperature threshold is configured to 2℃.

[0059] In this embodiment of the invention, the step of obtaining the initial information of the sensor and ECU storage unit is followed by:

[0060] During vehicle cold start, after the urea tank cold start flag Flg_coldStrt_Dnox is set to 1, the ECU diagnoses faults in the sensor signals required by the urea injection system. The urea tank status St_tank is configured to determine the status only if there are no hardware faults in the relevant sensors; otherwise, it reports the corresponding fault to guide the user to repair it promptly.

[0061] Figure 2As shown, in this embodiment of the invention, when the vehicle is in operation, a fourth, fifth, and sixth determination condition are set based on continuously updated ECU information, and the fourth, fifth, and sixth determination conditions are judged sequentially to confirm the urea tank status St_tank.

[0062] In this embodiment of the invention, the fourth determination condition includes sub-condition F. If sub-condition F is satisfied, the urea tank state St_tank is determined to enter "Frozen Frz"; otherwise, the fifth determination condition is determined.

[0063] The fifth judgment condition includes sub-conditions G and H. If the current urea tank status St_tank is not in the "Frozen Frz" state and sub-condition G or sub-condition H is met, then the urea tank is judged to have entered the "Suspected Frozen FrzSus" state; otherwise, the sixth judgment condition is judged.

[0064] The sixth determination condition includes sub-condition I, sub-condition J, and sub-condition K. If sub-condition I, sub-condition J, or sub-condition K is satisfied, the urea tank is determined to enter the "NotFrz" state.

[0065] In this embodiment of the invention, sub-condition F, sub-condition G, sub-condition H, sub-condition I, sub-condition J, and sub-condition K are respectively:

[0066] Subcondition F: The urea tank temperature T_tank is less than the fourth temperature threshold and remains so for a first time duration. Specifically, the fourth temperature threshold is configured to be -7℃ and the first time duration is configured to be 1800S.

[0067] Sub-condition G: The urea tank temperature T_tank is less than the first temperature threshold, and the urea concentration status St_conc_tank is in a state of being frozen and cannot be read (0) or empty and has no signal (1), and the remaining urea tank liquid level ELvl_len is higher than the urea tank dead liquid level threshold, and this condition persists for a second time length. Specifically, the first temperature threshold is configured to be 2℃, the urea tank dead liquid level threshold is configured to be 30mm, and the second time length is configured to be greater than or equal to 1min.

[0068] Subcondition H: If the single decompression command Flg_defReq fails to build up pressure, the decompression process continues, and Flg_defReq is set to 1 after the decompression process continues;

[0069] Sub-condition I: The current urea tank status St_tank is in "Frozen Frz" or "Suspected Frozen FrzSus", and the urea tank temperature T_tank is greater than the first temperature threshold, and the vehicle speed V_veh is higher than the first vehicle speed threshold for at least the third time length, and the real-time urea tank level Lvl_tank is greater than the negative correction value of the remaining urea tank level ELvl_len. When all the conditions in sub-condition I are met, the condition is maintained for at least the fourth time length. Specifically, the first temperature threshold is configured as 2℃, the first vehicle speed threshold is configured as 5km / h, the third time length is configured as 2min, and the fourth time length is configured as 10s.

[0070] Subcondition J: The current urea tank status St_tank is "NotFrz", the urea tank temperature is less than the fourth temperature threshold, and the ambient temperature is less than 0℃. If all conditions of subcondition J are met, continue to maintain the status for at least the fifth time length. Specifically, the fourth temperature threshold is configured to -7℃, and the fifth time length is configured to 30s.

[0071] Sub-condition K: The current urea tank status St_tank is in "Frozen Frz" or "Suspected Frozen FrzSus", and the real-time urea tank level reaches the calibration threshold. The various states of sub-condition K shall continue to be maintained for no less than the sixth time length. Specifically, the calibration threshold for the urea tank level here can be configured as follows: for example, if the full tank level of the urea tank is 210mm, the calibration threshold can be defined as a level of 200mm to ensure that the urea tank is in a fully thawed state. The sixth time length is configured as 1800s.

[0072] The urea tank defrosting control method provided in this invention, by setting multiple judgment conditions, can more accurately determine whether the urea tank needs to be defrosted, as well as the timing and extent of defrosting. This avoids defrosting too early or too late, ensuring that the urea tank can be defrosted promptly and effectively when needed. Furthermore, it can better adapt to changes in different environmental conditions, ensuring optimal defrosting results under various circumstances.

[0073] The urea tank defrosting control method provided by this invention integrates initial information such as urea tank level, urea tank concentration, ambient temperature, urea tank temperature, and vehicle speed to form an accurate urea tank defrosting strategy. Based on the initial information, the urea tank status is determined sequentially according to a first, second, and third determination condition. Furthermore, based on continuously updated ECU information, a fourth, fifth, and sixth determination condition are set to confirm the urea tank status. This significantly improves the rationality of urea tank defrosting entry and exit control, enabling the temperature inside the urea tank to be increased as needed, effectively preventing urea solution from freezing, and ensuring the urea injection system can operate continuously and stably in cold weather, thereby maintaining the normal operation of the vehicle.

[0074] In another embodiment of the present invention, a method for controlling the defrosting of a urea tank is provided, specifically including the following steps:

[0075] 1. When the vehicle is cold-started, after the cold start flag Flg_coldStrt_Dnox of the Dnox system in the urea tank is set to 1, the ECU does not diagnose any faults related to the sensor signals required by the DNOx system.

[0076] 2. After successful diagnosis, based on the sensor signals after ECU initialization: ambient temperature sensor value T_envt is -18℃, urea tank temperature sensor value T_tank is -11℃, urea concentration status St_conc_tank is 0, engine status St_eng is running, Dnox system cold start flag Flg_coldStrt_Dnox is set to 1, real-time urea tank level sensor value Lvl_tank is 82mm, and remaining urea tank level ELvl_len is 150mm;

[0077] 3. Based on the above information, the satisfaction of the first judgment condition, the second judgment condition and the third judgment condition are judged one by one. In this embodiment, the second judgment condition is judged to be satisfied, and the initial urea tank state St_tank is obtained as "Frozen Frz".

[0078] 4. The vehicle continuously operates and collects continuously updated sensor signals, monitoring the satisfaction of the fourth, fifth, and sixth judgment conditions. At 1800 seconds, the ambient temperature sensor value T_envt is -16℃, the urea tank temperature sensor value T_tank is -9℃, the real-time urea tank level sensor value Lvl_tank is 85mm, the remaining urea tank level ELvl_len is 150mm, the urea tank status St_tank is frozen (Frz), the urea concentration status St_conc_tank is icy and cannot be read (0), the vehicle speed V_veh is 40km / h, and the flag Flg_defReq for continuing thawing is set to 1 if a single thawing command fails to build pressure. Based on the above conditions, if the fourth judgment condition is met, the urea tank status St_tank will remain frozen (Frz). After 3.2 hours, the above sensor signals are updated as follows: ambient temperature sensor value T_envt: -10℃, urea tank temperature sensor value T_tank: 2.1℃, real-time urea tank level sensor value Lvl_tank: 145mm, remaining urea tank level ELvl_len: 146mm, urea tank status St_tank: Frz, urea concentration status St_conc_tank: 2, vehicle speed V_veh: 90km / h, and the flag Flg_defReq for continuing thawing after a single thawing command fails to build pressure: 0. At this time, sub-condition I in the sixth judgment condition is met, so the urea tank status St_tank changes to unfrozen NotFrz, and the urea tank thawing process ends.

[0079] In the urea tank thawing control method provided in this embodiment of the invention, when the ambient temperature or the urea tank temperature has not reached the crystallization temperature, auxiliary judgment based on liquid level and concentration can determine that the urea is in a completely liquid state without needing to enter the thawing state. Specifically, assuming that the current ambient temperature sensor value T_envt and the urea tank temperature sensor value T_tank are both -9℃, which has not reached the urea crystallization temperature, and Flg_coldStrt_Dnox is set to 1, indicating that the current urea system is in a cold start, and the real-time read urea tank liquid level sensor value Lvl_tank and the remaining urea tank liquid level ELvl_len are both 150mm. At this time, the sub-conditions C and D of the second judgment condition are not satisfied. Combined with the sub-condition E of the third judgment condition, the urea concentration status St_conc_tank is determined to be in a readable state. Therefore, it can be determined that the current urea tank is in a completely melted state without needing to enter the thawing procedure, thus achieving more reasonable thawing control.

[0080] Another embodiment of the present invention provides a urea tank defrosting control device, comprising:

[0081] The acquisition unit is used to acquire initial information from sensors and the ECU storage unit. The initial information includes engine status, urea concentration status, urea tank temperature, ambient temperature, vehicle speed, and urea tank level. The sensors include crankshaft position sensor, urea concentration sensor, urea tank temperature sensor, ambient temperature sensor, vehicle speed sensor, and urea tank level sensor. The crankshaft position sensor is used to detect the engine speed and crankshaft position to determine the engine's operating status.

[0082] The judgment control unit, based on initial information, sequentially judges the urea tank status according to the first, second, and third judgment conditions. If the urea tank status is determined to be "unfrozen," the urea tank does not enter or exits the thawing process, and the heating coil stops working. If the urea tank status is determined to be "suspected frozen" or "frozen," the urea tank enters the thawing state, and the heating coil is controlled to heat. Specifically, the judgment control unit includes a judgment module and a control module. The judgment module sequentially judges the urea tank status according to the first, second, and third judgment conditions based on the initial information. The control module controls the urea tank to enter or exit the thawing process based on the judged urea tank status.

[0083] Another embodiment of the present invention provides a vehicle, the vehicle including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the urea tank defrosting control method described above. The multiple determination conditions in the embodiments of the present invention ensure the accurate execution of the urea tank defrosting procedure, reducing vehicle performance degradation or emission problems caused by misjudgment or delayed defrosting, and helping to improve the user's driving experience and satisfaction with vehicle performance.

[0084] Another embodiment of the present invention also provides a computer-readable storage medium storing a computer program that, when executed, implements the above-described urea tank thawing control method.

[0085] The urea tank defrosting control method and apparatus provided by this invention integrates initial information such as urea tank level, urea tank concentration, ambient temperature, urea tank temperature, and vehicle speed to form an accurate urea tank defrosting strategy. Based on the initial information, the urea tank status is determined sequentially according to a first, second, and third determination condition. Furthermore, based on continuously updated ECU information, a fourth, fifth, and sixth determination condition are set, and these conditions are determined sequentially to confirm the urea tank status. For urea tanks using ultrasonic features, this significantly improves the rationality of defrosting entry and exit control, solving the problem of premature urea tank exiting defrosting under specific operating conditions, thus improving vehicle quality and customer satisfaction. When the ambient or urea tank temperature has not reached the crystallization temperature, the auxiliary judgment based on the urea tank level can be performed when the urea is in a completely liquid state, without needing to enter the defrosting state, achieving more rational defrosting control. The technical solution of this invention can accurately identify the urea tank status and control its timely entry and exit from the defrosting procedure.

[0086] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A method for controlling the thawing of a urea tank, characterized in that, Includes the following steps: Acquire initial information from the sensors and ECU storage unit, wherein the initial information includes engine status, urea concentration status, urea tank temperature, ambient temperature, vehicle speed, and urea tank level information; Based on the initial information, the urea tank status is judged sequentially according to the first judgment condition, the second judgment condition and the third judgment condition. If the urea tank status is judged to be "not frozen", the urea tank will not enter or exit the thawing process and the heating coil will be controlled to stop working. If the urea tank status is judged to be "suspected frozen" or "frozen", the urea tank will enter the thawing process and the heating coil will be controlled to heat. The specific steps for determining the status of the urea tank include: The first determination condition includes sub-condition A and sub-condition B. If sub-condition A or sub-condition B is satisfied, the urea tank status is determined to be "unfrozen"; otherwise, the second determination condition is determined. The second determination condition includes sub-condition C and sub-condition D. If sub-condition C or sub-condition D is satisfied, the urea tank status is determined to be "frozen"; otherwise, the third determination condition is determined. The third determination condition includes sub-condition E. If sub-condition E is met, the urea tank status is determined to be "suspected frozen"; otherwise, the urea tank status is determined to be "unfrozen". Wherein, sub-condition A, sub-condition B, sub-condition C, sub-condition D and sub-condition E are respectively: Sub-condition A: The urea concentration status is readable, the urea tank level is higher than the calibration threshold, and the cold start flag is in the cold start state; Subcondition B: The cold start flag is in cold start mode, and the urea tank temperature exceeds the first temperature threshold, and the ambient temperature exceeds the second temperature threshold. Sub-condition C: The temperature of the urea tank is less than the third temperature threshold; Sub-condition D: When the real-time urea tank level is less than or equal to the negative correction value of the remaining urea tank level, the urea tank temperature is less than or equal to the fourth temperature threshold or the current cold start flag is in a non-cold start state. Sub-condition E: The urea concentration is frozen and cannot be read, or the tank is empty and there is no signal, and the remaining urea tank level is higher than the dead level threshold, and the urea tank temperature is lower than the first temperature threshold.

2. The urea tank thawing control method according to claim 1, characterized in that, The steps preceding the acquisition of initial information from the sensors and ECU storage units also include: During the vehicle cold start process, after the urea tank cold start flag is set to 1, the ECU diagnoses the faults in the sensor signals required by the urea injection system.

3. The urea tank thawing control method according to claim 1, characterized in that, Once the vehicle is in operation, based on continuously updated ECU information, the fourth, fifth, and sixth judgment conditions are set, and the fourth, fifth, and sixth judgment conditions are judged one by one to confirm the status of the urea tank. The fourth determination condition includes sub-condition F. If sub-condition F is satisfied, the urea tank status is determined to be "frozen"; otherwise, the fifth determination condition is determined. The fifth determination condition includes sub-condition G and sub-condition H. If the current urea tank status is not in the "frozen" state and sub-condition G or sub-condition H is met, then the urea tank is determined to have entered the "suspected frozen" state; otherwise, the sixth determination condition is applied. The sixth determination condition includes sub-condition I, sub-condition J, and sub-condition K. If sub-condition I, sub-condition J, or sub-condition K is satisfied, the urea tank is determined to be in an "unfrozen" state. Wherein, the sub-conditions F, G, H, I, J, and K are respectively: Subcondition F: The temperature of the urea tank is less than the fourth temperature threshold and remains so for the first time duration; Sub-condition G: The temperature of the urea tank is less than the first temperature threshold, and the urea concentration is frozen and cannot be read, or the tank is empty and has no signal, and the remaining urea tank liquid level is higher than the urea tank dead liquid level threshold, and this condition persists for the second time period. Subcondition H: If a single unfreeze command fails to build up compression, the unfreeze process continues. Sub-condition I: The current urea tank status is "frozen" or "suspected frozen", and the urea tank temperature is greater than the first temperature threshold, and the vehicle speed is higher than the first vehicle speed threshold for at least the third time length, and the real-time urea tank liquid level is greater than the negative correction value of the remaining urea tank liquid level. If all of the conditions in sub-condition I are met, continue to maintain the condition for at least the fourth time length. Subcondition J: The current urea tank status is "unfrozen", and the urea tank temperature is less than the fourth temperature threshold, and the ambient temperature is less than 0°C. If all conditions of subcondition J are met, continue to maintain the status for at least the fifth time period. Sub-condition K: The current urea tank status is "frozen" or "suspected frozen", and the real-time urea tank level reaches the calibrated threshold. All states of sub-condition K shall remain unchanged for at least the sixth time period.

4. A vehicle, characterized in that, The vehicle includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the urea tank defrosting control method as described in any one of claims 1-3.

5. A computer-readable storage medium, characterized in that, A computer-readable storage medium stores a computer program that, when executed, implements the urea tank defrosting control method as described in any one of claims 1-3.

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