A water temperature control method and device based on power demand for a hybrid vehicle

Abstract

The application discloses a water temperature control method and device based on power demand for a hybrid vehicle, and belongs to the technical field of engine control. The method comprises the following steps: judging the engine power demand condition, updating the weighted parameters based on different air quantities, and performing weighted control on the target water temperature based on different air quantities. When the engine power demand is large, but the engine does not appear to be knocking and there is no risk of early combustion, the target water temperature is optimized based on the dynamic air quantity. At the same time, after adjustment, the weighting coefficient of the target water temperature optimization is learned and updated in real time according to the working condition, so that the torque in the hybrid vehicle is more accurately achieved and the engine is protected. The water temperature control optimization can be performed when the engine power demand is large, that is, the power demand mode is entered, so as to improve the engine power.

Description

Technical Field

[0001] This invention belongs to the field of engine control technology, and more specifically, relates to a method and device for controlling water temperature in hybrid vehicles based on power demand. Background Technology

[0002] Hybrid vehicles require high precision in engine power output to achieve optimal fuel economy and power performance. Engine coolant temperature plays a crucial role in both fuel economy and power output.

[0003] Referring to patent application CN103758629A, a method for protecting engine coolant temperature at high temperatures is disclosed, which reduces output power by controlling the current of the torque solenoid valve, thereby lowering the coolant temperature. However, this method does not consider coolant temperature optimization for the engine's power requirements in hybrid vehicles.

[0004] Referring to patent application CN115167565A, a temperature control device, method, and apparatus are disclosed. This device includes a detection module, a control module, and an adjustment module. The detection module detects the outlet water temperature of the cooling water pump; the control module compares the outlet water temperature with a preset temperature threshold and outputs a control signal to the adjustment module based on the comparison result; the adjustment module is located at the outlet of the cooling water pump and adjusts the outlet water temperature according to the received control signal. By using an adjustment module at the outlet of the cooling water pump to assist in adjusting the outlet water temperature, the outlet water temperature of the cooling water pump can be controlled more accurately, enhancing the working effect of the cooling circulation system and thus improving the engine's efficiency and safety. However, this method does not consider the water temperature optimization required for engine power in hybrid vehicles. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention proposes a water temperature control method and device for hybrid vehicles based on power demand. When the demand for engine power is large, water temperature control is optimized, that is, the power demand mode is entered to improve engine power.

[0006] To achieve the above objectives, according to one aspect of the present invention, a water temperature control method for hybrid vehicles based on power demand is provided, comprising:

[0007] Determine whether the requested torque of the engine is not less than the maximum torque of the engine multiplied by a preset coefficient, whether the requested torque of the engine has increased, whether there is no high-intensity knocking or pre-ignition, whether the octane rating is not less than the preset octane rating, whether the actual engine coolant temperature exceeds the preset coolant temperature, and whether the change in atmospheric pressure of the vehicle during this driving cycle is less than the preset atmospheric pressure value.

[0008] If the requested engine torque is not less than the maximum engine torque multiplied by a preset coefficient, the requested engine torque increases, no high-intensity knocking or pre-ignition occurs, the octane rating is not less than the preset octane rating, the actual engine coolant temperature exceeds the preset coolant temperature, and the atmospheric pressure change of the vehicle during this driving cycle is less than the preset atmospheric pressure value and the duration exceeds the preset time, then the power demand mode is entered. The actual air volume, the first target air volume, the second target air volume, the third target air volume, the maximum air volume, the specific air volume, and the target coolant temperature determined by looking up the table according to the target coolant temperature I are read in real time. The table in the table refers to the target coolant temperature I setting table.

[0009] The final target water temperature is obtained by looking up the target water temperature I in a table based on the actual gas volume, the first target gas volume, the second target gas volume, the third target gas volume, the maximum gas volume, and the specific gas volume.

[0010] In some alternative implementations, the target water temperature is determined by looking up a table based on the target water temperature I, including:

[0011] If the data on the horizontal and vertical axes do not fall within the table, including the middle and outside of the table, then the values ​​are determined by adjacent linear interpolation. If the values ​​are in the middle of the table, that is, within the minimum and maximum values ​​of the table's coordinate axes, then linear interpolation is used. If the values ​​are outside the table, that is, outside the minimum and maximum values ​​of the table's coordinate axes, then the values ​​are directly equal to the edge values.

[0012] In some alternative implementations, the actual air volume refers to the actual fresh air intake density entering the cylinder, which is also the engine load, and the target water temperature determined by looking up a table is the target water temperature a.

[0013] The first target air volume is the target air volume under the current sampling period, which refers to the fresh air intake density requested to enter the cylinder, and the corresponding target water temperature determined by looking up the table is the target water temperature b;

[0014] The second target gas volume refers to the target gas volume in the next sampling period, which is obtained by the first target gas volume + the first target gas volume change rate * sampling time, and the corresponding target water temperature determined by looking up the table is the target water temperature c;

[0015] The third target gas volume is obtained by the first target gas volume + ignition efficiency * sampling time, and the target water temperature determined by the table is the target water temperature d.

[0016] The maximum air volume represents the maximum allowable intake air density of the engine during this sampling period, and the target water temperature determined by looking up the table is the target water temperature e.

[0017] The specific gas volume refers to the gas volume on the gas volume axis of the target water temperature I setting table that is closest to and greater than the actual gas volume in the current period. The target water temperature f is determined by looking up the table.

[0018] In some alternative implementations, the final target water temperature is obtained by the combination of target water temperature a*k1 + target water temperature b*k2 + target water temperature c*k3 + target water temperature d*k4 + target water temperature e*k5 + target water temperature f*k6, where k1 + k2 + k3 + k4 + k5 + k6 = 1, and k2 depends on the target air volume change rate and engine speed. The smaller the engine speed but the larger the target air volume change rate, the larger k2 is.

[0019] In some optional implementations, the method further includes updating the weighting coefficients:

[0020] If the number of times the power demand mode is entered exceeds the preset number, the engine torque response accuracy can be guaranteed, and the power demand mode is not exited due to high-intensity knocking or pre-ignition after entering the power demand mode, then k2 is taken as the first multiple before the update, and k2 is saved after the vehicle is powered off.

[0021] If the number of times the power demand mode is entered exceeds the preset number, and the engine torque response accuracy is not consistently guaranteed, and the power demand mode is not exited due to high-intensity knocking or pre-ignition after entering the power demand mode, then k2 is taken as the second multiple of the previous value, and k2 is saved after the vehicle is powered off.

[0022] If the number of times the power demand mode is entered exceeds the preset number, the engine torque response accuracy cannot be guaranteed, and the power demand mode is exited due to high-intensity knocking or pre-ignition after entering the power demand mode, then k2 is the third multiple of the previous value, and k2 is saved after the vehicle is powered off.

[0023] The values ​​of the first, second, and third multiples increase sequentially.

[0024] According to another aspect of the present invention, a water temperature control device for a hybrid vehicle based on power demand is provided, comprising:

[0025] The trigger judgment module is used to determine whether the engine's requested firing torque is not less than the engine's maximum torque multiplied by a preset coefficient, whether the engine's requested firing torque has increased, whether high-intensity knocking or pre-ignition has occurred, whether the octane rating is not less than the preset octane rating, whether the engine's actual coolant temperature exceeds the preset coolant temperature, and whether the change in atmospheric pressure of the vehicle during this driving cycle is less than the preset atmospheric pressure value.

[0026] The trigger execution module is used to enter the power demand mode if the engine's requested firing torque is not less than the engine's maximum torque multiplied by a preset coefficient, the engine's requested firing torque increases, no high-intensity knocking or pre-ignition occurs, the octane rating is not less than the preset octane rating, the engine's actual coolant temperature exceeds the preset coolant temperature, and the vehicle's atmospheric pressure change during the current driving cycle is less than the preset atmospheric pressure value and the duration exceeds the preset time. In this mode, the module reads the actual air volume, the first target air volume, the second target air volume, the third target air volume, the maximum air volume, the specific air volume, and the target coolant temperature determined by looking up the table according to the target coolant temperature I. The table in the table refers to the target coolant temperature I setting table.

[0027] The water temperature control module is used to obtain the final target water temperature by looking up the target water temperature I from the actual gas volume, the first target gas volume, the second target gas volume, the third target gas volume, the maximum gas volume, and the specific gas volume.

[0028] In some alternative implementations, the triggering execution module is configured to determine, if the data on the horizontal and vertical axes do not fall within the table (including the middle and outside of the table), by means of adjacent linear interpolation; if the data is in the middle of the table (i.e., the value is within the minimum and maximum values ​​of the table's coordinate axes), by means of linear interpolation; and if the data is outside the table (i.e., the value is not within the minimum and maximum values ​​of the table's coordinate axes), by means of linear interpolation, directly equal to the edge value.

[0029] In some alternative implementations, the actual air volume refers to the actual fresh air intake density entering the cylinder, which is also the engine load, and the target water temperature determined by looking up a table is the target water temperature a.

[0030] The first target air volume is the target air volume under the current sampling period, which refers to the fresh air intake density requested to enter the cylinder, and the corresponding target water temperature determined by looking up the table is the target water temperature b;

[0031] The second target gas volume refers to the target gas volume in the next sampling period, which is obtained by the first target gas volume + the first target gas volume change rate * sampling time, and the corresponding target water temperature determined by looking up the table is the target water temperature c;

[0032] The third target gas volume is obtained by the first target gas volume + ignition efficiency * sampling time, and the target water temperature determined by the table is the target water temperature d.

[0033] The maximum air volume represents the maximum allowable intake air density of the engine during this sampling period, and the target water temperature determined by looking up the table is the target water temperature e.

[0034] The specific gas volume refers to the gas volume on the gas volume axis of the target water temperature I setting table that is closest to and greater than the actual gas volume in the current period. The target water temperature f is determined by looking up the table.

[0035] In some alternative implementations, the final target water temperature is obtained by the combination of target water temperature a*k1 + target water temperature b*k2 + target water temperature c*k3 + target water temperature d*k4 + target water temperature e*k5 + target water temperature f*k6, where k1 + k2 + k3 + k4 + k5 + k6 = 1, and k2 depends on the target air volume change rate and engine speed. The smaller the engine speed but the larger the target air volume change rate, the larger k2 is.

[0036] In some alternative embodiments, the apparatus further includes:

[0037] The update module is used to ensure that if the engine torque response accuracy is maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the first multiple of the previous value, and k2 is saved after the vehicle is powered off. If the engine torque response accuracy is not maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the second multiple of the previous value, and k2 is saved after the vehicle is powered off. If the engine torque response accuracy is not maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the third multiple of the previous value, and k2 is saved after the vehicle is powered off.

[0038] The values ​​of the first, second, and third multiples increase sequentially.

[0039] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0040] This invention uses a method that judges engine power demand conditions, updates weighted parameters based on different gas volumes, and controls target coolant temperature based on different gas volumes. When the engine power demand is high but the engine does not experience knocking or pre-ignition, the target coolant temperature is optimized based on dynamic gas volume. At the same time, after adjustment, the weighted coefficients of the target coolant temperature optimization are learned and updated in real time according to the operating conditions, thereby more accurately achieving torque and engine protection in hybrid vehicles. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of a water temperature control method for hybrid vehicles based on power demand, provided by an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of a water temperature control device for a hybrid vehicle based on power demand, provided in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0044] In the embodiments of the present invention, "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or sequence.

[0045] The conventional method for setting the target coolant temperature is as follows: The target coolant temperature I is determined based on the engine speed and the actual air volume (actual air volume refers to the actual fresh air intake density, and actual fresh air intake density refers to the actual fresh air density entering the cylinder). This target coolant temperature I is obtained through optimal calibration on an engine test bench, based on a trade-off between fuel economy and emissions. Based on this, the target coolant temperature I setting data for this example is shown in Table 1 below:

[0046] Table 1

[0047]

[0048] like Figure 1 As shown, a water temperature control method for hybrid vehicles based on power demand according to the present invention mainly includes: determining the triggering conditions of the power demand mode, setting the target water temperature based on different gas volumes, updating the weighting coefficients of each water temperature based on the operating performance, and re-weighting based on the new weighting coefficients to obtain a new target water temperature. The specific implementation of each step is described below:

[0049] (1) Determine the triggering conditions for dynamic demand patterns:

[0050] 1. The engine requests a spark torque that is not less than the engine's maximum torque (where the engine's maximum torque can be found in patent application CN202010632793.4, "Method for Determining the Maximum Output Torque of a Gasoline Engine") multiplied by a preset coefficient r1. This preset coefficient r1 is related to engine speed and ignition efficiency. At a given engine speed, a higher current ignition efficiency indicates that it is more difficult for the engine to increase torque through spark torque adjustment (i.e., ignition efficiency). In this case, coolant temperature optimization is more necessary to improve torque achievement. Therefore, the higher the ignition efficiency, the smaller the preset coefficient r1. (See Table 2.)

[0051] Table 2

[0052]

[0053] The calibration result is that the torque response accuracy is within ±5Nm under dynamic operating conditions with different ignition efficiencies.

[0054] 2. The engine requests an increase in the firing torque, i.e., the torque change rate dM SprkReq The value is greater than the preset value A, where the preset value A depends on the throttle opening change rate and engine speed. At different engine speeds, the greater the throttle opening change rate, the stronger the demand for power, and the smaller the preset value A. The preset value A is obtained by adjusting different throttle openings at different engine speeds. The calibration effect is that the torque response accuracy (the difference between the requested firing torque and the actual firing torque) of the engine under dynamic operating conditions is within ±5 Nm. The calibration data for this example is shown in Table 3 below:

[0055] Table 3

[0056]

[0057]

[0058] 3. No high-intensity detonation occurred (in this example, high-intensity is defined as a delay in ignition angle exceeding 4° after detonation) and no pre-ignition occurred;

[0059] 4. Octane number coefficient (refer to the octane number r of oil products mentioned in patent application CN202010608134.7 "A method and system for self-learning octane number of oil products"). OctaneRatio (With the same physical meaning and calculation method) not less than the octane rating (in this example, it can be -0.2). The smaller the octane rating, the greater the possibility of engine knocking. In this case, power demand needs to be limited to protect the engine.

[0060] 5. The actual engine coolant temperature exceeds the preset coolant temperature (0℃ in this example); if the engine coolant temperature is too low, the engine needs to warm up and cannot achieve rapid power response.

[0061] 6. The atmospheric pressure change of the vehicle during this driving cycle is less than the preset atmospheric pressure value. In this example, ±1 kPa can be used.

[0062] Only after all six conditions above are met simultaneously, and the duration of these conditions exceeds the preset time t0 (3 seconds in this example), is activation of the power demand mode permitted. Upon entering power demand mode, the following gas volumes and their respective target water temperatures, determined by referring to Table 1 based on the target water temperature I, are read in real time. (Table lookup method: If the data on the horizontal and vertical axes do not fall within the table (including the middle and outside the table), they are determined using adjacent linear interpolation. Values ​​within the middle of the table (i.e., values ​​within the minimum and maximum range of the table's coordinate axes) are interpolated linearly; values ​​outside the table (i.e., values ​​not within the minimum and maximum range of the table's coordinate axes) are directly equal to the edge value.)

[0063] 1. Actual air volume: Actual air volume refers to the actual density of fresh air entering the cylinder, which is also the engine load, i.e., the actual value of air volume; the target water temperature determined by referring to the table is the target water temperature a.

[0064] 2. The first target air volume, in the current sampling period, refers to the density of fresh air requested to enter the cylinder, i.e., the target value of the air volume. The power demand mode control method calculates this every 10ms, and 10ms constitutes one sampling period. The method for obtaining the target air volume can be found in patent application CN202210330714.3, "Target Intake Air Density Control Method, Device, Equipment and Readable Storage Medium". The target water temperature determined by looking up the table is the target water temperature b.

[0065] 3. The second target gas volume refers to the target gas volume in the next sampling period (the upcoming sampling period). It is obtained by adding the first target gas volume to the first target gas volume change rate and multiplying the sampling time. The corresponding target water temperature determined by looking up the table is the target water temperature c.

[0066] 4. The third target air volume is obtained by adding the first target air volume to the ignition efficiency and multiplying the sampling time. Based on patent application CN202010632793.4, "Method for Determining the Maximum Output Torque of a Gasoline Engine," it can be seen that ignition efficiency also affects the engine's airflow torque, thus affecting vehicle power. The corresponding target coolant temperature determined by looking up the table is the target coolant temperature d.

[0067] 5. Maximum air volume, i.e., the maximum allowable intake air density of the engine during this sampling period, is obtained by referring to the method described in patent application CN202111346615.6, "A Self-Learning Method, Device and Storage Medium for Maximum Air Volume of an Engine". The target water temperature determined by looking up the table is the target water temperature e.

[0068] 6. Specific gas volume: The specific gas volume refers to the gas volume on the gas volume axis of the target water temperature I setting table that is closest to and greater than the actual gas volume for the current period. The corresponding target water temperature determined by looking up the table is the target water temperature f.

[0069] (2) The target water temperature is set based on a weighted average of different gas volumes:

[0070] Based on the above, the target water temperature corresponding to the six gas volumes can be determined.

[0071] After the power demand mode is activated, the final target water temperature is: target water temperature a*k1 + target water temperature b*k2 + target water temperature c*k3 + target water temperature d*k4 + target water temperature e*k5 + target water temperature f*k6, where k1 + k2 + k3 + k4 + k5 + k6 = 1. Here, k2 depends on the target air volume change rate and engine speed. The smaller the engine speed but the larger the target air volume change rate, the larger k2 is, indicating a greater power demand to quickly achieve the target water temperature. In this example, the value of k2 is as follows, and it is updated and adjusted in real time during engine operation, as shown in Table 4:

[0072] Table 4

[0073]

[0074]

[0075] Where k1 takes the maximum value of (0.8-k2), 0; k3 takes the minimum value of (0.08, (1-k1-k2)); k4 takes the minimum value of (0.05, (1-k1-k2)); k5 takes the minimum value of (0.04, (1-k1-k2)); k6 takes the value of 1-(k1+k2+k3+k4+k5); k1, k2, k3, k4, k5, and k6 are all values ​​that are not less than 0 and not greater than 1.

[0076] (3) After entering the dynamic demand mode, perform the following operations:

[0077] 1) If the number of times the engine enters the power demand mode activation (the number is immediately reset to zero after each k2 update and starts to accumulate again after re-entering the power demand mode activation) exceeds the preset number (5000 in this example), and the engine torque response accuracy (the difference between the requested firing torque and the actual firing torque) is within ±5Nm, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition after entering the power demand mode activation, then k2 is taken as the first multiple of the previous value (a decrease in k2 increases the engine target water temperature, shortens the working time of the cooling system electronic control actuator, reduces the electrical load, and can further improve engine combustion efficiency and improve power output). The updated k2 will be used subsequently, and k2 is saved after the vehicle is powered off.

[0078] 2) If the number of times the engine enters the power demand mode activation (the number is immediately reset to zero after each k2 update and starts to accumulate again after re-entering the power demand mode activation) exceeds the preset number (5000 in this example), and the engine torque response accuracy (the difference between the requested firing torque and the actual firing torque) is not consistently guaranteed to be within ±5Nm, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition after entering the power demand mode activation, then k2 is taken as the second multiple of the previous value (increasing k2 makes the target coolant temperature more referential to the target air volume, thereby improving the achievement of the target air volume and torque). The updated k2 will be used subsequently, and k2 will be saved after the vehicle is powered off.

[0079] 3) If the number of times the engine enters the power demand mode activation (the count is immediately reset after each k2 update and starts accumulating again upon re-entering the power demand mode) exceeds the preset number (5000 in this example), and the engine torque response accuracy (the difference between the requested and actual firing torque) fails to consistently remain within ±5Nm, and the engine exits the power demand mode due to high-intensity knocking or pre-ignition after each activation, then k2 is increased to the third multiple of its original value. Increasing k2 references the target coolant temperature more closely to the target air volume, further lowering the target coolant temperature and thus protecting the engine and achieving the desired torque. In this case, the k2 update coefficient is larger than in the second case, aiming not only to improve engine torque but also to prevent high-intensity knocking or pre-ignition from recurring. The updated k2 is then used, and k2 is saved after the vehicle is powered off.

[0080] The values ​​of the first multiple, the second multiple, and the third multiple increase sequentially. In this embodiment of the invention, as an example, k1 can be 0.98, k2 can be 1.02, and k3 can be 1.08.

[0081] like Figure 2 The image shows a water temperature control device for a hybrid vehicle based on power demand, provided by an embodiment of the present invention, comprising:

[0082] The trigger judgment module is used to determine whether the engine's requested firing torque is not less than the engine's maximum torque multiplied by a preset coefficient, whether the engine's requested firing torque has increased, whether high-intensity knocking or pre-ignition has occurred, whether the octane rating is not less than the preset octane rating, whether the engine's actual coolant temperature exceeds the preset coolant temperature, and whether the change in atmospheric pressure of the vehicle during this driving cycle is less than the preset atmospheric pressure value.

[0083] The trigger execution module is used to enter the power demand mode if the engine's requested firing torque is not less than the engine's maximum torque multiplied by a preset coefficient, the engine's requested firing torque increases, no high-intensity knocking or pre-ignition occurs, the octane rating is not less than the preset octane rating, the engine's actual coolant temperature exceeds the preset coolant temperature, and the vehicle's atmospheric pressure change during the current driving cycle is less than the preset atmospheric pressure value and the duration exceeds the preset time. In this mode, the module reads the actual air volume, the first target air volume, the second target air volume, the third target air volume, the maximum air volume, the specific air volume, and the target coolant temperature determined by looking up the table according to the target coolant temperature I. The table in the table refers to the target coolant temperature I setting table.

[0084] The water temperature control module is used to obtain the final target water temperature by looking up the target water temperature I from the actual gas volume, the first target gas volume, the second target gas volume, the third target gas volume, the maximum gas volume, and the specific gas volume.

[0085] In some alternative implementations, the triggering execution module is configured to determine, if the data on the horizontal and vertical axes do not fall within the table (including the middle and outside of the table), by means of adjacent linear interpolation; if the data is in the middle of the table (i.e., the value is within the minimum and maximum values ​​of the table's coordinate axes), by means of linear interpolation; and if the data is outside the table (i.e., the value is not within the minimum and maximum values ​​of the table's coordinate axes), by means of linear interpolation, directly equal to the edge value.

[0086] In some alternative implementations, the actual air volume refers to the actual fresh air intake density entering the cylinder, which is also the engine load, and the target water temperature determined by looking up a table is the target water temperature a.

[0087] The first target air volume is the target air volume under the current sampling period, which refers to the fresh air intake density requested to enter the cylinder, and the corresponding target water temperature determined by looking up the table is the target water temperature b;

[0088] The second target gas volume refers to the target gas volume in the next sampling period, which is obtained by the first target gas volume + the first target gas volume change rate * sampling time, and the corresponding target water temperature determined by looking up the table is the target water temperature c;

[0089] The third target gas volume is obtained by the first target gas volume + ignition efficiency * sampling time, and the target water temperature determined by the table is the target water temperature d.

[0090] The maximum air volume represents the maximum allowable intake air density of the engine during this sampling period, and the target water temperature determined by looking up the table is the target water temperature e.

[0091] The specific gas volume refers to the gas volume on the gas volume axis of the target water temperature I setting table that is closest to and greater than the actual gas volume in the current period. The target water temperature f is determined by looking up the table.

[0092] In some alternative implementations, the final target water temperature is obtained by the combination of target water temperature a*k1 + target water temperature b*k2 + target water temperature c*k3 + target water temperature d*k4 + target water temperature e*k5 + target water temperature f*k6, where k1 + k2 + k3 + k4 + k5 + k6 = 1, and k2 depends on the target air volume change rate and engine speed. The smaller the engine speed but the larger the target air volume change rate, the larger k2 is.

[0093] In some alternative embodiments, the apparatus further includes:

[0094] The update module is used to ensure that if the engine torque response accuracy is maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the first multiple of the previous value, and k2 is saved after the vehicle is powered off. If the engine torque response accuracy is not maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the second multiple of the previous value, and k2 is saved after the vehicle is powered off. If the engine torque response accuracy is not maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the third multiple of the previous value, and k2 is saved after the vehicle is powered off. The values ​​of the first, second, and third multiples increase sequentially.

[0095] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0096] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A water temperature control method for hybrid vehicles based on power demand, characterized in that, include: Determine whether the requested torque of the engine is not less than the maximum torque of the engine multiplied by a preset coefficient, whether the requested torque of the engine has increased, whether there is no high-intensity knocking or pre-ignition, whether the octane rating is not less than the preset octane rating, whether the actual engine coolant temperature exceeds the preset coolant temperature, and whether the change in atmospheric pressure of the vehicle during this driving cycle is less than the preset atmospheric pressure value. If the requested engine torque is not less than the maximum engine torque multiplied by a preset coefficient, the requested engine torque increases, no high-intensity knocking or pre-ignition occurs, the octane rating is not less than the preset octane rating, the actual engine coolant temperature exceeds the preset coolant temperature, and the atmospheric pressure change of the vehicle during this driving cycle is less than the preset atmospheric pressure value and the duration exceeds the preset time, then the power demand mode is entered. The actual air volume, the first target air volume, the second target air volume, the third target air volume, the maximum air volume, the specific air volume, and the target coolant temperature determined by looking up the table according to the target coolant temperature I are read in real time. The table in the table refers to the target coolant temperature I setting table. The final target water temperature is obtained by looking up the target water temperature I in a table based on the actual gas volume, the first target gas volume, the second target gas volume, the third target gas volume, the maximum gas volume, and the specific gas volume.

2. The method according to claim 1, characterized in that, Determine the target water temperature by referring to the table based on target water temperature I, including: If the data on the horizontal and vertical axes do not fall within the table, including the middle and outside of the table, then the values ​​are determined by adjacent linear interpolation. If the values ​​are in the middle of the table, that is, within the minimum and maximum values ​​of the table's coordinate axes, then linear interpolation is used. If the values ​​are outside the table, that is, outside the minimum and maximum values ​​of the table's coordinate axes, then the values ​​are directly equal to the edge values.

3. The method according to claim 2, characterized in that, The actual air volume refers to the actual fresh air intake density entering the cylinder, which is also the engine load. The target water temperature determined by referring to the table is the target water temperature a. The first target air volume is the target air volume under the current sampling period, which refers to the fresh air intake density requested to enter the cylinder, and the corresponding target water temperature determined by looking up the table is the target water temperature b; The second target gas volume refers to the target gas volume in the next sampling period, which is obtained by the first target gas volume + the first target gas volume change rate * sampling time, and the corresponding target water temperature determined by looking up the table is the target water temperature c; The third target gas volume is obtained by the first target gas volume + ignition efficiency * sampling time, and the target water temperature determined by the table is the target water temperature d. The maximum air volume represents the maximum allowable intake air density of the engine during this sampling period, and the target water temperature determined by looking up the table is the target water temperature e. The specific gas volume refers to the gas volume on the gas volume axis of the target water temperature I setting table that is closest to and greater than the actual gas volume in the current period. The target water temperature f is determined by looking up the table.

4. The method according to claim 3, characterized in that, The final target water temperature is obtained by adding the target water temperature a*k1, target water temperature b*k2, target water temperature c*k3, target water temperature d*k4, target water temperature e*k5, and target water temperature f*k6. Among these, k1+k2+k3+k4+k5+k6=1, and k2 depends on the target air volume change rate and engine speed. The smaller the engine speed but the larger the target air volume change rate, the larger k2 will be.

5. The method according to claim 4, characterized in that, The method also includes updating the weighting coefficients: If the number of times the power demand mode is entered exceeds the preset number, the engine torque response accuracy can be guaranteed, and the power demand mode is not exited due to high-intensity knocking or pre-ignition after entering the power demand mode, then k2 is taken as the first multiple before the update, and k2 is saved after the vehicle is powered off. If the number of times the power demand mode is entered exceeds the preset number, and the engine torque response accuracy is not consistently guaranteed, and the power demand mode is not exited due to high-intensity knocking or pre-ignition after entering the power demand mode, then k2 is taken as the second multiple of the previous value, and k2 is saved after the vehicle is powered off. If the number of times the power demand mode is entered exceeds the preset number, the engine torque response accuracy cannot be guaranteed, and the power demand mode is exited due to high-intensity knocking or pre-ignition after entering the power demand mode, then k2 is the third multiple of the previous value, and k2 is saved after the vehicle is powered off. The values ​​of the first, second, and third multiples increase sequentially.

6. A water temperature control device for hybrid vehicles based on power demand, characterized in that, include: The trigger judgment module is used to determine whether the engine's requested firing torque is not less than the engine's maximum torque multiplied by a preset coefficient, whether the engine's requested firing torque has increased, whether high-intensity knocking or pre-ignition has occurred, whether the octane rating is not less than the preset octane rating, whether the engine's actual coolant temperature exceeds the preset coolant temperature, and whether the change in atmospheric pressure of the vehicle during this driving cycle is less than the preset atmospheric pressure value. The trigger execution module is used to enter the power demand mode if the engine's requested firing torque is not less than the engine's maximum torque multiplied by a preset coefficient, the engine's requested firing torque increases, no high-intensity knocking or pre-ignition occurs, the octane rating is not less than the preset octane rating, the engine's actual coolant temperature exceeds the preset coolant temperature, and the vehicle's atmospheric pressure change during the current driving cycle is less than the preset atmospheric pressure value and the duration exceeds the preset time. In this mode, the module reads the actual air volume, the first target air volume, the second target air volume, the third target air volume, the maximum air volume, the specific air volume, and the target coolant temperature determined by looking up the table according to the target coolant temperature I. The table in the table refers to the target coolant temperature I setting table. The water temperature control module is used to obtain the final target water temperature by looking up the target water temperature I from the actual gas volume, the first target gas volume, the second target gas volume, the third target gas volume, the maximum gas volume, and the specific gas volume.

7. The apparatus according to claim 6, characterized in that, The triggering module is used to determine the value if the data on the horizontal and vertical axes do not fall within the table, including the middle and outside of the table. If the data is in the middle of the table, i.e., the value is within the minimum and maximum values ​​of the table's coordinate axes, it is determined by linear interpolation. If the data is outside the table, i.e., the value is not ... direct interpolation to the edge value.

8. The apparatus according to claim 7, characterized in that, The actual air volume refers to the actual fresh air intake density entering the cylinder, which is also the engine load. The target water temperature determined by referring to the table is the target water temperature a. The first target air volume is the target air volume under the current sampling period, which refers to the fresh air intake density requested to enter the cylinder, and the corresponding target water temperature determined by looking up the table is the target water temperature b; The second target gas volume refers to the target gas volume in the next sampling period, which is obtained by the first target gas volume + the first target gas volume change rate * sampling time, and the corresponding target water temperature determined by looking up the table is the target water temperature c; The third target gas volume is obtained by the first target gas volume + ignition efficiency * sampling time, and the target water temperature determined by the table is the target water temperature d. The maximum air volume represents the maximum allowable intake air density of the engine during this sampling period, and the target water temperature determined by looking up the table is the target water temperature e. The specific gas volume refers to the gas volume on the gas volume axis of the target water temperature I setting table that is closest to and greater than the actual gas volume in the current period. The target water temperature f is determined by looking up the table.

9. The apparatus according to claim 8, characterized in that, The final target water temperature is obtained by adding the target water temperature a*k1, target water temperature b*k2, target water temperature c*k3, target water temperature d*k4, target water temperature e*k5, and target water temperature f*k6. Among these, k1+k2+k3+k4+k5+k6=1, and k2 depends on the target air volume change rate and engine speed. The smaller the engine speed but the larger the target air volume change rate, the larger k2 will be.

10. The apparatus according to claim 9, characterized in that, The device further includes: The update module is used to ensure that if the engine torque response accuracy is maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the first multiple of the previous value, and k2 is saved after the vehicle is powered off. If the engine torque response accuracy is not maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the second multiple of the previous value, and k2 is saved after the vehicle is powered off. If the engine torque response accuracy is not maintained even after entering the power demand mode more than a preset number of times, and the engine does not exit the power demand mode due to high-intensity knocking or pre-ignition, then k2 is set to the third multiple of the previous value, and k2 is saved after the vehicle is powered off. The values ​​of the first, second, and third multiples increase sequentially.

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