A power system control method, device and storage medium

Abstract

The application discloses a power system control method, equipment and storage medium. The power system control method comprises the following steps: determining whether a vehicle is in a non-power shift working condition and a braking working condition at the same time; if yes, determining a torque reduction control amount sent to an engine according to an engine speed, an engine speed change rate and / or a hydraulic torque converter turbine speed change rate in a shift-up process of the non-power shift working condition; and determining a first engagement pressure control amount of a clutch according to the engine speed and the engine speed change rate in the shift-up process of the non-power shift working condition; and determining a second engagement pressure control amount of the clutch according to the engine speed and the engine speed change rate in a shift-down process of the non-power shift working condition.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of automatic control, and particularly relate to a power system control method, device and storage medium. BACKGROUND

[0002] When a driver drives a vehicle equipped with a hydraulic mechanical automatic transmission from a stationary state to start 1st gear with small throttle, immediately releases the throttle pedal and performs emergency braking, the process is generally that the vehicle performs power-off upshift 1st gear to 2nd gear, and then performs power-off downshift 2nd gear to 1st gear. During the process of power-off upshift 1st gear to 2nd gear in a non-emergency braking state, to avoid slow engine speed regulation leading to too long shift time, the automatic transmission control unit (TCU) usually sends a very low torque reduction request value to the engine control unit (ECU) to achieve rapid regulation of engine speed; but when the vehicle performs emergency braking during the process of power-off upshift 1st gear to 2nd gear, since the engine torque is very small after responding to the torque reduction request value, and the vehicle end resistance is large to the load of the engine, combined with the hysteresis of the engine torque response, the engine speed is easily dragged down.

[0003] At present, there is no good solution to the problem of engine speed being dragged down due to TCU torque reduction request and engine torque response hysteresis during the process of power-off upshift 1st gear to 2nd gear. SUMMARY

[0004] The present application provides a power system control method, device and storage medium to achieve the purpose of solving the problems proposed in the background art.

[0005] In a first aspect, the embodiments of the present application provide a power system control method, comprising:

[0006] determining whether the vehicle is in a power-off shift condition and at the same time in a braking condition;

[0007] if yes, determining a torque reduction control amount sent to the engine according to the engine speed, the engine speed change rate and / or the hydraulic torque converter turbine speed change rate during the upshift stage of the power-off shift condition;

[0008] and determining a first engagement pressure control amount of the clutch according to the engine speed and the engine speed change rate during the upshift process of the power-off shift condition;

[0009] determining a second engagement pressure control amount of the clutch according to the engine speed and the engine speed change rate during the downshift process of the power-off shift condition.

[0010] Optionally, determining the torque reduction control amount sent to the engine according to the engine speed, the engine speed change rate and / or the torque converter turbine speed change rate comprises:

[0011] If the engine speed is less than the engine target idle speed and the torque converter turbine speed change rate is less than the change rate threshold, the automatic transmission control unit determines to immediately exit the torque reduction request, i.e. the automatic transmission control unit no longer sends the torque reduction request to the engine control unit.

[0012] Optionally, determining the torque reduction control amount sent to the engine according to the engine speed, the engine speed change rate and / or the torque converter turbine speed change rate comprises:

[0013] If the engine speed is greater than or equal to the engine target idle speed, the torque reduction control amount is controlled to be a preset torque reduction control amount;

[0014] If the engine speed is less than the engine target idle speed and the torque converter turbine speed change rate is greater than or equal to the change rate threshold, a first correction coefficient is used to correct the preset torque reduction control amount to obtain a corrected torque reduction control amount, and the torque reduction control amount is controlled to be the corrected torque reduction control amount.

[0015] Optionally, determining the first engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises:

[0016] Determining a speed difference between the engine speed and an engine target idle speed;

[0017] Using a first MAP table to determine a second correction coefficient corresponding to the speed difference and the engine speed change rate;

[0018] Using the second correction coefficient to correct a preset second-gear upshift engagement clutch pressure control amount, denoted as a corrected second-gear upshift engagement clutch pressure control amount;

[0019] Taking the corrected second-gear upshift engagement clutch pressure control amount as the first engagement pressure control amount.

[0020] Optionally, determining the second engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises:

[0021] Determining a speed difference between the engine speed and an engine target idle speed;

[0022] Using a second MAP table to determine a third correction coefficient corresponding to the speed difference and the engine speed change rate;

[0023] The third correction coefficient is used to correct a preset two-gear downshift separation clutch pressure control amount, which is recorded as a corrected two-gear downshift separation clutch pressure control amount.

[0024] The corrected two-gear downshift separation clutch pressure control amount is used as the second engagement pressure control amount.

[0025] Optionally, the engine speed is the engine speed in the clutch torque capacity rising phase in the upshift process.

[0026] Optionally, the engine speed is the engine speed in the clutch oil filling phase in the downshift process.

[0027] In a second aspect, an electronic device is also provided in the embodiments of the present application, which comprises at least one processor and a memory connected with the at least one processor in communication.

[0028] The memory stores a computer program which can be executed by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute any one of the power system control methods described in the embodiments of the present application.

[0029] In a third aspect, a computer readable storage medium is also provided in the embodiments of the present application, which stores computer instructions for enabling a processor to execute any one of the power system control methods described in the embodiments of the present application.

[0030] Compared with the prior art, the present application has the beneficial effects that: the present application provides a power system control method, in which, when a vehicle is in a non-power shift and at the same time in a braking condition, a torque reduction control amount for an engine, a first engagement pressure control amount of a clutch in an upshift process, and a second engagement pressure control amount of the clutch in a downshift process are regulated and controlled, and through the system control of the above-mentioned torque reduction control amount, first engagement pressure control amount, and second engagement pressure control amount, the problem that the engine speed is dragged down due to the automatic transmission control unit sending a torque reduction request and the engine torque response lag when a vehicle equipped with a hydro-mechanical automatic transmission is in an emergency braking state in a non-power upshift one-gear upshift two-gear upshift process can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a power system control method flowchart in the embodiments;

[0032] Figure 2 is a non-power upshift and downshift shifting process schematic diagram in the embodiments;

[0033] Figure 3 is another power system control method flowchart in the embodiments;

[0034] Figure 4 is an electronic device structure schematic diagram in the embodiment. DETAILED DESCRIPTION

[0035] The application will be further described below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application, but not to limit the application. In addition, it should be noted that, for the convenience of description, only the parts related to the application are shown in the drawings, but not all the structures.

[0036] Embodiment one

[0037] Figure 1 is a power system control method flow chart in the embodiment, referring to Figure 1 , the power system control method comprises:

[0038] S101. Determine whether the vehicle is in a no-power shift working condition and simultaneously in a braking working condition.

[0039] In the embodiment, the definition of the no-power shift working condition is set as: when the vehicle is in a stationary state and the gear is in first gear, the accelerator is slightly pressed to start the vehicle, and then the accelerator is immediately released, the gear of the vehicle is automatically upgraded from first gear to second gear, and / or when the accelerator is not pressed, the gear of the vehicle is automatically downgraded from second gear to first gear.

[0040] In the embodiment, the vehicle is in the no-power shift working condition and simultaneously in the braking working condition, which specifically corresponds to: in the process that the accelerator is slightly pressed to start the vehicle, and then the accelerator is immediately released, the gear of the vehicle is automatically upgraded from first gear to second gear, the brake pedal is quickly and deeply pressed to perform emergency braking.

[0041] In the embodiment, the power system of the vehicle at least comprises an engine and a hydro-mechanical automatic transmission;

[0042] In the embodiment, the connection mode and the basic working principle of the engine and the hydro-mechanical automatic transmission are the same as those of the prior art, and the specific content is not described in detail.

[0043] S102. If yes, in the upshift process of the no-power shift working condition, the torque reduction control amount sent to the engine is determined according to the engine speed, the engine speed change rate and / or the hydro-torque converter turbine speed change rate.

[0044] In the embodiment, in the upshift or downshift process, the shift process mainly comprises a preparation stage, a clutch oil filling stage, a clutch torque exchange stage, an engine speed regulation stage and a clutch torque capacity rising stage.

[0045] The clutch torque exchange stage is a process in which the engine torque is gradually transferred from being transmitted by an Off-going (normally closed) clutch (separating clutch) to being transmitted by an On-coming (normally open) clutch (engaging clutch).

[0046] In the shift process of the power-off upshift, when the engine torque is completely transferred to being transmitted by the On-coming clutch, the TCU (Transmission Control Unit) sends a torque reduction control request to the engine.

[0047] After the clutch torque exchange stage of the power-off upshift process, it is the engine speed regulation stage. In this stage, after the engine receives the torque reduction control request, the torque is reduced, and the speed is gradually reduced to be synchronized with the speed of the On-coming clutch.

[0048] In this embodiment, the torque control amount corresponding to the torque reduction control request sent by the TCU to the engine in the power-off upshift process when the vehicle is in the power-off shift condition and at the same time is in the braking condition is the torque reduction control amount sent to the engine.

[0049] In this embodiment, the way of determining the torque reduction control amount according to the engine speed, the engine speed change rate and / or the hydraulic torque converter turbine speed change rate is not limited;

[0050] For example, the corresponding relationship between the engine speed, the engine speed change rate and the torque reduction control amount can be determined through calibration test, and the above relationship can be made into a MAP table. In the actual operation of the vehicle, the MAP table is used to determine the required torque reduction control amount.

[0051] Further, the corresponding relationship between the engine speed, the engine speed change rate and the first correction coefficient related to the torque reduction control amount can be determined through calibration test, and the above torque reduction control amount can be further adjusted.

[0052] Alternatively, the engine speed and the engine speed change rate can be taken as inputs, and the torque reduction control amount can be determined through a preset function model. The function model can be determined through simulation test or experience, or a trained neural network model or machine learning model, etc.

[0053] In this embodiment, the torque reduction control amount determined according to the engine speed, the engine speed change rate and / or the hydraulic torque converter turbine speed change rate at least meets the following requirements:

[0054] When the vehicle is in the power-off shift condition and at the same time is in the braking condition, the torque of the engine is regulated and controlled by using the torque reduction control amount, and the engine speed can be maintained near the target idle speed without being dragged down.

[0055] S103. In the upshift process of the unpowered shift condition, a first engagement pressure control amount of the clutch is determined according to the engine speed and the engine speed change rate.

[0056] In this embodiment, the way of determining the first engagement pressure control amount according to the engine speed and the engine speed change rate is not limited;

[0057] For example, the corresponding relationship among the engine speed, the engine speed change rate and the first engagement pressure control amount can be determined through calibration test, and the above relationship is made into a MAP table, and the required first engagement pressure control amount is determined by using the MAP table in the actual operation of the vehicle;

[0058] Alternatively, a speed difference between the engine speed and the engine target idle speed is determined; a second correction coefficient corresponding to the speed difference and the engine speed change rate is determined by using a first MAP table (determined through calibration test based on the speed difference and the engine speed change rate); a preset second-gear upshift engagement clutch pressure control amount is corrected by using the second correction coefficient (wherein the preset second-gear upshift engagement clutch pressure control amount can be determined through calibration test according to the clutch engagement control program configured in the TCU), and the corrected second-gear upshift engagement clutch pressure control amount is recorded as the first engagement pressure control amount;

[0059] Alternatively, the engine speed and the engine speed change rate can be taken as inputs, and the first engagement pressure control amount is determined through a preset function model, wherein the function model can be determined through simulation test or experience, or a trained neural network model or machine learning model, etc.

[0060] In this embodiment, the first engagement pressure control amount at least meets the following requirements:

[0061] When the On-coming clutch is controlled to be engaged in the unpowered upshift process, the On-coming clutch pressure is stable and slowly rises, so as to slow down the descending rate of the hydraulic torque converter turbine speed, reduce the load effect of the hydraulic torque converter turbine on the engine, and avoid the engine speed being dragged down.

[0062] S104. In the downshift process of the unpowered shift condition, a second engagement pressure control amount of the clutch is determined according to the engine speed and the engine speed change rate.

[0063] In this embodiment, the way of determining the second engagement pressure control amount according to the engine speed and the engine speed change rate is not limited;

[0064] For example, a corresponding relationship between the engine speed, the engine speed change rate and the second engagement pressure control amount can be determined through calibration test, and a MAP table is made according to the above relationship, and the second engagement pressure control amount required is determined by using the MAP table during actual operation of the vehicle;

[0065] Alternatively, a speed difference between the engine speed and the target engine idle speed is determined, a third correction coefficient corresponding to the speed difference and the engine speed change rate is determined by using a second MAP table (determined through calibration test based on the speed difference and the engine speed change rate), the preset two-gear downshift separation clutch pressure control amount is corrected by using the third correction coefficient (wherein the preset two-gear downshift separation clutch pressure control amount can be determined according to the clutch separation control program configured in the TCU), and the corrected two-gear downshift separation clutch pressure control amount is recorded as the second engagement pressure control amount;

[0066] Alternatively, the engine speed and the engine speed change rate can be taken as inputs, and the second engagement pressure control amount is determined through a preset function model, wherein the function model can be determined through simulation test or experience, or a trained neural network model or machine learning model is used.

[0067] In the embodiment, the second engagement pressure control amount at least meets the following requirements:

[0068] During the control of the Off-going clutch separation in the power-off downshift process, the Off-going clutch pressure is rapidly reduced, so as to slow down the drop rate of the hydraulic torque converter turbine speed, reduce the load of the hydraulic torque converter turbine on the engine, and avoid the engine speed from being dragged down.

[0069] The embodiment proposes a power system control method, in which when the vehicle is in power-off shifting and at the same time in a braking working condition, the torque reduction control amount for the engine is adjusted, and the first engagement pressure control amount of the clutch during the upshift process and the second engagement pressure control amount of the clutch during the downshift process are adjusted. Through the system control of the above torque reduction control amount, the first engagement pressure control amount and the second engagement pressure control amount, the problem that the engine speed is dragged down due to the delay of the torque response of the engine caused by the torque reduction request sent by the automatic transmission control unit during the power-off upshift and the two-gear upshift process of the vehicle equipped with the hydraulic mechanical automatic transmission can be effectively improved.

[0070] In Figure 1 On the basis of the scheme shown in the figure, in an implementable scheme, the torque reduction control amount sent to the engine according to the engine speed, the engine speed change rate and / or the hydraulic torque converter turbine speed change rate comprises:

[0071] If the engine speed is less than the engine target idle speed and the turbine speed change rate is less than the change rate threshold, the automatic transmission control unit determines to immediately exit the torque reduction request, i.e., the automatic transmission control unit no longer sends the torque reduction request to the engine control unit.

[0072] In the scheme, the engine target idle speed and the turbine speed change rate threshold are preset values, which can be determined through calibration tests.

[0073] The turbine speed change rate threshold is set as r / (min·s) and has a negative value, which can be set by comprehensively considering the actual vehicle shift quality, shift time, and specific performance of the engine speed being dragged down (when the vehicle is in the power-off shift condition and at the same time in the braking condition, the engine and clutch control in the present application are used). For example, the turbine speed change rate threshold can be set as -5000 r / (min·s).

[0074] In the scheme, the engine speed is specifically set as the engine speed in the engine speed regulation stage in the power-off upshift process. When the engine speed obtained in the engine speed regulation stage is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate obtained in the engine speed regulation stage is less than the change rate threshold, the automatic transmission control unit determines to immediately exit the torque reduction request, i.e., the automatic transmission control unit no longer sends the torque reduction request to the engine control unit.

[0075] That is, in the engine speed regulation stage of the power-off upshift, if the engine speed and the hydraulic torque converter turbine speed change rate meet the above conditions, the engine is no longer controlled for torque reduction. At this time, the torque of the engine is controlled by the engine control unit according to the preset engine torque control program.

[0076] The function and implementation of the engine torque control program are the same as those in the prior art, and the specific content is not described in detail.

[0077] In the scheme, when the engine speed is lower than the engine target idle speed and the hydraulic torque converter turbine speed change rate is less than the change rate threshold, it indicates that the engine speed is relatively low and the hydraulic torque converter turbine speed drops rapidly. The rapid drop of the hydraulic torque converter turbine speed will lead to the rapid drop of the engine speed. Therefore, the engine is no longer controlled for torque reduction, and the engine torque is no longer actively controlled to improve the engine speed control ability and solve the problem of the engine speed being dragged down.

[0078] In the scheme shown in FIG. 8, the engine speed, the engine speed change rate, and / or the hydraulic torque converter turbine speed change rate are used to determine the torque reduction control amount sent to the engine. Figure 1 On the basis of the scheme shown in FIG. 8, in an implementable scheme, the torque reduction control amount sent to the engine according to the engine speed, the engine speed change rate, and / or the hydraulic torque converter turbine speed change rate includes:

[0079] If the engine speed is greater than or equal to the engine target idle speed, the control torque reduction control amount is a preset torque reduction control amount.

[0080] If the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is greater than or equal to a change rate threshold, a first correction coefficient is used to correct the preset torque reduction control amount to obtain a corrected torque reduction control amount, and the control torque reduction control amount is the corrected torque reduction control amount.

[0081] In this scheme, the engine target idle speed and the hydraulic torque converter turbine speed change rate threshold are preset values, which can be determined through calibration tests.

[0082] In this scheme, if the engine speed is greater than or equal to the engine target idle speed, the TCU sends a preset torque reduction control amount to the engine according to a preset torque reduction control program, regardless of the value of the hydraulic torque converter turbine speed change rate.

[0083] The torque reduction control program configured in the TCU is the same as the existing technology for controlling engine torque reduction during shifting.

[0084] In this scheme, the preset torque reduction control amount can be determined according to calibration tests. During calibration tests, the corresponding preset torque reduction control amount is determined according to the specific performance of the vehicle under non-emergency braking conditions, such as shifting quality, shifting time, etc.

[0085] In this scheme, if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is greater than or equal to the change rate threshold, a first correction coefficient is used to correct the preset torque reduction control amount to obtain a corrected torque reduction control amount, and the control torque reduction control amount is the corrected torque reduction control amount.

[0086] In this scheme, the corrected torque reduction control amount is determined by the following formula:

[0087] T rq = T rqo × β ij

[0088] In the formula, T rq is the corrected torque reduction control amount, T rqo is the preset torque reduction control amount, and β ij is the first correction coefficient.

[0089] In this scheme, the first correction coefficient is selected according to Table 1.

[0090] Table 1

[0091]

[0092] With reference to Table 1, in this scheme, the first correction coefficient is set to be related to the engine speed and the engine speed change rate, and the first correction coefficient β ij (i = 1, 2 …… 4; j = 1, 2 …… 5) are values greater than or equal to 1.

[0093] In this scheme, the value of the first correction coefficient is determined through calibration test. During calibration, the first correction coefficient can be calibrated according to the shift quality, shift time and specific performance of the engine speed being dragged down of the real vehicle without power upshift.

[0094] Specifically, the calibration principle adopted is that at the same engine speed, the smaller the engine speed change rate value, the faster the engine speed drops, and therefore the larger the β ij should be, so as to obtain a larger correction torque reduction control amount (T rq ), thereby obtaining a larger engine torque and improving the problem of the engine speed being dragged down.

[0095] At the same engine speed, the larger the engine speed change rate value, the smaller the β ij should be.

[0096] At the same engine speed change rate, the lower the engine speed, the larger the β ij should be, so as to obtain a larger correction torque reduction control amount (T rq ), thereby obtaining a larger engine torque and improving the problem of the engine speed being dragged down.

[0097] At the same engine speed change rate, the higher the engine speed, the smaller the β ij should be.

[0098] In Figure 1 the scheme, in one implementable scheme, the first engagement pressure control amount of the clutch in the automatic transmission is determined according to the engine speed and the engine speed change rate, which comprises:

[0099] determining the speed difference between the engine speed and the engine target idle speed;

[0100] determining the second correction coefficient corresponding to the speed difference and the engine speed change rate by using the first MAP table;

[0101] correcting the preset second upshift engagement clutch pressure control amount by using the second correction coefficient, and recording the corrected second upshift engagement clutch pressure control amount as the first engagement pressure control amount.

[0102] using the corrected second upshift engagement clutch pressure control amount as the first engagement pressure control amount.

[0103] In this scheme, the engine target idle speed is a preset value, which can be determined through calibration test.

[0104] In the present solution, when upshifting (i.e. power-free upshift from first gear to second gear), the second correction coefficient is used to correct the preset second-gear upshift clutch pressure control amount to obtain a first engagement pressure control amount, and the first engagement pressure control amount is used to control the second-gear On-coming clutch engagement.

[0105] In the present solution, the preset second-gear upshift clutch pressure control amount can be determined through calibration test according to the clutch engagement control program configured in the TCU. When performing the calibration test, the corresponding preset second-gear upshift clutch pressure control amount is determined according to the specific performance of the power-free upshift in the non-emergency braking state of the actual vehicle, such as shift quality and shift time. The implementation of the clutch engagement control program is the same as that of the prior art.

[0106] In the present solution, the set speed difference is determined according to the following formula:

[0107] Δn = n it -n e

[0108] In the formula, Δn is the speed difference, n it is the target engine idle speed, n e is the engine speed.

[0109] In the present solution, the second correction coefficient is selected according to Table 2.

[0110] Table 2

[0111]

[0112] In the present solution, the corrected second-gear upshift clutch pressure control amount is determined according to the following formula:

[0113] P 2tu = P 2ou × λ kj

[0114] In the formula, P 2tu is the corrected second-gear upshift clutch pressure control amount, P 2ou is the preset second-gear upshift clutch pressure control amount, and λ kj is the second correction coefficient.

[0115] Referring to Table 2, in the present solution, the second correction coefficient is related to the engine speed change rate and the speed difference, and λ kj (k = 1, 2 …… 5; j = 1, 2 …… 5) are all values less than or equal to 1.

[0116] In the scheme, the second correction coefficient is used to reduce the second-gear upshift clutch pressure in the process of power-off one-gear upshift and two-gear upshift, so as to reduce the load of the hydraulic torque converter turbine on the engine during emergency braking, and improve the problem of engine speed being dragged down.

[0117] In the scheme, the second correction coefficient can be calibrated according to the actual vehicle shift time, shift quality, and specific performance of engine speed being dragged down.

[0118] Specifically, the calibration principle is that under the same speed difference (Δn), the smaller the engine speed change rate, the faster the engine speed drops, and the smaller the second correction coefficient λ kj should be, so as to reduce the second-gear upshift clutch pressure control amount of the second-gear upshift clutch, and further reduce the first engagement pressure control amount, thereby slowing down the speed drop rate of the hydraulic torque converter turbine during emergency braking in the process of power-off one-gear upshift and two-gear upshift, reducing the load of the hydraulic torque converter turbine on the engine, and improving the problem of engine speed being dragged down.

[0119] Under the same speed difference (Δn), the larger the engine speed change rate, the larger the second correction coefficient λ kj should be.

[0120] Under the same engine speed change rate, the larger the speed difference (Δn), the lower the engine speed, and the smaller the second correction coefficient λ kj should be, so as to reduce the second-gear upshift clutch pressure control amount of the second-gear upshift clutch, and further reduce the first engagement pressure control amount, thereby slowing down the speed drop rate of the hydraulic torque converter turbine during emergency braking in the process of power-off one-gear upshift and two-gear upshift, reducing the load of the hydraulic torque converter turbine on the engine, and improving the problem of engine speed being dragged down.

[0121] Under the same engine speed change rate, the smaller the speed difference (Δn), the larger the second correction coefficient λ kj should be.

[0122] Further, in the scheme, the engine speed is the engine speed in the clutch torque capacity rising stage in the process of power-off upshift.

[0123] In the scheme, the clutch torque capacity rising stage corresponds to the process of the hydraulic pressure in the clutch oil chamber rising sharply in the process of power-off upshift, as shown in the e section of Figure 2 .

[0124] Figure 2 is a schematic diagram of the power-off upshift and downshift process in the embodiment, and reference is made to Figure 2The process of one-up two and two-down one can be divided into five stages, namely, a preparation stage a, a clutch oiling stage b, a clutch torque exchange stage c, an engine speed regulation stage d, and a clutch torque capacity rising stage e;

[0125] The engine torque reduction control is performed in the engine speed regulation stage d, and the engine torque reduction control amount used in the engine torque reduction control is determined according to the working condition, which can correspond to one of no engine torque reduction control amount, a preset torque reduction control amount, and a corrected torque control amount.

[0126] In this scheme, the clutch torque capacity rising stage can be the clutch torque capacity rising stage e in the process of upshift (powerless one-up two), and the first engagement pressure control amount is determined according to the corrected two-upshift engagement clutch pressure control amount, and the first engagement pressure control amount corresponds to the two-upshift clutch control pressure in the clutch torque capacity rising stage in the process of powerless upshift.

[0127] Based on the scheme shown in Figure 1 In an implementable scheme, the second engagement pressure control amount of the clutch in the automatic transmission is determined according to the engine speed and the engine speed change rate based on the scheme shown in

[0128] The speed difference between the engine speed and the engine target idle speed is determined.

[0129] A second MAP table is used to determine a third correction coefficient corresponding to the speed difference and the engine speed change rate.

[0130] The preset two-downshift disengagement clutch pressure control amount is corrected by using the third correction coefficient, and is recorded as a corrected two-downshift disengagement clutch pressure control amount.

[0131] The corrected two-downshift disengagement clutch pressure control amount is used as the second engagement pressure control amount.

[0132] In this scheme, the engine target idle speed is a preset value, which can be determined by calibration test.

[0133] In this scheme, when downshifting (i.e. powerless downshift from two to one), the second engagement pressure control amount is obtained by correcting the preset two-downshift disengagement clutch pressure control amount using the third correction coefficient, and the second engagement pressure control amount is used to control the two-off-coming clutch disengagement.

[0134] In the scheme, the preset second-gear downshift separation clutch pressure control amount can be determined by calibration test according to the clutch separation control program configured in the TCU. When performing the calibration test, the corresponding preset second-gear downshift separation clutch pressure control amount is determined according to the specific performance of the shift quality, shift time and other performances of the vehicle under the non-emergency braking state without power downshift. The implementation of the clutch separation control program is the same as the prior art.

[0135] In the scheme, the set speed difference is determined according to the following formula:

[0136] Δn = n it -n e

[0137] In the formula, Δn is the speed difference, n it is the target engine idle speed, n e is the engine speed.

[0138] In the scheme, the third correction coefficient is selected according to Table 3.

[0139] Table 3

[0140]

[0141] In the scheme, the second-gear downshift separation clutch pressure control amount is determined according to the following formula:

[0142] P 2td = P 2od × u kj

[0143] In the formula, P 2td is the second-gear downshift separation clutch pressure control amount, P 2od is the preset second-gear downshift separation clutch pressure control amount, and u kj is the third correction coefficient.

[0144] In the scheme, the third correction coefficient u kj (k = 1, 2 …… 5; j = 1, 2 …… 5) are all values less than or equal to 1, to reduce the second-gear downshift separation clutch pressure during the process of power downshift from the second gear to the first gear, thereby reducing the load of the hydraulic torque converter turbine on the engine when the vehicle is in the emergency braking state without power downshift, and improving the problem of the engine speed being dragged down.

[0145] In the scheme, the third correction coefficient can be calibrated and obtained according to the specific performance of the shift time, shift quality and engine speed being dragged down.

[0146] Specifically, the calibration principle is that: under the same speed difference, the smaller the engine speed change rate, the faster the engine speed drops (engine speed change rate < 0) or the slower the engine speed rises (engine speed change rate > 0), the smaller the third correction coefficient should be, so as to reduce the modified second-gear downshift separation clutch pressure control amount of the second-gear downshift separation clutch, and then reduce the second engagement pressure control amount, thereby slowing down the drop rate of the hydraulic torque converter turbine speed when the vehicle is in an emergency braking state and power downshifts from the second gear to the first gear, reducing the load of the hydraulic torque converter turbine on the engine, and improving the problem of the engine speed being dragged down.

[0147] Under the same speed difference, the greater the engine speed change rate, the greater the third correction coefficient should be.

[0148] Under the same engine speed change rate, the greater the speed difference, the lower the engine speed, and the smaller the third correction coefficient should be, so as to reduce the modified second-gear downshift separation clutch pressure control amount of the second-gear downshift separation clutch, and then reduce the second engagement pressure control amount, thereby slowing down the drop rate of the hydraulic torque converter turbine speed when the vehicle is in an emergency braking state and power downshifts from the second gear to the first gear, reducing the load of the hydraulic torque converter turbine on the engine, and improving the problem of the engine speed being dragged down.

[0149] Further, in the present scheme, the engine speed is the engine speed in the clutch oil filling stage during the power downshift process.

[0150] Reference Figure 2 In the present scheme, the clutch oil filling stage corresponds to the clutch oil filling stage b in the power downshift (second gear to first gear) process, and the second engagement pressure control amount is determined according to the modified second-gear downshift separation clutch pressure control amount, and the second engagement pressure control amount corresponds to the second-gear separation clutch control pressure in the clutch oil filling stage during the power downshift process.

[0151] In the present embodiment, any one of the above-mentioned power system control methods corresponds to a scheme that can be freely arranged and combined, Figure 3 is another power system control method flowchart in the embodiment, referring to Figure 3 For example, in an implementable scheme, the power system control method comprises:

[0152] S201. Determine whether the vehicle is in a power downshift working condition and at the same time in a braking working condition.

[0153] S202. If yes, determine whether to stop the engine torque reduction control according to the engine speed and the hydraulic torque converter turbine speed change rate.

[0154] In the scheme, if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is less than the change rate threshold, the engine torque reduction control is stopped, otherwise, the engine torque reduction control is not stopped.

[0155] S203. When the engine torque reduction control is not stopped, the engine torque reduction control amount is determined according to the engine speed, the engine speed change rate and the engine target idle speed.

[0156] In the scheme, if the engine speed is greater than or equal to the engine target idle speed, regardless of the value of the hydraulic torque converter turbine speed change rate, the TCU uses the preset torque reduction control amount to control the engine torque reduction according to the preset torque reduction control program.

[0157] In the scheme, if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is greater than or equal to the change rate threshold, the preset torque reduction control amount is corrected by a first correction coefficient to obtain a corrected torque reduction control amount, and the engine torque reduction is controlled by the corrected torque reduction control amount.

[0158] In the scheme, the first correction coefficient is determined according to Table 1, and the corrected torque reduction control amount is determined according to the following formula:

[0159] T rq = T rqo × β ij

[0160] In the formula, T rq is the corrected torque reduction control amount, T rqo is the preset torque reduction control amount, and β ij is the first correction coefficient.

[0161] S204. In the power-off shifting condition, the second correction coefficient is determined according to the engine speed, the engine target idle speed and the engine speed change rate.

[0162] In the scheme, the second correction coefficient is determined according to Table 2.

[0163] S205. The first engagement pressure control amount of the clutch in the power-off shifting condition is determined in combination with the second correction coefficient.

[0164] In the scheme, the first engagement pressure control amount is used for clutch pressure control in the clutch torque capacity rising stage in the power-off shifting process, and the first engagement pressure control amount is determined according to the following formula:

[0165] P 2tu = P 2ou × λ kj

[0166] In the formula, P 2tuP 2ou λ kj is a second correction coefficient.

[0167] S206. In the downshift process of the power-off shift condition, a third correction coefficient is determined according to the engine speed, the engine target idle speed and the engine speed change rate.

[0168] In this scheme, the third correction coefficient is determined according to Table 3.

[0169] S207. The second engagement pressure control amount of the clutch in the downshift process of the power-off shift condition is determined in combination with the third correction coefficient.

[0170] In this scheme, the second engagement pressure control amount is used for the clutch pressure control in the oil filling stage of the power-off downshift process, and the second engagement pressure control amount is determined according to the following formula:

[0171] P 2td = P 2od × u ij

[0172] In the formula, P 2td is the corrected second clutch pressure control amount (i.e., the second engagement pressure control amount), P 2od is the preset second clutch pressure control amount, and u ij is the third correction coefficient.

[0173] Example Two

[0174] Figure 4 A schematic diagram of an electronic device 10 that can be used to implement embodiments of the application is shown. The electronic device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular telephones, smart phones, wearable devices (e.g., headsets, glasses, watches, etc.), and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be examples only, and are not meant to limit implementations of the applications described and / or claimed in this document.

[0175] As Figure 4As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., communicatively connected to the at least one processor 11, where the memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0176] Various components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc., an output unit 17, such as various types of displays, a speaker, etc., a storage unit 18, such as a magnetic disk, an optical disk, etc., and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0177] The processor 11 can be various general and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs various methods and processes described above, such as the power system control method.

[0178] In some embodiments, the power system control method can be implemented as a computer program tangibly embodied in a computer readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the power system control method described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the power system control method by any other appropriate means, such as by means of firmware.

[0179] The various embodiments of the systems and techniques described above can be implemented in digital electronic circuitry, integrated circuitry, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system on a chip systems (SOCs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0180] Computer programs used to implement the processes of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer program

[0181] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. Computer-readable storage media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium will include one or more of an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0182] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0183] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0184] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0185] It should be noted that the above only describes the preferred embodiments of the present application and the principles of the applied technology. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A power system control method characterized by, The method comprises: determining whether the vehicle is in a power-off shift condition and simultaneously in a braking condition; if so, determining a torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate during an upshift process in the power-off shift condition; and determining a first engagement pressure control amount of a clutch in the automatic transmission according to the engine speed and the engine speed change rate during the upshift process in the power-off shift condition; determining a second engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate during a downshift process in the power-off shift condition; determining the torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate comprises: if the engine speed is greater than or equal to an engine target idle speed, controlling the torque reduction control amount to be a preset torque reduction control amount; if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is greater than or equal to a change rate threshold, correcting the preset torque reduction control amount by a first correction coefficient to obtain a corrected torque reduction control amount, and controlling the torque reduction control amount to be the corrected torque reduction control amount; determining the first engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises: determining a speed difference between the engine speed and an engine target idle speed; determining a second correction coefficient corresponding to the speed difference and the engine speed change rate by using a first MAP table; correcting a preset second-gear upshift engagement clutch pressure control amount by the second correction coefficient to obtain a corrected second-gear upshift engagement clutch pressure control amount; taking the corrected second-gear upshift engagement clutch pressure control amount as the first engagement pressure control amount.

2. The power system control method of claim 1 wherein, determining the torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate comprises: if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is less than the change rate threshold, the automatic transmission control unit determines to immediately exit the torque reduction request, i.e. the automatic transmission control unit no longer sends the torque reduction request to the engine control unit.

3. The power system control method of claim 1 wherein, determining the second engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises: determining a speed difference between the engine speed and an engine target idle speed; determining a third correction coefficient corresponding to the speed difference and the engine speed change rate by using a second MAP table; correcting a preset second-gear downshift separation clutch pressure control amount by the third correction coefficient to obtain a corrected second-gear downshift separation clutch pressure control amount; taking the corrected second-gear downshift separation clutch pressure control amount as the second engagement pressure control amount.

4. The power system control method of claim 1 wherein, The engine speed is the engine speed in a clutch torque capacity rising phase during the upshift process.

5. The power system control method of claim 3 wherein, The engine speed is the engine speed in a clutch oil filling phase during the downshift process.

6. An electronic device, comprising: The method comprises: determining whether the vehicle is in a power-off shift condition and simultaneously in a braking condition; if so, determining a torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate during an upshift process in the power-off shift condition; and determining a first engagement pressure control amount of a clutch in the automatic transmission according to the engine speed and the engine speed change rate during the upshift process in the power-off shift condition; determining a second engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate during a downshift process in the power-off shift condition; determining the torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate comprises: if the engine speed is greater than or equal to an engine target idle speed, controlling the torque reduction control amount to be a preset torque reduction control amount; if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is greater than or equal to a change rate threshold, correcting the preset torque reduction control amount by a first correction coefficient to obtain a corrected torque reduction control amount, and controlling the torque reduction control amount to be the corrected torque reduction control amount; determining the first engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises: determining a speed difference between the engine speed and an engine target idle speed; determining a second correction coefficient corresponding to the speed difference and the engine speed change rate by using a first MAP table; correcting a preset second-gear upshift engagement clutch pressure control amount by the second correction coefficient to obtain a corrected second-gear upshift engagement clutch pressure control amount; taking the corrected second-gear upshift engagement clutch pressure control amount as the first engagement pressure control amount. determining the torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate comprises: if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is less than the change rate threshold, the automatic transmission control unit determines to immediately exit the torque reduction request, i.e. the automatic transmission control unit no longer sends the torque reduction request to the engine control unit. determining the second engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises: determining a speed difference between the engine speed and an engine target idle speed; determining a third correction coefficient corresponding to the speed difference and the engine speed change rate by using a second MAP table; correcting a preset second-gear downshift separation clutch pressure control amount by the third correction coefficient to obtain a corrected second-gear downshift separation clutch pressure control amount; taking the corrected second-gear downshift separation clutch pressure control amount as the second engagement pressure control amount. The engine speed is the engine speed in a clutch torque capacity rising phase during the upshift process. The engine speed is the engine speed in a clutch oil filling phase during the downshift process. The method comprises: determining whether the vehicle is in a power-off shift condition and simultaneously in a braking condition; if so, determining a torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate during an upshift process in the power-off shift condition; and determining a first engagement pressure control amount of a clutch in the automatic transmission according to the engine speed and the engine speed change rate during the upshift process in the power-off shift condition; determining a second engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate during a downshift process in the power-off shift condition; determining the torque reduction control amount to be sent to the engine according to the engine speed, the engine speed change rate and the hydraulic torque converter turbine speed change rate comprises: if the engine speed is greater than or equal to an engine target idle speed, controlling the torque reduction control amount to be a preset torque reduction control amount; if the engine speed is less than the engine target idle speed and the hydraulic torque converter turbine speed change rate is greater than or equal to a change rate threshold, correcting the preset torque reduction control amount by a first correction coefficient to obtain a corrected torque reduction control amount, and controlling the torque reduction control amount to be the corrected torque reduction control amount; determining the first engagement pressure control amount of the clutch in the automatic transmission according to the engine speed and the engine speed change rate comprises: determining a speed difference between the engine speed and an engine target idle speed; determining a second correction coefficient corresponding to the speed difference and the engine speed change rate by using a first MAP table; correcting a preset second-gear upshift engagement clutch pressure control amount by the second correction coefficient to obtain a corrected second-gear upshift engagement clutch pressure control amount; taking the corrected second-gear upshift engagement clutch pressure control amount as the first engagement pressure control amount. The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the power system control method of any one of claims 1-5.

7. A computer readable storage medium characterized by The computer readable storage medium stores computer instructions for causing a processor to implement the power system control method of any one of claims 1-5 when executed.

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