An electronic oil pump control method that combines execution and lubrication

Abstract

This invention discloses an electronic oil pump control method that integrates execution and lubrication. The method includes: S1, vehicle powertrain activation; S2, PID closed-loop control of lubrication pressure rise and hold oil passage flow; S3, the BLDC motor control unit (MCU) determines the current BLDC motor-driven oil passage pressure based on feedback signals from a pressure sensor. When the oil passage pressure is less than a first pressure threshold P0, step S4 is executed; when the oil passage pressure is greater than or equal to the first pressure threshold P0, step S5 is executed, where the first pressure threshold P0 is lower than the clutch semi-engagement pressure; S4, oil passage filling strategy; S5, pressure closed-loop control; S6, clutch disengagement control. This invention reduces the actuators and costs of hybrid transmissions while simultaneously meeting the requirements of shaft lubrication and clutch engagement / disengagement.

Description

Technical Field

[0001] This invention belongs to the field of transmission control for new energy vehicles, and specifically relates to an electronic oil pump control method that combines execution and lubrication. Background Technology

[0002] With the further increase in domestic car ownership and the large-scale consumption of fossil fuels, a significant burden has been placed on the environment. Faced with the ever-growing transportation demands of humanity, future travel will place greater emphasis on low-carbon and environmentally friendly practices. Existing traditional gasoline-powered vehicles will be phased out, while new energy vehicles, primarily pure electric and hybrid vehicles, will become the new driving force supporting traditional automakers.

[0003] BLDC (brushless DC) motors are widely used as actuators in transmissions. Compared to mechanical hydraulic pumps, BLDC motors offer higher efficiency and simpler structure, significantly reducing energy consumption in power transmission systems. Therefore, they are widely adopted in the new energy field. Employing an integrated actuator and lubrication electronic pump structure reduces the mechanical structure and number of parts in hybrid transmissions, lowering manufacturing difficulty and cost, while also reducing energy consumption. However, because a single electronic pump produces limited flow while simultaneously needing to lubricate the shaft system, pressure control is challenging. Summary of the Invention

[0004] This invention provides an electronic oil pump control method that combines execution and lubrication. The invention aims to reduce the actuators and costs of hybrid transmissions while meeting the requirements of shaft lubrication and clutch engagement.

[0005] An electronic oil pump control method that combines execution and lubrication includes the following steps:

[0006] S1, the vehicle powertrain system is activated. The vehicle controller determines whether there is a need for clutch pressure build-up. If the BLDC motor control unit MCU receives a request from the vehicle controller to engage the clutch, then step S3 is executed; if the vehicle controller requests the clutch to disengage, then step S2 is executed.

[0007] S2, Lubrication pressure rise and hold oil passage flow PID closed-loop control: The BLDC motor control unit (MCU) controls the lubrication pressure rise and hold. Based on the drive motor speed and generator speed, the BLDC motor control unit (MCU) first obtains the required lubrication flow rate according to the gearbox temperature, and then calculates the BLDC motor speed R based on parameters such as lubrication flow rate and lubrication oil passage pressure. req1 After calculating the motor speed, the lubrication of the shaft system is satisfied while the clutch does not transmit torque.

[0008] S3, the BLDC motor control unit MCU determines the current oil passage pressure of the BLDC motor drive by the feedback signal provided by the pressure sensor. When the oil passage pressure is less than the first pressure threshold P0, step S4 is executed. When the oil passage pressure is greater than or equal to the first pressure threshold P0, step S5 is executed. The first pressure threshold P0 is lower than the clutch half-engagement pressure.

[0009] S4, Oil Passage Filling Strategy: The filling process includes two stages: the first stage is open-loop control, and the second stage is PID oil passage pressure closed-loop control, using the clutch half-engagement point pressure P. k Using pressure as the target, the BLDC motor speed correction value R is calculated. co At this time, the target rotational speed R req2 The critical point base speed R k With speed correction value R co The sum of the actual pressure P in the oil passage and the target pressure P t The difference is less than the calibration threshold P diff-b After a duration of T3, proceed to step S5;

[0010] S5, Pressure Closed-Loop Control: When the requested clutch torque is greater than 0 Nm, the fuzzy control rule is executed to request the BLDC motor speed to control the clutch oil passage pressure. The BLDC motor control unit MCU obtains the actual oil passage pressure P, the requested clutch torque T, and the calculated torque growth rate T through the CAN bus and pressure sensor signal. grd 1. Clutch drive plate speed R1 or engine speed or P1 motor speed; 2. Clutch driven plate speed R2 or P3 motor speed; 3. Transmission fluid temperature t oil As the input variable of the fuzzy control system for calculating the target speed of the BLDC motor, the target speed R of the BLDC motor is calculated according to the fuzzy rules of the fuzzy control system for identifying the target speed of the BLDC motor. req3 If the clutch torque request is less than 0 Nm, proceed to step S6.

[0011] S6, Clutch Disengagement Control: When the actual oil passage pressure P is greater than the first pressure threshold P0, the BLDC motor requests a speed of R. req4 When the actual pressure P in the oil passage is less than or equal to the first pressure threshold P0, proceed to step S2.

[0012] This invention is applied to the control process of a dedicated transmission for single-gear hybrid vehicles, separating two key control processes. When there is no clutch torque request, a PID closed-loop control for oil passage lubrication pressure build-up and holding is designed, involving two calculation paths: First, flow rate calculation: after obtaining the speeds of motors P1 and P3, the lubrication flow requirements for the P1 generator shaft system and the P3 drive shaft system are obtained according to the flow simulation table, and the maximum value is taken. The target speed of the BLDC motor is then calculated using a formula. Second, pressure regulation: when the actual oil passage pressure obtained at the given BLDC motor speed reaches the point where the clutch does not transmit torque, the PID algorithm is used to adjust and reduce the target BLDC speed to ensure the transmission of unexpected clutch torque. During the clutch torque request and oil passage pressurization process, a fuzzy control algorithm is applied to control the BLDC motor's requested speed. Considering three input parameters—the speed difference between the clutch master and slave plates (primarily affecting comfort), the pressure difference, and the torque slope—four fuzzy control rules are established. Three of these rules are based on conditions where the speed difference is relatively small, indicating that the clutch master and slave plates are essentially synchronized, and the BLDC motor speed can be controlled with a relatively rapid increase in slope. The remaining rule primarily considers the requested clutch torque slope. If the requested torque slope is rapid, it indicates a greater power demand from the driver, in which case some comfort will be sacrificed to meet power performance requirements. Through the fuzzy control algorithm, an appropriate BLDC target speed can be selected, achieving a balance between comfort, fuel efficiency, and power requirements in the vehicle.

[0013] In summary, the present invention has the following advantages:

[0014] 1. An electronic oil pump enables both lubrication and actuation functions, reducing the manufacturing cost of the transmission.

[0015] 2. Fuzzy algorithms are used to perform fuzzy control on the target speed of the BLDC motor, which can meet the clutch pressure requirements under different industrial control conditions.

[0016] 3. The lubrication flow is controlled by a dual control method of flow rate and pressure, which not only ensures the lubrication of the shaft system, but also protects the clutch from unexpected torque. Attached Figure Description

[0017] Figure 1 This is a flowchart of the present invention;

[0018] Figure 2 Schematic diagram of the pressure / BLDC speed process during clutch activation;

[0019] Figure 3 Schematic diagram of hydraulic oil passages in a hybrid transmission;

[0020] Figure 4 Schematic diagram of signal interaction in the control process. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] like Figures 1 to 4 As shown, the present invention provides an electronic oil pump control method that combines execution and lubrication, comprising the following steps:

[0023] S0: Signal acquisition and signal processing: The hybrid vehicle transmission controller unit acquires the engine speed or P1 motor speed, vehicle speed or P3 motor speed, and actual oil pressure P (referring to the actual clutch oil pressure) in real time.

[0024] S1, the vehicle power system is activated. The vehicle controller determines whether there is a need for clutch pressure build-up. If the BLDC motor control unit MCU receives a request from the vehicle controller to engage the clutch, then step S3 is executed; if the vehicle controller requests the clutch to disengage, then step S2 is executed.

[0025] S2, Lubrication pressure rise and hold oil passage flow PID closed-loop control: The BLDC motor control unit (MCU) controls the lubrication pressure rise and hold. Based on the drive motor speed and generator speed, the BLDC motor control unit (MCU) first obtains the required lubrication flow rate according to the gearbox temperature, and then calculates the BLDC motor speed R based on parameters such as lubrication flow rate and lubrication oil passage pressure. req1 After calculating the motor speed, the clutch does not transmit torque while ensuring shaft lubrication.

[0026] S3, the BLDC motor control unit MCU determines the current oil passage pressure of the BLDC motor drive by the feedback signal provided by the pressure sensor. When the oil passage pressure is less than the first pressure threshold P0, step S4 is executed. When the oil passage pressure is greater than or equal to the first pressure threshold P0, step S5 is executed. The first pressure threshold P0 is lower than the clutch half-engagement pressure.

[0027] S4, Oil Passage Filling Strategy: The filling process includes two stages: the first stage is open-loop control, and the second stage is PID oil passage pressure closed-loop control, using the clutch half-engagement point pressure P. k Using pressure as the target, the BLDC motor speed correction value R is calculated. co At this time, the target rotational speed R req2 The critical point base speed R k With speed correction value R co The sum of the actual pressure P in the oil passage and the target pressure P t The difference is less than the calibration threshold P diff-b After a duration of T3, proceed to step S5.

[0028] In step S4, the first stage of open-loop control uses the oil temperature and the current actual pressure of the oil passage to calculate the clutch drive plate speed R1, speed holding time T1, and drop time T2 when the BLDC motor is filled with oil. When the BLDC motor speed drops to the pressure critical point base speed R k Then, the second stage begins.

[0029] In step S4, the second stage is PID oil passage pressure closed-loop control. First, the basic speed R of the BLDC motor critical point is obtained by looking up the table based on the oil temperature. k With the clutch half-engagement point pressure P k With the target oil pressure P as the feedback signal, PID feedback regulation is performed to calculate the speed correction value R. co When the actual pressure P in the oil passage and the target pressure P t The difference is less than the calibration threshold P diff-b The counting begins at time T3. When the time exceeds the calibrated time T3, proceed to step S5.

[0030] S5, Pressure Closed-Loop Control: When the requested clutch torque is greater than 0 Nm, the fuzzy control rule is executed to request the BLDC motor speed to control the clutch oil passage pressure. The BLDC motor control unit MCU obtains the actual oil passage pressure P, the requested clutch torque T, and the calculated torque growth rate T through the CAN bus and pressure sensor signal. grd 1. Clutch drive plate speed R1 or engine speed or P1 motor speed; 2. Clutch driven plate speed R2 or P3 motor speed; 3. Transmission fluid temperature t oil As the input variable of the fuzzy control system for calculating the target speed of the BLDC motor, the target speed R of the BLDC motor is calculated according to the fuzzy rules of the fuzzy control system for identifying the target speed of the BLDC motor. req3 When the clutch torque request is less than 0 Nm, proceed to step S6.

[0031] The specific steps of pressure closed-loop control S5 are as follows:

[0032] S81: The BLDC motor control unit MCU obtains the actual oil pressure P and the target pressure P in the oil passage. t Pressure difference P diff The clutch master-slave disc speed difference d and the average filtered clutch requested torque slope Tg are used as input variables of the fuzzy system.

[0033] S82: Pressure difference P diff The absolute value of the clutch master-slave speed difference d and the average filtered clutch requested torque slope Tg are input into the membership function A(P). diff ), B(P diff C(d), D(Tg) respectively yield the corresponding output value A. pB p C d D T , where A(P diff B(P) represents the membership function for a positive pressure difference. diff ) represents the membership function where the pressure difference is negative, C(d) represents the membership function where the speed difference is less than α, and D(Tg) represents the membership function where the torque slope is greater than β, where α represents the speed difference threshold and β represents the torque slope threshold.

[0034] S83: Set the membership function A(P) diff ), B(P diff Output values ​​A for C(d) and D(Tg) p B p C d D T The input is fed into the fuzzy control rule to obtain the output value of the fuzzy control rule or the original values ​​A1, A2, A3, and A4 of the BLDC motor speed request value;

[0035] S84, the obtained BLDC motor speed request first raw value A1, second raw value A2, third raw value A3, and fourth raw value A4 are refined according to the following cumulative averaging formula to obtain the final required BLDC motor speed request. The cumulative averaging formula is:

[0036]

[0037] Where A i Request the original speed value of the BLDC motor output by the i-th fuzzy control rule, K. nj K is the coefficient of the regular numerator. dj The coefficient of the regular denominator.

[0038] The value of α ranges from 0 to 3000, and the value of β is less than 10 Nm / s; the fuzzy set pressure difference is positive, indicating that the actual oil pressure P is less than the target pressure P. t The negative fuzzy set pressure difference indicates that the actual oil pressure P is greater than the target pressure P. t .

[0039] The following content illustrates the above solution through examples:

[0040] 1) Signal Acquisition and Processing: The BLDC motor control unit MCU obtains the real-time generator shaft speed signal from the P1 motor via the CAN bus; the BLDC motor control unit MCU obtains the real-time drive shaft speed signal from the P3 motor via the CAN bus; the BLDC motor control unit MCU obtains the real-time clutch torque request signal from the vehicle controller (VCU) via the CAN bus; the BLDC motor control unit MCU obtains the oil passage pressure signal from the pressure sensor via an analog signal; the BLDC motor control unit MCU obtains the transmission oil temperature signal from the oil temperature sensor via an analog signal.

[0041] 2) Calculation of the clutch master-slave speed difference:

[0042] From the P1P3 hybrid structure, we know that the speed difference d between the clutch master and slave plates is equal to the speed of the clutch master plate converted from the speed ratio of the P1 motor to the speed of the clutch slave plate converted from the speed ratio of the P3 motor. Here, the speed of the P1 motor originates from the generator MCU, the speed of the P3 motor originates from the drive motor MCU, the speed ratio from P1 to the clutch master plate is r1, and the speed ratio from P3 to the clutch slave plate is r2.

[0043]

[0044] 3) Calculation of the actual pressure difference in the target oil passage:

[0045] Pressure difference P diff = Actual oil pressure P - Target pressure P t The actual pressure P in the oil passage is derived from the pressure sensor data.

[0046] 4) Request torque slope calculation:

[0047] The calculation of the requested torque slope is mainly to obtain the clutch torque growth rate as a feedforward for the BLDC motor speed request. The calculation method is Tg=((Tn-+Tn-1)+(Tn-1-+Tn-2)+..+(Tn-j+1-+Tn-j)) / j, where Tn is the torque request value in the current cycle, Tn-j is the torque request value in the previous j cycles, and j is the average filter coefficient.

[0048] 5) Lubrication process involves calculating the BLDC motor speed, including the following steps:

[0049] 51) Calculate the basic speed of the BLDC motor: The BLDC motor control unit (MCU) obtains the speeds of the generator and drive motor, obtains the lubrication demand flow table based on the shaft lubrication simulation, looks up the flow demand respectively, and obtains the basic required speed of the BLDC motor based on the efficiency characteristics of the BLDC electronic oil pump and the flow distribution characteristics of the oil passage. For example:

[0050] generator speed rpm 0 2000 4000 6000 8000 10000 Demand flow rate L / min 0.5 1 1 2 2 3 BLDC target speed / rpm 300 600 600 1000 1000 2000

[0051] Table 1

[0052] Drive speed rpm 0 1000 4000 7000 10000 16000 Demand flow rate L / min 0.5 1 1 2 2 3 BLDC target speed / rpm 300 600 600 1000 1000 2000

[0053] Table 2

[0054] When the drive motor is at 7000 rpm and the generator speed is at 2000 rpm, the target base speed of the BLDC motor is taken as the larger value R. req0 =1000rpm.

[0055] 52) BLDC motor lubrication pressure limiting control:

[0056] To ensure that no unexpected torque is generated in the clutch, the lubrication pressure must be kept below the clutch's semi-engaged point during lubrication control. The control method is as follows:

[0057] Set the maximum pressure to P k0 The actual pressure in the oil passage is P, and P is used. k0 The pressure difference with P is used for simple feedback adjustment, and the speed deviation R is calculated. offset This limits the oil passage pressure. Among them, P diff0 =PP k0 P diff0 With R offset The relationships are shown in Table 3 below:

[0058] <![CDATA[Pressure difference P diff0 / bar]]> 1 0.5 0 -0.5 -1 -2 <![CDATA[Rotational speed offset R offset / rpm]]> -500 -500 -200 -100 0 0

[0059] Table 3

[0060] When P = 2 bar, P K0 When = 1.5 bar, R offset = -100rpm;

[0061] 53) BLDC target speed calculation:

[0062] BLDC target speed is based on the base speed plus the pressure-limited offset speed.

[0063] R req =R req0 +R offset

[0064] As calculated above, R req0 =1000rpm, R offset = -100rpm, R req =1000-100=900rpm.

[0065] 6) Calculation of BLDC motor speed for clutch operation and oil-filled pressure activation:

[0066] The clutch performs two processes: rapid oil filling of the disengaging ring and closed-loop pressure control. The pressure and speed diagrams are shown in Figure 2.

[0067] 61) Clutch oil passage open-loop filling:

[0068] Three important parameters for open-loop oil filling are clutch drive disc speed R1, speed holding time T1, and speed drop time T2. Among them, R1 is mainly affected by temperature, while speed holding times T1 and T2 are mainly affected by the actual oil pressure in the oil passage before oil filling. These parameters can be calibrated using the parameter tables shown in Tables 4 and 5 below:

[0069] Oil temperature T / ℃ -40 -20 0 20 60 120 <![CDATA[Maximum rotational speed R1 / rpm]]> 3000 4000 4500 5000 5000 5000

[0070] Table 4

[0071] Pre-filling pressure / bar 0 0.2 0.5 1 2 3 <![CDATA[Duration T1 / ms]]> 400 300 150 50 0 0 <![CDATA[Fall time T2 / ms]]> 300 300 150 50 50 50

[0072] Table 5

[0073] Assuming the oil temperature is 20 degrees Celsius and the pressure before filling is 0.2 bar, the maximum speed R1 = 5000 rpm, the duration T1 = 150 ms, the descent time T2 = 150 ms, and the target speed descent rate of the BLDC motor is 34 rpm / ms.

[0074] 62) Clutch oil-filled state jump calculation:

[0075] When the actual speed R of the BLDC motor is less than or equal to R k At that time, it jumps into the closed-loop control state of the oil passage pressure, where R k The base speed for the BLDC motor at the clutch half-engagement point and critical point is mainly influenced by the transmission oil temperature, which can be obtained from Table 6.

[0076]

[0077] Table 6

[0078] 63) Clutch oil passage closed-loop pressure control calculation:

[0079] Similarly, Figure 2 As shown, the main control target of clutch closed-loop pressure control is the actual oil passage pressure P, and the target pressure is the clutch half-engagement point pressure P. k ,

[0080] e(k)=P k -P

[0081] R co =k pp [e(k)-e(k-1)]+k pi e(k)+k pd [e(k)-2e(k-1)+e(k-2)]

[0082] R req =R k +R co

[0083] In the formula, Pk is the target pressure value of the clutch at the current moment;

[0084] P represents the actual pressure in the oil passage (clutch at the current moment);

[0085] R k The critical point base speed;

[0086] e(k) is the difference between the clutch target pressure and the actual oil passage pressure at the kth sampling time;

[0087] e(k-1) is the difference between the clutch target pressure and the actual oil passage pressure at the (k-1)th sampling time;

[0088] e(k-2) is the difference between the clutch target pressure and the actual oil passage pressure at the (k-2)th sampling time;

[0089] R co This is the speed correction value for the brushless DC motor;

[0090] k pp The proportional control coefficient for the clutch pressure PID closed loop;

[0091] k pi The integral control coefficient for the clutch pressure PID closed loop;

[0092] k pd The differential control coefficient of the clutch pressure PID closed loop;

[0093] R req The target speed of the brushless DC motor;

[0094] 7) Clutch pressure calculation based on BLDC motor speed:

[0095] The pressure-following BLDC speed fuzzy calculation system calculates and obtains the real-time oil passage pressure difference P based on the BLDC motor control unit MCU. diff The membership function A(P) is calculated using the average filtered clutch requested torque slope Tg and the clutch master-slave plate speed difference d (absolute value) as input variables. diff ), B(P diff C(d), the specific process is as follows:

[0096] 71) Define the input signal. Pressure difference. Pdiff The three input variables are: torque request growth rate Tg, clutch master-slave disc speed difference d (absolute value), and torque request growth rate Tg.

[0097] Pressure difference P diff The value range is -3 to 3 (bar);

[0098] The torque request growth rate Tg ranges from 0 to 2000 (Nm / s);

[0099] The speed difference d between the clutch master and slave discs ranges from 0 to 2000 rpm.

[0100] 72) Membership Degree Calculation. Based on expert experience and knowledge, and considering vehicle dynamics and driver operation, this invention designs four membership degree functions, as shown below:

[0101] A(P diff ) represents the membership function for a positive pressure difference. In this example, A(P) diff The value range is 0-100, A(P) diff The value table is shown in Table 7 below:

[0102] <![CDATA[P diff ]]> 0 0.2 0.5 1 1.5 3 <![CDATA[A(P diff )]]> 0 20 40 60 80 100

[0103] Table 7

[0104] A( Pdiff The value is not limited to the above embodiments and can be determined based on the drivability calibration of the matched vehicle.

[0105] B( Pdiff B(P) represents a negative membership function for the pressure difference. In this example, B(P) diff The value range is 0-100, B(P) diff The value table is shown in Table 8 below:

[0106] <![CDATA[P diff ]]> 0 -0.2 -0.5 -1 -1.5 -3 <![CDATA[B(P diff )]]> 0 20 40 60 80 100

[0107] Table 8

[0108] B(P diff The value of C(d) is not limited to the above embodiments. It can be determined according to the drivability calibration of the matched vehicle. C(d) represents the membership function for speed difference less than α, where α represents the speed difference threshold. In this example, the value range of C(d) is 0-100, and the value of α is 0-3000 rpm. The values ​​of C(d) are shown in Table 9 below:

[0109] d 100 200 400 800 1600 3000 C(d) 100 100 70 40 10 0

[0110] Table 9

[0111] The value of C(d) is not limited to the above embodiments and can be determined based on the drivability calibration of the matched vehicle.

[0112] D(Tg) represents the membership function for torque slopes greater than β, where β represents the torque slope threshold. In this example, D(Tg) ranges from 0 to 100, and β is less than 10 rpm. The values ​​of D(Tg) are shown in Table 10 below.

[0113] Tg 0 10 100 200 500 2000 D(Tg) 100 100 70 40 10 0

[0114] Table 10

[0115] The value of D(Tg) is not limited to the above embodiments and can be determined based on the drivability calibration of the matched vehicle.

[0116] Pressure difference P diff The torque request growth rate Tg and the absolute value of the speed difference d are input into four membership functions A(P). diff ), B(P diff From C(d) and D(Tg), four corresponding output values ​​A are obtained respectively. p B p C d D T .

[0117] In Table 7, point P diff1 Corresponding to A(P) diff1 For example, point 0.2 corresponds to 20, and point P... diff2 Corresponding to A(P) diff2 For example, point 0.5 corresponds to 40, when the pressure difference P is obtained. diff Located at P diff1 With P diff2 When the two points are in a certain range, A can be obtained using the linear difference method between them. p =A(P diff1 )+(P diff -P diff1 ) / (P diff2 -P diff1 )*(A(P diff2 )-A(P diff1 B p C d D T The calculation is similar to the method described above.

[0118] In this example, when the BLDC motor control unit MCU is running, A is calculated every 10ms. p B p C d D T .

[0119] The fuzzy control rules in step S83 are characterized by including:

[0120] The first fuzzy rule is: if the absolute value of the speed difference is less than α and the pressure difference is negative, it means that the clutch speeds are basically synchronized, but the actual oil pressure P is greater than the target pressure P. t At this time, the BLDC motor speed request first original value is B. p and C d The smaller of the two;

[0121] The second fuzzy rule is: if the absolute value of the speed difference is less than α and the pressure difference is positive, then it means that the clutch speeds are basically synchronized, but the actual oil passage pressure P is less than the target pressure P. t At this time, the BLDC motor speed request second original value A2 is taken as A. p and C d The one with the larger median value;

[0122] The third fuzzy rule is: if the absolute value of the speed difference is less than α and the torque slope is greater than β, it indicates that the clutch speeds are basically synchronized, but the torque growth rate is very fast. In this case, the BLDC motor speed request for the third original value A3 is A. p With D T The one with the larger median value;

[0123] The fourth fuzzy rule is: if the torque slope is greater than β, then the BLDC motor speed requires the fourth original value A4 to be D. T .

[0124] S6, Clutch Disengagement Control: When the actual oil passage pressure P is greater than the first pressure threshold P0, the BLDC motor requests a speed of R. req4 When the actual pressure P in the oil passage is less than or equal to the first pressure threshold P0, proceed to step S2.

[0125] Finally, it should be noted that the above-described embodiments are merely preferred embodiments of the present invention used to illustrate the technical solutions of the present invention, and are not intended to limit them, much less limit the scope of protection of the present invention; although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the scope of protection of the claims.

Claims

1. A method for controlling an electronic oil pump that combines execution and lubrication, characterized in that, Includes the following steps: S1, the vehicle powertrain system is activated. The vehicle controller determines whether there is a need for clutch pressure build-up. If the BLDC motor control unit MCU receives a request from the vehicle controller to engage the clutch, then step S3 is executed; if the vehicle controller requests the clutch to disengage, then step S2 is executed. S2, Lubrication pressure rise and hold oil passage flow PID closed-loop control: The BLDC motor control unit (MCU) controls the lubrication pressure rise and hold. Based on the drive motor speed and generator speed, the BLDC motor control unit (MCU) first obtains the required lubrication flow rate according to the gearbox temperature, and then calculates the BLDC motor speed R based on parameters such as lubrication flow rate and lubrication oil passage pressure. req1 After calculating the motor speed, the lubrication of the shaft system is satisfied while the clutch does not transmit torque. S3, the BLDC motor control unit MCU determines the current oil passage pressure of the BLDC motor drive by the feedback signal provided by the pressure sensor. When the oil passage pressure is less than the first pressure threshold P0, step S4 is executed. When the oil passage pressure is greater than or equal to the first pressure threshold P0, step S5 is executed. The first pressure threshold P0 is lower than the clutch half-engagement pressure. S4, Oil Passage Filling Strategy: The filling process includes two stages: the first stage is open-loop control, and the second stage is PID oil passage pressure closed-loop control, using the clutch half-engagement point pressure P. k Using pressure as the target, the BLDC motor speed correction value R is calculated. co At this time, the target rotational speed R req2 The critical point base speed R k With speed correction value R co The sum of the actual pressure P in the oil passage and the target pressure P t The difference is less than the calibration threshold P diff-b After time T3, proceed to step S5; S5, Pressure Closed-Loop Control: When the requested clutch torque is greater than 0 Nm, the fuzzy control rule is executed to request the BLDC motor speed to control the clutch oil passage pressure. The BLDC motor control unit MCU obtains the actual oil passage pressure P, the requested clutch torque T, and the calculated torque growth rate T through the CAN bus and pressure sensor signal. grd 1. Clutch drive plate speed R1 or engine speed or P1 motor speed; 2. Clutch driven plate speed R2 or P3 motor speed; 3. Transmission fluid temperature t oil As the input variable of the fuzzy control system for calculating the target speed of the BLDC motor, the target speed R of the BLDC motor is calculated according to the fuzzy rules of the fuzzy control system for identifying the target speed of the BLDC motor. req3 If the clutch torque request is less than 0 Nm, proceed to step S6. S6, Clutch Disengagement Control: When the actual oil passage pressure P is greater than the first pressure threshold P0, the BLDC motor requests a speed of R. req4 When the actual pressure P in the oil passage is less than or equal to the first pressure threshold P0, proceed to step S2.

2. The electronic oil pump control method combining execution and lubrication according to claim 1, characterized in that, In step S4, the first stage of open-loop control uses the oil temperature and the current actual pressure of the oil passage to calculate the clutch drive plate speed R1, speed holding time T1, and drop time T2 when the BLDC motor is filled with oil. When the BLDC motor speed drops to the pressure critical point base speed R k Then, the second stage begins.

3. The electronic oil pump control method combining execution and lubrication according to claim 1, characterized in that, In step S4, the second stage is PID oil passage pressure closed-loop control. First, the basic speed R of the BLDC motor critical point is obtained by looking up the table based on the oil temperature. k With the clutch half-engagement point pressure P k With the target oil pressure P as the feedback signal, PID feedback regulation is performed to calculate the speed correction value R. co When the actual pressure P in the oil passage and the target pressure P t The difference is less than the calibration threshold P diff-b The counting begins at time T3. When the time exceeds the calibrated time T3, proceed to step S5.

4. The electronic oil pump control method combining execution and lubrication according to claim 1, characterized in that, The specific steps of pressure closed-loop control S5 are as follows: S81: The BLDC motor control unit MCU obtains the actual oil pressure P and the target pressure P in the oil passage. t Pressure difference P diff The clutch master-slave disc speed difference d and the average filtered clutch requested torque slope Tg are used as input variables of the fuzzy system. S82: Pressure difference P diff The clutch master-slave plate speed difference d and the average filtered clutch requested torque slope Tg are input into the membership function A(P). diff ), B(P diff C(d), D(Tg) respectively yield the corresponding output value A. p B p C d D T , where A(P diff B(P) represents the membership function for a positive pressure difference. diff ) represents the membership function where the pressure difference is negative, C(d) represents the membership function where the speed difference is less than α, and D(Tg) represents the membership function where the torque slope is greater than β, where α represents the speed difference threshold and β represents the torque slope threshold. S83: Set the membership function A(P) diff ), B(P diff Output values ​​A for C(d) and D(Tg) p B p C d D T The input is fed into the fuzzy control rule to obtain the output value of the fuzzy control rule or the original values ​​A1, A2, A3, and A4 of the BLDC motor speed request value; S84, the obtained BLDC motor speed request first raw value A1, second raw value A2, third raw value A3, and fourth raw value A4 are refined according to the following cumulative averaging formula to obtain the final required BLDC motor speed request. The cumulative averaging formula is: Where A i Request the original speed value of the BLDC motor output by the i-th fuzzy control rule, K. nj K is the coefficient of the regular numerator. dj The coefficient of the regular denominator.

5. The electronic oil pump control method combining execution and lubrication according to claim 4, characterized in that, The value of α ranges from 0 to 3000, and the value of β is less than 10 Nm / s; the fuzzy set pressure difference is positive, indicating that the actual oil pressure P is less than the target pressure P. t The negative fuzzy set pressure difference indicates that the actual oil pressure P is greater than the target pressure P. t .

6. The electronic oil pump control method combining execution and lubrication according to claim 4, characterized in that, Its features The fuzzy control rules in step S83 include: The first fuzzy rule is: if the absolute value of the speed difference is less than α and the pressure difference is negative, it means that the clutch speeds are basically synchronized, but the actual oil pressure P is greater than the target pressure P. t At this time, the BLDC motor speed request first original value is B. p and C d The smaller of the two; The second fuzzy rule is: if the absolute value of the speed difference is less than α and the pressure difference is positive, then it means that the clutch speeds are basically synchronized, but the actual oil passage pressure P is less than the target pressure P. t At this time, the BLDC motor speed request second original value A2 is taken as A. p and C d The one with the larger median value; The third fuzzy rule is: if the absolute value of the speed difference is less than α and the torque slope is greater than β, it indicates that the clutch speeds are basically synchronized, but the torque growth rate is very fast. In this case, the BLDC motor speed request for the third original value A3 is A. p With D T The one with the larger median value; The fourth fuzzy rule is: if the torque slope is greater than β, then the BLDC motor speed requires the fourth original value A4 to be D. T .

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