DCT transmission pressure sensor fault adaptation system

Abstract

This invention discloses a fault adaptation system for a DCT transmission pressure sensor. The system comprises: S1, judging the static electrical value ΔU of the clutch pressure sensor; S2, if |ΔU|≤X1, then using the existing PI curve Y1 for closed-loop control of the clutch; S3, if |ΔU|>X1 and U≠V... out min Open-loop control is performed using the existing PI curve Y1, and a new PI curve Y2 is fitted based on ΔU. Simultaneously, the differences ΔP1, ΔP2, ..., ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined; S4, if U = V out min The invention utilizes the existing PI curve Y1 for open-loop control, and simultaneously determines the differences ΔP1, ΔP2, ..., ΔPn between the actual pressure values ​​of the pressure sensor at each current point within n clutch engagement cycles and the newly fitted PI curve Y2. This invention can adapt to abnormal sudden changes after the pressure sensor experiences an overall high or low output fault.

Description

Technical Field

[0001] This invention relates to the field of DCT transmission systems, and particularly to a DCT transmission pressure sensor fault adaptation system. Background Technology

[0002] A wet dual-clutch transmission is a type of DCT transmission that senses clutch pressure through a pressure sensor. Vehicles equipped with this transmission need to monitor the oil pressure in real time during clutch operation in order to achieve closed-loop control of clutch pressure and improve the overall driving comfort of the vehicle.

[0003] Because the pressure sensor in a wet dual-clutch transmission is affected by factors such as harsh working environment, high oil pressure pulse frequency and pressure, and sensor malfunction, the output curve of the pressure sensor is prone to deviate after a period of use, which may cause the vehicle to experience driving shock or become unable to drive. Summary of the Invention

[0004] This invention provides a fault adaptation system for a DCT transmission pressure sensor, which can adapt to abnormal sudden changes after the pressure sensor outputs are too high or too low.

[0005] The technical solutions to the above problems are as follows:

[0006] A DCT transmission pressure sensor fault adaptation system includes the following steps:

[0007] S1, determine the static electrical value ΔU of the clutch pressure sensor, ΔU = static voltage value of pressure sensor U - basic static voltage value U0;

[0008] S2, if |ΔU|≤X1, then use the existing PI curve Y1 to perform closed-loop control of the clutch;

[0009] S3, if |ΔU|>X1 and U≠V out min The existing PI curve Y1 is used for open-loop control, and a new PI curve Y2 is fitted based on ΔU. At the same time, the differences ΔP1, ΔP2...ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined.

[0010] S4, if U = V out min The existing PI curve Y1 is used for open-loop control, and a new PI curve Y2 is fitted based on ΔU. At the same time, the differences ΔP1, ΔP2...ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined.

[0011] U is the static electrical value of the pressure sensor; U0 is the basic static voltage value of the pressure sensor; V out min is the output low clamp of the pressure sensor; X1 is the offset threshold value of the static electrical value of the pressure sensor; The PI curve is the curve corresponding to the relationship between the current of the clutch solenoid valve and the pressure of the pressure sensor; Y1 is the existing PI curve; Y2 is the PI curve fitted according to ΔU based on Y1; P is the pressure value of the clutch pressure sensor; ΔP (ΔP1, ΔP2, ΔPn, ΔPx) is the maximum difference between the actual pressure value of the pressure sensor at each current point during the clutch engagement period and the newly fitted PI curve Y2.

[0012] Further, in step S3, if at least one of ΔP1 to ΔPn is greater than X2, then keep using the existing PI curve Y1 for open-loop control and perform fault handling; if all of ΔP1 to ΔPn are less than or equal to X2, then use the newly fitted PI curve Y2 according to ΔU to perform closed-loop control on the clutch;

[0013] where: X2 is the offset threshold value of the actual pressure of the clutch relative to the PI.

[0014] Further, in step S4, when there is no ΔP X : ΔP X ~ΔPn are all less than X2, or P X >P 半结合点 , then keep using the existing PI curve Y1 for open-loop control and perform fault handling. If there is ΔP X : ΔP X ~ΔPn are all less than X2, and P X ≦P 半结合点 , then in the area where P≧Px, use the newly fitted PI curve Y2 according to ΔU to perform closed-loop control on the clutch, and in the area where P<Px, use the PI curve Y1 for open-loop control;

[0015] where, P 半结合点 is the pressure value of the pressure sensor corresponding to the half-engagement point of the clutch.

[0016] In the present invention, after the output curve of the pressure sensor as a whole shifts, the offset amount is fitted into the original PI curve, and the new PI curve is combined with the original PI curve to continue performing closed-loop control on the clutch, avoiding faults such as driving impact or inability to drive after the overall offset of the output of the pressure sensor for the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the pressure sensor fault adaptation system of the DCT transmission of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of the present invention. The embodiments described with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be simply construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] A DCT transmission pressure sensor fault adaptation system includes the following steps:

[0020] S1, determine the static electrical value ΔU of the clutch pressure sensor, ΔU = static voltage value of the pressure sensor U - basic static voltage value U0.

[0021] S2, if |ΔU|≤X1, then the existing PI curve Y1 is used to perform closed-loop control of the clutch.

[0022] S3, if |ΔU|>X1 and U≠V out min The existing PI curve Y1 is used for open-loop control, and a new PI curve Y2 is fitted based on ΔU. At the same time, the differences ΔP1, ΔP2, ..., ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined.

[0023] S4, if U = V out min The existing PI curve Y1 is used for open-loop control, and a new PI curve Y2 is fitted based on ΔU. At the same time, the differences ΔP1, ΔP2, ..., ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined.

[0024] U is the static electrical value of the pressure sensor; U0 is the basic static voltage value of the pressure sensor; V out min X1 is the pressure sensor output low clamping; X2 is the static electrical value offset threshold of the pressure sensor; the PI curve is the curve showing the relationship between the clutch solenoid valve current and the pressure of the pressure sensor; Y1 is the existing PI curve; Y2 is the PI curve fitted based on Y1 according to ΔU; P is the clutch pressure sensor pressure value; ΔP(ΔP1, ΔP2, ΔPn, ΔPx) is the maximum difference between the actual pressure value of the pressure sensor at each current point during the clutch engagement cycle and the newly fitted PI curve Y2.

[0025] Preferably, in step S3, if at least one of ΔP1 to ΔPn is greater than X2, the existing PI curve Y1 is maintained for open-loop control and fault handling is performed; if all of ΔP1 to ΔPn are less than or equal to X2, a new PI curve Y2 fitted according to ΔU is used to perform closed-loop control on the clutch.

[0026] Where: X2 is the offset threshold of the actual pressure of the clutch relative to the PI.

[0027] Preferably, in step S4, when there is no ΔP X : ΔP X to ΔPn are all less than X2, or P X > P 半结合点 , the existing PI curve Y1 is maintained for open-loop control and fault handling is performed. If there is a ΔP X : ΔP X to ΔPn are all less than X2, and P X ≦ P 半结合点 , then in the P ≥ Px region, a new PI curve Y2 fitted according to ΔU is used to perform closed-loop control on the clutch, and in the P < Px region, the PI curve Y1 is used for open-loop control. Where, P 半结合点 is the pressure sensor pressure value corresponding to the semi-engagement point of the clutch.

[0028] After the output curve of the pressure sensor in this system is offset as a whole, the offset amount is fitted into the original PI curve, and the new PI curve is combined with the original PI curve to continue performing closed-loop control on the clutch, avoiding faults such as driving impact or inability to drive after the overall offset of the pressure sensor output of the whole vehicle.

Claims

1. A DCT transmission pressure sensor fault adaptation system, characterized in that, Includes the following steps: S1, determine the static electrical value ΔU of the clutch pressure sensor, ΔU = static voltage value of pressure sensor U - basic static voltage value U0; S2, if |ΔU|≤X1, then use the existing PI curve Y1 to perform closed-loop control of the clutch; S3, if |ΔU|>X1 and U≠V out min The existing PI curve Y1 is used for open-loop control, and a new PI curve Y2 is fitted based on ΔU. At the same time, the differences ΔP1, ΔP2...ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined. S4, if U = V out min The existing PI curve Y1 is used for open-loop control, and a new PI curve Y2 is fitted based on ΔU. At the same time, the differences ΔP1, ΔP2...ΔPn between the actual pressure values ​​of the pressure sensors at each current point within n clutch engagement cycles and the newly fitted PI curve Y2 are determined. U is the static electrical value of the pressure sensor; U0 is the basic static voltage value of the pressure sensor; V out min X1 is the pressure sensor output low clamp; X2 is the static electrical value offset threshold of the pressure sensor; the PI curve is the curve showing the relationship between the clutch solenoid valve current and the pressure of the pressure sensor; Y1 is the existing PI curve; Y2 is the PI curve fitted based on Y1 according to ΔU; P is the pressure value of the clutch pressure sensor; ΔP (ΔP1, ΔP2, ΔPn, ΔPx) is the maximum difference between the actual pressure value of the pressure sensor at each current point during the clutch engagement cycle and the newly fitted PI curve Y2.

2. The DCT transmission pressure sensor fault adaptation system according to claim 1, characterized in that, In step S3, if at least one of ΔP1 to ΔPn is greater than X2, the existing PI curve Y1 is used for open-loop control and fault handling is performed; if all of ΔP1 to ΔPn are less than or equal to X2, the new PI curve Y2 fitted based on ΔU is used for closed-loop control of the clutch. Where: X2 is the offset threshold of the actual clutch pressure relative to PI.

3. The DCT transmission pressure sensor fault adaptation system according to claim 2, characterized in that, In step S4, when there is no ΔP X : ΔP X ~ΔPn are all less than X2, or P X >P 半结合点 , then keep the existing PI curve Y1 for open-loop control and perform fault handling. If there is ΔP X : ΔP X ~ΔPn are all less than X2, and P X ≦P 半结合点 , then for the P≧Px region, use the new PI curve Y2 fitted according to ΔU to perform closed-loop control on the clutch, and for the P<Px region, use the PI curve Y1 for open-loop control; Among them, P 半结合点 This is the pressure value from the pressure sensor corresponding to the clutch half-engagement point.

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