Torque converter clutch apply adapt and quality apply detection converter slip acceleration
View Patent ↗A torque converter clutch slip rate monitoring system includes a slip rate calculation module that receives a raw slip speed of a torque converter clutch and that calculates torque converter clutch slip acceleration based on the raw slip speed. A torque converter clutch slip rate monitoring module detects deviation of the slip acceleration from a predetermined range during a pulldown of the torque converter clutch.
1. A torque converter clutch slip rate monitoring system, comprising:
a slip rate calculation module that receives a raw slip speed of a torque converter clutch and that calculates torque converter clutch slip acceleration based on the raw slip speed;
a torque converter clutch slip rate monitoring module that detects deviation of the slip acceleration from a predetermined range during a pulldown of the torque converter clutch; and
an apply adapt cell update module that performs an adjustment to an apply adapt cell, wherein the cell being adapted corresponds to a turbine torque at which the deviation occurred.
2. The system of claim 1 , further comprising a data structure that stores apply adapt cells arranged according to turbine torque.
3. The system of claim 2 , further comprising a powertrain control module that employs the adapt cells to adjust control of a solenoid governing fluid pressure of the torque converter clutch.
4. The system of claim 2 , further comprising a solenoid governing fluid pressure in the torque converter clutch.
5. The system of claim 1 , wherein said monitoring module compares the slip acceleration during the pulldown of the torque converter clutch to predetermined thresholds defining the predetermined range of slip acceleration and, if the slip acceleration deviates from the range, records a value of greatest deviation along with the corresponding turbine torque at which the value of greatest deviation occurred.
6. The system of claim 5 , wherein said update module adds a signed pressure modifier correction to the apply adapt cell corresponding to the turbine torque at which the greatest deviation occurred, wherein a value of the signed pressure modifier correction is retrieved from a predetermined calibration table by the value of the greatest deviation.
7. The system of claim 1 , further comprising a rating module that generates a rating of torque converter clutch apply quality.
8. The system of claim 7 , wherein said rating module rates the pulldown based on slip rate and apply time with reference to a slip acceleration versus torque converter clutch quality rating table.
9. The system of claim 1 , further comprising a raw slip speed calculation module that calculates the raw slip speed by comparing a turbine speed to an engine speed.
10. The system of claim 9 , further comprising a turbine shaft speed sensor that detects speed of a turbine shaft of the torque converter clutch.
11. The system of claim 9 , further comprising an engine speed sensor that detects engine speed.
12. The system of claim 1 , wherein said slip rate calculation module is a third order Kalman filter.
13. The system of claim 12 , wherein said third order Kalman filter calculates speed, slip acceleration, and jerk, and calculates error by comparing a measured slip speed to an estimated slip speed, all in accordance with the following:
Error=raw measured signal−estimated signal;
E ( k )= Y ( k )− X 1( k− 1);
X 1( K )= X 1( K− 1)+ T*X 2( k− 1)+ E ( k )* K 1;
X 2( K )= X 2( K− 1)+ T*X 3( k− 1)+ E ( k )* K 2;
X 3( K )= X 3( K− 1)+ E ( k )* K 3;
Y(k): measured raw signal from a sensor;
X1: Estimated signal;
X2: Estimated acceleration;
X3: Estimated acceleration derivative (Jerk);
T: Filter sampling period; and
TCC Slip raw=Engine rpm raw−Turbine speed raw.
14. A torque converter clutch slip rate monitoring method, comprising:
receiving a signal indicative of a raw slip speed of a torque converter clutch;
calculating torque converter clutch slip acceleration as a function of the raw slip speed of the torque converter clutch;
detecting a deviation of the slip acceleration from a predetermined range during a pulldown of the torque converter clutch; and
performing an adjustment to an apply adapt cell, wherein the cell being adapted corresponds to a turbine torque at which the deviation occurred.
15. The method of claim 14 , further comprising employing a data structure that stores apply adapt cells arranged according to turbine torque.
16. The method of claim 15 , further comprising employing the adapt cells to adjust control of a solenoid governing fluid pressure in the torque converter clutch.
17. The method of claim 16 , further comprising controlling the solenoid to govern fluid pressure in the torque converter clutch.
18. The method of claim 14 , further comprising:
comparing the slip acceleration to predetermined thresholds defining the predetermined range of slip acceleration; and
if the slip acceleration deviates from the range, recording a value of greatest deviation of the slip acceleration along with the corresponding turbine torque at which the value of greatest deviation occurred.
19. The method of claim 18 , further comprising:
retrieving a value of a signed pressure modifier correction from a predetermined calibration table by the value of the greatest deviation; and
adding the signed pressure modifier correction to the apply adapt cell corresponding to the turbine torque at which the greatest deviation occurred.
20. The method of claim 14 , further comprising generating a rating of torque converter clutch apply quality.
21. The method of claim 20 , further comprising rating the pulldown based on slip rate and apply time with reference to a slip acceleration versus torque converter clutch quality rating table.
22. The method of claim 14 , further comprising calculating the raw slip speed by comparing a turbine speed to an engine speed.
23. The method of claim 22 , further comprising employing a turbine shaft speed sensor to detect speed of a turbine shaft of the torque converter clutch.
24. The method of claim 22 , further comprising employing an engine speed sensor to detect engine speed.
25. The method of claim 14 , further comprising employing a third order Kalman filter to calculate the torque converter clutch slip acceleration.
26. The method of claim 25 , wherein said third order Kalman filter calculates speed, slip acceleration, and jerk, and calculates error by comparing a measured slip speed to an estimated slip speed, all in accordance with the following:
Error=raw measured signal−estimated signal;
E ( k )= Y ( k )− X 1( k− 1);
X 1( K )= X 1( K− 1)+ T*X 2( k− 1)+ E ( k )* K 1;
X 2( K )= X 2( K− 1)+ T*X 3( k− 1)+ E ( k )* K 2;
X 3( K )= X 3( K− 1)+ E ( k )* K 3;
Y(k): measured raw signal from a sensor;
X1: Estimated signal;
X2: Estimated acceleration;
X3: Estimated acceleration derivative (Jerk);
T: Filter sampling period; and
TCC Slip raw=Engine rpm raw−Turbine speed raw.