Torque compensation method and system

Patent metadata

Field	Value
Publication number	US-9487207-B2
Application number	US-201414157580-A
Country	US
Kind code	B2
Filing date	Jan 17, 2014
Priority date	May 6, 2010
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A system and method of compensating for torque converter slip in a motor vehicle include measuring rotational speeds of an engine crankshaft and mainshaft, as well as measuring operating temperatures of a fluid associated with the motor vehicle. Engine output torque is adjusted as required by controlling some combination of ignition timing, intake air flow, fuel injection, and accessory load. A system and method for deactivating a torque compensation system retrieves a number of times the torque compensation system has been activated over a set period. If the number exceeds a predetermined number of activations, the torque compensation system is deactivated.

First claim

What is claimed is:

1. A system for adjusting output torque of an engine for a motor vehicle including a torque compensation system, comprising:
an electronic control unit;
a first sensor for detecting a rotational speed of a first shaft in a drive train of the motor vehicle, the first shaft being an input shaft;
a second sensor for detecting a rotational speed of a second shaft in the drive train of the motor vehicle, the second shaft of the motor vehicle being an output shaft hydraulically coupled to the first shaft; and
a temperature sensor for determining a vehicle fluid temperature;
wherein the electronic control unit is configured to calculate an actual slip ratio based on a measured speed from the first sensor and a measured speed from the second sensor;
wherein the electronic control unit is further configured to activate the torque compensation system by:
determining an expected slip ratio based on a measured vehicle fluid temperature from the temperature sensor, wherein the expected slip ratio is determined based on a correlation between the vehicle fluid temperature and the expected slip ratio stored in a database in communication with the electronic control unit;
determining whether the actual slip ratio between the first shaft and the second shaft exceeds the expected slip ratio corresponding to the measured vehicle fluid temperature; and
adjusting the output torque based on a result of the determining whether the actual slip ratio exceeds the expected slip ratio corresponding to the measured vehicle fluid temperature;

wherein the electronic control unit is further configured to retrieve a number of times the torque compensation system has been activated in a current driving cycle; and
wherein the electronic control unit is configured to deactivate the torque compensation system if the number of times the torque compensation system has been activated in the current driving cycle exceeds a predetermined number of activations.

2. The system according to claim 1 , wherein the electronic control unit is further configured to provide a signal to the engine to generate a normal torque output upon determining that the actual slip ratio does not exceed the expected slip ratio, the normal torque output being determined as a function of the measured vehicle fluid temperature; and
wherein the electronic control unit is further configured to provide a signal to the engine to generate an increased torque output upon determining that the actual slip ratio exceeds the expected slip ratio; the increased torque output being greater than the normal torque output and wherein the increased torque output is determined as a function of the measured vehicle fluid temperature.

3. The system according to claim 2 , wherein the signal to the engine to generate the increased torque output includes adjusting ignition timing.

4. The system according to claim 2 , wherein the signal to the engine to generate the increased torque output includes adjusting engine intake air supply.

5. The system according to claim 2 , wherein the signal to the engine to generate the increased torque output includes adjusting fuel injection.

6. The system according to claim 5 , wherein the fuel injection is adjusted by varying one or more of injection timing, injection pressure, and injection open time.

7. The system according to claim 2 , wherein the signal to the engine to generate the increased torque output includes decreasing accessory load.

8. The system according to claim 7 , wherein the accessory load is decreased by one or more of decreasing an alternator field, decoupling an alternator, decoupling a power steering pump, and reducing a power steering pump pressure.

9. The system according to claim 1 , wherein the predetermined number of activations is set for one or more of: a life of the motor vehicle, a single cycle of starting and shutting down the engine of the motor vehicle, and a given distance that the motor vehicle is driven.

10. The system according to claim 1 , further comprising a signal filter associated with at least one of the first sensor and the second sensor.

11. A method for adjusting output torque of an engine for a motor vehicle including a torque compensation system in communication with an electronic control unit, comprising the steps of:
detecting a rotational speed of a first shaft in a drive train of the motor vehicle using a first sensor, the first shaft being an input shaft;
detecting a rotational speed of a second shaft in the drive train of the motor using a second sensor, the second shaft of the motor vehicle being an output shaft hydraulically coupled to the first shaft;
determining a vehicle fluid temperature using a temperature sensor; and
wherein the electronic control unit further performs the steps of:
activating the torque compensation system by:
calculating an actual slip ratio based on a measured speed from the first sensor and a measured speed from the second sensor;
determining an expected slip ratio based on a measured vehicle fluid temperature from the temperature sensor, wherein the expected slip ratio is determined based on a correlation between the vehicle fluid temperature and the expected slip ratio stored in a database in communication with the electronic control unit;
determining whether the actual slip ratio between the first shaft and the second shaft exceeds the expected slip ratio corresponding to the measured vehicle fluid temperature;
adjusting the output torque based on a result of the determining whether the actual slip ratio exceeds the expected slip ratio corresponding to the measured vehicle fluid temperature;

wherein the electronic control unit further performs the steps of:
retrieving a number of times the torque compensation system has been activated; and
deactivating the torque compensation system if the number of times the torque compensation system has been activated exceeds a predetermined number of activations.

12. The method according to claim 11 , wherein the step of retrieving a number of times the torque compensation system has been activated further comprises retrieving a number of times the torque compensation system has been activated in a current driving cycle; and
wherein the step of deactivating the torque compensation system further comprises deactivating the torque compensation system if the number of times the torque compensation system has been activated in the current driving cycle exceeds the predetermined number of activations.

13. The method according to claim 11 , further comprising setting the predetermined number of activations using the electronic control system.

14. The method according to claim 13 , wherein the step of setting the predetermined number of activations comprises setting the predetermined number for one or more of: a life of the motor vehicle, a single cycle of starting and shutting down the engine of the motor vehicle, and a given distance that the motor vehicle is driven.

15. The method according to claim 11 , wherein upon determining by the electronic control unit that the number of times the torque compensation system has been activated does not exceed the predetermined number of activations, the electronic control unit activating the torque compensation system.

16. The method according to claim 15 , wherein the step of activating the torque compensation system further comprises varying operation of the engine of the motor vehicle using the electronic control unit to maintain a predetermined output torque of the engine of the motor vehicle.

17. The method according to cla

Assignees

• Honda Motor Co Ltd

Inventors

• Nagashima Dan
• Mizuno Takahide
• Toyoshima Hirokazu
• O'Donnell Lee
• Tonokura Naomichi
• Muto Akio
• Ishikawa Yutaka

Classifications

• B60W10/119 Primary

  including control of all-wheel-driveline means, e.g. transfer gears or clutches for dividing torque between front and rear axle (B60W10/14 takes precedence) · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60K28/16

  responsive to, or preventing, spinning or skidding of wheels · CPC title

• F02D2400/12

  Engine control specially adapted for a transmission comprising a torque converter or for continuously variable transmissions · CPC title

• F16H59/72

  dependent on oil characteristics, e.g. temperature, viscosity · CPC title