Systems and methods for increasing fuel efficiency

• US 9,221,451 B2
• Filed: 05/17/2012
• Issued: 12/29/2015
• Est. Priority Date: 05/17/2012
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Ahn, Samuel S.
• Primary Examiner(s): Algahaim, Helal A
• Assistant Examiner(s): SMITH, JELANI A
• Application Number:
  US13/474,416
• Publication Number:
  US 20130311048A1
• Time in Patent Office: 1,321 Days
• Field of Search: 180/65.23, 180/65.245, 180/62.27, 180/65.31, 388/822, 477/169, 477/182, 701/112, 701/113, 701/22, 701/36, 701/54, 701/58, 701/2, 701/48, 744/731
• US Class Current: 1/1
• CPC Class Codes: B60W 10/023 Fluid clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 30/1886 Controlling power supply to auxiliary devices
• CPC Class Codes: B60Y 2300/432 Control of engine fuel injection
• CPC Class Codes: B60Y 2300/46 Engine injection cut at coasting
• CPC Class Codes: B60Y 2400/302 Temperature sensors
• CPC Class Codes: B60Y 2400/88 Air conditioners, e.g. compressor drives

Abstract

The vehicle described herein employs an electronic control unit (“ECU”) and/or accessory control module configured to improve actual fuel, economy. The ECU and/or the accessory control module monitors vehicle operating conditions and reduces load from an accessory when the vehicle achieves predetermined operating conditions. The ECU and/or the accessory control module is also configured to engage a fuel cut and a torque converter lock up condition. The lock up condition causes the wheels to drive the motor to avoid engine stall. At a predetermined low level, the ECU and/or the accessory control module can re-engage the accessory and fuel supply and disengage the lock up condition.

Claims

1. A vehicle having wheels, comprising:

an engine configured to provide power at an engine speed;

a transmission having a transmission input speed and a transmission output speed for utilizing a first portion of the power provided by the engine to cause rotation of the wheels;

a torque converter coupled between the engine and the transmission, and configured to operate in a normal operation mode or a lock-up mode during which the engine speed is substantially the same as the transmission input speed;

an accessory operatively coupled to the engine and configured to utilize a second portion of the power provided by the engine;

an accelerator pedal configured to detect an acceleration input;

an input device configured to receive or detect a user input indicating a mode of operation of the vehicle including a fuel economy mode;

at least one sensor configured to detect at least one of an environmental condition or a vehicle operating parameter; and

an electronic control unit configured to set a current condition of the vehicle to a coast condition when the mode of operation of the vehicle is the fuel economy mode and the acceleration input indicates that the accelerator pedal is not depressed,

wherein when or after the current condition is the coast condition, the electronic control unit is further configured to;

determine whether the torque converter should operate in the lock-up mode based on the at least one of the environmental condition or the vehicle operating parameter, and

when the torque converter is operating in the lock-up mode, prevent the engine from providing power to the accessory based on at least the engine speed.

2. The vehicle of claim 1, wherein when the torque converter is operating in the lock-up mode and the current condition is the coast condition, the electronic control unit is configured to prevent the engine from providing power to the accessory when the engine speed is between approximately 400 rotations per minute of the engine and 1,000 rotations per minute of the engine.

3. The vehicle of claim 1, wherein the accessory is an alternator.

4. The vehicle of claim 1, wherein the accessory is an air conditioning compressor.

5. The vehicle of claim 4, wherein the at least one sensor includes a temperature sensor configured to measure an ambient temperature external to the vehicle, and wherein the environmental condition is based on the ambient temperature.

6. The vehicle of claim 5, wherein the electronic control unit is further configured to receive the ambient temperature from the temperature sensor, and wherein the electronic control unit does not prevent the engine from providing power to the accessory when the ambient temperature is equal to or greater than a temperature threshold.

7. The vehicle of claim 1, wherein when the torque converter is operating in the lock-up mode and the current condition is the coast condition, the electronic control unit is configured to prevent a fuel supply from flowing to the engine based on at least the engine speed.

8. The vehicle of claim 7, wherein the electronic control unit is configured to re-allow the fuel supply to flow to the engine and re-allow the engine to provide power to the accessory based on at least one of the second portion of the power provided by the engine, the engine speed, or a time period for the engine speed to stabilize after the engine is prevented from providing power to the accessory.

9. A method for enhancing energy efficiency of a vehicle having wheels and an engine configured to provide power at an engine speed, the method comprising:

providing a transmission having a transmission input speed and a transmission output speed for utilizing a first portion of the power provided by the engine to cause rotation of the wheels;

providing a torque converter coupled between the engine and the transmission, and configured to operate in a normal operation mode or a lock-up mode during which the engine speed is substantially the same as the transmission input speed;

providing an accessory configured to utilize a second portion of the power provided by the engine;

detecting, using an accelerator pedal, an acceleration input;

detecting, using an input device, a user input indicating a mode of operation of the vehicle including a fuel economy mode;

detecting, using at least one sensor, at least one of an environmental condition or a vehicle operating parameter;

setting, using an electronic control unit, a current condition of the vehicle to a coast condition when the mode of operation of the vehicle is the fuel economy mode and the acceleration input indicates that the accelerator pedal is not depressed;

determining, using the electronic control unit, whether the torque converter should operate in the lock-up mode based on the at least one of the environmental condition or the vehicle operating parameter, the determination being performed when or after the current condition is the coast condition; and

preventing, using the electronic control unit, the engine from power to the accessory based on at least one of the second portion of the power provided by the engine, the engine speed, or a time period for the engine speed to stabilize after the engine is prevented from providing power to the accessory.

10. The method of claim 9, wherein the step of preventing, using the electronic control unit, the engine from providing power to the accessory is performed when the torque converter is operating in the lock-up mode, the current condition is the coast condition, and the engine speed is within the range of approximately 250 rpms to approximately 350 rpms above a base idle speed of the engine.

11. The method of claim 9, wherein the accessory is an air conditioning compressor.

12. The method of claim 9, further comprising detecting, by a temperature sensor, a temperature external to the vehicle, wherein the environmental condition is based on the detected temperature.

13. The method of claim 12, wherein the temperature sensor is configured to communicate the temperature to the electronic control unit, and wherein when the torque converter is operating in the lock-up mode and the current condition is the coast condition, the electronic control unit is configured to prevent the engine from providing power to the accessory in response to the temperature being below a predetermined level.

14. An automobile, comprising:

a plurality of wheels;

an engine configured to provide power at an engine speed;

a transmission having a transmission input speed and a transmission output speed for utilizing a first portion of the power provided by the engine to cause rotation of the plurality of wheels;

a torque converter coupled between the engine and the transmission, and configured to operate in a normal operation mode or a lock-up mode during which the engine speed is substantially the same as the transmission input speed;

an accessory operatively coupled to the engine and configured to utilize a second portion of the power provided by the engine;

an accelerator pedal configured to detect an acceleration input;

an input device configured to receive or detect a user input indicating a mode of operation of the automobile including a fuel economy mode;

at least one sensor configured to detect at least one of an environmental condition or an automobile operating parameter; and

an electronic control unit in communication with the engine, the torque converter, the accessory, and the input device and configured to;

determine whether the torque converter should operate in the lock-up mode based on the at least one of the environmental condition or the automobile operating parameter, and

when the torque converter is operating in the lock-up mode, prevent the engine from providing power to the accessory based on at least one of the second portion of the power provided by the engine, the engine speed, or a time period for the engine speed to stabilize after the engine is prevented from providing power to the accessory.

15. The automobile of claim 14, wherein the accessory is at least one of a compressor or an alternator.

16. The automobile of claim 15, further comprising a battery configured to receive a charge from the alternator and wherein the electronic control unit is configured to prevent the engine from providing power to the alternator when or after the battery has a state of charge that is equal to or greater than a state of charge threshold value.

17. The automobile of claim 15, further comprising a sensor configured to measure and communicate an operating temperature of a device or a unit of the automobile to the electronic control unit, and wherein the electronic control unit is configured to prevent the engine from providing power to the compressor based on the operating temperature.