Coasting control device

• US 8,855,887 B2
• Filed: 07/07/2011
• Issued: 10/07/2014
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Transtron Inc. (Fujitsu Limited), Isuzu Motors Limited
• Original Assignee: Transtron Inc. (Fujitsu Limited), Isuzu Motors Limited
• Inventors: Iwao, Nobuyuki, Yamamoto, Yasushi, Kobayashi, Kazuhiko, Arai, Hiroyuki, Takama, Kouhei
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): PAIGE, TYLER D
• Application Number:
  US13/812,964
• Publication Number:
  US 20130131948A1
• Time in Patent Office: 1,188 Days
• Field of Search: 701/93, 477/169
• US Class Current: 701/93
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 2510/0283 Clutch input shaft speed
• CPC Class Codes: B60W 2520/06 Direction of travel
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/106 Rate of change
• CPC Class Codes: B60W 2710/0655 Coasting condition
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/18072 Coasting
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60Y 2300/18083 without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: F16D 2048/023 by pedal actuation
• CPC Class Codes: F16D 2048/0254 Double actuation, i.e. two actuation means can produce independently an engagement or disengagement of the clutch
• CPC Class Codes: F16D 2500/508 Relating driving conditions
• CPC Class Codes: F16D 2500/5085 Coasting
• CPC Class Codes: F16D 2500/51 Relating safety
• CPC Class Codes: F16D 2500/70424 Outputting a clutch engaged-disengaged signal
• CPC Class Codes: F16D 2500/7105 Inhibit control automatically
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence
• CPC Class Codes: Y02T 10/60 : Other road transportation technologies with climate change mitigation effect

Abstract

A coasting control device capable of avoiding coasting control during turning is provided. A turning recognition unit that recognizes that a vehicle is turning and a unit for prohibiting coasting control during turning that prohibits coasting control when the turning recognition unit recognizes that the vehicle is turning are provided.

Claims

1. A coasting control device for a vehicle comprising:

a coasting control execution unit that recognizes when coasting control start conditions are satisfied, and that disengages a clutch in a driving situation in which an engine does no work for the outside and lowers an engine RPM so as to start coasting control;

a turning recognition unit that recognizes that the vehicle is turning; and

a unit for prohibiting the coasting control during the turning that prohibits the coasting control when the turning recognition unit recognizes that the vehicle is turning,

wherein the unit for prohibiting the coasting control during the turning prohibits the coasting control execution unit from starting the coasting control, even if the coasting control start conditions are satisfied.

2. The coasting control device according to claim 1, wherein

the turning recognition unit recognizes that the vehicle is turning from a difference in rotation speeds between right and left wheels.

3. The coasting control device according to claim 2, wherein

the turning recognition unit recognizes that the vehicle starts turning when the difference in rotation speeds between the right and left wheels exceeds a first threshold value and recognizes that the vehicle terminates turning when the difference in rotation speeds between the right and left wheels falls to a second threshold value, which is smaller than the first threshold value, or less.

4. The coasting control device according to claim 3, further comprising:

a coasting control determination map based on a clutch rotation speed and an accelerator opening degree, wherein

the coasting control execution unit starts the coasting control by disengaging the clutch and lowering the engine RPM when plotted points of the clutch rotation speed and the accelerator opening degree on the coasting control determination map are within a coasting control available region, an accelerator pedal operation speed is within a predetermined range, and plotted points of the clutch rotation speed and the accelerator opening degree pass a coasting control threshold line in a direction where the accelerator opening degree decreases and terminates the coasting control when the accelerator pedal operation speed goes out of the predetermined range or the plotted points go out of the coasting control available region.

5. The coasting control device according to claim 2, further comprising:

a coasting control determination map based on a clutch rotation speed and an accelerator opening degree, wherein

the coasting control execution unit starts the coasting control by disengaging the clutch and lowering the engine RPM when plotted points of the clutch rotation speed and the accelerator opening degree on the coasting control determination map are within a coasting control available region, an accelerator pedal operation speed is within a predetermined range, and plotted points of the clutch rotation speed and the accelerator opening degree pass a coasting control threshold line in a direction where the accelerator opening degree decreases and terminates the coasting control when the accelerator pedal operation speed goes out of the predetermined range or the plotted points go out of the coasting control available region.

6. The coasting control device according to claim 1, further comprising:

a coasting control determination map based on a clutch rotation speed and an accelerator opening degree, wherein

the coasting control execution unit starts the coasting control by disengaging the clutch and lowering the engine RPM when plotted points of the clutch rotation speed and the accelerator opening degree on the coasting control determination map are within a coasting control available region, an accelerator pedal operation speed is within a predetermined range, and plotted points of the clutch rotation speed and the accelerator opening degree pass a coasting control threshold line in a direction where the accelerator opening degree decreases and terminates the coasting control when the accelerator pedal operation speed goes out of the predetermined range or the plotted points go out of the coasting control available region.

7. The coasting control device according to claim 1, wherein the turning recognition unit receives rotation speeds of the left and right wheels from an anti-lock braking system control unit mounted on the vehicle and recognizes that the vehicle is turning from a difference in the rotation speeds between the left and right wheels.

8. The coasting control device according to claim 1, wherein the turning recognition unit receives data regarding an operation angle of a steering shaft from a steering sensor in the vehicle to determine if the vehicle is turning.

9. The coasting control device according to claim 1, wherein the turning recognition unit receives data regarding a yaw angle of the vehicle from a yaw rate sensor in the vehicle to determine if the vehicle is turning.

10. The coasting control device according to claim 1, wherein the turning recognition unit receives data regarding lateral acceleration of the vehicle from a G-force sensor in the vehicle to determine if the vehicle is turning.