Method and apparatus of controlling acceleration/deceleration of a vehicle Number:7,386,381 from the United States Patent and Trademark Office (PTO) owispatent A method of reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel. The method includes the steps of detecting an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque, calculating a relative rotational position between the input shaft and an output shaft of the controlled section based on the detected information relating to the rotational speed of the input shaft, and accelerating or decelerating at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the calculated relative rotational position.<H deceleration, acceleration, Method, and, appa, 7386381.html, Patent, pto, 7386381

Title: Method and apparatus of controlling acceleration/deceleration of a vehicle

Abstract: A method of reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel. The method includes the steps of detecting an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque, calculating a relative rotational position between the input shaft and an output shaft of the controlled section based on the detected information relating to the rotational speed of the input shaft, and accelerating or decelerating at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the calculated relative rotational position.

Patent Number: 7,386,381 Issued on 06/10/2008 to Matsushima, et al.

Inventors: Matsushima; Hirohide (Kobe, JP), Jinja; Yoichi (Osaka, JP), Kawai; Daisuke (Akashi, JP), Suzuki; Ryo (Kobe, JP)
Assignee: Kawasaki Jukogyo Kabushiki Kaisha (Kobe-shi, JP)

Appl. No.: 11/102,451

Filed: April 8, 2005

Foreign Application Priority Data


Apr 09, 2004 [JP]			2004-115694
Dec 13, 2004 [JP]			2004-359969

Current U.S. Class: 701/51 ; 477/37; 477/80; 701/54; 701/70

Field of Search: 701/51,52,54,70,84,110 477/37,34,79,80

References Cited [Referenced By]

U.S. Patent Documents


7086978	August 2006	Aikawa et al.

Foreign Patent Documents


05-057363	Mar., 1993	JP
2003-065196	Mar., 2003	JP
2003-343408	Dec., 2003	JP

Primary Examiner: Jeangla; Gertrude Arthur
Attorney, Agent or Firm: Alleman Hall McCoy Russell & Tuttle LLP

Claims

The invention claimed is:

1. A method of reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel, the method comprising the steps of: detecting an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque; calculating a relative rotational position between the input shaft and an output shaft of the controlled section based on the detected information relating to the rotational speed of the input shaft; and accelerating or decelerating at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the calculated relative rotational position.

2. An apparatus for reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel, the apparatus comprising: an input shaft sensor configured to detect an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque; a relative rotational position calculating module configured to calculate a relative rotational position between the input shaft and an output shaft of the controlled section based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor; and an accelerating/decelerating module configured to accelerate or decelerate at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the relative rotational position calculated by the relative rotational position calculating module.

3. The apparatus of claim 2, further comprising an output shaft sensor configured to detect an information relating to a rotational speed of the output shaft of the controlled section, wherein the relative rotational position calculating module is configured to calculate the relative rotational position between the input shaft and the output shaft based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor and the information relating to the rotational speed of the output shaft detected by the output shaft sensor.

4. The apparatus of claim 3, wherein the drive source is an internal combustion engine; wherein the input shaft sensor is configured to detect information relating to the rotational speed of the crankshaft of the internal combustion engine; and wherein the output shaft sensor is configured to detect information relating to the rotational speed of an output shaft of a transmission device included in the controlled section.

5. The apparatus of claim 3 wherein the output shaft sensor is configured to detect information relating to a rotational speed of a drive wheel of a vehicle.

6. The apparatus of claim 3, wherein the output shaft sensor is configured to detect information relating to a rotational speed of a driven sprocket of a drive wheel of a vehicle, which is coupled to a drive sprocket attached to an output shaft of a transmission device through a chain.

7. The apparatus of claim 2, further comprising an output shaft estimating module configured to estimate an information relating to the rotational speed of the output shaft based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor, wherein the relative rotational position calculating module is configured to calculate the relative rotational position between the input shaft and the output shaft based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor and the information relating to the rotational speed of the output shaft estimated by the output shaft estimating module.

8. The apparatus of claim 7, wherein the output shaft estimating module is configured to store the rotational speed of the input shaft detected by the input shaft sensor and estimate the rotational speed of the output shaft at the stored rotational speed of the input shaft, while the slack between the power transmission members apparently exists.

9. The apparatus of claim 7, wherein the output shaft estimating module is configured to store the rotational speed of the input shaft detected by the input shaft sensor as a minimum value when it is determined that the power transmission members are in a state in which they are in contact with each other on the side as a vehicle is decelerated based on the relative rotational position calculated by the relative rotational position calculating module; wherein the output shaft estimating module is configured to restrict storing of a newly detected rotational speed of the input shaft and hold an old stored rotational speed as the minimum value when the newly detected rotational speed is greater than the old stored rotational speed; and wherein the output shaft estimating module is configured to estimate the rotational speed of the output shaft at the minimum value when it is determined that the power transmission members are in a transition to a state in which they are in contact with each other on the side as the vehicle is accelerated based on the relative rotational position calculated by the relative rotational position calculating module.

10. The apparatus of claim 9, wherein the output shaft estimating module is configured to determine that the power transmission members are in a state in which they are in contact with each other on the side as the vehicle is decelerated when a deceleration of the rotational speed of the input shaft detected by the input shaft sensor is continued for a predetermined time.

11. The apparatus of claim 7, wherein the output shaft estimating module is configured to store the rotational speed of the input shaft detected by the input shaft sensor as a maximum value when it is determined that the power transmission members are in a state in which they are in contact with each other on the side as a vehicle is accelerated based on the relative rotational position calculated by the relative rotational position calculating module; wherein the output shaft estimating module is configured to restrict storing of a newly detected rotational speed of the input shaft and hold an old stored rotational speed as the maximum value when the newly detected rotational speed is less than the old stored rotational speed; and wherein the output shaft estimating module is configured to estimate the rotational speed of the output shaft at the maximum value when it is determined that the power transmission members are in a transition to a state in which they are in contact with each other on the side as the vehicle is decelerated based on the relative rotational position calculated by the relative rotational position calculating module.

12. The apparatus of claim 11, wherein the output shaft estimating module is configured to determine that the power transmission members are in a state in which they are in contact with each other on the side as the vehicle is accelerated when an acceleration of the rotational speed of the input shaft detected by the input shaft sensor is continued for a predetermined time.

13. The apparatus of claim 7, wherein the output shaft estimating module is a low-path filter with a large time constant.

14. The apparatus of claim 2, further comprising a relative rotational speed calculating module configured to calculate a relative rotational speed between the input shaft and the output shaft based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor, and wherein the accelerating/decelerating module is configured to accelerate or decelerate the at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the relative rotational speed calculated by the relative rotational speed calculating module and the relative rotational position calculated by the relative rotational position calculating module.

15. The apparatus of claim 14, wherein the relative rotational speed calculating module is a differentiator.

16. The apparatus of claim 14, further comprising: a neutral detecting module configured to detect that a transmission device included in the controlled section is in a neutral position; an acceleration/deceleration adjusting module configured to permit or restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, based on the detection result from the neutral detecting module and the relative rotational speed calculated by the relative rotational speed calculating module.

17. The apparatus of claim 16, wherein the acceleration/deceleration adjusting module is configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when the neutral detecting module detects that the transmission device is in the neutral position.

18. The apparatus of claim 17, wherein the acceleration/deceleration adjusting module is configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when a state in which the relative rotational speed calculated by the relative rotational speed calculating module becomes less than a predetermined value continues for a predetermined time, after the acceleration or deceleration of at least one of the input shaft and the output shaft by the acceleration/decelerating module is restricted in response to a detection that the transmission module is in a neutral position, the detection being made by the neutral detecting module.

19. The apparatus of claim 18, wherein the acceleration/deceleration adjusting module is configured to keep permitting the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module for a predetermined time once after the acceleration or deceleration of the at least one of the input shaft and the output shaft is permitted.

20. The apparatus of claim 16, wherein the acceleration/deceleration adjusting module includes a control flag; wherein the acceleration/deceleration adjusting module is configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the control flag is in an ON-state, while being configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the control flag is in an OFF-state; and wherein the acceleration/deceleration adjusting module is configured to have the control flag in an OFF-state when the neutral detecting module detects that the transmission device is in the neutral position, and to have the control flag in an ON-state when a state in which the relative rotational speed calculated by the relative rotational speed calculating module becomes less than a predetermined value continues a first predetermined time.

21. The apparatus of claim 20, the acceleration/deceleration adjusting module is configured to maintain the control flag in an ON-state for a second predetermined time once the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module is started.

22. The apparatus of claim 14, further comprising an acceleration/deceleration adjusting module configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when the relative rotational position calculated by the relative rotational position calculating module which includes an integrator with a limit reaches an integration limit of the integrator.

23. The apparatus of claim 14, further comprising: an input shaft rotational acceleration calculating module configured to calculate a rotational acceleration of the input shaft based on the rotational speed of the input shaft detected by the input shaft sensor; a relative rotational acceleration calculating module configured to calculate a relative rotational acceleration based on the relative rotational speed calculated by the relative rotational speed calculating module; and an acceleration/deceleration adjusting module configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when the relative rotational speed calculated by the relative rotational speed calculating module, the rotational acceleration of the input shaft calculated by the input shaft rotational acceleration calculating module, or the relative rotational acceleration calculated by relative rotational acceleration calculating module exceeds a predetermined value.

24. The apparatus of claim 14, further comprising an acceleration/deceleration adjusting module configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when a state in which the relative rotational speed calculated by the relative rotational speed calculating module exceeded a predetermined value continues for a predetermined time.

25. The apparatus of claim 14, further comprising: a clutch connection/disconnection detecting module intervened between the input shaft and the output shaft in the power transmission path, and configured to detect a connection/disconnection of the clutch which connects/disconnects the power transmission path; and an acceleration/deceleration adjusting module configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the connection of the clutch is detected by the clutch connection/disconnection detecting module, while being configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the disconnection of the clutch is detected by the clutch connection/disconnection detecting module; wherein the acceleration/deceleration adjusting module is configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when conditions of passing of a predetermined time after a detection of the connection of the clutch by the clutch connection/disconnection detecting module is made and passing of a predetermined time after the relative rotational speed calculated by the relative rotational speed calculating module becomes less than a predetermined value are both met.

26. The apparatus of claim 14, further comprising: a clutch connection/disconnection detecting module intervened between the input shaft and the output shaft in the power transmission path, and configured to detect a connection/disconnection of the clutch which connects/disconnects the power transmission path; and an acceleration/deceleration adjusting module configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the connection of the clutch is detected by the clutch connection/disconnection detecting module, while being configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the disconnection of the clutch is detected by the clutch connection/disconnection detecting module; wherein the acceleration/deceleration adjusting module is configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, after passing of a predetermined time from the detection of the connection of the clutch by the clutch connection/disconnection detecting module, and when the predetermined time is passed after the relative rotational speed calculated by the relative rotational speed calculating module becomes less than a predetermined value.

27. The apparatus of claim 2, wherein the relative rotational position calculating module is an integrator or an integrator with a limit.

28. The apparatus of claim 2, wherein the drive source is an internal combustion engine of forced-ignition type, and the accelerating/decelerating module is configured to accelerate or decelerate the input shaft by advancing/retarding an ignition timing of the engine.

29. The apparatus of claim 2, wherein the drive source is an electric motor, and the accelerating/decelerating module is configured to accelerate or decelerate the input shaft by increasing or decreasing a supply current to the electric motor.

30. The apparatus of claim 2, wherein the accelerating/decelerating module includes an accelerating/decelerating device coupled to at least one of the input shaft and the output shaft.

31. The apparatus of claim 30, wherein the accelerating/decelerating module further includes a control module configured to output an instruction to the accelerating/decelerating device, and the instruction includes a timing to start the deceleration or acceleration, and at least one of an amount of deceleration or acceleration and a timing to end the deceleration or acceleration.

32. The apparatus of claim 31, wherein the control module is configured to calculate the timing to start the deceleration or acceleration based on the relative rotational position calculated by the relative rotational position calculating module.

33. The apparatus of claim 31, wherein the control module is configured to calculate the at least one of the amount of the deceleration or acceleration and a timing to end the deceleration or acceleration, based on at least one of a relative rotational position between the input shaft and the output shaft, a rotational speed of the input shaft and/or the output shaft, an increase/decrease rate of the rotational speed, a rotational speed difference between the input shaft and the output shaft, an increase/decrease rate of the rotational speed difference, and an opening of the throttle which is configured to adjust an output of the drive source, and an increase/decrease rate of the opening of the throttle.

34. The apparatus of claim 2, wherein the relative rotational position calculating module is configured to estimate the relative rotational position at a state in which the power transmission members are in contact with each other on the side as the vehicle is decelerated or accelerated, when the relative rotational speed between the input shaft and the output shaft is less than a predetermined value based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor, or when a deceleration or acceleration of rotation of the input shaft detected by the input shaft sensor continues for a predetermined time.

35. The apparatus of claim 2, further comprising: a path connecting/disconnecting module intervened between the input shaft and the output shaft in the power transmission path, and configured to connect/disconnect the power transmission path; and an acceleration/deceleration adjusting module configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module, when the power transmission path is disconnected by the path connecting/disconnecting module.

36. The apparatus of claim 35, wherein the path connecting/disconnecting module includes a transmission device having a neutral position, or a clutch.

37. The apparatus of claim 2, further comprising: a clutch connection/disconnection detecting module intervened between the input shaft and the output shaft in the power transmission path, and configured to detect a connection/disconnection of the clutch which connects/disconnects the power transmission path; and an acceleration/deceleration adjusting module configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the connection of the clutch is detected by the clutch connection/disconnection detecting module, while being configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the disconnection of the clutch is detected by the clutch connection/disconnection detecting module.

38. The apparatus of claim 37, wherein the acceleration/deceleration adjusting module is configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module until it passes a predetermined time after a detection of the connection of the clutch by the clutch connection/disconnection detecting module is made.

39. The apparatus of claim 38, wherein the acceleration/deceleration adjusting module is configured to change the predetermined time according to the traveling speed of the vehicle.

40. The apparatus of claim 37, further comprising a relative rotational speed calculating module configured to calculate the relative rotational speed between the input shaft and the output shaft based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor; wherein the acceleration/deceleration adjusting module includes a first sub-control flag, a second sub-control flag, and a main-control flag; wherein the acceleration/deceleration adjusting module is configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the main-control flag is in an ON-state, while being configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the main-control flag is in an OFF-state; wherein the acceleration/deceleration adjusting module is configured to have the main-control flag in the ON-state when both the first sub-control flag and the second sub-control flag are in an ON-state, while being configured to have the main-control flag in the OFF-state when either of the sub-control flags are in an OFF-state; wherein the acceleration/deceleration adjusting module is configured to have the first sub-control flag in an OFF-state until it passes a predetermined time after a detection of the connection of the clutch by the clutch connection/disconnection detecting module is made and, to have the first sub-control flag in an ON-state after a lapse of the predetermined time; wherein the acceleration/deceleration adjusting module is configured to have the second sub-control flag in an OFF-state until it passes a predetermined time after the relative rotational speed calculated by the relative rotational speed calculating module becomes less than a predetermined value and, then, to have the second sub-control flag in an ON-state.

41. The apparatus of claim 37, further comprising a relative rotational speed calculating module configured to calculate the relative rotational speed between the input shaft and the output shaft based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor, wherein the acceleration/deceleration adjusting module includes a sub-control flag and a main-control flag; wherein the acceleration/deceleration adjusting module is configured to have the sub-control flag in an OFF-state until it passes a predetermined time after a detection of the connection of the clutch by the clutch connection/disconnection detecting module and, then, to have the sub-control flag in an ON-state; wherein the acceleration/deceleration adjusting module is configured to have the main-control flag in an OFF-state if the relative rotational speed calculated by the relative rotational speed calculating module is less than a predetermined value when the sub-control flag becomes in the ON-state, until it passes a predetermined time since then, and to have the main-control flag in an ON-state. wherein the acceleration/deceleration adjusting module is configured to permit the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the main-control flag is in an OFF-state, while being configured to restrict the acceleration or deceleration of the at least one of the input shaft and the output shaft by the accelerating/decelerating module when the main-control flag is in an ON-state.

42. The apparatus of claim 2, wherein the accelerating/decelerating module includes: a deceleration/acceleration instruction value pattern memory module configured to store a time-sequential pattern of accelerating or decelerating the at least one of the input shaft and the output shaft; and a deceleration/acceleration instruction value calculating module configured to refer to the deceleration/acceleration instruction value pattern memory module based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor and the relative rotational position calculated by the relative rotational position calculating module, and to calculate an amount of acceleration or deceleration of the at least one of the input shaft and the output shaft; wherein the accelerating/decelerating module is configured to accelerate or decelerate the at least one of the input shaft and the output shaft based on the amount of acceleration or deceleration calculated by the deceleration/acceleration instruction value calculating module.

43. The apparatus of claim 42, wherein the deceleration/acceleration instruction value calculating module further includes: a rotational speed pattern memory module configured to store a time-sequential pattern of the information relating to the rotational speed of the input shaft; a relative rotational position pattern memory module configured to store a time-sequential pattern of the relative rotational position; and a simulation model which simulates a configuration of the vehicle to take the amount of acceleration or deceleration of the at least one of the input shaft and the output shaft as an input value, and output the rotational speed of the input shaft and the relative rotational position based on the input value; wherein the deceleration/acceleration instruction value calculating module is configured to calculate an information relating to the rotational speed of the input shaft, based on the pattern stored in the deceleration/acceleration instruction value pattern memory module; wherein the deceleration/acceleration instruction value calculating module is configured to optimize the pattern stored in the deceleration/acceleration instruction value pattern memory module so that the information relating to the calculated rotational speed and the rotational position approaches the patterns stored in the rotational speed pattern memory module and the relative rotational position pattern memory module, respectively.

44. The apparatus of claim 2, further comprising: a suspension displacement sensor configured to detect a displacement of a suspension; and a slack calculating module configured to calculate a slack in a chain or a belt which drives a drive wheel based on the displacement of the suspension detected by the suspension displacement sensor, wherein the accelerating/decelerating module is configured to accelerate or decelerate at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the relative rotational position calculated by the relative rotational position calculating module and the slack in the chain or belt calculated by slack calculating module.

45. A vehicle, comprising: an apparatus for reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel, the apparatus includes: an input shaft sensor configured to detect an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque; a relative rotational position calculating module configured to calculate a relative rotational position between the input shaft and an output shaft of the controlled section based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor; and an accelerating/decelerating module configured to accelerate or decelerate at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the relative rotational position calculated by the relative rotational position calculating module.

Description

TECHNICAL FIELD

The present invention relates to a method of reducing a contact speed and/or transmitting torque between power transmission members in the power transmission path from a drive source to a wheel, when a slack between the power transmission members is apparently gone upon an acceleration or deceleration of the drive source or the wheel, and to an apparatus carrying out the method and the vehicle being equipped with the apparatus.

BACKGROUND OF THE INVENTION

Typically, a vehicle having a drive source includes various power transmission members, such as mating gears, a dog clutch including a dog teeth and a dog hole, a chain and a sprocket, and mating splines in the power transmission path from the drive source to a wheel. Each of these power transmission members engages with other adjacent power transmission members with a predetermined slack. Apparently, this slack does not exist during steady power transmitting condition. However, by changing a rotational speed of the drive source or applying an engine brake, a rotational speed difference occurs between a power transmission member upstream in the power transmission path and another adjacent power transmission member downstream in the power transmitting path. Thereby, contact surfaces of these power transmission members depart from each other temporarily within a range of the slack. The departed power transmission members, eventually, re-contact with each other, but this time, with contact surfaces on the opposite direction of the slack. If the re-contact speed and/or transmitting torque at the time of re-contact is relatively large, an operator/passenger of the vehicle may feel an unpleasant shock transmitted throughout the entire body of the vehicle.

To address the problem, for example, Utility Model Publication Unexamined No. H5-57363 discloses a method of reducing the transmitting torque between the power transmission members by controlling an ignition based on a throttle opening of an internal combustion engine which is the drive source. However, in such control based on the throttle opening, since a retard compensation is performed irrespective of a change in torque of the internal combustion engine, the retard compensation is not carried out at a suitable timing. Therefore, another problem in which an acceleration performance falls arises.

Accordingly, Patent Publication Unexamined No. 2003-65196 and Patent Publication Unexamined No. 2003-343408 disclose a method of reducing the transmitting torque between the power transmission members by calculating a degree of acceleration/deceleration of one of the power transmission members based on a rate of increase/decrease (derivative value) in the rotational speed of the power transmission member, and controlling an ignition based on the degree of acceleration/deceleration when the degree of acceleration/deceleration exceeds a predetermined value. However, such control does not operate when the degree of acceleration/deceleration is relatively small.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the above-mentioned conditions and, thus, provides an improved method and apparatus of controlling the re-contact speed and/or the transmission torque at the time of re-contact between power transmission members in a power transmission path from a drive source to a wheel of a vehicle, when accelerating/decelerating the vehicle.

According to one aspect of the invention, the method of reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel. The method comprises the steps of detecting an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque, calculating a relative rotational position between the input shaft and an output shaft of the controlled section based on the detected information relating to the rotational speed of the input shaft, and accelerating or decelerating at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the calculated relative rotational position.

According to another aspect of the invention, the apparatus for reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel. The apparatus comprises an input shaft sensor configured to detect an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque, a relative rotational position calculating module configured to calculate a relative rotational position between the input shaft and an output shaft of the controlled section based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor, and an accelerating/decelerating module configured to accelerate or decelerate at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the relative rotational position calculated by the relative rotational position calculating module.

According to still another aspect of the invention, the vehicle comprises an apparatus for reducing at least one of a contact speed and a transmitting torque between power transmission members, when a slack between the power transmission members in a power transmission path from a drive source to a wheel is apparently gone upon an acceleration or deceleration of the drive source or the wheel. The apparatus includes an input shaft sensor configured to detect an information relating to a rotational speed of an input shaft of a controlled section in the power transmission path, the controlled section being defined as to be reduced in the at least one of the contact speed and the transmitting torque, a relative rotational position calculating module configured to calculate a relative rotational position between the input shaft and an output shaft of the controlled section based on the information relating to the rotational speed of the input shaft detected by the input shaft sensor, and an accelerating/decelerating module configured to accelerate or decelerate at least one of the input shaft and the output shaft so as to reduce the at least one of the contact speed and the transmitting torque between the power transmission members based on the relative rotational position calculated by the relative rotational position calculating module.

The vehicle is equipped with the drive source and arbitrary number of wheels such as a motorcycle, a four-wheel vehicle, etc. In the power transmission path of the vehicle from the drive source to the wheel, there typically exists a slack between the power transmission members (each of the power transmission members typically include a rotational shaft). In the method of controlling the re-contact described above, the information relating to the rotational speed of the rotational shaft of one of the power transmission members on the drive source side (i.e., the input shaft of the controlled section) is detected.

Here, the power transmission members with the slack to be controlled may be selected from any power transmission members which are engaged to each other, in the power transmission path. This section to which the slack thereof is controlled by the control is defined as the controlled section. When paying attention to the controlled section, the total amount of the slack never changes, however, an upstream-side slack increases while a downstream-side slack decreases, and vice versa, depending on acceleration and deceleration of at least one of the power transmission members, and directions of rotation of the power transmission members.

The power transmission members includes any gears, dog clutches, a sprocket and a chain, splines, and a coupling damper, in the power transmission path. Therefore, if a slack between two mating gears (i.e., a backlash of the gears) are to be controlled, a rotational shaft of the upstream-side gear is defined as the input shaft of the controlled section, and the rotational shaft of the downstream-side gear is defined as the output shaft of the controlled section. In addition if each of the gears are spline-fitted on the respective rotational shaft, a slack between the gear and the respective rotational shaft may be included in the slack to be controlled. As used herein, the term "slack" includes backlash.

The information relating to the shaft rotational speed (e.g., the rotational speed of the input shaft) may be detected using various well-known shaft rotational speed detecting devices. The detection value may be directly, the rotational speed of the rotational shaft, or other related information, such as a rate of increase/decrease in the rotational speed (i.e., a derivative value), an integration value of the rotational speeds, and a difference value of the rotational speeds, etc.

A relative rotational position between the input shaft and the output shaft of the controlled section is calculated based on the information relating to the rotational speed of the input shaft (e.g., a change in the rotational speed of the input shaft). Typically, in a steady traveling state of the vehicle, the input shaft and the output shaft are synchronized in rotation, and the relative rotational position between them remains unchanged. Thus, for example, if the rotational speed of the input shaft is changed from this steady traveling state, the rotational speed of the output shaft remains approximately unchanged while the movement of the input shaft and the output shaft is within a range of the slack. Therefore, it may be possible to assume the rotational speed of the output shaft is the same as the rotational speed of the input shaft when the power transmission members are departed from each other.

Since the total amount of the slack is never changed, it is possible to measure the amount beforehand. Thus, the contact speed and/or the transmitting torque (and/or a contact timing) between the power transmission members may be calculated based on the relative rotational speed or the relative rotational position calculated as mentioned above, and the rotational speed of the input shaft. Therefore, an acceleration/deceleration shock transmitted through the entire vehicle can be reduced, and discomfort given to an operator/passenger may also be reduced by accelerating or decelerating at least one of the input shaft and the output shaft so that the contact speed and/or the transmitting torque between the power transmission members calculated as above becomes less.

The relative rotational position between the input shaft and the output shaft is calculated only from the information relating to the rotational speed of the input shaft. As described above, this may be realized by estimating the information relating to the rotational speed of the output shaft based on the information relating to the rotational speed of the input shaft, and calculating the relative rotational position based on the information relating to the rotational speeds of both the input shaft and the output shaft. Instead of estimating the information relating to the rotational speed of the output shaft, the rotational speed may be detected directly.

Further, at least one of the input shaft and the output shaft is accelerated or decelerated based on the relative rotational position between the input shaft and the output shaft. Instead of this configuration, for example, the relative rotational speed between the input shaft and the output shaft may be calculated based on the information relating to the rotational speed of the input shaft which is detected, and the at least one of the input shaft and the output shaft may be accelerated or decelerated based on both the relative rotational speed and the relative rotational position so that the contact speed and/or the transmitting torque between the power transmission members become smaller. This configuration also achieves similar effects as that of the independent use of the relative rotational position as described above.

Since the amount of the slack may be measured beforehand, it is possible to re-contact the power transmission members in any desired pattern if the relative rotational position or the relative rotational position and the relative rotational speed between the power transmission members are obtained. The re-contact pattern may include information such as start timing of acceleration or deceleration of at least one of the input shaft and the output shaft. This is because the start timing is at least necessary if the time range of the acceleration/deceleration pattern is fixed.

In order to reliably make the re-contact speed and/or the transmitting torque between the power transmission members smaller by knowing the re-contact timing more precisely, it is possible to further determine an end timing of acceleration or deceleration, or a continuation time or an amount of the continuation of acceleration or deceleration from the start timing (the determined result typically is a control instruction value), and to terminate the acceleration or the deceleration at the re-contact timing of the power transmission members. The rate of the acceleration or the deceleration may be constant during the continuation of the acceleration or the deceleration. The rate of the acceleration or the deceleration may be variable so that the relative rotational speed between the power transmission members is zero at the time of re-contact between the power transmission members.

As the drive source, an internal combustion engine, an electric motor, etc. may be used. If an internal combustion engine of forced-ignition type is used, it may be possible to control the deceleration/acceleration by carrying out a retard/advance of an ignition timing. The acceleration/deceleration may also be controlled by adjusting an amount of fuel supply to the engine. Further, the acceleration/deceleration may be controlled by adjusting an amount of intake through a throttle or a bypass valve of the engine.

Instead, if an electric motor is used as the drive source, it may be possible to control the acceleration/deceleration by adjusting a supply current to the electric motor. Alternatively, it is possible to couple an accelerating/decelerating device with the input shaft and/or the output shaft of the controlled section, and to control the acceleration/deceleration by the accelerating/decelerating device independently from the drive source, or a combination of the accelerating/decelerating device and the drive source. As the accelerating/decelerating device, any types of power generating devices, frictional resistance generating devices, etc. which is capable of accelerating/decelerating the input shaft and/or the output shaft, or a combination of these devices may be used.

The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a conceptual diagram for explaining a power transmission path from a drive source to a wheel of a vehicle which includes the drive source according to an embodiment of the present invention, and a range which the present invention intends to control;

FIG. 2 is a block diagram showing a conceptual configuration of a control apparatus of the vehicle according to the embodiment of the present invention;

FIG. 3 is a table showing examples of control instruction values and detection data for calculating the instruction values, used for a control logic in the control module shown in FIG. 2;

FIG. 4 is a control block diagram showing an example of a calculating device shown in FIG. 2;

FIG. 5 is a control block diagram showing an example when using a value estimated from an input shaft rotational speed, as an output shaft rotational speed in the control system shown in FIG. 4;

FIG. 6 is a block diagram showing a 1st Embodiment, in which the control apparatus according to the present invention is applied to a vehicle which is equipped with an internal combustion engine of forced-ignition type as the drive source;

FIG. 7A is a sectional view showing an example of slack in a transmission device shown in FIG. 6;

FIG. 7B is a VIIb-VIIb view of FIG. 7A;

FIG. 8A is a graph for explaining effects of the control according to a method of the 1st Embodiment of the present invention, showing a change in a throttle opening on y-axis with respect to time on x-axis;

FIG. 8B is a corresponding graph of FIG. 8A, showing a change in rotational speeds of the input shaft and the output shaft when a particular control is not carried out;

FIG. 8C is a corresponding graph of FIG. 8A, showing a change in rotational speeds of the input shaft and the output shaft when a conventional ignition retard control based on an increase/decrease rate of throttle opening is carried out;

FIG. 8D is a corresponding graph of FIG. 8A, showing a change in rotational speeds of the input shaft and the output shaft when a control according to the present invention is carried out;

FIG. 8E is a corresponding graph of FIG. 8A, showing a change in an estimated value of a dog relative rotational position;

FIG. 9A is a graph showing results of a chassis test when no particular control such as of the present invention is carried out, showing a change in a throttle opening on y-axis with respect to time on x-axis;

FIG. 9B is a corresponding graph of FIG. 9A, showing a change in a longitudinal acceleration of the vehicle body;

FIG. 9C is a corresponding graph of FIG. 9A, showing a change in a rotational speed (where the thick line indicates an engine speed (i.e., an input shaft rotational speed), the two-dot chain line indicates a converted value of a rotational speed of a drive shaft (i.e., an output shaft rotational speed) so as to be equivalent to the engine speed considering the gear ratio, and the thin line indicates a converted value of a rotational speed of a wheel so as to be equivalent to the engine speed considering the gear ratio, respectively);

FIG. 9D is a corresponding graph of FIG. 9A, showing a change in a torque of the drive shaft;

FIG. 9E is a corresponding graph of FIG. 9A, showing a change in an average effective pressure in an internal combustion engine cylinder (here, the internal combustion engine is of four-cylinder, and the average effective pressure is an average value of four cylinders);

FIG. 9F is a corresponding graph of FIG. 9A, showing a change in an ignition retard amount;

FIG. 9G is a corresponding graph of FIG. 9A, showing a change in a dog relative rotational position (estimated value);

FIG. 10A is a graph showing results of the chassis test when the control according to the 1st Embodiment of the present invention is carried out, showing a change in a throttle opening on y-axis with respect to time on x-axis;

FIG. 10B is a corresponding graph of FIG. 10A, showing a change in a longitudinal acceleration of the vehicle body;

FIG. 10C is a corresponding graph of FIG. 10A, showing a change in a rotational speed (where the thick line indicates an engine speed (i.e., an input shaft rotational speed), the two-dot chain line indicates a converted value of a rotational speed of a drive shaft (i.e., an output shaft rotational speed) so as to be equivalent to the engine speed considering the gear ratio, and the thin line indicates a converted value of a rotational speed of a wheel so as to be equivalent to the engine speed considering the gear ratio, respectively);

FIG. 10D is a corresponding graph of FIG. 10A, showing a change in a torque of the drive shaft;

FIG. 10E is a corresponding graph of FIG. 10A, showing a change in an average effective pressure in an internal combustion engine cylinder (here, the internal combustion engine is of four-cylinder, and average effective pressure is an average value of four cylinders);

FIG. 10F is a corresponding graph of FIG. 10A, showing a change in an ignition retard amount;

FIG. 10G is a corresponding graph of FIG. 10A, showing a change in a dog relative rotational position (estimated value);

FIG. 11A is a graph showing results of a real vehicle run test when no particular control such as of the present invention is carried out, showing a change in a throttle opening on y-axis with respect to time on x-axis;

FIG. 11B is a corresponding graph of FIG. 11A, showing a change in a longitudinal acceleration of the vehicle body;

FIG. 11C is a corresponding graph of FIG. 11A, showing a change in a rotational speed (where the thick line indicates an engine speed (i.e., an input shaft rotational speed), the two-dot chain line indicates a converted value of a rotational speed of a drive shaft (i.e., an output shaft rotational speed) so as to be equivalent to the engine speed considering the gear ratio, and the thin line indicates a converted value of a rotational speed of a wheel so as to be equivalent to the engine speed considering the gear ratio, respectively);

FIG. 11D is a corresponding graph of FIG. 11A, showing a change in a torque of the drive shaft;

FIG. 12A is a graph showing the results of a real vehicle run test when the control according to the 1st Embodiment of the present invention is carried out, showing a change in a throttle opening on y-axis with respect to time on x-axis;

FIG. 12B is a corresponding graph of FIG. 12A, showing a change in a longitudinal acceleration of the vehicle body;

FIG. 12C is a corresponding graph of FIG. 12A, showing a change in a rotational speed (where the thick line indicates an engine speed (i.e., an input shaft rotational speed), the two-dot chain line indicates a converted value of a rotational speed of a drive shaft (i.e., an output shaft rotational speed) so as to be equivalent to the engine speed considering the gear ratio, and the thin line indicates a converted value of a rotational speed of a wheel so as to be equivalent to the engine speed considering the gear ratio, respectively);

FIG. 12D is a corresponding graph of FIG. 12A, showing a change in a torque of the drive shaft;

FIG. 13 is a block diagram showing a 2nd Embodiment in which the control apparatus according to the present invention is applied to a vehicle which is equipped with an electric motor as the drive source;

FIG. 14 is a control block diagram showing a 3rd Embodiment of the control apparatus according to the present invention, and shows another example of the calculating device when using a value estimated from the input shaft rotational speed shown in FIG. 5;

FIG. 15A is a graph for explaining a function of a control apparatus according to the 3rd Embodiment shown in FIG. 14, showing a change in rotational speeds of the input shaft and the output shaft on y-axis with respect to time on x-axis;

FIG. 15B is a corresponding graph of FIG. 15A, showing a change in a relative rotational position estimated value;

FIG. 16 is a flowchart for explaining an operation of the output shaft rotational speed estimating module of the control apparatus according to the 3rd Embodiment shown in FIG. 14;

FIG. 17 is a control block diagram showing a 4th Embodiment of the control apparatus according to the present invention, and shows still another example of the calculating device when using a value estimated from the input shaft rotational speed shown in FIG. 5;

FIG. 18A is a graph for explaining a function of a control apparatus according to the 4th Embodiment shown in FIG. 17, showing a change in rotational speeds of the input shaft and the output shaft;

FIG. 18B is a corresponding graph of FIG. 18A, showing a change in a relative rotational position estimated value;

FIG. 19 is a flowchart for explaining an operation of the output shaft rotational speed estimating module of the control apparatus according to the 4th Embodiment shown in FIG. 17;

FIG. 20 is a control block diagram showing a 5th Embodiment of the control apparatus according to the present invention, and shows still another example of the calculating device when using a value estimated from the input shaft rotational speed shown in FIG. 5;

FIG. 21A is a graph for explaining a function of a control apparatus according to the 5th Embodiment shown in FIG. 20, showing a change in rotational speeds of the input shaft and the output shaft;

FIG. 21B is a corresponding graph of FIG. 21A, showing a change in a relative rotational position estimated value;

FIG. 22 is a flowchart for explaining an operation of the output shaft rotational speed estimating module of the control apparatus according to the 5th Embodiment shown in FIG. 20;

FIG. 23A is a graph for explaining a function of a control apparatus according to a 6th Embodiment, showing a change in rotational speeds of the input shaft and an output shaft during a moderate deceleration on y-axis with respect to time on x-axis;

FIG. 23B is a corresponding graph of FIG. 23A, showing a change in a relative rotational position estimated value during the control according to the 1st Embodiment;

FIG. 23C is a corresponding graph of FIG. 23A, showing a change in a relative rotational position estimated value during the control according to the 6th Embodiment;

FIG. 24 is a control block diagram showing a configuration of the calculating device of the control apparatus according to the 6th Embodiment shown in FIG. 23C, and shows an example of the calculating device when using detection values of both the input shaft rotational speed and the output shaft rotational speed as shown in FIG. 4;

FIG. 25 is a control block diagram showing another configuration of the calculating device of the control apparatus according to the 6th Embodiment shown in FIG. 23C, and shows an example of the calculating device when using a value estimated from the input shaft rotational speed shown in FIG. 5;

FIG. 26 is a flowchart for explaining an operation of the control module of the calculating device according to the 6th Embodiment shown in FIGS. 24 and 25.

FIG. 27A is a graph for explaining a function of a control apparatus according to a 7th Embodiment, showing a change in rotational speeds of the input shaft and the output shaft during a moderate deceleration on y-axis with respect to time on x-axis;

FIG. 27B is a corresponding graph of FIG. 27A, and shows a relative rotational position estimated value during the control according to the 1st Embodiment;

FIG. 27C is a corresponding graph of FIG. 27A, and shows a relative rotational position estimated value during the control according to the 7th Embodiment;

FIG. 28 is a control block diagram showing a configuration of the calculating device of the control apparatus according to the 7th Embodiment shown in FIG. 27C, and shows an example of the calculating device when using detection values of both the input shaft rotational speed and the output shaft rotational speed as shown in FIG. 4;

FIG. 29 is a control block diagram showing another configuration of the calculating device of the control apparatus according to the 7th Embodiment shown in FIG. 27C, and shows an example of the calculating device when using a value estimated from the input shaft rotational speed shown in FIG. 5;

FIG. 30 is a flowchart for explaining an operation of the control module of the calculating device according to the 7th Embodiment shown in FIGS. 28 and 29;

FIG. 31 is a block diagram showing 8th through 11th Embodiments in which the control apparatus according to the present invention is applied to a vehicle which is equipped with an internal combustion engine of forced-ignition type as the drive source;

FIG. 32 is a control block diagram showing a configuration of the calculating device of the control apparatus according to the 8th Embodiment, and shows an example of the calculating device when using detection values of both the input shaft rotational speed and the output shaft rotational speed as shown in FIG. 4;

FIG. 33A is a graph for explaining a function of the control apparatus according to the 8th Embodiment shown in FIG. 32, showing a change in rotational speeds of the input shaft and the output shaft when shifting of gears through a neutral position;

FIG. 33B is a corresponding graph of FIG. 33A, showing a change in a relative rotational position estimated value;

FIG. 34 is a flowchart for explaining an operation of the instruction value output ON/OFF module of the calculating device according to the 8th Embodiment shown in FIG. 32;

FIG. 35 is a control block diagram showing a configuration of the calculating device of the control apparatus accordi