Control apparatus and control method for vehicular drive apparatus

• US 20080215214A1
• Filed: 11/30/2007
• Published: 09/04/2008
• Est. Priority Date: 12/04/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tabata, Atsushi, Matsubara, Tooru, Katoh, Hidenori, Kaifuku, Masakazu
• Granted Patent: US 8,655,560 B2
• Time in Patent Office: Days
• US Class Current: 701/51
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/485 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/068 Engine exhaust temperature
• CPC Class Codes: B60W 2510/0685 Engine crank angle
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/107 Temperature
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2520/10 : Longitudinal speed
• CPC Class Codes: B60W 2520/105 : Longitudinal acceleration
• CPC Class Codes: B60W 2520/28 : Wheel speed
• CPC Class Codes: B60W 2530/10 : Weight
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2540/16 : Ratio selector position
• CPC Class Codes: B60W 2710/0605 : Throttle position
• CPC Class Codes: B60W 50/02 : Ensuring safety in case of control system failures, e.g. by diagnosing, circumventing or fixing failures
• CPC Class Codes: F16H 2037/0873 : with switching, e.g. to change ranges
• CPC Class Codes: F16H 2061/1208 : with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 61/12 : Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A control apparatus and a control method for a vehicular drive apparatus that includes a driving power source, and a power transmission device that transmits power from the driving power source to a drive wheel are provided. It is determined that a malfunction occurs in the power transmission device, when a comparison value remains equal to or above a predetermined value for a predetermined period. The comparison value is obtained by making a comparison between an actual value and a theoretical value that relate to a rotational speed of a predetermined rotational member that constitutes at least a part of the vehicular drive apparatus. The predetermined period is set according to an operating state of the power transmission device. Thus, it is possible to reduce the possibility that it is erroneously determined that a malfunction occurs, and to quickly determine that a malfunction occurs.

Claims

1. A control apparatus for a vehicular drive apparatus that includes a driving power source, and a power transmission device that transmits power from the driving power source to a drive wheel, the control apparatus comprising

a malfunction determination device that determines that a malfunction occurs in the power transmission device, when a comparison value remains equal to or above a predetermined value for a predetermined period,

wherein:

the comparison value is obtained by making a comparison between an actual value and a theoretical value that relate to a rotational speed of a predetermined rotational member that constitutes at least a part of the vehicular drive apparatus; and

the malfunction determination device sets the predetermined period according to an operating state of the power transmission device.

2. The control apparatus according to claim 1, wherein

when an actual rotational speed of the predetermined rotational member is low, the malfunction determination device sets the predetermined period to a long period, as compared to when the actual rotational speed is high.

3. The control apparatus according to claim 1, wherein

when the comparison value is small, the malfunction determination device sets the predetermined period to a long period, as compared to when the comparison value is large.

4. The control apparatus according to claim 1, wherein

the comparison value is a difference between an actual rotational speed and a theoretical rotational speed of the predetermined rotational member.

5. The control apparatus according to claim 4, wherein

the theoretical rotational speed is calculated based on a value relating to an output rotational speed of at least a part of the power transmission device, and a speed ratio of the at least the part of the power transmission device.

6. The control apparatus according to claim 1, wherein

the comparison value is a ratio of an actual rotational speed of the predetermined rotational member to a theoretical rotational speed of the predetermined rotational member.

7. The control apparatus according to claim 6, wherein

the theoretical rotational speed is calculated based on a value relating to an output rotational speed of at least a part of the power transmission device, and a speed ratio of the at least the part of the power transmission device.

8. The control apparatus according to claim 1, wherein

the comparison value is a difference between an actual speed ratio and a theoretical speed ratio of at least a part of the power transmission device.

9. The control apparatus according to claim 1, further comprising

a fail-safe control device that executes a fail-safe control to prevent the predetermined rotational member from overspeeding, when the malfunction determination device determines that a malfunction occurs in the power transmission device.

10. The control apparatus according to claim 9, wherein

the fail-safe control device prevents the predetermined rotational member from overspeeding by reducing the driving power transmitted by the predetermined rotational member.

11. The control apparatus according to claim 1, wherein

the power transmission device includes a differential portion, and a shift portion;

the differential portion includes a differential mechanism that includes a first element connected to an engine, a second element connected to a first motor, and a third element connected to a transmitting member and a second motor, and the differential mechanism distributes output from the engine to the first motor and the transmitting member;

the shift portion is provided in a power transmission path from the transmitting member to the drive wheel, and functions as an automatic transmission; and

the malfunction determination device determines whether a malfunction occurs in the shift portion.

12. The control apparatus according to claim 11, further comprising

a fail-safe control device that executes a fail-safe control to prevent at least one of the transmitting member and the second motor from overspeeding, when the malfunction determination device determines that a malfunction occurs in the shift portion.

13. The control apparatus according to claim 12, wherein

the fail-safe control device executes the fail-safe control that reduces power that is output from at least one of the engine and the second motor, and that is input to the shift portion.

14. The control apparatus according to claim 12, wherein

the differential portion is operated as a continuously variable transmission by controlling an operating state of the first motor.

15. The control apparatus according to claim 11, wherein

the differential portion is operated as a continuously variable transmission by controlling an operating state of the first motor.

16. A control method for a vehicular drive apparatus that includes a driving power source, and a power transmission device that transmits power from the driving power source to a drive wheel, the control method comprising

determining that a malfunction occurs in the power transmission device, when a comparison value remains equal to or above a predetermined value for a predetermined period,

wherein:

the comparison value is obtained by making a comparison between an actual value and a theoretical value that relate to a rotational speed of a predetermined rotational member that constitutes at least a part of the vehicular drive apparatus; and

the predetermined period is set according to an operating state of the power transmission device.

17. The control method according to claim 16, wherein

when an actual rotational speed of the predetermined rotational member is low, the predetermined period is set to a long period, as compared to when the actual rotational speed is high.

18. The control method according to claim 16, wherein

when the comparison value is small, the predetermined period is set to a long period, as compared to when the comparison value is large.

19. The control method according to claim 16, wherein

the comparison value is a difference between an actual rotational speed and a theoretical rotational speed of the predetermined rotational member.

20. The control method according to claim 16, wherein

the comparison value is a ratio of an actual rotational speed of the predetermined rotational member to a theoretical rotational speed of the predetermined rotational member.

21. The control method according to claim 16, wherein

the comparison value is a difference between an actual speed ratio and a theoretical speed ratio of at least a part of the power transmission device.

22. The control method according to claim 16, further comprising

executing a fail-safe control to prevent the predetermined rotational member from overspeeding, when it is determined that a malfunction occurs in the power transmission device.