Method of controlling power output apparatus

• US 6,380,640 B1
• Filed: 09/18/2000
• Issued: 04/30/2002
• Est. Priority Date: 10/07/1999
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Eto, Jiro, Kanamori, Akihiko, Kawabata, Yasutomo
• Primary Examiner(s): Waks, Joseph
• Application Number:
  US09/664,961
• Time in Patent Office: 589 Days
• Field of Search: 290/40.C, 290/45, 290/38.R, 310/114, 310/112, 310/92, 310/78, 701/22, 701/113, 322/16, 180/65.2, 123/179.3
• US Class Current: 290/40.00C
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/448 Electrical distribution type
• 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 10/26 for electrical energy, e.g. batteries or capacitors
• 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 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: F16H 3/727 with at least two dynamo electric machines for creating an electric power path inside the gearing, e.g. using generator and motor for a variable power torque path special adapted for a hybrid electric vehicle B60K6/20
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/946 Characterized by control of driveline clutch

Abstract

A method of controlling a power output apparatus including an engine, a drive shaft, first and second electric motors and a coupling device is provided. When a hybrid vehicle starts from rest, ECU operates to run the vehicle in EV mode only by means of one of the electric motors. When the operating point of the drive shaft passes a boundary that separates the underdrive region from the overdrive region, and enters the overdrive region, fuel supply to the engine is started so as to start the engine, and the coupling device is controlled so that coupling of the rotary shaft of the second electric motor is switched from the first coupling state in which the rotary shaft is coupled with the drive shaft to the second coupling state in which the rotary shaft is coupled with the output shaft of the engine. After switching, the ECU operates to run the vehicle in HV mode, utilizing the engine and the first and second electric motors.

Claims

1. A method of controlling a power output apparatus which includes an engine including an output shaft, a drive shaft that outputs power, a power adjusting device that includes a first electric motor and is coupled with the output shaft and the drive shaft, said power adjusting device being capable of adjusting at least the power transmitted to the drive shaft by means of the first electric motor, a second electric motor having a rotary shaft, and a coupling device operable to couple the rotary shaft of the second electric motor to at least one of the drive shaft and the output shaft, said power output apparatus having an operating region represented by the relationship between the torque and the speed of rotation, said operating region being divided by a predetermined boundary into a first region in which the rotary shaft of the second electric motor is coupled with the drive shaft, and a second region in which the rotary shaft of the second electric motor is coupled with the output shaft, said method comprising the steps of:

(a) operating the second electric motor while keeping the engine stopped when an operating point of the drive shaft lies in the first region and the rotary shaft of the second electric motor is coupled with the drive shaft through the coupling device; and

(b) when the operating point of the drive shaft passes the boundary and enters the second region, starting fuel supply to the engine so as to start the engine, while at the same time causing the coupling device to switch coupling of the rotary shaft of the second electric motor from a first coupling state in which the rotary shaft is coupled with the drive shaft, to a second coupling state in which the rotary shaft is coupled with the output shaft of the engine.

2. A method according to claim 1, wherein the step (b) comprises the steps of:

starting fuel supply to the engine so as to start the engine when the operating point of the drive shaft passes the boundary and enters the second region;

controlling the first electric motor and the engine so that the rotation speed and torque of the output shaft of the engine become substantially equal to those of the drive shaft after the engine is started; and

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft, after the rotation speed and torque of the output shaft become substantially equal to those of the drive shaft.

3. A method according to claim 2, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

4. A method according to claim 2, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by uncoupling the rotary shaft of the second electric motor from the drive shaft, and subsequently coupling the rotary shaft of the second electric motor to the output shaft.

5. A method according to claim 1, wherein the step (b) comprises the steps of:

controlling the first electric motor and the engine so that the rotation speed and torque of the output shaft become substantially equal to those of the drive shaft when the operating point of the drive shaft passes the boundary and enters the second region;

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft, after the rotation speed and torque of the output shaft become substantially equal to those of the drive shaft; and

starting fuel supply to the engine so as to start the engine after switching to the second coupling state in which the rotary shaft of the second electric motor is coupled with the output shaft.

6. A method according to claim 2, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

7. A method according to claim 1, wherein

said power adjusting device comprises a doubled-rotor motor as said first electric motor, said doubled-rotor motor including a first rotor coupled to the output shaft and a second rotor coupled to the drive shaft.

8. A method according to claim 1, wherein

said power adjusting device comprises a planetary gear train in addition to the first electric motor, said planetary gear train including three rotary shafts that are respectively coupled to the output shaft, the drive shaft, and the rotary shaft of the first electric motor.

9. A method of controlling a power output apparatus which includes an engine including an output shaft, a drive shaft that outputs power, a power adjusting device that includes a first electric motor and is coupled with the output shaft and the drive shaft, said power adjusting device being capable of adjusting at least the power transmitted to the drive shaft by means of the first electric motor, a second electric motor having a rotary shaft, and a coupling device operable to couple the rotary shaft of the second electric motor to at least one of the drive shaft and the output shaft, said power output apparatus having an operating region represented by the relationship between the torque and the speed of rotation, said operating region being divided by a predetermined boundary into a first region in which the rotary shaft of the second electric motor is coupled with the drive shaft, and a second region in which the rotary shaft of the second electric motor is coupled with the output shaft, said method comprising the steps of:

(a) operating the second electric motor while keeping the engine stopped so that the second electric motor outputs driving torque to the drive shaft when an operating point of the drive shaft lies in the first region and the rotary shaft of the second electric motor is coupled with the drive shaft through the coupling device;

(b) causing the coupling device to switch coupling of the rotary shaft of the second electric motor from a first coupling state in which the rotary shaft is coupled with the drive shaft, to a second coupling state in which the rotary shaft is coupled with the output shaft of the engine, when the operating point of the drive shaft passes the boundary and enters the second region;

(c) after switching to the second coupling state in which the rotary shaft of the second electric motor is coupled with the output shaft of the engine, causing the first electric motor to output driving torque to the drive shaft, instead of the second electric motor, while causing the second electric motor to cancel reactive torque generated by the first electric motor at the output shaft.

10. A method according to claim 9, wherein the step (b) comprises the steps of:

controlling the first electric motor so that the rotation speed and torque of the output shaft become substantially equal to those of the drive shaft when the operating point of the drive shaft passes the boundary and enters the second region; and

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft, after the rotation speed and torque of the output shaft become substantially equal to those of the drive shaft.

11. A method according to claim 10, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

12. A method according to claim 9, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

13. A method according to claim 9, wherein

said power adjusting device comprises a doubled-rotor motor as said first electric motor, said doubled-rotor motor including a first rotor coupled to the output shaft and a second rotor coupled to the drive shaft.

14. A method according to claim 9, wherein

said power adjusting device comprises a planetary gear train in addition to the first electric motor, said planetary gear train including three rotary shafts that are respectively coupled to the output shaft, the drive shaft, and the rotary shaft of the first electric motor.

15. A method of controlling a power output apparatus which includes an engine including an output shaft, a drive shaft that outputs power, a power adjusting device that includes a first electric motor and is coupled with the output shaft and the drive shaft, said power adjusting device being capable of adjusting at least the power transmitted to the drive shaft by means of the first electric motor, a second electric motor having a rotary shaft, and a coupling device operable to couple the rotary shaft of the second electric motor to at least one of the drive shaft and the output shaft, said power output apparatus having an operating region represented by the relationship between the torque and the speed of rotation, said operating region being divided by a predetermined boundary into a first region in which the rotary shaft of the second electric motor is coupled with the drive shaft, and a second region in which the rotary shaft of the second electric motor is coupled with the output shaft, said method comprising the steps of:

(a) operating the second electric motor while keeping the engine stopped when an operating point of the drive shaft lies in the first region and the rotary shaft of the second electric motor is coupled with the drive shaft through the coupling device;

(b) when the operating point of the drive shaft passes the boundary and enters the second region, keeping the rotary shaft of the second electric motor coupled with the drive shaft through the coupling device, and operating the second electric motor while keeping the engine stopped; and

(c) when a target power to be outputted from the drive shaft satisfies a predetermined condition, starting fuel supply to the engine so as to start the engine, and causing the coupling device to switch from a first coupling state in which the rotary shaft of the second electric motor is coupled with the drive shaft, to a second coupling state in which the rotary shaft is coupled with the output shaft of the engine.

16. A method according to claim 15, wherein the step (c) comprises the steps of:

starting fuel supply to the engine so as to start the engine when the target power satisfies the predetermined condition;

controlling the first electric motor and the engine so that the rotation speed and torque of the output shaft of the engine become substantially equal to those of the drive shaft after the engine is started; and

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state to the second coupling state, after the rotation speed and torque of the output shaft become substantially equal to those of the drive shaft.

17. A method according to claim 16, wherein,

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

18. A method according to claim 16, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by uncoupling the rotary shaft of the second electric motor from the drive shaft, and subsequently coupling the rotary shaft of the second electric motor to the output shaft.

19. A method according to claim 15, wherein the step (c) comprises the steps of:

controlling the first electric motor so that the rotation speed of the output shaft of the engine becomes substantially equal to that of the drive shaft when the target power satisfies the predetermined condition;

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state to the second coupling state, after the rotation speed of the output shaft of the engine becomes substantially equal to that of the drive shaft; and

starting fuel supply to the engine so as to start the engine after switching to the second coupling state in which the rotary shaft of the second electric motor is coupled with the rotary shaft.

20. A method according to claim 19, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

21. A method according to claim 15, further comprising the step of:

(d) causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft when the rotation speed of the rotary shaft of the second electric motor exceeds a predetermined speed.

22. A method according to claim 21, wherein the step (d) comprises the steps of:

controlling the first electric motor so that the rotation speed of the output shaft of the engine becomes substantially equal to that of the drive shaft when the rotation speed of the rotary shaft of the second electric motor exceeds the predetermined speed; and

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft after the rotation speed of the output shaft becomes substantially equal to that of the drive shaft.

23. A method according to claim 15, wherein

said power adjusting device comprises a doubled-rotor motor as said first electric motor, said doubled-rotor motor including a first rotor coupled to the output shaft and a second rotor coupled to the drive shaft.

24. A method according to claim 15, wherein

said power adjusting device comprises a planetary gear train in addition to the first electric motor, said planetary gear train including three rotary shafts that are respectively coupled to the output shaft, the drive shaft, and the rotary shaft of the first electric motor.

25. A method of controlling a power output apparatus which includes an engine including an output shaft, a drive shaft that outputs power, a power adjusting device that includes a first electric motor and is coupled with the output shaft and the drive shaft, said power adjusting device being capable of adjusting at least the power transmitted to the drive shaft by means of the first electric motor, a second electric motor having a rotary shaft, and a coupling device operable to couple the rotary shaft of the second electric motor to at least one of the drive shaft and the output shaft, said power output apparatus having an operating region represented by the relationship between the torque and the speed of rotation, said operating region being divided by a predetermined boundary into a first region in which the rotary shaft of the second electric motor is coupled with the drive shaft, and a second region in which the rotary shaft of the second electric motor is coupled with the output shaft, said method comprising the steps of:

(a) operating the second electric motor while keeping the engine stopped when an operating point of the drive shaft lies in the first region and the rotary shaft of the second electric motor is coupled with the drive shaft through the coupling device;

(b) keeping the rotary shaft of the second electric motor coupled with the drive shaft through the coupling device, and operating the second electric motor while keeping the engine stopped, when the operating point of the drive shaft passes the boundary and enters the second region;

(c) controlling the first electric motor so that the rotation speed of the output shaft of the engine becomes substantially equal to that of the drive shaft when the operating point of the drive shaft passes the boundary and enters the second region; and

(d) when a target power to be outputted from the drive shaft satisfies a predetermined condition after the rotation speed of the output shaft of the engine is made substantially equal to that of the drive shaft, starting fuel supply to the engine so as to start the engine, and causing the coupling device to switch from a first coupling state in which the rotary shaft of the second electric motor is coupled with the drive shaft, to a second coupling state in which the rotary shaft is coupled with the output shaft of the engine.

26. A method according to claim 25, wherein the step (d) comprises the steps of:

starting fuel supply to the engine so as to start the engine when the target power satisfies the predetermined condition; and

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state to the second coupling state after the engine is started.

27. A method according to claim 26, wherein,

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

28. A method according to claim 26, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by uncoupling the rotary shaft of the second electric motor from the drive shaft, and subsequently coupling the rotary shaft of the second electric motor to the output shaft.

29. A method according to claim 25, wherein the step (d) comprises the steps of:

causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state to the second coupling state when the target power satisfies the predetermined condition; and

starting fuel supply to the engine so as to start the engine after switching to the second coupling state in which the rotary shaft of the second electric motor is coupled with the output shaft of the engine.

30. A method according to claim 29, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

31. A method according to claim 25, further comprising the step of:

(e) causing the coupling device to switch coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft when the rotation speed of the rotary shaft of the second electric motor exceeds a predetermined speed.

32. A method according to claim 25, wherein

said power adjusting device comprises a doubled-rotor motor as said first electric motor, said doubled-rotor motor including a first rotor coupled to the output shaft and a second rotor coupled to the drive shaft.

33. A method according to claim 25, wherein

said power adjusting device comprises a planetary gear train in addition to the first electric motor, said planetary gear train including three rotary shafts that are respectively coupled to the output shaft, the drive shaft, and the rotary shaft of the first electric motor.

34. A method of controlling a power output apparatus which includes an engine including an output shaft, a drive shaft that outputs power, a power adjusting device that includes a first electric motor and is coupled with the output shaft and the drive shaft, said power adjusting device being capable of adjusting at least the power transmitted to the drive shaft by means of the first electric motor, a second electric motor having a rotary shaft, and a coupling device operable to couple the rotary shaft of the second electric motor to at least one of the drive shaft and the output shaft, said power output apparatus having an operating region represented by the relationship between the torque and the speed of rotation, said operating region being divided by a predetermined boundary into a first region in which the rotary shaft of the second electric motor is coupled with the drive shaft, and a second region in which the rotary shaft of the second electric motor is coupled with the output shaft, said method comprising the steps of:

(a) operating the second electric motor while keeping the engine stopped when an operating point of the drive shaft lies in the first region and the rotary shaft of the second electric motor is coupled with the drive shaft through the coupling device; and

(b) causing the coupling device to switch from a first coupling state in which the rotary shaft of the second electric motor is coupled with the drive shaft, to a second coupling state in which the rotary shaft is coupled with the output shaft of the engine, when the rotation speed of the rotary shaft of the second electric motor exceeds a predetermined speed.

35. A method according to claim 34, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by coupling the rotary shaft of the second electric motor to the output shaft while maintaining coupling of the rotary shaft of the second electric motor with the drive shaft, and subsequently uncoupling the rotary shaft of the second electric motor from the drive shaft.

36. A method according to claim 34, wherein

the coupling device switches coupling of the rotary shaft of the second electric motor from the first coupling state with the drive shaft to the second coupling state with the output shaft of the engine, by uncoupling the rotary shaft of the second electric motor from the drive shaft, and subsequently coupling the rotary shaft of the second electric motor to the output shaft.

37. A method according to claim 34, wherein

said power adjusting device comprises a doubled-rotor motor as said first electric motor, said doubled-rotor motor including a first rotor coupled to the output shaft and a second rotor coupled to the drive shaft.

38. A method according to claim 34, wherein

said power adjusting device comprises a planetary gear train in addition to the first electric motor, said planetary gear train including three rotary shafts that are respectively coupled to the output shaft, the drive shaft, and the rotary shaft of the first electric motor.