Power output apparatus, method of controlling power output apparatus, and driving system with power output apparatus incorporated therein

• US RE38,790 E1
• Filed: 10/28/1996
• Issued: 09/06/2005
• Est. Priority Date: 11/14/1995
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nii, Yoshihide, Kawabata, Yasutomo, Maeda, Tomoharu, Yamada, Eiji, Sasaki, Shoichi, Kotani, Takeshi
• Primary Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US10/191,281
• Time in Patent Office: 3,235 Days
• Field of Search: 290/40.C, 290/40.B, 322/16, 322/14, 322/15, 318/77, 318/9, 318/140, 180/65.2
• US Class Current: 290/40.00C
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: B60K 2006/262 the motor or generator are used as clutch, e.g. between engine and driveshaft
• CPC Class Codes: B60K 6/22 characterised by apparatus, components or means specially adapted for HEVs
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/448 Electrical distribution type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/52 Clutch motors
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/486 : Operating parameters
• CPC Class Codes: B60L 2250/24 : by lever actuation
• CPC Class Codes: B60L 2250/26 : by pedal actuation
• CPC Class Codes: B60L 2260/28 : Four wheel or all wheel drive
• CPC Class Codes: B60L 2260/44 : by parameter estimation
• CPC Class Codes: B60L 2270/145 : Structure borne vibrations
• CPC Class Codes: B60L 50/15 : with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60L 50/16 : with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 : by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/12 : responding to state of charge [SoC]
• 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 20/10 : Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: H02K 51/00 : Dynamo-electric gears, i.e. dynamo-electric means for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts
• CPC Class Codes: Y02T 10/56 : Optimising drivetrain operating point
• CPC Class Codes: Y02T 10/6217 : of the series type or range extenders
• CPC Class Codes: Y02T 10/623 : of the series-parallel type
• CPC Class Codes: Y02T 10/6243 : Electrical distribution type
• CPC Class Codes: Y02T 10/6265 : Driving a plurality of axles
• CPC Class Codes: Y02T 10/6286 : Control systems for power distribution between ICE and other motor or motors
• CPC Class Codes: Y02T 10/641 : characterised by aspects of the electric machine
• CPC Class Codes: Y02T 10/645 : Control strategies for dc machines
• CPC Class Codes: Y02T 10/646 : With two or more electric drive machines
• CPC Class Codes: Y02T 10/7005 : Batteries
• CPC Class Codes: Y02T 10/7044 : Controlling the battery or capacitor state of charge
• CPC Class Codes: Y02T 10/705 : Controlling vehicles with one battery or one capacitor only
• CPC Class Codes: Y02T 10/7077 : on board the vehicle
• CPC Class Codes: Y02T 10/7241 : DC to AC or AC to DC power conversion
• CPC Class Codes: Y02T 10/7275 : Desired performance achievement
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/916 : with plurality of drive axles
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

A power output apparatus 20 includes a clutch motor, an assist motor, and a controller. The clutch motor and the assist motor are controlled by the controller to enable the power output from an engine to a crankshaft 56, and expressed as the product of its revolving speed and torque, to be converted to the power expressed as the product of a revolving speed and a torque of a drive shaft and to be output to the drive shaft. The engine can be driven at an arbitrary driving point defined by a revolving speed and a torque, as long as the energy or power output to the crankshaft is identical. A desired driving point that attains the highest possible efficiency with respect to each amount of output energy is determined in advance. In order to allow the engine to be driven at the desired driving point, the controller controls the clutch motor and the assist motor as well as the fuel injection and the throttle valve position. Such control procedures of the power output apparatus enhance the energy efficiency of the whole power output apparatus.

Claims

1. A power output apparatus for outputting power to a drive shaft, said power output apparatus, comprising:

an engine having an output shaft;

energy adjustment means having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment means adjusting a difference in energy between power one of power input into and power output from said first shaft and power one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy ;

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

target power setting means for setting a target power output to said drive shaft;

driving state setting means for setting a target driving state of said engine that outputs energy corresponding to the target power set by said target power setting means, based on a predetermined condition; and

control means for controlling said engine, so as to enable said engine to be driven in the target driving state set by said driving state setting means, and for controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

2. The power output apparatus in accordance with claim 1, wherein the predetermined condition in said driving state setting means comprises a condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power.

3. The power output apparatus in accordance with claim 1, wherein the predetermined condition in said driving state setting means comprises a condition for enhancing a comprehensive efficiency, which is calculated by multiplying an energy efficiency of said engine that outputs energy corresponding to the target power by a transmission efficiency of said energy adjustment means and said drive motor when the power output from said engine is subjected to torque conversion and output to said drive shaft.

4. The power output apparatus in accordance with claim 1, wherein the predetermined condition in said driving state setting means comprises a condition for continuously varying a driving state of said engine with a variation in target power.

5. The power output apparatus in accordance with claim 1, wherein said energy adjustment means comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

6. A power output apparatus in accordance with claim 5, wherein said drive motor comprises said second rotor included in said twin-rotor motor and a stator for rotating said second rotor.

7. The power output apparatus in accordance with claim 1, wherein said energy adjustment means further comprises:

three-shaft-type power input and output means connected with said first shaft, said second shaft, and a third shaft, said three-shaft-type power input and output means for, when powers one of powers input into and powers output from any two shafts among said three different shafts are determined, automatically setting a power one of power input into and power output from a residual shaft based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

8. The power output apparatus in accordance with claim 1, further comprising driving state detecting means for detecting a driving state of said engine,

wherein said control means further comprises means for controlling said energy adjustment means, so as to enable said engine to be driven in the target driving state, based on the driving state of said engine detected by said driving state detecting means.

9. The power output apparatus in accordance with claim 1, further comprising driving state detecting means for detecting a driving state of said engine,

wherein said control means further comprises tentative target driving state setting means for, when a state deviation of the driving state detected by said driving state detecting means from the target driving state is out of a predetermined range, selecting a driving state within the predetermined range based on the state deviation and the predetermined condition and setting the selected driving state as a tentative target driving state,

the tentative target driving state set by said tentative target driving state setting means being used in place of the target driving state for operation and control of said engine and control of said energy adjustment means and said drive motor, until the state deviation enters the predetermined range.

10. The power output apparatus in accordance with claim 9, wherein said tentative target driving state setting means further comprises predetermined range setting means for setting the predetermined range based on the driving state detected by said driving state detecting means.

11. The power output apparatus in accordance with claim 9, wherein said control means further comprises means for controlling said energy adjustment means, so as to enable said engine to be driven in the target driving state, based on the driving state detected by said driving state detecting means, when the state deviation is within the predetermined range.

12. The power output apparatus in accordance with claim 9, further comprising storage battery means that is charged with electrical energy taken out of said energy adjustment means, that is charged with electrical energy taken out of said drive motor, that is discharged to release electrical energy used in said energy adjustment means, and that is discharged to release electrical energy used in said drive motor,

wherein said control means further comprises means for, when the tentative target driving state is used in place of the target driving state for the operation and control of said engine and the control of said energy adjustment means and said drive motor, utilizing the electrical energy one of stored into and released from said storage battery means and controlling said drive motor, so as to enable said drive motor to one of input and output a specific power one of into and from said drive shaft, said specific power corresponding to an energy difference between the target power and the power output from said engine that is driven in the tentative target driving state.

13. The power output apparatus in accordance with claim 1, wherein said control means further comprises:

driving state estimating means for estimating a driving state of said engine when said target power setting means sets a different target power; and

estimated-condition control means for controlling said energy adjustment means and said drive motor based on the estimated driving state of said engine.

14. The power output apparatus in accordance with claim 13, wherein said driving state estimating means further comprises means for estimating the driving state of said engine based on a revolving speed of said output shaft of said engine and a state of said energy adjustment means.

15. The power output apparatus in accordance with claim 13, wherein said estimated-condition control means further comprises means for controlling said energy adjustment means and said drive motor, so as to enable an estimated power output from said engine corresponding to the driving state of said engine estimated by said driving state estimating means to be subjected to torque conversion and output as the target power to said drive shaft.

16. The power output apparatus in accordance with claim 13, further comprising storage battery means that is charged with electrical energy taken out of said energy adjustment means, that is charged with electrical energy taken out of said drive motor, that is discharged to release electrical energy used in said energy adjustment means, and that is discharged to release electrical energy used in said drive motor,

wherein said estimated-condition control means further comprises means for utilizing the electrical energy one of stored into and released from said storage battery means and controlling said drive motor, so as to enable said drive motor to one of input and output a specific power one of into and from said drive shaft, said specific power corresponding to an energy difference between the target power and the estimated power output from said engine corresponding to the driving state of said engine estimated by said driving state estimating means.

91. The power output apparatus in accordance with claim 5, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

17. A power output apparatus for outputting power to a drive shaft, said power output apparatus comprising:

an engine having an output shaft;

energy adjustment means having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment means adjusting a difference in energy between power one of power input into and power output from said first shaft and power one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy ;

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

target power setting means for setting a target power output to said drive shaft;

driving state setting means for setting a target driving state of said engine that outputs energy corresponding to the target power set by said target power setting means, based on a predetermined condition; and

control means for controlling said engine, so as to enable said engine to be driven in the target driving state set by said driving state setting means, and for controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

18. A The power output apparatus in accordance with claim 17, wherein the predetermined condition in said driving state setting means comprises a condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power.

19. A The power output apparatus in accordance with claim 17, wherein the predetermined condition in said driving state setting means comprises a condition for enhancing a comprehensive efficiency, which is calculated by multiplying an energy efficiency of said engine that outputs energy corresponding to the target power by a transmission efficiency of said energy adjustment means and said drive motor when the power output from said engine is subjected to torque conversion and output to said drive shaft.

20. A The power output apparatus in accordance with claim 17, wherein the predetermined condition in said driving state setting means comprises a condition for continuously varying a driving state of said engine with a variation in target power.

21. A The power output apparatus in accordance with claims- 17, 18, 49-r or20 claim 17, wherein saidenergy said energy adjustment means comprisesatwin-rotor comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

22. The power output apparatus in accordance with claim 21, wherein said drive motor comprises said first rotor included in said twin-rotor motor and a stator for rotating said first rotor.

23. The power output apparatus in accordance with claim 17, wherein said energy adjustment means further comprises:

three-shaft-type power input and output means connected with said first shaft, said second shaft, and a third shaft, said three-shaft-type power input and output means for, when powers one of powers input into and powers output from any two shafts among said three different shafts are determined, automatically setting a power one of power input into and power output from a residual shaft based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

24. The power output apparatus in accordance with claim 17, further comprising driving state detecting means for detecting a driving state of said engine,

wherein said control means further comprises tentative target driving state setting means for, when a state deviation of the driving state detected by said driving state detecting means from the target driving state is out of a predetermined range, selecting a driving state within the predetermined range based on the state deviation and the predetermined condition and setting the selected driving state as a tentative target driving state,

the tentative target driving state set by said tentative target driving state setting means being used in place of the target driving state for operation and control of said engine and control of said energy adjustment means and said drive motor, until the state deviation enters the predetermined range.

25. The power output apparatus in accordance with claim 17, wherein said control means further comprises:

driving state estimating means for estimating a driving state of said engine when said target power setting means sets a different target power; and

estimated-condition control means for controlling said energy adjustment means and said drive motor based on the estimated driving state of said engine.

26. The power output apparatus in accordance with claim 25, wherein said estimated-condition control means further comprises means for controlling said energy adjustment means and said drive motor, so as to enable an estimated power output from said engine corresponding to the driving state of said engine estimated by said driving state estimating means to be subjected to torque conversion and output as the target power to said drive shaft.

27. The power output apparatus in accordance with claim 25, further comprising storage battery means, that is charged with electrical energy taken out of said energy adjustment means, that is charged with electrical energy taken out of said drive motor, that is discharged to release electrical energy used in said energy adjustment means, and that is discharged to release electrical energy used in said drive motor,

wherein said estimated-condition control means further comprises means for utilizing the electrical energy one of stored into and released from said storage battery means and controlling said drive motor, so as to enable said drive motor to one of input and output a specific power one of into and from said output shaft of said engine, said specific power corresponding to an energy difference between the target power and the estimated power output from said engine corresponding to the driving state of said engine estimated by said driving state estimating means.

92. The power output apparatus in accordance with claim 21, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said driver shaft.

28. A driving system, comprising:

an engine having an output shaft;

energy adjustment means having a first shaft connected with said output shaft of said engine and a second shaft connected with a drive shaft of said driving system, said energy adjustment means adjusting a difference in energy between power one of power input into and power output from said first shaft and power one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy;

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

target power setting means for setting a target power output to said drive shaft;

driving state setting means for setting a target driving state of said engine that outputs energy corresponding to the target power set by said target power setting means, based on a first condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power and a second condition for making a vibration due to an operation of said engine out of a range of resonance frequency of said driving system; and

control means for controlling said engine, so as to enable said engine to be driven in the target driving state set by said driving state setting means, and for controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

29. The driving system in accordance with claim 28, wherein said energy adjustment means comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

30. The driving system in accordance with claim 29, wherein said drive motor comprises said second rotor included in said twin-rotor motor and a stator for rotating said second rotor.

31. The driving system in accordance with claim 28, wherein said energy adjustment means further comprises:

three-shaft-type power input and output means connected with said first shaft, said second shaft, and a third shaft, said three-shaft-type power input and output means for, when powers one of powers input into and powers output from any two shafts among said three different shafts are determined, automatically setting a power one of power input into and power output from a residual shaft based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

93. The driving system in accordance with claim 29, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

32. A driving system, comprising:

an engine having an output shaft;

energy adjustment means having a first shaft connected with said output shaft of said engine and a second shaft connected with a drive shaft of said driving system, said energy adjustment means adjusting a difference in energy between power one of power input into and power output from said first shaft and power one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy ;

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

target power setting means for setting a target power output to said drive shaft;

driving state setting means for setting a target driving state of said engine that outputs energy corresponding to the target power set by said target power setting means, based on a first condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power and a second condition for making a vibration due to an operation of said engine out of a range of resonance frequency of said driving system; and

control means for controlling said engine, so as to enable said engine to be driven in the target driving state set by said driving state setting means, and for controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

33. The driving system in accordance with claim 32, wherein said energy adjustment means comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

34. The driving system in accordance with claim 33, wherein said drive motor comprises said first rotor included in said twin-rotor motor and a stator for rotating said first rotor.

35. The driving system in accordance with claim 32, wherein said energy adjustment means further comprises:

three-shaft-type power input and output means connected with said first shaft, said second shaft, and a third shaft, said three-shaft-type power input and output means for, when powers one of powers input into and powers output from any two shafts among said three different shafts are determined, automatically setting a power one of power input into and power output from a residual shaft based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

94. The driving system in accordance with claim 33, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

36. A method of controlling a power output apparatus for outputting power to a drive shaft, said method comprising the steps of:

(a) providing an engine having an output shaft;

energy adjustment means having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment means adjusting a difference in energy between power one of power input into and power output from said first shaft and power one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy ; and

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

(b) setting a target power output to said drive shaft;

(c) setting a target driving state of said engine that outputs energy corresponding to the target power set in said step (b), based on a specific condition of selecting a specific driving point that attains a highest possible efficiency among a plurality of available driving points of said engine that outputs energy corresponding to the target power; and

(d) controlling said engine, so as to enable said engine to be driven in the target driving state set in said step (c), and for controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

37. The method in accordance with claim 36, wherein said step (d) further comprises the steps of:

(e) detecting a driving state of said engine;

(f) when a state deviation of the driving state of said engine detected in said step (e) from the target driving state is out of a predetermined range, selecting a driving state within the predetermined range based on the state deviation and the specific condition and setting the selected driving state as a tentative target driving state; and

(g) using the tentative target driving state set in said step (f) in place of the target driving state, in order to control said engine, said energy adjustment means, and said drive motor, until the state deviation enters the predetermined range.

38. The method in accordance with claim 36, wherein said step (d) further comprises the steps of:

(h) when a different target power is set, estimating a driving state of said engine based on a revolving speed of said output shaft of said engine and a state of said energy adjustment means; and

(i) controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output to said drive shaft, based on the estimated driving state of said engine.

39. A method of controlling a power output apparatus for outputting power to a drive shaft, said method comprising the steps of:

(a) providing an engine having an output shaft;

energy adjustment means having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment means adjusting a difference in energy between power one of power input into and power output from said first shaft and power one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy ; and

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

(b) setting a target power output to said drive shaft;

(c) setting a target driving state of said engine that outputs energy corresponding to the target power set in said step (b), based on a specific condition of selecting a specific driving point that attains a highest possible efficiency among a plurality of available driving points of said engine that outputs energy corresponding to the target power, said comprehensive highest possible efficiency being calculated by multiplying an energy efficiency of said engine by a transmission efficiency of said energy adjustment means and said drive motor when the power output from said engine is subject to torque conversion and output to said drive shaft; and

(d) controlling said engine, so as to enable said engine to be driven in the target driving state set in said step (c), and for controlling said energy adjustment means and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

40. The method in accordance with claim 39, wherein said step (d) further comprises the steps of:

(e) detecting a driving state of said engine;

(f) when a state deviation of the driving state of said engine detected in said step (e) from the target driving state is out of a predetermined range, selecting a driving state within the predetermined range based on the state deviation and the specific condition and setting the selected driving state as a tentative target driving state; and

(g) using the tentative target driving state set in said step (f) in place of the target driving state, in order to control said engine, said energy adjustment means, and said drive motor, until the state deviation enters the predetermined range.

41. The method in accordance with claim 39, wherein said step (d) further comprises the steps of:

(h) when a different target power is set, estimating a driving state of said engine based on a revolving speed of said output shaft of said engine and a state of said energy adjustment means; and

(i) controlling said energy adjustment means and said drive motor so as to enable power output from said engine to be subjected to torque conversion and output to said drive shaft, based on the estimated driving state of said engine.

42. A power output apparatus for outputting power to a drive shaft, said power output apparatus comprising:

an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft;

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

an accelerator used to set a target power output to said drive shaft;

a controller that sets a target driving state of said engine to output energy corresponding to the target power set by said accelerator, based on a predetermined condition;

that controls said engine, so as to enable said engine to be driven in the target driving state; and

that controls said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

43. The power output apparatus in accordance with claim 42, wherein the predetermined condition used by said controller comprises a condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power.

44. The power output apparatus in accordance with claim 42, wherein the predetermined condition used by said controller comprises a condition for enhancing a comprehensive efficiency, which is calculated by multiplying an energy efficiency of said engine that outputs energy corresponding to the target power by a transmission efficiency of said energy adjustment system and said drive motor when the power output from said engine is subjected to torque conversion and output to said drive shaft.

45. The power output apparatus in accordance with claim 42, wherein the predetermined condition used by said controller comprises a condition for continuously varying a driving state of said engine with a variation in target power.

46. The power output apparatus in accordance with claim 42, wherein said energy adjustment system comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

47. A power output apparatus in accordance with claim 46, wherein said drive motor comprises said second rotor included in said twin-rotor motor and a stator for rotating said second rotor.

48. The power output apparatus in accordance with claim 46, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

49. The power output apparatus in accordance with claim 42, wherein said energy adjustment system further comprises:

a three-shaft-type power input and output system connected with said first shaft, said second shaft, and a third shaft, said three shafts having a relationship such that, when one of powers input into and powers output from any two shafts among said three different shafts are determined, one of power input into and power output from a residual shaft is set automatically based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

50. The power output apparatus in accordance with claim 42, further comprising a driving state detecting system that detects a driving state of said engine,

wherein said controller controls said energy adjustment system, so as to enable said engine to be driven in the target driving state, based on the driving state of said engine detected by said driving state detecting system.

51. The power output apparatus in accordance with claim 50, wherein said driving state detecting system comprises a resolver used to measure a revolving speed of said drive shaft.

52. The power output apparatus in accordance with claim 42, further comprising a driving state detecting system that detects a driving state of said engine,

wherein said controller sets a tentative target driving state, such that when a state deviation of the driving state detected by said driving state detecting system from the target driving state is out of a predetermined range, the controller selects a driving state within the predetermined range based on the state deviation and the predetermined condition and sets the selected driving state as a tentative target driving state, said controller using the tentative target driving state in place of the target driving state for operation and control of said engine and control of said energy adjustment system and said drive motor, until the state deviation enters the predetermined range.

53. The power output apparatus in accordance with claim 52, wherein said controller sets a predetermined range based on the driving state detected by said driving state detecting system.

54. The power output apparatus in accordance with claim 52, wherein said controller controls said energy adjustment system, so as to enable said engine to be driven in the target driving state, based on the driving state detected by said driving state detecting system, when the state deviation is within the predetermined range.

55. The power output apparatus in accordance with claim 52, further comprising a storage battery that is charged with electrical energy taken out of said energy adjustment system, that is charged with electrical energy taken out of said drive motor, that is discharged to release electrical energy used in said energy adjustment system, and that is discharged to release electrical energy used in said drive motor,

wherein, when the tentative target driving state is used in place of the target driving state for the operation and control of said engine and the control of said energy adjustment system and said drive motor, said controller utilizes one of the electrical energy stored into and released from said storage battery and controls said drive motor, so as to enable said drive motor to one of input and output a specific power one of into and from said drive shaft, said specific power corresponding to an energy difference between the target power and the power output from said engine that is driven in the tentative target driving state.

56. The power output apparatus in accordance with claim 42, wherein said controller estimates a driving state of said engine when said accelerator sets a different target power, and controls said energy adjustment system and said drive motor based on the estimated driving state of said engine.

57. The power output apparatus in accordance with claim 56, wherein said controller estimates the driving state of said engine based on a revolving speed of said output shaft of said engine and a state of said energy adjustment system.

58. The power output apparatus in accordance with claim 56, wherein said controller controls said energy adjustment system and said drive motor, so as to enable an estimated power output from said engine corresponding to the driving state of said engine estimated by said controller to be subjected to torque conversion and output as the target power of said drive shaft.

59. The power output apparatus in accordance with claim 56, further comprising a storage battery that is charged with electrical energy taken out of said energy adjustment system, that is charged with electrical energy taken out of said drive motor, that is discharged to release electrical energy used in said energy adjustment system, and that is discharged to release electrical energy used in said drive motor,

wherein said controller utilizes one of the electrical energy stored into and released from said storage battery and controls said drive motor, so as to enable said drive motor to one of input and output a specific power one of into and from said drive shaft, said specific power corresponding to an energy difference between the target power and the estimated power output from said engine corresponding to the driving state of said engine estimated by said controller.

60. A power output apparatus for outputting power to a drive shaft, said power output apparatus comprising:

an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft;

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

an accelerator used to set a target power output to said drive shaft;

a controller that sets a target driving state of said engine to output energy corresponding to the target power set by said accelerator, based on a predetermined condition;

that controls said engine, so as to enable said engine to be driven in the target driving state; and

that controls said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

61. The power output apparatus in accordance with claim 60, wherein the predetermined condition used by said controller comprises a condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power.

62. The power output apparatus in accordance with claim 60, wherein the predetermined condition used by said controller comprises a condition for enhancing a comprehensive efficiency, which is calculated by multiplying an energy efficiency of said engine that outputs energy corresponding to the target power by a transmission efficiency of said energy adjustment system and said drive motor when the power output from said engine is subjected to torque conversion and output to said drive shaft.

63. The power output apparatus in accordance with claim 60, wherein the predetermined condition used by said controller comprises a condition for continuously varying a driving state of said engine with a variation in target power.

64. The power output apparatus in accordance with claim 60, wherein said energy adjustment system comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

65. The power output apparatus in accordance with claim 64, wherein said drive motor comprises said first rotor included in said twin-rotor motor and a stator for rotating said first rotor.

66. The power output apparatus in accordance with claim 64, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

67. The power output apparatus in accordance with claim 60, wherein said energy adjustment system further comprises:

a three-shaft-type power input and output system connected with said first shaft, said second shaft, and a third shaft, said three shafts having a relationship such that, when one of powers input into and powers output from any two shafts among said three different shafts are determined, one of power input into and power output from a residual shaft is automatically set based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

68. The power output apparatus in accordance with claim 60, further comprising a driving state detecting system that detects a driving state of said engine,

wherein said controller sets a tentative target driving state, such that when a state deviation of the driving state detected by said driving state detecting system from the target driving state is out of a predetermined range, the controller selects a driving state within the predetermined range based on the state deviation and the predetermined condition and sets the selected driving state as a tentative target driving state, said controller using the tentative target driving state in place of the target driving state for operation and control of said engine and control of said energy adjustment system and said drive motor, until the state deviation enters the predetermined range.

69. The power output apparatus in accordance with claim 68, wherein said driving state detecting system comprises a resolver used to measure a revolving speed of said drive shaft.

70. The power output apparatus in accordance with claim 60, wherein said controller estimates a driving state of said engine when said accelerator sets a different target power, and

controls said energy adjustment system and said drive motor based on the estimated driving state of said engine.

71. The power output apparatus in accordance with claim 70, wherein said controller controls said energy adjustment system and said drive motor, so as to enable an estimated power output from said engine corresponding to the driving state of said engine estimated by said controller to be subjected to torque conversion and output as the target power to said drive shaft.

72. The power output apparatus in accordance with claim 70, further comprising a storage battery that is charged with electrical energy taken out of said energy adjustment system, that is charged with electrical energy taken out of said drive motor, that is discharged to release electrical energy used in said energy adjustment system, and that is discharged to release electrical energy used in said drive motor,

wherein said controller utilizes one of the electrical energy stored into and released from said storage battery and controls said drive motor, so as to enable said drive motor to one of input and output a specific power one of into and from said output shaft of said engine, said specific power corresponding to an energy difference between the target power and the estimated power output from said engine corresponding to the driving state of said engine estimated by said controller.

73. A driving system, comprising:

an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with a drive shaft of said driving system, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft by regulating input and output of corresponding electrical energy;

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

an accelerator used to set a target power output to said drive shaft;

a controller that sets a target driving state of said engine to output energy corresponding to the target power set by said accelerator, based on a first condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power and a second condition for making a vibration due to an operation of said engine out of a range of resonance frequency of said driving system;

that controls said engine, so as to enable said engine to be driven in the target driving state; and

that controls said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

74. The driving system in accordance with claim 73, wherein said energy adjustment system comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

75. The driving system in accordance with claim 74, wherein said drive motor comprises said second rotor included in said twin-rotor motor and a stator for rotating said second rotor.

76. The driving system in accordance with claim 74, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

77. The driving system in accordance with claim 73, wherein said energy adjustment system further comprises:

a three-shaft-type power input and output system connected with said first shaft, said second shaft, and a third shaft, said three shafts having a relationship such that, when one of powers input into and powers output from any two shafts among said three different shafts are determined, one of power input into and power output from a residual shaft is automatically set based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

78. A driving system, comprising:

an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with a drive shaft of said driving system, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft;

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

an accelerator used to set a target power output to said drive shaft;

a controller that sets a target driving state of said engine to output energy corresponding to the target power set by said accelerator, based on a first condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power and a second condition for making a vibration due to an operation of said engine out of a range of resonance frequency of said driving system;

that controls said engine, so as to enable said engine to be driven in the target driving state; and

that controls said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

79. The driving system in accordance with claim 78, wherein said energy adjustment system comprises a twin-rotor motor comprising a first rotor connected with said first shaft and a second rotor connected with said second shaft, said second rotor being rotatable relative to said first rotor, whereby power is transmitted between said first shaft and said second shaft via an electromagnetic coupling of said first rotor with said second rotor, said twin-rotor motor inputting and outputting electrical energy based on the electromagnetic coupling of said first rotor with said second rotor and a difference in revolving speed between said first rotor and said second rotor.

80. The driving system in accordance with claim 79, wherein said drive motor comprises said first rotor included in said twin-rotor motor and a stator for rotating said first rotor.

81. The driving system in accordance with claim 79, wherein said first shaft comprises one end of said output shaft of said engine and said second shaft comprises one end of said drive shaft.

82. The driving system in accordance with claim 78, wherein said energy adjustment system further comprises:

a three-shaft-type power input and output system connected with said first shaft, said second shaft, and a third shaft, said three shafts having a relationship such that, when one of powers input into and powers output from any two shafts among said three different shafts are determined, one of power input into and power output from a residual shaft is automatically set based on the powers thus determined; and

a shaft motor connected with said third shaft, wherein power is transmitted between said third shaft and said shaft motor.

83. A method of controlling a power output apparatus for outputting power to a drive shaft, said method comprising the steps of:

(a) providing an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft; and

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

(b) setting a target power output to said drive shaft;

(c) setting a target driving state of said engine to output energy corresponding to the target power set in said step (b), based on a specific condition of selecting a specific driving point that attains a highest possible efficiency among a plurality of available driving points of said engine that outputs energy corresponding to the target power; and

(d) controlling said engine, so as to enable said engine to be driven in the target driving state set in said step (c), and controlling said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

84. The method in accordance with claim 83, wherein said step (d) further comprises the steps of:

(e) detecting a driving state of said engine;

(f) when a state deviation of the driving state of said engine detected in said step (e) from the target driving state is out of a predetermined range, selecting a driving state within the predetermined range based on the state deviation and the specific condition and setting the selected driving state as a tentative target driving state; and

(g) using the tentative target driving state set in said step (f) in place of the target driving state, in order to control said engine, said energy adjustment system, and said drive motor, until the state deviation enters the predetermined range.

85. The method in accordance with claim 83, wherein said step (d) further comprises the steps of:

(h) when a different target power is set, estimating a driving state of said engine based on a revolving speed of said output shaft of said engine and a state of said energy adjustment system; and

(i) controlling said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output to said drive shaft, based on the estimated driving state of said engine.

86. A method of controlling a power output apparatus for outputting power to a drive shaft, said method comprising the steps of:

(a) providing an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft; and

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

(b) setting a target power output to said drive shaft;

(c) setting a target driving state of said engine to output energy corresponding to the target power set in said step (b), based on a specific condition of selecting a specific driving point that attains a highest possible efficiency among a plurality of available driving points of said engine that outputs energy corresponding to the target power, said highest possible efficiency being calculated by multiplying an energy efficiency of said engine by a transmission efficiency of said energy adjustment system and said drive motor when the power output from said engine is subject to torque conversion and output to said drive shaft; and

(d) controlling said engine, so as to enable said engine to be driven in the target driving state set in said step (c), and controlling said energy adjustment system, and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

87. The method in accordance with claim 86, wherein said step (d) further comprises the steps of:

(e) detecting a driving state of said engine;

(f) when a state deviation of the driving state of said engine detected in said step (e) from the target driving state is out of a predetermined range, selecting a driving state within the predetermined range based on the state deviation and the specific condition and setting the selected driving state as a tentative target driving state; and

(g) using the tentative target driving state set in said step (f) in place of the target driving state, in order to control said engine, said energy adjustment system, and said drive motor, until the state deviation enters the predetermined range.

88. The method in accordance with claim 86, wherein said step (d) further comprises the steps of:

(h) when a different target power is set, estimating a driving state of said engine based on a revolving speed of said output shaft of said engine and a state of said energy adjustment system; and

(i) controlling said energy adjustment system and said drive motor so as to enable power output from said engine to be subjected to torque conversion and output to said drive shaft, based on the estimated driving state of said engine.

89. A power output apparatus for outputting power to a drive shaft, said power output apparatus comprising:

an engine having an output shaft;

an energy adjustment system having a twin-rotor motor, said twin-rotor motor comprising a first rotor connected with said output shaft of said engine and a second rotor connected with said drive shaft, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first rotor and one of power input into and power output from said second rotor by regulating input and output of corresponding electrical energy;

a drive motor, wherein power is transmitted between said drive motor and said drive shaft;

an accelerator used to set a target power output to said drive shaft;

a controller that sets a target driving state of said engine to output energy corresponding to the target power set by said accelerator, based on a predetermined condition;

that controls said engine, so as to enable said engine to be driven in the target driving state; and

that controls said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

90. A power output apparatus for outputting power to a drive shaft, said power output apparatus comprising:

an engine having an output shaft;

an energy adjustment system having a twin-rotor motor, said twin-rotor motor comprising a first rotor connected with said output shaft of said engine and a second rotor connected with said drive shaft, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first rotor and one of power input into and power output from said second rotor by regulating input and output of corresponding electrical energy;

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

an accelerator used to set a target power output to said drive shaft;

a controller that sets a target driving state of said engine to output energy corresponding to the target power set by said accelerator, based on a predetermined condition;

that controls said engine, so as to enable said engine to be driven in the target driving state; and

that controls said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

95. A method of controlling a power output apparatus for outputting power to a drive shaft, said method comprising the steps of:

(a) providing an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with said drive shaft, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft; and

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

(b) setting a target power output to said drive shaft;

(c) setting a target driving state of said engine to output energy corresponding to the target power set in said step (b), based on a predetermined condition; and

(d) controlling said engine, so as to enable said engine to be driven in the target driving state set in said step (c), and controlling said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.

96. A method of controlling a driving system, said method comprising the steps of:

(a) providing an engine having an output shaft;

an energy adjustment system having a first shaft connected with said output shaft of said engine and a second shaft connected with a drive shaft of said driving system, said energy adjustment system adjusting a difference in energy between one of power input into and power output from said first shaft and one of power input into and power output from said second shaft; and

a drive motor, wherein power is transmitted between said drive motor and said output shaft of said engine;

(b) setting a target power output to said drive shaft;

(c) setting a target driving state of said engine to output energy corresponding to the target power set in said step (b), based on a first condition for enhancing an energy efficiency of said engine that outputs energy corresponding to the target power and a second condition for making a vibration due to an operation of said engine out of a range of resonance frequency of said driving system; and

(d) controlling said engine, so as to enable said engine to be driven in the target driving state set in said step (c), and for controlling said energy adjustment system and said drive motor, so as to enable power output from said engine to be subjected to torque conversion and output as the target power to said drive shaft.