Method for controlling hybrid electric vehicle powertrain

• US 7,136,727 B2
• Filed: 03/30/2006
• Issued: 11/14/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Seo, Nobuhide, Douzono, Kazuho, Kawada, Takuji, Takemoto, Akira
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US11/393,416
• Publication Number:
  US 20060224282A1
• Time in Patent Office: 229 Days
• Field of Search: 701/22, 701/48, 701/101, 701/102, 701/103, 701/115, 701/53, 701/54, 606/98, 607/06, 607/10, 180/65.2, 180/65.3, 180/65.4, 290/40.C
• US Class Current: 701/22
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• 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 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 2710/0622 Air-fuel ratio
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: F02D 13/0207 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0253 Fully variable control of valve lift and timing using camless actuation systems such as hydraulic, pneumatic or electromagnetic actuators, e.g. solenoid valves
• CPC Class Codes: F02D 13/0269 Controlling the valves to perform a Miller-Atkinson cycle
• CPC Class Codes: F02D 13/06 Cutting-out cylinders
• CPC Class Codes: F02D 2041/001 : for engines with variable valve actuation
• CPC Class Codes: F02D 2250/18 : Control of the engine output torque
• CPC Class Codes: F02D 2250/24 : by using an external load, e.g. a generator
• CPC Class Codes: F02D 41/0027 : the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02D 41/0047 : Controlling exhaust gas recirculation [EGR] temperature control with cooler in recirculation circuit F02M26/33
• CPC Class Codes: F02D 41/0087 : Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02M 21/0206 : Non-hydrocarbon fuels, e.g. hydrogen, ammonia or carbon monoxide
• CPC Class Codes: F02M 26/01 : Internal exhaust gas recirculation, i.e. wherein the residual exhaust gases are trapped in the cylinder or pushed back from the intake or the exhaust manifold into the combustion chamber without the use of additional passages
• CPC Class Codes: F02M 26/48 : EGR valve position sensors details of the sensor installation in the valve housing F02M26/72
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 : Use of alternative fuels, e.g. biofuels
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

There is described a method for controlling a hybrid electric vehicle power-train comprising an internal combustion engine, an electric machine and a transmission, the transmission having a gear set with three rotational elements rotationally coupled to the internal combustion engine, the electric machine and the vehicle driving wheel, a rotational speed of any one of the three rotational elements being mechanically defined by the rotational velocity of the remainder of the three rotational elements. The method comprises adjusting the torque of the electric machine to change the speed of the internal combustion engine and to control the velocity of the electric machine above a predetermined value, and decreasing the torque of the internal combustion engine while substantially maintaining the intake manifold pressure of the internal combustion engine in response to a decrease in the demanded engine output. The method may advantageously improve both of the engine efficiency and the power transmission efficiency, then may improve the operating efficiency of the overall power-train system having the internal combustion engine and the transmission coupling the engine, the electric machine and the driving wheels.

Claims

1. A method for controlling a power-train of a hybrid electric vehicle comprising an internal combustion engine, an electric machine and a transmission, said transmission having a gear set with three rotational elements that are rotationally coupled to said internal combustion engine, said electric machine, and the vehicle driving wheel, the rotational velocity of any one of said three rotational elements being mechanically defined by the rotational velocity of the remainder of said three rotational elements, the method comprising:

adjusting the torque of said electric machine to change the speed of said internal combustion engine and to control the velocity of said electric machine above a predetermined value; and

decreasing the torque of said internal combustion engine while substantially maintaining the intake manifold pressure of said internal combustion engine in response to a decrease in the demanded engine output.

2. The method as described in claim 1, wherein said predetermined value of the velocity of said electric machine is different than zero.

3. The method as described in claim 2, wherein said predetermined value comprises two values positive and negative.

4. The method as described in claim 3, wherein said two predetermined values are selected in accordance with the current velocity of said electric machine.

5. The method as described in claim 1, wherein said decreasing the engine torque comprises decreasing the fuel into a combustion chamber of said internal combustion engine and making air fuel ratio in said combustion chamber to be leaner in accordance with said decreasing the fuel.

6. The method as described in claim 5, wherein hydrogen is supplied to said internal combustion engine as said fuel.

7. The method as described in claim 1, wherein said decreasing the engine torque comprises shutting off fuel into some of multiple cylinders of said internal combustion engine.

8. The method as described in claim 7, further comprising increasing fuel into the remainder of the cylinders of said internal combustion engine.

9. The method as described in claim 1, wherein said decreasing the engine torque comprises decreasing the fuel to a combustion chamber of said internal combustion engine and reintroducing exhaust gas to said combustion chamber in accordance with said decreasing the fuel.

10. The method as described in claim 9, wherein said reintroducing the exhaust gas comprises re-circulating the exhaust gas from an exhaust system to an intake system of said internal combustion engine.

11. The method as described in claim 9, wherein said reintroducing the exhaust gas comprises controlling an intake or exhaust valve timing so as to increase an overlapping period when both of the intake and exhaust valves open.

12. The method as described in claim 9, wherein said reintroducing the exhaust gas comprises controlling an exhaust valve timing so as to advance closing of said exhaust valve.

13. The method as described in claim 1, wherein said reducing the engine torque comprises controlling an intake valve timing so as to decrease a cylinder air charge of said internal combustion engine.

14. The method as described in claim 13, wherein said controlling the valve timing comprises advancing a closing timing of an intake valve before the bottom dead center at an end of an intake stroke of the cylinder.

15. The method as described in claim 13, wherein said controlling the valve timing comprises retarding a closing timing of an intake valve after the bottom dead center at an end of an intake stroke of the cylinder.

16. The method as described in claim 1, wherein said decreasing the engine torque comprises shutting off fuel into some of multiple cylinders of said internal combustion engine and holding closed an intake or exhaust valves of said some of cylinders.

17. The method as described in claim 16, further comprising increasing fuel into the remainder of the cylinders of said internal combustion engine.

18. A hybrid electric vehicle power-train comprising:

an internal combustion engine having an intake manifold introducing air into its combustion chamber;

a first electric machine;

a transmission having a gear set with three rotational elements rotationally coupled respectively to said internal combustion engine, said first electric machines and the vehicle driving wheel, a rotational velocity of any one of said three rotational elements being mechanically defined by the rotational velocity of the remainder of said three rotational elements; and

a controller configured to

adjust the torque of said first electric machine to change the speed of said internal combustion engine and to control the velocity of said first electric machine above a predetermined value; and

decrease the torque of said internal combustion engine while substantially maintaining the intake manifold pressure of said internal combustion engine in response to a decrease in the demanded engine output.

19. The hybrid electric vehicle power-train as described in claim 18, further comprising a second electric machine mechanically and rotationally coupled with said vehicle wheel and electrically coupled with said first electric machine.

20. The hybrid electric vehicle power-train as described in claim 19, wherein said internal combustion engine uses hydrogen as its fuel.