Method for operating a hybrid vehicle drive and a device for carrying out said method

• US 8,374,771 B2
• Filed: 02/21/2006
• Issued: 02/12/2013
• Est. Priority Date: 04/21/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Falkenstein, Jens-Werner
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): Nolan, Peter D
• Application Number:
  US11/918,909
• Publication Number:
  US 20080305921A1
• Time in Patent Office: 2,548 Days
• Field of Search: 701/22, 701/99, 701/101, 701/103, 701/105, 180/65.21, 180/65.25, 180/65.265, 180/65.275, 180/65.28, 180/65.285, 180/65.29
• US Class Current: 701/105
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• 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 2510/244 Charge state
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 50/038 Limiting the input power, torque or speed
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• 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

The invention relates to a method for operating a motor vehicle drive comprising at least one internal combusting engine (10), at least one electric machine (20) mechanically coupled to said internal combustion engine (10) and at least one power storage battery actively connectable to said electric machine (20) and to the internal combustion engine (1) in an on-board electric network, wherein said internal combustion engine (10) and electric machine (20) produces a nominal required drive torque (M) in a substantially common manner, the instant electromotive torque reserve (M_Eres) of the electric machines(s) (20) is determined and the internal combustion engine torque reserve is taken into account as a minimum reference torque reserve of the internal combustion engine for at least one or several internal combustion engines (10).

Claims

1. A method of operating a vehicle drive with at least one internal combustion engine and at least one electric machine mechanically coupled to said internal combustion engine and having at least one power storage battery operatively connected to the at least one electric machine and to the at least one internal combustion engine in at least one on-board electric network, wherein said internal combustion engine and electric machine jointly produce a nominal required drive torque, the method comprising:

ascertaining an instant electromotive torque reserve of the at least one electric machine; and

specifying an internal combustion engine torque reserve for the at least one internal combustion engine taking into account the instant electromotive torque reserve, so that the internal combustion engine torque reserve equals a minimum reference torque reserve of the internal combustion engine for the at least one internal combustion engine;

wherein the internal combustion engine torque reserve corresponds to a difference between a nominal lead drive torque of the internal combustion engine and a nominal drive torque of the internal combustion engine; and

wherein the nominal lead drive torque of the internal combustion engine is selected to be greater than the nominal drive torque of the internal combustion engine in at least some operating states of the vehicle drive.

2. A method according to claim 1, wherein ascertaining includes ascertaining the instant electromotive torque reserve on the basis of momentary operating states of the at least one electric machine, of the one power storage battery, and of the at least one on-board electric network.

3. A method according to claim 1, further comprising specifying a nominal lead drive torque and a nominal drive torque for the entire drive by an overriding control mechanism.

4. A method according to claim 3, wherein the torque reserve for the entire drive torque of the drive is equal to the difference between the nominal lead drive torque and the nominal drive torque, wherein the nominal lead drive torque is greater than the nominal drive torque or equal to the nominal drive torque.

5. A method according to claim 1, further comprising setting a nominal charging torque of the at least one electric machine in such a way that an electric supply of the at least one on-board electric network and of the at least one power storage battery is assured.

6. A method according to claim 5, wherein when a negative nominal charging torque occurs, the at least one of the electric machine is driven as a generator.

7. A method according to claim 6, further comprising increasing the nominal lead drive torque and a nominal drive torque for the entire vehicle drive in order to compensate for a load on the electric machines.

8. A method according to claim 1, further comprising ascertaining on the basis of the momentary operating states of the at least one electric machine, of the at least one power storage battery, and of the at least one on-board electric network, an instant maximum torque reserve and an instant minimum torque of the at least one electric machine.

9. A method according to claim 8, wherein the instant electromotive torque reserve is constructed as a difference between the instant maximum torque reserve and a nominal charging torque.

10. A method according to claim 9, comprising ascertaining a nominal lead torque for the internal combustion engine from the nominal lead drive torque corrected by the nominal charging torque, wherein the nominal lead torque is produced by a setting of an air volume flow.

11. A method according to claim 10, wherein the nominal lead torque for the internal combustion engine is always selected to be greater than or at least equal to the nominal lead drive torque for the internal combustion engine.

12. A method according to claim 1, wherein the internal combustion engine torque reserve is only adjusted if the instant electromotive torque reserve becomes smaller than a required torque reserve for the entire vehicle drive.

13. A method according to claim 1, comprising constructing a nominal internal combustion engine torque from the nominal drive torque for the entire vehicle drive corrected by the nominal charging torque, and further comprising adjusting the nominal internal combustion engine torque by means of an ignition angle displacement.

14. A method according to claim 1, further comprising impressing a differential torque between an actual torque of the internal combustion engine and a nominal torque on the at least one of the electric machine(s);

and constructing from a cumulative sum of the differential torque and a nominal charging torque, a nominal torque of the electric machine(s).

15. A system for implementation of a method for operating a vehicle drive, the system comprising:

at least one internal combustion engine and at least one electric machine mechanically coupled to said internal combustion engine as well as with at least one power storage battery operatively connected to said electric machine and to said internal combustion engine in at least one on-board electric network, wherein said internal combustion engine and electric machine jointly produce a required nominal drive torque and wherein an overriding control mechanism is disposed in order to specify a nominal lead torque for the entire vehicle drive and a nominal torque for the entire vehicle drive in such a way that an instant electromotive torque reserve of the at least one electric machine can be ascertained, and this is taken into account during specification of an internal combustion engine torque reserve for the at least one internal combustion engine so that said torque reserve equals a minimum reference torque reserve of the internal combustion engine for the at least one internal combustion engine;

wherein the internal combustion engine torque reserve corresponds to a difference between a nominal lead drive torque of the internal combustion engine and a nominal drive torque of the internal combustion engine; and

wherein the nominal lead drive torque of the internal combustion engine is selected by the overriding control mechanism to be greater than the nominal drive torque of the internal combustion engine in at least some operating states of the vehicle drive.