METHOD AND APPARATUS TO CONTROL LOGIC VALVES FOR HYDRAULIC FLOW CONTROL IN AN ELECTRO-MECHANICAL TRANSMISSION

• US 20090112422A1
• Filed: 10/10/2008
• Published: 04/30/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), GM Global Technology Operations Incorporated (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler LLC (Stellantis NV)
• Inventors: Sah, Jy-Jen F., Foster, Michael D., Naqvi, Ali K.
• Granted Patent: US 8,406,945 B2
• Time in Patent Office: Days
• US Class Current: 701/60
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/485 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• 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 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/087 Temperature
• CPC Class Codes: B60W 2510/104 : Output speed
• CPC Class Codes: B60W 2510/107 : Temperature
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• 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 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A method for controlling an electromechanical transmission includes monitoring a current hydraulic circuit oil temperature, monitoring a current state of flow management valves, monitoring a command for cooling of electric machines, monitoring a desired transmission operating range state, utilizing a state machine to determine a sequence for controlling positions of the flow management valves to achieve the desired transmission operating range state based upon the monitored properties.

Claims

1. Method for controlling an electromechanical transmission comprising first and second electric machines and a hydraulic circuit having a plurality of flow management valves and pressure control solenoids operative to actuate a plurality of clutches and a plurality of pressure monitoring devices adapted to monitor said hydraulic circuit, said transmission operative in fixed gear and continuously variable operating range states through selective actuation of said clutches, the method comprising:

monitoring a current hydraulic circuit oil temperature;

monitoring a current state of said flow management valves;

monitoring a command for cooling of said electric machines;

monitoring a desired transmission operating range state;

utilizing a state machine to determine a sequence for controlling positions of said flow management valves to achieve said desired transmission operating range state based upon said current hydraulic circuit oil temperature, said current state of said flow management valves, said command for cooling of said electric machines, and said desired transmission operating range state; and

controlling said flow management valves based upon said sequence.

2. The method of claim 1, wherein the utilizing said state machine to determine said sequence comprises:

determining a desired state of said flow management valves; and

applying valve logic-based rules to determine said sequence for controlling positions of said flow management valves based upon said desired state of said flow management valves.

3. The method of claim 2, wherein the applying valve logic-based rules comprises:

comparing said desired state of said flow management valves to said current state of said flow management valves;

identifying possible transitions to actuate said flow management valves from said current state of said flow management valves to said desired state of said flow management valves; and

prioritizing said possible transitions based upon said valve logic-based rules comprising

evaluating permissible clutch transitions,

evaluating effects to drivability, and

balancing said command for cooling of said electric machines

4. The method of claim 3, wherein the prioritizing said possible transitions further comprises evaluating diagnostic faults.

5. The method of claim 3,

wherein said flow management valves and said pressure control solenoids interact to form a multi-layered control system, and

wherein said prioritizing said possible transitions further comprises evaluating interaction between layers of said multi-layered control system.

6. The method of claim 5, wherein said flow management valves combine to exclusively control one of said layers of said multi-layered control system;

and wherein controlling said flow management valves based upon said sequence comprises actuating one of said flow management valves at a time.

7. The method of claim 5, further comprising utilizing a mute function upon one layer of said multi-layered control system during said controlling said flow management valves based upon said sequence.

8. Apparatus for controlling an electromechanical transmission comprising first and second electric machines and a plurality of hydraulically-actuated clutches, said transmission operative in fixed gear and continuously variable operating range states through selective actuation of said clutches, said apparatus comprising:

a hydraulic control system selectively directing a hydraulic flow to functions including actuation of said clutches, said hydraulic control system comprising flow management valves; and

a hydraulic control system control module, including logic operations comprising

monitoring requirements of said functions,

monitoring a desired transmission operating range state,

determining a desired valve configuration of said flow management valves based upon said requirements and said desired transmission operating range state,

monitoring a current valve configuration of said flow management valves, and

executing preferred valve transitions to reach said desired valve configuration based upon a state machine algorithm modeling potential valve transition paths between said current valve configuration and said desired valve configuration.

9. The apparatus of claim 8,

wherein said hydraulic control system further comprises pressure control solenoids;

wherein said hydraulic control system includes two layers of control devices comprising

a first layer comprising said flow management valves,

a second layer comprising said pressure control solenoids; and

wherein said modeling by said state machine algorithm includes interactions between said first layer and said second layer.

10. The apparatus of claim 9, wherein said logic operation further comprise, during transitions in said first layer, muting related operations of said second layer.