System for controlling particulate filter temperature

• US 6,901,751 B2
• Filed: 02/01/2002
• Issued: 06/07/2005
• Est. Priority Date: 02/01/2002
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Bunting, Bruce G., Suresh, S. Arvind, Stoia, Bradlee J., Miller, Paul R., Radovanovic, Rod
• Primary Examiner(s): Tran, Binh Q.
• Application Number:
  US10/062,385
• Publication Number:
  US 20030145582A1
• Time in Patent Office: 1,222 Days
• Field of Search: 602/74, 602/84, 602/85, 602/95, 602/97, 603/11, 180/65.1, 180/65.2, 180/65.3, 180/65.4
• US Class Current: 60/297
• CPC Class Codes: B01D 2279/30 for treatment of exhaust gases from IC Engines
• CPC Class Codes: B01D 46/444 by flow measuring
• CPC Class Codes: B01D 46/446 by pressure measuring
• CPC Class Codes: B01D 46/448 by temperature measuring
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• 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 2240/445 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/16 : by display
• CPC Class Codes: B60L 2250/26 : by pedal actuation
• CPC Class Codes: B60L 2270/12 : of exhaust
• CPC Class Codes: B60L 3/0023 : Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• 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: 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 10/10 : including control of change-speed gearings
• 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 20/15 : Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2050/143 : Alarm means
• CPC Class Codes: B60W 2510/068 : Engine exhaust temperature
• CPC Class Codes: B60Y 2300/476 : Regeneration of particle filters
• CPC Class Codes: F01N 11/002 : the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F01N 11/005 : the temperature or pressure being estimated, e.g. by means of a theoretical model
• CPC Class Codes: F01N 2430/00 : Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
• CPC Class Codes: F01N 2430/06 : by varying fuel-air ratio, e.g. by enriching fuel-air mixture
• CPC Class Codes: F01N 2550/04 : Filtering activity of particulate filters
• CPC Class Codes: F01N 3/023 : using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 9/002 : of filter regeneration, e.g. detection of clogging
• CPC Class Codes: F01N 9/005 : using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: F01N 9/007 : Storing data relevant to operation of exhaust systems for later retrieval and analysis, e.g. to research exhaust system malfunctions
• CPC Class Codes: F02B 37/00 : Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02D 2041/026 : using an external load, e.g. by increasing generator load or by changing the gear ratio
• CPC Class Codes: F02D 2041/0265 : to decrease temperature of the exhaust gas treating apparatus
• CPC Class Codes: F02D 2200/0802 : Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/503 : Battery correction, i.e. corrections as a function of the state of the battery, its output or its type
• CPC Class Codes: F02D 41/0235 : in relation with the state of the exhaust gas treating apparatus control of exhaust gas treating apparatus per se F01N
• CPC Class Codes: F02D 41/029 : the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: F02D 41/1445 : the characteristics being related to the exhaust flow
• CPC Class Codes: F02D 41/1448 : the characteristics being an exhaust gas pressure
• CPC Class Codes: F16H 2300/14 : Selecting a state of operation, e.g. depending on two wheel or four wheel drive mode
• 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 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y10S 903/917 : with transmission for changing gear ratio
• CPC Class Codes: Y10S 903/918 : Continuously variable
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio

Abstract

A system for controlling the temperature of a particulate filter coupled to an exhaust outlet of an internal combustion engine includes a controller responsive to volumetric flow and temperature of exhaust gas to determine a filter regeneration parameter. In a hybrid electric-engine vehicle application, various control strategies are implemented as a function of the regeneration parameter to control exhaust gas temperature suitably for proper regeneration of the particulate filter. Such strategies include shifting the duty cycle of the engine toward lower engine speed operation along lines of constant power output, modifying the ratio of electrical power and engine power and controlling recharging of the battery supplying electrical energy to the vehicle'"'"'s electric drive motor under vehicle deceleration conditions. In vehicle applications including a transmission coupled directly to the engine, shift points of the transmission are modified as a function of the regeneration parameter to control exhaust gas temperature.

Claims

1. System for controlling particulate filter temperature, the system comprising:

an internal combustion engine producing exhaust gas at an exhaust gas outlet;

a particulate filter having an filter inlet fluidly coupled to said exhaust outlet and a filter outlet;

means for determining a temperature of said particulate filter; and

a control circuit controlling rotational speed of said engine between an idle speed and a maximum speed, said control circuit increasing said idle speed from a first idle speed value to a second higher idle speed value if said temperature of said particulate filter exceeds a first temperature to thereby cool said particulate filter by increasing exhaust gas flow therethrough and decreasing said idle speed from said second idle speed value back to said first idle speed value if said temperature of said particulate filter drops below a second temperature less than said first temperature, said control circuit operable to log a fault code within a memory in communication with said control circuit if said temperature of said particulate filter exceeds a third temperature greater than said first temperature.

3. The system of claim 1 wherein the system is part of a hybrid engine-electric vehicle configured to drive the vehicle according to a ratio of electric power produced by an electric motor and engine output power produced by said engine.

2. System for controlling particulate filter temperature, the system comprising:

an internal combustion engine producing exhaust gas at an exhaust gas outlet;

a particulate filter having an filter inlet fluidly coupled to said exhaust outlet and a filter outlet;

means for determining a temperature of said particulate filter; and

a control circuit controlling rotational speed of said engine between an idle speed and a maximum speed, said control circuit increasing said idle speed from a first idle speed value to a second higher idle speed value if said temperature of said particulate filter exceeds a first temperature to thereby cool said particulate filter by increasing exhaust gas flow therethrough and decreasing said idle speed from said second idle speed value back to said first idle speed value if said temperature of said particulate filter drops below a second temperature less than said first temperature, said control circuit operable to activate a warning indicator if said temperature of said particulate filter exceeds a third temperature greater than said first temperature.

23. The system of claim 2 wherein the system is part of a hybrid engine-electric vehicle configured to drive the vehicle according to a ratio of electric power produced by an electric motor and engine output power produced by said engine.

4. System for controlling particulate filter temperature, the system comprising:

an internal combustion engine producing exhaust gas at an exhaust outlet;

a particulate filter having a filter inlet fluidly coupled to said exhaust outlet and a filter outlet;

means for determining a pressure differential between said filter inlet and said filter outlet;

means for determining a volumetric flow rate of said exhaust gas entering said filter inlet;

a temperature sensor producing a temperature signal indicative of exhaust gas temperature exiting said filter outlet; and

a control circuit determining a regeneration parameter as a function of said pressure differential and said volumetric flow rate, said control circuit responsive to said regeneration parameter falling within a predefined range of regeneration parameter values to control said particulate filter temperature by monitoring said temperature signal and commanding reduced engine rotational speeds along lines of constant engine output power to thereby increase said exhaust gas temperature and therefore said temperature of said particulate filter if said temperature signal is not greater than a regeneration temperature for at least a predefined portion of one of a temperature signal monitoring time period and a number of measurements of said temperature signal.

5. The system of claim 4 wherein the system is part of a hybrid engine-electric vehicle configured to drive the vehicle according to a ratio of electric power produced by an electric motor and engine output power produced by said engine.

6. The system of claim 4 further including a memory unit in communication with said control circuit, said control circuit responsive to said regeneration parameter falling within a predefined range of regeneration parameter values to log a corresponding fault code within said memory unit.

7. The system of claim 6 wherein said control circuit is further responsive to said regeneration parameter falling within said predefined range of regeneration parameters to activate a corresponding warning light.

8. System for controlling particulate filter temperature, the system comprising:

an internal combustion engine producing exhaust gas at an exhaust outlet;

an electric motor responsive to electrical energy provided by a rechargeable energy source to produce electric power in a hybrid engine-electric vehicle configured to drive the vehicle according to a ratio of electric power produced by said electric motor and engine output power produced by said engine;

a generator responsive to said engine output power to recharge said rechargeable energy source;

a particulate filter having a filter inlet fluidly coupled to said exhaust outlet and a filter outlet;

means for determining a pressure differential between said filter inlet and said filter outlet;

means for determining a volumetric flow rate of said exhaust gas entering said filter inlet; and

a control circuit controlling said ratio of electrical power and engine output power and determining a regeneration parameter as a function of said pressure differential and said volumetric flow rate, said control circuit responsive to said regeneration parameter falling within a predefined range of regeneration parameter values to control said temperature of said particulate filter by periodically increasing said ratio of said electrical power and said engine power to facilitate discharging of said energy source so that increased engine output power is then produced to recharge said energy source, said increased engine output power resulting in an increase in temperature of said exhaust gas and therefore an increase in said temperature of said particulate filter.

9. The system of claim 8 further including a memory unit in communication with said control circuit, said control circuit responsive to said regeneration parameter falling within a predefined range of regeneration parameter values to log a corresponding fault code within said memory unit.

10. The system of claim 9 wherein said control circuit is further responsive to said regeneration parameter falling within said predefined range of regeneration parameters to activate a corresponding warning light.

11. System for controlling particulate filter temperature, the system comprising:

an internal combustion engine producing exhaust gas at an exhaust outlet;

an electric motor having a generator coupled to a drive axle in a hybrid engine-electric vehicle configured to drive the vehicle according to a ratio of electric power produced by said electric motor and engine output power produced by said engine, said electric motor responsive in a motor mode to electrical energy provided by a rechargeable energy source to drive at least one wheel coupled to said drive axle and in a generator mode to torque produced by said drive axle to recharge said rechargeable energy source with said generator;

a particulate filter having a filter inlet fluidly coupled to said exhaust outlet and a filter outlet;

means for determining a pressure differential between said filter inlet and said filter outlet;

means for determining a volumetric flow rate of said exhaust gas entering said filter inlet; and

a control circuit determining an acceleration value indicative of vehicle acceleration and determining a regeneration parameter as a function of said pressure differential and said volumetric flow rate, said control circuit responsive to said regeneration parameter falling within a predefined range of regeneration parameter values to control said temperature of said particulate filter by inhibiting recharging of said energy source by said electric motor operating in said generator mode if said acceleration value is less than an acceleration threshold value so that increased engine output power is then produced to recharge said energy source, said increased engine output power resulting in an increase in temperature of said exhaust gas and therefore an increase in said temperature of said particulate filter.

12. The system of claim 11 further including a memory unit in communication with said control circuit, said control circuit responsive to said regeneration parameter falling within a predefined range of regeneration parameter values to log a corresponding fault code within said memory unit.

13. The system of claim 12 wherein said control circuit is further responsive to said regeneration parameter falling within said predefined range of regeneration parameters to activate a corresponding warning light.

14. System for controlling particulate filter temperature, the system comprising:

an internal combustion engine producing exhaust gas at an exhaust outlet;

a particulate filter having a filter inlet fluidly coupled to said exhaust outlet and a filter outlet;

means for determining a pressure differential between said filter inlet and said filter outlet;

means for determining a volumetric flow rate of said exhaust gas entering said filter inlet; and

a control circuit determining a regeneration parameter as a function of said pressure differential and said volumetric flow rate, and defining a number of boundaries each as a different function of said differential pressure of said volumetric flow rate, said control circuit controlling temperature of said particulate filter as a function of said regeneration parameter and of said number of boundaries.

15. The system of claim 14 further including a memory unit having a map stored therein defining said number of boundaries, said control circuit defining said number of boundaries by extracting said map from said memory unit.

16. The system of claim 14 further including a memory unit, said control circuit responsive to said regeneration parameter falling within a first regeneration region bounded by an axis of zero-valued volumetric flow rates of exhaust gas entering said filter inlet and an adjacent one of said number of boundaries to log a low back pressure fault within said memory unit.

17. The system of claim 16 wherein said control circuit is further responsive to said regeneration parameter falling within said first regeneration region to activate a warning light.

18. The system of claim 16 further including a temperature sensor producing a temperature signal indicative of exhaust gas temperature exiting said filter outlet;

wherein said control circuit is responsive to said regeneration parameter falling within a second regeneration region bounded by said first regeneration region and an adjacent one of said number of boundaries to execute a first control strategy to control said temperature of said particulate filter by monitoring said temperature signal and commanding reduced engine rotational speeds along lines of constant engine output power to thereby increase temperature of said exhaust gas and therefore said temperature of said particulate filter if said temperature signal is not greater than a regeneration temperature for at least a predefined portion of one of a temperature signal monitoring time period and a number of measurements of said temperature signal.

19. The system of claim 18 wherein said electric motor is responsive to electrical energy provided by a rechargeable energy source to produce said electrical power, the system further including a first generator responsive to engine output power to recharge said energy source;

and wherein said control circuit is operable to control said ratio of electrical power and engine output power, said control circuit responsive to said regeneration parameter falling within a third regeneration region bounded by said second regeneration region and an adjacent one of said number of boundaries to execute said first control strategy and to execute a second control strategy operable to control said temperature of said particulate filter by periodically increasing said ratio of said electrical power and said engine power to facilitate discharging of said energy source so that increased engine output power is then produced to recharge said energy source, said increased engine output power resulting in an increase in temperature of said exhaust gas and therefore an increase in said temperature of said particulate filter.

20. The system of claim 19 wherein said electric motor includes a second generator coupled to a drive axle of said vehicle, said electric motor responsive in a motor mode to electrical energy provided by a rechargeable energy source to drive at least one wheel coupled to said drive axle, and in a generator mode to torque produced by said drive axle to recharge said energy source with said second generator;

and wherein said control circuit is operable to determine an acceleration value indicative of vehicle acceleration, said control circuit responsive to said regeneration parameter falling within a fourth regeneration region bounded by said third regeneration region and an adjacent one of said number of boundaries to execute said first and second control strategies and to execute a third control strategy to control said temperature of said particulate filter by inhibiting recharging of said energy source by said electric motor operating in said generator mode if said acceleration value is less than an acceleration threshold value so that increased engine output power is then produced to recharge said energy source, said increased engine output power resulting in an increase in temperature of said exhaust gas and therefore an increase in said temperature of said particulate filter.

21. The system of claim 20 wherein said control circuit responsive to said regeneration parameter falling within a fifth regeneration region bounded by said fourth regeneration region and an axis of zero-valued pressure differentials between said inlet and said outlet of said particulate filter to log a plugged particulate filter fault within said memory unit.

22. The system of claim 21 wherein said control circuit is further responsive to said regeneration parameter falling within said fifth regeneration region to activate a warning light.