Hybrid vehicle

• US 6,209,672 B1
• Filed: 03/09/1999
• Issued: 04/03/2001
• Est. Priority Date: 09/14/1998
• Status: Expired due to Term

• Current Assignee: Abell Foundation Incorporated
• Original Assignee: Paice LLC
• Inventors: Severinsky, Alex J.
• Primary Examiner(s): Swann, J. J.
• Assistant Examiner(s): Dunn, David R.
• Application Number:
  US09/264,817
• Time in Patent Office: 756 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.4, 180/65.6, 180/65.8, 180/165, 60/716, 60/718, 60/706, 60/711, 290/17, 290/40 R, 290/40 C, 322/16
• US Class Current: 180/65.23
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/40 DC to AC converters
• 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 2240/445 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2270/12 of exhaust
• 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 10/18 including control of braking systems
• 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: B60Y 2400/435 : Supercharger or turbochargers
• CPC Class Codes: F02D 2250/18 : Control of the engine output torque
• CPC Class Codes: F02N 11/0818 : Conditions for starting or stopping the engine or for deactivating the idle-start-stop mode
• 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: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

A hybrid vehicle comprising an an internal combustion engine controllably coupled to road wheels of the vehicle by a clutch, a traction motor coupled to road wheels of said vehicle, a starting motor coupled to the engine, both motors being operable as generators, a battery bank for providing electrical energy to and accepting energy from said motors, and a microprocessor for controlling these components is operated in different modes, depending on its instantaneous torque requirements, the state of charge of the battery bank, and other operating parameters. The mode of operation is selected by the microprocessor in response to a control strategy.

Claims

1. A hybrid vehicle, comprising:

a controller capable of accepting inputs indicative of vehicle operating parameters and providing control signals in response to a control program;

a battery bank;

an internal combustion engine;

a first electric starting motor electrically coupled to said battery bank for (a) accepting electrical energy from said battery bank and (b) providing electrical energy to said battery bank, and said first motor being mechanically coupled to said internal combustion engine, the combination of said internal combustion engine and said first electric motor being mechanically coupled to a clutch controlled by said controller for controllable torque-transmitting connection between said combination and road wheels of said vehicle,

said first motor being responsive to commands from said controller, such that said first electric motor can be controlled to (1) accept torque from said engine to charge said battery bank, (2) accept energy from said battery bank to apply torque to said engine for starting said engine, (3) accept energy from said battery bank to apply torque to said road wheels to propel said vehicle, and (4) accept torque from said road wheels to charge said battery bank; and

a second electric traction motor, electrically coupled to said battery bank, such that said second electric motor can be controlled for (a) accepting electrical energy from said battery bank and (b) providing electrical energy to said battery bank, said second motor being directly coupled to road wheels of said vehicle, without a controllable clutch disposed therebetween, such that said second motor is permanently connected to said road wheels for torque transmission therebetween, and said second motor being responsive to commands from said controller in order to (1) accept energy from said battery bank to apply torque to said road wheels to propel said vehicle, and (2) accept torque from said road wheels to charge said battery bank.

2. The hybrid vehicle of claim 1, wherein said controller is provided with signals indicative of the instantaneous road load experienced by said vehicle and of the state of charge of said battery bank, and controls operation of said engine, said clutch, and said first and second motors so that said vehicle is operated in a plurality of operating modes responsive to said signals.

3. The hybrid vehicle of claim 2 wherein said signal indicative of the instantaneous road load experienced by said vehicle is determined by said controller at least in part by monitoring commands provided by the vehicle operator.

4. The hybrid vehicle of claim 2, wherein road load (RL) is expressed as a percentage of the maximum torque output of the engine (MTO), and said operating modes include:

a low-speed mode I, wherein said vehicle is propelled by torque provided by said traction motor in response to energy supplied from said battery bank, while RL<

SP, wherein SP is a setpoint expressed as a predetermined percentage of MTO,

a highway cruising mode IV, wherein said vehicle is propelled by torque provided by said engine in response to supply of combustible fuel, while SP<

RL<

100% of MTO, and

an acceleration mode V, wherein said vehicle is propelled by torque provided by said engine in response to supply of combustible fuel and by torque provided by said traction motor in response to energy supplied from said battery bank, while RL>

100% of MTO.

5. The hybrid vehicle of claim 4, wherein said clutch is disengaged during operation in mode I and engaged during operation in modes IV and V.

6. The hybrid vehicle of claim 4, wherein said operating modes further include a low-speed battery charging mode II, entered while RL<

SP and the state of charge of the battery bank is below a predetermined level, and wherein said vehicle is propelled by torque provided by said traction motor in response to energy supplied from said battery bank, and wherein said battery bank is simultaneously charged by supply of electrical energy from said starting motor, being driven by torque by said engine in response to supply of combustible fuel, said clutch being disengaged during operation in mode II.

7. The hybrid vehicle of claim 4, wherein said setpoint SP may be varied by said controller in response to monitoring patterns of vehicle operation over time.

8. The hybrid vehicle of claim 4, wherein the transition between operation in modes I and IV is controlled to occur only when RL>

SP for at least a predetermined time, or when RL>

SP2, wherein SP2 is a larger percentage of MTO than SP.

9. The hybrid vehicle of claim 4, wherein the transition between operation in modes IV and I is controlled to occur only when RL<

SP for at least a predetermined time.

10. The hybrid vehicle of claim 4, wherein the controller may control transition of the operating mode from operation in mode I directly to operation in mode V where a rapid increase in RL is detected.

11. The hybrid vehicle of claim 4, wherein the controller may accept operator input of a desired cruising speed, and thereafter controls the instantaneous engine torque output in accordance with variation in RL so as to maintain vehicle speed substantially constant, and does not permit transition to mode I operation until the operator provides a further signal indicating that the desired cruising speed is no longer desired.

12. The hybrid vehicle of claim 4, wherein regenerative charging of the battery bank is performed when the engine'"'"'s instantaneous torque output >

RL, when RL is negative, or when braking is initiated by the operator.

13. The hybrid vehicle of claim 1, wherein the total torque available at the road wheels from said engine is no greater than the total torque available from said first and second motors combined.

14. The hybrid vehicle of claim 1, wherein the maximum speed of at least said traction motor is least 150% of the maximum speed of said engine.

15. A method for controlling the operation of a hybrid vehicle operable in a plurality of differing modes, comprising the steps of:

providing a hybrid vehicle comprising an internal combustion engine for providing torque up to a maximum torque output (MTO), said engine being controllably coupled to road wheels of said vehicle by a clutch, a traction motor being coupled to road wheels of said vehicle, a starting motor coupled to said engine, both said motors being operable as generators, a battery bank for providing electrical energy to and accepting energy from said motors, and a controller for controlling operation of said engine, clutch, and first and second motors, and controlling flow of electrical energy between said motors and said battery bank,

and operating said controller to control selection of the operational mode of said vehicle between a low-speed mode I, a cruising mode IV, and an acceleration mode V, wherein torque to propel said vehicle is provided by said traction motor, said engine, and both, respectively, in response to monitoring the instantaneous torque requirements required for propulsion of the vehicle (RL).

16. The method of claim 15, wherein said controller controls said vehicle to operate in

said low speed mode I while RL< SP, wherein SP is a setpoint expressed as a predetermined percentage of MTO,

said highway cruising mode IV while SP<

RL<

100% of MTO, and

said acceleration mode V while RL>

100% of MTO.

17. The method of claim 16, comprising the further step of disengaging said clutch during operation in mode I and engaging said clutch during operation in modes IV and V.

18. The method of claim 16, wherein said controller further controls said vehicle to operate in a low-speed battery charging mode II, entered while RL<

SP and the state of charge of the battery bank is below a predetermined level, during which said vehicle is propelled by torque provided by said traction motor in response to energy supplied from said battery bank, and wherein said battery bank is simultaneously charged by supply of electrical energy from said starting motor, being driven by torque by said engine in response to supply of combustible fuel, said clutch being disengaged during operation in mode II.

19. The method of claim 16, comprising the further step of employing said controller to monitor patterns of vehicle operation over time and vary said setpoint SP accordingly.

20. The method of claim 16, comprising the further step of employing said controller to monitor RL over time, and to control transition between operation in modes I and IV accordingly, such that said transition occurs only when RL>

SP for at least a predetermined time, or when RL>

SP2, wherein SP2 is a larger percentage of MTO than SP.

21. The method of claim 16, comprising the further step of employing said controller to monitor RL over time, and to control transition between operation in modes I and IV accordingly, such that said transition occurs only when RL<

SP for at least a predetermined time.

22. The method of claim 16, comprising the further step of operating said controller to a monitor RL over time, and to control the operating mode to change from from operation in mode I directly to operation in mode V where a rapid increase in RL is detected.

23. The method of claim 16, comprising the further step of operating said controller to accept operator input of a desired cruising speed, said controller thereafter controlling the instantaneous engine torque output in accordance with variation in RL so as to maintain vehicle speed substantially constant, and to prevent transition to mode I operation until the operator provides a further signal indicative that the desired cruising speed is no longer desired.

24. The method of claim 16, comprising the further step of performing regenerative charge of the battery bank under controller control when the engine'"'"'s instantaneous torque output>

RL, when RL is negative, or when braking is initiated by the operator.

25. The method of claim 16, wherein said motors are controlled together to provide maximum torque at least equal to the maximum torque of said engine.

26. The method of claim 16, wherein the maximum speed of at least said traction motor is controlled to be at least 150% of the maximum speed of said engine.

27. A method for controlling the operation of a hybrid vehicle operable in a plurality of differing modes, comprising the steps of:

providing a hybrid vehicle comprising an internal combustion engine for providing torque up to a maximum torque output (MTO), said engine being controllably coupled to road wheels of said vehicle by a clutch, a traction motor being coupled to road wheels of said vehicle, a starting motor coupled to said engine, both said motors being operable as generators, a battery bank for providing electrical energy to and accepting energy from said motors, and a controller for controlling operation of said engine, clutch, and first and second motors, and controlling flow of electrical energy between said motors and said battery bank,

and operating said controller to control selection of the operational mode of said vehicle between a low-speed mode I and a cruising mode IV, wherein torque to propel said vehicle is provided by said traction motor or said engine, respectively, in response to monitoring the instantaneous torque requirements required for propulsion of the vehicle (RL), and

wherein further according to said method, when said controller determines that transition of the operating mode of said vehicle from mode I to mode IV is desirable, said controller controls said starting motor to spin said engine for starting at a minimum speed of at least 300 rpm, and said clutch is not engaged for supply of torque from said engine to said road wheels until said engine is running at a speed at which it efficiently produces torque.

28. The method of claim 27, wherein said vehicle further comprises a catalytic converter comprising a catalyst for reducing noxious emissions from said engine to harmless products, said catalytic converter being provided with a heater controlled by said controller for heating said catalyst to an effective working temperature, and wherein when said controller determines that transition of the operating mode of said vehicle from mode I to mode IV is desirable, said controller heats said catalyst to a minimum effective working temperature if necessary before controlling said starting motor to spin said engine for starting.

29. A hybrid vehicle operable in a plurality of differing modes, said vehicle comprising an internal combustion engine for providing torque up to a maximum torque output (MTO) and at least one traction motor being coupled to road wheels of said vehicle, said at least one motor being operable as a generator, a battery bank for providing electrical energy to and accepting energy from said motor, a controller for controlling operation of said engine, and said at least one motor, and controlling flow of electrical energy between said motor and said battery bank, and at least one controllable inverter/charger connected between said motor and said battery bank, said controllable inverter/charger comprising a plurality of pairs of elements controllably switched in response to commands from said controller for operating said motor to supply propulsive torque to said road wheels in response to energy from said battery bank, and for converting torque transmitted from said road wheels to said motor into energy for recharging said battery bank,

wherein said battery bank is configured as two separate battery sub-banks, each having positive and negative poles, the positive pole of one of said sub-banks being connected to the negative pole of the other of said sub-banks at a vehicle chassis connection, and the opposite poles of said battery sub-banks being connected across said pairs of elements of said at least one inverter/charger.

30. A hybrid vehicle operable in a plurality of differing modes, said vehicle comprising an internal combustion engine for providing torque up to a maximum torque output (MTO) and at least one traction motor being coupled to road wheels of said vehicle, said at least one motor being operable as a generator, a battery bank for providing electrical energy to and accepting energy from said motor, a controller for controlling operation of said engine and said at least one motor, and controlling flow of electrical energy between said motor and said battery bank, and at least one controllable inverter/charger connected between said motor and said battery bank, said controllable inverter/charger comprising a plurality of pairs of elements controllably switched in response to commands from said controller for operating said motor to supply propulsive torque to said road wheels in response to energy from said battery bank, and for converting torque transmitted from said road wheels to said motor into energy for recharging said battery bank,

wherein said battery bank is configured as a number of batteries connected by normally-open switching devices, such that said batteries are electrically isolated from one another in the event power is cut off from said switching devices.

31. A hybrid vehicle operable in a plurality of differing modes, said vehicle comprising an internal combustion engine for providing torque up to a maximum torque output (MTO) and at least one traction motor being coupled to road wheels of said vehicle, without a controllable clutch disposed therebetween, such that said at least one motor is permanently connected to said road wheels for torque transmission therebetween, said at least one motor being operable as a generator, a battery bank for providing electrical energy to and accepting energy from said motor, a controller for controlling operation of said engine and said at least one motor, and controlling flow of electrical energy between said motor and said battery bank, and at least one controllable inverter/charger connected between said motor and said battery bank, said controllable inverter/charger comprising a plurality of pairs of elements controllably switched in response to commands from said controller for operating said motor to supply propulsive torque to said road wheels in response to energy from said battery bank, and for converting torque transmitted from said road wheels to said motor into energy for recharging said battery bank,

wherein said motor has at least four phases, and wherein said motor is operated by said inverter/charger in response to control signals provided by said controller so that said motor provides constant torque from zero rpm to a base speed, and provides constant power at speeds greater than said base speed and less than a maximum speed.

32. A hybrid vehicle operable in a plurality of differing modes, said vehicle comprising an internal combustion engine for providing torque up to a maximum torque output (MTO) and at least one traction motor being coupled to road wheels of said vehicle, without a controllable clutch disposed therebetween, such that said at least one motor is permanently connected to said road wheels for torque transmission therebetween, said at least one motor being operable as a generator, a battery bank for providing electrical energy to and accepting energy from said motor, a controller for controlling operation of said engine and said at least one motor, and controlling flow of electrical energy between said motor and said battery bank, and at least one controllable inverter/charger connected between said motor and said battery bank, said controllable inverter/charger comprising a plurality of pairs of elements controllably switched in response to commands from said controller for operating said motor to supply propulsive torque to said road wheels in response to energy from said battery bank, and for converting torque transmitted from said road wheels to said motor into energy for recharging said battery bank, wherein said motor is operated by said inverter/charger in response to control signals provided by said controller so that said motor provides constant torque from zero rpm to a base speed, and provides constant power at speeds greater than said bass speed and less than a maximum speed, and wherein the ratio between said base speed and said maximum speed is between about 3 and about 6:

1.

33. The vehicle of claim 32, wherein the maximum speed of said motor is at least about 150% the maximum speed of said engine.