Method and a system for controlling the propulsion of a hybrid motor vehicle

• US 20030010548A1
• Filed: 08/02/2002
• Published: 01/16/2003
• Est. Priority Date: 02/04/2000
• Status: Active Grant

• Current Assignee: C.R.F. Societa Consortile Per Azioni
• Original Assignee: C.R.F. Societa Consortile Per Azioni
• Inventors: Osella, Giancarlo, Ellena, Giovanni, Porta, Attilio, Mesiti, Domenico
• Granted Patent: US 6,997,275 B2
• Time in Patent Office: Days
• US Class Current: 180/65.2
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• 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 10/11 Stepped 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 20/40 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 30/18018 Start-stop drive, e.g. in a traffic jam
• 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

Abstract

The system comprises control devices (CS) arranged to implement a stop-start function in which, during a stop stage, the internal combustion engine (1) is disconnected from the electric machine (4) and from the transmission system (2) and is switched off in first predetermined operating conditions of the vehicle (V) and then, in a subsequent start stage, is automatically restarted by an electric machine (4), operating as a motor, and is then reconnected to the transmission system (2).

Claims

1. A propulsion-control system for a motor vehicle (V) provided with:

an internal combustion engine (1);

a transmission system (2) comprising a transmission (3) with discrete ratios, provided with actuator means (22) for engaging/disengaging the ratios,

a reversible electric machine (4) which includes a rotor (5) and a stator (6), is interposed between the internal combustion engine (1) and the transmission system (2), and is suitable for operating as a generator and as an electric motor;

a first clutch and a second clutch (7, 8) which can be operated selectively to control the connection of the rotor (5) of the electric machine (4) to the transmission system (2) and to the internal combustion engine (1), respectively;

sensor means (14, 16, 24) for supplying electrical signals indicative of operating conditions of the vehicle (V), of the internal combustion engine (1), and of the electric machine (4), and

control means (CS) for controlling the internal combustion engine (1), the electric machine (4), the first and second clutches (7, 8), and the actuator means (22) for engaging/disengaging the ratios of the transmission, in accordance with predetermined procedures in dependence on the signals supplied by the sensor means (14, 16, 24);

the control means (CS) being arranged, in particular, to implement a stop-start function in which, during a stop stage, the internal combustion engine (1) is disconnected from the electric machine (4) and from the transmission system (2) and is switched off in first predetermined operating conditions of the vehicle (V) and then, as a result of the occurrence of second operating conditions such as a command imparted by the driver, in a subsequent start stage, is automatically restarted by the electric machine (4), operating as a motor, and is then reconnected to the transmission system (2);

the propulsion-control system being characterized in that the control means (CS) are arranged to bring about, during the start stage

the connection of the electric machine (4), operating as an electric motor, to the transmission system (2), whilst a predetermined ratio, preferably the first ratio, is engaged in the transmission (3) so that, during the start stage, the vehicle (V) is initially propelled by the electric machine (4), and then

the implementation, in predetermined operating conditions, of a change from the predetermined ratio to a higher ratio and, during this change of ratio, the connection of the internal combustion engine (1) to the electric machine (4), operating as a motor, in order to bring about starting of the internal combustion engine, and then the connection of the internal combustion engine (1) to the transmission system (2) so that, upon completion of the start stage, the vehicle (V) is propelled by the internal combustion engine (1), and possibly also by the electric machine (4).

2. A system according to claim 1 in which the change of ratio is a change from the first ratio to the second ratio.

3. A system according to claim 1 or claim 2 in which, during the start stage, the control means CS are arranged to bring about in succession:

disengagement of the first clutch (7),

disengagement of the predetermined ratio,

engagement of the higher ratio and, simultaneously, engagement of the second clutch (8),

engagement of the first clutch (7).

4. A method of controlling propulsion in a motor vehicle provided with:

an internal combustion engine (1),

a transmission system (2) comprising a transmission (3) with discrete ratios, provided with actuator means (22) for engaging/disengaging the ratios,

a reversible electric machine (4) which includes a rotor (5) and a stator (6), is interposed between the internal combustion engine (1) and the transmission system (2), and is suitable for operating as a generator and as an electric motor,

a first clutch and a second clutch (7, 8) which can be operated selectively to control the connection of the rotor (5) of the electric machine (4) to the transmission system (2) and to the internal combustion engine (1), respectively,

the method comprising the implementation of a stop-start function, including;

a stop stage in which the internal combustion engine (1) is disconnected from the electric machine (4) and from the transmission system (2) and is switched off, and

a subsequent start stage in which the internal combustion engine (1) is restarted by the electric machine (4), operating as a motor, and is then reconnected to the transmission system (2);

the method being characterized in that, during the start stage;

the electric machine (4), operating as an electric motor, is connected to the transmission system (2), whilst a predetermined ratio, preferably the first ratio, is engaged in the transmission (3) so that, during the start stage, the vehicle (V) is initially propelled by the electric machine (4), and

a change from the predetermined ratio to a higher ratio is subsequently implemented and, during this change of ratio, the internal combustion engine (1) is connected to the electric machine (4), operating as a motor, in order to bring about starting of the internal combustion engine (1), and then the restarted internal combustion engine (1) is connected to the transmission system (2) so that, upon completion of the start stage, the vehicle (V) is propelled by the internal combustion engine (1), and possibly also by the electric machine (4).

5. A method according to claim 4 in which the change of ratio is a change from the first ratio to the second ratio.

6. A method according to claim 4 or claim 5 in which, during the start stage, the following steps are implemented in succession:

disengagement of the first clutch (7),

disengagement of said predetermined ratio,

engagement of the higher ratio and, simultaneously, engagement of the second clutch (8), and

engagement of the first clutch (7).