Control system for hybrid vehicle and method

• US 10,196,056 B2
• Filed: 05/20/2015
• Issued: 02/05/2019
• Est. Priority Date: 06/23/2014
• Status: Active Grant

• Current Assignee: Jaguar Land Rover Limited (TATA Motors Limited)
• Original Assignee: Jaguar Land Rover Limited (TATA Motors Limited)
• Inventors: Owen, Simon
• Primary Examiner(s): Walters, John D
• Application Number:
  US15/320,549
• Publication Number:
  US 20180208178A1
• Time in Patent Office: 1,357 Days
• Field of Search: 180 6528
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/46 Series type
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 20/19 for achieving enhanced acceleration
• 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 2510/0676 Engine temperature
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/16 Pitch
• CPC Class Codes: B60W 2520/18 Roll
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2530/207 Towing force
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/106 Rate of change
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2540/18 : Steering angle
• CPC Class Codes: B60W 2540/215 : Selection or confirmation of options
• CPC Class Codes: B60W 2540/30 : Driving style
• CPC Class Codes: B60W 2552/00 : Input parameters relating to infrastructure
• CPC Class Codes: B60W 2552/15 : Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2555/20 : Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2555/40 : Altitude
• CPC Class Codes: B60W 30/18027 : Drive off, accelerating from standstill
• CPC Class Codes: B60W 50/0097 : Predicting future conditions
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles

Abstract

The disclosure relates to a system for controlling a hybrid vehicle having a primary power source such as an electric motor and a secondary power source such as an internal combustion engine, the electric motor and internal combustion engine each being connectable to a driveline of the vehicle. The system comprises a control unit operable to cause the internal combustion engine to be pre-emptively initiated and subsequently connected to the driveline. The control unit is configured and arranged to determine when the vehicle is in a first driving mode (wherein the internal combustion engine is not initiated and is disconnected from the driveline of the vehicle and wherein the electric motor and battery pack are delivering a torque to the driveline in response to a driver demanded torque). The control unit is further configured and arranged to determine that a steering angle of the vehicle and a situational status of the vehicle are indicative of a driving situation in which an expected driver demanded torque will not be met by the primary power source alone. In response thereto, the control unit is configured and arranged to automatically and pre-emptively cause the internal combustion engine to be initiated and connected to the driveline at a time before the actual driver demanded torque reaches or exceeds said expected driver demanded torque.

Claims

1. A system for controlling a hybrid vehicle having a primary power source and a secondary power source, each connectable to a driveline of the vehicle, the system comprising:

a control unit configured to cause the secondary power source to be pre-emptively initiated and subsequently connected to the driveline and configured to determine that the vehicle is in a first driving mode wherein the secondary power source is not initiated and/or is disconnected from the driveline of the vehicle, wherein the primary power source is for delivering a torque to the driveline, and wherein the vehicle is stationary;

wherein the control unit is configured to determine that a steering angle of the vehicle and a situational status of the vehicle are indicative of a driving situation in which an expected pull-away torque will not be met by the primary power source alone, and in response thereto, the control unit is configured to automatically and pre-emptively cause the secondary power source to be initiated and/or connected to the driveline at a time before an actual demanded torque reaches or exceeds said expected pull-away torque.

2. The system of claim 1, wherein the control unit is configured to automatically and preemptively cause the secondary power source to be initiated and/or connected to the driveline in dependence upon one or more of the following triggers:

(i) a driver input to commence vehicle movement;

(ii) a cruise control system input to commence vehicle movement;

(iii) activation of a human-machine-interfacing element by which a driver of the vehicle can demand torque;

(iv) a decrease of brake pressure below a brake pressure threshold;

(v) a rate of decrease of brake pressure occurring at or above a specified rate of reduction of brake pressure threshold; and

(vi) engagement of a drive gear in an intended direction that corresponds to a drive direction in which the steering angle of the vehicle and the situational status of the vehicle are indicative of the driving situation in which the expected pull-away torque will not be met by the primary power source alone.

3. The system of claim 2, wherein the control unit is further configured:

(i) to determine the situational status of the vehicle;

(ii) to monitor the steering angle of the vehicle;

(iii) to determine an expected time at which the expected pull-away torque will exceed a threshold torque output of the primary power source;

(iv) to determine a suitable time at which the secondary power source is to be automatically initiated, in dependence upon;

said expected time, said expected pull-away torque, and/or one or more parameters associated with the vehicle or the secondary power source, and, in response thereto, the control unit is configured to cause the secondary power source to be initiated at said suitable time such that the secondary power source is prepared to deliver an appropriate supplementary output torque at or before said expected time;

wherein the control unit is configured to determine said suitable time in dependence on one or more of the following;

the situational status of the vehicle, the steering angle or a rate of change of the steering angle, a temperature of the secondary power source, an ambient temperature, an altitude of the vehicle, and an initiation time of the secondary power source.

4. The system of claim 3, wherein the secondary power source is engaged to the driveline substantially at or before said expected time, such that at said expected time, an actual total torque output by the secondary power source and the primary power source substantially matches said expected pull-away torque.

5. The system of claim 3, wherein the control unit is configured to determine said expected pull-away torque in dependence upon one or more of:

(i) the one or more parameters associated with the vehicle;

(ii) whether the vehicle is heavily laden and/or towing;

(iii) the situational status of the vehicle;

(iv) the steering angle or rate of change of steering angle;

(v) a current driver demanded torque;

(vi) a rate of change of driver demanded torque; and

(vii) a driver style model.

6. The system of claim 3, wherein the control unit is further configured to temporarily increase the threshold torque output of the primary power source.

7. The system of claim 1, wherein the vehicle is a hybrid electric vehicle, wherein the primary power source is an electric motor and wherein the secondary power source is an internal combustion engine.

8. The system of claim 1, wherein said situational status of the vehicle is determined in consideration of one or more of the following:

(i) vehicle drive speed;

(ii) vehicle longitudinal angle of inclination;

(iii) vehicle lateral angle of inclination;

(iv) a combination of longitudinal and lateral angle of inclination of the vehicle;

(v) a correspondence between a vehicle longitudinal angle of inclination and a direction of travel or of intended travel of the vehicle;

(vi) a selection of a low range gear;

(vii) a position of an adjustable suspension system or a current ride height; and

(viii) a status of a terrain response mode.

9. The system of claim 8, wherein said situational status of the vehicle is determined as indicative of the driving situation in which the expected pull-away torque will not be met by the primary power source alone, in consideration of one or more of the following:

(i) the steering angle of the vehicle being greater than about 90°

or less than about −

90′

;

(ii) the vehicle drive speed being about 0 kmh<sup>−

1</sup>;

(iii) the vehicle longitudinal angle of inclination being less than about 10°

or greater than about −

10°

;

(iv) the vehicle lateral angle of inclination being less than 7°

or greater than −

7′

;

(v) the vehicle longitudinal angle of inclination being less than 7°

or greater than −

7° and

the vehicle lateral angle of inclination being less than 5°

or greater than −

5°

;

(vi) the correspondence between a vehicle longitudinal angle of inclination of less than about 10°

or greater than about −

10° and

the direction of travel or of intended travel of the vehicle;

(vii) the selection of a low range gear;

(viii) a high-ride height position selection of the adjustable suspension system; and

(ix) the terrain response mode being in a rock crawl mode, a grass/gravel/snow mode, or a mud and ruts mode.

10. The system of claim 8, wherein:

(i) if the vehicle speed is less than 0.5 kmh<sup>−

1</sup> or substantially about 0 kmh<sup>−

1</sup>; and

(ii) if said steering angle is greater than 90°

or less than −

90°

; and

(iii) if said vehicle longitudinal angle of inclination is less than 10°

or is greater than −

10°

; and

(iv) if said direction of travel or intended direction of travel and the vehicle longitudinal angle of inclination correlates to the vehicle being in an uphill situation,

then, the control unit will automatically and pre-emptively cause the secondary power source to be initiated and connected to the driveline at a time before an actual demanded torque reaches or exceeds said expected pull-away torque.

11. A hybrid electric vehicle comprising:

a primary power source in the form of an electric motor;

a secondary power source in the form of an internal combustion engine; and

a system for controlling the hybrid electric vehicle according to claim 1.

12. A method of controlling a hybrid vehicle having a primary power source and a secondary power source, each being connectable to a driveline of the vehicle, the method comprising:

(i) determining that the vehicle is in a first driving mode, wherein the secondary power source is not initiated and/or is disconnected from the driveline of the vehicle and wherein the vehicle is stationary;

(ii) determining that a steering angle and a situational status of the vehicle are indicative of a driving situation in which an expected pull-away torque will not be met by the primary power source alone; and

in response thereto,

(iii) automatically and pre-emptively causing the secondary power source to be initiated and connected to the driveline at a time before an actual demanded torque reaches or exceeds said expected pull-away torque.

13. The method of claim 12, wherein automatically and pre-emptively causing the secondary power source to be initiated and/or connected to the driveline is performed in dependence upon one or more of the following triggers:

(i) a driver input to commence vehicle movement;

(ii) a cruise control system input to commence vehicle movement;

(iii) activation of a human-machine-interfacing element by which a driver of the vehicle can demand torque;

(iv) a decrease of brake pressure below a brake pressure threshold;

(v) a rate of decrease of brake pressure occurring at or above a specified rate of reduction of brake pressure threshold; and

(vi) engagement of a drive gear in an intended direction that corresponds to a drive direction in which the steering angle of the vehicle and a situational status of the vehicle are indicative of a driving situation in which an expected pull-away torque will not be met by the primary power source alone.

14. The method of claim 12, further comprising:

(i) determining the situational status of the vehicle;

(ii) determining the steering angle of the vehicle;

(iii) determining, in dependence upon the situational status of the vehicle and the steering angle of the vehicle, an expected time at which the expected pull-away torque will reach or exceed an accepted maximum threshold torque output of the primary power source; and

(iv) in dependence upon said expected time, said expected pull-away torque and/or one or more parameters associated with the vehicle or the secondary power source, determining a suitable time, prior to said expected time, to initiate active operation of the secondary power source.

15. The method of claim 14, further comprising engaging the secondary power source to the driveline substantially at or before said expected time, such that at said expected time, an actual total torque output by the secondary power source and the primary power source substantially matches said expected pull-away torque.

16. The method of claim 14, wherein determining said suitable time is carried out in dependence upon one or more of:

(i) the situational status of the vehicle;

(ii) the steering angle or rate of change of steering angle;

(iii) a temperature of the secondary power source;

(iv) an ambient temperature;

(v) the altitude of the vehicle; and

(vi) an initiation time of the secondary power source.

17. The method of claim 12, wherein determining said situational status of the vehicle is carried out in consideration of one or more of the following:

(i) vehicle drive speed;

(ii) vehicle longitudinal angle of inclination;

(iii) vehicle lateral angle of inclination;

(iv) a combination of longitudinal and lateral angle of inclination of the vehicle;

(v) a correspondence between a vehicle longitudinal angle of inclination and a direction of travel or of intended travel of the vehicle;

(vi) a selection of a low range gear;

(vii) a position of an adjustable suspension system or a current ride height; and

(viii) a status of a terrain response mode.

18. The method of claim 17, wherein determining said situational status of the vehicle is carried out in consideration of one or more of the following:

(i) a steering angle of the vehicle being greater than about 90°

or less than about −

90°

;

(ii) the vehicle drive speed being about 0 kmh<sup>−

1</sup>;

(iii) the vehicle longitudinal angle of inclination being less than about 10°

or greater than about −

10°

;

(iv) the vehicle lateral angle of inclination being less than 7°

or greater than −

7°

;

(v) the vehicle longitudinal angle of inclination being less than 7°

or greater than −

7° and

the vehicle lateral angle of inclination being less than 5°

or greater than −

5°

;

(vi) the correspondence between the vehicle longitudinal angle of inclination of less than about 10°

or greater than about −

10° and

a direction of travel or of intended travel of the vehicle;

(vii) the selection of a low range gear;

(viii) the position of the current high-ride height of the adjustable suspension system;

(ix) the terrain response mode being in a rock crawl mode, a grass/gravel/snow mode, or a mud and ruts mode.

19. The method of claim 18, wherein:

(i) if the vehicle speed is less than 0.5 kmh<sup>−

1</sup> or substantially about 0 kmh<sup>−

1</sup>; and

(ii) if said steering angle is greater than 90°

or less than −

90°

; and

(iii) if said vehicle longitudinal angle of inclination is less than 10°

or is greater than −

10°

; and

(iv) if said direction of travel or intended direction of travel and the vehicle longitudinal angle of inclination correlates to the vehicle being in an uphill situation,

then, the secondary power source is automatically initiated and connected to the driveline at a time before an actual demanded torque reaches or exceeds the expected pull-away torque.

20. The method of claim 19, further comprising determining said expected pull-away torque in dependence upon one or more of:

(i) one or more vehicle parameters;

(ii) whether the vehicle is heavily laden and/or towing;

(iii) the situational status of the vehicle;

(iv) the steering angle or rate of change of steering angle;

(v) a current driver demanded torque;

(vi) a rate of change of driver demanded torque; and

(vii) a driver style model.