Method of determination of driving mode of hybrid vehicle

• US 20070112484A1
• Filed: 12/08/2005
• Published: 05/17/2007
• Est. Priority Date: 11/15/2005
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Lee, Se-Yong
• Granted Patent: US 7,617,895 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• 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 10/26 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 20/11 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 20/12 using control strategies taking into account route information estimation or calculation of non-directly measurable driving parameters B60W40/00
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/30 Wheel torque
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: B60W 50/035 Bringing the control units into a predefined state, e.g. giving priority to particular actuators
• 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 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

The present invention provides a method of determination of the driving mode of a hybrid vehicle. The method is executed by a hybrid control unit (HCU) and includes the step of modeling a PNGV (Partnership for a New Generation of Vehicles) systems analysis toolkit (PSAT) to calculate power reserved to drive a motor. Thereafter, whether or not the driving mode of the hybrid vehicle is consistent with an electric vehicle (EV) mode is determined using the power reserved to drive the motor, which has been calculated using the PSAT model. If the driving mode is not consistent with the EV mode, whether or not the driving mode is consistent with a maximum (MAX) torque mode is determined. If the driving mode is not consistent with the MAX torque mode, the driving mode is determined to be a hybrid-electric vehicle (HEV) mode.

Claims

1. A method of determination of a driving mode of a hybrid vehicle, the method being executed by a hybrid control unit (HCU) and comprising the steps of:

modeling a PNGV (Partnership for a New Generation of Vehicles) systems analysis toolkit (PSAT) to calculate reserved power to drive a motor;

determining whether the driving mode of the hybrid vehicle is consistent with an electric vehicle (EV) mode or not, using the power reserved to drive the motor, which has been calculated using the PSAT model;

if the driving mode is not consistent with the EV mode, determining whether or not the driving mode is consistent with a maximum (MAX) torque mode; and

if the driving mode is not consistent with the MAX torque mode, determining that driving mode to be a hybrid-electric vehicle (HEV) mode.

2. The method as defined in claim 1, wherein said step of modeling the PSAT comprises the steps of:

inputting both a throttle position sensor (TPS) signal and a vehicle speed signal;

calculating a required torque and required power;

detecting the state of charge (SOC) of a battery;

recalculating the required power according to the SOC of the battery;

recalculating the required torque using both the recalculated required power and a vehicle speed;

presetting an optimal mileage of an engine corresponding both to the recalculated required torque and to the vehicle speed;

calculating both a target engine rpm and a target engine torque corresponding to the preset optimal mileage of the engine;

calculating a target generator speed using the target engine rpm;

detecting a present generator speed;

calculating both a generator torque and generator power using both the present generator speed and the target generator speed;

detecting surplus power of the battery using a battery management system (BMS);

calculating the reserved power using both the surplus power of the battery and the generator power; and

calculating an engine torque, a motor torque and a wheel torque using the calculated reserved power.

3. The method as defined in claim 2, wherein said reserved power is calculated using the following expression.

Reserved power=surplus power of battery−

generator power

4. The method as defined in claim 1, wherein said step of determining whether the driving mode is consistent with the EV mode comprises the steps of:

inputting the power-reserved;

determining whether the input reserved power is not lower than a preset first reference value;

if the input reserved power is not lower than the preset first reference value, inputting the state of charge (SOC) of the battery;

determining whether the SOC value of the battery is not lower than a preset second reference value;

if the SOC value of the battery is not lower than the preset second reference value, inputting both a present engine rpm and a present engine load;

detecting an operating point of both the present engine rpm and the present engine load on an EV mode map;

determining whether the operating point of both the present engine rpm and the present engine load is present on the EV mode map;

if the operating point of both the present engine rpm and the present engine load is not present on the EV mode map, determining whether the driving mode is consistent with a regeneration mode;

if the driving mode is not consistent with the regeneration mode, determining whether a required torque is zero;

if the required torque is not zero, determining whether the motor is in an ON state and an engine is in an OFF state; and

if the engine is in the OFF state and the motor is not in the ON state, determining that the driving mode is not consistent with the EV mode.

5. The method as defined in claim 4, wherein said first reference value is set to 50% of a total discharge amount of the battery.

6. The method as defined in claim 4, wherein said second reference value is set to 60% of the SOC value of the battery.

7. The method as defined in claim 1, wherein said step of determining whether the driving mode is consistent with the MAX torque mode comprises the steps of:

producing an engine MAX torque diagram using engine rpm and storing the engine MAX torque diagram in the HCU;

inputting a present engine output torque;

comparing the present engine output torque to the engine MAX torque of the diagram;

if the present engine output torque is equal to the engine MAX torque, inputting a present engine rpm;

comparing the present engine rpm to an engine MAX torque rpm;

if the present engine rpm is equal to the engine MAX torque rpm, determining that the driving mode is consistent with the MAX torque mode;

inputting a wheel torque calculated using the PSAT model;

calculating a present wheel torque; and

if the wheel torque calculated using the PSAT model is not lower than the present wheel torque, determining that the driving mode is not consistent with the MAX torque mode.

8. The method as defined in claim 7, wherein, when the present engine output torque is compared to the engine MAX torque, an allowable error of ±

5 Nm is recommended.

9. The method as defined in claim 7, wherein, when the present engine rpm is compared to the engine MAX torque rpm, an allowable error of ±

100 rpm is recommended.