Hybrid vehicle and travel control method of hybrid vehicle

• US 20090277701A1
• Filed: 09/11/2007
• Published: 11/12/2009
• Est. Priority Date: 09/29/2006
• Status: Abandoned Application

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Niwa, Tosiaki, Soma, Takaya, Ang, Wanleng
• Application Number:
  US12/311,336
• Publication Number:
  US 20090277701A1
• Time in Patent Office: Days
• US Class Current: 180/65.250
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2220/54 Windings for different functions
• CPC Class Codes: B60L 2240/62 Vehicle position
• CPC Class Codes: B60L 2260/52 drive range estimation, e.g. of estimation of available travel distance
• CPC Class Codes: B60L 2260/54 Energy consumption estimation
• CPC Class Codes: B60L 2260/56 Temperature prediction, e.g. for pre-cooling
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/24 Using the vehicle's propulsion converter for charging
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• 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 20/12 using control strategies taking into account route information estimation or calculation of non-directly measurable driving parameters B60W40/00
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2510/246 : Temperature
• CPC Class Codes: B60W 2540/215 : Selection or confirmation of options
• CPC Class Codes: B60W 2556/50 : of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2710/244 : Charge state
• CPC Class Codes: B60W 50/082 : Selecting or switching between different modes of propelling
• CPC Class Codes: B60W 50/085 : Changing the parameters of the control units, e.g. changing limit values, working points by control input
• CPC Class Codes: G01C 21/26 : specially adapted for navigation in a road network
• 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 10/84 : Data processing systems or methods, management, administration
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

An SOC target is a control target of a remaining capacity of an accumulation device having a characteristic that the internal loss increases in a low SOC region. The SOC target is set to a first value corresponding to a remaining capacity target upon reaching a predetermined point when the remaining travel distance up to a predetermined point where the accumulation device can be charged from outside has become shorter than a predetermined distance. Thus, the hybrid vehicle can perform EV travel by power consumption of the accumulation device. On the other hand, when the remaining travel distance is not smaller than the predetermined distance Dr, the SOC target is set to a second value in the SOC region where the loss of the accumulation device is smaller than the first value. Thus, it is possible to reduce the power consumption in the hybrid vehicle which performs such a remaining capacity management that the remaining capacity of the accumulation device upon arrival at a predetermined point is a predetermined value.

Claims

1. A hybrid vehicle comprising:

an internal combustion engine and an electric motor each configured to generate a vehicle drive power;

a chargeable power storage device having a loss characteristic changing an internal power loss during charging/discharging according to an SOC and relatively increasing the internal power loss during the charging/discharging when the SOC is low;

an electric power converting unit performing electric power conversion for controlling drive of said electric motor between said power storage device and said electric motor; and

a control device for controlling a whole operation of said hybrid vehicle,

said control device including;

an output share determining unit determining output shares of said internal combustion engine and said electric motor with respect to a required whole vehicle drive power, based on a vehicle drive state and a comparison between the SOC of said power storage device and an SOC target,

an estimated travel distance obtaining unit obtaining an estimated travel distance to a predetermined point during traveling to said predetermined point, and

a target setting unit setting said SOC target during traveling to said predetermined point such that said SOC attains a predetermined level when the vehicle arrives at said predetermined point, and

said target setting unit variably sets said SOC target according to said estimated travel distance obtained by said travel distance obtaining unit according to the loss characteristic of said power storage device, sets said SOC target to be attained when said estimated travel distance is shorter than said predetermined distance to a level corresponding to said predetermined level, and sets said SOC target to be attained when said estimated travel distance is equal to or longer than said predetermined distance to fall within a region higher than said predetermined level.

2. The hybrid vehicle according to claim 1, further comprising a charge mechanism for charging said power storage device with an externally supplied electric power, wherein

said predetermined point is a preregistered point allowing external charging by said charging mechanism.

3. The hybrid vehicle according to claim 1, wherein

said target setting unit sets said SOC target to be set when said estimated travel distance is equal to or longer than a predetermined distance to fall within a region causing an internal power loss in said power storage device smaller than the internal power loss caused by said predetermined level.

5. The hybrid vehicle according to claim 1, wherein

said output share determining unit includes an estimating unit estimating an allowed vehicle travel distance attainable only by said electric motor, based on the SOC of said power storage device, and

said output share determining unit causes said electric motor to output said whole vehicle drive power when the allowed vehicle travel distance estimated by said estimating unit is longer than said estimated travel distance obtained by said estimated travel distance obtaining unit.

6. The hybrid vehicle according to claim 1, wherein

said output share determining unit causes said electric motor to output said whole vehicle drive power when the SOC of said power storage device is equal to or larger than an upper management limit value.

7. The hybrid vehicle according to claim 1, wherein

said control device further includes a deterioration determining unit for obtaining a deterioration degree of said power storage device, and

said target setting unit sets said SOC target to be attained when said estimated travel distance is longer than a predetermined distance, according to a loss characteristic corrected based on the deterioration degree obtained by said deterioration determining unit.

8. The hybrid vehicle according to claim 1, wherein

said estimated travel distance obtaining unit obtains said estimated travel distance based on information provided from a navigation device capable of sensing a travel position of said hybrid vehicle.

9. The hybrid vehicle according to claim 8, wherein

said estimated travel distance obtaining unit obtains said estimated travel distance based on a position relationship between said predetermined point and said travel position on a map used by said navigation device, when a destination for route guidance is not set in said navigation device.

10. The hybrid vehicle according to claim 1, wherein

said control device disables the variable setting of said SOC target by said target setting unit, when a distance between a drive start point of said hybrid vehicle and said predetermined point is equal to or shorter than a predetermined distance.

11. The hybrid vehicle according to claim 2, wherein

said control device disables the variable setting of said SOC target by said target setting unit, when the SOC of said power storage device at the start of the drive of said hybrid vehicle falls within a predetermined region corresponding to the time of completion of charging by said charging mechanism.

4. (canceled)

12. A travel control method of a hybrid vehicle, wherein

said hybrid vehicle including:

an internal combustion engine and an electric motor each configured to generate a vehicle drive power,

a chargeable power storage device having a loss characteristic changing an internal power loss during charging/discharging according to an SOC and relatively increasing the internal power loss during the charging/discharging when the SOC is low, and

an electric power converting unit performing electric power conversion for controlling drive of said electric motor between said power storage device and said electric motor; and

said travel control method comprising the steps of;

determining output shares of said internal combustion engine and said electric motor with respect to a required whole vehicle drive power, based on a vehicle drive state and a comparison between the SOC of said power storage device and an SOC target;

obtaining an estimated travel distance to a predetermined point during traveling to said predetermined point; and

setting said SOC target during traveling to said predetermined point such that said SOC attains a predetermined level when the vehicle arrives at said predetermined point; and

said step of setting variably sets said SOC target according to said estimated travel distance obtained by said step of obtaining according to the loss characteristic of said power storage device, sets said SOC target to be attained when said estimated travel distance is shorter than said predetermined distance to a level corresponding to said predetermined level, and sets said SOC target to be attained when said estimated travel distance is equal to or longer than said predetermined distance to fall within a region higher than said predetermined level.

13. The travel control method of the hybrid vehicle according to claim 12, wherein

said hybrid vehicle further includes a charge mechanism for charging said power storage device with an externally supplied electric power, and

said predetermined point is a preregistered point allowing external charging by said charging mechanism.

14. The travel control method of the hybrid vehicle according to claim 12, wherein

said step of setting sets said SOC target to be set when said estimated travel distance obtained by said step of obtaining is equal to or longer than a predetermined distance to fall within a region causing an internal power loss in said power storage device smaller than the internal power loss caused by said predetermined level.

16. The travel control method of the hybrid vehicle according to claim 12, further comprising;

the step of estimating an allowed vehicle travel distance attainable only by said electric motor based on the SOC of said power storage device, and

said step of determining causes said electric motor to output said whole vehicle drive power when the allowed vehicle travel distance estimated by said step of estimating is longer than said estimated travel distance obtained by said step of obtaining.

17. The travel control method of the hybrid vehicle according to claim 12, wherein

said step of determining causes said electric motor to output said whole vehicle drive power when the SOC of said power storage device is larger than an upper management limit value.

18. The travel control method of the hybrid vehicle according to claim 12, further comprising:

the step of obtaining a deterioration degree of said power storage device, wherein

said step of setting sets said SOC target to be attained when said estimated travel distance is equal to or longer than a predetermined distance, according to a loss characteristic corrected based on the deterioration degree obtained by said step of obtaining the deterioration degree.

15. (canceled)