WO2013021262A2

WO2013021262A2 - Drive support system

Info

Publication number: WO2013021262A2
Application number: PCT/IB2012/001517
Authority: WO
Inventors: Shojiro Takeuchi; Kengo Hayashi
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2011-08-09
Filing date: 2012-08-08
Publication date: 2013-02-14
Also published as: JP2013038955A; WO2013021262A3

Abstract

A drive support system for a vehicle that includes a motor as a drive source includes an electric power amount detecting unit, a required electric power amount calculation unit and a display unit. The electric power amount detecting unit detects a current amount of electric power stored in a battery that supplies electric power to the motor. The required electric power amount calculation unit calculates a required amount of electric power, obtained by converting a distance between a current location of the vehicle and a preset location (for example, home) into an amount of electric power. The display unit relatively displays the current amount of electric power and the required amount of electric power to reach the preset location.

Description

DRIVE SUPPORT SYSTEM

BACKGROUND OF THE INVENTION

1 . Field of the Invention

[0001] The invention relates to a drive support system for a vehicle that includes a motor as a drive source. 2. Description of Related Art

[0002] An electric vehicle supplies electric power from a battery to a motor and travels by driving force generated by the motor. Thus, the electric vehicle is not able to travel unless the battery is charged before the amount of electric power stored in the battery is short. Therefore, it is important to recognize whether the electric vehicle is able to reach home or a general charging sport, other than home, with the amount of electric power remaining in the battery. In the invention described in Japanese Patent Application Publication No. 2004-229448 (JP 2004-229448 A), it is determined whether a vehicle is able to return from a current location of the vehicle to a home position by a margin on the basis of a distance-to-empty for the amount of electric power remaining in a battery, a route distance from the current location to the home position and a distance correction coefficient (road gradient), and, when it is predicted that the vehicle is not able to return to the home position by a margin, an alarm is provided.

[0003] In the invention described in JP 2004-229448 A, the vehicle determines whether the vehicle is able to return to the home position and, when the vehicle predicts that the vehicle is not able to return to the home position, an alarm is output. In this way, when an alarm is provided at the timing at which it becomes impossible for the vehicle to return to the home position or the timing at which it is likely to become impossible for the vehicle to return to the home position, a user (driver) is suddenly informed of a shortage of the amount of electric power stored in the battery only. Therefore, for example, the user is not able to determine whether the vehicle is able to reach home or. even when the vehicle is able to reach home, the user is not allowed to detennine the degree of margin of the amount of electric power, so the user is not able to drive the vehicle in an electric vehicle (EV) drive mode safely.

SUMMARY OF THE INVENTION

[0004] The invention provides a drive support system that allows a user to easily recognize whether a vehicle is able to reach home, or the like, on the basis of the amount of electric power stored in a battery.

[0005] An aspect of the invention provides a drive support system for a vehicle that includes a motor as a drive source. The drive support system includes: an electric power amount detecting unit that detects a current amount of electric power stored in a battery that supplies electric power to the motor; a required electric power amount calculation unit that calculates a required amount of electric power, obtained by converting a distance between a current location of the vehicle and a preset location into an amount of electric power; and a display unit that displays the current amount of electric power, detected by the electric power amount detecting unit, and the required amount of electric power, calculated by the required electric power amount calculation unit.

[0006] In the drive support system, the electric power amount detecting unit is used to detect the current amount of electric power stored in the battery. In addition, in the drive support system, the required electric power amount calculation unit is used to calculate the required amount of electric power in order to travel the distance between the current location of the vehicle and the preset location by the motor. The preset location is a location preset as a location at which the battery is chargeable, and is, for example, home, a charging spot (charging station), other than home, at which general charging is performed, and a destination. Then, in the drive support system, the current amount of electric power and the required amount of electric power to the preset location are displayed on the display unit. In this way, in the drive support system, by displaying the cun-ent amount of electric power and the required amount of electric power to the preset location, it is possible to relatively recognize the current amount of electric power and the required amount of electric power, the user is able to easily determine whether the vehicle is able to reach the preset location with the current amount of electric power, and. when it is determined that the vehicle is able to reach the preset location as well, it is possible to easily determine how much the amount of electric power is sufficient. As a result, the user is able to drive the vehicle in the EV drive mode safely, and. when the user determines that the amount of electric power becomes short or determines that it is likely that the amount of electric power becomes short, the user is able to drive the vehicle to a charging spot by a margin.

[0007] In the display unit of the drive support system according to the above aspect, the cun-ent amount of electric power and the required amount of electric power may be displayed side by side. In this way, by displaying the current amount of electric power and the required amount of electric power side by side, the user is able to easily compare the cunent amount of electric power with the required amount of electric power and easily determine how much the amount of electric power is sufficient. Note that the way of arrangement may be any way, such as a vertical arrangement and a horizontal arrangement.

[0008] In the display unit of the drive support system according to the above aspect, the cun-ent amount of electric power and the required amount of electric power may be displayed by varying a luminance or a color tone in a stepwise manner. In this way, by varying a luminance or a color tone in a stepwise manner, it is possible to easily determine how much the amount of electric power is sufficient.

[0009] In the drive support system according to the above aspect, the preset location may be home. In the drive support system, the required electric power amount calculation unit is used to calculate the required amount of electric power in order to travel a distance to reach home by the motor, and the current remaining amount of electric power and the required amount of electric power to reach home are displayed on the display unit. In this way, in the drive support system, by displaying the current amount of electric power and the required amount of electric power to reach home, it is possible to easily determine whether the vehicle is able to return home.

[0010] In the drive support system according to the above aspect, when a destination is set between the current location of the vehicle and the preset location, the required electric power amount calculation unit may calculate a required amount of electric power, obtained by converting a distance between the current location of the vehicle and the preset location by way of the destination into an amount of electric power. In the drive support system, the required electric power amount calculation unit is used to calculate the required amount of electric power in order to travel a distance by way of the destination by the motor, and the current amount ^"of electric power and the required amount of electric power by way of the destination are displayed on the display unit. In this way, in the drive support system, by displaying the current amount of electric power and the required amount of electric power by way of the destination, it is possible to easily determine whether the vehicle is able to reach the preset location even by way of the destination.

[0011] According to the above aspect, by displaying the current amount of electric power and the required amount of electric power to reach the preset location, it is possible to relatively recognize the current amount of electric power and the required amount of electric power, the user is able to easily determine whether the vehicle is able to reach the preset location with the current amount of electric power, and, when it is detennined that the vehicle is able to reach the preset location as well, it is possible to easily determine how much the amount of electric power is sufficient.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 is a configuration view of a navigation system according to an embodiment; FIG. 2 is an example of a display image related to the amount of electric power; and FIG. 3 is another example of a display image related to the amount of electric power. DETAILED DESCRIPTION OF EMBODIMENTS

[0013] Hereinafter, an embodiment of a drive support system according to the aspect of the invention will be described with reference to the accompanying drawings. Note that like reference numerals denote the same or corresponding components in the drawings and the overlap description is omitted.

(0014] In the present embodiment, the drive support system according to the aspect of the invention is applied to a navigation system mounted on an electric vehicle. The electric vehicle according to the present embodiment includes a battery and a motor. The battery is externally chargeable. The motor serves as a drive source. The electric vehicle supplies electric power from the battery to the motor, and travels by driving force generated by the motor. The navigation system according to the present embodiment has the function of providing information related to the amount of electric power to a user (driver). In the present embodiment, only the information providing function in the navigation system will be described.

[0015] The navigation system 1 according to the present embodiment will be described with reference to FIG. 1 to FIG. 3. FIG. 1 is a configuration view of the navigation system according to the present embodiment. FIG. 2 is an example of a display image related to the amount of electric power. FIG. 3 is another example of a display image related to the amount of electric power.

[0016] The navigation system 1 relatively indicates the current amount of electric power stored in the battery and the required amount of electric power to retuni home (or home by way of a destination) while the vehicle is travelling. Therefore, the navigation system 1 includes an electric power amount detecting unit 2, a required return electric power amount calculation unit 3, an information integration unit 4 and a display unit 5. The required return electric power amount calculation unit 3 and the information integration unit 4 are implemented in an electronic control unit (ECU) of the navigation system 1 .

[0017] Note that, in the present embodiment, the electric power amount detecting unit 2 coiTesponds to an electric power amount detecting unit according to the aspect of the invention, the required return electric power amount calculation unit 3 and the information integration unit 4 correspond to a required electric power amount calculation unit according to the aspect of the invention, and the display unit 5 coiTesponds to a display unit according to the aspect of the invention.

[0018] The electric power amount detecting unit 2 is a sensor (particularly, an SOC sensor) that detects the current amount of electric power (the remaining amount of charge) stored in the battery. In the present embodiment, the state of charge (SOC) (the percentage (%) of the amount of electric power remaining in the battery with respect to the maximum amount of electric power of the battery) is used as the amount of electric power. The electric power amount detecting unit 2 detects the current amount of electric power and outputs the detected amount of electric power to the information integration unit 4 at set time intervals.

[0019] The required return electric power amount calculation unit 3 calculates the amount of electric power required for the vehicle to travel by the motor from the current location of the vehicle to home (when a destination is set, home via the destination). The current location of the vehicle is detected by the navigation system 1 at set time intervals. The home is registered in advance by the user through location registration of the navigation system 1 . The required return electric power amount calculation unit 3 calculates the required amount of electric power to home and outputs the required amount of electric power to the information integration unit 4 at set time intervals.

[0020] An example of a calculation method employed in the required return electric power amount calculation unit 3 will be described. A route from the current location to home is searched by the route search function of the navigation system 1 , and the required amount of electric power is calculated from the distance of the route. In addition, the distance of the route from the current location to home is recorded when the route has been travelled in the past, and the required amount of electric power is calculated from the recorded distance of the route. By so doing, when the current location is on the route that has been travelled in the past, it is not necessary to make a route search in the navigation system 1 , so it is possible to reduce a computation load. Furthermore, the required amount of electric power may be calculated in consideration of environment information (that influences an electrical load on the motor), such as a road gradient in the route. In addition, a linear distance from the current location to home is calculated, and the required amount of electric power is calculated from the linear distance. By so doing, it is possible to suppress a computation load, and this is suitable for the navigation system 1 having a low computing power. Note that, when a destination is set on the way. the required amount of electric power from the current location to the destination and the required amount of electric power from the destination to home are calculated.

[0021] The information integration unit 4 integrates the current amount of electric power, detected by the electric power amount detecting unit 2, and the required amount of electric power, calculated by the required return electric power amount calculation unit 3, and then creates an image that relatively indicates the maximum amount of electric power (SOC: 100%) of the battery, the current amount of electric power (SOC: a%) of the battery and the required amount of electric power to reach home. Here, the required amount of electric power to reach home is converted to SOC (b%), and the image relatively indicates the current SOC (a%) and the required SOC (b%) to reach home with respect to the SOC of 0 to 100%. Furthermore, the image is configured such that the region of a spent SOC (( 100-a)%) and the region of a remaining SOC (a%) are separated by color and the region of the remaining SOC is separated by color in a stepwise manner. The information integration unit 4 creates an image and outputs the image information to the display unit 5 at set time intervals.

[0022] The display unit 5 is a display of the navigation system 1 . Each time image information is input from the information integration unit 4 to the display unit 5, the display unit 5 displays the corresponding image. An image is basically constantly displayed; however, an image may be blanked by user's setting. Note that the display unit 5 may be not only the display of the navigation system 1 but also a display, or the like, provided in a combination meter.

[0023] An example of an image to be displayed will be described with reference to FIG. 2 and FIG. 3. In this example, a mark indicated by the reference sign HM is a home mark, a mark indicated by the reference sign VM is a current location mark of the vehicle, and a mark indicated by the reference sign GM is a destination mark. In addition, a bar chart indicated by the reference sign CM is an SOC. and indicates 0 to 100% of the SOC. A black portion (thickest color portion) US in the bar chart CM is a portion that indicates a spent SOC, and occupies the amount of spent SOC (( 100-a)%) from the end of 100% of the SOC. The black portion US is a critical region, and is a region in which the amount of electric power becomes short before the vehicle returns home for the current amount of electric power even when the vehicle travels in an EV drive mode smoothly. A gradation portion RS in the bar chart CM is a portion that indicates a currently remaining SOC, and occupies the amount of the current SOC (a%) from the end of 0% of the SOC. The gradation portion RS is separated by color in a stepwise manner such that the region from 0% to a% of the SOC gradually thickens. As the color of the gradation portion RS thickens, it indicates an alarm region in which it is highly likely that the amount of electric power becomes short. In this region, the vehicle is able to return home by the current amount of electric power when the vehicle smoothly travels in the EV drive mode; however, the amount of electric power becomes short when the amount of electric power used increases because of stopping on the way, a road environment such as a rising slope, and an electrical load, other than the motor, such as an air conditioner. Note that gradation may be implemented by varying a luminance or varying a color tone.

[0024] The home mark HM is arranged at the end of 0% of the SOC in the bar chart CM. Using the required SOC (b%), the current location mark VM is arranged at a position spaced apart by the amount of the required SOC (b%) from the end of 0% in the bar chart CM. Thus, a distance L between the home mark HM and the current location mark VM, shown in FIG. 2, is a distance indicated by normalizing a distance from the current location of the vehicle to home into the SOC. Using the required SOC (c%) required to travel from the destination to home, the destination mark GM is arranged at a position that is spaced apart by the amount of the required SOC (c%) from the end of 0% in the bar chart CM. At this time, using the required SOC (d (= b-c)%) required to travel from the current location to the destination, the current location mark VM may be arranged at a position that is spaced apart by the required SOC (d%) from the end of 0% in the bar chart CM.

[0025] In the case where the current SOC (a%) is larger than the required SOC

(b%), as the difference between the current SOC and the required SOC increases, the current location mark VM is located at a lighter color portion in the gradation portion RS. Thus, it appears that the amount of electric power is sufficient as the color at the position of the current location mark VM becomes lighter in the gradation portion RS, and it appears that the amount of electric power is not sufficient and falls within an alarm region as the color at the position of the current location mark VM becomes thicker in the gradation portion RS. In the case of the alarm region, it is required to consider suppressing the amount of electricity used or charging the battery on the way. On the other hand, when the current SOC (a%) is smaller than the required SOC (b%), the current location mark VM is located in the black portion US, and it appears that the amount of electric power falls within a critical region in which the amount of electric power becomes short. In this case, it is required to charge the battery on the way; however, the user is able to recognize that in an early stage, so the user is allowed to look for a charging spot (charging station, or the like) by a margin.

[0026] In the case of the example shown in FIG. 2 and FIG. 3, because the current location mark VM is positioned in the gradation portion RS. it is possible to recognize the fact that the current SOC (a%) is larger than the required SOC (b%) at a sight, and it appears that the vehicle is able to return home by the current amount of electric power without charging the battery on the way when the vehicle smoothly travels in the EV drive mode. Particularly, in the case of the example shown in FIG. 3, it appears that the vehicle is able to return home by the current amount of electric power even by way of a destination. In the case of the example of FIG 2 and FIG. 3, the color at the position of the current location mark VM in the gradation portion RS is thicker in the example of FIG. 3 than in the example of FIG. 2, so the amount of electric power is more insufficient in the example of FIG. 3. Note that, in the example of FIG. 2, the distal end of the triangle of the current location mark VM is directed in the direction opposite to the home mark HM, and this indicates that the vehicle is leaving from home; whereas, in the example of FIG. 3, the distal end of the triangle of the current location mark VM is directed in the direction toward the destination mark GM, and this indicates that the vehicle is approaching the destination in the case where the vehicle heads from home toward the destination and returns from the destination to home.

[0027] The operation of the navigation system 1 will be described with reference to FIG. 1 . The electric power amount detecting unit 2 detects the amount of electric power stored in the battery and outputs the detected value to the information integration unit 4 at set time intervals. The required return electric power amount calculation unit 3 calculates the amount of electric power required for the vehicle to ^■ travel from the current location to home by the motor and outputs the required amount of electric power to the information integration unit 4 at set time intervals. When the current amount of electric power and the required amount of electric power are input into the information integration unit 4, the information integration unit 4 creates an image that relatively indicates the maximum amount of electric power (maximum SOC) of the battery, the current amount of electric power (current SOC) of the battery and the required amount electric power (required SOC ) of the battery, and outputs the image information to the display unit 5. Each time the image information is input to the display unit 5, the display unit 5 shows an image that relatively indicates the maximum SOC, the current SOC of the battery and the required SOC to reach home. In this way, the image that relatively indicates the maximum SOC, the current SOC and the required SOC is updated at set time intervals. [0028] When the user (driver) looks at the image, the user (driver) is able to instantaneously recognize the relative relationship among the maximum SOC, the current SOC, home, the current location of the vehicle, normalized to the SOC, and the destination normalized to the SOC when the destination is set. At this time, when it is determined that the amount of electric power becomes short before the vehicle returns home for the current amount of electric power (in the case of the critical region) or when it is determined that the amount of electric power may become short before the vehicle returns home for the current amount of electric power (in the case of the alarm region), the user charges the battery at a charging spot on the way home on the basis of the degree of the shortage. On the other hand, when it is determined that the vehicle is able to return home by a margin with the current amount of electric power (in the case of the sufficient region), the user goes home without charging the battery on the way home.

(0029] With the navigation system 1 , by relatively indicating the maximum amount of electric power, the current amount of electric power and the required amount of electric power to reach home, it is possible to instantaneously relatively recognize the current amount of electric power and the required amount of electric power, the user is able to easily determine whether the vehicle is able to return home with the current remaining amount of electric power, and, when it is determined that the vehicle is able to return home as well, the user is able to easily determine how much the amount of electric power is sufficient. As a result, the user is able to drive the vehicle in the EV drive mode safely, and, when the user determines that the amount of electric power becomes short or determines that the amount of electric power may become short, the user is able to drive the vehicle to a charging spot by a margin.

[0030] Particularly, with the navigation system 1 , by indicating the current SOC, the home mark, the current location mark and the destination mark on the bar chart of the SOC of 0% to 100%, it is possible to instantaneously recognize the relative relationship among home, the current location of the vehicle, the location of the destination, the maximum amount of electric power and the current amount of electric power. Furthermore, with the navigation system 1 , by indicating the region of the spent SOC in black and indicating the region of the currently remaining SOC in gradation that is lighter than black, it is possible to instantaneously recognize the critical region, the alarm region and the sufficient region.

[0031] Note that the amount of electricity used in the vehicle fluctuates depending on various conditions, such as stopping on the way home, a road environment such as a road gradient, usage of electricity in an air conditioner, or the like, other than the motor, so a distance-to-empty for the predicted current amount of electric power (the required amount of electric power calculated by the required return electric power amount calculation unit 3) is not accurate. Then, in consideration of that, the bar chart is indicated in gradation to show the critical region, the alarm region and the sufficient region. By so doing, even when the amount of electricity used increases more than prediction, the user has checked the cuirent location mark that falls within the alarm region in advance, so the user is able to charge the battery on the way by a margin.

[0032] The embodiment according to the aspect of the invention is described above; however, the aspect of the invention is not limited to the above embodiment and may be implemented in various forms.

[0033] For example, the aspect of the invention is applied to the navigation system in the above embodiment; instead, the aspect of the invention is also applicable to another system, such as a drive support system, a motor control device and a meter device. In addition, all the components are formed in the vehicle in the above embodiment; instead, the process of the required return electric power amount calculation unit, or the like, may be executed by an external device, such as a center, in order to suppress a computation load.

[0034] In addition, a preset location is home in the above embodiment; instead, a location other than home may be set and the possibility of reaching the location may be provided. For example, the location may be a charging spot at which the vehicle is often charged, a working company having a charging sport, and a destination having a charging spot.

[0035] In addition, an image that relatively indicates the current amount of electric power and the required amount of electric power in bar chart is provided in the above embodiment; instead, another information providing method, such as a text form, may be used. For example, the values of the current amount of electric power and the required amount of electric power may be indicated in a vertical arrangement, a horizontal arrangement, or the like. In addition, the region inside the SOC is separated by color in black and gradation lighter than black in a stepwise manner; instead, such gradation may not be provided or the region inside the SOC may be separated into three, that is, the sufficient region, the alarm region and the critical region.

Claims

CLAIMS:

1. A drive support system for a vehicle that includes a motor as a drive source, comprising:

an electric power amount detecting unit that detects a current amount of electric power stored in a battery that supplies electric power to the motor;

a required electric power amount calculation unit that calculates a required amount of electric power, obtained by converting a distance between a cun-ent location of the vehicle and a preset location into an amount of electric power; and

a display unit that displays the current amount of electric power, detected by the electric power amount detecting unit, and the required amount of electric power, calculated by the required electric power amount calculation unit.

2. The drive support system according to claim 1 , wherein

in the display unit, the current amount of electric power and the required amount of electric power are displayed side by side.

3. The drive support system according to claim 1 or 2, wherein

in the display unit, the current amount of electric power and the required amount of electric power are displayed by varying a luminance or a color tone in a stepwise manner.

4. The drive support system according to any one of claims 1 to 3, wherein the preset location is home.

5. The drive support system according to any one of claims 1 to 4, wherein when a destination is set between the current location of the vehicle and the preset location, the required electric power amount calculation unit calculates a required amount of electric power, obtained by converting a distance between the current location of the vehicle and the preset location by way of the destination into an amount of electric power.