JP2014035746A - Parking assistance device in non-contact charging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking assistance device that enables the driver of a vehicle to park the vehicle at an optimum position while easily checking the magnitude of power that a power receiving part receives from a power transmitting part.SOLUTION: A parking assistance device comprises: a first parking assistance section configured to guide a vehicle to a parking area by using vehicle position information indicating a relative position from the parking area to the vehicle; and a second parting assistance section configured such that, after the vehicle is guided to the parking area by the first parking assistance section, the vehicle is further guided to an efficient power supply point in the parking area by use of the magnitude of power that the vehicle receives from power supply equipment in the parking area to which the vehicle is guided.

Description

  The present invention relates to a parking assistance device for a vehicle, and more particularly to a parking assistance device mounted on a vehicle that uses a non-contact charging system.

As is well known, various driving support technologies have been developed and used to allow a driver who is not confident in driving a car to easily park the car in a parking lot.
In addition, vehicles such as plug-in hybrid vehicles and electric vehicles that use electric power stored in a battery to drive motors to convert them into power are becoming widespread.

  Charging of a battery such as a plug-in hybrid vehicle or an electric vehicle is typically performed via a power supply facility on an infrastructure side provided in a so-called parking area such as a garage or a desk lamp at home. Particularly in recent years, charging from a power supply facility to an automobile battery has been developed not only by a wired connection using a power cord or a power transmission cable, but also by a wireless non-contact charging technique.

As an example of using a non-contact charging technology, the following system can be considered.
As equipment, a power transmission unit (such as a power transmission coil) is installed in advance on the ground of the parking area, and a power reception unit (such as a power reception coil) is installed on the bottom of the automobile. The battery is charged by stopping the vehicle in the parking area and supplying an alternating current to the power transmission unit. The alternating current supplied to the power transmission unit generates an alternating current in the power receiving unit by electromagnetic induction. And the non-contact charge is performed by giving the alternating current generated in the power receiving unit to the battery.

JP 2011-015549 A

  When the power supply facility and the vehicle are connected with a power cord or a power transmission cable or the like, it is not necessary to worry about the parking position of the vehicle in the parking area. However, when the power supply facility and the automobile are connected in a non-contact manner, the parking position of the automobile in the parking area becomes important. Here, since the positional deviation in the left-right direction between the power transmission unit and the power reception unit is suppressed to a small extent by a mark such as a white line frame in the parking area, the positional deviation in the front-rear direction between the power transmission unit and the power reception unit is particularly important.

  However, the driver cannot grasp in detail neither the position of the power transmission unit installed on the ground of the parking area nor the position of the power reception unit installed on the bottom surface of the automobile. For this reason, depending on the parking position of the automobile in the parking area, the positional deviation in the front-rear direction between the power transmission unit and the power reception unit increases, and the battery may not be charged efficiently.

  For such a problem, in the parking assistance system described in Patent Document 1 described above, the positional relationship between the power transmission unit and the power reception unit is displayed with two marks (auxiliary images), and the power transmission unit and the power reception unit. The distance between and is displayed numerically (distance display). With these two displays, the parking support system described in Patent Document 1 supports the optimum parking position of the automobile in the parking area.

  The present invention is a further development of the above technical contents, and parking assistance that enables a driver of an automobile to park the automobile at an optimal position while easily checking the power intensity received by the power receiving section from the power transmission section. An apparatus is disclosed.

The present invention is directed to a parking assistance device used in a vehicle equipped with a non-contact charging system.
And in order to achieve the said objective, the parking assistance apparatus of this invention uses the vehicle position information which shows the relative position from a parking area to a vehicle, The 1st parking assistance part which guides a vehicle to this parking area, After the vehicle is guided to the parking area by the first parking support unit, an efficient power supply point in the parking area is further determined using the strength of the power received by the vehicle from the power supply facility in the guided parking area. And a second parking support section for guiding.

  According to the parking assist device of the present invention described above, the vehicle driver can efficiently charge the battery while confirming the guidance provided by the device without knowing the positional relationship between the power transmission unit and the power reception unit. The car can be easily parked at the optimal position to be implemented.

The figure which shows schematic structure of the non-contact charge system 1 whole containing the parking assistance apparatus 20 which concerns on one Embodiment of this invention. Functional block diagram for explaining detailed configurations of the power supply facility 10 and the parking assist device 20 shown in FIG. The figure which showed the example of arrangement | positioning regarding a part of structure of the electric power feeding installation 10 installed in a parking area in the state parallel to the road surface The flowchart explaining the process sequence of the 1st parking assistance performed with the parking assistance apparatus 20. The flowchart explaining the process procedure of the 2nd parking assistance performed with the parking assistance apparatus 20. The figure which shows an example of a parking position meter and a reception intensity meter The figure which shows an example of a parking position meter and a reception intensity meter The figure which shows an example of the reception strength meter

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a schematic configuration of an entire contactless charging system 1 including a parking assistance device 20 according to an embodiment of the present invention. The non-contact charging system 1 in FIG. 1 includes a power supply facility 10 and a parking assistance device 20.

  The power supply facility 10 is an infrastructure facility provided in a place where a vehicle such as a garage at home or an electric charging station can be parked and stopped (hereinafter referred to as a parking area). The parking assist device 20 is a device mounted on a vehicle such as a plug-in hybrid vehicle or an electric vehicle that converts electric power stored in a battery to a drive motor to convert it into power.

In the non-contact charging system 1 shown in FIG. 1, wireless communication is performed between the power supply facility 10 and the parking assistance device 20 to realize both parking assistance to the parking area of the vehicle and power charging to the battery of the vehicle. In the parking assistance device 20 of the present invention constituting the non-contact charging system 1, a parking assistance method by which the driver can park the vehicle at a position where the battery can be charged efficiently by providing parking guidance in two stages. Is realized.
Details will be described below.

1. 2. Description of Configuration FIG. 2 is a functional block diagram for explaining detailed configurations of the power supply facility 10 and the parking assist device 20 shown in FIG. FIG. 3 shows an arrangement example related to a part of the configuration of the power supply facility 10 installed in the parking area in a state parallel to the road surface.

First, each structure of the power supply facility 10 provided in the parking area will be described.
The power supply facility 10 includes an antenna 11, a wireless communication unit 12, a vehicle detection unit 13, a high frequency power supply unit 14, a power transmission unit 15, and a control unit 18.

The wireless communication unit 12 is a communication interface for transmitting and receiving a control signal related to non-contact charging to and from the parking assistance device 20 mounted on the vehicle by wireless communication via the antenna 11. The wireless communication unit 12 uses communication media such as WiFi and Zigbee (registered trademark) conforming to the IEEE (The Institute of Electrical and Electronics Engineers) standard.
The vehicle detection unit 13 is a sensor for detecting whether a vehicle has entered a parking area (typically, a parking frame drawn with a white line on the road surface, see FIG. 3). For example, a pressure sensor or an infrared sensor is used for the vehicle detection unit 13. 1 and 3 show an example in which the vehicle detection unit 13 is embedded in the road surface on the entry side in the parking area.
The high frequency power supply unit 14 generates a high frequency current for generating electric power for charging the vehicle battery. The frequency of the high-frequency current is, for example, 1 kHz to several tens of MHz.

The power transmission unit 15 includes a coil around which an electric wire is wound (including a Z matching unit). 1 and 3 show an example in which the power transmission unit 15 is embedded on the road surface near the center in the parking area. A magnetic field is changed by applying a high-frequency current generated by the high-frequency power supply unit 14 to the coil of the power transmission unit 15, that is, the primary coil, and the coil on the power receiving unit 24 side of the parking assistance device 20 described later, that is, the secondary coil. An induced current is generated.
The control unit 18 is typically an electronic control unit (ECU), and controls the antenna 11, the wireless communication unit 12, the vehicle detection unit 13, the high frequency power supply unit 14, and the power transmission unit 15.

Next, each structure of the parking assistance apparatus 20 mounted in a vehicle is demonstrated.
The parking assistance device 20 includes an antenna 21, a wireless communication unit 22, a vehicle position acquisition unit 23, a power reception unit 24, a received power measurement unit 25, a non-contact charging unit 26, a battery 27, and a control unit 28. And a guide unit 29.

The wireless communication unit 22 is a communication interface for transmitting and receiving a control signal related to non-contact charging with the power supply facility 10 provided in the parking area by wireless communication via the antenna 21. Similar to the wireless communication unit 12 described above, a communication medium such as WiFi or Zigbee conforming to the IEEE standard is used for the wireless communication unit 22.
The vehicle position acquisition unit 23 acquires information regarding the relative position of the vehicle with respect to the power supply facility 10. For example, a vehicle speed pulse generator that detects the speed of the vehicle or calculates a travel distance, a distance sensor, and a GPS (Global Positioning System) are used as the vehicle position acquisition unit 23.

The power receiving unit 24 includes a coil around which an electric wire is wound (including a Z matching unit). FIG. 1 shows an example in which the power receiving unit 24 is installed on the bottom surface (lower surface of the floor panel) of the vehicle. An induced current is generated in the secondary coil of the power receiving unit 24 by the magnetic field changing action of the primary coil of the power transmitting unit 15 of the power supply facility 10 described above.
The received power measuring unit 25 measures the intensity of the induced current generated by the power receiving unit 24. Information on the power intensity measured by the received power measuring unit 25 is used for assisting parking in the parking area of the vehicle.

The non-contact charging unit 26 is an electric circuit for storing the electric power by outputting the induced current generated in the power receiving unit 24 to the battery 27, and includes a rectifier, a DC / DC converter, a sensor, and the like. The battery 27 is a rechargeable DC power source, for example, a secondary battery such as lithium ion or nickel metal hydride.
The guide unit 29 is an information output device such as a display or a speaker. The guide unit 29 outputs a parking guide to the parking area of the vehicle based on the vehicle position information acquired by the vehicle position acquisition unit 23, outputs a voice, or measures received power. Based on the power intensity measured by the unit 25, a more detailed parking guidance within the parking area of the vehicle is displayed on the screen or output as a sound.
The control unit 28 is typically an electronic control unit (ECU), and includes an antenna 21, a wireless communication unit 22, a vehicle position acquisition unit 23, a power reception unit 24, a received power measurement unit 25, a non-contact charging unit 26, and a guide. The unit 29 is controlled.

  In the parking support device 20, the antenna 21, the wireless communication unit 22, the vehicle position acquisition unit 23, the control unit 28, and the guide unit 29 function as a first parking support unit. In the parking support device 20, the power reception unit 24, the received power measurement unit 25, the control unit 28, and the guide unit 29 function as a second parking support unit.

2. Details of parking assistance The contents of parking assistance will be described in detail with reference to FIGS. In the following description, a case where the guide unit 29 of the parking assistance apparatus 20 is a display and the vehicle parking guidance for the driver is displayed on the screen is taken as an example.
FIG. 4 is a flowchart illustrating a first parking assistance processing procedure performed by the parking assistance device 20. FIG. 5 is a flowchart for explaining a second parking assistance processing procedure performed by the parking assistance apparatus 20. 6 and 7 are diagrams showing examples of the parking position meter and the reception intensity meter. FIG. 8 is a diagram illustrating an example of a reception intensity meter.

(1) First Parking Support The first parking support shown in FIG. 4 is started when a vehicle is detected by the vehicle detection unit 13 shown in FIG. For example, if the vehicle detection unit 13 is a pressure sensor, the vehicle detection unit 13 is an infrared sensor when the weight of a vehicle that has entered the parking area (for example, wheel climbing) is detected (see FIG. 6A). If there is, the vehicle body (for example, rear bumper) that has entered the parking area is detected.

  When the vehicle that has entered the parking area is detected by the vehicle detection unit 13, the control unit 18 detects a vehicle detection signal indicating that the vehicle has been detected, from the vehicle detection unit 13 to the power transmission unit 15 provided in the parking area. Information including the distance D1 (see FIG. 3) and the distance D2 (see FIG. 3) from the vehicle detection unit 13 to the entry allowable position (for example, the wheel stop position) of the parking area, the wireless communication unit 12 and the antenna 11 to transmit.

  The parking assistance apparatus 20 receives the information transmitted from the power supply facility 10 via the antenna 21 and the wireless communication unit 22 (FIG. 4, step S41). Based on the information received by the wireless communication unit 22 and the position of the power receiving unit 24 in the vehicle, the control unit 28 creates a parking position meter that indicates to the driver the current position of the vehicle in the parking area and the optimal parking position. The information is displayed on the guide unit 29 (FIG. 4, step S42).

  An example of a parking position meter, which is a screen display related to the first parking assistance, is shown in FIG. In the example of FIG. 6, the distance D2 is divided into a plurality of position blocks (seven position blocks in the figure) at equal intervals, and the current position of the vehicle is shaded. Furthermore, the optimum parking position obtained from the relationship between the distance D1 and the power receiving unit 24, specifically, the position block in which the position of the power transmitting unit 15 and the position of the power receiving unit 24 overlap in the vertical direction is highlighted with a thick frame display. (This is the sixth position block from the top in the figure).

  When the driver moves the vehicle, the vehicle position acquisition unit 23, in the present embodiment, the vehicle speed pulse generator calculates the travel distance Dx based on the vehicle speed pulse interval (FIG. 4, step S43). The control unit 28 monitors the travel distance Dx calculated by the vehicle position acquisition unit 23, and every time the travel distance Dx reaches one position block (one scale) of the parking position meter (FIG. 4, step S44), The shaded display of the current position of the vehicle in the parking position meter is moved by one position block (FIG. 4, step S45). At this time, the direction of moving the shaded display is controlled according to the shift position of the vehicle. That is, if the shift position is reverse “R”, the shaded position block of the parking position meter is moved downward (reverse side), and other shift positions (“D”, “B”, “L” ”), The shaded position block of the parking position meter is moved upward (forward).

  As a result of repeating the processes of steps S43 to S45, when the vehicle comes to the optimal parking position (position block indicated by a thick frame), the first parking support process by the parking position meter is finished (FIG. 4, step S46). ). Note that the first parking assistance process naturally ends when the parking action is completed by the driver's intention before the vehicle reaches the optimal parking position.

(2) Second parking assistance When the vehicle comes to the optimal parking position, the first parking assistance process is terminated and the second parking assistance process is started. In the second parking assistance process, the parking assistance device 20 starts receiving power transmitted from the power transmission unit 15 in the power reception unit 24 (FIG. 5, step S51). The received power measuring unit 25 measures the strength (level) of the power received by the power receiving unit 24 and detects the misalignment direction between the power receiving unit 24 (secondary coil) and the power transmitting unit 15 (primary coil). (FIG. 5, step S52). Based on the power intensity measured by the received power measurement unit 25 and the coil position shift, the control unit 28 creates a reception intensity meter that indicates to the driver the position (feeding point) with the highest charging efficiency within the optimal parking position. The information is displayed on the guide unit 29 (FIG. 5, step S53).

  An example of the reception intensity meter, which is a screen display related to the second parking assistance, is shown in FIGS. In the examples of FIGS. 7 and 8, the thick frame display position block, which is the optimal parking position, is further divided into a plurality of position blocks (five position blocks in the figure), and shaded display is performed according to the reception strength. ing. For example, as shown in FIG. 8, at the position where the reception intensity is maximum, all of the plurality of divided position blocks are shaded, and each time the reception intensity meter is reduced from the maximum reception intensity, the shaded display of the reception intensity meter is displayed one position block at a time. It is moved (FIG. 5, step S54). The amount of change in one position block may be determined from a reception intensity map with respect to a positional deviation between the power transmission unit 15 and the power reception unit 24. In this case as well, the direction in which the shaded display is moved is controlled according to the vehicle shift position. In other words, if the shift position is reverse “R”, the position block of the reception intensity meter is moved downward (reverse side), and at other shift positions (“D”, “B”, “L”, etc.) If there is, the position block of the reception intensity meter is moved upward (forward).

  By repeating the processes in steps S51 to S54, the driver can park the vehicle at a position (power feeding point) with the highest charging efficiency. Thereby, the 2nd parking assistance processing by a receiving intensity meter is completed (Drawing 5, Step S55). It should be noted that the second parking assistance process is naturally terminated also when the parking action is completed by the driver's intention before the vehicle reaches the parking position with the highest charging efficiency.

As described above, according to the parking assistance device 20 according to the embodiment of the present invention, the first parking assistance process first roughly guides the vehicle to the parking position where the power transmission unit 15 and the power reception unit 24 approach, Next, according to the power intensity received by the power receiving unit 24, the vehicle is guided in detail to a parking position where the power transmitting unit 15 and the power receiving unit 24 overlap in the vertical direction.
As a result, even if the driver of the car does not know the positional relationship between the power transmission unit and the power reception unit, the battery charging is performed efficiently while checking the guidance (power intensity) provided from the device. The car can be easily parked in position.

Moreover, according to the parking assistance apparatus 20 which concerns on one Embodiment of this invention, without performing parking assistance only by an electric power intensity level from beginning to end, the vehicle detection part 13 of the electric power feeding equipment 10 and the vehicle position detection of the parking assistance apparatus 20 are carried out first. After the power receiving unit 24 is brought close to the power transmitting unit 15 to some extent by the unit 23, parking assistance based on the power intensity level is performed next.
For this reason, in a parking lot with overlapping wireless communication ranges in which there are a plurality of parking areas in which the power transmission unit 14 is embedded, it is possible to avoid a phenomenon in which it is not known to which parking area parking assistance based on power intensity is performed. can do.

In addition, the guidance by the screen display demonstrated by the said embodiment is an example, and does not limit invention. For example, when using the screen display, the current position of the vehicle and the level of reception intensity may be displayed by changing the size and color of the position block, or the position block may be displayed transparently or blinking. May be.
In addition, when using audio output, the pitch and intensity of the output sound may be changed to inform the driver of the optimal parking position and reception intensity level of the vehicle, and the sound output interval may change. May be provided.

  The parking assist device of the present invention can be used for a vehicle using a non-contact charging system, and in particular, the vehicle driver wants to park the vehicle at an optimal position while easily confirming the positional relationship between the power feeding unit and the power receiving unit. This is useful in some cases.

DESCRIPTION OF SYMBOLS 1 Contactless charging system 10 Power supply equipment 11, 21 Antenna 12, 22 Wireless communication part 13 Vehicle detection part 14 High frequency power supply part 15 Power transmission part 18, 28 Control part 20 Parking assistance device 23 Vehicle position acquisition part 24 Power reception part 25 Received power measurement Part 26 non-contact charging part 27 battery 29 guide part

Claims (1)

A parking assistance device used in a vehicle equipped with a non-contact charging system,
A first parking support unit for guiding the vehicle to the parking area using vehicle position information indicating a relative position from the parking area to the vehicle;
After the vehicle is guided to the parking area by the first parking support unit, an efficient power supply point in the parking area using the strength of the power received by the vehicle from the power supply facility in the guided parking area And a second parking support unit that further guides the parking support device.

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