JP2006279500A - In-vehicle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle-mounted device for specifying a cause of communication quality deterioration of a wireless LAN and transmitting it to a vehicle occupant.
Position determining means for determining whether or not the vehicle is parked near a noise source that can interfere with wireless LAN radio waves (for example, a parking lot at a convenience store) is mounted on an in-vehicle device having a wireless LAN function. The communication quality determination means for determining whether or not the communication quality of the wireless LAN communication by the wireless LAN function is equal to or higher than a predetermined level, and the vehicle is parked near a noise source that can interfere with the wireless LAN radio wave by the position determination means. When the wireless LAN communication quality is determined to be less than the predetermined level by the communication quality determination means, the wireless LAN communication quality is degraded because the noise source is operating. And a notifying means for notifying the vehicle occupant of the estimated contents as character information / voice information.
[Selection] Figure 1

Description

  The present invention generally relates to an in-vehicle device having a wireless LAN function, and more particularly to an in-vehicle device that identifies a cause of communication quality deterioration of a wireless LAN and transmits the cause to a vehicle occupant.

  Conventionally, a wireless LAN function such as IEEE802.11g is installed in an in-vehicle device that provides communication functions and provides various information, and various information (eg music files) is downloaded from an access point outside the vehicle and used in the in-vehicle device. It has been proposed to be able to do so.

  By the way, since the wireless LAN standard represented by IEEE802.11g uses 2.4 GHz as a frequency band, it is known that the wireless LAN standard can interfere with radio waves of ISM devices using the same 2.4 GHz band (for example, non-standard). Patent Document 1). Microwave ovens, which are particularly popular among ISM devices, are recognized as a significant source of interference with wireless LANs, and various measures have been proposed to ensure communication quality even in a microwave oven noise environment. (For example, see Patent Documents 1 and 2).

  Patent Document 1 discloses a wireless communication device that detects the periodicity of jamming waves from a microwave oven and performs data transmission / reception in a period in which no jamming waves are emitted.

Patent Document 2 discloses a wireless communication apparatus that aims to remove interference noise by using radio wave interference model pattern data of interference radio waves radiated from a microwave oven.
JP 2002-111603 A JP 2002-300171 A Matsumoto Yasushi, “Wireless Communication and EMC”, IEICE Journal Vol. 87 no. 10, October 2004, pp. 832-834

  However, in the conventional devices disclosed in Patent Documents 1 and 2, the microwave oven noise is detected at an unexpected timing or pattern that deviates from the radiation period of the detected microwave oven noise or the microwave oven radio wave interference model pattern data stored in advance. If this is emitted, communication may not be performed properly.

  In addition, as in the conventional device disclosed in the above-mentioned Patent Document 1, if transmission / reception of data is not performed during microwave radio wave radiation, no transmission / reception is performed until the microwave radio wave radiation ends, Transmission efficiency is significantly reduced.

  Furthermore, in the conventional devices such as those disclosed in Patent Documents 1 and 2 described above, when the communication speed of wireless LAN communication is significantly reduced due to microwave oven noise or when communication interruption occurs, it is caused by microwave oven noise. It is not communicated to the user.

  If the user can recognize that the communication speed is significantly reduced or disrupted due to microwave oven noise, for example, “The heating time by the microwave oven is at most tens of seconds, and the original communication quality / connection is immediately restored. Can be guessed. However, if the cause cannot be recognized as noise from the microwave oven, or if there is no knowledge that the microwave oven can affect the wireless LAN in the first place, it may be a failure of the own device and / or the communication partner device. There is a possibility of doubt.

  The present invention has been made to solve such problems, and it is a main object of the present invention to provide a vehicle-mounted device that identifies a cause of wireless LAN communication quality deterioration and transmits it to a vehicle occupant.

  One aspect of the present invention for achieving the above object is an in-vehicle device having a wireless LAN function, which determines whether or not the own vehicle is stopped near a noise source capable of interfering with a wireless LAN radio wave. Position determining means, communication quality determining means for determining whether or not the communication quality of wireless LAN communication by the wireless LAN function is equal to or higher than a predetermined level, and the vehicle can interfere with wireless LAN radio waves by the position determining means. When it is determined that the vehicle is parked near the noise source, and the communication quality determination means determines that the wireless LAN communication quality is less than the predetermined level, wireless communication is performed because the noise source is in operation. It is an in-vehicle device having cause estimating means for estimating that the LAN communication quality is deteriorated.

  In this embodiment, “a noise source capable of interfering with a wireless LAN radio wave” refers to an ISM device that uses the same frequency band (usually 2.4 GHz band) as the current wireless LAN standard. A typical example of such an ISM device is a microwave oven.

  In this embodiment, “near a noise source” refers to, for example, a parking lot of a retail store (for example, a convenience store) where a microwave oven is placed.

  Further, in this one aspect, the position determination unit detects, for example, the vehicle speed of the own vehicle, illuminates the current position of the own vehicle acquired using the GPS receiver when the vehicle speed is zero, on the map data, and the own vehicle It is determined whether or not the map data is located near a noise source that can interfere with a preset wireless LAN radio wave.

  According to this aspect, when the communication quality of the wireless LAN communication is deteriorated due to the presence of the noise source, it is determined that the cause is that the interference wave is radiated from the noise source, not the cause of the equipment failure or the like. can do.

  In this aspect, when the cause estimation means estimates that the wireless LAN communication quality is deteriorated because the noise source is operating, a notification for notifying the vehicle occupant of the estimated content It is preferable to further have means.

  In this case, the notification means includes display means (for example, an in-vehicle display) for displaying character information for transmitting to the vehicle occupant that the wireless LAN communication quality is deteriorated because the noise source is operating. Audio output means (for example, a speaker) that outputs audio information is included.

  Moreover, in this aspect, in order to share information regarding the wireless LAN radio wave interference situation with other vehicles, the in-vehicle device further includes a communication unit for communicating with another vehicle or a predetermined communication station, and the communication unit includes: When it is estimated by the cause estimating means that the wireless LAN communication quality is deteriorated because the noise source is operating, the other vehicle or a predetermined communication station is informed that the noise source is operating. You may make it transmit.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle-mounted apparatus which pinpoints the communication quality degradation cause of wireless LAN and transmits it to a vehicle passenger can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. In the following description of the embodiments, it is assumed that a wireless LAN standard using the 2.4 GHz band such as IEEE802.11g is used as an example of the wireless LAN, and a microwave oven is used as an ISM device using the same frequency band that can interfere with the standard. An example will be described. It should be noted that the basic concept, the main hardware configuration, the operating principle, the basic control method, and the like of the wireless LAN device compliant with the wireless LAN standard such as IEEE802.11g are known to those skilled in the art. Is omitted.

  The configuration and operation of the in-vehicle device according to an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, as an example, as shown in FIG. 1, a vehicle 100 equipped with the in-vehicle device 101 according to the present embodiment stops at a parking lot of the convenience store 102 and is installed in the convenience store 102. Consider a case where data such as a music file is downloaded from a point (AP) 103 using a wireless LAN. Convenience stores 102 are often equipped with a microwave oven 104 for heating take-out lunch boxes, prepared dishes, etc., and when the microwave oven 104 is activated, the leaked radio waves interfere with downloading from the access point 103 as noise. Can do.

  FIG. 2 is a schematic configuration diagram of the in-vehicle device 101 according to the present embodiment. Here, for convenience, only the components for mainly identifying the cause of interference of the wireless LAN and transmitting it to the vehicle occupant are shown, but the in-vehicle device 101 has other functions as a car navigation system, A function as a car audio system and / or a function as a hands-free telephone system may be provided.

  The in-vehicle device 101 includes a wireless LAN communication unit 201 that executes all processes necessary for transmitting and receiving packets to and from a wireless LAN device that is a communication partner in accordance with the wireless LAN standard.

  The in-vehicle device 101 further includes a communication quality measurement unit 202 that measures the communication quality of wireless LAN communication by the wireless LAN communication unit 201. Here, the communication quality of the wireless LAN communication is, for example, a packet error rate, a bit error rate, a reception sensitivity, and the like.

  The in-vehicle device 101 further includes a vehicle speed detection unit 203 that detects the vehicle speed of the host vehicle. In the present embodiment, the vehicle speed detection unit 203 detects the vehicle speed from an output signal of a wheel speed sensor, for example.

  The in-vehicle device 101 further includes a host vehicle position detection unit 204 that detects the current position of the host vehicle. In this embodiment, the own vehicle position detection unit 204 includes, for example, a GPS (Global Positioning System) receiver, and detects the latitude and longitude of the current position of the own vehicle from the GPS reception signal.

  The in-vehicle device 101 further includes a map data storage unit 205 that stores map information. In the present embodiment, the map data storage unit 205 may be an arbitrary storage medium. Further, it is assumed that the map information includes the location of the convenience store where the microwave oven is installed as information.

  The in-vehicle device 101 further includes a display unit 206 for presenting character information to the vehicle occupant. In the present embodiment, the display unit 206 is, for example, a display device common to the navigation system, and may be a display device installed on the instrument panel, or is realized by projecting a virtual hologram image on the windshield. It may be a head-up display device.

  The in-vehicle device 101 further includes a communication unit 207 that communicates with other vehicles and a center (communication station) using wireless communication such as a mobile phone. The communication unit 207 may be used, for example, for connection to a telephone line of a hands-free telephone system, or may be used for uploading the vehicle position to the center when the IG is off.

  Further, the in-vehicle device 101 further includes a control unit 208 that comprehensively controls these components. In the present embodiment, the control unit 208 is, for example, an ECU (Electronic Control Unit).

  Next, the operation and action of the vehicle-mounted device 101 having such a configuration will be described with reference to FIG. FIG. 3 is a flowchart illustrating the flow of processing of the in-vehicle device 101 according to the present embodiment.

  First, the control unit 208 determines whether or not a session is established for wireless LAN communication and is in a connected state (S301).

  If it is determined that the wireless LAN is connected (“YES” in S301), it is then determined whether or not the wireless LAN communication unit 201 has requested download of data such as a music file or a movie from the access point ( S302).

  When it is determined that the download is requested (“YES” in S302), the control unit 208 then determines whether or not the vehicle speed of the host vehicle has become zero based on the detection result of the vehicle speed detection unit 203, that is, the host vehicle. Determines whether or not the vehicle is stopped (S303).

  When it is determined that the vehicle speed is zero and the host vehicle is stopped (“YES” in S303), the control unit 208 then displays the host vehicle current position detected by the host vehicle position detection unit 204 as map data. In light of the map information stored in the storage unit 205, it is determined whether or not the host vehicle is parked at a convenience store parking lot (S304).

  When it is determined that the host vehicle is parked in the convenience store parking lot (“YES” in S304), the control unit 208 then performs wireless LAN communication communication based on the measurement result of the communication quality measurement unit 202. It is determined whether or not the quality has deteriorated below a predetermined level (S305). If the communication quality is good (“NO” in S305), the process proceeds to S310 and download is started.

  When it is determined that the communication quality has deteriorated below a predetermined level (“YES” in S305), the control unit 208 is located in the parking lot of the convenience store, and therefore the microwave oven installed in the convenience store. Is used, and it is determined that the leaked radio wave interferes with the wireless LAN communication (S306).

  Then, when it is determined that the microwave oven noise is the cause of communication quality deterioration, the control unit 208 then instructs the display unit 206 to display a display screen as shown in FIG. 4, for example. Then, the vehicle occupant is informed that communication quality degradation due to microwave oven interference is occurring (S307).

  At this time, if the download is in progress, the control unit 208 instructs the wireless LAN communication unit 201 to maintain the session without releasing it so that the download can be resumed later.

  In addition to or instead of the display (S307), a voice output unit (not shown) such as a speaker may transmit a microwave message to the vehicle occupant as a voice message.

  Next, the control unit 208 uses the communication unit 207 to confirm that the microwave oven of the convenience store is in use, and the wireless LAN communication with the access point installed in the convenience store is poor in communication quality at the present time. This is transmitted to another vehicle and / or the center (S308).

  For example, in the example illustrated in FIG. 1, when the vehicle 100 is downloading data from the access point 103 installed in the convenience store 102, interference occurs due to the use of the microwave oven 104 and communication quality deteriorates. In order to transmit this information to surrounding vehicles through the communication unit 207, the other vehicle 105 entering the parking lot of the convenience store 102 receives this information, thereby establishing a session with the access point 103 and measuring the communication quality. Even without this, it is possible to know the wireless LAN communication quality and the microwave oven use status at the present time.

  Next, the control unit 208 determines whether or not the communication quality of the wireless LAN communication has been recovered based on the measurement result by the communication quality measurement unit 202 (S309). Since the operation time of a single microwave oven at a convenience store is considered to be about 10 to 30 seconds, it is considered that the use of the microwave oven has ended by counting the time from when it was determined that the communication quality was deteriorated (S305). You may make it perform this process of S309 after predetermined time progress.

  If it is determined that the communication quality of the wireless LAN communication has not been recovered (“NO” in S309), it is determined that microwave interference is continuing, and the process returns to S305.

  If it is determined that the communication quality has been recovered (“YES” in S309), download from the access point is started / resumed (S310).

  As described above, according to the present embodiment, when a vehicle occupant who is downloading data from an access point using an in-vehicle device equipped with a wireless LAN function has interference caused by microwave noise, the download speed is slow. Since it is informed that the interference is caused by the microwave oven, there is no doubt about the failure of the in-vehicle device or the access point.

  In addition, since the occurrence of microwave interference is transmitted to the surrounding vehicles and the center, the surrounding vehicles and the center can grasp the use state of the microwave oven without monitoring the communication quality of the wireless LAN.

  The present invention can be widely applied to in-vehicle devices having a wireless LAN function. The noise source is not limited to the microwave oven described above, and any noise source may be used as long as it emits radio waves in the same frequency band as the adopted wireless LAN standard. Further, the location of the noise source is not limited to the convenience store, and may be any location as long as it is near the wireless LAN access point.

It is a figure which shows a mode that the vehicle carrying the vehicle-mounted apparatus which concerns on one Example of this invention is stopping at a convenience store. It is a schematic block diagram of the vehicle-mounted apparatus which concerns on one Example of this invention. It is a flowchart which shows the flow of a process of the vehicle-mounted apparatus which concerns on one Example of this invention. It is a figure which shows an example of the display display by the vehicle-mounted apparatus which concerns on one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Vehicle 101 In-vehicle apparatus 102 Convenience store 103 Access point (AP)
DESCRIPTION OF SYMBOLS 104 Microwave oven 105 Other vehicle 201 Wireless LAN communication part 202 Communication quality measurement part 203 Vehicle speed detection part 204 Own vehicle position detection part 205 Map data storage part 206 Display part 207 Communication part 208 Control part

Claims (6)

An in-vehicle device having a wireless LAN function,
Position determining means for determining whether or not the own vehicle is parked near a noise source capable of interfering with a wireless LAN radio wave;
Communication quality determination means for determining whether or not the communication quality of wireless LAN communication by the wireless LAN function is equal to or higher than a predetermined level;
The position determining means determines that the vehicle is parked near a noise source that can interfere with the wireless LAN radio wave, and the communication quality determining means determines that the wireless LAN communication quality is less than the predetermined level. And a cause estimating means for estimating that the wireless LAN communication quality is deteriorated because the noise source is in operation. The in-vehicle device according to claim 1,
A notification means for notifying a vehicle occupant of the estimated content when the cause estimation means estimates that the wireless LAN communication quality is deteriorated because the noise source is operating; In-vehicle device characterized. The in-vehicle device according to claim 2,
The in-vehicle device characterized in that the notification means includes display means for displaying character information for transmitting to the vehicle occupant that wireless LAN communication quality has deteriorated because the noise source is operating. . The in-vehicle device according to claim 2,
The notification means includes an audio output means for outputting audio information for transmitting to a vehicle occupant that the wireless LAN communication quality is deteriorated because the noise source is operating. apparatus. The in-vehicle device according to claim 1,
It further has a communication means for communicating with another vehicle or a predetermined communication station,
The communication means determines that the noise source is operating when the cause estimation means estimates that the wireless LAN communication quality is deteriorated because the noise source is operating. An in-vehicle device, which transmits to a predetermined communication station. It is an in-vehicle device according to any one of claims 1 to 5,
The position determining means determines whether or not the vehicle is parked in a parking lot of a retail store where a microwave oven is placed,
The cause estimating means is determined by the position determining means to be parked in a parking lot of a retail store where the own vehicle is placed, and the communication quality determining means has a wireless LAN communication quality at the predetermined level. When it is determined that the wireless LAN communication quality is deteriorated, it is estimated that the wireless LAN communication quality is deteriorated because the microwave oven is operating.

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