1335422 九、發明說明： 【發明所屬之技術領域】 本發明係關於取得現在之位置資訊與行進方向之資訊， 施行導航之可攜式導航裝置及記憶有導航程式之記憶媒 體。 【先前技術】 以往已知之設置於汽車之導航裝置係利用GPS (Global Positioning System ;全球定位系統）信號及陀螺感測器、 速度計等之資訊檢測自己車子之位置，並施行導航。近年 籲 來，也已開發出在攜帶式之PDA (Personal Digital Assistants ;個人數位助理）機器上裝載GPS晶片，並施行 導航之可攜式導航裝置。 圖4係表示以往之可攜式導航裝置之處理之模式圖。在 圖 4 中，由 GPS 晶片 41 經由 UART (Universal Asynchronous Receiver Transmitter :通用非同步從發器）通信部42輸出依 據 NMEA (National Marine Electronics Association :國家 海洋電子協會）規格之信息格式之資料（以下稱為NMEA信 ® 息）。 此NMEA信息係被假想COM (Communication:通訊）驅動 器43由CPU之COM埠被取入，並被輸出至其上位應用程式 之地圖導航應用程式44。地圖導航應用程式44係由NMEA 信息參照現在之位置資訊及方位資訊，並施行導航。 又，在專利文獻1中，揭示連接於車輛，由車輛接收陀 螺感測器及車速脈衝之信號之輕便型導航裝置。 120168.doc 1335422 [專利文獻1]日本特開2〇〇5-195387號 【發明内容】 [發明所欲解決之問題] 但在以往之可攜式導航裝置中，在裝置之電源通電之狀 訂’在裝置低速移動中之情形、以及裝置在隧道内、高 層建築物街道及位於地下等時’有不能正常接收GPS信 號，不能判斷行進方向或現在朝向之方位之情形。 又’在專利文獻丨之輕便型導航裝置中，雖可由陀螺感 測器之信號等判斷車輛之行進方向，但為達該目的雖說 輕便’但卻有必要與車輛連接。 本發明係相到上述情況所完成者，其目的在於提供一 種即使在不能由GPS信號正確地接收到方位資訊之情形， 也能自動地取得精度良好之方位資訊，並施行導航之可攜 式導航裝置。 [解決問題之技術手段] 本發明係為解決上述問題而設計者H本發明之可 攜式導航裝置之特徵在於包含：位置檢測機構，其係接收 GPS信號，輪出現在地點之位置資訊與顯示行進方向之第 一方位資訊；地磁感測器，其係檢測地磁，輸出第二方位 資訊；判定機構，其係依據特定之判定基準判定前述第一 方位資訊之正確性；選擇機構，其係在以前述判二_ 定為正確之情形’選擇第一方位資訊，在判定為非正確 情形’選擇第二方位資訊；及導航機構’其係依據以前述 位置檢測機構檢測出之位置資訊與以前述選擇機構選擇出 120168.doc -6 - 丄奶422 之第一或第二方位資訊執行導航者。 1在本發明之可攜式導航裝置中前述判定機構也可在以 月1j述位置檢測機構可正常接收Gps信號之情形，判定前述 第一方位資訊為正4，在以前述位置檢測機構不可正常接 收刖述GPSk號之情形，判定前述第一方位資訊為非正 確。 又’在本發明之可攜式導航裝置中，前述位置檢測機構 # 纟可進-步輸出顯示前述裝置之移動速度前述判定機構 在裝置之速度為特定值以上之情形，判定前述第一方位資 s為正確在裝置之移動速度不足特定值之情形，判定前 述第一方位資訊為非正確。 記憶本發明之導航程式之記憶媒體之特徵在於記憶有供 使電腦執行下列程序：輸入現在地點之位置資訊與顯示行 進方向之第一方位資訊之程序；輸入依據地磁所求得之第 二方位資訊之程序；判定程序，其係依據特定之判定基準 定前述m資訊之正輕；選擇程序，其係在 述判定程序判定為正確之情形’選擇第一方位資訊，在判 定為非正確之情形，選擇第二方位資訊；及導航程序盆 係依據前述位置資訊與以前述選擇程序選擇出之方 執行導航。 [發明之效果] 依據本發明，可獲得具有下列特徵之可攜式導航裝置. 即在依據⑽信號之第一方位資訊非正確 登 擇機構選擇地磁感測器所求得 11秸’、 第一方位資訊，以供導航 120I68.doc 1335422 使用》因Λ ’即使在不能正常接收Gps信號之環境及裝置 低速移動之情形，導航機構也可利用高精度之方位資訊進 行導航。 【實施方式】 以下’參照圖式說明有關本發明之實施型態。 圖1係表示本發明之一實施型態之可攜式導航裝置之構 成圖。在圖1中’可攜式導航裝置1之天線U係接收來自 GPS衛星（未圖示）之電波信號。 GPS接收部12(位置檢測機構）係由解調接收自Gps衛星 之電波信號，產生NMEA信息之GPS晶片、依據UART而與 CPU 13施行通信之UART通信部所構成《在NMEA信息 t ’除了以可攜式導航裝置1之緯度.經度（3維模式之情 形’進一步含高度等）表示之現在之位置資訊及方位資訊 以外，亦含速度資訊。 CPU 13係控制可攜式導航裝置1内之各部之cpu (Central Processing Unit :中央處理單元）。地磁感測器部 14係由在CPU 13之控制下檢測地磁，由所檢測之地磁算出 並輸出方位之地磁感測器、及藉I2C (Inter Integrated Circuit :積體電路間）方式與CPU 13施行通信之I2C通信部 所構成。又’地磁感測器部14既可檢測2軸之地磁，也可 檢測3軸之地磁。又，地磁感測器部14所執行之方位算出 也可由CPU 13執行》 RAM (Random Access Memory;隨機存取記憶體）i5 係 提供在動作中供CPU 13使用於資料記憶等之工作區域等。 120168.doc 1335422 ROM (Read Only Memory :唯讀記憶體）16係記憶供 CPU 13執行用之程式及各種資料。 顯示部17係依據由CPU 13輸入之顯示用之信號，顯示圖 像及文子。操作部18係將使用者所輸入之輸入内容輸出至 CPU 13。匯流排線19係使可攜式導航裝置i内之各部互相 連接。 上述之地磁感測器部14係輸出由2轴或3轴之感測器所檢 測之地磁作為計測資料而施行依據該計測資料之計算處 理，藉以輸出方位。但，地磁感測器部14會連在可攜式導 航裝置1之内部中裝載於其附近之揚聲器、微音器、附磁 之電子零件之金屬封裝體等所漏出之漏磁場引起之磁場也 一併檢測出來。從而’地磁感測器部14所檢測的是將此等 地球之磁場以外之磁場與地球之磁場合成後之合成磁場。 因此，為了求出實際之方位，有必要由地磁感測器所檢測 之磁場中扣除上述地球之磁場以外之磁場之成分。因此， 需預先計算上述地球之磁場以外之磁場之成分作為偏離 值。 此偏離值之計算處理稱為校準，利用下列程序進行校 準首先，可攜式導航裝置1之方向在特定範圍中變化 時在CPU 13之控制下，利用地磁感測器部丨4取得複數之 十* !—貝料其次’將取得之多數之計測資料暫且記憶於 RAM 15依據所記憶之複數之計測資料，由CPU 13施行偏 離值之计算。A 了正確地求出實際之方位有必要施行此 校準將正確之偏離值設定於地磁感測器。又利用校準所 120168.doc 獲得之偏離值也可設定於RAM 15而非設定於地磁感測器 部14。 其次，參照圖2及圖3說明上述實施型態之動作。 圖2係表示圖1之可攜式導航裝置1之處理之圖。在圖2 中，GPS晶片21及UART通信部22係包含於GPS接收部12之 硬體，地磁感測器23及I2C通信部24係包含於地磁感測器 部14之硬體。另一方面，假想COM驅動器25、I2C驅動器 26、假想COM軟體27、及地圖導航應用程式28係在 CPU 13上執行動作之軟體。 由GPS晶片21輸出之NMEA信息係經由UART通信部22被 輸出至CPU 13之COM埠。假想COM驅動器25係取入被輸 入至COM埠之NMEA信息，並輸出至假想COM軟體27。 另一方面，由地磁感測器23輸出之方位資訊係經由I2C 通信部24被輸出至CPU 13之I2C埠。I2C驅動器26係取入被 輸入至I2C埠之方位資訊，並輸出至假想COM軟體27。 假想COM軟體27係暫且讀入來自GPS晶片21之NMEA信 息而加以分析，判定NMEA信息内之方位資訊（第一方位資 訊）是否可靠（判定機構）。判定為可靠之情形，假想€01^軟 體27照樣將NMEA信息輸出至地圖導航應用程式28。 另一方面，判定為不可靠之情形’假想COM軟體27將 NMEA信息内之方位資訊置換成來自地磁感測器23之方位 資訊（第二方位資訊）後，換成後之NMEA信息輸出至地圖 導航應用程式28。 地圖導航應用程式28係依據由假想COM軟體27輸入之 120168.doc 1335422 NMEA信息内之資訊施行導航之處理。因此，不管NMEA 信息内之方位資訊是來自GPS晶片21之資訊或來自地磁感 測器23之資訊，地圖導航應用程式28均可使用精度非常良 好之方位資訊。 接著，參照圖3說明假想COM軟體27之處理之說明。 圖3係表示假想COM軟體27所執行之處理之流程圖。 在圖3中，CPU 13由GPS晶片21輸入NMEA信息，此 NMEA信息經由假想COM驅動器25被假想COM軟體27所取 得（步驟S301)。假想COM軟體27進行NMEA信息之分析（步 驟S302) 〇 在NMEA信息之分析中，首先判定來自GPS衛星之信號 是否正確被接收（正確）（步驟S3 03)。判斷未正確被接收之 情形（步驟S303 :否）進入步驟S308，判斷有正確被接收之 情形（步驟S303 :是）進入步驟S304。 在步驟S304，假想COM軟體27由NMEA信息所含之速度 資訊判定可攜式導航裝置1是否處在移動中。判定非處在 移動中（步驟S304:否）進入步驟S3 08，判定處在移動中（步 驟S304:是）進入步驟S305。 在步驟S305，假想COM軟體27由NMEA信息所含之速度 資訊判定可攜式導航裝置1之移動速度是否非處在特定速 度以下（低速移動中）。判定處在低速移動中（步驟S305 : 否）進入步驟S308，判定非處在低速移動中（步驟S305 :是） 進入步驟S306。 在步驟S306，假想COM軟體27由NMEA信息所含之精度 120168.doc 資訊判定GPS信號之精度是否充分。判定GPS信號之精度 非充分（步驟S306 :否）進入步驟S308，判定GPS信號之精 度充分（步驟S306:是）進入步驟S307。 在步驟S303〜步驟S306之全部中，判定為是之情形，假 想COM軟體27判定由GPS晶片21輸入之NMEA信息内之方 位資訊正確，而直接使用（步驟S307)。即，選擇由GPS晶 片21輸入之方位資訊。 另一方面，在步驟S303〜步驟S306之全部中，判定為非 之情形，假想COM軟體27判定由GPS晶片21輸入之NMEA 信息内之方位資訊非正確，選擇由地磁感測器23輸入之方 位資訊，以置換由GPS晶片21輸入之方位資訊。（步驟308) 在步驟S307或步驟S308之處理結束後，假想COM軟體27 將NMEA信息輸出至地圖導航應用程式28(上位應用程 式）。 如此，在本實施型態中，利用假想COM軟體27暫且讀入 來自GPS晶片21之NMEA信息而加以分析，判定NMEA信 息内之方位資訊正確之情形，選擇該方位資訊，在假想方 位資訊不正確之狀況下，將NMEA信息内之方位資訊置換 成地磁感測器23所檢測之方位資訊。 從而，假想COM軟體27可一直對地圖導航應用程式28提 供正確之方位資訊。因此，地圖導航應用程式28可配合使 用者之行進方向，例如旋轉地圖使行進方向一直向上而顯 示於顯示部17，可進行高精度之導航。 如上所述，在圖3步驟S303〜步驟S306中之一個步驟，判 120168.doc 12 1335422 定為否時，GPS晶片21之方位資訊會被置換成地磁感測器 23之方位資訊。但，因某些理由，未被執行適切之校準， 正確之偏離值未被設定於地磁感測器23之情形時，不正確 之地磁感測器23之方位資訊容易被提供至地圓導航應用程 式28。為防止此現象，在步驟S3〇3〜步驟S3〇6中之一個步 驟，在判定為否之時點，已距離前次校準經過特定時間之 情形，也可將GPS晶片21之方位訊息照樣提供至地圖導航 應用程式28，並產生校準之開始執行指示。依據此開始執 行指示’地磁感測器部14逐次取得計測資料，將複數計測 資料暫且記憶於RAM 15。CPU 13利用記憶於RAM 15之複 數計測資料執行偏離值之計算。如此偏離值之計算（校準） 結束後，只要在步驟S303〜步驟S306中之一個步驟，判定 為否之情形’由GPS晶片21之方位資訊置換成地磁感測器 23之方位資訊即可。 在本實施型態中’說明了有關假想COM軟體27分析 NMEA信息而判斷GPS晶片21之方位資訊之正確性之例。 作為另一方法，也可考慮利用地圖導航應用程式28由現在 位置與行進方向判斷應選擇GPS晶片之方位資訊或地磁感 測器之方位資訊中之哪一方，並利用假想C〇M軟體27切換 所選擇之方位資訊。 具體上’在預料可能朝向難以接收到GPS信號之情形， 地圖導航應用程式28只要指示假想COM軟體27使其選擇地 磁感測器之方位資訊即可。又’在預料可能朝向鐵橋等磁 場強烈之場所（對地磁之檢測造成影響之場所）之情形，地 120168.doc 1335422 圖導航應用程式28只要指示假想COM軟體27使其選擇地 GPS晶片之方位資訊即可。 另外，考慮使用者攜帶可攜式導航裝置丨之情形等一直 使用地磁感測器23之方位資訊之情形。此情形，利用自動 或手動，開始施行利用CPU 13之地磁感測器部14之校準 時’其則面所計算之偏離值有可能含有大的誤差’導致不 能輸出來自地磁感測器23之正確之方位資訊。因此，在地 磁感測器部14之校準開始後至結束為止，也可強制地使用 來自GPS晶片21之方位資訊而不使用地磁感測器23之方位 資訊。 在僅利用GPS信號取得方位資訊之構成中，在不能正常 收到GPS彳s號等之狀況下，不能正確地獲得方位資訊， 又，在僅利用地磁感測器取得方位資訊之構成中，在磁場 較強之處，不能正確地檢測地磁，故方位資訊也不正確。 但，如上述之實施型態一般，採用取得依據Gps信號之方 位資訊與依據地磁感測器之方位資訊之雙方之構成，由該 二種方位資訊選擇精度較高之一方時，即可一直取得適= 之方位資訊。 以上’已詳述本發明之實施型態，但具體的構成並不限 定於本實施型態，也包含不脫離本發明之要旨之範圍之設 計變更等》 [產業上之可利用性] 本發明適合使用於取得現在之位置資訊與行進方向之資 訊，並施行導航之可攜式導航裝置。 120168.doc -14- 1335422 【圖式簡單說明】 圖1係表示本發明之一實施型態之可攜式導航裝置之構 成之圖。 圖2係表示圖1之可攜式導航裝置之處理之圖。 圖3係表示圖2之假想COM軟體所執行之處理之流程圖。 圖4係表示以往之可攜式導航裝置之處理之模式圖。 【主要元件符號說明】1335422 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a portable navigation device that performs navigation and a memory medium in which a navigation program is stored, in order to obtain information on current position information and direction of travel. [Prior Art] Conventionally known navigation devices installed in automobiles use GPS (Global Positioning System) signals, gyro sensors, speedometers, and the like to detect the position of their own cars and perform navigation. In recent years, it has also been developed to develop a portable navigation device that mounts a GPS chip on a portable PDA (Personal Digital Assistants) machine and performs navigation. Fig. 4 is a schematic view showing the processing of a conventional portable navigation device. In FIG. 4, the GPS chip 41 outputs information according to the NMEA (National Marine Electronics Association) specification information format via the UART (Universal Asynchronous Receiver Transmitter) communication unit 42 (hereinafter referred to as For NMEA Letter®). This NMEA information is fetched by the imaginary COM (Communication) driver 43 from the CPU of the CPU and output to the map navigation application 44 of its host application. The map navigation application 44 refers to the current location information and location information from the NMEA information and performs navigation. Further, Patent Document 1 discloses a portable navigation device that is connected to a vehicle and receives signals of a gyro sensor and a vehicle speed pulse from the vehicle. 120168.doc 1335422 [Patent Document 1] Japanese Patent Laid-Open No. Hei 5-195387 [Draft of the Invention] [Problems to be Solved by the Invention] However, in the conventional portable navigation device, the power supply of the device is set. 'In the case of low-speed movement of the device, and when the device is inside the tunnel, on the street of a high-rise building and in the underground, etc., there is a situation in which the GPS signal cannot be received normally, and the direction of travel or the orientation of the current direction cannot be judged. Further, in the portable navigation device of the patent document, although the traveling direction of the vehicle can be judged by the signal of the gyro sensor or the like, it is lighter for the purpose, but it is necessary to be connected to the vehicle. The present invention has been made in view of the above circumstances, and an object thereof is to provide a portable navigation capable of automatically obtaining azimuth information with high precision even when azimuth information cannot be correctly received by a GPS signal, and performing navigation. Device. [Technical means for solving the problem] The present invention is to solve the above problems. The portable navigation device of the present invention is characterized in that it comprises: a position detecting mechanism that receives a GPS signal, and displays the position information and display of the wheel at the place. a first orientation information of a traveling direction; a geomagnetic sensor that detects geomagnetism and outputs second orientation information; and a determination mechanism that determines the correctness of the first orientation information according to a specific determination criterion; the selection mechanism is attached Selecting the first orientation information in the case where the foregoing judgment is correct, and selecting the second orientation information in the case of determining that the situation is not correct; and the navigation mechanism 'based on the position information detected by the position detection mechanism and the foregoing The selection mechanism selects the first or second orientation information of the 120168.doc -6 - milk 422 to execute the navigator. In the portable navigation device of the present invention, the determining means may determine that the first orientation information is positive 4 in the case where the position detecting mechanism can normally receive the GPS signal in the month 1j, and the position detecting mechanism is not normal. When the GPSk number is received, it is determined that the first orientation information is incorrect. Further, in the portable navigation device of the present invention, the position detecting means # 纟 can further output and display the moving speed of the device, and the determining means determines the first position by the fact that the speed of the device is equal to or greater than a specific value. s is correct in the case where the moving speed of the device is less than a specific value, and the first orientation information is determined to be incorrect. The memory medium of the navigation program of the present invention is characterized by a program for causing the computer to execute the following procedures: inputting the location information of the current location and displaying the first orientation information of the traveling direction; and inputting the second orientation information obtained by the geomagnetic field. a program; a determination program that determines the positiveness of the m information according to a specific determination criterion; and a selection process that selects the first orientation information when the determination program determines that the determination is correct, and determines that the information is incorrect. The second orientation information is selected; and the navigation program basin performs navigation according to the foregoing location information and the party selected by the foregoing selection procedure. [Effect of the Invention] According to the present invention, a portable navigation device having the following features can be obtained. That is, the magnetic sensor is selected according to the first orientation information of the (10) signal, and the magnetic sensor is used to obtain 11 straw', first. Orientation information for navigation 120I68.doc 1335422 Use "Cause" 'The navigation mechanism can use high-precision orientation information to navigate even in environments where GPS signals cannot be received normally and the device moves at low speed. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the construction of a portable navigation device according to an embodiment of the present invention. In Fig. 1, the antenna U of the portable navigation device 1 receives a radio wave signal from a GPS satellite (not shown). The GPS receiving unit 12 (position detecting unit) is composed of a GPS chip that demodulates a radio wave signal received from a GPS satellite, generates NMEA information, and a UART communication unit that communicates with the CPU 13 in accordance with the UART. The latitude and longitude of the portable navigation device 1 (in the case of the 3-dimensional mode, further including the height, etc.), the current location information and the orientation information also include speed information. The CPU 13 controls a CPU (Central Processing Unit) of each unit in the portable navigation device 1. The geomagnetism sensor unit 14 is a geomagnetic sensor that detects geomagnetism under the control of the CPU 13, calculates and outputs an azimuth from the detected geomagnetism, and performs an I2C (Inter Integrated Circuit) method with the CPU 13. The I2C communication unit of communication is constituted. Further, the geomagnetic sensor unit 14 can detect two-axis geomagnetism and can detect three-axis geomagnetism. Further, the calculation of the azimuth performed by the geomagnetism sensor unit 14 can be performed by the CPU 13 by means of a RAM (Random Access Memory) i5, which provides a work area for the CPU 13 to use for data storage or the like during operation. 120168.doc 1335422 ROM (Read Only Memory) 16 is a program for storing programs and various data for the CPU 13. The display unit 17 displays an image and a text based on a signal for display input by the CPU 13. The operation unit 18 outputs the input content input by the user to the CPU 13. The bus bar 19 connects the components in the portable navigation device i to each other. The above-described geomagnetic sensor unit 14 outputs geomagnetism detected by a 2-axis or 3-axis sensor as measurement data, and performs calculation processing based on the measurement data, thereby outputting an orientation. However, the geomagnetic sensor unit 14 is connected to a magnetic field caused by a leakage magnetic field leaking from a speaker, a microphone, a metal package of a magnetic component, etc., which are mounted in the vicinity of the portable navigation device 1 Check it out together. Therefore, the geomagnetic sensor unit 14 detects a synthetic magnetic field in which the magnetic field other than the magnetic field of the earth is combined with the magnetic field of the earth. Therefore, in order to obtain the actual orientation, it is necessary to subtract the component of the magnetic field other than the magnetic field of the earth from the magnetic field detected by the geomagnetic sensor. Therefore, it is necessary to calculate in advance the composition of the magnetic field other than the magnetic field of the earth as a deviation value. The calculation process of the deviation value is called calibration, and the calibration is performed by the following procedure. First, when the direction of the portable navigation device 1 changes in a specific range, under the control of the CPU 13, the magnetic sensor unit 丨4 is used to obtain the plural ten. *! - Beakers Next, the majority of the measured data is temporarily stored in the RAM 15 based on the measured data of the complex number, and the CPU 13 performs the calculation of the deviation value. A It is necessary to perform this calibration to correctly determine the actual orientation. The correct deviation value is set to the geomagnetic sensor. The offset value obtained by the calibration station 120168.doc can also be set in the RAM 15 instead of the geomagnetic sensor portion 14. Next, the operation of the above embodiment will be described with reference to Figs. 2 and 3 . FIG. 2 is a diagram showing the processing of the portable navigation device 1 of FIG. 1. In Fig. 2, the GPS chip 21 and the UART communication unit 22 are included in the hardware of the GPS receiving unit 12, and the geomagnet sensor 23 and the I2C communication unit 24 are included in the hardware of the geomagnet sensor unit 14. On the other hand, the virtual COM driver 25, the I2C driver 26, the virtual COM software 27, and the map navigation application 28 are softwares that execute operations on the CPU 13. The NMEA information outputted from the GPS chip 21 is output to the COM port of the CPU 13 via the UART communication unit 22. The imaginary COM driver 25 takes in the NMEA information input to the COM , and outputs it to the imaginary COM software 27. On the other hand, the orientation information output by the geomagnet sensor 23 is output to the I2C of the CPU 13 via the I2C communication unit 24. The I2C driver 26 takes in the orientation information input to the I2C, and outputs it to the virtual COM software 27. The imaginary COM software 27 temporarily reads the NMEA information from the GPS chip 21 and analyzes it to determine whether the orientation information (first orientation information) in the NMEA information is reliable (determination mechanism). In the case where it is judged to be reliable, the hypothetical €01^ software 27 outputs the NMEA information to the map navigation application 28. On the other hand, if it is determined to be unreliable, the imaginary COM software 27 replaces the orientation information in the NMEA information with the orientation information (second orientation information) from the geomagnetic sensor 23, and outputs the replaced NMEA information to the map. Navigation application 28. The map navigation application 28 performs navigation processing based on the information in the 120168.doc 1335422 NMEA information input by the imaginary COM software 27. Therefore, regardless of whether the orientation information in the NMEA information is information from the GPS chip 21 or information from the geomagnetic sensor 23, the map navigation application 28 can use the orientation information with very good precision. Next, the description of the processing of the virtual COM software 27 will be described with reference to FIG. FIG. 3 is a flow chart showing the processing executed by the virtual COM software 27. In Fig. 3, the CPU 13 inputs NMEA information from the GPS chip 21, and this NMEA information is obtained by the virtual COM driver 27 via the virtual COM driver 25 (step S301). The imaginary COM software 27 performs analysis of NMEA information (step S302) 〇 In the analysis of the NMEA information, it is first determined whether or not the signal from the GPS satellite is correctly received (correct) (step S3 03). When it is judged that the reception is not correctly received (step S303: NO), the flow proceeds to step S308, and it is judged that the situation is correctly received (step S303: YES), and the flow proceeds to step S304. In step S304, the imaginary COM software 27 determines whether the portable navigation device 1 is in motion by the speed information contained in the NMEA information. It is determined that the non-location is moving (step S304: NO), and the process proceeds to step S3 08, and it is determined that the vehicle is moving (step S304: YES) to step S305. In step S305, the imaginary COM software 27 determines from the speed information contained in the NMEA information whether or not the moving speed of the portable navigation device 1 is not below a certain speed (low speed moving). The determination is made in the low speed movement (step S305: NO), and the flow proceeds to step S308, where it is determined that the vehicle is not in the low speed movement (step S305: YES), and the flow proceeds to step S306. In step S306, the imaginary COM software 27 determines whether the accuracy of the GPS signal is sufficient by the accuracy 120168.doc information contained in the NMEA information. It is determined that the accuracy of the GPS signal is insufficient (step S306: NO), and the flow proceeds to step S308, where it is determined that the accuracy of the GPS signal is sufficient (step S306: YES), and the flow proceeds to step S307. In all of the steps S303 to S306, if the determination is YES, the virtual COM device 27 determines that the information in the NMEA information input by the GPS chip 21 is correct, and uses it directly (step S307). That is, the orientation information input by the GPS chip 21 is selected. On the other hand, in all of steps S303 to S306, if the determination is negative, the virtual COM software 27 determines that the orientation information in the NMEA information input by the GPS chip 21 is incorrect, and selects the orientation input by the geomagnetic sensor 23. Information to replace the orientation information input by the GPS chip 21. (Step 308) After the processing of Step S307 or Step S308 ends, the imaginary COM software 27 outputs the NMEA information to the map navigation application 28 (upper application). As described above, in the present embodiment, the virtual COM software 27 temporarily reads the NMEA information from the GPS chip 21 and analyzes it, determines that the orientation information in the NMEA information is correct, and selects the orientation information, and the information in the virtual orientation is incorrect. In this case, the orientation information in the NMEA information is replaced with the orientation information detected by the geomagnetic sensor 23. Thus, the hypothetical COM software 27 can always provide the correct orientation information to the map navigation application 28. Therefore, the map navigation application 28 can display the direction of travel of the user, for example, by rotating the map so that the traveling direction is always upward and displayed on the display unit 17, enabling high-precision navigation. As described above, in one of the steps S303 to S306 of Fig. 3, when 120168.doc 12 1335422 is determined as NO, the orientation information of the GPS chip 21 is replaced with the orientation information of the geomagnet sensor 23. However, for some reason, if the proper calibration is not performed and the correct deviation value is not set in the geomagnetic sensor 23, the orientation information of the incorrect geomagnetic sensor 23 is easily provided to the ground navigation application. Program 28. In order to prevent this, in one of the steps S3〇3 to S3〇6, when the determination is no, the positional information of the GPS chip 21 can be provided to the case where the previous calibration has passed a certain time. The map navigation application 28 generates an indication of the start of calibration. In response to this, the geomagnetic sensor unit 14 sequentially acquires the measurement data, and temporarily stores the plurality of measurement data in the RAM 15. The CPU 13 performs the calculation of the deviation value using the complex measurement data stored in the RAM 15. After the calculation of the deviation value (calibration) is completed, it is only necessary to replace the position information of the GPS chip 21 with the orientation information of the geomagnet sensor 23 by the position information of the GPS chip 21 in one of the steps S303 to S306. In the present embodiment, an example has been described in which the hypothetical COM software 27 analyzes the NMEA information to determine the accuracy of the orientation information of the GPS chip 21. As another method, it is also conceivable to use the map navigation application 28 to determine which one of the orientation information of the GPS chip or the orientation information of the geomagnetic sensor should be selected from the current position and the traveling direction, and switch with the virtual C〇M software 27 The location information selected. Specifically, in the case where it is expected that the GPS signal is difficult to receive, the map navigation application 28 may simply instruct the virtual COM software 27 to select the orientation information of the magnetic sensor. Also, in the case where it is expected to face a strong magnetic field such as an iron bridge (a place that affects the detection of geomagnetism), the map navigation application 28 simply indicates the orientation of the pseudo-COM software 27 to select the GPS chip. Information can be. In addition, the situation in which the orientation information of the geomagnetic sensor 23 is used is always considered in the case where the user carries the portable navigation device. In this case, when the calibration using the geomagnetic sensor portion 14 of the CPU 13 is started automatically or manually, the deviation value calculated by the surface may have a large error, resulting in failure to output the correctness from the geomagnetic sensor 23. Direction information. Therefore, the orientation information from the GPS chip 21 can be forcibly used without using the orientation information of the geomagnetic sensor 23 after the calibration of the geomagnetic sensor portion 14 is started. In the configuration in which only the GPS signal is used to obtain the orientation information, the position information cannot be correctly obtained in the case where the GPS 彳s number cannot be received normally, and in the configuration in which the position information is acquired only by the geomagnetic sensor, Where the magnetic field is strong, the geomagnetic field cannot be detected correctly, so the orientation information is not correct. However, as in the above-mentioned implementation mode, the combination of the orientation information based on the GPS signal and the orientation information based on the geomagnetic sensor is used, and when the accuracy of the two orientation information selection is higher, the acquisition can be always obtained. Suitable = direction information. The embodiment of the present invention has been described in detail above, but the specific configuration is not limited to the embodiment, and includes design changes and the like without departing from the gist of the present invention. [Industrial Applicability] The present invention It is suitable for portable navigation devices that use the information of current location information and direction of travel and implement navigation. 120168.doc -14- 1335422 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the construction of a portable navigation device according to an embodiment of the present invention. 2 is a diagram showing the processing of the portable navigation device of FIG. 1. Figure 3 is a flow chart showing the processing performed by the hypothetical COM software of Figure 2. Fig. 4 is a schematic view showing the processing of a conventional portable navigation device. [Main component symbol description]
1 可攜式導航裝置 11 天線 12 GPS接收部 13 CPU 14 地磁感測器部 15 RAM 16 ROM 17 顯示部 18 操作部 19 匯流排線 21 GPS晶片 22 U ART通信部 23 地磁感測器 24 I2C通信部 25 假想COM驅動器 26 I2C驅動器 27 假想COM軟體 28 地圖導航應用程式 120168.doc -15-1 Portable navigation device 11 Antenna 12 GPS receiving unit 13 CPU 14 Geomagnetic sensor unit 15 RAM 16 ROM 17 Display unit 18 Operating unit 19 Bus bar 21 GPS chip 22 U ART communication unit 23 Geomagnetic sensor 24 I2C communication Part 25 Hypothetical COM Drive 26 I2C Driver 27 Imagine COM Software 28 Map Navigation Application 120168.doc -15-