JP2005043068A - Route guidance device, center, and route search method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a route guidance device and a route search method that match route search conditions that a user desires, and search an optimum route having improved user travel efficiency. <P>SOLUTION: A microcomputer 21 searches a plurality of candidate routes from the present location to the destination of a vehicle, based on route search conditions selected by the user. Then, the microcomputer 21 calculates the cost for each route by utilizing a plurality of parameters α, β, γ, and δ for reflecting route search conditions selected for the searched route candidate, and attributes of roads constituting the candidate route. At this time, the microcomputer 21 calculates the cost for each route while changing parameters so that the sum of respective parameters becomes constant along with the calculation of the cost for the route. Then, the microcomputer 21 determines a candidate route having the minimum route cost among the calculated route costs as a guidance route. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４５】
【数２】

【００４６】
ここで、経路コストＡｉは、リンクｉまでの経路コストであり、経路コストＡｉ＋１は、次のリンク（リンクｉ＋１）までの経路コストである。また、ｄ_ｉおよびｄ_ｉ＋１は、リンクｉおよびリンクｉ＋１の経路距離であり、ｖ_ｉおよびｖ_ｉ＋１は、リンクｉおよびリンクｉ＋１の法定速度である。また、ｅ_ｉおよびｅ_ｉ＋１は、リンクｉおよびリンクｉ＋１の道路種別であり、ｆ_ｉおよびｆ_ｉ＋１は、リンクｉおよびリンクｉ＋１の車両の推定燃費である。また、Σｄ_ｉおよびΣｄ_ｉ＋１は現在地からリンクｉおよびリンクｉ＋１までの合計距離、Σ（ｄ_ｉ／ｖ_ｉ）およびΣ（ｄ_ｉ＋１／ｖ_ｉ＋１）は現在地からリンクｉおよびリンクｉ＋１までの合計所要時間、Σ（ｅ_ｉ×ｄ_ｉ）およびΣ（ｅ_ｉ＋１×ｄ_ｉ＋１）は、現在地からリンクｉおよびリンクｉ＋１までの合計通行料金、Σ（ｆ_ｉ×ｄ_ｉ）およびΣ（ｆ_ｉ＋１×ｄ_ｉ＋１）は現在地からリンクｉおよびリンクｉ＋１までの合計消費燃料を表している。
【００４７】
また、α，β，γおよびδは、運転者または同乗者が入力した経路探索条件を候補経路に反映するためのパラメータであって、上記数１または数２の距離、所要時間、通行料金および消費燃料のうち、経路探索条件に関係する項目に重み付けするものである。
【００４８】
すなわち、運転者または同乗者によって、”快適ボタン”が入力された場合には、探索する経路の所要時間と通行費用とのバランスを保つように、α，β，γおよびδの値が決定される。また、”時間ボタン”が入力された場合には、目的地まで移動するための所要時間が最短となるように、δ＝”０”として、α，βおよびγの値が決定される。また、”コストボタン”が入力された場合には、目的地までの移動費用が最小となるように、α＝”０”，δ＝”０”として、βおよびγの値が決定される。さらに、”快適ボタン”が入力された場合には、探索する経路を交通事情が良好な道路を優先的に選択するように、α＝”０”，β＝”０”として、γおよびδの値が決定される。
【００４９】
これら各パラメータの値を決定するにあたり、各パラメータの値は、以下に詳細に説明する制約１から制約３を満たすように決定される。なお、以下の説明においては、決定される各パラメータの組み合わせをパラメータセットという。
【００５０】
パラメータセットは、図４に示す制約１から制約３の要件を満足させるように決定される。これらの要件は、制約１が各パラメータ値の和を一定とすることあり、制約２が各パラメータ値を所定の変動幅内で変更することであり、制約３が所定の変動幅を標準偏差に基づいて決定することである。ここで、制約３の標準偏差は、例えば、運転者が自らの経験に基づいて、敢えて案内経路を逸脱して走行する頻度を経路案内装置２０が学習することにより、計算される標準偏差である。
【００５１】
この経路案内装置２０による学習について、以下に説明する。この経路案内装置２０による学習は、同装置２０が探索した案内経路（推奨経路）と、運転者が実際に走行した走行経路との差分に基づいて行われるものである。まず、学習の過程について説明する。経路案内装置２０は、後述するように、経路コストを計算し、運転者に対して案内経路（推奨経路）を探索する。この案内経路（推奨経路）の探索に際し、経路案内装置２０は、初回の探索には、初期値として予め設定されているパラメータセット（α_０，β_０，γ_０，δ_０）を利用して、案内経路（推奨経路）を探索する。
【００５２】
また、経路案内装置２０は、過去に計算した経路コスト計算回数が５回以下である場合には、学習による標準偏差がなく図４に示すΔが定義できないため、簡易的に、初期値として予め設定されているパラメータセットを構成する各値の５０％をΔと定義する。そして、経路案内装置２０は、この定義したΔを利用して、経路コスト計算を実行し、案内経路（推奨経路）を探索する。
【００５３】
さらに、経路案内装置２０は、過去に計算した経路コスト計算回数が６回以上である場合には、過去５回の経路コスト計算によって決定したパラメータセットに基づいて標準偏差すなわちΔを求め、Δを定義する。そして、経路案内装置２０は、以降、経路コスト計算を計算するごとにΔを求め、前回定義したΔを更新する。このように、標準偏差すなわちΔを繰り返し更新することにより、経路案内装置２０は、運転者の案内経路（推奨経路）に対する走行パターンを学習することができる。これにより、経路案内装置２０が探索する案内経路（推奨経路）に対して、運転者の走行パターンがより反映され、運転者にとって好適な案内経路（推奨経路）とすることができる。
【００５４】
次に、経路案内装置２０の学習方法について説明する。経路案内装置２０は、案内経路（推奨経路）と走行経路との差分から最適計算を実施してパラメータセット（α_ｉ，β_ｉ，γ_ｉ，δ_ｉ）を求める。すなわち、上記数１によって定義される経路コストＡにて、例えば、出発地から目的地間の経路距離、法定速度、道路種別、（推定）燃費は、車両の走行後において、各値が既知の値となる。また、経路コストＡは、パラメータセットの組み合わせによって変化するが、パラメータセットがドライバにとって最適に設定されていれば、経路コストＡが最小である案内経路（推奨経路）と走行経路とは一致する。このように、案内経路（推奨経路）と走行経路が一致する場合には、経路案内装置２０は、学習する必要がなくて、Δを「０」とする。
【００５５】
一方、案内経路（推奨経路）と走行経路とが一致しない場合には、経路案内装置２０は、パラメータセットすなわちα，β，γ，δを適宜変化させて、経路コストＡを最小とするα，β，γ，δを演算して求める。そして、経路案内装置２０は、演算して求めたα，β，γ，δをα_ｉ，β_ｉ，γ_ｉ，δ_ｉとし、ある案内経路（推奨経路）に対する学習結果パラメータセットとして蓄積しておく。そして、経路案内装置２０は、蓄積した学習結果パラメータセットが５セット以上蓄積され、かつ、同蓄積した学習結果パラメータセットのうち、異なる目的地までの案内経路（推奨経路）に対する学習パラメータセットが３セット以上含まれる場合には、下記数３および数４の演算を実施する。
【００５６】
【数３】

【００５７】
【数４】

【００５８】
ここで、Ｎは、蓄積した学習結果パラメータセットのセット数である。ここで、他のパラメータすなわちβ_ｉ，γ_ｉ，δ_ｉについても数３および数４に基づいて同様に演算されて、Δ_β，Δ_γ，Δ_δが演算されることはいうまでもない。そして、経路案内装置２０は、演算したΔ_α，Δ_β，Δ_γ，Δ_δを、上記した制約３のΔとして設定する。なお、運転者の走行経路に明らかに偏りがある場合は、例えば、「お好み走行モード」などを新たに設けて、α_ｉ，β_ｉ，γ_ｉ，δ_ｉを別途設定するようにすることも可能である。
【００５９】
そして、マイクロコンピュータ２１は、上記数１および数２に基づく経路コストの計算に併せて、α，β，γおよびδを制約１から制約３を満足させながらそれぞれ変更する。まず、マイクロコンピュータ２１は、車両の現在地から１番目のリンク１（以下、現在地からｉ番目のリンクをリンクｉという）について、記憶装置２２に予め設定されて記憶しているパラメータセットを利用して、経路コストＡ１を計算する。具体的に説明すると、マイクロコンピュータ２１は、前記ステップＳ１３にて記憶装置２２の所定記憶位置に記憶した経路探索条件情報を取得する。また、マイクロコンピュータ２１は、取得した経路探索条件情報が表す経路探索条件に対応するパラメータセットを記憶装置２２から取得する。
【００６０】
すなわち、前記ステップＳ１３にて、”効率ボタン”が選択されていれば、マイクロコンピュータ２１は、記憶装置２２から、図５に示すように、パラメータセットとして、α＝０．２，β＝０．３，γ＝０．３，δ＝０．２を取得する。また、”時間ボタン”が選択されていれば、パラメータセットとして、α＝０．２５，β＝０．５，γ＝０．２５，δ＝０を取得する。また、”コストボタン”が選択されていれば、パラメータセットとして、α＝０，β＝０．５，γ＝０．５，δ＝０を取得する。さらに、”快適ボタン”が選択されていれば、パラメータセットとして、α＝０，β＝０，γ＝０．５，δ＝０．５を取得する。なお、以下の説明においては、運転者または同乗者によって、”効率ボタン”が選択されているものとして説明する。
【００６１】
次に、マイクロコンピュータ２１は、記憶装置２２に記憶している地図データおよび通行状態情報を利用して、候補経路のリンク１に関する距離、法定速度、道路種別および推定燃費を表す各情報を取得する。そして、マイクロコンピュータ２１は、取得した各情報によって表される数値およびパラメータセットによって表されるパラメータ値を数１に代入して、リンク１の経路コストＡ１を計算する。
【００６２】
次に、マイクロコンピュータ２１は、リンク２の経路コストＡ２を数２に基づいて計算する。この場合においても、マイクロコンピュータ２１は、記憶装置２２から候補経路のリンク２に関する距離、法定速度、道路種別および推定燃費を表す各情報を取得する。そして、マイクロコンピュータ２１は、経路コストＡ１の計算に用いた各パラメータ値をα，β，γ，δの順に変更して経路コストＡ２を計算する。
【００６３】
すなわち、マイクロコンピュータ２１は、制約２および制約３に基づいてαを変更して最小となる経路コストＡ２を計算する。このとき、マイクロコンピュータ２１は、β，γ，δについて制約１から制約３を満足するように変更してαを決定し、経路コストＡ２が最小となるパラメータセットを決定する。以下、このαを変化させたときの経路コストを経路コストＡ２αという。
【００６４】
また、マイクロコンピュータ２１は、制約２および制約３に基づいてβを変更して最小となる経路コストＡ２を計算する。このとき、マイクロコンピュータ２１は、γ，δについて制約１から制約３を満足するように変更してβを決定し、経路コストＡ２が最小となるパラメータセットを決定する。以下、このβを変化させたときの経路コストを経路コストＡ２βという。なお、この場合においては、αの値は変化させない。
【００６５】
さらに、マイクロコンピュータ２１は、制約２および制約３に基づいてγを変更して最小となる経路コストＡ２を計算する。このとき、マイクロコンピュータ２１は、δについて制約１から制約３を満足するように変更してγを決定し、経路コストＡ２が最小となるパラメータセットを決定する。以下、このγを変化させたときの経路コストを経路コストＡ２γという。なお、この場合においては、αおよびβの値は変化させない。ここで、δは、決定されたα，βおよびγを利用して制約１に基づいて決定される。
【００６６】
そして、マイクロコンピュータ２１は、上記計算した経路コストＡ２α、Ａ２βおよびＡ２γのうち最小となる経路コストを選択し、この選択した経路コストを経路コストＡ２として決定する。このように、リンク２の経路コストＡ２を決定すると、マイクロコンピュータ２１は、リンク２の経路コスト計算と同様の計算を繰り返して、リンク３の経路コストＡ３、リンク４の経路コストＡ４、…、リンクｉの経路コストＡｉ、…、リンクｊすなわち目的地に接続するリンクの経路コストＡｊを計算する。
【００６７】
このように、一の候補経路の経路コストＡ１、…、経路コストＡｊを決定すると、マイクロコンピュータ２１は、決定した経路コストを平均処理することにより、この候補経路のトータルの経路コストＡを決定する。また、マイクロコンピュータ２１は、他の候補経路の経路コストも同様に計算して決定し、これら決定した複数の候補経路の経路コストのうち、最小となる候補経路を案内経路として決定する。そして、マイクロコンピュータ２１は、案内経路を決定すると、同決定した案内経路を表す案内経路情報を記憶装置２２の所定記憶位置に記憶して、ステップＳ１６に進む。
【００６８】
また、前記ステップＳ１３にて、運転者または同乗者により、所定の時間（例えば、１０ｓｅｃ程度）が経過するまでに経路探索条件が選択されなければ、マイクロコンピュータ２１は、「Ｎｏ」と判定して、ステップＳ１５に進む。ステップＳ１５においては、マイクロコンピュータ２１は、前回の経路案内プログラム実行時に運転者または同乗者によって選択され、記憶装置２２の所定記憶位置に記憶した経路探索条件に基づいて、目的地までの案内経路を探索する。ここで、ステップＳ１５における経路探索処理は、前記ステップＳ１４の経路探索処理と同様に、上記数１および数２に基づいて、リンクごとにパラメータセットを変化させて経路コストを計算する。そして、計算した経路コストが最小となるとなる候補経路を案内経路として決定し、決定した案内経路を表す案内経路情報を記憶装置２２の所定記憶位置に記憶して、ステップＳ１６に進む。
【００６９】
前記ステップＳ１４または前記ステップＳ１５の処理後、ステップＳ１６にて、マイクロコンピュータ２１は、運転者に対して、決定した案内経路の案内を開始する。具体的に説明すると、マイクロコンピュータ２１は、前記ステップＳ１４または前記ステップＳ１５の実行により、記憶装置２２の所定記憶位置に記憶した案内経路情報を表示装置２３に供給するとともに、液晶表示器上に案内画面を表示するように指示する。表示装置２３は、同指示に従って、記憶装置２２に記憶されている地図データを利用して、液晶表示器上に道路地図や背景を表示するとともに、供給された案内経路情報に基づく案内経路を表示する。また、マイクロコンピュータ２１は、案内経路情報の音声データを、スピーカ２６を介して再生し、運転者に対して、案内経路を音声によって案内する。
【００７０】
前記ステップＳ１６にて探索経路案内処理が実行された後、ステップＳ１７にて、マイクロコンピュータ２１は、車両が目的地に到着しているか否かを判定する。すなわち、マイクロコンピュータ２１は、位置検出器１０からの各検出値に基づいて、車両が目的地に到着していなければ、「Ｎｏ」と判定して、前記ステップＳ１６に戻り、探索経路案内処理を実行する。そして、マイクロコンピュータ２１は、車両が目的地に到着して「Ｙｅｓ」と判定されるまで繰り返し前記ステップＳ１６の探索経路案内処理を実行する。一方、車両が目的地に到着していると判定すると、「Ｙｅｓ」と判定してステップＳ１８に進み、運転者に対して、例えば、「目的地に到着しました。」などの音声案内を実行し、ステップＳ１９にて経路案内プログラムの実行を終了する。
【００７１】
以上の説明からも理解できるように、本第１実施形態によれば、運転者または同乗者は、経路探索条件を選択することができる。そして、マイクロコンピュータ２１は、選択された経路探索条件を反映すべく、パラメータセットを経路コスト計算において制約１から制約３を満たしながら変更することができる。このように、パラメータセットを変更して計算した経路コストが最小となる候補経路を案内経路として決定することにより、運転者または同乗者が希望する経路探索条件における経路コスト計算を最適化することができる。これにより、運転者または同乗者が希望する経路探索条件に最も合致した案内経路を探索することができて、案内経路を好適に提供することができる。
【００７２】
上記第１実施形態においては、車両に搭載された経路案内装置２０のマイクロコンピュータ２１がパラメータセットを構成する各パラメータ値を変更して候補経路の経路コストを計算した。そして、計算した経路コストが最小となる候補経路を、運転者または同乗者が選択した経路探索条件に最も適した案内経路として、案内するように実施した。しかしながら、経路案内装置２０がセンターと通信可能であり、経路案内装置２０が案内経路を表す案内経路情報を受信して案内経路を案内する場合には、センターにて、パラメータセットを構成する各パラメータ値を変更して経路コストを計算し、最適な案内経路を決定するように実施してもよい。以下、この第２実施形態について説明するが、上記第１実施形態と同一部分には同一の符号を付して、その説明を省略する。
【００７３】
この第２実施形態に係る経路案内装置２０は、図６に示すように、案内経路情報を提供するセンター３０と通信可能とされている。そして、センター３０は、交通情報を提供する交通情報センター４０と通信可能に接続されている。この第２実施形態に係る経路案内装置２０は、図７に示すように、上記第１実施形態の交通情報受信機２７が省略されて、通信装置２８が設けられている。通信装置２８は、センター３０との無線交信を可能とするものであり、無線交信するアンテナ２８ａが接続されている。
【００７４】
センター３０は、図８に示すように、互いに通信可能に接続された制御装置３１、記憶装置３２、通信装置３３および外部通信インターフェース３４（以下、外部通信Ｉ／Ｆ３４という）を備えている。制御装置３１は、ＣＰＵ、ＲＯＭ、ＲＡＭ、タイマなどを主要構成部品とするもので、図９のセンター側プログラムを含む各種プログラムの実行により、記憶装置３２、通信装置３３および外部通信Ｉ／Ｆ３４の作動を統括的に制御する。そして、経路案内装置２０より受信した車両の現在地から目的地までの経路探索および提供などの処理を実行する。
【００７５】
記憶装置３２は、ハードディスク、ＣＤ−ＲＯＭ、ＤＶＤ−ＲＯＭなどの記録媒体および同記録媒体のドライブ装置を含むものであり、制御装置３１で実行される前記プログラムを含む各種プログラムおよび各種データを記憶している。また、記憶装置３２のハードディスク内には、全国の最新かつ詳細な地図データを記憶しておくための地図データベース３２ａが構築されている。ここで、地図データベース３２ａに記憶されている地図データは、上述した地図データと同様に構成されている。
【００７６】
通信装置３３は、経路案内装置２０と無線通信可能とするものである。そして、通信装置３３には、無線交信するためのアンテナ３３ａが接続されている。ここで、経路案内装置２０とセンター３０との間の交信は、アンテナ２８ａおよびアンテナ３３ａを用いて無線で行われるものであるが、通常の方法で行われて特徴を有するものではない。したがって、以降の説明において、受信、送信などと単にいう場合にはこれらに交信方法の適当な方法を採用しているものとする。外部通信Ｉ／Ｆ３４は、通信回線ＮＷに接続しており、交通情報センター４０から提供される交通情報や渋滞情報を制御装置３１に提供する。
【００７７】
次に、上記のように構成した第２実施形態の動作について説明する。運転者によって図示しないイグニッションスイッチがオン状態とされると、経路案内装置２０のマイクロコンピュータ２１は、図８に示す経路案内装置側のプログラムの実行をステップＳ１００にて開始する。
【００７８】
そして、ステップＳ１３にて、経路探索条件が選択されていれば、マイクロコンピュータ２１は「Ｙｅｓ」と判定して、ステップＳ１０１に進む。ステップＳ１０１においては、マイクロコンピュータ２１は、前記ステップＳ１１にて検出した現在地を表す現在地情報、ステップＳ１２にて入力された目的地を表す目的地情報および前記ステップＳ１３にて選択された経路探索条件を表す経路探索条件情報をセンター３０に送信する。
【００７９】
また、ステップＳ１３にて、所定時間内に経路探索条件が選択されていなければ、マイクロコンピュータ２１は「Ｎｏ」と判定して、ステップＳ１０２に進む。ステップＳ１０２においては、マイクロコンピュータ２１は、現在地情報、目的地情報および前回のプログラム実行時に運転者または同乗者によって選択されて記憶装置２２の所定記憶位置に記憶した経路探索条件を表す経路探索条件情報をセンター３０に送信する。
【００８０】
センター３０においては、制御装置３１が、ステップＣ１０にて、前記ステップＳ１０１またはステップＳ１０２の送信処理によって送信された各情報を受信するとともに、同受信した各情報を記憶装置３２の所定記憶位置に記憶する。そして、各情報を記憶装置３２に記憶すると、ステップＣ１１に進む。
【００８１】
ステップＣ１１においては、制御装置３１は、前記ステップＣ１０にて受信した車両の現在地情報、目的地情報および経路探索条件情報に基づいて、車両の現在地から目的地までの案内経路を探索する。この制御装置３１による案内経路の探索は、実質的に上記第１実施形態に係る経路案内装置２０の案内経路の探索と同一であるため、その詳細な説明は省略するが、以下に簡単に説明する。
【００８２】
制御装置３１は、まず、外部通信Ｉ／Ｆ３４を介して、交通情報センター４０から交通情報や渋滞情報を取得するとともに、前記受信した経路探索条件情報によって表される経路探索条件に基づいて、車両の現在地から目的地までの複数の候補経路を探索する。次に、制御装置３１は、上記数１および数２を利用して、複数探索した候補経路の経路コストをそれぞれ計算する。制御装置３１は、記憶装置３２に予め設定されて記憶している図５に示すパラメータセットを取得するとともに、地図データベース３２ａに記憶している地図データを利用して、候補経路のリンク１に関する各情報を取得する。そして、制御装置３１は、取得した各情報およびパラメータセットを上記数１に代入して、リンク１に経路コストＡ１を計算する。
【００８３】
次に、制御装置３１は、リンク２の経路コストを数２に基づいて計算する。このとき、制御装置３１は、経路コストＡ１の計算に用いたパラメータセットの各パラメータ値を変更して経路コストＡ２を計算する。すなわち、制御装置３１は、パラメータα，β，γおよびδをそれぞれ変更したときの経路コストＡ２α、Ａ２βおよびＡ２γを比較して、最小となる経路コストを選択して、リンク２の経路コストＡ２を決定する。そして、制御装置３１は、目的地に接続するリンクｊの経路コストＡｊまで決定し、これら決定した経路コストを平均処理することにより、この候補経路のトータルの経路コストＡを決定する。また、制御装置３１は、他の候補経路についても同様に、トータルの経路コストを決定し、これら決定したトータルの経路コストを比較して、経路コストが最小となる候補経路を案内経路として決定する。このように、案内経路を決定すると、制御装置３１は、同決定した案内経路を表す案内経路情報を記憶装置３２の所定記憶位置に記憶して、ステップＣ１２に進む。
【００８４】
ステップＣ１２においては、制御装置３１は、前記ステップＣ１１にて記憶した案内経路情報を経路案内装置２０に送信する。すなわち、制御装置３１は、記憶装置３２を利用して、記憶した案内経路情報を取得するとともに、同取得した案内経路情報を通信装置３３に供給する。通信装置３３は、供給された案内経路情報をアンテナ３３ａを介して、経路案内装置２０に送信する。
【００８５】
経路案内装置２０においては、マイクロコンピュータ２１が、ステップＳ１０３にて、前記ステップＣ１２の送信処理によって送信された案内経路情報を通信装置２８を介して受信する。そして、マイクロコンピュータ２１は、受信した案内経路情報を記憶装置２２の所定記憶位置に記憶して、ステップＳ１６に進む。
【００８６】
以上の説明からも理解できるように、この第２実施形態においても、運転者または同乗者は、経路探索条件を選択することができる。そして、センター３０の制御装置３１は、受信した経路探索条件情報により表される経路探索条件を反映すべく、パラメータセットを経路コスト計算において制約１から制約３を満たしながら変更することができる。このように、パラメータセットを変更して計算した経路コストが最小となる候補経路を案内経路として決定することにより、運転者または同乗者が希望する経路探索条件における経路コスト計算を最適化することができる。これにより、運転者または同乗者が希望する経路探索条件に最も合致した案内経路を探索することができて、案内経路を好適に提供することができる。
【００８７】
ここで、上記第１実施形態および第２実施形態においては、運転者または同乗者の選択可能な経路探索条件を、”効率”、”時間”、”コスト”および”快適”として実施したが、本発明の目的を逸脱しない限り、これらの項目に限定されないことはいうまでもない。同様に、上記第１実施形態および第２実施形態においては、経路コストの計算において、パラメータセットを構成するパラメータをα，β，γおよびδとして実施したが、本発明の目的を逸脱しない限り、これらのパラメータに限定されないことはいうまでもない。さらに、上記第１実施形態および第２実施形態においては、各パラメータを変化させるときに、それぞれのパラメータを一つずつ変化させて、最小となる経路コストを計算するように実施したが、他の方法（例えば、動的計画法など）を利用して、経路コストを計算することも可能である。
【図面の簡単な説明】
【図１】本発明の第１実施形態に係る経路案内装置の概略を示すブロック図である。
【図２】図１の経路案内装置にて実行される第１実施形態に係る経路案内プログラムのフローチャートである。
【図３】経路探索条件を説明するための図である。
【図４】パラメータの制約を説明するための図である。
【図５】記憶装置に記憶されているパラメータセットを説明するための図である。
【図６】本発明の第２実施形態に係る経路案内システムの全体を示す概略ブロック図である。
【図７】図６の経路案内装置の概略を示すブロック図である。
【図８】図６のセンターの概略を示すブロック図である。
【図９】図６の経路案内装置およびセンターにて実行される第２実施形態に係る経路案内プログラムのフローチャートである。
【符号の説明】
１０…位置検出器、２０…経路案内装置、２１…マイクロコンピュータ、２２…記憶装置、２７…交通情報受信機、２８…通信装置、３０…センター、３１…制御装置、３２…記憶装置、３３…通信装置、４０…交通情報センター[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a route guidance device, a center, and a route search method for searching a route between predetermined points designated by a user and guiding the searched route to a user.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, a delivery / allocation planning apparatus and method for searching for and planning an optimal delivery route as shown in Patent Document 1 are known. This conventional delivery / vehicle allocation planning apparatus and method uses the dynamic planning method for the delivery route to each delivery destination determined based on the demand prediction result and various data, and provides the most delivery cost. The best route to get cheaper is to be determined.
[0003]
Conventionally, for example, a navigator device as shown in Patent Document 2 is also known. In this conventional navigator device, a weighting factor can be set for each of the distance from the departure point to the destination, the required time to the destination, and the travel cost to the destination. Then, using the set weighting coefficient, the distance, the required time, and the travel cost are weighted and added, and a route that minimizes the added value is displayed.
[0004]
Conventionally, for example, an in-vehicle navigation device as shown in Patent Document 3 is also known. This navigation apparatus holds in advance a plurality of calculation formulas used for the weighting coefficient of each heuristic term used for the evaluation function or the evaluation function. When performing the search, an appropriate or suboptimal route is searched in a short time by selecting an appropriate weighting factor or calculation formula according to the road conditions of the read map data and the search conditions.
[0005]
Furthermore, conventionally, for example, a route search device as shown in Patent Document 4 is also known. This route search device searches a plurality of routes with a lower priority in order of decreasing the numerical value of the comprehensive evaluation function, and arbitrarily selects one of them. Then, a corresponding comparison is made between the cost value of each parameter in the selected route and the cost value of each parameter in another route. As a result of this comparison, the comprehensive evaluation function is rewritten so that the weight of the parameter having a large cost value in the selected route is decreased and the weight of the parameter having a small cost value is increased.
[0006]
[Patent Document 1]
JP 2002-183264 A
[Patent Document 2]
JP-A-1-136300
[Patent Document 3]
JP-A-8-201087
[Patent Document 4]
Japanese Patent Laid-Open No. 5-224601
[0007]
[Problems to be solved by the invention]
In each of the above conventional devices, when searching for a route or a route, a search condition preset by the user is selected, and an optimum route or route is searched based on the selected search condition. . For this reason, for example, when a search condition “highway priority” is selected as a search condition set in advance by the user, each of the conventional devices searches for a route passing through the interchange of the highway around the destination. can do. In this case, if the destination and the interchange are close to each other, the user can travel to the destination suitably because the required time to the destination is short.
[0008]
However, if the destination is far from the interchange, the user may have to travel on a road with poor traffic conditions from the expressway interchange to the destination. In this case, each of the above-described conventional devices guides a route that requires a long travel time to the destination and costs travel, despite using the highway. On the other hand, if the user is familiar with the destination area, he / she can get off the expressway halfway and use a bypass or the like with good road conditions to travel on a route that shortens the required time and reduces the travel cost. There is a case. For this reason, it is desired that the guide route from the departure point to the destination is searched as a guide route that reduces the required time and travel cost through the entire route and has high movement efficiency to the user's destination.
[0009]
SUMMARY OF THE INVENTION
The present invention has been made in order to cope with the above-described problems, and an object of the present invention is to provide a route guidance device that searches for an optimal route that satisfies a user's desired route search condition and that has high user movement efficiency. It is to provide a route search method.
[0010]
A feature of the present invention is that a vehicle can travel in a route guidance device that searches a guidance route from a current location of a vehicle to a destination input by a user of the vehicle and guides the guidance route to the user of the vehicle. Storage means for storing the attribute of the road together with map data of a road, search condition selection means for selecting a search condition related to a route search from the current location of the vehicle to the destination, operated by a user of the vehicle, Candidate route search means for searching for a plurality of candidate routes from the current position of the vehicle to the destination using the map data stored in the storage means, and the search conditions selected by the search condition selection means as the candidate route search Including at least a plurality of parameters reflected in the candidate route searched by the means and attributes stored in the storage means of the roads constituting the candidate route. And a route cost calculation unit that calculates a route cost that represents the priority of the candidate route that matches the search condition, and the plurality of parameters are each changed in accordance with the calculation of the route cost by the route cost calculation unit. A guide that compares the parameter costs of the plurality of candidate routes calculated by the route cost calculating unit with the parameter changing unit that changes by the width, and determines a candidate route having the smallest route cost among the route costs as a guide route And a route comparison / determination means.
[0011]
In this case, the vehicle further comprises a traffic condition acquisition unit that acquires traffic condition information related to the traffic condition of the road from the outside, and the candidate route search unit uses the traffic condition information acquired by the traffic condition acquisition unit, and A plurality of candidate routes may be searched. The road attributes may include at least a type of the road, a distance of the road, a legal speed of the road, and a cost required to pass the road. The parameter changing means may optimize and change the plurality of parameters based on dynamic programming. The parameter changing means may change the sum of the plurality of parameters as constant. Further, the predetermined fluctuation range may be a standard deviation calculated based on a difference between a guide route determined by the guide route comparison and determination unit and a travel route actually traveled by the user of the vehicle.
[0012]
Another feature of the present invention is that a search is made for a guide route from the current location of the vehicle to a destination with respect to an external vehicle, and the center is provided with the searched guide route to the vehicle. Receiving means for receiving current location information representing the current location of the vehicle, destination information representing the destination, and search condition information representing a search condition for route search from the current location to the destination, and map data of a road on which the vehicle can travel And the present location represented by the present location information using the map data stored in the storage means based on the present location information and the destination information received by the receiving means, the storage means for storing the attribute of the road A candidate route searching means for searching a plurality of candidate routes from the destination to the destination represented by the destination information, and the search condition information received by the receiving means. A candidate that matches the search condition, including at least a plurality of parameters that reflect the search condition that is reflected in the candidate route searched by the candidate route search means and the attribute stored in the storage means of the road that constitutes the candidate route A route cost calculating unit that calculates a route cost that represents a priority of the route, a parameter changing unit that changes the plurality of parameters with a predetermined fluctuation range in addition to the calculation of the route cost of the route cost calculating unit; A guide route comparison / determination unit that compares route costs of the plurality of candidate routes calculated by a route cost calculation unit, and determines a candidate route having a minimum route cost among the route costs as a guide route; and the guide route comparison Guide route information transmitting means for transmitting guide route information representing the guide route determined by the determining means to the external vehicle is provided. There is also to be had.
[0013]
In this case, the vehicle further comprises a traffic condition acquisition unit that acquires traffic condition information related to the traffic condition of the road from the outside, and the candidate route search unit uses the traffic condition information acquired by the traffic condition acquisition unit, and A plurality of candidate routes may be searched. The road attributes may include at least a type of the road, a distance of the road, a legal speed of the road, and a cost required to pass the road. The parameter changing means may optimize and change the plurality of parameters based on dynamic programming. The parameter changing means may change the sum of the plurality of parameters as constant. Further, the predetermined fluctuation range may be a standard deviation calculated based on a difference between a guide route determined by the guide route comparison and determination unit and a travel route on which the external vehicle actually travels.
[0014]
Further, when the present invention is viewed from another point of view, a feature of the present invention is that a vehicle stored in advance in a route search method for searching for a guide route from the current location of the vehicle to a destination input by a user of the vehicle. Search for a plurality of candidate routes from the current location of the vehicle to the destination using the map data of the road where the vehicle can travel, and search for a route search from the current location of the vehicle to the destination selected by the user of the vehicle A route cost that represents a priority of a candidate route that matches the search condition includes at least a plurality of parameters that reflect a condition on the candidate route and a prestored attribute of a road that constitutes the candidate route. The candidate having the smallest route cost among the same route costs by calculating by changing a plurality of parameters, comparing the route costs of the plurality of candidate routes calculated. In that so as to determine the road as the guidance route.
[0015]
In this case, further, it is preferable to obtain the traffic condition information regarding the traffic condition of the road from the outside, and search for the plurality of candidate routes using the acquired traffic condition information. The road attributes may include at least a type of the road, a distance of the road, a legal speed of the road, and a cost required to pass the road. The plurality of parameters may be optimized and changed based on dynamic programming. The plurality of parameters may be changed with a sum of the plurality of parameters being constant. Further, the plurality of parameters may be changed within a standard deviation calculated based on a difference between the determined guide route and a travel route actually traveled by a user of the vehicle.
[0016]
Another feature of the present invention is that the route guidance device detects a route search method in which a center capable of communicating with a route guidance device mounted on a vehicle searches for a guidance route from the current location of the vehicle to a destination. Centering the present location information representing the current location of the vehicle, the destination information representing the destination input by the user of the vehicle, and the route search condition information representing the search conditions for the route search from the current location to the destination selected by the user The center receives the transmitted current location information, destination information and route search condition information, and is capable of traveling a vehicle stored in advance based on the received current location information and destination information. A plurality of candidate routes from the current location of the vehicle to the destination are searched using road map data, and are represented by the received route search condition information. A route cost that represents at least a plurality of parameters that reflect the search condition to the candidate route and a prestored attribute of the road that constitutes the candidate route, and represents the priority of the candidate route that matches the search condition , Changing the plurality of parameters, comparing the calculated route costs of the plurality of candidate routes, and determining a candidate route having the minimum route cost among the route costs as a guide route, The guide route information indicating the determined guide route may be transmitted to the route guide device.
[0017]
In this case, the center may further acquire the traffic state information regarding the road traffic state from the outside, and search for the plurality of candidate routes using the acquired traffic state information. The road attributes may include at least a type of the road, a distance of the road, a legal speed of the road, and a cost required to pass the road. The plurality of parameters may be optimized and changed based on dynamic programming. The plurality of parameters may be changed with a sum of the plurality of parameters being constant. Further, the plurality of parameters may be changed within a standard deviation calculated based on a difference between the determined guide route and a travel route actually traveled by a user of the vehicle.
[0018]
According to these, the route guidance device or the center can calculate the route cost while changing each of the plurality of parameters reflecting the search condition selected by the user. For this reason, if the search condition selected by the user is, for example, “the required time is short and the travel cost is low”, the route guidance device or the center sets the required time among a plurality of parameters reflecting the search condition. It is possible to calculate the route cost of the candidate route by changing the parameter to be reflected and the parameter to reflect the travel time larger (or smaller). Then, the candidate route that minimizes the route cost to the destination can be determined as the guide route.
[0019]
Thereby, the route guidance device or the center calculates the route cost by changing the parameter value optimally so as to satisfy the search condition selected by the user in the entire route from the current location of the vehicle to the destination. As a result, the determined guide route can be a guide route that uses a bypass with good road conditions from the interchange to the destination after getting off at the interchange of the highway far from the destination. Therefore, the user can travel to the destination suitably by reducing the time required for traveling to the destination and the travel cost.
[0020]
In addition, the route guidance device or the center can search for candidate routes by excluding roads where traffic jams or accidents occur by receiving traffic condition information from the outside. As a result, the user can travel on a guide route composed only of roads in which no traffic jams or accidents occur, and can travel appropriately.
[0021]
In addition, by optimizing and changing a plurality of parameters based on the dynamic programming method (DP method), it is possible to reflect the conditions desired by the user and reflect them in the guide route. Further, by changing each parameter with the sum of a plurality of parameters being constant, the search condition selected by the user can be reflected in the guidance route in a well-balanced manner. That is, an extreme change of one parameter can be prevented by changing the parameter with a predetermined fluctuation range while keeping the sum of a plurality of parameters constant. For this reason, even if the search condition selected by the user is, for example, a search condition that reduces traffic costs, it is possible to effectively prevent searching for a route that extremely reflects the search condition, such as by always excluding toll roads. be able to.
[0022]
Furthermore, the fluctuation range of a plurality of parameters can be set as a standard deviation based on the difference between the guide route and the travel route. As a result, for example, the user has many opportunities to travel on a route that he / she knows well and does not travel on the guide route. For example, the user can learn a user-specific travel pattern and search for a guide route that reflects the user's travel pattern. can do. For this reason, the user can travel along the guide route suitably.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a position detector 10 mounted on a vehicle according to the present embodiment and a route guidance device 20 connected to the detector 10.
[0024]
The position detector 10 includes a GPS (Global Positioning System) receiver 11, a gyroscope 12, and a vehicle speed sensor 13, and is used to detect the current location of the vehicle. The GPS receiver 11 receives a radio wave for detecting the current location of the vehicle from the satellite, and detects and outputs the position of the vehicle as coordinate data. The gyroscope 12 detects and outputs the turning speed of the vehicle for detecting the traveling direction of the vehicle. The vehicle speed sensor 13 detects and outputs the traveling speed of the vehicle. The detected values output from the GPS receiver 11, the gyroscope 12, and the vehicle speed sensor 13 are supplied to the microcomputer 21 of the route guidance device 20 described later, so that the microcomputer 21 detects the current location of the vehicle. can do.
[0025]
The route guidance device 20 includes a microcomputer 21, and a storage device 22, a display device 23, and an operation switch group 24 are connected to the microcomputer 21. The microcomputer 21 includes CPU, ROM, RAM, and the like as main components. By executing the route guidance program shown in FIG. 2, the current location of the vehicle is detected and the route from the current location of the vehicle to the destination is searched and searched. Processing such as route guidance according to the route is executed.
[0026]
The storage device 22 includes a recording medium such as a hard disk, a nonvolatile RAM, a CD-ROM, a DVD-ROM, and a drive device for the recording medium, and stores the program executed by the microcomputer 21 and various data. To do. The recording medium of the storage device 22 includes map data used for the route search process of the microcomputer 21, voice data used for the route guidance process, and information related to vehicle travel (such as fuel consumption information and travel route information). Stored in advance.
[0027]
Here, the map data will be described. The map data is composed of a plurality of road data and background data related to the background such as mountains and the sea. The road data consists of a set of a plurality of link data 1, 2,..., And each link data includes a link data name representing a link connecting two nodes on the road map, a road type (toll road) , National roads, prefectural roads, and the like) and node data representing the position of the node. Nodes are determined in advance, such as where roads intersect, interchanges and junctions on toll roads, where roads are bent, where road width changes, where road types change, and where the degree of congestion changes. ing.
[0028]
The display device 23 is configured by a liquid crystal display (not shown) and the like, and displays a road map, a current location of the vehicle, a guidance route, various operation instruction buttons, and the like. The operation switch group 24 gives various instructions (for example, input of a destination and selection of a route search condition) from the outside to the microcomputer 21 by a driver or a passenger, and the liquid crystal display in the display device 23 A plurality of operation switches provided in the periphery of the display device and a touch switch configured integrally with the liquid crystal display of the display device 23. This touch switch is provided on the back side of the liquid crystal display, and is provided for detecting a touch operation position on the liquid crystal display by the driver or a passenger.
[0029]
As shown in FIG. 3, the operation switch group 24 includes a selection button group 24 a that is displayed on the liquid crystal display of the display device 23 and for selecting a search condition for route search. The selection button group 24a includes “efficiency buttons”, “time buttons”, cost buttons ”, and“ comfort buttons ”.
[0030]
The “efficiency button” is a button for instructing a route search under the condition that both the required time to the destination and the necessary toll are small. The “time button” is a button for instructing a route search under the condition that the required time to the destination is minimized. The “cost button” is a button for instructing a route search under the condition that the required toll and the fuel consumption of the vehicle detected by a known method are reduced. The “comfortable button” is a button for preferentially selecting a traffic situation, that is, a road having a large road width or a road in which no traffic jam occurs, or instructing a route search under a condition for reducing the number of right turns.
[0031]
The microcomputer 21 is also connected with a voice recognition unit 25, a speaker 26, and a traffic information receiver 27. The voice recognition unit 25 is used in place of the operation switch group 24, and has a built-in microphone. The voice recognition unit 25 recognizes a voice instruction from a driver or a passenger and gives the instruction contents to the microcomputer 21. is there. The speaker 26 provides the driver with guidance for the searched guidance route by voice.
[0032]
The traffic information receiver 27 includes a receiving antenna 27a and receives traffic state information such as traffic jam information and accident information provided from the outside (for example, a traffic information center). The traffic information receiver 27 supplies the acquired traffic state information to the storage device 22 via the microcomputer 21, thereby storing the traffic state information in a predetermined storage position of the storage device 22. . Here, as the traffic information receiver 27, for example, a VICS (Vehicle Information and Communication System) receiver that receives an FM radio wave, a radio wave beacon transmitted from a transmitter installed along a road, or an optical beacon is adopted. be able to. Or LCX (Leaky) buried along the road
An LCX leaky radio wave receiver that receives radio waves leaked from a cable can be used.
[0033]
Next, the operation of the first embodiment configured as described above will be described. When the driver turns on an ignition switch (not shown), the microcomputer 21 of the route guidance device 20 repeatedly executes the route guidance program shown in FIG. 2 every predetermined short time.
[0034]
This main program is started in step S10. In step S11, the microcomputer 21 detects the current location of the vehicle based on the detection value output from the position detector 10, and presents current location information (for example, coordinate data) representing the detected current location to a RAM (not shown). Memorize temporarily.
[0035]
Subsequently, in step S12, the microcomputer 21 prompts the driver or passenger to input a destination. That is, the microcomputer 21 instructs the display device 23 to display a destination input screen on a liquid crystal display (not shown). The display device 23 displays a predetermined destination input screen on the liquid crystal display according to the instruction. A driver or a passenger touches the operation instruction button of the operation switch group 24 displayed at a predetermined position of the liquid crystal display to display a map around the destination, a telephone number, a facility name, etc. Enter the destination by displaying the screen for entering. As described above, when the destination is input, the microcomputer 21 temporarily stores the destination information (for example, coordinate data) indicating the input destination in a RAM (not shown), and proceeds to step S13.
[0036]
In step S13, the microcomputer 21 determines whether or not a search condition for searching for a route is input by the driver or the passenger. Specifically, the microcomputer 21 displays a route search condition setting screen on the liquid crystal display on the display device 23 when the destination is input by the driver or the passenger in step S12. To instruct.
[0037]
In accordance with the instruction, the display device 23 displays a route search condition setting screen on the liquid crystal display as shown in FIG. A driver or a passenger selects a route search condition by touching a button representing a desired search condition in the displayed selection button group 24a. Here, when the route search condition is selected by the driver or the passenger, the microcomputer 21 updates and stores the route search condition information representing the selected route search condition in a predetermined storage position of the storage device 22. Thus, when the route search condition is selected, the microcomputer 21 determines “Yes” in step S13 and proceeds to step S14.
[0038]
In step S12 and step S13, the driver or passenger can use the voice recognition unit 25 to input a destination or select a route search condition. That is, the driver or the passenger speaks the microphone of the voice recognition unit 25 with, for example, “XX shopping center” or the like to input the destination, or pronounces “comfortable” or the like to obtain the route search condition. It is also possible to select. In this case, the voice recognition unit 25 recognizes the voice input content of the driver or passenger and supplies the same content to the microcomputer 21. Thereby, the microcomputer 21 can recognize the destination and the route search condition, and can execute the processes of step S12 and step S13.
[0039]
In step S14, the microcomputer 21 searches for the guidance route to the destination input in step S12 based on the route search condition input in step S13. This route search process will be specifically described.
[0040]
First, the microcomputer 21 searches for a plurality of routes (hereinafter referred to as candidate routes) to the destination input by the driver or the passenger based on the route search condition selected in step S13. To do.
[0041]
That is, if the “efficiency button” is selected by the driver or the passenger, the microcomputer 21 searches for a plurality of candidate routes from the current location to the destination using, for example, a national road and a highway. If the “time button” is selected, the microcomputer 21 searches for a plurality of candidate routes from the current location to the destination using, for example, a road (highway) with a high legal speed. If the “cost button” is selected, the microcomputer 21 uses a road other than the toll road, for example, to search for a plurality of candidate routes from the current location to the destination. Further, if the “comfort button” is selected, the microcomputer 21 has, for example, no traffic congestion and a large number of road lanes based on the traffic information acquired via the traffic information receiver 27. A plurality of candidate routes from the current location to the destination are searched using the road.
[0042]
Next, the microcomputer 21 calculates the route cost of the searched candidate routes. The calculated route cost is an index representing a route that matches the route search condition selected by the driver or the passenger, and represents the priority of the route. Then, the microcomputer 21 finally determines the route that minimizes the route cost calculated for each candidate route as the guide route. Hereinafter, the processing of the microcomputer 21 for finally determining the guidance route will be described in detail.
[0043]
The microcomputer 21 calculates the route cost A of the candidate route using the following equations 1 and 2.
[0044]
[Expression 1]

[0045]
[Expression 2]

[0046]
Here, the route cost Ai is a route cost to the link i, and the route cost Ai + 1 is a route cost to the next link (link i + 1). D _i And d _{i + 1} Is the path distance of link i and link i + 1, and v _i And v _{i + 1} Is the legal speed of link i and link i + 1. E _i And e _{i + 1} Is the road type of link i and link i + 1, and f _i And f _{i + 1} Is the estimated fuel consumption of the link i and link i + 1 vehicles. Also, Σd _i And Σd _{i + 1} Is the total distance from the current location to link i and link i + 1, Σ (d _i / V _i ) And Σ (d _{i + 1} / V _{i + 1} ) Is the total required time from the current location to link i and link i + 1, Σ (e _i Xd _i ) And Σ (e _{i + 1} Xd _{i + 1} ) Is the total toll from the current location to link i and link i + 1, Σ (f _i Xd _i ) And Σ (f _{i + 1} Xd _{i + 1} ) Represents the total fuel consumption from the current location to link i and link i + 1.
[0047]
Α, β, γ, and δ are parameters for reflecting the route search condition input by the driver or the passenger to the candidate route, and the distance, required time, toll, Of the fuel consumption, items related to the route search condition are weighted.
[0048]
That is, when a “comfort button” is input by a driver or a passenger, the values of α, β, γ, and δ are determined so that the required time of the route to be searched and the travel cost are kept in balance. The When the “time button” is input, the values of α, β, and γ are determined with δ = “0” so that the time required for moving to the destination is the shortest. When the “cost button” is input, the values of β and γ are determined as α = “0” and δ = “0” so that the travel cost to the destination is minimized. Furthermore, when the “comfort button” is input, α = “0”, β = “0”, and γ and δ are set so that the road to be searched is preferentially selected as a road with good traffic conditions. The value is determined.
[0049]
In determining the values of these parameters, the values of the parameters are determined so as to satisfy the constraints 1 to 3 described in detail below. In the following description, the determined combination of parameters is referred to as a parameter set.
[0050]
The parameter set is determined so as to satisfy the requirements of constraints 1 to 3 shown in FIG. These requirements are that constraint 1 makes the sum of each parameter value constant, constraint 2 changes each parameter value within a predetermined fluctuation range, and constraint 3 changes the predetermined fluctuation range to a standard deviation. Is to make a decision based on. Here, the standard deviation of the restriction 3 is a standard deviation calculated by the route guidance device 20 learning the frequency with which the driver deviates from the guidance route based on his / her own experience, for example. .
[0051]
Learning by the route guidance device 20 will be described below. The learning by the route guidance device 20 is performed based on the difference between the guidance route (recommended route) searched by the device 20 and the travel route actually traveled by the driver. First, the learning process will be described. As will be described later, the route guidance device 20 calculates a route cost and searches for a guidance route (recommended route) for the driver. When searching for this guidance route (recommended route), the route guidance device 20 performs the initial search for a parameter set (α ₀ , Β ₀ , Γ ₀ , Δ ₀ ) To search for a guidance route (recommended route).
[0052]
In addition, when the number of route cost calculations calculated in the past is 5 or less, the route guidance device 20 has no standard deviation due to learning and cannot define Δ shown in FIG. 50% of each value constituting the set parameter set is defined as Δ. Then, the route guidance device 20 performs route cost calculation using the defined Δ and searches for a guidance route (recommended route).
[0053]
Furthermore, when the number of route cost calculations calculated in the past is 6 or more, the route guidance device 20 obtains a standard deviation, that is, Δ based on the parameter set determined by the past five route cost calculations, and Δ Define. Thereafter, the route guidance device 20 obtains Δ every time route cost calculation is performed, and updates Δ defined previously. Thus, by repeatedly updating the standard deviation, that is, Δ, the route guidance device 20 can learn a traveling pattern for the driver's guidance route (recommended route). Thereby, the driving pattern of the driver is more reflected on the guidance route (recommended route) searched by the route guidance device 20, and the guidance route (recommended route) suitable for the driver can be obtained.
[0054]
Next, a learning method of the route guidance device 20 will be described. The route guidance device 20 performs an optimal calculation from the difference between the guidance route (recommended route) and the travel route, and sets the parameter set (α _i , Β _i , Γ _i , Δ _i ) That is, at the route cost A defined by the above equation 1, for example, the route distance from the departure point to the destination, the legal speed, the road type, and the (estimated) fuel consumption are known after the vehicle travels. Value. In addition, the route cost A varies depending on the combination of parameter sets, but if the parameter set is optimally set for the driver, the guide route (recommended route) with the smallest route cost A matches the travel route. As described above, when the guide route (recommended route) and the travel route coincide with each other, the route guide device 20 does not need to learn and sets Δ to “0”.
[0055]
On the other hand, when the guide route (recommended route) and the travel route do not match, the route guide device 20 appropriately changes the parameter set, that is, α, β, γ, δ, to minimize the route cost A, α, Calculate β, γ, and δ. Then, the route guidance device 20 calculates α, β, γ, and δ obtained by calculation as α _i , Β _i , Γ _i , Δ _i And stored as a learning result parameter set for a certain guide route (recommended route). The route guidance device 20 accumulates five or more accumulated learning result parameter sets, and among the accumulated learning result parameter sets, there are three learning parameter sets for guidance routes (recommended routes) to different destinations. If more than one set is included, the following equations 3 and 4 are performed.
[0056]
[Equation 3]

[0057]
[Expression 4]

[0058]
Here, N is the number of accumulated learning result parameter sets. Where the other parameter, β _i , Γ _i , Δ _i Is similarly calculated based on Equation 3 and Equation 4, and Δ _β , Δ _γ , Δ _δ Needless to say, is calculated. The route guidance device 20 calculates the calculated Δ _α , Δ _β , Δ _γ , Δ _δ Is set as Δ of the constraint 3 described above. If the driver's travel route is clearly biased, for example, a “favorite travel mode” is newly provided, and α _i , Β _i , Γ _i , Δ _i Can also be set separately.
[0059]
The microcomputer 21 changes α, β, γ, and δ while satisfying the constraints 1 to 3 in accordance with the calculation of the route cost based on the above equations 1 and 2. First, the microcomputer 21 uses a parameter set that is preset and stored in the storage device 22 for the first link 1 from the current location of the vehicle (hereinafter, the i-th link from the current location is referred to as a link i). The route cost A1 is calculated. More specifically, the microcomputer 21 acquires the route search condition information stored in the predetermined storage position of the storage device 22 in step S13. Further, the microcomputer 21 acquires a parameter set corresponding to the route search condition represented by the acquired route search condition information from the storage device 22.
[0060]
That is, if the “efficiency button” is selected in step S13, the microcomputer 21 sends α = 0.2, β = 0... As a parameter set from the storage device 22 as shown in FIG. 3. Obtain γ = 0.3 and δ = 0.2. If the “time button” is selected, α = 0.25, β = 0.5, γ = 0.25, δ = 0 are acquired as the parameter set. If the “cost button” is selected, α = 0, β = 0.5, γ = 0.5, and δ = 0 are acquired as the parameter set. Furthermore, if “comfort button” is selected, α = 0, β = 0, γ = 0.5, and δ = 0.5 are acquired as the parameter set. In the following description, it is assumed that the “efficiency button” is selected by the driver or the passenger.
[0061]
Next, the microcomputer 21 uses the map data and the traffic state information stored in the storage device 22 to acquire each piece of information representing the distance, legal speed, road type, and estimated fuel consumption regarding the link 1 of the candidate route. . Then, the microcomputer 21 calculates the route cost A1 of the link 1 by substituting the numerical value represented by each acquired information and the parameter value represented by the parameter set into Equation 1.
[0062]
Next, the microcomputer 21 calculates the path cost A2 of the link 2 based on the formula 2. Also in this case, the microcomputer 21 acquires each piece of information representing the distance, legal speed, road type, and estimated fuel consumption related to the link 2 of the candidate route from the storage device 22. The microcomputer 21 calculates the route cost A2 by changing the parameter values used in the calculation of the route cost A1 in the order of α, β, γ, and δ.
[0063]
That is, the microcomputer 21 changes α based on the constraints 2 and 3, and calculates the minimum route cost A2. At this time, the microcomputer 21 determines α by changing β, γ, and δ so as to satisfy the constraints 1 to 3, and determines a parameter set that minimizes the path cost A2. Hereinafter, the route cost when α is changed is referred to as route cost A2α.
[0064]
Further, the microcomputer 21 calculates the minimum route cost A2 by changing β based on the constraints 2 and 3. At this time, the microcomputer 21 changes γ and δ so as to satisfy Constraint 1 to Constraint 3 and determines β, and determines a parameter set that minimizes the path cost A2. Hereinafter, the route cost when β is changed is referred to as route cost A2β. In this case, the value of α is not changed.
[0065]
Further, the microcomputer 21 calculates the minimum path cost A2 by changing γ based on the constraints 2 and 3. At this time, the microcomputer 21 determines γ by changing δ so as to satisfy Constraint 1 to Constraint 3, and determines a parameter set that minimizes the path cost A2. Hereinafter, the route cost when γ is changed is referred to as route cost A2γ. In this case, the values of α and β are not changed. Here, δ is determined based on Constraint 1 using the determined α, β, and γ.
[0066]
Then, the microcomputer 21 selects the minimum path cost among the calculated path costs A2α, A2β, and A2γ, and determines the selected path cost as the path cost A2. Thus, when the path cost A2 of the link 2 is determined, the microcomputer 21 repeats the same calculation as the path cost calculation of the link 2, and the path cost A3 of the link 3, the path cost A4 of the link 4,. Route cost Ai of i,..., link j, that is, the route cost Aj of the link connected to the destination is calculated.
[0067]
As described above, when the route cost A1,..., Route cost Aj of one candidate route is determined, the microcomputer 21 determines the total route cost A of this candidate route by averaging the determined route cost. . Further, the microcomputer 21 similarly calculates and determines the route costs of other candidate routes, and determines the smallest candidate route as the guide route among the determined route costs of the plurality of candidate routes. When the microcomputer 21 determines the guide route, the microcomputer 21 stores the guide route information representing the determined guide route in a predetermined storage position of the storage device 22, and proceeds to step S16.
[0068]
In step S13, if the route search condition is not selected by the driver or the passenger until a predetermined time (for example, about 10 seconds) elapses, the microcomputer 21 determines “No”. The process proceeds to step S15. In step S15, the microcomputer 21 selects a guidance route to the destination based on the route search condition selected by the driver or passenger when the route guidance program was executed last time and stored in the predetermined storage position of the storage device 22. Explore. Here, in the route search process in step S15, the route cost is calculated by changing the parameter set for each link based on the above formulas 1 and 2 as in the route search process in step S14. Then, a candidate route that minimizes the calculated route cost is determined as a guide route, guide route information representing the determined guide route is stored in a predetermined storage position of the storage device 22, and the process proceeds to step S16.
[0069]
After the processing of step S14 or step S15, in step S16, the microcomputer 21 starts guiding the determined guidance route to the driver. Specifically, the microcomputer 21 supplies the guide route information stored in the predetermined storage position of the storage device 22 to the display device 23 and performs the guidance on the liquid crystal display by executing the step S14 or the step S15. Instruct to display the screen. The display device 23 uses the map data stored in the storage device 22 according to the instruction to display a road map and a background on the liquid crystal display and also displays a guide route based on the supplied guide route information. To do. Further, the microcomputer 21 reproduces the voice data of the guide route information through the speaker 26, and guides the guide route by voice to the driver.
[0070]
After the search route guidance process is executed in step S16, in step S17, the microcomputer 21 determines whether or not the vehicle has arrived at the destination. That is, the microcomputer 21 determines “No” based on each detection value from the position detector 10 if the vehicle has not arrived at the destination, returns to step S16, and performs the search route guidance process. Execute. Then, the microcomputer 21 repeatedly executes the search route guidance process in step S16 until the vehicle arrives at the destination and is determined to be “Yes”. On the other hand, if it is determined that the vehicle has arrived at the destination, it is determined as “Yes” and the process proceeds to step S18, and voice guidance such as “arrived at the destination” is executed for the driver. In step S19, the route guidance program is terminated.
[0071]
As can be understood from the above description, according to the first embodiment, the driver or the passenger can select the route search condition. The microcomputer 21 can change the parameter set while satisfying the constraints 1 to 3 in the route cost calculation so as to reflect the selected route search condition. In this way, by determining the candidate route that minimizes the calculated route cost by changing the parameter set as the guide route, it is possible to optimize the route cost calculation in the route search condition desired by the driver or the passenger. it can. As a result, it is possible to search for a guidance route that best matches the route search condition desired by the driver or passenger, and to provide the guidance route suitably.
[0072]
In the first embodiment, the microcomputer 21 of the route guidance device 20 mounted on the vehicle calculates the route cost of the candidate route by changing each parameter value constituting the parameter set. And it implemented so that the candidate path | route where the calculated path | route cost might become the minimum as a guidance path | route most suitable for the path | route search condition which the driver | operator or the passenger selected. However, when the route guidance device 20 can communicate with the center and the route guidance device 20 receives the guidance route information indicating the guidance route and guides the guidance route, each parameter constituting the parameter set at the center. The route cost may be calculated by changing the value, and the optimum guide route may be determined. Hereinafter, although this 2nd Embodiment is described, the same code | symbol is attached | subjected to the same part as the said 1st Embodiment, and the description is abbreviate | omitted.
[0073]
The route guidance apparatus 20 according to the second embodiment is capable of communicating with a center 30 that provides guidance route information, as shown in FIG. The center 30 is communicably connected to a traffic information center 40 that provides traffic information. In the route guidance device 20 according to the second embodiment, as shown in FIG. 7, the traffic information receiver 27 of the first embodiment is omitted, and a communication device 28 is provided. The communication device 28 enables wireless communication with the center 30 and is connected to an antenna 28a for wireless communication.
[0074]
As shown in FIG. 8, the center 30 includes a control device 31, a storage device 32, a communication device 33, and an external communication interface 34 (hereinafter referred to as an external communication I / F 34) that are communicably connected to each other. The control device 31 includes a CPU, ROM, RAM, timer, and the like as main components. By executing various programs including the center side program in FIG. 9, the storage device 32, the communication device 33, and the external communication I / F 34 are controlled. Centralized control of operation. Then, processing such as route search and provision from the current location to the destination of the vehicle received from the route guidance device 20 is executed.
[0075]
The storage device 32 includes a recording medium such as a hard disk, a CD-ROM, a DVD-ROM, and a drive device for the recording medium, and stores various programs including the program executed by the control device 31 and various data. ing. In addition, a map database 32a for storing the latest and detailed map data of the whole country is built in the hard disk of the storage device 32. Here, the map data memorize | stored in the map database 32a is comprised similarly to the map data mentioned above.
[0076]
The communication device 33 enables wireless communication with the route guidance device 20. The communication device 33 is connected to an antenna 33a for wireless communication. Here, the communication between the route guidance device 20 and the center 30 is performed wirelessly using the antenna 28a and the antenna 33a, but is not performed with a normal method. Therefore, in the following description, when simply referred to as reception, transmission, etc., it is assumed that an appropriate communication method is adopted for these. The external communication I / F 34 is connected to the communication line NW and provides traffic information and traffic jam information provided from the traffic information center 40 to the control device 31.
[0077]
Next, the operation of the second embodiment configured as described above will be described. When an ignition switch (not shown) is turned on by the driver, the microcomputer 21 of the route guidance device 20 starts executing the program on the route guidance device side shown in FIG. 8 in step S100.
[0078]
If the route search condition is selected in step S13, the microcomputer 21 determines “Yes” and proceeds to step S101. In step S101, the microcomputer 21 obtains the current location information indicating the current location detected in step S11, the destination information indicating the destination input in step S12, and the route search condition selected in step S13. The route search condition information to be expressed is transmitted to the center 30.
[0079]
If the route search condition is not selected within the predetermined time in step S13, the microcomputer 21 determines “No” and proceeds to step S102. In step S102, the microcomputer 21 determines the current position information, the destination information, and the route search condition information indicating the route search condition selected by the driver or the passenger during the previous program execution and stored in the predetermined storage position of the storage device 22. Is sent to the center 30.
[0080]
In the center 30, the control device 31 receives each piece of information transmitted by the transmission process of step S 101 or step S 102 in step C 10 and stores the received information in a predetermined storage position of the storage device 32. To do. When each information is stored in the storage device 32, the process proceeds to step C11.
[0081]
In step C11, the control device 31 searches for a guide route from the current location of the vehicle to the destination based on the current location information, destination information, and route search condition information received in step C10. The search for the guide route by the control device 31 is substantially the same as the search for the guide route of the route guide device 20 according to the first embodiment, and a detailed description thereof will be omitted. To do.
[0082]
First, the control device 31 acquires traffic information and traffic jam information from the traffic information center 40 via the external communication I / F 34, and based on the route search condition represented by the received route search condition information, the vehicle Search for multiple candidate routes from your current location to your destination. Next, the control device 31 calculates the route cost of the plurality of candidate routes searched using the above Equation 1 and Equation 2. The control device 31 obtains the parameter set shown in FIG. 5 that is preset and stored in the storage device 32, and uses the map data stored in the map database 32a to obtain each parameter related to the link 1 of the candidate route. Get information. And the control apparatus 31 substitutes each acquired information and parameter set for the said Formula 1, and calculates path | route cost A1 to the link 1. FIG.
[0083]
Next, the control device 31 calculates the route cost of the link 2 based on the formula 2. At this time, the control device 31 calculates the route cost A2 by changing each parameter value of the parameter set used for calculating the route cost A1. That is, the control device 31 compares the path costs A2α, A2β, and A2γ when the parameters α, β, γ, and δ are changed, selects the minimum path cost, and sets the path cost A2 of the link 2 decide. Then, the control device 31 determines up to the route cost Aj of the link j connected to the destination, and determines the total route cost A of the candidate route by averaging these determined route costs. Similarly, the control device 31 determines the total route cost for other candidate routes, compares the determined total route costs, and determines the candidate route with the minimum route cost as the guide route. . When the guide route is determined in this way, the control device 31 stores the guide route information representing the determined guide route in a predetermined storage position of the storage device 32, and proceeds to step C12.
[0084]
In step C12, the control device 31 transmits the guide route information stored in step C11 to the route guide device 20. That is, the control device 31 uses the storage device 32 to acquire the stored guide route information and supplies the acquired guide route information to the communication device 33. The communication device 33 transmits the supplied guide route information to the route guide device 20 via the antenna 33a.
[0085]
In the route guidance device 20, the microcomputer 21 receives the guidance route information transmitted by the transmission process in step C <b> 12 via the communication device 28 in step S <b> 103. Then, the microcomputer 21 stores the received guide route information in a predetermined storage position of the storage device 22, and proceeds to step S16.
[0086]
As can be understood from the above description, also in the second embodiment, the driver or the passenger can select the route search condition. Then, the control device 31 of the center 30 can change the parameter set while satisfying the constraints 1 to 3 in the route cost calculation so as to reflect the route search conditions represented by the received route search condition information. In this way, by determining the candidate route that minimizes the calculated route cost by changing the parameter set as the guide route, it is possible to optimize the route cost calculation in the route search condition desired by the driver or the passenger. it can. As a result, it is possible to search for a guidance route that best matches the route search condition desired by the driver or passenger, and to provide the guidance route suitably.
[0087]
Here, in the first embodiment and the second embodiment, the route search conditions that can be selected by the driver or the passenger are implemented as “efficiency”, “time”, “cost”, and “comfort”. Needless to say, the present invention is not limited to these items without departing from the object of the present invention. Similarly, in the first embodiment and the second embodiment, the parameters constituting the parameter set are set as α, β, γ, and δ in the calculation of the route cost. However, unless departing from the object of the present invention, Needless to say, these parameters are not limitative. Further, in the first embodiment and the second embodiment, when changing each parameter, each parameter is changed one by one to calculate the minimum route cost. It is also possible to calculate the route cost by using a method (for example, dynamic programming).
[Brief description of the drawings]
FIG. 1 is a block diagram showing an outline of a route guidance apparatus according to a first embodiment of the present invention.
FIG. 2 is a flowchart of a route guidance program according to the first embodiment executed by the route guidance device of FIG.
FIG. 3 is a diagram for explaining route search conditions;
FIG. 4 is a diagram for explaining parameter restrictions;
FIG. 5 is a diagram for explaining parameter sets stored in a storage device;
FIG. 6 is a schematic block diagram showing an entire route guidance system according to a second embodiment of the present invention.
7 is a block diagram showing an outline of the route guidance apparatus of FIG. 6. FIG.
FIG. 8 is a block diagram showing an outline of the center of FIG. 6;
9 is a flowchart of a route guidance program according to a second embodiment executed in the route guidance device and center of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Position detector, 20 ... Route guidance device, 21 ... Microcomputer, 22 ... Storage device, 27 ... Traffic information receiver, 28 ... Communication device, 30 ... Center, 31 ... Control device, 32 ... Storage device, 33 ... Communication device, 40 ... Traffic Information Center

Claims (24)

In a route guidance device for searching for a guidance route from a current location of a vehicle to a destination input by a user of the vehicle and guiding the guidance route to the user of the vehicle,
Storage means for storing the road attributes together with map data of roads on which the vehicle can travel;
Search condition selection means for selecting a search condition related to a route search from the current position of the vehicle to the destination, operated by a user of the vehicle;
Candidate route search means for searching a plurality of candidate routes from the current location of the vehicle to the destination using the map data stored in the storage means;
A plurality of parameters that reflect the search conditions selected by the search condition selection means on the candidate routes searched by the candidate route search means, and at least attributes stored in the storage means of the roads constituting the candidate routes. Route cost calculation means for calculating a route cost representing the priority of candidate routes that match the search condition;
Along with the calculation of the route cost of the route cost calculation unit, a parameter change unit that changes each of the plurality of parameters with a predetermined fluctuation range;
Comparing route costs of the plurality of candidate routes calculated by the route cost calculating unit, and including a guide route comparison determining unit that determines a candidate route having the smallest route cost among the route costs as a guide route. A route guidance device characterized by the above. In the route guidance device according to claim 1,
Furthermore, it has a traffic condition acquisition means for acquiring traffic condition information regarding the traffic condition of the road from the outside,
The route guidance device, wherein the candidate route search means searches for the plurality of candidate routes using the traffic state information acquired by the traffic state acquisition means. The attribute of the road is
The route guidance device according to claim 1 or 2, wherein the route guidance device includes at least a type of the road, a distance of the road, a legal speed of the road, and a cost required to pass the road. The parameter changing means includes
The route guidance device according to any one of claims 1 to 3, wherein the plurality of parameters are optimized and changed based on dynamic programming. The parameter changing means includes
The route guidance device according to any one of claims 1 to 4, wherein a sum of the plurality of parameters is changed to be constant. The predetermined fluctuation range is:
6. The standard deviation calculated based on a difference between a guide route determined by the guide route comparison determining means and a travel route actually traveled by a user of the vehicle. The route guidance apparatus described in one. In a center that searches an external vehicle for a guide route from the current location of the vehicle to a destination and provides the searched guide route to the vehicle,
Receiving means for receiving, from an external vehicle, current location information representing the current location of the vehicle, destination information representing the destination, and search condition information representing a search condition for a route search from the current location to the destination;
Storage means for storing the road attributes together with map data of roads on which the vehicle can travel;
Based on the current location information and destination information received by the receiving means, using the map data stored in the storage means, from the current location represented by the current location information to the destination represented by the destination information Candidate route searching means for searching for a plurality of candidate routes;
A plurality of parameters reflecting the search conditions represented by the search condition information received by the receiving means in the candidate routes searched by the candidate route searching means, and attributes stored in the storage means of the roads constituting the candidate routes; A route cost calculating means for calculating a route cost representing the priority of the candidate route that matches the search condition,
Along with the calculation of the route cost of the route cost calculation unit, a parameter changing unit that changes the plurality of parameters with a predetermined fluctuation range;
A guide route comparison / determination unit that compares route costs of the plurality of candidate routes calculated by the route cost calculation unit, and determines a candidate route having a minimum route cost among the route costs as a guide route;
A center comprising guide route information transmitting means for transmitting guide route information representing the guide route determined by the guide route comparison and determination means to the external vehicle. In the center according to claim 7,
Furthermore, it has a traffic condition acquisition means for acquiring traffic condition information regarding the traffic condition of the road from the outside,
The center, wherein the candidate route search means searches for the plurality of candidate routes using the traffic state information acquired by the traffic state acquisition means. The attribute of the road is
9. The center according to claim 7, wherein the center includes at least the road type, the road distance, the legal speed of the road, and the cost required to pass the road. The parameter changing means includes
The center according to any one of claims 7 to 9, wherein the plurality of parameters are optimized and changed based on dynamic programming. The parameter changing means includes
The center according to any one of claims 7 to 10, wherein a sum of the plurality of parameters is changed to be constant. The predetermined fluctuation range is:
The standard deviation calculated based on the difference between the guide route determined by the guide route comparison and determination unit and the travel route on which the external vehicle actually traveled. Center listed in one. In a route search method for searching a guide route from a current location of a vehicle to a destination input by a user of the vehicle,
Search for a plurality of candidate routes from the current location of the vehicle to the destination using the map data of the road where the vehicle can be stored in advance,
A plurality of parameters reflecting the search conditions for route search from the current location to the destination of the vehicle selected by the user of the vehicle in the candidate route, and prestored attributes of the roads constituting the candidate route Including, at least, calculating a route cost representing the priority of a candidate route that matches the search condition by changing the plurality of parameters;
A route search method comprising comparing the calculated route costs of a plurality of candidate routes and determining a candidate route having a minimum route cost among the route costs as a guide route. The route search method according to claim 13,
In addition, traffic condition information on road traffic conditions is obtained from outside,
A route search method, wherein the plurality of candidate routes are searched using the acquired traffic state information. The attribute of the road is
15. The route search method according to claim 13 or 14, wherein the route search method includes at least the type of the road, the distance of the road, the legal speed of the road, and the cost required to pass the road. The plurality of parameters,
The route search method according to any one of claims 13 to 15, wherein the route search method is optimized and changed based on dynamic programming. The plurality of parameters,
The route search method according to any one of claims 13 to 16, wherein the sum of the plurality of parameters is changed to be constant. 18. The method according to claim 13, wherein the plurality of parameters are changed within a standard deviation calculated based on a difference between the determined guide route and a travel route actually traveled by a user of the vehicle. The route guidance method described in one. In a route search method in which a center capable of communicating with a route guide device mounted on a vehicle searches for a guide route from the current location of the vehicle to a destination,
The route guidance device
Current location information representing the current location of the detected vehicle, destination information representing the destination input by the user of the vehicle, and route search condition information representing the search conditions for route search from the current location to the destination selected by the user To the center,
The center
Receiving the transmitted current location information, destination information and route search condition information;
Based on the received current location information and destination information, search for a plurality of candidate routes from the current location of the vehicle to the destination using map data of roads on which the vehicle can be stored in advance,
The search condition represented by the received route search condition information includes at least a plurality of parameters reflecting the candidate route and the prestored attribute of the road that constitutes the candidate route, and matches the search condition Calculating the route cost representing the priority of the candidate route to be performed by changing the plurality of parameters,
Compare the calculated route costs of the plurality of candidate routes, determine a candidate route having the smallest route cost among the route costs as a guide route,
A route search method, characterized in that guide route information representing the determined guide route is transmitted to the route guide device. The route search method according to claim 19, wherein
The center
In addition, traffic condition information on road traffic conditions is obtained from outside,
A route search method, wherein the plurality of candidate routes are searched using the acquired traffic state information. The attribute of the road is
21. The route search method according to claim 19 or 20, wherein the route search method includes at least the type of the road, the distance of the road, the legal speed of the road, and the cost required for the passage of the road. The plurality of parameters,
The route search method according to any one of claims 19 to 21, wherein the route search method is optimized and changed based on dynamic programming. The plurality of parameters,
23. The route search method according to claim 19, wherein the sum of the plurality of parameters is changed to be constant. 24. Any one of claims 19 to 23, wherein the plurality of parameters are changed within a standard deviation calculated based on a difference between the determined guide route and a travel route actually traveled by a user of the vehicle. The route guidance method described in one.

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