JP2004331009A - Tire state quantity detecting method and tire state quantity detecting device - Google Patents

Tire state quantity detecting method and tire state quantity detecting device Download PDF

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JP2004331009A
JP2004331009A JP2003133492A JP2003133492A JP2004331009A JP 2004331009 A JP2004331009 A JP 2004331009A JP 2003133492 A JP2003133492 A JP 2003133492A JP 2003133492 A JP2003133492 A JP 2003133492A JP 2004331009 A JP2004331009 A JP 2004331009A
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tire
physical quantity
output
transmitter
temperature
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JP4069798B2 (en
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Hideki Kusunoki
秀樹 楠
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Toyota Motor Corp
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Toyota Motor Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/20—Devices for measuring or signalling tyre temperature only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire state quantity detecting method and a tire state quantity detecting device for improving safety or power saving of a vehicle. <P>SOLUTION: In a tire state quantity detecting system 10, a first wheel 20, a second wheel 22, a third wheel 24, and a fourth wheel 26 include a first physical quantity sensor 30 and a first transmitter 40, a second physical quantity sensor 32 and a second transmitter 42, a third physical quantity sensor 34 and a third transmitter 44, a fourth physical quantity sensor 36 and a fourth transmitter 46, respectively. The first physical quantity sensor 30, second physical quantity sensor 32, third physical quantity sensor 34, and fourth physical quantity sensor 36 detect a first physical quantity and a second physical quantity related to tire states, respectively. The first transmitter 40, second transmitter 42, third transmitter 44, and fourth transmitter 46 transmits the first physical quantity and second physical quantity to an ECU 64 side in a form where the output state of the second physical quantity is varied in response to the size of the first physical quantity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明はタイヤ状態量検出方法およびタイヤ状態量検出装置に関し、特に、車両の安全性向上との関連でタイヤの状態を監視する技術に関する。
【０００２】
【従来の技術】
従来から、パンクによって内圧が低下しても一定距離の走行が可能なランフラットタイヤの技術が知られている（例えば、特許文献１参照。）。このランフラットタイヤは内部に中子組立体が設けてあり、タイヤの内圧が低下したときはその中子組立体がタイヤに掛かる荷重を支える。
【０００３】
【特許文献１】
特開平６−２９７９２２号公報（全文、図１）
【０００４】
【発明が解決しようとする課題】
ここでランフラットタイヤは、フラット状態に至った非常時でも、あくまでもしばらくの間だけタイヤ交換せずに臨時の走行を可能にするものであって、必ずしも非フラット状態でなされるような走行を維持するものではない。したがって、フラット状態になったランフラットタイヤで高速走行を延々続けてしまうと、タイヤの接地面積が増加することによって摩擦エネルギーや応力集中によるエネルギーが増加してしまい、次第にタイヤの温度が上昇する。もし、タイヤの温度が許容量を超えて上昇してしまうと、熱によりタイヤの耐久性に影響が出る可能性がある。一方、タイヤの空気圧を監視するとしても、そもそもフラット状態ではもはや空気圧が変化しないので、さらなるタイヤの状態変化を検知できず不十分である。
【０００５】
本発明はこうした状況に鑑みてなされたものであり、その目的は、タイヤの耐久性を左右するような状況変化を監視するためのタイヤ状態量検出方法およびタイヤ状態量検出装置を提供することにある。
【０００６】
【課題を解決するための手段】
上記課題を解決するために、本発明のある態様は、タイヤ状態量として第１の物理量を出力するステップと、前記第１の物理量と異なるタイヤ状態量として第２の物理量を出力するステップと、を含むタイヤ状態量検出方法を提供する。前記第２の物理量を出力するステップは、前記第１の物理量の大きさに応じて、前記第２の物理量を示す情報の出力量が増加するようにその出力状態を変化させる。
【０００７】
本態様のタイヤ状態量検出方法によれば、タイヤの状況に関する複数種の物理量に基づいてその物理量の出力状態を制御することができる。したがって、特に非常時に必要な情報の出力頻度、出力解像度、または出力量を高めて車両の安全性をより向上させることができる。一方、通常時には情報出力の頻度を低くして消費電力を低減させることができる。なお、「出力状態を変化」として、第２の物理量を送信する頻度を変化させてもよいし、第２の物理量を検出する頻度を変化させてもよい。
【０００８】
前記第２の物理量を出力するステップは、少なくとも前記第２の物理量の大きさに基づき、前記第２の物理量の検出重要性が増加したと判断された場合に、前記第２の物理量を示す情報の単位時間あたりの出力量が増加するように前記出力状態を変化させてもよい。したがって、第１の物理量と第２の物理量のうち、より重要性の高い情報を集中的に出力させることができるので、車両の安全性をより向上させることができる。
【０００９】
本発明の別の態様は、タイヤ状態量として第１の物理量を検出する第１の検出手段と、前記第１の物理量と異なるタイヤ状態量として第２の物理量を検出する第２の検出手段と、前記第１の物理量および前記第２の物理量を出力する出力手段と、を備えたタイヤ状態量検出装置を提供する。前記出力手段は、前記第１の検出手段により検出された前記第１の物理量の大きさに応じて、前記第２の検出手段により検出された前記第２の物理量を示す情報の単位時間あたりの出力量が増加するようにその出力状態を変化させる。
【００１０】
本態様のタイヤ状態量検出装置によれば、タイヤの状況に関する複数種の情報に基づいて出力手段による出力状態を変化させることができる。したがって、特に非常時には情報出力の頻度を高めて車両の安全性をより向上させることができる。一方、通常時には情報出力の頻度を低くして消費電力を低減させることができる。
【００１１】
前記出力手段は、少なくとも前記第２の物理量の大きさに基づき、前記第２の物理量の検出重要性が増加したと判断された場合に、前記第２の物理量を示す情報の単位時間あたりの出力量が増加するように前記出力状態を変化させてもよい。したがって、第１の物理量と第２の物理量のうち、より重要性の高い情報を集中的に出力させることができるので、車両の安全性をより向上させることができる。
【００１２】
前記第２の検出手段は、前記第１の検出手段により検出された前記第１の物理量の大きさに応じて前記第２の物理量の検出頻度を高めることにより、前記出力手段による前記第２の物理量を示す情報の単位時間あたりの出力量を増加させてもよい。この場合、第２の物理量の検出頻度を高めることにより出力手段による出力量自体を変化させることと同様の効果が得られる。
【００１３】
前記第１の検出手段は、前記第１の物理量としてタイヤの空気圧を検出してもよく、前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出してもよい。前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの空気圧が小さいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させてもよい。これにより、例えばランフラットタイヤの空気圧がそのランフラットタイヤで安全が保証される空気圧より低くなる場合にタイヤ温度の出力頻度が高められる。したがって、特に温度を監視すべき期間に温度情報の変化を確実に把握でき、車両の安全性をより向上させることができる。
【００１４】
前記第１の検出手段は、前記第１の物理量としてタイヤの運動エネルギーを検出してもよく、前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出してもよい。前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの運動エネルギーが大きいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させてもよい。これにより、例えばランフラットタイヤの運動エネルギーがその許容範囲を超えるような場合にタイヤ温度の出力頻度が高められる。したがって、特に温度を監視すべき期間に温度情報の変化を確実に把握でき、車両の安全性をより向上させることができる。
【００１５】
前記第１の検出手段は、前記第１の物理量としてタイヤの接地度を検出してもよく、前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出してもよい。前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの接地度が大きいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させてもよい。これにより、例えばランフラットタイヤの接地度がその許容範囲を超えるような場合にタイヤ温度の出力頻度が高められる。したがって、特に温度を監視すべき期間に温度情報の変化を確実に把握でき、車両の安全性をより向上させることができる。
【００１６】
前記第１の検出手段は、前記第１の物理量としてタイヤの変形量を検出してもよく、前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出してもよい。前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの変形量が大きいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させてもよい。これにより、例えばランフラットタイヤの変形量がその許容範囲を超えるような場合にタイヤ温度の出力頻度が高められる。したがって、特に温度を監視すべき期間に温度情報の変化を確実に把握でき、車両の安全性をより向上させることができる。
【００１７】
前記出力手段は、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度の上昇率が所定の閾値を超えた場合、前記第１の検出手段により検出された前記第１の物理量の大きさにかかわらず前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させてもよい。これにより、ランフラットタイヤの温度が急上昇したような非常時には、優先的にタイヤ温度の出力頻度、出力解像度、または出力量が高められる。したがって、特に温度を監視すべき期間に温度情報の変化を確実に把握でき、車両の安全性をより向上させることができる。
【００１８】
前記出力手段は、タイヤがフラット状態になったことを示す所定値以下までタイヤの空気圧が低下したことを条件に、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させてもよい。これにより、例えばランフラットタイヤがフラット状態になったような非常時に、タイヤ温度の出力頻度、出力解像度、または出力量が高められる。したがって、特に温度を監視すべき期間に温度情報の変化を確実に把握でき、車両の安全性をより向上させることができる。
【００１９】
【発明の実施の形態】
（第１の実施の形態）
本発明の第１の実施の形態においては、タイヤから検出された温度の情報を車体側へ送信するにあたり、そのタイヤから検出された空気圧の大きさに応じて、タイヤの温度を示す情報の送信間隔を変化させる。例えば、タイヤの空気圧が所定値を下回っていればタイヤの温度を示す情報の送信間隔を短くしてタイヤ温度の変化をリアルタイムに車体側へ伝達する。逆に、タイヤの空気圧が所定値を上回っていればタイヤ温度を示す情報の送信間隔を長くして消費電力を低減させる。
【００２０】
図１は、本発明の第１の実施の形態に係るタイヤ状態量検出システムの構成を示す。車両１２に搭載されたタイヤ状態量検出システム１０において、第１車輪２０、第２車輪２２、第３車輪２４、および第４車輪２６のそれぞれには、タイヤ状態量を検出するセンサ、タイヤ状態量を送信する送信機、およびアンテナが設けられている。具体的には、第１車輪２０のホイールに第１物理量センサ３０、第１送信機４０、および第１アンテナ５０が設けられている。第２車輪２２のホイールには、第２物理量センサ３２、第２送信機４２、および第２アンテナ５２が設けられている。第３車輪２４には、第３物理量センサ３４、第３送信機４４、および第３アンテナ５４が設けられている。第４車輪２６には、第４物理量センサ３６、第４送信機４６、および第４アンテナ５６が設けられている。第１車輪２０、第２車輪２２、第３車輪２４、および第４車輪２６のそれぞれのタイヤはランフラットタイヤである。
【００２１】
本実施の形態の第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれタイヤの空気圧およびタイヤの温度をタイヤ状態量として検出する。第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６が検出したタイヤ状態量の情報をそれぞれ第１アンテナ５０、第２アンテナ５２、第３アンテナ５４、および第４アンテナ５６を介して車体側へ送信する。
【００２２】
なお、第１物理量センサ３０または第１送信機４０には、第１物理量センサ３０および第１送信機４０へ電力を供給する電池が内蔵されている。同様に、第２物理量センサ３２または第２送信機４２、第３物理量センサ３４または第３送信機４４、第４物理量センサ３６または第４送信機４６にも電池が内蔵されている。
【００２３】
車体側に設けられた受信機６２は、受信側アンテナ６０を介して第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６のそれぞれからタイヤ状態量の情報を受信し、受信したタイヤ状態量の情報を電子制御装置６４（以下、電子制御装置６４を「ＥＣＵ６４」と表記する）へ送る。ＥＣＵ６４は、受信機６２から受け取ったタイヤ状態量の情報に基づいてタイヤの状態を把握する。ＥＣＵ６４は、受信機６２から受け取ったタイヤ状態量に応じて警告ランプ７２を点灯させるとともに、ブザー７０に警告音を鳴らせる。例えば、受信機６２が受信するタイヤ状態量に含まれるタイヤ空気圧が所定値以上減少した場合に、ＥＣＵ６４は警告ランプ７２を点灯させ、ブザー７０を鳴らす。また例えば、受信機６２が受信するタイヤ状態量に含まれるタイヤ温度が所定値以上に増加した場合に、ＥＣＵ６４は車両の安全性に対してタイヤの状態が及ぼす影響について乗員に警告する。
【００２４】
初期化スイッチ６８は、ＥＣＵ６４によるタイヤ状態の監視動作を初期化する。タイヤセレクタ６６は、第１車輪２０、第２車輪２２、第３車輪２４、および第４車輪２６のうち、監視対象となるタイヤを選択する。
【００２５】
以下、上述の各構成による動作を説明する。図２は、本実施の形態におけるタイヤ状態量を検出する方法を示すフローチャートである。ここでは、第１車輪２０のタイヤ空気圧およびタイヤ温度を検出する第１物理量センサ３０と、第１物理量センサ３０が検出した第１車輪２０のタイヤ空気圧およびタイヤ温度をタイヤ状態量の情報として車体側へ送信する第１送信機４０の動作を例示する。ただし、第２物理量センサ３２および第２送信機４２、第３物理量センサ３４および第３送信機４４、第４物理量センサ３６および第４送信機４６も、第１物理量センサ３０および第１送信機４０と同様に機能する。
【００２６】
第１物理量センサ３０によって検出された第１車輪２０のタイヤ空気圧Ｐがタイヤ空気圧閾値Ｐ０を下回らない間は（Ｓ１０Ｎ）、第１送信機４０によるタイヤ状態量の送信間隔は１５分に維持され（Ｓ１２）、Ｓ１０におけるタイヤ空気圧の監視が繰り返し行われる。タイヤ空気圧閾値Ｐ０は第１車輪２０の設計上の空気圧から例えば１０％〜２０％ほど低い値である。Ｓ１０とＳ１２の処理を繰り返す間、第１送信機４０は１５分間隔で第１車輪２０に関するタイヤ状態量の情報を車体側へ送信する。
【００２７】
第１物理量センサ３０によって検出された第１車輪２０のタイヤ空気圧Ｐがタイヤ空気圧閾値Ｐ０を下回ったときは（Ｓ１０Ｙ）、第１車輪２０のタイヤ耐久性不足の状態ないしほぼフラット状態であるとみなされる。それ以降、第１車輪２０のタイヤ空気圧の情報については、第１送信機４０による情報送信間隔が１０秒に変更される（Ｓ１４）。第１車輪２０のタイヤ空気圧の情報について送信間隔が１０秒に変更されてから２分が経過するまでは、その情報送信間隔の設定が１０秒のまま維持される（Ｓ１６Ｎ）。
【００２８】
第１車輪２０のタイヤ空気圧の情報について送信間隔が１０秒に変更されてから２分が経過した後（Ｓ１６Ｙ）、第１車輪２０のタイヤ空気圧の情報について送信間隔が１５分に戻される（Ｓ１８）。第１車輪２０のタイヤ温度Ｔが第１のタイヤ温度閾値Ｔ０を上回った場合であって（Ｓ２０Ｙ）、タイヤ温度の勾配ΔＴが所定のタイヤ温度勾配閾値ΔＴ０を上回った場合（Ｓ２２Ｙ）、第１車輪２０のタイヤ温度が急上昇したとみなして第１車輪２０のタイヤ温度の情報について送信間隔を３０秒に変更する（Ｓ２６）。
【００２９】
Ｓ２０において第１車輪２０のタイヤ温度Ｔが第１のタイヤ温度閾値Ｔ０を上回らなかった場合（Ｓ２０Ｎ）、またはＳ２２においてタイヤ温度の勾配ΔＴが所定のタイヤ温度勾配閾値ΔＴ０を上回らなかった場合であっても（Ｓ２２Ｎ）、第１車輪２０のタイヤ温度Ｔが第２のタイヤ温度閾値Ｔ１を上回っていれば（Ｓ２４Ｙ）、第１車輪２０のタイヤ温度の情報について送信間隔を３０秒に変更する（Ｓ２６）。すなわち、タイヤ温度が飽和してくるともはやタイヤ温度勾配は大きくならないが、タイヤ温度の絶対値が大きければタイヤの耐久性に影響を及ぼす可能性が生じるためにＳ２４の判断がなされるものである。第２のタイヤ温度閾値Ｔ１は、例えば８０度〜１００度ほどに設定される。ただし、第２のタイヤ温度閾値Ｔ１として相応しい値は走行状態や周囲の状況によって定まるので、例えば車速、ブレーキの回数、外気の温度、横Ｇ、蛇角、操舵量などの各パラメータと第２のタイヤ温度閾値Ｔ１の対応関係を規定したテーブルを第１物理量センサ３０または第１送信機４０が保持し、その第１物理量センサ３０または第１送信機４０が第２のタイヤ温度閾値Ｔ１をその都度決定してもよい。
【００３０】
Ｓ２４において第１車輪２０のタイヤ温度Ｔが第２のタイヤ温度閾値Ｔ１を上回っていない場合（Ｓ２４Ｎ）、Ｓ２６をスキップする。車両１２を停車するまで（Ｓ２８Ｎ）、Ｓ２０からＳ２６までの処理を繰り返す。
【００３１】
図３は、タイヤのパンク前後の情報送信間隔および情報送信割合の変化を示す。本図の上部に情報送信間隔を示し、本図の下部に情報送信割合を示す。横軸は時間経過を示す。ここでは、第１車輪２０のタイヤ空気圧およびタイヤ温度をタイヤ状態量の情報として車体側へ送信する第１送信機４０の動作を例示する。ただし、第２送信機４２、第３送信機４４、および第４送信機４６も、第１送信機４０と同様に機能する。
【００３２】
パンク前の段階では、第１送信機４０は第１車輪２０のタイヤ空気圧およびタイヤ温度をともに１５分間隔で送信するとともに、第１送信機４０が送信するタイヤ状態量を占めるタイヤ空気圧とタイヤ温度の情報量の割合は５０％と５０％で等しい。第１車輪２０のタイヤがパンクしてからその２分後までの間は、タイヤ空気圧の送信間隔は１０秒に変更されるがタイヤ温度の送信間隔は依然１５分のままなので、第１送信機４０が送信するタイヤ状態量はタイヤ空気圧の情報量が１００％の割合ないし１００％に近い割合を占める。パンクから２分経過後の段階では、タイヤ空気圧の送信間隔が１５分に戻されるが、タイヤ温度の送信間隔はそのタイヤ温度の上昇度合いによっては３０秒に変更されるので、第１送信機４０が送信するタイヤ状態量はタイヤ温度の情報量が１００％に近い割合を占める。このように、第１送信機４０が送信するタイヤ温度の情報の単位時間あたりの出力量は、情報送信間隔を変化させることによって増減されている。
（第２の実施の形態）
本発明の第２の実施の形態は、タイヤの運動エネルギーの大きさに応じてタイヤ温度の情報の出力状態を変化させる点で、タイヤ空気圧の大きさに応じてタイヤ温度の情報の出力状態を変化させる本発明の第１の実施の形態と異なる。以下、第１の実施の形態との相違点を中心に説明する。本実施の形態の構成は、第１の実施の形態と同様、図１に示される。
【００３３】
図１における第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれ対応する第１車輪２０、第２車輪２２、第３車輪２４、第４車輪２６の運動エネルギーおよびタイヤ温度を検出する。ここでいう運動エネルギーはタイヤの回転数であり、第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれ加速度センサと温度センサを含む。第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、加速度センサで検出したタイヤ回転の加速度成分を積分することによりタイヤの回転数を求める。
【００３４】
第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、それぞれ第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６によって検出されたタイヤ温度およびタイヤ回転数を、タイヤ状態量として車体側へ送信する。ただし、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ回転数の大きさに応じてタイヤ温度の送信間隔を変化させる。例えば第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ回転数が大きいほどタイヤ温度の情報送信間隔を短くする。すなわち、タイヤの運動エネルギーが大きいほどタイヤ温度が上昇してタイヤの耐久性に影響を及ぼす可能性が高くなるので、タイヤの運動エネルギーが大きいときにはタイヤ温度の変化を確実に捕捉すべくタイヤ温度の情報送信間隔を短くする。一方、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ回転数が小さいほどタイヤ温度の情報送信間隔を長くする。これによりタイヤ温度が過度に上昇しないような状況では必要以上にタイヤ温度の情報を送信しないので、内蔵電池の消費電力を低減できる。
【００３５】
なお、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６が空気圧センサをさらに含む場合、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ空気圧が所定閾値を下回ったことを条件としてタイヤ温度の情報送信間隔を変化させてもよい。ここでいうタイヤ空気圧の所定閾値は、タイヤがフラット状態であるとみなすことのできる値である。この場合、タイヤがフラット状態であるとみなされた状況においてタイヤ温度の情報送信間隔を短くできるので、タイヤ温度の変化を確実に捕捉して安全性をより高めることができる。
（第３の実施の形態）
本発明の第３の実施の形態は、タイヤの変形量に応じてタイヤ温度の情報の出力状態を変化させる点で、タイヤ空気圧の大きさに応じてタイヤ温度の情報の出力状態を変化させる本発明の第１の実施の形態と異なる。以下、第１の実施の形態との相違点を中心に説明する。本実施の形態の構成もまた、第１の実施の形態と同様、図１に示される。
【００３６】
図１における第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれ対応する第１車輪２０、第２車輪２２、第３車輪２４、第４車輪２６のタイヤ変形量およびタイヤ温度を検出する。第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれタイヤ変形量を検出する歪ゲージとタイヤ温度を検出する温度センサを含む。
【００３７】
第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、それぞれ第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６によって検出されたタイヤ変形量およびタイヤ温度を、タイヤ状態量として車体側へ送信する。ただし、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ変形量の大きさに応じてタイヤ温度の情報送信間隔を変化させる。例えば第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ変形量が大きいほどタイヤ温度の情報送信間隔を短くする。すなわち、タイヤ変形量が大きいほどタイヤ温度が上昇してタイヤの耐久性に影響を及ぼす可能性が高くなるので、タイヤ変形量が大きいときにはタイヤ温度の変化を確実に捕捉すべくタイヤ温度の情報送信間隔を短くする。一方、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ変形量が小さいほどタイヤ温度の情報送信間隔を長くする。これによりタイヤ温度が過度に上昇しないような状況では必要以上にタイヤ温度の情報を送信しないので、内蔵電池の消費電力を低減できる。
【００３８】
図４は、車輪およびその車輪のタイヤ表面に装着した歪ゲージを示す。図示するように、タイヤ８０のサイドウォール表面に歪ゲージ８２が複数装着されており、これら複数の歪ゲージ８２がタイヤ８０のサイドウォールの変形量を検出する。
【００３９】
なお、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６が空気圧センサをさらに含む場合、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ空気圧が所定閾値を下回ったことを条件としてタイヤ温度の情報送信間隔を変化させてもよい。ここでいうタイヤ空気圧の所定閾値は、タイヤがフラット状態であるとみなすことのできる値である。この場合、タイヤがフラット状態であるとみなされた状況においてタイヤ温度の情報送信間隔を短くできるので、タイヤ温度の変化を確実に捕捉して安全性をより高めることができる。
（第４の実施の形態）
本発明の第４の実施の形態は、タイヤの接地性に応じてタイヤ温度の情報の出力状態を変化させる点で、タイヤ空気圧の大きさに応じてタイヤ温度の情報の出力状態を変化させる本発明の第１の実施の形態と異なる。以下、第１の実施の形態との相違点を中心に説明する。本実施の形態の構成もまた、第１の実施の形態と同様、図１に示される。
【００４０】
図１における第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれ対応する第１車輪２０、第２車輪２２、第３車輪２４、第４車輪２６のタイヤ接地性およびタイヤ温度を検出する。ここでいうタイヤ接地性はタイヤの接地面積であり、第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、それぞれ空気圧センサ、歪ゲージ、温度センサを含む。第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、図４のようなタイヤ表面に装着された歪ゲージで検出されるサイドウォールの変形量と空気圧センサで検出されるタイヤ空気圧に基づいてタイヤの接地面積を求める。
【００４１】
第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、それぞれ第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６によって検出されたタイヤ温度およびタイヤの接地面積を、タイヤ状態量として車体側へ送信する。ただし、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤの接地面積の大きさに応じてタイヤ温度の情報送信間隔を変化させる。例えば第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ接地面積が大きいほどタイヤ温度の情報送信間隔を短くする。すなわち、タイヤ接地面積が大きいほどタイヤ温度が上昇してタイヤの耐久性に影響を及ぼす可能性が高くなるので、タイヤ接地面積が大きいときにはタイヤ温度の変化を確実に捕捉すべくタイヤ温度の情報送信間隔を短くする。一方、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ接地面積が小さいほどタイヤ温度の情報送信間隔を長くする。これによりタイヤ温度が過度に上昇しないような状況では必要以上にタイヤ温度の情報を送信しないので、内蔵電池の消費電力を低減できる。
【００４２】
なお、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ空気圧が所定閾値を下回ったことを条件として、タイヤ温度の情報送信間隔を変化させてもよい。ここでいうタイヤ空気圧の所定閾値は、タイヤがフラット状態であるとみなすことのできる値である。この場合、タイヤがフラット状態であるとみなされた状況においてタイヤ温度の情報送信間隔を短くできるので、タイヤ温度の変化を確実に捕捉して安全性をより高めることができる。（第５の実施の形態）
本発明の第５の実施の形態は、各車輪の送信機が情報の送信回数を変化させる点で、各車輪の送信機が情報の送信間隔を変化させる本発明の第１〜４の実施の形態と異なる。以下、第１〜４の実施の形態との相違点を中心に説明する。
【００４３】
図５は、通常時と非常時における情報送信回数の変化を示す。図示するように、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、タイヤ状態量としてＩＤ、タイヤ空気圧、タイヤ温度の各情報を車体側へ送信する。ＩＤは、第１車輪２０、第２車輪２２、第３車輪２４、第４車輪２６のそれぞれに一意に割り当てられた識別情報であり、他の車両に装着された車輪やタイヤ交換で装着される市販の車輪とも区別される。
【００４４】
通常時、すなわち第１車輪２０、第２車輪２２、第３車輪２４、第４車輪２６がパンクしていない状態では、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、ＩＤ、タイヤ空気圧、タイヤ温度がそれぞれ１回ずつ送られるように構成されたタイヤ状態量の情報を送信する。
【００４５】
非常時、すなわち第１車輪２０、第２車輪２２、第３車輪２４、第４車輪２６がパンクした状態では、第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、ＩＤが１回とタイヤ温度が３回送られるように構成されたタイヤ状態量の情報を送信する。
【００４６】
なお、本実施の形態の第１送信機４０、第２送信機４２、第３送信機４４、第４送信機４６による情報出力状態の変化は情報送信回数の変化という形で実現される。本発明の第１〜４の実施の形態においては、第１送信機４０、第２送信機４２、第３送信機４４、第４送信機４６による情報出力状態の変化として情報送信間隔の変化を説明したが、これらを本実施の形態の情報送信回数の変化で置き換えることができる。例えば第１の実施の形態を応用すると、第１送信機４０以下の各送信機は、タイヤ空気圧が小さいほどタイヤ温度の情報送信回数を増加させる。第２の実施の形態を応用すると、第１送信機４０以下の各送信機は、タイヤ運動エネルギーが大きいほどタイヤ温度の情報送信回数を増加させる。第３の実施の形態を応用すると、第１送信機４０以下の各送信機は、タイヤ変形量が大きいほどタイヤ温度の情報送信回数を増加させる。第４の実施の形態を応用すると、第１送信機４０以下の各送信機は、タイヤ接地度が大きいほどタイヤ温度の情報送信回数を増加させる。このように、第１送信機４０以下の各送信機が送信するタイヤ温度の情報の単位時間あたりの出力量は、情報送信回数の増減によって変化している。
【００４７】
以上、実施の形態をもとに本発明を説明した。なお本発明はこの実施の形態に限定されることなく、その様々な変形例もまた本発明の態様として有効である。以下、変形例を挙げる。
【００４８】
本発明の第２の実施の形態においては、第１物理量センサ３０以下の各物理量センサは、それぞれ対応する第１車輪２０以下の各車輪のタイヤの運動エネルギーとしてタイヤ回転数を検出する構成としている。変形例においては、第１物理量センサ３０以下の各物理量センサは、それぞれ対応する第１車輪２０以下の各車輪のタイヤの運動エネルギーとしてタイヤの駆動トルクを検出してもよい。この場合、第１物理量センサ３０以下の各物理量センサは、それぞれ加速度センサを含むとともに、その加速度センサで検出した加速度成分に基づいてタイヤの駆動トルクを求めてもよい。さらに他の変形例においては、第１物理量センサ３０以下の各物理量センサは、それぞれ対応する第１車輪２０以下の各車輪のタイヤの運動エネルギーとしてタイヤの荷重を検出してもよい。この場合、第１物理量センサ３０以下の各物理量センサは、それぞれ歪ゲージと空気圧センサを含むとともに、その歪ゲージで検出したタイヤ変形量と空気圧センサで検出したタイヤ空気圧に基づいてタイヤの荷重を求めてもよい。
【００４９】
本発明の第３の実施の形態においては、第１物理量センサ３０以下の各物理量センサはタイヤのサイドウォールに設けられた歪ゲージを含む構成であり、その歪ゲージがタイヤ変形量を検出する構成であった。変形例においては、タイヤとホイールの間の距離測定によってタイヤ変形量を求める構成としてもよい。また、第３の実施の形態においては、タイヤ変形量の大きさに応じてタイヤ温度の情報送信間隔を変化させる構成を説明した。変形例においては、第１送信機４０以下の各送信機は、タイヤ温度の高さに応じてタイヤ変形量の情報送信間隔を変化させてもよい。
【００５０】
本発明の第４の実施の形態においては、第１物理量センサ３０以下の各物理量センサは、それぞれ対応する第１車輪２０以下の各車輪のタイヤ接地度としてタイヤの接地面積を検出する構成としている。変形例においては、第１物理量センサ３０以下の各物理量センサは、それぞれ対応する第１車輪２０以下の各車輪のタイヤ接地度としてタイヤと路面との摩擦係数を検出してもよい。この場合、第１物理量センサ３０以下の各物理量センサは、それぞれ歪ゲージを含むとともに、その歪ゲージで検出したタイヤ変形量に基づいてタイヤの路面μを求めてもよい。
【００５１】
本発明の第１〜４の実施の形態において、第１送信機４０以下の各送信機による情報送信間隔は１０秒、３０秒、１５分のいずれかに設定されるが、これに合わせて第１物理量センサ３０以下の各物理量センサによるタイヤ状態量の検出間隔も１０秒、３０秒、１５分のいずれかに設定してもよい。また、本発明の第１〜４の実施の形態においては、第１送信機４０以下の各送信機による情報送信間隔を変化させる構成としていたが、変形例においては、第１物理量センサ３０以下の各物理量センサによるタイヤ状態量の検出間隔を変化させることにより、結果として第１送信機４０以下の各送信機による情報送信間隔を変化させる構成としてもよい。
【００５２】
以下、本発明の各実施の形態のタイヤ状態量検出システム１０を構成する部材と特許請求の範囲に記載した部材との対応関係を例示する。図１における第１物理量センサ３０、第２物理量センサ３２、第３物理量センサ３４、および第４物理量センサ３６は、請求項３における「第１の検出手段」および「第２の検出手段」に対応する。第１送信機４０、第２送信機４２、第３送信機４４、および第４送信機４６は、請求項３に記載のおける「出力手段」に対応する。なお、「第１の検出手段」、「第２の検出手段」、および「出力手段」は、それぞれ別々のユニットで構成されてもよいし、任意の組み合わせにおいて一体的なユニットで構成されてもよい。
【００５３】
なお、特許請求の範囲に記載した文言は以下の通り解釈してもよい。「第１の物理量」および「第２の物理量」は、検出すべき物理量の種類を２通りに限定する趣旨ではなく、３種類以上を含む複数の物理量を示してもよい。「第１の検出手段」および「第２の検出手段」は、検出手段としてのセンサの種類を２通りに限定する趣旨ではなく、３種類以上を含む複数のセンサを示してもよい。「単位時間あたりの出力状態」は、例えば出力すべき情報の送信間隔や、出力すべき情報の送信回数またはデータ量など、その変化が受信側の受信率を左右するような送信状態またはその変化が受信側の電力消費を左右するような送信状態を示してもよい。
【００５４】
【発明の効果】
本発明によると、車両の安全性または省電力を向上させるタイヤ状態量検出方法およびタイヤ状態量検出装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の各実施の形態に係るタイヤ状態量検出システムの構成を示す図である。
【図２】本発明の第１の実施の形態におけるタイヤ状態量を検出する方法を示すフローチャートである。
【図３】タイヤのパンク前後の情報送信間隔および情報送信割合の変化を示す図である。
【図４】車輪およびその車輪のタイヤ表面に装着した歪ゲージを示す図である。
【図５】本発明の第５の実施の形態に係る通常時と非常時における情報送信回数の変化を示す図である。
【符号の説明】
１０・・・タイヤ状態量検出システム、１２・・・車両、２０・・・第１車輪、２２・・・第２車輪、２４・・・第３車輪、２６・・・第４車輪、３０・・・第１物理量センサ、３２・・・第２物理量センサ、３４・・・第３物理量センサ、３６・・・第４物理量センサ、４０・・・第１送信機、４２・・・第２送信機、４４・・・第３送信機、４６・・・第４送信機、６２・・・受信機、６４・・・ＥＣＵ、７０・・・ブザー、７２・・・警告ランプ。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tire state quantity detection method and a tire state quantity detection device, and more particularly, to a technique for monitoring a tire state in relation to improving vehicle safety.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a technology of a run-flat tire that can run for a fixed distance even if the internal pressure is reduced due to puncture (for example, see Patent Document 1). The run flat tire has a core assembly provided therein, and when the internal pressure of the tire decreases, the core assembly supports the load applied to the tire.
[0003]
[Patent Document 1]
JP-A-6-297922 (full text, FIG. 1)
[0004]
[Problems to be solved by the invention]
Here, run-flat tires allow for extraordinary driving without changing tires for a while, even in an emergency when the vehicle is in a flat state, and always maintain the running that is performed in a non-flat state It does not do. Therefore, if the run flat tire in the flat state continues running at high speed for a long time, the contact area of the tire increases, so that friction energy and energy due to stress concentration increase, and the temperature of the tire gradually increases. If the temperature of the tire rises beyond an allowable amount, heat may affect the durability of the tire. On the other hand, even if the air pressure of the tire is monitored, the air pressure no longer changes in the flat state in the first place, so that a further change in the state of the tire cannot be detected, which is insufficient.
[0005]
The present invention has been made in view of such a situation, and an object of the present invention is to provide a tire state quantity detection method and a tire state quantity detection device for monitoring a situation change that affects tire durability. is there.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, an aspect of the present invention includes a step of outputting a first physical quantity as a tire state quantity, and a step of outputting a second physical quantity as a tire state quantity different from the first physical quantity, And a method for detecting a tire state quantity. The step of outputting the second physical quantity changes an output state of the information indicating the second physical quantity so that the output quantity increases in accordance with the magnitude of the first physical quantity.
[0007]
According to the tire state quantity detection method of this aspect, the output state of the physical quantity can be controlled based on a plurality of types of physical quantities related to the condition of the tire. Therefore, the output frequency, output resolution, or output amount of the information necessary especially in an emergency can be increased to further improve the safety of the vehicle. On the other hand, at normal times, the frequency of information output can be reduced to reduce power consumption. Note that the frequency of transmitting the second physical quantity may be changed or the frequency of detecting the second physical quantity may be changed as “change the output state”.
[0008]
The step of outputting the second physical quantity includes information indicating the second physical quantity when it is determined based on at least the magnitude of the second physical quantity that the detection importance of the second physical quantity has increased. The output state may be changed so that the output amount per unit time increases. Therefore, more important information among the first physical quantity and the second physical quantity can be intensively output, so that the safety of the vehicle can be further improved.
[0009]
According to another aspect of the present invention, a first detecting means for detecting a first physical quantity as a tire state quantity, and a second detecting means for detecting a second physical quantity as a tire state quantity different from the first physical quantity, And an output unit for outputting the first physical quantity and the second physical quantity. The output unit is configured to output, per unit time, information indicating the second physical quantity detected by the second detection unit in accordance with the magnitude of the first physical quantity detected by the first detection unit. The output state is changed so that the output amount increases.
[0010]
According to the tire state quantity detection device of this aspect, the output state of the output unit can be changed based on a plurality of types of information on the condition of the tire. Therefore, especially in an emergency, the frequency of information output can be increased to further improve the safety of the vehicle. On the other hand, at normal times, the frequency of information output can be reduced to reduce power consumption.
[0011]
The output means outputs the information indicating the second physical quantity per unit time when it is determined based on at least the magnitude of the second physical quantity that the importance of detecting the second physical quantity has increased. The output state may be changed so that the power increases. Therefore, more important information among the first physical quantity and the second physical quantity can be intensively output, so that the safety of the vehicle can be further improved.
[0012]
The second detection means increases the frequency of detection of the second physical quantity according to the magnitude of the first physical quantity detected by the first detection means, thereby increasing the frequency of the second physical quantity by the output means. The output amount of the information indicating the physical quantity per unit time may be increased. In this case, the same effect as changing the output amount itself by the output unit by increasing the detection frequency of the second physical amount can be obtained.
[0013]
The first detecting means may detect a tire pressure as the first physical quantity, and the second detecting means may detect a tire temperature as the second physical quantity. The output means includes information indicating the temperature of the tire detected as the second physical quantity by the second detection means as the air pressure of the tire detected by the first detection means as the first physical quantity is smaller. May be increased per unit time. Thereby, for example, when the air pressure of the run flat tire becomes lower than the air pressure at which safety is guaranteed in the run flat tire, the output frequency of the tire temperature is increased. Therefore, a change in the temperature information can be reliably grasped particularly during the period in which the temperature is to be monitored, and the safety of the vehicle can be further improved.
[0014]
The first detector may detect a kinetic energy of the tire as the first physical quantity, and the second detector may detect a temperature of the tire as the second physical quantity. The output means indicates the temperature of the tire detected as the second physical quantity by the second detection means as the kinetic energy of the tire detected by the first detection means as the first physical quantity is large. The output amount of information per unit time may be increased. Thereby, for example, when the kinetic energy of the run flat tire exceeds the allowable range, the output frequency of the tire temperature is increased. Therefore, a change in the temperature information can be reliably grasped particularly during the period in which the temperature is to be monitored, and the safety of the vehicle can be further improved.
[0015]
The first detection means may detect a tire contact level as the first physical quantity, and the second detection means may detect a tire temperature as the second physical quantity. The output means indicates the temperature of the tire detected as the second physical quantity by the second detection means as the ground contact degree of the tire detected by the first detection means as the first physical quantity is large. The output amount of information per unit time may be increased. Thereby, for example, when the contact level of the run flat tire exceeds the allowable range, the output frequency of the tire temperature is increased. Therefore, a change in the temperature information can be reliably grasped particularly during the period in which the temperature is to be monitored, and the safety of the vehicle can be further improved.
[0016]
The first detecting means may detect a deformation amount of the tire as the first physical quantity, and the second detecting means may detect a temperature of the tire as the second physical quantity. The output means indicates the temperature of the tire detected as the second physical quantity by the second detection means as the deformation amount of the tire detected by the first detection means as the first physical quantity is large. The output amount of information per unit time may be increased. Thus, for example, when the deformation amount of the run flat tire exceeds the allowable range, the output frequency of the tire temperature is increased. Therefore, a change in the temperature information can be reliably grasped particularly during the period in which the temperature is to be monitored, and the safety of the vehicle can be further improved.
[0017]
The output unit is configured to, when the rate of increase in the temperature of the tire detected as the second physical quantity by the second detection unit exceeds a predetermined threshold, output the first detection value detected by the first detection unit. Regardless of the magnitude of the physical quantity, the output amount per unit time of the information indicating the temperature of the tire detected as the second physical quantity by the second detecting means may be increased. As a result, in an emergency such as when the temperature of the run flat tire suddenly rises, the output frequency, output resolution, or output amount of the tire temperature is preferentially increased. Therefore, a change in the temperature information can be reliably grasped particularly during the period in which the temperature is to be monitored, and the safety of the vehicle can be further improved.
[0018]
The output means detects the temperature of the tire detected as the second physical quantity by the second detection means on condition that the air pressure of the tire has decreased to a predetermined value or less indicating that the tire has become flat. The output amount of the indicated information per unit time may be increased. As a result, for example, in an emergency such as when the run flat tire is in a flat state, the output frequency, output resolution, or output amount of the tire temperature is increased. Therefore, a change in the temperature information can be reliably grasped particularly during the period in which the temperature is to be monitored, and the safety of the vehicle can be further improved.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
(First Embodiment)
In the first embodiment of the present invention, when transmitting the information on the temperature detected from the tire to the vehicle body, the transmission of the information indicating the temperature of the tire is performed in accordance with the magnitude of the air pressure detected from the tire. Change the spacing. For example, if the tire air pressure is lower than a predetermined value, the transmission interval of the information indicating the tire temperature is shortened, and the change in the tire temperature is transmitted to the vehicle body in real time. Conversely, if the tire air pressure exceeds a predetermined value, the transmission interval of information indicating the tire temperature is lengthened to reduce power consumption.
[0020]
FIG. 1 shows a configuration of a tire state quantity detection system according to a first embodiment of the present invention. In the tire state quantity detection system 10 mounted on the vehicle 12, each of the first wheel 20, the second wheel 22, the third wheel 24, and the fourth wheel 26 has a sensor for detecting a tire state quantity, a tire state quantity. , And an antenna. Specifically, a first physical quantity sensor 30, a first transmitter 40, and a first antenna 50 are provided on the first wheel 20. A second physical quantity sensor 32, a second transmitter 42, and a second antenna 52 are provided on a wheel of the second wheel 22. The third wheel 24 is provided with a third physical quantity sensor 34, a third transmitter 44, and a third antenna 54. The fourth wheel 26 is provided with a fourth physical quantity sensor 36, a fourth transmitter 46, and a fourth antenna 56. Each tire of the first wheel 20, the second wheel 22, the third wheel 24, and the fourth wheel 26 is a run flat tire.
[0021]
The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 of the present embodiment respectively detect the tire pressure and the tire temperature as tire state quantities. The first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 include the first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36. Transmits the detected tire state information to the vehicle body via the first antenna 50, the second antenna 52, the third antenna 54, and the fourth antenna 56, respectively.
[0022]
Note that the first physical quantity sensor 30 or the first transmitter 40 has a built-in battery for supplying power to the first physical quantity sensor 30 and the first transmitter 40. Similarly, the second physical quantity sensor 32 or the second transmitter 42, the third physical quantity sensor 34 or the third transmitter 44, and the fourth physical quantity sensor 36 or the fourth transmitter 46 also include a battery.
[0023]
The receiver 62 provided on the vehicle body side receives information of the tire state amount from each of the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 via the receiving antenna 60. And sends the received information of the tire state quantity to an electronic control device 64 (hereinafter, the electronic control device 64 is referred to as “ECU 64”). The ECU 64 grasps the state of the tire based on the information of the state of the tire received from the receiver 62. The ECU 64 turns on the warning lamp 72 according to the tire state quantity received from the receiver 62 and makes the buzzer 70 emit a warning sound. For example, when the tire pressure included in the tire state quantity received by the receiver 62 decreases by a predetermined value or more, the ECU 64 turns on the warning lamp 72 and sounds the buzzer 70. Further, for example, when the tire temperature included in the tire state quantity received by the receiver 62 has increased to a predetermined value or more, the ECU 64 warns the occupant about the influence of the tire state on vehicle safety.
[0024]
The initialization switch 68 initializes the monitoring operation of the tire state by the ECU 64. The tire selector 66 selects a tire to be monitored from the first wheel 20, the second wheel 22, the third wheel 24, and the fourth wheel 26.
[0025]
Hereinafter, the operation of each of the above-described configurations will be described. FIG. 2 is a flowchart illustrating a method for detecting a tire state quantity in the present embodiment. Here, a first physical quantity sensor 30 for detecting a tire pressure and a tire temperature of the first wheel 20 and a tire pressure and a tire temperature of the first wheel 20 detected by the first physical quantity sensor 30 are used as information of a tire state quantity on the vehicle body side. An example of the operation of the first transmitter 40 for transmitting the data to is described below. However, the second physical quantity sensor 32 and the second transmitter 42, the third physical quantity sensor 34 and the third transmitter 44, the fourth physical quantity sensor 36 and the fourth transmitter 46 are also the first physical quantity sensor 30 and the first transmitter 40. Works the same as.
[0026]
The tire pressure P of the first wheel 20 detected by the first physical quantity sensor 30 is equal to the tire pressure threshold P. 0 Unless it falls below (S10N), the transmission interval of the tire state quantity by the first transmitter 40 is maintained at 15 minutes (S12), and the monitoring of the tire pressure in S10 is repeatedly performed. Tire pressure threshold P 0 Is a value about 10% to 20% lower than the designed air pressure of the first wheel 20, for example. While repeating the processes of S10 and S12, the first transmitter 40 transmits the information of the tire state quantity relating to the first wheel 20 to the vehicle body at intervals of 15 minutes.
[0027]
The tire pressure P of the first wheel 20 detected by the first physical quantity sensor 30 is equal to the tire pressure threshold P. 0 Is less than (S10Y), it is considered that the first wheel 20 is in a state of insufficient tire durability or in a substantially flat state. Thereafter, the information transmission interval of the first transmitter 40 is changed to 10 seconds for the tire pressure information of the first wheel 20 (S14). The setting of the information transmission interval is maintained at 10 seconds until two minutes elapse after the transmission interval of the tire pressure information of the first wheel 20 is changed to 10 seconds (S16N).
[0028]
After 2 minutes have passed since the transmission interval of the tire pressure information of the first wheel 20 was changed to 10 seconds (S16Y), the transmission interval of the tire pressure information of the first wheel 20 is returned to 15 minutes (S18). ). When the tire temperature T of the first wheel 20 is equal to the first tire temperature threshold T 0 Is exceeded (S20Y), and the tire temperature gradient ΔT is equal to a predetermined tire temperature gradient threshold ΔT. 0 Is exceeded (S22Y), it is considered that the tire temperature of the first wheel 20 has risen sharply, and the transmission interval for the tire temperature information of the first wheel 20 is changed to 30 seconds (S26).
[0029]
In S20, the tire temperature T of the first wheel 20 becomes equal to the first tire temperature threshold T. 0 Does not exceed (S20N), or the tire temperature gradient ΔT is equal to the predetermined tire temperature gradient threshold ΔT in S22. 0 Is not exceeded (S22N), the tire temperature T of the first wheel 20 becomes equal to the second tire temperature threshold T. 1 If it exceeds (S24Y), the transmission interval of the tire temperature information of the first wheel 20 is changed to 30 seconds (S26). That is, the tire temperature gradient no longer increases when the tire temperature is saturated, but if the absolute value of the tire temperature is large, there is a possibility that the durability of the tire will be affected, so the determination in S24 is made. . Second tire temperature threshold T 1 Is set to, for example, about 80 degrees to 100 degrees. However, the second tire temperature threshold T 1 The appropriate value is determined by the running state and the surrounding conditions, and therefore, for example, each parameter such as the vehicle speed, the number of brakes, the outside air temperature, the side G, the steering angle, the steering amount, and the second tire temperature threshold T 1 Is stored in the first physical quantity sensor 30 or the first transmitter 40, and the first physical quantity sensor 30 or the first transmitter 40 stores the table in the second tire temperature threshold T. 1 May be determined each time.
[0030]
In S24, the tire temperature T of the first wheel 20 becomes equal to the second tire temperature threshold T. 1 If it does not exceed (S24N), S26 is skipped. Until the vehicle 12 stops (S28N), the processing from S20 to S26 is repeated.
[0031]
FIG. 3 shows changes in the information transmission interval and the information transmission ratio before and after the tire puncture. The upper part of the figure shows the information transmission interval, and the lower part of the figure shows the information transmission ratio. The horizontal axis indicates the time elapsed. Here, an example of the operation of the first transmitter 40 that transmits the tire pressure and the tire temperature of the first wheel 20 to the vehicle body as information of the tire state quantity will be described. However, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 also function similarly to the first transmitter 40.
[0032]
At the stage before the puncture, the first transmitter 40 transmits both the tire pressure and the tire temperature of the first wheel 20 at intervals of 15 minutes, and the tire pressure and the tire temperature occupying the tire state quantity transmitted by the first transmitter 40. Are equal between 50% and 50%. The transmission interval of the tire pressure is changed to 10 seconds from the time when the tire of the first wheel 20 is punctured to two minutes later, but the transmission interval of the tire temperature is still 15 minutes. The tire state quantity transmitted by 40 occupies a ratio of the information amount of the tire pressure to 100% or close to 100%. At a stage two minutes after the puncture, the transmission interval of the tire pressure is returned to 15 minutes. However, the transmission interval of the tire temperature is changed to 30 seconds depending on the degree of increase in the tire temperature. Transmits the ratio of the information amount of the tire temperature close to 100%. As described above, the output amount per unit time of the tire temperature information transmitted by the first transmitter 40 is increased or decreased by changing the information transmission interval.
(Second embodiment)
The second embodiment of the present invention changes the output state of the tire temperature information according to the magnitude of the tire pressure in that the output state of the tire temperature information is changed according to the magnitude of the kinetic energy of the tire. This is different from the first embodiment of the present invention which is changed. Hereinafter, a description will be given focusing on differences from the first embodiment. The configuration of the present embodiment is shown in FIG. 1 as in the first embodiment.
[0033]
The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 in FIG. 1 correspond to the corresponding first wheel 20, second wheel 22, third wheel 24, and fourth wheel, respectively. 26, the kinetic energy and tire temperature are detected. The kinetic energy here is the number of revolutions of the tire, and the first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 each include an acceleration sensor and a temperature sensor. The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 determine the number of rotations of the tire by integrating the tire rotation acceleration component detected by the acceleration sensor.
[0034]
The first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 are a first physical quantity sensor 30, a second physical quantity sensor 32, a third physical quantity sensor 34, and a fourth physical quantity sensor, respectively. The tire temperature and the tire rotation speed detected by the control unit 36 are transmitted to the vehicle body as tire state quantities. However, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 change the transmission interval of the tire temperature according to the magnitude of the tire rotation speed. For example, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 shorten the tire temperature information transmission interval as the tire rotation speed increases. That is, as the kinetic energy of the tire increases, the possibility that the tire temperature rises and influences the durability of the tire increases. Therefore, when the kinetic energy of the tire is large, the tire temperature is increased in order to reliably capture the change in the tire temperature. Shorten the information transmission interval. On the other hand, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 make the information transmission interval of the tire temperature longer as the tire rotation speed becomes smaller. As a result, in a situation where the tire temperature does not rise excessively, the tire temperature information is not transmitted more than necessary, so that the power consumption of the built-in battery can be reduced.
[0035]
When the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 further include an air pressure sensor, the first transmitter 40, the second transmitter 42, the third transmitter 44 and the fourth transmitter 46 may change the information transmission interval of the tire temperature on condition that the tire air pressure falls below a predetermined threshold. Here, the predetermined threshold value of the tire air pressure is a value that can be considered as the tire being in a flat state. In this case, since the information transmission interval of the tire temperature can be shortened in a situation where the tire is considered to be in the flat state, a change in the tire temperature can be reliably captured and safety can be further improved.
(Third embodiment)
The third embodiment of the present invention is directed to a method for changing the output state of the tire temperature information according to the magnitude of the tire pressure, in that the output state of the tire temperature information is changed according to the amount of deformation of the tire. This is different from the first embodiment of the invention. Hereinafter, a description will be given focusing on differences from the first embodiment. The configuration of the present embodiment is also shown in FIG. 1 as in the first embodiment.
[0036]
The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 in FIG. 1 correspond to the corresponding first wheel 20, second wheel 22, third wheel 24, and fourth wheel, respectively. 26, the tire deformation amount and the tire temperature are detected. The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 each include a strain gauge for detecting a tire deformation and a temperature sensor for detecting a tire temperature.
[0037]
The first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 are a first physical quantity sensor 30, a second physical quantity sensor 32, a third physical quantity sensor 34, and a fourth physical quantity sensor, respectively. The tire deformation amount and the tire temperature detected by 36 are transmitted to the vehicle body as tire state quantities. However, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 change the information transmission interval of the tire temperature according to the amount of the tire deformation. For example, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 shorten the tire temperature information transmission interval as the amount of tire deformation increases. In other words, the larger the amount of tire deformation, the higher the possibility that the tire temperature will increase and affect the durability of the tire. Therefore, when the amount of tire deformation is large, information on the tire temperature is transmitted to reliably capture the change in the tire temperature. Shorten the interval. On the other hand, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 make the information transmission interval of the tire temperature longer as the tire deformation amount is smaller. As a result, in a situation where the tire temperature does not rise excessively, the tire temperature information is not transmitted more than necessary, so that the power consumption of the built-in battery can be reduced.
[0038]
FIG. 4 shows a wheel and a strain gauge mounted on a tire surface of the wheel. As illustrated, a plurality of strain gauges 82 are mounted on the sidewall surface of the tire 80, and the plurality of strain gauges 82 detect the amount of deformation of the sidewall of the tire 80.
[0039]
When the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 further include an air pressure sensor, the first transmitter 40, the second transmitter 42, the third transmitter 44 and the fourth transmitter 46 may change the information transmission interval of the tire temperature on condition that the tire air pressure falls below a predetermined threshold. Here, the predetermined threshold value of the tire air pressure is a value that can be considered as the tire being in a flat state. In this case, since the information transmission interval of the tire temperature can be shortened in a situation where the tire is considered to be in the flat state, a change in the tire temperature can be reliably captured and safety can be further improved.
(Fourth embodiment)
The fourth embodiment of the present invention is directed to a method for changing the output state of the tire temperature information according to the magnitude of the tire air pressure, in that the output state of the tire temperature information is changed according to the contact property of the tire. This is different from the first embodiment of the invention. Hereinafter, a description will be given focusing on differences from the first embodiment. The configuration of the present embodiment is also shown in FIG. 1 as in the first embodiment.
[0040]
The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 in FIG. 1 correspond to the corresponding first wheel 20, second wheel 22, third wheel 24, and fourth wheel, respectively. 26, a tire contact property and a tire temperature are detected. Here, the tire contact property is the contact area of the tire, and the first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 are respectively an air pressure sensor, a strain gauge, and a temperature sensor. Including. The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 are provided with a deformation amount of a sidewall and an air pressure detected by a strain gauge mounted on a tire surface as shown in FIG. The contact area of the tire is determined based on the tire pressure detected by the sensor.
[0041]
The first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 are a first physical quantity sensor 30, a second physical quantity sensor 32, a third physical quantity sensor 34, and a fourth physical quantity sensor, respectively. The tire temperature and the ground contact area of the tire detected by 36 are transmitted to the vehicle body as tire state quantities. However, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 change the information transmission interval of the tire temperature according to the size of the tire contact area. For example, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 shorten the information transmission interval of the tire temperature as the tire contact area increases. In other words, the larger the tire contact area, the higher the possibility that the tire temperature will increase and affect the durability of the tire. Therefore, when the tire contact area is large, the tire temperature information is transmitted to reliably capture the change in the tire temperature. Shorten the interval. On the other hand, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 make the information transmission interval of the tire temperature longer as the tire contact area is smaller. As a result, in a situation where the tire temperature does not rise excessively, the tire temperature information is not transmitted more than necessary, so that the power consumption of the built-in battery can be reduced.
[0042]
The first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 change the tire temperature information transmission interval on condition that the tire air pressure falls below a predetermined threshold. May be. Here, the predetermined threshold value of the tire air pressure is a value that can be considered as the tire being in a flat state. In this case, since the information transmission interval of the tire temperature can be shortened in a situation where the tire is considered to be in the flat state, a change in the tire temperature can be reliably captured and safety can be further improved. (Fifth embodiment)
The fifth embodiment of the present invention is the first to fourth embodiments of the present invention in which the transmitter of each wheel changes the information transmission interval in that the transmitter of each wheel changes the number of times of transmitting information. Different from form. The following description focuses on the differences from the first to fourth embodiments.
[0043]
FIG. 5 shows a change in the number of times of information transmission between a normal state and an emergency. As shown in the drawing, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 transmit each information of the ID, the tire pressure, and the tire temperature as the tire state quantity to the vehicle body side. I do. The ID is identification information uniquely assigned to each of the first wheel 20, the second wheel 22, the third wheel 24, and the fourth wheel 26, and is mounted by a wheel mounted on another vehicle or by tire replacement. Also distinguished from commercially available wheels.
[0044]
Normally, that is, in a state where the first wheel 20, the second wheel 22, the third wheel 24, and the fourth wheel 26 are not punctured, the first transmitter 40, the second transmitter 42, the third transmitter 44, and The fourth transmitter 46 transmits the information of the tire state quantity configured to send the ID, the tire pressure, and the tire temperature once each.
[0045]
In an emergency, that is, when the first wheel 20, the second wheel 22, the third wheel 24, and the fourth wheel 26 are punctured, the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth The transmitter 46 transmits information of the tire state quantity configured so that the ID is transmitted once and the tire temperature is transmitted three times.
[0046]
The change in the information output state by the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 according to the present embodiment is realized in the form of a change in the number of times of information transmission. In the first to fourth embodiments of the present invention, the change in the information transmission interval by the first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 is referred to as a change in the information output state. Although described, these can be replaced by the change in the number of times of information transmission of the present embodiment. For example, when the first embodiment is applied, the transmitters below the first transmitter 40 increase the number of times of transmitting the information of the tire temperature as the tire pressure becomes smaller. When the second embodiment is applied, the transmitters below the first transmitter 40 increase the number of transmissions of the tire temperature information as the tire kinetic energy increases. When the third embodiment is applied, each of the transmitters below the first transmitter 40 increases the number of times of transmitting the information on the tire temperature as the amount of deformation of the tire increases. When the fourth embodiment is applied, the transmitters below the first transmitter 40 increase the number of times of transmitting the tire temperature information as the tire contact level increases. As described above, the output amount per unit time of the tire temperature information transmitted by each transmitter below the first transmitter 40 changes depending on the increase / decrease of the number of times of information transmission.
[0047]
The present invention has been described based on the embodiments. Note that the present invention is not limited to this embodiment, and various modifications thereof are also effective as aspects of the present invention. Hereinafter, modified examples will be described.
[0048]
In the second embodiment of the present invention, each of the physical quantity sensors below the first physical quantity sensor 30 is configured to detect the tire rotation speed as the kinetic energy of the tire of each corresponding wheel below the first wheel 20. . In a modified example, each physical quantity sensor below the first physical quantity sensor 30 may detect the driving torque of the tire as the kinetic energy of the tire of each corresponding wheel below the first wheel 20. In this case, each of the physical quantity sensors below the first physical quantity sensor 30 may include an acceleration sensor, and may calculate the tire driving torque based on the acceleration component detected by the acceleration sensor. In still another modified example, each physical quantity sensor below the first physical quantity sensor 30 may detect the load of the tire as the kinetic energy of the tire of each corresponding wheel below the first wheel 20. In this case, each of the physical quantity sensors below the first physical quantity sensor 30 includes a strain gauge and an air pressure sensor, and calculates the tire load based on the tire deformation detected by the strain gauge and the tire pressure detected by the air pressure sensor. You may.
[0049]
In the third embodiment of the present invention, each of the physical quantity sensors below the first physical quantity sensor 30 includes a strain gauge provided on the sidewall of the tire, and the strain gauge detects a tire deformation amount. Met. In a modified example, the tire deformation amount may be obtained by measuring the distance between the tire and the wheel. Further, in the third embodiment, the configuration in which the information transmission interval of the tire temperature is changed according to the magnitude of the tire deformation amount has been described. In a modified example, each of the transmitters below the first transmitter 40 may change the information transmission interval of the tire deformation amount according to the height of the tire temperature.
[0050]
In the fourth embodiment of the present invention, each physical quantity sensor below the first physical quantity sensor 30 is configured to detect the contact area of the tire as the tire contact level of each corresponding wheel below the first wheel 20. . In a modified example, each of the physical quantity sensors below the first physical quantity sensor 30 may detect the coefficient of friction between the tire and the road surface as the tire contact level of each corresponding wheel below the first wheel 20. In this case, each of the physical quantity sensors below the first physical quantity sensor 30 may include a strain gauge, and may determine the road surface μ of the tire based on the amount of tire deformation detected by the strain gauge.
[0051]
In the first to fourth embodiments of the present invention, the information transmission interval of each transmitter below the first transmitter 40 is set to any one of 10 seconds, 30 seconds, and 15 minutes. The detection interval of the tire state quantity by each physical quantity sensor equal to or less than one physical quantity sensor 30 may be set to 10 seconds, 30 seconds, or 15 minutes. Further, in the first to fourth embodiments of the present invention, the information transmission intervals of the respective transmitters below the first transmitter 40 are changed. By changing the detection interval of the tire state quantity by each physical quantity sensor, the information transmission interval by each transmitter below the first transmitter 40 may be changed as a result.
[0052]
Hereinafter, the correspondence between the members constituting the tire state quantity detection system 10 of each embodiment of the present invention and the members described in the claims will be exemplified. The first physical quantity sensor 30, the second physical quantity sensor 32, the third physical quantity sensor 34, and the fourth physical quantity sensor 36 in FIG. 1 correspond to the "first detecting means" and the "second detecting means" in claim 3. I do. The first transmitter 40, the second transmitter 42, the third transmitter 44, and the fourth transmitter 46 correspond to “output means” according to claim 3. The “first detecting means”, the “second detecting means”, and the “output means” may be configured as separate units, or may be configured as an integrated unit in any combination. Good.
[0053]
The wording described in the claims may be interpreted as follows. The “first physical quantity” and the “second physical quantity” are not intended to limit the types of physical quantities to be detected to two types, but may indicate a plurality of physical quantities including three or more types. The "first detecting means" and the "second detecting means" are not intended to limit the types of sensors as the detecting means to two types, but may indicate a plurality of sensors including three or more types. The "output state per unit time" is, for example, a transmission state or a change thereof such as a transmission interval of information to be output, the number of times of transmission of information to be output or a data amount, the change of which affects the reception rate of the receiving side. May indicate a transmission state in which power consumption on the receiving side is affected.
[0054]
【The invention's effect】
According to the present invention, it is possible to provide a tire state quantity detection method and a tire state quantity detection device that improve vehicle safety or power saving.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a tire state quantity detection system according to each embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method for detecting a tire state quantity according to the first embodiment of the present invention.
FIG. 3 is a diagram illustrating changes in an information transmission interval and an information transmission ratio before and after a tire puncture.
FIG. 4 is a diagram showing a wheel and a strain gauge mounted on a tire surface of the wheel.
FIG. 5 is a diagram illustrating a change in the number of times of information transmission between a normal time and an emergency according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... tire state quantity detection system, 12 ... vehicle, 20 ... 1st wheel, 22 ... 2nd wheel, 24 ... 3rd wheel, 26 ... 4th wheel, 30 ... ..First physical quantity sensor, 32 ... second physical quantity sensor, 34 ... third physical quantity sensor, 36 ... fourth physical quantity sensor, 40 ... first transmitter, 42 ... second transmission , 44 ... third transmitter, 46 ... fourth transmitter, 62 ... receiver, 64 ... ECU, 70 ... buzzer, 72 ... warning lamp.

Claims (11)

タイヤ状態量として第１の物理量を出力するステップと、
前記第１の物理量と異なるタイヤ状態量として第２の物理量を出力するステップと、を含み、
前記第２の物理量を出力するステップは、前記第１の物理量の大きさに応じて、前記第２の物理量を示す情報の出力量が増加するようにその出力状態を変化させることを特徴とするタイヤ状態量検出方法。Outputting a first physical quantity as a tire state quantity;
Outputting a second physical quantity as a tire state quantity different from the first physical quantity,
The step of outputting the second physical quantity changes an output state of the information indicating the second physical quantity so that the output quantity increases in accordance with the magnitude of the first physical quantity. Tire state quantity detection method. 前記第２の物理量を出力するステップは、少なくとも前記第２の物理量の大きさに基づき、前記第２の物理量の検出重要性が増加したと判断された場合に、前記第２の物理量を示す情報の単位時間あたりの出力量が増加するように前記出力状態を変化させることを特徴とする請求項１に記載のタイヤ状態量検出方法。The step of outputting the second physical quantity includes information indicating the second physical quantity when it is determined based on at least the magnitude of the second physical quantity that the importance of detecting the second physical quantity has increased. The tire state quantity detection method according to claim 1, wherein the output state is changed such that the output quantity per unit time increases. タイヤ状態量として第１の物理量を検出する第１の検出手段と、前記第１の物理量と異なるタイヤ状態量として第２の物理量を検出する第２の検出手段と、前記第１の物理量および前記第２の物理量を出力する出力手段と、を備えたタイヤ状態量検出装置において、
前記出力手段は、前記第１の検出手段により検出された前記第１の物理量の大きさに応じて、前記第２の検出手段により検出された前記第２の物理量を示す情報の単位時間あたりの出力量が増加するようにその出力状態を変化させることを特徴とするタイヤ状態量検出装置。First detecting means for detecting a first physical quantity as a tire state quantity; second detecting means for detecting a second physical quantity as a tire state quantity different from the first physical quantity; Output means for outputting a second physical quantity, the tire state quantity detection device comprising:
The output unit is configured to output, per unit time, information indicating the second physical quantity detected by the second detection unit in accordance with the magnitude of the first physical quantity detected by the first detection unit. A tire state quantity detecting device that changes the output state so that the output amount increases. 前記出力手段は、少なくとも前記第２の物理量の大きさに基づき、前記第２の物理量の検出重要性が増加したと判断された場合に、前記第２の物理量を示す情報の単位時間あたりの出力量が増加するように前記出力状態を変化させることを特徴とする請求項３に記載のタイヤ状態量検出装置。The output unit outputs the information indicating the second physical quantity per unit time when it is determined that the detection importance of the second physical quantity has increased based on at least the magnitude of the second physical quantity. The tire state quantity detecting device according to claim 3, wherein the output state is changed so that the force amount increases. 前記第２の検出手段は、前記第１の検出手段により検出された前記第１の物理量の大きさに応じて前記第２の物理量の検出頻度を高めることにより、前記出力手段による前記第２の物理量を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項３または４に記載のタイヤ状態量検出装置。The second detection means increases the frequency of detection of the second physical quantity according to the magnitude of the first physical quantity detected by the first detection means, so that the second The tire state quantity detection device according to claim 3 or 4, wherein an output amount per unit time of information indicating a physical quantity is increased. 前記第１の検出手段は、前記第１の物理量としてタイヤの空気圧を検出し、
前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出し、
前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの空気圧が小さいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項３から５のいずれかに記載のタイヤ状態量検出装置。The first detecting means detects a tire air pressure as the first physical quantity,
The second detection means detects a tire temperature as the second physical quantity,
The output means includes information indicating the temperature of the tire detected as the second physical quantity by the second detection means as the air pressure of the tire detected by the first detection means as the first physical quantity is smaller. The tire state quantity detection device according to any one of claims 3 to 5, wherein the output amount per unit time is increased. 前記第１の検出手段は、前記第１の物理量としてタイヤの運動エネルギーを検出し、
前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出し、
前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの運動エネルギーが大きいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項３から５のいずれかに記載のタイヤ状態量検出装置。The first detection means detects a kinetic energy of the tire as the first physical quantity,
The second detection means detects a tire temperature as the second physical quantity,
The output means indicates the temperature of the tire detected as the second physical quantity by the second detection means as the kinetic energy of the tire detected by the first detection means as the first physical quantity is large. The tire state quantity detecting device according to any one of claims 3 to 5, wherein an output amount of information per unit time is increased. 前記第１の検出手段は、前記第１の物理量としてタイヤの接地度を検出し、
前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出し、
前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの接地度が大きいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項３から５のいずれかに記載のタイヤ状態量検出装置。The first detection means detects a tire contact level as the first physical quantity,
The second detection means detects a tire temperature as the second physical quantity,
The output means indicates the temperature of the tire detected as the second physical quantity by the second detection means as the ground contact degree of the tire detected by the first detection means as the first physical quantity is large. The tire state quantity detecting device according to any one of claims 3 to 5, wherein an output amount of information per unit time is increased. 前記第１の検出手段は、前記第１の物理量としてタイヤの変形量を検出し、
前記第２の検出手段は、前記第２の物理量としてタイヤの温度を検出し、
前記出力手段は、前記第１の検出手段により前記第１の物理量として検出されたタイヤの変形量が大きいほど、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項３から５のいずれかに記載のタイヤ状態量検出装置。The first detecting means detects a tire deformation amount as the first physical quantity,
The second detection means detects a tire temperature as the second physical quantity,
The output means indicates the temperature of the tire detected as the second physical quantity by the second detection means as the deformation amount of the tire detected by the first detection means as the first physical quantity is large. The tire state quantity detecting device according to any one of claims 3 to 5, wherein an output amount of information per unit time is increased. 前記出力手段は、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度の上昇率が所定の閾値を超えた場合、前記第１の検出手段により検出された前記第１の物理量の大きさにかかわらず前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項６から９のいずれかに記載のタイヤ状態量検出装置。The output unit is configured to, when the rate of increase in the temperature of the tire detected as the second physical quantity by the second detection unit exceeds a predetermined threshold, output the first detection value detected by the first detection unit. The output amount per unit time of information indicating the temperature of the tire detected as the second physical quantity by the second detecting means regardless of the magnitude of the physical quantity is increased. The tire state quantity detection device according to any one of the above. 前記出力手段は、タイヤがフラット状態になったことを示す所定値以下までタイヤの空気圧が低下したことを条件に、前記第２の検出手段により前記第２の物理量として検出されたタイヤの温度を示す情報の単位時間あたりの出力量を増加させることを特徴とする請求項６から１０のいずれかに記載のタイヤ状態量検出装置。The output means detects the temperature of the tire detected as the second physical quantity by the second detection means on condition that the air pressure of the tire has decreased to a predetermined value or less indicating that the tire has become flat. The tire state quantity detecting device according to any one of claims 6 to 10, wherein an output amount of the information to be displayed per unit time is increased.
JP2003133492A 2003-05-12 2003-05-12 Tire state quantity detection method and tire state quantity detection device Expired - Fee Related JP4069798B2 (en)

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US7427915B2 (en) 2003-09-25 2008-09-23 Toyota Jidosha Kabushiki Kaisha Vehicle wheel information processing device and method therefor
WO2005100053A1 (en) * 2004-04-12 2005-10-27 Bridgestone Corporation Method and device for determining end of run-flat run life of run-flat tire
US7543489B2 (en) 2004-04-12 2009-06-09 Bridgestone Corporation Method and device for determining endstage of lifetime of run-flat tire under run-flat state
JP2006193058A (en) * 2005-01-14 2006-07-27 Yokohama Rubber Co Ltd:The Tire cooling device
JP2006208052A (en) * 2005-01-25 2006-08-10 Bridgestone Corp Distortion sensor for rubber article
JP2006224715A (en) * 2005-02-15 2006-08-31 Yokohama Rubber Co Ltd:The Tire information transmitting device, and tire information collecting system using it
JP4604755B2 (en) * 2005-02-15 2011-01-05 横浜ゴム株式会社 Tire information transmitting apparatus and tire information acquiring system using the same
JP2006327324A (en) * 2005-05-24 2006-12-07 Fuji Heavy Ind Ltd Tire state monitoring device
JP2007261288A (en) * 2006-03-27 2007-10-11 Alps Electric Co Ltd Apparatus for detecting information about tire
JP2007334465A (en) * 2006-06-13 2007-12-27 Rkc Instrument Inc Radio measurement device
JP2008292318A (en) * 2007-05-24 2008-12-04 Kobe Steel Ltd Temperature sensor system
WO2009025172A1 (en) * 2007-08-21 2009-02-26 Sumitomo Rubber Industries, Ltd. Tire action force detecting method, and pneumatic tire used in the method
US7971477B2 (en) 2007-08-21 2011-07-05 Sumitomo Rubber Industries, Ltd. Detection method for forces acting on tire and pneumatic tire used therein
JP2010122168A (en) * 2008-11-21 2010-06-03 Nissan Motor Co Ltd Device and method for detecting wheel air pressure
JP2015174523A (en) * 2014-03-14 2015-10-05 太平洋工業株式会社 Tire condition monitoring device
CN113195262A (en) * 2018-12-21 2021-07-30 米其林集团总公司 Method for obtaining the deformation of a tyre under load during running
CN113195262B (en) * 2018-12-21 2023-05-05 米其林集团总公司 Method for obtaining deformation of a tyre under load during driving
CN113272160A (en) * 2019-01-09 2021-08-17 横滨橡胶株式会社 Tire failure prediction system and tire failure prediction method

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