JP2003182476A - Device for estimating road surface condition and tire traveling condition, and vehicle control device - Google Patents
Device for estimating road surface condition and tire traveling condition, and vehicle control deviceInfo
- Publication number
- JP2003182476A JP2003182476A JP2001390560A JP2001390560A JP2003182476A JP 2003182476 A JP2003182476 A JP 2003182476A JP 2001390560 A JP2001390560 A JP 2001390560A JP 2001390560 A JP2001390560 A JP 2001390560A JP 2003182476 A JP2003182476 A JP 2003182476A
- Authority
- JP
- Japan
- Prior art keywords
- tire
- vibration
- road surface
- condition
- running
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、走行時のタイヤの
走行状態及びタイヤが接地している路面の状態を推定す
るための装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for estimating a running state of a tire during running and a state of a road surface on which the tire is in contact with the ground.
【０００２】[0002]
【従来の技術】自動車の走行安定性を高めるため、走行
時のタイヤの状態やタイヤが接地している路面状態を精
度良く推定し、車両制御へフィードバックすることが求
められている。ここで、タイヤの状態は、タイヤ内圧、
摩耗、故障の予知等であり、路面状態は主に路面とタイ
ヤとの摩擦係数（路面摩擦係数μ）を指す。予めタイヤ
の走行状態や路面状態を推定することができれば、タイ
ヤが故障を起こす前に車を停めて点検を行ったり、制駆
動や操舵といった危険回避の操作を起こす前に、例え
ば、ＡＢＳブレーキのより高度な制御等が可能になり、
安全性が一段と高まることが予想される。また、運転者
に走行中の路面状態の危険度を伝えるだけでも、運転者
が早めの減速動作を行えるようになり、事故の減少が期
待できる。従来、路面摩擦係数を推定する方法として
は、車輪の回転速度の変動を表わす物理量であるタイヤ
のユニフォミティレベルが、路面摩擦係数の大きさによ
って変化することを利用して路面摩擦係数を推定する方
法（特開２０００−５５７９０号公報）や、前輪と車体
とを連結するロアアームに加速度計を取付けて、トー角
がついているタイヤの横振動を検出し、その振動レベル
が路面摩擦係数によって変化することを利用して路面摩
擦係数を推定する方法（特開平６−２５８１９６号公
報）などが提案されている。2. Description of the Related Art In order to improve the running stability of an automobile, it is required to accurately estimate the condition of the tire during running and the condition of the road surface on which the tire is in contact with the ground and feed it back to the vehicle control. Here, the state of the tire is the tire internal pressure,
The road surface condition mainly indicates the friction coefficient between the road surface and the tire (road surface friction coefficient μ), such as wear and failure prediction. If it is possible to estimate the running condition and road condition of the tires in advance, stop the vehicle before the tires break down and inspect it, or perform the risk avoidance operation such as braking / driving or steering, for example, if the ABS brake It enables more advanced control,
It is expected that safety will be further enhanced. In addition, it is possible to expect a reduction in accidents by allowing the driver to carry out a deceleration operation earlier by simply notifying the driver of the degree of danger of the road surface condition during traveling. Conventionally, as a method of estimating the road surface friction coefficient, a method of estimating the road surface friction coefficient by utilizing that the uniformity level of the tire, which is a physical quantity that represents the fluctuation of the wheel rotation speed, changes depending on the magnitude of the road surface friction coefficient. (Japanese Patent Laid-Open No. 2000-55790) or an accelerometer attached to a lower arm that connects a front wheel and a vehicle body to detect lateral vibration of a tire having a toe angle, and the vibration level changes depending on a road surface friction coefficient. There is proposed a method of estimating a road surface friction coefficient by utilizing (JP-A-6-258196).
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記タ
イヤのユニフォミティレベルから路面摩擦係数を推定す
る方法では、タイヤにフラットスポットが生じてユニフ
ォミティが悪化し、これが回復していく過程では、正確
な推定が困難であった。一方、上記トー角がついている
前輪の横振動から路面摩擦係数を推定する方法では、タ
イヤのスリップ角が完全にゼロになった場合や、大きな
スリップ角がついた場合などでの測定精度が低いといっ
た問題点があった。また、車輪の上下方向の加速度であ
るバネ下加速度と、車体の上下方向の加速度であるバネ
上加速度間の伝達特性から路面摩擦係数を推定する方法
も提案されている（特開平１１−９４６６１号公報）。
この方法では、路面摩擦係数の推定に操舵力を用いてい
ないため、操舵がほとんど行われない直線路においても
路面摩擦係数を推定することができるという利点がある
が、バネやダンパー等の緩衝特性の大きな懸架装置を介
した２点間の振動の伝達特性から路面摩擦係数を推定し
ているため、路面の凹凸の影響を受けやすいといった問
題点があった。例えば、雪上などの荒れた路面上におい
ては、バネ下の振動が大きくなるため、サスペンション
によって振動が吸収されるバネ上の振動と、上記バネ下
の振動との振動レベル差が大きくなってしまい、路面摩
擦係数を正確に推定することができなかった。However, in the method of estimating the road surface friction coefficient from the uniformity level of the tire, a flat spot occurs on the tire to deteriorate the uniformity, and in the process of recovering it, accurate estimation is not possible. It was difficult. On the other hand, in the method of estimating the road surface friction coefficient from the lateral vibration of the front wheel with the toe angle, the measurement accuracy is low when the tire slip angle becomes completely zero or when a large slip angle is attached. There was a problem such as. Further, a method of estimating a road surface friction coefficient from a transfer characteristic between an unsprung acceleration which is a vertical acceleration of a wheel and an unsprung acceleration which is a vertical acceleration of a vehicle body has been proposed (Japanese Patent Laid-Open No. 11-94661). Gazette).
Since this method does not use the steering force to estimate the road surface friction coefficient, it has the advantage that the road surface friction coefficient can be estimated even on a straight road where steering is rarely performed. Since the road surface friction coefficient is estimated from the transmission characteristics of vibration between two points via a large suspension device, there is a problem that it is easily affected by road surface irregularities. For example, on a rough road surface such as snow, the unsprung vibration becomes large, so the vibration level difference between the unsprung vibration and the unsprung vibration that is absorbed by the suspension becomes large. The road surface friction coefficient could not be estimated accurately.
【０００４】本発明は、従来の問題点に鑑みてなされた
もので、制駆動や操舵といった動作が加わらない一定速
走行時に、タイヤの接地している路面状態やタイヤの走
行状態を精度良く推定して、車両の走行安全性を向上さ
せることを目的とする。The present invention has been made in view of the problems of the prior art, and accurately estimates the road surface state where the tire is in contact with the ground and the running state of the tire at the time of running at a constant speed where operations such as braking and driving are not added. Then, it aims at improving the running safety of the vehicle.
【０００５】[0005]
【課題を解決するための手段】本発明者らは、走行中の
タイヤの接地挙動や、故障時のタイヤ挙動を詳細に検討
した結果、走行中のタイヤの周方向の振動、あるいは、
幅方向の振動を周波数分析して得られた上記振動の周波
数スペクトル（振動スペクトル）の、１つあるいは複数
の周波数帯域での振動レベルが、タイヤが接地している
路面の状態やタイヤの故障形態によって特徴的に変化し
ていることを把握した。そこで、このような振動をタイ
ヤ自体の振動、あるいは、上記タイヤから伝播したホイ
ールやサスペンション部の振動として検出することによ
り、路面状態及びタイヤ走行状態を精度良く推定するこ
とができることを見出し本発明に到ったものである。す
なわち、請求項１に記載の路面状態及びタイヤ走行状態
推定装置は、タイヤが接地する路面状態及び走行中のタ
イヤの状態を推定する路面状態及びタイヤ走行状態推定
装置であって、走行中の車両のタイヤまたはホイールの
振動を検出する振動検出手段と、上記検出された振動を
周波数分析して得られる周波数スペクトルの、路面状態
やタイヤの走行状態によって、その振動レベルが特徴的
に変化する周波数範囲、すなわち、少なくとも１０〜１
００００Ｈｚの範囲に含まれる周波数帯域の振動レベル
を検出する手段と、上記検出された振動レベルから、走
行時の路面状態及びタイヤの走行状態を推定する手段と
を備えたものである。請求項２に記載の路面状態及びタ
イヤ走行状態推定装置は、上記振動を、タイヤまたはホ
イールの幅方向の振動としたものである。請求項３に記
載の路面状態及びタイヤ走行状態推定装置は、上記振動
を、タイヤまたはホイールの周方向の振動としたもので
ある。Means for Solving the Problems As a result of detailed examination of the ground contact behavior of a tire during traveling and the tire behavior at the time of failure, the present inventors have found that the tire vibrates in the circumferential direction during traveling, or
The vibration level in one or more frequency bands of the frequency spectrum (vibration spectrum) of the above-mentioned vibration obtained by frequency-analyzing the vibration in the width direction indicates the condition of the road surface on which the tire is grounded or the tire failure mode. It was understood that it changed characteristically by. Therefore, by detecting such vibration as the vibration of the tire itself, or the vibration of the wheel or the suspension portion propagated from the tire, it is found that the road surface state and the tire running state can be accurately estimated. It has arrived. That is, the road surface state and tire running state estimation device according to claim 1 is a road surface state and tire running state estimation device for estimating a road surface state where a tire is in contact with a ground and a running tire state. Vibration detection means for detecting the vibration of the tire or wheel, and the frequency spectrum obtained by frequency-analyzing the detected vibration, the frequency range in which the vibration level characteristically changes depending on the road surface condition and the running condition of the tire. , Ie at least 10-1
It is provided with means for detecting a vibration level in a frequency band included in the range of 0000 Hz, and means for estimating a road surface state and a running state of tires during running from the detected vibration level. In the road surface condition and tire running condition estimating device according to the second aspect, the vibration is vibration in the width direction of the tire or the wheel. In the road surface condition and tire running condition estimating device according to the third aspect, the vibration is vibration in the circumferential direction of the tire or the wheel.
【０００６】また、請求項４に記載の路面状態及びタイ
ヤ走行状態推定装置は、上記振動検出手段を、タイヤ内
に充填された気体の圧力をモニタリングする圧力センサ
と同一の基板上、または、同一の筐体内に設置したもの
で、これにより、基板を共有化することができ、装置の
小型化と低コスト化を実現することが可能となる。請求
項５に記載の路面状態及びタイヤ走行状態推定装置は、
上記振動検出手段または上記振動検出手段を設置する基
板を、タイヤまたはホイールに取付けたものである。In the road surface condition and tire running condition estimating device according to a fourth aspect of the present invention, the vibration detecting means is provided on the same substrate as or on the same substrate as a pressure sensor for monitoring the pressure of gas filled in the tire. It is installed in the housing of the above, and by doing so, the substrate can be shared, and it becomes possible to realize the downsizing and cost reduction of the device. The road surface state and tire running state estimation device according to claim 5,
The vibration detecting means or the substrate on which the vibration detecting means is installed is attached to a tire or a wheel.
【０００７】請求項６に記載の路面状態及びタイヤ走行
状態推定装置は、非転動部である車体側から、無線に
て、転動部であるタイヤまたはホイールに取付けられた
上記振動検出手段を駆動するようにしたもので、これに
より、転動部に設けられていた、センサ駆動・検出用電
源などのバッテリーを省略することができるので、振動
検出部を小型軽量化することが可能となる。According to a sixth aspect of the present invention, there is provided a road surface state and tire running state estimating apparatus which wirelessly detects vibrations from the vehicle body side which is a non-rolling portion and which is attached to a tire or a wheel which is a rolling portion. The vibration detector can be made smaller and lighter because the battery for the sensor drive / detection power supply, etc., which is provided in the rolling portion, can be omitted. .
【０００８】請求項７に記載の路面状態及びタイヤ走行
状態推定装置は、タイヤまたはホイール部に信号処理手
段を設け、上記振動検出手段で検出された振動情報信号
をデジタル変換するとともにこれを圧縮して車体側に送
信し、車体側にて上記圧縮信号を受信して復元し、これ
を周波数分析するようにしたもので、このように、デジ
タルデータ圧縮技術を応用してデータ量を少なくして送
信することにより、連続データ通信が可能となるととも
に、振動レベルの検出精度を向上させることが可能とな
る。また、請求項８に記載の路面状態及びタイヤ走行状
態推定装置は、送信するデータ量を少なくして連続デー
タ通信を可能とするため、タイヤまたはホイール部に信
号処理手段を設置し、上記振動検出手段で検出された振
動情報信号をタイヤまたはホイール部にて周波数分析し
て走行時の路面状態及びタイヤの走行状態を推定し、こ
の推定された走行時の路面状態及びタイヤの走行状態を
表わすデータを車体側に送信するようにしたものであ
る。A road surface condition and tire running condition estimating device according to a seventh aspect of the present invention is provided with a signal processing means in a tire or a wheel portion, which digitally converts a vibration information signal detected by the vibration detecting means and compresses it. It transmits to the vehicle body side, receives the above compressed signal on the vehicle body side, decompresses it, and frequency analyzes this.In this way, the amount of data is reduced by applying digital data compression technology. By transmitting, it becomes possible to perform continuous data communication and to improve the detection accuracy of the vibration level. Further, the road surface condition and tire running condition estimating device according to claim 8 reduces the amount of data to be transmitted to enable continuous data communication. The vibration information signal detected by the means is subjected to frequency analysis at the tire or wheel to estimate the road surface condition and the tire running condition during running, and the data representing the estimated road surface condition and running condition of the tire during running. Is transmitted to the vehicle body side.
【０００９】請求項９に記載の路面状態及びタイヤ走行
状態推定装置は、上記データの通信を行うためのアンテ
ナ機能を、ホイール部に取付けられているタイヤバルブ
に持たせたものである。また、請求項１０に記載の路面
状態及びタイヤ走行状態推定装置は、上記データの通信
を行うためのアンテナを、ホイールリム部の周上に設け
たものである。In the road surface condition and tire running condition estimating device according to a ninth aspect, a tire valve attached to a wheel portion is provided with an antenna function for communicating the above data. In the road surface condition and tire running condition estimating device according to the tenth aspect, an antenna for communicating the data is provided on the circumference of the wheel rim portion.
【００１０】請求項１１に記載の路面状態及びタイヤ走
行状態推定装置は、走行中の車両のサスペンション部の
振動を検出する振動検出手段と、上記検出された振動を
周波数分析して得られる周波数スペクトルの、少なくと
も１０〜１００００Ｈｚの範囲に含まれる周波数帯域の
振動レベルを検出する手段と、上記検出された振動レベ
ルから、走行時の路面状態及びタイヤの走行状態を推定
する手段とを備え、タイヤからサスペンション部に伝播
されたタイヤの振動を検出して、路面状態及びタイヤ走
行状態を推定するようにしたものである。請求項１２に
記載の路面状態及びタイヤ走行状態推定装置は、上記サ
スペンション部の振動を検出する振動検出手段を、ホイ
ールが取付けられているハブと一体化された部位に取付
けたものである。A road surface condition and tire running condition estimating apparatus according to claim 11 is a vibration detecting means for detecting a vibration of a suspension portion of a running vehicle, and a frequency spectrum obtained by frequency-analyzing the detected vibration. Of the tire, comprising means for detecting a vibration level in a frequency band included in a range of at least 10 to 10000 Hz, and means for estimating a road surface condition during running and a running condition of the tire from the detected vibration level. The tire vibration propagated to the suspension is detected to estimate the road surface condition and the tire running condition. According to a twelfth aspect of the present invention, the road surface state and tire running state estimating apparatus has a vibration detecting means for detecting the vibration of the suspension portion, which is attached to a portion integrated with a hub to which a wheel is attached.
【００１１】また、請求項１３に記載の路面状態及びタ
イヤ走行状態推定置は、リセットボタンを設けて、自動
車やホイール、タイヤの種類によって異なる振動情報を
初期化するようにしたもので、これにより、路面状態及
びタイヤ走行状態の推定精度を更に向上させることがで
きる。The road surface condition and tire running condition estimating device according to the thirteenth aspect is provided with a reset button to initialize different vibration information depending on the type of vehicle, wheel or tire. It is possible to further improve the estimation accuracy of the road surface state and the tire running state.
【００１２】請求項１４に記載の路面状態及びタイヤ走
行状態推定装置は、車両の各輪に荷重測定装置を備え、
車両各輪の荷重データに基づいて走行時の路面状態及び
タイヤの走行状態を推定するようにしたもので、これに
より、大型の運搬車などように、車輪に加わる荷重変動
が大きな車両であっても、上記各輪の荷重データに応じ
て路面状態及びタイヤ走行状態を推定することができる
ので、推定精度の向上を図ることが可能となる。A road surface condition and tire running condition estimating device according to a fourteenth aspect comprises a load measuring device for each wheel of the vehicle,
It is designed to estimate the road condition and the running condition of tires based on the load data of each wheel of a vehicle. Also, since the road surface condition and the tire traveling condition can be estimated according to the load data of each wheel, the estimation accuracy can be improved.
【００１３】また、請求項１５に記載の発明は、車両の
走行状態を制御する車両制御装置であって、上記請求項
１〜請求項１４のいずれかに記載の路面状態及びタイヤ
走行状態推定装置と、上記装置で推定された路面状態及
び／または走行中のタイヤの状態に基づいて、ＡＢＳブ
レーキの油圧制御手段や車輪のロック状態制御手段、あ
るいは、車両の姿勢制御手段などのような、車両の走行
状態を制御する車両制御手段を備えたものである。The invention according to a fifteenth aspect is a vehicle control device for controlling a traveling state of a vehicle, wherein the road surface state and tire traveling state estimation device according to any one of the first to fourteenth aspects. And a vehicle such as an ABS brake hydraulic control unit, a wheel lock state control unit, or a vehicle attitude control unit based on the road surface state and / or the running tire state estimated by the device. The vehicle control means for controlling the traveling state of the vehicle is provided.
【００１４】[0014]
【発明の実施の形態】以下、本発明の実施の形態につい
て、図面に基づき説明する。
実施の形態１．図１は、本実施の形態１に係わる路面状
態及びタイヤ走行状態推定装置１０の構成を示す機能ブ
ロック図で、本装置１０は振動検出部１０Ａと信号処理
部１０Ｂとを備えている。振動検出部１０Ａは、ホイー
ルに伝播されたタイヤの振動を検出する振動検出手段で
ある加速度センサ１１を備えており、信号処理部１０Ｂ
は、周波数帯域設定手段１２と振動レベル検出手段１３
とを備え、上記加速度センサ１１で検出されたホイール
振動の振動情報信号を周波数分析して、上記振動の周波
数スペクトル（以下、振動スペクトルという）の、路面
状態やタイヤの走行状態によってその振動レベルが特徴
的に変化する周波数範囲、すなわち、少なくとも１０〜
１００００Ｈｚの範囲に含まれる周波数帯域の振動レベ
ルを検出する周波数分析手段１４と、予め求められた路
面状態、あるいは、走行中のタイヤの状態と、上記振動
スペクトルの所定の周波数帯域での振動レベルとの関係
を示すＧ−テーブル１５Ｇを記憶する振動レベル記憶手
段１５と、上記周波数分析手段１４で検出された振動レ
ベルを上記Ｇ−テーブル１５Ｇに対応させて、上記振動
レベルから路面摩擦係数μ及び走行中のタイヤの状態を
推定する路面状態及びタイヤ走行状態推定手段１６とを
備え、上記加速度センサ１１で検出されたホイールの振
動情報信号から、走行時の路面状態及びタイヤの走行状
態を推定する。なお、上記Ｇ−テーブル１５Ｇは、後述
するように、試験車両に加速度センサ１１を取付け、上
記車両を、所定の速度Ｖで路面摩擦係数μの異なる路面
を走行させたり、例えば、トレッドの一部を剥離させた
故障タイヤに相当する試作タイヤを装着した車両を走行
させたりして、ホイール１の振動を実測することにより
作成される。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1. FIG. 1 is a functional block diagram showing a configuration of a road surface state and tire running state estimation device 10 according to the first embodiment, and this device 10 includes a vibration detection unit 10A and a signal processing unit 10B. The vibration detection unit 10A includes an acceleration sensor 11, which is a vibration detection unit that detects the vibration of the tire transmitted to the wheel, and the signal processing unit 10B.
Is a frequency band setting means 12 and a vibration level detecting means 13
And frequency-analyzing the vibration information signal of the wheel vibration detected by the acceleration sensor 11, and the vibration level of the frequency spectrum of the vibration (hereinafter referred to as vibration spectrum) depends on the road surface condition and the running condition of the tire. Characteristically changing frequency range, i.e. at least 10
The frequency analysis means 14 for detecting the vibration level in the frequency band included in the range of 10000 Hz, the road surface condition obtained in advance, or the condition of the running tire, and the vibration level in the predetermined frequency band of the vibration spectrum. The vibration level storage means 15 for storing the G-table 15G indicating the relationship between the vibration level and the vibration level detected by the frequency analysis means 14 are made to correspond to the G-table 15G. A road surface state and tire running state estimation means 16 for estimating the state of the inside tire is provided, and the road surface state during running and the running state of tires are estimated from the vibration information signal of the wheel detected by the acceleration sensor 11. As will be described later, the G-table 15G has an acceleration sensor 11 attached to a test vehicle, and the vehicle is caused to travel on a road surface having a different road surface friction coefficient μ at a predetermined speed V, for example, a part of a tread. It is created by running a vehicle equipped with a trial tire corresponding to the broken tire from which the tire has been peeled off and actually measuring the vibration of the wheel 1.
【００１５】本例では、上記加速度センサ１１としてバ
イモルフ圧電式の表面実装型加速度センサを用い、この
加速度センサ１１を、図２（ａ），（ｂ）に示すよう
に、ホイール１のホイールリム２の、タイヤ側の凹部に
取付けられたセンサーボックス１７内に収納した。な
お、同図において、３はホイール１に取付けられたタイ
ヤバルブである。上記センサーボックス１７には、タイ
ヤ内に充填された気体の圧力をモニタリングする圧力セ
ンサ１８が収納されており、上記加速度センサ１１は、
圧力検出回路やバッテリー等が搭載された上記圧力セン
サ１８が装着された基板１９に装着される。この基板１
９はセンサ共通基板であり、加速度センサ１１の駆動・
検出回路も上記基板１９に搭載され、上記バッテリーは
加速度センサ１１及び圧力センサ１８の共用電源とな
る。なお、加速度センサ１１または加速度センサ１１を
設置する基板をホイール１に設置してもよいし、加速度
センサ１１の駆動・検出回路を搭載した基板を加速度セ
ンサ１１とは別体に設置してもよいが、装置を小型化す
る上では、上記のように、加速度センサ１１とその基板
を、圧力センサ１８と同一の筐体（センサーボックス１
７）内に設置することが好ましく、少なくとも、基板に
ついては上記基板１９と共有化することが好ましい。In this example, a bimorph piezoelectric surface mount type acceleration sensor is used as the acceleration sensor 11, and the acceleration sensor 11 is used as shown in FIGS. 2 (a) and 2 (b). It was stored in the sensor box 17 attached to the concave portion on the tire side. In the figure, 3 is a tire valve attached to the wheel 1. The sensor box 17 contains a pressure sensor 18 for monitoring the pressure of the gas filled in the tire, and the acceleration sensor 11 is
It is mounted on a substrate 19 on which the pressure sensor 18 having a pressure detection circuit, a battery, etc. is mounted. This board 1
Reference numeral 9 denotes a sensor common substrate, which drives the acceleration sensor 11.
A detection circuit is also mounted on the substrate 19, and the battery serves as a common power source for the acceleration sensor 11 and the pressure sensor 18. The acceleration sensor 11 or the substrate on which the acceleration sensor 11 is installed may be installed on the wheel 1, or the substrate on which the drive / detection circuit of the acceleration sensor 11 is installed may be installed separately from the acceleration sensor 11. However, in order to miniaturize the device, as described above, the acceleration sensor 11 and its substrate are in the same housing as the pressure sensor 18 (sensor box 1
7), and at least the substrate is preferably shared with the substrate 19.
【００１６】次に、上記構成の路面状態及びタイヤ走行
状態推定装置１０の動作について、路面摩擦係数μの推
定値を求める場合を例にとって説明する。まず、加速度
センサ１１により走行中のホイール１の振動を検出し、
この検出されたホイール１の振動情報信号を周波数分析
手段１４により周波数分析して所定の周波数帯域の振動
レベルを検出する。詳細には、周波数分析手段１４の検
出する上記振動レベルは、中心周波数が、路面状態やタ
イヤの走行状態によってその振動レベルが特徴的に変化
する周波数範囲、すなわち、少なくとも１０〜１０００
０Ｈｚの範囲にある、所定の帯域幅を有する周波数帯域
の振動レベルであり、例えば、８００〜３５００Ｈｚの
ような、比較的広い帯域幅を有する１つの周波数帯域の
振動レベルでもよいし、８００〜１０００Ｈｚ，１６０
０〜２０００Ｈｚ，３０００〜３５００Ｈｚでの振動レ
ベルなどのように、比較的狭い帯域幅を有する複数の周
波数帯域での振動レベル（複数個）でもよい。周波数分
析手段１４では、上記１つあるいは複数の周波数帯域を
周波数帯域設定手段１２で設定し、振動レベル検出手段
１３により、その振動レベルを検出する。上記検出され
た振動レベルは、路面状態及びタイヤ走行状態推定手段
１６に送られ、路面状態及びタイヤ走行状態推定手段１
６において、上記検出された振動レベルと、予め振動レ
ベル記憶手段１５に記憶されている路面摩擦係数μと振
動レベルとの関係を示すＧ−テーブル１５Ｇと対応させ
て、路面摩擦係数の推定値（μ推定値）を求めることに
より、加速度センサ１１により検出されたホイールのタ
イヤ周方向またはタイヤ幅方向の振動情報信号から、路
面摩擦係数μを精度良く推定することができる。Next, the operation of the road surface condition and tire running condition estimation device 10 having the above-described configuration will be described by taking an example of obtaining an estimated value of the road surface friction coefficient μ. First, the acceleration sensor 11 detects the vibration of the running wheel 1,
The detected vibration information signal of the wheel 1 is subjected to frequency analysis by the frequency analysis means 14 to detect the vibration level in a predetermined frequency band. Specifically, the vibration level detected by the frequency analysis unit 14 has a center frequency in a frequency range in which the vibration level characteristically changes depending on the road surface condition and the running condition of the tire, that is, at least 10 to 1000.
It is a vibration level of a frequency band having a predetermined band width in the range of 0 Hz, and may be a vibration level of one frequency band having a relatively wide band such as 800 to 3500 Hz, or 800 to 1000 Hz. , 160
It may be a plurality of vibration levels in a plurality of frequency bands having a relatively narrow bandwidth, such as a vibration level at 0 to 2000 Hz and 3000 to 3500 Hz. In the frequency analysis means 14, the one or more frequency bands are set by the frequency band setting means 12, and the vibration level detecting means 13 detects the vibration level. The detected vibration level is sent to the road surface state and tire running state estimation means 16, and the road surface state and tire running state estimation means 1 is sent.
6, the estimated value of the road surface friction coefficient (corresponding to the detected vibration level and the G-table 15G indicating the relationship between the road surface friction coefficient μ and the vibration level stored in advance in the vibration level storage means 15) By obtaining the μ estimated value), the road surface friction coefficient μ can be accurately estimated from the vibration information signal of the wheel in the tire circumferential direction or the tire width direction detected by the acceleration sensor 11.
【００１７】図３は、タイヤ周方向の振動を検出する加
速度センサとタイヤ幅方向の振動を検出する加速度セン
サの２個の加速度センサを取付けたホイールを備えたタ
イヤを乗用車に搭載し、通常の乾燥アスファルト路面上
を６０ｋｍ／ｈの一定速度で走行させ、このときのホイ
ールのタイヤ周方向振動とタイヤ幅方向振動とをそれぞ
れ測定して周波数分析して得られた振動スペクトルであ
る。このグラフの横軸は周波数、縦軸は１Ｇを０ｄＢと
したときの振動レベルの大きさであり、同図の実線がホ
イールのタイヤ周方向振動スペクトル、破線がタイヤ幅
方向振動スペクトルである。次に、路面摩擦係数μの異
なる様々な路面上で、上記と同様の実験を行い、ホイー
ルのタイヤ周方向及びタイヤ幅方向の振動スペクトルを
求め、上記乾燥アスファルト路面上を走行して得られた
振動スペクトルと比較すると、１０〜１００００Ｈｚの
範囲に含まれる複数の周波数帯域において、上記振動レ
ベルが異なっていることが確認された。一般に、路面摩
擦係数μが低くなると、タイヤトレッドのすべり（ここ
では幅向のすべり）によって複数の周波数帯域の振動レ
ベルが上昇する。FIG. 3 shows a tire equipped with a wheel equipped with two acceleration sensors, an acceleration sensor for detecting vibrations in the tire circumferential direction and an acceleration sensor for detecting vibrations in the tire width direction, mounted on a passenger car. It is a vibration spectrum obtained by traveling on a dry asphalt road surface at a constant speed of 60 km / h, measuring the tire circumferential vibration and the tire width vibration of the wheel at this time, and performing a frequency analysis. The horizontal axis of this graph is the frequency, and the vertical axis is the magnitude of the vibration level when 1 G is 0 dB. The solid line in the figure shows the tire circumferential vibration spectrum of the wheel, and the broken line shows the tire width vibration spectrum. Next, the same experiment as above was performed on various road surfaces having different road friction coefficients μ, and the vibration spectra in the tire circumferential direction and the tire width direction of the wheel were obtained and obtained by running on the dry asphalt road surface. When compared with the vibration spectrum, it was confirmed that the vibration levels were different in a plurality of frequency bands included in the range of 10 to 10000 Hz. Generally, when the road surface friction coefficient μ decreases, the vibration level in a plurality of frequency bands increases due to the slip of the tire tread (here, the slip in the width direction).
【００１８】図４は、予め測定した路面摩擦係数μと、
検出したホイールの振動情報信号を用いて推定した路面
摩擦係数の推定値（μ推定値）との関係を示すグラフで
ある。この結果から明らかなように、上記μ推定値と実
際の路面摩擦係数μとは良好な相関関係を示している。
したがって、加速度センサ１１によりホイール１のタイ
ヤ周方向またはタイヤ幅方向の振動を検出し、この振動
情報信号と、予め求められた、上記複数の周波数帯域の
振動レベルと路面摩擦係数μとの関係を示すＧ−テーブ
ル１５Ｇとを対応させることにより、路面摩擦係数μを
精度良く推定することが可能であることが確認された。FIG. 4 shows a road surface friction coefficient μ measured in advance,
It is a graph which shows the relationship with the estimated value (mu estimated value) of the road surface friction coefficient estimated using the detected vibration information signal of a wheel. As is clear from this result, there is a good correlation between the estimated μ value and the actual road friction coefficient μ.
Therefore, the acceleration sensor 11 detects the vibration of the wheel 1 in the tire circumferential direction or the tire width direction, and the relationship between the vibration information signal and the vibration level of the plurality of frequency bands and the road surface friction coefficient μ that are obtained in advance is calculated. It was confirmed that the road surface friction coefficient μ can be accurately estimated by associating with the G-table 15G shown.
【００１９】このように、本実施の形態１によれば、ホ
イールリム２に取付けられた加速度センサ１１で検出し
たホイール１の振動情報信号を、周波数分析手段１４で
周波数分析してその振動スペクトルの振動レベルを検出
し、路面状態及びタイヤ走行状態推定手段１６により、
この検出された振動レベルと、振動レベル記憶手段１５
に記憶された路面摩擦係数μと振動レベルとの関係を示
すＧ−テーブル１５Ｇとを比較して、路面摩擦係数μを
推定するようにしたので、路面摩擦係数μの値を精度良
く推定することができ、車両の安全性を向上させること
ができる。As described above, according to the first embodiment, the vibration information signal of the wheel 1 detected by the acceleration sensor 11 attached to the wheel rim 2 is frequency-analyzed by the frequency analysis means 14 to obtain its vibration spectrum. The vibration level is detected, and the road surface state and tire running state estimation means 16
The detected vibration level and the vibration level storage means 15
Since the road surface friction coefficient μ is estimated by comparing the road surface friction coefficient μ stored in the table with the G-table 15G indicating the relationship between the vibration level and the vibration level, the value of the road surface friction coefficient μ can be accurately estimated. Therefore, the safety of the vehicle can be improved.
【００２０】なお、上記実施の形態１では、加速度セン
サ１１を、ホイールリム２のタイヤ側に取付けて、ホイ
ール１に伝播されるタイヤの振動を検出するようにした
が、図５に示すように、加速度センサ１１をタイヤ４の
トレッド５の内面側５ａに取付けて、タイヤ４の振動を
直接検出するようにしてもよい。また、上記例では、路
面摩擦係数μを推定する場合について説明したが、路面
摩擦係数μそのものではなく、通常路面状態（ドラ
イ）、要注意路面状態（ウエット路、雪路、など）、危
険路面状態（ハイドロプレーニング状態、圧雪路、ミラ
ーバーンなど）などのような、路面状態を推定するよう
にしてもよい。また、上記路面摩擦係数μから、走行中
のタイヤの状態である滑り易さを推定するようにしても
よい。また、上記振動スペクトルを用いて、タイヤの故
障状態を推定することも可能である。具体的には、タイ
ヤトレッドの一部に剥離が生じた場合などには、その部
分が路面に接する度に特有の振動が発生するので、上記
振動スペクトルの、１０〜１００Ｈｚの周波数帯域の振
動レベルを検出し、正常なタイヤの上記と同じ周波数帯
域の振動レベルと比較することにより、タイヤに何らか
の異常が生じていることを推定することができる。In the first embodiment, the acceleration sensor 11 is mounted on the tire side of the wheel rim 2 to detect the vibration of the tire propagated to the wheel 1. However, as shown in FIG. Alternatively, the acceleration sensor 11 may be attached to the inner surface side 5a of the tread 5 of the tire 4 so as to directly detect the vibration of the tire 4. Also, in the above example, the case of estimating the road surface friction coefficient μ has been described, but not the road surface friction coefficient μ itself, but a normal road surface state (dry), a cautionary road surface state (wet road, snow road, etc.), a dangerous road surface. Road surface conditions such as conditions (hydroplaning conditions, snow-covered roads, mirror burns, etc.) may be estimated. Further, the slipperiness, which is the state of the tire during traveling, may be estimated from the road surface friction coefficient μ. It is also possible to estimate the tire failure state using the vibration spectrum. Specifically, when a part of the tire tread is peeled off, a peculiar vibration is generated each time the part comes into contact with the road surface. Therefore, the vibration level in the frequency band of 10 to 100 Hz in the vibration spectrum described above. Is detected and compared with the vibration level of the normal tire in the same frequency band as above, it can be estimated that some abnormality has occurred in the tire.
【００２１】また車両の各輪に荷重測定装置を設置して
車両各輪に作用する荷重を検出し、車両各輪の荷重デー
タに基づいて、走行時の路面状態及びタイヤの走行状態
の推定を行うことも可能である。すなわち、大型の運搬
車などのように、積み荷の重さにより車輪に加わる荷重
が大きく変動する車両においては、荷重による摩擦係数
の変化が大きいため、荷重によりタイヤの振動状態が変
化する（荷重が大きくなると摩擦係数が減少して滑り易
くなる）ので、これを補正するため、路面摩擦係数μと
振動レベルとの関係を示すＧ−テーブル１５Ｇを各荷重
毎に作成して記憶しておき、上記荷重測定装置で検出さ
れた車両各輪の荷重データに応じて、路面状態及びタイ
ヤ走行状態を推定するようにすれば、推定精度を更に向
上させることができる。Further, a load measuring device is installed on each wheel of the vehicle to detect the load acting on each wheel of the vehicle, and the road surface condition and the running condition of the tire during running can be estimated based on the load data of each vehicle wheel. It is also possible to do so. That is, in a vehicle such as a large truck in which the load applied to the wheels fluctuates greatly due to the weight of the load, the change in the friction coefficient due to the load is large, so the vibration state of the tire changes due to the load. (The larger the friction coefficient becomes, the more slippery it becomes.) Therefore, in order to correct this, a G-table 15G showing the relationship between the road surface friction coefficient μ and the vibration level is created and stored for each load. If the road surface condition and the tire running condition are estimated according to the load data of each wheel of the vehicle detected by the load measuring device, the estimation accuracy can be further improved.
【００２２】また、本装置１０に、システムを初期化す
るためのリセットボタンを設け、ある程度の距離を走行
してタイヤと路面間の実際の摩擦状態を把握することが
好ましい。路面状態を推定するために用いる振動スペク
トルとしては、予めインプットされた実車試験の振動ス
ペクトルであっても問題はないが、振動スペクトルは自
動車やホイール、タイヤの種類により微妙に異なること
から、当該車両をドライ、ウエット、氷雪のいずれかの
路面、あるいは、複数の路面で走行させて、その時の振
動スペクトルを求め、この求められた振動スペクトルに
基づいて路面状態あるいは路面摩擦係数μを推定するよ
うにすれば、推定精度を更に向上させることができる。
このとき、乗員がリセットボタンを押し、走行した路面
の状態がドライかウエットかあるいは氷雪かをインプッ
トする。なお、装置１０内において、予め記憶された路
面状態毎の振動スペクトルと上記初期化時に得られた振
動スペクトルとを比較して、上記走行した路面の状態が
ドライかウエットかあるいは氷雪かが自動的にインプッ
トされるようにしてもよい。Further, it is preferable that the present apparatus 10 is provided with a reset button for initializing the system, and the actual friction state between the tire and the road surface is grasped by traveling a certain distance. As the vibration spectrum used to estimate the road surface condition, there is no problem even if it is the vibration spectrum of the actual vehicle test input in advance, but since the vibration spectrum is subtly different depending on the type of car, wheel, tire, On a dry, wet, or snowy road surface, or on multiple road surfaces, obtain the vibration spectrum at that time, and estimate the road surface condition or the road surface friction coefficient μ based on the obtained vibration spectrum. If so, the estimation accuracy can be further improved.
At this time, the occupant pushes the reset button and inputs whether the road surface on which the vehicle has traveled is dry, wet, or snowy. In the device 10, the vibration spectrum for each road surface state stored in advance is compared with the vibration spectrum obtained at the time of initialization to automatically determine whether the road surface on which the vehicle has traveled is dry, wet, or snowy. May be input to.
【００２３】実施の形態２．上記実施の形態１では、ホ
イール１の振動を検出したが、図６に示すように、加速
度センサ１１をサスペンション部６に取付け、サスペン
ション部６に伝播されるタイヤの振動を検出して路面状
態及びタイヤ走行状態を推定することも可能である。サ
スペンション部６には、振動緩衝のため、ゴムブッシュ
７等の弾性部材が複数取付けられているので、本例で
は、上記伝播されたタイヤの振動を効率よく検出するた
め、加速度センサ１１をサスペンションアーム６ａ，６
ｂ上ではなく、ホイール１が取付けられているハブ部８
に取付けるようにしている。なお、サスペンション部６
には、タイヤ幅方向の振動の方が比較的減衰なく伝播さ
れるので、上記加速度センサ１１は、ハブ部８のタイヤ
幅方向の振動を検出するように取り付けることが好まし
い。Embodiment 2. Although the vibration of the wheel 1 is detected in the first embodiment, as shown in FIG. 6, the acceleration sensor 11 is attached to the suspension portion 6 and the vibration of the tire propagated to the suspension portion 6 is detected to detect the road surface condition and the road surface condition. It is also possible to estimate the tire running state. Since a plurality of elastic members such as a rubber bush 7 are attached to the suspension portion 6 for damping vibrations, in this example, in order to efficiently detect the propagated vibration of the tire, the acceleration sensor 11 is used as a suspension arm. 6a, 6
Hub part 8 to which the wheel 1 is attached, not on b
I am trying to install it on. The suspension part 6
Since the vibration in the tire width direction is propagated to the tire with relatively less attenuation, the acceleration sensor 11 is preferably attached so as to detect the vibration of the hub portion 8 in the tire width direction.
【００２４】図７は、加速度センサを乗用車のサスペン
ション部に装着し、通常の乾燥アスファルト路面上を３
０ｋｍ／ｈ〜９０ｋｍ／ｈの範囲内で一定速度で走行さ
せ、このときのサスペンション部の振動を測定して周波
数分析して得られた振動スペクトルを示す図で、この振
動スペクトルを用いて、上記実施の形態１と同様に、路
面摩擦係数μを推定することができる。図８は、予め測
定した路面摩擦係数μと、検出したサスペンション部６
の振動から推定したμ推定値との関係を示すグラフで、
この結果から明らかなように、検出された振動レベルか
ら求めたμ推定値と実際の路面摩擦係数μとは良好な相
関関係を示しており、サスペンション部６の振動からで
も路面摩擦係数μを精度良く推定することができること
がわかる。In FIG. 7, the acceleration sensor is mounted on the suspension portion of a passenger car, and the acceleration sensor is mounted on a normal dry asphalt road surface.
It is a diagram showing a vibration spectrum obtained by traveling at a constant speed within a range of 0 km / h to 90 km / h, measuring the vibration of the suspension portion at this time, and performing a frequency analysis. As in the first embodiment, the road surface friction coefficient μ can be estimated. FIG. 8 shows the road surface friction coefficient μ measured in advance and the suspension portion 6 detected.
Is a graph showing the relationship with the μ estimation value estimated from the vibration of
As is clear from this result, there is a good correlation between the μ estimated value obtained from the detected vibration level and the actual road surface friction coefficient μ, and the road surface friction coefficient μ can be accurately determined even from the vibration of the suspension portion 6. It turns out that it can be estimated well.
【００２５】実施の形態３．図９は、本発明の路面状態
及びタイヤ走行状態推定装置を用いた車両制御装置２０
の構成を示す図で、本装置２０は、加速度センサ１１が
取付けられた転動側（タイヤまたはホイール側）Ａと、
非転動側である車体側Ｂとを無線により接続するように
構成したものである。転動側Ａには、加速度センサ１１
と、この加速度センサ１１で検出された振動情報信号を
デジタル変換して圧縮するデータ処理部２１と、この圧
縮された信号を車体側Ｂに無線により送信するととも
に、車体側Ｂから送信される、加速度センサ１１及びデ
ータ処理部２１を駆動するための無線信号を受信するＲ
Ｆ（Radio Frequency）部２２とを設ける。また、車体
側Ｂには、上記圧縮された振動情報信号を受信するとと
もに、転動側Ａに上記無線信号を送信する無線送信・受
信部（以下、送受信部という）２３と、上記受信された
振動情報信号を復元して周波数分析し、得られた振動ス
ペクトルから走行時の路面状態及びタイヤの走行状態を
推定する路面状態及びタイヤ走行状態演算部２４と、上
記演算部２４で推定された路面状態及びタイヤ走行状態
に基づいて、ＡＢＳブレーキの油圧を制御するＡＢＳ制
御部（車両制御手段）２５とを設ける。これにより、信
号接続線を設けることなく、タイヤまたはホイール部で
検出された振動情報信号を車体側Ｂにて処理して路面状
態及びタイヤ走行状態を推定することができる。また、
上記推定された路面状態及びタイヤ走行状態のデータを
ＡＢＳ制御部２５に送ることにより、路面状態及びタイ
ヤ走行状態に応じてＡＢＳブレーキの油圧を制御するこ
とができるので、車両の走行状態を安定して制御するこ
とができる。また、車体側Ｂから、無線にて、加速度セ
ンサ１１及びデータ処理部２１を駆動するようにしたの
で、転動側Ａに備えられていたバッテリーを省略するこ
とができる。なお、上記路面状態及びタイヤの走行状態
演算部２４の構成は、上記実施の形態１の図１で示し
た、路面状態及びタイヤ走行状態推定装置１０の信号処
理部１０Ｂと同様である。Embodiment 3. FIG. 9 is a vehicle control device 20 using the road surface state and tire running state estimation device of the present invention.
In this figure, the present device 20 has a rolling side (tire or wheel side) A to which the acceleration sensor 11 is attached,
The vehicle body side B, which is the non-rolling side, is configured to be wirelessly connected. The acceleration sensor 11 is provided on the rolling side A.
A data processing unit 21 for digitally converting and compressing the vibration information signal detected by the acceleration sensor 11, and transmitting the compressed signal to the vehicle body side B wirelessly and from the vehicle body side B. R for receiving a radio signal for driving the acceleration sensor 11 and the data processing unit 21
An F (Radio Frequency) unit 22 is provided. The vehicle body side B receives the compressed vibration information signal and transmits the wireless signal to the rolling side A, and a wireless transmission / reception section (hereinafter referred to as a transmission / reception section) 23 and the received signal. A road surface state and tire running state calculation unit 24 that estimates a road state state and a running state of a tire during running from the obtained vibration spectrum by restoring the vibration information signal and frequency analysis, and the road surface estimated by the calculation unit 24. An ABS control unit (vehicle control means) 25 for controlling the hydraulic pressure of the ABS brake based on the state and the tire running state is provided. Thereby, the road surface condition and the tire running condition can be estimated by processing the vibration information signal detected at the tire or the wheel portion on the vehicle body side B without providing the signal connection line. Also,
By sending the estimated road surface condition and tire traveling condition data to the ABS control unit 25, the hydraulic pressure of the ABS brake can be controlled according to the road condition and tire traveling condition, so that the vehicle traveling condition is stabilized. Can be controlled. Further, since the acceleration sensor 11 and the data processing unit 21 are wirelessly driven from the vehicle body side B, the battery provided on the rolling side A can be omitted. The configuration of the road surface condition and tire running condition calculation unit 24 is the same as that of the signal processing unit 10B of the road surface condition and tire running condition estimation device 10 shown in FIG. 1 of the first embodiment.
【００２６】また、車体側Ｂには、タイヤ円周上での電
波サービスエリアを極力広くするアンテナ部を設け、転
動側Ａ（タイヤまたはホイール側）のＲＦ部２２には、
送受信部２４から上記アンテナ部を介して送信された微
弱電波を受信して発生する誘導起電力により稼動するパ
ッシブモード非接触ＩＣチップを備え、加速度センサ１
１とデータ処理部２１を稼動させるとともに、加速度セ
ンサ１１で検出した振動データをデジタル変換・圧縮し
て車体側Ａに送信する。なお、上記データの送信を行う
ためのアンテナ機能を、ホイール１に取付けられている
タイヤバルブ３（図１参照）に持たせてもよいし、別
途、ホイールリム２の周上にアンテナを設けるようにし
てもよい。実際に本装置２０を用いて転動中のホイール
振動を検出し、車体側Ｂにてその振動スペクトルを測定
し、上記実施の形態１の図３に示す振動スペクトルと比
較したところ、同様の振動スペクトルが得られることが
確認された。Further, the vehicle body side B is provided with an antenna section for maximizing the radio wave service area on the tire circumference, and the RF section 22 on the rolling side A (tire or wheel side) is
The acceleration sensor 1 is provided with a passive mode non-contact IC chip that operates by an induced electromotive force generated by receiving a weak electric wave transmitted from the transmitting / receiving unit 24 via the antenna unit.
1 and the data processing unit 21 are operated, and the vibration data detected by the acceleration sensor 11 is digitally converted / compressed and transmitted to the vehicle body side A. The tire valve 3 (see FIG. 1) attached to the wheel 1 may be provided with an antenna function for transmitting the above data, or an antenna may be separately provided on the circumference of the wheel rim 2. You may By actually detecting the wheel vibration during rolling using the present device 20, measuring the vibration spectrum on the vehicle body side B, and comparing it with the vibration spectrum shown in FIG. It was confirmed that a spectrum was obtained.
【００２７】このように、本実施の形態３によれば、加
速度センサ１１が取付けられる転動側Ａ（タイヤまたは
ホイール側）にデータ処理部２１を設置し、上記加速度
センサ１１で検出された振動情報信号をデジタル変換・
圧縮して車体側Ｂに送信し、車体側Ｂに設けられた路面
状態及びタイヤの走行状態演算部２４において、上記受
信した上記振動情報信号を復元して周波数分析し、タイ
ヤまたはホイールの振動から走行時の路面状態及びタイ
ヤの走行状態を推定するようにしたので、転動側Ａと車
体側Ｂとの連続データ通信が可能となり、振動の検出精
度を向上させることができ、車両の走行状態を安定して
制御することができる。また、加速度センサ１１及びデ
ータ処理部２１を、車体側Ｂから、無線にて駆動するよ
うにしたので、バッテリーを省略することができ、振動
検出部を小型軽量化することができる。なお、バッテリ
ーを用いてデータ通信を行った場合には、バッテリー寿
命が短かくなり、交換が必要となるが、本例では、この
ような問題がなく、長期的に安定して路面状態及びタイ
ヤの走行状態を推定することが可能となる。As described above, according to the third embodiment, the data processing unit 21 is installed on the rolling side A (tire or wheel side) to which the acceleration sensor 11 is attached, and the vibration detected by the acceleration sensor 11 is set. Digital conversion of information signals
Compressed and transmitted to the vehicle body side B, the road surface state and tire running state calculation unit 24 provided on the vehicle body side B restores the received vibration information signal and analyzes the frequency, and from the vibration of the tire or the wheel. Since the road surface state and the tire running state during running are estimated, continuous data communication between the rolling side A and the vehicle body side B is possible, the accuracy of vibration detection can be improved, and the running state of the vehicle can be improved. Can be controlled stably. Further, since the acceleration sensor 11 and the data processing unit 21 are wirelessly driven from the vehicle body side B, the battery can be omitted, and the vibration detection unit can be reduced in size and weight. In addition, when data communication is performed using a battery, the battery life becomes short and replacement is required, but in this example, there is no such problem and stable road surface condition and tire It is possible to estimate the running state of the vehicle.
【００２８】また、タイヤまたはホイール部にＦＦＴ処
理部を設けて、転動側Ａにて振動情報信号を周波数分析
してμ推定値を求め、これを車体側Ｂに送信するように
してもよい。具体的には、図１０に示すように、転動側
Ａ（タイヤまたはホイール側）に路面状態及びタイヤ走
行状態演算部２４を設け、加速度センサ１１で検出した
タイヤまたはホイールの振動情報信号を周波数分析し、
走行時の路面状態及びタイヤの走行状態を推定し、この
推定された走行時の路面状態及びタイヤの走行状態を表
わすデータをＲＦ部２２から車体側Ｂに送信する。車体
側Ｂでは、受信したデータをＡＢＳ制御部２５に送りＡ
ＢＳブレーキの油圧を制御する。上記のような車両制御
装置２０Ａを構成することにより、上記実施の形態３と
同様に、転動側Ａと車体側Ｂとの連続データ通信を可能
とし、かつ、路面状態及びタイヤ走行状態の推定精度を
向上させて、車両の走行状態を安定に制御することがで
きる。実際に、タイヤまたはホイール部において、振動
情報信号を周波数分析して、得られた振動スペクトルか
らμ推定値を求め、このμ推定値を車体側Ｂに送信して
路面摩擦係数μとの対応を調べたところ、上記実施の形
態１の図４と同様な良好な相関関係が見られた。Further, an FFT processing section may be provided in the tire or wheel section to frequency analyze the vibration information signal on the rolling side A to obtain a μ estimated value and transmit it to the vehicle body side B. . Specifically, as shown in FIG. 10, a road surface state and tire running state calculation unit 24 is provided on the rolling side A (tire or wheel side), and the vibration information signal of the tire or wheel detected by the acceleration sensor 11 is used as a frequency. Analyze
The road condition during running and the running condition of the tire are estimated, and the data representing the estimated road condition during running and the running condition of the tire are transmitted from the RF unit 22 to the vehicle body side B. On the vehicle body side B, the received data is sent to the ABS control unit 25
Controls the hydraulic pressure of the BS brake. By configuring the vehicle control device 20A as described above, it is possible to perform continuous data communication between the rolling side A and the vehicle body side B, and to estimate the road surface state and the tire running state, as in the third embodiment. The accuracy can be improved and the running state of the vehicle can be stably controlled. Actually, in the tire or wheel portion, the vibration information signal is frequency-analyzed, the μ estimation value is obtained from the obtained vibration spectrum, and the μ estimation value is transmitted to the vehicle body side B to determine the correspondence with the road friction coefficient μ. Upon examination, a good correlation similar to that shown in FIG. 4 of the first embodiment was found.
【００２９】[0029]
【発明の効果】以上説明したように本発明によれば、振
動検出手段により、走行中の車両のタイヤ、ホイール、
あるいは、サスペンション部の振動を検出し、これを周
波数分析して得られる上記振動の周波数スペクトルの、
少なくとも１０〜１００００Ｈｚの範囲に含まれる周波
数帯域の振動レベルを検出して、上記検出された振動レ
ベルから、走行時の路面状態及びタイヤの走行状態を推
定するようにしたので、路面状態及びタイヤ走行状態を
精度よく推定することができ、車両の安全性を著しく高
めることができる。また、振動検出手段を、タイヤ内に
充填された気体の圧力をモニタリングする圧力センサと
同一の基板上、または、同一の筐体内に設置するように
したので、基板が共有でき、装置の小型化と低コスト化
を実現することができる。更に、タイヤまたはホイール
部に信号処理手段を設け、上記振動検出手段で検出され
た振動情報信号をデジタル変換するとともにこれを圧縮
して車体側に送信し、車体側で受信した上記圧縮された
信号を周波数分析するようにしたので、無線による連続
データ通信を行うことができ、振動の検出精度を向上さ
せることができる。As described above, according to the present invention, the vibration detecting means allows the tires, wheels, and
Alternatively, the vibration of the suspension is detected, and the frequency spectrum of the vibration obtained by frequency-analyzing this is analyzed,
Since the vibration level in the frequency band included in the range of at least 10 to 10000 Hz is detected and the road surface condition and the running condition of the tire during running are estimated from the detected vibration level, the road surface condition and the tire running The state can be accurately estimated, and the safety of the vehicle can be significantly improved. Further, since the vibration detecting means is arranged on the same substrate as the pressure sensor for monitoring the pressure of the gas filled in the tire or in the same housing, the substrate can be shared and the device can be downsized. And cost reduction can be realized. Further, the tire or wheel portion is provided with a signal processing means for converting the vibration information signal detected by the vibration detecting means into a digital signal and compressing it to transmit it to the vehicle body side, and the compressed signal received at the vehicle body side. Since frequency analysis is performed, continuous data communication can be performed wirelessly, and vibration detection accuracy can be improved.
【図１】 本発明の実施の形態１に係わる路面状態及び
タイヤ走行状態推定装置の構成を示す機能ブロック図で
ある。FIG. 1 is a functional block diagram showing a configuration of a road surface state and tire running state estimation device according to a first embodiment of the present invention.
【図２】 加速度センサの装着箇所を示す図である。FIG. 2 is a diagram showing a mounting location of an acceleration sensor.
【図３】 ホイールの振動スペクトルを示す図である。FIG. 3 is a diagram showing a vibration spectrum of a wheel.
【図４】 実際の路面摩擦係数μと本発明によるμ推定
値との相関関係を示す図である。FIG. 4 is a diagram showing a correlation between an actual road surface friction coefficient μ and an estimated μ value according to the present invention.
【図５】 加速度センサの他の装着箇所を示す図であ
る。FIG. 5 is a diagram showing another mounting location of the acceleration sensor.
【図６】 本実施の形態２に係わるサスペンション部の
振動を検出する方法を示す図である。FIG. 6 is a diagram showing a method for detecting vibration of a suspension section according to the second embodiment.
【図７】 サスペンション部の振動スペクトルを示す図
である。FIG. 7 is a diagram showing a vibration spectrum of a suspension portion.
【図８】 実際の路面摩擦係数μとサスペンション部の
振動を検出して推定したμ推定値との相関関係を示す図
である。FIG. 8 is a diagram showing a correlation between an actual road surface friction coefficient μ and a μ estimated value estimated by detecting vibration of a suspension portion.
【図９】 本実施の形態３に係る車両制御装置の構成を
示す図である。FIG. 9 is a diagram showing a configuration of a vehicle control device according to a third embodiment.
【図１０】 本発明による車両制御装置の他の構成を示
す図である。FIG. 10 is a diagram showing another configuration of the vehicle control device according to the present invention.
１ ホイール、２ ホイールリム、３ タイヤバルブ、
４ タイヤ、５ トレッド、５ａ トレッドの内面側、
６ サスペンション部、６ａ，６ｂ サスペンションア
ーム、７ ゴムブッシュ、８ ハブ部、１０ 路面状態
及びタイヤ走行状態推定装置、１０Ａ 振動検出部、１
０Ｂ 信号処理部、１１ 加速度センサ、１２ 周波数
帯域設定手段、１３ 振動レベル検出手段、１４ 周波
数分析手段、１５ 振動レベル記憶手段、１５Ｇ Ｇ−
テーブル、１６ 路面状態及びタイヤ走行状態推定手
段、１７ センサーボックス、１８ 圧力センサ、１９
基板、２０，２０Ａ 車両制御装置、２１ データ処
理部、２２ ＲＦ部、２３ 無線送信・受信部（送受信
部）、２４ 路面状態及びタイヤ走行状態演算部、２５
ＡＢＳ制御部（車両制御手段）。1 wheel, 2 wheel rims, 3 tire valves,
4 tires, 5 treads, 5a tread inner surface side,
6 suspension parts, 6a, 6b suspension arms, 7 rubber bushes, 8 hub parts, 10 road surface condition and tire running condition estimation device, 10A vibration detection part, 1
0B signal processing unit, 11 acceleration sensor, 12 frequency band setting unit, 13 vibration level detecting unit, 14 frequency analyzing unit, 15 vibration level storing unit, 15G G-
Table, 16 road surface state and tire running state estimation means, 17 sensor box, 18 pressure sensor, 19
Substrate, 20, 20A Vehicle control device, 21 Data processing unit, 22 RF unit, 23 Wireless transmission / reception unit (transmission / reception unit), 24 Road surface state and tire running state calculation unit, 25
ABS control unit (vehicle control means).
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2G064 AA14 AB01 BA02 CC42 3D001 AA02 AA18 BA01 DA16 DA17 EA03 EA44 EC07 ED02 ED04 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 2G064 AA14 AB01 BA02 CC42 3D001 AA02 AA18 BA01 DA16 DA17 EA03 EA44 EC07 ED02 ED04
Claims (15)
振動を検出する振動検出手段と、上記検出された振動を
周波数分析して得られる上記振動の周波数スペクトル
の、少なくとも１０〜１００００Ｈｚの範囲に含まれる
周波数帯域の振動レベルを検出する手段と、上記検出さ
れた振動レベルから、走行時の路面状態及びタイヤの走
行状態を推定する手段とを備えたことを特徴とする路面
状態及びタイヤ走行状態推定装置。1. A vibration detecting means for detecting a vibration of a tire or a wheel of a running vehicle, and a frequency spectrum of the vibration obtained by frequency-analyzing the detected vibration, which is included in at least a range of 10 to 10000 Hz. Of a road surface state and a tire running state, which comprises a means for detecting a vibration level in a frequency band to be used, and a means for estimating a road surface state and a running state of a tire during running from the detected vibration level. apparatus.
方向の振動としたことを特徴とする請求項１に記載の路
面状態及びタイヤ走行状態推定装置。2. The road surface condition and tire running condition estimating device according to claim 1, wherein the vibration is vibration in a width direction of a tire or a wheel.
方向の振動としたことを特徴とする請求項１に記載の路
面状態及びタイヤ走行状態推定装置。3. The road surface condition and tire running condition estimating device according to claim 1, wherein the vibration is vibration in a circumferential direction of a tire or a wheel.
れた気体の圧力をモニタリングする圧力センサと同一の
基板上、または、同一の筐体内に設置したことを特徴と
する請求項１〜請求項３のいずれかに記載の路面状態及
びタイヤ走行状態推定装置。4. The vibration detecting means is installed on the same substrate or in the same housing as a pressure sensor for monitoring the pressure of gas filled in the tire. Item 5. The road surface condition and tire running condition estimation device according to any one of Item 3.
段を設置する基板を、タイヤまたはホイールに取付けた
ことを特徴とする請求項１〜請求項３のいずれかに記載
の路面状態及びタイヤ走行状態推定装置。5. The road surface state and tire running state according to claim 1, wherein the vibration detecting means or a substrate on which the vibration detecting means is installed is attached to a tire or a wheel. Estimator.
段を駆動するようにしたことを特徴とする請求項１〜請
求項５のいずれかに記載の路面状態及びタイヤ走行状態
推定装置。6. The road surface condition and tire running condition estimating device according to claim 1, wherein the vibration detecting means is wirelessly driven from the vehicle body side.
を設け、上記振動検出手段で検出された振動情報信号を
デジタル変換するとともにこれを圧縮して車体側に送信
し、車体側にて上記圧縮信号を受信して復元し、周波数
分析するようにしたことを特徴とする請求項１〜請求項
６のいずれかに記載の路面状態及びタイヤ走行状態推定
装置。7. A tire or a wheel portion is provided with a signal processing means, and the vibration information signal detected by the vibration detecting means is converted into a digital signal and is compressed and transmitted to the vehicle body side. 7. The road surface condition and tire running condition estimating device according to claim 1, wherein the road condition and tire running condition are received, restored and frequency analyzed.
を設け、上記振動検出手段で検出された振動情報信号を
タイヤまたはホイール部にて周波数分析して走行時の路
面状態及びタイヤの走行状態を推定し、この推定された
走行時の路面状態及びタイヤの走行状態を表わすデータ
を車体側に送信するようにしたことを特徴とする請求項
１〜請求項６のいずれかに記載の路面状態及びタイヤ走
行状態推定装置。8. A tire or a wheel portion is provided with a signal processing means, and a vibration information signal detected by the vibration detecting means is frequency-analyzed by the tire or the wheel portion to estimate a road surface state and a running state of the tire during traveling. The road surface condition and the tire according to any one of claims 1 to 6, wherein the estimated road condition during running and the tire running condition are transmitted to the vehicle body. Running condition estimation device.
機能を、ホイール部に取付けられているタイヤバルブに
持たせたことを特徴とする請求項７または請求項８に記
載の路面状態及びタイヤ走行状態推定装置。9. The road surface condition and tire running according to claim 7 or 8, wherein a tire valve attached to a wheel portion is provided with an antenna function for communicating the data. State estimation device.
ナを、ホイールリム部の周上に設けたことを特徴とする
請求項７または請求項８に記載の路面状態及びタイヤ走
行状態推定装置。10. The road surface condition and tire running condition estimation device according to claim 7, wherein an antenna for communicating the data is provided on the circumference of the wheel rim portion.
動を検出する振動検出手段と、上記検出された振動を周
波数分析して得られる上記振動の周波数スペクトルの、
少なくとも１０〜１００００Ｈｚの範囲に含まれる周波
数帯域の振動レベルを検出する手段と、上記検出された
振動レベルから、走行時の路面状態及びタイヤの走行状
態を推定する手段とを備えたことを特徴とする路面状態
及びタイヤ走行状態推定装置。11. A vibration detecting means for detecting a vibration of a suspension portion of a running vehicle, and a frequency spectrum of the vibration obtained by frequency-analyzing the detected vibration,
A means for detecting a vibration level in a frequency band included in a range of at least 10 to 10000 Hz; and a means for estimating a road surface condition and a tire running condition during traveling from the detected vibration level. Road surface condition and tire running condition estimation device.
けられているハブと一体化された部位に取付けたことを
特徴とする請求項１１に記載の路面状態及びタイヤ走行
状態推定装置。12. The road surface state and tire running state estimating device according to claim 11, wherein the vibration detecting means is attached to a portion integrated with a hub to which a wheel is attached.
って異なる振動情報を初期化するためのリセットボタン
を設けたことを特徴とする請求項１〜請求項１２のいず
れかに記載の路面状態及びタイヤ走行状態推定装置。13. A road surface condition and tire running according to any one of claims 1 to 12, further comprising a reset button for initializing vibration information which differs depending on types of automobiles, wheels and tires. State estimation device.
両各輪の荷重データに基づいて走行時の路面状態及びタ
イヤの走行状態を推定するようにしたことを特徴とする
請求項１〜請求項１３のいずれかに記載の路面状態及び
タイヤ走行状態推定装置。14. A load measuring device is provided for each wheel of a vehicle, and a road surface condition and a running condition of a tire during running are estimated based on load data of each wheel of the vehicle. The road surface state and tire running state estimation device according to claim 13.
に記載の路面状態及びタイヤ走行状態推定装置と、上記
装置で推定された路面状態及び／または走行中のタイヤ
の状態に基づいて車両の走行状態を制御する車両制御手
段を備えたことを特徴とする車両制御装置。15. A vehicle based on the road surface condition and tire running condition estimation device according to any one of claims 1 to 14, and the road surface condition and / or running tire condition estimated by the device. A vehicle control device comprising vehicle control means for controlling the traveling state of the vehicle.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001390560A JP3892722B2 (en) | 2001-12-21 | 2001-12-21 | Road surface state and tire running state estimation device and vehicle control device |
| EP02805488.0A EP1457388B1 (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimating road surface state and tire running state |
| CNB028258762A CN1321838C (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimating road surface state and tire running state, abs and vehicle control using the same |
| PCT/JP2002/013332 WO2003053747A1 (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimating road surface state and tire running state, abs and vehicle control using the same |
| ES02805488.0T ES2534480T3 (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimating the state of the surface of a road and the running state of a tire |
| ES12176597.8T ES2552509T3 (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimating the conditions of a road and the running state of a tire, ABS and car control using them |
| EP12176597.8A EP2514640B1 (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimation of road condition and tire running state, ABS and car control making use thereof |
| US10/499,431 US7203579B2 (en) | 2001-12-21 | 2002-12-20 | Method and apparatus for estimating road surface state and tire running state, ABS and vehicle control using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001390560A JP3892722B2 (en) | 2001-12-21 | 2001-12-21 | Road surface state and tire running state estimation device and vehicle control device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003182476A true JP2003182476A (en) | 2003-07-03 |
| JP3892722B2 JP3892722B2 (en) | 2007-03-14 |
Family
ID=27598443
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001390560A Expired - Lifetime JP3892722B2 (en) | 2001-12-21 | 2001-12-21 | Road surface state and tire running state estimation device and vehicle control device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3892722B2 (en) |
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