JP2000318417A - Warning method of air pressure drop of tire and device thereof - Google Patents
Warning method of air pressure drop of tire and device thereofInfo
- Publication number
- JP2000318417A JP2000318417A JP11081388A JP8138899A JP2000318417A JP 2000318417 A JP2000318417 A JP 2000318417A JP 11081388 A JP11081388 A JP 11081388A JP 8138899 A JP8138899 A JP 8138899A JP 2000318417 A JP2000318417 A JP 2000318417A
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- Prior art keywords
- tire
- air pressure
- wheel
- difference
- rotation speed
- Prior art date
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Links
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はタイヤの空気圧低下
警報方法およびその装置に関する。さらに詳しくは、前
輪と後輪のトレッド幅（左右のタイヤ位置の車軸間隔）
の差が大きい、たとえばトラックやバスなどの車両にお
けるタイヤの空気圧低下を検出するタイヤの空気圧低下
警報方法およびその装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for alarming a decrease in tire air pressure. More specifically, the tread width of the front and rear wheels (axle spacing between left and right tire positions)
The present invention relates to a tire pressure decrease warning method for detecting a decrease in tire pressure in vehicles such as trucks and buses, and a device therefor.
【０００２】[0002]
【従来の技術】従来より、タイヤの空気圧の低下を車輪
速の相対比較によって検出する装置が提案されている
（特公平５−５５３２２号公報など）。これによると、
検出の精度を向上するために、対角の車輪速の和同士の
比較をもちいたり、外乱要因の少ない車両の直進時のみ
に判定するなどが行なわれている。ところが、このばあ
い、減圧の検出機会が減ってしまうため、旋回中も判定
を実施する必要があり、さらに進んで、判定値に横方向
加速度を導入した関数として、旋回中の外乱（影響）を
補正する方法が提案されている（特開平６−８７１３号
公報、特表平８−５０１０４０号公報および特開平８−
１６４７２０号公報など）。2. Description of the Related Art Conventionally, there has been proposed a device for detecting a decrease in tire air pressure by relative comparison of wheel speeds (Japanese Patent Publication No. 5-55322). according to this,
In order to improve the accuracy of the detection, a comparison between the sums of the diagonal wheel speeds is used, or a determination is made only when the vehicle with few disturbance factors travels straight. However, in this case, since the chance of detecting the pressure reduction is reduced, it is necessary to perform the determination during the turning. Further, the disturbance (influence) during the turning is obtained as a function obtained by introducing the lateral acceleration into the determination value. (Japanese Patent Application Laid-Open No. 6-8713, Japanese Patent Application Laid-Open No. 8-501040 and Japanese Patent Application Laid-Open
164720 and the like).
【０００３】[0003]
【発明が解決しようとする課題】前記横方向加速度によ
る補正は、たとえば乗用車のような前輪と後輪のトレッ
ド幅の差が小さいばあいについては問題はない。しかし
ながら、後輪を複輪とすることが多いトラックやバスな
どのような前輪と後輪のトレッド幅の差が大きい車両で
は、判定誤差を補正しきれず、判定精度を向上させるこ
とが難しいという問題がある。There is no problem in the correction based on the lateral acceleration when the difference in tread width between the front wheels and the rear wheels is small, such as in a passenger car. However, in a vehicle such as a truck or a bus in which the rear wheel is often a double wheel, the difference between the tread widths of the front wheel and the rear wheel is large, and it is difficult to correct the determination error, and it is difficult to improve the determination accuracy. There is.
【０００４】本発明は、叙上の事情に鑑み、タイヤの空
気圧判定の精度を向上させることができるタイヤ空気圧
低下警報方法およびその装置を提供することを目的とす
る。[0004] In view of the circumstances described above, an object of the present invention is to provide a tire pressure drop warning method and device capable of improving the accuracy of tire pressure determination.
【０００５】[0005]
【課題を解決するための手段】本発明のタイヤの空気圧
低下警報方法は、タイヤの回転数を検出し、当該検出さ
れた回転数に基づいて、タイヤの空気圧が低下している
か否かを判定し、タイヤの内圧が低下しているばあい
に、警報を発生する空気圧低下警報方法であって、２つ
の対角和の差を比較することによりタイヤの減圧を検知
する判定値を算出する式において、車両の前輪および後
輪のトレッド幅の差に関する補正項を設けることを特徴
とする。SUMMARY OF THE INVENTION A method for alarming a decrease in tire air pressure according to the present invention detects the number of revolutions of a tire, and determines whether or not the air pressure of the tire has decreased based on the detected number of revolutions. An air pressure drop warning method for generating a warning when the internal pressure of the tire is reduced, wherein a formula for calculating a determination value for detecting pressure reduction of the tire by comparing a difference between two diagonal sums. Wherein a correction term relating to a difference in tread width between a front wheel and a rear wheel of the vehicle is provided.
【０００６】また本発明のタイヤの空気圧低下警報装置
は、タイヤの回転数を検出し、当該検出された回転数に
基づいて、タイヤの空気圧が低下しているか否かを判定
し、タイヤの内圧が低下しているばあいに、警報を発生
する空気圧低下警報装置であって、各タイヤの車輪速を
検出するための速度検出手段と、該速度検出手段で検出
される車輪速から求められる回転数に基づいて前輪タイ
ヤの回転数と後輪タイヤの回転数との２つの対角和の差
を比較する減圧判定値を演算処理する判定手段とからな
り、該判定手段における減圧判定値に車両の前輪および
後輪のトレッド軸幅の差に関する補正項が含まれてなる
ことを特徴とする。Further, the tire air pressure drop warning device of the present invention detects the tire rotation speed, and determines whether or not the tire air pressure has decreased based on the detected rotation speed. An air pressure drop warning device that generates a warning when the vehicle speed is low, the speed detection means for detecting the wheel speed of each tire, and the rotation obtained from the wheel speed detected by the speed detection means. Determining means for comparing a difference between two diagonal sums of a rotational speed of a front wheel tire and a rotational speed of a rear wheel tire based on the number of rotations. A correction term relating to the difference in tread shaft width between the front wheel and the rear wheel.
【０００７】[0007]
【発明の実施の形態】本発明は、前後輪のトレッド幅が
大きく異なるトラックやバスなどの車両のばあい、車両
のトレッド幅を含む関数で減圧判定値を補正して、タイ
ヤの空気圧の減圧判定の精度を向上させている。DETAILED DESCRIPTION OF THE INVENTION In the case of a vehicle such as a truck or a bus, in which tread widths of front and rear wheels are largely different, the present invention corrects a decompression judgment value by a function including a tread width of a vehicle to reduce tire pressure. The accuracy of the judgment is improved.
【０００８】以下、添付図面に基づいて、本発明のタイ
ヤの空気圧低下警報方法およびその装置を説明する。Hereinafter, a method and an apparatus for alarming a decrease in tire air pressure according to the present invention will be described with reference to the accompanying drawings.
【０００９】図１は本発明のタイヤの空気圧低下警報装
置の電気的構成を示すブロック図、図２は車輪タイヤの
旋回半径を求めるための説明図、図３は４０ｍ、１１０
ｍおよび１５０ｍの旋回半径で旋回したばあいのＤＥＬ
値と横Ｇの関係を示す図、図４は図３におけるＤＥＬ値
と旋回半径の逆数の関係を示す図、図５はトレッド幅の
差を補正項として入れたときの判定値と旋回半径の逆数
の関係を示す図である。FIG. 1 is a block diagram showing an electrical configuration of a tire pressure drop warning device according to the present invention, FIG. 2 is an explanatory diagram for obtaining a turning radius of a wheel tire, and FIG.
DEL when turning with a turning radius of 150 m and 150 m
FIG. 4 is a diagram showing the relationship between the DEL value and the reciprocal of the turning radius in FIG. 3, and FIG. 5 is a diagram showing the determination value and the turning radius when the difference in tread width is entered as a correction term. It is a figure which shows the relationship of a reciprocal.
【００１０】図１に示すように、本発明の一実施の形態
にかかわるタイヤの空気圧低下警報装置は、たとえば４
輪車両にそなえられた４つのタイヤＷ1、Ｗ2、Ｗ3およ
びＷ4の空気圧が低下しているか否かを検出するもの
で、各タイヤＷ1、Ｗ2、Ｗ3およびＷ4にそれぞれ関連し
て設けられた通常の車輪速センサー１を備えている。車
輪速センサー１の出力は制御ユニット２に与えらえる。
制御ユニット２には、空気圧が低下したタイヤＷiを知
らせるための液晶表示素子、プラズマ表示素子またはＣ
ＲＴなどで構成された表示器３が接続されている。な
お、４は初期化スイッチである。As shown in FIG. 1, a tire pressure drop warning device according to an embodiment of the present invention
It detects whether or not the air pressure of the four tires W 1 , W 2 , W 3, and W 4 provided in the wheeled vehicle is reduced. Each of the tires W 1 , W 2 , W 3, and W 4 is respectively detected. It has a normal wheel speed sensor 1 provided in association therewith. The output of the wheel speed sensor 1 is provided to the control unit 2.
The control unit 2, a liquid crystal display device for informing a tire W i whose pneumatic pressure drops, a plasma display element or C
The display 3 constituted by an RT or the like is connected. 4 is an initialization switch.
【００１１】制御ユニット２は、外部装置との信号の受
け渡しに必要なＩ／Ｏインターフェイス２ａと、演算処
理の中枢として機能するＣＰＵ２ｂと、該ＣＰＵ２ｂの
制御動作プログラムが格納されたＲＯＭ２ｃと、前記Ｃ
ＰＵ２ｂが制御動作を行なう際にデータなどが一時的に
書き込まれたり、その書き込まれたデータなどが読み出
されるＲＡＭ２ｄとから構成されている。本実施の形態
における判定手段は、前記制御ユニット２に含まれてい
る。The control unit 2 includes an I / O interface 2a required for transmitting and receiving signals to and from an external device, a CPU 2b functioning as a center of arithmetic processing, a ROM 2c storing a control operation program of the CPU 2b,
A RAM 2d from which data and the like are temporarily written when the PU 2b performs a control operation, and from which the written data and the like are read. The determination means in the present embodiment is included in the control unit 2.
【００１２】前記車両速度センサー１では、タイヤＷi
の回転数に対応したパルス信号（以下、車輪速パルスと
いう）が出力される。またＣＰＵ２ｂでは、車輪速セン
サー１から出力された車輪速パルスに基づき、所定のサ
ンプリング周期ΔＴ(sec)、たとえばΔＴ＝１秒ごとに
各タイヤＷiの回転数Ｎiが算出される。In the vehicle speed sensor 1, the tire W i
A pulse signal (hereinafter, referred to as a wheel speed pulse) corresponding to the number of rotations is output. Also the CPU 2b, based on the wheel speed pulse outputted from the wheel speed sensor 1, a predetermined sampling period [Delta] T (sec), for example [Delta] T = rotational speed N i of each tire W i every second is calculated.
【００１３】まず、図２に示すように、タイヤの車輪速
はそれぞれ、つぎのように表される。First, as shown in FIG. 2, the wheel speeds of the tires are expressed as follows.
【００１４】Ｖ１＝Ｒ１（ｄθ／ｄｔ） Ｖ２＝Ｒ２（ｄθ／ｄｔ） Ｖ３＝Ｒ３（ｄθ／ｄｔ） Ｖ４＝Ｒ４（ｄθ／ｄｔ） Ｒｉ：各車輪位置での旋回半径 ｄθ／ｄｔ：車両の旋回角速度 ここで、 Ｒ１＝（（Ｒ−Ｔｆ／２）2＋ＷＢ2）0.5 Ｒ２＝（（Ｒ＋Ｔｆ／２）2＋ＷＢ2）０．５ Ｒ３＝（Ｒ−Ｔｒ／２） Ｒ４＝（Ｒ＋Ｔｒ／２） Ｔｆ：前輪のトレッド幅 Ｔｒ：後輪のトレッド幅 ＷＢ：ホイールベース Ｒ：車両の旋回半径 なお、車両の旋回半径Ｒは、後輪駆動のばあい、従動輪
の旋回外側車輪と内側車輪の車輪速からつぎのように求
められる。V1 = R1 (dθ / dt) V2 = R2 (dθ / dt) V3 = R3 (dθ / dt) V4 = R4 (dθ / dt) Ri: turning radius at each wheel position dθ / dt: vehicle Swing angular velocity Here, R1 = ((R−Tf / 2) 2 + WB 2 ) 0.5 R2 = ((R + Tf / 2) 2 + WB 2 ) 0.5 R3 = (R−Tr / 2) R4 = (R + Tr / 2) Tf: tread width of front wheel Tr: tread width of rear wheel WB: wheel base R: turning radius of vehicle Note that, in the case of rear wheel driving, turning radius R of the driven wheel is determined by the turning outer wheel and the inner wheel of the driven wheel. It is obtained from the wheel speed as follows.
【００１５】１／Ｒ＝（Ｖ１−Ｖ２）／（Ｖ１＋Ｖ２）
×（２／Ｔｆ） ただし、旋回中は、旋回内側車輪から外側車輪へ荷重移
動があるので、内側車輪の動荷重半径は大きく、外側車
輪の動荷重半径は小さくなるので、測定された車輪速
は、正確な車輪速度よりズレるため、より正確な旋回半
径をえるためには、実測によって、実旋回半径と計算旋
回半径の関係を求めておいて、補正を行なうのが好まし
い。1 / R = (V1-V2) / (V1 + V2)
× (2 / Tf) However, during turning, since the load moves from the turning inner wheel to the outer wheel, the dynamic load radius of the inner wheel becomes larger and the dynamic load radius of the outer wheel becomes smaller. In order to obtain a more accurate turning radius, it is preferable that the relationship between the actual turning radius and the calculated turning radius be determined by actual measurement and correction be performed in order to obtain a more accurate turning radius.
【００１６】またタイヤＷｉの空気圧低下の検出のため
の減圧判定値（ＤＥＬ値）は、前輪タイヤと後輪タイヤ
との２つの対角和の差を比較するものであって、対角線
上にある一対の車輪からの信号の合計から対角線上にあ
る他の一対の車輪からの信号の合計を引算し、その結果
と２つの合計の平均値との比率として、つぎの式（１）
から求められる（たとえば特公平５−５５３２２号公報
参照）。Further pressure judgment values for detecting decrease in air-pressure of the tire W i (DEL value) is for comparing the difference between two diagonal sums of the rear tires and front tires, diagonally The sum of the signals from one pair of wheels is subtracted from the sum of the signals from the other pair of wheels on the diagonal line, and the ratio of the result to the average of the two sums is expressed by the following equation (1).
(For example, see Japanese Patent Publication No. 5-55322).
【００１７】[0017]
【数１】 (Equation 1)
【００１８】ここで、Ｒが充分大きいばあい、 Ｒ１−Ｒ２≒−Ｔｆ Ｒ３−Ｒ４≒−Ｔｒ Ｒ１＋Ｒ２＋Ｒ３＋Ｒ４≒４×Ｒ と考えられるので、式（１）はつぎの式（２）に近似的
に表現できる。Here, when R is sufficiently large, it can be considered that R1−R2 ≒ −Tf R3−R4 ≒ −Tr R1 + R2 + R3 + R4 ≒ 4 × R, so that equation (1) is approximately expressed by the following equation (2). it can.
【００１９】[0019]
【数２】 (Equation 2)
【００２０】従来では、通常の車両のばあい、Ｔｆ≒Ｔ
ｒであるため、トレッド幅の差＝０となり、ＤＥＬ値＝
０となる。しかし、トラックやバスなど後輪車輪に複輪
をもつ車両では、車両の車幅が長手方向に一定であるに
もかかわらず、複輪のトレッド幅がタイヤの幅の２倍だ
け小さくなっている。このため、トレッド幅の差が大き
いトラックやバスなどのばあい、ＤＥＬ値はシフトし、
減圧検出に大きな影響を与えることが、この式（２）か
らわかる。現実の車両では、車輪速は直接測定すること
はできず、各車輪の１秒あたりの回転数をもとに、つぎ
のように計算されている。Conventionally, in the case of a normal vehicle, Tf ≒ T
r, the difference in tread width = 0, and the DEL value =
It becomes 0. However, in a vehicle having two or more rear wheels such as a truck and a bus, the tread width of the two wheels is twice as small as the tire width, even though the vehicle width is constant in the longitudinal direction. . Therefore, in the case of a truck or a bus having a large difference in tread width, the DEL value shifts,
It can be seen from equation (2) that this has a great effect on the detection of reduced pressure. In a real vehicle, the wheel speed cannot be directly measured, but is calculated as follows based on the number of revolutions per second of each wheel.
【００２１】 Ｖ１＝Ｒ１×（ｄθ／ｄｔ）＝Ｎ１×２π×ｒ１ Ｖ２＝Ｒ２×（ｄθ／ｄｔ）＝Ｎ２×２π×ｒ２ Ｖ３＝Ｒ３×（ｄθ／ｄｔ）＝Ｎ３×２π×ｒ３ Ｖ４＝Ｒ４×（ｄθ／ｄｔ）＝Ｎ４×２π×ｒ４ ここで、Ｎｉ：各車輪の１秒あたりの回転数 ｒｉ：各車輪の動荷重半径 Ｒｉ：各車輪位置での旋回半径 ｄθ／ｄｔ：車両の旋回角速度 各車輪の動荷重半径は、初期化によって一定値になって
いるため、ｒ１＝ｒ、ｒ２＝ｒ、ｒ３＝ｒおよびｒ４＝
ｒとすると、Ｖｉ＝２πｒ×ＮｉとなりＤＥＬ値は、つ
ぎの式（３）に変換される。V1 = R1 × (dθ / dt) = N1 × 2π × r1 V2 = R2 × (dθ / dt) = N2 × 2π × r2 V3 = R3 × (dθ / dt) = N3 × 2π × r3 V4 = R4 × (dθ / dt) = N4 × 2π × r4 where Ni: number of rotations of each wheel per second ri: dynamic load radius of each wheel Ri: turning radius at each wheel position dθ / dt: vehicle Turning angular velocity Since the dynamic load radius of each wheel is constant by initialization, r1 = r, r2 = r, r3 = r and r4 =
If r, Vi = 2πr × Ni, and the DEL value is converted to the following equation (3).
【００２２】[0022]
【数３】 (Equation 3)
【００２３】このＤＥＬ値はタイヤの回転数で表され
る。このＤＥＬ値は、タイヤが正常空気圧で、スリップ
や、左右輪での荷重移動がなければ、すなわち動荷重半
径ｒに変動がなければ、式（１）と一致するが、いずれ
か１個のタイヤが減圧すると、回転数ＮｉがＮｉ＋Δ
Ｎ、動荷重半径ｒがｒ−Δｒとなるため、ＤＥＬ値が変
動する。This DEL value is represented by the number of revolutions of the tire. This DEL value agrees with the equation (1) if the tire is under normal air pressure and there is no slip or load movement on the left and right wheels, that is, if there is no change in the dynamic load radius r. Is reduced, the rotation speed Ni becomes Ni + Δ
N, since the dynamic load radius r is r−Δr, the DEL value fluctuates.
【００２４】たとえば、１のタイヤが減圧すると、Ｎ１
→Ｎ１＋ΔＮとなり、前記式（３）はつぎの式（４）に
変換される。For example, when one tire decompresses, N1
→ N1 + ΔN, and the above equation (3) is converted to the following equation (4).
【００２５】[0025]
【数４】 (Equation 4)
【００２６】ここで、ΔＮは、Ｎ１＋Ｎ２＋Ｎ３＋Ｎ４
に比べて非常に小さいので、 Ｎ１＋Ｎ２＋Ｎ３＋Ｎ４＋ΔＮ≒Ｎ１＋Ｎ２＋Ｎ３＋Ｎ
４ とおくと、前記式（４）はさらにつぎの式（５）のよう
に変換される。Here, ΔN is N1 + N2 + N3 + N4
N1 + N2 + N3 + N4 + ΔN ≒ N1 + N2 + N3 + N
4, the above equation (4) is further transformed as the following equation (5).
【００２７】[0027]
【数５】 (Equation 5)
【００２８】したがって、式（５）から、トレッド幅の
差に起因するＤＥＬ値も減圧判定値に含め、タイヤの減
圧判定の精度を向上させる必要があることがわかる。Therefore, from the equation (5), it is understood that it is necessary to improve the accuracy of the tire pressure reduction determination by including the DEL value caused by the difference in tread width in the pressure reduction determination value.
【００２９】つぎに本発明を実施例に基づいて説明する
が、本発明はかかる実施例のみに限定されるものではな
い。Next, the present invention will be described based on examples, but the present invention is not limited to only these examples.
【００３０】実施例 前輪の２輪が操舵輪であり、後輪の４輪（複輪）が駆動
輪である２−Ｄ・４の車両のばあい、前輪（操舵輪）の
トレッド軸に比べて、後輪の駆動輪のトレッド軸が１９
５ｍｍ短くなっている。Embodiment In the case of a 2-D · 4 vehicle in which two front wheels are steered wheels and four rear wheels (compound wheels) are drive wheels, compared to the tread shaft of the front wheels (steered wheels). The tread axis of the rear drive wheel is 19
5 mm shorter.
【００３１】図３は、この車両で、４０ｍ、１１０ｍお
よび１５０ｍの旋回半径Ｒでそれぞれ旋回したばあい
の、前輪と複輪のうち、内側後輪との前記式（３）から
算出したＲａｗＤＥＬ値と横Ｇ（横方向加速度）Ｌａｔ
Ｇの関係を示している。なお、図３中のＴ1aは４０ｍの
左旋回、Ｔ1bは４０ｍの右旋回、Ｔ2は１１０ｍの左旋
回、およびＴ3は１５０ｍの左旋回を示している。FIG. 3 shows Raw DEL values calculated from the above equation (3) for the front rear wheel and the inner rear wheel among the front wheels and the double wheels when the vehicle turns with a turning radius R of 40 m, 110 m and 150 m, respectively. Lateral G (lateral acceleration) Lat
The relation of G is shown. In FIG. 3, T 1a indicates a left turn of 40 m, T 1b indicates a right turn of 40 m, T 2 indicates a left turn of 110 m, and T 3 indicates a left turn of 150 m.
【００３２】前後軸のトレッド幅に差のほとんどない乗
用車のばあい、データ点は、前記式（２）からほぼ原点
を通る直線上に分布するが、本実施例では、前後軸のト
レッド幅に差があるため、各旋回半径条件の中で、横Ｇ
の変化に対して、ＲａｗＤＥＬ値が変化せずほぼ一定
で、むしろＲａｗＤＥＬ値は旋回半径に依存しているよ
うに見える。このため、このＲａｗＤＥＬ値を旋回半径
Ｒの逆数で整理すると、図４のようになり、全てのデー
タ点は、同一直線上に存在しているように見える。In the case of a passenger car having almost no difference in the tread width of the front-rear axis, the data points are distributed on a straight line substantially passing through the origin from the equation (2). Because of the difference, the lateral G
The value of RawDEL does not change and remains almost constant with respect to the change in the value, but rather, the RawDEL value appears to be dependent on the turning radius. Therefore, when this RawDEL value is arranged by the reciprocal of the turning radius R, it becomes as shown in FIG. 4, and all data points appear to be on the same straight line.
【００３３】そこで、前記式（２）にしたがい、トレッ
ド幅の差（１９５ｍｍ）から生じるＤＥＬ値を計算し
て、図４に書き込むと、直線Ｌのようになり、実測値と
良く一致していることがわかる。Therefore, when the DEL value generated from the difference in tread width (195 mm) is calculated according to the above equation (2) and is written in FIG. 4, the result becomes a straight line L, which is in good agreement with the actually measured value. You can see that.
【００３４】したがって、本発明では、つぎの式（６）
による補正式により、補正を行なうと、図５のようにＣ
ｏｒＤＥＬ値はほぼゼロとなり、ＣｏｒＤＥＬ値はトレ
ッドの差による影響をほとんど受けないため、ＣｏｒＤ
ＥＬ値がゼロからシフトすることにより、タイヤの減圧
を判定できる。Therefore, in the present invention, the following equation (6)
When the correction is performed by the correction formula according to
The orDEL value is almost zero, and the CorDEL value is hardly affected by the difference in tread.
By shifting the EL value from zero, the pressure reduction of the tire can be determined.
【００３５】[0035]
【数６】 (Equation 6)
【００３６】ここで、ａは理論と実際の差を補正するた
めの係数であり、前記係数ａは、つぎのようにして求め
ることができる。まず、旋回半径を、ある速度で惰行走
行する。これは、旋回中の駆動力による旋回内側駆動輪
のスリップの影響をなくすためである。ついで、このと
きのＲａｗＤＥＬ値を、横軸に横Ｇをとりプロットし、
横Ｇ＝０のときのＲａｗＤＥＬ値を求める。これは、旋
回中の荷重移動によるＲａｗＤＥＬ値への影響をなくす
ためである。なお、本実施例における図３のばあいで
は、ＲａｗＤＥＬ値が荷重移動の影響をほとんど受けて
おらず、横Ｇに対して、ＲａｗＤＥＬ値が一定（水平）
になっている。Here, a is a coefficient for correcting the difference between the theory and the actual, and the coefficient a can be obtained as follows. First, the vehicle is coasted at a turning radius at a certain speed. This is to eliminate the influence of the slip of the inside driving wheel due to the driving force during turning. Then, the RawDEL value at this time is plotted with the horizontal G taken on the horizontal axis,
The RawDEL value when the horizontal G = 0 is obtained. This is to eliminate the influence on the RawDEL value due to the load movement during turning. In the case of FIG. 3 in this embodiment, the RawDEL value is hardly affected by the load movement, and the RawDEL value is constant (horizontal) with respect to the horizontal G.
It has become.
【００３７】つぎに、これを様々な旋回半径で実施し、
前記求めたＲａｗＤＥＬ値を、横軸に（トレッド幅の
差）／（旋回半径の逆数×２）をとって、プロットす
る。そして最小２乗法により算出される回帰直線の傾き
から係数ａを求める。本実施例では、ａ＝１．２０１９
であった。Next, this is performed with various turning radii,
The obtained RawDEL value is plotted by taking (the difference in tread width) / (the reciprocal of the turning radius × 2) on the horizontal axis. Then, the coefficient a is obtained from the slope of the regression line calculated by the least square method. In this embodiment, a = 1.2019
Met.
【００３８】[0038]
【発明の効果】以上説明したとおり、本発明によれば、
車両のトレッド幅の差に関する補正項を設けることによ
り、空気圧の減圧判定の精度を向上させることができ
る。As described above, according to the present invention,
By providing a correction term relating to the difference in the tread width of the vehicle, it is possible to improve the accuracy of the air pressure reduction determination.
【図１】本発明のタイヤの空気圧低下警報装置の電気的
構成を示すブロック図である。FIG. 1 is a block diagram showing an electric configuration of a tire pressure drop warning device of the present invention.
【図２】車輪タイヤの旋回半径を求めるための説明図で
ある。FIG. 2 is an explanatory diagram for obtaining a turning radius of a wheel tire.
【図３】４０ｍ、１１０ｍおよび１５０ｍの旋回半径で
旋回したばあいのＤＥＬ値と横Ｇの関係を示す図であ
る。FIG. 3 is a diagram showing a relationship between a DEL value and a lateral G when the vehicle turns at a turning radius of 40 m, 110 m, and 150 m.
【図４】図１におけるＤＥＬ値と旋回半径の逆数の関係
を示す図である。FIG. 4 is a diagram showing a relationship between a DEL value and a reciprocal of a turning radius in FIG. 1;
【図５】トレッド幅の差を補正項として入れたときの判
定値と旋回半径の逆数の関係を示す図である。FIG. 5 is a diagram illustrating a relationship between a determination value and a reciprocal of a turning radius when a difference in tread width is included as a correction term.
１ 車輪速センサー ２ 制御ユニット ３ 表示器 ４ 初期化スイッチ 1 wheel speed sensor 2 control unit 3 display 4 initialization switch
Claims (4)
た回転数に基づいて、タイヤの空気圧が低下しているか
否かを判定し、タイヤの内圧が低下しているばあいに、
警報を発生する空気圧低下警報方法であって、２つの対
角和の差を比較することによりタイヤの減圧を検知する
判定値を算出する式において、車両の前輪および後輪の
トレッド幅の差に関する補正項を設けることを特徴とす
るタイヤの空気圧低下警報方法。1. A tire rotation speed is detected, and based on the detected rotation speed, it is determined whether or not the tire air pressure is decreasing. When the tire internal pressure is decreasing,
An air pressure drop warning method for generating a warning, wherein a formula for calculating a determination value for detecting pressure reduction of a tire by comparing a difference between two diagonal sums relates to a difference between tread widths of a front wheel and a rear wheel of a vehicle. A method for alarming a decrease in tire air pressure, comprising providing a correction term.
て、複数の車軸の組み合わせに適用する請求項１記載の
タイヤの空気圧低下警報方法。2. The method according to claim 1, wherein the method is applied to a combination of a plurality of axles in a multi-axle vehicle having three or more axles.
た回転数に基づいて、タイヤの空気圧が低下しているか
否かを判定し、タイヤの内圧が低下しているばあいに、
警報を発生する空気圧低下警報装置であって、各タイヤ
の車輪速を検出するための速度検出手段と、該速度検出
手段で検出される車輪速から求められる回転数に基づい
て前輪タイヤの回転数と後輪タイヤの回転数との２つの
対角和の差を比較する減圧判定値を演算処理する判定手
段とからなり、該判定手段における減圧判定値に車両の
前輪および後輪のトレッド幅の差に関する補正項が含ま
れてなるタイヤの空気圧警報装置。3. The tire rotation speed is detected, and based on the detected rotation speed, it is determined whether or not the tire air pressure is decreasing. When the tire internal pressure is decreasing,
An air pressure drop warning device that generates a warning, comprising: speed detection means for detecting a wheel speed of each tire; and a rotation speed of a front wheel tire based on a rotation speed obtained from the wheel speed detected by the speed detection means. And a determining means for calculating a decompression judgment value for comparing a difference between two diagonal sums of the rotation speed of the rear wheel tires and the rotation speed of the rear wheel tire. A tire pressure warning device including a correction term relating to a difference.
て、複数の車軸の組み合わせに適用する請求項３記載の
タイヤの空気圧低下警報装置。4. The tire air pressure drop warning device according to claim 3, which is applied to a combination of a plurality of axles in a multi-axle vehicle having three or more axles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08138899A JP3594833B2 (en) | 1998-04-02 | 1999-03-25 | Tire air pressure drop warning method and device |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8980398 | 1998-04-02 | ||
| JP6040099 | 1999-03-08 | ||
| JP11-60400 | 1999-03-08 | ||
| JP10-89803 | 1999-03-08 | ||
| JP08138899A JP3594833B2 (en) | 1998-04-02 | 1999-03-25 | Tire air pressure drop warning method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000318417A true JP2000318417A (en) | 2000-11-21 |
| JP3594833B2 JP3594833B2 (en) | 2004-12-02 |
Family
ID=27297175
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08138899A Expired - Lifetime JP3594833B2 (en) | 1998-04-02 | 1999-03-25 | Tire air pressure drop warning method and device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3594833B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8554498B2 (en) | 2007-03-16 | 2013-10-08 | Nira Dynamics Ab | Method, system and computer program for estimation of the pressure |
| US9079462B2 (en) | 2007-03-16 | 2015-07-14 | Nira Dynamics Ab | System, method and computer program of estimating tire pressure deviations |
| US9145033B2 (en) | 2007-03-16 | 2015-09-29 | Nira Dynamics Ab | Tire pressure classification based tire pressure monitoring |
-
1999
- 1999-03-25 JP JP08138899A patent/JP3594833B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8554498B2 (en) | 2007-03-16 | 2013-10-08 | Nira Dynamics Ab | Method, system and computer program for estimation of the pressure |
| US9079462B2 (en) | 2007-03-16 | 2015-07-14 | Nira Dynamics Ab | System, method and computer program of estimating tire pressure deviations |
| US9145033B2 (en) | 2007-03-16 | 2015-09-29 | Nira Dynamics Ab | Tire pressure classification based tire pressure monitoring |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3594833B2 (en) | 2004-12-02 |
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