JP3733754B2

JP3733754B2 - Brake hydraulic pressure control device

Info

Publication number: JP3733754B2
Application number: JP23962098A
Authority: JP
Inventors: 智之松▲沢▼
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1998-08-26
Filing date: 1998-08-26
Publication date: 2006-01-11
Anticipated expiration: 2018-08-26
Also published as: JP2000071965A

Description

【０００１】
【発明の属する技術分野】
この発明はブレーキ液圧制御装置に関する。
【０００２】
【従来の技術】
従来のブレーキ液圧制御装置としては、例えば特開平０６−１９１３９３号公報に示すように、通常の制動がマスタシリンダとは別に設けられた液圧源の液圧に基づいて行われる電気制御式液圧ブレーキがある。この従来のブレーキ液圧制御装置においては、液圧制御装置が、液圧源の液圧をコイルへの供給電流に比例した高さに制御する比例電磁液圧制御装置とされるとともに、ブレーキ操作部材の操作量を検出する操作量検出手段が設けられる。また、制御手段は操作量検出手段の検出結果に基づいて目標ホイールシリンダ圧を設定するとともに、比例電磁液圧制御装置のコイルヘの供給電流を液圧源の液圧が目標ホイールシリンダ圧に制御される大きさに設定し、ホイールシリンダには、ブレーキ操作部材の操作量に見合った高さの液圧、例えば、操作量に比例する液圧や、操作力に比例した車体減速度が得られる液圧が供給されて車輪の回転が抑制される。また電気制御式液圧ブレーキに異常が発生し、液圧源からの液圧をホイールシリンダに供給できなくなる場合は、マスタシリンダからの液圧を直接ホイールシリンダに供給する機械式ブレーキに切り換わるようになっている。
【０００３】
【発明が解決しようとする課題】
しかしながら、このような従来のブレーキ液圧制御装置にあっては、ホイールシリンダの液圧を検知する圧力センサに故障等の異常が発生した場合に、ブレーキ液圧制御装置は所定のホイールシリンダ圧が得られていないとみなすため、液圧源や比例電磁液圧制御装置に異常がないにもかかわらず、電気制御式液圧ブレーキを維持することができずに、マスタシリンダからの液圧を直接ホイールシリンダに供給する機械式ブレーキに切り換えてしまうという問題点があった。
この発明は、このような従来の問題点に着目してなされたもので、ホイールシリンダの液圧を検知する圧力センサに故障等の異常が発生した場合においても電気制御式液圧ブレーキシステムを維持することにより、従来の問題点を解決することを目的としている。
【０００４】
【課題を解決するための手段】
本課題を解決するために、請求項１記載の発明においては、ブレーキ操作部材と、そのブレーキ操作部材の操作に応じて液圧を発生させるマスタシリンダと、前記ブレーキ操作部材の操作量を検出する操作量検出手段と、ポンプ等からなる液圧源と、その液圧源の液圧を検出する液圧源液圧検出手段と、前記液圧源液圧検出手段の検出量に基づいて前記ポンプの駆動を制御するポンプ駆動制御手段と、複数の車輪の回転をそれぞれ抑制する複数のホイールシリンダと、その複数のホイールシリンダの各々の液圧を検出する複数のホイールシリンダ圧検出手段と、前記液圧源と前記複数のホイールシリンダとをそれぞれ接続する複数の第１の液通路と、それら第１の液通路の各々に設けられ前記ホイールシリンダの液圧を制御する複数の液圧制御装置と、前記マスタシリンダと前記複数のホイールシリンダとをそれぞれ接続する複数の第２の液通路と、前記操作量検出手段の検出量に基づいて前記複数のホイールシリンダの目標液圧を設定し、前記複数のホイールシリンダ圧検出手段による検出液圧が前記複数のホイールシリンダの目標液圧に一致するように前記液圧制御装置を制御する液圧制御装置制御手段と、前記液圧源が正常に作動する状態では前記マスタシリンダを前記ホイールシリンダから遮断して前記液圧源の液圧を前記ホイールシリンダに伝達する第１の状態と、前記液圧源が正常に液圧を生じきせない状態では前記液圧源を前記ホイールシリンダから遮断して前記マスタリンダの液圧を前記ホイールシリンダに伝達する第２の状態とに切り換え可能で、通常は第１の状態にある複数の切換装置と、を含むブレーキ液圧制御装置において、前記液圧制御装置制御手段の指令値から前記ホイールシリンダの液圧を推定するホイールシリンダ圧推定手段を有し、そのホイールシリンダ圧推定手段の推定量と前記ホイールシリンダ圧検出手段の検出量との差の絶対値が１つのホイールシリンダについてだけ第１の閾値以上である場合に、第１の閾値以上であるホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置のみを前記第１の状態から前記第２の状態に切り換えて、第１の閾値以上であるホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダのホイールシリンダ圧検出手段の検出量の差の絶対値が第２の閾値以上である場合に、第１の閾値以上であるホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置のみを前記第２の状態から前記第１の状態に再び切り換えて、前記液圧源の目標液圧を設定し、前記液圧源液圧検出手段による検出液圧が前記液圧源の目標液圧に一致するように前記液圧制御装置制御手段を第１の閾値以上であるホイールシリンダについてのみ変更することを特徴としている。
請求項２記載の発明においては、ブレーキ操作部材と、そのブレーキ操作部材の操作に応じて液圧を発生させるマスタシリンダと、前記ブレーキ操作部材の操作量を検出する操作量検出手段と、ポンプ等からなる液圧源と、その液圧源の液圧を検出する液圧源液圧検出手段と、前記液圧源液圧検出手段の検出量に基づいて前記ポンプの駆動を制御するポンプ駆動制御手段と、複数の車輪の回転をそれぞれ抑制する複数のホイールシリンダと、その複数のホイールシリンダの各々の液圧を検出する複数のホイールシリンダ圧検出手段と、前記液圧源と前記複数のホイールシリンダとをそれぞれ接続する複数の第１の液通路と、それら第１の液通路の各々に設けられ前記ホイールシリンダの液圧を制御する複数の液圧制御装置と、前記マスタシリンダと前記複数のホイールシリンダとをそれぞれ接続する複数の第２の液通路と、前記操作量検出手段の検出量に基づいて前記複数のホイールシリンダの目標液圧を設定し、前記複数のホイールシリンダ圧検出手段による検出液圧が前記複数のホイールシリンダの目標液圧に一致するように前記液圧制御装置を制御する液圧制御装置制御手段と、前記液圧源が正常に作動する状態では前記マスタシリンダを前記ホイールシリンダから遮断して前記液圧源の液圧を前記ホイールシリンダに伝達する第１の状態と、前記液圧源が正常に液圧を生じさせない状態では前記液圧源を前記ホイールシリンダから遮断して前記マスタシリンダの液圧を前記ホイールシリンダに伝達する第２の状態とに切り換え可能で、通常は第１の状態にある複数の切換装置と、を含むブレーキ液圧制御装置において、前記液圧制御装置制御手段の指令値から前記ホイールシリンダの液圧を推定する第１のホイールシリンダ圧推定手段と、前記切換装置が第２の状態にある場合に前記操作量検出手段の検出量から前記ホイールシリンダの液圧を推定する第２のホイールシリンダ圧推定手段とを有し、前記第１のホイールシリンダ圧推定手段の推定量と前記ホイールシリンダ圧検出手段の検出量との差の絶対値が１つのホイールシリンダについてだけ第１の閾値以上である場合に、第１の閾値以上であるホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置のみを前記第１の状態から前記第２の状態に切り換えて、第１の閾値以上であるホイールシリンダにおける前記第２のホイールシリンダ圧推定手段の推定量とホイールシリンダ圧検出手段の検出量の差の絶対値が第３の閾値以上である場合に、第１の閾値以上であるホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置のみを前記第２の状態から前記第１の状態に再び切り換えて、前記液圧源の目標液圧を設定し、前記液圧源液圧検出手段による検出液圧が前記液圧源の目標液圧に一致するように前記液圧制御装置制御手段を第１の閾値以上であるホイールシリンダについてのみ変更することを特徴としている。
請求項３記載の発明においては、請求項１または２記載のブレーキ液圧制御装置において、前記液圧源液圧検出手段による検出液圧が前記液圧源の目標液圧に一致するように前記液圧制御装置制御手段を第１の閾値以上であるホイールシリンダについてのみ変更した揚合に、前記ブレーキ操作部材操作中は前記ポンプ駆動制御手段への指令値を一定値にすることを特徴としている。
【０００５】
【作用】
請求項１記載の発明においては、ホイールシリンダ圧推定手段の推定量とホイールシリンダ圧検出手段の検出量とを各ホイールシリンダごとに比較することで、電気制御式ブレーキが正常であるかを判定し、その差の絶対値が１つのホイールシリンダについてだけ第１の閾値以上である場合は、１輪分のホイールシリンダが異常であると判断する。１輪分のホイールシリンダが異常であると判断された場合は、異常が検出されたホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置をマスタシリンダとホイールシリンダとを連通する第２の状態に切り換えて、ホイールシリンダ圧検出手段の検出量を比較し、その差の絶対値が第２の閾値以上である場合は、ホイールシリンダ圧検出手段が異常であると判断する。ホイールシリンダ圧検出手段が異常であると判断された場合は、異常が検出されたホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置を液圧源とホイールシリンダとを連通する第１の状態に切り換えて、目標ホイールシリンダ圧から液圧源の目標液圧を設定し、液圧源液圧検出手段による検出液圧が液圧源の目標液圧に一致するように液圧制御装置制御手段を異常が検出されたホイールシリンダについてのみ変更することにより、電気制御式液圧ブレーキを維持する。
請求項２記載の発明においては、第１のホイールシリンダ圧推定手段の推定量とホイールシリンダ圧検出手段の検出量とを各ホイールシリンダごとに比較することで電気制御式ブレーキが正常であるかを判定し、その差の絶対値が１つのホイールシリンダについてだけ第１の閾値以上である場合は、１輪分のホイールシリンダが異常であると判断する。１輪分のホイールシリンダが異常であると判断された場合は、異常が検出されたホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置をマスタシリンダとホイールシリンダとを連通する第２の状態に切り換えて、異常が検出されたホイールシリンダについて第２のホイールシリンダ圧推定手段とホイールシリンダ圧検出手段の検出量を比較し、その差の絶対値が第３の閾値以上である場合は、ホイールシリンダ圧検出手段が異常であると判断する。ホイールシリンダ圧検出手段が異常であると判断された場合は、異常が検出されたホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置を液圧源とホイールシリンダとを連通する第１の状態に切り換えて、目標ホイールシリンダ圧から液圧源の目標液圧を設定し、液圧源液圧検出手段による検出液圧が液圧源の目標液圧に一致するように液圧制御装置制御手段を異常が検出されたホイールシリンダについてのみ変更することにより、電気制御式液圧ブレーキを維持する。
請求項３記載の発明においては、請求項１、２記載の発明の作用に加えて、ブレーキ操作部材操作中はポンプ駆動制御手段への指令値を一定値にすることにより、異常が検出されたホイールシリンダについて目標ホイールシリンダ圧からより精度よく液圧源の目標液圧を算出する。
【０００６】
【発明の実施の形態】
以下、この発明の実施の形態を図面に基づいて説明する。図１〜図５は、本発明の実施の形態１を示す図である。まず構成を図１で説明すると、１０はブレーキ操作部材としてのブレーキペダル１０である。ブレーキペダル１０はマスタシリンダ１２に接続されており、マスタシリンダ１２の２個の加圧室にそれぞれ、ブレーキペダル１０の踏力に対応する液圧（マスタシリンダ圧と称する）が発生させられる。マスタシリンダ１２の一方の加圧室は、液通路１４、１６及び分岐通路１８、２０により、左右前輪２２、２４にそれぞれ設けられたブレーキのフロントホイールシリンダ２６、２８に接続されており、他方の加圧室は、液通路３０、３２及び分岐通路３４、３６により、左右後輪３８、４０にそれぞれ設けられたブレーキのリアホイールシリンダ４２、４４に接続されている。４６は後輪３８、４０用の液通路３２に設けられたプロポーショニングバルブである。
【０００７】
上記分岐通路１８、２０、３４、３６にはそれぞれ、電磁方向切換弁５０、５２、５４、５６が設けられ、比例電磁液圧制御弁５８、６０、６２、６４が接続されている。電磁方向切換弁５０、５２、５４、５６のソレノイドは常には消磁されて図１に示す原位置にあり、ホイールシリンダ２６、２８、４２、４４を比例電磁液圧制御弁５８、６０、６２、６４に連通させているが、ソレノイドが励磁されれば反対側の位置に切り換えられ、ホイールシリンダ２６、２８、４２、４４をマスタシリンダ１２に連通させる。
【０００８】
比例電磁液圧制御弁５８、６０、６２、６４はそれぞれ、液圧源としてのアキュムレータ７０とリザーバ７２とに液通路７４、７６により接続されており、アキュムレータ７０の液圧がある閾値より下がった揚合には、モータ７８によって駆動されるポンプ８０によって、リザーバ７２の液がアキュムレータ７０の液圧がある別の閾値に達するまで汲み上げられ、アキュムレータ７０には一定の範囲の液圧で液が蓄えられる。
【０００９】
比例電磁液圧制御弁５８、６０、６２、６４は、ソレノイドの励磁電流の制御により、アキュムレータ７０の液圧（アキュムレータ圧と称する）を制御してホイールシリンダ２６、２８、４２、４４に供給し、そのホイールシリンダ２６、２８、４２、４４の液圧（ホイールシリンダ圧と称する）に基づいてブレーキが作動し、車輪の回転が抑制される。
【００１０】
前記マスタシリンダ１２とフロントホイールシリンダ２６、２８とを接続する液通路１４と１６との間、及びマスタシリンダ１２とリアホイールシリンダ４２、４４とを接続する液通路３０と３２との間にはそれぞれ電磁方向切換弁８４、８６が設けられ、ストロークシミュレータ８８、９０が接続されている。ストロークシミュレータ８８、９０は、マスタシリンダ１２から排出されるブレーキ液を収容してブレーキペダル１０の踏み込みを許容するとともに、踏み込みストロークに応じた反力をブレーキペダル１０に与えるものである。車輪の回転が比例電磁液圧制御弁５８、６０、６２、６４によって制御されたホイールシリンダ圧に基づいて抑制される状態においては、電磁方向切換弁８４、８６のソレノイドが消磁されてマスタシリンダ１２がストロークシミュレータ８８、９０に連通させられ、運転者にあたかもホイールシリンダ２６、２８、４２、４４に接続されているかのような操作フィーリングを与えるようにされているのである。
【００１１】
本ブレーキ液圧制御装置は制御装置１００によって制御される。制御装置１００はＣＰＵ１０２、ＲＯＭ１０４、ＲＡＭ１０６、入力部１０８、出力部１１０及びバスを含んでいる。制御装置１００の入力部１０８には、ブレーキペダル１０の踏み込みを検出するブレーキスイッチ１１２、ブレーキペダル１０の踏み込み力を検出する操作量検出手段としての踏力検出装置１１４、アキュムレータ７０の液圧を検出する液圧センサ１１６、ホイールシリンダ２６、２８、４２、４４のホイールシリンダ圧を検出するホイールシリンダ圧検出手段としての液圧センサ１１８、１２０、１２２、１２４、左右の前輪２２、２４及び後輪３８、４０の各回転速度を検出する車輪速センサ１２６、１２８、１３０、１３２、車体の前後方向及び横方向の減速度をそれぞれ検出する前後Ｇセンサ１４４、横Ｇセンサ１４６が接続されている。入力部１０８は、各検出装置、センサから供給される信号がアナログ信号である場合にそれをディジタル信号に変える等、適宜の信号処理を行う回路を備えている。
【００１２】
出力部１１０には、比例電磁液圧制御弁５８、６０、６２、６４及び電磁方向切換弁５０、５２、５４、５６、８４、８６が接続されている。出力部１１０には比例電磁液圧制御弁５８、６０、６２、６４及び電磁方向切換弁５０、５２、５４、５６、８４、８６の各々に対応した駆動回路が設けられており、各弁はこれら駆動回路に接続されているのである。出力部１１０にはさらに、比例電磁液圧制御弁５８、６０、６２、６４の各駆動回路に対してディジタル値で決定される指令値をアナログ信号に変換して駆動回路に供給するＤ／Ａ変換器も設けられている。またＲＯＭ１０４にはブレーキペダル１０の踏み込み力と目標減速度との関係を規定するマップ、後述する車輪回転抑制ルーチン、ホイールシリンダ圧検出手段の異常検出ルーチン、ホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンが格納されている。
【００１３】
本ブレーキ液圧制御装置による制動は、通常は比例電磁液圧制御弁５８、６０、６２、６４の出力液圧に基づいて行われるのであって、電磁方向切換弁５０、５２、５４、５６、８４、８６は常には消磁され、ホイールシリンダ２６、２８、４２、４４は比例電磁液圧制御弁５８、６０、６２、６４に連通させられ、マスタシリンダ１２はストロークシミュレータ８８、９０に連通させられている。しかし、本ブレーキ液圧制御装置に異常が発生し、液圧源からの液圧を比例電磁液圧制御弁５８、６０、６２、６４の出力液圧に基づいてホイールシリンダ２６、２８、４２、４４に供給できなくなる場合は、電磁方向切換弁５０、５２、５４、５６、８４、８６のソレノイドが励磁されて、図１に示す原位置と反対側の位置に切り換えられ、ホイールシリンダ２６、２８、４２、４４の液圧は、マスタシリンダ１２の液圧に基づいて機械的に制御される。
【００１４】
次に、作用を図２〜図４のフローチャートに基づいて説明する。
図２は車輪回転抑制ルーチンのフローチャートである。ただし、このルーチンは、ホイールシリンダ圧検出手段の異常時には、後述するホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンに変更される。まず、ステップＳ１（以下、Ｓ１と略記する。他のステップについても同じ）が実行され、ブレーキペダル１０が踏み込まれているか否かにより制動中か否かの判定が行われる。ブレーキペダル１０が踏み込まれていなければＳ１の判定結果はＮＯとなり、ルーチンの実行は終了する。ブレーキペダル１０が踏み込まれていればＳ１の判定結果はＹＥＳとなってＳ２が実行され、ブレーキペダル１０の踏み込み力、車体の減速度が読み込まれた後、Ｓ３において目標減速度が決定される。次に、Ｓ４が実行され、ホイールシリンダ２６、２８、４２、４４へ供給する目標ホイールシリンダ圧が設定される。次に、Ｓ５において比例電磁液圧制御弁５８、６０、６２、６４の駆動回路に対する指令値（ディジタル値）が決定される。Ｓ５で決定された指令値は、Ｓ６において、Ｄ／Ａ変換器によりアナログ信号に変換された上で駆動回路に供給され、それに応じて比例電磁液圧制御弁５８、６０、６２、６４が駆動される。次にＳ７においてホイールシリンダ圧検出手段である液圧センサ１１８、１２０、１２２、１２４により各輪のホイールシリンダ圧が読み込まれる。次にＳ８においてホイールシリンダ２６、２８、４２、４４へ供給する目標ホイールシリンダ圧と液圧センサ１１８、１２０、１２２、１２４による液圧との差の絶対値が４輪とも閾値Ｘ１より小さいかを判定し、ＹＥＳの場合はルーチンの実行を終了する。ＮＯの場合はＳ９に進み、閾値以上であるホイールシリンダについて比例電磁液圧制御弁５８、６０、６２、６４の駆動回路に対する指令値（ディジタル値）を目標ホイールシリンダ圧に近づくように変更し、Ｓ６に戻る。
【００１５】
図３はホイールシリンダ２６、２８、４２、４４の液圧の検出手段である液圧センサ１１８、１２０、１２２、１２４の異常検出ルーチンのフローチャートであって、このルーチンは、制動中か否かに関係なく、ある一定時間おきに行われる。
【００１６】
まず、Ｓ１０１が実行され、比例電磁液圧制御弁５８、６０、６２、６４の駆動回路に対する指令値及びホイールシリンダ２６、２８、４２、４４の液圧であるホイールシリンダ圧が読み込まれる。次にＳ１０２において、比例電磁液圧制御弁５８、６０、６２、６４の駆動回路に対する指令値から各輪のホイールシリンダ圧推定値が算出される。次にＳ１０３が実行され、すべてのホイールシリンダ２６、２８、４２、４４について、
｜ホイールシリンダ圧測定値−ホイールシリンダ圧推定値｜＜Ｘ２（閾値）
かどうかを判定し、ＹＥＳの場合はルーチンの実行を終了する。ＮＯの場合はＳ１０４に進み、閾値以上であるホイールシリンダが１輪のみであるかどうかを判定する。ＮＯの場合はルーチンの実行を終了し、さらに電磁方向切換弁５０、５２、５４、５６、８４、８６のソレノイドが励磁されて、図１に示す原位置と反対側の位置に切り換えられ、ホイールシリンダ２６、２８、４２、４４の液圧は、マスタシリンダ１２の液圧に基づいて機械的に制御される。ＹＥＳの場合はＳ１０５に進む。また本実施の形態では閾値以上であるホイールシリンダが左後輪４２である場合について説明するが、他のホイールシリンダ２６、２８、４４の場合についても同様に説明できる。Ｓ１０５では、電磁方向切換弁５４、５６、８４、８６のソレノイドが励磁されて、図１に示す原位置と反対側の位置に切り換えられ、ホイールシリンダ４２、４４の液圧は、マスタシリンダ１２の液圧に基づいて機械的に制御される状態になる。次にＳ１０６において、ホイールシリンダ４２、４４の液圧であるホイールシリンダ圧が読み込まれる。次にＳ１０７において、２つのホイールシリンダ４２、４４の液圧の差の絶対値が閾値Ｘ３より小さいかどうかを判定し、ＹＥＳの場合はルーチンの実行を終了し、ホイールシリンダ４２、４４の液圧は、マスタシリンダ１２の液圧に基づいて機械的に制御されたままとする。ＮＯの場合はＳ１０８に進み、電磁方向切換弁５４、５６、８４、８６のソレノイドが消磁されて、図１に示す原位置に切り換えられ、ホイールシリンダ４２、４４の液圧は、比例電磁液圧制御弁６２、６４の出力液圧に基づいて制御される状態になる。次にルーチンの実行を終了し、通常の車輪回転抑制ルーチンから後述する図４のホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンヘの変更を行う。
【００１７】
ホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンにおいては、まずＳ２０１が実行され、ブレーキペダル１０が踏み込まれているか否かにより制動中か否かの判定が行われる。ブレーキペダル１０が踏み込まれていなければＳ２０１の判定結果はＮＯとなり、ルーチンの実行は終了する。ブレーキペダル１０が踏み込まれていればＳ２０１の判定結果はＹＥＳとなってＳ２０２が実行され、ブレーキペダル１０の踏み込み力、車体の減速度、モータ７８の電圧が読み込まれた後、Ｓ２０３において目標減速度が決定される。次にＳ２０４が実行され、ホイールシリンダ２６、２８、４２、、４４へ供給する目標ホイールシリンダ圧が設定される。次にＳ２０５において、目標ホイールシリンダ圧、モータ電圧から以下のようにして目標アキュムレータ圧が算出される。各輪の目標ホイールシリンダ圧の値と、各輪のホイールシリンダ２６、２８、４２、４４における液量−液圧の特性から各輪のホイールシリンダ２６、２８、４２、４４で消費される目標液量が算出される。この各輪のホイールシリンダ２６、２８、４２、４４で消費される目標液量の和を求めることでアキュムレータ７０の目標消費液量が算出される。一方モータ７８の電圧値とモータ電圧−ポンプ液量の特性からポンプ８０からアキュムレータ７０に供給される液量が算出される。このアキュムレータ７０の目標消費液量とポンプ８０からアキュムレータ７０に供給される液量とアキュムレータ７０の液量−液圧特性により目標アキュムレータ圧が算出される。
【００１８】
次にＳ２０６に進み、比例電磁液圧制御弁５８、６０、６２、６４の駆動回路に対する指令値（ディジタル値）が決定される。Ｓ２０６で決定された指令値は、Ｓ２０７において、Ｄ／Ａ変換器によりアナログ信号に変換された上で駆動回路に供給され、それに応じて比例電磁液圧制御弁５８、６０、６２、６４が駆動される。次にＳ２０８においてホイールシリンダ圧検出手段である液圧センサ１１８、１２０、１２４により３輪分のホイールシリンダ圧、アキュムレータ７０の液圧を検出する液圧センサ１１６によりアキュムレータ圧が読み込まれる。次にＳ２０９においてホイールシリンダ２６、２８、４４へ供給する目標ホイールシリンダ圧と液圧センサ１１８、１２０、１２４による液圧との差の絶対値が３輪とも閾値Ｘ１より小さく、かつ目標アキュムレータ圧と液圧センサ１１６による液圧との差の絶対値が閾値Ｘ１より小さいかを判定し、ＹＥＳの場合はルーチンの実行を終了する。ＮＯの場合はＳ２１０に進み、モータ７８の電圧が読み込まれる。次にＳ２１１に進み、Ｓ２０５と同様に目標アキュムレータ圧が算出される。次にＳ２１２においては、閾値以上であるホイールシリンダ及びアキュムレータ７０について比例電磁液圧制御弁の駆動回路に対する指令値（ディジタル値）を目標ホイールシリンダ圧及び目標アキュムレータ圧に近づくように変更し、Ｓ２０７に戻る。
【００１９】
本実施の形態によれば、ホイールシリンダ圧検出手段の異常検出ルーチンのＳ１０３において、電気制御式ブレーキが正常であるかどうかを判定し、異常が見られる場合はＳ１０４において異常が見られるホイールシリンダを特定する。２〜４輪に異常が見られる場合は、液圧源の異常または確率的には極めて低いものの２輪以上のホイールシリンダの液圧を検出する液圧センサまたは比例電磁液圧制御弁の異常が考えられ、この場合は４輪のホイールシリンダ２６、２８、４２、４４ともマスタシリンダ１２からの液圧を直接ホイールシリンダ２６、２８、４２、４４に供給する機械式ブレーキに切り換える。１輪だけに異常が見られる場合（本実施の形態では左後輪３８とする）は、Ｓ１０５において左右後輪３８、４０のホイールシリンダ４２、４４のみを、マスタシリンダ１２からの液圧を直接ホイールシリンダ４２、４４に供給する機械式ブレーキに切り換え、Ｓ１０７において左右後輪３８、４０のホイールシリンダ４２、４４の液圧を検出する液圧センサ１２２、１２４の値を比較する。値の差が閾値より小さい場合は液圧センサ１２２、１２４に異常がなく、左後輪３８の比例電磁液圧制御弁６２の異常が考えられ、この場合は左右後輪３８、４０のホイールシリンダ４２、４４のみを、マスタシリンダ１２からの液圧を直接ホイールシリンダ４２、４４に供給する機械式ブレーキに切り換えたままとする。値の差が閾値以上である場合は左後輪３８の液圧センサ１２２の異常が考えられ、左右後輪３８、４０のホイールシリンダ４２、４４を再び比例電磁液圧制御弁６２、６４の出力液圧に基づいて制御される状態にし、ホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンを実行する。ホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンにおいては、モータ電圧及び目標ホイールシリンダ圧から目標アキュムレータ圧を算出し、異常が検出されたホイールシリンダについては、ホイールシリンダ圧を検出する液圧センサが目標ホイールシリンダ圧に一致するように比例電磁液圧制御弁への指令値を決めていたのを、アキュムレータ圧を検出する液圧センサ１１６が目標アキュムレータ圧に一致するように比例電磁液圧制御弁への指令値を決めるように変更することで電気制御式液圧ブレーキの維持を行う。
【００２０】
以上のようにして、本実施の形態によればホイールシリンダ２６、２８、４２、４４の液圧を検出する液圧センサ１１８、１２０、１２２、１２４の異常を検出することが可能であり、ホイールシリンダ２６、２８、４２、４４の液圧を検出する液圧センサ１１８、１２０、１２２、１２４の異常を検出した場合は、異常が検出されたホイールシリンダについてアキュムレータ圧を検出する液圧センサ１１６が目標アキュムレータ圧に一致するように比例電磁液圧制御弁への指令値を決めるように変更したので、ホイールシリンダ２６、２８、４２、４４の液圧を検出する液圧センサ１１８、１２０、１２２、１２４に異常が発生した場合でも、マスタシリンダ１２からの液圧を直接ホイールシリンダ２６、２８、４２、４４に供給する機械式ブレーキに切り換えることなく、電気制御式液圧ブレーキを維持することができるといった利点が得られる。
【００２１】
図５には、実施の形態２を示す。
実施の形態２の構成については実施の形態１と同様である。
次に、作用を図５のフローチャートに基づいて説明するが、車輪回転抑制ルーチン及びホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンのフローチャートについては実施の形態１と同様なので省略し、図５のホイールシリンダ圧検出手段の異常検出ルーチンについても実施の形態１と異なる点についてのみ説明する。
【００２２】
Ｓ３０６においてブレーキペダル１０の踏み込み力、ホイールシリンダ４２の液圧であるホイールシリンダ圧が読み込まれる。次にＳ３０７に進み、ブレーキペダル１０の踏み込み力からホイールシリンダ４２の液圧の推定値が算出される。次にＳ３０８においては、ホイールシリンダ４２について、
｜ホイールシリンダ圧測定値−ホイールシリンダ圧推定値｜＜Ｘ４（閾値）
かどうかを判定し、ＹＥＳの場合はルーチンの実行を終了し、ホイールシリンダ４２、４４の液圧は、マスタシリンダ１２の液圧に基づいて機械的に制御されたままとする。ＮＯの場合はＳ３０９に進み、電磁方向切換弁５４、５６、８４、８６のソレノイドが消磁されて、図１に示す原位置に切り換えられ、ホイールシリンダ４２、４４の液圧は、比例電磁液圧制御弁６２、６４の出力液圧に基づいて制御される状態になる。次にルーチンの実行を終了し、通常の車輪回転抑制ルーチンから図４のホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンへの変更を行う。
【００２３】
本実施の形態によれば、ホイールシリンダ圧検出手段の異常検出ルーチンのＳ３０８において、異常が検出されたホイールシリンダ（本実施の形態では左後輪３８とする）についてホイールシリンダ４２の液圧を検出する液圧センサ１２２の値とブレーキペダル踏力検出装置からのホイールシリンダ圧推定値とを比較する。値の差が閾値より小さい場合は液圧センサ１２２に異常がなく、左後輪３８の比例電磁液圧制御弁６２の異常が考えられ、この場合は左右後輪３８、４０のホイールシリンダ４２、４４のみを、マスタシリンダ１２からの液圧を直接ホイールシリンダ４２、４４に供給する機械式ブレーキに切り換えたままとする。
【００２４】
値の差が閾値以上である場合は左後輪３８の液圧センサ１２２の異常が考えられ、左右後輪３８、４０のホイールシリンダ４２、４４を再び比例電磁液圧制御弁６２、６４の出力液圧に基づいて制御される状態にし、実施の形態１と同様にホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンを実行する。
【００２５】
従ってこの実施の形態２においても、ホイールシリンダの液圧を検出する液圧センサに異常が発生した場合でも、マスタシリンダ１２からの液圧を直接ホイールシリンダに供給する機械式ブレーキに切り換えることなく、電気制御式液圧ブレーキを維持することができるといった利点が得られる。
【００２６】
図６には、実施の形態３を示す。
実施の形態３の構成については、実施の形態１，２と同様である。
次に、作用を図６のフローチャートに基づいて説明するが、車輪回転抑制ルーチン及びホイールシリンダ圧検出手段の異常検出ルーチンのフローチャートについては実施の形態１，２と同様なので省略し、図６のホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチンについても実施の形態１，２と異なる点についてのみ説明する。
Ｓ４０１でＹＥＳの場合は、Ｓ４０２に進み、モータ７８の電圧をある一定値に設定する。
【００２７】
本実施の形態によれば、ホイールシリンダ圧検出手段異常時の車輪回転抑制ルーチン実行中はモータ電圧が一定値に保たれるので、異常が検出されたホイールシリンダについて目標ホイールシリンダ圧からより精度よく目標アキュムレータ圧を算出することが可能である。
従って、この実施の形態３においても、実施の形態１，２と同様の作用効果を奏する他、より正確なホイールシリンダ圧の制御が可能であるといった利点がある。
【００２８】
【発明の効果】
以上説明してきたように、請求項１記載の発明によれば、ホイールシリンダ圧推定手段の推定量とホイールシリンダ圧検出手段の検出量とを各ホイールシリンダごとに比較し、その差の絶対値が１つのホイールシリンダについてだけ第１の閾値以上である場合に、異常が検出されたホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置をマスタシリンダとホイールシリンダとを連通する第２の状態に切り換えて、ホイールシリンダ圧検出手段の検出量を比較することにより、ホイールシリンダ圧検出手段の異常を検出することが可能であり、ホイールシリンダ圧検出手段の異常を検出した場合は、目標ホイールシリンダ圧から液圧源の目標液圧を設定し、液圧源液圧検出手段による検出液圧が液圧源の目標液圧に一致するように液圧制御装置制御手段を異常が検出されたホイールシリンダについてのみ変更するので、ホイールシリンダ圧検出手段の異常が発生した場合でも、マスタシリンダからの液圧を直接ホイールシリンダに供給する機械式ブレーキに切り換えることなく、電気制御式液圧ブレーキを維持できるといった効果が得られる。
請求項２記載の発明によれば、第１のホイールシリンダ圧推定手段の推定量とホイールシリンダ圧検出手段の検出量とを各ホイールシリンダごとに比較し、その差の絶対値が１つのホイールシリンダについてだけ第１の閾値以上である場合に、異常が検出されたホイールシリンダとそのホイールシリンダと車両で左右対称位置にあるホイールシリンダに接続する切換装置をマスタシリンダとホイールシリンダとを連通する第２の状態に切り換えて、異常が検出されたホイールシリンダについて第２のホイールシリンダ圧推定手段とホイールシリンダ圧検出手段の検出量を比較することにより、ホイールシリンダ圧検出手段の異常を検出することが可能であり、ホイールシリンダ圧検出手段の異常を検出した場合は、目標ホイールシリンダ圧から液圧源の目標液圧を設定し、液圧源液圧検出手段による検出液圧が液圧源の目標液圧に一致するように液圧制御装置制御手段を異常が検出されたホイールシリンダについてのみ変更するので、ホイールシリンダ圧検出手段の異常が発生した場合でも、マスタシリンダからの液圧を直接ホイールシリンダに供給する機械式ブレーキに切り換えることなく、電気制御式液圧ブレーキを維持できるといった効果が得られる。
請求項３記載の発明によれば、請求項１および２記載の発明の効果に加えて、ブレーキ操作部材操作中はポンプ駆動制御手段への指令値を一定値にすることにより、異常が検出されたホイールシリンダについて目標ホイールシリンダ圧からより精度よく液圧源の目標液圧を算出することができるので、電気制御式液圧ブレーキの信頼性が高まるといった効果が得られる。
【図面の簡単な説明】
【図１】本発明実施の形態１〜３の構成を示す図である。
【図２】実施の形態１〜３における車輪回転抑制ルーチンを示すフローチャートである。
【図３】実施の形態１，３におけるホイールシリンダ圧検出手段の異常検出ルーチンを示すフローチャートである。
【図４】実施の形態１，２のおけるホイールシリンダ圧検出手段異常制御ルーチンを示すフローチャートである。
【図５】実施の形態２，３におけるホイールシリンダ圧検出手段の異常検出ルーチンを示すフローチャートである。
【図６】実施の形態３におけるホイールシリンダ圧検出手段の異常検出ルーチンを示すフローチャートである。
【符号の説明】
１０ブレーキペダル
１２マスタシリンダ
１４液通路
１６液通路
１８分岐通路
２０分岐通路
２２左前輪
２４右前輪
２６フロントホイールシリンダ
２８フロントホイールシリンダ
３０液通路
３２液通路
３４分岐通路
３６分岐通路
３８左後輪
４０右後輪
４２リアホイールシリンダ
４４リアホイールシリンダ
４６プロポーショニングバルブ
５０電磁方向切換弁
５２電磁方向切換弁
５４電磁方向切換弁
５６電磁方向切換弁
５８比例電磁液圧制御弁
６０比例電磁液圧制御弁
６２比例電磁液圧制御弁
６４比例電磁液圧制御弁
７０アキュムレータ
７２リザーバ
７４液通路
７６液通路
７８モータ
８０ポンプ
８４電磁方向切換弁
８６電磁方向切換弁
８８ストロークシミュレータ
９０ストロークシミュレータ
１００制御装置
１０２ＣＰＵ
１０４ＲＯＭ
１０６ＲＡＭ
１０８入力部
１１０出力部
１１２ブレーキスイッチ
１１４踏力検出装置
１１６液圧センサ
１１８液圧センサ
１２０液圧センサ
１２２液圧センサ
１２４液圧センサ
１２６車輪速センサ
１２８車輪速センサ
１３０車輪速センサ
１３２車輪速センサ
１４４前後Ｇセンサ
１４６横Ｇセンサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brake fluid pressure control device.
[0002]
[Prior art]
As a conventional brake fluid pressure control device, as shown in, for example, Japanese Patent Laid-Open No. 06-191393, an electrically controlled fluid is used in which normal braking is performed based on the fluid pressure of a fluid pressure source provided separately from the master cylinder. There is a pressure brake. In this conventional brake hydraulic pressure control device, the hydraulic pressure control device is a proportional electromagnetic hydraulic pressure control device that controls the hydraulic pressure of the hydraulic pressure source to a height proportional to the current supplied to the coil, and the brake operation An operation amount detection means for detecting the operation amount of the member is provided. The control means sets the target wheel cylinder pressure based on the detection result of the operation amount detection means, and the supply current to the coil of the proportional electromagnetic hydraulic pressure control device is controlled so that the hydraulic pressure of the hydraulic pressure source is the target wheel cylinder pressure. The wheel cylinder has a hydraulic pressure with a height corresponding to the operation amount of the brake operation member, for example, a liquid pressure proportional to the operation amount or a vehicle body deceleration proportional to the operation force. Pressure is supplied and rotation of the wheel is suppressed. In addition, when an abnormality occurs in the electrically controlled hydraulic brake and the hydraulic pressure from the hydraulic pressure source cannot be supplied to the wheel cylinder, it is switched to a mechanical brake that supplies the hydraulic pressure from the master cylinder directly to the wheel cylinder. It has become.
[0003]
[Problems to be solved by the invention]
However, in such a conventional brake hydraulic pressure control device, when an abnormality such as a failure occurs in the pressure sensor that detects the hydraulic pressure of the wheel cylinder, the brake hydraulic pressure control device has a predetermined wheel cylinder pressure. Since the fluid pressure source and the proportional electromagnetic fluid pressure control device are normal, the fluid pressure from the master cylinder cannot be directly maintained without maintaining the electrical control fluid pressure brake. There was a problem of switching to a mechanical brake to be supplied to the wheel cylinder.
The present invention has been made paying attention to such a conventional problem, and maintains an electrically controlled hydraulic brake system even when an abnormality such as a failure occurs in a pressure sensor that detects the hydraulic pressure of a wheel cylinder. This is intended to solve the conventional problems.
[0004]
[Means for Solving the Problems]
In order to solve this problem, in the first aspect of the present invention, a brake operation member, a master cylinder that generates hydraulic pressure in response to an operation of the brake operation member, and an operation amount of the brake operation member are detected. An operation amount detection means, a hydraulic pressure source comprising a pump or the like, a hydraulic pressure source hydraulic pressure detection means for detecting the hydraulic pressure of the hydraulic pressure source, and the pump based on the detection amount of the hydraulic pressure source hydraulic pressure detection means A pump drive control means for controlling the driving of the plurality of wheel cylinders, a plurality of wheel cylinders for respectively suppressing rotation of the plurality of wheels, a plurality of wheel cylinder pressure detecting means for detecting the fluid pressure of each of the plurality of wheel cylinders, and the liquid A plurality of first fluid passages respectively connecting a pressure source and the plurality of wheel cylinders, and a plurality of fluid pressure controls provided in each of the first fluid passages for controlling the fluid pressure of the wheel cylinders. A target fluid pressure of the plurality of wheel cylinders based on a detected amount of the device, a plurality of second fluid passages respectively connecting the master cylinder and the plurality of wheel cylinders, and an operation amount detection means; The hydraulic pressure control device control means for controlling the hydraulic pressure control device so that the hydraulic pressure detected by the multiple wheel cylinder pressure detection means matches the target hydraulic pressure of the multiple wheel cylinders, and the hydraulic pressure source is normally In the operating state, the master cylinder is disconnected from the wheel cylinder to transmit the hydraulic pressure of the hydraulic pressure source to the wheel cylinder, and the hydraulic pressure source cannot normally generate the hydraulic pressure. The hydraulic pressure source can be cut off from the wheel cylinder to switch to a second state in which the hydraulic pressure of the master cylinder is transmitted to the wheel cylinder. A brake hydraulic pressure control device including a plurality of switching devices in a state, and having wheel cylinder pressure estimation means for estimating a hydraulic pressure of the wheel cylinder from a command value of the hydraulic pressure control device control means, the wheel cylinder When the absolute value of the difference between the estimated amount of the pressure estimating means and the detected amount of the wheel cylinder pressure detecting means is greater than or equal to the first threshold value for only one wheel cylinder, Only the switching device connected to the wheel cylinder and the wheel cylinder in the left-right symmetric position between the vehicle and the second state is switched from the first state to the wheel cylinder that is equal to or greater than the first threshold, the wheel cylinder and the vehicle. If the absolute value of the difference in the detection amount of the wheel cylinder pressure detecting means of the wheel cylinder at the left-right symmetrical position is equal to or greater than the second threshold value In this case, only the wheel cylinder that is equal to or greater than the first threshold value and the switching device that is connected to the wheel cylinder and the wheel cylinder that is in a symmetrical position in the vehicle are switched again from the second state to the first state, A target hydraulic pressure of the hydraulic pressure source is set, and the hydraulic pressure control device control means is set to be equal to or higher than a first threshold value so that the hydraulic pressure detected by the hydraulic pressure source hydraulic pressure detection means matches the target hydraulic pressure of the hydraulic pressure source. It is characterized by changing only the wheel cylinder.
In the invention of claim 2, a brake operation member, a master cylinder that generates hydraulic pressure in response to the operation of the brake operation member, an operation amount detection means for detecting an operation amount of the brake operation member, a pump, etc. A hydraulic pressure source comprising: a hydraulic pressure source hydraulic pressure detecting means for detecting the hydraulic pressure of the hydraulic pressure source; and a pump drive control for controlling the driving of the pump based on a detection amount of the hydraulic pressure source hydraulic pressure detecting means Means, a plurality of wheel cylinders for respectively suppressing rotation of the plurality of wheels, a plurality of wheel cylinder pressure detecting means for detecting the fluid pressure of each of the plurality of wheel cylinders, the fluid pressure source, and the plurality of wheel cylinders A plurality of first fluid passages that respectively connect to the first fluid passage, a plurality of fluid pressure control devices that are provided in each of the first fluid passages to control the fluid pressure of the wheel cylinder, and the master series A plurality of second fluid passages respectively connecting the cylinder and the plurality of wheel cylinders, and a target fluid pressure of the plurality of wheel cylinders is set based on a detection amount of the operation amount detection means, and the plurality of wheel cylinders A hydraulic pressure control device control means for controlling the hydraulic pressure control device so that a hydraulic pressure detected by the pressure detection means matches a target hydraulic pressure of the plurality of wheel cylinders; and in a state where the hydraulic pressure source is normally operated, In a first state where the master cylinder is disconnected from the wheel cylinder and the hydraulic pressure of the hydraulic pressure source is transmitted to the wheel cylinder, and in a state where the hydraulic pressure source does not normally generate hydraulic pressure, the hydraulic pressure source is A plurality of switching devices that can be switched to a second state in which the hydraulic pressure of the master cylinder is transmitted to the wheel cylinder by being cut off from the wheel cylinder and are normally in the first state. A first wheel cylinder pressure estimating means for estimating a hydraulic pressure of the wheel cylinder from a command value of the hydraulic pressure control apparatus control means, and the switching device in a second state. Second wheel cylinder pressure estimating means for estimating the hydraulic pressure of the wheel cylinder from the detected amount of the operation amount detecting means in some cases, the estimated amount of the first wheel cylinder pressure estimating means and the wheel cylinder When the absolute value of the difference from the detection amount of the pressure detection means is equal to or greater than the first threshold value for only one wheel cylinder, the wheel cylinder that is equal to or greater than the first threshold value, and the wheel cylinder and the vehicle are in left-right symmetric positions. Only the switching device connected to the wheel cylinder is switched from the first state to the second state, so that the wheel cylinder that is equal to or greater than the first threshold value. When the absolute value of the difference between the estimated amount of the second wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means is equal to or greater than a third threshold, the wheel cylinder and the wheel that are equal to or greater than the first threshold Only the switching device connected to the wheel cylinder in the left-right symmetrical position between the cylinder and the vehicle is switched again from the second state to the first state, the target hydraulic pressure of the hydraulic pressure source is set, and the hydraulic pressure source The hydraulic pressure control device control means is changed only for wheel cylinders that are equal to or greater than a first threshold value so that the hydraulic pressure detected by the hydraulic pressure detection means matches the target hydraulic pressure of the hydraulic pressure source.
According to a third aspect of the present invention, in the brake hydraulic pressure control device according to the first or second aspect, the hydraulic pressure detected by the hydraulic pressure source hydraulic pressure detecting means matches the target hydraulic pressure of the hydraulic pressure source. A command value to the pump drive control means is set to a constant value during operation of the brake operation member when the hydraulic pressure control device control means is changed only for the wheel cylinder that is equal to or greater than the first threshold value. .
[0005]
[Action]
In the first aspect of the invention, it is determined whether or not the electrically controlled brake is normal by comparing the estimated amount of the wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means for each wheel cylinder. When the absolute value of the difference is not less than the first threshold value for only one wheel cylinder, it is determined that the wheel cylinder for one wheel is abnormal. When it is determined that the wheel cylinder for one wheel is abnormal, the wheel cylinder in which the abnormality is detected and the switching device connected to the wheel cylinder and the wheel cylinder in the left-right symmetrical position in the vehicle are connected to the master cylinder and the wheel cylinder. Is switched to the second state communicating, and the detection amount of the wheel cylinder pressure detection means is compared. If the absolute value of the difference is equal to or greater than the second threshold value, it is determined that the wheel cylinder pressure detection means is abnormal. To do. If it is determined that the wheel cylinder pressure detecting means is abnormal, the hydraulic cylinder, the wheel cylinder and the switching device connected to the wheel cylinder in the left-right symmetrical position in the vehicle and the wheel cylinder are detected. The target hydraulic pressure of the hydraulic pressure source is set from the target wheel cylinder pressure so that the detected hydraulic pressure by the hydraulic pressure source hydraulic pressure detecting means matches the target hydraulic pressure of the hydraulic pressure source. In addition, the electric control type hydraulic brake is maintained by changing the hydraulic pressure control device control means only for the wheel cylinder in which the abnormality is detected.
In the invention described in claim 2, it is determined whether or not the electrically controlled brake is normal by comparing the estimated amount of the first wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means for each wheel cylinder. When the absolute value of the difference is equal to or more than the first threshold value for only one wheel cylinder, it is determined that the wheel cylinder for one wheel is abnormal. When it is determined that the wheel cylinder for one wheel is abnormal, the wheel cylinder in which the abnormality is detected and the switching device connected to the wheel cylinder and the wheel cylinder in the left-right symmetrical position in the vehicle are connected to the master cylinder and the wheel cylinder. Are switched to the second state, the detected amounts of the second wheel cylinder pressure estimating means and the wheel cylinder pressure detecting means are compared for the wheel cylinder in which the abnormality is detected, and the absolute value of the difference is the third threshold value. When it is above, it is determined that the wheel cylinder pressure detecting means is abnormal. If it is determined that the wheel cylinder pressure detecting means is abnormal, the hydraulic cylinder, the wheel cylinder and the switching device connected to the wheel cylinder in the left-right symmetrical position in the vehicle and the wheel cylinder are detected. The target hydraulic pressure of the hydraulic pressure source is set from the target wheel cylinder pressure so that the detected hydraulic pressure by the hydraulic pressure source hydraulic pressure detecting means matches the target hydraulic pressure of the hydraulic pressure source. In addition, the electric control type hydraulic brake is maintained by changing the hydraulic pressure control device control means only for the wheel cylinder in which the abnormality is detected.
In the invention described in claim 3, in addition to the effects of the invention described in claims 1 and 2, an abnormality is detected by setting the command value to the pump drive control means to a constant value during operation of the brake operating member. For the wheel cylinder, the target hydraulic pressure of the hydraulic pressure source is calculated more accurately from the target wheel cylinder pressure.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1-5 is a figure which shows Embodiment 1 of this invention. First, the configuration will be described with reference to FIG. 1. Reference numeral 10 denotes a brake pedal 10 as a brake operation member. The brake pedal 10 is connected to the master cylinder 12, and hydraulic pressure (referred to as master cylinder pressure) corresponding to the depression force of the brake pedal 10 is generated in each of the two pressurizing chambers of the master cylinder 12. One pressurizing chamber of the master cylinder 12 is connected to the front wheel cylinders 26 and 28 of the brakes provided on the left and right front wheels 22 and 24 by the liquid passages 14 and 16 and the branch passages 18 and 20, respectively. The pressurizing chamber is connected to brake rear wheel cylinders 42 and 44 provided on the left and right rear wheels 38 and 40 by liquid passages 30 and 32 and branch passages 34 and 36, respectively. A proportioning valve 46 is provided in the liquid passage 32 for the rear wheels 38 and 40.
[0007]
The branch passages 18, 20, 34, and 36 are respectively provided with electromagnetic direction switching valves 50, 52, 54, and 56, and proportional electromagnetic hydraulic control valves 58, 60, 62, and 64 are connected thereto. The solenoids of the electromagnetic direction switching valves 50, 52, 54, 56 are always demagnetized and in the original position shown in FIG. 1, and the wheel cylinders 26, 28, 42, 44 are connected to the proportional electromagnetic hydraulic control valves 58, 60, 62, 64, but when the solenoid is excited, the position is switched to the opposite side, and the wheel cylinders 26, 28, 42, and 44 are communicated with the master cylinder 12.
[0008]
The proportional electromagnetic hydraulic pressure control valves 58, 60, 62, and 64 are connected to an accumulator 70 and a reservoir 72 as a hydraulic pressure source by liquid passages 74 and 76, respectively, and the hydraulic pressure of the accumulator 70 falls below a certain threshold value. For pumping, the liquid in the reservoir 72 is pumped up by the pump 80 driven by the motor 78 until the hydraulic pressure in the accumulator 70 reaches another threshold value, and the accumulator 70 stores the liquid in a certain range of hydraulic pressure. It is done.
[0009]
The proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64 control the hydraulic pressure of the accumulator 70 (referred to as accumulator pressure) and supply it to the wheel cylinders 26, 28, 42, 44 by controlling the excitation current of the solenoid. The brake is operated based on the hydraulic pressure of the wheel cylinders 26, 28, 42, 44 (referred to as wheel cylinder pressure), and the rotation of the wheels is suppressed.
[0010]
Between the liquid passages 14 and 16 connecting the master cylinder 12 and the front wheel cylinders 26 and 28, and between the liquid passages 30 and 32 connecting the master cylinder 12 and the rear wheel cylinders 42 and 44, respectively. Electromagnetic direction switching valves 84 and 86 are provided, and stroke simulators 88 and 90 are connected. The stroke simulators 88 and 90 store the brake fluid discharged from the master cylinder 12 and allow the brake pedal 10 to be depressed, and apply a reaction force corresponding to the depression stroke to the brake pedal 10. In a state where the rotation of the wheel is suppressed based on the wheel cylinder pressure controlled by the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64, the solenoids of the electromagnetic direction switching valves 84, 86 are demagnetized and the master cylinder 12 is demagnetized. Are communicated with the stroke simulators 88 and 90 to give the driver an operational feeling as if they are connected to the wheel cylinders 26, 28, 42 and 44.
[0011]
The brake fluid pressure control device is controlled by the control device 100. The control device 100 includes a CPU 102, a ROM 104, a RAM 106, an input unit 108, an output unit 110, and a bus. The input unit 108 of the control device 100 detects a brake switch 112 that detects the depression of the brake pedal 10, a pedaling force detection device 114 that serves as an operation amount detection unit that detects the depression force of the brake pedal 10, and the hydraulic pressure of the accumulator 70. Fluid pressure sensor 116, fluid pressure sensors 118, 120, 122, 124 as wheel cylinder pressure detecting means for detecting wheel cylinder pressure of wheel cylinders 26, 28, 42, 44, left and right front wheels 22, 24 and rear wheel 38, Wheel speed sensors 126, 128, 130, and 132 that detect the respective rotational speeds of 40, front and rear G sensors 144 and lateral G sensors 146 that respectively detect the longitudinal and lateral decelerations of the vehicle body are connected. The input unit 108 includes a circuit that performs appropriate signal processing, such as changing a digital signal when a signal supplied from each detection device or sensor is an analog signal.
[0012]
Proportional electromagnetic fluid pressure control valves 58, 60, 62, 64 and electromagnetic direction switching valves 50, 52, 54, 56, 84, 86 are connected to the output unit 110. The output unit 110 is provided with drive circuits corresponding to the proportional electromagnetic fluid pressure control valves 58, 60, 62, 64 and the electromagnetic direction switching valves 50, 52, 54, 56, 84, 86. They are connected to these drive circuits. The output unit 110 further converts a command value determined by a digital value to each drive circuit of the proportional electromagnetic hydraulic control valves 58, 60, 62, and 64 into an analog signal and supplies the analog signal to the drive circuit. A transducer is also provided. The ROM 104 also includes a map that defines the relationship between the depression force of the brake pedal 10 and the target deceleration, a wheel rotation suppression routine, a wheel cylinder pressure detection means abnormality detection routine, and a wheel cylinder pressure detection means abnormality detection wheel rotation suppression function that will be described later. Contains routines.
[0013]
The braking by the brake fluid pressure control device is normally performed based on the output fluid pressure of the proportional electromagnetic fluid pressure control valves 58, 60, 62, 64, and the electromagnetic direction switching valves 50, 52, 54, 56, 84 and 86 are always demagnetized, the wheel cylinders 26, 28, 42 and 44 are connected to the proportional electromagnetic hydraulic control valves 58, 60, 62 and 64, and the master cylinder 12 is connected to the stroke simulators 88 and 90. ing. However, when an abnormality occurs in the brake hydraulic pressure control device, the hydraulic pressure from the hydraulic pressure source is changed to the wheel cylinders 26, 28, 42, based on the output hydraulic pressure of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64. When it becomes impossible to supply to 44, the solenoids of the electromagnetic direction switching valves 50, 52, 54, 56, 84, 86 are excited and switched to positions opposite to the original positions shown in FIG. , 42 and 44 are mechanically controlled based on the hydraulic pressure of the master cylinder 12.
[0014]
Next, the operation will be described based on the flowcharts of FIGS.
FIG. 2 is a flowchart of a wheel rotation suppression routine. However, this routine is changed to a wheel rotation suppression routine when the wheel cylinder pressure detecting means is abnormal, which will be described later, when the wheel cylinder pressure detecting means is abnormal. First, step S1 (hereinafter abbreviated as S1; the same applies to other steps) is executed, and whether or not braking is being performed is determined by whether or not the brake pedal 10 is depressed. If the brake pedal 10 is not depressed, the determination result in S1 is NO and the execution of the routine ends. If the brake pedal 10 is depressed, the determination result of S1 is YES and S2 is executed. After the depression force of the brake pedal 10 and the deceleration of the vehicle body are read, the target deceleration is determined in S3. Next, S4 is executed, and a target wheel cylinder pressure to be supplied to the wheel cylinders 26, 28, 42, 44 is set. Next, in S5, command values (digital values) for the drive circuits of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64 are determined. The command value determined in S5 is converted to an analog signal by a D / A converter in S6 and then supplied to the drive circuit, and the proportional electromagnetic pressure control valves 58, 60, 62, and 64 are driven accordingly. Is done. Next, in S7, the wheel cylinder pressure of each wheel is read by the hydraulic pressure sensors 118, 120, 122, and 124 which are wheel cylinder pressure detecting means. Next, in S8, whether or not the absolute value of the difference between the target wheel cylinder pressure supplied to the wheel cylinders 26, 28, 42, 44 and the hydraulic pressure by the hydraulic pressure sensors 118, 120, 122, 124 is smaller than the threshold value X1. If YES, the routine execution is terminated. In the case of NO, the process proceeds to S9, and the command value (digital value) for the drive circuit of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64 is changed so as to approach the target wheel cylinder pressure for the wheel cylinder that is equal to or greater than the threshold value. Return to S6.
[0015]
FIG. 3 is a flowchart of an abnormality detection routine for the hydraulic pressure sensors 118, 120, 122, and 124, which are means for detecting the hydraulic pressure of the wheel cylinders 26, 28, 42, and 44. Regardless, it is performed at certain intervals.
[0016]
First, S101 is executed, and command values for the drive circuits of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, and 64 and wheel cylinder pressures that are hydraulic pressures of the wheel cylinders 26, 28, 42, and 44 are read. Next, in S102, an estimated wheel cylinder pressure value for each wheel is calculated from command values for the drive circuits of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, and 64. Next, S103 is executed, and for all the wheel cylinders 26, 28, 42, 44,
｜ Wheel cylinder pressure measurement value−Wheel cylinder pressure estimated value | <X2 (threshold value)
If YES, the routine execution is terminated. If NO, the process proceeds to S104, and it is determined whether or not there is only one wheel cylinder that is equal to or greater than the threshold value. In the case of NO, the execution of the routine is terminated, and the solenoids of the electromagnetic direction switching valves 50, 52, 54, 56, 84, 86 are excited and switched to a position opposite to the original position shown in FIG. The hydraulic pressures of the cylinders 26, 28, 42 and 44 are mechanically controlled based on the hydraulic pressure of the master cylinder 12. If YES, the process proceeds to S105. In the present embodiment, the case where the wheel cylinder that is equal to or greater than the threshold value is the left rear wheel 42 will be described. However, the case of the other wheel cylinders 26, 28, and 44 can be similarly described. In S105, the solenoids of the electromagnetic direction switching valves 54, 56, 84, 86 are excited and switched to positions opposite to the original positions shown in FIG. It will be in the state controlled mechanically based on hydraulic pressure. Next, in S106, the wheel cylinder pressure which is the hydraulic pressure of the wheel cylinders 42 and 44 is read. Next, in S107, it is determined whether or not the absolute value of the difference between the hydraulic pressures of the two wheel cylinders 42 and 44 is smaller than the threshold value X3. If YES, the routine is terminated and the hydraulic pressures of the wheel cylinders 42 and 44 are terminated. Is kept mechanically controlled based on the hydraulic pressure of the master cylinder 12. If NO, the process proceeds to S108, the solenoids of the electromagnetic direction switching valves 54, 56, 84, 86 are demagnetized and switched to the original position shown in FIG. 1, and the hydraulic pressures of the wheel cylinders 42, 44 are proportional electromagnetic hydraulic pressures. The control valve 62 or 64 is controlled based on the output hydraulic pressure. Next, the execution of the routine is terminated, and the normal wheel rotation suppression routine is changed to a wheel rotation suppression routine in FIG.
[0017]
In the wheel rotation suppression routine when the wheel cylinder pressure detecting means is abnormal, first, S201 is executed, and it is determined whether braking is being performed based on whether the brake pedal 10 is depressed. If the brake pedal 10 is not depressed, the determination result in S201 is NO, and the execution of the routine ends. If the brake pedal 10 is depressed, the determination result in S201 is YES and S202 is executed. After the depression force of the brake pedal 10, the deceleration of the vehicle body, and the voltage of the motor 78 are read, the target deceleration is performed in S203. Is determined. Next, S204 is executed, and a target wheel cylinder pressure to be supplied to the wheel cylinders 26, 28, 42, 44 is set. Next, in S205, the target accumulator pressure is calculated from the target wheel cylinder pressure and the motor voltage as follows. The target liquid consumed in the wheel cylinders 26, 28, 42, 44 of each wheel from the value of the target wheel cylinder pressure of each wheel and the characteristics of the fluid amount-hydraulic pressure in the wheel cylinders 26, 28, 42, 44 of each wheel A quantity is calculated. The target liquid consumption amount of the accumulator 70 is calculated by calculating the sum of the target liquid amounts consumed by the wheel cylinders 26, 28, 42, 44 of each wheel. On the other hand, the amount of liquid supplied from the pump 80 to the accumulator 70 is calculated from the voltage value of the motor 78 and the characteristics of the motor voltage-pump liquid amount. The target accumulator pressure is calculated from the target consumption liquid amount of the accumulator 70, the amount of liquid supplied from the pump 80 to the accumulator 70, and the liquid amount-hydraulic pressure characteristic of the accumulator 70.
[0018]
Next, in S206, command values (digital values) for the drive circuits of the proportional electromagnetic hydraulic pressure control valves 58, 60, 62, 64 are determined. The command value determined in S206 is converted into an analog signal by the D / A converter in S207 and then supplied to the drive circuit, and the proportional electromagnetic pressure control valves 58, 60, 62, and 64 are driven accordingly. Is done. Next, in S208, the accumulator pressure is read by the hydraulic pressure sensor 116 which detects the wheel cylinder pressure for the three wheels and the hydraulic pressure of the accumulator 70 by the hydraulic pressure sensors 118, 120 and 124 which are wheel cylinder pressure detecting means. Next, in S209, the absolute value of the difference between the target wheel cylinder pressure supplied to the wheel cylinders 26, 28, 44 and the hydraulic pressure by the hydraulic pressure sensors 118, 120, 124 is smaller than the threshold value X1 for all three wheels, and the target accumulator pressure is It is determined whether or not the absolute value of the difference from the hydraulic pressure by the hydraulic pressure sensor 116 is smaller than the threshold value X1, and if YES, execution of the routine is terminated. If NO, the process proceeds to S210, and the voltage of the motor 78 is read. Next, in S211, the target accumulator pressure is calculated in the same manner as in S205. Next, in S212, the command value (digital value) for the drive circuit of the proportional electromagnetic hydraulic pressure control valve for the wheel cylinder and accumulator 70 that is equal to or greater than the threshold is changed so as to approach the target wheel cylinder pressure and the target accumulator pressure, and the process proceeds to S207. Return.
[0019]
According to the present embodiment, in S103 of the abnormality detection routine of the wheel cylinder pressure detection means, it is determined whether or not the electrically controlled brake is normal. If an abnormality is found, the wheel cylinder in which abnormality is found in S104 is determined. Identify. If an abnormality is found in 2 to 4 wheels, there is an abnormality in the hydraulic pressure source or the proportional electromagnetic hydraulic pressure control valve that detects the hydraulic pressure in the wheel cylinders of two or more wheels although the probability is extremely low. In this case, the four wheel cylinders 26, 28, 42, 44 are switched to a mechanical brake that supplies the hydraulic pressure from the master cylinder 12 directly to the wheel cylinders 26, 28, 42, 44. If an abnormality is observed in only one wheel (the left rear wheel 38 in this embodiment), only the wheel cylinders 42 and 44 of the left and right rear wheels 38 and 40 are directly subjected to the hydraulic pressure from the master cylinder 12 in S105. Switching to the mechanical brake supplied to the wheel cylinders 42 and 44, the values of the hydraulic pressure sensors 122 and 124 for detecting the hydraulic pressures of the wheel cylinders 42 and 44 of the left and right rear wheels 38 and 40 are compared in S107. When the difference in value is smaller than the threshold value, there is no abnormality in the hydraulic pressure sensors 122 and 124, and an abnormality in the proportional electromagnetic hydraulic pressure control valve 62 of the left rear wheel 38 is considered. In this case, the wheel cylinders of the left and right rear wheels 38 and 40 are considered. Only the mechanical brakes 42 and 44 are switched to the mechanical brake that supplies the hydraulic pressure from the master cylinder 12 directly to the wheel cylinders 42 and 44. If the difference between the values is equal to or greater than the threshold value, the hydraulic pressure sensor 122 of the left rear wheel 38 may be abnormal, and the wheel cylinders 42 and 44 of the left and right rear wheels 38 and 40 are output again from the proportional electromagnetic hydraulic control valves 62 and 64. A control state is made based on the hydraulic pressure, and a wheel rotation suppression routine is executed when the wheel cylinder pressure detecting means is abnormal. In the wheel rotation suppression routine when the wheel cylinder pressure detection means is abnormal, a target accumulator pressure is calculated from the motor voltage and the target wheel cylinder pressure, and a hydraulic pressure sensor that detects the wheel cylinder pressure is calculated for the wheel cylinder in which the abnormality is detected. The command value for the proportional electromagnetic hydraulic pressure control valve is determined so as to match the target wheel cylinder pressure. The proportional electromagnetic hydraulic pressure control valve is set so that the hydraulic pressure sensor 116 for detecting the accumulator pressure matches the target accumulator pressure. The electric control type hydraulic brake is maintained by changing so as to determine the command value.
[0020]
As described above, according to the present embodiment, it is possible to detect an abnormality of the hydraulic pressure sensors 118, 120, 122, and 124 that detect the hydraulic pressures of the wheel cylinders 26, 28, 42, and 44. When an abnormality is detected in the hydraulic pressure sensors 118, 120, 122, and 124 that detect the hydraulic pressure in the cylinders 26, 28, 42, and 44, the hydraulic pressure sensor 116 that detects the accumulator pressure is detected for the wheel cylinder in which the abnormality is detected. Since the command value to the proportional electromagnetic hydraulic pressure control valve is determined so as to coincide with the target accumulator pressure, the hydraulic pressure sensors 118, 120, 122, which detect the hydraulic pressure of the wheel cylinders 26, 28, 42, 44 are changed. A machine that supplies the hydraulic pressure from the master cylinder 12 directly to the wheel cylinders 26, 28, 42, 44 even if an abnormality occurs in 124. Without switching on the brake, advantages such can maintain the electrically controlled hydraulic brake.
[0021]
FIG. 5 shows the second embodiment.
The configuration of the second embodiment is the same as that of the first embodiment.
Next, the operation will be described with reference to the flowchart of FIG. 5. The flowchart of the wheel rotation suppression routine and the wheel rotation suppression routine when the wheel cylinder pressure detecting means is abnormal is the same as that of the first embodiment, and is omitted. Regarding the abnormality detection routine of the wheel cylinder pressure detecting means, only the points different from the first embodiment will be described.
[0022]
In S306, the depression force of the brake pedal 10 and the wheel cylinder pressure, which is the hydraulic pressure of the wheel cylinder 42, are read. Next, in S307, the estimated value of the hydraulic pressure of the wheel cylinder 42 is calculated from the depression force of the brake pedal 10. Next, in S308, for the wheel cylinder 42,
｜ Wheel cylinder pressure measurement value−Wheel cylinder pressure estimated value | <X4 (threshold value)
In the case of YES, the execution of the routine is terminated, and the hydraulic pressures of the wheel cylinders 42 and 44 remain mechanically controlled based on the hydraulic pressure of the master cylinder 12. If NO, the process proceeds to S309, the solenoids of the electromagnetic direction switching valves 54, 56, 84, 86 are demagnetized and switched to the original positions shown in FIG. 1, and the hydraulic pressures of the wheel cylinders 42, 44 are proportional electromagnetic hydraulic pressures. The control valve 62 or 64 is controlled based on the output hydraulic pressure. Next, the execution of the routine is terminated, and the normal wheel rotation suppression routine is changed to the wheel rotation suppression routine when the wheel cylinder pressure detecting means is abnormal in FIG.
[0023]
According to the present embodiment, in S308 of the abnormality detection routine of the wheel cylinder pressure detecting means, the hydraulic pressure of the wheel cylinder 42 is detected for the wheel cylinder (in this embodiment, the left rear wheel 38) in which an abnormality has been detected. The value of the hydraulic pressure sensor 122 to be compared is compared with the estimated wheel cylinder pressure value from the brake pedal depression force detection device. When the difference in value is smaller than the threshold value, there is no abnormality in the hydraulic pressure sensor 122, and an abnormality in the proportional electromagnetic hydraulic pressure control valve 62 in the left rear wheel 38 is considered. In this case, the wheel cylinders 42 in the left and right rear wheels 38, 40, Only 44 is switched to a mechanical brake that supplies the hydraulic pressure from the master cylinder 12 directly to the wheel cylinders 42, 44.
[0024]
If the difference between the values is equal to or greater than the threshold value, the hydraulic pressure sensor 122 of the left rear wheel 38 may be abnormal, and the wheel cylinders 42 and 44 of the left and right rear wheels 38 and 40 are output again from the proportional electromagnetic hydraulic control valves 62 and 64. As in the first embodiment, the wheel rotation suppression routine is executed when the wheel cylinder pressure detecting means is abnormal, in a state where the control is performed based on the hydraulic pressure.
[0025]
Therefore, even in the second embodiment, even when an abnormality occurs in the hydraulic pressure sensor that detects the hydraulic pressure in the wheel cylinder, the hydraulic pressure from the master cylinder 12 is not switched to the mechanical brake that directly supplies the wheel cylinder. The advantage is that an electrically controlled hydraulic brake can be maintained.
[0026]
FIG. 6 shows a third embodiment.
The configuration of the third embodiment is the same as that of the first and second embodiments.
Next, the operation will be described with reference to the flowchart of FIG. 6, but the flowcharts of the wheel rotation suppression routine and the abnormality detection routine of the wheel cylinder pressure detecting means are the same as those in the first and second embodiments, and are omitted. Only the differences from the first and second embodiments will be described for the wheel rotation suppression routine when the cylinder pressure detecting means is abnormal.
If YES in S401, the process proceeds to S402, and the voltage of the motor 78 is set to a certain constant value.
[0027]
According to the present embodiment, the motor voltage is maintained at a constant value during execution of the wheel rotation suppression routine when the wheel cylinder pressure detecting means is abnormal, so the wheel cylinder in which the abnormality is detected is more accurately determined from the target wheel cylinder pressure. It is possible to calculate the target accumulator pressure.
Therefore, the third embodiment also has the advantage that the wheel cylinder pressure can be controlled more accurately in addition to the same effects as the first and second embodiments.
[0028]
【The invention's effect】
As described above, according to the first aspect of the present invention, the estimated amount of the wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means are compared for each wheel cylinder, and the absolute value of the difference is obtained. When only one wheel cylinder is greater than or equal to the first threshold value, a wheel cylinder in which an abnormality has been detected, and a switching device that connects the wheel cylinder and the wheel cylinder in the left-right symmetrical position in the vehicle are connected to the master cylinder and the wheel cylinder. It is possible to detect the abnormality of the wheel cylinder pressure detecting means by switching to the second state in communication and comparing the detection amount of the wheel cylinder pressure detecting means, and the abnormality of the wheel cylinder pressure detecting means is detected. In this case, the target hydraulic pressure of the hydraulic pressure source is set from the target wheel cylinder pressure and detected by the hydraulic pressure source hydraulic pressure detection means. Since the hydraulic pressure control device control means is changed only for the wheel cylinder in which the abnormality is detected so that the pressure matches the target hydraulic pressure of the hydraulic pressure source, even if an abnormality in the wheel cylinder pressure detection means occurs, the master cylinder The effect is that the electrically controlled hydraulic brake can be maintained without switching to the mechanical brake that directly supplies the hydraulic pressure to the wheel cylinder.
According to the invention described in claim 2, the estimated amount of the first wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means are compared for each wheel cylinder, and the absolute value of the difference is one wheel cylinder. And the second cylinder that connects the master cylinder and the wheel cylinder to the wheel cylinder in which the abnormality is detected and the switching device that connects the wheel cylinder and the wheel cylinder that is in the left-right symmetrical position in the vehicle. It is possible to detect the abnormality of the wheel cylinder pressure detecting means by switching to the state of and comparing the detected amounts of the second wheel cylinder pressure estimating means and the wheel cylinder pressure detecting means for the wheel cylinder in which the abnormality is detected. If an abnormality in the wheel cylinder pressure detection means is detected, the target wheel cylinder pressure Regarding the wheel cylinder in which an abnormality is detected in the hydraulic pressure control device control means so that the target hydraulic pressure of the hydraulic pressure source is set and the hydraulic pressure detected by the hydraulic pressure source hydraulic pressure detecting means matches the target hydraulic pressure of the hydraulic pressure source Because only the change is made, even if an abnormality occurs in the wheel cylinder pressure detection means, the electric control type hydraulic brake can be maintained without switching to the mechanical brake that supplies the hydraulic pressure from the master cylinder directly to the wheel cylinder. Is obtained.
According to the invention described in claim 3, in addition to the effects of the inventions described in claims 1 and 2, an abnormality is detected by setting the command value to the pump drive control means to a constant value during operation of the brake operating member. Since the target hydraulic pressure of the hydraulic pressure source can be calculated more accurately from the target wheel cylinder pressure with respect to the wheel cylinder, the effect of increasing the reliability of the electrically controlled hydraulic brake can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of first to third embodiments of the present invention.
FIG. 2 is a flowchart showing a wheel rotation suppression routine in the first to third embodiments.
FIG. 3 is a flowchart showing an abnormality detection routine of wheel cylinder pressure detection means in the first and third embodiments.
FIG. 4 is a flowchart showing a wheel cylinder pressure detecting means abnormality control routine in the first and second embodiments.
FIG. 5 is a flowchart showing an abnormality detection routine of wheel cylinder pressure detection means in the second and third embodiments.
FIG. 6 is a flowchart showing an abnormality detection routine of wheel cylinder pressure detection means in the third embodiment.
[Explanation of symbols]
10 Brake pedal
12 Master cylinder
14 Liquid passage
16 Liquid passage
18 branch passage
20 branch passage
22 Front left wheel
24 Right front wheel
26 Front wheel cylinder
28 Front wheel cylinder
30 Liquid passage
32 Liquid passage
34 Branch passage
36 Branch passage
38 Left rear wheel
40 Right rear wheel
42 Rear wheel cylinder
44 Rear wheel cylinder
46 Proportioning Valve
50 Solenoid directional valve
52 Electromagnetic directional control valve
54 Electromagnetic directional control valve
56 Electromagnetic directional control valve
58 Proportional electromagnetic hydraulic control valve
60 proportional electromagnetic hydraulic control valve
62 Proportional electromagnetic hydraulic control valve
64 proportional electromagnetic hydraulic control valve
70 Accumulator
72 Reservoir
74 Liquid passage
76 Liquid passage
78 motor
80 pump
84 Solenoid directional valve
86 Electromagnetic directional control valve
88 Stroke simulator
90 stroke simulator
100 Control device
102 CPU
104 ROM
106 RAM
108 Input section
110 Output unit
112 Brake switch
114 Treading force detection device
116 Hydraulic pressure sensor
118 Hydraulic sensor
120 Hydraulic sensor
122 Hydraulic sensor
124 Hydraulic sensor
126 Wheel speed sensor
128 Wheel speed sensor
130 Wheel speed sensor
132 Wheel speed sensor
144 Front and rear G sensor
146 Horizontal G sensor

Claims

A brake operating member, a master cylinder that generates a hydraulic pressure in response to an operation of the brake operating member, an operation amount detecting means for detecting an operation amount of the brake operating member, a hydraulic pressure source including a pump and the like, A hydraulic pressure source hydraulic pressure detecting means for detecting the hydraulic pressure of the pressure source; a pump drive control means for controlling the driving of the pump based on a detection amount of the hydraulic pressure source hydraulic pressure detecting means; and rotation of a plurality of wheels. A plurality of wheel cylinders for suppressing each of the plurality of wheel cylinders, a plurality of wheel cylinder pressure detecting means for detecting a hydraulic pressure of each of the plurality of wheel cylinders, and a plurality of first cylinders respectively connecting the hydraulic pressure source and the plurality of wheel cylinders. Fluid passages, a plurality of fluid pressure control devices that are provided in each of the first fluid passages to control the fluid pressure of the wheel cylinder, the master cylinder, and the plurality of wheel cylinders And a plurality of second fluid passages respectively connected to each other, and a target fluid pressure of the plurality of wheel cylinders is set based on a detected amount of the operation amount detecting means, and a detected fluid pressure by the plurality of wheel cylinder pressure detecting means Hydraulic pressure control device control means for controlling the hydraulic pressure control device so as to match the target hydraulic pressure of the plurality of wheel cylinders, and when the hydraulic pressure source is operating normally, the master cylinder is removed from the wheel cylinder. In the first state where the hydraulic pressure of the hydraulic pressure source is cut off and transmitted to the wheel cylinder, and in the state where the hydraulic pressure source cannot normally generate the hydraulic pressure, the hydraulic pressure source is cut off from the wheel cylinder. Brake hydraulic pressure control device including a plurality of switching devices that are switchable to a second state in which the hydraulic pressure of the master cylinder is transmitted to the wheel cylinder and are normally in the first state Oite,
Wheel cylinder pressure estimating means for estimating the hydraulic pressure of the wheel cylinder from a command value of the hydraulic pressure control device control means, and an estimated amount of the wheel cylinder pressure estimating means and a detected amount of the wheel cylinder pressure detecting means When the absolute value of the difference is greater than or equal to the first threshold value for only one wheel cylinder, only the wheel cylinder that is greater than or equal to the first threshold value and the switching device that is connected to the wheel cylinder and the wheel cylinder that is in a symmetrical position in the vehicle Is switched from the first state to the second state, and the difference in the detected amount of the wheel cylinder pressure detecting means of the wheel cylinder that is equal to or greater than the first threshold value and the wheel cylinder and the wheel cylinder in the left-right symmetric position in the vehicle. Wheel cylinder and its wheel cylinder that are greater than or equal to the first threshold when the absolute value of is greater than or equal to the second threshold And switching only the switching device connected to the wheel cylinder at the symmetrical position in the vehicle from the second state to the first state to set the target hydraulic pressure of the hydraulic pressure source, and the hydraulic pressure source liquid Brake hydraulic pressure, wherein the hydraulic pressure control device control means is changed only for wheel cylinders that are equal to or greater than a first threshold value so that a hydraulic pressure detected by the pressure detection means matches a target hydraulic pressure of the hydraulic pressure source. Control device.

A brake operating member, a master cylinder that generates a hydraulic pressure in response to an operation of the brake operating member, an operation amount detecting means for detecting an operation amount of the brake operating member, a hydraulic pressure source including a pump and the like, A hydraulic pressure source hydraulic pressure detecting means for detecting the hydraulic pressure of the pressure source; a pump drive control means for controlling the driving of the pump based on a detection amount of the hydraulic pressure source hydraulic pressure detecting means; and rotation of a plurality of wheels. A plurality of wheel cylinders for suppressing each of the plurality of wheel cylinders, a plurality of wheel cylinder pressure detecting means for detecting a hydraulic pressure of each of the plurality of wheel cylinders, and a plurality of first cylinders respectively connecting the hydraulic pressure source and the plurality of wheel cylinders. Fluid passages, a plurality of fluid pressure control devices that are provided in each of the first fluid passages to control the fluid pressure of the wheel cylinder, the master cylinder, and the plurality of wheel cylinders And a plurality of second fluid passages respectively connected to each other, and a target fluid pressure of the plurality of wheel cylinders is set based on a detected amount of the operation amount detecting means, and a detected fluid pressure by the plurality of wheel cylinder pressure detecting means Hydraulic pressure control device control means for controlling the hydraulic pressure control device so as to match the target hydraulic pressure of the plurality of wheel cylinders, and when the hydraulic pressure source is operating normally, the master cylinder is removed from the wheel cylinder. In a first state where the hydraulic pressure source is cut off and the hydraulic pressure of the hydraulic pressure source is transmitted to the wheel cylinder, and in a state where the hydraulic pressure source does not normally generate hydraulic pressure, the hydraulic pressure source is cut off from the wheel cylinder A brake fluid pressure control device including a plurality of switching devices that are switchable to a second state in which the fluid pressure of the master cylinder is transmitted to the wheel cylinder and is normally in the first state. In,
First wheel cylinder pressure estimating means for estimating the hydraulic pressure of the wheel cylinder from a command value of the hydraulic pressure control apparatus control means, and a detected amount of the operation amount detecting means when the switching device is in the second state. Second wheel cylinder pressure estimating means for estimating the hydraulic pressure of the wheel cylinder from the absolute value of the difference between the estimated amount of the first wheel cylinder pressure estimating means and the detected amount of the wheel cylinder pressure detecting means When the value is equal to or greater than the first threshold value for only one wheel cylinder, only the wheel cylinder that is equal to or greater than the first threshold value and the switching device that is connected to the wheel cylinder and the wheel cylinder that is in the left-right symmetrical position in the vehicle are described above. The state of the second wheel cylinder pressure estimating means in the wheel cylinder which is switched from the first state to the second state and which is equal to or greater than the first threshold value. When the absolute value of the difference between the fixed amount and the detected amount of the wheel cylinder pressure detecting means is equal to or greater than the third threshold, the wheel cylinder that is equal to or greater than the first threshold and the wheel cylinder that is symmetrically positioned between the wheel cylinder and the vehicle Only the switching device to be connected is switched again from the second state to the first state, the target hydraulic pressure of the hydraulic pressure source is set, and the hydraulic pressure detected by the hydraulic pressure source hydraulic pressure detecting means is the hydraulic pressure. A brake hydraulic pressure control device, wherein the hydraulic pressure control device control means is changed only for a wheel cylinder that is equal to or greater than a first threshold value so as to coincide with a target hydraulic pressure of a source.

The brake fluid pressure control device according to claim 1 or 2,
The hydraulic pressure control device control means is changed only for the wheel cylinders that are equal to or higher than the first threshold so that the hydraulic pressure detected by the hydraulic pressure source hydraulic pressure detection means matches the target hydraulic pressure of the hydraulic pressure source. The brake hydraulic pressure control device is characterized in that a command value to the pump drive control means is set to a constant value during operation of the brake operation member.