JP2012111373A5

JP2012111373A5 -

Info

Publication number: JP2012111373A5
Application number: JP2010262479A
Authority: JP
Filing date: 2010-11-25
Publication date: 2013-12-19
Anticipated expiration: 2030-11-25

Description

上記課題を解決するための手段として、本発明は、ブレーキペダルの操作量を検出する操作量検出手段と、前記ブレーキペダルの操作量に基づいて動作する電動アクチュエータと、該電動アクチュエータにより液圧を発生させる倍力機構と、車両が停車しているときに前記ブレーキペダルがリリースされた場合に、算出される液圧指令値に基づいてマスタシリンダ内の液圧を制御するべく前記電動アクチュエータを制御するヒルスタートアシスト制御を行うコントローラと、を備えたブレーキ装置であって、前記コントローラは、ヒルスタートアシスト制御を行っている際で、前記操作量検出手段により前記ブレーキペダルの操作を検出した際、その時点で検出された液圧値である液圧指令値と、前記ブレーキペダルの操作量に対応した踏込み液圧指令値とを比較して前記電動アクチュエータを制御することを特徴とするものである。 As means for solving the above problems, the present invention provides an operation amount detection means for detecting an operation amount of a brake pedal, an electric actuator that operates based on the operation amount of the brake pedal, and a hydraulic pressure by the electric actuator. control and booster mechanism for generating the said electric actuator to the brake pedal is when it is released, to control the hydraulic pressure in the master cylinder based on the hydraulic pressure command value calculated when the vehicle is stopped A controller that performs hill start assist control , wherein the controller is performing hill start assist control, and when detecting the operation of the brake pedal by the operation amount detection means , a liquid pressure command value is detected hydraulic pressure value at that time, depression corresponding to the operation amount of the brake pedal It is characterized in that for controlling the electric actuator by comparing the hydraulic pressure command value.

ステップＳ３では、強制液圧保持解除判定が行われる。この判定は、車両システムからの異常信号の有無により、ＨＳＡ制御（液圧制御）の開始後、車両のシステムに異常が存在するかを判定する。その結果、異常が存在しないと判定された場合にはステップＳ４に進み、一方、異常が存在すると判定された場合には、ステップＳ１０１に進み即減圧処理が行なわれる。すなわち、図４に示すタイムチャートも参照しながら説明する。時間ｔ１にて車両が登坂路で停車していると判定された後、ＨＳＡ制御（液圧制御）がスタートする。時間ｔ１〜ｔ２の間はブレーキペダルＢの踏み込みから踏込み液圧指令値による液圧が液圧指令値として出力される。その後、ブレーキペダルＢが戻されると、それに対応して踏込み液圧指令値が小さくなり（時間ｔ２〜ｔ３）、時間ｔ３にてブレーキペダルＢのリリース判定が成立するころには、ＨＳＡ制御液圧指令値（この場合、停車圧力となる）より踏込み液圧指令値が小さくなりＨＳＡ制御液圧指令値、すなわち、停車圧力の液圧がアシストピストン１０により保持される（図２（ｂ）の状態）。その後、時間ｔ４にて車両システムに異常が発生したと検知されると減圧制御が開始される。
なお、ブレーキペダルＢのリリース判定は、ブレーキペダルＢを完全に離した状態を判断しても良いが、本実施の形態では、完全に離した状態ではなく、若干踏み込んだ状態でブレーキペダルＢのリリース判定を行っている。 In step S3, forced hydraulic pressure retention release determination is performed. This determination is based on the presence / absence of an abnormality signal from the vehicle system to determine whether there is an abnormality in the vehicle system after the start of HSA control (hydraulic pressure control). As a result, if it is determined that there is no abnormality, the process proceeds to step S4. On the other hand, if it is determined that there is an abnormality, the process proceeds to step S101 and an immediate decompression process is performed. That is, the description will be made with reference to the time chart shown in FIG. After it is determined that the vehicle is stopped on the uphill road at time t1, HSA control (hydraulic pressure control) starts. During the time t1 to t2, the hydraulic pressure based on the depression hydraulic pressure command value is output as the hydraulic pressure command value from the depression of the brake pedal B. Thereafter, when the brake pedal B is returned, the stepping hydraulic pressure command value correspondingly decreases (time t2 to t3), and when the release determination of the brake pedal B is established at time t3, the HSA control hydraulic pressure is reached. (in this case, stop vehicles pressure to become) the command value from depression liquid pressure command value is reduced HSA control hydraulic pressure command value, i.e., the hydraulic pressure in the stop pressure is maintained by the assist piston 10 (see FIG. 2 (b) State). Thereafter, when it is detected that an abnormality has occurred in the vehicle system at time t4, the pressure reduction control is started.
The release determination of the brake pedal B may be made by determining whether the brake pedal B is completely released. However, in this embodiment, the brake pedal B is not fully released but is depressed slightly. Release judgment is performed.

次に、ステップＳ１０４において液圧保持されるが、その時の液圧指令値は次のように決定される。ます、ブレーキペダルＢの踏み込みによる、ストロークセンサ８０からのストローク量に基づいた入力ピストン３２の位置と、入力ピストン３２とアシストピストン１０との相対位置制御によって算出されるアシストピストン１０の位置とから踏込み液圧指令値を算出し、前述のＨＳＡ制御液圧指令値（ブレーキペダルＢのリリース判定が成立した時点の液圧）と、前記踏込み液圧指令値とが比較されて高いほうの液圧指令値が選択される。そして、選択された液圧指令値を保持するのに必要なアシストピストン１０の位置を算出して、現在のアシストピストン１０の位置から必要なアシストピストン１０の位置までアシストピストン１０を移動させて液圧を保持する。 Next, the hydraulic pressure is maintained in step S104, and the hydraulic pressure command value at that time is determined as follows. Masu, by depression of the brake pedal B, a position of the input piston 32 based on the stroke amount of the stroke sensor 80, the position Toka et input piston 32 and the assist piston 10, which is calculated by the relative position control of the assist piston 10 depression The hydraulic pressure command value is calculated, and the above-mentioned HSA control hydraulic pressure command value (the hydraulic pressure at the time when the release determination of the brake pedal B is established) is compared with the stepping hydraulic pressure command value, and the higher hydraulic pressure is calculated. The command value is selected. Then, the position of the assist piston 10 necessary to hold the selected hydraulic pressure command value is calculated, and the assist piston 10 is moved from the current position of the assist piston 10 to the position of the assist piston 10 necessary to move the liquid. Hold pressure.

Claims

An operation amount detection means for detecting an operation amount of the brake pedal;
An electric actuator that operates based on an operation amount of the brake pedal;
A booster mechanism for generating hydraulic pressure by the electric actuator;
Controller when said brake pedal is released, it performs hill start assist control for controlling the electric actuator to control the hydraulic pressure in the master cylinder on the basis of a predetermined hydraulic pressure command value when the vehicle is stopped A brake device comprising:
Wherein the controller is in when performing a hill start assist control, when detecting the operation of the brake pedal by the operation amount detecting means, and the liquid pressure command value is detected hydraulic pressure value at that time, the brake braking device and controls the electric actuator by comparing the depression hydraulic pressure command value corresponding to the operation amount of the pedal.

Said controller, said when detecting the operation of the brake pedal, and compares the liquid pressure command value is detected hydraulic pressure value at that time, and a Stepping included liquid pressure command value corresponding to the operation amount of the brake pedal The brake device according to claim 1 , wherein a high value is selected.

Wherein the controller, when the vehicle is stopped, when the brake pedal is released, a predetermined time the hydraulic pressure in the master cylinder, and controlled so as to maintain a predetermined pressure, the control for reducing the pressure after a predetermined time The brake device according to claim 1 or 2 .

The controller controls the hydraulic pressure in the master cylinder to be maintained at a predetermined pressure when the brake pedal is released when the vehicle is stopped, and reduces the master cylinder pressure according to a predetermined condition. The brake device according to claim 1 or 2 , further comprising:

An input piston that moves directly by operation of the brake pedal, and an assist piston that moves by driving the electric actuator as the booster mechanism;
The brake device according to any one of claims 1 to 4, wherein the release determination of the brake pedal is determined from a relative position of the input piston to the assist piston and an absolute position of the input piston.