JP6812691B2 - Vehicle braking control device - Google Patents

Description

The present invention relates to a vehicle braking control device.

In Patent Document 1, for the purpose of "appropriately determining an abnormality in the output of the stroke sensor in comparing the two output values of the stroke sensor", "the first abnormality determination unit 90 has the first output value and the first output value. If the sum with the two output values deviates from the predetermined range, it is determined that the output of the first stroke sensor 46a or the second stroke sensor 46b is abnormal. The second abnormality determination unit 92 is determined by the first abnormality determination unit 90. When the sum of the first output value and the second output value is within a predetermined range, the absolute value of the difference between the first output value and the second output value is equal to or less than the predetermined threshold value, and the master output value. If is smaller than the predetermined pressure value, it is determined that the output of the first stroke sensor 46a or the second stroke sensor 46b is abnormal. "

In Patent Document 2, for the purpose of "suppressing the supply of hydraulic pressure to the wheel cylinder by both the hydraulic pressure control mechanism and the booster mechanism", "the first ECU 26 is an electric booster 16". The second ECU 33 controls the operation of the hydraulic pressure control device ESC31. The second ECU 33 determines when the failure of the first ECU 26 is determined. , ESC31 is operated to perform backup control to supply the brake liquid to the wheel cylinders 3L, 3R, 4L, 4R. On the other hand, the first ECU 26 performs backup control when the second ECU 33 performs backup control. , Do not control the electric actuator 20 ".

In order to improve the reliability of the control device, Patent Document 1 describes that a plurality of sensors (first and second stroke sensors) are provided. Further, Patent Document 2 describes that two hydraulic pressure control devices are provided, and when one device malfunctions, the other device performs backup. In a device composed of a plurality of control devices described in Patent Document 2, a large number of sensors are required in order to improve the reliability thereof. Therefore, it is desired that the device has a simple structure and the reliability of the entire device is ensured.

JP-A-2010-167970 Japanese Unexamined Patent Publication No. 2014-097678

An object of the present invention is to provide a vehicle braking control device composed of a plurality of control devices, which has a simple structure and can ensure reliability.

The vehicle braking control device according to the present invention applies a braking force to the wheels (WH) by increasing the braking hydraulic pressure (Pwc) of the wheel cylinder (WC) in response to the operation of the vehicle braking operation member (BP). appear. The vehicle braking control device increases the braking fluid pressure (Pwc) of the wheel cylinder (WC) instead of the master cylinder (MC), and operates the braking operation member (BP) via the stroke simulator (SSM). The wheel cylinder (WC) is provided between the first hydraulic unit (EAA) that generates a force, the first hydraulic unit (EAA), and the wheel cylinder (WC) so as to execute vehicle stability control. ), A second hydraulic pressure unit (EAB) that increases the braking hydraulic pressure (Pwc), and a first hydraulic pressure sensor (PWA) that detects the output hydraulic pressure (Pwa) of the first hydraulic pressure unit (EAA). The second hydraulic pressure sensor (PWB) that detects the input hydraulic pressure (Pwb) of the second hydraulic pressure unit (EAB), the first hydraulic pressure unit (EAA), and the second hydraulic pressure unit (EAB). It is provided with a communication bus (CMB) for transmitting signals between the wheels.

In the vehicle braking control device according to the present invention, the first hydraulic pressure unit (EAA) determines "whether or not the output hydraulic pressure (Pwa) is appropriate" and "the output hydraulic pressure (Pwa). ) Is appropriate, based on the output hydraulic pressure (Pwa).By feedback controlWhen the braking hydraulic pressure (Pwc) is increased and it is determined that "the output hydraulic pressure (Pwa) is not appropriate", the input hydraulic pressure (Pwb) is transmitted via the communication bus (CMB). Obtained and said output hydraulic pressure (Pwa)Feedback control based onBased on the input hydraulic pressure (Pwb) instead ofBy feedback controlThe braking fluid pressure (Pwc) is increased.

The vehicle braking control device according to the present invention includes a first operating amount sensor (SBA, FBA) for detecting a first operating amount (Sba, Fba) of the braking operating member (BP) and the first operating amount (Sba). , Fba), a second operation amount sensor (SBB, FBB) for detecting the second operation amount (Sbb, Fbb) of the braking operation member, and the first operation amount (Sba, Fba) are input. The first hydraulic pressure that increases the braking hydraulic pressure (Pwc) of the wheel cylinder (WC) instead of the master cylinder (MC) and generates an operating force on the braking operating member (BP) via the stroke simulator (SSM). The unit (EAA) and the second operation amount (Sbb, Fbb) are input and provided between the first hydraulic pressure unit (EAA) and the wheel cylinder (WC) to execute vehicle stability control. Between the second hydraulic pressure unit (EAB) that increases the braking hydraulic pressure (Pwc) of the wheel cylinder (WC), the first hydraulic pressure unit (EAA), and the second hydraulic pressure unit (EAB). It is equipped with a communication bus (CMB) that transmits signals.

In the vehicle braking control device according to the present invention, the first hydraulic pressure unit (EAA) determines "whether or not the first operation amount (Sba, Fba) is appropriate" and "the first When it is determined that the operation amount (Sba, Fba) is appropriate, the braking hydraulic pressure (Pwc) is increased based on the first operation amount (Sba, Fba), and the first operation amount (Sba, Fba) is increased. When it is determined that "Sba, Fba) is not appropriate", the second operation amount (Sbb, Fbb) is acquired via the communication bus (CMB), and the first operation amount (Sba, Fba) Instead, the braking fluid pressure (Pwc) is increased based on the second operation amount (Sbb, Fbb).

According to the above configuration, even if at least one of the first hydraulic pressure sensor PWA and the first operation displacement sensor SBA malfunctions, the operation of the first hydraulic pressure unit EAA is not stopped and continues. This is because the malfunction of the first hydraulic pressure sensor PWA and the first operation displacement sensor SBA is backed up by the second hydraulic pressure sensor PWB and the second operation displacement sensor SBB for the second hydraulic pressure unit EAB. Thereby, the reliability of the braking control device BCS can be improved with a simple configuration.

It is an overall block diagram for demonstrating 1st Embodiment of the vehicle braking control device BCS which concerns on this invention. It is a functional block diagram for demonstrating the process in 1st controller ECA. It is a flow chart for demonstrating the processing in a hydraulic pressure determination block HPW. It is a flow diagram for demonstrating the processing in operation amount determination block HBP. It is an overall block diagram for demonstrating the 2nd Embodiment of the vehicle braking control device BCS which concerns on this invention.

<Overall configuration of vehicle braking control device according to the present invention>
A first embodiment of the braking control device BCS according to the present invention will be described with reference to the overall configuration diagram of FIG. In the following description, the components, arithmetic processing, signals, characteristics, and values with the same symbols perform the same functions. Therefore, duplicate description may be omitted.

As shown in FIG. 1, the vehicle is provided with two different hydraulic units EAA, EAB. In this vehicle, in addition to the first and second hydraulic units EAA and EAB, braking operation member BP, two operation displacement sensors SBA, SBB, master cylinder MC, stroke simulator SSM, shutoff valve VSM, switching valve VKR, A fluid path (braking pipe) HMC, HKC, HKD, HWC, and a notification device HC are provided. Further, each wheel WH of the vehicle is provided with a brake caliper CP, a wheel cylinder WC, a rotating member KT, and a friction member MS.

The braking operation member (for example, the brake pedal) BP is a member operated by the driver to decelerate the vehicle. By operating the braking operation member BP, the braking torque of the wheel WH is adjusted, and a braking force is generated on the wheel WH. Specifically, a rotating member (for example, a brake disc) KT is fixed to the wheel WH of the vehicle. The brake caliper CP is arranged so as to sandwich the rotating member KT. A wheel cylinder WC is provided on the brake caliper (simply also referred to as caliper) CP. By increasing the pressure Pwc of the braking fluid in the wheel cylinder WC, the friction member (for example, the brake pad) MS is pressed against the rotating member KT. The rotating member KT and the wheel WH are fixed by the wheel shaft DSF so as to rotate integrally. Therefore, a braking torque (braking force) is generated in the wheel WH by the frictional force generated when the friction member MS is pressed by the rotating member KT. As the caliper CP, a floating caliper or an opposed caliper may be adopted.

Two operation displacement sensors SBA and SBB are separately provided so as to detect the operation amount of the braking operation member BP. The first and second operation displacement sensors SBA and SBB separately detect the state variables (operational displacements) related to the "displacement" of the braking operation member BP as the first and second operation displacements Sba and Sbb. Here, the first operation displacement Sba corresponds to the "first operation amount", and the second operation displacement Sbb corresponds to the "second operation amount". It is desirable that the first manipulated quantity and the second manipulated quantity are the same physical quantity. For example, the "physical quantity of the first operation displacement Sba" and the "physical quantity of the second operation displacement Sbb" are the same, and are physical quantities related to the "displacement".

For example, in the braking operation member BP rotatably fixed to the vehicle body BD by the first and second operation displacement sensors SBA and SBB, the rotation angle (first and second operation displacement) of the braking operation member BP with respect to the vehicle body BD. Sba, Sbb) is detected. That is, a rotation angle sensor (one of the displacement sensors) is adopted as the first and second operation displacement sensors SBA and SBB. In addition, linear displacement sensors are adopted as the first and second operation displacement sensors SBA and SBB, and the displacement of the brake rod BRD that mechanically connects the braking operation member BP and the piston in the master cylinder MC with respect to the vehicle body BD is It can be detected as the second operation displacement Sba, Sbb. For example, the operation displacement sensor SBA of the first rotation angle sensor and the second operation displacement sensor SBB of the linear displacement sensor can be combined.

The first operating displacement sensor SBA is connected to the first hydraulic unit EAA (particularly, the first controller ECA) via the first displacement signal line SLA. Further, the second operation displacement sensor SBB is connected to the second hydraulic unit EAB (particularly, the second controller ECB) via the second displacement signal line SLB. Here, the first and second displacement signal lines SLA and SLB are cables (general term for an insulator, an electric wire covered with a protective coating, and an optical fiber). In the first displacement signal line SLA, only the first operation displacement Sba is transmitted, and other signals are not transmitted. Further, in the second displacement signal line SLB, only the second operation displacement Sbb is transmitted, and other signals are not transmitted.

The tandem master cylinder (also simply referred to as the master cylinder) MC is connected to the braking operation member BP via the brake rod BRD. The master cylinder MC converts the operating force (brake pedal pedaling force) of the braking operating member BP into the pressure of the braking fluid. A fluid path (master cylinder piping) HMC is connected to the master cylinder MC, and when the braking operation member BP is operated, the braking fluid is discharged (pumped) from the master cylinder MC to the fluid path HMC.

A stroke simulator (simply also referred to as a simulator) SSM is provided to generate an operating force on the braking operating member BP. A simulator shutoff valve (simply also referred to as a shutoff valve) VSM is provided between the hydraulic chamber in the master cylinder MC and the simulator SSM. The shutoff valve VSM is a two-position solenoid valve having an open position and a closed position. When the shutoff valve VSM is in the open position, the master cylinder MC and the simulator SSM are in a communication state, and when the shutoff valve VSM is in the closed position, the master cylinder MC and the simulator SSM are in a shutoff state (non-communication state). ). The shutoff valve VSM is controlled by a drive signal Vsm from the first controller ECA. As the shutoff valve VSM, a normally closed solenoid valve (NC valve) can be adopted.

A piston and an elastic body (for example, a compression spring) are provided inside the simulator SSM. The braking fluid is moved from the master cylinder MC to the simulator SSM, and the piston is pushed by the inflowing braking fluid. A force is applied to the piston in a direction that prevents the inflow of the braking fluid by the elastic body. The elastic body forms an operating force (for example, a brake pedal pedaling force) when the braking operation member BP is operated.

A simulator hydraulic pressure sensor PSM is provided to detect the simulator hydraulic pressure Psm. Here, the simulator hydraulic pressure sensor PSM is connected to the first controller ECA of the first hydraulic pressure unit EAA via the simulator signal line SMA. A pin (sensor pin) is adopted as the simulator signal line SMA. The simulator hydraulic pressure Psm is input to the first controller ECA via the simulator signal line SMA.

A switching valve VKR is provided in the fluid path (master cylinder piping) HMC that connects the master cylinder MC and the wheel cylinder WC. By the switching valve VKR, "a state in which the master cylinder MC is connected to the wheel cylinder WC through the second hydraulic pressure unit EAB" and "the first hydraulic pressure unit EAA (pressure adjusting cylinder KCL) is the second hydraulic pressure unit. Through the EAB, the state of being connected to the wheel cylinder WC "is switched. The switching valve VKR is controlled based on the drive signal Vkr from the controller ECA. Specifically, when the braking operation is not performed (in the case of "Bps <bp0"), the wheel cylinder fluid path HWC is communicated with the master cylinder fluid path HMC via the switching valve VKR. It is in a non-communication (blocking) state with the pressure adjusting cylinder fluid path HKC. Here, the wheel cylinder fluid path HWC is a fluid path connected to the wheel cylinder WC. When the braking operation is performed (that is, when “Bps ≧ bp0” is reached), the switching valve VKR is excited based on the drive signal Vkr, and the communication between the wheel cylinder fluid path HWC and the master cylinder fluid path HMC is cut off. , The wheel cylinder fluid passage HWC and the pressure adjusting cylinder fluid passage HKC are brought into communication with each other.

≪1st hydraulic unit EAA≫
The first hydraulic unit EAA generates hydraulic pressure in the wheel cylinders WC provided on the four wheels WH of the vehicle instead of the master cylinder MC. When the first hydraulic pressure unit EAA is operated, the pressure adjusting cylinder KCL is communicated with the wheel cylinder WC by the drive signal Vkr, and the movement of the braking fluid from the master cylinder MC to the wheel cylinder WC is prevented. In this case, since the shutoff valve VSM is opened in the drive signal Vsm, the braking fluid from the master cylinder MC is moved to the simulator SSM. The first hydraulic unit EAA is a so-called brake-by-wire braking control device.

The first hydraulic unit EAA includes a first controller ECA, a first electric motor MTA, a drive circuit DRV, a power transmission mechanism DDK, a pressure adjusting rod KRD, a pressure adjusting cylinder KCL, a pressure adjusting piston PKC, and a first hydraulic pressure sensor. It is composed of PWA. The first hydraulic unit EAA uses the first electric motor MTA as a power source to discharge (pressure feed) the braking fluid to the pressure adjusting cylinder fluid path HKC. Then, the pumped braking fluid is moved to the wheel cylinder WC through the fluid passage HKD, the second hydraulic pressure unit EAB, and the fluid passage HWC. Therefore, the first hydraulic pressure unit EAA presses (presses) the friction member MS against the rotating member KT to apply braking torque (braking force) to the wheel WH.

The first controller (electronic control unit) ECA is composed of an electric circuit board on which a microprocessor or the like is mounted and a control algorithm programmed in the microprocessor. The first controller ECA controls the first electric motor MTA, the shutoff valve VSM, and the switching valve VKR based on the first operation displacement (corresponding to the first operation amount) Sba. Specifically, signals for controlling the first electric motor MTA, the shutoff valve VSM, and the switching valve VKR are calculated based on the programmed control algorithm and output from the first controller ECA.

The first controller ECA outputs a drive signal Vsm for opening the shutoff valve VSM when the combined operation amount Bps becomes a predetermined value bp0 or more, and the switching valve VKR has a pressure regulating cylinder fluid path HKC and a wheel cylinder. The drive signal Vkr that communicates with the fluid path HWC is output. In this case, the master cylinder MC is in a communication state with the simulator SSM, and the pressure adjusting cylinder KCL is in a communication state with the wheel cylinder WC.

The first controller ECA is based on the first operating displacement Sba (or the second operating displacement Sbb), the angle of rotation Mka, and the first hydraulic pressure Pwa (or the second hydraulic pressure Pwb), and the first electric motor MTA. The drive signal (Su1 etc.) for driving is calculated and output to the drive circuit DRV. Here, the first and second operation displacements Sba and Sbb are detected by the first and second operation displacement sensors SBA and SBB. Further, the first and second hydraulic pressure (actual values) Pwa and Pwb are detected by the first and second hydraulic pressure sensors PWA and PWB. Further, the actual rotation angle Mka is detected by the rotation angle sensor MKA. The pressure Pwc of the braking fluid in the wheel cylinder WC is controlled (maintained, increased, or decreased) by the first hydraulic pressure unit EAA.

Further, the first controller ECA is connected to the second controller ECB of the second hydraulic unit EAB via a communication bus CMB (for example, a serial communication bus). Therefore, the first controller ECA and the second controller ECB are in a state where they can transmit signals to each other. For example, CAN (Controller Area Network) can be adopted as the communication bus CMB. At least one of the second operation displacement (detection value) Sbb and the second hydraulic pressure (detection value) Pwb is transmitted from the second controller ECB to the first controller ECA via the communication bus CMB.

The first electric motor MTA is a power source for the pressure adjusting cylinder KCL (a part of the first hydraulic pressure unit EAA) to adjust (pressurize, reduce pressure, etc.) the pressure Pwc of the braking fluid in the wheel cylinder WC. .. For example, a three-phase brushless motor is adopted as the first electric motor MTA. The electric motor MTA has three coils CLU, CLV and CLW and is driven by a drive circuit DRV. The electric motor MTA is provided with a rotation angle sensor MKA that detects the rotor position (rotation angle) Mka of the electric motor. The rotation angle Mka is input to the first controller ECA.

The drive circuit DRV is an electric circuit board on which a switching element (power semiconductor device) or the like for driving the first electric motor MTA is mounted. Specifically, a bridge circuit BRG (three-phase bridge circuit) is formed in the drive circuit DRV, and the energization state of the first electric motor MTA is controlled based on the drive signal (Su1 or the like). The drive circuit DRV is provided with an energization amount sensor (for example, a current sensor) IMA that detects the actual energization amount (general term for each phase) Ima of the electric motor MTA. The energization amount (detection value) Ima of each phase is input to the first controller ECA.

The power transmission mechanism DDK decelerates the rotational power of the electric motor MTA, converts it into linear power, and outputs it to the pressure regulating rod KRD. Specifically, the power transmission mechanism DDK is provided with a speed reducer (not shown), and the rotational power from the electric motor MTA is reduced and output to a screw member (not shown). Then, the rotational power is converted into the linear power of the pressure adjusting rod KRD by the screw member. That is, the power transmission mechanism DDK is a rotation / linear motion conversion mechanism.

A pressure adjusting piston PKC is fixed to the pressure adjusting rod KRD. The pressure adjusting piston PKC is inserted into the inner hole of the pressure adjusting cylinder KCL to form a combination of the piston and the cylinder. Specifically, a seal member (not shown) is provided on the outer periphery of the pressure adjusting piston PKC to ensure liquidtightness with the inner hole (inner wall) of the pressure adjusting cylinder KCL. That is, a fluid chamber Rkc (referred to as "pressure regulating chamber Rkc"), which is partitioned by the pressure adjusting cylinder KCL and the pressure adjusting piston PKC and filled with the braking fluid, is formed.

The volume of the pressure adjusting chamber Rkc is changed by moving the pressure adjusting piston PKC in the central axis direction in the pressure adjusting cylinder KCL. Due to this volume change, the braking fluid is moved between the pressure adjusting cylinder KCL and the wheel cylinder WC via the fluid passages (braking pipes) HKC and HWC. By taking in and out the braking fluid from the pressure adjusting cylinder KCL, the hydraulic pressure in the wheel cylinder WC is adjusted, and as a result, the force (hydraulic pressure) at which the friction member MS presses the rotating member KT is adjusted.

For example, as the first hydraulic pressure sensor PWA, a hydraulic pressure sensor that detects the output hydraulic pressure (first hydraulic pressure) Pwa of the pressure regulating chamber Rkc is built in the first hydraulic pressure unit EAA (particularly, the pressure regulating cylinder KCL). Cylinder. The first hydraulic pressure sensor PWA is fixed to the pressure adjusting cylinder KCL and is integrally configured as the first hydraulic pressure unit EAA. The detected value (first hydraulic pressure) Pwa of the output hydraulic pressure (that is, the hydraulic pressure of the pressure regulating chamber Rkc) is input to the first controller ECA via the first hydraulic pressure signal line SPA. The first hydraulic unit EAA has been described above.

≪2nd hydraulic unit EAB≫
Next, the second hydraulic pressure unit EAB will be described. The vehicle is provided with a second hydraulic unit EAB in addition to the first hydraulic unit EAA. That is, the vehicle is provided with two hydraulic units EAA and EAB. The second hydraulic unit EAB is provided in the fluid path between the first hydraulic unit EAA and the wheel cylinder WC. The fluid passages HKC and HKD between the first hydraulic pressure unit EAA and the second hydraulic pressure unit EAB are pressure regulating fluid passages (braking pipes), and the fluid passages between the second hydraulic pressure unit EAB and the wheel cylinder WC. HWC is the wheel cylinder piping. That is, the first hydraulic pressure unit EAA and the second hydraulic pressure unit EAB are arranged in series with respect to the wheel cylinder WC.

The second hydraulic unit EAB adjusts the hydraulic pressure Pwc of the wheel cylinder WC of each wheel WH independently of the driver's braking operation based on the turning state of the vehicle. Therefore, the hydraulic pressure generated by the first hydraulic pressure unit EAA (that is, the output hydraulic pressure Pwa) is adjusted by the second hydraulic pressure unit EAB, and the final wheel cylinder hydraulic pressure Pwc is generated. The second hydraulic unit EAB is a so-called hydraulic unit for ESC (Electronic Stability Control).

The second hydraulic unit EAB is composed of a second electric motor MTB, a fluid pump PMP, a linear solenoid valve SOL, a second controller (electronic control unit) ECB, and a second hydraulic pressure sensor PWB.

A hydraulic pressure is generated by a fluid pump PMP driven by a second electric motor MTB, and is controlled to a desired hydraulic pressure by a plurality of solenoid valves SOL. The second electric motor MTB and the solenoid valve SOL are controlled by the second controller ECB. Specifically, the hydraulic pressure is increased by the fluid pump PMP driven by the electric motor MTB, and the hydraulic pressure is adjusted by the differential pressure valve (for example, a linear solenoid valve) SOL. Further, the hydraulic pressure Pwc in the wheel cylinder WC of each wheel WH is independently adjusted by the combination of the pressure increasing solenoid valve and the depressurizing solenoid valve.

Similar to the first controller ECA, the second controller ECB of the second hydraulic unit EAB has a control algorithm programmed in the microprocessor and an electric circuit (driving) for driving the second electric motor MTB and the electromagnetic valve SOL by the algorithm. Circuit) and.

The yaw rate Yra from the yaw rate sensor YRA, the lateral acceleration Gya from the lateral acceleration sensor GYA, the steering angle Swa from the operation angle sensor SWA, and the wheel speed Vwa from the wheel speed sensor VWA are input to the second controller ECB. .. Based on these signals (Yra, Vwa, etc.), vehicle stability control (control to suppress excessive understeer and oversteer based on yaw rate Yra, etc.), anti-skid control (control to suppress wheel lock based on wheel speed Vwa, etc.) In order to execute the control), etc., the target value Pwt of the braking hydraulic pressure (hydraulic pressure in the wheel cylinder WC) is calculated in each wheel WH. Then, the wheel cylinder hydraulic pressure Pwc is adjusted so that the target value Pwt is achieved.

In the second hydraulic unit EAB, in addition to executing vehicle stability control and the like, when the first hydraulic unit EAA is in a malfunction state, the hydraulic pressure of the wheel cylinder WC is adjusted according to the second operation displacement Sbb. Can be executed. This is because the second hydraulic unit EAB is provided with a power source (second electric motor MTB and fluid pump PMP) and a linear solenoid valve SOL different from those of the first hydraulic unit EAA.

The second operation displacement Sbb is input from the second operation displacement sensor SBB to the second controller ECB of the second hydraulic unit EAB via the second displacement signal line SLB (for example, an electric wire). Further, the second operation displacement Sbb is transmitted from the second controller ECB to the first controller ECA via the communication bus CMB (for example, the serial communication bus). When the first hydraulic unit EAA is malfunctioning, the second hydraulic unit EAB replaces the first hydraulic unit EAA with the hydraulic pressure Pwc in the wheel cylinder WC based on the second operation displacement Sbb. increase. At this time, the operation of the first hydraulic pressure unit EAA is stopped.

The first hydraulic pressure unit EAA and the second hydraulic pressure unit EAB are fluidly connected via fluid passages (pressure adjusting fluid passages) HKC and HKD. The second hydraulic pressure sensor PWB detects the hydraulic pressure of the braking fluid flowing from the first hydraulic pressure unit EAA into the second hydraulic pressure unit EAB as the input hydraulic pressure (second hydraulic pressure) Pwb. The second hydraulic pressure sensor PWB is built in the second hydraulic pressure unit EAB.

The second hydraulic pressure (detection value) Pwb, which is the input hydraulic pressure to the second hydraulic pressure unit EAB, is the hydraulic pressure in the fluid path HKD, and is the second hydraulic pressure signal line SPB (for example, a sensor pin). 2 Input to the controller ECB. The second hydraulic pressure Pwb is used to perform vehicle stability control and the like. When the operating states of the first and second hydraulic pressure sensors PWA and PWB are appropriate, the detected value Pwb of the second hydraulic pressure sensor PWB and the detected value Pwa of the first hydraulic pressure sensor PWA match.

From the second hydraulic pressure unit EAB, the brake fluid regulated with pressure is discharged and inflowed from each wheel cylinder WC via the fluid path (wheel cylinder piping) HWC. By adjusting the hydraulic pressure Pwc in the wheel cylinder WC of the caliper CP, the piston in the wheel cylinder WC is moved (advanced or retracted) with respect to the rotating member KT, and the braking force of the wheel WH is adjusted (increased). , Or is reduced). The second hydraulic unit EAB has been described above.

The vehicle is provided with a notification device HC. If the device is in an unsuitable state, the notification device HC notifies the driver to that effect. For example, the notification device HC notifies the driver of the inappropriate state by sound, light, or the like.

<Processing in the 1st controller>
The processing of the first hydraulic unit EAA in the first controller ECA will be described with reference to the functional block diagram of FIG. Here, an example in which a brushless motor is adopted as the first electric motor MTA will be described.

The first controller ECA includes a determination calculation block HNT, a displacement conversion calculation block SBH, a target hydraulic pressure calculation block PWT, an indicated energization amount calculation block IMS, a hydraulic feedback control block PFB, a target energization amount calculation block IMT, and a switching control block SWT. It is composed of a drive circuit DRV. The processing of the determination calculation block HNT or the switching control block SWT is a calculation algorithm and is programmed in the microcomputer of the first controller ECA.

The determination calculation block HNT is composed of a hydraulic pressure determination block HPW and an operation amount determination block HBP. In the determination calculation block HNT, the suitability of the sensor signal (Pwa, etc.) is determined, and the final hydraulic pressure (final result of the actual value) Pws and the combined operation amount (final operation amount of the braking operation member) Bps are determined. Will be done. Specifically, the final hydraulic pressure Pws is determined by the hydraulic pressure determination block HPW, and the combined manipulated variable Bps is calculated by the manipulated variable determination block HBP.

In the hydraulic pressure determination block HPW of the determination calculation block HNT, the suitability of the first hydraulic pressure (detection value) Pwa is determined based on the first and second hydraulic pressures Pwa, Pwb, and the wheel speed Vwa. The first and second hydraulic pressures Pwa, Pwb, and wheel speed Vwa are input to the hydraulic pressure determination block HPW. The first hydraulic pressure Pwa is directly input from the first hydraulic pressure sensor PWA provided in the first hydraulic pressure unit EAA to the first controller ECA via the first hydraulic pressure signal line SPA (for example, a sensor pin). .. The second hydraulic pressure Pwb is input to the second controller ECB from the second hydraulic pressure sensor PWB provided in the second hydraulic pressure unit EAB via the second hydraulic pressure signal line SPB (for example, a sensor pin). It is input to the first controller ECA via the communication bus CMB. The wheel speed Vwa is detected by the wheel speed sensor VWA provided on the wheel WH, is input to the second controller ECB via a signal line (for example, a cable), and is input to the first controller ECA via the communication bus CMB. Wheel.

In the hydraulic pressure determination block HPW, "determination of disconnection of the first hydraulic pressure signal line SPA that transmits the signal of the first hydraulic pressure Pwa", "determination by comparison between the first hydraulic pressure Pwa and the second hydraulic pressure Pwb", and , "The vehicle deceleration Gxa is calculated from the wheel speed Vwa, and the conversion determination based on the deviation hPw between the hydraulic pressure conversion value Pwh converted from the vehicle deceleration Gxa and the first hydraulic pressure Pwa" is executed, respectively. Details of each determination method will be described later. The vehicle deceleration Gxa can be directly detected by the front-rear acceleration sensor GXA.

The final hydraulic pressure detection value (referred to as "final hydraulic pressure") Pws is output from the hydraulic pressure determination block HPW based on the suitability determination result of the first hydraulic pressure Pwa. When it is determined that the first hydraulic pressure Pwa is appropriate, the first hydraulic pressure Pwa is output as the final hydraulic pressure Pws. On the other hand, when it is determined that the first hydraulic pressure Pwa is unsuitable, the second hydraulic pressure Pwb is output as the final hydraulic pressure Pws. When both the first hydraulic pressure Pwa and the second hydraulic pressure Pwb are appropriate, the first hydraulic pressure Pwa and the second hydraulic pressure Pwb match.

In the operation amount determination block HBP of the determination calculation block HNT, the suitability of the first operation displacement Sba is determined based on the first and second operation displacements Sba, Sbb, and the simulator hydraulic pressure Psm. The first and second operation displacements Sba, Sbb, and the simulator hydraulic pressure Psm are input to the operation amount determination block HBP. The first operation displacement Sba (corresponding to the first operation amount) is from the first operation displacement sensor SBA (corresponding to the first operation amount sensor) provided on the braking operation member BP to the first displacement signal line SLA (for example, a cable). ) Is directly input to the first controller ECA. The second operation displacement Sbb (corresponding to the second operation amount) is from the second operation displacement sensor SBB (corresponding to the second operation amount sensor) provided on the braking operation member BP to the second displacement signal line SLB (for example, a cable). ) Is input to the second controller ECB. Then, the second operation displacement Sbb is input to the first controller ECA via the communication bus CMB. The simulator hydraulic pressure Psm is detected by the simulator hydraulic pressure sensor PSM provided in the simulator SSM, and is directly input to the first controller ECA via the signal line SMA (for example, the sensor pin).

In the operation amount determination block HBP, "determination of disconnection of the first displacement signal line SLA that transmits the signal of the first operation displacement Sba", "determination by comparison between the first operation displacement Sba and the second operation displacement Sbab", and "Conversion determination based on the deviation hSb between the displacement conversion value Sb converted from the simulator hydraulic pressure Psm and the first operation displacement Sba" is executed, respectively. Details of each determination method will be described later.

From the operation amount determination block HBP, the combined operation amount Bps is calculated and output based on the suitability determination result of the first operation displacement Sba. When it is determined that the first operation displacement Sba is appropriate, the combined operation amount Bps is calculated based on the first operation displacement Sba. On the other hand, when it is determined that the first operation displacement Sba is unsuitable, the combined operation amount Bps is calculated based on the second operation displacement Sbb.

In the displacement conversion calculation block SBH, the displacement conversion value Sbh is calculated based on the simulator hydraulic pressure Psm and the conversion characteristic CHps. The simulator hydraulic pressure Psm is detected by the simulator hydraulic pressure sensor PSM provided in the first hydraulic pressure unit EAA, and is input to the first controller ECA via the simulator hydraulic pressure signal line SMA. The simulator hydraulic pressure Psm is a "state variable related to force" of the braking operation member BP. The displacement conversion value Sbh is used for determining the suitability of the first operation displacement Sba in the operation amount determination block HBP.

The rigidity of the simulator SSM (eg, the spring constant of the elastic body inside) is known. Therefore, the simulator hydraulic pressure Psm can be converted into a "state variable related to displacement" based on the rigidity of the simulator SSM. Therefore, the simulator hydraulic pressure Psm is converted into the displacement conversion value Sb based on the conversion characteristic (calculation map) CHps. Here, the displacement characteristic CHps is preset so that the displacement conversion value Sb increases monotonically from “0” in an “upwardly convex” shape as the simulator hydraulic pressure Psm increases from “0”. .. The displacement conversion value Sbh is input to the manipulated variable determination block HBP of the determination calculation block HNT. The rigidity of the simulator SSM is set to correspond to the rigidity of each fluid path (HWC or the like) (that is, the spring constant), the rigidity of the caliper CP, the rigidity of the friction member MS, and the like.

In the operation amount determination block HBP, "whether or not the first operation displacement Sba is appropriate" is determined. In addition, the combined operation amount Bps is calculated based on the first and second operation displacements Sba and Sbb and the displacement conversion value Sbh. Here, the combined operation amount Bps is the operation amount of the braking operation member BP calculated by synthesizing the "state variable Sba (or Sbb) related to displacement" and the "state variable Psm related to force".

When the first operation displacement Sba is appropriate, the operation amount determination block HBP calculates the combined operation amount Bps based on the first operation displacement Sba and the displacement conversion value Sbh. Specifically, the combined operation amount Bps is calculated by the equation (1).
Bps = Ksb x Sba + (1-Ksb) x Sbh ... Equation (1)
Here, the contribution coefficient Ksb is a coefficient of "0" or more and "1" or less, and decreases as the first operation displacement Sba (or simulator hydraulic pressure Psm) increases. Therefore, when the first operation displacement Sba is relatively small, the contribution of the first operation displacement Sba to the combined operation amount Bps is relatively large. As the first operational displacement Sba increases, the contribution of the first operational displacement Sba decreases. Then, when the first operation displacement Sba becomes relatively large, the contribution of the simulator hydraulic pressure Psm to the combined operation amount Bps is relatively large.

On the other hand, when the first operation displacement Sba is unsuitable, the second operation displacement Sbb is adopted instead of the first operation displacement Sba, and the synthesis operation is performed based on the second operation displacement Sbb and the displacement conversion value Sb. The quantity Bps is calculated. Specifically, the combined operation amount Bps is calculated by the equation (2) using the above contribution coefficient Ksb.
Bps = Ksb x Sbb + (1-Ksb) x Sbh ... Equation (2)

In the target hydraulic pressure calculation block PWT, the target hydraulic pressure Pwt is calculated based on the combined operation amount Bps and the calculation characteristic CHpw. The target hydraulic pressure Pwt is the target value of the output hydraulic pressure of the first hydraulic pressure unit EAA. Here, the calculation characteristic CHpw is a preset calculation map for determining the target hydraulic pressure Pwt.

In the calculation characteristic CHpw, when the combined operation amount Bps is "0" or more and less than the predetermined value bp0, the target hydraulic pressure Pwt is determined to be "0", and when the combined operation amount Bps is the predetermined value bp0 or more, the composition is performed. The target hydraulic pressure Pwt is calculated to increase monotonically as the manipulated variable Bps increases. Here, the predetermined value bp0 is a value corresponding to the "play" of the braking operation member BP.

The first controller ECA outputs a drive signal Vsm for opening the simulator shutoff valve VSM when the combined operation amount Bps becomes a predetermined value bp0 or more. At the same time, in the first controller ECA, the master cylinder MC and the second hydraulic unit EAB are not communicated with each other, and the drive signal Vkr (switching valve VKR) in which the first hydraulic pressure unit EAA and the second hydraulic unit EAB are communicated with each other. Signal) is output. The drive signals Vsm and Vkr allow the master cylinder MC to communicate with the simulator SSM, and the first hydraulic unit EAA to communicate with the wheel cylinder WC via the second hydraulic unit EAB.

In the indicated energization amount calculation block IMS, the indicated energization amount of the electric motor MTA that drives the first hydraulic pressure unit EAA based on the target hydraulic pressure Pwt and two preset calculation characteristics (calculation maps) Cup and CHdw. Ims is calculated. The indicated energization amount Ims is a target value of the energization amount for controlling the first electric motor MTA. In the calculation map of the indicated energization amount Ims, the characteristic CHup when the target hydraulic pressure Pwt increases and the characteristic CHdw when the target hydraulic pressure Pwt decreases are 2 in consideration of the influence of hysteresis by the power transmission mechanism DDK or the like. It consists of two characteristics.

Here, the "energized amount" is a state amount (state variable) for controlling the output torque of the first electric motor MTA. Since the electric motor MTA outputs a torque substantially proportional to the current, the current target value of the electric motor MTA can be used as the target value (target energization amount) of the energization amount. Further, if the supply voltage to the electric motor MTA is increased, the current is increased as a result, so that the supply voltage value can be used as the target energization amount. Further, since the supply voltage value can be adjusted by the duty ratio in pulse width modulation, this duty ratio (ratio of energization time in one cycle) can be used as the energization amount.

In the hydraulic feedback control block PFB, the target value (target hydraulic pressure) Pwt of the hydraulic pressure and the actual value (hydraulic pressure detection value) Pws of the hydraulic pressure are used as control state variables, and the electric motor MTA is based on these. The compensation energization amount Ipw is calculated. Here, the final hydraulic pressure Pws is a "final hydraulic pressure actual value (actual hydraulic pressure)" determined by the hydraulic pressure determination block HPW based on the suitability determination of the sensor signal.

Since an error occurs in the hydraulic pressure only by the control based on the indicated energization amount Ims, the hydraulic feedback control block PFB compensates for this error. The hydraulic feedback control block PFB is composed of a comparison calculation and a compensation energization amount calculation block IPW.

By the comparison calculation, the target value Pwt of the hydraulic pressure and the actual value Pws are compared. Here, the actual value Pws of the hydraulic pressure is a detected value acquired by the first hydraulic pressure sensor PWA. In the comparison calculation, the deviation (hydraulic pressure deviation) ePw between the target hydraulic pressure (target value) Pwt and the actual hydraulic pressure (detected value) Pws is calculated. The hydraulic pressure deviation ePw (control variable, “pressure” as a physical quantity) is input to the compensation energization amount calculation block IPW.

The compensation energization amount calculation block IPW includes a proportional element block, a differential element block, and an integral element block. In the proportional element block, the proportional gain Kp is multiplied by the hydraulic pressure deviation ePw to calculate the proportional element of the hydraulic pressure deviation ePw. In the differential element block, the hydraulic pressure deviation ePw is differentiated, multiplied by the differential gain Kd, and the differential element of the hydraulic pressure deviation ePw is calculated. In the integrating element block, the hydraulic pressure deviation ePw is integrated, and the integral gain Ki is multiplied by this to calculate the integrating element of the hydraulic pressure deviation ePw. Then, the proportional element, the differential element, and the integral element are added to calculate the hydraulic pressure compensation energization amount Ipw. That is, in the compensation energization amount calculation block IPW, the actual hydraulic pressure (detection value) Pws matches the target hydraulic pressure (target value) Pwt of the hydraulic pressure based on the comparison result between the target hydraulic pressure Pwt and the actual hydraulic pressure Pws. (That is, the deviation ePw approaches "0 (zero)"), so-called feedback loop of PID control based on hydraulic pressure is formed.

In the target energization amount calculation block IMT, the target energization amount Imt, which is the final target value of the energization amount, is calculated based on the indicated energization amount (target value) Ims and the hydraulic pressure compensation energization amount Ipw. Specifically, the compensated energization amount Ipw is added to the indicated energization amount Ims, and the sum of them is calculated as the target energization amount Imt (that is, Imt = Ims + Ipw).

In the target energization amount calculation block IMT, the sign (positive or negative of the value) of the target energization amount Imt is determined based on the direction in which the first electric motor MTA should rotate (that is, the direction in which the hydraulic pressure increases or decreases). Further, the magnitude of the target energization amount Imt is calculated based on the rotational power to be output (that is, the amount of increase / decrease in hydraulic pressure) of the electric motor MTA. Specifically, when the braking pressure is increased, the sign of the target energization amount Imt is calculated as a positive sign (Imt> 0), and the electric motor MTA is driven in the forward rotation direction. On the other hand, when the braking pressure is reduced, the sign of the target energization amount Imt is determined to be a negative sign (Imt <0), and the electric motor MTA is driven in the reverse direction. Further, the larger the absolute value of the target energization amount Imt, the larger the output torque (rotational power) of the electric motor MTA is controlled, and the smaller the absolute value of the target energization amount Imt, the smaller the output torque is controlled. ..

In the switching control block SWT, based on the target energization amount Imt, in the drive circuit DRV, each switching element SU1, SU2, SV1, SV2, SW1, SW2 (also simply referred to as "SU1 to SW2") constituting the bridge circuit BRG). Signals Su1, Su2, Sv1, Sv2, Sw1, Sw2 (simply also referred to as "Su1 to Sw2") for driving the above are calculated. Here, the drive signals Su1 to Sw2 are for performing pulse width modulation for each switching element SU1 to SW2.

Specifically, in the switching control block SWT, the target value Imt of the energization amount of each phase (U phase, V phase, W phase) based on the target energization amount Imt and the rotation angle Mka (general term for each phase). Is calculated. The duty ratio (ratio of on-time to one cycle) Dut of the pulse width of each phase is determined based on the target energization amount Imt of each phase. Then, based on the duty ratio (target value) Dut, each switching element SU1 to SW2 constituting the bridge circuit BRG is driven to be turned on (energized state) or off state (non-energized state). The signals Su1 to Sw2 are calculated. The drive signals Su1 to Sw2 are output to the drive circuit DRV.

The energized or de-energized state of the six switching elements SU1 to SW2 is individually controlled by the six drive signals Su1 to Sw2. Here, as the duty ratio Dut is larger, the energization time per unit time is lengthened in each switching element, and a larger current is passed through the coil. Therefore, the rotational power of the electric motor MTA is large.

The drive circuit DRV is provided with an energization amount sensor (for example, a current sensor) IMA in each phase, and an actual energization amount Ima (general term for each phase) is detected. The detected value (for example, the actual current value) Ima of each phase is input to the switching control block SWT. Then, so-called current feedback control is executed so that the detected value Ima of each phase matches the target value Imt. Specifically, in each phase, the duty ratio Dut is corrected (finely adjusted) based on the deviation between the actual energization amount Ima and the target energization amount Imt. Highly accurate motor control can be achieved by this current feedback control.

<Processing with hydraulic pressure judgment block HPW>
The processing in the hydraulic pressure determination block HPW will be described with reference to the flow chart of FIG. In the hydraulic pressure determination block HPW, the suitability of the first hydraulic pressure Pwa is determined based on the first and second hydraulic pressures Pwa, Pwb, and the wheel speed Vwa (or vehicle deceleration Gxa), and the braking hydraulic pressure is determined. The final actual value Pws is calculated. Here, the first hydraulic pressure Pwa is the output hydraulic pressure of the first hydraulic pressure unit EAA. The second hydraulic pressure Pwb is the input hydraulic pressure of the second hydraulic pressure unit EAB.

In step S110, the first and second hydraulic pressures Pwa, Pwb, and wheel speed Vwa are read. The first hydraulic pressure Pwa is directly input to and read from the first hydraulic pressure sensor PWA provided in the first hydraulic pressure unit EAA to the first controller ECA via the first hydraulic pressure signal line SPA. The second hydraulic pressure Pwb is input to the second controller ECB from the second hydraulic pressure sensor PWB provided in the second hydraulic pressure unit EAB via the second hydraulic pressure signal line SPB, and is input to the second controller ECB via the communication bus CMB. Then, it is input to the first controller ECA and read. The wheel speed Vwa is detected by the wheel speed sensor VWA provided on the wheel WH, is input to the second controller ECB via a signal line, is input to the first controller ECA via the communication bus CMB, and is read.

Further, in step S110, the vehicle deceleration Gxa is calculated based on the wheel speed Vwa. Here, the vehicle is provided with the front-rear acceleration sensor GXA, and the vehicle deceleration Gxa detected by the front-rear acceleration sensor GXA can be read in step S110.

In step S120, "whether or not the first hydraulic pressure signal line SPA for the first hydraulic pressure sensor PWA is broken" is determined based on the value of the first hydraulic pressure Pwa. Step S120 is referred to as "determination of disconnection of the first hydraulic pressure Pwa". When the first hydraulic pressure signal line SPA is broken, the first hydraulic pressure Pwa is read as "a value that cannot be realized in reality". Therefore, in the disconnection determination of the first hydraulic pressure signal line SPA, the suitability of the first hydraulic pressure Pwa is determined based on the value of the first hydraulic pressure Pwa itself. When the first hydraulic pressure signal line SPA is in a disconnected state and step S120 is affirmed (when “YES”), the process proceeds to step S170. On the other hand, if the first hydraulic signal line SPA is not broken and step S120 is denied (in the case of "NO"), the process proceeds to step S130.

In step S130, it is determined whether or not the first hydraulic pressure Pwa and the second hydraulic pressure Pwb match. Step S130 is referred to as "contrast determination of first hydraulic pressure Pwa". When the first hydraulic pressure Pwa and the second hydraulic pressure Pwb match, it is determined that both the first and second hydraulic pressures (detected values) Pwa and Pwb are appropriate. Therefore, if step S130 is affirmed (if “YES”), the process proceeds to step S160. On the other hand, when the first hydraulic pressure Pwa and the second hydraulic pressure Pwb do not match, one of the first hydraulic pressure Pwa and the second hydraulic pressure Pwb is appropriate and the other is unsuitable. If step S130 is denied (“NO”), the process proceeds to step S140.

In step S140, the hydraulic pressure conversion value Pwh is calculated based on the vehicle deceleration Gxa. Since the vehicle is decelerated as a result of the braking hydraulic pressure Pwc, the braking hydraulic pressure Pwc and the vehicle deceleration Gxa have a predetermined relationship. Therefore, the hydraulic pressure conversion value Pwh is calculated based on the vehicle deceleration Gxa and the calculation characteristic CHgp. Here, the calculation characteristic CHgp is called "conversion characteristic of the hydraulic pressure conversion value Pwh", and is a calculation map preset based on the specifications of the vehicle (vehicle mass, specifications of the braking device, etc.). In the calculation characteristic CHgp, it is determined that the hydraulic pressure conversion value Pwh increases monotonically as the vehicle deceleration Gxa increases. After step S140, the process proceeds to step S150.

In step S150, it is determined whether or not the deviation hPw between the first hydraulic pressure Pwa and the hydraulic pressure conversion value Pwh is less than the predetermined hydraulic pressure hpz. Step S150 is referred to as "determination of conversion of first hydraulic pressure Pwa". Here, the predetermined hydraulic pressure (predetermined value) hpz is a preset threshold value for the conversion determination. If “hPw <hpz” and step S150 is affirmed (if “YES”), the process proceeds to step S160. On the other hand, when “hPw ≧ hpz” and step S150 is denied (when “NO”), the process proceeds to step S170.

In step S160, since it was determined that the first hydraulic pressure Pwa is appropriate, the first hydraulic pressure Pwa is output from the hydraulic pressure determination block HPW to the hydraulic pressure feedback control block PFB as the final hydraulic pressure detection value Pws. To. On the other hand, in step S170, since it was determined that the first hydraulic pressure Pwa is unsuitable, the second hydraulic pressure Pwb is set as the final hydraulic pressure Pws instead of the first hydraulic pressure Pwa, and the hydraulic pressure is determined from the hydraulic pressure determination block HPW. It is output to the feedback control block PFB.

Then, in the hydraulic feedback control block PFB in step S180, the hydraulic feedback control based on the target hydraulic pressure Pwt and the final hydraulic pressure Pws is executed. Specifically, when the first hydraulic pressure Pwa is appropriate, the first hydraulic pressure Pwa is adopted as the final hydraulic pressure Pws, and the target hydraulic pressure Pwt and the final hydraulic pressure Pws (that is, the first hydraulic pressure Pwa). The hydraulic pressure compensation energization amount Ipw is calculated based on the deviation ePw from. On the other hand, when the first hydraulic pressure Pwa is unsuitable, the second hydraulic pressure Pwb is adopted as the final hydraulic pressure Pws, and the deviation between the target hydraulic pressure Pwt and the final hydraulic pressure Pws (that is, the second hydraulic pressure Pwb). The hydraulic pressure compensation energization amount Ipw is determined based on the ePw. Then, the energization amount of the first electric motor MTA is controlled so that the final hydraulic pressure (actual value) Pws matches the target hydraulic pressure (target value) Pwt.

The second hydraulic unit EAB is provided for vehicle stability control. Therefore, as a redundant system of the first hydraulic unit EAA, a redundant system can be formed by the second hydraulic pressure sensor PWB of the second hydraulic pressure unit EAB without being newly provided. For example, according to the braking control device BCS, when the first hydraulic pressure sensor PWA becomes unsuitable, the operation of the first hydraulic pressure unit EAA is immediately stopped, and the function of the first hydraulic pressure unit EAA is changed to the second liquid. It is not replaced by the pressure unit EAB. In the braking control device BCS, the operation of the first hydraulic pressure unit EAA is continued by the second hydraulic pressure sensor PWB instead of the first hydraulic pressure sensor PWA. Therefore, the reliability of the operation of the braking control device BCS can be ensured with a simple configuration as a whole device.

<Processing by operation amount judgment block HBP>
The processing in the manipulated variable determination block HBP will be described with reference to the flow chart of FIG. In the operation amount determination block HBP, the suitability of the first operation displacement Sba is determined based on the first and second operation displacements Sba and Sbb, and the simulator hydraulic pressure Psm, and the combined operation amount Bps is calculated.

In step S210, the first and second operation displacements Sba, Sbb, and the simulator hydraulic pressure Psm are read. The first operation displacement Sba (corresponding to the first operation amount) is the first from the first operation displacement sensor SBA (corresponding to the first operation amount sensor) provided on the braking operation member BP via the first displacement signal line SLA. 1 Input directly to the controller ECA and read. The second operation displacement Sbb (corresponding to the second operation amount) is transmitted from the second operation displacement sensor SBB (corresponding to the second operation amount sensor) provided on the braking operation member BP via the second displacement signal line SLB. It is input to the second controller ECB, input to the first controller ECA via the communication bus CMB, and read. The simulator hydraulic pressure Psm is detected by the simulator hydraulic pressure sensor PSM provided in the simulator SSM, is input to the first controller ECA via the signal line SMA, and is read. The first and second displacement signal lines SLA and SLB are cables, and signals other than the first and second operation displacements Sba and Sbb are not transmitted.

In step S220, "whether or not the first displacement signal line SLA for the first operation displacement sensor SBA is broken" is determined based on the value of the first operation displacement Sba. Step S220 is referred to as "determination of disconnection of the first operation displacement Sba". When the first displacement signal line SLA is broken, the first operation displacement Sba is read as an "unrealistic value". Therefore, in the disconnection determination of the first displacement signal line SLA, the suitability of the first operation displacement Sba is determined based on the value itself of the first operation displacement Sba. When the first displacement signal line SLA is in a disconnected state and step S220 is affirmed (when “YES”), the process proceeds to step S270. On the other hand, if the first displacement signal line SLA is not broken and step S220 is denied (“NO”), the process proceeds to step S230.

In step S230, it is determined whether or not the first operation displacement Sba and the second operation displacement Sbb match. Step S230 is referred to as "contrast determination of first operation displacement Sba". When the first operation displacement Sba and the second operation displacement Sbb match, it is determined that both the first and second operation displacements (detected values) Sba and Sbb are appropriate. Therefore, if step S230 is affirmed (if “YES”), the process proceeds to step S260. On the other hand, when the first operation displacement Sba and the second operation displacement Sbb do not match, one of the first operation displacement Sba and the second operation displacement Sbb is appropriate and the other is inappropriate. If step S230 is denied (“NO”), the process proceeds to step S240.

In step S240, the displacement conversion value Sbh is calculated based on the simulator hydraulic pressure Psm. The simulator hydraulic pressure Psm is a "state quantity related to force", but since the rigidity of the simulator SSM is known, this can be converted into a "state quantity related to displacement". Therefore, the displacement conversion value Sb is calculated based on the simulator hydraulic pressure Psm and the calculation characteristic CHps. Here, the calculation characteristic CHps is called "conversion characteristic of the displacement conversion value Sbh", and is a calculation map set in advance based on the rigidity of the simulator SSM (for example, the spring constant of the elastic body inside). In the calculation characteristic CHps, the displacement conversion value Sb is monotonically increased by the characteristic of "convex upward" as the simulator hydraulic pressure Psm increases. After step S240, the process proceeds to step S250.

In step S250, it is determined whether or not the deviation hSb between the first operation displacement Sba and the displacement conversion value Sb is less than the predetermined displacement hsz. Step S250 is referred to as "conversion determination of first operation displacement Sba". Here, the predetermined displacement (predetermined value) hsz is a preset threshold value for the conversion determination. If "hSb <hsz" and step S250 is affirmed (if "YES"), the process proceeds to step S260. On the other hand, when “hSb ≧ hsz” and step S250 is denied (when “NO”), the process proceeds to step S270.

In step S260, since it is determined that the first operation displacement Sba is appropriate, the first operation displacement Sba is adopted for the calculation of the combined operation amount Bps (see equation (1)). On the other hand, in step S270, since it was determined that the first operation displacement Sba is unsuitable, the second operation displacement Sbb is adopted in the calculation of the combined operation amount Bps instead of the first operation displacement Sba (Equation (2). )reference).

Then, in the target hydraulic pressure calculation block PWT in step S280, the target hydraulic pressure Pwt is calculated based on the combined operation amount Bps and the calculation characteristic CHpw. That is, when the first operation displacement Sba is appropriate, the target hydraulic pressure Pwt is calculated based on the first operation displacement Sba. On the other hand, if the first operational displacement Sba is unsuitable, the target hydraulic pressure Pwt is determined based on the second operational displacement Sbb.

The second hydraulic unit EAB functions not only for vehicle stability control but also as a substitute when the first hydraulic unit EAA becomes unsuitable. Therefore, two operation displacement sensors SBA and SBB are provided, one (specifically, the first operation displacement sensor SBA) is in the first hydraulic unit EAA, and the other (second operation displacement sensor SBB) is the second liquid. It is connected to the pressure unit EAB via the first and second displacement signal lines SLA and SLB, respectively. In the braking control device BCS, when the first operation displacement sensor SBA becomes unsuitable due to disconnection of the first displacement signal line SLA, the operation of the first hydraulic pressure unit EAA is immediately stopped, and the first hydraulic pressure unit The function of the EAA is not replaced by the second hydraulic unit EAB. In the braking control device BCS, the operation of the first hydraulic unit EAA is continued by the second operation displacement sensor SBB instead of the first operation displacement sensor SBA. Therefore, the reliability of the operation of the braking control device BCS can be ensured with a simple configuration as a whole device.

<Second Embodiment of Vehicle Braking Control Device>
A second embodiment of the vehicle braking control device according to the present invention will be described with reference to the overall configuration diagram of FIG. In the first embodiment, the wheel cylinder WC is selectively pressurized by either the first hydraulic unit EAA or the master cylinder MC (so-called brake-by-wire configuration). In the second embodiment, the first hydraulic pressure unit EAA is provided between the master cylinder MC and the braking operation member BP, and the pressurization of the wheel cylinder WC is always performed via the master cylinder MC. As described above, since the members, arithmetic processing, signals, characteristics, and values with the same symbols are the same, the differences from the first embodiment will be described in terms of displacement.

The first hydraulic pressure unit EAA is provided between the master cylinder MC and the braking operation member BP. As shown in the cross-sectional view of the blowout portion, the master cylinder MC is a tandem type, and the first and second master pistons PSN, PSO, and two master cylinder chambers Rmc partitioned by the inner wall of the master cylinder MC are formed. Cylinder. A compression spring SPR is provided between the first master piston PSN and the second master piston PSO. The master cylinder chamber Rmc is fluidly connected to the second hydraulic unit EAB through the fluid passage HKA. When the first and second master pistons PSN and PSO are moved in the forward direction (leftward in the figure), the volume of the master cylinder chamber Rmc is reduced, and the braking fluid is pumped from the master cylinder MC toward the wheel cylinder WC. Cylinder. As a result, the hydraulic pressure Pwc of the wheel cylinder WC rises. On the contrary, when the master pistons PSN and PSO are moved in the backward direction (to the right in the figure), the volume of the master cylinder chamber Rmc is increased, and the braking fluid is absorbed from the wheel cylinder WC to the master cylinder MC. As a result, the hydraulic pressure Pwc of the wheel cylinder WC is reduced.

The first hydraulic unit EAA is provided with a pressure piston PSH so as to press the first master piston PSN in the master cylinder MC. The pressurizing chamber Rka is formed by the inner wall of the first hydraulic unit EAA and the pressurizing piston PSH. Further, the reservoir chamber Rrs is formed by the inner wall of the first hydraulic unit EAA, the master piston PSN, and the pressure piston PSH. The reservoir chamber Rrs is connected to the reservoir RSV and the internal pressure is set to atmospheric pressure. A pressure adjusting cylinder KCL is fluidly connected to the pressurizing chamber Rka. The pressure-regulated braking fluid is supplied from the pressure-regulating cylinder KCL driven by the first electric motor MTA to the pressurizing chamber Rka.

When the hydraulic pressure in the pressurizing chamber Rka is increased, the pressurizing piston PSH presses the master piston PSN in the forward direction. As a result, the first and second master pistons PSN and PSO are moved in the forward direction, and the hydraulic pressure Pwc of the wheel cylinder WC is increased. On the other hand, when the hydraulic pressure in the pressurizing chamber Rka is reduced, the force of pressing the master piston PSN in the forward direction by the pressurizing piston PSH is reduced. As a result, the first and second master pistons PSN and PSO are moved in the backward direction by the return spring SPR and the like, and the hydraulic pressure Pwc of the wheel cylinder WC is reduced.

Similar to the first embodiment, a simulator SSM may be provided. In this case, the braking control device has a brake-by-wire type configuration, and the operating force of the braking operating member BP is generated by the simulator SSM.

Further, a configuration in which the simulator SSM is omitted can be adopted. In the configuration without the simulator SSM, the operating force of the braking operation member BP is generated via the master cylinder MC. Here, the first hydraulic pressure unit EAA functions as a booster (brake booster). In this case, the conversion characteristic CHps is set based on the rigidity of each fluid path HKA and HKW (that is, the spring constant), the rigidity of the caliper CP, the rigidity of the friction member, and the like.

In the second embodiment as well, as in the first embodiment, at least one of disconnection determination, comparison determination, and comparison determination is executed for Pwa and Sba, and the first hydraulic pressure Pwa and the first hydraulic pressure Pwa and the first embodiment are executed. 1 The suitability of the operation displacement Sba is determined. When it is determined that the first hydraulic pressure Pwa is unsuitable, the first hydraulic pressure Pwa is not adopted for the hydraulic pressure feedback control, and the hydraulic pressure feedback control is executed based on the second hydraulic pressure Pwb. .. When it is determined that the first operation displacement Sba is inappropriate, the first operation displacement Sba is not adopted for control, the combined operation amount Bps is determined based on the second operation displacement Sbb, and the braking fluid is braked. The pressure Pwc is controlled. The second embodiment also has the same effect as that of the first embodiment (simplification of the device configuration and ensuring reliability).

<Other embodiments>
Hereinafter, other embodiments will be described. The same effect as described above can be obtained with the configurations shown in other embodiments. That is, in the braking control device BSC, even if at least one of the first hydraulic pressure sensor PWA and the first operation displacement sensor SBA malfunctions, the operation of the first hydraulic pressure unit EAA is not stopped and continues. To. In the braking control device BCS, the malfunction of the first hydraulic pressure sensor PWA and the first operation displacement sensor SBA is backed up by the second hydraulic pressure sensor PWB and the second operation displacement sensor SBB for the second hydraulic pressure unit EAB. Due to. Thereby, the reliability of the braking control device BCS can be improved with a simple configuration.

In the above description, the configuration of the disc type braking device (disc brake) has been exemplified. In this case, the friction member MS is a brake pad, and the rotating member KT is a brake disc. A drum type braking device (drum brake) may be adopted instead of the disc type braking device. In the case of a drum brake, a brake drum is adopted instead of the caliper CP. The friction member MS is a brake shoe, and the rotating member KT is a brake drum.

The first hydraulic pressure unit EAA is regulated by the first electric motor MTA and the pressure regulating cylinder KCL, but can be regulated by other methods (linear solenoid valve, self-sufficient pump, etc.). Even if other methods are adopted, a power source other than the driver's muscle strength is required.

The displacement conversion value Sbh was adopted for the calculation of the combined operation amount Bps, but this can be omitted. That is, the combined operation amount Bps can be calculated based only on the first operation displacement Sba (or the second operation displacement Sbb). In the formulas (1) and (2), "Ksb = 1" corresponds to this case.

In addition to (or instead of) the first and second operation displacements Sba and Sbb, a state variable (that is, an operation force) related to the "force" of the braking operation member BP can be detected. Two operating force sensors FBA and FBB are provided separately, and the first and second operating force (detection values) Fba and Fbb are detected. As described above, it is desirable that the first manipulated quantity and the second manipulated quantity are the same physical quantity. When the first and second operating force sensors FBA and FBB are adopted, the same physical quantity is "force".

The first operating force Fba (corresponding to the first operating amount) is first from the first operating force sensor SBA (corresponding to the first operating amount sensor) provided on the braking operation member BP via the first force signal line SNA. 1 Input directly to the controller ECA and read. The second operating force Fbb (corresponding to the second operating amount) is transmitted from the second operating force sensor SBB (corresponding to the second operating amount sensor) provided on the braking operation member BP via the second force signal line SNB. It is input to the second controller ECB, is input to the first controller ECA via the communication bus CMB, and is read. Here, the first and second force signal lines SNA and SNB are cables, and signals other than the first and second operating forces Fba and Fbb are not transmitted. The combined operation amount Bps is calculated based on the first operation force Fba (or the second operation force Fbb).

Also in the first operating force Fba, the same suitability determination (disconnection determination, comparison determination, and conversion determination) as in the first operation displacement Sba is executed. When the first operating force Fba is appropriate, the combined operation amount Bps is calculated based on the first operating force Fba. On the other hand, when the first operating force Fba is not good, the combined operation amount Bps is calculated based on the second operating force Fbb instead of the first operating force Fba. As in the case of the first operation displacement Sba, even if the first operation amount sensor FBA is malfunctioning, the operation of the first hydraulic unit EAA is not stopped, and the first liquid is generated by the signal Fbb of the second operation amount sensor FBB. The operation of the pressure unit EAA is continued. Therefore, the reliability of the braking control device BCS can be improved.

It is desirable that the first manipulated quantity and the second manipulated quantity are the same physical quantity, but a sensor related to "displacement" and a sensor related to "force" can be used in combination. For example, the first operating displacement sensor SBA may be connected to the first hydraulic unit EAA and the second operating force sensor FBB may be connected to the second hydraulic unit EAB. The reverse combination is also possible.

Two different operating displacement sensors SBA and SBB can be formed as an integral sensor. Even in this case, at least two or more displacement detection elements (sensor elements) are provided in the integrated sensor. Therefore, the first and second operation displacements Sba and Sbb are detected separately by each detection element. Then, the first and second operation displacements Sba and Sbb are separately transmitted from the integrated sensor to the first and second controllers ECA and ECB by the first and second displacement signal lines SLA and SLB. That is, the integrated displacement sensor has two or more displacement detection elements and two displacement signal lines SLA and SLB.

Similarly, in two separate operating force sensors FBA and FBB, an integrated sensor structure having two or more force detecting elements and two force signal lines SNA and SNB can be adopted.

As the electric motor MTA, a brushed motor (simply also referred to as a brush motor) may be adopted instead of the brushless motor. In this case, as the bridge circuit BRG, an H-bridge circuit formed by four switching elements (power transistors) is used. That is, in the bridge circuit BRG of the brush motor, one of the three phases of the brushless motor is omitted. As in the case of the brushless motor, the electric motor MTA is provided with the rotation angle sensor MKA, and the drive circuit DRV is provided with the energization amount sensor IMA.

BP ... Braking operation member, EAA, EAB ... 1st and 2nd hydraulic units, ECA, ECB ... 1st and 2nd controllers, PWA, PWB ... 1st and 2nd hydraulic sensors, Pwa, Pwb ... 1st, 2nd hydraulic pressure (corresponding to output hydraulic pressure and input hydraulic pressure), SBA, SBB ... 1st and 2nd operation displacement sensors (corresponding to 1st and 2nd operation amount sensors), Sba, Sbb ... 1st and 2nd Operational displacement (corresponding to the first and second operation amounts), CMB ... Communication bus.

Claims (2)

In a vehicle braking control device that generates braking force on wheels by increasing the braking fluid pressure of the wheel cylinder in response to the operation of the vehicle braking operation member.
A first hydraulic pressure unit that increases the braking hydraulic pressure of the wheel cylinder instead of the master cylinder and generates an operating force on the braking operating member via a stroke simulator .
A second hydraulic unit provided between the first hydraulic unit and the wheel cylinder to increase the braking hydraulic pressure of the wheel cylinder so as to execute vehicle stability control .
A first hydraulic pressure sensor that detects the output hydraulic pressure of the first hydraulic pressure unit, and
A second hydraulic pressure sensor that detects the input hydraulic pressure of the second hydraulic pressure unit, and
A communication bus that transmits signals between the first hydraulic unit and the second hydraulic unit,
With
The first hydraulic unit is
Judging "whether or not the output hydraulic pressure is appropriate",
When the CPU 51 determines "the output hydraulic pressure is properly" increases the brake fluid pressure by the output liquid pressure based rather feedback control,
When it is determined that "the output hydraulic pressure is not appropriate", the input hydraulic pressure is acquired via the communication bus and is based on the input hydraulic pressure instead of the feedback control based on the output hydraulic pressure. increasing the brake fluid pressure by the Dzu rather feedback control, the braking control device for a vehicle. In a vehicle braking control device that generates braking force on wheels by increasing the braking fluid pressure of the wheel cylinder in response to the operation of the vehicle braking operation member.
A first operation amount sensor that detects the first operation amount of the braking operation member, and
In addition to the first operation amount, a second operation amount sensor that detects the second operation amount of the braking operation member, and
A first hydraulic unit in which the first operation amount is input, the braking hydraulic pressure of the wheel cylinder is increased instead of the master cylinder, and an operating force is generated in the braking operation member via a stroke simulator .
A second hydraulic pressure unit that receives the second operation amount and is provided between the first hydraulic pressure unit and the wheel cylinder to increase the braking hydraulic pressure of the wheel cylinder so as to execute vehicle stability control. ,
A communication bus that transmits signals between the first hydraulic unit and the second hydraulic unit,
With
The first hydraulic unit is
Judging "whether or not the first operation amount is appropriate",
When it is determined that "the first manipulated variable is appropriate", the braking fluid pressure is increased based on the first manipulated variable.
When it is determined that "the first operation amount is not appropriate", the second operation amount is acquired via the communication bus and is based on the second operation amount instead of the first operation amount. A vehicle braking control device that increases the braking fluid pressure.