EPB功能安全笔记(5)：EPB系统软件接口定义

Task and Interface Content

SSM → PBC:

Transmitting EPB requests to the PBC.

· None

· ParkApply (apply request in “parking situation”)

· HoldApply (apply request in “stopping situation”)

· RollerbenchApply (apply request for the technical

inspection of the parking brake function)

· Release

· DynamicApply

· PadAdjustment (brake pad wear adjustment)

· EmergencyParkApply (apply request in “emergency situation”)

· HapPreparation (actuation request to achieve an open, for a HAP situation optimized, condition)

SSM → PBC:

Transmitting a detected roller bench situation.

In this situation, the Brake Assy will react to a RollerbenchApply request with a Brake Assy specific roller bench function. Upon discontinuation of the roller bench situation, an active roller bench function is terminated by release of the EPB.

PBC → SSM:

Transmitting the current logical brake state for the individual wheels.

A distinction is made between final states and transition states.

Final states:

· ParkApplied (parking situation, vehicle is held by

EPB)

· Released

· Unknown (final state not defined)

· HoldApplied (stopping situation, vehicle held by EPB)

· CompletelyReleased

Transition states:

· Applying (electromechanical locking of the brake in

progress)

· Releasing (electromechanical opening of the brake on progress)

· HapPrepared (the park brake is in an open, for a HAP situation optimized, condition)

PBC →SSM:

The PBC informs SSM about the necessity of a PadAdjustment. As soon as possible, SSM will based on this information trigger a PadAdjustment request by sending PbcInApplyReleaseRequest = PadAdjustment.

· NotRequested

· Requested

Task and Interface Content

EPB HW Driver Control → PBC:

Transmitting the currently measured motor current of the parking brake actuator upon activation of the parking brake actuators.

EPB HW Driver Control → PBC:

Transmitting the currently measured voltage of the parking brake actuators at the motor terminals of the ECU.

EPB HW Driver Control → PBC:

Transmitting the current logical brake state for the individual wheels. A distinction is made between final states and transition states.

EPB HW Driver Control → PBC:

Transmitting the supply voltage currently

measured

EPB HW Driver Control→ PBC:

Transmitting the current availability of the

electric supply lines2 of the HOST for the

respective side. This signal gives feedback

about which basic functionality of the EPB

hardware driver control is still available.

· None

· Apply

· Release

· ApplyAndRelease

EPB HW Driver Control → PBC:

Transmitting the switching state of the EPB

hardware driver control currently being executed

· None (parking brake actuators in idle mode, passive

output stage)

· Apply

· Release

· Stop (parking brake actuators in braking mode,

active output stage in short circuit of the parking brake

actuators without provision of all electric parking brake

actuator signals)

· FreeRun (parking brake actuators in free run

mode, active output stage with provision of all electric

parking brake actuator signals)

EPB HW Driver Control → PBC:

Transmitting the current power supply state to the PBC.

· Normal

· Limited (definition of “limited” and the system

reaction are to be specified by the OEM to the ESC

Assy OES and Brake Assy OES)

Task and Interface Content

PBC → ESC Control & Actuator:

Transmitting the request for hydraulic support from the parking brake actuators

- None

- Normal Pressure Gradient

- Maximum Pressure Gradient

PBC → ESC Control & Actuator:

Transmitting the current pressure request in

the EPB brakes as absolute pressure for the hydraulic support to achieve safe vehicle holding.

ESC Control & Actuator → PBC:

Confirming that the pressure requested by the PBC via the signal PbcOutHpsPressure is achieved by the ESC Assy.

Task and Interface Content

Environmental Data → PBC:

Measured longitudinal acceleration of the chassis.

Environmental Data → PBC:

Detected pulses of the wheel rotary speed sensor.

Environmental Data → PBC:

Measured ambient temperature of the vehicle.

Environmental Data → PBC:

Measured signal of the pressure sensor at the master cylinder.

Environmental Data → PBC:

Estimated (modeled) wheel pressure of the respective wheel brake.

Environmental Data → PBC:

Additional information on the accuracy of the estimated (modeled) wheel pressure of the respective wheel brake.

· Reliable

· NotReliable

Environmental Data → PBC:

Information that vehicle engine is in cranking phase.

· NoEngineCranking

· EngineCranking

· EngineCrankingUnavailable

· EngineCrankingInvalid

Environmental Data → PBC:

Current mileage of the vehicle.

Task and Interface Content

Diagnosis→ PBC:

This signal provides information about which mode the PBC shall adopt.

· Normal Mode“

· „Diagnosis Mode“ (HOST informs

PBC, about System is in Diagnose Mode.)

Possible additional modes may include transport mode, factory mode, etc.

Diagnosis→ PBC:

Diagnostic request for Brake Assy specific diagnostic functions:

· OpenBrakeRearLeft,

OpenBrakeRearRight,

OpenBrakeBoth,

· CloseBrakeRearLeft,

CloseBrakeRearRight,

CloseBrakeBoth,

· TouchBrakeRearLeft,

TouchBrakeRearRight,

TouchBrakeBoth,

· StepCloseRearLeft

StepCloseRearRight

StepCloseBoth

· AssemblyCheck,

· EnterMaintenanceMode,

· ExitMaintenanceMode

· DataResetA (Reset of PBC EEPROMData.

Definition to be defined within application

project)

· DataResetB (Reset of PBC EEPROMData. Definition to be defined within application project)

· FactoryReset (Reset of all PBC EERPOM

Data: Area 1 till 3)

Diagnosis→ PBC:

Provision of current HOST software

version.

PBC →Diagnosis:

Status feedback about the diagnosis

request from Brake Assy specific diagnostic functions:

· Idle

· Started

· Running

· Done

· Error

​PBC →Diagnosis:

Feedback about the diagnosis request from Brake Assy specific diagnostic functions:

· OpenBrakeRearLeft,

OpenBrakeRearRight,

OpenBrakeBoth,

· CloseBrakeRearLeft,

CloseBrakeRearRight,

CloseBrakeBoth,

· TouchBrakeRearLeft,

TouchBrakeRearRight,

TouchBrakeBoth,

· StepCloseRearLeft

StepCloseRearRight

StepCloseBoth

· AssemblyCheck,

· EnterMaintenanceMode,

· ExitMaintenanceMode

· DataResetA (Reset of PBC EEPROM

Data. Definition to be defined within application

project)

· DataResetB (Reset of PBC EEPROM

Data. Definition to be defined within application

project)

FactoryReset (Reset of all PBC EERPOM

Data: Area 1 till 3)

PBC →Diagnosis:

Provision of Brake Assy specific diagnosis relevant information: brake temperature left

PBC →Diagnosis:

Provision of Brake Assy specific diagnosis relevant information: brake temperature right

PBC →Diagnosis:

Provision of Brake Assy specific diagnosis relevant information: actuation counter left

PBC →Diagnosis:

Provision of Brake Assy specific diagnosis relevant information: actuation counter right

PBC →Diagnosis:

Provision of Brake Assy specific diagnosis relevant information: clamping force left

PBC →Diagnosis:

Provision of Brake Assy specific diagnosis relevant information: clamping force right

Task and Interface Content

Persistent Data Storage→ PBC:

Validity information from the HOST to the Brake Assy. Selective for each of the three specified ranges of stored data from the nonvolatile rewritable memory.

Persistent Data Storage→ PBC:

Information from the HOST to the PBC on whether the HOST system has not been properly shut down (e.g.unexpected power failure)

Persistent Data Storage→PBC:

Coding items 1 to 64 (coding commands from the HOST to the PBC).

The HOST does not have to have any

knowledge of the content of the data.

PBC →Persistent Data Storage:

Provision of Brake Assy specific data for

storage in the non-volatile rewritable memory.

Task and Interface Content

Task and Interface Content

Fault Management → PBC:

Request for the relevant monitor to execute the recovery request.

Task and Interface Content

Task and Interface Content