Modeling Car Periphery Supervision (CPS) System Robert Bosch GmbH case study for AMETIST project...

Modeling Car Periphery Supervision (CPS) System

Robert Bosch GmbH case study for AMETIST project

Tomas Krilavičius¹ & Biniam Gebremichael²

¹ - University of Twente, ² - University of Nijmegen

2 Tomas Krilavičius & Biniam Gebremichael Modeling Car Periphery Supervision System

Outline

SourcesCar Periphery Supervision (CPS)

Informal descriptionGeneral model

Model of Car Periphery Supervision systemCPS model

Timed modelSensorMeasurement Control

Plans for a hybrid modelResultsFurther plans & questions


Sources

Pre-crash Sensing – Functional Evolution based on Short Range Radar Sensor Platform Rainer MORITZ, Robert Bosch GmbH

A Case Study in Applying a Product Line Approach for Car Periphery Supervision Systems

Steffen THIEL, Stefan FERBER, Thomas Fischer, Andreas HEIN, Michael SCHLICK, Robert Bosch GmbH

OSEK/VDX, Time-Triggered Operating System OSEK group

Real-Time Service Allocation for Car Periphery Supervision

Stefan KOWALEWSKI, M. RITTEL, Robert Bosch GmbH


CPS obtains and makes available for other systems information about environment of a car. This information may be used for:

Parking assistancePre-crash detectionBlind spot supervisionLane change assistanceStop & goEtc

Based on Short Range Radar (SRR) technology

The CPS considered in this case study

Reduced to one sensor group (1..6 sensors)Only the front sensors and corresponding controllersApplication: pre-crash detection, parking assistance, stop & go

CPS: Informal description


HybridEnvironmentSensorsMeasurement control (ECU)

StochasticECU – tasks running on OSEK

CarAirbag controlBelt TensionerHMIEtc

SensorSensor

Sensor

CAR

ECU

Tasks

running

on

OSEK

HYBRID STOCHASTIC

TIMED

W

O

R

L

D

CPS: General model


CPS Model

SensorSensor

Sensor

ECU

Tasks

running

on

OSEK

HYBRID TIMED

W

O

R

L

D

Measu

rement

Control

Step-wise modelingFirst step - timed

SensorsMeasurement Control

Second step - hybridWorldSensorsMeasurement Control

On every step – input from a stochastic model


CPS: Timed model

UPPAAL (based on timed automaton) model

Sensors – send and receive radar signals and make basic data processingMeasurement control - sends the commands DScan (reqDScan) and CVMeasurement (CVScan) to all sensors and receives responses

ProblemsBehavior with given parametersSafe limits for the different parametersBehavior of the different configurations (different number of sensors)


CPS: Sensor

Sensor – sends and receives radar signals and makes basic data processing

Failure mode – a sensor is broken, but it can be repaired, if it gets command Repair

ModesCVMode – delivers the radial velocity of the object passing the gateDMode – delivers a one-dimensional list of objects (radial velocity, radial distance, etc)


CPS: Measurement Control

Measurement control – sends the commands DScan (reqDScan) and CVMeasurement (CVScan) to all sensors and receives responses

Failure mode – a sensor is broken, but it can be repaired by sending Repair command

ModesCVMode – delivers the radial velocity of the object passing the gateDMode – delivers a one-dimensional list of objects (radial velocity, radial distance, etc)


CPS: Plans for a hybrid model

Hybrid automaton based modelProblems

Minimal and maximal speeds handled with given parametersHandling of several dangerous objects

X

Y

v


Results

A timed model (draft version) in UPPAAL

Some results from analysis of systems:If a speed of an approaching object is <13km/h (3,6m/s), CPS looses it, because timeout occurs in CVMode processingIf a speed of an approaching object is >270km/h (75m/s), a deadline of 30ms (section 2.3.3.4 Situation Analysis) combined with 15ms and 7m (section 2.3.3.1 Measurement Control) can not be satisfied


Further plans

Iterative extension of modelDevelopment and analysis of the timed modelExchange of the results between the stochastic and the timed modelsDevelopment and analysis of the hybrid modelExchange of the results between the modelsStochastic-hybrid model (?)


Questions

More communication with Robert Bosch GmbHProperties of sensors – maximal and minimal velocities, distancesBehavior of the system, when several objects are in the “dangerous area”Timeouts for Sensor in DSMode(2) modeTimeouts for Measurement Control (TCVM, TDScan)

Are these questions are interesting? Comments?

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Modeling Car Periphery Supervision (CPS) System Robert Bosch GmbH case study for AMETIST project...

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