dspace user conference japan 2004 at daimlerchrysler...

Tools used for the development ofnew automatic climate control concepts

at DaimlerChrysler GermanyAndré Strobel, Research & Technology, REM/AC

dSPACE User Conference Japan 2004

André Manfred Strobel, REM/AC 2

Lecturer's background

André Manfred Strobel

29, married

1994 - 1999 Diploma Degree in Technical Cybernetics,Focus on Aerospace EngineeringUniversity of Stuttgart

1999 - 2002 Doctorand „Modelbased climate control“Research & Technology, DaimlerChrysler AG, Stuttgart

since 2000 Guest lecturer in Automotive EngineeringFocus on MechatronicsFHTE University of Applied Sciences, Esslingen

since 2002 Research EngineerClimate Comfort, Simulation and Concepts (SIL/HIL)Research Electronics & Mechatronics, DaimlerChrysler AG, Stuttgart


Contents

Tools to simplify the development of complexclimate control systems

� Rapid Control Prototyping (RCP)

� dSPACE AutoBox / MicroAutoBox

� dSPACE RapidPro System

� Hardware-in-the-loop (HIL)

� dSPACE HIL-Simulator


Abstract

In general the development of an electronic climate control unit (ECU) is not a straight forwardprocess. A lot of iterations are necessary between the OEM and the supplier of the ECU, becausethe specification of the desired system behavior is not only based on physical data, but also onsubjective perception. The well-known V-process model with the two branches control softwaredesign and ECU testing and calibration has to be executed several times.

In order to reduce the number of iterations that are necessary due to subjective, incomplete ormisinterpreted system specifications it is necessary to rapidly generate a variable prototype fromthe given system specification. Therewith the system specification and the subjective perceptioncan be tested even before the first prototype of the real ECU exists.

The remaining iterations should be executed very fast. This can be achieved by the intensive useof tools for all steps in the V-process model. In the ideal case a single, continuous tool chain is usedthroughout the whole development process. DaimlerChrysler Germany and many suppliers are usingdSPACE tools for climate control applications.

For the creation of a very good system specification dSPACE AutoBox and dSPACE RapidProsystems are used for Rapid Control Prototyping (RCP).

dSPACE Simulators are used for Hardware-in-the-loop (HIL) testing. This allows functional testingas well as virtual testing of customer relevant test cases. Test drives can be rerun. Integration testsare used to test the ECU prototype inside the overall ECU network.


ECU development process

Idea Product

Time


ECU development processfor climate control applications


Implementation

Automatic code generationwith dSPACE TargetLink

Idea Product

Time

OEM

Supplier

Testing and calibration

Virtual test drives withdSPACE HIL-Simulatorand real test drives

Control software design

Control concept validationwith dSPACE Prototyper(AutoBox, RapidPro)


Real ECU development process


Idea

Product

Time

First loopSecond loop

Third loop

Final loop

Error loops

Subjective, incomplete or misinterpretedsystem specifications, general mistakes

Continuous tool chain

• Avoid error loops• Reduce time needed for one loop


Rapid Control Prototyping (RCP)

Idea Product

Time

RCP


Targets


� High product quality in early development stages

Fully functional control system, preoptimization of parameters

� Testing the subjective perception ofa control system specification

Avoid high level error loops, e.g., misinterpreted system specifications

� Automatic generation of a prototypefrom the control system specification

Avoid low level error loops, e.g., programming mistakes

� Parallel development of the climate control systemand the according control unit


RCP system layout


V220 test vehicle

• Standard 4 zone climate control system• Programmable user interface

dSPACE Tandem-AutoBox

• PowerPC 750 (480 MHz)• 32 A/D channels• 6 D/A channels• 40 Digital I/O lines• 4 RS232 channels• 4 CAN controllers• Automatic powerup/shutdown

Bypass KLA

• ECU with bypass on CAN• Selectable bypass functions

– 14 hardware outputs– 37 KLA CAN messages– 7 sensor inputs– 16 user interface keys

• KLA calibration data(314 values)



dSPACE AutoBox / MicroAutoBox

� What we like

� Designed and feasible for automotive applications

� Choose between flexibility and small size

� Same software on all platforms (dSPACE RTI blocksets)

� Powerfull front-end software (dSPACE ControlDesk)

� What we miss

� Direct parameter manipulation in the Simulink modelin connection with the real-time hardware

� Power electronics not included => New: dSPACE RapidPro System



Control software

� Separation of hardware access fromsoftware routines (algorithms, logic)

Transparent structure, exchangeable hardware

� 100% multitasking approach

Flat turnaround time profile, high flexibility

� Global variable structure

Management of more than 1300 variables

� Special features

FlighRecorder, nonvolatile data, menu structurefor display, powerup and shutdown routines

V220_KLA_RPT.mdl

Current number of blocks: 65026Future number of blocks: 150000

Model sample time: 10 msTurnaround time: 5 ms


New: dSPACE RapidPro System

� Targets

� Programmable, variable and reusable power electronics

� Integration into dSPACE tool chain

� Usable without special E/E knowledge

� No soldering (except connectors)

� Application

� Standardized, portable RCP-System

� Test of new sensor and actuator concepts




dSPACE TargetLink

� Implementation is done by a supplier

� Suppliers use dSPACE TargetLinkfor automatic code generation

� First products are on the road(fan control, intelligent solar sensor)

� Next generation of cars will containmuch more automatically generated code

� Future? 32-Bit processors with floating point arithmetics!

Idea Product

TimeImplementation


Hardware-in-the-loop (HIL)

Idea Product

Time

HIL


Targets

� Real-time simulation of the climate control system

HVAC system (heating, ventilation, air conditioning), cabin, environment

� Functional test of a prototypic ECU

Switchpoint tests, customer relevant test cases

� Integration tests for the complete ECU network

Communication tests

� Virtual rerun of test drives

� Reduce the number of test drivesfor finding basic mistakes



Basic principle


+

HIL-SimulationVirtual test drives

MeasurementReal test drives

+


dSPACE HIL-Simulator

� What we like

� Support including complete E/E setup of HIL-Simulator

� Flexibility of hardware layout

� Integration into dSPACE tool chain

� Powerfull front-end software (dSPACE ControlDesk)

� Automated test runs with dSPACE AutomationDesk

� What we miss

� Standard macro language(Python is powerful and for free, but everybody has to learn it first)

� Direct parameter manipulation in the Simulink modelin connection with the real-time hardware



vm_hil_BR211.mdl

Model structure

� Separation of hardware access andsignal conditioning from plant models

Transparent structure, exchangeable hardware,error simulation

� 100% multitasking approach

Flat turnaround time profile, high flexibility

� Intensive use of Simulink bus signals

Busses are more than just a structured vector

� Model exchange with supplier

HIL-Simulators are built-up in cooperation with the supplier


Plant model blocks: 33621Total model blocks: < 100000

Sample time: 1-100 msTurnaround time: < 1 ms


Summary


Conclusions

� We will continue to use dSPACEsystems for RCP and HIL

� The interface between the OEM and the suppliermust be managed carefully

� RCP and HIL will become standard proceduresin the development process

� Multitasking increased the performanceof our systems dramatically

� The availability of accurate real-time plant modelswill be a key success factor in the future

Summary


Thank you very muchfor your attention!

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