30 renewable energy
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and control capability to control fuel cell operation and research and development arm of Chinese automotive
experiments. manufacturer Dongfeng Motor Company. DFEV
The Labview Datalogging and Supervisory Control undertook a project to develop a battery management
Module meets the needs of fuel cell researchers and testers system within 18 months; it is now installed in
thanks to its built-in high-channel-count data acquisition, Dongfeng’s EQ6110 hybrid electric city bus, which
data logging, interface and security capabilities. Fuel cell delivers 30 per cent better fuel efficiency and lower
test systems may require hundreds of data acquisition emissions than standard city buses (Fig. 4).
sensors and controls for temperature, humidity, Faced with the challenge of developing a battery
atmospheric pressure, oxygen and other parameters. A management system in 18 months, the six-person
typical test may involve increasing a parameter such as DFEV engineering team determined that it needed
temperature to a certain point, holding it steady and to eliminate the debugging and maintenance effort of
graphing the resulting voltage and current across the fuel traditional hand-coding implementations. The team
cell. The Labview Datalogging and Supervisory Control developed models of the controller and battery using
module includes an extensive historical database in which test data, both in Simulink. Engineers then performed
all measurement and test data acquired can be saved simulations and used rapid control prototyping to run the
for later review and correlation with Diadem, National control algorithm against a real battery before generating
Instruments’ software for technical data management that production code using Real-Time Workshop Embedded
enables users to load test data and perform interactive Coder for the target ECU. Tools for model-based design
offline analysis and then generate reports. helped the team model, verify and generate all the
application code for the battery management system
Vehicle performance
within a single environment. Furthermore, the DFEV
Fuel cells are attractive to designers of electric vehicles, engineers are now reusing the controller design for a
but so too are battery storage systems. Model-based hybrid electric car that is currently in development.
design tools were used by Tesla Motors when it developed
the Tesla Roadster, which the company describes as the
Trial data
world’s first electric production sports car (Fig. 3). To When engineers from Daimler (formerly
meet aggressive technology goals on a strict budget and DaimlerChrysler) started a user trial of 100 hydrogen fuel
timeline, the design team relied on Simulink and Matlab cell vehicles in Japan, Singapore, USA, Europe, China and
from The Mathworks to model the entire vehicle and its Australia they needed a way to process the vast amounts of
major subsystems. Engineers combined individual models data that would be collected for the vehicles’ performance
for each major system of the car – including the motor, and usage patterns. This data included information
battery, transmission, brakes, tyres, power electronics relating to the level in the fuel tank, vehicle speed, the
and control systems – into one full-system model for position of the accelerator pedal and location data from
simulating and predicting overall vehicle performance. an onboard GPS device. By converting the millions of
These results were then compared against results obtained drive files into Matlab-based reports and web applications,
from prototype vehicles to refine the full-system model. the engineers were able to understand the vehicle usage
Mathworks model-based design tools have also patterns, track fuel consumption, understand how driving
been used by Dongfeng Electric Vehicle (DFEV), a patterns affect vehicle performance, and start planning a
hydrogen refuelling infrastructure.
Daimler’s engineers use Matlab and the Database
Toolbox to query the central database and retrieve
odometer and GPS data. A specially written Matlab script
filters out anomalous data, such as zero points reported
by the GPS system and non-drive files. The script then
processes all the data, generating a plot that sums distance
travelled by time period and geographic region. Previously
Daimler used Microsoft Excel to perform the analysis,
but this required hundreds of hours to set up, a full-time
employee to maintain, and many manual steps had to be
completed each time. In contrast, the automated Matlab
script lets the team access the results via a Web browser.
Using a tool that was developed with Matlab and
the Mapping Toolbox, Daimler’s engineers can also
reconstruct any test vehicle journey. The engineers can
therefore track the fuel tank state of charge (SOC) on
Fig. 3. Tesla Motors used Simulink and Matlab from The Mathworks a satellite geographic map, making use of a script that
to help it meet aggressive technology goals on a strict budget and produces Keyhole Markup Language (KML) files for use
timeline. with Google Earth – which offers greater flexibility than
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