Stephan Tarnutzer, DGE Inc.
Designing a tool to rapidly and efficiently test telematics control unit (TCU) integration in a vehicle within a lab environment as opposed to physically performing the tests on the road.
Developing a vehicle drive simulator (VDS) using the National Instruments PXI platform and NI LabVIEW software to test the TCU using an on-road experience simulation in a controlled environment.
HUGHES Telematics, an Atlanta-based company, designs, engineers, and manages vehicle- and driver-centric solutions to increase vehicle value, ownership, experience, convenience, efficiency, safety, and security. As a part of HUGHES Telematics’ proprietary engineering, DGE Inc., a full-service engineering and design company in Rochester Hills, Michigan, that serves the automotive and transportation industries, designed a tool to rapidly and efficiently test TCU integration in a vehicle. The VDS expedites the process while the TCU supplier and OEM validate interface functionality in a controlled setting without using a test vehicle.
HUGHES Telematics asked DGE to develop the VDS, which simulates the cellular, satellite, and controller area network (CAN) signals involved in an on-road experience. The test system controls feedback as it relates to the TCU so that a user can load a configuration file that contains the particulars of a specific vehicle as well as scenarios featuring weather, RF signal reflections, geographic locations, and paths that simulate all drive-related data. Faults such as opens and shorts to battery or ground, as well as satellite and cellular anomalies, may be inserted to assess TCU behaviors. The system also runs scripts remotely so that design and test teams in different locations can use the system.
With our application, engineers can create a virtual driving scenario that includes GPS satellites, GSM cellular networks, hardware I/O, and vehicle network communications to develop and test automotive telematics control units. We use a rack PC with a graphical user interface (GUI) based on LabVIEW software to control multiple telematics-related and I/O subsystems. The GUI can control and monitor the following subsystems:
To realistically simulate a moving vehicle, the VDS needed to combine the various elements of the drive scenario and time them properly. Each simulation element contained a large number of options and settings that were critical for accurate moving vehicle reproduction.
Because time is such a valued commodity, we chose LabVIEW to create the GUI for the VDS. This saved time as we created the complex subsystem interfaces to the GPS satellite and GSM cellular network simulators. Validation engineers also needed a way to run extremely complex scripts on the VDS. Instead of inventing a new scripting language, we quickly created a stable remote link that gave engineers complete access to every control contained in the VDS GUI. Engineers can write scripts in their host languages using this solution.
With a combination of NI hardware and software, we quickly generated a complex simulator using a small team of engineers. The LabVIEW library included VIs that simplified the VDS subsystem integration. We would not have met our project timeline without the LabVIEW graphical programming environment to rapidly develop our software. LabVIEW also provides the interfaces to all of our system’s components not produced by NI.
Additionally, NI hardware including the NI PXI-8105 dual core 2.0 GHz controller, NI PXI-6259 M Series data acquisition module, NI PXI-6602 counter/timer module, and NI PXI-6723 analog output module, is the backbone of our system, and we rely on the speed and accuracy of National Instruments products.
We greatly reduced the amount of time required to integrate a TCU into the vehicle environment using the VDS system. The VDS expedites the process as the TCU supplier and OEM validate the interface functionality in a controlled setting without testing in a vehicle on the road. There is no need to wait for the perfect time and location to conduct testing because the VDS can simulate any road, weather, and electromagnetic conditions. Now engineers can run simulations in the lab instead of incurring the transportation expenses for equipment and personnel all over the globe to conduct geographic testing. They can prove TCU functionality in the lab environment without road testing on a fleet of OEM vehicles.
With its flexible and expandable design, the VDS changes the platform for future telematics system development, and test engineers no longer need to rely on empirical data obtained from OEM test vehicles. Additionally, engineers can create controlled and repeatable test scenarios, which would ordinarily be impossible to achieve with test vehicles, using the closed-loop system. As a result, the VDS is unparalleled by any other testing system in the telematics industry.
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