Speakers Information - Controls, Measurement & Calibration Congress
Frontloading through Virtualization Shruthi Ananthachar Nithin Nath ETAS Automotive India Private Limited
ABSTRACT Engine control complexity has seen a steady rise over the last decade. Electronics is the driving force for innovation in the embedded systems industry today. Automotive embedded systems also follow the same trend and nearly 90% of the new functions use software for innovation.
INTRODUCTION Continuous addition of advanced features in vehicles demands introduction of new technologies & complex electronics (including software & hardware). New and demanding challenges: Reduced time-to-market, increased productivity and Reduced development costs, calls for frontloading of the development process. Frontloading not only enables reduced time to market, but also reduces financial and person-power investments drastically through effective virtualization techniques. This enables efficient tracking and correction of possible faults in the function or process at a very early stage in the development phase. Virtual simulation tools in combination with the classic calibration package improve the quality of the delivery and aid effective usage of resources during the product development cycle. Process planning can be complimented with effective calibration sequences with model based development utilizing proven Design of Experiment (DoE) followed by testing and calibration that is capable of simulating, partially or completely, vehicle/engine functions without the need for expensive test systems or vehicles. Guided or complete automation of the calibration process brings in a level of efficiency previously impossible with the classic calibration approach. The pre-calibrated or optimized solution can then be road-tested for verification and conformance to pre-set pass criteria.
SOFTWARE DEVELOPMENT PROCESS The V-Model or the Verification and validation model is most common development model followed for Automotive Software development. From a white board to function development, hardware and software development and calibration, the tasks progress in a linear way.
Each stage in the development cycle is a closed loop of validation activities with Edit-Integrate-Validate-Correct model. The validation feedback loop is a key to the efficiency of the development process. The maturity index of the product at each stage is defined by this feedback loop.
The idea of virtualization is to fold/left shift the V-model enabling parallel development activities which were not possible before either due to resource constraints/ infrastructure limitations; with a focus on PC based development. Apart from minimization / elimination of traditional development hardware, this can result in tremendous schedule and cost savings, as well as an increase in the quality and maturity of the work product. Left shifting of activities can be applied at each stage of the development cycle, starting even from calibration. Control models developed are usually simulated for analysis and validation of the functionality.
VIRTUAL CALIBRATION & VALIDATION With virtual calibration solutions, tasks can begin as soon as the controller models are developed. The controller models can be tuned early with parameters by using production dataset. This reduces the need for the actual test vehicle. The virtual environment ensures complicated and safety-critical functions that need a target vehicle can now be calibrated and tested in a desk environment. Furthermore, Calibration frontloading to increase maturity of calibrations early in the cycle for instance, with global measurements, a DoE engine model could be created to determine the relevant output variables, where the input
variables for the engine model are initial, non-optimized speed / load maps that are mapped and used to calculate the output variables (consumption, emissions) over the speed / load range.
Together with the values from the last collective one cycle forecast for emissions and fuel consumption over the complete cycle is calculated with high levels of accuracy thus enabling offline verification of calibrations Apart from accurate modeling of transient phenomena and reducing the number of rolls tests, such validating emissions can be used to predict other complex engine behaviors like noise and fuel consumption.
VIRTUAL PROTOTYPING Prototyping solutions enable highly efficient collaboration between OEM and Tier 1 suppliers hence improving the model quality before turning into embedded software. Simulation within the modelling tool is typically insufficient to validate new behavior as they don’t allow easy incorporation of timing behavior of ECU or other functional components from within the ECU. Integrating all necessary aspects together to allow detailed experimentation and validation of new functions: − New control behavior − Existing Tier 1 functional components (SW) − ECU timing behavior − Plant models − Stimuli data − Generate a virtual prototype which executes on windows and can be connected directly to INCA − Easy migration to on-target bypass or bypass rapid prototyping for in-vehicle validation if needed in the ECU ETAS’ INTECRIO-VP supports the above functionalities and enables easy virtual prototyping on a user PC. Is also allows easy access to INCA for calibration with an INCA-EIP add-on.
VIRTUAL ECU AUTOSAR allows clear demarcation between communication layers. With this it is easier to create a PC based ECU and Runtime Environment. Virtual ECU brings in the following advantage for the Validate early − Test your ECU SW on the developer PC (just as your models) − Virtually integrate your SW components prior to their release − Independent of the availability of HW prototypes or test benches Speed up the functional validation − Faster cycles – no reprogramming/flashing after every change − Easier debugging /reproducing of problems on the PC Utilize the flexibility of a PC (full access to variables) − Fault stimulation, single-step debugging, “unlimited” data logging − Keep the same interfaces as the ECU (e.g. access via XCP) Save even more costs − Less ECU samples (especially of the costly ones in early phases) − Reuse your test assets (from virtual to real ECU)
ETAS ISOLAR-EVE and the RTPC-EVE provide the PC based ECU and execution environment enabling desktop based validation. With the aid of ISOLAR-EVE, the C code for AUTOSAR application software can be flexibly integrated and validated. This is true for software components of individual applications and for an entire application software suite.
VIRTUAL HiL & SYSTEM ENGINEERING Virtual ECUs enable virtual HiLs. With virtualization solutions, HiL tests can be created in parallel to rather than only once the ECU HW is available by exploiting the virtual ECUs.
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Functional problems could be found much earlier in the ECU development − Optimizing overall development costs by finding problems earlier − Optimizing problem root-causing as virtual ECUs offer deep insight possibilities − Complete re-use of developed test-cases in “real” HiL set-up maximize test coverage for minimized investments − Complete re-use and optimization of HiL investments Functional Mockup Interface (FMI) for model exchange and co-simulation enable complete vehicle. Through this interface, models from a variety of domains can be exchanged across tool environment boundaries and subjected to collaborative,
or co-simulation. To this end, the implementation of a model, its FMI interface, and associated metadata are provided in the form of a Functional Mockup Unit (FMU).
CONCLUSION Frontloading, as we have seen so far is the way forward in a development process to ensure efficient and quality product delivery. Each stage in the development cycle aims at improved controls maturity which is one of the key advantages of virtual platforms against the classic approach. The process planning performed by model based development which includes state of the art tools and techniques even for calibration in the virtual environment followed by guided or fully-automated execution strengthens the robustness levels of mid-term deliverables. Virtualization can seamlessly blend into the classical approach and work in tandem or compliment physical target based activities.
REFERENCES 1. Dr. Natalia Esau, Christoph Malz, and Corina Mitrohin, ETAS ‘EVE Now Available’ 2. Michel Dietrich, Michael Ebert, Guillaume Francois, and Dr. Ulrich Lauff, ETAS ‘Seamless Virtualization and Visualization‘
CONTACT Shruthi Ananthachar Technical Sales Engineer ETAS Automotive India Private Limited Shruthi.Ananthachar@etas.com
DEFINITIONS, ACRONYMS, ABBREVIATIONS OEM – Original Equipment Manufacturer INCA – Integrated Calibration and Acquisition ECU – Electronic Control Unit HiL – Hardware in Loop RTPC – Real Time PC XCP – Universal Measurement and Calibration Protocol