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There is a new testing procedure (WLTP, Worldwide harmonized Light vehicles Test Procedures). Major carmakers just want to delay it: http://www.transportenviro

There is a new testing procedure (WLTP, Worldwide harmonized Light vehicles Test Procedures). Major carmakers just want to delay it: http://www.transportenvironment.org/news/carmakers-pushing-3-year-delay-tougher-co2-tests http://www.transportenvironment.org/news/carmakers-pushing-3... The emission cycle used now (New European Driving Cycle, or NEDC) is actually a joke, nobody drives like that: https://en.wikipedia.org/wiki/New_European_Driving_Cycle#/media/File:New_European_Driving_Cycle.svg https://en.wikipedia.org/wiki/New_European_Driving_Cycle#/me... comparing to the new one (WLTP): https://en.wikipedia.org/wiki/Worldwide_harmonized_Light_vehicles_Test_Procedures#/media/File:WLTC_class_3.svg https://en.wikipedia.org/wiki/Worldwide_harmonized_Light_veh... With the new testing procedure in place, you can still cheat like Volkswagen. But it will benefit the customers more, when the OEMs try to game the system by optimizing solely for the cycle.

sitkack 11y ago
What they need to do is more like a clinical trial for a drug. Step 0) measure on a dyno Step 1) measure on small closed course with a handful of drivers who are unknown to the car companies Step 2) measure on a larger group of cars in the real world If these "costs" are unacceptable, then auto manufacturers shouldn't be putting cars on the road. I always thought trusting the ECU to tell the truth was ridiculous, mostly because over end user tampering not the original code. But the effect is the same. It really is bullshit that so much time has been spent overfitting to the test when real universe exists right here. No model required.
- dongping 11y ago
  It makes technically no sense if you can harmonize the regular driving condition into one single realistic cycle. Then the results are reproducible and comparable. OEMs all have their in-house driving cycle to better reflect the reality[1] than the boring standard cycles. The emission/consumption performance for some given customers is easily predictable. To prevent cheating, you'll just have to open source the software inside. [1] Lino Guzzella, Antonio Sciarretta: Vehicle Propulsion Systems: Introduction to Modeling and Optimization (page 22) https://books.google.de/books?id=aVNEAAAAQBAJ&pg=PA22&lpg=PA22&dq=%22driving+cycles%22+%22in+house%22&source=bl&ots=ZzyX2KaxGv&sig=8KAXxVNv6VJCsn3NjUV6px8p558&hl=en&sa=X&ved=0CDAQ6AEwA2oVChMIy5ifgbm4yAIVTJUsCh1P0AqU https://books.google.de/books?id=aVNEAAAAQBAJ&pg=PA22&lpg=PA...
  - sitkack 11y ago
    My assertion is that you can't do that with a single realistic cycle precisely because there is a single one. Overfitting will occur, an ensemble of actors can't be gamed.

sitkack 11y ago

What they need to do is more like a clinical trial for a drug. Step 0) measure on a dyno Step 1) measure on small closed course with a handful of drivers who are unknown to the car companies Step 2) measure on a larger group of cars in the real world If these "costs" are unacceptable, then auto manufacturers shouldn't be putting cars on the road. I always thought trusting the ECU to tell the truth was ridiculous, mostly because over end user tampering not the original code. But the effect is the same. It really is bullshit that so much time has been spent overfitting to the test when real universe exists right here. No model required.

dongping 11y ago
It makes technically no sense if you can harmonize the regular driving condition into one single realistic cycle. Then the results are reproducible and comparable. OEMs all have their in-house driving cycle to better reflect the reality[1] than the boring standard cycles. The emission/consumption performance for some given customers is easily predictable. To prevent cheating, you'll just have to open source the software inside. [1] Lino Guzzella, Antonio Sciarretta: Vehicle Propulsion Systems: Introduction to Modeling and Optimization (page 22) https://books.google.de/books?id=aVNEAAAAQBAJ&pg=PA22&lpg=PA22&dq=%22driving+cycles%22+%22in+house%22&source=bl&ots=ZzyX2KaxGv&sig=8KAXxVNv6VJCsn3NjUV6px8p558&hl=en&sa=X&ved=0CDAQ6AEwA2oVChMIy5ifgbm4yAIVTJUsCh1P0AqU https://books.google.de/books?id=aVNEAAAAQBAJ&pg=PA22&lpg=PA...
- sitkack 11y ago
  My assertion is that you can't do that with a single realistic cycle precisely because there is a single one. Overfitting will occur, an ensemble of actors can't be gamed.