How to test cars for real-world emissions figures

24 Sep, 2015 12:15pm Joe Finnerty

We meet academics at the world’s most advanced car efficiency research lab in Bath – they want to help increase real-world mpg

Car manufacturers face tougher emissions regulations than ever before. By 2021, all new models must achieve 95g/km of CO2, and the existing New European Driving Cycle (NEDC) is set to be replaced to prevent manufacturers using laboratory loopholes in the tests.

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The new test cycle – the World Harmonized Light Vehicles Test Procedure (WLTP) – is scheduled to come into force in 2017, making testing conditions more ‘real-world’ than ever. Unachievable economy has long been a concern for car buyers, and it’s hoped the new measures will change that. The aim is they’ll give consumers more confidence they can hit quoted mpg targets on the road, and be able to use the figures to better influence their buying decisions.

But such stringent measures need research and investment – especially with only a handful of years remaining until targets must be met. While huge strides have already been made in cutting CO2 emissions levels, the lower numbers fall the harder manufacturers have to battle for the ever-diminishing returns. It’s an industry-wide struggle, and car makers are being assisted by some of the brightest minds in the business.

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To find out more, Auto Express was invited behind the scenes at a new £2.6million Centre for Low Emission Vehicle Research (CLEVeR) at Bath University, where the very latest tech is helping cut emissions. CLEVeR is the latest expansion to the university’s highly rated Powertrain and Vehicle Research Centre (PVRC).

Deputy director Professor Chris Brace was on hand to give Auto Express a guided tour of what his team has achieved so far, and what the future holds. The facility is one of the most unique set-ups in the industry, providing researchers with the ability to repeat real-world driving situations while collecting all the necessary data with increasing accuracy.

The centrepiece – and biggest source of investment – is the rolling road (or dynamometer), which has four 48-foot-circumference rollers for the car to sit on and can be adjusted for different wheelbases.

While we were there, a Land Rover Discovery Sport was in action, and a VW Sharan was ready to go next door. Heat exchangers and cooling fans help to create real-world temperatures anywhere between 10 and 50 degrees Celsius. Prof Brace said: “If you take all the features here, it makes it unique in the university sector, in Europe and probably among car manufacturers as well. There are a lot of things we can do here that you can’t do anywhere else.”

It’s a pricey business, though. A set of £30,000 metal wheel adapters is fitted to each car so the variables and unpredictability associated with tyres can be eliminated from results. By closing the loop on the data to exclude tyre inflation and road resistance, you understand much more closely what the engine and emissions are doing.

This constant pursuit of accuracy and precision leads us on to the most impressive and hi-tech element of CLEVeR: the driving robot. If you want to generate real-world results, a precise driver – no matter how well trained – just won’t cut it. So, CLEVeR has shelled out around £200,000 for the self-learning robot.

Dr Ed Chappell, a research associate in the PVRC, is the man responsible for it. Dr Chappell talked us through the system, and explained how the robot will find the bite point on a clutch and run through the gears on its own. It will automatically switch the ignition on and off, and there’s even a paddleshift adapter. It drives like a human, too – and, as more research is done, it’ll get better at imitating people. Plus, unlike a human, it doesn’t need to stop for lunch.

Prof Brace added: “Our robot is pretty good, but part of the research we are doing is improving the driver behaviour model to make it more human. Then we can adapt it to different human styles of driving.” With emissions legislation changing right now, it puts Bath University in a unique position, as its set-up has been designed to accommodate the new WLTP tests.

Prof Brace explained the problems facing other facilities: “How in a laboratory are you going to do the real-world stuff? There are potentially huge varieties of things you have to take into account, and the labs in the industry have been built over 30 years for the NEDC, which is 25 degrees on a gentle cycle focusing on high precision. That’s completely different if you’re trying to replicate real-world driving – most facilities in the world can’t do that.”

The research being done at Bath University isn’t only for academic papers and theoretical analysis, either. The PVRC is already heavily involved with manufacturers through its engine and transmission bays. High-level research took place with Ford to develop the 1.0-litre EcoBoost engine, plus ongoing work on ultraboost with JLR helped towards the latest 2.0-litre Ingenium engines.

There’s also a project on Tata Motors’ next-generation range-extender. Prof Brace said it’s not only industry that benefits from research and investment, but consumers, too: “We’re not going back to the original Mini in terms of weight, and we can’t compromise on comfort, safety or fun, but we still need to be clean and efficient. Manufacturers won’t be able to sell vehicles unless they comply with the coming legislation. “If there are going to be products to buy, we have to do this. The better we can do it, the cleaner the vehicles will be in the real world – so we’ll all benefit from air quality improvements and use less fuel.”

And as Prof Brace admits, this isn’t a research project that academics can pore over for years; the results need to be accurate and available now. “We don’t have forever to do this, and you get maybe only six months on the dyno,” he said. “The better our tools, the more often we’ll get closer to the optimum performance – and that means better economy.”

Plugging the UK’s R&D shortfall

Auto Express got exclusive access to the CLEVeR facilities a few days before it officially opened, but already the new set-up isn’t enough. Along with Bath University’s PVRC, it’s fully booked with projects way into the future. Any other research programmes will have to wait or look elsewhere – but where?

Prof Brace says that’s the crux of the UK’s R&D problem. He said: “We’re booked for the foreseeable future – we’re at capacity already. We think the UK needs more capacity for auto R&D, because it’s so important to future prosperity. There are other universities, but even if you include them, you need more.”

The long-term goal for Prof Brace and his team is to move its whole set-up into one purpose-built centre off-campus – a £50million global auto research facility at the Bristol and Bath Science Park.

With so much change already, he isn’t giving the university too much breathing space before undertaking this mammoth task. He said: “We want to build an institute in two to five years.”

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