The devil is in the detail

According to Mahle Powertrain, it is well-equipped to meet the challenges of the upcoming RDE test standards that is due to be introduced in September 2017. While accommodating the various routes that include urban, rural and motorway driving is difficult enough, the company’s engineers have highlighted another crucial layer of test compliance that presents a significant challenge for test centers, consultancies and vehicle manufacturers alike.

Simon Williams, head of PEMS development at Mahle Powertrain, UK, says, “To certify a vehicle, it needs to pass a minimum of two tests under the RDE rules – which can be undertaken by an approved test facility or by the OEM themselves. However, a final sting in the tail rests within the legislative document for vehicle sign off that states: ‘The manufacturer of this vehicle confirms that this vehicle complies with all RDE conditions’.”

Examining the details of the RDE conditions highlights the fact that a number of new parameters have been set, based on external temperature, altitude, speed, driver aggressivity and gradient.

So while the manufacturer could sign off their new vehicle using the two approved RDE tests, they also now have to ensure that this performance can be achieved across all eventualities, as laid down in the new regulations.

Williams continues, “Meeting RDE requirements can be challenging enough for OEMs under normal conditions, but undertaking these tests to meet the new temperature, altitude, speed, driver aggressivity and gradient measures is causing huge headaches for many in the industry. Under the new regime, OEMs will ultimately need to meet RDE emissions targets from -7°C up to 35°C. Similarly, tests will have to be conducted at altitudes of up to 1,300m – which is higher than Mount Snowdon or Scafell Pike.
“Clearly, replicating such stringent conditions consistently is a challenge that the automotive sector has yet to overcome.”

The Mahle Powertrain team has already developed an approved real-world RDE solution using a PEMS. However, given its analysis of the emerging detail of RDE, the company’s experts believe that upfront simulation of RDE cycles is fundamental to ensuring that RDE emissions can be achieved over all RDE conditions. These simulations can then be validated on the rolling road to ensure the most accurate, reliable and resilient simulation process for the development of vehicles to be fully compliant with RDE requirements.

As well as meeting the new RDE regulations, a dyno-based solution would ensure consistency and also address the understandable concerns about time and cost. Furthermore, getting the data wrong, especially where emissions are concerned, could wreak havoc to an OEM’s reputation and profits, should a vehicle not live up to its published RDE results.

Williams concludes, “Given the huge pressure on OEMs to achieve in-service conformity across all of their new vehicles, getting the RDE data right first time is crucial. This far broader set of test conditions – that include the altitude and temperature elements – is not yet widely understood within the vehicle manufacturing community. However, given the tight timescales involved, we’re suggesting that OEMs make this their number one strategic priority in 2017.”