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Global MRV is testing prototypes of its Firefly PEMS in various passenger and commercial vehicles. The on-board device continuously monitors tailpipe emissions and can be adapted for diesel, gasoline, and CNG engines.

New compact PEMS aims to plug the emissions-compliance gap

A patented emissions assessment system for on-the-road testing is coming to market just as governments expand their vehicle test procedures in the wake of the Volkswagen cheating scandal.

The compact size of Global MRV’s Firefly portable emissions measurement system (PEMS) will enable fleet operators to obtain previously untapped information while a vehicle is on the road.

“Fleet operators can use the Firefly to measure, report, and verify in real-time that the fleet’s light- and heavy-duty vehicles are meeting emissions requirements and performance targets,” said Jeremy Burne, Business Development Director of Global MRV Inc., in an Automotive Engineering interview.

Due to enter the market as early as mid-2016, the Firefly is substantially smaller and lighter than a conventional PEMS. Burne claims it is the world’s first "embedded micro PEMS" for real-time emissions and engine performance monitoring. He noted that the Firefly’s U.S. patent addresses the algorithms used to calculate the emissions.

Firefly’s package measures 11 x 11 x 3-in (280 x 280 x 6 mm). The 7-lb (3.2 kg) unit provides continuous analysis of diesel or gasoline emission constituents—specifically CO, CO2, NOx, HC, and O2—while simultaneously collecting and combining the mass-flow emissions information with engine and global positioning satellite data.

Firefly’s collection and processing unit is mounted onboard the vehicle (typically inside the cabin or inside the trunk) with a sensor attached to the tailpipe and another sensor attached to the vehicle’s OBD-II system. Proprietary software analyzes the collected data, which is streamed to the cloud and downloaded by the user.

“The data output can be tailored to the fleet operator’s needs. For example, a fleet operator can look at the CO2 emissions to ascertain the fleet’s carbon footprint,” said Burne.

Prototype units are being tested on several passenger cars, and a heavy-duty Freightliner truck was involved in a five-month testing event, according to Earl Leatherland, Global MRV’s Operations Manager.

“The Firefly makes it possible for a fleet operator to determine how rpm, throttle, and driver behavior correlates with the release of CO2, NOx, and other emissions over a specific driving route,” Leatherland explained.

PEMS devices could become part of the standard "toolkit" in government-mandated testing for emissions certification, pending decisions on future dynamometer and on-road test procedures in the aftermath of the VW scandal, which began unfolding Sept. 3, 2015.

Said Burne, “The topicality of what’s happened recently has shed light on the questions of how emissions are measured, what the discrepancies are, and how the different data sets can be potentially manipulated.”

Nick Molden, Founder and Chief Executive Officer of U.K.-based Emissions Analytics, said the independent commercial test and analysis firm’s use of Sensors, Inc.-supplied PEMS on passenger vehicles tested reveal a compliance gap.

“Over the past four years, we’ve tested more than 200 diesel vehicles in Europe and only five met the official European regulated limits in real world driving,” Molden noted.

Euro 6c emissions mandates for 2017 will add real world PEMS testing as an additional validation mechanism, according to Molden. “The 80 mg-per-km limit for diesels is unchanged, but the addition of PEMS [testing] makes it much tougher,” Molden asserted.

In the U.S., Emissions Analytics has focused its passenger vehicle PEMS testing on fuel economy and CO2 emissions. “Because it is mostly gasoline engines in the U.S. passenger car market, we naively thought that the NOx from diesel engines wasn’t a big issue,” said Molden, “We’re now adding NOx emission testing in the U.S. as part of our ongoing program.”

The EPA announced on September 25 that it was expanding its testing of pre-production, production, and customer-owned vehicles to screen for defeat devices and other causes of high emissions. According to EPA spokesperson Laura Allen, the agency is applying a variety of approaches but is not releasing details about how it is conducting the testing.

The EPA issued a Notice of Violation (NOV) to VW AG, Audi AG, Porsche AG, Volkswagen Group of America Inc., and Porsche Cars North America for certain 2014, 2015, and 2016 vehicles with 3.0-L diesel engines, alleging that the vehicles included defeat devices.

During a meeting on November 19, VW and Audi officials told the EPA that the issues addressed in the Nov. 2 NOV extend to all 3.0-L diesel engines from model years 2009 to 2016. The EPA and the California Air Resources Board are continuing to investigate.

In light of the increased attention on vehicle emissions during real-world driving, the Firefly’s market launch could get fast-tracked from its current late-2016 launch timing.

“If Firefly is of interest to regulators and OEMs, it’s possible the product could reach the market as soon as mid-2016,” Burne said, noting that engineering work is now focused on developing a graphical user interface.

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