Cleaner diesel sensing a lucrative market

An ambitious EU project created new pollution sensors for the automotive industry that could enable a multibillion euro market in emission control systems by 2010. The sensors will also help Europe to meet its CO2 obligations under the Kyoto Protocol.

The IMITEC project developed an emission control system for light duty diesel vehicles. Diesel powered vehicles are increasingly becoming a major part of the European market and already occupy more than 50 per cent of the car fleet in several European countries such as France.

During its research IMITEC scored a remarkable number of firsts. “I think when we started the project it was considered highly ambitious, but we have met out targets and we now have several technologies that will be commercialised,” says Dr Athanasios G. Konstandopoulos, project coordinator and director of the Aerosol and Particle Technology Laboratory at CERTH/CPERI in Thessaloniki, Greece.

Diesel is the most efficient combustion engine currently available, says Konstandopoulos, but it comes with emissions of particulates, a soot made mainly of carbon, and Nitrogen Oxides (NOx) as by-products. IMITEC’s major innovation was to create the first particulate sensors for next generation diesel exhaust emission control systems.

Emission control invariably consists of a particulate filter, and the particulate sensor developed by IMITEC is vital for the so called ‘closed-loop’ control of this filter. As the filter is clogged by the collected particulate it needs to be cleaned by oxidation of the accumulated soot and this requires the raising of the exhaust temperature as diesel engines are so efficient the regular exhaust temperature is too low to oxidise soot. This process is termed ‘regeneration’.

The IMITEC sensor platform enables the activation of ‘regeneration’ in an adaptive and efficient fashion leading to fuel savings and increased reliability of the emission control system.

Sometimes filters need to regenerate after 500km, or 1000km, but to know exactly when, you need a sensor. “But the only way to know when to begin the regeneration process is to know the history of the filter, the driving profile of the vehicle,” says Konstandopoulos. “It’s a key part of the whole system.”

But IMITEC built more than sensors; they built an entire Emissions Control System for diesel engines, initially for light duty and passenger cars but the technology could be adapted for trucks. Particulate sensing and filter regeneration strategy, however, were the key parts of the project.

IMITEC developed two types of sensors during its research. Hardware sensors measure directly the values of particulates, temperature and pressure in the exhaust. Virtual sensors, on the other hand, are software that measure other sensors in the car and then apply an algorithm to discover a given measurement.

An example is the virtual sensor that computes the amount of soot load in a Diesel Particulate Filter from signals of filter pressure drop, exhaust flow and exhaust temperature. The output of these virtual sensors are used by the Engine Control Unit to adaptively and efficiently manage the emission control system.

All of IMITEC’s achievements go a long way to fulfilling the need for emission controls of the future.

It also attracted the intense interest of the automotive industry. The research centre of Fiat, one of Europe’s leading carmakers joined the project, as did UK-based Johnson Matthey, the world’s number one supplier of automotive catalysts, and Bosch Germany, the world’s leading supplier of exhaust sensors, fuel injection systems, and engine control units. The consortium also included Austria-based AVL, the largest independent automotive engineering company in the world and the CDL-ACT laboratory of the University of Leoben.

“We’ve been approached by many carmakers, and there are a lot of opportunities for spin-offs products, too,” says Konstandopoulos. For example, the team may develop a highly portable unit for use in garages, to aid repairs and system monitoring.

Konstandopoulos believes the diesel emission control market could reach €10bn to €15bn a year by 2010. “Projections indicate that 50 per cent of European cars will be diesel by 2010, or 10m to 15m annually. If we estimate the cost of the entire emission control system at €1,000, which may be a reasonable estimate today, then you have a very important economic impact,” he says.

The team developed a demonstrator of their Emissions Control System, fitted into a Fiat Ducato. “We have a demonstrator, in a real car, that will meet the anticipated Euro V emission standards expected to be finalised by the end of 2005,” says Konstandopoulos. “This is another major result.”

It’s just one more ambition achieved by a very ambitious project.