Sometimes, things just don’t work out as planned. Taking coffee with John Fuerst, Delphi’s Vice President Engineering, Powertrain Systems, was one of those moments. Having come prepared to discuss the company’s developments in diesel, gasoline and hybrid vehicle technologies, Fuerst’s approach to portfolio management was so intriguing that the interview finished with barely a mention of 48 volt architectures or cylinder deactivation.
As Delphi’s most senior powertrain engineer, Fuerst’s role is more about vision and planning than it is about the details of each innovation. He is an engineer in business, thinking like an entrepreneur on behalf of Delphi’s investors and customers. To the man in the street it may look like globalisation is creating uniformity, but from Fuerst’s perspective it is opening up a challenging gap that requires increasingly clever thinking to ensure that each regional requirement is met with the most appropriate technologies.
“My challenge is working out how to help our customers be more competitive while meeting all the regulations worldwide,” he explains. “That makes cost a very important element of our strategy, but we must not lose connection with the other factors that increase competitiveness such as fuel economy, durability, low warranty, light weight, serviceability and how the car drives. The balance of priorities is different in each market, and so are the challenges – such as fuel quality and service capability – that set the boundaries for our technology choices.”
Take fuel quality as an example, described by Fuerst as “the only mission-critical component over which we have no control”. Figures from Volvo suggest that while the UK and Northern Europe have consistently less that 10 ppm of Sulphur, some of Southern and Eastern Europe retails fuel with multiples of this level. On the South Eastern perimeter, the level of fuel illegally imported from Africa is so high that a long-distance haulier could unknowingly fill his Euro VI truck with fuel at 500 ppm or more. Some of the additive blends have been described as ‘frankly bizarre’.
“As countries industrialise, they adopt Western standards in their big, wealthy cities, but the rural areas typically advance far more slowly,” says Fuerst. “China is an example where we will increasingly have to meet world-class emissions standards in the cities, but the vehicle may then be driven 50 miles into the countryside and filled-up with fuel that really shouldn’t go anywhere near modern fuel injection and emissions control systems.”
Electronics exceeds hardware investment
Having a robust strategy for solving these challenges is vital to Delphi, which anticipates 95% the world vehicle market will still be fuelled by diesel or gasoline by 2040. “Our strategy can be characterised as finding the simplest approach that delivers the greatest value,” says Fuerst. “The key here is a detailed understanding of what creates value for our customers and how this changes in each of their markets. We then develop flexible, modular hardware that offers a high level of adaptability, greatly enhanced by sophisticated electronic control. It’s this latter area where we see the big advances over the next 10-15 years, allowing us to provide a stable physical platform that can accommodate a huge diversity of requirements.”
Delphi already ships 20 billion lines of software code every day, across all of its product lines (which includes active safety, infotainment and electrical / electronic architectures) and sees this figure rising rapidly. In a candid moment, Fuerst reveals that calibrating powertrain software already consumes more time than developing the hardware, and that the company’s accelerating investment in test systems – traditionally for hardware validation – is now largely focused on refining the control calibrations.
Equally vital is the ability to acquire robust, high-resolution data to feed the software, but there is a risk here of growing complexity. “Sensing technologies like this will be key to improving emissions during highly transient events, which due to planned changes in the test cycle are very much the immediate challenge,” reveals Fuerst. “High resolution data will also simplify the calibration process and reduce the engineering investment required by our customers.”
An example is the company’s new single wire, closed loop diesel injector, which uses current flow between the needle and the valve seat to provide precise needle lift data. This could send its output to a new type of controller that uses physics-based models to provide a much faster response than can be achieved with today’s ‘look up’ type controllers. “The key to further improvements in transient emissions is an ability to open and close the injector valve extremely quickly and accurately. In a diesel application, we are heading for event separations of less than 100 µs, which will allow digital rate shaping. We already have the valve technology in production; we now need to ensure we can deliver the control signal with the required resolution,” explains Fuerst. “The Model Based Controller will anticipate where the control requirement is going, removing latency so the optimum setting can be achieved more quickly.”
In some respects, the synergies between gasoline and diesel have come a full circle. “When Delphi acquired the diesel business, it was greatly enhanced by the electronics capability we had developed at our gasoline business,” says Fuerst. “Now we are using capabilities developed in our diesel hardware to enhance our gasoline systems as they move to higher injection pressures with more, smaller injection events, possibly cooled EGR and advanced valve trains that allow cylinder deactivation and reduce pumping losses by allowing the throttle to stay wider open, more like a diesel. We are already seeing gasoline engines with Miller timing operating at a 14:1 compression ratio, compared with around 10:1 for conventional gasoline engines and 15:1 – 17:1 for diesel.”
Delphi has already worked with one major European vehicle manufacturer on a single control system for both gasoline and diesel. The injector hole shapes and manufacturing processes have aligned, and the understanding of fatigue developed in the diesel business is now proving invaluable as gasoline injection pressures potentially double (to about 400 bar) as the next generation of GDi is introduced.
This trend is particularly apparent in Delphi’s work on Gasoline Direct Compression Ignition (GDCI), which uses compression ignition of gasoline over the full engine speed and load range. Testing has demonstrated low NOx and soot emissions with fuel savings up to 35% compared with conventional gasoline. “This is a conventional multi-cylinder engine with conventional parts. What we’re doing is improving efficiency by using proven technologies in an innovative ways, taking full advantage of sophisticated electronic control. That cuts the cost of innovation as well as the risks and the timescales,” states Fuerst. “For me, that’s an ideal strategy.”