At the April 12-14 SAE 2011 World Congress in Detroit, MBtech will show a 1:4-scale Reporter pickup truck concept that it designed and developed with an innovative drivetrain. Engineering highlights of the concept, according to David Sobeus, Project Manager of the Reporter, are “the DualX E-Drive concept drive; another one would be the platform, the body-in-white concept with several different materials and technology within it; and another one is the solar module, which is divided into two parts—the roof module and the mobile solar top.”
The cost-effectiveness of the concept is also emphasized by the company. “A very good example for cost-effectiveness is the DualX E-Drive concept,” said Juergen Kiehne, President, MBtech NA LLC & MBtech ATP LLC. “Instead of heavy, huge, and expensive batteries, we have minimized the batteries for non-emissions mobility within city and suburban range. The combination between a downsized and very efficient combustion engine together with an intelligent e-drive system provides the complete range of mobility or zero-emission driving based on consumer needs at a certain moment.”
The company says that the study is both functional and feasible, the futuristic four-seat pickup showcasing MBtech’s range of engineering and consulting competencies. Because of its modular setup, the Reporter can be further developed, with MBtech envisioning a whole range of possible variants in alignment with a customer’s requirements.
The first viewing of the Reporter was in September 2010 at the 63rd IAA Commercial Vehicles show in Hanover, there shown as a 1:1-scale, see-through model. The company’s designers began work on the concept six months before Hanover from a “clean sheet of paper.” The full-vehicle development and calculation (digital prototype) team was tasked with finding the ideal packaging. The next step consisted of virtual testing. Simulations were performed for flow, multibody, and rigidity optimization.
“A digital prototype and CAD have become essential parts of our work; they help our customers save time and money,” said Hartmut Tresp, President MBtech Group.
MBtech’s body-in-white team faced the major challenge of determining the right technology and material mix. The result is the design of a modular framework that demonstrates a broad spectrum of manufacturing processes, from aluminum die casting, which replaces 37 individual parts on the Reporter’s main chassis beam unit, to aluminum shell construction and extruded aluminum profiles, to carbon-fiber-reinforced plastic for the B-pillar.
The platform’s modularity means that it can accommodate various drive variants, from a gasoline engine to a natural gas drive and a purely electric drive. Operation adjusts to the driving situation, so if more power is needed, for instance, the extender automatically turns on and then turns back off when it is no longer needed. Electric and zero-emissions driving is possible in a city, while still providing unimpeded mobility—and doing so at an optimum cost-benefit ratio.
As a plug-in full-hybrid solution, the DualX E-Drive combines a 70-kW electric motor with a 1.2-L natural gas combustion engine that delivers 75 kW (101 hp) and serves as both a range- and performance-extender. This combination enables a calculated top speed of 81 mph (130 km/h) and a total operating range of more than 186 mi (300 km). Using the electric engine alone, the vehicle has a range of 35 mi (55 km), calculated in accordance with the New European Driving Cycle.
The four-cylinder combustion engine with exhaust gas turbocharger is designed for use with both compressed natural gas (CNG) and gasoline. “CNG costs less than gasoline, the exhaust-gas aftertreatment is simpler, the engine runs more quietly, and, above all, the combustion process is cleaner,” explained Tresp. “The commercial vehicle sector has not even begun to utilize the full potential of natural gas.”
“As the Reporter is a concept study, we could have taken the easy road by developing a concept using an e-drive with a middle range of 150 km and a maximum speed of approximately 110 km/h. However, that was not our goal; we wanted to create a low-emission vehicle drive for urban and regional transport, which is realistically feasible today and not in 2025—while providing an optimal cost-benefit ratio.”
Compared to existing approaches, MBtech says its concept stands out by its optimal combination and integration of the components, along with intelligent energy management. The E-drive unit is at least the equal of the combustion engine, both serving to provide propulsion.
“The completely new feature is that the two engines can act completely autonomously; the e-motor drives the rear axle, and the four-cylinder combustion engine drives the front wheels—either alternating or simultaneously—meaning that an intelligent all-wheel-drive system is available when required,” said Tresp.
The drivers can choose between three different modes. Eco is for emissions-free electric operation in the inner city; 4range is for low fuel consumption and long range using the combustion engine; 4dynamic uses the power of both “engines” for maximum acceleration and driving pleasure.
Collaborative efforts played a role in the concept study with the development of the tires with Hankook and the implementation of a solar top in collaboration with CleanSolPower (CSP).
The “solar top” solution includes cells attached to the cargo area cover. “Naturally we could not utilize conventional solar cells—these are too large and too heavy, not flexible enough; and because they contain glass, they’re not safe enough for automotive applications,” explained Tresp. MBtech turned to CSP for a top using Flex3 panels.
The system is composed of many small spherical solar cells pressed between two plastic layers. The flexible solar system generates up to 266 W—enough to easily power the air-conditioning, interior lighting, or sound system. The system reduces the load on the vehicle’s electrical system and uses surplus solar energy to recharge the 12-V battery. “This reduces the energy consumption, thus the fuel consumption, which in turn increases the vehicle’s range,” explained Tresp. Another advantage is that the solar top can easily be zipped off, stored compactly in a bag, and set up anywhere to recharge batteries when camping or provide a power source for lighting, cool boxes, or laptops.
MBtech created the Reporter to showcase its service portfolio, know-how, and experience in developing full vehicles. The project brought together interdisciplinary teams to benefit customers and increase the confidence of the company’s diverse teams in their own development and consulting capabilities. The concept was developed primarily as an invitation to initiate discussions among teams and customers about future technologies and mobility concepts.