Sustainable Mobility: Simulation's Critical Role
Ora Research Letter on Digital Prototyping, Simulation & Analysis November 3, 2009
By Bruce Jenkins, CEO
Sustainable mobility has become the rallying cry of the global automotive industry. Ultimately, the industry's challenge is to craft and implement sustainable mobility principles that connect transportation and accessibility issues to holistic strategies for sustainable economic development. These include the improvement and long-term well-being of the environment, the development of local and regional economies, and an engagement with a panoply of social justice issues. Sustainable mobility goals integrate efficient and accessible private, public, and pedestrian mobility systems, vehicles, and technology into a systems-based vision of a cleaner and more equitable society.
For now, though, auto makers' urgent focus is on achieving compliance with aggressively timed regulatory mandates as well as consumer preferences for greener vehicles – key elements include more fuel-efficient, lower-emission powertrains; alternate-fuel engines; lighter-weight and more aerodynamically efficient vehicles; fabrication from recyclable materials, and more. In working toward these goals, auto makers are finding that digital simulation and analysis is the gateway to green.
Sustainable mobility: It starts with fuel efficiency and emissions reduction Hybrid and electric powertrains are key elements of the solution. Michael Abelson, Executive Director of Global Advanced Vehicle Development at General Motors, described to attendees at the Automotive News Green Car Conference in November 2008 how GM plans to meet the business imperatives to improve fuel economy and reduce emissions, while moving to reduce and ultimately displace dependence on petroleum-based energy sources – “energy security” is the policy objective. The pathway he sketched begins with improvements to conventional internal-combustion engines and transmissions, moves through development of hybrid and plug-in electric vehicles, to extended-range electric cars, and ultimately to vehicles powered by hydrogen fuel cells.
Likewise at other car makers. This is how Josephine Cooper, Group Vice President for Public Policy & Government/Industry Affairs, Toyota Motor North America, put it for attendees at the Center for Automotive Research’s Management Briefing Seminars in August 2009:
“At Toyota, our top public policy priority is sustainable mobility. This means making vehicles that meet customer needs and expectations, while also being safe, sustainable, and better for the environment. We take a system approach to sustainable mobility, with four basic components. The first part involves our vehicles and the vast array of emerging automotive technologies. We must reduce CO2 and smog-forming emissions through pursuit of diverse and alternate technologies. The second component is the energy required to power these products. What sources and forms of energy will be sustainably available in the future? Which of these can be scaled up to accommodate hundreds of thousands, or possibly millions, of vehicles? Can we contribute to energy security? The third component is partnerships… The issues we all face – auto manufacturers, cities, states and countries – are so great that solutions require partnerships across many different sectors… Finally, our approach considers tomorrow’s urban environment. For example, we know urbanization is increasing globally. This year, the United Nations reported that half the planet’s citizens now live in cities, for the first time in history. We need to address this trend with new kinds of vehicles. At the same time, we must localize production and ensure our business decisions result in sustainable communities in which our products contribute to improving people’s lives.” – Josephine Cooper, Group Vice President for Public Policy & Government/Industry Affairs, Toyota Motor North America
Systems complexity: Mechatronics However, all this brings a set of significant new development challenges:
“The name of the game in hybrid systems is integration. You can’t make an engine and a transmission separately any more and then integrate them at the last minute. This has to be conceptualized as a family – as a system. If the system isn’t conceptualized well, your end product’s not going to work very well.” – Kent Helfrich, Director of Software Engineering, General Motors Powertrain
Hybrid powertrain and electric powertrain control systems, as well as the many other mechatronic systems being introduced or extended in new auto models to improve driver experience as well as vehicle performance and efficiency – drive-by-wire, automatic stability control, intelligent braking, active all-wheel drive – require new levels of coordination between design of hardware, electrical and electronic subsystems, and software control systems. Critical to answering these challenges is to move from slow, disjointed, sequentially bound physical prototype-based development processes to those grounded in digital simulation and functional modeling. Describing development of the hybrid powertrain control system launched in 2008 on the GMC Yukon and Chevrolet Tahoe SUVs, GM’s Helfrich says:
“I don’t think you could do a hybrid control system without model-based design and development…That really allowed engineers to do what they needed to do to ensure that the system actually worked, prior to even having hardware available.” – Helfrich, GM Powertrain
The benefits? Lowering development costs and cutting weeks from control-systems development schedules, as well as reducing cycle time on design changes without sacrificing quality:
“We can now do those iterations virtually, and then commit ourselves to hardware later in the design center. It saved us a lot of money in terms of eliminated [physical] prototypes and rework.” – Helfrich, GM Powertrain
Vehicle-level optimization and integration are the key pathways to improved fuel economy, GM’s Ableson notes. The challenges include improving vehicle aerodynamics, reducing weight and achieving mass efficiency in every component and system, minimizing tire rolling resistance while meeting vehicle dynamics requirements, designing high-efficiency and low-loss electrical systems optimized for battery charging, and optimizing the control systems governing all these.
“Segment-leading fuel economy requires comprehensive reduction of energy losses with vehicle-level optimization during the early stages of design and throughout vehicle development.” – Ableson, GM Global Advanced Vehicle Development
The crucial role of simulation and analysis in making total-vehicle optimization possible is evident.
Auto industry business crisis Of course the 2008-2009 recession, and the consequent collapse in vehicle sales worldwide, has put most every auto maker under pressure to slash costs across the board, while doing everything possible to make its products stand out in the market.
Cost A single physical prototype can cost $250,000 to $500,000 to produce, depending on complexity, and 100 prototypes or even more may be required over the 30-month development cycle for a new car model. The goal of lowering development costs by reducing prototype counts is a leading driver of simulation and analysis investments:
“The pressure is on to reduce and eliminate costly prototypes – they can cost anywhere from a quarter-million dollars to half a million, depending on whether you have a ‘top hat’ [new sheet metal on an existing platform] or a full brand-new platform. Because prototypes used in crash and safety applications are destroyed, demands for physical prototype reduction have been most severe on the crash and safety groups. [In all these cases], building fewer and fewer in hopes of someday having zero prototypes has always been the vision. [To make this possible], I and others in the analysis disciplines are always working to improve the methods.” – CAE service provider
“…[there are two major constraints on product development]…first is quality but a close second is cost…simulation is a tool to reduce the number of physical prototypes and to reduce part count for the final product…” – Japanese automotive OEM
Quality Equally critical is product quality. Here, the value of simulation and analysis lies in its power to help detect and correct failure modes before product ships. According to the Automotive Industry Action Group, a typical recall takes 250 days to complete, at an average cost to the auto maker of $1 million per day. Given the industry’s history of recalls, physical test-based processes are clearly failing to find the failure modes – something more is needed.
Schedule Prototype fabrication and testing is a major factor that lengthens development schedules:
“…if we reduce the number of physical prototypes or overall development time, that’s sufficient to justify the use of simulation…if you can save some prototypes, you can save a lot of money and time…” – German automotive OEM
This research is excerpted from our new white paper Strengthening Simulation's Business Impact: New Strategies in the Automotive Industry. In this project we interviewed discipline leads and methods experts at major automotive OEMs, suppliers and CAE service providers around the world. Our investigation focused on business drivers for sustaining or increasing simulation investments, current state of industry practice, constraints on maximizing simulation’s value, and new strategies for overcoming these constraints. Request your copy of the white paper | 
