Beyond the EV technology horizon: now it’s all about speed
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Aston Martin Lagonda’s Vision concept drives towards the auto industry's electric future. (AML)

Beyond the EV technology horizon: now it’s all about speed

Speed is absolutely essential for electric vehicles (EVs). Not speed in terms of acceleration and maximum velocity, but the time it takes to conceive, develop and produce dedicated new models that not only can meet all range requirements but a host of other criteria: safety, reliability, longevity, performance requirements and affordability.

The need-for-speed warning from James McGeachie, Engineering Director of motorsport and advanced-engineering company Prodrive. The company is playing an increasingly significant development role in the emerging automotive world of electric power and autonomous intelligence.

“We are in an era of unprecedented change and we need to make that change very quickly. There are many ways to shorten the timescale and to achieve much faster development time,” McGeachie said.

Electric and autonomous Road Map
McGeachie spoke at a recent two-day briefing for a small group of international journalists representing a variety of publications that included Automotive Engineering. Held under the aegis of the United Kingdom’s Advanced Propulsion Centre (APC) and based on its “Road Map” for beyond-the-horizon low-carbon technology projections, (https://www.sae.org/news/2018/08/advanced-propulsion-center-future-propulsion-report), other companies involved in the briefing included Aston Martin Lagonda, Williams Advanced Engineering, Drive System Design (DSD), GKN, JLR and Hyperdrive.

Sharp focus on the concept development plan to get EV “unknowns” out of the way is crucial, he believes. “That’s where we will see most change, so shorten it to bring it almost in parallel with prototype development to achieve a validation-ready vehicle. But pick your battles: what to design, what to carry over, what to analyze. Don’t over-engineer, use carry-over (validated) components even for applications different from their originally-designated function. But don’t cut corners on legislation, best practice or standards.”

McGeachie also made the point that designers and engineers need to think outside the automotive manufacturing world for solutions and capacity, citing aerospace as an example: “It’s no good having a beautiful virtual design that cannot be manufactured.”

Prodrive’s EV involvement has included a joint project with Ford to develop a PHEV Transit van, leading to 20 demonstrator vehicles. The project’s “musts” include retaining cargo-area utility, no change to gross vehicle weight (GVW) and no major structural changes. Prodrive’s content involved more than 2000 components, while extensive use was made of Ford’s development facilities.

AML’s electric Vision
At the opposite end of the EV spectrum is the Lagonda Vision Concept, shown at this year’s Geneva Motor Show to indicate what Andy Haslam, Aston Martin Lagonda (AML) Vehicle Line Director, terms “a radically new approach to luxury.”

The Lagonda Vision Concept promises some 400 “real-world” miles (640 km) between charges. The Concept also places emphasis on highly-efficient packaging and delivery of what the company describes as “unique module accessibility.”

It will form a significant portion of Aston’s portfolio expansion between now and 2022, including seven core models, a second manufacturing plant and full EV capability. “We believe electric to be part of Aston Martin Lagonda,” said Haslam. “People will want a hand-crafted car but not one that impacts the environment.” Buyers and car makers also will want confidence that their vehicles will be safe from cyber-attack, he added.

Williams Advanced Engineering sees hybrid-electric vehicles—notably plug-in hybrid-electrics (PHEVs)—playing a major transitional role in the greater electrification of the market. Williams also emphasizes the importance of aerodynamics for increased EV efficiency at higher speeds. Commenting on the financial comparison between EVs and today’s ICE-propelled vehicles, Technical Director Paul McNamara said, “Cost reductions driven by higher adoption rates will make electric vehicles cost-competitive—or better.”

He sees future batteries typically covering the 40-kW/h to 100-kW/h range and pack mass spanning 300 kg (661 lb) to 500 kg (1102 kg) “with 60% as cell mass.”

McNamara also highlighted the learning benefits gained from involvement in Formula E racing that can be extrapolated to benefit production EVs. Particularly significant are high vibration and shock loads’ effect on battery cells, coupled with high temperatures and the necessity of achieving a minimum weight-thermal tradeoff.

Predictive maintenance and post-race intervention also are on his list, together with crash and fire resistance/containment.

Third-generation e-drive
John Morton, Engineering Director of Drive System Design (DSD), said the company now is looking far into the future with third-generation integrated e-drive systems and components. APC’s Road Maps play a significant part in this, allowing DSD to convert data for application in areas where they think the company will have impact.

“Now we have an engineering industry starting to behave rather like a technology industry with very rapid change. We have to be even more dynamic and responsive with a mix of communal and individual vehicles,” Morton said. “But possible design shortages must be considered now.”

The drivetrain of the future needs to be powered, optimized, integrated and intelligent, he said, with the need to major on small, lightweight solutions with controlled NVH: “With the advent of autonomous vehicles, there cannot be any transmission interruptions for passengers. We are going to create a super-optimized system.”

Integration and intelligence are vital, Morton continued, as is cost control. The auto industry has targets for 2021 of battery packs achieving around $100 per kW/h, “But with today’s batteries [comprising] two-thirds the cost of the vehicle, there’s a lot of work to do.”

Autonomous vehicles present problems in themselves, said Morton; the autonomous technology alone burns up around 4 kW/h of onboard electricity.

Morton said DSD has developed a tool chain to take efficiency optimization further at the architecture-concept level to assess all combined power losses in the drivetline. It looks at interactions and creates optimum solutions to achieve significant gains: “We can incorporate some very detailed power loss map software to solve the problems,” he said. “In the real world this could reduce the need for 2 kWh to 5kWh.”

He regards most current powertrains as being over-engineered and believes it will be unnecessary in the future for connected electric and autonomous vehicles to cater for the 99-percentile driver—i.e., the harshest user. But if a connected vehicle records live usage data from all customers, the information obtained could enable transmission systems that are 20% lighter and 20% cheaper. Any resultant warranty costs would be offset by these savings, as connectivity would allow dealers to schedule preventative servicing for vehicles suffering extensive use/abuse. Autonomy could remove another degree of misuse as drive cycles become increasingly consistent and predictable.

But then it’s back to the NVH challenge, Morton said. Controlling excitation from every resource is essential.

Million-mile through-life?
Eventually, true autonomous vehicles may be expected to have a through-life use of a million miles, Morton believes. But how to test a drivetrain with such targeted longevity?

“Maybe we wouldn’t. We would integrate simulation models that can help us accurately predict life and durability usage on every component of the system. The small number of vehicles that detect a mature failure could be fixed with minimum disruption—or an autonomous vehicle may be able to deal with its own reliability.”

Achieving and expanding systems-integration capability is a salient target at GKN Driveline. Said Theo Gassman, Vice President Advanced Engineering: “We work to bring gearbox and motor together; doing our own inverter is the next logical step and our global engineering (technology and innovation centers in the US, UK, China, Germany and Japan) is supporting this.”

Part of this will involve the creation of enhanced test facilities able to deal with complete systems—and like Williams, GKN regards Formula E as a useful technology-development hub. The company also will have a 1000-kW test rig in place in 2019. Gassman underlined the importance of APC’s Roadmap regarding fault tolerance for CAVs, with prediction essential.

Looking beyond 2035, he said radical new motors would be required for both high-performance and low-cost applications, with advanced-manufacturing methods theoretically driving down cost. As for higher-performance machines, these could be “novel designs leveraged from other sectors” aggressively cooled and contain advanced materials in the stator, rotor and windings.

APC’s material view
The APC Road Map pays attention to the entire spectrum of design, development and manufacture of over-the-horizon vehicles. Singling out a salient technology is almost impossible because the key to that future is systems’ integration, the APC concludes.

But arguably, the common thread crucial to success concerns materials.  

On the APC’s vision list is the use of critical materials—including cobalt, nickel and manganese—to drive R&D into new battery anode, cathode and electrolyte materials; the manufacture of battery packs designed for disassembly with second life applications and the development of cost-effective recycling processes that can recover critical elements and feed them back into the supply chain.

The APC’s Road Map regards the use of materials including neodymium and dysprosium, as driving the use of alternative magnetic materials such as ferrite magnets; the proliferation of new motor topologies that do not require rare-earth magnets (such as switched-reluctance or induction motors) and the development of cost-effective processes that can recover and recycle rare earths, electrical steels and copper and maintain required material properties.

So ironically, in an increasingly image-driven materialistic society, advanced materials will be the “must haves” of the automotive future. Albeit not on display. Continue reading »
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