Reducing product development time is among the industry’s top priorities, particularly as vehicle makers transition into an electrified future. Waiting on the environment – climate, weather, terrain and the logistics of on-road testing – is a costly impediment when the program clock is ticking. For commercial-vehicle OEMs, the need for a comprehensive testing facility that offers complete seasonal independence and utmost process efficiency has been growing. The solution now is in service at Allison Transmission’s new Vehicle Environment Test center in Indianapolis.
The 60,000-ft2 VET, as it’s known, is part of Allison’s $400 million investment in engineering resources and new products this decade, including a new 95,000-ft2 Innovation Center also based on the Indy headquarters campus. The VET is unique among U.S. Midwestern vehicle test facilities (and rare in North America) in having what some customers have called “an ideal combination:” two chassis-dynamometer-equipped environmental chambers capable of generating temperature extremes of between -54 degrees and 125 degrees F; full simulation of altitudes up to 18,000 ft (5,486 m) and duty cycles that are vital for regulatory compliance; on-board diagnostic (OBD) development, and vehicle performance optimization.
The CFR 1066-compliant (Code of Federal Regulations, the required test procedures for measuring exhaust, evaporative, and refueling emissions) test cells can conduct performance, emissions and fuel-consumption testing of alt-fuel, hybrid and electric vehicles and is planning to add hydrogen fueling and fuel-cell vehicle (FCV) capabilities.
“With the VET, development teams don’t need to take a two-week road trip to get three days of testing,” noted Brad Stamper, customer program manager at Allison Transmission. “We can get any environment we want here. Our goal is ‘road replication’: Instead of taking five different trucks in five configurations on a test trip somewhere, we can use one truck, simulate the different configurations, and get it all done in a week. We bring a laboratory environment into the various development stages.”
A new business model
When Allison Transmission began planning the VET in 2018, the company spent a lot of time benchmarking, both with its internal product-development teams and by visiting OEM and third-party test sites. In terms of overall capabilities, the VET’s closest North American competitor is PACCAR’s test facility on the west coast, but its focus is exclusively internal. “We view them as a potential customer,” Stamper said. “When they get into capacity constraints, we want to partner with them. We’re looking for those relationships with our OEMs and our competitors as well, where it makes sense.”
According to Jeanne Rues, Allison Transmissions’ veteran managing director of Engineering Services, the voice of Allison engineers “helped planners identify needs and challenges in compressing product development times, getting products into vehicles sooner and being able to take vehicle-level results back into the modeling-and-simulation space faster,” Rues told SAE’s Automotive Engineering. “Those were keys to creating this facility.”
The VET’s official launch in summer 2020 came with news for the industry: Allison is expanding into testing for external customers. It is devoting half the new facility’s resources to this enterprise, the other half for internal programs. “The dividing line was put in place within our business case for capitalizing this facility,” Stamper noted. “We know there is Allison internal demand to book 50 percent of the facility. And we need our partners to be able to execute as quickly as we’ll be able to execute. Our leadership quickly moved to make that capability available. That drove having two test cells here.”
Robust measures are in place to keep the two parties separate. All customers to the VET, internal and external, are considered proprietary with the same security safeguards. “Our customers’ IP is paramount,” said David Proctor, facilities general manager. “The data we collect goes directly to the cloud; only the customer has access to that data storage. After 21 days, that data, which we provide in raw-state form, is erased.”
Swallowing a city bus
Allison Transmission partnered with AVL for the majority of the VET’s equipment, including dual-channel emissions-test systems and two of the largest chassis dynos the Austrian company has ever built. The dynos are calibrated to regenerate electric power back into the grid, and their rollers can be moved 330 in. (838 cm) longitudinally in their subfloor saddles to accommodate long vehicle wheelbases.
“We’re also working to automate systems so that the whole building will ‘tell us’ what’s wrong. It’ll notify us in the future if we have an issue, through our mobile phones,” Proctor said. “Currently, we get the info on an HMI screen pinpointing where the problem is.”
<figure "half-width">The VET’s ‘hot’ chamber can generate Death Valley-levels of heat, any day of the year. (Allison Transmission)
Following strict health and safety guidelines during SAE’s visit in December 2020, Proctor and the author walked from the building’s control- and meeting-rooms area into the voluminous high-ceilinged ambient-soak area, where two customer step vans were the objects of engineers’ attention. The entire space is maintained at 72 deg. F (22 deg. C) year-round. Vehicles that arrive for emissions testing in the dead of winter are parked here until their engine-sump temperatures come up to the 72-F ambient before they’re submitted for testing. It’s also an area where fabrication is done, such as adding thermocouples, transducers and sensors.
Prototype and pre-production vehicles not yet approved for the public’s eyes enter directly from their transport trailers through secure doors. Some get covered or dedicated partitions, according to the owner’s instructions.
The hot and cold soak chambers are enormous – each is large enough to accommodate two articulated city buses, or up to nine smaller vehicles. “We were able to test multiple vehicles at -40 F [-40 C] and reduce overall test time by one third, compared to past practice, by rapidly returning the [engine] sump temperature to -40 F after a test. This allowed a second test to be performed within an 8-hour shift,” Proctor noted. Attention to thermal control enables temperatures in the huge chambers to hold within +/- 2.5 deg. Humidity in the hot-soak chamber can be varied from 5% up to 95% if required.
Throughout our tour, Allison Transmissions’ speed-and-efficiency mantra was evident in workplace organization. All hand tools and equipment needed for vehicle and subsystems hook-ups are stationed on carts for mobility and easy access. The concept is similar to that used for quick tooling changes in plants.
“We want to be as efficient as we can in all aspects of this facility, because our customers’ time is money,” Proctor said. “We have about a seven-minute window to move vehicles from the soak areas into our test dynes to meet specifications. Once it’s within the test cell, the hookup time is within 30 minutes.” Proctor has plans to bring the VET’s techs to Indy’s famous Motor Speedway to study racing pit stops and benchmark best practices.
EV testing expands
With combustion engines expected to evolve and remain as prime-movers for decades, including in hybrid vehicles – and tighter emission standards facing OEMs, in the form of the Phase 2 regs through model year 2027 – the Allison VET team is preparing for steady business in emissions testing this decade. As the executives noted, however, electrification and testing electrified vehicles are steadily growing priorities. Proctor showed one of the VET’s major assets in this area: the AV900.
Made by AeroVironment, the AV900 is a multi-use, programmable device designed to serve as a battery emulator. It is a workhorse for testing and emulating energy storage and drivetrain components of large hybrids and EVs, including trucks, buses and military vehicles. Allison Transmission owns “a number of” AV900s, with two currently located at the VET. One is mounted on wheels for portability. Both are used for battery charging and for delivering a constant power supply.
“Our E-Axle development team wanted to test on one of our dynos,” Proctor shared. “They can run 30 minutes to one hour on the road, then they have to shut the electric vehicle down to charge the battery. This is where the battery emulator really helped save time. The team tested here; we were able to reduce their downtime by 40 percent by eliminating their charging. We ran that vehicle for six hours continuous, at 70-mph, on our dyno with no problem. Those are the types of advantages we can provide our customers.”
With EVs, the industry is heading to higher voltages and higher kilowatt-hour requirements for more efficiency. Each of the VET’s AV900s are capable of 250 kW and can be combined in parallel to deliver 500 kW, either on the dynos or in another test. “Moving forward, we see the need for more capability with hybrids and EVs,” Proctor said. “We can provide DC power for EVs in any configuration needed, to allow them to run continuous, making the batteries’ charge virtually infinite. That eliminates time and cost in design and testing.”
And although hydrogen-fueled propulsion systems weren’t in the original VET plan, they are quickly entering the picture,” Stamper said. “EV will be a growing business for us, with the ‘E’ coming from a variety of sources. Hydrogen capability is not here at VET today, but it’s coming to fruition sooner than later. We’re exploring a bulk hydrogen-feed system into the test facilities to provide, like we do with EVs, a continuous fueling capability.”
Still in its nascent stages, Allison Transmissions’ unique VET already is shaping up to be a vanguard testing facility in North America. For details about the VET, click here .