GM is making the Hummer EV in record time. that’s how

The techniques and technologies that GM uses to cut development and manufacturing costs are not unique to the company. But it shows how new technologies, such as virtual product testing and hardware-in-the-loop testing, which mix computers and machines, are accelerating what had long been a slow and expensive process.

Test in the virtual world

In the case of the Hummer EV, there were also a few things that helped shorten the process. Since this is a fully electric truck, for example, it is mechanically much simpler than a gasoline vehicle involving a complex engine, transmission, and mechanical all-wheel drive system.

GM had been working on the Ultium battery system behind the Hummer for a while before this particular model was invented. So having an existing electric vehicle architecture helped.

Furthermore, the Hummer EV’s essential goal was simple: to create “a legitimate off-roader,” he said Michael Colville, one of the principal engineers working on the project. It is much easier and faster to work towards creating a mass market vehicle with the competitive goals of desirability and practicality. With a typical crossover SUV, for example, engineers and designers are constantly comparing aspects such as sportiness and attractive design with practicality, fuel economy and comfort.

But computing power will also play an important role in Hummer’s rapid turnaround. And it is something that affects the development of all modern vehicles, electric or not. Not all vehicle design programs will be as short as Hummer’s, but they can be shorter, according to GM engineers.

Engineers and designers can now design parts virtually before they actually have to produce them. This way they can see how reshaping the piece or making it with different materials would affect performance and weight without having to make it first..

It’s the type of technology that automakers rely on most, and with the advent of electric vehicles, there will be more common components among models, said Sam Abuelsamid, an analyst at consulting firm Guidehouse.

“Once those core bits are aligned, it gives you a lot more flexibility for what [type of vehicle body] you want to put it on top, “he said,” then I think we’ll all see it. “

Testing virtual parts has enabled GM to dramatically reduce the number of 3D printed prototype parts, which can cost 10 to 20 times more than a mass-produced part, said Jim Hentschel, GM’s global vice president for systems. security and integration.

As a result, GM now spends less than half of what it did in 2018 on prototype parts, Hentschel said. Likewise, the time it took to test parts was cut in half, he said.

In addition, you can virtually run many more tests than using real parts and vehicles. This can sometimes reveal problems that previously may not have been discovered until late in the development process, when solving them would have been difficult and costly.

For example, to test skid plates, which protect parts under the bodywork of an off-road vehicle from damage, engineers typically drag the vehicle over rocks. Reinforcements would then be added or the weak points of the plates would be thickened, an expensive process that involves making new metal moldings. For the Hummer EV, the engineers used virtual testing. They were able to refine the skid plate design without having to create and test new skid plates.

It has also become much easier to collect detailed data from virtual tests, Hentschel said. With virtual crash tests, for example, engineers can study in great detail how individual parts of the car, including the deep parts inside, behaved on impact, he said.

In some cases, the computer software itself can “learn” from tests and make its own changes to the virtual models. The tests can then be run again with the new “parts” and the computer can measure the results of its work. This machine learning approach was used to design fasteners that hold interior door panels, Hentschel said. Tens of thousands of virtual door slams helped ensure fasteners didn’t break with the changes and improvements made along the way.

“We were able to automate the way the engineer thinks and basically do it all in an automated way much faster and with significantly fewer errors than if the engineers had to do it all on their own,” Hentschel said.

Combining virtual and real

However, automakers need to be very careful when relying on virtual rather than real testing, Abuelsamid said. There can be no surprises when the real parts are ultimately put to the test.

“If you are going to simulate things, your simulation models must have a very high degree of fidelity,” he said, “so that the simulation results match the results you will get if you were to do a physical test of the same component or of the same system. “

When that time comes, computers can be connected to physical testbeds to create so-called hardware-in-the-loop systems. Systems like this have been used to test engines, batteries, and braking systems for Hummer EVs, Colville said.

With computers monitoring tests and collecting data, tests can be run continuously day and night. Engineers can check results and edit tests remotely from home, which helped keep work during Covid arrests

Human testers were able to use virtual reality systems that emulated the sensations of driving a Hummer electric vehicle long before the first truck prototypes were built. The first complete Hummers prototype is only now being assembled and is expected to be completed soon, a GM spokesperson said.

The software settings on the VR test drive system can even recreate the driving experience on wet roads, soft sand or mud. As a result, changes can be made to the suspension, tires and other systems of the virtual truck.

Real-world testing can’t be postponed forever, of course. That’s why GM is building real Hummer EV prototypes now. Winter is coming and they need to go outside to test the cold on real snow.

“In the end, I’m not selling a virtual product, I’m selling a real product,” said Hentschel, “and so we have to make sure that everything we’ve done virtually happens.”