“I was a vehicle-dynamics engineer my entire career—but maybe not a good one, because they put me in charge of a self-driving car!” jokes Jason Fischer, chief engineer for the Cruise Origin, the autonomous vehicle co-developed by General Motors, Honda and Cruise Automation, GM’s self-driving division. The electric, six-passenger AV is designed for SAE Level 4 driverless duty—it has no steering wheel or pedals. Origin is slated to begin mobility-as-a-service (MaaS) pilot operations, on geo-fenced routes, soon after production starts at GM’s Detroit-Hamtramck plant in early 2022. It is engineered for a 1-million-mile (1.6-million-km) duty cycle.
Fischer, a 21-year GM engineering veteran, is responsible for coordinating the tri-partite development partnership, including a cross-functional team of about 300 at GM. He spoke with SAE’s Autonomous Vehicle Engineering at the GM Technical Center in Warren, Michigan. Highlights of our conversation, some of which included Origin design director Stuart Norris, follow.
Where is the demarcation among the GM, Honda, and Cruise design and engineering teams—and is it challenging to manage?
We’re collaborative. Technically Cruise is responsible for the AV hardware and software. GM and Honda are responsible for the vehicle platform. But it’s not transactional—the Honda folks are working in the GM facility with me. That’s been great. I regularly travel to San Francisco to work with the Cruise team, and they visit us in Michigan. Having GM, Honda and Cruise working together is an integrated solution that, I think, may be a new model for vehicle development.
Adds Norris: We have a mutually respectful view of each other’s design discipline. We always collaborate and speak directly with each other about issues. Typically, my counterpart at Cruise will look to us for guidance on manufacturing or hardware-engineering issues—the things we’ve done thousands of times before on regular products. They show us their considerable ability with the digital tools. Even the way Cruise does their back office, the way the vehicle is managed at the Fleet/operational level, has given us great insight into how the business is going to be run generally.
Is Origin’s structure a multi-material matrix?
It’s actually mainly steel. We do have some aluminum components for mass savings. We’re trying to make it as efficient as possible, but also cost effective.
Having ridden in a half-dozen AV prototypes and demonstrators, I don’t feel safe in them. Some are essentially thin-walled aluminum extrusions, bolted together. No dedicated side impact structure. No side airbags. I don’t want to be riding in them when they get T-boned at an intersection. Pretty scary. Your thoughts?
I know what you mean. Of course, Origin will have a NHTSA crash rating. It will be as safe as any vehicle on the road. We’re working with NHTSA right now and they’ve been very flexible and open with us in what we need to do to make this vehicle FMVSS certified for deployment at scale. Our vehicle has ‘plant quality’—the body structure is welded, not bolted together. It will have the same level of quality that a unibody vehicle would have.
Origin has two large, center-opening sliding doors. But without B-pillars, where are you getting the necessary side-intrusion performance?
We achieve FMVSS side-impact performance through the door inner structure, through the door and body geometry, and how we tie the door latches into the body structure. There is a lot of careful CAE analysis in the sill and underbody structure, tying both sides of the vehicle together strongly. This all effectively functions as a B-pillar. The latch design is unique and robust: the doors can’t open during a side crash; they can’t peel. We’ve designed to meet and exceed all the major test requirements, including side-pole crash and the NBB [a child-restraint metric in sled-impact testing].
I’m 100% confident in putting my children in this vehicle. From the structural standpoint, it’s safe. Obviously with our AV technology we’re going to avoid collisions—we’re not going to hit anything with this vehicle. But you can’t always prevent someone hitting you, from a driving perspective. But from a safety perspective, we’re there. There’s a level of maturity in Origin that we haven’t seen elsewhere in the industry and safety is our No. 1 priority.
How is your team approaching the issue of Motion Sickness, given the Origin has backward-facing seats?
As a career vehicle-dynamics engineer I’m in tune with motion sickness. We have a lot of CAE analysis and market research in Origin’s low- and high-frequency content and how it can upset the human body. We’ve designed the vehicle from the inside out and put the customer first.
We’re trying to create an environment where the DLO [daylight openings in the body] help with the vestibular cueing We have huge DLOs to give passengers that visual frame of reference, to avoid the condition where your vestibular cueing [signals from the inner ear] gets a bit confused about the motion your eyes are seeing and your body is feeling. We’re trying to match what the inner ear and equilibrium ‘feel’ with what the eyes see with what the body feels on the frequency side. We have a state-of-the-art simulation facility, called Building 144, at our Milford Proving Grounds, that focus intensely on this.
But as vehicle dynamics engineers we understand what frequencies, amplitudes and time duration the human body needs to stay away from. Our Noise & Vibration team then maps those modal frequencies throughout the vehicle, to ensure we don’t have a transmission path that goes up through the seats to transmit those frequencies. Engineering to minimize and avoid motion sickness is a complex aspect of autonomous-vehicle development.