Engineers are usually all business. In Hollywood terms, they are the straight man in the scene. That is, until they get a new engineering tool and they are instantly transformed into elementary-school kids excited to show off their new Nintendo. In this case, those engineers/pre-teens are from Fiat Chrysler Automobiles (FCA), and their Nintendo is a new nine-axis driving simulator, not even two months old yet. When it's used as a tool and not a video game, as we are doing today, it will help FCA vehicle development around the world.
Walking up to the Vehicle Dynamic Simulator, a $10 million investment FCA made in its Windsor, Ontario, Automotive Research and Development Centre (ARDC), you wouldn’t be surprised if the rig was also used as the head of one of Michael Bay's Transformers. A Ram 1500 cab perched on six actuators (the neck to the Ram's head) gives the simulator six of its nine freedoms of movement: left-right, up-down, fore-aft in small doses (high-frequency stuff, think rumble strips), as well as pitch, roll, and yaw. The other three movements come from what they call the tripod. That consists of—you guessed it—three more, significantly larger, actuators that allow the simulator to inflict as much as 2.0 g’s of force on occupants in the X and Y axis, as well as introduce simulated slip angles into high-dynamics cornering. The 4.5-ton rig glides on what are essentially three inverted air hockey tables on a stainless-steel plate.
The crux of any high-level simulator is sustained acceleration. It's easier to successfully simulate small braking and acceleration forces. But when it's a long braking event, corner, or acceleration, the sensation of movement is down to images on the wraparound screen. From the dead center of its range of movement, the tripod can move the base about 4.1 feet in any direction. And while a force of 2.0 g’s is possible, a maximum spike may only be a second or two. And most of the forces are less severe, but for longer duration, so the sensation of acceleration can be sustained for a longer period of time. Aiding in the sensation of braking, the seatbelts in the cab cinch down to simulate hard braking. When operating at full tilt, the simulator draws a whopping 87 kilowatts.
FCA’s new toy comes from the Italian firm VI Grade. According to James Lyijynen, FCA director of advanced concepts engineering, it turns some of the later vehicle validation work, which takes place at a proving ground, into verification work. This isn't a revolutionary tool that will cut years from the development of a vehicle; it's more like a few months. Modern vehicles have so many discrete systems, and every one of those influences the others.
The simulator is primarily a ride-and-handling tool. However, because it is an advanced simulator, kinks in the human-machine interface of interior components—something as simple as a problem with a light switch—could be identified early in development and addressed before all the systems come together in a prototype.
In its current configuration, the simulator is set up to work on pickup trucks and vehicles with similar seating heights. Because the geometry of the cab is fixed, so is the simulator's roll center. Therefore, trying to develop the other end of the automotive spectrum, say a sports car, would be a fruitless exercise. But not to worry: ARDC has another cab on order with VI Grade. Swapping the cab involves 12 bolts and about 40 wire connections, and the process takes a few hours.
Piloting the sim takes some acclimation. The initial experience is best described as getting into a car with someone who doesn't know how to drive; Dramamine takers need not apply. FCA admittedly needs to work on some of the calibrations, but even in our limited exposure, one can tell it is a powerful tool. Too bad it sucks power like an EV at Vmax and that ARDC has security, because otherwise the simulator would turn into a playhouse for overgrown kids every Friday evening. And why not? We'll bring the sodas.