Why speed matters in AV simulations

How it works: Speed plays a critical role in simulations, because if sensing does not keep up with the rate at which events actually happen, it limits the vehicle’s ability to respond effectively to critical real-time, rate-dependent phenomena and adapt its driving pattern accordingly.

• Additionally, if a simulation does not process an event quickly enough, it could lose track of how the consequences of key events affect future behavior, leading to a loss of fidelity in both data and control of the vehicle.

Between the lines: In a research setting, advanced cameras in vehicles with automated features typically capture images at a speed of up to 300 frames-per-second, and this speed informs simulations.

• But cameras in anticipated road models are more likely work at just 30 frames-per-second and this 30 millisecond lag-time is significant, as it limits the ability of a vehicle to identify and respond to an event in near real-time.
• Meanwhile, dense urban environments filled with pedestrians, unusual traffic patterns, and construction increase the amount of computation that needs to occur nearly instantaneously.
• Additionally, as the technology in vehicles catches up to and surpasses what it is used in simulations, current simulation data might be rendered obsolete.

The bottom line: Data from varying sources, simulations included, will be crucial to getting AVs safely on the roadways — but simulation technology can improve when it comes to speed, and those improvements will yield better data and stronger AV training.

Chris Gill is a professor at Washington University's McKelvey School of Engineering.