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This report describes the SafeTrip-21, Networked Traveler Foresighted Driving Field Experiment conducted as part of the US DOT’s SafeTrip-21 initiative. This experiment developed and evaluated an Advanced Driver Assistance System providing soft-safety or situational awareness alerts regarding “Slow Traffic Ahead” when driving on a freeway. The Networked Traveler system detects slow traffic or queues at several thousand locations in the Bay area, monitors the locations and speeds of its test subjects as they drive, and determines if the driver is approaching the slow traffic fast enough to...

The internal states of Lithium-ion batteries, notably state of charge (SOC), need to be carefully monitored during battery operation to manage energy and safety. In this paper, we propose an interval observer for SOC estimation in an electrically and thermally coupled parallel connection of cells. This is a particularly challenging problem because mathematically cells in parallel yield a system of differential-algebraic equations (DAE), which are more difficult to handle than ordinary differential equations (e.g. a series string of cells). For a large battery pack with thousands of cells,...

Battery electrode particle fracture due to stress generation is a critical mechanism causing capacity fade, and thus reducing battery life. This paper develops a nonlinear adaptive observer for lithium-ion battery state of charge (SOC), electrode particle stress, and solid phase diffusivity estimation using a high-fidelity coupled single particle-mechanical stress model, where the stress submodel captures stress development during lithium-ion intercalation and deintercalation. Simultaneous state and parameter estimation based on coupled single particle and mechanical stress model is...

This paper derives provably optimal control trajectories for the Li-ion battery fast charging problem. Conventionally, battery charging protocols must satisfy safety constraints while maximizing the state of charge (SoC) level. In the literature, both computational and experimental studies promote a diversity of algorithms, including pulse charging, multi-step constant currents, and more. Although these approaches yield applicable charging algorithms, the literature lacks a rigorous analytical insight into optimal charging trajectories. In this paper, we focus on the Pontryagin's Minimum...