Research

Mobility technologies are transforming our cities. How can we develop them to support both efficiency and safer user interactions?

Waymo’s fully autonomous Jaguar I-PACE

Dephy ExoBoot (Peng et al., 2022)

Mobility Assist Classification

There are several forms of mobility technologies designed to augment and assist mobility.

These technologies can be categorized by the extent of their body conformity (physical fit to the user's body) and automation (ability to operate independently from the user).

Comparing driver and pedestrian street crossing decisions

Leveraging a simulated traffic intersection to evaluate an individual’s crossing decisions from both driver and pedestrian perspectives.

Motivation

Signalized traffic intersections are variable decision-making environments where safety is paramount. Safe decision outcomes require road users to consider the interaction of many environmental factors including their proximity to an intersection, the changing states of traffic lights, and whether they are walking or driving. Individuals often encounter traffic intersections as both drivers and pedestrians, so understanding how crossing decisions differ between perspectives can help support the development of targeted traffic policies for these road users.

In this experiment, each participant views a series of pre-recorded videos of the traffic intersection from first-person driver and pedestrian perspectives. Presenting both perspectives to the same participant sample allows us to characterize the differences in their decision outcomes as they assume the role of driver and pedestrian.

Simulated intersection created in Unity with vehicle and pedestrian models present.

Pedestrian perspective

Driver perspective

Quantifying Risk

We incorporated the DOSPERT risk-taking assessment (Blais and Weber, 2006) to contextualize particiant crossing decisions.

Effect of a powered ankle exoskeleton on street crossing decisions

A collaborative effort with MIT Lincoln Lab to explore how wearable robotics might impact naturalistic decision making.

Motivation

This study examined whether a powered ankle exoskeleton affected street crossing decisions and perceived mental workload of novice users without mobility limitations at a simulated traffic intersection.

Exoskeletons are wearable mobility devices that can impact physical and cognitive performance. Exoskeleton commercialization for the public necessitates evaluations into how these systems influence novices’ cognitive reasoning and directed attention in urban environments. The Dephy ExoBoot used in this study is a commercially available powered ankle exoskeleton that is worn on both legs and has been designed to reduce the metabolic cost of walking.

The impact that lower-limb exoskeletons have on users’ cognitive abilities remains unclear, especially for novices. As users continue to operate exoskeletons in their communities while performing other activities, it is important to consider whether these devices affect decision making and mental workload so that these tools can support movement while permitting the user to efficiently and safely interact with their tasks and the environment.

Motek Medical Computer Assisted Rehabilitation Environment (CAREN)

Instrumented dual belt treadmill

Dephy ExoBoot

Quantifying Mental Workload

Particularly for novice exoskeleton users, movement-modulating forces applied to their bodies might be distracting and negatively affect their ability to focus on other tasks.

The NASA-TLX survey (Hart & Staveland, 1988) is commonly used by researchers to evaluate how an exoskeleton impacts the user’s perceived mental workload.