Think back to the last time you were waiting for a bus. How miserable were you? If you’re in Boston, your experience may have included high winds and icy rain—or, more recently, a punch of pollen sent straight to your sinuses. But in Florida’s Miami-Dade County, where the effects of climate change are both dramatic and intensifying, commuters must contend with an entirely different set of challenges: scorching temperatures and scorching humidity that make long waits in the sun almost unbearable.
One of Miami’s most pressing transportation needs is that of car-clogged Boston: directing citizens to use the municipal transit network instead of the emissions-heavy personal vehicles that currently contribute to climate change. But in sunny cities where humidity hovers between 60 and 80 percent year-round, buses can be a tough sell.
MIT Department of Electrical Engineering and Computer Science (EECS) and MIT Priscilla King Gray (PKG) Center for Public Service. The 6.900 category (Engineering for Impact) is the result of a close collaboration between the two organizations and challenges EECS students to apply their engineering savvy to real-world problems beyond the MIT campus.
The real-world problem this spring semester is heat.
“We talk a lot about the cities we want to live in, about getting the right mix of public transit, on-demand transit,” explained Carlos Cruz-Casas, chief innovation officer for the Miami-Dade County Department of Transportation and Public Works. and other mobility solutions, such as e-bikes and e-scooters, can help our communities live a car-less life. However, none of this is possible if riders feel uncomfortable while doing so.”
“When people think about South Florida and climate change, they often think about rising sea levels,” said Juan Felipe Visser, deputy director of equity and engagement for the Miami-Dade County Mayor’s Office. “But heat is truly a silent killer. So it’s very appropriate that this lesson focuses on the heat at bus stops.” Commuters in Miami-Dade County gather as some of the hottest stations have little to no tree cover A small patch of shade behind the bus stop, sometimes given up when the heat becomes unbearable.
A more traditional electrical engineering course might use temperature monitoring as an abstract example, build the example monitor separately and grade it as a purely academic exercise. But Professor Joel Volman, chair of the EECS Department of Electrical Engineering, and Joe Steinmeyer, a senior lecturer at EECS, thought of something even more impactful.
“Miami-Dade County has a large population that lives in poverty, is undocumented, or is marginalized,” Waldman said. “Waiting for buses on hot days, sometimes for long periods of time, is just one aspect of urban populations that are underserved, but by measuring the number of people waiting for buses, how long they wait, and the patterns of wait times, and under what circumstances, we can Start to understand which services are not keeping up with demand.”
Only after quantifying this gap can city and transportation planners begin their work, Cruz-Casas explains: “We need to quantify the amount of time passengers are exposed to extreme heat and prioritize improvements, including on-time performance improvements, increased Service frequency or a desire to enhance the tree canopy near bus stops.”
However, quantifying this time—and the subjective experience of waiting—proves tricky. Miami-Dade County’s transportation network has more than 7,500 bus stops along 101 bus routes, which creates significant data collection challenges. A network of physical temperature monitors could be useful, but only if it is carefully calibrated to meet a city’s budgetary, environmental, privacy, and implementation requirements. But how do you work with city officials more than 2,000 miles away (not to mention all the Miamians riding the bus)?
This is where the PKG Center comes in. “We are a hub, connector and facilitator of best practices,” explains Jill Bassett, associate dean and director of the center, who worked with Voldman and Steinmeyer to find municipal partner organizations for PKG. course. “We provide knowledge of current pedagogy around community-engaged learning, which includes: helping to build mutually beneficial partnerships centered on community-identified concerns; identifying and learning from community partners; discussing how to create opportunities for student learners Reflect on power dynamics, reciprocity, systems thinking, long-term planning, continuity, ethics, and all the types of things that come up in a shared project like this.”
Through a series of brainstorming conversations, Bassett helped Waldman and Steinmeier develop a clear project plan, while Cruz-Casas weighed the technical specifications the county needed, including affordability, privacy protections and accessibility. implementation).
“This course brings together experts from many subject areas,” Voldman said. “We invited guest speakers including Abby Berenson from the Sloan Leadership Center to discuss teamwork; engineers from BOSE to discuss product design, certification, and environmental resistance; Engineering leaders talk about their low-power occupancy sensors; Tony Hu from MIT IDM [Integrated Design and Management] Talk about industrial design; talk about communications and networking with Katrina LaCurts from EECS. “
Supported by two generous donations and a software gift from Altium, 6.900 evolved into a hands-on exercise in hardware/software product development with a practical goal: to build a better bus monitor.
The challenges of the effort became apparent as 6,900 students began designing their displays. “The most challenging requirement to meet is for the monitor to be able to count how many people are waiting and how long they have been standing there, while still maintaining privacy,” said EECS graduate Fabian Velazquez, 23. This task is difficult because commuters naturally tend to stand in the shade of trees or awnings, or meander in a row against a nearby wall, rather than standing directly next to a bus sign or inside a bus shelter. becomes complicated. “Accurately measuring people with cameras – the most straightforward option – is already quite difficult because you have to incorporate machine learning to identify which objects in the frame are people. Maintaining privacy adds an extra layer of constraints… because there is no guarantee that the collected The data is not compromised.”
As groups weighed various privacy options, including lidar, radar, and thermal imaging, the class realized that a Wi-Fi “sniffer”—which counts the number of Wi-Fi-enabled signals in a nearby area—was their The best option is to count the waiting passengers. “We’re all excited and ready for this amazing radar sensor that solves all our problems for counting people,” Velasquez said. “However, this component is very complex, and this complexity ultimately cost my team a lot of time and resources to integrate with our system. We also developed this system with a very short time to market. We have a very good balance between complexity and robustness. Trade-offs were made.”
The weather also presents its own set of challenges. “Environmental conditions are an important factor that affects the structure and design of our equipment,” said Yong Yan (Crystal) Yang, a junior majoring in EECS. “We incorporate humidity and temperature sensors into our data to show the weather at various sites. Additionally, we consider how our enclosures may be affected by extreme heat or potential hurricanes.”
The caloric variable has proven problematic in a number of ways. “Person detection is particularly difficult because thermal cameras may not be able to differentiate between human body temperature and surrounding air temperature in Miami’s hot weather, and the sun’s glare from other surfaces in the area makes most forms of imaging difficult.”, Katherine Mohr ‘ 23 said. “My team considered using mmWave sensors to get around these limitations, but we found it was too difficult to process, and (like others in the class) we decided to just stick with Wi-Fi/BLE [Bluetooth Low Energy] sniffer. “
Quite possibly the most valuable component of the new course is students’ exposure to real-world hardware/software engineering product development, where time and budget constraints are always present, and customer requirements must be carefully considered. “Working with actual customers forces us to learn how to translate their needs into more specific technical specifications,” Mohr said. “We select deliverables each week that are due to be completed by Friday, prioritizing tasks that will lead to a minimum viable product, as well as tasks that require additional manufacturing time, such as designing printed circuit boards and enclosures.”
Crystal Liang counts conversations with city representatives as one of her 6,900 most valuable experiences. “We asked a lot of questions and were able to communicate with the community leaders of the project in Miami-Dade County, who took the time to answer all the questions and provide us with ideas based on what they were trying to accomplish,” she reported. “This project gave me a new perspective on problem-solving because it taught me to see things from the perspective of a community member.” Some of those community leaders, including Miami Transportation Alliance co-founder Marta Viciedo, attended the class for the final time on May 16 meeting to review student-proposed solutions.
The students’ thoughtful approach paid off when the thermal monitor was demonstrated to class clients. During a group call with Miami Dade University officials at the end of the semester, the student team shared their findings and the prototypes they created, as well as videos of the devices in action. Juan Felipe Visser was one of those in attendance. “This is a tough job,” he told students after his speech. “First of all, thank you for what you do and for introducing us. I love the concept. I took the bus this morning, like every morning, and was tortured by the sun and the heat. So I personally appreciate the attention.”
Cruz-Casas agrees: “I was pleasantly surprised by the diverse approach the students took. We presented a challenge and they responded to it and managed to think beyond the immediate problem. I was surprised by the results of the project I’m very optimistic about how this will have a long-term impact on our community. At the very least, I think the more we learn about this topic, the better chance we have of getting the brightest minds to work on solutions.”
The creators of 6.900 agree, and hope their course will help more MIT engineers broaden their perspectives on the meaning and applications of their work.
“We’re really excited for students to be able to apply their skills in real-world, complex environments that impact real people,” Bassett said. “We’re excited for them to understand that it’s not just technology design that matters, but climate; The environment and the built environment; issues surrounding socioeconomics, race, and equity all come into play. There are layers upon layers of technology being created and deployed in multilingual communities with diverse populations that are at the center of climate change.”