Senior Design: Finding the Right Balance

A bike without handles, attached to a bike stand, and with a hard plastic case where the seat would be.

The senior design process tasks Drexel Engineering students with putting everything they’ve learned over four-plus years in the classroom and on co-op into one three-term long project. The collaboration with other students, faculty and industry partners is a creative and scientific quest to solve a problem, invent a gadget or innovate in an area of interest.

The sequence is meant to simulate real-world scenarios and teamwork as well as to validate their earned skills as an engineer, which should come naturally as they get set for graduation. In some ways, it’s like riding a bike.

Or, in the case of one team, like teaching a bike to ride itself.

Under the mentorship of Thomas Chmielewski, PhD ’95 , teaching professor of electrical and computer engineering and Paul Kalata PhD , associate professor emeritus of electrical and computer engineering, the team is working to build a self-balancing bicycle that could be used as an autonomous vehicle for delivery companies.

In addition to senior design, the project is part of the SICK TiM$10K University Challenge , a nationwide competition organized by SICK, a leader in sensor technology. Teams are asked to use one of SICK’s LiDAR (light detecting and ranging) sensors in a novel application that could be used for business purposes. The Drexel team is one of 15 finalists who were provided with a LiDAR sensor to continue their project after presenting their case to judges.

The group consists of six students: electrical engineering majors Jacob Longstreet and ShuoWen (Willie) Gu, computer engineering major Alix House, and mechanical engineering majors Thomas Parker, Gaurav Pandey, and Avi Majumdar.

To achieve balance, the team uses a number of sensors, including a Hall effect sensor to measure the speed output of the motor attached to the bike’s rear wheel, gyroscopes and accelerometers to monitor its lean angle, and SICK’s LiDAR sensor to detect obstacles. The data is fed into a processor, which creates a feedback loop that can tell the bike to go faster or make steering adjustments to stay upright, or to slow down and deploy its training wheels to navigate a busy area. Longstreet, the team leader, explained that the team was constructed knowing that the project would require multidisciplinary thinking.

“We knew we wanted to gather engineers from different backgrounds,” he said. “Willie and I are working on making sure the sensors and the motors work, Alix is working with the LiDAR sensor and coding the instructions that are sent through the processor, and Thomas, Gaurav and Avi are working on a miniature version of the bike using an Arduino processor that we can use to test different ideas and get a sense of the equations we need to use to keep angular momentum, velocity and other factors in mind.”

The team is still exploring multiple solutions for the project, including a fly wheel installed at the bike’s center of gravity to generate torque to counteract angular momentum and gravity, a servo motor to steer the bike’s front wheel, and linear actuators to lower the safety wheels if needed. They are also working on how to house the components in a protective case that mounts to the bike, making sure that it doesn’t upset the center of gravity, or at least that their sensors can account for it plus whatever future delivery partners might want to carry on the bike.

They must consider all these factors while keeping the project safe and cost effective to make the best case to the TIM$10K judges. The team makes its final presentation for the competition in mid-April and will continue to work on the bike through the end of the term to ensure that meets the highest standards for a senior design project.

No matter what the outcome of the competition, the team is grateful for the opportunity to work together to see a project through from inception to completion.

“Senior design is an opportunity to use what you’ve learned over the past four or five years, but also to learn from your peers,” Longstreet said. “You get to enrich each other and understand how different backgrounds can contribute to a project. It’s a fantastic opportunity to experience real-world collaboration before graduating.”