A new robot is designed to automate the process of cleaning recessed windows in buildings that present problems for more traditional washers — both human and machine.
A team of Rice University seniors, which includes Julia Bleck, Michael Liu, Erin O’Malley, and Andria Remirez based at the Oshman Engineering Design Kitchen, in collaboration with Nourelhouda Derbeli and Ali Abdmouleh, students from Tunisia, built the WashBOT as part of a multiyear robotics project.
Washing a window seems simple for a person, but it’s complicated for a robot. First, one has to get the machine in position. Then there are variables to account for: the size of the window, depth of the recess, application of the cleaning agent … and the squeegee.
“That’s the most difficult part,” Remirez says.
The students were charged with biting off a piece of the engineering challenge that could be handled within a year, says team advisor Fathi Ghorbel, professor of mechanical engineering and materials science and of bioengineering.
“This is a problem with a large scope that usually requires a company, several years, and a lot of funding to solve,” he says. “So the challenge to the students was to decide on the scope and deliver, because their grade depends on it.”
So the team got to the heart of the matter: the cleaning.
“We had to narrow it down to something we could physically create,” Bleck says. “We decided to focus on recessed windows because there’s nothing in the market that cleans them right now. And then we narrowed it to washing one portion of one window. Moving within a window is in itself a project; moving from window to window is another project.”The system soaps the window with a sponge-like mop on a horizontal track and follows with a squeegee to finish the job. “We have designs to move the robot down the window to do the next horizontal pass,” Bleck says, but that job may be left to the next team.
“We’ve had to do a lot of integration between the attachment system and the cleaning system,” O’Malley says. “There are a lot of things to do, but they all depend on other things.”
The robot’s tension system can be adjusted for window widths. Sensors stop the brush at the end of the glass, rotate the mechanism, and move it back across. “So there’s no need to reprogram the robot to have it know the size of the window,” O’Malley says.
The team spent the fall testing cleaning materials, watching and talking to window washers, and visiting car washes to study how glass gets clean.
“A lot of the current solutions use big, round rotating brushes, which work really well for flat-front buildings but not as well for buildings that have things sticking out between the windows,” O’Malley says.
“So we tried to make the robot as close to what a window washer would do: spraywater, wipe it down with a sponge, and use a squeegee,” Remirez says. “Getting the applied pressure right has been the hardest part. We did a lot of research for that.”
This article originally appeared at Futurity.org.
Source: Rice University.