
UV-C robot disinfects warehouse in half an hour
Using a custom UV-C light fixture designed at CSAIL that is integrated with telepresence robot maker Ava Robotics’ mobile robot base, the system, say the researchers, can disinfect a warehouse floor in half an hour — and could one day be employed in grocery stores, schools, and other spaces. In tests at the Greater Boston Food Bank, the robot system was able to disinfect a 4,000-square-foot space in just half an hour.
“Food banks provide an essential service to our communities, so it is critical to help keep these operations running,” says Alyssa Pierson, CSAIL research scientist and technical lead of the UV-C lamp assembly. “Here, there was a unique opportunity to provide additional disinfecting power to their current workflow, and help reduce the risks of Covid-19 exposure.”
While proven to be effective at killing viruses and bacteria on surfaces and aerosols, UV-C light is unsafe for human exposure. Using a telepresence robot such as those from Ava Robotics removes the need for any human supervision. In this case, the researchers replaced the robot’s standard telepresence top with a UV-C array, which uses short-wavelength ultraviolet light to kill microorganisms and disrupt their DNA in a process called ultraviolet germicidal irradiation.
The complete robot system is capable of mapping the space — in this case, GBFB’s warehouse — and navigating between waypoints and other specified areas. In testing the system, the researchers used a UV-C dosimeter, which confirmed that the robot was delivering the expected dosage of UV-C light predicted by the model.
During the tests, the robot was able to drive by the pallets and storage aisles at a speed of roughly 0.22 miles per hour, enabling it to cover a 4,000-ft space in half an hour. The UV-C dosage delivered during this time, say the researchers, can neutralize approximately 90 percent of coronaviruses on surfaces.
For many surfaces, this dose will be higher, resulting in more of the virus neutralized. In addition, say the researchers, while UV-C is most effective in direct “line of sight,” it can get to nooks and crannies as the light bounces off surfaces and onto other surfaces.
As a first step in the process, the researchers teleoperated the robot – which is equipped with autonomy to move around – to teach it the path around the warehouse. It can then go to defined waypoints on its map – originally defined from the expert human user in teleop mode – and add new waypoints to the map as needed.
Currently, the researchers are exploring how to use the robot’s onboard sensors to adapt to changes in the environment, such that in new territory the robot would adjust its speed to ensure the recommended dosage is applied to new objects and surfaces. In addition, say the researchers, they need to teach the robot to differentiate between occupied and unoccupied aisles, so it can change its planned path accordingly.
“As we drive the robot around the food bank, we are also researching new control policies that will allow the robot to adapt to changes in the environment and ensure all areas receive the proper estimated dosage,” says Pierson. “We are focused on remote operation to minimize human supervision, and, therefore, the additional risk of spreading Covid-19, while running our system.”
Next, say the researchers, they are focused on increasing the capabilities of the robot at GBFB, as well as eventually implementing design upgrades. Their broader intention focuses on how to make these systems more capable at adapting to our world: how a robot can dynamically change its plan based on estimated UV-C dosages, how it can work in new environments, and how to coordinate teams of UV-C robots to work together.
“We are excited to see the UV-C disinfecting robot support our community in this time of need,” says CSAIL director and project lead Daniela Rus. “The insights we received from the work at GBFB has highlighted several algorithmic challenges. We plan to tackle these in order to extend the scope of autonomous UV disinfection in complex spaces, including dorms, schools, airplanes, and grocery stores.”
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