Robots can do many things but they cannot open a door and go through the doorway. Researchers have solved this problem in three-dimensional digital simulations and are building an autonomous robot that can do just that. This simple advance in independence represents a huge leap forward for helper robots that vacuum and disinfect office buildings, airports, and hospitals.
Previously, researchers addressed the problem by scanning an entire room to create a 3D digital model so the robot can locate a door. But that is a time-consuming custom solution that works only for the particular room that is scanned. Developing an autonomous robot to open a door for itself poses several challenges.
Doors come in different colors and sizes with different handles that might be slightly higher or lower. Robots must know how much force to use to open doors to overcome resistance. Most public doors are self-closing, which means if the robot loses its grip, it must start over. When a door opens away from the robot, it can simply turn the door handle and push forward to enter a room. But when a door opens toward the robot, the task becomes far more difficult, especially if the door has built-in resistance for the purpose of closing on its own.
Some engineers have mounted an arm with multiple joints on robots to grasp a knob or door handle but these can be extremely expensive. A single robot arm with six joints, or degrees of freedom, that mimics the full range of motion of a human arm can cost tens of thousands of dollars.
The problem was solved by designing an appendage on a simple motorized lift the robot can raise and lower to reach a door handle. A small arm at the base holds the door open while the robot pivots around it and carries on with its duties in the next room. Since the team is using machine learning, the robot has to “teach” itself how to open a door, essentially through trial and error. This can be time-consuming initially but the robot corrects its mistakes as it goes. Simulations help the robot prepare for the actual task.
Service robots have become more useful, particularly during the COVID-19 pandemic when tedious tasks such as disinfecting rooms with mists or ultraviolet light could be automated. Similarly, a robot that can recharge using the nearest convenient electric wall outlet would be extremely helpful. The current solution is to install a docking station. When the robot runs low on power, it returns to its docking station. However, it loses time returning to the dock and there cannot be a dock in every room.
The new robot will be able to identify a wall outlet and insert the plug without human help, which is a combination of challenges. An electric socket is very small, so the robot must identify it first. Humans have the dexterity to find the socket and plug it in quickly. But asking a robot to do that is not as easy; if the robot doesn’t align perfectly, it will fail. The researchers’ algorithm, however, gives the robot more flexibility to “feel” around for the plug when it gets close.