FLYING GLASS WIPER / Intelligent drones

At present, the tools for cleaning the glass in the upper air are: glass cleaning robot, manual magnetic glass eraser and so on. Manually operated magnetic glass wipes have the following shortcomings: 1 the troublesome operation makes people tired. 2 the lack of magnetic force or improper usage make glass wiper fall from the glass crashing to the wall forming fracture. 3 it can pinch some people's hands. The drawback of the glass cleaning robot is that it is expensive.