Concept I did for the Gnomon 2D challenge (April 2014).
"This month's theme is to design a robotic military or police unit designed to patrol the streets. This could be humanoid, or not, but keep in mind that this needs to be able to move fast and fit into tight spaces. It also doesn't need to be legged, could be aerial."
Since the patrol should be able to move into tight spaces, I imagined the scene inside the "Walled City" in Hong Kong, and consequently adapted the the robot's uniform with the local police force colours...