US Patent 10918252 Dirt detection layer and laser backscatter dirt detection

This disclosure describes various methods and apparatus for detecting and characterizing debris pickup during a cleaning operation. A debris detection sensor is described capable of counting the number of particles retrieved by a robotic vacuum during the cleaning operation and associating particles identified with particular areas. The location information can be obtained using various sensors on-board the robotic vacuum. In some embodiments, a cleaning operation can be rerouted when senor readings from the debris detection sensor deviate from historical sensor readings by a predetermined amount.