Abstract: An autonomous electric mower for mowing a lawn comprises a frame, drive wheels, cutting deck, computer, a Lidar sensor, at least one color and depth sensing camera. The computer is programmed and operable to: determine the location of the mower; detect obstacles; and to instruct the mower to avoid the obstacles. Advantageously, the system is operable to analyze the data from the multiple sensors and to instruct the mower to continue to safely operate and cut the lawn despite one or more of the sensors being obstructed. Novel route planning methods are also described.