Autonomous coverage robot sensing

Abstract

An autonomous coverage robot detection system includes an emitter configured to emit a directed beam, a detector configured to detect the directed beam and a controller configured to direct the robot in response to a signal detected by the detector. In some examples, the detection system detects a stasis condition of the robot. In some examples, the detection system detects a wall and can follow the wall in response to the detected signal.

1 - 19 . (canceled) 
     
     
         20 . An autonomous robot comprising:
 a body configured to move over a surface;   two driven wheels carried by the body and defining a transverse axis, with each wheel carried on a respective side of the body;   a stasis sensor carried by the body and responsive to inertia of the body; and   a controller configured to change the rotation speed and direction of each wheel to rotate the body, the controller in electrical communication with the stasis sensor and configured to determine a stasis condition based at least in part on the inertia sensed by the stasis sensor in response to the changed speed and direction of the wheels.   
     
     
         21 . The autonomous robot of  claim 20 , wherein the stasis sensor is in non-load bearing contact with the surface. 
     
     
         22 . The autonomous robot of  claim 20 , wherein the stasis sensor is substantially aligned along the transverse axis. 
     
     
         23 . The autonomous robot of  claim 20 , further comprising a wetting element forward of the two driven wheels as the robot moves forward along a fore-aft axis. 
     
     
         24 . The autonomous robot of  claim 23 , wherein the wetting element is configured to spread a cleaning liquid on the surface during rotation of the body. 
     
     
         25 . The autonomous robot of  claim 20 , wherein the controller is further configured to change the rotation speed and direction of each wheel to rotate the body back and forth. 
     
     
         26 . The autonomous robot of  claim 20 , wherein, in response to the change in the rotation speed and direction of each wheel to rotate the body, the controller is further configured to interpret an uninterrupted signal from the stasis sensor as a stasis condition. 
     
     
         27 . The autonomous robot of  claim 20 , further comprising a second stasis sensor carried by the body, wherein the controller is in electrical communication with the second stasis sensor, and the controller is further configured to determine a stasis condition based at least in part on the inertia sensed by the second stasis sensor in response to the changed speed and direction of the wheels. 
     
     
         28 . The autonomous robot of  claim 20 , further configured to transition from determining a stasis condition based on the stasis sensor to determining a stasis condition based the second stasis sensor. 
     
     
         29 . The autonomous robot of  claim 20 , further comprising a second stasis sensor carried by the body, wherein the controller is in electrical communication with the second stasis sensor, and the controller is further configured to evaluate simultaneously inputs from the stasis sensor and the second stasis sensor. 
     
     
         30 . A method of detecting stasis of an autonomous robot, the method comprising:
 changing the direction and speed of two driven wheels carried by a body of an autonomous robot;   sensing inertia of the body in response to the change in direction and speed of the two driven wheels; and   determining a stasis condition of the autonomous robot based at least in part on the sensed inertia of the body.   
     
     
         31 . The method of  claim 30 , further comprising changing the rotation speed and direction of each wheel to rotate the body back and forth. 
     
     
         32 . The method of  claim 30 , wherein determining the stasis condition of the autonomous robot based at least in part on the sensed inertia of the body comprises evaluating inputs from a first stasis sensor and a second stasis sensor.