System and method for autonomous mopping of a floor surface

An autonomous cleaning robot comprising:

• a housing;
• a drive to move the housing across a surface;
• a dispenser to apply fluid to the surface;
• a cleaning assembly pivotally attached the housing, the cleaning assembly configured to attach a detachable cleaning pad to a bottom surface of the autonomous cleaning robot;
• and
• a controller to operate the drive to move the autonomous cleaning robot along a cleaning trajectory in which the autonomous cleaning robot repeatedly moves forward along a first path and backward along a second path across the surface such that the cleaning assembly pivots relative to the housing while the autonomous cleaning robot moves along the cleaning trajectory.