A mobile cleaning robot comprising: a removable filter unit configured to receive a supply airflow generated by a blower and to filter debris from the supply airflow; a filter seat ; a filter access opening ; a filter access door pivotable between a closed position, wherein the filter access door covers the filter access opening, and an open position, wherein the filter access door is displaced from the filter access opening to permit access to the filter seat; and a filter presence system configured to: permit the filter access door to move from the open position into the closed position when the filter unit is disposed in the filter seat; and prevent the filter access door from being moved into the closed position when the filter unit is not disposed in the filter seat; characterized in that : the filter presence system includes a lift arm movable between an extended position and a retracted position; when the filter access door is open, the lift arm assumes the extended position to receive the filter unit in the filter seat; and moving the filter access door from the open position into the closed position when the filter unit is disposed in the filter seat causes the lift arm to move to the retracted position. a removable filter unit configured to receive a supply airflow generated by a blower and to filter debris from the supply airflow; a filter seat ; a filter access opening ; a filter access door pivotable between a closed position, wherein the filter access door covers the filter access opening, and an open position, wherein the filter access door is displaced from the filter access opening to permit access to the filter seat; and a filter presence system configured to: permit the filter access door to move from the open position into the closed position when the filter unit is disposed in the filter seat; and prevent the filter access door from being moved into the closed position when the filter unit is not disposed in the filter seat; characterized in that : the filter presence system includes a lift arm movable between an extended position and a retracted position; when the filter access door is open, the lift arm assumes the extended position to receive the filter unit in the filter seat; and moving the filter access door from the open position into the closed position when the filter unit is disposed in the filter seat causes the lift arm to move to the retracted position. permit the filter access door to move from the open position into the closed position when the filter unit is disposed in the filter seat; and prevent the filter access door from being moved into the closed position when the filter unit is not disposed in the filter seat; characterized in that : the filter presence system includes a lift arm movable between an extended position and a retracted position; when the filter access door is open, the lift arm assumes the extended position to receive the filter unit in the filter seat; and moving the filter access door from the open position into the closed position when the filter unit is disposed in the filter seat causes the lift arm to move to the retracted position. the filter presence system includes a lift arm movable between an extended position and a retracted position; when the filter access door is open, the lift arm assumes the extended position to receive the filter unit in the filter seat; and moving the filter access door from the open position into the closed position when the filter unit is disposed in the filter seat causes the lift arm to move to the retracted position. <EOS>