Navigational control system for a robotic device

1. A robotic cleaner, comprising:

a chassis and an outer shell secured to the chassis;

left and right main drive wheel assemblies and respective independent electric motors, independently mounted in pivotally-biased combination with the chassis for pivotal motion with respect thereto at opposed ends of the transverse diameter of the chassis, and movable between a retracted position under the weight of the robotic cleaner during operation and an extended position wherein their axes of rotation are below the bottom plane of the chassis;

a navigational control system operative to monitor movement activity of the robotic cleaner within a defined working area, the monitored movement activity including at least one of a position history of the robotic cleaner and an instantaneous position of the robotic cleaner; and

a transmitting subsystem including a mechanical sweeping transmitter laser, wherein the mechanical sweeping transmitter laser:

is configured to sweep to redirect a transmitting element of the mechanical sweeping transmitter laser;

is configured to cover the defined working area by transmitting a beam substantially parallel to a surface of the defined working area;

is mounted in combination with the outer shell secured to the chassis to define an overall structural envelope of a height to enable movement of the robotic cleaner under furniture; and

is integrated in combination with a high point of a housing infrastructure of the robotic cleaner so that none of the structural features of the robotic cleaner interfere with sweeping of the transmitting element of the mechanical sweeping transmitter laser.

2. The robotic cleaner of claim 1 , further comprising a receiver unit configured to receive control signals.

3. The robotic cleaner of claim 1 , wherein the navigational control system is configured to create a tessellation of the defined working area by segmenting the defined working area into a set of individual cells.

4. The robotic cleaner of claim 3 , wherein the navigational control system is configured to define a size of each individual cell based on a width of a cleaning head system of the robotic cleaner.

5. The robotic cleaner of claim 1 , further comprising a rechargeable battery pack integrated in combination with the chassis.

6. The robotic cleaner of claim 1 , further comprising a forward bumper integrated in movable combination with the chassis, wherein the forward bumper is configured so that when the chassis encounters an obstacle, the bumper is displaced towards the chassis and returns to an extended position when contact with the obstacle is terminated.

7. The robotic cleaner of claim 1 , further comprising a wheel drop sensor integrated in combination with each of the main drive wheel assemblies and operative to generate a signal whenever any of the wheel assemblies is in an extended position in which the axes of rotation thereof is below the bottom plane of the chassis.

8. The robotic cleaner of claim 1 , further comprising an obstacle-following unit comprising an IR emitter-detector pair configured to transmit a signal to a control module if reflected radiation is not detected by the detector.

9. The robotic cleaner of claim 1 , further comprising respective stall-sensor units integrated in combination with each respective independent electric motor and operative to transmit a signal to the control module when a change in current is detected in the respective independent electric motor.

10. The robotic cleaner of claim 1 , further comprising at least one cliff detection unit comprising an IR emitter-detector pair configured to transmit a signal to the control module when a drop-off is encountered.

11. The robotic cleaner of claim 1 , wherein the mechanical sweeping transmitter laser is configured to cycle on/off sequentially.