Robot navigational sensor system

1. An autonomous robot comprising:

a robot body defining a forward drive direction, the robot body having a bottom surface and a top surface located at a robot height above a floor surface;

a drive configured to propel the autonomous robot over a floor surface;

a sensor system disposed on a front portion of the robot body; and

a navigation controller circuit in communication with the drive and the sensor system, the controller circuit configured to process a signal received from the sensor system and to control the drive as a function of the signal received for processing;

wherein the sensor system comprises at least one proximity sensor comprising:

a sensor body, and

a first emitter, a second emitter and a receiver housed by the sensor body, the sensor system configured to emit emission beams in an upwardly angled direction with respect to the floor surface, the emission beams generated from light emitted by the first emitter and the second emitter and twice reshaped,

wherein the receiver is arranged to detect radiation reflected from objects in a bounded detection volume of a field of view of the receiver aimed outward and downward beyond a periphery of the robot body,

wherein the receiver is disposed above and between the first emitter and the second emitter, wherein the emission beams intersect the field of view of the receiver at a fixed range of distances from the periphery of the robot body to define the bounded detection volume,

wherein the receiver is configured to generate a signal in response to receiving reflected radiation produced by the first emitter and the second emitter as the first emitter and the second emitter are activated sequentially, and

wherein the first emitter and the second emitter are spaced from the top surface of the robot body by a distance of less than 35-45% of a height of the autonomous robot, and the receiver is spaced from the top surface of the robot body at a distance of less than 20-35% of the height of the autonomous robot.

2. The autonomous robot of claim 1 , wherein the first emitter and the second emitter are arranged side by side and the receiver is centered along a midline between the first emitter and the second emitter.

3. The autonomous robot of claim 1 , wherein, an upper bound of the field of view of the receiver is parallel to the floor surface.

4. The autonomous robot of claim 3 , wherein a lower bound of the twice-reshaped emission beams is angled at about 10 to about 20 degrees with respect to the floor surface.

5. The autonomous robot of claim 3 , wherein a lower bound of the field of view the receiver is angled downward to intersect the floor surface at a distance from the robot body that is less than 30 percent of a length of the robot body.

6. The autonomous robot of claim 5 , wherein the upper bound of field of view is angled downward between about 0 and about 15 degrees with respect to the floor surface.

7. The autonomous robot of claim 1 , wherein the field of view of the receiver subtends an angle on a plane parallel to the floor surface which is greater than an angle on a plane parallel to the floor surface subtended by the twice-reshaped beam of an emitter.

8. The autonomous robot of claim 1 , wherein the sensor system comprises two or more proximity sensors.

9. The autonomous robot of claim 8 , wherein the two or more proximity sensors are arranged laterally in an array across a front of the robot body.

10. The autonomous robot of claim 9 , wherein two proximity sensors arranged laterally in the array are separated by a distance of less than 25% of a maximum width of the robot body.

11. The autonomous robot of claim 1 , wherein a distance from an outermost proximity sensor in the array to a lateral side of the robot body is less than 10% of a maximum width of the robot body.

12. The autonomous robot of claim 1 , wherein the bounded detection volumes of at least a first portion of the array of proximity sensors are located forward of a front of the robot body, with respect to a non-turning drive direction of the autonomous robot.

13. The autonomous robot of claim 12 , wherein the bounded detection volumes are disposed completely within a distance of approximately 55 mm from the robot body.

14. The autonomous robot of claim 12 , wherein the bounded detection volumes of a second portion of the array of proximity sensors partially extend beyond a lateral side of the robot body.

15. The autonomous robot of claim 1 , wherein upper and lower bounds of the twice-reshaped emission beams and upper and lower bounds of the receiver field of view are determined by respective sets of emission and receiver baffles of the sensor body.

16. The autonomous robot of claim 15 , wherein at least one emission baffle is a pin point aperture located at an emission source.

17. The autonomous robot of claim 15 , wherein at least one emission baffle has sharp edges that further define upper and lower bounds of an emission to form the twice-reshaped emission beam.

18. The autonomous robot of claim 15 , wherein the set receiver baffles includes a blunt upper baffle edge and angled lower baffle edge that define the upper and lower bounds of the receiver field of view.

19. The autonomous robot of claim 1 , wherein intersection of the receiver field of view and a first of the twice-reshaped emission beam defines a first bounded detection volume and an intersection of the receiver field of view and a second of the twice-reshaped emission beam defines a second bounded detection volume, the first bounded detection volume overlapping the second bounded detection volume at a minimum distance of 2 mm from the robot body.