Robot navigational sensor system

• US 10,674,885 B2
• Filed: 02/07/2018
• Issued: 06/09/2020
• Est. Priority Date: 07/01/2015
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Bushman, Tom, Herman, James, Blitzblau, Seth, Deschaine, Nathan J., Reichel, Andrew Scott
• Primary Examiner(s): Oh, Harry Y
• Application Number:
  US15/890,791
• Publication Number:
  US 20180169863A1
• Time in Patent Office: 853 Days
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/28 Installation of the electric equipment, e.g. adaptation or attachment to the suction cleaner; Controlling suction cleaners by electric means
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2852 Elements for displacement of the vacuum cleaner or the accessories therefor, e.g. wheels, casters or nozzles
• CPC Class Codes: G01S 17/93 for anti-collision purposes
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: Y10S 901/01 Mobile robot
• CPC Class Codes: Y10S 901/47 Optical

Abstract

An autonomous robot comprises a robot body, a drive configured to propel the robot, a sensor system disposed on the robot body, and a navigation controller circuit in communication with the drive and the sensor system. 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, wherein the receiver detects objects in a bounded detection volume of the receiver field of view aimed outward and downward beyond a periphery of the robot body. The receiver is disposed above and between the first and second emitters, the emitters having a twice-reshaped emission beams angled upward to intersect the receiver field of view at a fixed range of distances from the periphery of the robot body to define the bounded detection volume.

Claims

1. A proximity sensor system for an autonomous robot, the proximity sensor system comprising:

a sensor arranged to respond to presence of objects beyond a perimeter of the autonomous robot as the autonomous robot moves over a floor surface, the sensor comprising a receiver and emitters; and

a controller configured to sequentially enable and disable the emitters,

wherein the receiver is disposed at a different height than the emitters, and wherein the receiver and the emitters are oriented with different axis orientations with respect to the floor surface, such that a field of view of the receiver intersects with emission beams of the emitters to define a bounded detection volume disposed within a distance of 2 to 55 mm from a periphery of the autonomous robot.

2. The proximity sensor system of claim 1, wherein the controller sequentially enables and disables each of the emitters such that only one of the emitters is enabled at one time.

3. The proximity sensor system of claim 1, wherein the controller is configured to issue a direction-changing or a speed-changing drive command in response to an object interfering with the bounded detection volume.

4. The proximity sensor system of claim 1, wherein the sensor comprises:

a sensor body; and

wherein a first of the emitters, a second of the emitters, and the receiver are housed by the sensor body, the sensor configured to emit the emission beams in an upwardly angled direction with respect to the floor surface, the emission beams being generated from light emitted by the first of the emitters and the second of the emitters.

5. The proximity sensor system of claim 4, wherein the receiver is disposed above and between the first of the emitters and the second of the emitters, wherein the emission beams intersect the field of view of the receiver at the distance of 2 to 55 mm from the periphery of the autonomous robot to define the bounded detection volume.

6. The proximity sensor system of claim 4, wherein the first of the emitters and the second of the emitters are spaced from a top surface of the autonomous robot 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 autonomous robot at a distance of less than 20-35% of the height of the autonomous robot.

7. The proximity sensor system of claim 4, wherein the first of the emitters and the second of the emitters are arranged side by side and the receiver is centered along a midline between the first of the emitters and the second of the emitters.

8. The proximity sensor system of claim 4, wherein an upper bound of the field of view of the receiver is angled downward between 0 and 15 degrees with respect to the floor surface, and a lower bound of the emission beams is angled at 10 to 20 degrees with respect to the floor surface.

9. The proximity sensor system of claim 4, 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 an emission beam of the first of the emitters or the second of the emitters.

10. The proximity sensor system of claim 4, wherein upper and lower bounds of the emission beams and upper and lower bounds of the field of view of the receiver are determined by a set of emission baffles and a set of receiver baffles, respectively, of the sensor body.

11. The proximity sensor system of claim 1, comprising two or more sensors, each sensor comprising a receiver and a set of multiple emitters, the two or more sensors being arranged laterally in an array across a front of the autonomous robot.

12. The proximity sensor system of claim 11, wherein two sensors of the two or more sensors are arranged laterally in the array are separated by a distance of less than 25% of a maximum width of the autonomous robot, and a distance from an outermost sensor in the array to a lateral side of the autonomous robot is less than 10% of the maximum width of the autonomous robot.

13. The proximity sensor system of claim 11, wherein bounded detection volumes of at least a first portion of the array are located forward of a front of the autonomous robot with respect to a non-turning drive direction of the autonomous robot, and bounded detection volumes of a second portion of the array partially extend beyond a lateral side of the autonomous robot.

14. The proximity sensor system of claim 1, wherein an intersection of the field of view of the receiver and a first of the emission beams defines a first bounded detection volume and an intersection of the field of view of the receiver and a second of the emission beams defines a second bounded detection volume, the first bounded detection volume overlapping the second bounded detection volume at a minimum distance of 2 millimeters from the autonomous robot.

15. The proximity sensor system of claim 1, wherein the field of view of the receiver includes a first portion that intersects an emission beam of a first of the emitters, the field of view of the receiver includes a second portion that does not intersect the emission beam of the first of the emitters, and the second portion intersects an emission beam of a second of the emitters.

16. The proximity sensor system of claim 15, wherein in response to detecting reflected light when the first of the emitters is enabled and the second of the emitters is not enabled, and not detecting reflected light when the second of the emitters is enabled and the first of the emitters is not enabled, the controller is configured to:

determine that at least an obstacle is located in a first bounded detection volume defined by an intersection of the field of view of the receiver and the emission beam of the first of the emitters, and no obstacle is located in a second bounded detection volume defined by an intersection of the field of view of the receiver and the emission beam of the second of the emitters, and

issue a drive command based on determining that at least the obstacle is located in the first bounded detection volume.

17. A proximity sensor system for an autonomous robot, the proximity sensor system comprising:

a sensor arranged to respond to presence of objects beyond a perimeter of the autonomous robot as the autonomous robot moves over a floor surface, the sensor comprising;

a sensor body,

at least a first emitter and a second emitter, and

a receiver, in which the at least first and second emitters and the receiver are housed by the sensor body, the sensor is configured to emit emission beams in an upwardly angled direction with respect to the floor surface, and the emission beams are generated from light emitted by the first emitter and the second emitter,

wherein the receiver is disposed at a different height than the first and second emitters, and the receiver and the first and second emitters are oriented with different axis orientations with respect to the floor surface, such that a field of view of the receiver intersects with a first emission beam of the first emitter and a second emission beam of the second emitter to define a bounded detection volume disposed within a distance of 2 mm to 55 mm from a periphery of the autonomous robot.

18. A method of detecting presence of objects beyond a perimeter of an autonomous robot as the autonomous robot moves over a floor surface, the method comprising:

providing at least one proximity sensor on the autonomous robot, in which the at least one proximity sensor comprises a receiver and emitters, wherein the receiver is disposed at a height different than a height of the emitters;

orienting the receiver and the emitters with different axis orientations with respect to the floor surface, intersecting a field of view of the receiver with emission beams of the emitters, and defining a bounded detection volume disposed within a distance of 2 to 55 mm from a periphery of the autonomous robot;

sequentially enabling and disabling the emitters of the at least one proximity sensor; and

detecting, based on reflected emissions, a presence of one or more objects beyond the perimeter of the autonomous robot.

19. The method of claim 18, wherein sequentially enabling and disabling the emitters of the at least one proximity sensor comprises:

generating emission beams from light emitted by the emitters of the at least one proximity sensor, and emitting the emission beams in an upwardly angled direction with respect to the floor surface.

20. The method of claim 19, comprising emitting the emission beams in an upwardly angled direction such that a lower bound of the emission beams is angled upward at 10 to 20 degrees with respect to the floor surface.