Proximity sensing on mobile robots

• US 8,862,271 B2
• Filed: 09/23/2013
• Issued: 10/14/2014
• Est. Priority Date: 09/21/2012
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Shamlian, Steven V., Duffley, Samuel, Romanov, Nikolai, Munich, Mario E., Goel, Dhiraj, Hook, Frederick D.
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): NGUYEN, ROBERT T
• Application Number:
  US14/033,922
• Publication Number:
  US 20140088761A1
• Time in Patent Office: 386 Days
• Field of Search: 700/245, 700/254, 700/255, 700/258, 700/259, 901/1, 901/46, 901/47, 701/208
• US Class Current: 700/259
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0238 using obstacle or wall sensors G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165

Abstract

A proximity sensor includes first and second sensors disposed on a sensor body adjacent to one another. The first sensor is one of an emitter and a receiver. The second sensor is the other one of an emitter and a receiver. A third sensor is disposed adjacent the second sensor opposite the first sensor. The third sensor is an emitter if the first sensor is an emitter or a receiver if the first sensor is a receiver. Each sensor is positioned at an angle with respect to the other two sensors. Each sensor has a respective field of view. A first field of view intersects a second field of view defining a first volume that detects a floor surface within a first threshold distance. The second field of view intersects a third field of view defining a second volume that detects a floor surface within a second threshold distance.

Claims

1. An autonomous robot comprising:

a robot body defining a forward drive direction;

a drive system supporting the robot body and configured to maneuver the robot over a floor surface;

a sensor system disposed on the robot body, the sensor system comprising at least one proximity sensor, wherein the proximity sensor comprises;

a sensor body;

first, second, and third components housed by the sensor body, the first component being one of an emitter and a receiver and each of the second component and the third component being the remaining one of an emitter and a receiver;

wherein the first component has a first field of view, the second component has a second field of view, and the third component has a third field of view, the first field of view intersecting the second field of view and the third field of view; and

wherein the intersection of the first and second fields of views defines a first volume and the intersection of the first and third fields of view defines a second volume, the first volume detecting a first surface within a first threshold distance from a sensing reference point and the second volume detecting a second surface within a second threshold distance from the sensing reference point, the second threshold distance being greater than the first threshold distance; and

a controller in communication with the drive system and the sensor system and having a computing processor processing data received from the sensor system, the controller issuing a command based on the received data.

2. The robot of claim 1, further comprising two or more proximity sensors, the controller sequentially enabling and disabling each proximity sensor with a threshold period of time between disabling one sensor and enabling another sensor.

3. The robot of claim 1, wherein the controller determines a target distance between a sensing reference point and a sensed object and issues a drive command to the drive system if the target distance to the object is within the second threshold distance, the drive command changing the direction of the robot from a forward drive direction to a drive direction other than forward.

4. The robot of claim 1, wherein the sensor body comprises at least two baffles arranged to define the field of view of at least one component.

5. The robot of claim 1, wherein a first distance between the first component and the second component is less than a second distance between the second component and the third component.

6. The robot of claim 1, wherein each component defines a field of view axis and the sensor body defines a transverse axis and a longitudinal axis, the components disposed along the transverse axis with their field of view axes arranged at an angle with respect to the longitudinal axis.

7. The robot of claim 6, wherein the field of view axes of the second component and the third component are not parallel.

8. The robot of claim 7, wherein field of view axes of the second component and the third component are each arranged at an angle of between 0 and about 10 degrees with respect to a longitudinal axis defines by the sensor body towards a rearward portion of the robot body.

9. The robot of claim 6, wherein the field of view axis of the first component is arranged at an angle between about 5 degrees and about 15 degrees with respect to the longitudinal axis, the angle of the field of view axis of the first sensor component being greater than the angles of the field of view axes of the second and third components.

10. The robot of claim 1, wherein the first threshold distance is about 1 to 3 inches and/or the second threshold distance is greater than 3 inches.

11. An autonomous robot comprising:

a robot body defining a forward drive direction;

a drive system supporting the robot body and configured to maneuver the robot over a surface;

at least one proximity sensor comprising;

a first component having a first field of view;

a second component having a second field of view, the first field of view intersecting the second field of view to form a first volume of intersection;

a third component having a third field of view, the first field of view intersecting the third field of view to form a second volume of intersection, the second volume of intersection being more distant from the robot body than the first volume of intersection;

wherein the first component is one of an emitter and a receiver, and each of the second component and third component is the remaining one of an emitter and a receiver, and

a controller in communication with the drive system and configured to issue a drive command to the drive system to maneuver the robot based on a signal from the at least one proximity sensor generated when an object interferes with at least one of the first and second volumes of intersection.

12. The robot of claim 11, the controller sequentially enabling and disabling each of the second and third components such that only one of the second and third components is actuated at one time.

13. The robot of claim 11, wherein the controller issues a drive command to the drive system if the object interferes with the second volume of intersection, the drive command changing the direction of the robot from a forward drive direction to a drive direction other than forward.

14. The robot of claim 11, wherein the at least one proximity sensor further comprises a sensor body having at least two baffles arranged to define the field of view of at least one component.

15. The robot of claim 14, wherein each component defines a field of view axis and the sensor body defines a transverse axis and a longitudinal axis, the components disposed along the transverse axis with their field of view axes arranged at an angle with respect to the longitudinal axis.

16. The robot of claim 14, wherein a first distance between the first component and the second component is less than a second distance between the second component and the third component.

17. The robot of claim 16, wherein the field of view axes of the second component and the third component are not parallel.

18. The robot of claim 17, wherein field of view axes of the second component and the third component are each arranged at an angle of between 0 and about 10 degrees with respect to a longitudinal axis defined by the sensor body towards a rearward portion of the robot body.

19. The robot of claim 16, wherein the field of view axis of the first component is arranged at an angle between about 5 degrees and about 15 degrees with respect to the longitudinal axis, the angle of the field of view axis of the first component being greater than the angles of the field of view axes of the second and third components.

20. The robot of claim 11, wherein the first volume of intersection extends approximately from the robot body to approximately 5 cm, and the second volume of intersection extends approximately from 3 to 5 cm from the robot body to a distance remote from the robot body.