Contact sensors for a mobile robot

• US 9,505,140 B1
• Filed: 06/02/2015
• Issued: 11/29/2016
• Est. Priority Date: 06/02/2015
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Blitzblau, Seth, Dumont, Kyle, Woodman, Justin H., Fay, Victor, Duffley, Samuel
• Primary Examiner(s): Kiswanto, Nicholas
• Application Number:
  US14/728,406
• Publication Number:
  US 20160354935A1
• Time in Patent Office: 546 Days
• US Class Current: 1/1
• CPC Class Codes: A47L 11/4061 Steering means; Means for avoiding obstacles; Details related to the place where the driver is accommodated
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: B25J 13/085 Force or torque sensors B25J13/082, B25J13/084 take precedence
• CPC Class Codes: B25J 19/0075 Means for protecting the manipulator from its environment or vice versa
• CPC Class Codes: B25J 5/00 Manipulators mounted on wheels or on carriages B25J1/00 takes precedence; programme-controlled manipulators B25J9/00 ; vehicle aspects B60, B62, e.g. remote-controlled steering for motor vehicles B62D1/24; control of position of vehicles G05D1/00
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
• CPC Class Codes: G01D 5/142 using Hall-effect devices measuring magnetic variables using Hall-effect or other galvanomagnetic devices G01R33/06
• CPC Class Codes: G01D 5/20 by varying inductance, e.g. by a movable armature
• CPC Class Codes: G01D 5/2403 by moving plates, not forming part of the capacitor itself, e.g. shields
• CPC Class Codes: G01L 1/14 by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A robot includes a body and a bumper. The body is movable relative to a surface and includes a first portion of a sensor. The bumper is mounted on the body and movable relative to the body and includes a backing and a second portion of the sensor. The backing is movable relative to the body in response to a force applied to the bumper. The second portion of the sensor is attached to the backing and movable with the backing relative to the first portion of the sensor in response to a force applied to the bumper. The sensor is configured to output an electrical signal in response to a movement of the backing. The electrical signal is proportional to an amount of displacement of the second portion relative to the first portion.

Claims

1. A robot comprising:

a body movable relative to a surface, the body comprising a first portion of a sensor; and

a bumper mounted on the body and movable relative to the body, the bumper comprising;

a backing movable relative to the body in response to a force applied to the bumper; and

a second portion of the sensor, the second portion of the sensor being attached to the backing and movable with the backing relative to the first portion of the sensor in response to the force applied to the bumper,

wherein the sensor is configured to output an electrical signal in response to a movement of the backing, the electrical signal being proportional to an amount of displacement of the second portion relative to the first portion.

2. The robot of claim 1, wherein:

the sensor comprises a capacitive sensor;

the first portion comprises a first plate of the capacitive sensor;

the second portion comprises a second plate of the capacitive sensor; and

the electrical signal varies proportionally to an amount of displacement of the first plate relative to the second plate.

3. The robot of claim 2, wherein the backing comprises rigid regions that are interconnected by flexible regions, at least one of the rigid regions comprising a post that extends toward the body and through a hole in the body, the second plate being attached to the post on a side of the body facing away from the backing such that the second plate is movable with the post relative to the first plate.

4. The robot of claim 3, wherein the bumper is movable between a compressed position and an uncompressed position;

and

wherein, in the uncompressed position, the first plate touches the second plate and, in the compressed position, motion of the post through the hole results in a separation between the first plate and the second plate.

5. The robot of claim 2, wherein:

a displacement of the first plate relative to the second plate comprises a horizontal displacement parallel to the surface, and

the electrical signal varies proportionally to an amount of the horizontal displacement.

6. The robot of claim 2, wherein the first plate is attached to the body on a surface of the body facing towards the backing, and the second plate is attached to the backing on a side of the backing facing towards the body, a dielectric being between the first plate and the second plate.

7. The robot of claim 6, further comprising:

a spacer having a thickness, the spacer connecting the first plate to the body and being between the first plate and the body.

8. The robot of claim 1, wherein the backing comprises an integrated structure having a substantially constant rigidity across an entirety of the integrated structure.

9. The robot of claim 1, wherein:

the sensor comprises an inductive sensor;

the first portion comprises a winding of the inductive sensor;

the second portion comprises a core of the inductive sensor; and

the electrical signal varies proportionally to an amount of displacement of the winding relative to the core.

10. The robot of claim 1, wherein:

the first portion of the sensor comprises a Hall effect sensor;

the second portion of the sensor comprises a magnet; and

,

the electrical signal varies proportionally to an amount of displacement of the magnet relative to the Hall effect sensor.

11. A robot comprising:

a body movable relative to a surface;

a bumper mounted on the body and movable relative to the body, the bumper comprising a backing movable relative to the body in response to a force applied to the bumper;

a first sensor to output a first electrical signal that varies with an amount of movement of the bumper, at least part of the first sensor being mounted to the backing, and

a second sensor to output a second electrical signal that varies with the amount of the movement of the bumper, at least part of the second sensor being mounted to the backing; and

a controller to receive the first electrical signal and the second electrical signal, and to determine one or more attributes of the force applied to the bumper based on the first electrical signal and the second electrical signal.

12. The robot of claim 11, wherein the backing comprises multiple segments including a first segment and a second segment, the at least part of the first sensor being mounted to the first segment, and the at least part of the second sensor being mounted to the second segment.

13. The robot of claim 12, wherein the multiple segments are interconnected by connection elements to form an integrated structure, the connection elements having greater flexibility than flexibilities of the multiple segments.

14. The robot of claim 13, wherein the connection elements comprise a same material as the multiple segments and thicknesses that are less than thicknesses of the multiple segments.

15. The robot of claim 13, wherein at least some of the multiple segments are disconnected from others of the multiple segments.

16. The robot of claim 12, wherein the one or more attributes comprises a location of the force applied to the bumper.

17. The robot of claim 11, wherein the controller is configured to execute instructions to determine the one or more attributes by performing one or more interpolation processes based on the first and second electrical signals.

18. The robot of claim 11, wherein the backing has a first side that is in series with, and angled relative to, a second side;

wherein the backing comprises a first segment aligned to the first sensor on the first side and a second segment aligned to the second sensor on the second side; and

wherein the first segment is connected to the second segment by a connection element having a length that is greater than a length from the first segment along the first side to the second segment along the second side.

19. The robot of claim 18, wherein the connection element is angled away from the first segment at the first side, and the connection element is angled away from the second segment at the second side.

20. The robot of claim 11, wherein the first and/or the second electrical signal varies linearly with the movement of the bumper.