Time of flight sensor arrangement for robot navigation and methods of localization using same

Patent metadata

Field	Value
Publication number	US-11525921-B2
Application number	US-201916374714-A
Country	US
Kind code	B2
Filing date	Apr 3, 2019
Priority date	Apr 3, 2018
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

In general, the present disclosure is directed to a time of flight (ToF) sensor arrangement that may be utilized by a robot (e.g., a robot vacuum) to identify and detect objects in a surrounding environment for mapping and localization purposes. In an embodiment, a robot is disclosed that includes a plurality of ToF sensors disposed about a housing of the robot. Two or more ToF sensors may be angled/aligned to establish overlapping field of views to form redundant detection regions around the robot. Objects that appear therein may then be detected by the robot and utilized to positively identify, e.g., with a high degree of confidence, the presence of the object. The identified objects may then be utilized as data points by the robot to build/update a map. The identified objects may also be utilized during pose routines that allow the robot to orient itself within the map.

First claim

What is claimed is:

1. A robotic surface cleaning device comprising:
a housing;
a motor coupled to at least one wheel to drive the robotic surface cleaning device;
a first plurality of Time of Flight (ToF) sensors comprising at least a first ToF sensor and a third ToF sensor coupled to the housing;
a second plurality of ToF sensors comprising at least a second ToF sensor and a fourth ToF sensor coupled to the housing,
the first and second ToF sensors being vertically offset relative to each other and having a first and a second field of view (FOV), respectively, the first and second FOV vertically overlapping each other to form a first redundant detection region; and
the third and fourth ToF sensors being vertically offset relative to each other and having a third and fourth FOV, respectively, the third and fourth FOV vertically overlapping each other to form a second redundant detection region; and

a navigation controller disposed in the housing, the navigation controller to:
receive a first and second measurement signal from the first and second ToF sensors, respectively;
detect an object based, at least in part, on the first and second measurement signals indicating a presence of the object within the first redundant detection region;
cause the robotic surface cleaning device to rotate in place according to a rotation direction for a predetermined rotation angle;
receive a third and fourth measurement signal from the third and fourth ToF sensors, respectively;
detect the object based, at least in part, on the third and fourth measurement signals indicating a presence of the object within the second redundant detection region;
track movement of the object between the first redundant detection region and the second redundant detection region based, at least in part, on the first, second, third, and fourth measurement signals;
determine an actual rotation angle through which the robotic surface cleaning device rotated based, at least in part, on the tracked movement of the object; and
compare the actual rotation angle to the predetermined rotation angle to determine a difference between the actual rotation angle and the predetermined rotation angle.

2. The robotic surface cleaning device of claim 1 , wherein the first and second ToF sensors are infrared-type ToF sensors.

3. The robotic surface cleaning device of claim 1 , wherein each ToF sensor of the first plurality of ToF sensors is vertically offset relative to a corresponding ToF sensor of the second plurality of ToF sensors.

4. The robotic surface cleaning device of claim 1 , wherein the first and second ToF sensors are arranged in a first staggered configuration such that a first imaginary line drawn substantially transverse from a surface to be cleaned intersects with the first ToF sensor does not intersect with the second ToF sensor.

5. The robotic surface cleaning device of claim 1 , wherein navigation controller is further to calculate a height of the object relative to the robotic cleaning device based, at least in part, on the geometry of the first redundant detection region and the relative distance between the robotic cleaning device and the object.

6. The robotic surface cleaning device of claim 1 , wherein navigation controller uses the first and second ToF sensors during a pose routine to determine an orientation of the robotic surface cleaning device in a map stored in a memory of the robotic surface cleaning device.

7. A robotic surface cleaning device to navigate in a surrounding environment to perform cleaning operations, the robotic surface cleaning device comprising:
a housing having:
a first plurality of Time of Flight (ToF) sensors to identify and/or track an object in an environment surrounding the housing, the first plurality of ToF sensors having at least a first and a second ToF sensor being vertically offset relative to each other, the first and second ToF sensors having detection regions that at least partially vertically overlap each other to form a first redundant detection region; and
a second plurality of ToF sensors to identify and/or track objects in the environment, the second plurality of ToF sensors having a third and a fourth ToF sensor being vertically offset relative to each other, the third and fourth ToF sensors having detection regions that at least partially vertically overlap each other to form a second redundant detection region; and

a controller disposed in the housing to:
determine a location of the object in the surrounding environment relative to the housing based, at least in part, on the first redundant detection region;
cause the robotic surface cleaning device to rotate in place according to a rotation direction for a predetermined rotation angle;
track movement of the object between the first redundant detection region and the second redundant detection region;
determine an actual rotation angle through which the robotic surface cleaning device rotated based, at least in part, on the tracked movement of the object; and
compare the actual rotation angle to the predetermined rotation angle to determine a difference between the actual rotation angle and the predetermined rotation angle.

8. The robotic surface cleaning device of claim 7 , wherein at least one ToF sensor of the second plurality of ToF sensors has a detection region that at least partially overlaps with the detection region of the first and/or second ToF sensor to provide a third redundant detection region, and wherein the controller is further to calculate a height of the object based on the object being detected in the third redundant detection region.

9. A computer-implemented method for navigation of a robotic surface cleaning device, the method comprising:
establishing at least a first redundant detection region based, at least in part, on a first plurality of Time of Flight (ToF) sensors comprising a first ToF sensor and a second ToF sensor, the first and second ToF sensors being vertically offset relative to each other and having associated detection regions that at least partially overlap each other;
establishing at least a second redundant detection region based, at least in part, on a second plurality of ToF sensors comprising at least a third ToF sensor and a fourth ToF sensor, the third and fourth ToF sensors being vertically offset relative to each other and having associated detection regions that at least partially overlap each other;
receiving, by a controller, first and second measurement signals from the first and second ToF sensors, respectively;
detecting, by the controller, a location of an object relative to the robotic surface cleaning device based on the first and second measurement signals indicating a presence of the object within the first redundant detection region;
causing the robotic surface cleaning device to rotate in place according to a rotation direction for a predetermined rotation angle;
receiving a third and fourth measurement signal from the third and fourth ToF sensors, respectively;
detecting the object based, at least in part, on the third and fourth measurement signals indicating a presence of the object within the second redundant detection region;
tracking movement of the object between the first redundant detection region and the second redundant detection region based, at least in part, on the first, second, third, and fourth measurement signals
determining an actual rotation angle through which the robotic surface cleaning device rotated based, at least in part, on the tracked movement of the object; and
comparing the actual rotation angle to the predetermined rotation angle to determine a difference between the actual rotation angle and the predetermined rotation angle.

Assignees

• Sharkninja Operating Llc

Inventors

• Leech Adam
• Hopke Frederick K
• Kamada Isaku D

Classifications

• G01S7/4808

  Evaluating distance, position or velocity data · CPC title

• G01S17/87 Primary

  Combinations of systems using electromagnetic waves other than radio waves · CPC title

• G01S7/4865

  Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak (peak detection in noise, signal conditioning G01S7/487) · CPC title

• G01S17/931

  of land vehicles · CPC title

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title