Pool cleaner with laser range finder system and method

• US 9,086,274 B2
• Filed: 06/27/2013
• Issued: 07/21/2015
• Est. Priority Date: 06/27/2012
• Status: Active Grant

• Current Assignee: Pentair Water Pool And Spa Incorporated (Pentair Plc (Ireland)), Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Original Assignee: Pentair Water Pool And Spa Incorporated (Pentair Plc (Ireland)), Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Inventors: Leonessa, Alexander, Cain, Christopher H., Boothe, Brian J.
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US13/929,715
• Publication Number:
  US 20140009748A1
• Time in Patent Office: 754 Days
• Field of Search: 356 301- 285
• US Class Current: 1/1
• CPC Class Codes: E04H 4/1654 Self-propelled cleaners
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G05D 1/0214 in accordance with safety or protection criteria, e.g. avoiding hazardous areas monitoring the location of vehicles within a certain area, e.g. forbidden or allowed areas, in traffic control systems for road vehicles G08G1/13
• 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 1/024 in combination with a laser lasers per se H01S

Abstract

Embodiments of the invention provide a pool cleaner control system including a laser range finder with a first laser line generator, a second laser line generator, and a camera. The first laser line generator and the second laser line generator are positioned to emit parallel laser lines and the camera is positioned to capture an image of the laser lines projected on an object. The control system also includes a controller in communication with the laser range finder and configured to control operation of the laser line generators to emit the laser lines and to control the camera to capture the image. The controller is also configured to receive the image from the camera, calculate a pixel distance between the laser lines in the image, and calculate the physical distance between the camera and the object based on the pixel distance.

Claims

1. A pool cleaner control system to detect a physical distance to an object in front of the pool cleaner, the control system comprising:

a laser range finder including a first laser line generator, a second laser line generator, and a camera, the first laser line generator and the second laser line generator positioned to emit parallel laser lines and the camera positioned relative to the first laser line generator and the second laser line generator to capture an image of the laser lines projected on the object; and

a controller in communication with the laser range finder and configured to

control operation of the first laser line generator and the second laser line generator to emit the laser lines,

control the camera to capture the image of the laser lines projected on the object,

receive the image from the camera,

calculate a pixel distance between the laser lines in the image, and

calculate the physical distance between the camera and the object based on the pixel distance.

2. The control system of claim 1, wherein the first laser line generator and the second laser line generator are vertically mounted on top of each other and separated by a vertical distance.

3. The control system of claim 2, wherein the controller is further configured to calculate the physical distance between the camera and the object based on the vertical distance between the first laser line generator and the second laser line generator.

4. The control system of claim 1, wherein the first laser line generator and the second laser line generator are positioned relative to the camera to emit the laser lines parallel to a viewing axis of the camera.

5. The control system of claim 1, wherein the first laser line generator and the second laser line generator are green laser line generators.

6. The control system of claim 1, wherein the first laser line generator and the second laser line generator are positioned relative to the camera to emit the laser lines parallel to a ground surface.

7. The control system of claim 1, wherein the first laser line generator and the second laser line generator each emit the laser lines at an approximate 60-degree fan angle.

8. An autonomous robotic pool cleaner for an underwater environment, the pool cleaner comprising:

a range finder configured to emit first and second lines and detect a projection of the first and second lines on a feature of the environment;

a camera configured to capture images of a floor surface of the environment under the pool cleaner;

a controller in communication with the range finder and the camera, the controller configured to;

determine a physical distance between the range finder and the feature based on the detected projection of the first and second lines on the feature,

determine visual odometry data based on the captured images,

map the environment based on the physical distance and the visual odometry data, and

track a position of the pool cleaner within the environment.

9. The pool cleaner of claim 8 and further comprising a directional control system in communication with the controller and configured to move the pool cleaner across the floor surface, the controller configured to operate the directional control system to move the pool cleaner based on the mapped environment.

10. The pool cleaner of claim 9, wherein the controller is configured to create a cleaning route of the pool cleaner based on the mapped environment and operate the directional control system to move the pool cleaner along the cleaning route.

11. The pool cleaner of claim 8, wherein detecting a projection of the first and second lines on a feature including capturing an image of the first and second lines projected on the feature, and the controller is configured to determine the physical distance between the range finder and the feature by relating a pixel distance between the first and second lines projected on the feature in the image to the physical distance.

12. The pool cleaner of claim 8, wherein the controller is configured to map the environment using feature-based Extended Kalman Filter Simultaneous Localization and Mapping.

13. A method of determining a distance to an object in an underwater environment using a dual-plane laser range finder, the method comprising the steps of:

projecting a first line onto the object;

projecting a second line onto the object parallel to the first line;

capturing an image of the projected first line and the projected second line on the object;

segmenting the image into separate image segments;

for each image segment;

extracting color planes in the image segment to obtain a grayscale image segment;

detecting potential line edges in the grayscale image segment;

extracting line segments using the potential line edges;

grouping the line segments to obtain the first projected line and the second projected line in the grayscale image segment;

calculating a pixel distance between the first projected line and the second projected line in the grayscale image segment; and

calculating the distance to the object based on the pixel distance.