Computer-controlled power wheelchair navigation system

• US 20040267442A1
• Filed: 07/14/2004
• Published: 12/30/2004
• Est. Priority Date: 07/02/2002
• Status: Active Grant

• Current Assignee: U.S. Department Of Veterans Affairs Of Edward Hines, Jr. Hospital
• Original Assignee: U.S. Department Of Veterans Affairs Of Edward Hines, Jr. Hospital
• Inventors: Del Castillo, Guillermo, Skaar, Steven B., Fehr, Linda
• Granted Patent: US 7,383,107 B2
• Time in Patent Office: Days
• US Class Current: 701/200
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means

Abstract

A wheelchair navigation system for a motorized wheelchair includes dual cameras, proximity sensors, microphones, and rotation sensors for the wheels. Small markers are placed on the walls of a location or room. The navigation system uses the proximity sensors, rotation sensors and cameras in conjunction with the specialized software to determine where objects or impediments are located in the room and thereby redirect the path of the wheelchair so as to avoid such objects. The wheelchair is walked through the marked location thereby ‘teaching’ various paths which are recorded in the computer and recalled later when the wheelchair is in use. The proximity sensor perform sensing operations during performance of the teaching functions for thereby permitting avoidance of wheelchair collision with obstacles during navigation of the wheelchair through a taught trajectory and allowing for close approach of the wheelchair to solid bodies present during performance of the teaching functions.

Claims

1. A wheelchair navigation system comprising:

a motorized wheelchair;

at least one computer having software that performs

navigational functions,

teaching functions,

obstacle detection,

supervisory tasks, and

diagnostic analysis;

at least one camera;

at least one proximity sensor;

at least one rotation sensor;

at least one visual sensor;

at least one visual marker; and

an input device including one of a switch and a microphone,

wherein said at least one rotation sensor, said at least one visual sensor and said input device are interfaced to said at least one computer which runs specialized software, and said at least one proximity sensor performs sensing operations during performance of said teaching functions for thereby permitting avoidance of wheelchair collision with obstacles during navigation of said wheelchair through a taught trajectory and allowing for close approach of said wheelchair to solid bodies present during performance of said teaching functions.

2. A wheelchair navigation system according to claim 1, wherein:

said at least one computer has a screen with a visual display.

3. A wheelchair navigation system according to claim 1, wherein:

said computer receives information from said cameras and said sensors, processes said information and determines a path of travel for said wheelchair from such information.

4. A wheelchair navigation system according to claim 1, wherein:

said computer is voice activated.

5. A wheelchair navigation system according to claim 1, wherein:

said computer is manually operated.

6. A wheelchair navigation system comprising:

a motorized wheelchair;

at least one battery;

a battery charger;

a filter-based estimator with interface software;

a computer having software that performs navigational functions and teaching functions;

at least one camera;

at least one proximity sensor;

at least one microphone;

at least one rotation sensor for the wheels, said at least one sensor is mounted on the wheelchair; and

a plurality of visual markers capable of being placed on the walls of a specific location

wherein said at least one proximity sensor performs sensing operations during performance of said teaching functions for thereby permitting avoidance of wheelchair collision with obstacles during navigation of said wheelchair through a taught trajectory and allowing for close approach of said wheelchair to solid bodies present during performance of said teaching functions.

7. A wheelchair navigation system according to claim 6, wherein:

said at least one computer has a screen with a visual display that is visible to a person using the wheelchair.

8. A wheelchair navigation system according to claim 6, wherein:

said computer receives information from said cameras and said sensors, processes said information and determines a path of travel for said wheelchair from such information.

9. A wheelchair navigation system according to claim 6, wherein:

said computer is voice activated.

10. A wheelchair navigation system according to claim 6, wherein:

said computer is manually operated.

11. A method of navigation using a powered wheelchair comprising the steps of:

providing a motorized wheelchair, said wheelchair being powered by at least one onboard battery, and a battery charger and having dual cameras, proximity sensors, a microphone and rotation sensors for sensing wheel rotation;

providing a filter-based estimator with interface software running that is operated on at least one computer including a control system;

providing markers at various locations within a specific area;

teaching at least one path by walking said wheelchair through said at least one path prior to said wheelchair navigation system being used for independent travel, and recording said at least one path in said computer;

sensing said markers with said proximity sensors and said cameras during performance of said teaching for thereby permitting avoidance of wheelchair collision with obstacles during navigation of said wheelchair through a taught trajectory and allowing for close approach of said wheelchair to solid bodies present during performance of said teaching;

providing information about said markers from said proximity sensors and said cameras to said at least one computer;

operating said software to determine the location of various objects within a location;

creating a path for said wheelchair to avoid said objects with said software;

recalling said at least one taught path; and

directing said wheelchair on said path via said software.

12. A method of navigation using a powered wheelchair according to claim 11, further comprising the step of:

operating said computer via voice control.

13. A method of navigation using a powered wheelchair according to claim 11, further comprising the step of:

operating said computer manually.

14. A method of navigation using a powered wheelchair according to claim 11, further comprising the step of:

establishing ultrasound profiles at various junctures throughout a path during performance of said teaching.

15. A method of navigation using a powered wheelchair according to claim 14, further comprising the step of:

simplifying said profiles in a postprocessed computer event; and

comparing said profiles during tracking through a taught path with current ultrasound sensed profiles.

16. A method of navigation using a powered wheelchair according to claim 15, further comprising the step of:

comparing disparities between said current ultrasound sensed profiles of objects to determine if a configuration of an object close to the taught path has changed since said teaching, and if said configuration has changed by a predetermined threshold, halting said wheelchair.