Pool cleaning method and apparatus

• US 20040021439A1
• Filed: 07/30/2002
• Published: 02/05/2004
• Est. Priority Date: 10/15/2001
• Status: Active Grant

• Current Assignee: Aquatron Robotic Technology Ltd.
• Original Assignee: Aqua Products Incorporated
• Inventors: Fridman, Igor, Porat, Joseph
• Granted Patent: US 6,815,918 B2
• Time in Patent Office: Days
• US Class Current: 318/567
• CPC Class Codes: E04H 4/1654 Self-propelled cleaners

Abstract

A method for cleaning the bottom of a pool uses an automated programmed pool cleaner capable of reversing movement and turning that is initially placed at an arbitrary location on the bottom of the pool and moved in a forward direction until it encounters an upright pool wall; the unit is reversed until it is a first predetermined distance from the wall, turned through a predetermined angle less than 180° and advanced until it again encounters an upright wall; these steps are repeated until the unit has encountered upright walls a predetermined number of times, after which the first predetermined distance is changed to one or more subsequent predetermined distances. All of the previous steps are repeated until all or substantially all of the pool has been cleaned. In a preferred embodiment, a rectangular pool is cleaned by setting the turning angle to 90° and the number of turns before changing the predetermined distance to seven. In another aspect of the invention, the unit has a rotary impeller driven in a horizontal plane, and the robot is turned by interrupting motive force to the impeller a plurality of times during a predetermined period of time to create a sufficient torque or torsional force to rotate the nearly neutrally buoyant unit through the desired turning angle.

Claims

1. A method for cleaning the bottom surface of a pool by a pool cleaning robot initially set at an arbitrary position on the bottom of the pool, the method comprising:

advancing the robot until it encounters a wall;

reversing the robot and advancing it away from the wall, allowing the robot to travel a leg of predetermined distance;

turning the robot through a predetermined angle of turn;

repeating the above steps until a predetermined number of wall encounters are counted, after which the predetermined distance of the leg is altered; and

repeating the above steps, whereby a substantial area of the bottom surface is cleaned by the robot.

2. The method of claim 1, wherein the predetermined angle of turn 15 varied in some turns during the cleaning of the floor.

3. The method of claim 1, wherein the robot is initially positioned near a side end of the wall.

4. The method of claim 3, wherein the robot is initially positioned within a distance of 1 to 3 times the width of the robot from the side end of the wall.

5. The method of claim 1, wherein the angle of turn is substantially a right angle turn.

6. The method of claim 1, wherein the robot is turned in an angle of turn positioning the robot in a perpendicular direction to a facing wall.

7. The method of claim 1, wherein the alteration of the predetermined distance of the leg consists of increasing the length.

8. The method of claim 7, wherein the length of the leg is increased up to about half the length of the pool.

9. The method of claim 1, wherein the alteration of the predetermined distance of the leg consists of decreasing the length.

10. The method of claim 9, wherein the initial position of the robot at the commencing of the sweeping of the pool is about half way across the wall.

11. The method of claim 1, wherein the turn is taken constantly to the right with respect to the traveling robot.

12. The method of claim 1, wherein the turn is taken constantly to the left with respect to the traveling robot.

13. The method of claim 1, wherein the predetermined number of wall encounters counted prior to alteration of the length of the leg is 7.

14. The method of claim 1, wherein the alteration of the length of the leg is done in steps of constant lengths.

15. The method of claim 1, wherein the robot is a single motor driven robot having a powered horizontal impeller, and wherein the robot is turned by applying at least one of a plurality of predetermined number of interrupts in the impeller power thus causing the robot to acquire bias momentum directed sideways and hence move in the direction of the bias.

16. The method of claim 15, wherein the predetermined number of interrupts is between 15 to 25.

17. The method of claim 15, wherein the duration of the application of predetermined number of interrupts is in the range of about 10 to 20 seconds.

18. The method of claim 15, wherein each interrupt lasts about 0.5 to 0.8 seconds.

19. A method for turning sideways a pool cleaning robot having a single motor drive and a powered horizontal impeller, the method comprising applying at least one of a plurality of predetermined number of interrupts in the impeller power thus causing the robot to acquire bias momentum directed sideways and hence move in the direction of the bias.

20. The method of claim 19, wherein the predetermined number of interrupts is between 15 to 25.

21. The method of claim 19, wherein the duration of the application of predetermined number of interrupts is in the range of about 10 to 20 seconds.

22. The method of claim 19, wherein each interrupt lasts about 0.5 to 0.8 seconds.

23. A pool cleaning robot comprising:

a reversible motorized drive;

an impeller driven by a pump motor;

power supply;

a processor for counting wall encounters and including a programmed algorithm for navigating and operating, the algorithm comprising the following steps;

advancing the robot to until it encounters a wall;

reversing the robot and advancing it away from the wall, allowing the robot to travel a leg of predetermined distance;

turning the robot sideways in a predetermined angle of turn;

repeating the above steps until a predetermined number of wall encounters was counted, after which the predetermined distance of the leg is altered; and

repeating the above steps whereby substantial area of the floor is covered by the robot;

a controller for receiving commands from the processor and reversing the robot and initiating turning of the robot upon the appropriate commands from the processor; and

a wall encounter sensor for sensing a wall encounter and sending a signal to the processor.

24. The robot of claim 23, wherein the wall encounter sensor comprises a proximity sensor or a collision sensor or a tilt sensor or a sonar sensor.

25. The robot of claim 23, wherein the reversible motorized drive is a reversible motorized caterpillar drive.

26. The robot of claim 23, wherein it further comprises a GPS receiver for determining its position and direction.

27. A pool cleaning robot comprising:

a reversible motorized drive;

an impeller driven by a pump motor;

power supply;

a processor having a programmed algorithm for navigating and operating the robot, the algorithm includes inter alia applying at least one of a plurality of predetermined number of interrupts in the impeller power thus causing the robot to acquire bias momentum directed sideways and hence move in the direction of the bias; and

a controller for receiving commands from the processor and reversing the robot and initiating turning of the robot upon the appropriate commands from the processor.

28. The robot of claim 27, wherein the reversible motorized drive is a reversible motorized caterpillar drive.

29. The robot of claim 27, wherein it further comprises a GPS receiver for determining its position and direction.