Method for controlling twisting of pool cleaner power cable

• US 7,621,014 B2
• Filed: 09/29/2006
• Issued: 11/24/2009
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Zodiac Pool Systems, LLC (Fluidra, S.A.)
• Original Assignee: Aquatron Incorporated (Fluidra, S.A.)
• Inventors: Katz, Pesach
• Primary Examiner(s): NGUYEN, DUNG V
• Application Number:
  US11/529,966
• Publication Number:
  US 20080078039A1
• Time in Patent Office: 1,152 Days
• Field of Search: 15/17, 210/167.14, 210/167.15, 210/167.2, 210/85, 210/91, 210/136, 210/143, 134/56.R, 134/57.R
• US Class Current: 15/1.7
• CPC Class Codes: E04H 4/1654 Self-propelled cleaners

Abstract

An apparatus and method is provided for removing undesired twists and loops in a power supply cable attached to a robotic swimming pool cleaner during the cleaner'"'"'s pre-programmed movement over the bottom and/or side walls of the pool. An on-board electronic compass determines an initial reference directional heading of the pool cleaner and the subsequent true or actual directional heading of the pool cleaner is determined intermittently or continuously as the pool cleaner moves through the program cycle. The subsequent directional headings of the moving pool cleaner are compared to the reference directional heading to provide a cumulative positive or negative value. When the cumulative value indicates that one or more complete 360° turns have been made from the reference directional heading, a correction signal is generated for immediate or delayed transmission to the directional control means to turn the pool cleaner in a direction to remove any twists or loops that have formed in the power cable.

Claims

1. A method for removing and preventing undesired twists and coils in a pool cleaner power supply cable extending between a remote power supply and a self-propelled pool cleaner, the pool cleaner moving on the bottom and/or side walls of a swimming pool during a cleaning cycle according to a scanning algorithm directed by a microprocessor on board the pool cleaner, a directional controller on board the pool cleaner for changing the directional heading of the pool cleaner in response to signals from the processor, and a memory device operatively coupled to the processor for storing the scanning algorithm, the method comprising steps of:

a. providing the swimming pool cleaner with an electronic compass for determining the directional heading of the moving pool cleaner;

b. providing a tilt sensor for sensing the pitch and the roll of the electronic compass that is operatively connected to the processor for determining the actual directional headings of the pool cleaner, the actual directional heading being a pitch and/or roll compensated heading that corrects the directional heading for the effects of any pitch and/or roll experienced by the pool cleaner while moving;

c. transmitting an initial reference directional heading of the moving pool cleaner to the memory device as determined by the electronic compass upon initiation of the scanning algorithm;

d. transmitting sensed pitch and/or roll data to the microprocessor and calculating an actual directional heading as the pool cleaner moves across the pool surface being cleaned;

e. transmitting a series of actual directional headings of the moving pool cleaner to the memory device during the cleaning cycle;

f. comparing each of the series of actual directional headings of the pool cleaner with the reference directional heading and transmitting to the memory device for storage the result of each comparison in the form of a positive or negative value to represent, respectively, a right or left deviation value in degrees from the reference directional heading;

g. registering the completion of an entire turn either in a number of right turns or a number of left turns depending upon the left or right deviation from the reference directional heading, when the cumulative difference between the subsequent actual directional headings and the reference directional heading is equal to, or greater than 360°

; and

h. turning the pool cleaner to the left when the number of right turns is greater than a predetermined number of left turns and turning the pool cleaner to the right when the number of right turns is less than a predetermined number of left turns, until the number of the right and left turns are equalized, thereby minimizing undesired twists and coils in the pool cleaner power supply cable.

2. The method of claim 1 in which the scanning algorithm is interrupted for the purpose of equalizing the number of right and left turns when the difference is equal to one complete turn.

3. The pool cleaner of claim 1, wherein the electronic compass is selected from the group consisting of magnetic sensors, micro-electro-mechanical systems and gyroscopic compasses.

4. A pool cleaner which moves on a bottom and/or sidewall surface of a swimming pool according to a scanning algorithm, the pool cleaner comprising:

a. a housing;

b. a power cable extending from the housing to a remote power supply;

c. an on-board memory device for storing the scanning algorithm, a start-up reference heading and a plurality of actual directional headings taken while the pool cleaner is moving after start-up, and the difference between the reference heading and the actual directional headings;

d. an electronic compass on board the pool cleaner that is coupled to the memory device for determining an initial reference directional heading and subsequent actual directional headings that are calculated by the microprocessor to correct a directional heading for any pitch and/or roll of the pool cleaner and transmitting the reference heading and actual directional headings to the memory device, wherein the electronic compass includes a tilt sensor for sensing the pitch and/or the roll of the electronic compass and the actual directional headings are directional headings corrected for any pitch and/or the roll;

e. a microprocessor operatively coupled to the memory device and the electronic compass for (i) comparing the subsequent actual directional headings of the pool cleaner with the reference directional heading stored in the memory device, (ii) transmitting the result of each comparison in the form of a positive or negative value to represent, respectively, a right or left deviation from the reference directional heading in degrees, and (iii) registering the completion of an entire turn either in a number of right turns or a number of left turns depending upon the left or right deviation from the reference directional heading, when the cumulative difference between the subsequent true directional headings and the reference directional heading is equal to or greater than 360°

or a multiple of 360°

; and

f. a directional controller on board the housing operatively coupled to the microprocessor for turning the pool cleaner to the left when the number of right turns is greater than the number of left turns and turning the pool cleaner to the right when the number of left turns is greater than the number of right turns, until the number of the right and left turns are equalized, thereby minimizing undesired twists and coils in the power cable.

5. The pool cleaner of claim 4 in which the reference heading is tilt-compensated.

6. The pool cleaner of claim 4 in which the scanning algorithm is interrupted for the purpose of equalizing the number of right and left turns when the difference is equal to or greater than a predetermined number of turns.

7. The pool cleaner of claim 6 in which the scanning algorithm is interrupted when the difference between right and left turns is equal to at least two.

8. The pool cleaner of claim 4 in which the electronic compass is selected from the group consisting of magnetic sensors, micro-electro-mechanical systems and gyroscopic compasses.

9. A method for preventing or minimizing undesired twists and coils of a tethered cable attached to a pool cleaner moving along the bottom and/or sidewall surfaces of a pool during a cleaning cycle, said cleaner including a microprocessor for executing a scanning algorithm for controlling the directional heading of the pool cleaner and responding to signals received from directional sensing circuitry including a tilt sensor and a magnetic field sensor, the method comprising steps of:

a) sensing, by the magnetic field sensor, directional deviations of the cleaner with respect to a straight path of movement, said directional deviations including clockwise and counter-clockwise deviations from the straight path;

b) sensing, by the tilt sensor, the pitch and/or the roll of the cleaner and determining the actual directional headings of the pool cleaner, the actual directional heading being a pitch and/or roll compensated heading that corrects the directional heading for any pitch and/or roll experienced by the pool cleaner while moving;

c) communicating directional deviation information from the magnetic field sensor to the microprocessor;

d) storing the number of clockwise and counter-clockwise turns made by the cleaner in memory of the directional sensing circuitry;

e) comparing the number of clockwise and counter-clockwise turns made by the cleaner and registering the difference in the number of turns in each direction; and

f) turning the pool cleaner clockwise when the number of counter-clockwise turns exceeds a predetermined number of clockwise turns, and turning the pool cleaner counter-clockwise when the number of clockwise turns exceeds a predetermined number of counter-clockwise turns so as to equalize the number of turns in each direction, thereby minimizing undesired twists and coils in the tethered cable.

10. The method of claim 9 wherein the scanning algorithm is interrupted when the difference between the number of clockwise and counter-clockwise turns made by the cleaner is greater than the predetermined number.

11. The method of claim 9, wherein the tilt sensor indicates the orientation of the directional sensing circuit in pitch/roll axes, the orientation data being communicated to the directional sensing circuitry to determine whether the orientation of the magnetic field sensor will prevent accurate directional measurement.

12. The method of claim 9, wherein the tilt sensor indicates the orientation of the directional sensing circuit in pitch/roll axes and transmits information to the directional sensing circuitry to compensate for errors in measurement caused by a deviation of the magnetic field sensor from a horizontal attitude.

13. A pool cleaner which moves on a bottom and/or sidewall surface of a swimming pool according to a scanning algorithm, the pool cleaner comprising:

a. a housing having at least a pair of rotational support members for moving said cleaner along the surface of the pool;

b. a power cable extending from the housing for receiving electrical power from a remote power supply;

c. at least one motor for rotating said rotational support members;

d. directional sensing circuitry for sensing movement deviations of the pool cleaner with respect to a straight line path, said directional sensing circuitry including an electronic compass and a tilt sensor for sensing the pitch and/or roll of the cleaner and a microprocessor for receiving a signal from the electronic compass corresponding to the directional heading and for receiving a signal from the tilt sensor corresponding to any pitch and/or roll experienced by the pool cleaner, and determining an actual directional heading that corrects the directional heading for the pitch and/or roll;

e. a directional controller having memory for storing the scanning algorithm and a processor operatively coupled to the directional sensing circuitry for (i) receiving, from said directional sensing circuitry, communication signals representing clockwise and counter-clockwise turns made by the cleaner;

(ii) comparing the number of clockwise and counter-clockwise turns made by the cleaner;

(iii) registering the number of clockwise and counter-clockwise turns made by the cleaner, and calculating the difference therebetween; and

(iv) controlling power to the at least one motor to turn the pool cleaner counter-clockwise when the number of clockwise turns exceeds the number of counter-clockwise turns by a pre-determined amount and turning the pool cleaner clockwise when the number of counter-clockwise turns exceeds the number of clockwise turns by a predetermined amount, wherein the twisting of the power cable during cleaning does not exceed a predetermined operational limit, thereby minimizing undesired twists and coils in the power cable.

14. The pool cleaner of claim 13 in which the directional sensing circuit comprises a magnetic field sensor.

15. The pool cleaner of claim 13, wherein the directional sensing circuitry includes an electronic compass which is selected from the group consisting of magnetic sensors, micro-electro-mechanical systems and gyroscopic compasses.