Drain cover detection systems and methods
Systems and methods of detecting when an automatic swimming pool cleaner (APC) has contacted a main drain cover or other object protruding from a surface of a swimming pool are described. An APC may include equipment for detecting a change in its pitch or yaw (or both its pitch and yaw). Changes in pitch and yaw may be determined as a function of time, identifying encounters of the APC with certain protruding objects.
1. A method for detecting an encounter of an automatic swimming pool cleaner with an object protruding from a pool surface, comprising:
a. causing the automatic swimming pool cleaner to move along the pool surface; and
b. causing detection of a change of pitch of a body of the automatic swimming pool cleaner from a first position to a predetermined pitch angle;
c. activating a time counter based on the detected change of pitch; and
d. causing detection of the encounter of the automatic swimming pool cleaner based on the body returning to a pitch angle less than the predetermined pitch angle within a determined time period.
2. A method according to claim 1 in which the change of pitch is detected as a function of time.
3. A method according to claim 1 in which the step of causing detection of a change of pitch of a body of an automatic swimming pool cleaner comprises:
(a) detecting transition of the body from a substantially level position as the first position to the predetermined pitch angle, wherein the predetermined pitch angle is between approximately 5-15°; and
(b) detecting transition of the body to a second pitch angle of no greater than approximately 5° as the pitch angle less than the predetermined pitch angle within the determined time period.
4. A method according to claim 1 in which the object is a main drain cover.
5. A method for detecting an encounter of an automatic swimming pool cleaner with an object protruding from a pool surface, comprising:
a. causing the automatic swimming pool cleaner to move along the pool surface; and
b. causing detection of a change of yaw of a body of the automatic swimming pool cleaner from a first position to a predetermined yaw angle;
c. activating a time counter based on the detected change of yaw; and
d. causing detection of the encounter of the automatic swimming pool cleaner based on the body returning to a yaw angle less than the predetermined yaw angle within a determined time period.
6. A method according to claim 5 in which the change of yaw is detected as a function of time.
7. A method according to claim 5 in which the step of causing detection of a change of yaw of a body of an automatic swimming pool cleaner comprises detecting whether the body has turned through a yaw angle of no greater than approximately 5° as the predetermined yaw angle within the determined time period.
8. A method according to claim 5 in which the object is a main drain cover.
9. A method for detecting an encounter of an automatic swimming pool cleaner with an object protruding from a pool surface, comprising:
a. causing the automatic swimming pool cleaner to move along the pool surface;
b. causing detection of changes of both pitch and yaw of a body of the automatic swimming pool cleaner;
c. activating a time counter based on the detected change of pitch and the detected change of yaw; and
d. causing detection of the encounter of the automatic swimming pool cleaner with the object protruding from the pool surface based on the body returning to a lesser pitch angle or a lesser yaw angle within a determined time period.
10. A method according to claim 9 in which the changes of both pitch and yaw are detected as at least one function of time.
11. A method according to claim 9 in which the step of causing detection of changes of body pitch and yaw of a body of an automatic swimming pool cleaner comprises:
(a) detecting transition of the body from a substantially level position to a pitch angle between approximately 5-15°; and
(b) detecting whether the body has turned through a yaw angle of no greater than approximately 5° within the determined time period.
12. A method according to claim 9 in which the object is a main drain cover.