The present invention relates to controls for plumbing devices, and more particularly to plumbing devices automatically triggered by infrared-based object detection.
Object detection systems that use infrared (IR) signals to trigger plumbing device operation, such as operation of an automatic faucet, are known. Typically, these systems utilize a single IR emitter and an IR detector to control fluid flow based upon object detection within a defined region. A control activates the IR emitter and then monitors the IR detector for reflections of infrared light from objects (such as a user's hands) that are sensed and used to determine whether to activate or deactivate a solenoid valve.
The object detection systems are typically designed and implemented integral to the plumbing device. Disadvantageously, this may result in the failure of the plumbing device to trigger operation until the user's hand is directly under the faucet. The object detection systems also are prone to false triggering as a result of unwanted reflections off of surrounding objects, such as a sink, or off the water stream itself. If the reflection off the water stream is not avoided, the solenoid valve may become locked-on, thus resulting in a waste of water and annoyance to the user.
Accordingly, it is desirable to provide an improved automatic plumbing device that provides a more tailored detection area and reduces false triggering caused by reflections.
An automatic plumbing device according to the present invention provides improved object detection in a desired volume.
The automatic plumbing device of the present invention includes a first IR emitter, a second IR emitter and an IR receiver mounted within a plumbing body. The two IR emitters and the IR receiver are configured so that objects in a sensitivity volume are detected. A controller manages the detection process and controls the operation of the IR emitters in sequence to yield emissions within a first region of sensitivity and a second region of sensitivity. Based on emitted returns received through the IR receiver from the first region of sensitivity and the second region of sensitivity, the controller opens or closes a valve using a solenoid control. In some forms of the invention, the first region of sensitivity and the second region of sensitivity are more narrowly tailored by a first and second mask.
Delay circuitry may allow water to flow for a period of time after the last object is detected, and limits the total length of time that water can constantly run. A voltage regulator and low battery detector detects whether the power being supplied to the circuit is adequate (e.g., above a certain threshold voltage).
The invention may be used as part of a faucet, although other plumbing applications are within the scope of this invention.
The automatic plumbing device according to the present invention provides a more tailored detection region and reduces false triggering of the device caused by reflections.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
Referring to
The water faucet 10 defines a spout section 11 and a base section 14. The base section 14 includes a housing 16 for housing the object detection system 12 of the present invention. A pipe 17 communicates a liquid, such as water, through the base section 14 to the spout section 11 where the water exits the water faucet 10.
Referring to
Referring to
The controller 36 selectively and periodically activates the IR emitter 18 and the IR emitter 20 to cause returns to be received at the IR receiver 22. The levels of these returns vary depending on whether an object is present within the sensitivity volume 34. A filter/amplifier 40 conditions the signal from the IR receiver 22 and provides it to a comparator 42. The comparator 42 compares the filtered and amplified signal from the filter/amplifier 40 to a threshold provided by the controller 36 to provide a comparison output to controller 36. The controller 36 applies the logic and method described below to actuate a solenoid control 44, which turns the associated plumbing device on and off when appropriate. Power to the controller 36, such as by one or more dry cells (not shown), is monitored by a voltage regulator/low battery detector 46. If the voltage regulator/low battery detector 46 indicates a power problem, or if another error condition is indicated, the controller 36 activates a status alert 48 to notify a user or maintenance worker of the problem.
Referring to
The system determines at decision block 130 whether a faucet valve is in an “on” position. If so, a watchdog timer (implemented using the controller 36 or other means as would occur to one skilled in the art) is updated at block 133. If the updated watchdog timer reflects that the faucet valve has been on more than a predetermined amount of time (thirty seconds, for example), as determined at decision block 135, the microcontroller 36 closes the faucet valve using the solenoid control 44 and sets the watch dog timer (“WDT”) flag, these steps being combined at block 137. Then, or following a negative result at block 135, or upon a negative result of block 130, the system proceeds to decision block 140.
At decision block 140, the controller 36 checks its input from the voltage regulator/low battery detector 46 to determine whether the power supply is low. If so, the controller 36 executes a power monitor and status routine at block 145 and returns to decision block 130. This routine determines whether to initiate low-power-consumption measures; set an audio, visual, or other alarm; and/or take other action as would occur to one skilled in the art.
Upon a negative result at decision block 140, the controller 36 refreshes the sensor reference voltage at block 150 using one or more techniques that would occur to one skilled in the art. The controller 36 then runs a detection test at block 160. In doing so, the elements of system 100 cooperate to “ping” the faucet environment using the IR emitter 18 and receive the result using the IR receiver 22. The controller 36 then pauses to allow the system to settle and verify that the IR return being received has returned to a nominal level. The system then emits a ping using the IR emitter 20 and reads the return using the IR receiver 22, then pauses to allow the system to settle again and verify once more that the IR return has dropped to a nominal level.
Then, at decision block 170, the system evaluates whether an object has been detected in the sensitivity volume 34 by comparing the returns received at the IR receiver 22 during the detection test at decision block 160 to a threshold value provided by the controller 36. The threshold value is a stored return level value representing what the return level value would be (plus or minus a range of error) in the event an object, such as a hand, is within the sensitivity volume 34. The threshold value must be detected during the first ping and the second ping of the detection test at decision block 160 before the controller 36 recognizes an object within the sensitivity volume 34. If an object has been detected at decision block 170, the system determines at decision block 172 whether the WDT flag is set. After a negative result at decision block 172, the system returns to decision block 130.
If the result of decision block 172 is positive (i.e., the WDT flag is reset), the system determines (using the solenoid control 44 or an internal copy of its state) whether the faucet valve is in an “on” position. If so, the “off delay timer” is reset at block 176, and the system returns to decision block 130. If, however, the result of decision block 174 is negative (i.e., the faucet valve is off), the system turns on the faucet valve and sets the ON flag at block 178. The system then returns to decision block 130.
If there is a negative result at decision block 170 (i.e., one or both pings at decision block 160 produced negative results), the WDT flag is reset at block 180. The system then tests the ON flag to determine at block 190 whether the faucet valve is on. If not, the system returns to decision block 130.
If the faucet valve is on (i.e., there is a positive result at decision block 190), the off delay timer is updated at block 192. The off delay timer is tested at decision block 194 to determine whether it reflects a period greater than a predetermined length of time (e.g., two seconds). If the time is less than the predetermined amount (negative result at block 194), the system returns to decision block 130. Otherwise (positive result at block 194) the faucet valve is turned off and the flags are reset at block 196, then the system returns to decision block 130.
An alternative embodiment of the present invention is shown in
While IR emitters have been disclosed, other emitters capable of creating a deflected signal may be utilized within this invention.
That the foregoing description shall be interpreted as illustrative and not in a limiting sense is thus made apparent. A worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claim should be studied to determine the true scope and content of this invention.