Patent Grant
8769747
The present invention relates to a system and method for adjusting the pressure in an inflatable object. More particularly, the present invention relates to a system and method for adjusting the pressure in an air bed in less time and with greater accuracy.
Advances made in the quality of air beds having air chambers as support bases have resulted in vastly increased popularity and sales of such air beds. These air beds are advantageous in that they have an electronic control panel which allows a user to select a desired inflation setting for optimal comfort and to change the inflation setting at any time, thereby providing changes in the firmness of the bed.
Air bed systems, such as the one described in U.S. Pat. No. 5,904,172 which is incorporated herein by reference in its entirety, generally allow a user to select a desired pressure for each air chamber within the mattress. Upon selecting the desired pressure, a signal is sent to a pump and valve assembly in order to inflate or deflate the air bladders as necessary in order to achieve approximately the desired pressure within the air bladders.
In one embodiment of an air bed system, there are two separate air hoses coupled to each of the air bladders. A first air hose extends between the interior of the air bladder and the valve assembly associated with the pump. This first air hose fluidly couples the pump to the air bladder, and is structured to allow air to be added or removed from the air bladder. A second hose extends from the air bladder to a pressure transducer, which continuously monitors the pressure within the air bladder. Thus, as air is being added or removed from the air bladder, the pressure transducer coupled to the second hose is able to continuously check the actual air bladder pressure, which may then be compared to the desired air pressure in order to determine when the desired air pressure within the bladder has been reached.
In another embodiment of an air bed system, there is only a single hose coupled to each of the air bladders. In particular, the hose extends between the interior of the air bladder and the valve assembly associated with the pump, and is structured to allow air to be added or removed from the air bladder. Instead of having a second hose with a pressure transducer coupled thereto for continuously reading the pressure within the air bladder, a pressure transducer is positioned within a chamber of the valve assembly. Once the user selects the desired air pressure within the air bladder, the pressure transducer first senses a pressure in the chamber, which it equates to an actual pressure in the air bladder. Then, air is added or removed from the bladder as necessary based upon feedback from the sensed pressure. After a first iteration of sensing the pressure and adding or removing air, the pump turns off and the pressure within the chamber is once again sensed by the pressure transducer and compared to the desired air pressure. The process of adding or removing air, turning off the pump, and sensing pressure within the chamber is repeated for several more iterations until the pressure sensed within the chamber is within an acceptable range close to the desired pressure. As one skilled in the art will appreciate, numerous iterations of inflating and deflating the air bladder may be required until the sensed chamber pressure falls within the acceptable range of the desired pressure.
Thus, while this second embodiment of an air bed system may be desired because it minimizes the necessary number of hoses, it is rather inefficient in that numerous iterations may be required before the sensed pressure reaches the desired pressure. Furthermore, the pump must be turned off each time the pressure transducer takes a pressure measurement, which increases the amount of time that the user must wait until the air bladder reaches the desired pressure.
Therefore, there is a need for an improved pressure adjustment system and method for an air bed that is able to minimize the amount of time and the number of adjustment iterations necessary to achieve a desired pressure in an air bladder, while also increasing the accuracy of the actual bladder pressure.
The present invention solves the foregoing problems by providing a method for adjusting pressure within an air bed comprising providing an air bed that includes an air chamber and a pump having a pump housing, selecting a desired pressure setpoint for the air chamber, calculating a pressure target, adjusting pressure within the air chamber until a pressure within the pump housing is substantially equal to the pressure target, determining an actual chamber pressure within the air chamber, and comparing the actual chamber pressure to the desired pressure setpoint to determine an adjustment factor error. The pressure target may be calculated based upon the desired pressure setpoint and a pressure adjustment factor. Furthermore, the pressure adjustment factor may be modified based upon the adjustment factor error determined by comparing the actual chamber pressure to the desired pressure setpoint.
The present invention also provides a pressure adjustment system for an air bed comprising an air chamber, a pump in fluid communication with the air chamber and including a pump manifold and at least one valve, an input device adapted to receive a desired pressure setpoint selected by a user, a pressure sensing means adapted to monitor pressure within the pump manifold, and a control device operably connected to the input device and to the pressure sensing means. The control device includes control logic that is capable of calculating a manifold pressure target based upon the desired pressure setpoint and a pressure adjustment factor, monitoring pressure within the pump manifold, adjusting pressure within the air chamber until the sensed manifold pressure is within an acceptable pressure target error range of the manifold pressure target, comparing an actual chamber pressure to the desired pressure setpoint to quantify an adjustment factor error, and calculating an updated pressure adjustment factor based upon the adjustment factor error.
Referring now to the figures, and first to
As illustrated in
Pump 20 is preferably in two-way communication with control box 24. Also in two-way communication with control box 24 is hand-held remote control 22. Pump 20 includes motor 42, pump manifold 43, relief valve 44, first control valve 45A, second control valve 45B, and pressure transducer 46, and is fluidly connected with left chamber 14A and right chamber 14B via first tube 48A and second tube 48B, respectively. First and second control valves 45A and 45B are controllable by switching means 38, and are structured to regulate the flow of fluid between pump 20 and first and second chambers 14A and 14B, respectively.
In operation, power supply 34 receives power, preferably 110 VAC power, from an external source and converts it to the various forms required by the different components. Microprocessor 36 is used to control various logic sequences of the present invention. Examples of such sequences are illustrated in
The embodiment of system 10 shown in
In the event that microprocessor 36 sends a decrease pressure command to one of the chambers, switching means 38 is used to convert the low voltage command signals sent by microprocessor 36 to higher operating voltages sufficient to operate relief valve 44 of pump 20. Alternatively, switching means 38 could be located within pump 20. Opening relief valve 44 allows air to escape from first and second chambers 14A and 14B through air tubes 48A and 48B. During deflation, pressure transducer 46 sends pressure readings to microprocessor 36 via A/D converter 40. ND converter 40 receives analog information from pressure transducer 46 and converts that information to digital information useable by microprocessor 36.
In the event that microprocessor 36 sends an increase pressure command, pump motor 42 may be energized, sending air to the designated chamber through air tube 48A or 48B via the corresponding valve 45A or 45B. While air is being delivered to the designated chamber in order to increase the firmness of the chamber, pressure transducer 46 senses pressure within pump manifold 43. Again, pressure transducer 46 sends pressure readings to microprocessor 36 via A/D converter 40. Microprocessor 36 uses the information received from A/D converter 40 to determine the difference between the actual pressure in the chamber 14 and the desired pressure. Microprocessor 36 sends the digital signal to remote control 22 to update display 26 on the remote control in order to convey the pressure information to the user.
Generally speaking, during an inflation or deflation process, the pressure sensed within pump manifold 43 provides an approximation of the pressure within the chamber. However, when it is necessary to obtain an accurate approximation of the chamber pressure, other methods must be used.
One method of obtaining a pump manifold pressure reading that is substantially equivalent to the actual pressure within a chamber is to turn off the pump, allow the pressure within the chamber and the pump manifold to equalize, and then sense the pressure within the pump manifold with a pressure transducer. Thus, providing a sufficient amount of time to allow the pressures within the pump manifold 43 and the chamber to equalize may result in pressure readings that are accurate approximations of the actual pressure within the chamber. One obvious drawback to this type of method is the need to turn off the pump prior to obtaining the pump manifold pressure reading.
A second method of obtaining a pump manifold pressure reading that is substantially equivalent to the actual pressure within a chamber is through use of the pressure adjustment method in accordance with the present invention. The pressure adjustment method is described in detail in
As those skilled in the art will appreciate, by assuming current source 52 is a constant current source, pressure readings may be analogized with voltage readings. Thus, in reference to the circuit diagram 50 in
Furthermore, weight positioned on a chamber (such as that caused by the user lying on bed 12) is directly related to the volume of the chamber and does not affect the ability of the system to measure the pressure within the chamber. In addition, because the system measures pressure in real time, weight changes do not affect the ability of the control system to accurately measure chamber pressure.
The relationship between the voltage on first or second capacitors 51A or 51B and the voltage sensed at voltage sensing lead 57 is dependent upon whether current is flowing toward the capacitor (i.e., the chamber is going through an inflation cycle) or away from the capacitor (i.e., the chamber is going through a deflation cycle). In particular, and as will be discussed in detail with reference to
The relationship between voltage associated with a chamber capacitor (i.e., the “chamber voltage”) and the sensed “manifold” voltage during an inflation cycle may be stated as follows:
Chamber Voltage=(Manifold Voltage)−(Inflate Factor) (Eq. 1)
Restated in terms of pressure, the relationship between the pressure within a chamber and a sensed manifold pressure during an inflation cycle may be stated as follows:
Chamber Pressure=(Manifold Pressure)−(Inflate Factor) (Eq. 2)
In one exemplary embodiment, the inflate offset factor may generally fall in a range between about 0.0201 and about 0.1601. Because pressure readings may be analogous to voltage readings as discussed previously, the value of the inflate offset factor will be the same regardless of whether the relationship between the chamber and the pump manifold is being stated in terms of pressure or voltage.
The relationship between voltage associated with a chamber capacitor and the sensed manifold voltage during a deflation cycle may be stated as follows:
Chamber Voltage=(Manifold Voltage)×(Deflate Factor) (Eq. 3)
Restated in terms of pressure, the relationship between the pressure within a chamber and a sensed manifold pressure during a deflation cycle may be stated as follows:
Chamber Pressure=(Manifold Pressure)×(Deflate Factor) (Eq. 4)
In one exemplary embodiment, the deflate factor may generally fall in a range between about 1.6 and about 6.5. Once again, because pressure readings may be analogous to voltage readings as discussed previously, the value of the deflate factor will be the same regardless of whether the relationship between the chamber and the pump manifold is being stated in terms of pressure or voltage.
In particular, a first portion 71 of the graph 70 between about 0 ms and about 65000 ms represents the inflation of a chamber from about 0 psi to about 0.6 psi. A second portion 72 of the graph 70 between about 65000 ms and about 135000 ms represents the pressure in the chamber being maintained at about 0.6 psi. Finally, a third portion 73 of the graph 70 between about 135000 ms and about 200000 ms represents deflation of the chamber from about 0.6 psi to about 0 psi.
With further reference to the graph in
Now that a brief description of an air bed system and the relationship between chamber and pump manifold pressures have been provided, one embodiment of an improved pressure adjustment method according to the present invention will be described in detail. For purposes of discussion only, the pressure adjustment method in accordance with the present invention will be described in reference to first chamber 14A. However, those skilled in the art will appreciate that the pressure adjustment method applies in a similar manner to other chambers, such as second chamber 14B of bed 12.
In particular,
The sequence continues at step 106 where microprocessor 36 detects whether a new pressure setpoint has been selected by the user to either increase or decrease the pressure in first chamber 14A. The new pressure setpoint may be a pressure that is either higher or lower than the current pressure in first chamber 14A, as desired by the user. As will be appreciated by those skilled in the art, the range of possible chamber pressures is not important to the operation of the present invention. Thus, numerous pressure ranges are contemplated. The new pressure setpoint may be selected by, for example, manipulating pressure increase button 29 or pressure decrease button 30 on manual remote control 22. Alternatively, the pressure increase and decrease buttons may be provided on another component of system 10, such as pump 20.
If microprocessor 36 does not detect that a new pressure setpoint has been selected, the sequence then continues at step 108 where microprocessor 36 determines whether or not there has been an interfering event, such as a loss in power. If microprocessor 36 determines that a loss in power has occurred, the adjustment factors are then discarded in step 110 and the sequence loops back to step 102 to monitor for the occurrence of another power-on event. However, if microprocessor 36 determines that a loss in power has not occurred, the sequence enters monitoring loop 112 where microprocessor 36 continually monitors whether a new pressure setpoint is selected in step 106 or whether a loss in power has occurred in step 108.
Alternatively, if microprocessor 36 detects that a new pressure setpoint has been selected in step 106, then the sequence continues to pressure adjustment method 150 as will be described in detail in reference to
As will be appreciated by those skilled in the art, air bed system 10 may include a back-up power source such that if the power to power supply 34 is interrupted, the pressure adjustment factors remain stored within memory 37. As a result, it may be possible to avoid the discarding step previously described.
In step 158, microprocessor 36 determines if inflation or deflation of first chamber 14A is required. If it is determined in step 158 that deflation of first chamber 14A is required, the method continues at step 160 where microprocessor 36 calculates a deflate pressure target, which corresponds to the sensed manifold pressure that will yield the desired pressure setpoint during a deflation cycle. In particular, the deflate pressure target may be calculated through use of Equation 4 above. Based upon the relationship between chamber pressure and manifold pressure during a deflation cycle recited in Equation 4, the deflate pressure target may calculate as follows:
Deflate Manifold Pressure Target=(Desired Pressure Setpoint)/(Deflate Factor)
The first time the user selects a new pressure setpoint that requires deflation of first chamber 14A, the deflate factor will be set to the default value of 2.25 discussed above in step 104. However, as will be discussed in further detail to follow, this deflate factor will be modified at a later step in order to more accurately reflect the mathematical relationship between the chamber pressure and the sensed manifold pressure for that particular user.
Once the deflate pressure target is calculated in step 160, microprocessor 36 instructs pump 20 to begin the deflate operation in step 162.
Alternatively, if it is determined in step 158 that inflation of first chamber 14A is required, the method continues at step 164 where microprocessor 36 calculates an inflate pressure target. The inflate pressure target corresponds to the sensed manifold pressure that will yield the desired pressure setpoint during an inflation cycle. In particular, the inflate pressure target may be calculated through use of Equation 2 above. Based upon the relationship between chamber pressure and manifold pressure during an inflation cycle recited in Equation 2, the inflate pressure target may calculate as follows:
Inflate Manifold Pressure Target=(Desired Pressure Setpoint)+(Inflate Offset Factor)
The first time the user selects a new pressure setpoint that requires inflation of first chamber 14A, the inflate factor will be set to the default value of 0.0505 discussed above in step 104. However, as will be discussed in further detail to follow, this inflate factor will be modified at a later step in order to more accurately reflect the mathematical relationship between the chamber pressure and the sensed manifold pressure for that particular user.
Once the inflate pressure target is calculated in step 164, microprocessor 36 instructs pump 20 to begin the inflate operation in step 166.
After performing the pressure deflate operation in step 162 or the pressure inflate operation in step 166 as required, the manifold pressure within pump manifold 43 is once again sampled in step 168. Because either motor 42 of pump 20 has been running in order to inflate first chamber 14A, or relief valve 44 has been open in order to deflate first chamber 14A, the manifold pressure sampled in step 168 is now instable and by itself does not provide an accurate representation of the actual pressure within first chamber 14A. However, because of the known relationship between manifold pressure and chamber pressure discussed previously, the present invention is able to accurately approximate the actual chamber pressure based upon a sensed manifold pressure. Therefore, after the manifold pressure has once again been sampled, the method continues at step 170 where microprocessor 36 compares the sampled manifold pressure to the manifold pressure target calculated in either step 160 or step 164 to determine if the manifold pressure target has been achieved.
Similar to the process utilized in step 154, microprocessor 36 calculates the difference between the sampled manifold pressure and the manifold pressure target and compares the difference to a predetermined, pressure target error. The pressure target error may be any value greater than or equal to zero. If the absolute value of the difference between the sampled manifold pressure and the manifold pressure target is greater than the acceptable pressure target error, then further inflation or deflation is required. As a result, pressure adjustment method 150 returns along path 172 to either deflate operation 162 or inflate operation 166, depending upon whether the manifold pressure sampled in step 168 was less than or greater than the manifold pressure target. On the other hand, if the difference between the sampled manifold pressure and the manifold pressure target is within the pressure target error limit, then no further inflation or deflation is necessary, and the pressure adjustment method continues at step 174 where the inflate or deflate operation is ended.
Next, pressure transducer 46 once again samples the pressure within pump manifold 43 at step 176. Because all inflate or deflate operations have ceased, air is neither flowing into nor out of first chamber 14A, and the manifold pressure sampled in step 176 is substantially stable and a fairly accurate approximation of the actual pressure within first chamber 14A. After the manifold pressure has been sampled again in step 176, the sequence continues at step 178 where microprocessor 36 compares the “actual” manifold pressure sampled in step 176 with the “expected” user setpoint pressure previously selected by the user (in step 106) to determine if the desired setpoint pressure has been achieved. If the actual manifold pressure sampled in step 176 is not substantially equal to the expected setpoint pressure selected by the user, then an adjustment must be made to the pressure adjustment factor. An updated adjustment factor is therefore determined based upon a comparison between the sensed pressure and the desired setpoint pressure, and the pressure adjustment factor is thereafter modified in step 180.
With regard to the deflate pressure adjustment factor, an updated factor may be calculated in the following manner:
Updated Deflate Adjustment Factor=(Pressure Setpoint from Step 106)/(Manifold Pressure from Step 168)
With regard to the inflate pressure adjustment factor, an updated factor may be calculated in the following manner:
Updated Inflate Adjustment Factor=(Manifold Pressure from Step 168)−(Pressure Setpoint from Step 106)
Next, the method loops back to step 152 where pressure transducer 46 samples the pressure within pump manifold 43. Once the manifold pressure has again been sampled in step 152 after a first “iteration” of adjustments, the method continues at step 154 where microprocessor 36 compares the sampled manifold pressure to the desired pressure selected by the user (in step 106) to determine if a further adjustment is required. For instance, if the pressure adjustment factor had to be modified in step 180 of the previous pressure adjustment iteration, then a further adjustment will most likely be required because the fact that the pressure adjustment factor had to be modified indicates that the actual pressure in chamber 14A is not equal to the desired pressure setpoint selected by the user. In this case, at least one more pressure adjustment iteration will be required before the actual chamber pressure is substantially equal to the desired pressure setpoint. However, if it is determined in step 154 that the absolute value of the difference between the sampled manifold pressure and the desired pressure setpoint is less than or equal to the acceptable error, then no adjustment is required, and the pressure adjustment method ends at step 156 where microprocessor 36 determines that the pressure adjustment process is complete.
After completing the pressure adjustment method 150, microprocessor 36 return back to pressure setpoint monitoring method 100 illustrated in
As those skilled in the art will appreciate, the default pressure adjustment factors corresponding to both the deflate and inflate operations must be replaced after the detection of a power-on event because these default factors are only temporary and based upon the size of an average user. Therefore, when microprocessor 36 detects an increase in the desired pressure setpoint for the first time at step 106, then execution of pressure adjustment method 150 will result in a customized inflate pressure adjustment constant being determined that replaces the temporary default constant. Similarly, when microprocessor 36 detects a decrease in the desired pressure setpoint for the first time at step 106, then execution of pressure adjustment method 150 will result in a customized default pressure adjustment constant being determined that replaces the temporary default constant. Furthermore, when microprocessor 36 detects subsequent increases or decreases in the desired pressure setpoint after the default constants have been replaced, the customized default constants may continue to be updated and replaced in step 114 to maintain the highest degree of accuracy when performing pressure adjustments and to take into account changes in the user such as, for example, an increase or decrease in the weight of the user. Thus, while it is not necessary to “update” the customized adjustment constants after initially replacing the temporary default adjustment constants after a power-on event, performing such updates may increase the accuracy of future pressure adjustments.
In addition to the steps previously described above in reference to
With regard to steps 151 and 182, the number of pressure adjustment “attempts” may be tracked to limit the number of pressure adjustment iterations that pressure adjustment method 150A may perform after a new pressure setpoint has been selected. In particular, prior to sensing manifold pressure in step 152, microprocessor 36 determines if the number of remaining attempts is greater than zero. If the number of attempts remaining is greater than zero, then the method continues at step 154 where microprocessor 36 determines if a pressure adjustment is required. However, if the number of attempts remaining is not greater than zero, then the method instead continues at step 156 where the pressure adjustment is presumed to be complete. Thus, pressure adjustment method 150A may allow for a predetermined number of iterations before the pressure adjustment method “times out.” In one exemplary embodiment, the default number of attempts may be set to four. However, any number of attempts are possible and within the intended scope of the present invention.
If the pressure adjustment factor (either inflate or deflate) is modified in step 180, then the number of remaining attempts is decremented by one attempt in step 182. Therefore, if the desired pressure setpoint is not reached within four attempts, no further pressure adjustment is attempted and the pressure adjustment factor corresponding to the final iteration will be used to update the temporary default adjustment constant as previously discussed.
With regard to step 173, the amount of time elapsed during a pressure adjustment operation may also be also be tracked. As discussed above, if it is determined in step 170 that the pressure target has not been achieved, pressure adjustment method 150A returns along path 172 to either deflate operation 162 or inflate operation 166, depending upon whether the manifold pressure sampled in step 168 was less than or greater than the manifold pressure target. However, prior to reaching either deflate operation step 162 or inflate operation step 166, the method first enters step 173 where microprocessor 36 monitors the time that has elapsed since the initial determination was made in step 170 regarding whether or not the manifold pressure target has been achieved. Thus, if the amount of elapsed time is less than a maximum, predetermined time period, the sequence continues within loop 172 to inflate or deflate first chamber 14A as necessary in an attempt to achieve the manifold pressure target. However, if the desired pressure target has not been reached when microprocessor 36 determines that the maximum time period has expired, then the method exits loop 172 and advances directly to step 156, where no further adjustment will be attempted.
The maximum, predetermined time period may be any value greater than zero. However, in one exemplary embodiment of pressure adjustment method 150A, the maximum time period may be about 30 minutes. Generally speaking, the maximum time period may be selected such that the manifold pressure target is not achieved prior to the expiration of the maximum time period only if air bed system 10 is not functioning properly. For example, if first tube 48A becomes disconnected from first chamber 14A, it will most likely not be possible to attain the manifold pressure target in step 170. Under these circumstances, and without the addition of the time tracking step 173, pump 20 may continue to run until the user disconnects power from the pump or notices that first tube 48A has been disconnected from first chamber 14A.
Workers skilled in the art will appreciate that although the features added in steps 151, 173, and 182 are not necessary components of the present invention, their presence helps to optimize the operation of the pressure adjustment method by preventing the method from being trapped in a “continuous loop” of attempting to reach the desired pressure setpoint. Furthermore, it will be obvious to those skilled in the art that the order and number of steps described in reference to
Referring now to
Network 200 may be integrated either locally or accessible via a public network protocol such as the Internet 202 and optionally through an Internet service provider 204. Connection to network 200 may be wired or wireless, and may incorporate control from a detached device (e.g., handheld, laptop, tablet, or other mobile device). In addition, microprocessor 36 may be accessible remotely by a third party user 206 via Internet 202 and/or Internet service provider 204.
Network 200 may be configured to enable remote pressure adjustment of an air bed system by a third party user 206, such as by a customer service representative at a remote location. In particular, the customer service representative may be able to remotely connect to Internet 202 and assist the user in performing a pressure adjustment set-up, such as pressure adjustment method 150 previously described, in order to optimize the accuracy and operation of the pressure adjustment method. Network 200 may also be configured to allow the customer service representative to access and store the customized pressure adjustment factors in, for example, a central storage system in case of a power loss or similar event. Numerous other advantages of network 200 will be appreciated by those having ordinary skill in the art.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2008/059409 | 4/4/2008 | WO | 00 | 10/1/2010 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2009/123641 | 10/8/2009 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20110138539 A1 | Jun 2011 | US |
