Abstract:
A low-power, wireless, inflatable bladder damper device for controlling the flow of air through an airflow channel, and a method of operation for the same. Rather than requiring power supply and/or control wiring for operation of a wireless damper device, a low-power inflatable bladder damper device that requires no external wiring for operation can be used. A completely wireless damper device can reduce the cost of installation of damping devices in airflow channels, as well as the complexity of installation, while at the same time providing improved control of airflow throughout an airflow system.

Description:
BACKGROUND  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates in general to the control of airflow in forced air systems, and more particularly to a low power, wireless, inflatable bladder zoning damper.  
         [0003]     2. Description of Related Art  
         [0004]     Dampers have applications in airflow systems to control the flow of air throughout a system. They may be used in, for example, airflow channels (i.e. ducts) of a heating, ventilation, and air conditioning (HVAC) system in a building or automobile to improve the control of air temperature at various locations. Such improved control can enhance the effectiveness and efficiency of the airflow system by more effectively utilizing the system to control the temperature of a room and/or the temperature of portions of a larger room.  
         [0005]     Dampers previously used in HVAC systems include those that are activated and controlled by a user manually modifying the position of the damper at the location of the damper in the airflow system. Such dampers include butterfly plates and vane dampers. This type of damper system can be undesirable because it requires the user to physically access dampers at their locations in the airflow system in order control the flow of air throughout the system. Dampers in certain locations in the airflow system may not be easily accessible, and in large and/or complex systems, it may be inefficient to require each damper to be physically accessed at its location in the airflow system and manually activated and controlled to optimize airflow in the system. Additionally, such systems do not permit airflow to be responsively controlled by a control system to continually optimize system effectiveness and efficiency.  
         [0006]     Other types of dampers that have been used in HVAC systems include electromechanically activated dampers that can be controlled remotely by a user or by a programmable control system. Dampers used in such systems include electronically operated butterfly plates, vane dampers, and electronically inflated air bladders. These types of systems typically use an electric motor, an electronic pump, a high-pressure air line with an electronically operated valve, etc. to control damper position. Such a system may be undesirable because special wiring might be required for activation and control of the damper, as well as for connection to a power supply (i.e. electrical system). Additionally, for dampers using high-pressure air lines, such lines must be installed in or near the airflow system and must be attached to each damper device.  
         [0007]     Another type of damper that has been used in airflow systems is a wirelessly controlled damper system that may be controlled using a wireless control device. Wirelessly controlled damper systems provide added convenience because no wiring is required to activate or control the damper. However, such systems typically still require wiring for connecting the damper with an external power supply that is able to provide sufficient power to drive the electric motor, electric pump, etc. that controls the damper&#39;s position, as well as to power the wireless damper device&#39;s wireless receiving and/or transmitting device.  
         [0008]     One consequence of the external control/power supply wiring is that damper systems capable of responsively optimizing airflow system operation are expensive and complex to install, and as a result, may not be implemented effectively, if at all. Thus, a wireless damper design that would not require external control/power supply wiring would be desirable.  
       SUMMARY  
       [0009]     An exemplary embodiment provides a damper device for controlling airflow in a controlled airflow system. The damper device is comprised of an inflatable bladder, a valve coupled to the inflatable bladder, a micro-pump coupled to the valve, a wireless signal device arranged to receive wireless signals, and a self-contained power source. The inflatable bladder has an inflation level that is adjustable to restrict varying amounts of airflow in an airflow channel.  
         [0010]     These as well as other aspects and advantages of the present invention will become apparent to those of ordinary skill in the art by reading the following detailed description, with appropriate reference to the accompanying drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     An exemplary embodiment of the present invention is described herein with reference to the following drawings, wherein:  
         [0012]      FIG. 1  is a block diagram illustrating components of an exemplary damper device that may be used in accordance with the exemplary embodiment;  
         [0013]      FIGS. 2A-2D  are side views and head-on views of inflated bladders that can be used in accordance with the exemplary embodiment;  
         [0014]      FIG. 3  is a simplified block diagram illustrating components of an exemplary HVAC airflow control system that may be used in accordance with the exemplary embodiment;  
         [0015]      FIG. 4  is a block diagram illustrating components of an exemplary control apparatus that may be used in accordance with the exemplary embodiment;  
         [0016]      FIG. 5  is a simplified block diagram illustrating components of an exemplary HVAC airflow control system that may be used in accordance with the exemplary embodiment;  
         [0017]      FIG. 6  is a flowchart illustrating a functional process flow in accordance with the exemplary embodiment; and  
         [0018]      FIG. 7  is a flowchart illustrating a functional process flow in accordance with the exemplary embodiment.  
     
    
     DETAILED DESCRIPTION  
       [0019]     In view of the wide variety of embodiments to which the principles of the present invention can be applied, it should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the present invention.  
         [0020]      FIG. 1  is a block diagram of a damper device  100  in accordance with an exemplary embodiment of the present invention. As illustrated, the damper device  100  may include an inflatable bladder  102 , a valve  104  coupled to the inflatable bladder  102 , a micro-pump  106  coupled to the valve  104 , a self-contained power source  108 , a wireless device  110 , and fill-air  112  contained within the inflatable bladder  102 . While electrical connections would likely exist between the self-contained power source  108  and the valve  104 , the micro-pump  106 , and the wireless device  110 , such connections are omitted from  FIG. 1  for purposes of clarity.  
         [0021]     In an exemplary embodiment, the inflatable bladder  102  can be used to restrict airflow through an airflow channel, and may be fabricated from any substantially airtight, deformable or elastic material, such as a rubberized material. Such materials allow the inflatable bladder  102  to have various inflation levels as the bladder  102  is inflated or deflated. An inflatable bladder  102  may take various shapes suitable for use in an airflow channel in which a user installs the damper  100 .  
         [0022]      FIG. 2  Illustrates several examples of possible shapes for the inflatable bladder  102 .  FIG. 2A  is a side view of an inflatable bladder and  FIGS. 2B-2D  are head-on views, as would be presented to airflow upstream from the inflatable bladder  102  in an airflow channel.  FIG. 2A  shows an elongated triangular inflatable bladder  200 . An elongated triangular bladder  200  allows for at least partial restriction of upstream airflow (airflow from the left of the bladder) while minimizing the disruption to the non-restricted airflow within the airflow channel. The elongated triangular inflatable bladder  200  may be a used in a variety of airflow system configurations, however, it is particularly well suited for use in airflow systems utilizing rectangular or square airflow channels (i.e. ducts).  FIG. 2B  shows a spherical inflatable bladder  202 . A spherical inflatable bladder  202  may also be used in a variety of airflow system configurations, however, it is particularly well suited for use in airflow systems utilizing circular airflow channels.  FIG. 2C  shows a star shaped inflatable bladder  204 , which may be well suited for use in airflow channels of a wide variety of shapes.  FIG. 2D  shows a rounded-edge rectangular inflatable bladder  206 . A rounded-edge rectangular inflatable bladder  206  may be particularly well suited for use in airflow systems utilizing rectangular airflow channels. Many other inflatable bladder shapes are possible as well.  
         [0023]     Turning back to  FIG. 1 , damper device  100  could use the valve  104 , coupled to the inflatable bladder  102 , to control the passage of air through an opening in the inflatable bladder  102  to adjust the inflatable bladder&#39;s inflation level. The self-contained power source  108  could power the valve  104  and the valve could have a closed mode requiring a low power, and an open mode requiring relatively higher power. When the valve  104  is in the open mode, air might flow into or out of the inflatable bladder  102 , thereby adjusting the inflation level of the inflatable bladder  102 . When the valve  104  is in the closed mode, it could prevent air from passing through the opening in the inflatable bladder  102 , thereby fixing the inflation level of the inflatable bladder  102  at a relatively constant state.  
         [0024]     The damper device  100  could use the micro-pump  106  shown in  FIG. 1  to force air into or out of the inflatable bladder  102 , and the self-contained power source  108  could power the micro-pump  106 .  
         [0025]     The damper device  100  can use the self-contained power source  108  to power the wireless device  110  shown in  FIG. 1 , allowing the wireless device  110  to receive control information from one or more wireless transmitting devices. The control information received by the wireless device  110  might include control commands that could cause the damper device to adjust the inflation level of the inflatable damper  102 . Alternatively, the control information could contain information (i.e. downstream temperature readings) needed for the damper  100  to make a determination of whether the inflation level of the inflatable bladder  102  requires adjustment. This determination could be made using programmed control logic and/or a microcontroller in conjunction with standard HVAC control algorithms, for instance. However, additional processing capabilities at the damper device  100  will also likely require a larger self-contained power source  108  and/or more frequent power source  108  replacement.  
         [0026]     In an alternative embodiment, the wireless device  110  could also be a wireless transmitter. The damper device  100  could use the wireless transmitter to transmit operation data regarding the damper device  100  to one or more wireless receivers. Information that may be communicated might include the damper device&#39;s  100  remaining battery life, and/or the level of inflation of the inflatable bladder  102 , as well as other information. This information could be used for damper device  100  diagnostic purposes, for energy saving purposes, or for maintenance scheduling purposes, as well as for other purposes.  
         [0027]     The self-contained power source  108  shown in  FIG. 1  preferably powers all elements of the damper device  100 , including the valve  104 , the micro-pump  106 , and the wireless device  110 . As a result, it is desirable for these devices to be low power devices in order to reduce the size of the self-contained power source  108 , and increase its life. The smaller the self-contained power source  108  is, the less expensive and smaller the damper device  100  could be, which could enable the device to be easier to install. In addition, the longer the life of the self-contained power source  108 , the less frequently the power-source  108  would have to be replaced, thereby reducing maintenance costs. In one embodiment, the self-contained power source  108  could be two standard AA batteries, for instance, electrically connected to the valve  104 , the micro-pump  106 , and the wireless device  110 .  
         [0028]     In addition to using low power devices in the damper device  100 , the damper device  100  could use power management features to reduce the size of and frequency of replacement of the self-contained power source  108 . Such power management techniques could include a damper  100  sleep mode. The sleep mode could include duty cycle sleeping with periodic brief wakeups, allowing the damper device&#39;s wireless device  110  to receive wireless control information and adjust the inflation level of the inflatable bladder  102 . Additionally, the damper device  100  could adjust the inflation level of the inflatable bladder  102  in small increments to conserve power. Other power management techniques are possible as well.  
         [0029]     As shown in  FIG. 1 , in one embodiment of the present invention the damper device  102  can include at least one inflation sensor  114  (i.e. a pressure sensor) for determining the inflation level of the inflatable bladder  102 . Using such a sensor  114 , the damper device  100  could have programmed upper and lower inflation level limits to prevent over-inflation or needless valve  104  cycling and/or needless micro-pump  106  operation.  
         [0030]      FIG. 3  is a block diagram of an HVAC system  316  having the damper device  100  of  FIG. 1 , installed in an airflow channel  318  (i.e. air duct). The damper device  300  can be used to control the airflow downstream from the damper device  300  (i.e. controlled airflow  322 ) by restricting, to various degrees, the upstream airflow  324  at the location of the damper device  300  in the HVAC system  316 . In one embodiment, as shown in  FIG. 3 , the HVAC system  316  may further include a control apparatus  320 .  
         [0031]     Referring to  FIG. 4 , a block diagram of an exemplary control apparatus  400  is shown. As illustrated, the control apparatus  400  may include input/output components  402  (i.e. a user interface), a sensing device  404 , a wireless transmitter  406 , data storage  408 , and a processing unit  410 , all coupled to at least one bus, illustrated as a bus  412 . In an exemplary embodiment, the data storage may store data, including temperature-information data  414 , and computer instructions, including control-logic  416 , executable by the processing unit  410 .  
         [0032]     The input/output components  402  of the control apparatus  400  can allow a user to program the control apparatus with at least one desired temperature level, for instance. As such, the input/output components  402  might include buttons  418  as an input mechanism, and a display screen  420  as an output mechanism. The control apparatus  400  might also comprise other or additional input and/or output components, or fewer input and/or output components than shown in  FIG. 4 .  
         [0033]     The sensing device  404  shown in  FIG. 4  has a temperature sensor  422  for measuring air temperature. However, in another embodiment, the sensing device  404  could be include at least one temperature sensor, humidity sensor, carbon monoxide sensor, carbon dioxide sensor, or volatile organic compound sensor, or a combination thereof, for measuring actual air property values. Other combinations of sensors and types of sensors are possible as well.  
         [0034]     The control apparatus can use the wireless transmitter  406  shown in  FIG. 4  to transmit control information to the wireless device  310  of the damper device  300 . The control information transmitted by the wireless transmitter  406  might include control commands that could cause the damper device to adjust the inflation level of the inflatable bladder  302 . Alternatively, the control information could contain sensor measurement information (i.e. downstream temperature readings) needed for the damper  300  to make a determination of whether the inflation level of the inflatable bladder  302  requires adjustment.  
         [0035]     In another embodiment, the wireless transmitter  406  could also be a wireless receiver. The wireless transmitter/receiver  406  could receive operation data regarding the damper device  300 . The control apparatus  400  could use such information to monitor damper performance indicators, such as estimated self-contained power source  308  life remaining. Such information could be useful for damper  300  maintenance and operation troubleshooting.  
         [0036]     The stored temperature-information data  414  shown in  FIG. 4  can define a plurality of user-programmed desired temperature levels, for instance, corresponding to various times of day. By way of example, the temperature-information data  414  may be contained in a table having a first column containing a temperature, a second column containing a start time of day, a third column containing an end time of day.  
         [0037]     The control-logic  416  shown in  FIG. 4  may contain instructions for monitoring air property levels using the sensing device  404 , and for determining when the inflation level of the inflatable bladder  302  requires adjustment. For example, the control logic  416  could use the programmed air temperature level and the measured air temperature in conjunction with standard HVAC control algorithms to make such a determination. In an alternative embodiment, the determination to adjust the inflation level of the inflatable bladder  302  could be made at the bladder device  300 .  
         [0038]     Although the control apparatus  400  is shown as a single physical device in  FIG. 4 , the various components of the apparatus  400  could also be separate, discrete devices in direct communication, either wirelessly or otherwise, or indirect communication (i.e. via one or more intermediate devices). Additional or fewer devices are possible as well.  
         [0039]     Turning back to  FIG. 3 , the inflatable bladder  302  shown in  FIG. 3  is substantially deflated, and as a result, contains only a small amount of fill-air  312 . This permits the upstream airflow  324  to be substantially equivalent to the controlled airflow  322 . As a result, the controlled airflow  322  is not substantially inhibited by the damper device  300  and the at least one air property being monitored by the sensor device at the outlet of the airflow system, for instance, may be increased or decreased more quickly depending on what effect the air in the airflow system has on that air property.  
         [0040]      FIG. 5  is a block diagram of the HVAC system of  FIG. 3 , but with the inflatable bladder  502  partially inflated with fill-air  512 . The partially inflated bladder  502  restricts a portion of the upstream airflow  524  from reaching areas downstream from the wireless damper device  500 , resulting in a controlled airflow  522  that is restricted. As a result, the air in the areas downstream from the wireless damper device  500  that receive the controlled air flow  522  are heated or cooled less quickly, depending upon whether the UVAC system is running in a heating or cooling mode.  
         [0041]     In an alternative embodiment, a plurality of damper devices  500  can be implemented in a plurality of air channels in an airflow system with one or more sensing devices  404 . HVAC systems with multiple damper devices  500  and/or a plurality of temperature sensing devices, for instance, could provide for better temperature control in various locations in a building.  
         [0042]     For systems with multiple damper devices  500 , in order to allow a wireless transmitter  406  to communicate particular information with only certain damper devices  500  within range of the wireless transmitter  406 , the wireless transmitter  406  could send specifically designated transmissions that would only be acted upon by damper devices  500  that have been configured to act on the specifically designated transmitted message. In one exemplary embodiment each damper device  500  could be programmed with a code (i.e. 1, 2, 3, etc.) that the wireless transmitter  406  could use to communicate with only damper devices  500  set to that code. In another embodiment, wireless transmission frequency could be used to allow the wireless transmitter  406  to communicate particular information with only certain damper devices  500  set to receive transmissions at only certain frequencies. Other transmission specific designation methods are possible as well.  
         [0043]     Embodiments of the present invention may either be installed in existing airflow systems or designed into new airflow systems. Installation in an existing system could involve cutting a small hole into an airflow channel  518 , feeding a deflated inflatable bladder  502  into the hole, and securing the damper device  500  to the outside of the air channel. Designing an embodiment of the present invention into a new airflow system could involve creating a specialized section of airflow channel specifically designed to accommodate an inflatable damper device  500 , or simply cutting a hole into a section of a standard airflow channel, similar to what can be done with existing systems.  
         [0044]      FIG. 6  is a flow chart that illustrates exemplary functions performed by the damper device  500  in accordance with an exemplary embodiment of the present invention. At step  600 , the damper device powers the wireless device  510  using the self-contained power source  506  to enable the wireless device  510  to receive control information.  
         [0045]     While the self-contained power source  506  is powering the wireless device  510 , the wireless device  510  receives a signal containing control information at step  602 . The control information can contain a command for the damper device to further inflate or deflate the damper device&#39;s  500  inflatable bladder  502 , or to leave the inflation level unchanged. Alternatively, the information control signal can contain only air property measurement data, allowing the damper device  500  to determine whether to adjust the inflation level of the inflatable bladder  502 . Other and/or additional information could also be contained in the control information.  
         [0046]     After the damper device  500  receives the control information, a determination is made at step  604  whether or not to adjust the inflation level of the inflatable bladder  502 . If the control information received is a command to increase, decrease, or maintain the inflation level of the inflatable bladder  502 , the bladder device  500  simply acts on that command. If however, the control information is only air property measurement data, the bladder device  500  must make a determination whether to adjust the inflation level of the inflatable bladder  502 , using, for example, standard control algorithms and a microprocessor.  
         [0047]     If an adjustment to the inflation level of the inflatable bladder  502  is required, at step  606 , the self-contained power source  506  powers the damper device  500  to effect the desired change. If at step  604  it is determined that a decrease in the inflation level of the inflatable bladder is required to effect such a decrease, the damper device  500  might open the valve  504  for a period, thus releasing an amount of fill-air  512  from inside the inflatable bladder  502  to the relatively lower pressure ambient air. The valve  504  could either be left open for a specific length of time to allow an amount of fill-air  512  to escape from the inflatable bladder  502 , or the valve  504  might be repeatedly cycled, thereby releasing a small amount of fill-air  512  during each cycle to achieve the desired reduction in the inflation level of the inflatable bladder  502 .  
         [0048]     To decrease further the inflation level of the inflatable bladder  502 , the damper device  500  might also activate the micro-pump  506 . With the valve  504  in an open mode, the micro-pump  506  could be activated to more quickly lower the inflation level of the inflatable bladder  502 , or it may be used only when the air pressure of the fill-air  512  in the inflatable bladder  502  approaches that of the ambient air, thus necessitating the use of the micro-pump  506  to remove additional fill-air  512  from the inflatable bladder  502 . Additionally, with the valve  504  in an open mode, the damper may use the micro-pump  506  to increase the inflation level of the inflatable bladder  502  by pumping ambient air into the inflatable bladder  502 . Once the micro-pump  506  has filled the inflatable bladder  502  with an adequate amount of ambient air to achieve the desired inflation level of the inflatable bladder  502 , the damper device  500  may turn the micro-pump  506  off and put the valve  504  in closed mode, thus trapping the fill-air  512  in the inflatable bladder  502 .  
         [0049]     Alternatively, to maintain the inflation level of the inflatable bladder  502 , the valve  504  could remain closed, sealing the opening in the inflatable bladder, and requiring only a relatively low power. After the inflation level of the inflatable bladder  502  has been adjusted, or it has been determined that no adjustment is required, the damper device  500  may enter a power conservation mode, at step  610 , for a predetermined period of time, at the end or which the process will start again at step  600 .  
         [0050]      FIG. 7  is a flow chart that illustrates exemplary functions performed by an HVAC airflow control system  516  in accordance with an exemplary embodiment of the present invention. At step  700 , a user programs the control apparatus  520  with at least one desired air property setting, temperature is used in the present embodiment, however, additional and/or other desired air property settings could be programmed as well. The user could program the control apparatus  520  by using the apparatus&#39; buttons  418  and display screen  420  for feedback. Other input/output components  402  for programming are possible as well. During programming, the control apparatus  520  could store the programmed temperature settings in the temperature-information data  414  stored in the apparatus&#39; data storage  408 .  
         [0051]     After the user has programmed the control apparatus  520  with a temperature setting, a temperature sensor  422 , of the sensing device  404  measures the temperature of the air immediately surrounding the sensor and communicates the measurement to the sensing device  404  at step  702 . In other embodiments, other types of air property sensors  422 , such a humidity sensor, a carbon monoxide sensor, a carbon dioxide sensor, and a volatile organic compound sensor could alone, or in combination, measure actual air properties in close proximity to the sensor.  
         [0052]     After the sensor  422  measures the air temperature, the processing unit  410  executes the control-logic  416  at step  704  to compare the measured air temperature to the programmed air temperature. The control-logic  416  can do this by applying standard HVAC control algorithms, for instance, to the measured and programmed temperatures. If the control-logic determines that no inflation level adjustment is required at step  706 , the process starts over at step  702 . However, if the control-logic  416  does determine that an inflation level adjustment is required, it can cause its wireless transmitter  406  to transmit a control signal containing control information to the wireless device  510  of the damper device  500 . The control information can include a command to increase or decrease the inflation level of the inflatable bladder  502 . Alternatively, the control apparatus  520  could simply send the measured and programmed temperature information to the wireless device  510  of the inflatable bladder, and the decision to adjust the inflation level of the inflatable bladder  502  could be made at the damper device  500 . The damper device  500  receives the control signal at step  710  and if required, adjusts the inflation level of the inflatable bladder at step  712 , using the methods discussed above.  
         [0053]     By way of example, when the HVAC system is being used for heating, typically if the measured air temperature is higher than the programmed temperature, the control apparatus  520  wirelessly transmits a signal to an upstream damper device  500  indicating that the inflation level of the wireless damper device&#39;s inflatable bladder  502  should be increased in order to restrict a portion of the upstream airflow  524  from reaching the location downstream from the wireless damper device  500  where the temperature sensor  422  is located.  
         [0054]     Conversely, when in heating mode, if the temperature sensor  422  measures an air temperature and finds it to be lower than the programmed temperature, the control apparatus  520  can transmit a wireless signal to the upstream damper device  500  indicating that the inflation level of the wireless damper device&#39;s inflatable bladder  502  should be decreased in order to allow additional heated upstream airflow  524  to reach the location of the temperature sensor  422  downstream from the wireless damper device  500 , thus allowing the air located in the area of the air temperature sensor  422  to be warmed more quickly and efficiently to the programmed temperature. If, however, the measured air temperature is substantially similar to the programmed air temperature, the control apparatus  520  may send a signal indicating that the damper device  500  need not adjust the inflation level of the inflatable bladder  502 , or in another embodiment, the control apparatus  520  may send no signal at all.  
       CONCLUSION  
       [0055]     Prior attempts to control airflow automatically in forced air systems have typically involved dampers requiring wired power supplies, which tended to result in high installation expense and complexity. The low power, wireless, inflatable bladder damper design, however, provides for a completely wireless damper system. This wireless damper may be useful in such applications as large and/or complex HVAC systems, for example. Further, this wireless damper design allows a control device to continually monitor and optimize the performance of a forced air system. Thus, if used in a large office building, for example, the low power wireless design could allow a user to control temperature more efficiently and effectively throughout the building. Other applications may include home and vehicle use.  
         [0056]     An exemplary embodiment of the present invention has been described above. Those skilled in the art will understand, however, that changes and modifications may be made to this embodiment without departing from the true scope and spirit of the present invention, which is defined by the claims.