Abstract:
A vehicle energy harvester including a subunit having an upper surface forming a roadway surface; a vehicle activated treadle on the subunit, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface; a generator that generates power in response to movement of the vehicle activated treadle; and a treadle locking device that selectively locks the vehicle activated treadle in the second position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present invention claims the benefit of U.S. Provisional Patent Application No. 61/147,747, filed Jan. 27, 2009, and entitled “TRANSIENT ABSORBER FOR POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,748, filed Jan. 27, 2009, and entitled “WEATHER RESPONSIVE TREADLE LOCKING MEANS FOR POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,749, filed Jan. 27, 2009, and entitled “LOW PROFILE, SURFACE-MOUNTED POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,750, filed Jan. 27, 2009, and entitled “VEHICLE SPEED DETECTION MEANS FOR POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,752, filed Jan. 27, 2009, and entitled “RECIPROCAL SPRING ARRANGEMENT FOR POWER GENERATION SYSTEM”, and U.S. Provisional Patent Application No. 61/147,754, filed Jan. 27, 2009, and entitled “LOSSLESS SHORT-DURATION ELECTRICAL STORAGE MEANS FOR POWER GENERATION SYSTEM”, the entire contents of which are incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is directed toward devices and methods of harvesting vehicle energy, and more specifically, toward a weather responsive treadle locking means for power generation system for harvesting vehicle energy. 
       BACKGROUND OF THE INVENTION 
       [0003]    Very few devices that capture energy from passing vehicles have been implemented, despite numerous designs put forth by various parties over the years. Issues of efficiency, reliability, and manufacturability, among others, have limited the practicality of vehicle energy harvesting devices. Added to the challenge is the variability of vehicle sizes, speeds, axle configurations, and lane positions, all of which can greatly influence the operation of a device trying to capture the motion energy of vehicles and convert it into a useful form of energy. 
         [0004]    Therefore, a need exists for an energy capture device and method having improved efficiency, reliability, and manufacturability, as well as practicality. A need also exists for an energy capture device and method that takes into account the variability of vehicle sizes, speeds, axle configurations, and lane positions in converting the captured motion energy of vehicles into a useful form of energy. 
       SUMMARY OF THE INVENTION 
       [0005]    These problems and others are addressed by the present invention, which provides a novel vehicle energy harvester that overcomes many of the issues with the conventional devices and is therefore better suited for real-world implementation than the conventional devices. 
         [0006]    The exemplary embodiments of the invention make productive use of the energy that is normally wasted (in the form of heat) in reducing the speed of motor vehicles on exit ramps, toll plazas etc., etc. The vehicle energy harvester can absorb mechanical energy from passing (or breaking) vehicles and convert the mechanical energy to electrical energy using, for example, shaft driven generators. 
         [0007]    The disclosed embodiments provide a vehicle energy harvester and power generation system that is simple to install, provides a short payback period, and has a scalable configuration. More particularly, the disclosed embodiments can provide a simple and reliable mechanical configuration that can withstand sever environments. The low cost configuration of the system may provide for faster payback of the expense of the system, and therefore, make the system more practical and desirable for practical applications. 
         [0008]    Additionally, the ease with which the system can be installed also may make the system more practical and desirable for practical applications. The disclosed embodiments require little or no excavation and can be installed in a few hours, instead of over several days as with conventional devices. 
         [0009]    The disclosed embodiment also can provide a scalable configuration that may be particularly advantageous for use at locations, such as exits ramps, toll plazas, hills, among other locations. 
         [0010]    An embodiment also can include monitoring the status or operation of the unit, either periodically or 24 hours per day, seven days per week, using for example, a wireless link or other wired or wireless communication device. 
         [0011]    The exemplary embodiments improve the durability of the system under practical use scenarios. The exemplary embodiments of the invention are capable of withstanding the stresses placed upon the system during normal use. The exemplary embodiments of the invention recognize that numerous factors may reduce the durability of the system under normal use including, for example, motor vehicles impacting the treadles at highway/freeway speeds of 60 to 70 miles per hour or more, and ice build-up restricting free movement of the treadle assembly, among other things. 
         [0012]    The exemplary embodiments of the invention address and solve these problems and improve the durability of a treadle based energy conversion systems according to the exemplary embodiments of the invention. 
         [0013]    In order to reduce the wear and tear on the treadle assembly, exemplary embodiments of the present invention can include a temperature sensor that aids in determining whether icy (freezing) conditions might prevent normal operation of the treadle assembly. 
         [0014]    Additionally or alternatively, exemplary embodiments of the present invention can include a precipitation detector that aids in determining whether icy (freezing) conditions might prevent normal operation of the treadle assembly. 
         [0015]    Additionally or alternatively, exemplary embodiments of the present invention can include a treadle locking means such that the unit can be locked safely in a flat (level with the road surface) position until more favorable weather conditions are detected. 
         [0016]    An exemplary embodiment of the invention is directed to, for example, a vehicle energy harvester comprising a subunit having an upper surface forming a roadway surface, a vehicle activated treadle on the subunit, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface, a generator that generates power in response to movement of the vehicle activated treadle, and a treadle locking device that selectively locks the vehicle activated treadle in the second position. 
         [0017]    Another exemplary embodiment of the invention is directed to, for example, a vehicle energy harvester comprising a plurality of subunits each having an upper surface forming a roadway surface, a vehicle activated treadle on at least one of the plurality of subunits, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface, a generator that generates power in response to movement of the vehicle activated treadle, and a treadle locking device that selectively locks the vehicle activated treadle in the second position. 
         [0018]    Another exemplary embodiment of the invention is directed to, for example, a vehicle energy harvester comprising a subunit having an upper surface forming a roadway surface, a vehicle activated treadle on the subunit, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface, a generator that generates power in response to movement of the vehicle activated treadle, and treadle locking means for selectively locking the vehicle activated treadle in the second position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    These and other aspects and features of embodiments of the present invention will be better understood after a reading of the following detailed description, together with the attached drawings, wherein: 
           [0020]      FIGS. 1  is a schematic top view of a power absorber unit of a vehicle energy harvester. 
           [0021]      FIG. 2  is a schematic perspective side view illustrating a portion of a vehicle energy harvester. 
           [0022]      FIG. 3  is a schematic top view of a vehicle energy harvester having a temperature sensor. 
           [0023]      FIG. 4  is a schematic top view of a vehicle energy harvester having a precipitation sensor. 
           [0024]      FIG. 5  is a schematic side view of a vehicle energy harvester having a treadle locking means. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0026]    Referring now to the drawings,  FIGS. 1-5  illustrate an exemplary vehicle energy harvester. 
         [0027]    The exemplary embodiments can make productive use of the energy that is normally wasted (in the form of heat) in reducing the speed of motor vehicles on exit ramps, toll plazas etc., etc. The vehicle energy harvester can absorb mechanical energy from passing (or breaking) vehicles and convert the mechanical energy to electrical energy using, for example, shaft driven generators. Other means for converting the mechanical energy to electrical energy also are contemplated. In an exemplary aspect, the electric power from the generators can be converted, metered, and fed into the commercial power grid. In another exemplary aspect, each site can be equipped with wireless communications to monitor the status and/or output of the system. 
         [0028]    Power Absorber Configuration 
         [0029]    The disclosed embodiments can include individual assemblies with integral generators. Other generator configurations also are possible, such as separate generators. 
         [0030]    As shown in  FIG. 1 , the vehicle energy harvester unit  10  can be a low-profile surface mounted assembly. The vehicle energy harvester unit  10  can include an entry ramp  12  and an exit ramp  14 . The vehicle energy harvester unit  10  can include a plurality of subunits  16  having a top surface or driving surface  17 . Each subunit can include one or more vehicle activated treadles  18 . In an embodiment, each subunit  16  can include a generator unit  20 . 
         [0031]    In other embodiments, the vehicle energy harvester unit  10  can be set into the road surface. The surface mounted assembly may require minimal installation effort. Additionally, the unit count can be scaled to road/breaking needs. In an embodiment, each generator unit  20  can feed a common power summing/conversion unit  22 . A simple cable interconnect  24  can be provided to connect each generator unit  20  to the common power summing/conversion unit  22 . A fail safe configuration can protect the system against individual unit failures. 
         [0032]    Power Conversion Unit 
         [0033]    In a disclosed embodiment, the individual absorber units  16  can be connected via cable assemblies  24 . The input power can be summed and applied to a low-loss inverter unit. The power can be converted immediately to a form that is transmittable to the power grid. The output can be metered and applied to the power grid for transmission. 
         [0034]    Absorber Unit Operation 
         [0035]    With reference to  FIG. 2 , an exemplary embodiment of a subunit  16  of a vehicle energy harvester unit  10  can include spring-loaded treadles  18  having a treadles gear  30  engaging a drive gear  32 . The drive gear  32  is coupled to a shaft  34 . In operation, one or more vehicle tires force the spring-loaded treadles  18  down as they roll over the treadles  18 . The treadle gears  30  drive the plurality of drive gears  32 , which rotate the shaft  34 . The shaft  34  winds a torsion spring  36 , thereby absorbing the treadle drive transient. A pawl can lock the shaft  34  as rotation ends. The torsion spring  36  rotates a flywheel  38 , thereby spreading the impulse of the treadle drive over time to extend output to a generator  40 . The flywheel  38  can turn a generator  40 , such as a hydro pump. The generator  40 , in turn, can generate electric power for sale/use/storage. 
         [0036]    The exemplary embodiments improve the durability of the system under practical use scenarios. The exemplary embodiments of the invention are capable of withstanding the stresses placed upon the system during normal use, as well as minimizing or preventing interference or damage to the system resulting from other factors. The exemplary embodiments of the invention recognize that factors that may reduce the durability of the system under normal use further include, for example, environmental conditions such as ambient temperature, rain, sleet, snow, or ice, among other things. 
         [0037]    The exemplary embodiments of the invention address and solve these problems and improve the durability of a treadle based energy conversion systems according to the exemplary embodiments of the invention. 
         [0038]    Temperature Detector 
         [0039]    With reference to  FIG. 3 , an exemplary embodiment of a vehicle energy harvester having at least one temperature detector  50  will now be described. 
         [0040]    In order to reduce the wear and tear on the treadle assembly (e.g.,  18 ), exemplary embodiments of the present invention can include one or more temperature sensors  50  that aid in determining whether icy (freezing) conditions may prevent normal operation of the treadle assembly. The temperature sensor  50  can be mounted, for example, under a top cover plate or driving surface  17  of one or more subunits  16 . In other embodiments, the temperature sensor  50  can be mounted on or in a surface of the top cover plate or driving surface  17  of one or more subunits  16 , or on another part of the vehicle energy harvester unit  10 . Alternatively, the temperature sensor  50  can be separate from the vehicle energy harvester unit  10  and communicate with the vehicle energy harvester unit  10  via a wired connection or wireless connection. In this manner, the temperature sensor  50  can accurately measure surface temperatures of the vehicle energy harvester unit  10 . 
         [0041]    A common, commercially available, semiconductor temperature sensor  50 , such as the XXX-111 temperature sensor or the like, can be used in conjunction with a low-cost micro-controller unit (MCU) (not shown) to determine if hazardous conditions exist. An embodiment having a low-cost single chip (IC) arrangement can provide a very reliable and durable design. One of ordinary skill in the art will recognize that integrated circuits (ICs) with temperature conversion accuracy of 0.5 degrees are readily available. These circuits can provide a simple serial (digital) output to the micro-controller unit (MCU). The micro-controller unit (MCU) can use the temperature sensor  50  to control overall operation of the vehicle energy harvester unit  10 . In other embodiments, the temperature sensor  50  can be used in conjunction with other sensors or detectors, for example, as described in the exemplary embodiments below. 
         [0042]    Precipitation Detector 
         [0043]    With reference to  FIG. 4 , an exemplary embodiment of a vehicle energy harvester having at least one precipitation detector  60  and/or a snow/ice sensor  70  will now be described. 
         [0044]    An exemplary embodiment of the present invention can include one or more precipitation detectors  60  that aid in determining whether icy (e.g., freezing) conditions may prevent normal operation of the treadle assembly (e.g.,  18 ). One of ordinary skill in the art will recognize that a common operational amplifier can be as a precipitation detector  60  and configured as shown, for example, in  FIG. 4  to detect the presence of liquid precipitation (rain). The precipitation detector  60  can be mounted, for example, under a top cover plate or driving surface  17  of one or more subunits  16 . In other embodiments, the precipitation detector  60  can be mounted on or in a surface of the top cover plate or driving surface  17  of one or more subunits  16 , or on another part of the vehicle energy harvester unit  10 . Alternatively, the precipitation detector  60  can be separate from the vehicle energy harvester unit  10  and communicate with the vehicle energy harvester unit  10  via a wired connection or wireless connection. In this manner, the precipitation detector  60  can accurately detect the presence of liquid on or in one or more subunits  16  of the vehicle energy harvester unit  10 . In other embodiments, the precipitation detector  60  can include a plurality of contacts that can be used to estimate the amount of rain fall. The precipitation detector  60  can take samples continuously or periodically to conserve power usage. 
         [0045]    In addition, one or more snow/ice sensors  70  having, for example, a small, low-cost infrared emitter/detector  72 ,  74  can be used as illustrated in  FIG. 4  to detect the presence of snow and/or ice obscuring a channel between the emitter and detector  72 ,  74 . Other conventional devices for detecting the presence of snow and/or ice can be used. 
         [0046]    The snow/ice sensor  70  can be mounted, for example, on or in a surface of the top cover plate or driving surface  17  of one or more subunits  16 , or on another part of the vehicle energy harvester unit  10 . Alternatively, the snow/ice sensor  70  can be separate from the vehicle energy harvester unit  10  and communicate with the vehicle energy harvester unit  10  via a wired connection or wireless connection. In this manner, the snow/ice sensor  70  can accurately detect the presence of snow or ice on one or more subunits  16  of the vehicle energy harvester unit  10 . The snow/ice sensor  70  can take samples continuously or periodically to conserve power usage. One or more snow/ice sensors  70  can be used in conjunction with, for example, the temperature sensor  50  and a low-cost micro-controller unit (MCU), for example, to determine if hazardous conditions exist. 
         [0047]    Treadle Locking Means 
         [0048]    With reference to  FIG. 5 , an exemplary embodiment of a vehicle energy harvester having at least one treadle locking means will now be described. 
         [0049]    In an exemplary aspect, during normal operation, the treadle  18  is in the active (elevated) position and pushed downward upon impact with a tire of an oncoming motor vehicle. If ice is formed inside the vehicle energy harvester unit  10 , the treadle assembly may no longer be free to move when struck by the tire of the vehicle. Instead, the momentum of the vehicle may be applied directly and entirely to the mechanical components connected to the treadle  18 . This type of collision may result (or will almost certainly result) in physical damage to the vehicle energy harvester unit  10  (e.g., bending or breaking of mechanical members, stripping gearbox assemblies, etc.). To minimize or prevent such damage in freezing weather, the exemplary embodiments of a vehicle energy harvester unit  10  can be equipped with a solenoid operated locking pawl such that the unit can be locked safely in a flat (i.e., level with the driving surface  17 ) position until more favorable weather conditions are detected. This locking means also can minimize or prevent damage to the vehicle energy harvester unit  10  that may be caused by snow removal equipment operating on the road surface or driving surface  17 . 
         [0050]    As illustrated in  FIG. 5 , the spring-loaded treadles  18  can be configured to pivot about one end. In operation, one or more vehicle tires force the spring-loaded treadles  18  down into a flush position with the driving surface  17  as they roll over the treadles  18 . An exemplary embodiment of treadle locking means for a vehicle energy harvester unit  10  can include a locking latch  80  coupled to a portion of the treadle  18 , for example, a free or open end of the treadle  18  as shown in  FIG. 5 . A portion of the subunit  16  that is opposite to the hinged side of the treadle  18  can include a sliding lock pawl  82  configured to selectively engage the locking latch  80  to secure the treadle  18  in a closed or flush position with the driving surface  17  of the subunit  16 . The sliding lock pawl  82  can be moved into a locked or unlocked position by a solenoid  84  or the like. The solenoid  84  can move the locking pawl  82  in or out (e.g., right or left as shown in  FIG. 5 ) under control of the micro-controller unit (MCU). For example, the application of voltage to the solenoid  84  can push the pawl to the left to lock the treadle down. 
         [0051]    In operation, the impact of the tire of a vehicle travelling on the driving surface  17  can force the treadle  18  downward into a flush position with the driving surface  17  and cause the locking latch  80  to engage with the sliding lock pawl  82 . The power to the solenoid  84  can be removed to conserve power after the treadle  18  is locked. By reversing the voltage to the solenoid  84 , the solenoid  84  momentarily will move the sliding lock pawl  82  to the right and release the locking latch  80  of the treadle  18  such that the treadle  18  can return to an elevated or open position (e.g., active position). 
         [0052]    Other locking means are possible for securing and locking the treadle  18  in a flush position with the driving surface  17 . The locking means can be using in conjunction with a micro-controller unit (MCU) and one or more of the temperature sensor  50 , precipitation sensor  60 , and snow/ice sensor  70 . In this manner, the micro-controller unit (MCU) can apply or remove voltage from the solenoid  84  to lock or unlock the treadle  18  based on signals or input received from one or more of the temperature sensor  50 , precipitation sensor  60 , and snow/ice sensor  70 , thereby locking or securing the treadle  18  in a flush position with the driving surface  17  when conditions exist that may affect the operation of the vehicle energy harvester unit  10 . Accordingly, the exemplary embodiments can improve the durability of the system under practical use scenarios. The exemplary embodiments of the invention are capable of withstanding the stresses placed upon the system during normal use, as well as minimizing or preventing interference or damage to the system resulting from other factors, for example, including environmental conditions such as ambient temperature, rain, sleet, snow, or ice, among other things. 
         [0053]    The present invention has been described herein in terms of several preferred embodiments. However, modifications and additions to these embodiments will become apparent to those of ordinary skill in the art upon a reading of the foregoing description. It is intended that all such modifications and additions comprise a part of the present invention to the extent that they fall within the scope of the several claims appended hereto. 
         [0054]    Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. 
         [0055]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity. 
         [0056]    As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.” 
         [0057]    It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature. 
         [0058]    Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “lateral”, “left”, “right” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the descriptors of relative spatial relationships used herein interpreted accordingly.